US2923938A - Stapling machine - Google Patents

Description

Feb. 9, 1960 A. J. RINEHARDT STAPLING MACHINE Filed Sept. 26, 1955 wlw WI'QIPNEYS United States Patent STAPLING MACHINE Albert J. Rinehardt, Garfield Heights, Ohio, assignor, by mesne assignments, to Heller Roberts Manufacturing Corporation, a corporation of New York Application September 26, 1955, Serial No. 536,702

1 Claim. (Cl. 149) This invention relates to stapling machines and more particularly to hand-operated stapling machines having novel staple driving mechanism.

An object of the present invention is to provide a hand operated stapling machine which employs compressed spring means to drive the plunger and a staple driving blade associated with novel adjustable means through which the normal tension on said compressed spring may be regulated.

Another object of the present invention is to provide a stapling machine that employs a novel staple driving blade which not only drives the legs of a staple into a support, but also permits the crown portion of the staple to bend and more closely conform to the contour of the article to be secured, without the liability of crushing such article during the driving process.

Another object of the present invention is to provide a stapling machine characterized by its structural simplicity, the ease of assembly of its parts, its strong and sturdy nature and its low manufacturing cost. Other features of this invention reside in the arrangement and design of the parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be apparent from the accompanying drawings and the following description. The essential features of the invention will be set forth in the appended claim.

In the drawings,

Fig. 1 is a vertical longitudinal sectional view of the stapling machine embodying the present invention;

Fig. 2 is a cross sectional view taken along the plane of lines 22 as shown in Fig. l, with additional parts broken away to more clearly expose the interior construction of the stapling machine;

Fig. 3 is a perspective view of the novel staple driving blade or tool employed in the present invention;

Fig. 4 is a fragmentary view in elevation of the staple driver blade with the driving end of the same engaging the staple in the initial stage of its driving stroke and with the legs of said staple partially driven into th workpiece supporting member;

Fig. 5 is a view similar to Fig. 4 and shows the relationship between the stapler blade and the staple some time later in the staple driving stroke of said blade; and

Fig. 6 is a fragmentary view showing the staple in its driven position so as to extend over in close engagement with the cylindrical workpiece, said workpiece and support therefor being shown in section.

' proper position with reference to and upon the article to be secured, the stapling operation being performed by pressure or impact of the other hand upon the hand lever of the machine.

7 2,923,938 Patented Feb. 9, 1960 The staple tacker here illustrated comprises a metal frame having an upright head portion 10 at its front end, said head portion providing an elongated hollow cham ber 11 for the reception of suitable driving mechanism. A rearwardly extending base portion 12 of downwardly opening channel shape has removably mounted therein a supporting bar 13 for a strip of adhesively united staples 14. The staple strip is normally urged forwardly along said bar by a follower 15. A handle having an upper section 16 extends rearwardly from the upright head portion 10 and downwardly from the rear end of the top section to the base portion 12 adjacent its rear end. The upper section of the handle is generally parallel to the base portion 12 and is spaced therefrom to provide an elongated opening 17 for the fingers of the operators hand during manipulation of the tacker. The frame of the upright head portion 10 is provided on its rear surface with a pair of laterally spaced rearwardly extending mounting flanges 18 for a hand lever 19, which is operatively connected to the staple driving mechanism as will be hereinafter described.

The elongated hollow chamber 11 of the upright head portion 10 for the staple driving mechanism, is closed except at its front and lower ends. A pair of upper and lower front cover members 20 and 21 respectively are removably secured to the front edges of the upright head portion 10 by means of screws 22 or other suitable fastening means. I

Closely fitting and slidably mounted within the cham'- ber 11 is a plunger 23 which is normally urged downwardly against a stop or ledge 24 which is integrally connected to the base portion 12. The plunger 23 is urged downwardly by a single heavy-duty coiled compression spring 25, the lower end of which is seated in a bored recess 26 provided on the upper surface of the plunger 23. The upper end of the compression spring 25 engages the lower surface of the enlarged headed upper end of a guide pin 27 arranged within said spring 25. The enlarged headed upper end of the guide pin 27 threadably engages the side walls of a through bore 28 provided in the top of the upright head portion'10 of the stapling machine. To cushion the downward impact of the plunger 23 against the stop 24 a resilient pad 30 of rubber or the like may be placed on the upper surface of said stop, as shown in Fig. 1. By means of the adjustable guide pin 27, the normal tension on compression spring 25, as viewed in Fig. 1 may be regulated externally of the stapling machine. Increasing the tension upon the coil spring causes the plunger to be urged downwardly with a greater force.

As shown in Fig. 1, the front portion of the plunger is recessed to receive the upper end portion of a staple driving blade o'r tool 32, which is rigidly secured to said plunger by means of enlarged rivet or bolt 33 which projects through suitable openings in blade 32 and plunger 23. The staple driving blade 32 is thereby securely interlocked with the plunger 23 for endless reciprocatory movement therewith; the blade and the plunger may be easily disassembled and reassembled when desired. The inner surfaces of the front cover members 20 and 21 provide smooth bearing and guiding surfaces for the outer surface of the staple driving blade 32 during its reciprocatory movement. It should be noted that the top of the plunger 23 overhangs the top of the staple driving blade at 23a to prevent upward movement of the blade during a downward endwise movement of the plunger. The inner surface of the staple driving blade 32 is suppo'rted by the outermost end of the stop 24 which is spaced from the inner surface of the cover members-a distance only slightly greater than the thickness of the plate-like staple driving blade 32. 1;:

In the arrangement shown, the staple driving tool 32 is a metal plate whose thickness is approximately the same as that of each staple. At its lower or working end,the blade is provided with an open recess 32a having agently curved upperportion and straight parallel side edges 33. The recess 32a has a horizontal width somewhat less than the corresponding dimension of the article with which the stapler is to be employed, but the recess 32a is, never-the-less narrower than the total width of the end of the driving blade so that it provides the blade with two vertically aligned downwardly extending driv ing arms 34 of equal width. One of these driving arms is located at each end of the recess 32a. The working edges of the driving arms are provided with curved surfaces having a radius of curvature approximately equal to that of the curvedupper portion of the recess 32a. The width of the entire working edge of the staple driving blade is approximately equal to the width of the staple to be driven. The depth of the recess 32a is substantially less than the corersponding through dimension of the article with which the stapler is to be employed and never greater than the width of one of the driving arms 34.

' The operating means for the staple driving mechanism, by which the plunger 23 and the staple driving blade 32 are manually raised to compress the coil spring 25 and thereby enablev the spring to forcibly propel the plunger and staple driving blade downwardly for staple driving purposes, includes a pivoted pawl 35 movable in a vertical slot in the rear wall of the frame head portion 10. As shown in Fig. 1, the nose or front end of the pawl normally projects into a transverse groove or slot 36 in the rear face of the plunger 23 and thereby operatively connects the pawl and the plunger and enables the pawl to raise the plunger upon clockwise movement of the pawl, as viewed in Fig. 1. The pawl 35 is pivotally mounted intermediate its endsat 37 between the front end portions of the side arms of a channel-shaped lever 38, which in turn is pivotally mounted intermediate its ends at 39 on the flanges 18 of the tacker frame. A leaf spring 40 is secured to the lever 38 and engages the rear end portion of thepawl 35 to normally swing the pawl in a counterclockwise direction, and thus resiliently maintain the pawl in proper position for cooperation with the plunger 23. Pivotally connected at 41 to the rear end portion of the pawl carrying lever 38' is the lower end of a link 42, the upper end of which is pivotally connected at 43 to the pending side wall of achannelshaped bracket 44 rigidly secured to the lower surface of the handoperating lever 19.

The hand operating lever 19 conveniently overlies the handle section 16 of the tacker, with the front end of said lever being pivotally connected at 45 to the rearwardly extending flanges 18 to the rear of the frame head portion 10. The coil tension spring 46 normally maintains the hand lever 19 in a raised position such as shown in Fig. 1 and the toggle forming pawl carrying lever 38 and link 42 in the positions there shown.

' For automatic release of the plunger 23 from the pawl 35 when the plunger has been raised by such pawl to a predetermined height, sufiicient to compress or load the compression spring 25 for staple driving purposes, the pawl 35 is provided on its lower surface, between its nose or front end and its pivot 37, with a cam boss 47, as shown in Fig. 1.

As the plunger is elevated by clockwise movement of the pawl 35, the pawl nose is cammed out of the plunger slot 36 when the plunger has been raised to its predetermined maximum height. Upon release of the plunger from its engagement by the pawl 35, the plunger and the staple driving blade carried thereby are driven downwardly with great force by the compressed spring 25. The staple driving blade, by its downward movement,

:severs a staple from. the front end. of th staple Strip and drives each; severed, staple into, a workpiece. Thus,

t upon depression of the hand operating lever 19, the plunger'engaging-nose of the pawl 35 moves upwardly and then rearwardly, for elevation and then release of the plunger, with the pawl nose returning to its normal lowermost position, upon upward return movement of the lever 19, for reconnection with the now lowered plunger.

The final plunger release movement of the hand lever 19 is effected with comparatively little effort on the part of the user of the tacker when thehand lever 19 reaches a position substantially. parallel with the handle top section 16 of the tacker frame. At this time the tension spring 25 is under maximum. tension and no increased force is necessary for the final plunger release movement of the hand lever. This is, of course, of great importance, for ease of operation of a staple tacker is essential. By means of the novel adjustable guiding pin 27 it is possible to adjust the. tension in coil spring 25, at such an adjustment that it will reach its. maximum tension at the proper time for final plunger release movement, even though the spring may wear or become somewhat fatigued after longuse.

The staples 14 for use in the present tacker are ofthe typehaving parallel spaced legs and an arched crown having a substantially flat central portion. The staples are adhesively united in strip form, as is usual, and are successively severed from the front end of the strip when driven into the work by the downward movement of the staple driving blade 32.

As heretofore mentioned, thebar 13 for the support of the staple strip is positioned within the downwardly opened channel shaped base portion 12 of the tacker frame. The follower 15 normally urges the staple strip forwardly along the staple supporting bar 13 and feeds the staples of the strip to a position in the path of movement of the staple driving blade. The follower comprises a simple metal member of inverted U-shape, which straddles the bar 13 just behind the staple strip and is normally urged forwardly by apressure coil spring 48 carried by rod 49. In order to prevent disassembly of the rodandthe follower member, the rear end portion of the rod 49 is bent forwardly and then rearwardly to form a hook 49a for detachable connection to the frame base portion,12 through an aperture contained therein. The book 49a is yieldably and releasably held against the frame base portion by the pressure of the follower spring 48 and by a latch member 50. The latch member 50 is secured to the rear portion of handle 16 by a screw 51 and is provided with an elongated slot 50a to permit axial reciprocation of said latch member 50, as seen in Fig. 1. A leaf spring 52 is secured to the top of handle 16 by means of screw 53 and secured at its other end to the latch member 50 so as to normally urge the latch member downwardly into a position wherein it exerts pressure against the hook member 49a, as seen in Fig. 1 and thereby. retains it. In order to free the hook member. 49a, the latch member is raised vertically by means of outwardly projecting flange 5012 (limited movement of this member being made possible by the elongated slot 50a) through which bolt 51 extends.

During operation of the. stapler the. staple driving tool is raised to a retracted position, with each of the two aligned driving arm. portions of the blade lying directly above the spaced legs of the staple. Release of the plunger from its engagement with the pawl 35, causes the plunger and the staple driving blade to be driven downwardly with great force. The staple driving tool impacts upon the staple and first drives the staple legs into the supporting workpiece to a point wherein the crown of the staple contacts the uppermost surface of the cylindrical or other shaped article to be secured. Upon further downward movement of the staple driving blade, the end portions of the crown directly adjacent the legs of the staple are bent slightly inwardly around the cylindrical member and the hat central portion ofthe crow upon touching the article to be fastened, expands into the open recess 32a of the staple driving blade and bends to conform to the outer contour of the cylindrical member without crushing or breaking said cylindrical member. Thus, the crown of the staple has been more or less closely molded to hug the cylindrical member. With this construction, substantially no pressure is applied to the article which is to be retained by the staple driving tool. Since the only driving action takes place along the curved working edges of the aligned driving arm portions 34.

As seen in Fig. 4 the stapler driver 32 is shown in the first stage of its driving stroke wherein the driver arms 34 have engaged with the staple 14 and have forced the legs thereof into the supporting surface S. There is also indicated by arrows A, the direction of the force thence exerted on the staple on the top of the leg portions. At this first stage of the working stroke, the crown portion of the staple has moved to be against the top of the article W, and there may be a slight pressure exerted thereon. However, said pressure is not intended to be of any significant magnitude.

As the driver 32 continues in its working stroke it begins to force the upper ends of the leg portions in the direction of the aforementioned arrows A. At some point during the working stroke, the force exerted by said driver is such as to cause the central portion C of the staple to be flexed upwardly away from the article W and partially into the driver recess 32a. At the same time, the portions of the staple engageable with the legs 34 are also flexed inwardly such that the crown portion of the staple takes on a contour substantially similar to the contour of the article. This last described condition for said staple is best seen in Fig. 5.

With the staple thus modified, the driver then continues its stroke to drive said staple to a position such as is shown in Fig. 6, wherein the upper staple portion closely surrounds the periphery of the article without biting into the article, and the legs of said staple are firmly embedded in the workpiece. The working stroke of the driver ends at the same time it has moved the staple to its Fig. 6 position.

The present tacker is so formed that it can be placed over and along the article to be secured, to insure that the securing staples will properly straddle the article. For such purpose, the frame cross webs 12a upon which the staple supporting bar 13 rests, are located slightly above the lower edges 12b of the adjacent side wall portions of the tacker frame, with the consequent provision of article receiving grooves below said web, as seen in Fig. 2. The bottom end of the lower front cover member 21 is also provided with a suitable groove. Thus, the present tacker is of special use to electricians and the like, although its use is not limited to the stapling of wires and, if desired, the wire receiving grooves may be eliminated. The construction of the tacker parts is such as to make their assembly and disassembly easy, quick and convenient, and the operation of the tacker is simple and relatively easy.

In view of the foregoing description, taken in conjunction with the accompanying drawings, it is believed that a clear understanding of the construction, operation and advantages of the device will be quite apparent to those skilled in this art.

It is to be understood, however, that even though there is herein shown and described a preferred embodiment of the invention, the same is susceptible to certain changes fully comprehended by the spirit of the invention.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

In a stapling machine for attaching an elongated cylindrical member to a supporting structure by means of a staple having substantially parallel straight legs spaced apart by a connecting crown portion having a substantially straight central section, said machine having a frame provided with staple guiding means so formed that the legs of said staple straddle said cylindrical member when presented thereto; a staple driving blade slidable in said frame in a direction parallel to the legs of the staple to be driven and having a working edge, said blade having at the central portion of its working edge an open recess provided with straight parallel side edges and a curved upper portion, the formation of said recess resulting in two aligned driving arm portions of equal width, one at each side of said recess, said driving arms having curved end surfaces defining portions of the blade working edge directly above the spaced legs of the staple, the radius of curvature of said curved upper portion of said recess and said curved end surfaces of said driving arms being substantially equal, the width of the entire working edge of said staple driving blade being approximately as wide as the staple, the depth of said recess being substantially less than the diameter of said cylindrical member, whereby the staple driving blade by impact upon the staple first drives said staple legs into the supporting structure to a point wherein the crown portion of the staple contacts the uppermost surface of said cylindrical member, the portions of said staple on the ends of said crown portion being thereby bent slightly inwardly to closely fit around the cylindrical member by said driving arm end surfaces, and said straight central crown portion of the staple expanding into said open. recess of said blade while simultaneously bending to conform to the contour of said cylindrical member.

References Cited in the file of this patent UNITED STATES PATENTS 1,655,275 La Place Jan. 3, 1928 1,757,812 Polzer May 6, 1930 1,994,567 Cavanagh Mar. 19, 1935 2,066,157 Pankonin Dec. 29, 1936 2,143,384 Peterson Jan. 10, 1939 2,285,512 Harley June 9, 1942 2,351,043 Heller June 13, 1944 2,351,044 Heller June 13, 1944 2,668,290 Heller Feb. 8, 1954 2,746,043 Heller May 22, 1956

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