US2488547A - Land mine - Google Patents

Description

Nov. 22, 1949 l.. K. LlLJf-:GREN

LAND MINE 5 Sheets-Sheet 1 Filed Feb. 22, 1944 m QQ mm -www NOV. 22, 1949 K, LlLJEGREN 2,488,547

LAND MINE Filed Feb. 22, 1944 5 Sheets-Sheet 2 Eff-E- Nov. 22, 1949 L.. K. LILJEGREN 2,488,547

LAND MINE Filed Feb. 22, 1944 5 Sheets-Sheet 3 i L le Kfli'ljgrn E15-E4 j Nov. 22, 1949 A L. K. LILJEGREN 2,488,547

LAND MINE` l Filed Feb. 22, 1944 5 Sheets-Sheet 4 E Ju- F 15- E 9, l E

l; IIIA fly/Q44 gmc/who@ I Lyle K limggfren NOV. 22, 1949 1 K, L [LJEGREN 2,488,547

LAND MINE Filed Feb. 22. 1944 5 sheets-Sheet 5 L-ljle K Lilie gran Patented Nov. 22, 1949 UNITED STATES PATENT OFFICE LAND MINE Lyle K. Liljegren, Alexandria, Va., assignor to the United States oi America as represented by the Secretary of War (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 19 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

The invention relates to mines and particularly land mines, or the like intended to be detonated by enemy personnel or matriel movement and other activity.

It has for an important aim to present a mine which may be used for delaying or impairing enemy activities by use as an anti-tank mine or as a trap mine; that is to say, one which may be made operative in response to compression such as might occur if the device were set in a roadway and run upon by a Vehicle; and which may also or alternatively be connected to cords or tension wires so as to be operated by a pull on such cord or wire, and whereby the device may be connected to timing or timed operating means.

It is an important object of the invention to enable such a mine to be easily made safe up to the instant it is required to be armed for destructive response to enemy activity affecting the mine or its control devices.

A paramount purpose in this invention is to enable production of a mine having the desired qualities and advantages indicated as Well as others hereinafter mentioned or apparent, which may be made practically entire, by the use of non-metallic materials.

In the direction last named a strongly inspiring need is the provision of an eiiective and powerful spring device of a novel kind adequate for detonating a percussion primer and at the same time capable of sustaining high pressures within non-operating limits required in such devices.

A further consideration impelling the conception of this invention is the production of a mine responsive to pressure of heavy vehicles such as tanks which may be set for safety while in position for oensive action and will withstand pressures of such vehicles without detonating and Without suffering impairment of functions or deformations or displacement of operating or structural parts.

It is another important motive to present such a mine which may be easily and simply manipulated to place it in either armed or safe condition with great certainty and with `a minimum liability of accident.

A specic desire is to offer a novel form of encasement for such a mine.

It is also a desire to oler a novel operating head and sealed assembly for such a mine.

An attainment sought is the construction of a mine having the essentials above indicated which will involve a minimum number of parts adapted to quantity production with a minimum of factory operations and enabling certainty of proper functional relation of parts with a minimum liability of fault through variation from standard.

Another obj ect in View is to enable assembly of principal members without requiring great exactitude in deterimning measurement and relative placing of parts by the assembler.

It is contemplated to enable the setting of the safety means in either safe or armed position while the mine is in situ offensively and without disturbing its emplacement materially.

It will thus be practicable to avoid last minute placing of mines in the event of a planned movement of a military organization and matriel, but to carry out a thorough and systematic planting of fuzed mines before the planned movement is begun, and arm the mines after movement of matriel, gby a simple manual key-turning operation, which will involve a minimum of haste and of liability of mistake.

It is also in mind to provide a mine having the foregoing advantages and also Well adapted to use under water, so that fordng places in streams, beaches, and inshore sea bottoms adjacent to beaches may be mined for offense against vehicles and engineering operations, landing boats, etc.

A still further object is to present a mine for the uses indicated which may be easily and effectively made water proof Without detracting from its effective functioning.

Additional objects, advantages and features of invention reside in the construction, arrangement and combination of parts involved in the embodiment of the invention as will appear from the following description and accompanying drawings, wherein:

Figure 1 is a diametrical section of a mine embodying my invention;

Figure 2 is a fragmentary section on the line 2--2 of Figure 1;

Figure 3 is a reduced section similar to Figure 1 of the operating plate, firing pin and detonator in safe position under load-operation;

Figure 4 is an elevation of the mine to a reduced scale;

Figure 5 is a horizontal section on the line 5-5 of Figure l, reduced;

Figure 6 is an enlarged detail section of the pull igniter in operated position;

Figure 7 is a perspective of the safety key;

Figure 8 is a similar View of the setting knob;

Figure 9 is a section on line 9-9 of Figure 1 to an enlarged scale;

Figure 10 is a fragmentary vertical section of a modification;

Figure 11 is a top view on an enlarged scale of the modified primer carrier of Figure 10, in safe condition. Figure 11a. is a development of the arming barrel of Figures l0, 11 and 12 as indicated by the line 11a-11a of Figure 11.

Figure 12 is a view of the primer carrier of Fig. 10 armed;

Figure 13'is'1a ViewV ofta modiycationof the carrier of Figure 1l in safe position;

Figure 14 is a View of the modification of Figure 13 in armed position;

Figure 15 is a view similar to Figure 10, of a further modication in sai'eppsition;

Figure 16 is a similar vieiytnereof in armed position;

Figure 1"! is an elevation 0f` the detonator assembly of the last mentioned modification;

Figure 18 is a section on the line lf3- i8 oi Figure 17;

Figure 19 is a section on the line {v9- t9 of- Figure 18;

Figure 20 is a fragmentary View similar to Figure l of a still-fur`ther modication;

v Figure'Zl is` a fragmentary section of a modification of theirin'gpin mounting;

v"Figure 22 is'asi'milar view'off` a combined push-pull single detonator mine;

Figure 23 is a similar view of a further modiicratiln using coil' springs;

l Figure '245 is` asimilar view ofa small pressure operated mine oir/simpler 'detail- Referring to the drawings, there is shown a mine comprising af base cup'20, offcircular form l'iaving aV 'flat lo'ottoxfn- 2|- and a bounding substantially cylindrical `Wall- 22l thickened at its p laniformftopedge andrabbeted at its inner side to receive a flat Vtop-plate 23 and. interposed gasket '23", thetwor constituting a case within ii'fhich" a suitable'explosive may be contained. The cup may be formed of ceramic material (for which Vreason itisr shown asbeing comparatively tl'iiclr'throughout` the cupA bottom` and wall), while time plate` 3jl is preferably Yformed ofA one of the strong rigid plastics which are adapted to be machined andassembled' in mechanisms with 4close tolerances.

ClifzrcrV dctomtor The plate 23 -is heldingplace by a plastic detonator assembly case 7243 connected between the bottom 2l and plate 23V. The plate isl formed with laV central irriteriorl'y threaded opening and depending flange 2.15- into whichY is screwed the teneredhead-'Zfof the caseZ; The plate irsesfssd. 0.1' dighd atti-1 upper. Sid@ as Vat 2l, in its central'partfora purpose which will appear. The detonatpr case is f ormed with a thin cylindrical wall Zll'of,*suitable diameter the. lower edge ofI which hasformed thereon a planiform perimetralwfl'ange 29, set in a rabbet 3pr formed around the lower edge of aA central opening 3i through, the bottom 2L A'suitable gasket or other. sealSZis'interposed between the flange 29` and' the bottom offthe rabbet. The head' 25 `is `centrally Ytapped to receive an exteriorly threaded; tenons and" detonator cup 33 formed on a concentric cylindrical'v body. 3e of plastic materialy havingV a, large transverse chamber' borev 35`and, aroundy which there issecured a thin, cylindrical coverL orcase wall 36 also formatta. 'page sequestered mannered eipherelmert Slet thebcdy.. Se?. This, bedris formedwitll -ahead flangey Sluset flush in the rabbet. 3l?!outwardly,of.` the4 flangeZeSi of the case lill,v withv a gasket'or other seal 39. interposed` The: chamber 3@ accommodates a, booster charge 4D. The'bodyxf'lthasan outer.l flash port il cen.- trally j therethrough outwardly of whichthere is aninteri'orly threadedrecess 14,2 in which may b e. screwed thev tenen l3nt acase @grof the, pull ignite 45..Whi-f1t1ey be. uedeltefnetively with tle'top detonatorl'to be later described.

Y a bore el through the tenon 43, this bore being it. have.. eilblvei. a larger bedyioi .lead 2212.121@ i213 slightly larger than the port BI. A waterproof cover disc 38.- is secured in the bottom of the recess 12- against and-' across the flash port i and at the innerend of the bore a similar cover 9 is. set in an enlargement of the bore. lmmedately below this the case 64 is enlarged to afford a cylindrical coaxial chamber 53 in which there isy reciprocable a.A head 5|, slotted to avoid dash pot action and.. having an upwardly projected firing pin 52 proportioned to enter the primer @di on upward.A movement ofz the. headl 5t. This head Yhas onl its underside. a tubular shank;v 53 havingftwo opposed openings.v through itswallx A safety sleeve 55,"mounted in thev case t, and has@ a. cylindrical; wel! Dart 'Srad from' the Sides @1fl the QeSe, eeer Geniaal annuler flange 0r seat 5B, and anouteange 5l, the latter being set against the end 'of the case til, with-a gasket 5l gelegt-bya.- Cee 5.5@ threaded;- tf the end; 0f CaSe-44. rlhe- Capi is; centraux aperture and necked. es @#59 et its Outer. Der-tto. Supportslid.: eelt aderent- 01# 1111111131115 Slt Whihfhas' a head 6I exposedy for wnpetion; t0 trip. Wires. 0r te various operating means, aswwell understood in the. art.

The pie is liedued. at; its upper part. 62- t0. engage; slidabll in the` tubular shank 5 3 of the ring'pin. latter extends downwardly throughV the. seat. 56, andf the reduced part of the g pull` pinv extends upwardly withinthershank 53 to a distance; above; the seat 5,6.; Confined between the head. 5t and-cap aroundfthe sleeve 55;, there isa. pin operating. spring. 6.3; Thispin is held against action,- by, means of Iballs G4 set loosely'ir'il the-openings offthe .pin shank next toL theY seat: 5;,61. andi. between thelreduced-.pull pin party 62 and :sleeve 55; The; reduced. part of the pull pin` is. circumferentiallyi grooved-l to .receive A a portion yof the-balls. thereinsoxthat upward :movee r ment of the pin is prevented byf'theballs.

All the parts in the.pull igniter may be of. vplasticv materials except--possibl'yfthe springjliSv and rubber gaskets. Y

Cameoitien Oflfcmtors The. detonator cup- 33: is formed with a nashport! at itsllower endfcommunicatingfwith-the tule is prevdd'ieeafli '0f these detonetors, a

body Offffllminfeef 'mercury being,alsouitable. f0.1?. this Percussion.' csmpjoeent Inwardly of and inwardly of the latter a still larger quantity 13 of tetryl. The booster has also consisted of tetryl, and in the space in the cup around the detonator assembly case 24 I have used a bursting charge 69 of T. N. T.

It will be seen that the cup 33 is of such length that when screwed into the head 26 its upper end is slightly above the head, and projects upwardly within the dished or recessed part 21.

Belleville spring and mounting side to4 provide ananlar seat 'I5 for the base or periphery of a disc or Belleville spring 16. This disc has a central opening and is formed with an initial set in slightly dished or conical form.

The spring 16 is preferably formed of a multilaminated plywood, impregnated thoroughly and bound with a suitable plastic or other hardening and waterproofing material or materials. The boss 14, and consequently the diameter of the spring, is of little less diameter than the cup, and the altitude of the dished shape is very small in proportion to its diameter. Its extent of movement for full stroke of the ring pin in the particular construction illustrated is in the neighborhood of one-thirteenth of the diameter of the disc, although this may be varied to some degree either way. The drawing Fig. 1 is approximately full size of one embodiment of the invention. The disc is secured or retained over the seat by a series of circumferentially spaced large headed fillister screws 11 engaged in the boss and projecting inwardly over the rabbet l5 and also projecting outwardly from the boss a short distance for a purpose to be explained. The screws are of a strong plastic.

Operating plate mounting An operating plate 88 of strong ceramic material is mounted over the cup, spaced above the plate 23 a distance and arranged for vertical movement a short distance. It is nearly equal in diameter to the cup wall, and is provided with a depending perimetral wall 19, having a broadened lower edge adapted to rest at times on the top edge of the cup wall 22, where a cushion facing 8l may be applied if desired to distribute pressures communicated through the operating plate in case of lack of sufliciently uniform contact between the opposed wall surfaces which might cause fracture of one or the other with possibility of failure to operate subsequently, or a premature action.

The lower edge portion of the wall 79 is formed with inwardly projecting segmental flanges 82 of a number equal to the number of screws 11, being so spaced and each of such extent as to enter between the projecting parts 'I8 of any two screws 'l1 when the plate 88v is presented from above in concentric relation to the cup. Eight each of the screws and flanges are shown, but a greater number may be used if desired. By rotating the plate 88 slightly after passage of the flanges 82 below the level of the heads of the screws l1, the flanges will engage under the screw heads and so retain the parts against separation and in initial operative relation. The lower sides of the flanges 82 form continuations of the lower edge face of the wall 'I9 and are of such thickness in relation to the height of the annular boss 14 that a range of vertical movement of the operating plate over the cup is permitted, sucient to operate the Belleville spring 'I6 from its initial set position toward its lower operating limit over a distance slightly beyond its dead center or position of static force condition, as will appear. For so operating the spring 18, a downwardly projecting transversely rounded annular forcing or pushing rib 83 is formed on the under side of the operating plate, of such altitude when the plate is in its stated initial operative position that the rib B3 engages the upper side of disc 16 in a circle having a radius equal to about half the radius of the disc, `and holding the disc under stress-appropriate for effective action and to hold the operating plate rmly pressed upward, so as to prevent looseness of the latter when free from depressing force, as well as to insure immediate response of the spring to downward movement of the operating plate, compensating for some variation from standard thickess of the disc, and other errors in proportions of parts, and for wear which might occur from repeated safety operations which will be referred to herein.

The rib 83 as shown engages the disc midway between its inner and outer edges, but for greater acceleration of spring action may be nearer the outer boundary within practical operating limits. The operating plate is sufciently recessed on its underside adjacent the depending wall 19 to clear the boss and screws 'I1 for all operating positions of the plate. The raised perimetral outer part 84 thus formed on the plate 88 is extended inwardly somewhat to afford a broad flat annular loadreceiving top surface adapted to be readily depressed by engaging loads. the forcing rib 83 being located at the inner boundary of this broad annular part 84, so that depressing force applied to the plate is transmitted to the disc through material immediately adjacent the point of origin of such force in the device.

Setting device The plate 88 is formed with a central depression 85 within the radius of the rib 83 and raised part 84, and a circular setter key opening 86 is formed through the center of the plate, bounded by a circular boss 81 recessed or rabbeted as at 88 (Fig. 2) around the opening 86 over an angle of 280 degrees, more or less leaving a lug or abutment 89 within an angle of 80 degrees more or less at one side of the recess extending to the opening 86. Diametrically opposite radial slots 98 are formed through the plate extending from the opening 86 in a plane parallel to one side of the abutment 89, so 4that one slot is immediately beside the abutment and the other opening through the rabbet or recess 88 opposite.

A setting key 9| (Figures 1, 2 and 7) is set revolubly in the center opening 92 through the Belleville disc 'I6 and also revoluble in the opening `8i over a limited distance. The key has a lower circular head 93 ntted and revoluble in the opening of the disc and is formed With a downwardly oiset horizontal peripheral ange 94 receiving the inner edge portion of the disc thereover. A flat retainer ring 95 is set in the periphery of the head over the disc, and may be a split planiform spring washer sprung into a suitable groove in the head. An upwardly extended circular stem 96 (Figure 7) of the key is revoluble in the opening 86, being attened at its upper part to the same thickness as the 75 width of the slots 98 and at its extremity is formed with a T-shaped head 91 with a, thickness and radius to permit it to pass upward through the slots 90 and into the recess orrabbet 88, and, when turned out of alinement with the slots, to extend over the rabbet shoulder at 88, whereby it will be held against relativedownward movement through the plate 80.

Over and enclosing the boss 81, there is a revoluble operating or setting knob 98 having a depending ilange 99 snugly and revolubly fitted around the boss 8l close to 'the top surface Vof the plate 80. Opposed circumferential grooves are formed on the side of the boss and inner face of the flange 99, in which there is set a rubber ring |0| serving as a retainer for the knob and as a seal, yieldable to manual force for removal or rotation of the knob, Vthe friction between the ring |0| and abutting parts of the boss and knob being least while the grooves |00 are alined, and the ring |0| tending to return the knob to proper position if partly displaced. The flat top part of the knob lies closely over the boss and top of the T-head of the key no1'- mally, and is formed with two downwardly extended arms |02' tting closely and slidably beside opposite faces of the T-head, so that when the knob is turned the key also will be rotated. The outer sides of the arms |02 are semi-cylindrical, conforming to the opening 86 so as to pass the abutment 89. The ends of the arms of the T-head project from between the arms Waterproof closure Circumscribing horizontal `channels |03 are formed in the exterior surfaces of the cup wall 22 and the wall T9 respectively, spaced from the respective wall edges, and a septum consisting of a closely tted endless band or sheeting |04 of waterproof ilexible fabric is engaged around the cup and operating plate `extending upwardly and downwardly across both channels |03. A cord or other non-metallic tension element |06 is engaged tightly around the operative plate wall so as to press the material |04 snugly in the channel, and a similar binding |06 is laid around the loweredge por-tion of the waterproof fabric pressing it into the channel |03 in the wall 22. The space between the opposed edge portions of cup and operating plate is `thus closed so as to prevent access of water or debris to -this space or to the space over the Belleville disc, yet leaving the operating plate 80 free for repeated operation under safety conditions as will beexplained and for final detonating action when required.

In the device as illustrated, when constructed with an external cup diameter of ten inches, and in the proportions shown in Fig. l, a plywood one-eighth` of an inch in thickness has been ernployed for the Belleville disc. Modification may however be made in accordance with the nature of materials available.

Firing vpin and action A firing pin is provided axially on the underside of the head 93 of the key 9|. This pin may be integral and of the same material with the head, or may be a small metallic spine set in the material of the head.

It is important to note `that the space between the opposed edges of the operating plate and cup 2t is substantially less than the distance between the detonator 10 and the point ofthe ring pin |95 when the parts are in initial position. Since the space between the edges mentioned determines the limit of `operating 'movement oi the plate 80, it will be clear that while the key 9| is in safe position the firing pin |05 cannot move further than Vthe plate, and so cannot engage the detonator thereunder.

M a'nufacture In the manufacture of this device, the cupV assembly and operating plate, but exclusive of the pull igniter (which includesV all .partsin or on the case element lle and its tenen-.43), may be conventionally assembled as described, including the case element 24, bushing 31 and remainder of the detonator assembly, the guard vdisc i8 being in place. The pull igniter may thenbe put in place in the ield, as required. Or the mine may be assembled with the pull igniter, and the latter discarded when the device is set as an anti-tank mine or the like. Before mounting on the base, the Belleville spring disc 'It is secured by the screws l'i after setting the key 9| therein, and the plate then introduced thereover the T- head being positioned so as to enter the slots 90 by rotating the knob until proper alinement is secured, while the flanges 32 are alined with the intervals between the screws ll. The entry of the T-head being assured, the-setting knob is rotated to the left, or counterclockwise until stopped by engagement of the T-head against the abutment 89, which is the safe position, so that the key and ring pin cannot be driven downward far enough to engage the detonatorthereunder. The plate 80 is then pressed downward until the iianges 82 are below the screw heads ll and finally rotated to engage the anges fully under the outer edges of the screw heads :11. The material |04 isv now applied and secured, whereby the plate 89 is held against further rotation on the cup. The knob 98 may be secured in place by positioning the ring |9| at the upper edge of the boss and pressing the knob downward into place, the ring |9| rolling against the opposed surfaces until it encounters the grooves |00 into which it immediately expands, holding the knob in place until drawn upward with considerable force. The key is kept in safe position until the mine is armed for explosive action. The detonator assembly including the bushing 3l, case wall 35, head 34, and cup 3'3 may now be safely put in place from beneath the cup by simply screwing the cup 33 into the head' 26 in the base of the mine.

Use and operation The mine may beset in roadways, tracks and elds in the manner usual withr prior mines for anti-tank and other uses.

However, my mine may be set in suchsituations while still occupied and in use by the forces setting the mines, by rst insuring that the key 9| is in the safe position. The mine may then be placed in roads and elds flush with the surface and suitably camouaged, or may be set below the surface and covered with a Vproper amount of road or field material, sod,. or earth,v as the case may be.

While thus located in final position, with the key in safe position when a vehicle wheel or track element passes thereover, the operating plate will be depressed until its depending wall 'i9 rests on the cup, where movement of the plate will stop, and the load will -be sustained by the cup Eil. In this movement of the operating plate the rib S3 will engage and press the intermediate portion of the Belleville disc downward, as shown in Fig. 3. The key 9|, however is supported by its T-head on the rabbet shoulder at 8B, and the inner edge of the disc resting on the key head iange 94, is thus prevented from moving downward to its normal operating or full stroke limit, but as the rib 83 presses downward, the inner portion of the disc flexes upwardly while the firing pin stops short of the detonator.

When it is desired to arm such a mine while located as last described suicient covering material is removed, or the ngers inserted through the covering material to permit rotation of the knob 98, without disturbing the placement of the mine otherwise, and the knob turned to the right until stopped by one arm of the T-head engaging the abutment t9 (Fig. 2). This arms the mine, positioning the T-head in line with the slots 90, free to move downwardly therethrough. On account of the upward pressure and position of the spring disc, however, the key is retained in its elevated position and may at any time be turned back to safe position in case of need for further safe action. This makes it possible to pass delayed material after arming of mines in a mined area.

When armed as described, on engagement of the mine by a Weight or force sufficient to depress the plate 8G, the operating plate 8i] yields and its rib 83 presses the underlying portion of the spring downward so that the conical elements of the spring move downward pivotally with a lever action corresponding to a lever of the third order having the shoulder of the boss 14 as a fulcrum, the operating force applied by the rib 83, and the load being represented by the resistance of the central portion of the disc material to compresn sion which the movement described involves.

The degree of movement permitted the plate 8U is suiicient for the rib 83 to press the disc to a planiform shape or to dead center position and suiciently beyond for the stress and inherent elasticity of the strained material of the disc to react with sufficient force to initiate an independent further and accelerated downward movement of the central portion of the disc, capable of moving the firing pin |05 into the detonator 10.

If the pull igniter is to be utilized, the key 9| is left in safe position in most cases, although the mine may be armed at top and bottom, so as to operate by either pressure on top, or a pull communicated to the head 6| of the pull pin Bil.

The operating plate 80 may be readily removed in order to permit installation of the mine in more confined situations, where the pull igniter is to be employed. Draw wires, cords or other means may be connected to the head 6| of the mine, and extended to objects or means which may be moved by enemy action, as well understood. When installed as a pull operated mine, the necessary connections being made to the head 6| of the pull pin, and the necessary preparation of the emplacement having been made, the safety pin 66 is drawn and the mine set in place in accordance with usual practices with pull-operated mines.

My mine may be quickly set in beach sands and on-shore sea bottoms where pressure of landl0 ing boats and vehicles in course of unloading may cause its detonation.

It is an advantage of my invention that tilting of the operating plate 80 in any direction causing contact of the edge portions of the plate and cup will result in operative functions of the mine, due to the leverage exerted when a side portion only of the disc is depressed, the radial structural parts of the disc at the depressed part serving to depress the whole central part of the same, so that it passes dead center.

For the last named purpose, the disc is made of sufficient thickness to afford the necessary rigidity for the function indicated and the range of relative movement between cup and operating plate, as well as the related spacing of the firing pin |05 from the detonator 10, should be provided for. That is to say, when constructed for detonating action by tilting movement of the plate 80, complete translativc depression thereof will afford a greater degree of movement, and the spacing of the firing pin from the primer initially must include this extent of movement and such addition as the margin of safety requires.

To enable introduction of the bursting charge 69 after assembly of the top plate 23 on the cup, a circular loading port |01 is provided in the plate 23 in a suitable location and closed by a friction cap |08 of a bellows type, so that if a liquid or fluid explosive is employed, its expansion and contraction will be accommodated.

In Figures 10 to 12 there is illustrated a modification of the invention in which I have avoided exposing the upper detonator directly under the ring pin except after the device begins to function normally after arming. By this construction, while the device is set in safe position, if there should be such fracture of the operating plate as to allow depression of the firing pin, it will not encounter the detonator 1U.

In this construction, the mine may be identical with that first described, except as to the manner in which the upper detonator is constructed and incorporated (the firing means being the same as before) and in the views mentioned parts previously described and here unchanged bear the same reference characters. Those modified and closely corresponding to previously described elements may bear the reference character previously applied but with the addition of a prime mark.

The top plate 23 of the base part of the mine remains the same as before, but has an assembly case 24 Screwed into the depending neck flange 25 of the case 24 being substantially the same as the case 24 except that the head portion 26' thereof is formed with a larger interiorly threaded opening, the lower part of this case being flanged and set in the bottom of the cup as at 29 in the species of Figure 1.

The body 34 of Figure 1 is replaced by an upper body |||l of cylindrical form exteriorly threaded at its upper part and screwed into the opening in the head 26 and extending downwardly a distance. Fitted snugly around the lower periphery of body ||0 there is a thin case wall the lower edge of which is set in a rabbet ||2 formed around the upper edge of a lower body ||3 similar to the lower part of the body 34, and constituting a bushing, recessed and interiorly threaded in the same size and shape as the recess 42 in the body 34, so as to receive the pull igniter as before shown. Within the case wall between the parts I0 and I3 there is a booster charge |I4.

A ash port I I5 is formed vconcentrically in the lower end of the body I I0, and an eccentric cylindrical chamber H6 is formed in the upper part of this body open at its upper part on an axis parallel to the vertical axis of the body IIO; and set revolubly therein is a cylindrical barrel I'I'I. Formed through the barrel there is a small vertical bore eccentric to the axis of the barrel and constituting a primer cup H8, located so that on rotation of the barrel it will move in an arc including the axis of the body H and consequently at one position of the barrel in rotation the cup will be valined With the ring pin and flash port H5. In this cup there is set flush with the top of the barrel a detonator H9 of conventional composition. The upper end of the barrel sets above the body H0. Near the cup IIB in a clockwise direction as viewed from above, a bore |20 is formed in barrel II'I and over which there is vertically reciprocable an arming pin I2I, depending from the lower key head 93 on which it is rigidly fixed. The top end of the barrel III is formed with a curved channel |22 extending in a clockwise direction from the hole |20 concentric with the axis of the body H0 over an `angle of ninety degrees, from which point a spiral cam surface |23 extends downwardly clockwise, this cam 'being concentric with the barrel H1 rather than body I I0 and including an angle of ninety degrees about the axis of said barrel within a depth a little less than the full stroke of the pin |2I. There a drop |2I occurs to a depth measured from the bottom of the channel |22 parallel with the axis of barrel I II at least equal to the vertical movement of the pin |2I. At the upper position of the keyhead 93 the pin |2I clears the hole |20` so as to be movable in the channel |22 clockwise when the key is rotated from safe position of Figure 11 to armed position as heretofore described. In the armed position the pin` I2| 'is .disposed over the upper end of the cam surface |23. When in this position downward full stroke of the head 9'3 will cause the pin I2I to engage surface |23 and rotate the barrel II'I counterclockwise through an angle of ninety degrees.

The cup H8 is located on a radius of t-he barrel II'I at an .angle of ninety degrees in a clock- Wise direction from that radius of the barrel which intersects the axis of the body H0 when the fparts are in salfe position as shown in Fig. 11. Consequently, as the cam surface |23 is inclined so that pin |2| rotates barre-1 I I'I through ninety degreesl in a little less `than the full stroke of the pin, the cup H0 and its primer H9 will become alined with the ring pin |05 just :prior to completion of a full stroke of the pin I2 I, `pin |05 will Ibe driven into primer I9 as the end of pin I2I is forced into drop I 2|. A hole |24 is located in barrel II'I, 90 counterclockwise about the axis of the barrel from cup H8, in position aligned `with firing pin |05 when the mine is in .safe condition as shown at Figure 11. In order :to hold the barrel against accidental rotation, a spring |25 is mounted on the body I I 0 beside the barrel. This spring has an arm |26 extending clockwise and inclined inwardly across the channel I 22 with its extremity |25 curved outwardly to form Aa, detent |21. See Figure 11. This detent engages ,la notch |28V in barrel III to yieldingly resist rotation thereof. The material of the barrel between its periphery and the channel is cut :away to permit voutward movement lof detent |28, clear of the barrel. Then, as `pin I2! rotates clockwise :as key 9| is turned to arm the mine. its final movement 12 in rotation cams detent |21 out of notch |28 and clear of barrel II'I. Spring |25 includes a short arm |29 frictionally engaging the barrel at all times.

In the operation of this modification, the ring pin |05 is controlled as before, but the primer I I9 is out of the path of the firing pin until the operating plate is depressed after arming. In safe position, lwhen the plate 80 is depressed, the arming pin I2! simply moves into the hole |20, keeping the barrel in safe ,position `while the ring pin moves lpart way down. Ilf the operating plate should become fractured or the firing pin freed in :any way the firing pin would simply enter hole |20 without effect. The detonator is protected from the head 93 by engagement of the depending flange part 94' upon the upper end of the body I I0.

In operating the knob 98 and setting key 9| for arming, the struct-ure of the T-head, and on ythe .plate 80, together with the knob 98, function as in the species of Figure 1 to stop the rotating parts in armed position, although the primer I I9 is still `out of line with the firing pin, and so complete arming is not accomplished. The setting operation moves the arming pin |2| along the channel I 22 to position over the Vstart of the cam surface |23, pressing the spring arm |25 aside to Ifree detent |21 from notch |28; When, now, the plate 00 is depressed, the lpin |2| contacts vsurlface |23 causing counterclock'wise rotation of the barrel I Il in body I I0, and positioning the [primer I I9 in the path of the firing 'pin immediately before the latter engages the primer, and while the pin has a substantial distance over which it will be moved by spring 76. In the completion of this movement pin |05 is driven into the primer with resultant detonation of the booster charge H4 and bursting charge.

In Figures 13 and 14 a further modification of the general form and function last described is shown wherein the detonator assembly includes the same principal elements, and the same arming pin I2| is utilized. 'I'hey barrel II'I' has the detonator I I9 and 'well hole lid located :as in the species of Figures 11 and l2, but the hole |20, channel |22, cam |23, and spring |25 of Figures 11 and 12, are omitted. Instead, the barrel is lprovided with a short radial slot |30 in its top surface of a depth throughout to accommodate the pin IZI to its full stroke depth, the end portion of the pin |2I remains in the slot at all times, so that rotation of the setting key (accomplished as before) will turn the barrel likewise.

Whenthe device of Figures 13 and 14 is in safe position as in Fig. 13, the pin I2| is at the outer end of the slot |30, the well hole |24 is on the axis of the firing pin, and the device then functions as in the previously described modication when in safe position.

This device is armed by turning the knob 98 as before, "which causes the arming pin |2| to :press against the side of the slot |30 so as to turn the barrel toward the armed position. In this movement due to the difference off location of the axes of rotation of the key and the barrel, the Ipin I2! slides inwardly in the slot |30 and `outward until, when the key is stopped at armed position by the abutment 09, the pin |2| will be located little i'f any further from the outer end of the slot |30, and the detonator will have been moved to position under the firing pin, :as in Fig. 14.

A still further modification of the detonator assembly is ydisclosed in Figures 15 to 19 inclusive where the benefits of safety in case of -fracture or fault permitting premature depression of the firing pin excessively, are attained. In the illustrations thereof, parts previously described and which are unchanged :are designated by the same reference characters and those closely corresponding to previously described parts have similar reference characters with the addition lof a double prime mark.

All of the parts required are the same as before Adescribed in reference to Figures 10 to 12 except the arming pin and the barrel and its manner of mounting. An upper detonator assembly body is provided of identical size and external form as the one ||0 and likewise mounted. Provision for a barrel mounting consists of a transverse horizontal cylindrical bore |3| through one side nof thebody |'I0" but stopping Vshior't of the opposite side, and a concentric stud |32 is formed on the closed end, on which rests one end of a barrel |33 having a suitable bearing recess in one end fitted on the stud but of a depth longitudinally of the barrel less than the length of the stud, the barrel resting freely for rotation in the bore. A flash port |34 opens from the lower side of the bore through the bottom of the body I0". In the barrel 33 a diametrical detonator cup bore |35 is formed, stopping short of the periphery of the barrel at the right hand side as viewed in Fig. 15, where a slightly reduced port and shoulder |36 are formed adapted to aline with the port |34 when the barrel has been rotated to armed position. The end of the barrel opposite the stud |32 has connected eccentrically thereto one end of a spiral torsion spring |31, the opposite outer end of which is anchored on the body H0" and urging the barrel counterclockwise from the position shown in Fig. 15. A hole or recess |38 is formed in the end of the barrel next the stud and close to the periphery of the barrel and set longitudinally into this hole there is a short arm |39 formed at right angles on the lower end of an upstanding vertical push rod or arming rod |40 engaged slidably in a suitable guide hole |4| formed in body l0 the rod being extended upwardly a distance above the body H0 and top plate 23. This rod is offset from the vertical axial plane of the barrel in a clockwise direction as seen in Figure 15. The key head 93'l in this device may be flat across its underside, instead of recessed as in the previously-described species, but otherwise the key device 9|" here shown is the same as the key 9| rst described, and similarly controlled and set for safety or action. There is a coaxial firing pin on the under face of the head 93".

|40 lies in a space |30 between the end of the barrel and the end of the bore, caused by difference in length of the stud |32 and recess in the end of the barrel. The upper end of rod |40 is spaced below surface |42 as shown in Figure 15. This permits a certain free movement of the head 93" without operating the arming rod |40. A slot |43 is formed in and radially across the upper side of the body H0" opening through the side of the bore |3| over somewhat more than a radius of ninety degrees and alined with the cup bore |35. The slot is laterally or radially extended from the barrel a point adjacent the side of the body ||0" distant from the rod |40, and stops close to the hole |4| through which the rod |40 operates. The hole |38 may be extended radially inward to permit movement of the arm |39 in a straight path from its upper to its lower position in operation.

Set in the cup bore |35 there is a primer |44 Within the bore |3| the rod the sensitive end of which projects from the barrel, its inner end being set against the reduced bottom or shoulder end |35. The projecting end of the primer extends into the laterally extended part of the slot, engaging the lower end thereof when the primer is in horizontal position as in Fig. 15, and serving as a stop opposing reaction of the spring |31. Movement of the barrel clockwise as viewed in Fig. 15, will be checked by the projecting end of the primer engaging the material of the body ||0" at the inner end of the slot |43.

In the operation of the device of Figures 15-19 when the setting key is in safe position, depression of the plate will move the head 93" downward only the distance represented by the space between the/wall 19 and cup 20 (Fig. 1') since the key is locked to the plate 80. This movement will move the under face of the head 93 downward to or slightly beyond the upper extremity of the rod |40 with little, if any, movement of the rod. Such movement of the latter as may occur will rotate the barrel |33 slightly, but not suiciently to expose the sensitive end of the primer to the action of pin |05. Upon relief of pressure on the plate 80, the spring |31 will return the barrel to initial position as the head 93" r1ses.

In the active or arming position of the key 9|", when the plate 80 is depressed, the spring 16 will be pressed downward slightly beyond dead center, and will then react further driving the head 93" downwardly with full stroke, so as to engage and push the rod |40 downward a suiiicient distance for the arm |39 to rotate the barrel clockwise through an angle of ninety degrees from the position shown in Fig. 15 to that shown in Fig. 16, at which time the firing pin will have engaged and entered the primer |44 initiating detonation of the explosive train as before indicated.

In Fig. 20 there is illustrated a modication 0f the manner of sealing the space between the base and operating plate, and a simplified safety device.

In this view the operating plate 80a may be constructed to rest on the Belleville spring 16 as before, but the securing screws 11 are omitted, the spring 10 being simply set in the rabbet seat 15 before described. The wall of the cup 22aI however is made of substantially larger diameter, or the diameter of the operating plate reduced, and the wall |45 of the cup 22a, extended upwardly beside the depending wall 19a of the operating plate in slightly spaced relation.

Circumferential grooves |46|41 are formed in the opposed faces of the wall parts 19a and |45, and an elastic rubber ring |48 or the like is set between the walls under lateral compression thereby. The grooves are of substantial vertical extent so that the ring may be spaced from the upper and lower sides of the grooves at times, and when the device is free of pressure, with the plate 80a supported by the spring 16, the groove |46 extends some distance above the ring while the groove |41 extends a distance therebelow. The ring |48 is engaged by the lower and upper sides of the grooves |46, |41 by the upward pressure of the spring 16 on the operating plate and serves as a means to limit the upward movement of the operating plate. On depression of the operating plate, downward movement of the Wall 4 10a relative to the wall |45 causes the ring to roll on the bottoms of the opposed parts of the 15 grooves, maintaining a seal throughout this movement.

The operating plate in this last named device is provided with an operating rib 83a on its underside bearing upon the top of the spring midway between the seat and the central support key 91a. This key is formed with a simple cylindrical stem |59 of a length to project above the central plain central part of the operating plate, and its lower part includes a head 93a with supporting flange or rabbet supporting the edge portions of the spring around its central opening, and having a ring pin '|95 on its underside as before.

The key @3a may be held in safe position by the insertion of a safety pin |50 through an aperture in the upper end part of the key close to the top face of the operating plate. Withdrawal of the pin arms the device.

In Fig. 2l a further modication of the mine is shown, in which the top plate 23h of the base, set in a rabbet of the cup as before, is provided with an upstanding flange |5| having a cylindrical outer face close beside the depending wall 19D of the operating plate 86h. The latter has the presser rib 33h and the spring 16 is rested on top of the flange |5| sof-as to be engaged by the rib 83h and so support the plate. The firing pin is fixed on the underside of a spool-like driver |52 corresponding to the head 93, but having no part extending through the plate 86h. The driver is formed with a flange 84h receiving and supporting the inner edge of the spring and retained by a flat ring |53 sprung into a groove in the driver above the spring and projecting over the latter. A hole |54 is formed in the rupper side of the driver with a lateral horizontal extension |55 at its lower part, the hole being eccentric to the center of the plate 89D and springend of larger diameter. Engaged concentrically and revolubly through the plate 89h there is a safety key |56, consisting of a simple bar stock extended through the hole |54 as a shank |51 and having Ya key arm |58 extending initially into the extension |55 of the hole '55e With the spring and driver in elevated positions and the arm |51 in the lateral extension of the hole |54, the upper end portion of the key extends at right angles close against the top face of the plate 39D, forming a setting lever |59. It may be noted that the hole |54 is of suicient extent opposite the extension |55 to permit the arm ld to be withdrawn upwardly therethrough when the key is rotated so as to swing the 'arm ,les out of the extension |55. Consequently, swinging of the lever |59 over an angle of 180 degrees will arm the mine, freeing the driver for movement with its firing pin in the manner before described. A seal |69 consisting of a disc of flexible tough material may be laid over the lever while in safe position as illustrated in Fig. 21 and cemented to the plate 80h, so as to hold the mine in safe condition until it is to be armed, when the seal may be removed while the key is moved to armed position. If the seal has a permanently tack adhesive under face, it may be returned to sealing position to hold the device armed.

In Fig. 22 the mine is illustrated as a combined push-pull detonator, without requiring more than the single detonator and ring pin operated by the Belleville spring.

The base element may be the same as before described if desired or provision for an additional pull igniter omitted. The Belleville spring is arranged to be purposely and permanently placed under strain at will, so as to tend to operate theA ring pin, restrained by the previous vsafety key arrangement, and Va, pull-operated release providedv operable after the key is set in armed position. A

A link |61 is connected pivotally between ears |62 on the top plate 23o near the center of the mine and extended through an opening or slot |63 in the spring 16e with a clearance al1 round and slidably through an opening |63 in the operating plate 39e Iand above. The upper end of the link is provided with a transverse rigid cross pin |64. A straight lever |65 is provided having two spaced fulcrum cam plates V| 66 receiving the link between them. The identical plates |66 have a low lat 61 resting on the plate 89e in the raised position of the lever shown at Figure 22. Each plate has a slot |69 extending from its back edge inwardly and downwardly when the flat |61 is engaged with the plate 89e, each slot receiving av respective end of the cross pin |64, but movable along the slot when the lever is swung counterclockwise from the position shown in Figure VY22, so that lever |65 may be removed from the mine. The plates are shaped to form cam risers |19, from ats |61. The ats |61 are located at such distance from the axis of the pin that the rib 83 engages the spring sufficiently to hold the iiats against the plate 99C snugly and so hold the lever in raised or inoperative position.

When the lever is pressed downward the risers .|16 press upon the plate 89o forcing it downward against the spring and the high parts of the cam portions pass dead center and so oppose return of the lever.

The upper end of the key device includes the same elements and the plate e and knob 98e include the same parts cooperative with each other and with the key 9| c as in the case of the key 9| before described. In addition however, the key vstern 96e isk axially bored to receive slidably a pull pin |12 substantially similar to the one 60 before described, its inner end portion being split and the tangs thus formed being recessed on their outer sides to receive parts of balls |13 set in two diametrically opposite openings |13" in the tubular part of the stem 96o. The opening |116A through the plate 89C is enlarged in its upper part so as to form a lower conical seat |15 at each side of the stem below the openings |13' and to receive substantial parts of the balls over the seat. The knob 98e is apertured to receive an enlargement |18 of the pull pin and a pull ring 11 is formed at the upper end of the enlargement. The knob has two ears |13 extended upwardly beside the eye, and the enlarged part of the pin and the lears are apertured to receive commonly therethrough a safety pin |19 of usual form for such uses. The ears also prevent relative rotation of the pin.

In the use of the last described modification the mine may be used as rst described (as an antitank mine) b-y swinging the lever |65 to the left (Fig. 22) until the slots |69 are in a position permitting the lever to be removed from the mine. The safety pin |19 is removed and the pull pin |12 also withdrawn.

The mine may then be made safe by turning the knob 98e as in the case of the structure rst described, or may be armed by a reverse operation of the knob. The spring 16o is free of tension when the lever |65 is removed', and may operate in response to loading as at rst.

In case it is desired to operate the mine by the pull pin, instead of removing the lever, the lever is turned clockwise as seen in Figure 22 to thereby place spring V under tension. The

17 spring will then drive the firing pin against the upper detonator when the key 98c is in armed position and the pull pin |12 withdrawn.

The ring |11 is first connected to the draw wires or anchoring means before withdrawing the safety pin |19. The key is then turned to armed position and the safety pin |19 withdrawn. Thereafter, when the pull pin |12 is withdrawn, its split portion yields to the balls |13, and after clearing the latter they are free to move further inward.

The spring 16e being under strain by reason of the pressure of the rib 83 thereon, now draws the stem 96o downward to cam the balls inward and thus permit unrestrained movement of the stem 96o, firing pin and spring downward.

It will be clear that while an important feature of my inventionis a novel utilization of a disc type spring so that a non-metallic material may be used, other forms of springs corresponding to known forms of metal springs may be used should suitable new non-metallic materials of adequate strength and resilience become available, and metal springs of various forms may be employed as substitutions, with or without slight modifications of adaption.

Thus a simple metal bow spring can be substituted for the Belleville spring with practically no modification of structure although a simple straight bow spring of wood, as at present advised, would not function reliably.

In Fig. 23 there is illustrated a use of coil springs. In this instance the mine base 20d and an operating plate |80 are provided, of proportion and relative arrangement similar to those of parts 20 and 88 of Fig. 1. In place of the small annular flange 98, however, the ring pin |8| is provided with radial arms I 82 extended radially a distance substantially equal to the radius of the rib 83, and supporting at their extremities helical springs |83 engaging the operating plate. A bridge plate |88 is mounted on the base, below the operating plate but above the arms |82, and having a central aperture in which the pin |8| is slidable, and holes |85 through which the upper end of a respective spring may pass.

On the underside of the plate |80 respective presser lugs |88 are engaged initially in the upper parts of the openings |85 and slidable downwardly through the latter to compress the springs. The firing pin stem is reduced and extended slidably through the operating plate and secured against downward relative movement therein by a manually removable safety pin |81. A flange |80' is formed on the under side of the plate |80 arranged to engage the large part of the firing pin before completion of full downward movement of the plate |80. On the large part of the pin within the opening |89 in the bridge plate a circumscribing groove |88 is formed spaced slightly from the top of the opening |89 when the firing pin is at the upper limit of its movement. A groove |90 is also formed circumferentially in the side of the opening |89, opposed to the groove |88 at the position of the parts stated and set between and fitting into these grooves there is a soft rubber ring 19|, or the like. If desired the side of the opening |89 may be slightly relieved below the groove |90 as at |92. 'I'his rubber ring thus serves as a seal and also as a yieldable detent, opposing movement of the firing pin when the springs are initially compressed.

The downward movement of the plate |80 is limited to a distance less ythan that between the point of the firing pin and detonator, so that with 18 the safety pin |81 in place, under full depression of the plate |80 the firing pin stops short of the detonator notwithstanding the compression of the springs.

With the safety pin out, when the plate |80 is depressed, it moves slidably downward around the firing pin, compressing the springs |83, and the force thus communicated through the springs to the arms |82 will cause compression of the rubber ring |9|, the resistance of which will b e overcome suddenly shortly before downward movement of the plate |80 is completed. The force of the spring may be proportioned to effect this action without positive aid, but the ange |80 engages the large partV of the pin |8| after a substantial compression of the springs has occurred, and positively initiates movement of the pin to overcome opposition of the ring |9|. Further movement of the firing pin requires substantially less force, the ring rolling between opposed cylindrical surfaces of the pin and hole |89. The large part of the pin clears the ring after a very short movement (which may occur during functioning of the flange |80') and the pin is then driven into the detonator.

It should be noted that the springs may be initially free of compression in the elevated position of the firing pin, so that the ring |9| is not required to sustain material compression until operative action of the plate |80 occurs.

In Fig. 24 a simplication of the device is shown in which a base |95 is provided having a main charge |96 and having set in its top a detonator and firing unit combined including a fuse body |91 suitably set into the main charge. The body is cylindrical, on a vertical axis, having a concentric chamber |98 open flush through the top of the body and having a central port |99 opening therefrom into a lower chamber concentric with the body and having a booster charge 200 therein. A primer 20| is fixed in the port and a ring pin 202 is vertically reciprocable in the chamber |98. The pin comprises a head 203 having a peripheral groove 2|4 and a pin 292 to detonate the primer. The wall of the chamber |98 is also grooved at 204 in alinement with the groove of the pin. The head is centrally recessed to seat a helical spring 205 the upper end of which is entered loosely in a recess in the underside of a dome-like pusher 208 of a diameter less than that of the chamber 98, but having a base ange 201 slidable in the chamber and retained by a screw ring 208 engaged on a relieved and externally threaded upper part 209 of the body |91.

The top plate 2|0 of the base |95 is formed with a flanged opening to receive the ring snugly fitted therein, and a case 2|| fits the flange and is secured to the underside of the plate 2|0. A C-spring 2 2 is set under the flange of the opening in the plate 2 |0, and over the shoulder 2 3 formed by the relief of the upper periphery of the body |91 to hold the detonator assembly in place.

An elastic ring 2|3 fits grooves 204 and 2 I4 and functions in the same manner as previously described for ring |9|, Figure 23. Groove 2M is closely adjacent the top surface of head 203 so that only a small movement thereof is suflicient to free it from ring 2|3.

I claim:

1. A full stroke firing device comprising a bowed plate spring, a support for its outer parts, a reciprocable member and operative connection between the same and spring connected centrally with the bow of the plate, operating means including a pushing member positioned to engage agenti? the spring intermediately of said connection and the base of the bowed part, and means to limit operative movement of 'the pushing member to that position immediately beyond dead center position of the spring where the latterrnay independently react further in the direction or push pplied, and a releasable connection between the operating means and said reciprocable member eenstructed to hold the latter in initial relation to said-connection with the plate! whereby to limit movement of the nring device short of full stroke, at will'.

2n A mine ofthe character described comprising a broad base element including' a bursting charge anda central upper primer xed therein, a circular dished plate type spring of comparatively slight altitude relation to its diameter seated erect on said base elementand secured in ceaxial relation thereto, a tiring pin mounted centrally-thereofpresented downwardly in alinement with said primer for detonative engagement, with the latter under downward reaction oil the spring when pressed beyond dead center, an operating member vertically reciproeable over the spring and having a downwardly projected portion arranged to engage the spring around its-f center and resting on the spring intermediately of its,A center and base,l means being included to retain the, operating member in concentric relation to the spring, said operating member hav-ing peripheral portions positioned to rest; on the base member beyond operative positions ofthe operating member.

3-. The structure ofclaim 2- in which the firing pin includesv a safety eonnectionl with the operating member separable at will; whereby at safe position of the connectioni movement ofthe firpin is limited to that of the operating member, the full stroke of the firing, pin including a substantial component of njiotionr beyonddead eenter position of 'thespringand'l the operating member beingarranged.l to engage the base short of` full; stroke movement thereofV with the spring.,

4. A fuilA stroke ringdevice comprising a support, a bowed spring deviee having its extremities engaged with the, support,L an operating member Qver the spring having pushingv partsy thereon engaged with the spring intermediately betweerr its centralpart and* sai'dextremities and movable to press the spring; to andgbeyond' its dead center posi-tion, means to limit movement ofthe Vop:y rati-n-g 'memberto an operatedposition when the springis past dead center position a firing pinandsupport for the central part o i the springcomprising` a member reyoliibie on; the spring,

and `revoluble in said operating member;K a key e'lementthereon, said; operati-ng member and keyelement being constructed ior sliding movement of the ring pin awayfromthe opera-ting member at one positionof-` the keyelement in its rotation in the operating-memberand to interlockwiththe latter at anotherA position, and means outwardly of the operatingmeinber; to rotate the keyelementforthepurposes deseribeda ELY The structure oiclaim lin which s aidkey` portion is a T-sha-pedheads and; the operati-ng memberA is formed with an Opening to ttheI stem ofsaid head-A revolubly-witli thearmsof the. head projecting beyond the sidesof-l the opening, and having diametrically opposite slotstor'eoeive the arms o'fthe head sl-id'ablfy therethrough;

6.- The structure oi?v claim 4 inwhich saidfl key` portion is a T-shaped'- headf, andthe operatingl member is formed with an opening-to tthe stemosaid headrevolubly withthe armsof-the headj protecting beyond, the sides 0f, the opening and having diametrically opposite. slots to receive the arms of' the headj slidablgy therethrough, said head having a stem portion in said opening ini'- tially and being attened transversely to a thickness substantially less. than the diameter of. said opening,K an annular boss being formed on the operating member and of an interior diameter coincident with the slots and having an abutment besidev one of the slots extending over an angle of' 90 degrees, andA a key operating means on the operating member separably connected with the key. Y

'7. A mine device comprising a base body having; a bursting charge and anexposed` detonator primer thereon,` an operating plate of similar horizontal area and form vertically movable thereover, a bowed spring having extremities supported Qn the base, a firing pin medially on the spring ali-ned with said primer, saidv operating member havingpusher parts engaged with the spring intermediately between the center and extremities of the spring', a member being included revolubly connected tothe spring centrally to support itin an initial inoperative position at vtimes and having a key head fixed thereon said plate being centrally apertured and said key head having a stempart revoluble in said open-V ing, said opening being-slotted to receive the key head therethrough slidably when in one position` only in rotation,I an annularboss onA the plate having an internal diameter coincident with the s-lotting of' the opening and' havingv an abutment beside the slot-ting subtend-ing an angle of 90 degrees at the opening, a yieldable circumscribingj septum between the plate and base, a seal for-said opening and means to rotate the key.

8. 'The structurev of claim 7 including a knob havinga depending annular ange tted' aroundv theboss, opposed perimetral grooves being formed' inthe opposedfaces of" the last named flange and' boss, said sealVA consisting of a compressible elasticy ringfittedbetween andfin` said grooves, said key head-beingiattenedf and said cap having depending: arms;- spaced to engage on opposite sides of' the k-eyhead' when at the upper limit of its slid'- ing movementv i-nthe said p1ate.

9;'The structure off-claim '7 in which the operating plate includes a depending perimetral Walt, inward projections on its inner side spacedv circumferentially, ands correspondingly arranged. retainer devices-iixed-onthe base adapted to engage over` saidc Projectionswhen alined therei with; and adaptedtog. pass between the saidl projectiqns when the plate and base are rotated rela, tivelythrough an angle toV aline the projectionsV with the intervals between said retainer devices.

10; The structure of claimU in which, the op,- eratingplate includes a depending perimetrali supporting wall;A opposed to a top surface ofthe base, projections on` the wallu spaced1 circumferentia-Hy; and correspondingly arranged retainer devicesadapt'ed to coengagewith thel projectionswhenl al-ln'ed therewith and adapted tol pass between the projections when alinedwith the in;- t'ervalstherebetween, the space between the supportingwallI and said; top surface ofthe base beingless than; the extentl ofj full stroke movement of that-partof the spring enga-ged by the pusher partsbut` more than the extent of movement of said' parts frominitial inoperative position to dead center positiont 11n-,The Structure O f; claim, '7; in. which said` spring is an annular plateJE an elevated annular seat being provi'cled4 onithe base receiving the edge of the spring plate, retainers secured on the seat extending over the edge portion of the spring and also outwardly and constructed to form circumferentially spaced retainers for the operating plate spaced above adjacent top surface of the base, said plate being formed with depending support portions adapted to rest on the base at the lower limit of movement of the operating plate and having circumferentially spaced projections arranged to engage under the retainers at one position in relative angular movement of the operating plate and base on their axis and for passage of the projections between the retainers at another position in said relative movement.

12. A detonator means comprising a base member, a pressure responsive operating means thereover including a ring pin and safe settingr means, a detonator comprising a booster case set through the base and having a primer exposed to said ring pin and having a second primer, a firing means including a spring loaded ring pin in operative relation to the second primer, and pull responsive releasing means opposed to ring movement of the second firing pin.

13. The structure of claim 1 including in addition a detent for the ring pin on said pushing means, pull pin means to release said detent, and manually operable means to move and hold said pushing member in pushing relation to the spring. o

14. In a mine detonator, a base having a primer thereon a load responsive operating member having limited movement from an initial distal position toward the base, a ring pin reciprocable thereon in line with the primer having a full stroke movement to the primer greater than that of the operating member, a spring device in cooperative relation to the operating member and ring pin constructed and arranged to be tensioned against the ring pin by said movement of the operating member, said iiring pin including a manually releasable safety setting key revoluble in the operating member to lock therewith at one position of the key, and free and slidable therein at another position, said key being tubular at the outer part in the operating member, and having a radial hole therethrough, the operating member having a slot beside the key inwardly of the hole, a detent in the hole and over said seat, movable into the key to clear the seat and a pull pin inserted in the tubular end of the key holding the detent outward and exposed exteriorly for extraction, and manually operable means to move said operating member to full operated position and to hold it fixed there.

15. The structure of claim 4 in which said key portion is a T-shaped head, and the operating member is formed with an opening to fit the stem of said head revolubly with the arms of the head projecting beyond the sides of the opening, and having diametrically opposite slots to receive the arms of the head slidably therethrough, said head having a stem portion in said opening initially and being flattened transversely to a thickness substantially less than the diameter of said opening, an annular boss being formed on the operating member and of an interior diameter coincident with the slots and having an abutment beside one of the slots extending over an angle of 90 degrees, and means to operate the key.

16. In a device of the character described, a circular base member, a relatively vertically movable `circular operating member thereover a yielding supporting for the operating member.

detonating devices operatively associated between the two said members responsive to downward movement of the operating member, said members having matched opposed bearing faces arranged to coengage at the lower limit of movement of the operating member, inward projections formed on one of said members spaced concentrically thereon, and outward projections on the other of said members correspondingly spaced and being of a size and adapted to pass between the projections of the opposite said member under axial relative convergent movement of the members, and to coengage therewith under relative rotation of the members to limit divergent axial movement of the members to a predetermined initial position.

17. The structure of claim 16 in which a flexible septum element is engaged around the two members and xed thereto so as to form a seal, yieldable to downward movement of the operating member.

18. In a mine, a base element having a detonator, an operating member having limited movement toward and relative to the base, a firing pin mounted for full stroke movement to the detonator, greater than the movement of the operating member, a spring connection between the operating member and the iiring pin, means on the operating member positively contacting the ring pin prior to full compression of the spring, manually removable means limiting the firing pin to the total motion of the operating means, and yieldable means to anchor the pin to the operating member in initial position in respect thereto.

19. In a detonator, a cylindrical case, a centrally-apertured cap secured over and closing the rear end of said case, a sleeve within said case and having a rear outwardly-flanged end clamped between said case and cap and having a reduced inwardly-hanged forward end, a hollow ring pin in said sleeve and slidably tting and extending through said forwardly-flanged end, there being a plurality of apertures through the wall of said ring pin within said sleeve, a ball within each opening, spring means urging said ring pin forwardly into firing movement, and a safety pin extending through the aperture in said cap and having a split end extending within said ring pin, said spilt end engaging said balls to yieldingly hold the same in said opening and in engagement with the inwardly-flanged forward end of said sleeve to thereby hold said Iiring pin against firing movement under the urge of said spring means.

LYLE K. LILJEGREN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,512,249 Sprague et al. Oct. 21, 1924 1,781,328 Grayson Nov. 11, 1930 2,123,829 Grayson July 12, 1938 2,324,846 Joyce et al July 20, 1943 2,336,701 Rasmussen Dec. 14, 1943 FOREIGN PATENTS Number Country Date 69,728 Sweden July 1, 1930 742,598 France Jan. 4, 1933

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