US2239935A

US2239935A - Stapling mechanism

Info

Publication number: US2239935A
Application number: US236178A
Authority: US
Inventors: Fred A Scherman
Original assignee: AJAX TOOL AND DIE Co
Current assignee: AJAX TOOL AND DIE Co
Priority date: 1938-10-21
Filing date: 1938-10-21
Publication date: 1941-04-29
Anticipated expiration: 1958-04-29

Description

April 29, 1941. F. A. scHl-:RMAN

sTAPLING MECHANISM Filed oet. 21. 1958 2 Sheets-Sheet l ZI@ 77) l@ 5 INVENTOR.

ATTORNEY April 29, 1941. F, A, SCHERMAN u 2,239,935

STAPLING MECHANISM Fil'ed Oct. 21, 192,58 2 Sheets-Sheet 2 l n INVENTOR,

52 FEED 4. .5a/wwf MM MMM f ATTORNEY.;

`parts and reduceassembly costs.

Patented Apr. 29, 1941 STAPLING MECHANISM FredA. Scherman, Racine,\Wis.,assignor `towltgiax Tool-and Die Company, Racine,-Wis.,'a corporation of Wisconsin Application: october 21, lsasyseriai Normans 4 Claims.

'This invention relates to improvements in staplingmechanisrn,

It is the primary object of the invention to provide a lnovel and simplified type of lstapler kwhich-can readily be manufactured of simple stampings, requiring `few parts, providing substantially complete enclosure for the operating mechanism,.and avoiding any possibility of stoppage.

The construction is such that the detailed organization of parts is highly significant tothe Ygeneralobjectives as above stated, `and raccordingly. further objects of the .invention will be found in the followingzdisclosure.

In the drawings:

Fig, 1 is aperspectve View of the assembled apparatus.

Fig. 2 is a view of the apparatus in longitudinal section.

Fig. 3 is a'view taken in transverse section on the line 3-3 of Fig. 2.

Fig. 4 is a view taken in ltransverse section on the line 4-4 of Fig. 2.

Fig, 5 is a fragmentarybottom plan view of the stapling head as viewed on the line5-5 of Fig. 2.

Fig. 6 is a View showing `in perspective the several component parts lof the device, with the exception of one of the casing elements, as such partsiappear when separated preparatory =to` assembly.

'Fig- 7 is a detail view in perspective showing the staple slide follower.

` Like parts are identified by the same reference characters throughout the several views.

As the description proceeds, attention should r be given to theV manner in which the several stampings comprising the frame and casing of the stapler `are each designed` to perform a variety of functions so as to minimize the number of The base 8 comprises a shallow box-like stamping marginally provided at 9 with a flangewhich is preferably engaged by the complementary `flange of a shoe I of rubber or the like.

A shallow recess at 'I I assists in positioning the clinching die I2 which is of generally conventional form. Upstanding ears I formed integrally from the material of the base serve to support the pi-ntle bolt I5 upon which the stapling head oscillates on to the thrust of ya leaf spring I'I of the cantilever type which is provided at I8 `with an aperture engaged by a tongue I9 formed integrally from the base. The tongue I9 lprojects into an opening in the basefwhlch receives the-end of thev spring. The spring ful' crumsacross the forward edge 2I of the portion `of v'thebaseadjacentopen-ing 20. 4

The centralstructural member ofthe oscillating-stapling head comprises lanlinverted channel havingl sides'provided with shouldered offsets at26 and' terminatingrin marginal flanges 2l. The ilanges 21 Aserve as spacers'

forthestamped sides

28 and 29 which have downwardly-extending-ears 30 apertured at 300 to receive the pintle it, jwhereby the staplinghead is tiltably mounted. vThe'sides AZtand 29 "(Figures 2 and 6) and interveningchannel 25 areconnected by vrivets 3|, '32 ,and 33. At a levelf above the channel 25 the sides'are also connected by a bridge Vmember 35 `which has 'integral tonguesl36'extended through suitableapertures 3E0'in the sidesand there upset vorfrivetedto connect the: sides together. Bridge `-inernber535 is, like the base '8,'provided with an anchorage ior a cantileverspring which is shown at'SI. 'This' spring fulcrums onl the edge '38 of thebridgemember adjacent'an opening 39 therein into which the tongue 40 projects to engage the-'opening 4I inthe endof the spring, Spring 31 supports the stapling plunger as will hereinafter be described. It isa stronger spring than Spring I1.

-Extending longitudinally of the two

sides

28 and 29 are inwardly turned`flanges'42 and'43 respectively, which overliethe'top of the inverted channel 25 in spaced relation thereto. The sides of the channel, above shoulders 26, are Ialso `in spaced relation to thesides of the members 28 Iand `29, There is thus providedaboutthe upper side `and top portions of channe1-25 aguide slot of such dimensions as' tobe adapted toreceive the preformed stick of staplesas best shown in Fig. 3. Also-receivable'into the Iguide slotis the follower 46 which has a crosssectionf'sirnilar to that of the staples, and has'an upstanding lug 4l traveling betweenthemargins of the inwardly directedfflanges 42 andl43. The ears 48 andl 49 on Vthe follower 46 are 'engaged lby a rod 50 encircled by alight compression spr-ing 5I andprovidedat itsend with a hook 52 releasably engageable vinthe opening 53 of the channel as shown in Fig. 2. The' follower is free to slide on `rodll to transmit to the staples V45 the pressure ofthe springfSI which rimpels the staples succesi sively to the driveslot.

The side `

frame members

28 and 29 of .the Vstapling head yare connected at theirl forward ends by a front member 54 whichv is riveted `theretoiby` rivets 3|, 55 and 56 (see Fig. 2 and Fig..l 5). The front wall '51 of thev member 54 tightly :abuts the frontmargins of the side frame channel 25 (Figs. 2 and 5).

elements

28 and 29 but is spaced forwardly from the end of channel 25 to provide a feed throat at 60 (Fig. 2 and Fig. 5) through which successive staples are forced by the driving slide hereinafter to be described.

The front wall '5l is centrally notched at 6i as shown in Fig. 1, Fig. 2 and Fig. 4, to receive spring B2 which is secured to the outer surface of wall 51 and extends first forwardly therefrom and then back upon itself through the slot 6| to a position normally underlying the top of ually forced forwardly out of the way by a staple impelled downwardly through the guideway 60, but the staple does not clear the spring until it is substantially fully engaged with the work. If the pressure on the staple is released before the staple is engaged with the work, the s-taple will be retracted by spring 62 with the feed slide, thereby preventing clogging of the guideway.

The feed Aslide or driver 63 is vertically reciprocable in the guideway 6U Vand is connected with a manually operable` spring supported -plunger 64 for its actuation. A rivet 65 (Fig. 2), serves as one means of connection of the slide to the plunger. The front wall 5l of the front plate 54 is channeled at 66 to accommodate the movement of the rivet.

The, plunger may conveniently be made from a single stamping folded into a hollow oblong form as shown in Fig. 2 and Fig. 6. Its sides are slotted at 61 to receive the transverse bolt 610 upon which the lower end of the plunger is guided. The free margins of the stamping constituting plunger 64 are provided with corresponding upwardly extending lugsat 68, both of which are together received through the stamped opening 69 in the pressure plate T0. A wider opening 1I near the forward margin of plate 'l0 receives the lug 'I2 of the plunger stamping 64, and also receives the lug 13 at the upper end of the drive slide 63. The lug 12 on the plunger stamping is slight-ly longer than lug 'i3 on the driver slide to enable it to be upset or riveted over the surface of plate lll, the same procedure being followed with lug 68. The upsetting of lug 'l2 wedges lug 13 of the driver` slide rigidly into unitary connection with the pressure plate l0. The lug of the driver slide is notv upset because this slide is usually made of hard material.

An opening at 'Min the back of the tubular plunger 6d receives the end of the spring 3l whereby the plunger is normally supported in the raised position in which it is illustrated in the drawings. ered with a rubber cap 'I5 applied in the same manner that the rubber shoe l is applied to the base of the instrument.

Theentire tilting stapling head is preferably encased in a two part housing which tilts therewith and is readily removable. The housing elements 'i6 and 'i1 each comprise hollow box-like stampings having their side flanges in marginal abutment on the vertical longitudinal center line of the apparatus. The bolt 610 which guides plunger 64 extends through the sides of this case to connect such sides lat the forward end of the apparatus. Their only other means of connection is the pivot bolt I upon which the stapling head pivots. This also extends through the case and serves to connect the parts 18 and 1l thereof together.

There are only three exposed openings through 4the case. The spring 62 which prevents clogging projects through a notch at 18 in the front end This spring is grad- Pressure plate 'l0 is preferably covof the case. The rod 5l] which serves as a guide for the compression spring of the staple follower projects through an opening at 'i9 in the rear end of the case. The plunger 64 projects upwardly through an opening at the top of the case `and is guided by the case for vertical reciprocation. Thus the case performs a mechanical function of the device as well as concealing the mechanism and thereby beautifying the entire assembly.

The staples used are inserted and fed through the feed slot under the pressure of spring 5| in much the usual manner. When the workfis insented beneath the stapling head on the clinching anvil I2 the pad 15 on the pressure plate 10 is struck to impel the driving slide 63 downwardly, thus forcing the foremost staple down through the drive slot 60 into engagement with the work. Since the spring l1 is weaker than spring 3l, the initial pressure on the plunger will first tilt the staplng head into engagement with the work, following which the driving action will occur as described.

I am aware that there are other stapling devices which are made partially or principally of stampings, but the present device can be made more cheaply than any other with which I am familiar because of the way in which the stampings are formed and the manner in which they coact.

I claim:

l. In a device of 'the character described, the combination with 1a base provided with an aperture and having a tongue projecting into the aperture, of a leaf spring fulcrumed across the top of the base adjacent the aperture and remote from the tongue and -provided with an opening in which said tongue is engaged for releasably securing said spring against displacement, a stapling -head pivot/ally `connected with the base for limited movement with respect thereto and provided with a part engaged by the end of said spring remote from said base, the limit of movement of said head andthe point of engagement of said spring therewith being such as to urge said head toward one extreme of its movement and to maintain said spring under slight initial deflection at such extreme.

2. In a device of the character described, a stapling head :comprising side plates and an inverted channel connecting said side plates and provided at its top with a transverse web having an openingtherewithin, said channel having marginal anges connected with the side plates and offset -to provide a staple guideway vbetween said plates and web, a follower movable in the guideway, a guide rod upon which said follower is slidable, said rod beingdisposed between said plates and above said web, spring means on said rod, rand a reversely curved hook at the end of said rod extending about said web and engaged with the opening therein from beneath for maintaining said rod in position and sustaining the compression of said spring.

3. In a device of the character described, a stapler head frame comprising a pair of side plates, a plunger, means guiding said plunger for reciprocation between said plates, means connecting said plates comprising a spring anchorage, and a leaf spring engaged in said anchorage and having an end in supporting relation to said plunger.

4. In a device of theV character described, a stapling head comprising a pair of side plates having apertures, a connecting web having tongues extending through said iapertures and riveted upon said plates to maintain their assembly, said Web having a `central `opening and a nger projecting into said opening, a plunger reciprocable between said plates, means for guiding said plunger for recipr-ocation, ya leaf spring having a free end engaged With said plunger .and provided with an opening in Which said nger is engaged, said spring being fulfcrumed over the edge of said web adjacent the opening therein, whereby said spring has a `cantilever' mounting yon said frame.

FRED A. SCHERMAN.