US2501703A

US2501703A - Stapling tool

Info

Publication number: US2501703A
Application number: US16809A
Authority: US
Inventors: Walter E Wember
Original assignee: NAT AUTOSTITCH CORP
Current assignee: NAT AUTOSTITCH CORP; NATIONAL AUTOSTITCH Corp
Priority date: 1948-03-24
Filing date: 1948-03-24
Publication date: 1950-03-28
Anticipated expiration: 1967-03-28

Description

March 28, 1950 w. E. WEMBER STAPLING TOOL 3 Sheets-Sheet l Filed March 24, 1948 INVENTOR. WALTER E.WEM BER ATTORIS March 28, 1950 w. E. WEMBER STAPLING TOOL Filed March 24, 1948 5 Sheets-Sheet 2` WALTER E. WEMBER ATTORN YS March 28, 1950 w. E. wl-:MBER

STAPLING TOOL 3 Sheets-Sheet 3 Filed March 24, 1948 INVENTOR. WALTER E. WEM BER www om wwwwww ww ww www QN ww 0E www E www www w uw www. ww www www w www w ww www www .ww ww ww www ww www www Lwww www TTORNES Patented Mar. 28, V1950 UNITED STATES PATENT IOFFICE STAPLING TOOL Walter E. Wembcr, Waukegan, Ill., assignor, by

mesne assignments., to National AutostitchCorporation, a corporation `of Illinois Application March .24, 1948, Serial No. 16,809

12 Claims.

This invention relates to stapling devices or tools and particularly to stapling tools of the hammer type.

Hammer type stapling devices as heretofore manufactured have been the subject of many objections despite the convenience with which they were effective to drive staples into the work. These objections have centered in a large .measure about the difficulty and cost of manufacture and the large number of parts that were needed in such manufacture. It is, therefore, an important object of this invention to simplify the manufacture of hammer type stapling devices, and van object related to the foregoing is vto enable such stapling devices to be constructed in such a way as to involve but a very few parts that must be .made and fitted together at relatively close tolerances.

Other and related objects are to enable such hammer type stapling devices .to be Vso constructed as to avoid the necessity for accurate pivotal connection of the two major yelements of the device; to simplify the matching ofthe staple driving ram `with the guiding element therefor; to enable the ramand its guide to be mounted on a single element of the device; and to enable the staple driving action tob'e attained without marring of the surface in which the staple is driven.

In the use of stapling devices of the aforesaid character, the convenience `of loading of the staples is of course an important factor, and it is therefore another important object of this invention to simplify and facilitate the staple loading operation.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the' accompanying drawings which, by way of illustration, show a preferred embodiment yand the principles thereof and what I now consider to be the best mode in which I have contemplated applying those principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present inven tion and the purview of the appended claims.

In the drawings:

Fig. 1 is a side elevational view of a stapling device embodying the invention;

Fig. 2 is a vertical sectional view taken longitudinally of Fig. 1;

Fig. 3 isy a. vertical sectional view showi-ngv the 2 parts upon completion of a staple driving operation;

Fig. 4 is a horizontal sectional view taken along the line 4-4 of Fig. 2;

Fig. 5 is a Vfront Yor yleft hand end elevational view;

Fig.. 6 is an enlargedr vertical lsection similar to Fig. 2, taken lalong the line 6--6 .of Fig. 5 and showing an enlarged portion of the staple driving ram and the associated mechanism;

Fig. '7 is a vertical section taken along the line 'i-J of Fig. 6;

Fig.. 8 is a vertical section taken along the line B--il of Fig. 6;

Fig. 9 isa vertical section taken alongV the line 9 9 of Fig. 6;

Fig. i0 is a vplan section taken along the line t--l of Fig. 6;

Fig. l1 is a plan section taken along the line i--H of Fig. 6;

Fig.. 12 is a plan section taken along the line 1.2--12 of Fig. 6;

Figs. 13, 14 and l5 are fragmental vertical sectional views showing portions of the staple loading and advancing mechanism in diiere-nt positions.;

Figs. 16, 17 and 18 are vertical sectional views taken respectively along the lines `lili-AB, Huil and Iii-I8 of Fig. 13;

Fig. 19 is a fragmentary plan .section taken along the line l-9--l9'1of Fig. 13; and

Fig. 20 is a vertical section taken along the line 2li-2B of Fig. 14.

For purposes of disclosure the invention is herein illustrated as embodied in a hammer type stapling device or tool which comprisesa pair of elongated channel members 32 and 36 made from `sheet metal stampings and arranged with the lower channel 32 disposed in a partially housed relation within the upper channel 34, and theseY channels 3.2 and 34 are pivoted together at their right hand or .rear ends by pivot screws 35 so that in a staple driving operation the forward or left. hand end of the upper channel 34 may.

move downwardly with respect to the channel 3'2 from the position of Fig. 2 tothe position 'of Fig.. 3.v

The right hander rear portion of the upper :cham nel 34A constitutes the handle portion or the device or tool, and while grasping this handle the tool is swung downwardly through a hammer'- like driving stroke so that the lower Vleft hand face. of the-lower channel 32 is brought intocontact with the surface-of the work, such as a pair of .superposed Work pieces W--l and W-2. which are to be connected together by a staple The staples S as herein shown are of the type wherein the upper cross barI has two legs of equal length extended downwardly therefrom, but it will be understood that conventional staples having legs of unequal length may be employed where this is desirable.

The lower channel member 312 is utilized under the present invention to carry the staple holding and feeding means F and the staple driving ram mechanism R, such ram mechanism being disposed on channel 32 adjacent to the left hand or forward end as shown in Figs. 1 to 3 of the drawings. The other or upper channel member 34 serves primarily as a housing member and as a handle, since the right hand or rear end of this upper channel 34 is grasped by the user when the tool is to be utilized rto drive a'staple into the work.

The upper channel 34 is formed so as to be of substantially uniform cross section throughout most of its length, but at its forward or left hand end as shown in Figs. 1 to 3 of the drawings, the channel 34 has an upward extension 34E whereby operative clearance is provided within the channel for elements of the ram mechanism R (Fig. 3), as will hereinafter be described. The upper channel 34 has a top wall 34T, a forward end wall 34F and a rear end wall 34R, and at the opposite edges of the top wall 34T, side walls 34S are extended downwardly and are connected to the

end walls

34F and 34R. Near the rear wall 34R, a bottom wall 34B is provided for a limited distance between the lower edges of the side walls 34S, and in the plane of the bottom wall 34B, each of the side walls 34S has an inwardly extended guide flange 34G which, as will be evident in Fig. 4 of the drawings, extends in a forward or left hand direction throughout -a substantial portion of the length of the channel member 34. However, at a point spaced a short distance from the left hand or forward end of the member 34, the flanges B4G are terminated as at 34C so as to afford a clearance opening in this area that is of the full width of the channel and this clearance opening, and the flanges B4G, are important, as will hereinafter be described, in permitting ready assembly of the parts as well as in attaining a guiding action between the parts after such assembly.

The lower channel 32 is formed so las to face upwardly and this channel has, in the left hand or forward portion thereof, a true channel form, while at the right hand end portion, the web or cross member of the channel is cut away to afford clearance to facilitate loading of staples S into the staple holding and feeding mechanism, as will hereinafter be described. In this portion it will also be noted that the vertical width of the side walls 32S has been reduced so that the handle portion of the channel 34 may be grasped without contact with the side walls 32S. Thus, the lower channel 32, in the forward or left hand portion thereof, has a bottom wall 32B and upstanding side walls 32S, and these side walls are so spaced that they have what may be termed a loose sliding fit against and between the two guide flanges 34G of the upper channel 34. The bottom channel wall 32B terminates at its rear end at 32T substantially midway between the ends of the member 32, and from the edge 32T and substantially to the forward or left hand end of the channel 32, a staple supporting and guiding means is provided within the channel and on top of the bottom wall 32B. This guiding means may be attained in a simple manner through the mounting of a channel member 38 within the channel 32, and with the cross wall or web of the channel 38 secured as by means of screws 3B disposed within the channel 38 and extended through the bottom wall or web thereof into the bottom wall 32B of the channel 32. The side walls of the channel 38 are spaced from the side walls 32S of the channel 32 so that the legs of the staples S may ride between the channel 33 and the walls 32S, and when the staples S are in this position, the cross members of the staples extend across the open top of the channel 38 and ride upon the upper edges of these side walls, as shown in Fig. 9 of the drawings. When the staples S are in this position, they are held downwardly with respect to the channel 38 by guide plates 4B that are secured as by welding to the inner faces of the side walls 32S.

The staples S that are thus supported and guided on the channel 38 are normally urged in a forward or left hand direction, Fig. 2, by a staple-advancing follower mechanism that includes a channel shaped follower 4| that rides A on the channel 38 and within the space traversed by the staples S. The follower 4| has the web portion thereof arranged to ride on the upper edges of the side walls of the channel 38, and lianges 4|F on the follower 4| ride in the spaces I between the side walls 32S and the channel 38.

On the web of the follower 4| a bracket 42 is secured, and an elongated actuating rod 43 is slidably extended through the bracket 42 longitudinally of the channel 32. This rod 43 extends E. rearwardly or to the right through an upwardly faced spacing channel 45 that is disposed between head 43H formed thereon so that by withdrawing the rod 43 in a rearward or right hand direction the follower 4| may be withdrawn from its position within the staple guideway. This operation is facilitated through the provision of a knurled head 48 that is screw-threaded onto the rear or right hand end of the rod 43. To enable this to be done, a clearance opening 34C is provided in the rear wall 34R of the upper channel. The head 48 has a flange 48F formed thereon so as to be disposed within the channel 34, and a spring latch 49 secured to the web of the channel 45 is arranged to engage this flange to latch the rod in its forward or left hand position as shown in Fig. 2.

When the tool is to be loaded with staples, the handle 48 of the rod 43 is grasped and the follower 4| is withdrawn, and when the follower has been completely moved out of the staple guiding channel or passage the rod 43 is tilted so as to move the follower 4| upwardly into a clearance space 50 formed between the plates 4D and the channel 45, such clearance space being shown in Fig. 2, and the location of the follower 4| in such clearance space being illustrated in Fig. 14 of the drawings. With respect to this positioning of the follower 4| it should be observed that the lower face of the web of the channel 45 is disposed substantially in the plane of the lower edges of the guide plates 4U, and the lower edges of the flanges 4|F of the follower are disposed oelrfeislieh-tf distance above` thislplerie; ther .hief eolireeaare i .i .ci groeps-,orf 1mi-te oonrentona es hionfm. read. y; loaded eta the tool. merely leef:-Y plao1...g;, the. 1.11. .rtedipoeition ton oitliewele,

Imelr 4.5;'. These Staples-may,

werdlt-orfto, th

ureethefster the guide n.

.. ,M ,f W 5.1.

eairwardy exten ons. of the lower chan 32 an the.u o

webnortion reihe-Spesen member; 45 is located. above-f medewer-edges.. ofrthe rearward. eXtensonsof-f thelower member 32d as*clearly:fllustratednin-EieSl 2.. and 1.6; ofthe: drawings .andwhen the tool is.inrertedzzforfloedf f inapurposes1the--welo; of.` the Spacer meinber- 45,; aclantedfto., sunioort-- areroup. ci staples: in: 130:-, Sition for.A` feeding; onto; the Stanley Supporting; member-which,sfmounted upon-.thefbottomvo-fg therlowerfohannel member-B2` at thefffront por.-

tion. thereof:`

The desirerif pivotal connection.=.betweenf,the: Channels, 3.121',- anda; 351:, and, atthe yright hand or; rear enel:vv thereoit is:v afforded .by meanethat-are-z best hownrin Eiger-1, 1 7 and: 1.9,.'y Thus,.,itwi11. be. eridenti thatthe. eide., Walls.: 3.415-v are recessed.. atfv 55ste receive theV h eadsdof;y the frnountingfpivot; Studs orfsorews 3.5:- Whoh-- here shouldered; porey tiene;extendineethroueh pirotorenines provided, ettliefbottoms, of-.thereoesses 5.5., andtheithreaded, portions of the pivot screws or studs-j; 355;.. arey threaded.; into. they Side walls. 32S/ 2- and. the Side anees; or thepeoine. ebennelff It-,Wilifbe v.olo- Servedfthetfet: thefeortione Surrounding Vthe pir-- ots-A1. 3'5, tljiegv side walls 32S are,somewhaty thick-v eedf a-Sfet; 32T., Feeeendr 1.9, and: therefo.refI whensthegdevice--isto be assembled; thi-sgthicls eneii, portion isinsertediinto the Vo-leararioe.Sioeoe forwardly/oi the endsrMC-ojf the iiangesv 346;,- and A thelowerfobennel 3,2` is.fthenmovedlloneitildnallr interne,- Qhan-nei aauntii .therthicrened perdons., 32,'11.L are disposed in,4 the-proper; position j for'fin.- sertionzof the; pivot ,screwsI 35p Thepresent invention aiordsI anhextrernelyy simpleway vin which to afford accuratecooperari. tionQoi theieleinents of the ram.meohanisni- R,k audio acoomplishneths-,the rammeohanism, isproydefl vwith. a relatively, simple.. but., dei, curately forrried,l casting or machined-:element-in theuform of` ayer-tical bar-60 which actsas aguid;

ingelement. The. bael) isdisposed betweenthe forward edges off. th'e.. side.v wal-ls 32.S, and this ban 60;.-is securedin positionploy a pluralityfof rivets.,

62.that extend transversely;thiough theside walls.j V

32,S andthebar Bil, These rivets,62..a ls.o serve.; to secure a pair of angle members-.64.. on. opposite. outer sides oftheitwo side wa1ls.3 2S, and these.

ellisieangies have flanges, sur` that ride :with:

relatively loose slidingaction againstthe inner faces ofthe slidepwalls 34S, to serveas a lateral guiding means for the front portion of the chang. nel/34 withvrespect to thefrontporton of the eliarinel?. Initsrear, face, the, `vertical...guideJ,-. bar.: 6.0, besser Semroiroulelt ellide.groovel sus, formedithereia. and .ia staple-driving?.plunger E?,V

isv arranged. to ride' vertically;- alonef this-f smicirqular; guideway. 60G.. The; DlungerfxB has therL lower portion thereoicutgawayasati., and-.aflatl driving platell is secured asby welding; against: .l this. out ,await portionoff` the plungenR so.` tnatr this driving plate;V 'Hl will ride. againstf; ther rear# wardly flat; faces; ESR of thebloek or baril); on;l the oppositesideof theguide groove..lzr.'` The@ driving plateV 'HlA is` thus disposed in;v a., ver-tic 11.,V guideway defined at the front by the-.svurfaces;i BDR', at the rear by the forward ends; of@ the platesv 40 andA the,Y forward end surfaces' of, ther: channel 3.8, and at itsl side edges byv the,si.d s walls 32S,ras will beevident in- Figsllandf 1 end, and below this, head` an expansive.; coil:4 spring 14, surrounds the cylindrical; portion of;y the plunger P. The lower endr of this spring;:f[4;-v acts onthe upper end of. the.guide.,bar :60,andz. on .aretaining and guiding, web 18 that'is formed-1f, by extensions from the two guiding.. platesflll; The web '18 cooperates with the guide channel 60G to aord a full circular bearing for, the lindrical upper portion, of the plunger It willv be observed (Fig. .6.) struck lug 341i is alordedinth the-upper channel 3.4, 68H on the bar 6G eng upward movement. of theforward end, of the L channel 34 that is causedby thespringlll., In.. theassembly of the tool', the channel'zjismoyed. rearwardly in the channel 34. in,.an amountsuffl. cient to let the hook EDI-I move upwardli7 pastthei: lug-34L-, andl is then returnedto theileft or fronte-v wardly to align the pivot elements of 'thestrucrv tures. When the plunger P is-inV the upper or fully retracted position that is determinedibyq-the engagement-ofthelug 4L withthevhlook jlillIvIgtljieA lower end offthe `Adriving plate 'lll' is disposedl just... above the plane of the upper surfaces?, oflthel staples'l iny the staple guiding channel, ,as will be.; evident in Figs. 2 and 6. Thus, thestaple..adir` vancing A,rneansrwill urge the leading Staple s into1 a positionimmediatelylbeneath;the staple driving.,r pla-te 1li; andy inthis position the staplewillber. 'disposedV over/the lower discharge openingitha afforded-between the forward'end ede'feofthe bot tomfwall 32E-andthe reargiace StR; of,t1'i`e,glliole'l baly': The 4lower portion ofthe plungerQP-isf, preferablycutaway as atfillcgsovthat whentherV plunger is fully projected, only. the rectangulan; lower end ofthe plate 'illwillbe exposed,V

Itwill be observedthat the rounded.upper.isurif:A face of 'the headi l2. of, ,the :plunger P. is.- engagedl. with a relatively thick! and. hardened bearings plate 80.. that v is` xed as by, welding. on the innen-z surface of. the topv of theextensioru @Eoithefupff.

e front wall MFof ,and ahook shaped. member;y

Per, channeh.; andin the, use l of, the y present ,.tool1,g. the actionoiltlieelements. is such .that.'wlfien.they lower surface of. tlielforgward end of the channelZqf.

is brought into Contact with .tineworlrvv.atithe-gy end of a harnrrieiflilrerstroke, theplungersPzwi-ll be driven downwardly soaasto impart thlrdes`` de drivingy force to the leading:staples:aslwillbeievifs. dent from Ya comparisonoifFigsiZ andf3.foiyitlief4 drawings. In this connectionit.willibeiobser/eda that the V forward lowes corner4 .offthegbottom1 walls` 32MB` and ofV the .giviidingfbar 59.; as .well as lthe sides walls SZSfand theangles @filare somewhatzbeveled' androunded as., aty ,82; Eig. 1, therebyy totaio greater latitude in the. zangleat, which` thatool .lnayf` beibrought intolcooperation:withtheworle Sima-- i Theplunger P has ahead. 12 formedat its upper#- that; an'. inwardly:

ages the 1ug.,3,4L.to limit-their I It has been found in practice that the present tool operates without any objectionable tendency to mark or scar work at the point where the tool strikes the work, and while the Work must, of course, absorb some of the inertia of the parts, it is the applicants` present theory that the avoidance of denting or marking of the work is due in a large measure to the novel cooperation of the elements of the ram mechanism whereby all binding is avoided.

From the foregoing it will be apparent that the present invention greatly simplifies the manufacture of hammer type stapling devices, and that it enables these stapling devices to be constructed in such a way as to involve but very few parts that may be manufactured and assembled in a simple and economical manner. It will also be evident that the present invention materially simplifies the loading of staples into the stapling tool, and that the parts of the staple holding and loading mechanism are of a simple character.

It will also be apparent that the present invention enables hammer type stapling devices to be used in many situations where prior devices of this type could not be used, since the present device avoids an objectionable marking or denting of the work surface adjacent to the point where the staple is driven.

y Thus, while I have illustrated and described the preferred embodiment of my invention, it is to be understood that this is capable of variation and modidcation and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. In a stapling tool of the hammer type, a pair of elongated channel members having front and rear ends and disposed in a reversed relation and one within the other, means pivoting said channels together adjacent said rear ends thereof, the inner one of said channels at said front end thereof havingr vertical side walls and a bottom wall formed so that said side walls extend longitudinally beyond the front end of said bottom wall, a vertically extended guide bar secured between said extended portions of said side walls and having a at guide surface facing toward said rear end of said inner channel, said guide bar having a vertical guide groove formed therein, a plunger mounted for vertical movement in said guide groove, spring means urging said plunger upwardly, a driving plate secured on a lower portion of said plunger and riding against said guide surface, staple feeding means for feeding staples into position against said guide surface and beneath said driving plate, and a bearing plate within the upper one of said channels and bearing against the upper end of said plunger to apply driving force to said plunger in a harnmer-like driving stroke of said tool.

2. In a stapling tool of the hammer type, a pair of elongated channel members having front and rear ends and disposed in a reversed relation and one within the other, means pivoting said channels together adjacent the rear ends thereof, the inner one of said channels at the front end thereof having vertical side walls and a bottom wall formed so that said side walls extend longitudinally beyond the forward end of said bottom wall, a vertically extended guide bar secured between said extended portions of said side walls and having a flat guide surface facing toward said rear end of said inner channel, said guide bar having a vertical guide groove formed therein, a plunger mounted for vertical movement in said guide groove, spring means urging said plunger upwardly,v a driving plate secured on a lower portion of said plunger and having one face riding against said guide surface, staple guiding and feeding means for feeding staples into position against said guide surface and beneath said driving plate, said last mentioned means including stationary guiding elements opposing said guide surface and engaging the opposite face of said driving plate, and means within the upper one of said channels affording a bearing surface opposing the upper end of said plunger to apply driving force to said plunger in a hammer-like driving stroke of said tool.

3. In a stapling tool of the hammer type, an elongated channel member having front and rear ends, said channel at the forward end thereof having vertical side walls and a bottom Wall formed so that said side walls extend longitudinally beyond the forward end of said bottom wall, a vertically extended guide bar secured between said extended portions of said side walls and having a fiat guide surface facing toward r the rear end of said inner channel, said guide bar having a vertical guide groove formed therein, a plunger mounted for vertical movement in said guide groove, spring means urging said plunger upwardly, a driving plate secured on a lower portion of said plunger and riding against said guide surface, staple feeding means disposed within said channel for feeding staples into position against said guide surface and beneath said driving plate, and an elongated housing member substantially enclosing said channel and pivoted thereto at the rear end thereof, said housing having means thereon disposed opposite the forward end of said channel and bearing against the upper end of said plunger to apply driving force to said plunger in a hammer-like driving stroke of said tool.

4. In a stapling tool of the hammer type, an enlongated channel member having front and rear ends, said channel at the front end thereof having vertical side walls and a bottom wall formed so that said side walls extend longitudinally beyond the front end of said bottom wall, a vertically extended guide bar secured between said extended portions of said side walls and having a flat guide surface facing toward the rear end of said inner channel, said guide bar having 'a vertical guide groove formed in said flat guide Ysurface thereof, a plunger mounted for vertical movement in said guide groove, springs means acting between said guide bar and said plunger to urge said plunger upwardly, a driving plate secured on a lower portion of said plunger and having one face thereof riding against said guide surface, staple guiding means for guiding staples into position against said guide surface and beneath said driving plate, said guiding means including guide elements having end faces dening guide surfaces for bearing against the opposite face of said driving plate, and a housing pivoted to said channel near the rear end thereof and affording a handle portion at such rear end, said housing having means disposed above and opposite said plunger and bearing against the upper end of said plunger to apply driving force to said plunger in a hammer-like driving stroke of said tool.

5. In a hammer type stapling tool, an elongated lower channel member affording front and rear ends and having side walls and a bottom wall ex.. tending from substantially midway between the ends of said side walls toa discharge point relatively close to but spaced from the forward ends ofVV said side walls, staple-supporting and guiding 'means mounted on said bottom wall within said channel and extending to said discharge point, spacer means xed between said side walls and extending for a substantial distance rearwardly of the staple guiding means in position to support and guide staples into the rear end of said guiding means, spring means operable to urge staples along said guiding means toward said discharge point, staple driving means comprising a driving plunger and a guide block therefor, said guide block being rigidly secured between said side walls forwardly of-said` discharge point, a spring acting between said block 'and said plunger for retracting said plunger in an upward direction, a housing surrounding a substantial portion of said lower channel and pivoted theretol at said rear end, said housing having means thereon bearing against the upper end of said plunger, and means for limiting pivotal movement of said housing-by the retracting spring of said plunger.

6. In a hammer type stapling tool, an elongated lower channel member affording front and rear ends and having side walls and a'bottom wall ex*- tending from substantially midway between the ends of saidside Walls to a discharge point relatively close to but spaced from the forward ends of said side walls,'a staple-supporting channel having the web thereof secured on said bottom wall within said channel so that said staple supporting channel extends to said discharge point, the side walls of saidV channels being spaced from each other to denne spaces in which the legs of staples may depend when the cross members of such staples rest on the upper edges of the side walls of said supporting channel, guide plates secured to the inner surfaces of the side walls ofsaid main channel to hold staples downwardly in position on said supporting channel, spacer means xed between said side walls and extending for a substantial distance rearwardly of the staple supporting means in position to support and guide staples ontol the rear end of said supporting means, spring means operable to urge staples along said supporting means toward said discharge point, staple driving means comprising a driving plunger and a guide block therefor, said guide block being rigidly secured between said side walls forwardly of said discharge point, a spring acting between said block and said plunger for retracting said plunger in an upward direction, a housing surrounding a substantial portion of said lower channel and pivoted thereto at said rear end, means on said housing bearing on the upper end of said plunger, and means for limiting pivotal movement of said housing by the retracting spring of said plunger.

'7. In a hammer type stapling tool, an elongated lower member affording front and rear ends and having spaced side walls and a bottom wall extending forwardly to a discharge point relatively close to but spaced from the forward ends of said side walls, staple-supporting and guiding means mounted on said bottom wall between said side walls and extending to said discharge point, spring means operable to urge staples along said guiding means toward said discharge point, staple driving means comprising a driving plunger and a guide block therefor, said guide block being rigidly secured between said side walls forwardly of said discharge point, a spring acting between said block and said 10 plunger for retracting said plunger in an upward direction, a housing'surrounding a substantial portion ofsaid lower channel and'pivoted thereto at said rearend, and means for limiting pivotal movement ofv said housing by the retracting spring of saidplunger.

8.- In a-hammer type stapling tool, an elongated lower member arording front and rear ends and having spaced side walls and a bottom wall extending forwardly to a discharge point relatively close to but spaced from the forward ends `of'said side walls, staple-supporting and guiding'means mounted on said. bottom wall be'- tween said side walls and extending to said discharge peint, spring lmeans operable to urge staples along said` guiding means toward said discharge point, staple driving means comprising a driving plunger of cylindrical form in its upper portion andv of semi-cylindrical form in. its lower portion and having a flut driving plate Secured to the nat face of said semi-cylindrical portion, a guide block secured rigidly between said vside walls forwardlyv of said discharge point and having a semi-cylindrical guide groove formed vertically inthe rear face thereof, said semi-cylindrical portion of said plunger being guided in said groove with said plate bearing against said dat surface of said block, a spring acting between said block and said plunger for retract.- ing said plunger in an upward direction, a housing surrounding a substantial portion of said lower channel and pivoted thereto at said rear end, and means for limiting pivotal movement of said housing by the retracting spring of said plunger.

9. In a hammer type stapling tool, an elongated upper channel formed from sheet metal to afford a top wall, front and rear end walls, downwardly extended side walls connectingsaid top and end walls, and guide flanges extended inwardly from the lower edges of said'side walls throughout a substantial portion of the length thereof to define spaced parallel guiding edges, an elongated lower channel formed from sheet metal to afford a bottom wall having front and rear edges, upstanding side walls extended along opposite side edges of said bottom wall and having forward extensions beyond said forward edge and rearward extensions of substantial length extending beyond said rear edge, staple holding and guiding means mounted within said lower channel in part on said bottom wall and in part on said upstanding Side walls, a driving ram, means rigidly secured between said forward extensions for guiding said ram vertically past the forward end of said staple holding and guiding means, spring means for retracting said ram, and means pivoting said rearward extensions to the side walls of said upper channel to dispose said lower channel pivotally on and in part within said upper channel with said upstanding side walls in sliding guided contact with said guide flanges of said upper channel..

10. In a hammer type stapling tool, an elongated upper channel formed from sheet metal to afford a top wall, front and rear end walls, side walls connecting said top and end walls, and guide iianges extended inwardly from the lower edges of said side walls throughout a substantial portion of the length thereof to deiine spaced parallel guiding edges, an elongated lower channel formed from sheet metal to aiford a bottom wall having front and rear edges, upstanding side walls extended along opposite side edges of said bottom wall and having forward extensions beyond said forward edge and rearward extensions of substantial length extending beyond said rear edge, staple holding and guiding means mounted within said lower channel in part on said bottom wall and in part on said upstanding side walls, a driving ram, means rigidly secured between said forward extensions for guiding said ram vertically past the forward end of said staple holding and guiding means, spring means for retracting said ram, spacer means xed between said rearward extensions and affording a surface for supporting groups of staples in alignment with said holding and guiding means when the tool is inverted in the course of a loading operation, and means pivoting said rearward extensions to the side walls of said upper channel to dispose said lower channel pivotally on and in partwithin said upper channel with said upstanding side walls in sliding guided contact with said guide flanges of said upper channel.

l1. In a stapling tool of the hammer type, upper and lower elongated channel members disposed 1n reverse relation and one within the other, means for pivoting said channel members together adjacent the re'ar ends thereof, the lower channel member having a bottom wall and Vertical side walls extending beyond the front end of the bottom wall, a vertically extended guide bar secured between said extended portions of said side walls and having a ilat guide surface facing towards the rear end of said lower channel member, said guide bar having a vertical guide groove formed therein, a plunger mounted for vertical movement in said guide groove, spring means urging said plunger upwardiy, a driving plate extending from a lower portion of said plunger and riding against said guide surface, and staple feeding means for feeding staples into position against said guide surface and beneath the driving plate, the upper member being arranged to apply driving force to said plunger in a hammer-like driving stroke of said tool.

12. In a stapling tool of the hammer type, upper and lower elongated channel members disposed in reverse relation and one within the other, means for pivoting said channel members together adjacent the rear ends thereof, the lower channel member having a bottom wall and vertical side walls extending beyond the front end of the bottom wall, a vertically extended guide bar secured between said extended portions of said side walls and having a flat guide surface facing towards the rear end of said lower channel member, said guide bar having a vertical guide groove formed therein and provided at the front with a hook-shaped member, a plunger mounted for vertical movement in said guide groove, spring means urging said plunger and upper channel member upwardly, said upper channel member being provided at kthe front end with a lug arranged to be engaged by said hookshaped member for limiting the upward movement of the upper channel member, a driving plate extending from a lower portion of said plunger and riding against said guide surface, and staple feeding means for feeding staples into position against said guide surface and beneath the driving plate, the upper member being arranged to apply driving force to said plunger in a hammer-like driving stroke of said tool.

VALTER E. WEMBER..

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

UNITED STATES PATENTS Number Name Date 1,687,871 Maynard Oct. 16, 1928 2,268,102 Attula Dec. 30, 1941 2,311,412 Pankonin Feb. 16, 1943 2,325,341 Polzer l July 27, 1943 2,342,818 Polzer Feb. 29, 1944