US2463579A - Staple hammer - Google Patents

Description

March 8, W49 w. J. VAIL STAPLE HAMMER Filed May 12, 1947 1NVENTOR. walter J; ma

Patented Mar. 8, 1949 STAPLE HAMMER Walter J. Vail, Chicago, Ill., assgnor to Vail Manufacturing Company, Chicago, Ill., a corporation of Illinois Application May 12, 1947, Serial No. 747,419

(Cl. 1-49l 8 Claims.

This invention relates to a manual implement for feeding and driving staples, tacks, or other fasteners, usually in strip form, and is adapted for operation in the manner of a hammer to drive the staples, tacks, or the like, into wood or other penetrable material.

It is a primary object of this invention to devise, for the purpose mentioned, an implement which is inexpensive, simple, sturdy in construction, and dependable in operation. In accomplishing these ends I utilize a minimum of working parts, all of which are of rugged design. The construction attains lightness in weight, and is one that will afford years of hard service.

According to my invention, a sturdy linkage system connects a vertically reciprocable driver with a pivoted work striker, this linkage comprising a channelled arm enclosing a channelled link within which is contained a wire spring which exerts an expansive force tending to restore the parts to their normal position of rest. This work striker itself is of duplex construction so as to embrace the channelled arm whereby to distribute through spaced lines the thrust forces which are transmitted through the operating parts. The spring being Wholly enclosed is better protected, and may be formed of wire which is contoured in duplex fashion so as to distribute its expansive force at a plurality of places.

Also, as a feature of my invention, 1' have devised a protecting casing for the handle which contains a magazine, and for the head of the implement as well. This casing is of general channelled form with opposite sides that are pivoted near one end to the head of the implement and releasibly secured to the handle near its other end. Such a casing, because of the mounting provided therefor, may be upwardly swung so as to expose the top of the handle whereby the magazine therewithin may be replenished with staples whenever the supply is low. Also, when the casing is swung back far enough, the operating parts which are carried by the implement head are made accessible for inspection, cleaning, repair, or replacement. In addition, the forward end of the guideway along which staples are advanced toward the head is covered by a wall in spaced relation thereto, this Wall being formed with an opening therethrough opposite the staple guideway so as to permit insertion of a tool to free the foremost staple if it be jammed at this point. This slotted Wallis normally enclosed by the casing but, when the casing has been swung upwardly and around a sufficient distance, the slot is exposed to view so as to permit insertion of a tool therethrough for the purpose indicated.

These and other objects of my invention, as will hereinafter appear, are attainable by a construction of which a certain preferred embodiment is set forth in the accompanying drawings, wherein:

Figure 1 is a longitudinal section through the implement in its entirety, with a portion of the casing therefor shown in elevation;

Fig. 2 is a section in a generally horizontal plane, as indicated by the line 2-2 of Fig. 1;

Fig. 3 is a side elevational View of the head end of the implement, with a portion of the enclosing casing in longitudinal section, the Working parts being shown in their operated positions; and

Figs. 4 and 5 are vertical sections, taken respectively on lines 4 4 and 5-5 of Fig. 1.

The. present implement comprises an arm swingingly mounted upon a head carried by a hollow handle in which is provided a magazine for holding a supply of staples or other fasteners; it comprises also means for automatically feeding the staples or fasteners into driving position in the hammer-head, and a driver positively released for actuation by movement of a striker in response to impact with the work, the driver then being free to advance against an operatively positioned staple to drive it into the Work. While the invention as illustrated and described is referred to as an implement for driving substantially U-shaped staples, it is to be understood that it may, with slight modification, feed and drive fasteners of other types, such as tacks, brads, nails, or the like. Throughout the specication and claims, therefore, the term staple is used to indicate broadly all forms of pointed fasteners which may be driven to position by the implement of my invention.

The working parts of my staple hammer are protected by an exterior casing C of channel form having an arched top wall I0 connecting a pair of spaced side walls I l. The casing top wall extends horizontally as at a. for the major portion of the length of the implement handle, then rises upwardly at b to level off again through the head end region of the implement. At its forward end, the connecting wall Ill is extended downwardly at c to provide a front enclosure. At its rear end an enclosure is afforded by a depending connecting wall d whose lower end is inturned at e in the form of a lip adapted to be engaged by a spring catch l2 with which is connected an operating button I4. In its normal advanced position, the catch engages the lip so as to prevent any upward movement of the casing at the rear end.

Within the casing is the implement framework comprising a longitudinally extending channel rail R with flanges I at the top extending in wardly toward each other, and therewithin a staple rail S channelled in cross section to provide a top and spaced side walls depending therefrom and in their lower portions laterally offset to lie adjacent the inner sides of the frame rail to which they may be xedly secured as by rivets I 6. A stick of staple s is adapted to stradd-le the staple rail, the legs of the staples depending into the spaces between the channel rail `and the inset upper portions of the staple rail. By some such means as this I provide a. magazine for the staple stick.

A channelled follower block I1 is adapted to ride on the staple rails S beneath the flanges I5 to engage with its forward edge the rearmost staple whereby lto apply an endwise pressure to the entire stick. Secured to the top facevof this block between the flanges I5 is a fitting having at its forward end an upstanding ear I8 and at its opposite end a second ear I9 which provides a linger piece. To the forward ear is connected one end of a spring 20 in the form of .a ribbon adapted to be coiled about a pin 2I which is supported between spaced plates 22 secured as by rivets 2 3 to the channel rail R. By some such means as this, a tension is maintained upon the staple stick tending to advance it toward the head end 5f the implement along the staple rail which serves as a guideway for this purpose.

The casing which forms a housing for the working parts of the implement is pivotally secured thereto at the head end as by means of a shaft 25 which is extended transversely through an anvil block 21 as well as the adjacent walls of the channel rail R. This anvil block is thus secured in place adjacent the base of the implement head. Screw studs 28-may be fitted tothe shaft ends, as shown. The anvil blockvat its forward end is spaced slightly from a front wall 30 which may be formed integral with the channel rail R. A slot 3I is provided in the front wall for a purpose that will shortly be explained. The space 32 between the anvil block and front wall 3U forms a way through which staples s may be successively driven downwardly into the work. This way is constituted in part by a guide block 33 which is positioned just above the staple stick at the iront end of the guideway therefor, this block being secured by rivets 34 between upper extensions 35 of the side walls of the channel rail R. The anvil block 21 is also secured between these same walls as by rivets 36.

A simple and dependable means for driving the staples into the work is a feature of this invention. This may comprise a driver 31 in the form of a heavy blade which is vertically reciprocable within the way 32 so as to engage, with each downward stroke, the top of the foremost staple s that is then positioned in line therewith. This blade depends from a head 38 through which is extended a pivot pin 39 whose opposite ends traverse elongated openings 40 in the spaced flanges 4I of a channelled arm A which at its rear end is pivoted by a pin 42 between the spaced Walls 22. The pin 33 establishes a pivotal and sliding connection between the driver 31 and the arm A so as to permit the former to reciprocate within a vertical path While the latter is oscillated through an arcuate path.

A pin 43 extending between the spaced flanges 4I of the arm A traverses the spaced flanges 44 of a channelled link 45 which is fitted within the channelled arm A so as to remain centered therewith. This link depends from the arm to connect through a second pin 41 with the upper end 48 of a work striker in the form of a bell crank lever L which is pivoted to rock on the shaft 25. This lever is duplex in that it comprises a pair of spaced arms of like contour adapted at their upper ends to lie to the outside of the arm flanges 4I. Below the shaft 25 these arms extend forwardly and below the anvil block toA join with a connecting bar 5U which constitutes a striking nose. This nose lies just forwardly of the way 32 so that a staple s descending into the work will pass to the inside thereof.

The normal position of the operating parts is as indicated in Fig. 1. In this relationship they are maintained by the tension of a duplex wire spring 52 which is coiled about the pin 42 to form one leg a: which extends to the pin 42 for connection therewith and a second leg y which extends to the pin 41 for connection therewith (see Figs. 1 and 3). The tension of the wire is expansive, whereby the legs :I: and y are urged apart to increase the angle between the axes of the pins 42, 43 and 41. In consequence the arm A will normally be maintained in its upper position (see Fig. 1) with the driver in elevated positiony above the level of the staple stick.

In operation, the implement head is advanced toward the workv with the striker nose 50 aimed close to the point where a staple is to be driven. Upon impact of the striker with the work, its nose will .be raised thereby rocking the striker to approximately theI position of Fig. 3. This same impact jolts the arm A with the result that its free end to which the driver is connected will be downwardly moved. Because the striker L and arm A then move oppositely, there will be little or no interference of one with the other through the connecting link. Whether one will amplify the force operating upon the other will depend upon such factors as the linkage ratio, the force of the impact, the strength of the opposing spring, etc. The movement of the working parts takes place very rapidly so that the endmost staple s in the stick is displaced by the acting end of the driver blade, and forced downwardly into the Work. When the implement is lifted from the work, the parts are restored under the influence of the spring 52 to the position indicated in Fig. 1.

Normally the casing C will remain in its enclosing position as indicated by the showing in full lines in Fig. l. Its opposite side walls will then extend down along the implement framework to enclose the handle and also the operating parts within the head. This casing is secured in place near its front end by the pivot pin 25 and at its rear end by the releasable spring catch I2. A leaf spring 53 secured to the top wall Ill of the casing engages resiliently with the top of the channel rail R close to its rear end to prevent looseness at that point. In case a new stick of staples vis to be introduced into the handle, the catch I2 is released to permit the casing to be lifted up to a position somewhat as indicated by the dot and dash lines in Fig. 1. If desired, the casing may be swung through more than 90 so as to expose'the working parts in the head. The simplicity of this operation whereby the parts interiorly of the implement are exposed tends greatly to facilitate vreloading of the handle magazine as well as oiling, cleaning and repair of the operating mechanism.

The movement range of the striker is between two stops one of which may be the pin 43. In order thatthe initial position of the striker may be as shown in Fig. l, the arms 48 are recessed at 55 close to their upper ends, the pin 48 then engaging with the edges of such recesses when the lever is retracted to its normal position. At the opposite Aextremity of its rocking movement the striker engages with the confronting edges 56 of the plates 22 at a point where recesses therein are provided to afford a desired amplitude of movement. Positive stops are thereby provided for the striker lever in each of its opposite positions, and because of its link connection with the arm A the latter may also be limited in its movements by the same two stops. This means that when the driver blade 3l has come to rest in a down position, where its acting end is disposed substantially at the surface of the work, the upper end of the striker lever will be abutting the plate stops 56, or be very close thereto.

A feature of this invention is the enclosing casing of sheet metal or the like which is movably secured to the framework of the staple hammer in a way which is free from lost motion. To accomplish this, I employ a pivotal connection near the forward end of the implement, the shaft 25 whereon the casing is pivoted being provided with removable cap screws 28 at its ends so that, when removed, the casing itself may also be taken on or the implement. The spring catch at the rear end. of the casing holds the latter securely in position against movement relative to the framework of the implement in cooperation with the leaf spring 53 which maintains a constant tension upon the top of the channel rail R to prevent any play or lost motion at this point. Obviously it is a simple matter to release the casing at the rear end for a limited upward swinging movement which will be ample for replenishing the supply of staples in the hammer magazine; it is equally simple to continue the swinging movement of the casing through 180 or more whereby to expose the operating parts at the head end of the implement. This will permit a ready inspection, cleaning, or oiling of any of the parts. It also affords access for a tool to be entered through the front slot 3| to loosen any staple that may be clogged at the way 32. In these operations it is necessary only to release the spring catch I2 preliminary to swinging of the casing to either of these positions just noted.

The spring 52 is one which remains protected within the enclosing walls of the channels of the arm A and link 45. It is so formed and disposed as to occupy a minimum of space, and on account of its duplex character (see Fig. 2) exerts an abundance of force for return of the operating parts to their normal position as indicated in Fig. 1. Its mounting in operative position involves no additional parts since it utilizes for this purpose only the three pins 42, 43, and 41 which pivotally interconnect the linkage system of the arm A and striker lever L. This is an important advantage from the standpoints of cost and assembly.

I claim:

l. A staple hammer having a handle with a head at one end, and staple driving mechanism carried by the head comprising a vertically reciprocable driver, an arm extending longitudinally of the head and pivoted thereto at its rear end and at its front end having a sliding pivotal connection with the driver, a work striker in the form of a lever located below the arm and pivoted intermediately of its ends to the head and having forwardly of its pivot point a nose which is movable upwardly by impact with the work, a link pivoted to the work striker at a point rearwardly of its pivotal connection with the head and in pivotal connection with the arm intermediately of its ends whereby the driver and arm are moved downwardly together whenever the striker nose is moved upwardly upon impact with the work, and a spring in engagementv with the three pivotal connections (l) in the rear of the arm, (2) between the arm and link, and (3) between the link and lever exerting an expansive force tending to move the upper end of the lever forwardly and raise the arm and driver upwardly.

2. A staple hammer having a handle with a head at one end, and staple driving mechanism carried by the head comprising a vertically reciprocable driver, an arm having a sliding pivotal connection with the driver and rearwardly thereof a pivotal connection with the head, a work striker in the form of a lever pivoted intermediately of its ends near the base of the head and extending both forwardly therebelow and rearwardly thereabove, a link pivotally interconnecting the arm and the lever near its upper end which latter is adapted in one extreme position to engage the pivotal connection between the link and the arm, and stop means rearwardly of the upper end of the lever adapted to engage the same when the latter has been rocked about its pivot to its opposite extreme position.

3. A staple hammer having a handle with a head at one end, and staple driving mechanism carried by the head comprising a vertically reciprocable driver, a channelled arm having a sliding pivotal connection with the driver at one end, a channelled link tted within the channel of the arm and pivotally connected thereto intermediately thereof, a striker having spaced arms on opposite sides of the arm and pivoted to the link, a pivotal connection between the striker and the head, and spring means enclosed within the channels of the arm and the link exerting an expansive force tending to raise the arm and with it the driver blade.

4. A staple hammer having a handle with a head at one end, and staple driving mechanism lcomprising a vertically reciprocable driver, a

pivoted work striker, a channelled linkage system interconnecting the driver and striker, and spring means for restoring the driver and striker to initial positions disposed wholly within the channelled linkage system for protection thereby.

5. A staple hammer having a handle with a head at one end, and staple driving mechanism comprising a vertically reciprocable driver, a pivoted work striker, a pivoted linkage system interconnecting the driver and striker, and a pair of stops engageable successively by the work striker for limiting its range of pivotal movements, one of the said stops being a pivot pin included in the pivoted linkage system.

6. A staple ha-mmer having a handle with a head at one end, and staple driving mechanism carried by the head comprising a vertically reciprocable driver with a weighted upper end, a channelled arm embracing at its forward end the Weighted upper end of the driver and in sliding pivotal connection therewith, a pivotal connection between the rearward end of the arm and 7 the head, a channelled link fitted Within the ehannelled arm and pivotally connected thereto at a point intermediatels7 of its ends, a work striker in the form of a duplex lever pivoted intermediately of its ends at a point close to the base of the head near the forward end thereof, the lever extending both forwardly and downwardly from its pivot point and upwardly and ,rearwardly thereof to embrace the channelled arm, .a pivotal connection between the duplex lever and the chanelled link, stop means carried by the head opposite the upper end of the lever for arresting the rearward movement thereof, the `duplex link in its other extreme position being adapted to engage the pivotal connection between .the channelled link and the channelled arm, and. spring means contained wholly 4within the channelled link and channelled arm exerting an expansive force tending to straighten lthe angle between the pivotal connections between (1) the link and the arm, (2) the link and the lever, and (3) the lever and the head.

7. A staple hammer having a handle with a head at one end, and staple driving mechanism carried by the head comprising a Work striker pivoted intermediately of its ends to the head adjacent its base, a vertically reciprocable driver, means interconnecting the striker and driver including an arm'pivoted to the driver at Ione end and to the head at the other end, a link pivoted at one end to the arm and .at its other end to the striker, the arm having a channelled cross section embracing the link .and the lever being duplex to embrace the arm, and spring means -contained wholly within the arm and link extending from the pivotal connection between the arm and the head to the pivotal connection between the arm and the link and thence to the pivotal connection between the link and the lever, exerting an expansive force tending to widen the 4angle between the axes of these three points.

8. A staple hammer having a handle with a head at one end, the handle comprisinga channel rail closed by a front wall through which is a slot, .an anvil block carried by the channel rail close to the front end thereof but spaced from the slotted front wall to provide avertical way therebetween, means for advancing staples processionally along the channel rail to a point in alignment with the way, staple driving mechanism carried by ythe head adapted with each operation to displace the foremost staple-downwardly through the way for advance into the work, a channelled protecting-casing enclosing the handle and head, a pivotal connection between opposite walls of the casing and the implement head, and a releasable connection between the casing and the handle adjacent its rear end such as to permit the casing, when free, to be swung upwardly above the handle and forwardly thereof whereby to expose the operating mechanism carried by the head, including the slotted front wall of the channel rail whereby to afford access to the foremost staple positioned in the way.

WALTER J. VAIL.

REFERENCES CITED UNITED STATES PATENTS Name Date Vancura Aug. 7, 1945 Number

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