Fastener driving tool

Abstract

An improved working head for attachment to a conventional power-activated fastener tool driving base for driving fasteners of the type having a T-head and a bifurcated shank. A pair of spring biased guides align and direct the fastener while it is being driven. An anvil in the path of the fastener controllably deforms the prongs to increase the retention ability of the fastener.

Description

This invention relates to power-activated fastener driving tools.

More particularly, the present invention concerns an improved working head securable to a conventional power-activated fastener driving tool base for driving fasteners of the type having a T-head and a bifurcated shank extending therefrom.

Throughout the years, the fastening of one device to another has posed considerable problems to mankind. The problem has motivated substantial research, resulting in numerous specialized and improved fasteners, fastening tools, and a general advancement of the art. The preponderance of patents issued in this area is testimony to the continued quest for advancement in the art.

The fastening art ranges from simple binding twine used in the home to complex automated welding machines for industrial fabrication. In between are such fastening methods as the common paper clip, hammer and nail, bolts and wrenches, and staples and staplers. Inevitably, man has sought to develop specialized fasteners more capable of fulfilling a particular requirement than any prior art device. With the advent of each new fastening device, man has attempted to construct a power-activated mechanical device for utilizing the fastener.

The history of the rivet witnesses the logical progression of one area of the fastening art. The first rivet, while being an exceedingly simply device, required numerous inconvenient and time-consuming operations to utilize. The pieces to be adjoined were first aligned and the place for the rivet marked upon one of the pieces. A hole was then drilled or otherwise formed through the several pieces at the specified place. Thereafter, the rivet was inserted into the hole and while the head of the rivet was "bucked up" the end of the shank of the rivet was pinged over. If the article being fabricated was large, it was necessary that one worker be on one side of the work piece to buck up the rivet while another worker on the other side of the work piece set the rivet. Later, the blind rivet was developed whereby a single worker could install and set rivets from one side of the work piece. However, it was still necessary to have a pre-formed hole through which the rivet was inserted. Today, we have self-drilling blind rivets which enables a worker with the use of a sophisticated power-driven tool to efficiently drill, insert and set a rivet in a rapid single operation.

One area of the fastening art, which is the subject of the present invention, has not kept pace. This area is the one employing fasteners where the base material is neither rigid nor solid, thereby having no body or substance which will embeddedly retain the fastener. Exemplary is the attachment of identification and shipping tags to bales of waste or cotton wherein the fibrous material is lacking in substance to embeddedly retain a conventional fastener.

Generally, bulk fibrous material such as cotton is compressed into substantially rectangular bales encased in a loosely-woven cloth mesh and secured with binding straps. The binding straps, several of which may be circled around the bale in either direction, are applied with sufficient force to form substantial indentations in the bale. After being so formed, the bales are stored in rows, each row being stacked several bales high. An identification tag is affixed to each bale.

Several prior art methods and devices are used to attach the tags to the bales. One of these methods utilizes a tag having a doubled length of wire secured thereto. One strand of the wire is passed through the edge of the bale and then twisted together with the other strand of wire. Another method employs a wire fastener commonly referred to as a hog ring. Held by a special pair of pliars, the open loop ring is simultaneously passed through an edge of the tag and an edge of the bale, whereafter pressure is applied to the pliars to close the loop of the ring.

When compared with present technological advancements in other areas, both methods appear antiquated and have serious inherent limitations. Both are slow, tedious, manual operations. The nature of the fastener requires that it be secured through an edge, thus restricting the attachment of the tag to a particular part of the bale.

While being moved, bales are often dropped, rolled and turned, in which the vulnerable corners and edges receive severe abuse. It is apparent, then, that the attachment of a tag to a corner is highly undesirable. The most protective position for a tag is upon the side of a bale at a location where the tag may partially reside in and receive the protection of the indentation caused by the binding strap. The ring-type fastener cannot grasp enough material to render it effective upon a substantially flat surface. Neither can it be forced into the identation to encircle the binding strap. The wire tie-type tag is equally ineffective since the wire cannot be manually manipulated to enter the surface of the bale and then return to be secured to the other end of the wire, nor can it be passed under the exceedingly tight binding strap.

Obviously, a nail having the tag under the head thereof could be driven into any point of the bale. However, the fibrous material lacks body or substance for retaining the nail. Similar deficiencies exist in other areas where it is necessary or desirous to utilize a fastener in a base material not having properties capable of embeddedly retaining a fastener.

It would be highly advantageous, therefore, to provide a means whereby a given material may be efficiently secured to a supple base material.

Accordingly, it is a primary object of the present invention to provide an expeditious means for affixing sheet material to a substantially flaccid base material.

Another object of the present invention is the provision of a fastening means whereby the fastener may be securely embeddedly retained in a supple material.

Yet another object of the present invention is to provide an improved fastener and an improved driving tool therefor, which fastener is particularly suited for use in soft material.

Yet still another object of the present invention is the provision of an improved fastener and improved fastener driving tool wherein the fastener so driven by the tool will form an enduring mechanical bond with the material into which it is driven.

Briefly, to accomplish the desired objectives of the present invention, first provided is an improved fastener having a T-head and a shank extending perpendicularly therefrom. The shank is bifurcated along a portion or all of the length thereof to form a pair of mutually parallel equal-length prongs. The fastener may be variously manufactured as in the cold-heading process commonly used for making nails or by the wire-bending process. Fabrication by the cold-heading process would upset a T-head integral with the driven end of an elongate shank and divide a portion of the shank beginning at the penetrating end. The wire-forming process would bend a T-head intermediate of a given length of wire with the loose ends of the wire extending as equal-length prongs perpendicular to the T-head wherein all sections of the wire of the integrally formed fastener lie in a single plane.

To drive the fastener, first provided is an improved working head securable to and operative with an activator base. Activator bases, variously termed tackers and staplers in the trade, are generally specially constructed to have various working heads secured thereto. The working head retains the fastener therein and guides the fastener as it is driven. A reciprocal hammer powered by an integral or remote energy source, as selectively controlled by an activating means, drives the fastener.

Numerous tackers and staplers are commercially available. While most activator bases are operationally analogous, especially preferred is the one sold under the trade name "Haubold Tacker Model No. PN764L." This particular tacker is pneumatically operated having an air line communicating between the device and a remote supply of compressed air, it being understood, however, that numerous other activator bases, whether hand-operated, electrically energized or otherwise activated, are equally adaptable to the purpose.

In accordance with a preferred embodiment of the improved working head of the present invention, first provided is an elongate base adapted at the upper end to be secured to the tacker and having a lower end for abutting the material into which the fastener is to be driven. A pair of fixed guides upstanding from the face of the base extend longitudinally from the upper end along a substantial portion of the length thereof. The fixed guides are arranged in parallel, having a distance therebetween corresponding to the length of the T-head and having a height relative the material thickness of the fastener. A pair of opposed movable guides are disposed below the fixed guides. Biasing means, such as conventional springs, normally urge the movable guides inward. A cover plate having an aperture therein sized and shaped for insertion of the fastener is secured to the face of the base upon the fixed guides. The lower end of the cover plate terminates proximate the movable guides. An anvil is incorporated into the lower end of the base in the discharge path of the fastener. A spring clip is secured to the base immediately above the anvil.

When preparing for use, as in attaching identification tags to cotton bales, an improved fastener as hereinbefore described is inserted through the aperture in the cover plate. With one hand, the operator inserts one end of the identification tag under the spring clip, wherein the tag extends perpendicularly from the face of the working head and in the discharge path of the fastener. Then, with the other hand, the operator places the lower end of the working head against the identification tag and depresses the trigger of the tacker. As the hammer begins its reciprocal stroke, it enters the working head between the fixed guides to abut the T-head of the fastener. The fixed guides direct the T-head while the movable guides urged inwardly by their respective biasing means align and direct the prongs of the fastener. Continued movement of the hammer passes the prongs over the anvil which controllably deforms the prongs to increase the retention power of the fastener. Near the end of the hammer stroke, the T-head contacts the movable guides which retract against their biasing means to permit the T-head to pass therebetween.

In actuality, the above-described process is completed within a fraction of a second, having required no manipulative skills nor physical exertion of the operator beyond holding the fastener driving device and depressing the trigger thereof. The completed operation leaves the identification tag securely affixed under the T-head of the fastener while the deformed prongs are engaged in a secure mechanical bond with the fibers of the bale.

Additional advantages are obtained by an alternately preferred embodiment of the present invention, in which the anvil thereof is carried by a slide movable along the longitudinal axis of the working head. A detent is operatively associated with the slide for selectively retaining the anvil in the working position to intercept the prongs of the fastener, as hereinbefore described. After the fastener has been driven and the prongs thereof deformed, the detent is disengaged, whereupon spring biasing means urge the slide in the direction of the lower end of the working head to facilitate disengagement of the anvil from the deformed prongs. Subsequently, the slide is moved upwardly, either by hand or pressing the device against a stationary surface, to return the anvil to the working position. When the working position is reached, the detent automatically engages the slide.

A transverse slot extends across the working head between the anvil and the lower end of the fastener to be driven. An edge of the identification tag is inserted into the slot when the anvil is in the extended position. A finger movable with the slide crimps the tag against one wall of the slot as the slide is moved upwardly. A sear interconnected with the slide interlocks the trigger or activating means of the activator base, such that the hammer thereof is operable only when the anvil is in the working position. This prevents the accidental premature discharge of a subsequent fastener as would otherwise be possible when the working head incorporates a magazine for automatically supplying fasteners thereto.

Further objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiment thereof, taken in conjunction with the drawings, in which:

FIG. 1 is an exploded perspective view of the improved working head chosen for purposes of illustrating a preferred embodiment of the present invention;

FIG. 2 is a perspective view of the improved fastener of the present invention to be used in combination with the improved working head of FIG. 1;

FIG. 3 is an isometric view of the improved fastener of FIG. 2 as said fastener might appear after having been driven and controllably deformed by the working head of FIG. 1;

FIG. 4 is a perspective view of the improved fastener corresponding to the view of FIG. 3 and showing an alternately controllably deformed variation thereof;

FIG. 5 is a frontal elevation view of the improved working head of the present invention having an improved fastening device therein specifically shown during an initial stage of driving the fastener;

FIG. 6 is an illustration corresponding to the view of FIG. 5 except at an operational instant subsequent thereto;

FIG. 7 graphically depicts an operator utilizing the device of the present invention and a tag appropriately secured thereby to a cotton bale;

FIG. 8 is an exploded perspective view of an alternately perferred embodiment of the improved working head of the present invention;

FIG. 9 is a perspective view of the assembled device of FIG. 8 as it would appear when attached to an activator base and operationally ready for driving a fastener;

FIG. 10 is a perspective view corresponding to the view of FIG. 9, except at a subsequent operation mode;

FIG. 11 is a side elevational view of the embodiment of FIG. 8 as it would appear when attached to an activator base;

FIG. 12 is a bottom view of the alternate embodiment of the improved working head corresponding to the operational mode of FIG. 10; and

FIG. 13 is a bottom view of the alternately preferred embodiment of the improved working head of the present invention and corresponding to the operational mode of FIG. 9.

Turning now to the drawings, in which the same reference characters indicate corresponding elements throughout the several views, attention is first directed to FIG. 1 which illustrates an improved working head constructed in accordance with the teachings of the present invention. The improved working head has an elongate base 10 with an upper end 11 and a lower end 12. While the upper end 11 may be variously shaped, the particular configuration shown herein is adaptable for securement to the preferred activator base or tacker previously described. As shown herein, the working head has an intermediate component 13 so constructed to facilitate manufacture. It is particularly noted that the intermediate component 13 may be integral with the base 10 and will be described as such herein. The base 10 has a substantially flat face 14 which supports a pair of parallel fixed guides 17 and 18 upstanding therefrom. A pair of movable guides 19 and 20 having inwardly directed projections 21 and 22 disposed below the lower terminus of the fixed guides 17 and 18 are pivotable about the pins 23 and 24, respectively. Biasing means, here shown as conventional compression springs 26 and 27, respectively, urge the inwardly directed projections 21 and 22 inwardly. A cover plate 28, having an aperture 29 therein sized and shaped to permit passage of the improved fastener therethrough, rests upon the guides 17 and 18 and is secured to the base 10 by the bolt-and-nut combination 30 and 31, respecitvely. While only one bolt 30 is shown herein, four bolts are preferably used, one extending through each of the apertures 32. The lower end 33 of the cover plate 28 terminates proximate the inwardly directed projections 21 and 22 of the movable guides.

An anvil 34 integral with the lower end of the base 10 is formed by upstanding sides 37 and 38 which converge to an upwardly directed apex 39. A projection 40 having downwardly outwardly curved segments 41 and 42 is disposed between the anvil 34 and the movable guides 19 and 20. A lateral groove 43 extends across the face of the base 10. An L-shaped spring clip 44 is secured by one leg thereof to the side of the base 10 while the other leg resides within the groove 43. The functional operation of the elemental components of the improved working head will be hereinafter described in considerable detail.

FIG. 2 illustrates an improved fastener for use in combination with the improved working head described in connection with FIG. 1. As shown herein, in accordance with a preferred embodiment of the present invention, the improved fastener is integrally formed from a single length of wire. The fastener is symmetrically formed having a relatively short intermediate first section 50 with U-bends 51 at each end thereof to form corresponding second sections 52 doubled back upon the first section 50. Each second section 52 is terminated proximate the center of the first section 50 with an L-bend 53. A pair of mutually parallel equal-length third sections 54 extend from the L-bends 53. The first and second sections 50 and 52, respectively, form the T-head of the fastener while the third sections 54 form the prongs thereof. The penetrating end 57 of each prong 54 is beveled by a single plane perpendicular to the head of the fastener in one direction and extending diagonally inwardly upward from the penetrating end of the prong in the other direction.

FIGS. 3 and 4 illustrate two variously deformed fasteners as they might appear after having been driven by the improved working head. In FIG. 3, the prongs 54 have been directed curvilineally outward to form a substantial half-curl. In FIG. 4, the curvature of the prongs 54 has progressed until the penetrating end 57 has contacted the prongs at a point thereon below the T-head 50 such that a short straight section of the prongs 54 exists between the T-head and the ends of the prongs. The fastener may be deformed in other modified variations thereof in accordance with the particular shape of the anvil as will be described hereinafter in detail.

Attention is now directed to FIG. 5, in which the improved fastener is shown in combination with the improved working head at substantially the instant of the initial driving operation. The fastener has been inserted through the aperture 29 with the first section 50, or T-head, aligned between the fixed guides 17 and 18 while the shanks 54 are aligned between the inward projections 21 and 22 of the movable guides 19 and 20, respectively. Although not specifically shown herein, an identification tag has been inserted between one edge of the groove 43 and the spring clip 44. The hammer 60 of the activating base during the beginning of the downward stroke has abutted the first section 50 of the fastener, driving the penetrating ends 57 of the prongs 54 downwardly, through the retained end of the tag, to contact the anvil 34. The fixed guides 17 and 18 and the movable guides 19 and 20 cooperate to direct the head 50 and prongs 54 such that the prongs will be divided by the apex 39.

Continued downward movement of the hammer 60 as specifically shown in FIG. 6 forces the U-bends 51 to contact the inward projections 21 and 22, thus retracting the movable guides 19 and 20 against their respective springs 26 and 27 to permit the T-head to pass therebetween. The prongs 54 are spread curvilineally outward as directed by the curvilinear diverging sides 37 and 38 of the anvil 34. Retaining guides 61 insure that the prongs 54 maintain constant contact with the curved sides 37 and 38 of the anvil 34. Hereafter, subsequent movement terminating the downward stroke of the hammer 60 discharges the T-head below the lower end of the cover plate 28, whereupon the T-head is deflected from the face of the holding tool by the curved faces 41 and 42 of the projection 40. Having completed the driving operation, the hammer 60 retracts upwardly to normally reside above the aperture 29 while the movable guides 19 and 20 relax normally inward.

FIG. 7 illustrates a cotton bale 70 having encircling binding straps 71. A tag 72 has been secured thereto in accordance with the procedure hereinbefore described such that the tag 72 substantially resides within the impression created from the binding straps 71. An operator is shown holding an activator base or tacker 80 graphically illustrative of the type hereinbefore described. The operator has completed fastening the tag 72 to the bale 70, has inserted a subsequent tag 72a into the working head where it is retained by the spring clip arrangement, and is preparing to insert another fastener into the working head.

FIG. 8 illustrates an alternately preferred embodiment of an improved working head constructed in accordance with the teachings of the present invention and having an elongate base 100 with an upper end 101 and a lower end 102. The particular configuration shown for the upper end 101 is adapted for securement to a preferred activator base as previously noted in connection with FIG. 1. Associated with the working head is an intermediate component 103, which is considered a part of elongate base 100 but separately fabricated to facilitate manufacture. As the detailed description proceeds, intermediate component 103 will be referred to as integral with elongate base 100. It is also noted herein that the particular embodiment as illustrated in FIG. 8 is rotated 180.degree. from the embodiment illustrated in FIG. 1. This is due to the orientation in reference to the activator base. However, similar to FIG. 1, the face or front of the device of FIG. 8 is considered to be that side through which the fastener enters the working head.

Slide member 104 is movably disposed along the longitudinal axis of working head 100 within slot 107. The limit of movement of slide 104 is defined by lug 108 which extends from slide 104 into a second slot (not specifically shown) within elongate member 100 adjacent slot 107. Rear cover plate 109 retains slide member 104 within slot 107. Cover plate 109 is affixed with bolts, as will be hereinafter described.

Longitudinal slot 110 within intermediate member 103 extends the length of elongate base 100. The reciprocal hammer of the activator base projects into slot 110 when driving a fastener. The fastener is discharged through the lower end of slot 100. Anvil 111 carried by the forwardly projected lower end 112 of slide 104 lies in the discharge path of the fastener. Roller guides 113 cooperate with anvil 111 to controllably deform the prongs of the fastener. Anvil 111 and roller guides 113 supplant anvil 34 and guide pin 61, respectively, as particularly seen in FIG. 6.

First and second lateral grooves 114 and 117, respectively, extend across the face of base 100. Detent 118 is slidably carried within first lateral groove 114. Operating handle 119 has a blade-like lower end 120 received within recess 121 of base 100. Operating handle 119 is pivotal about doll pin 122, press-fitted into appropriate apertures on either side of recess 121 and extending through aperture 123. The lower end 120 of operating handle 119 is also received within the slot 124 within detent 118 such that the recess 127 engages the doll pin 128 extending through slot 124. Compression spring 129 located within aperture 130 bears against operating rod 119 to normally urge the upper end thereof outwardly from base 100.

As will be apparent to those skilled in the art from the immediately preceding description, detent 118 is normally urged inward by spring 129 and is retractable by pressure against operating rod 119. Therefore, as slide 104 is urged upwardly within slot 107, detent 118, in response to the action of spring 129, will engage under the lower end of lug 108 to retain anvil 111 in a first working position. Plunger 131, abutting lug 108 and responsive to spring 132, normally urges slide 104 in the direction of the lower end of the working head. Although not specifically herein shown, it is understood that the upper end of spring 132 is retained within a suitable aperture within elongate base 100. The exact function of the slide, the detent and the operating handle, 104, 118 and 119, respectively, will be described presently. It is also noted in this connection that a pin 133 extends upwardly from the lower end 112 of slide 104 through aperture 134 within base 100 and is projectable into lateral groove 117.

As earlier noted in connection with a previous embodiment, sides 137 and 138 upstanding from the flat face of slot 110 form a pair of parallel fixed guides. The fixed guides 137 and 138 are spaced to receive and pass therebetween the head of the fastener after it enters the improved working head of the present invention through T-shaped aperture 139 within cover plate 140. A pair of movable guides 141 and 142 are carried between intermediate member 103 and base plate 140. Each movable guide 141 and 142 has an aperture 143 therethrough, by which the guides are pivotal about a respective assembly bolt. Compression springs 144 partially retained within apertures within the movable guides 141 and 142 and abutting outwardly directed projections 147 normally urges the lower ends of the movable guides inward until the shoulders 148 and 149 associated with the movable guides 141 and 142, respectively, abut the lateral edges of base 100. Movable guides 141 and 142 function analogously to movable guides 19 and 20, as hereinbefore described. As illustrated, each movable guide 141 and 142 has a curved inner surface to form an inwardly directed projection. In the normal or rest position, the spacing between the lower ends of the inwardly curved surfaces of the movable guides 141 and 142 have a spacing therebetween which generally corresponds to the width of the shank of the fastener. Each movable guide 141 and 142 replaces an appropriate length of fixed guide 138 and 137, respectively.

A U-shaped member having forwardly directed parallel legs 151 and 152 has a tang 153 extending downwardly therefrom to be slidably received within groove 154. A pair of screws 157 (only one herein shown) are received within the counterbore holes 158 in slide 104 and threadedly engage the apertures 159 in tang 153 and secure tang 153 to the face of lug 108. U-shaped member 150, therefore, moves with slide 104. A sear 160 extends between legs 151 and 152. For clarity of description, the L-shaped trigger 161, as conventionally supplied with the preferred activator base herein previously noted, is included in the instant figure. The trigger 161 is pivotal about a pin extending through aperture 162. Aperture 162 is located approximate the apex of legs 163 and 164 of the L-shaped trigger 161. Leg 163 projects from the activator base and is generally curved to accommodate the operator's finger. Leg 164 terminates with a curved lip 167. As the first leg 163 is depressed in the direction of the arrow A to activate the hammer, the lip 167 moves in the direction of the arrow B. When slide 104 is moved upwardly within slot 107 and engaged by detent 118, sear 160 resides between lip 167 and leg 163, whereby trigger 161 may be moved freely. When detent 118 is disengaged from lug 108 and slide 104 has moved downwardly to space anvil 111 from the end of the working head, sear 160 moves adjacent lip 167 to provide an interlock to prevent accidental activation of the working head and the subsequent discharge of a fastener.

An elongate magazine 168, having a T-shaped slot 169 extending therethrough, supplies fasteners to the working head. A spring and slide arrangement between the supply of fasteners, as is well known in the staple art, continuously positions a subsequent fastener into the working head. Assembly bolts 170 extend through the apertures 171 in the several components of the working head and threadedly engage within the threaded apertures 172 within the magazine 168 to hold the various components together, provide pivot means for the movable guides 141 and 142, and align the aperture 139 within face plate 140 with the slot 169 within magazine 168. Assembly bolts 173 also extend through apertures 174 and threadedly engage apertures 175 within the magazine 168.

FIG. 9 illustrates the assembled improved working head as described in connection with FIG. 8 as it would appear when operatively attached to an activator base 180 and including the fastener magazine 168. Activator base 180 has a handle 181 and a nose 182 which is so arranged for the attachment of various working heads in accordance with the user's requirements. The activator base herein shown is generally illustrative of the one sold under the trade name "Haubold Tacker Model No. PN764L," as previously noted. While various activator bases are alternately pneumatically or electrically driven, the instant tacker under consideration utilizes air as an energy source to drive the reciprocal hammer which is activated in response to the pressing of the trigger. When the trigger is depressed, the hammer protrudes from the nose 182 with a driving force and subsequently retracts within the housing of activator base 180 to await another reciprocal cycle in response to activation of the trigger 161. In general, the attachment of specialized working heads to various activator bases is convention and well known in the art. The novelty of the instant invention resides, therefore, not in attaching a working head to an activator base, but rather in the structure of the improved working head as described herein and the operative arrangement of components thereof which are arranged to achieve a new and useful result.

As specifically shown in FIG. 9, slide 104 has been retracted upwardly in the direction of the arrow C within base 100. Slide 104 is retained in this position by the engagement of detent 118 with lug 108. Anvil 111 is properly spaced from guides 113 for the passage of the prongs of the bifurcated shank of the fastener therebetween. It is also noted that operating handle 119 extends outwardly from the working head and U-shaped member 150 is moved upwardly to be disengaged from the trigger and place the assembled device in the ready position. Although not specifically herein seen, but as is immediately apparent, the first fastener contained within magazine 168 has been automatically fed through aperture 169 into slot 110 and in alignment with the hammer of activator base 180. Subsequent manipulation of the trigger activates the hammer, which is driven downwardly entering slot 110 and driving the fastener therefrom, whereupon the prongs thereof are divided upon contact with the apex of the anvil 111 and are deformed arcuately outward on either side thereof between anvil 111 and corresponding guide 113.

It will be immediately apparent that the deformed prongs of the fastener exert pressure against anvil 111 and guides 113, which inhibit the disengagement of the working head from the driven fastener. Although it is perfectly feasible with a twisting, lifting motion to free the working head from the fastener, FIG. 10 illustrates an improved feature of the working head of FIG. 8, which greatly facilitates the release of the driven fastener. For the operator, the release consists simply of pushing operating rod 119 inwardly against the elongate base 100. This operation retracts detent 118 from engagement with lug 108, at which time slide 104 is driven downwardly by spring 132. As a result, the lower end 112 of slide 104 projects from the lower end 102 of base 100, spacing anvil 111 therefrom and concurrently from guides 113. At this time, a subsequent fastener has been positioned in slot 100. However, since U-shaped member 150 is movable with slide 104, sear 160 has moved downwardly under lip 167 to interlock trigger 161, thereby preventing the accidental activation of activator base 180 and discharge of the subsequent fastener until the working head has again been positioned, as illustrated in FIG. 9. As a practical matter, slide 104 is urged upwardly to the first working position by pushing the lower end 112 against a firm surface until lug 108 is retracted above detent 118.

FIG. 11 is a side view of the improved working head as illustrated in FIG. 10, with the alternate position of the operative elements thereof as seen in FIG. 9 shown in dashed outline. Reference numerals having the suffix A refer to the dashed line position of the various components. Particularly noted herein is the relative positions of the sear 160. When the lower end 112 of slide 104 is moved downwardly or extended from the lower end of the working head, spacing anvil 111 in a non-working relationship with guide 113, sear 160 is also moved downwardly. As herein previously noted, sear 160 now resides under lip 167 of trigger 161 to provide an inner lock and render trigger 161 inoperative. As the slide lower end 112A is urged upwardly, whereupon slide 104 is retained by detent 118 bringing the anvil into an operative relationship with guide 113, the U-shaped member 150A has moved upwardly to position sear 160A in non-interference with trigger 161.

Anvil 111, as seen in FIG. 12, includes an upwardly directed apex 185 having curved working surfaces extending downwardly outwardly therefrom. When moved upwardly into the working position, as best seen in FIG. 13, the curved sides 186 of anvil 111 cooperate with roller guides 113 to force the prongs of the bifurcated shank of the fastener in opposed outwardly curved directions for retention into relatively soft material. Concurrent with the upward movement of slide 104 to position anvil 111 in the working position, pin 133 projects through aperture 134 into second lateral groove 117. An identification tag 190, positioned into groove 117 prior to the upward movement of slide 104, is thus crimped between the upper side wall of groove 117 and pin 133 when slide 104 is urged into the working position. As seen in FIG. 13, identification tag 190 is held below the lower end of the shank of the fastener and in alignment therewith such that when the fastener is driven downwardly, the prongs thereof will pass through tag 190 and subsequently into the base material. The holding pressure exerted upon tag 190 is a function of the spacing between the end of pin 133 and the side wall of groove 117. Alternately, the upper end of pin 133 may incorporate a spring-biased plunger.

The device of the instant application has been specifically described in connection with the fastening identification tags to cotton bales. While the invention will have substantial utility in fastening identification tags to cotton bales, cotton bales are highly illustrative of materials so lacking in substance and body to form a mechanical bond for retaining an embedded fastener. It is readily apparent that the device has utility in other areas where the fastening art is applied. Exemplary is furniture making, particularly where upholstery material is attached to a wooden frame. Conventionally, the upholstery is affixed to the frame with upholstery tacks or staples. With use, the fasteners tend to work loose from the frame, especially if the frame is of a soft wood. The embedded and uniquely deformed fastener of the present invention would provide a lasting securement.

The beveled penetrating end of the prongs assist the anvil in directional penetration of the prongs into the material into which the fastener is driven. Pressure exerted by the material against the flat bevel tends to repel the prong while the sharp leading edge of the prong slices cleanly through the material. The prongs are therefore deflected in the direction of the pointed ends. The angle of the bevel may, of course, be varied or alternately eliminated in favor of a modified end configuration.

It will be readily apparent to those skilled in the art that the sides of the anvil may be variously shaped to control the deformation of the prongs. Similarly, the fastener may be fashioned from wire of various thickness and strength and having various T-head sizes and prong lengths. Combining various point configurations, modified anvil shapes and alternate fastener geometrics adapts the device to numerous fastening applications.

Claims

Having fully described and disclosed my invention and the preferred embodiments thereof in such clear and concise terms as to enable those skilled in the art to understand and practice the same, the invention claimed is:

1. For use in combination with an actuator base including:

engaging means for securing a working head thereto,

reciprocal hammer means driven in response to an energy source, and

activating means for selectively energizing said hammer,

an improved working head for first holding a fastener having a head and a bifurcated shank in alignment with said hammer and then guiding said fastener as said fastener is forcibly discharged therefrom by said hammer whereby the prongs of said bifurcated shank enter a preselected material in controlled deformed relationship, said improved working head comprising:

a. an elongate base having an upper end adapted to be secured to said activator base and a lower end for abutting said preselected material;

b. a pair of fixed guides upstanding from the face of said base and extending longitudinally from the upper end along a substantial portion of the length thereof,

said fixed guides being in parallel arrangement and having a distance therebetween corresponding to the distance across the head of said fastener and having a height relative the material thickness of said fastener;

c. a pair of opposed movable guides disposed below said fixed guides;

d. biasing means for normally urging said movable guides inwardly to contact the shank of said fastener and permitting retraction of said movable guide for passage of said head therebetween;

e. a cover plate secured to the face of said base, disposed upon said fixed guides and terminating proximate the movable guides and having an aperture therein sized and shaped for insertion of said fastener; and

f. an anvil proximate the lower end of said base in the discharge path of said fastener for controllably deforming the prongs of said fastener.

2. The improved working head of claim 1, further including means disposed between the lower end of said cover plate and said anvil to deflect the head of said fastener from the face of said base.

3. The improved working head of claim 1, wherein said anvil is carried by a slide movable along the longitudinal axis of said elongate base and having a first selective position in which said anvil is operatively positioned adjacent the lower end of said base for controllably deforming the prongs of said fastener and having a second position in which said anvil is spaced from the lower end of said base for disengagement from the deformed prongs of said fastener.

4. The improved working head of claim 3, further including:

a. biasing means associated with said slide for normally urging said anvil into said second position; and

b. detent means operatively associated with said slide for selectively retaining said anvil in said first position.

5. The improved working head of claim 3, further including a sear operatively associated with said slide to interlock said activating means when said anvil is in said second position.