US1564670A - Metal-working machine - Google Patents

Description

Dec. 8, I925 1,564,670

B. M. W. HANSON METAL WORKING MACHINE Filed Nov. 1, 1919 11 Sheets-Sheet 1 INVENTOR.

5 any! H0050 BY M- HIS ATTORNEYf Dec. 8., 192 5- 1,564, 70

B. M. w. HANSON METAL WORKING MACHINE Filed Nov. 1, 1919 11 Sheets-Sheet 2 u a I a i r. g; P 9 0' 9 I N VEN TOR.

Hen y) M. Wf/mson HIS ATTORNEY.

Dec. 8, 1925. 1,564,670

B. M. W. HANSON METAL WORKING MACHINE Filed Nov. 1, 1919 ll Sheets-Sheet 5 Fig. 3.

V f V 1 I INVENTOR.

Be/1 97 M W Hanson His ATTORNEY.

Dec. 8, 1925- 1,564,670

B. M. w. HANSON METAL WORKING MACHINE Filed Nov. 1, 191%; 11 Sheets-Sheet 4 INVEN TOR.

Beryl/1 Whauson H I S ATTORNEY.

Dec. 8, 1925- B. W. HANSON METAL WORKING MACHINE 11 Sheets-Sheet 5 Filed Nov. l 1919 Bengf M. Wfianson Dec. 8, 1925- B. M. w. HANSON METAL WIORKING MACHINE Filed Nov 1, 1919 11 Sheets-Sheet 6 INVENTOR. Bang) M. Wfianwn H]S ATTORNEY.

,B. M. W. HANSON METAL WORKING MACHINE Filed Nov. 1, 1919 l] Sheets-Sheet 7 INVENTORQ Blinpf/Vl. W. Hanson H13 ATTORNEY.

11 Sheets-Sheet 8 B. M. W. HANSON METAL WORKING MACHINE Flled Nov 1 1919 Dec. 8, 1925- HIS .ITTORNEY.

Dec. 8, 1925- 1.564.670

B. M. w. HANSON METAL WORKING MACHINE Filed Nov. 1, 1919 11 Sheets$heet 9 III INVENTOR.

B any/f1. W. Hanson BY/W HIS A TTORNE Y.

- Dec. 8,1925. 1.564.670

B. M. W. HANSON METAL WORKING MACHINE INVENIOR. Ben gi' M VV. Hanson H15 A TTQRNEY.

Dec. 8, 1925- 1 .564.670

. B. M. W. HANSON METAL WORKING MACHINE Filed Nov. 1, 1919 11 Sheets-Sheet l1 INVENTOR.

" Bang/M. Wh'anson BY-%7L [115 A TTORNEY.

Patented Dec. 8, 1925 UNITED STATES PATENT OFFICE.

BENGT M. W. HANSON, OF HARTFORD, CONNECTICUT; EINAR A. HANSON AND CLAR- ENCE E. WHITNEY EXEC'UTORS OF SAID BENGT M. W. HANSON, DECEASED.

METAL-WORKING MACHINE.

Application filed November To all wi'iom. it may concern. Be it known that I, BnNorM. IV. HAN son, a citizen of the United States, and a resident: of Hartford, county of Hartford. State of Connecticut, have invented certain new and useful Improvements in MetaL \Vorking Machines, of which the following is a specification.

This invention relates to metalworking machines and has particular reference to machines for shaping, contouring or otherwise machining or finishing curved surfaces.

As an instance of one use to which the machine forming the subject matter of this invention may be applied, reference may be had to the final finishing operation on a thread for the purpose of giving to that thread extreme accuracy in its shape, finish and size. In accordance with this invention, means are provided for bringing the work and the Ci tting tool into contact with extreme niccty both as to position and as to the amount of feed which would determine the amount of the cut to be taken. Also, the me accurate positioning of the tool to the w ort: is provided for. Also means are provided for sharpening or resurfacing the tool without disturbing its relation to the work with the "consequent advantage that after such sharpening operation the work and tool have the same relative relationship as when originally positioned, a feature which insures the greatest uniformity and accuracy and saving of time. There are also other features of novelty and advantage present in the machine to which reference will be made and which will be more particularly pointed out in the appended claims.

In the present disclosure of my invention, which is by way of illustration only and is not to be taken as restrictive of my conception, I show and describe my invention mcorporated in a machine for grinding threaded members or the like and while the invention has peculiar adaptability for this use, I wish it clearly understood that it is not limited thereto, as it is susceptible of use in various operations upon members having concentric. eccentric or irregularly curved surfaces. Furthermore, while I have shown but one embodiment of my invention in the drawings, this showing is by way of exemplification only, the invention being Fig. 5 is a sectional View taken substantially $011 line 5 5 of Fig. 4 and looking in the direction ofthe arrows.

Fig. 6 is a sectional view taken substantially on line (3--6 of Fig. 4 and looking in the direction of the arrows.

Fig. 7 is a plan view of the left hand end of the machine, some parts being in section and other parts being removed for purposes of clearness.

Fig. 8 is an elcvational View of a ratchet clutch mecl anism.

Fig. 8 is a fragmentary View of certain parts thereof.

Fig. 9 is an elevational view of the ratchet clutch looking toward the right of Fig. 8.

Fig. 10 is a view'of a work gauge, the

trunnion therefor being in section.

Fig. 11 1s a vertical section through the gauge, the mounting therefor being 1n elevation.

Fig.12 is a plan view of a truing device. Fig. 13 is a sectional view thereof taken on line 13-13 of Fig. 12.

Fig. 14 is a front jview of the truing device with parts thereof in section.

Fig. 15 is a sectional view taken on line 15 15 of Fig. 12.

Fig. 16 is a front elevation of the mounting for the grinding wheel shaft, and

Fig. 17 is an end view thereof.

Referring now to Figs. 1, 2, 3 and 4, the general arrangement and organization of the principal parts of the machine can be clearly seen. a. is the pedestal or fixed bed, at either end thereof are fulcrums such as knife edges 5, 5, upon which the front of the rocking bed I) is mounted. At the left hand end of this rocking bed there s a rearwardly extending arm 0 upon which a gearbox Z is mounted and with which is associated mechanism which will he hereinafter described and by means of which this llltl rocking bed is rocked on its fulcrums.

By reference to Figs. 4, 5 and 6, it will be seen that the front of the rocking bed is of substantially the full width of the base and except for the rearwardly projecting arm 0, it is relatively narrow but suiiicient to provide lengthwise ways upon which the work holder, indicated generally at f, slides. This work holder comprises the main car-' riage g with which the lead screw it of the machine is engaged, a supplemental carriage 2' adjustable t ereon and by which the position of the work relative to the work gauge and tool can be obtained and upon which the head and tail stocks k, Z, are mounted, one of these, namely the tail stock 7,.being also adjustable. Of course, as will be understood, the work itself is supported between the head and tail stocks in. the usual manner, and driven by the usual connection with the head stock s indle.

At the right hand en of the machine and rearwardly of the rocking bed and work holder mounted thereon is a slide m extending from front to rear of the machine and upon this slide is mount-ed the journal box a supporting the tool 25, here shown as a grinding wheel.

From the foregoing description, it will be observed that the rocking bed has no movement relative to the pedestal except a rocking movement on its fulcruins, the knife edges 5, 5; that the complete work holder f slides longitudinally on the rocking bed moved by the lead screw 71.; and that the tool slide moves from front to rear .of the machine but not longitudinally thereof, operated from the front of the machine by the hand wheel 0 or from the rear of the machine by the hand wheel 0 either of which operates the screw p connected with the slide 127-. u is a feed shaft which may be operated either by the hand wheel 1; or automa-tically by mechanism indicated generally at w and which will be more particularly described hereafter It will be noted that the grinding wheel is solidly and rigidly supported on a fixed bed while the work is carried by a rocking bed mounted on knife edges. This arrangement is of the utmost importance in that it insures the greatest nicety in adjustment and maximum smoothness in operation, which means that very delicate grinding operations may be carried out with accuracy; vibrations, friction and other disturbing influences being reduced to a minimum or entirely eliminated. More particularly, the grinding wheel being mounted on a relatively heavy wheel slide, and the latter being securely clamped to and rigidly held at rest on the solid bed or pedestal, vibration of the wheelis practically eliminated. The grinding wheel is rotated at relatively high speeds vwhich necessitates the use of a belt. Owing to uneveness and irregularity in the belt, it has a tendency to set up vibrations in the grinding wheel shaft, but with the present arrangement, these vibration are absorbed by the solid grinding wheel slide and the fixed bed, and thus the grinding wheel is held steady and will rotate smoothly and evenly, which would not be the case were the grinding wheel mounted for movement (other than rotary) during the grinding operation. The work spindle is driven at a relatively slow speed through a mechani cal train of gears and, therefore, is not subjected to any excessive strains or stresses such as are exerted by a belt passing about a pulley. This means that the work holder may be mounted for movement on the rocking bed and the latter fulcrumed on knife edges, with the result that there is little or no friction at the fulcrum point of the rocking bed. This bed may be moved with great nicety permitting very delicate grinding operations, as where a fine relief is to be had on a threaded member, and smoothness in operation and accuracy in the finished product are obtained. The means for reciprocating the work holder and the various instrumentalities for rocking the rocking bed. together with the mechanism for controlling and driving the lead screw, work spindle and the rocking instrumentalities, are all mounted on the rocking bed. As hereinafter described, the rocking bed is rocked through the means of a rocking beam pivoted on the bed, this arrangement being of advantage in that the various'instrunrentali- 'ties for rocking the bed may operate in the proper relation to one another to perform their desired functions and, owing to the fact that the rocking beam, in some instances, functions as a lever, the power required in rocking the bed. together with the parts thereon, is materially reduced.

I am aware that in certain cam grinding machines and gun stock lathes, a pivoted arm carrying the. tool or fixed work support. is provided but. it is customary to journal such arm in a closed hearing. such as a sleeve, the result being that great difficulty is experienced in accurately fitting the arm and sleeve, and due to relatively large contacting surfaces, wear and friction therebetween will seriously interfere with the small and accurate fine adjustments sential in machines like that herein described. The feature of supporting the rock ing bed on knife edges is of advantage in that the objections just noted are entirely overcome. With this arrangement the rocking bed may be positioned with the greatest accuracy, very fine feed adjustments arepossible, and there is practically no friction or wear on the knife edges.

The bearings for the knife edges 5' each comprise a pair of blocks 201 and 202 which are clamped in place in a groove 200 in the rocking bed, or a part thereof, by means of plates 203 and screws 204. The faces'of the blocks 201 and 202, before they are mountedin the groove 200, are ground b a suitable machine to substantially per ect planes. Thus, when the two blocks are fitted together, with the end of one block abutting a face of the other one, as shown in Fig. 6, two of the faces form a V-shaped groove which is adapted to receive the knife edge 5. This groove will have a very sharp apex at the bottom such as would be impractical to make in a single block. Thus, I find it more practical and economical to form the bearing of the two blocks 201 and 202 ground before being-fitted together. On the rear end of the rearwa-rdly extending arm a of the rocking bed is a bracket 10 formed with a housing 11 within which is mounted a nut 12 to the lower end of which is keyed a worm wheel 13 in mesh with a worm 13, Fig. 7, at the end of the feed shaft '11-. This nut is free to slide through the worm wheel. 14 is a screw having threaded engagement with the nut,keyed to the housing as at 15 to prevent its rotation, and having a hearing at its lower end on a block 16 on the base of the machine. Supported in the upper end of the nut is a pin 17 which is preferably nonrotatable and engages the short end of a lever 20 which is 'fulcrumed on the bracket 10. For the purpose of describing the feed of the work to the tool'when a new out 'is to be taken, it may be considered that the lever 20 is an integral part of the bracket and has no motion relative thereto. It will be observed that this rocking bed, supported at the front on the knife edges 5, 5, is supported from the block 16 by the screw 14, nut 12, and pin 17 on which the lever 20 rests. Assuming now that the tool is free of the work and it is desired to take a new cut, the feed shaft '11 is turned so as to cause the nut 12 to travel down on the screw 14. This means that the distance between the block 16 and the lever 20'is decreased and as that decrease takes place, the rearwardly extending arm 0 drops slightly; the rocking bed rocking on the knife edges 5, 5, bringing the work near to the tool. For this feed, it is not necessary that the nut 12 shall be capable of sliding through the worm wheel 13, for the worm wheel, nut, pin 17 and lever 20 are, for all intents and purposes, fixed against longitudinal movement relative to the bracket 10 and rearwardly extending arms 0. The nut, screw, pin, may be conveniently referred to as avariable connection forming part of the feed mechanism.

Assuming now that the tool has finished its out and it is desired to return it to its pedestal of the machine, it will be obvious that, as the cam raises the long end of the lever 20, the bracket 10 and the rearwardly extending arm 0 are raised so that the rocking bed is rocked in a direction to move the work away from the tool. It is in this reversing action that the longitudinal movement of the nut 12 relative to the worm wheel 13 becomes necessary.

In a case where the contour of the work is irregular, as in the case of a tap which is relieved back of the cutting edge, a pattern disc 27 may be mounted on a shaft 28 suitably driven as will be hereinafter described, this pattern disc being shaped to correspond to the contour of the work which is being finished. It is engaged by a shoe 29 at the outer end of the lever 20. It will be apparent that, as the pattern disc is rotated,.the lever 20 will be rocked about its fulcrum on the end of the pin 17 and raise and lower the rearwardly extending arm 0 which brings about a rocking of the rocking bedto and from the tool with the result that the tool is caused to operate on the work-to produce a shape corresponding to the shape of the pattern disc and, of course, for this movement, the housing 11 must slide slightly up and down on the nut 12.

Whenever it is desired to put the pattern disc 27 out of action, this can be. done by runi'iing down the screw 30 mounted in the lever 20 to engage the stop 31 and raise the lever just enough to clear the pattern disc 2? without raising the lever out of cooperative relation to the reversing cam. In this case the feed for the new cut and the reversing cam will be operative but the pat-- tern disc will be inoperative. It will be seen that the contouring or shaping cam 27 is rendered ineffectual on the return stroke of the work holder, in the present instance it being rendered inoperative by separating the cam 27 from the rocking beam, the latter being raised and held out ofengagement with the cam on the reverse stroke of the work by the lifting cam 25. This is of advantage in that chattering, noise and vibrations (which would resultif the beam rested on the contouring cam while the work holder is being quickly moved on its return stroke) are obviated.

From a consideration of the foregoing description taken inconnection with the illusand through described tration of Fig. 6, it will be seen that this mechanism provides first for feeding the work to the tool for the purpose of taking out a cut or chip; second, for removing the work from the tool during the reverse stroke of the work. for the tool because of. backlash or lost motion in the driving connections will not properly cut the work on its reverse stroke; and third, that a piece of work having any irregular contour can be accurately and properly presented to the tool so that its entire surface can be accurately finished to thedesire'd shape. It will, of course, be understood that by a proper timing all of this mechanism is brought into play in proper sequence.

The feed shaft to has at its front end a hand wheel '0 by means of which the work can be quickly raised or lowered into and out of engagement with the tool. 'Back of the hand wheel and mounted on this feed shaft u is the ratchet mechanism w controlled by the movement of the work holder 7 so that the work may be automatically fed towards the tool after each operative stroke of the holder. This ratchet mechanism may be of any suitable construction, that shown in the drawings comprising a ratchet wheel 34 fixed to the feed shaft 'u; and a lever 35 pivoted on this shaft and carrying a pivoted pawl 36 cooperating with the teeth of the ratchet wheel. The lever 35 is connected, as

shown in Fig. '1, by means of the link 37 with one end of a bell crank lever 38 fixed on a shaft 39, and the other arm of lever 38 is connected through a link 40 with a rocker 41 carrying a rod 42 which is actuated through the collars 43,44, by a dog 45 on the work holder f. It will thus be obvious that, when the work holder 7 reaches the end of its operative stroke, the dog 45 engages the collar 43 on the rod 42 moving the rocker 41 connections the ratchet mechanism w is actuated to turn the feed shaft u and thus permit the rocking bed to rock down, slightly to take a new or deeper cut when a new cutting stroke is inaugurated. When the work holder reaches the end of its reverse stroke, the dog 45 engages the collar 44 and through the connections described the pawl 36 will be moved back into its initial position, shown in Fig. 1.

The mechanism for the control and timing of the reversing cam 25, the pattern disc 27, the lead screw it and other operative parts is mounted on the rearwardly extending arm 0 of the rocking bed within the gear box (26'.

Within this gear box, the shaft 26 carrying the reversing cam 25 and the shaft 28 carrying the pattern disc 27 are journaled. 50v

desi nates a constantly rotating shaft journale in the gear box and having a pulley 51 whereby it is driven. Fixed to the shaft 50 is a gear 52 meshing with a gear 53 norgagement with the tool.

mally running loose on'the shaft 26. Between the gear 53 and a cam sleeve 54 fixed to the shaft'26 is a ratchet clutch mechanism. most clearly shown in Figs, 8. 8* and 9.

Referring to these figures, 55 is a ratchet wheel fixed to the hub of the gear wheel 53, and 56 is a ratchet pawl pivoted to a flange or disc 58 carried by the sleeve 54. An escapement device controlled by the movement of the work carriage is employed to throw the pawl 56 into and out of engagement with the ratchet wheel 55 so as to intermittently rotatethe reversing cam 25 one-half revolutions and operate a reverse clutch for the lead screw it.

This escapement mechanism is mounted upon a bracket 60 secured to the gear box fl and has a pair of pivoted levers 61, the inner ends of which are diametrically disposed relative to the ratchet wheel 55. The outer this arrangement, when themembers are in the position shown in Fig. 8, the lower escapement lever 61 holds the pawl 56 out of engagement with the ratchet wheel 55 so that the shaft 26 is not rotated and the cam 25 is then in the position shown in Fig. 6. When the work holder reaches the end of its forward or cutting stroke the rod 42 is moved in a direction to rock the shaft 39, the rod 64 will be raised with the result that the lower lever 61 willrelease the pawl 56 permittingit to engage the teeth of the ratchet wheel 55; the shaft 26 together with the cam 25 will thereupon rotate until the pawl 56 is again thrown out of engagement with the ratchet teeth by the upper lever 61 the inner of which has been lowered into the path of the pawl. The cam 25 is thus rocking lever 20 and lift the work out of enlVhen the work carriage reaches the end of its reverse stroke. the shaft 39 will be rotated in the opposite direction, the rod 64 will be lowered, the inner end of the upper lever 61 will be raised to release the pawl, and the shaft 26 wili rotate with the gear 53 until the lower escapement lever 61 trips the pawl 56 and the cam 25 is then again in the position shown in Fig. 6.

For the purpose of preventing the shaft 26 from rebounding when its rotation is stopped, a spring pressed plunger 67 carried by the bracket 60 is provided, and the disc 58 has notches into which the forward end of the plunger 67 engages at about the same new lid

time as the pawl engages the escapeinent levers 61.

The mechanism for reversing the lead screw it is carried by the shaft 28 on which the pattern disc 27 is mounted. Referring to Fig. 7, upon this shaft is a pair of gears 70, 71. The gear 7 0 meshes with a gear 72' fixed on a shaft 50, and the other gear 71 meshes with a small pinion 73, fixed upon the stub shaft 7 4, having a gear 7 5 meshing with a gear 76 fixed to the shaft 50. It will thus be seen that the gears 70, 71 are constantly rotating in'opposite directions. In the present instance the clutch mechanism, for connecting the gears 70, 71 with the shaft 28 is not shown in detail as the specific construction thereof forms no part of the present invention. It is sufficient to say that when a sleeve 77 slidably mounted upon the shaft- 28 is moved to the left (referring to Fig. 7) the gear .will be fixed to the shaft and the gear 71'will run loose, and when this sleeve is moved to the right gear 71 is fixed and gear 70 is loose. Upon the outer end of the shaft 28 is a gear 78 driving a gear 79 fixed to a sleeve 80 to which the head stock spindle 81 is keyed. The lead screw it for the work holder is geared to the sleeve 80 through a gear 82 fixed to the sleeve 80; gear 83 meshing therewith; gear 81 fixed to the same shaft as is the gear 83; change gear 85, and gear 86 fixed to the lead screw it all of this gearing being similar to the common practice in an engine lathe.

The clutch mechanism just described is controlled by the ratchet clutch mechanism which is in turn controlled, as heretofore stated. by movement of the work'carriage. The sleeve 54 fixed to the shaft 26 has :11 cam groove 90 in which works a pin carried by a shipper 91 having at its other'end a pin working in a groove in the sleeve 77 of the reversing clutch mechanism. hen the reverse clutch mechanism is in the position shown in Fig. 7 the gear 71 rotates with the shaft 28, and the shaft 50 drives the lead screw, through the gears 76, 75, 7?), 71 and thetrain of gears leading from 78 to 8G in a direction to advance the work. 1V hen the work holder reaches the end of its forward stroke, the ratchet clutch mechanism is auto matically thrown in so that the sleeve 54: is rotated through an angle of 180, and the shipper lever 91 will be shifted to move the sleeve 77 of the reversing mechanism to the left whereupon the gear 70 will rotate with the shaft 28 and the lead screw will be rotated in'the reverse direction through the gears 7 078. 79. etc. 'hen the work holder 7 reaches the end of its reverse stroke the ratchet clutch mechanism shown in Figs.

8 and 9 is again actuated. shaft 26 rotates one half a revolution, and the cam groove 90 will shiftthe shipper 91 to fix the gear 71 to the shaft 26 and the reverse gear '70 will run loose.

The shipper lever 91 is fixed on a vertical shaft on the upper end of which is a hantile 92 (see Fig. 4) whereby movement of the work may be instantly stopped when desired by throwing the clutch mechanism into neutral position, the cam groove 90 in the sleeve 54 being of increased width or offset as at 93 (see Fig. 7) so as to permit of this movement.

For the purpose of automatically stopping the work when it reaches the end of one of its strokes a lever 91 cooperating with the ratchet clutch mechanism is provided. The lever 94 is pivoted to the bracket (30 and at its lower end is connected to a slide. 95 which is norinall out of the path of the pawl 50. When it is desired to stop the work, the slide 95 is moved into the path of the pawl, as shown in Fig. 8 and the sleeve 54 will then be stopped in such position that the shipper 91 will have moved the sleeve 77 of the reverse clutch mechanism into neutral position, that is, where both the gears 70 and 71 will be running loose on the shaft 28. It will be seen that it is not necessary for the operator to wait until the work has reached the end of one of its strokes before stopping the machine, for it is merely necessary for him, at any desired time, to throw the lever 94: into position so that the slide 95 will be in the path of the pawl 56 and the machine will then stop automatically at the end of its forward stroke, the operator in the meanwhile having his time free to attend to other matters.

97 is a constantly driven main shaft connected to the grinding wheel shaft 98 by means of a belt 99 so that the grinding wheel is also constantly driven. Passing about a' pulley on the main shaft 97 and a pulley ona shaft 100 passing through the pedestal a is a belt 101. On the left end of this shaft 100 is a pulley 102 connected to the pulley 51 on the shaft 50 by means of a belt 102- A suitable idler 104 is provided to keep the belt 103 taut. It will be noted that the work holder including the spindle. the lead screw for moving the work holder, the various instrumentalities for rocking the bed, and the mechanism for driving and controlling all of these elements are located on the rocking bed. This driving mechanism is driven by a belt 103, the tendency of which is to hold the rocking bed to its fulcrums while at the same time permitting of substantially free rocking movementof the bed.

It. being necessary to angularly adjust the grinding wheel in accordance with the lead of the thread to be ground, the journal box a in which the grinding wheel shaft 98 is journaled' is mounted in a way 108 on the ion slide m and the center of curvature of this way is the center of the wheel t by which 1s meant a point at the axis of the wheel which is included in a plane bisecting the angle of the cutting edge of the wheel so that the axis about which the wheel may be angularly adjusted is on a line a:a (Fig. 5) intersecting the, axis of rotation of the work. The journal box it is locked in adjusted position by means of bolts 109, the heads of which work in undercut grooves 110 having the same center of curvature as has the way 108.

In briefly describing the operation of the machine it will be assumed that the threads of a tap are to be ground. The tap'is positioned between thehead and tail stocks k, Z and is so adjusted that its eccentric surfaces have the same relation to the grinding wheel t as the corresponding surfaces-on the pattern wheel 27 have to the rocking beam or lever 20. The work is then adjusted longitudinally so that the thread to be ground is in proper alinement with the grinding wheel, and to get this adjustment the work gauge hereinafter described may be used to advantage. It will be seen that the extent to which the rocking bed maybe swung on its fulcrums is limited to the distance which the screw 14 can move relative to the nut or sleeve 12 of the variable feed connection and by other considerations, and therefore,

the rocking bed will be adjusted with the view of allowing for further automatic feeding of the work to the tool. The tool is then roughly moved up to the work by means of the handle wheel 10. If necessary, the feed shaft u is then manually turned in a direct on'to lower the pin 17 of the feeding mechanism until the rocking bed has been swung downwardly and rearwardly into a position where the tool engages the work. In the event the handle 92 has been employed to stop the machine, this handle is swung to throw the shipper 91 of the reverse clutch mechanism and thus connect one of the gears 7 0 or 71 to the shaft 28 and the lever 94 ofthe ratchet clutch mechanism is moved to permit actuation of the escapement mechanism of the ratchet clutch so that the cam 25 is rotated one-half a revolution in a drection to lift the rocking lever 20 sufficiently so that the work is' held, on its reverse stroke, out of engagement with the tool. At the same time, due to the half revolution of the shaft 26 and the cam sleeve 54 carried thereby, the reverse clutch mechanism in the train of gears leading to the lead screw it is operated to reverse the work. When the work reaches the end of its reverse stroke, the rod 42 is-moved in the opposite direction, resulting, through the escapement mechanism and the ratchet clutch, in another half revolution of the cam 25 so that the work will be lowered into engagement with the tool, and at the same time the reverse clutch mechanism is actuated so that the lead screw is driven in a direction to advance the work.

I wish it to be clearly understood that a machine constructed in accordance with the present invention is not limited to a use wherein threadedomembers are machined. It is susceptible of use for various opera tions upon unthreaded members; for instance it may be employed to machinereamers, cams or other parts having concentrically or irregularly curved unthreaded surfaces. If a part having. an unthreaded cylindrical surface provided with portions in relief is to be ground, a grinding wheel having a relatively wide cylindrical grinding surface may be employed. Nor is the invention limited to grinding or other op erations where it is customary to use a r0- tating tool, for a stationary tool of any desired shape may be employed for the purposes in hand.

Where a threaded piece of work is being operated on and the operating tool is, for instance, a grinding wheel, it is extremely diflicult to properly and accurately position the tool with respect to the work, mainly because of the large size of the grinding wheel, its rough and uneven surface, and the relatively small sze of the threads. In the present invention, I provide an improved gauge which is so constructed and arranged that the work can be quickly adjusted with the greatest accuracy and precision.

The construction of the work gauge is most clearly shown in Figs. 10 and 11 and its relation to the grinding wheel and the truing device is most clearly shown in Fig. 5. The gauge is pivotally carried by a bracket 115 mounted on the front of the rockin bed I). The rocking bed I) has a T slot 116 in which work the heads of bolts 117 passing through the bracket so that the bracket is adapted for rough adjustment relative to the tool holder.

Thepointer 120 of the gauge is carried by an arm 121 fixed, as most clearly shown in Fig. 10, to a pivot pin 122 trunnioned in hearings on the opposed ends of plungers 123, 124 mounted in sleeves 125 on the bracket 115. The plunger 123 may be adjusted longitudinally by a, screw 126 and behind the plunger 121- is a spring 127. The plnngers may be clamped in adjusted position by turning set screws 128 down onto dogs engaging the plungers. Vith this arrangement a fine adjustment of the gauge on a line parallel to the axis of the work may be had by turning the screw 126. The spring 127 serves to prevent any backlash or looseness between the bearings.

The forward end of the pointer is preferably SQlIll-COIllCtll so that the flat sur-* face thereof, which is in a plane passing through the axis of the work, has true or sharp edges. The forward end of this flat surface is of the same shape as the thread so as to closely tit therein. This pointer is carried by a slide 130 adjustable radial- 1y of the work Within a barrel 131. Preferably the pointer 120 is Slll'lOllDClQtl by a shield 132 having a top sight opening and immediately beneath the pointer is a source of illumination such as an electric light bulb 133. \Vhen adjusting the work and gauge relative to each other the operator may, by looking down through the sight.

opening, determine when the pointer fits the thread.

In practice, to set the gauge relative to the grinding wheel, a test piece, preferably unhardened and of any diameter but having the same number of threads to the inch as has the part to be finished, is positioned between the head and tail stocks and the threads thereon are ground. Then the work gauge is thrown over into the full line position shown in Figs. 5 and 11. The gauge is adjusted to the test plece by rotating the screw 126 until the for a d end of the pointer 120 accurately .tits in the thread. After the gauge is so adjusted. it is locked in position so that its relation to the grinding wheel will remain fixed, but it may be thrown back into the dotted line position of Fig. 11 when not in use; the

test piece is taken out and the threaded member to be finished is substituted therefor; the gauge is then thrown forward and by adjusting the slide g by the screw shown the work adjusted longitudinally until the pointer accurately fits the thread thereof. As the work is now properlysct to the gauge, the operator knows that it in correct position relative to the grmdmg wheel for the gauge has already been set to the wheel by using the test piece. As the gauge is carried by the rocking bed Z), which has no rectilinear movement on the base a, and the tool or grinding wheel t is fixed to the base against, movement longitudinally of the axis of the work, the relative positions of the wheel and gauge remain fixed. Furthermore, as the gauge is carried by the rocking bed, the gauge and work move in unison to and from the tool. After the work is properlyadjusted to the gauge, the gauge-is thrown back into inoperative position and the grinding operation proceeded with. After the gauge is set for one part having a. given number of threads per inch it may be employed to accurately set any number of pieces having alike number of threads per inch, always with the knowledge that when the work is set properly to the gauge it will be iD PI'OPGL relation to the wheel.

A truing device for reshaping or resharpening the tool is provided which, in its construction and arrangement and relation to and combination with other parts of the machine permits of resharpening without disturbing the relation of the tool to the worn and when once set to one face of the wheel will so operate on all faces as to generate a cutting edge which accurately conforms in shape and size to the thread which is being cut. The construction of this truing device will first be described, and then its relation to the tool and other parts will be pointed out.

Referring to Figs. 5 and 12-15 inclusive. where the truing device is most clearly shown, 135 designates a bracket mounted upon the base of the machine and which,

.if desired, may be adjustable by sliding in a T slot 136 on the base a and is provided with means for securely locking it in position. Pivoted on a vertical pin 13? upstanding from this bracket is a carriage 138 which moves in a horizontal plane over a segmental plate 139 fixed at the top of the bracket 135. 140 is a horizontal shaft titted in an upper part of the carriage with its axis at right angles to that of the vertical pin 137 about which the carriage turns. In other words, the vertical plane which includes the of this shaft 140 would also include the axis of the vertical pin 13?. Mounted on the forward end of this shaft Ht), is an arm 141 within which is positioned subject to longitudinal adjustment on a line parallel to the axis of the shaft 140 the sharpening tool H2 shown as a (lltlll'lOllCl point which is well adapted for resurfacing such a tool as is here illustrated, namely the grinding wheel IL. In certain of the appended claims the arm 141. is referred to for convenience as the tool carrying part. ()n the shaft 140 is a worm wheel H8 with which meshes a worm 1 19 on a. shaft mounted in asuitabl-e bearing in the carriage and having at its ou er end a hand wheel 151. The extent of rotation of the worm wheel 148 is limited by means of a fixed pin 153 extending into a notch 1% in the periphery of the worm wheel 148. Upon turning the wheel 151 in opposite directions the shaft 140 is turned and the diamond point will be oscillated back and forth across a face or edge of the grindlng wheel WlllCl'l is being resurfaced. The

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whole carriage may be swung around the pivotal pin 137 in order to bring the diamond point into operative relation with any face of the grinding wheel, and for the purpose of indexing it to the proper position and holding it there, the segmental plate 139 is notched as at 155 to receive a spring pressed plunger 156. Means for withdrawing the plunger from the notches 155 consists of an operating handle 15.7 on a rod 158 having at its lower end a lever 159 engaging a pin 160 carried by the plunger. The position of the notches 155 will, of course, vary in accordance with the angle of the thread to be out. 'If a United States standard thread is beingcut, in which instance the faces of the thread are at an angle of and the thread is truncated,

the notches 155 will be three in number and spaced 60 apart. Of course, the same segmental plate can have two or moreseries of corresponding notches to make it usable in connection with threads. of varying types or sizes. .When the parts are in the position shown in Fig-12, the diamond point is in position to resurface the truncated part of the wheel and when the carriage is in the position shown indotted lines in Fig.12, the diamond point is in position to resurface one side face of the wheel. If the carriage were thrown to its extreme opposite position, the diamond point would be in position to resurface the other side face of the wheel.

During the resurfacing operation, the center about which the resurfacing tool is indexed, i. e., a point lying in the axis" of the shaft 137, is in a plane passing through the center of the edge of the grinding wheel. It is evident that because of the roughness of the grinding wheel and extremely fine adjustments required to givethe grinding edge thereof the precise shape of the thread, it is practically impossible toproperly true the wheel by using a separate resurfacing tool for each face ofthe wheel or employing asingle resurfacing tool requiring a separate setting for each face. Certainly such arrangements would require the greatest care and patience on the part of the operator and necessitate a great waste of time without any assurance that the grinding wheel as resurl'accd was al'isolutcly true. This is particularly true when a truncated thread is to be ground, for the'flat of the thread has-a definite relation to the pitch, under the United States standard it being one-eighth of the pitch, and it is obvious that after the two side faces of a grinding wheel were resurfaced there would be the greatest difficult-y in then so adjusting the resurfacing tool that the flat would be of the precise size required.

With thetruing device herein described the objections to the arrangements just noted are entirely eliminated for, as the diamond point is indexible about a fixed axis, a single diamond point may be used and a single setting, which may be obtained with the gauge hereinafter described, is necessary to resurface both faces of the grinding wheel where a V-shaped thread is cut, and all three faces of the wheel where a truncated thread is to be ground, with the assurance that in the latter case the flat will have the proper size in relation to the pitch of the thread. 1

It is, of course, evident that during the final resurfacing operation the wheel has a fixed relation to the centerabout which the diamond point is indexed, which center is in the plane of the; center of the edge of the wheel and consequently the angular disposition of the side faces will accord with the angular disposition of the thread which/is being cut depending upon what type of thread it is. If it is a United States standard, the side walls of the thread are'at an 'angle of 60 and consequently the side cutting faces of the wheel will be disposed, at an angle of 60 to one another for the reason that the carriage is so indexed and, furthermore, this angle will, at all times and no matter to what extent the Wheel is resurfaced or resharpened, be bisected by the center line of the wheel edge. When the diamond point is indexed to mid-position for resurfacing the. fiat or truncated part of the wheel, and because of the fixed relation of the wheel to the center about which the carriage is indexed and the fixed relation of the diamond point to that center, the extent of truncation will be correct.

For the purpose of making certain that the extent of the flat of the wheel shall be correct for any given pitch of thread, a gauge is provided for setting the diamond point so far as its longitudinal adjustment in the .arm 141 is concerned. This gauge comprises a pivoted arm 165, mounted on the arm 141, which can be thrown over in front of the diamond point position, as indicated in dotted lines in Fig. 13, and the end of this pivoted member is threaded to receive gauge plugs 166. A gauge plug will be provided to correspond to the various thread pitches. it will be seen that the gauge arm 165 has a fixed or dclinitc relation to the tool carrying part or arm 141 in that it is pivoted for swinging movement only thereon,

and as the arm 141 is fixed against longituis properly adjusted relative to the fixed axis about which it is indexed. That gauge plug is selected which corresponds to the pitch of the thread which is being operated on, it is screwed home into the member 165, thrown down in front of the diamond point and the diamond point is moved througl'i the arm 141 until it touches the end of this plug, when it is clamped into-position. The gauge is then thrown back out of position, as shown in full lines in Fig. 13. By indexing the carriage, the active faces of the wheel are roughed out to substantially final form. the wheel being fed up to the diamond point for this purpose and then fastened in position so that its relation to the indexible carriage is fixed. Then by taking a final cut on all three faces of the wheel, the side faces will be properly shaped and properly sized and at the proper angular relation with respect ,to one another and the fiat will be accurately finished to correspond in extent to precisely what it should be for the pitch of the thread being cut.

As has heretofore been stated, when a thread is being operated on, the wheel must have an angular adjustment corresponding to the lead of the thread. To properly shape the edge of the grinding tool so that it will correspond to the shape of the tooth it is necessary that theresurfacing or reshaping cperation be carried out on a line lying in a plane which includes the axis of the work and the line about which the wheel is angularly adjustable, this latter line, as previously stated, being the line aa of Fig. 5. In the present instance, the diamond point is diametrically opposite to the point of contact of the work and the tool, and when the diamond point is indexed, and also when it is reciprm-ated' for resurfacing, it moves in the plane whichincludes the line a.aand the axis of the work. It is obvious that the grinding faces of the wheel have a line contact with the corresponding faces of the thread operated upon, and the plane, in rahich this line of contact lies is a plane in which the diamond point is indexed. Thus it will be seen that the angular adjustment of the grinding wheel is not disturbed in any particular during the resurfacing operation.

As the diamond point oscillates about the axis of the shaft 140, it moves slightly out of a horizontal plane but for practical purposes the are of movement is so small a to be negligible.

Since the bracket 135 upon which the truing device is carried. though adjustable, is for practical purposes fixed to the pedestal (I of the machine, and as the grinding Wheel is also mounted on this base and movable only in a direction at right angles to the axis of workto and from the truing device, the.

alinement of .the truing device and the wheel is never changed. Thus, the Wheel may be resurfaced as many times as may be necessary and it is always certain that when it is piece of Work of a given character, always remain so set with relation to one another for other work of like character.

In describing the invention herein illustrated the conventional terms have been used but it is to be understood that they have been used solely for the purpose of description and they are not to be taken as having any limiting effect. For instance, in certain of the claims the tool which operates upon the worl; 1s recited as a grinding wheel but this terminology has been employed solely for the purpose ofconvenience and to avoid confusion, it being obvious that a tool of other kind or character may be utilized in the combinations recited.

What I claim'is 1. In a machine of the character described, and in combination, a fixed bed, a grinding wheel thereon, a rocking bed fulcrumed on said fixed bed, i a Work holder slidably mounted onsaid rocking bed and having means for rota'tably supporting a piece of work, and automatically operated means for rocking said bed.

2. In a machine of the character described, and in combination. a fixed bed, a grinding wheel thereon, a rocking bed fulcrumed on said fixed bed, 'a work holder slidably mounted on said rocking bed for movement on a line parallel to the axis on which said rocking bed swings, said work holder including means for rotatably supporting a piece of Work on an axis substantially parallel to the direction of movement of said Work holder, and automatically operated means for rocking said bed.

3. In a machine of the character described, a fixed bed, knife edges thereon, a tool on said fixed bed, a rocking bed fulcrumed on 7 said knife edges, a work holder mounted for reciprocation on said rocking bed and including a Work spindle, means for reciprocating said work holder, and means for rocking said rocking bed;

4. In a machine of the character described, a fixed bechknife edges thereon, a grinding wheel on said fixed bed. a rocking bed fulcrunied on said knife edges. aWork holder slidably mounted on said rocking bed and rovided with a work spindle. a lead screw on said rocking bed for moving said Work

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