US2635234A - Staple forming and driving machine - Google Patents

Description

April 21, 1953 G. H. REED STAPLE FORMING AND DRIVING MACHINE 3 Sheets-Sheet 1 Filed July 26, 1950 VIII/AYI/I INVENTOR. Gear e17. Reed,

April 21, 1953 G. H. REED 2,635,234

STAPLE FORMING AND DRIVING MACHINE Filed July 26, 1950 5 Sheets-Sheet 2 April 21, 1953 G. H. REED 2,635,234

STAPLE FORMING AND DRIVING MACHINE Filed July 26, 1950 3 Sheets-Sheet .5

I F4. a I 5% IN V EN TOR.

G 09 [ffieed BY Patented Apr. 21, 1953 STAPLE FORMING AND DRIVING MACHINE George H. Reed, Chicago, Ill., assignor to Acme Steel Company, Chicago, 111., a corporation of Illinois Application July 26, 1950, Serial No. 175,971

Claims.

This invention relates to improvements in staple forming and driving machines wherein the stapling wire is fed from a source of supply, is cut into successive lengths, the cut length is formed into a staple over a supporting anvil device, the anvil device is withdrawn and the formed staple is driven while being supported by a movable shoe which is retracted as the driving proceeds.

The principal object of the invention is to provide a machine of the type referred to having improved anvil mechanism for gripping and supporting a cut length of wire while it is being formed into a staple. A further object is to provide a wire stitching machine having anvil mechanism comprising an anvil die which permits the formation of staples of very small sizes and which may be replaced by other anvil dies of other forms andsizes in order to form staples of other sizes and shapes. Another ob- -ject is to provide an improved machine of the type referred to wherein increments of stitching wire may be fed intermittently without the necessity of timing any wire gripping mechanisms in relation to these feeding operations as in prior machines. Still another object is to provide improved anvil mechanism which will not deform the wire fed thereto but will tend to remove irregularities in the wire. A further object is to provide means for permitting the length of wire to be cut off to move bodily in response to the motion of the cutting blade so that any tendency to deform the wire adjacent the cut is avoided. Another object is to provide anvil mechanism comprising means for holding the wire and permitting it to shift slightly, if necessary, as it is engaged by the formers, whereby a proper alignment of the wire is obtained without employing any special aligning device. Other objects relate to various features of construction and arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings in which one embodiment is illustrated. In the drawings,

Figure 1 shows a partial front elevation of a staple forming and driving machine embodying the features of the present invention with parts thereof removed and parts thereof shown in vertical section; I

Fig. 2 shows a sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 shows a vertical section taken on the 9 7 O ig.

Fig. 4 shows a horizontal section taken on the line 4-4 of Fig. 1;

Fig. 5 is a perspective view of the anvil mechanism which is embodied in the machine shown in Figs. 1-4, inclusive;

Fig. 6 is a perspective view, similar to that of Fig. 5, showing the parts of the anvil mechanism separated from each other;

Fig. '7 shows a perspective view of a modified form of anvil die which may be embodied in the anvil mechanism illustrated particularly in Figs. 5 and 6;

Fig. 8 shows a perspective view of another form of anvil die which may be embodied inthe. construction illustrated in Figs. 5 and 6;

Fig. 9 shows a vertical section similar to the lower right-hand portion of Fig. 3, illustrating the relative positions of the parts of the anvil mechanism when it is engaged by the length of stapling wire to be formed into a stable, with the staple driver and the staple formers occupying elevated positions;

Fig. 10 shows a sectional view taken on the line l0|0 of Fig. 9;

Fig. 11 shows a sectional view similar to that of Fig. 9 illustrating the relative positions of the parts after the staple formers have been moved downwardly and the staple has been formed and with the supporting shoe occupying a position to support the staple as it is being driven;

Fig. 12 shows a sectional view taken on the line l2|2 of Fig. 11;

Fig. 13 shows a sectional view similar to that of Fig. 9 illustrating the relative positions of the parts after the anvil mechanism has been.

retracted by the downward movement of the staple driver and illustrating the driver after it has partially driven the staple into the work; and r Fig. 14 shows a sectional view taken on the line l4-l4 of Fig. 13.

As illustrated in the drawings, the invention is embodied in a stapling machine of the general construction and arrangement of that disclosed in U. S. Patent No. 644,754, granted on March 6, 1900, to Matthew V. Allen, and essentially comprising a stapling head i5 which carries the staple forming and driving mechanism andwhich is adapted to cooperate with a clincher arm [6 carrying a clincher die I! adapted. to be engaged by the legs of the staple to clinch them on the underside of the parts which are stapled together. The flaps of a fibreboard box, for example, or other parts to be stapled, are placed over the clincher arm 16. and theclincher die end of a crank arm 40. crank arm is provided with a transversely extendl1 occupies a position beneath the point where the staple is to be applied. The stapling wire l8, drawn from a spool or the like, by means of feeding mechanism indicated generally at 20, and including cooperating feed wheels 51 and 58 arranged in an associated casing 52, is fed through a guideway 2| and through a tubular shearing die22 where it is out 01f to form a length of wire [Ba which is to be formed into a staple above the clincher die l1. While the staple is being formed, it is held by the anvil mechanism indicated generally at 24 a'nd'as the. staple is driven, this anvil mechanism is retracted to permit the driving of'the staple into the work.

The head. it of the machine comprises a frame or housing 25 having a face plate-26 secured to the front side thereof by means of screws 2?. The face plate 26 is provided on the inner sidethereof with a vertical guideway 25a in which a former bar 28'is mounted to reciprocate. The former bar 1 is provided on its outer side with a longitudinal groove ZSa'of' rectangularci'oss section which is s'lidablyeng'aged by a drivingbar 30; The former bar 2 8 has secured to the'lower end thereof two "staple formers BlyshOwn particularly in Figs. 1, ""10', 'l2'and 14, which are held in place :by screws 32 and which are provided on their opposed faces with longitudinal grooves am adapted to engage the projectingpor'tions of the length of'stapling wire 18a "to cause the formation of a U-shaped staple in cooperation with parts of the anvil mech- 'anism'z when the former bar 28 is-moved downwardly.

The driving ba'rtll has keyed to the lower end.

1 thereof a staple-driver 33 which is adapted to engage'gthe head'of the U-shaped staple and drive it downwardly through the work while at the same time causing the retraction of the anvil mechanism 24 as hereinafter-more fullydescribed.

- For the purpose of actuating the former bar 28, it is provided between its ends with an aperture engaged by a threaded pin 34 which is held in place by a nut 35 and which'isprovided with a This groove Bl'a has the This hub portion is keyed to a shaft 38 which is also journaled in a bearing formed in the hous- 'ing 25 and which is adapted to be driven at uniform-speed by an electric motor or the like. With this arrangement, it will be apparentthat. during rotation of the shaft 38, the former bar 28 will be periodically moved downwardly and then retracted so that a staple is formed during, each rotation of the cam.

. In order to effect the reciprocation of the driv-L ing bar 30, this bar is provided'at its upper end with a transversely extending pin 36a upon which is journaled a bushing 39 secured in the upper The lower end of this ing pin 4|, shown particularly in Fig. 4, which is journaled in a sleeve 42a formed upon the end of a link d2. This sleeve 42a is journaled in a cylindrical recess 37c formed in the face of the cam 3l-at a point displaced laterally from the axis of this cam. Thus, whenthe cam 37 is rotated, the pin ll revolves about the axis of the cam and thereby causes the crank arm to effect a reciprocation of the driving bar 3% The'recess 3lc in 20 ing 63 by a pivotally mounted plate 41.

ment of the driving bar 30 will be effected in proper timed relation to the movement of the former bar 28 so that a staple will be formed and will be in readiness to be driven when the staple driver 33 carried by the driving bar arrives at a position where it is about to engage the formed staple. As disclosed in the Allen patent mentioned reciprocation of the link 52 brings about intermittent operation of'the wire feeding mech- 10 anism 2% so that suitable increments of wire lSa cut-off bythe blade 69 and supplied to the anvil 24 to-provide the successive staples.

In the arrangement, a rotatably mounted handle 59 is carried by the. face plate 26 and suitably interconnected with the lever @2 by a pivotally mounted lever 45 and suitably interconnected with the cas- More particularly, the handle59 may be selectively rotatably set to adjust the strokeof the lever nl2l, and consequently vthe length of the increment'of vwire :Hlathat is fed by the wire feed mechanism-'20 to 25 the anvil 24, and'simultaneously to adjust the "position ofthe casing {53 carrying the lade 60 with respect to the anvil 2t, andconsequently to maintain substantially-equal the lengths of; the two legs of the substantially U-shapedstaple that 30 is ultimately formed. Specifically; the blade 60 is secured on the projecting portion 62a of a bar 62 that reciprocates verticallyin the-casing63f-and the bar '62 I is intermittently operated downwardly against the biasof an associated compression spring 65 byan arrangement including a ated by a curved arm 68fcooperating witha projection Mia provided on the lowerend ofthe link as. v g V s As the staple-is being driven the legs of the staple are supported against buckling byfa supporting shoe in which is pivoted at ll ina recess formed in the former bar 28, as shown in Fig. 3. This shoe has a lower pointed extremity 10a whichis adapted to be projected [between th'e'legs of the staple to hold'them against bending inwardly while they are being driven and itfhas a rear 'cam surface Tfib"which 'coacts with a roller 72 carried by'the end'of a plunger "5'3 which is'niount'ed to reciprocate in a tubular bore 14a formed in a cylinder'i i'attac'hedto the lower-part of the housing 25. A heavy coilspring'm nora lnally" tends to hold the plunger 13' and "the roller 72 intheir' forward pdsmens'gscmevmm to the right of that shown in Fig.3. the extentof the movement in this direction'being limited by a rod 16 having 'a'rear shoulder which engages astop, not illustrated. Therolleri3jnormallyoccupies a forward position; soinewhat'to' the right of that shown'in Fig. 3, but itis'adapted' to yield when the supporting shoe E6 i'sjfor'c'ed toward the left,

"'asviewedin' Fig. 3 by the'downwardmovement of the driving bar 30 and the'stapledriver 33 which have beveledlower extremities 36a and 33a, respectively, adapted to engage the inclined'front 65 face of thetip portion lflaof the supporting'shoe.

The shoe l'll isheld inengagement with the roller 52 by a coil spring 1''? which extendsinto a recess V 700 formed-in the shoe and into another recess 30b which is'formed in the face of theformer 0 hair.

Having described the generaroperation of the machine and the constructionfof some of its parts,

a more particular reference-will now :be made to v I v V I y V the'construction andoperat'ionfoftheanvil mechthe' cam ls'so locatedthat-thedownward-move- 75 anism 24 which has previously -been'refeired to.

shaftfiljournaled in the-face plate Z a-and oper- This mechanism is illustrated particularly in Figs. 3, 5, s, 9, 1o, 11, 12, 13 and 14 of the drawings 7 and comprises the anvil proper or anvil die 80 which is mounted at the lower end of an anvil carrier Bi pivotally mounted by a pin 82 in a chamber 83a formed in the lower part of a block 83 which is secured by screws 84 to the front face of the carrier 8i are normally caused to swing toward the path of movement of the driving bar of the plate 26. The anvil 80 and the lower part 30 by the action of a leaf-spring 85 which has its lower end mounted in a recess Bia formed in the anvil carrier as illustrated particularly in Figs.

5 and 6. The side walls Bib of the recess 8ia are bent inwardly to interlock with the curved portion 85a of the spring which is adjacent its lower extremity 85b. The upper end of the spring 85 extends into a recess 33b formed in the upper a U-shaped staple as shown in Figs. 11 and 12. As this downward movement proceeds, the anvil 83 is adapted to tilt about its pivot 8'! until the surface 800 engages the surface 8i as shown in Fig. 11, thus causing the anvil to be firmly supported during the formation of the staple. This movement of the anvil separates the part 80a of cams this member 8i toward the right as viewed inner side of the block 83 where it coacts with the bottom edge of the plate 26, as shown in Fig. 3, so that it operates normally to swing the lower end of the carrier 8i with its anvil 80 to a position where a V-shaped projection Sic, formed on the anvil carrier, lies in the path of movement of the staple driver 33 in the manner shown, for example, in Fig. 9. At this time, the rib Sid which extends upwardly from the projection Bic, is positioned between the forming dies 3 i as shown in Figs. 9 and 10. The spring 85 may be readily removed for replacement by pulling on its upper end.

The anvil die 8!} has a part 89a over which the I cut-off piece of wire i8a is adapted to be bent to form a staple having a U-shaped top. This part 80a is carried by a small block 831) which is pivotally mounted by a pin 81 between the flanges Bie which constitute the lower extremity of the anvil carrier 8!. The part 801) of the anvil die has a tail portion which extends upwardly and V rearwardly from the top of the part Bila and this tail portion has an inclined surface 800 which is adapted to engage an inclined surface 8 if formed on the anvil carrier 8! between the flanges 8ie,

and in the lower part of the'anvil carrier and .this spring tends normally to move the anvil proper 80a to the position shown in Fig. 9 where in Fig. 11 against the action of the leaf spring 85. Meanwhile, the supporting shoe 10 will have been moved inwardly by the spring 15 until its pointed extremity Hid occupies a position between the legs of the staple. As the driving member 33 moves downwardly the anvil carrier 8| and the anvil are moved to the position shown in Fig. 13, the staple is disengaged from the anvil 80, and the staple is then driven downwardly by the driver 33 through the work which is supported on the clincher die ii. As the staple is drive-n, the driving member 33 gradually cams the supporting shoe is out of its supporting position by coaction with the upper inclined face of the portion iila thereof so that the sup-porting shoe is gradually retracted against the compression of the coil spring 15. While these operations are taking place, the anvil carrier 8i and the anvil are retained in the position shown in Fig. 13 by the driving member 33 which then coacts with the tip of the part Sic.

After the staple has been driven, the driving bar 30 is moved upwardly, following the former bar 28 which will have previously been moved upwardly by the action of the cam 31. When "the driving member 33 has moved upwardly beyond the projection Bio of the anvil carrier, this the pressure of the spring 88 is adapted to cause the anvil to grip the section itia ofstapling wire between its top face and the lower face of the The side of the part 8ic is provided with a notch or guideway Big of V-shaped cross section which is projection sic formed onthe' carrier.

adapted to engage the end of the wire i8 as it is V 'being fed by the wire feeding mechanism 23 in order to direct the wire into proper position beneath the portion tie and above the portion 80a of theanvil. The gripping of the, wire by the spring actuated anvil continues until the anvil' is moved downwardly during the staple forming operation to the position shown in Fig. 11.

After the wire has been positioned in the anvil mechanism in the manner illustrated in Figs. 1, 9 and 10, and after the section of wire has been cut off by the downward movement of the cutting blade (it, the cam 37 actuates the former bar 28 T to cause the former dies 3i to move downwardly and engage the projecting: ends of the. cut-off piece i8a of the wire. These end portions of this piece of wirepass into the grooves 3iaformed 1 in the former dies andas the former bar 28 moves 1 d e i t y t? st; dqwnwei i ie f carrier is again moved to the position shown in Fig.9 by the action of the spring 85, and the anvil 88 will be moved by the spring 88 to the position shown in Fig. 9 where it engages a new length of wire fed by the mechanism 26. Thus, the cycle of operations may again be repeated with the feeding of a section of wire, the cutting off of that section, the forming of a staple and the driving of a staple taking place during each rotation of the cam 31.

The machine is provided with mechanism, not shown, for insuring that each time a staple is formed and driven, the cam 31 will rotate a single revolution so that all of the parts start and stop their operations in the same relative positions in each cycle.

The present construction has the advantage that when the wire is is fed by the feeding mechanism 29 through the stationary die 22 it moves to its position between the projection. 8ic of the carrier 8i and the portion 86a of the anvil and is automatically gripped by the action of the spring 88 without the necessity of operating or timing any gripper actuating mechanism causing the operation of any other gripping device. As the wire moves to this position it may be guided. if necessary, by the beveled V-shaped surface 3 ig formed on the part 8 ie of the carrier, so that the [wire is ordinarily properly located and gripped even though the end ofthe wire is not initially wire is. gpccupmbetw s he-p t s.Ic n p rttlla. -In;-the .=eventt thewi ee no -.90 ioned w th 8 ii ntaccura b t ershap urfacmflla. 1t.-... r. th -the-..W r ;.wi 1. b shifted tra v r e i len t on t war 1 a the-stapl is entb t ar 3 l; due-t t action of-th he l-s p d mo 1 ottheierm which is shown particularlyin Figs. 10,12 and 14. As the bending of thecut-off wire takesplace to form the t pl ..-,t uim i s c Bib i l a cause a shiftingof thewiretc effect a surficiently accurate positioning thereof. This alignment of th .wi byt e pa s. 8; g and H t ke place regardless of the size of-the wire and the adjustab e mo n in of th p 8 t re nt -invention has the I advantage .thatit permitsthe ;s 1 ze;;of the .wireto be changed without; any haneeofthe anv l c o t s n r g fz ire;e p ne dcv e. nc h part fi has su .cient. amplitude: f m v e ri var n sizeso Wir withi a on e b an un th n u nce. Qithe s in Wh n he e a suhs anti kcb n e.inthe.s e of t ew i 110W- ever, it is necessary to change the formers 3 l ,the driver 3 3,;the feed whee l .58, andtheguideway 2i. The; tubular shearingdie may be .used with a substantial range of=, g rire sizes without change but the;p assageway thro ugh this member should preferably bepf thesame shape and only slightly l-ar er than thewire. As the wire is pushed into 1 nes tie Qw-t adie c ripp he di operates with the, .p-art Bic of the anvil carrier w. st ai ht n,- outsmah irregularities n the r which is of i great advantage particularly ,when fin wi 1 s., m love Asthe. stap s formedby bending, thecut section of wire overthe portion 89a of the anvil, this part of the anvilrnoves bodily downward to theposition shown in Fig. ll and the passage of -the par ts of the forming dies 3! over the staple legs tends tqcause them to become 1 straight it there are any irregularities present in l the wirewhen it; is cut ofi. This actiomarises ;.from the factthat the portions of the wirewhich become-the-legsof the staple occupyjthegrooves in -the edges of -the dies S-l-asthe staple is formed and the diesmove downwardly to a point beyond the staple legs. Also, asthe formerdies 3- I;njlove clownwa 'dlpto form the staple legs, the staplc wire may shift slightly, -cn the anvil, which .moves O -W rdly ti he. pos t o wn in .Fi .11, to cause the legs to assume the proper positions on driving, if itis not initially aligned correctly. A further advantage ofthe presentinvention is that the anvil die; 8!} may be, shaped, to give any. desired contour. to the crown of the,,-staple and the anvil provides a continuous support for the wire which is bent overit so thatacrown of any desired shape maybe perfectly, formed. 'The die 88 shown in Figs. 5 and 6 is slightlyflat on the top with roundedcorners so that the crown of the staple 1% has a corresponding configuration. If desiredfthe anvil die may have the.

form shown at so in Fig. 7' where the part; 90a.

. over whichthe stapleilt c is formed has; av top surface formed by a single radius. sothat the crown of the staple issubstantially semicircular in form. InFig. iltheanvil die 9!, issh own as having aportjion Sta provided with a flattopsurface Siibso thatthe top or crown of the-staple lj8d is substantially at rightangles to its legs. 7 When such ananvil i's employed it is, of course, necessary to change the dimensions of the formers 3|,

the driver 3.3, and associated parts in order to a moda he ice-ren Wampum cr w of the staple being formed.

s ed way, or illustration.- tog cations o f the anyildieit will be understood that the invention .may be con- 5 re ra e eg us,other r s wi gperi e r t ew c e the e de la m I lairni 1 'lfhe.oombination in a wire stitching machine, .of -lmeansfor. feeding a .wire. endwise, a m a de a a il .Q i' mo eb ri by. S 1. 5 3 fin PFW- Ph l ns Wire may ;;.*b,e bent,v a stationary part carried by said carrier and ;positioned opposite said die, yieldingmeans 7 gau e nd ai p t wa a other is.;-.- .-sri -tha /ir het heiwee a m an for g i in ir h fe d'pif pe. reni senew e ?d .93 9 2 he weensa ds ie. and s arts as au omatical tit-s par te a e. an sa part ...a a nst e bia o sa dr el m m a t rec 203%. wi eihe ebe ee 2 The wire t tching ma chine set .forth in i ms-. wherein. sa i i me n n de a 3 .d'P T5 an r ins-thei th .w re- Thew s itc n m h n s forth in .e m where n. sa u din Y meansincludes an i a lineinote e med. e. eie o a part .eneme i natbeend. f e wi lfll 'he combination; in' a wire stitching na- 30. mm msen fo e eedine-w r nd e. an anvil having a die about which a length of the wire may be bent, a v carrier having said anvil ;pivotally mounted thereon said carrier having a 7 part positioned opposite saiddie, resilient means .35 ,for causing said part and said dieto grip the wire therebetween, said die, and said part being 1 automaticallyseparated to receive the, end of he-Wire therebetween by the feeding-movement 0f-thewire endwise between saiddie and, said p art, means including. a shearing blade. for cut- .-ting ofi a length .of wire, held between said die and said part, and,means forbending the. cut. off length of wire, oversaid die to form a staple, said resilierit ;means, accommodating limited, movement of said anvil with respect to, saidcarrier duririgthe cutting operation and accommodating substantial movement: of said anvil with respect ,tq;.;said carrier'during the bend operation.

5 ,Thecombination in a wire stitchingmachine of an anvilhaving a die about which a len gth 0f wire maybe bent, a. carrier having spaced flanges at its lower end between which said anvil is pivotallymounted Withsaid die project- .-ing laterally, saidcarrier having a partproject- 5. ins-over said die, and resilientmeans engaging said-carrier; and, said. anvil for effecting pivotal movement of said anvil with respect tosaid carrien'and-thereby causing said dieto cooperate with .said, part to grip the wire therebetwee'n. 6. Thefcombination ina wire stitching machine ofemeansfor feeding wire endwise, an anvil having. adie about which a length of said llwire may be bent, a carrier having spaced flanges at its lower end between which said anvilis pivotally-amounted; withsaid die projecting laterally, 1 said-carrier having a part" projecting over said die, resilient meansenga'gingsaid carrier and said anvil f or eiiec tingpivotal movement of said anvil withrespect to'said carrier and thereby causing 1 7 said die to cooperatewithsaid part to grip the L wire therebetween, means including a' downwardly mqving cuttingbladeim cutting off alength M of wire positioned over said die and heldbetween .sa c id e. .anq-sai ..p t sa d res nt means acccmmodating limited movement of said anvil with respect to said carrier while the cutting takes place.

7. The combination in a wire stitching machine, an anvil having a die about which a length of wire may be bent, a carrier having said anvil pivotally mounted on the lower end thereof, said carrier having a projecting part adapted to cooperate with said die to grip the wire therebetween, a support to which the upper portion of said carrier is pivotally connected, a staple former movable transversely to the wire held on said die, said carrier having a recess on the side thereon on which said part is located, and a leaf spring seated in said recess and engaging said support for causing said carrier to be actuated to move said part and said die toward the path of travel of said staple former.

8. The combination in a wire stitching machine, of means for feeding wire endwise, an anvil having a die about which a length of the wire may be bent, a carrier having said anvil movably mounted thereon, said carrier having a part positioned opposite said die, yielding means for causing said die to cooperate with said part to grip the wire therebetween, said die being automatically moved away from said part against the bias of said yielding means to receive the end of the wire therebetween by the feeding movement of the wire endwise between said die and said part, forming means adapted to coact with the wire held upon said die to bend it about said die, said die being adapted to move to a predetermined extent away from said part upon the initial movement of said forming means, and means engageable with said anvil for limiting said movement of said die away from said part.

9. The combination in a wire stitching machine, of an anvil having a die about which a length of wire may be bent, a carrier having spaced flanges at its lower end between which said anvil is pivotally mounted with said die projecting laterally, said carrier having a part projecting over said die, and resilient means engaging said carrier and said anvil for effecting pivotal movement of said anvil with respect to said carrier and thereby causing said die to cooperate with said part to grip the wire therebetween, said carrier and said anvil having parts adapted to coact to limit the separation of said projecting part and said die.

10. The combination in a wire stitching machine, of an anvil having a die about which a length of wire may be bent, a carrier having said anvil pivotally mounted on the lower end. thereof, said carrier having a projecting part adapted to cooperate with said die to grip the Wire therebetween, a support to which the upper portion of said carrier is pivotally connected, a staple former movable transversely to the wire held on said die, said carrier having a recess on the side thereon on which said part is located, and a leaf spring seated in said recess and engaging said support for causing said carrier to be actuated to move said part and said die toward the path of travel of said staple former, the walls of said recess and said leaf spring being formed to interlock detachably for holding said spring attached to said carrier and permitting the removal of said spring.

GEORGE H. REED.

References Cited in the file of this patent UNITED STATES PATENTS

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