US2574875A - Fastener driving device - Google Patents

Description

Nov. 13, 1951 fJ. c. LANG 'FASTENER DRIVING DEVICE 4 shees-sheet 1 Filed June 5, 1947 40 I Snvntor fase/via Lang 43 Fay. 3.

Gttomegs NOV. I3, J' Q LANG .FASTENER DRIVING DEVICE v 4 SheeJcS-Sheel 3 l Filed June 5, 1947 C w' 1 42 U O )l O F6 40 fose,v C.

Snnentor any Cttornegs Nov'. 13, 1951 J, C, LANG 2,574,875

FASTENER DRIVING DEVICE )Filed June 5, 1947 4 Sheets-Sheec 4 tical.

Patented Nov. 13, 1951 UNITED emr 'HQE tion of Delaware ZLGlaims. 21 "This invention*is1for-afastener driving device, and-relatesparticularly to-a tool for-converting aprepared strip of fastener blanks into individual fasteners and for= drivingL thesame.

The linvention is f especially applicable tocompleting the Yformation-pf and driving'whatl-If term -Ttacksand will be. hereinafter specicallydescribed in1 thisconnection,- but it may: bev-adapted for useindriving rvarious other ltypes'of fastenersfstaples `and i the like.

'The invention -is particularly designed A-fcr Vuse in theifurniture,l automobilel `and.' other industries Where great quantitiesloftacks arerequired. In 'the furniture and automobile industries, forexample, larg -quantities "of tacks` are :individually driven in securing upholstery lto Wooden frames.

the HVpresent time -this '-isdone by tack-spittersp; -skilled Workmen who :hold i a -quantity of `tacks in their mouths and who remove them oneata-timeand drive them. These persons `not onlyrequire -considerableftraining to= acquire their skill, Abut -'their number vis limited. -Often they disgorge-a mouthful "of tacks, just=tofspeak a Word,V andy it isrestimated that many moreftons v of tacks are wasted every' year than areused. Sanitary laws Vmake the use of-vvasteltacks imprac- IAdditionally, in the "furniture industry. much-Work is -done Yon furniture that 'has -been otherwise finished, that --is assembled, stained, and varnishedtoatnished condition; and va carelessblow vby the Vtack spitter frequently `-sends furniture back forY repair orrenishing.

My invention'has fora primary purpose to'pro vide an air-operated driver of light, compactconstructiomadapting it to easy handling. Itsd-riving nosev may be exactly positionedl on the work and the tack driven. Itrrequires little skill to .use or operate; tacks can be accurately posi- .tioned; theunsanitary conditions oftack spitting areeliminated, and the speed of operation, .besides beingmore sure, is faster,` and aA great Waste of tacks is avoided.

-The invention further provides -an `impact driver in which the` air pressure andpressure responsivemechanisms serve to cock afspringpropelled driver, so that the driver ,is ,operated .with la uniform, quick, sharp blow, while .the

mechanism itself iscompact,light, positive, and relatively inexpensive.

.My invention may be more fully:understood-.by

reference to the ,accompanying drawings,

fwhich:

f Fig.;1; is aplanzview of-,a typical blank lforforming :'l-tacksfsuch as is'usegd-inithemachine con- :stitutingfmy invention;

fFig. @2 is la perspective .vie-W of `a .single tack aftenithas been -separated :from the strip;

Fig..islassidefelevation of a driver embodying my invention;

FigA is. afragmentary.view,sbeing a transverse vertical section -in the 'plane of line HP-LV A of Figgbutrvvith thedriverLinthe upper position shown in Fig.f'6;

`Alig.i5fisfa=vievv:partly in'elevation and partly inivertcal rsectionsof 4the complete tool, `:showing ther driver in its 1 lowermost position;

'-IFigfis a'rsimilarivew showing Ythe driver. in;` its lelevated position;

SFigJAi is a transverse sectioniinrthe planeof `line A.-Afof Fig.i6,.andfshowingza'cover onA the magazine;

tFig. -7 lisaa'i front.` elevation of the'tool 1-Fig.18 is a .fragmentary nsideelevationfonfa larger l:scale :showing l the positionof f the i parts.` `at the `instant' ofA the .release of i the driver;

l'Fifg.y 9- is aI detailvievv.V showing. a section: through the trigger-operated vair valve, the section `fleeing inthe pla-ne. offline IX-IXof Fig.:l0;

IFig. 210i is aside-elevation ofthe airzvalve;

1Fig. A11 isla transverse section f through .the air valveiin substantlallythe plane of lineXI-XI of lig.lv9,-`showingl the Vvalve in positionrto `vent .the cylinder; and

Fig. 12 is a detail view showing`the=modied linkagevv between thel triggery and the v-alve.

Referringfrst -to fFigs. l and' 2, these ydisclose oneform Voffastener which; the tool of the present invention is 'especiallyvvellttedv to2 handle. -This fastener'constitutes the'su-bject-matter of fmy' cc pending application *Serial No.63o";e67,filed December 2l, l9 45, in which* itis more `fully shown and described. iIn the making of the fastener, a narrow ribbon or strip of' metal is slitinWard-ly from ione edge, and'thenlongitudinally at regu lar intervals, Aproviding a succession v,of legforming elements @,'the strip'itself being designatedgenerallyr as A. The'leg-forming elements are-,connected,tothebodyof the ,stripby a por tionfbWhile the` other marginofy the'strip, desighated .,c, .substantially uncut u.and continuous, exceptJ `for lratchet-dike nnotches d which are formed at regular intervals in the edge, and Whicnmarkthe point wherethestripis severed to; form-individualY fasteners, .and which also serve for indexing orlfeeding the strip.

:Thefstripfof,blanks,as shown. inA Fig. .1, may. be formedin-rolls or coils containing several hundred v er several thousandblanks.

;-In the-operation cf thelmaclnne Vabouttolbe described, `one :blank is,cut.roi from the leading end of the strip and is driven. 'Ihe blank so cut off is of T form, having a head-forming portion c' constituting a part of the continuous margin c of the original strip, while the leg-forming element is bent down on an axis transverse to the axis of the strip, the leg-forming element in the finished fastener being designated a'. The fastener thus produced is of generally T shape, with the head set o to one side of the leg, and with the grain of the metal constituting the fastener running lengthwise of both the head and the leg.

In the operation of the machine about to be described, a coil of the prepared strip is placed in the machine and fed to the driver. As indicated above, the endmost blank is sheared off and driven, and at the time of driving, has the form shown in Fig. 2. The machine is so constructed that as the endmost blank is being severed and driven, the leg-forming element of the next succeeding blank is bent down into vertical position so that the fastener is otherwise completed before it is severed and driven. The particular formation of the driver and die for accomplishing this result is disclosed in my copending application Serial No. 634,537 led December 12, 1945, and the details need not be described in 'the present application.

The tool constituting the present invention has a foundation plate 2 which may be a relatively,7 thin, flat sheet of metal. It is provided with an op ening 3 to provide a hand grip 4. Riveted onto one face of the flat plate 2 is an angular channel 5 having spaced flanges 5a and 5b. The circular trough between the two flanges 5a and 5b constitutes a magazine for holding a coil of fastener blanks designated A. The outer flange 5a. of the annular channel is cut away at 5c (see Fig. 3) providing an opening through which the leading end of the strip may pass, the end of the strip being carried down through a guide to the driving mechanism. As the strip is consumed, it rolls or unwinds in the trough-shaped magazine 5. Plastic filler pieces 4a and 4b (see Fig. 6A) are secured on the plate at each side of the channel to provide a better hand grip, and in Fig. 6A a movable friction cover plate 5c is shown over the channel. For clearness of illustration the cover plate is not elsewhere shown.

Secured to the forward edge of the plate 2 is an operating cylinder 6. As shown in Figs. 5 and 6, this cylinder is provided with a piston 1 which operates a piston rod 8 that slidably passes through an end member 9 at the top of the cylinder. There is a compression spring I interposed between the piston and the cylinder head 9.

At the bottom end of the cylinder there is a second end member or cylinder head II having a port I2 therethrough leading into a nipple I3 to which is connected a tube I4. The tube I4 is connected to a nipple I on a control valve designated generally as I6. From the other side of the control valve I6 there is a pipe I1 which, as shown in Figs. 3, 5 and 6, extends across the plate 2 and terminates in a nipple I8 to which is secured air hose coupling (not shown) and through which air under pressure for operating the tool may be supplied.

Directly below the cylinder 1, and in axial alignment therewith is a sleeve having a guide bushing 2I in its upper end. Passing through the sleeve 20 and guided in the bushing 2I is a rod 22 having a nut or other abutment 23 on its upper end for limiting the downward travel of the rod. There is a disk of cushioning material such as rubber, leather or the like, attached to the under side of the nut 23, this disk of cushion material being designated 24. Its purpose is to cushion the shock of the downward travel of the rod 22 when the rod moves from the elevated position shown in Fig. 6 to the lowered position in Fig. 5, as will be hereinafter more fully described.

The lower end of the rod 22 is attached to the upper part 25 of the driver and forms a part of the driver assembly, the driver itself having a depending driving element -26 terminating in a square end 21. As indicated by dotted lines in Figs. 5 and 6, the driver may have a narrow lip 23 down one face thereof. The driver also has a portion 29 positioned along one side of the portion 28, and which terminates in a plate above the end surfaces 21 of the driver. The function of the portion 29 is more fully described in the latter of my aforesaid applications, and is the part of the die which operates to bend the leg of the blank from the horiozntal to the vertical position. The part 28 of course is the part which shears off the endmost blank on the strip and drives it, and for accomplishing this purpose the driver 28 operates in a guideway 30 which is formed partly by a forwardly-projecting portion 2a of the plate 2, and partly by a keeper member 3I which is secured to the extension 2a by machine screws 32 (see Fig. 3). The keeper member has a block 34 secured thereto by a screw 33 (see Figs. 3 and 4). 'l'here is a compression spring 35 that operates to force a yieldable guide 35 to the left as viewed in Fig. 4. Transversely yieldable guide member 36 normally projects across the guidevvay 3D below the driver and as shown, it has an inclined face which will cause it to be cammed toward the right as viewed in Fig. 4 as the driver pushes a fastener downwardly along the guideway. Th'e slidable block 36 is offset at one edge so as to form a guideway for the leg of the tack and keep it from bending during the initial part of the driving stroke, but as indicated above, the guide block 36 is cammed out of the way as the driver continues its downward movement. This guide arrangement is more or less incidental to the present invention. The fastener is projected from the bottom or end of the guideway 30, and this portion of the driving tool I term the driving nose.

As shown in Fig. 5, when the driver is in its lowermost position, the end 21 is substantially iiush with the end of the guide 3D, while the fastener or tack itself is designated t.

There is a contoured plate 40 secured to the bottom edge portion of the plate 2, as viewed in Figs. 3, 5 and 6, the bottom edge of this plate being flush with the edge of the plate 2, but the contour of the top plate is generally curved to define the curvature which the strip of fasteners follows in passing from the magazine to the driver. This plate 40 may be secured to the plate 2 by screws or rivets. Above the plate 40 is another plate 4I, Whose lower edge is contoured to conform to the top edge of the plate 49 and is spaced above the plate 40 a distance corresponding to just slightly more than the thickness of the fastener strip, so that there is provided a guiding channel 42 between the lower edge of the plate 4I and the top edge of the plate 40. The strip is so delivered through the channel that the notches d in the edge, as described in connection with Fig. l, are outermost. There is a member 43 secured to the plate 40 which has two upwardly-extending arms 44 and 45. Each of these arms is resilient, and each carries a resilient pawl or tooth (not shown in detail) these ratchet teeth being so spaced as to engage :the inotches= dinthecedge of the strip in the .-guideway and :prevent reverse 'movement o'f the strip. The constructionandarrangement of .thesearms andiratchet teeth is substantially the same as described in my said copending application erial No. 634,537.

Villhere isa pivotipinisecuredato thezplate .L2 .at lili,...and.an osciliating plate ilisrpivotailycarried on.this'..pin. and arrangedto slide. over-.the plate .4 l This plate is provided with a slot i8 throughwhich anaanchor pin d'9 proiects, thefan'chor pin .being xedon the..plate12 andfpassingthroughthe slot 4:3. 'itprcvidesan anchorage for-.oneendof a tension spring 50. :The other .endof .thetension spring 5t issconnected.toaapinllonthe oscillating plated?. The arrangementis such .that .the plate .di '.rnayfmove back andforth inanfarc a predetermined. distance. .Whenzit ismoved to the right, as .viewed in iEig. :5,..thel tension. spring .5G is extended and urgesitlbaok toward=the left when suchinovementisLperrnitted. The plate il carries Ytwolngers .52,.each of .which carry a pawl forengaging notchesdinnthe edgne of .the strip, thengersf beingspring ngers. .The teeth arev so arrangedithat -whentheymovetoward the leftas'zviewedinFigs. 3 .and 5, their pawls vwill engagethenotchesin the. strip and push the strip forward:or..to.the.left. `Theyare. so shaped that whentheymove to the right frornthe position shown infFigy, they merely spring out of the notches andslide over the edge of the strip, all as .more fully ydescribed in my application last abovermentioned.

The .guide channelfor the strip d2 terminates atthe guide `3iforthe driven-and as shown in Eig. 6,thefastener blank enters-the driving guide below theuppermostilirnit of travel of the lower endi.2lrof;the.driver,. and well above the bottom o1" Vthe driving guide. .Aspreviously indicated, when the driver 28 .moves down, itfunctions to shear .of the .blank which is then in the driving guide,

and expel it from the end of the driving guide,

while thewportion 25 of the driver, alsoion the down stroke of the driver, catches the leg-forming element of the next succeeding blank and bendsit'down toa vertical position.

The driver is provided with a cam element 3a `havinga riser .25H31 and-a dwell 2de (see Fig. A5). vThe oscillating'platef/Z.h'as'a roller 5d which cooperates withithis cam. 'When the driver is in .the elevated positionrshown in Fig. 6, the roller isin its position furthest to the left, and is at the base of the riser 28h. As the driver moves .'down, the riser 28h rocks the plate 4'? toward the right from the position shown in Fig. 6 to the `position shown inlFig, and thereafter the plate :di isheld over toward the right by the roller beling engagediwith the dwell-'23C of the cam. When @the driver Areturns to its elevated position, the

spring 5t tends to rock the driver back to the posi- `|tion shown in Fig. 6, and in this position the strip of fastener blanks'is advanced.

An important andnovel part ofthe present in- -vention resides in the mechanism through which the'air cylinder is utilized toI operate the driver. The upper end ofthe piston rod 8 is secured to Ya connector-56, through which passes a trans- "verse pin 6l. To the opposite endsof the pin 6| are connected the two arms '-62 of a yokevmemfleeri that is-sonewhat curved to conform'to the =curvature of the-cylinder 6. The lower end of Zthe yoke is bifurcated to provide two arms 6d, `each of which is formed'with a hook t5. A `block t5 having a sloping cam surface-Slis secured to sthe sleeve iL-andit `is-provided withf'a Amachine -which carries a cain roller gli.

tothe lower piston head element vIl is a lever 9|, the pivot for the lever being designated'g. The

screwfii, .wh-i'ch-'screw passes .through the bie furcated end :i0: of a lleafspring 'il ,nwhose upper end is attached at ila to the yoke. Themea'd of the screwlie `thusf provides an abutment against which-the leaf spring .ill'actsforurging the yoke towardthe right-as viewed-in-Figs. 3,"5and 6. When-.the-driver is inits lowermost pesitiomand when :thepiston Y'i vis .in `its lowerrnost position, the hooks of .the yoke are pusheduunderlthe fendsnof a-transverse pin 'l2 in 'the top of the dri-ver block. When-airis admitted ato the'cylindertto drivethe-piston upwardly,the upward motion 'of .the piston willlbetransmittedthrough the-yoke, and through :thesehookslto the driver, so Vthatlftherdriver Awillbe raisedY against the coinpression 'of f apowerful -spring T3. Thisl spring Ais confined betweenftheupper parti of then driver and l.the bushing :2i atthe toprof the sieeve12. 'As-the piston Il' continues lits l upward movement, thespring 1?-3 Will. be compressed -to an increasing extent. Aifi-tia predetermined pointinthetravel of 'thefpistonfand driver, a rollerl''lithe-.yokewili engagethe-risev6lf ofthe can/1555 tofforce theyoke .tothe fleft,as viewed in fFig. 5, tothe position shown in Fig. 6. This will cause the hooksii 'to become diseiigagedfromthe ends of the pin Y'52, whereupon -the spring .iii Awill act 4to push Lthe 'driverdown with great force. This-may happen notwithstanding the factithatthe piston l may 'continueto `thereafter move up=to1a 'veryslight ldistanceffer the purposehereinafterto-be de 'ascribed I haveheretofore referred to -the-valvel for controllingtheadmission of air to the cylinder "6. This `valve includes a body -i having-a rotary valve element li-5 therein. As shown'invFig. 11, this valveJ `element has avthrough passageway 'i6 which in `one position may permit the flow of --air from the air supply pipe ii to the air-supply pipe lili. It has la second passageway 'El in its periphery whichfinthe'position shown in Fig. 11, allows air to iiow from the'tube lfithrough a vent "t3 to theatrnosphere. When the port 18 is in Iposition to'permit the escape of air from the pipe ltithe passage it of course is inoperative, and

lwhen-the valve plug is rotated'to bring theport i6 into itsoperative position, 'the passageway l'l isrfendered inoperative. The'valve plug l'has-a disk 19 thereon at one -end thereof/outside the valve casing, and it is providedwith a radial pin ('seerparticularly Figs. 8, 9, l0 and11). yThe Aotheren'd ofthe valveplug 'i5 has a steinSl that passes-throughl the plate 2, and which is provided with an operating crank or lever^82. vAn operating`link`83 is-pivotally connectedat one end t0 the crank 82, and has its other end connected at 184 to av trigger leveri,- which has a finger-engaging portion--86,and which is pivotally hung to the Yplate -2 at 81, the-trigger beingon the opposite side of the plate V2frorn the magazine wihch holds the spool of fasteners.

The trigger mechanism'being coupled in the manner indicated, serves to move the valve in `one direction,-i. e., vfrom the position shown in `Fig. 11 `tothe position shown in Figs. 9 and 16.

lTheyoke 63 has anedge portion 89 (see Fig. 8) Pivotally secured lower end of this lever is turned inwardly asbest shown-in Fig. 7 to provide a valve-operating finger "93. This finger is imposition to engage'the K'pinliron'the vdisk TQ atone end'of the rotatable valve'body. -When theY triggeris-operatedin one "directionyi, e., "tothe position-shown'in 'Figui the pin contacts the linger 93 and pushes the lever 9| toward the left from the position shown in Fig. 8.

After the hooks 65 have been released from the driver in the manner hereinbefore indicated, and the piston continues its upward movement, the roller 9|) engages cam surface Sla. on the lever 9| and forces the lever toward the right to the position shown in Fig. 8. The finger 93 engaging the pin 80 on the valve disk 19, rotates the valve to the vent position shown in Fig. 11. Thus just as the piston reaches the upper limit of its travel, the valve I6 is kicked into the off position, l. e., to the position shown in Fig. 11. The supply of compressed air to the cylinder 6 is cut 0E, and the air which is in the cylinder is vented through the port 18. By this time the driving of the tack will have been completed and the spring l will act to push the piston back to its lowermost position. As the piston 1 comes down, the hooks 65 on the operating yoke are again lowered to a position where the leaf spring 1| will be effective for engaging the pin 12 and connect the yoke with the driver in preparation for the next operating cycle.

The complete operation may now be readily followed. Assume rst that the machine is coupled to a source of high pressure air. Pressure of the order of 50 to '15 pounds will be suicient, but this may be changed if spring 13 is made stronger or weaker. The operator positions the driving nose of the tool in the position where the tack is to be driven. The parts at this time are ln the position shown in Figs. 3 and 5, but the trigger is shown in the position which it assumes immediately after it has been pressed. The operation of the trigger rotates the valve to bring the passage 16 into operative position, whereupon air enters the bottom of the cylinder and lifts the piston. The upward motion of the piston transmits motion through the yoke and hooks 65 to the driver which is raised against the compression of spring 13, and as the upward motion continues, the roller 14, striking the incline on cam block 61, moves the yoke to the left, disengaging the hooks 65 from the driver, thus disconnecting the driver from the piston, and the spring 13 immediately expands, forcing the driver down with a quick, sharp blow.

It might be pointed out that as the driver moves up, it clears the end of the strip of blanks,

at which time the feed plate 41 which is then in the position shown in Fig. 5, snaps to the left, forcing the endmost blank on the strip into position under the driver as shown in Fig. 6, so that when the driver comes down in the manner above described, it shears the fastener and drives it with great force. After the release of the hooks\65 the yoke will continue to lift a slight distance until the roller 90 rocks the lever 9| to the position shown in Fig. 8, at which time the finger 93 on the lever 9| hits the radial pin 80 and turns the valve to the olf position. In so doing it resets the trigger. As soon as the trigger is reset and the valve is in off position, the air is vented from the cylinder, the piston 1 drops down, the hooks 65 are lowered, and the spring 1| restores the' connecting yoke to its operating position where the hooks 65 are again engaged with the pin 12 on the driver.

For the purposes of simplicity of operation, I have shown a simple connection between the valve and the trigger. The particular mechanism shown has the disadvantage that the trigger might be rocked forward, notwithstanding the fact that the operator had not had time to release the pressure from the trigger. In order to overcome this difficulty, lost motion linkage may be employed such for example, as that shown in Fig. l2.

In Fig. 12 the valve |6 is the same as heretofore described, and it has the radial pin 89. The link 9| is the same as previously described, and it has the inwardly-turned finger 93 as previously described.

In lieu of the link 83 as previously described, however, there is used in the modification shown in Fig. 12 a link 95 having a bayonet type of slot S6 at one end, this slot having a notch portion 96a and an elongated portion 95h. In Fig. 12 the plate 2 is not shown, but it may be borne in mind that actually 9| and 95 are on opposite sides of the plate. A tension spring 91 is connected to the end of the link 95, and tends to urge it to the left, and downwardly as viewed in Fig. 12. The link 95 has a raised abutment or lug 98 thereon intermediate its ends, which abutment is in a position to be engaged by the fixed lug 98a. Fig. 12 shows the position of the parts after the trigger has been pulled and the valve has been reset to the off position at the completion of the driving stroke. At this time the pin 99 on the valveoperating crank is at the end of the slot 9619 most reniote from the notch 96a. In other words, pressure is still being put on the trigger. When the trigger pressure is released, link 95 will be pulled down (as viewed in Fig. 12) under action of spring 91, after which it is caused by the same spring to move to the left so as to cause the pin 99 to seat in the notch 96a.. When the trigger is next pulled, the link 95 will move up. as viewed in Fig. 12. The pin 99 will be seated in the notch 96a so as to transmit motion to turn the valve. When the lug 98 strikes the fixed lug 98a a lever 95 is forced to the right to move the pin 99 out of the notch, so that the pin 99 is free to move lengthwise along the slot 96h without imparting a corresponding movement to the trigger-operated link when the valve is operated to the "oif or "vent position.

The advantage of this lost motion connection is, as above indicated, that even though pressure continues to be applied to the trigger, the parts will all rest themselves without disturbing the relation of the trigger, and then when the pressure is released from the trigger, the link 95 will automatically be restored to an operating position.

While air impact tools of many types have been developed, the present invention is unique in that the air cylinder is used only to raise the driver and compress the spring 13, while the force of the actual blow is delivered by the compressed spring itself. Each impact blow is of the same force as the other, that is, the blows are of uniform force. The air operated piston can make only one stroke with one operation of the trigger, and hence the trigger must be pressed each time that a tack is to be driven. This is a denite advantage because it would be extremely undesirable and dangerous to have an automatically-operated air hammer such as is commonly used in air-operated impact tools moving the driver in rapid succession.

The construction of the tool itself is also novel by reason of the use of a single plate or web 2 as the support for the magazine, and all of the operating parts. It makes a tool of extremely compact construction, and one which is very light, so that it can be handled very easily, and

off veryf small dimension: so that. tacks can. be driven: closefinto.-V crevices and; corners. The.- pofsitioningl ofi the'- tacks and. thedriving. can"A be accomplished: quick-ly: and accurately; and. very little-skill isireduired onithe partf-ofthe operator to successfully usethe machine. Azsingle row of tacks may conta-in; several hundred or.Y severalA thousand blanks-so thatthecapaoit-y ofthe machine isrelatively large, and littlef time is lost in: recharging'. the machine: At the. Sametime the. feed mechanism and thefmagazineare` eX- posed for ready access-forthreading. a -new strip into the machine, or for removing any-imperfect blanksthat might possibly clog. the.V driverf.

While I have shown one formzof strip-feeder; itwill be understood thatgother mechanisms may be substituted, and. that` bysubstitutingother known or. preferred. feed mechanisms -and...proper designofthe driver and guide, various typesand shapes of` fasteners, tacks or staples may' be driveirinlike manner. Also, while I have. show-n asingledriven.twoor. more may be groupedin gangsandthethin compact construction enables them to be. put` close together. when desired, and a. cluster. of. several will. bev quite light .to suspend and maneuver about.

While I, have. illustrated. and described one specic embodiment of my machine, it will be understood .that this is by way of illustration, and that various changes. and.-- modifications in the construction andiv arrangement. of, parts may be made within the-contemplation. of my, invention.

I claim:

l; An impact tool oftheclass. describedlcomprising a. reciprocable driver. which moves in one` direction to deliver an impact and; inthe opposite direction to. a retracted position, av springt-'or moving the driver on itsimpactstroke, a fiuid pressure piston and cylinder. for. moving. the driver to compress the spring, andA rigid means releasably` connectingtlie pistonfanddriv.- er during such spring compressing stroke,A and means for releasing said lastnamedmeanswhen the spring is compressed.

2. An impact tool of theclass described comprising. a' reciprocable driver. Which.mov-es in one direction to deliver an impact and in theopposite direction to a retracted'. position, a springY for moving the driver on its impact stroke,.a.fluid.

releasably connecting the pistonandfdriver duringsuch spring compressing stroke, and means for releasing saidlast named means. whenthe spring is compressed, saidllast named. meansin.- cluding a cam engagedby. saidconnectingi` means during4 its travel..

3. Anfimpacttool comprising a cylinder and aA piston movable therein, .means Vfor controllably supplying fluid underpressure to the cylinder to move the'pistonzinone direction, means for: returningthe'pistonafter it has been so moved, areciprocabledriver; asspringfor. operating the driver on its oppositeror impact stroke, and a rigid linkage operable. toconnect the piston and driverto move the driver ina direction to com= pressthe spring,` means. for disconnecting the linkage from the. driver when, the driver has been moved against the 'compression oi? tl'iezspring to a .predetermined position, and means for movingj the linkage into engagement-'with the driver after the driverhas'beenz moved. under the .opveration of the spring tothe opposite limit of its travel andwhen the piston .hasbeen returnedto the-V oppositelimit of itsv travelA 4.Anf impact tooli comprising ai cylinder and a' pistonfmovable therein,.meansfor controllably supplying fluid under'pressure to the cylinder to move the piston: one direction,.means for returning the-piston after it has been' so moved, af reciprocable. driver, a: spring for operating the driver on'V its opposite orl impact stroke rigid means for'automatically.y connecting the piston and driver toA movethev driver to compress the springv and release the driver when: the spring has been compressed; said lastI means including a: yoke: pivotally connected with the piston and having: ahook element for'releasably `engaging the driverga spring; for urging, the yoke into a position forthefhookz toengage the driver, and a cam engaged in the travel of the yoke for moving. theV yoke on. its pivot to release the driver.

5.- An impact tool comprising. a: reciprocable driver movable in one direction to strike'a blow,` a spring for operating the driver on saidstroke, a iluidy pressure motor means for moving the driver in the opposite direction to compress the spring,` al mechanicalA connection between the motor and driver operable tol transmit motion from the motor tovtheidriver only in a direction to compress'. the spring;V and a control forl the motor.

6. An impact tool comprising a reciprocable driver movablein onedirection to strike a blow, a spring for operating'. thedriver on said stroke, a fluid pressure; motor means for moving the driver in the opposite direction to compress the spring, at connection between the motor and driver operable to transmit motionVv from the motor to the driver. only` in a direction toicompress theV` spring, a. control' for the motor, said control including a' valve movable from.` an oitr position to ar motor-operating position, a manually operable` trigger for movingv the valve to motor-operating'` position, and means actuated? through movement of the driver under the power of said motorV4 for moving the valve to; its off position whenthefspring has been compressed.

'1. An impact tool comprising a. reciprocable. driver movable. in-one direction tonstrike a blow, a. springfor sofmoving thedriver, aV fluid' pressure motor-means for moving the driver in the opposite direction tofcompress the'spring, aconnection between the motor and driver operable to transmitmotion from themotor. to 'the-1 driver only in a direction to' compressthespring, a` controlforthemotor, said control-including a valve movablefrom an oli positionto a motor-operating-v position, a. trigger movable manually for turning the valve to a, motor-operating position,- motor-driven means for turningathefvalve to an off positionmeans for operatingisaid connection between the motor andy driver to release itY when: the driver has moved to the limit of its travel'in a.direction-tocompress the spring, and means` for urging' said connection intov engagement with the driver` to re-establish said connection after' thedriver hasbeen actuated bythe spring.`

8*. Animpact toolhavinga driver movable from alraised positionto-azdown position, a spring for propelling theV driver from the first to the second position, a pistonand-cylinder. in which the piston. is moved inone direction by fluid pressure, a springA for moving the piston inthe opposite direction, means for connecting the piston tothe driver when the pistonis being operated by fluid pressure for retractingthe driver and compressing the spring which propels it,.means for releasing said connection when the spring is compressed, and trigger means for controlling the iiow of iluid into and out of the cylinder.

9. An impact tool having a driver movable from a raised position to a down position, a spring for propelling the driver from the rst to the second position, a piston and cylinder in which the piston is moved in one direction by fluid pressure, a spring for moving the piston in the opposite direction, means for connecting the piston to the driver when the piston is being operated by fluid pressure for retracting the driver and compressing the spring which propels it, means for releasing said connection when the spring is compressed, trigger means for controlling the flow of fluid into and out of the cylinder, said means including a valve movable from an on position to a vent position, a trigger for moving the valve to the one position, and means operated by the piston for moving it to the vent position.

10. An impact tool of the class described comprising a metal plate having a hand hole therethrough, a cylinder secured along one edge of the plate and parallel therewith, a piston in said cylinder, a guide on the same edge of the plate in line with the cylinder, a driver in said guide, a spring for moving the driver in one direction, a link on the piston detachably engaging the driver, means for operating the link to transmit motion from the piston to the driver to compress the spring, and means for disconnecting the link from the driver when the spring has been cornpressed, and means for controlling the operation of the piston.

11. An impact tool having a reciprocable driver With a spring for moving it one direction and a fluid pressure operated piston for moving it the other direction characterized by the provision of link for releasably and directly connecting the piston and driver, means operable through movement of the piston for releasing the link when the spring has been compressed, and means for connecting the link when the driver has been operated.

12. An impact tool as defined in claim 11, wherein a fixed cam co-acting with means on the link effects movement of the link to release the driver and a spring acts to reconnect the link.

13. An impact tool as defined in claim 12, wherein the link is a yoke-like member pivotally connected with the piston for movement transversely of the axis of the piston and has hooks at its other end for releasably engaging the driver.

14. An impact tool of the class described including a cylinder, a piston in the cylinder, a fluid pressure connection and control valve for effecting operation of the piston in one direction, a spring for operating the piston in the return direction, a driver and a spring for moving it one direction, a yoke secured to the piston and releasably connected to the driver to provide a non-yielding linkage for transmitting motion from the piston to the driver for moving the driver in the other direction to compress the spring, means for releasing the yoke connection between the piston and driver when the spring for operating the driver has been compressed, and means for automatically operating said valve to vent the cylinder and relieve pressure therein after the driver has been released, whereby the spring for returning the piston may then be effective.

15. The driver dened in claim 14 wherein the said cylinder is secured along the edge of a metal plate and there is a guide sleeve for the driver secured to the same edge under the cylinder, said metal plate having an opening therethrough to provide a hand grip.

16. The driver defined in claim 15 wherein said plate has a U-shaped annulus secured to one face thereof to provide a magazine for a coiled strip of fastener blanks, the plate also having a pair of smaller plates thereon providing a guideway for the strip of fastener blanks, said guideway being located to deliver the end of the strip under the driver, and means for feeding the strip.

17. An impact tool for driving fasteners and the like comprising a driver, a spring for moving the driver in one direction, an air operated piston for moving the driver to compress the spring, a releasable connection through which the piston is made effective for moving the driver and means for operating the releasable connection for disconnecting the piston and the driver when the spring has been compressed, said releasable connection providing a non-yielding linkage between the piston and the driver when it is operating the transmit motion between the two.

18. An impact tool comprising a movable driver, a spring for propelling the driver on its working stroke, a iluid pressure operated piston for moving the driver to compress the spring, and a self-operating connection for coupling the piston and driver to move the driver to compress the spring and for releasing the piston when the spring has been compressed, said connection being movable into coupling position when the driver is at the end of its working stroke and means for moving it to a released position adjacent the limit of the spring compressing stroke, said releasable connection providing a non-yielding linkage between the piston and driver when it is operative to transmit motion between the two.

19. A tool of the class described comprising a reciprocable driver movable in one direction to deliver an impact and movable in the other direction to a retracted position, a spring for moving the driver on the impact stroke, a fluid pressure operated cylinder member and piston member, one of which is movable relative to the other, a latch mechanism on the movable member operable to engage the driver at the limit of its impact stroke and retract it against the pressure of the spring and operable to release the driver when it reaches its retracted position and providing a rigid linkage between the movable member and the driver when it is transmitting motion between them, means for operating the latch to release the driver at the end of the retracting stroke, means for operating the latch to effect its re-engagement with the driver at the end of the impact stroke of the driver, and a control valve for operating the cylinder and piston.

20. An impact tool comprising a reciprocable driver, a spring for moving the driver in one direction, a fluid pressure cylinder and piston assembly for operating the driver in the other direction and for stressing the spring, said cylinder and piston assembly having one part movable relatively to the other, means rigidly connecting the driver to the movable part of the uid pressure cylinder and piston assembly adjacent one limit of the cycle of movement of the driver to effect such movement of the driver and stress the spring, and means eiective at a. predetermined position in such movement for releasing the connection between the driver and the cylinder and piston assembly whereby the",`

driver is then operated in the reverse direction able piston assembly for moving the driver in'v the opposite direction for compressing the driver spring and for compressing a cylinder spring to return the piston, a link for connecting the piston and the driver which is movable with the piston, the connection between the driver and the link being releasable, a. spring connected with the link for eiecting the connection of the link with the driver when the driver is at the limit of its travel of operation under the driver spring, a xed cam mounted adjacent the link to operate the link to disconnect the piston and driver when the driver is at its opposite limit 14 i of travel and the driver spring is compressed, and a. valve for controlling the admission of iluid under pressure to the cylinder to operate the pisvton to compress the cylinder spring and for releasing pressure uid from the cylinder for the return movement of the piston by the spring.

JOSEPH CONRAD LANG.

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

UNITED STATES PATENTS Number Name Date 351.310 Clark Oct. 19, 1886 577,887 Stanton Mar. 2, 1897 1,828,604 HumphreysV Oct. 20, 1931 1,934,979 Hopkins Nov. 14, 1933 FOREIGN PATENTS Number Country Date 51,501 Sweden Mar. 29, 1921 Certificate of Correction Pet/ent No. 2,574,875 November 13, 1951 JOSEPH CONRAD LANG It is hereby certified that error appears in the printed specification of the above numbered patent requirmg correction as follows:

Column 8, line 49, for rest read met; column 12, line 27, for the transmit read to transmit; and that the said Letters Patent should be read as corrected above, so that the mme may conform to the record of the case in the Patent Oflice.

Signed and sealed this 5th day of February, A. D. 1952.

THOMAS F. MURPHY,

Aumont Uomms'uoner of Patenh.

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