US3183944A - Apparatus for forming terminal loops on coil springs - Google Patents

Description

May 18, 1965 a. A. REDDINGTON v 3,

APPARATUS FOR FORMING TERMINAL LOOPS ON COIL SPRINGS Filed March 8, 1960 3 Sheets-Sheet 1 Fig.1..

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//V VE' N 70R 6EOR6 A. Reap/Na ra/v May' 18,1965 s. A. REDDINGTON APPARATUS FOR FORMING TERMINAL LOOPVS'ON con, srnmes Fi1ed March s, 1960- 3 Sheets-Sheet 2 ATTURA EKS' y 1955 G. A. REDDiNGTON 3,183,944

APPARATUS FOR FORMING TERMINAL LOOPS ON COIL SPRINGS Filed March 8, 1960 3 Sheets-Sheet 3 camp/75.9550 1 Am JUPPL Y A 7' ram/5 r5 9 Geo/me- A. Reva/Nara 3,183344 APPARATUS FOR FORMING TERMINAL LOOPS ON COIL SPRINGS George A. Reddington, 2635 Vistagrand Court,

San Leandro, Calif. Filed Mar. 8, 1960, Ser. No. 13,511 13 Claims. (Cl. 140-103) The present invention relates to mechanisms for the production of coil springs and more particularly to an automatic apparatus for forming fastening loops at the extremities of springs United States Patent Coil springs in various sizes are widely used in mechanical apparatus to maintain parts under tension, to provide for the return movement of parts, to provide for a resilient attachment between machine elements, and for many other purposes well known to those skilled in the art. The springs, and particularly those of tension type, are commonly fastened in place by means of a loop or link formed .on each end of the spring by bending the terminal turns of the spring at right angles to the axis thereof.

In a typical production facility, such springs are generally required in large numbers and considerable savings in costs and time are realized by providing automatic machinery for the loop forming operation. In machines of this type, means must be provided for manipulating the springs to a work station and for precisely positioning the springs against a forming anvil so that a reciprocating element may pry the final turn of the spring outward and bend it against the anvil toform the desired loop. Such means must remove the spring from the anvil and deliver it to a suitable receiver.

The manipulation of the spring, and particularly the .step of positioning and holding the spring against the forming anvil, is complicated by the inherently resilient character of the spring. Owing to this property, it is not generally convenient togrip or manipulate the springs by rigid mechanical elements. Accordingly various other means for manipulating the springs have been devised. In one form of prior machine, for example, mechanical vibration is used to urge the spring through guide channels and to agitate the spring until proper positioning on the anvil comes about. Heretofore all such machines have been unduly cumbersome and complex.

The present invention provides a relatively compact and lightweight machine in which the manipulation and positioning of the springs at the forming anvil is accomplished by compressed air jets acting in combination with other novel mechanisms. As will hereinafter be described in detail, the invention is rapid acting, relatively free from break-down, and substantially eliminates losses from damaged and mal-formed springs.

It is accordingly an object of this invention to provide a compact and light-weight automatic mechanism for forming fastening loops at the extremities of coil springs.

It is an object of the present invention to provide apparatus for forming fastening loops at the ends of springs in which the manipulation and positioning of the springs is accomplished by pneumatic means. 3

It is another object of this invention to provide automatic apparatus for forming terminal fastener loops on coil springs which apparatus is rapid acting, relatively free from breakdown, and substantially eliminates damaged or malformed springs.

It is a further object of the invention to provide a mechism for automatically bending the terminal turn of a coil spring at right angles to the axis thereof to form a fastening loop-thereon and in which mechanism the spring-is carried to a work station and positioned thereat by directed compressed air jets.

3,183,944 Patented May 18, 1965 "ice It is an object of this invention to provide an automatic apparatus for forming terminal fastening loops on coil springs which apparatus is readily adapted to handling springs of various sizes and with which apparatus such loops may be conveniently formed on either or both ends of a spring.

It is another object of the present invention to provide automatic apparatus for forming terminal fastening loops on a coil spring in which the loop formed at one end of the spring may be'of a substantially larger diameter than that of the spring. a

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. to be understood, however, that variations in the showing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claims.

FIGURE 1 is a perspective view, partially in section, showing the portions of the invention which are directly involved in forming the fastening loops on the spring.

FIGURE 2 is a section view taken along line 2-.2 of FIGURE 1 and showing the relationship in which a spring is positioned on the forming anvil.

FIGURE 3 is an elevation view of portions of the apparatus of FIGURE 1 and showing a loop forming element moved downward against the forming anvil to bend the terminal turn of the spring outward.

FIGURE 4 is a perspective view showing the fastening loop formed at the end of a spring by the mechanism of FIGURES 1 to 3.

FIGURE 5 is a section view showing a modification of the apparatusof FIGURES 1 through 3. 7

FIGURE 6 is a cross sectional view showing a further modified form of the apparatus as shown in FIGURES 1 through 3.

FIGURE 7 is a side elevation view of the complete loop forming apparatus including the actuating and control elements thereof.

FIGURE 8 is a frontal elevation view of the loop forming apparatus.

FIGURE 9 is a schematic diagram showing the electrical circuitry and pneumatic connections of the apparatus.-

Referring now. to the drawing and more particularly to FIGURES 1 and 2 thereof, there is shown a portion of a carrier wheel 11 which is transpierced by a plurality of bores 12, the bores being located on a circle concentric with the axis of the wheel and being uniformly spaced around the periphery thereof. A tubular spring carrier cylinder 13 is disposed in each of the bores '12 in coaxial relationship therein, the cylinders being of greater length than the bores so that each end of the cylinders projects outward a small distance from the wheel 11.

By means to be hereinafter described,springs 14 are inserted into the cylinders 13 and are successively carried to a work station established by a forming anvil 16 by intermittent rotation of wheel 11 in the direction indicated by arrow 17.

The forming anvil 16 is comprised of a vertical shank 18, the upper end surface 19 of which is flat and inclined slightly downwardly in a direction away from wheel 11. The uppermost edge of surface 19 is at the level of the center of cylinder 13 and the upper portion of the anvil projects a slight distance towards wheel 11 so that the ends of cylinders 13 are brought to a position adjacent the forward face of the anvil.

To provide for the insertion of a pick as will hereinafter be described, a vertical slot 21 is formed in the It is 3 center of the upper end of the anvil, the slot being centered on a line transecting the axis of cylinder 13 and dividing the upper end of the anvil into two separate blocks 22. and 23. As best shown in FIGURE 2, the block 23 is set back from the end of the cylinder a distance substantially equal to the diameter of the wire' -When, as in the present instance, the spring 14 is turned clockwise as viewed from the end nearest the nozzle 27, the nozzle is tilted to direct a jet of air somewhat upwardly and sidewardly in a direction for turning of the spring. The nozzle 27 is positioned so that the air jet strikes the upper inner surface of cylinder 13 and thus a spiralling air current is created therein and the spring turned as indicated by arrow 28. Owing to the air current, the spring 14 is forced through cylinder 13 into abutment against anvil '16. The spring 14 is then rotated by the. air current until the end 26 of the final turn of the spring abuts shelf 24 as shown in FIGURE 2. The

spring is then in the proper position for forming the fastening loop thereon.

Referring now to FIGURE 1 in particular, bending of the final turn of spring 14 to form a loop thereon is eifected by an upright reciprocable pick assembly 29 mounted above anvil 16. The forward portion 30 of the lower face of pick assembly 29 is flat and inclined downwardly in a direction away from wheel 11, the inclination being similar to that of surface 19 of anvil 16 so that the two surfaces are parallel.

A vertical pick element is secured inia slot 32 in the forward vertical surface 25 of the pick assembly 2%, the pick element having a fiat forward face and having a width equal to that of the slot 21 in anvil 1.6 so that the pick may enter the slot when reciprocate'd in a downward direction. The lower rear surface of pick element 31 is inclined sharply upward to form a point 33 at the lower end of the pick assembly. 7

The pick assembly 29 is positioned so that-point 33 passes across the end of cylinder 13 when traveled downward and is driven between the upper portions of the first and second turns of the spring 14. As will be evident on further downward travel of the pick assembly 29, the pick element will bend the upper half of the final turn of the spring 14 outward as indicated in FIGURE 3. In such position, the outer peripheral extremity of the coil will be engaged by the lower surface 30 of the pick assembly, a finger 20 provided on the pick assembly being arranged at such time to strike the portion of the spring coil overlying the edge of the anvil 16 so as to permanently deform the resilient spring material at the base of the loop into a position substantially at right angles to the axis of the spring. Thus when the pick assembly 29 is retracted upwardly, the desired loop 34 will have been formed at the end of spring 14 as shown in FIGURE 4.

Considering now a further advantageous feature of the foregoing structure, the pick assembly 29 is inclined slightly off vertical, the upper end thereof being more forwardly. Thus, and as shown in FIGURE 3, the point 33 will wedge between the final and adjacent turn of the spring at the top thereof but will not intercept the final turn at the bottom of the spring. The ends of cylinders 13 are similarly inclined to conform to the pick.

It will be understood that where springs having an opposite turn inclination are to be processed, the direction of air nozzle 27 is altered and the anvil blocks 22 and 23 are reversed. 7

Referring now to FIGURE 5, a modification of a portion of the foregoing structure is shown in which modification the external air nozzle is replaced with an internal directed air jet within the cylinder 13, the structure being otherwise similar. To form the internal jet, a radially directed passage 35 is provided in the periphery of wheel 11, the passage connecting the outer surface thereof with an opening 36 in bore 12, the opening being off-center in the bore.

A passage 37 through the wall of cylinder 13 connects opening 36 with the interior of the cylinder, the passage 37 being directed downwardly and towards anvil 16. To supply air to the passages 34 and 37, a tubulation 38, having an open lower end 39, is disposed against the outer surface of wheel 11. Wheel 11'slides against the under surface of tubulation 38 as it turns and, to provide an air tight seal therebetween, an Ct-ring 40 is mounted under the tubulation. A conduit 41 connects tubulation 38 with a source of compressed air.

Owing to the described inclination and position of the passage 37, a spiralling air flow is established within the cylinder 13 as indicated by arrow 42. The air flow is established in each of the cylinders 13 in turn as it is brought into position at anvil 16 and functions to position the springs thereat as hereinbefore described.

Referring now to FIGURES 6 and 7 additional mechanism for mounting, driving and controlling the elements hereinbefore described is shown, the mechanism being an automatic machine capable of processing springs in large quantities and at a rapid rate.

To provide .a basic frame structure for the apparatus, an upright post 43 of hollow rectangular cross-section is mounted on a base plate 44. To carry successive springs to the work stations, the carrierwheel 11, hereinbefore described, is rotatably mounted at the side of post 43, the wheel being secured to an axle 47 which extends through openings in the post and which is journalled thereto. As

hereinbefore described, a plurality of bores 12 are transpierced through wheel 11 near the periphery thereof, the bores being equi-angularly spacedaround a circle concentric with the wheel. As was also described, a spring receiver cylinder 13 is mounted in each bore 12 and projects from each side of the wheel.

To turn the wheel 11 an angular distance equal to the angular spacing of bores 12 in order to bring successive springs to a work station, an upright pneumatic drive cylinder 48 is secured to baseplate 44 forwardly from axle 4'7. Cylinder 48 has a drive rod 46 extendable by operation of the cylinder, and is spring returned. An annular ratchet wheel 49 is mounted coaxially on axle 47 and is provided with teeth 51 which slope in the direction of travel of the wheel 11 and which are out along a radius of the ratchet Wheel on the opposite side. An annulus 52 is rotatably disposed on axle 47 and an arm 53 projecting radially from the annulus is pivotably connected with the upper end of the cylinder drive rod 46, the arm having an elongated slot 54 for making such connection so that a bending force on the drive rod will not be brought about.

An angled pawl 56 is pivotably mounted on arm 53 and rides along the periphery of ratchet wheel 49 so that extension of drive cylinder 48 acts to turn the wheel and thus to turn wheel 11. Since pawl 56 can slip over the sloped edges of teethSl, contraction of the drive cylinder does not return the wheel. To insure that the pawl 56 rides against the teeth 51, a tension spring 57 is connected between the pawl and arm 53.

To insure that the contraction of drive cylinder 48 does not rotate the mechanism, a second and oppositely oriented pawl 58 is mounted to ride along the periphery of ratchet wheel 49, the pawl 58 being pivotably mounted on a bracket 59 secured to post 43 and being held against teeth by a tension spring 61.

To insure that the wheel 11 turns to the precise positions desired, a circular indexing plate 62 is secured against the inside face of wheel 11 in coaxial relationship therewith, the plate 62 having notches 63 around the periphery at angular spacings Corresponding ofbores 12 on wheel 11. 7

'An index arm 64 is pivotably attached at the center to a bracket 66 on post 43, the arm having a sidewardly directed detent pin 67 at the forward end which enters notches 63 to lock the plate 62 at fixed positions. To exert a force on arm 64 tending to enter the pin 67 into the notches, a tension spring 68 is connected between the rearward portion of the arm and bracket 66.

To pivot the index arm 64 to release pin 67 from a notch 63 whereby further rotationof the mechanism can be effected, and to control the timing of other components of the apparatus, an electrical motor 69 is mounted on baseplate 44. Motor 69 drives a camshaft '71 which is 'journalled between two bearings 72 secured to the baseplate, the camshaft being parallel to axle 47.

A disc 73 is mounted coaxially on camshaft 71which to the spacing disc has a laterally projecting pin 74 positioned to catch under the rearward end of index arm 64-and pivot the arm upwardly once during each revolution of the disc.

Thus the plate 62 and associated wheel 11 are releasedforrotation periodically, the drive cylinder 48 being simultaneously actuated to eifect the rotation by means to be described. 7

To control the drive cylinder 48, as well as further components of the invention, three cams 76, 77 and 78 are mounted on camshaft 71, such cams having followers 79, d

I which is mounted on an upright support 87 secured to base plate 44. A reciprocating pick assembly 29 is slidably disposed in'a guide member 88 which member is also attached to support 87, the pick being movable downward against the upper face of forming anvil 16 along an inclined axisas hereinbefore described. An air jet nozzle 27 is disposed on the opposite side of wheel 11 from anvil Hand is mounted on a bracket 89 attached to post 43. The arrangement, detailed structure and operation of the anvil 16, pick'assembly 29 and jet nozzle 27 are as previously described with reference to FIGURES 1 to 4. V

Considering now the means by which pick assembly 29 .movement of the spring in the cyl1nder.

is reciprocated, a second upright spring returned pneumatic drive cylinder 91 is mounted on post 43, the cylinder having an upwardly projecting drive rod 92. A lever 93 is pivotably attached at the center to a fulcrum post 94 end engaged with the end of drive rod 92. Extension of drive cylinder 91 thus. acts to lower the pick assembly 29 against anvil 16 in the manner hereinbefore described.

Downward travel of the pick element 29 may be adjustably controlled by means of a set screw 90 threadably mounted in the first end of the lever 93 and arranged to engage a stop member 95' upon extension of the drive cylinder 91.

To form the loops at the oppositeends of the springs, a second work station is established at the opposite In this manner a uniform length'of stroke I is provided for.

side of wheel'll by a second forming anvil 16 which is mounted on post 43 adjacent the inner face of wheel 11 at a position rearward from that of anvil 16 an angular pick assembly 29', sliding in' a guide member 88, and a compressed air.

second spring locating air jet nozzle 27' which is positioned on the opposite side of wheel 11 from anvil 16,

all of the foregoing elements being similar in design and operation to those hereinbefore described.

Reciprocation of the second pick assembly 29' is effected by a third upright spring-returned pneumatic drive cylinder 96 mounted on post 43 and having an upwardly projecting extending drive rod 97. A lever 98 is pivot-ably mounted at the center to a second fulcrum post 99 extending upwardly from post 43, the lever being pivotable in a vertical plane and extending from the region above cylinder 96 to the region above pick assembly 29'. One end of lever 98 pivotably engages the upper .end of pick assembly 29' and the other end. of the lever is pivotably engaged with the end of drive rod 97 so that extension of drive cylinder 96 acts to drive pick assembly 29 downwardly against anvil 16 in the manner hereinbefore described and thus forming the desired loop at the second end of the springs. 7

To eject springs from the cylinders 13 after loops have been formed at each end thereof, a compressed air conduit 101 is mounted adjacent the outer face of wheel 11 to direct an airflow through the cylinders at a point rearward from the two work stations. Such air flow impels the springs out of the cylinders where they are carried by a chute 102 to any suitable receptacle or conyeyor system. It will be understood that springs may be fed into the cylinders at a position forward from the work stations either manually or by a suitable feed mechanism.

Sometimes it is desired that one of the terminal loops have a greater diameter than that of the spring coils. The apparatus of the present invention has accordingly been designed so as to permit forming the loops of any desired size. In this respect it will be seen that the picks 31; may be vertically adjusted in the slots 32 by means of set screws 15 (see FIGURE 1) so that the picks may selectively engage a desired portion of the terminal loop of the spring to produce a loop of the required size. In forming loops having a larger diameter than that of the spring, it is preferably that such loops be formed at the second work station by the pick element 29' after which operation the spring is ejected from the cylinder 13 by the air jet from the conduit 101. It should be noted,

however, that in view of the air jet locating means here employed for properly positioning the springs at the work stations, that the diameter of the cylinder bores may be considerably larger than that of the springs. Therefore, if desired, comparatively large loops may be formed at the first work station without impeding A further modification of the spring locating means is illustrated in FIGURE 6 in which a pair of air jet nozzles 121 and 122 are utilized at each work station. Thus for the first station as illustrated in this figure an air jet from nozzle 121 is introduced into the cylinder and opposite the anvil 16 in a manner similar to that shown in FIGURES 1 through 3. .Air from second nozzle 122 enters the cylinder through a radial bore 123 provided in the wheel 11 and communicating with a bore 124 in the wall of the cylinder 13, and located adjacent'and angularly directed toward the anvil in a manner similar to that illustrated in FIGURE 5. The nozzles 121 and 122 are suitably mounted on an angle bracket 126 having a passage 127 therein for; the supply of air to the pair of nozzles from a conduit 128 connected with a source of A valve 129 is located in the passage between the two nozzles to control the flow of air to the nozzle 12.2 As will be understood, identical spring locating means is likewise provided at the second work station where, as previously described, the anvil 16' is mounted adjacent the inner face of the wheel 11. Thus the nozzle 121 at the second station will be disposed adjacent the cylinder end which extends from the outer face of the wheel and nozzle 122 will be positioned adja 7 switch 86.

cent theopposite end of the cylinder where it will be aligned with a bore 123 associated with a bore 124' the spring.

Referring now to FIGURE 9, the pneumatic and electrical system of the apparatus is shown schematically. An

air supply conduit 103 from a compressed air source 104 is communicated with the inlet 106 to a solenoid operated valve 197. Valve 107 has two outlets 1118 and 109, the first of which is vented to atmosphere and the second of which is branched and communicated with the pick assembly operating drivecylinders 91 and 96. Valve 107 has a normal position in which outlet 108 is connected to outlet 109 and a second energized position at which outlet 1118 is closed and outlet 109 is communicated with air inlet 1% so thatthe cylinders 91 and 96 are actuated and the pick assemblies are lowered.

The spring locating air jet nozzles 27 and 27 are communicated with air supply conduit 103 through a normally closed solenoid operated valve 111. For regulat' ing the force of the air jets from the nozzles, a manually adjustable control valve 112 is disposed between each nozzle 27 and 27' and the solenoid valve 111.

To control the carrier wheel rotating drive cylinder 48 and spring ejector conduit 1tl1,wa third solenoid operated valve 113 is provided, such valve having a pair of outlets 114 and 116 connected to drive cylinder 48 and ejector conduit 101 respectively and having a third outlet 117 vented to atmosphere. The inlet 118 to valve 113 connects with air supply conduit 1% and at the energized position of the valve is communicated with the drive cylinder 48. At the normal or unenergized position of valve 113, air inlet 118 is communicated with ejector 161 and cylinder 48 is vented through outlet 117.

Considering now the electrical system for controlling operation of the solenoid valves, the three cams 76, 77 and 78are mounted on camshaft '71 as hereinbefore described and are turned byimotor 69. The secondary winding of a power supply transformer 119 is connected saidganvil, a cylindrical tubulation for receiving said spring, means positioning said tubulation with a first end thereof adjacent said first face of said anvil and with a diameter of said tubulation substantially contiguous with said edge of said anvil, a compressed air source conected to provide an air current within said tubulation in the direction of said first end thereof'whereby'said spring is forced against said anvil, said air current having an angular component of motion within said tubulation to rotate said spring into position adjacent said anvil, and a pick element having a terminal point which pick is mov able towards said second face of said anvil across said first end of said tabulation whereby said point pries said terminal turn from said spring and bendssaid turn towards said second surface of said anvil.

2. In an apparatus for bending the terminal turns of coil springs to form fastening loops thereon," the combination comprising a forming anvil having an edge defined by intersecting first and second faces, a first of said faces having a'shelf formed thereon at right angles to said edge, a cylinder for receiving said springs, means for positioning a first end of said cylinder against said first face of said anvil with a diameter of said cylinder substantially contiguous with said edge of said anvil, a compressed air conduit oriented to directzan air current within said cylinder in the direction of said first end thereof and with an angular component of motion whereby said springs are driven against said first face of. said anvil and are rotated to abut the end of said terminal turnagainst said shelf, and a pick assembly having a terminal point, movable across said first end of said cylinder and towards said anvil to pry said terminal turn from said spring and bend the same against said anvil.

3. Apparatus substantially as described in claim 2 and wherein said pick assembly includes a finger element adjacent said terminal point and positioned inopposed relation to said edge of the anvil whereby the terminal turn a will be engaged between said finger and edge when the with motor 69 and is connected to solenoid valve 107 7 through microsW-itch 84, to solenoid valve 1 1-1 through rnicroswitch 83 and to solenoid valve 113 through micro- A substantial portion of the periphery of cam 76 is raised to closemicroswitch 83 and thereby open valve 11-1 and acuate spring locator nozzles 27 and 27'. Cam 77 has a more limited raised peripheral surface which is confined to the terminal portion of the raised surface of cam 76 with respect to angular position. Thus cam 7'7 closes microswitch 8 d, and operates valve 1'97 to lower the picks, an interval after the locating air jets have been in operation. Cam 78 has a raised peripheral surface occupying an angular position opposite to that of the raise surface of cam 76. Thus cam 78 closes microswitch 86, and actuates carrier wheel rotating cylinder ecoil spring to form a loop at the end thereof, the combmation comprising a forming anvil having a first face and having a second face inclined with respect to said first face and intersecting therewith to form an edge on pick assembly is moved across the end of the cylinder.

4. An apparatus substantially as described in claim 2 and wherein said compressed air conduit comprises an air jet forming nozzle disposed adjacent the second end of said cylinder, said nozzle being directed into said cylinder along an axis which is skewed-with respect to the axis of said cylinder. v i

5. An apparatus substantially as describedin claim 2 and wherein said cylinder is provided with a passage in the wall thereof which passage is directed towards said first end of said cylinder and skewed with respect to the axis thereof and wherein said compressed air conduit connects with said passage to provide said air current within said cylinder.

6. An apparatus substantially as described in claim 2 and wherein said cylinder is provided with a passage directed angularly toward said first end of said cylinder, said compressed air conduit comprisingfirst and second air jet nozzles, said first nozzle being disposed adjacent the second end of said cylinder and positioned to direct the air into the cylinder in oblique relation with respect to the axis of the cylinder, and said second nozzle being in communication with the passage in the cylinder.

7. A mechanism for forming the terminal turns of coil springs into fastening loops thereon comprising, in combination, a frame structure, a rotating wheel mounted thereon and transpierced by a plurality of spring receiver current within said bores at the position of said'anvil and in the direction thereof whereby said springs are driven against said anvil and rotated to abut the end of said terminal turn against said shelf, and a pick assembly slidably mounted on said frame :for movement across the end of said bores and towards said anvil and having a 'pick element operative to engage said terminal turn to pry same from said springs and bend same toward said anvil on movement of said assembly as aforesaid.

8. An apparatus substantially as described in Jclaim 7 and comprising the further combination of a second generally similar forming anvil secured to said frame adjacent said wheel and on the opposite side thereof from said first anvil and at a diliering angular position with respect to the axis of said wheel, a second compressed air conduit establishing a spiralling air current within said bores at the position of said second forming anvil, said air current being directed towards said second forming, anvil, and a second pointed pick element slidably mounted on said frame for movement across the end of said bores and towards said second forming anvil.

9. In an apparatus for bending a terminal turn of a coil spring to form a fastening loop, an anvil having an edge portion, a supporting member for receiving the spring, means directing a jet of air against said spring to rotate and advance same axially in said support, stop means positioned to engage an end of the spring to limit the rotational movement of the spring and locate the terminal coil in a predetermined position, a pick assembly mounted for reciprocation to and from said anvil and having a pick element arranged to displace the terminal coil outwardly from the rest of the spring, and means included on said assembly for forcing a portion of said displaced coil over said edge on the forward stroke of said assembly. a

10. In an apparatus for bending the terminal turn of a coil spring to form a fastening loop thereof in angular relation to the other turns, the combination comprising a cylinder for enclosing the spring and having an opening in which the terminal turn of said spring may be exposed, an abutment positioned adjacent said opening for engagement with the free endof the terminal turn to hold the spring against rotation when the terminal turn is exposed in the opening, an anvil having an edge opposite said opening, a pick element mounted for movement across said opening for insertion between the ter: minal and the adjoining turns, means mounted for movement with the pick element and positioned to engage the terminal turn and bend same over said anvil edge to form the loop, and pneumatic means positioned to direct an air current circumferentially within said cylinder and axially towards said opening whereby when the spring is inserted in the cylinder the terminal turn of the spring will be moved to said opening and rotated to place the free end of the terminal turn into engagement with said abutment.

11. In an apparatus for bending the terminal turns of coil springs to form fastening loops thereon, the combination comprising a support member provided with a passage for the spring and having an inlet at one end for admission of the spring, an opening at the opposite end,

means directing a jet of air into the passage obliquely of the axis thereof so that the spring will .be advanced and rotated in said passage, means positioned in the path of the spring in the passage to provide a stop against the advance of the spring therein; a second means in the path of the spring providing a stop against rotation of the spring and anvil at said second end, and means at said second end positioned to pry the terminal loop of the spring outwardly and over said anvil when the spring is engaged with said first and second stop means.

12. Apparatus for bending the terminal turn of a coil spring to form a fastening loop thereof in angular relation to the other turns, comprising means defining a cylindrical bore for enclosing the spring and having an opening in which the terminal turn of said spring may be exposed, stop means positioned to hold said spring against movement through said bore and against rotation when said terminal turn is exposed in said opening, means defining a forming edge opposite said opening, a pick element mounted for movement across said opening for insertion etween the terminal and adjoining turns and engageable with the terminal turn to bend same over said forming edge to thereby form said loop, and means for directing an air current circumferentially and axially within said bore towards said opening whereby said spring upon being inserted in said bore is rotated and moved by said air current through said bore to said opening whereat the spring is held by said stop means in position to expose said terminal turn.

13. Apparatus for bending the terminal turn of acoil spring to form a loop at the end thereof, comprising a forming anvil having first and second angularly related faces defining an edge, means defining a cylindrical bore for receiving a coil spring, means positioning said last named means with a first end of said bore adjacent said first face of said anvil with a chord of the cross section of said first end of said bore substantially contiguous with said edge of said anvil, means for directing an air current within said bore in the direction of said first end thereof and with an angularcomponent of motion, to thereby force the spring against said anvil and rotate the spring into position adjacent said anvil, and a pick element movable towards said second face of said anvil across said first end of said bore to pry the terminal turn from said spring and bend said terminal turn towards said second face of said anvil.

References Cited by the Examiner UNITED STATES PATENTS 1,311,187 7/19 Sleeper -403 1,873,626 8/32 Nigro 140--103 2,188,705 1/40 Cook 140--103 2,505,942 5/50 Burge et al. 140103 2,906,011 9/59 Focht 29-2405 CHARLES W. LANHAM, Primary Examiner.

NEDWIN BERGER, RICHARD A. WAHL, WILLIAM F. PURDY, Examiners.

Claims (1)

1. IN AN APPARATUS FOR BENDING THE TERMINAL TURN OF A COIL SPRING TO FORM A LOOP AT THE END THEREOF, THE COMBINATION COMPRISING A FORMING ANVIL HAVING A FIRST FACE AND HAVING A SECOND FACE INCLINED WITH RESPECT TO SAID FIRST FACE AND INTERSECTING THEREWITH TO FORM AN EDGE ON SAID ANVIL, A CYLINDRICAL TUBULATION FOR RECEIVING SAID SPRING, MEANS POSITIONING SAID TUBULATION WITH A FIRST END THEREOF ADJACENT SAID FIRST FACE OF SAID ANVIL AND WITH A DIAMETER OF SAID TUBULATION SUBSTANTIALLY CONTIGUOUS WITH SAID EDGE OF SAID ANVIL, A COMPRESSED AIR SOURCE CONNECTED TO PROVIDE AN AIR CURRENT WITHIN SAID TUBULATION IN THE DIRECTION OF SAID FIRST END THEREOF WHEREBY SAID SPRING IS FORCED AGAINST SAID ANVIL, SAID AIR CURRENT HAVING AN ANGULAR COMPONENT OF MOTION WITHIN SAID TUBULATION TO ROTATE SAID SPRING INTO POSITION ADJACENT SAID ANVIL, AND A PICK ELEMENT HAVING A TERMINAL POINT WHICH PICK IS MOVABLE TOWARDS SAID SECOND FACE OF SAID ANVIL ACROSS SAID FIRST END OF SAID TUBULATION WHEREBY SAID POINT PRISES SAID TERMINAL TURN FROM SAID SPRING AND BENDS SAID TURN TOWARDS SAID SECOND SURFACE OF SAID ANVIL.

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