Title:
Rebar fasteners dispensing gun and method for its use
Kind Code:
A1


Abstract:
An auto-feed device and method for serially dispensing and applying plural reinforcement bar (rebar) fasteners features an elongate frame configured to carry plural rebar fasteners, the frame including a race for guiding the fasteners therealong; a feed mechanism coupled with the elongate frame for urging the fasteners toward a distal end of the frame; and a dispensing head adjacent a distal end of the frame, the frame and the dispensing head configured to serially dispense and apply the plural rebar fasteners at corresponding rebar junctions.



Inventors:
Carraher, John M. (Salem, OR, US)
Newton, Terry D. (Turner, OR, US)
Application Number:
11/663328
Publication Date:
12/13/2007
Filing Date:
09/13/2005
Primary Class:
Other Classes:
221/1
International Classes:
A47F1/04; B31B50/68
View Patent Images:



Primary Examiner:
KOEHLER, CHRISTOPHER M
Attorney, Agent or Firm:
ALLEMAN HALL MCCOY RUSSELL & TUTTLE LLP (PORTLAND, OR, US)
Claims:
We claim:

1. A device for serially dispensing and applying plural reinforcement bar (rebar) fasteners, the device comprising: an elongate frame configured to carry plural rebar fasteners, the frame including a race for guiding the fasteners therealong; a feed mechanism coupled with the elongate frame for urging the fasteners toward a distal end of the frame; and a dispensing head adjacent a distal end of the frame, the frame and the dispensing head configured to serially dispense and apply the plural rebar fasteners at corresponding rebar junctions.

2. The device of claim 1, wherein the feed mechanism includes an elongate coil spring and a slide member.

3. The device of claim 2, wherein the elongate frame is configured adjacent the distal end thereof to curve approximately 90 degrees.

4. The device of claim 3, wherein the frame includes an elongate formed channel member including dual opposing races configured to capture for elongate advancement therealong the plural rebar fasteners by engagement with oppositely extending guide pins of the plural rebar fasteners, the elongate formed channel member including an approximately 90 degree curved distal end.

5. The device of claim 4 which further comprises: a loading mechanism coupled with the elongate frame and with the feed mechanism, the loading mechanism including a gate associated with the slide member, the gate being deployable in a first closed position to press against a proximal one of the fasteners to advance the fasteners distally for dispensing and being deployable in a second open position to permit passage of the fasteners therethrough for loading.

6. The device of claim 5, wherein the gate is hinged to pivot a free end thereof proximally from the second closed position and the first open position.

7. The device of claim 4, wherein the loading mechanism further includes a knob for manually sliding the slide member along an elongate rod toward a proximal end of the elongate frame to capture within the channel member in a region thereof distal of the slide member a plurality of interlocked rebar fasteners.

8. The device of claim 7, wherein the dispensing head includes an open face oriented outwardly along an axis parallel with a long axis of the elongate frame, the open face including transverse open channels configured to receive therein two lengths of rebar in either parallel or perpendicular relative orientation.

9. The device of claim 8 which further comprises: one or more handles nearer a proximal end of the elongate frame, the one or more handles configured for manual support of the gun.

10. The device of claim 9 in which there are two or more handles, wherein one of the two or more handles adjacent a proximal end is fixedly positioned and wherein another of the two or more handles is pivotally adjustably positionable inwardly from the proximal end of the frame.

11. An automatic rebar fastener-dispensing gun comprising: an elongate frame including a magazine and a slide member slidable therealong; a feed mechanism operatively coupled with the slide member for automatically urging the slide member along the magazine from a proximal end of the frame toward a distal end thereof; a loading mechanism for introducing into the magazine, in a region thereof distal the slide member, an interlocked plurality of rebar fasteners; and a dispensing head configured to position and orient successive distal ones of the interlocked plurality of rebar fasteners therein for serially dispensing the same one at a time from the dispensing head.

12. The gun of claim 11, wherein the feed mechanism includes an elongate spring coiled around a rod.

13. The gun of claim 12, wherein the elongate frame including the magazine is configured adjacent the distal end of the magazine to curve approximately 90 degrees.

14. The gun of claim 13, wherein the magazine includes an elongate formed channel member including dual opposing races configured to capture therein oppositely extending guide pins of the plural rebar fasteners, the elongate formed channel member including an approximately 90 degree curved distal end.

15. The gun of claim 14, wherein the slide member includes a pivotable gate deployable in a first closed position to urge the plural rebar fasteners along the magazine toward the distal end thereof and being deployable in a second open position to permit passage of the plural rebar fasteners therethrough during operation of the loading mechanism.

16. The gun of claim 15, wherein the dispensing head includes an open face oriented outwardly along an axis parallel with a long axis of the elongate frame, the open face including transverse open channels configured temporarily to receive therein two lengths of rebar in either parallel or perpendicular orientation relative to one another.

17. A method of automatically applying rebar fasteners comprising: providing a dispenser including an elongate magazine having plural snap-fit rebar fastener capacity, the dispenser further including a cocking mechanism and a feeding mechanism operatively coupled with the magazine; activating the cocking mechanism, the activating including: opening the magazine for loading thereof, loading plural snap-fit rebar fasteners into the magazine, and arming the feeding mechanism to urge the plural snap-fit rebar fasteners toward a dispending end of the dispenser; pushing the dispensing end of the dispenser containing an ultimate one of the plural snap-fit rebar fasteners onto a rebar junction to fasten the junction; pulling the dispensing end of the dispenser from the rebar junction to permit the auto-feeding of a penultimate one of the snap-fit rebar fasteners to automatically feed into the dispensing end of the dispenser via action thereon by the feeding mechanism; and first repeating the pushing and pulling steps until the plural snap-fit rebar fasteners in the magazine are substantially exhausted.

18. The method of claim 17 which further comprises: second repeating the activating, pushing and pulling and first repeating steps.

19. The method of claim 18, wherein the dispenser includes a handle opposite the dispensing end thereof, which further comprises: holding the dispenser by the handle during at least the pushing and pulling and first repeating steps.

20. The method of claim 19, wherein the magazine includes an elongate channel member having oppositely inwardly facing races, wherein each one of a train of interlocked adjacent ones of the fasteners includes one or more oppositely outwardly facing guide pins, and wherein the loading step includes sliding each of the one or more guide pins of the fasteners into the corresponding races temporarily to secure the train of fasteners within the magazine.

Description:

RELATED APPLICATIONS

The present application claims priority from PCT Patent Application Serial No. 05/30270, entitled REBAR JUNCTION CLIP and filed Aug. 26, 2005, and from U.S. Provisional Patent Application Ser. No. 60/610,601, entitled UTILITY CLIP REBAR GUN and filed Sep. 17, 2004, the disclosures of which are incorporated herein in their entirety by this reference.

BACKGROUND OF THE INVENTION

This invention relates generally to the field of reinforcement bar (rebar) fasteners as they are used to join two or more length of rebar to reinforce a concrete slab, pillar, footing or wall. More particularly, it concerns mechanical means for conveying, dispensing and applying serial ones of such rebar fasteners to sequentially, securely fasten together two length of rebar in various relative orientations at a two-rebar junction.

SUMMARY OF THE INVENTION

A device and method for serially dispensing and applying plural reinforcement bar (rebar) fasteners features an elongate frame configured to carry plural rebar fasteners, the frame including a race for guiding the fasteners therealong; a feed mechanism coupled with the elongate frame for urging the fasteners toward a distal end of the frame; and a dispensing head adjacent a distal end of the frame, the frame and the dispensing head configured to serially dispense and apply the plural rebar fasteners at corresponding rebar junctions. The method of automatically applying rebar fasteners features providing a dispenser including an elongate magazine having plural snap-fit rebar fastener capacity, the dispenser further including a cocking mechanism and a feeding mechanism operatively coupled with the magazine; activating the cocking mechanism, the activating including: opening the magazine for loading thereof, loading plural snap-fit rebar fasteners into the magazine, and arming the feeding mechanism to urge the plural snap-fit rebar fasteners toward a dispensing end of the dispenser; pushing the dispensing end of the dispenser containing an ultimate one of the plural snap-fit rebar fasteners onto a rebar junction to fasten the junction; pulling the dispensing end of the dispenser from the rebar junction to permit the auto-feeding of a penultimate one of the snap-fit rebar fasteners to automatically feed into the dispensing end of the dispenser via action thereon by the feeding mechanism; first repeating the pushing and pulling steps until the plural snap-fit rebar fasteners in the magazine are substantially exhausted; and second repeating the activating, pushing and pulling and first repeating steps.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of the gun made in accordance with one embodiment of the invention, with a nearly full magazine of fasteners.

FIG. 2 is a left-side elevation of the gun of FIG. 1, with a nearly empty magazine of fasteners shown in phantom.

FIG. 3 is a front elevation of the gun of FIG. 1.

FIG. 4 is a bottom view of the gun of FIG. 1.

FIGS. 5A, 5B, 5C, 5D, 5C′ and 5D′ are enlarged fragmentary views of the gun used in various phases to load, dispense and apply rebar fasteners, in accordance with one embodiment of the invention. Specifically, FIGS. 5A and 5B illustrate loading and ‘cocking’ of the gun adjacent its proximate end, FIGS. 5C and 5D illustrate dispensing and applying a rebar fastener therefrom adjacent its distal end to form a perpendicular rebar junction and FIGS. 5C′ and 5D′ illustrate dispensing and applying a rebar fastener therefrom adjacent its distal end to form a parallel rebar junction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention in accordance with a preferred embodiment involves a semi-automatic rebar fastener-dispensing applicator or so-called ‘gun’ including a magazine for at least semi-automatically advancing a train of interlocked plural rebar fasteners toward a dispensing head where each successive one in the train is applied by manual pressure to a corresponding rebar junction thereby to fasten two lengths of rebar in a desired relative orientation whether parallel or perpendicular. By semi-automatic is meant broadly either semi-automatic or fully automatic, whereby (respectively) little or no manual effort is required between successive rebar fastener applications. Thus, a fully automatic embodiment is described and illustrated herein whereby only one so-called ‘cocking’ operation is required to dispense and apply an entire magazine of plural, interlocked rebar fasteners. Alternative embodiments are contemplated as being within the spirit and scope of the invention.

Those of skill in the art will appreciate that near and far from the supportive hands of the user of the invented rebar fastener gun will be referred to herein, respectively, as proximal and distal. In other words, the proximal end of the gun is that end normally nearer to the user's hand or hands and the distal end of the gun is that end normally farther from the user's hand or hands. Generally speaking, the proximal end of the gun in accordance with one embodiment of the invention is a rebar fastener feeding and gun holding end and the distal end of the gun in accordance with the one embodiment of the invention is a rebar fastener dispensing end near the site of the rebar junction to be fastened. Those of skill also will appreciate that the invented gun is useful for dispensing and applying fasteners of the type described for joining any two or more elongate, generally cylindrical objects (e.g. solid or hollow and relatively stiff pins, rods, tubes, pipes, electrical cords, etc.) relative to one another in a parallel or perpendicular orientation to one another, only one illustrative example of which is two lengths of rebar used in concrete construction.

FIG. 1 is an isometric view of rebar fastener gun or applicator (device) 10 dimensioned and configured to apply rebar fasteners at ground level, with gun 10 in a generally vertical orientation. Gun 10 includes an elongate frame 12 configured to carry plural rebar fasteners F (shown in phantom), the frame including one or more elongate, preferably opposing races 14a, 14b for smoothly and securely guiding the fasteners therealong. Gun 10 further includes a feed mechanism 16 coupled with frame 12 for urging the fasteners toward a distal end 12a of the frame. Gun 10 further includes a dispensing head 18 adjacent the distal end of the frame. In accordance with one embodiment of the invention, elongate frame 12 is configured adjacent distal end 12a thereof to curve approximately 90 degrees, such that forces exerted generally along the long axis of the elongate frame are transmitted outwardly therealong in a distal direction from dispensing head 18. Those of skill in the art will appreciate that frame 12 and dispensing head 18 are configured to dispense and apply plural fasteners F one at a time at corresponding rebar junctions, as will be described below by reference to FIGS. 5C, 5D, 5C′ and 5D′.

In accordance with one embodiment of the invention, feed mechanism 16 includes an elongate coil spring 20 and a slide member 22. Elongate frame 12 in accordance with one embodiment of the invention includes one or more formed channel members 24a, 24b that include the opposing races 14a, 14b. Opposing races 14a, 14b will be understood to extend substantially along the entire length of elongate frame 12 from distal end 12a to a proximal end 12b, thereby to smoothly and securely guide rebar fasteners F from an open feed inlet 26 to a closed feed outlet 28 within dispensing head 18. Thus, it will be understood that races 14a, 14b are configured within channel members 24a, 24b to capture, for elongate advancement therealong, the plural rebar fasteners F by engagement with oppositely extending guide pins thereof.

Those of skill in the art will appreciate that such fasteners having such guide pins preferably are manufactured in accordance with the teachings of the above-referenced PCT Patent Application Serial No. 05/30270. It will also be appreciated that, also in accordance with the teachings of that patent application, adjacent ones of the fasteners F in the so-called ‘train’ are interlocked with one another so that they remain securely in a train as they travel from the proximal end 12b of frame 12 to the distal end 12a thereof. In FIG. 1, it may be seen that preferably applicator 10 is dimensioned such that a full magazine capacity is preferably approximately twenty-four (shorter gun) or thirty-nine (longer gun) fasteners F sized to accommodate 4-guage (½ inch) rebar lengths. Those skilled in the art will appreciate that larger gauge fasteners F proportionately reduce the magazine's capacity.

In accordance with one embodiment of the invention, it can be seen that straight and elongate channel member 24a and curved channel member 24b are affixed to one another effectively to produce a single, contiguous, elongate channel member that includes an approximately 90 degree curved distal end. Those of skill in the art will appreciate that elongate channel members 24a, 24b alternatively can be integrally or unitarily formed, as by casting or milling, within the spirit and scope of the invention, to produce a substantially equivalent structure serving a substantially equivalent function in a substantially equivalent manner.

Referring still to FIG. 1, it may be seen that gun 10 preferably includes an elongate rod 30 extending along and in parallel with and outer surface of channel member 24a between two frame-mounted capture mechanisms 32 and 34. It will be appreciated that a preferably tensile coil spring 20 (one that, when expanded, has a tendency to contract back to its original, normally compressed, relatively short extent) is coiled around a distal region of rod 30 and is captured between a frame-mounted stop member 36 and slide member 22. Those of skill in the art will appreciate that opposite extreme ends of coil spring 20 are captured within slide member 22 and within stop member 36 so that, when a knob 38 mounted on slide member 22 is pulled by the user toward the proximal end of frame 12, coil spring 20 is extended and stores potential energy. Thus, when knob 38 is released by the operator, slide member 22 and a pivotal gate 40 coupled therewith (the latter being in its first closed position illustrated in FIG. 1) are urged by conversion of stored energy into kinetic energy (i.e. by tensile force producing contraction) of spring 20 toward the distal end of frame 12 for the continuous feeding and dispensing of consecutive ones of plural interlocked fasteners F. While in accordance with one embodiment of the invention, spring 20 provides approximately five pounds of force, those of skill in the art will appreciate that alternative spring forces are contemplated as being within the spirit and scope of the invention. Those of skill in the art also will appreciate that gate 40 normally is in a first, closed position against stop fingers 40a, 40b (refer briefly to FIG. 4). Those of skill in the art will also appreciate that gate 40 alternatively can be pivoted into a second, open position (refer briefly to FIG. 5A) for loading the magazine in a region thereof that is distal on frame 12 to slide member 22.

Those of skill in the art will appreciate that coil spring 20 alternatively can be a compressile spring (one that, when compressed, has a tendency to expand back to its original, normally expanded, relatively long extent) that is coiled around a distal region of rod 30, as between fixed mounting member 32 and movable slide member 22. Instead of coil spring 20, the means for leveraging for urging slide member 22 toward the distal end of frame 12 can take the form of a durable, reliable elastic member such as a woven elastic cord or hollow tube having adequate spring force. A sufficient force for feed mechanism to exert on the slide member will be understood to be that which quickly and reliably urges the train of interlocked fasteners F toward the distal end of frame 12 and snaps the penultimate fastener into dispensing position within dispensing head 18 of gun 10 when the ultimate fastener therein is removed (refer briefly to FIGS. 5C, 5D, 5C′ and 5D′), regardless of the mass or orientation of the gun or the mass of the fastener clips. (It will be appreciated that the invented gun alternatively may be used in a vertical orientation with the handle-end up and with the dispensing end up, e.g. to fasten rebar junctions in preparation for forming a concrete ceiling or roof, in which case the force of gravity must be overcome). Thus any suitable alternative embodiments of the feed mechanism are contemplated as being within the spirit and scope of the invention.

As may be seen from FIG. 1, open face 28 of dispensing head 18 includes transverse channels 42, 44 configured to receive therein two lengths of rebar in either parallel or perpendicular relative orientation, thus facilitating the dispensing and application of a distal one of plural rebar fasteners F therearound to form a rebar junction. This operation of dispensing and applying a rebar fastener F to a rebar junction will be discussed in further detail below by reference to FIGS. 5C, 5D, 5C′ and 5D′. Those of skill in the art will appreciate that generally U-shaped channel 42 is configured temporarily to receive therein one or more lengths of rebar extending along one or more axes C1, C2 while generally U-shaped channel 44 transverse (and preferably perpendicular) thereto is configured temporarily to receive therein a length of rebar extending along axis C3.

Gun 10 preferably includes one or more handles and preferably two or more handles, e.g. 46, 48, as shown, adjacent proximal end 12b of elongate frame 12. It can be seen that preferably the handles include comfortable grips, e.g. those made of durable, contoured rubber. One of the preferably two handles, e.g. handle 46, is adjacent a proximal end of frame 12 and is fixedly positioned, as shown, to extend downwardly at a slight angle (refer briefly to FIG. 2), i.e. to form a slightly acute angle with the long axis of frame 12. The other of the preferably two handles, e.g. handle 48, is pivotally adjustably positionable inwardly from proximal end 12b of elongate frame 12. Thus, in use, gun 10 can be held by the user with left or right hands on handles 46, 48 to ‘point’ the gun and to force dispensing head 18 against a rebar junction to dispense and apply the distal rebar fastener thereat to securely capture two lengths of rebar in parallel orientation (along axes C1, C2) or in perpendicular orientation (along axes C3 and C2) relative to one another. Those of skill in the art will appreciate that handle 48 is pivotally adjustable through 360 degrees to accommodate various user preferences and to increase force and torque efficiencies and to render the use of the gun as quick, effective and ergonomically strain- and repetitive motion-free as possible.

Referring briefly to FIG. 2, it will be appreciated that the magazine is nearly empty, that is only approximately nine fasteners remain therein and the slide member is against the stop. Thus, FIG. 2 represents what will be referred to herein as an empty gun that needs to be refilled in accordance with the method illustrated in FIGS. 5A-5B. It will also be appreciated that FIG. 2 illustrates the variable overall length L of gun 10 for accommodating different methods of use thereof, e.g. a greater length L of a gun in a generally vertical orientation for applying fasteners to horizontal junctions for concrete slabs or a lesser length L of a gun in a generally horizontal orientation for applying fasteners to vertical junctions for concrete walls or pillars.

Those of skill in the art will appreciate that the specific structure of gun 10 in accordance with one embodiment of the invention is described below in terms of specific dimensions, materials and construction details. The preferred embodiment described below will be understood by those of skill in the art to be exemplary, and not limiting, of the scope of the invention defined by the claims herein.

Handle 46 is attached to proximal end 12b of frame 12 by a U-shaped bracket 50 including dual lateral holes, as indicated, for alternative left- or right-handed placement thereof by appropriate fastening hardware such as Allen-headed machine screws. Gate 40 is pivotally mounted to U-shaped slide member 22 by rotatable Allen-headed machine screws attaching a generally cylindrical, formed channel in a proximal (hinged) end of the gate. Proximal mount 32 includes a machined clevis formed of opposing members 32a, 32b and suitable fastener hardware such as Allen-headed machine screws, the members having formed therein opposing semi-cylindrical channels for the interference fitted, fixed capture of rod 30 therein. Slide member 22 is provided with an oversize cylindrical bore 22a in a finger region 22b thereof to accommodate a polymer sleeve 22c for smoothly, slidably accommodating rod 30 therethrough. Dispensing head 18 includes two opposing formed bracket members 18a, 18b Allen-headed machine screwed into a terminal end of curved channel member 24b.

Most of the piece parts of gun 10 are of molded, machined or die stamped preferably from a lightweight, durable material such as aluminum or graphite. However, stop 36, bracket members 18a, 18b and machine screws are molded, die stamped or cast preferably from a less lightweight but more durable metal such as stainless steel. Those of skill in the art will appreciate that any suitable materials can be used to achieve durability and reliable operation of the gun. Thus, alternative structural embodiments and materials are contemplated as being within the spirit and scope of the invention.

Dimensionally, the overall length of gun 10 in accordance with one embodiment intended to extend vertically and to reach the ground is approximately forty-one inches, with a depth including that of the fixed handle of approximately twelve inches and a width including the adjustable handle of approximately eight inches. Alternatively, and in accordance with another embodiment of the invention, the overall length of gun 10 intended to extend horizontally and to reach a wall or pillar is approximately twenty-seven inches. This variable length L (see FIG. 2) is indicated in FIGS. 1-4 by a curved line pair discontiguity in frame members intermediate the proximal and distal ends of frame 12, e.g. channel member 24a.

Those of skill in the art will appreciate that gun 10 in these two different embodiments are preferably identically constructed, except that they have different length dimensions including a longer or shorter frame 12 including a longer or shorter straight channel member 24a. The longer gun will be understood to be used to fasten horizontal rebar junctions by holding it generally waist high with the frame in a generally vertical orientation. The shorter gun will be understood to be used to fasten vertical rebar junctions by holding it generally chest high with the frame in a generally horizontal orientation. Those of skill in the art will appreciate that the magazine capacity of the longer gun is approximately thirty-nine fasteners F of a size that accommodates 4-guage (½-inch) rebar lengths and that the magazine capacity of the shorter gun is approximately twenty-four fasteners F of a size that accommodates 4-gauge rebar lengths. While the longer gun could be used to fasten vertical rebar junctions, those of skill in the art will appreciate that the slightly smaller capacity, smaller length and smaller weight of the shorter gun renders it easier to support in this cantilevered orientation relative to the user and that the shorter gun is somewhat more easier to use in smaller spaces providing smaller wingspan for the user.

Those of skill in the art will appreciated that, within the spirit and scope of the invention, alternative overall dimensions are possible and perhaps desirable, e.g. for persons of lesser or greater than average height or strength to accommodate comfortable and ergonomic dispensing and application of rebar fasteners. Those of skill in the art also will appreciate that slide member 22 and gate 40 preferably are dimensioned to accommodate therein and therethrough (respectively) rebar fasteners of various gauges, e.g. gauges from 3 to 10. Thus, a gun made in accordance with the present invention accommodates rebar fasteners of all sizes that are made in accordance with the teachings of above-referenced PCT Patent Application Serial No. 05/30270.

Those of skill in the art also will appreciate that the gun embodiments described herein are both extremely durable and reliable, yet lightweight, e.g. only a few of pounds fully loaded with fasteners. This renders it very easy to maneuver during use and reduces labor and stress. The gun embodiments described herein also require no pneumatic or electrical power or umbilical cord, as they are manually operated. And despite the fact that they are manually operated and thus less expensive to use than power-assisted guns, nevertheless the gun embodiments described herein are very efficient and productive and fast to operate, with fully automatic manual cycle times as low as approximately 1-2 seconds and corresponding throughput rates as high as approximately 2000 fasteners per hour.

Referring collectively now to FIGS. 2 and 3, FIG. 2 is a left-side elevation of gun 10 and FIG. 3 is a front elevation thereof. FIG. 2 perhaps best illustrates the 90 degree curved distal end 12a of frame 12 imparted by channel member 24b. FIG. 2 also best illustrates pivotable gate 40, which is shown in phantom in a second open position of its free (unhinged) end in which plural interlocked rebar fasteners F (not shown in FIG. 2 or 3 for the sake of simplicity and clarity) can pass therethrough to load the gun. This loading feature of the present invention will be further described below by reference to FIGS. 5A-5B. FIG. 2 more clearly illustrates second channel 44 extending laterally through dispensing head 18, while FIG. 3 more clearly illustrates first channel 42 extending front-to-rear through dispensing head 18, the two channels extending transversely and preferably perpendicularly to one another. FIGS. 2 and 3 also show a pivotable elongate arm 52 that mounts handle 48 for positioning. It will be appreciated that arm 52 is provided in accordance with one embodiment of the invention with plural axially arranged holes 52a, 52b, 52c, 52d (the last not being visible) for mounting handle 48 at a desired ‘throw’ radius from a central pivotal axis and adjustable mounting bolt 54, thereby providing a range of torques for manual gripping of gun 10 by the user. Thus, second handle 48 is adjustable in two ways—one positional and one angular—in accordance with one embodiment of the invention.

FIG. 4 is a bottom view of gun 10. It shows how an ultimate or terminal fastener FU is staged within dispensing head 18 for dispensing onto a rebar junction. Those of skill in the art will appreciate that transverse channels 42, 44 are aligned with corresponding conduits formed within fastener FU made in accordance with the above-referenced PCT Patent Application Serial No. 05/30270. Those of skill in the art also will appreciate that races 14a, 14b terminate within the dispensing head so that ultimate fastener FU travels no farther than shown, thereby precisely aligning it for dispensing and applying to a rebar junction. Finally, those of skill in the art will appreciate that opposite nylon bushings 56a, 56b and corresponding cinch plates 58a, 58b having inward recesses 58a′, 58b′ are provided in dispensing head in accordance with one embodiment of the invention. Recesses 58a′, 58b′ are dimensioned in their depth and length to correspond with the spacing apart of the guide pins of fastener FU within races 14a, 14b. A thick plate 60 (preferably of machined aluminum) is provided to partially close dispensing head 18, as illustrated, and to mount the nylon bushings and the cinch plates. When fastener FU is secured to a rebar junction (as will be described below by reference to FIGS. 5C, 5D, 5C′ and 5D′) the nylon guide pins and the nylon bushings yield (deform) slightly to release the ultimate fastener FU from dispensing head 18 of gun 10 (and from heretofore interlocked next-to-terminal or penultimate fastener FP), thereby completing the application of fastener FU.

Thus, the cooperative arrangement of bushings 56a, 56b and cinch plates 58a, 58b mounted on plate 60 as described and illustrated herein will be referred to herein as a fastener capture-release mechanism that forms a part of dispensing head 18, the capture-release mechanism normally capturing the fastener positioned and oriented therein but being capable by a sufficient distally directed, axial force generally along frame 12 (as by the fastener's grip on a rebar junction and the forceful manual retreat or pull back of gun 10) to release the fastener from the dispensing head. (Those of skill in the art will appreciate that the same forceful retreat of the gun from the fastened rebar junction also disengages the male and female appendages that interlock fastener FU and fastener FP.)

Thus, after forceful manual retreat of gun 10 away from the fastened rebar junction, and by automatic spring action on the plural interlocked rebar fastener train, it will be understood, penultimate fastener FP slides quickly into the place of dispensed fastener FU for dispensing of the next in succession of the interlocked plurality of rebar fasteners.

Those of skill in the art will appreciate that the magazine of gun 10 in the side elevation of FIG. 2 is nearly or substantially exhausted of fasteners F, with slide 22 engaged at its extreme distal travel along rod 30 against stop 36, leaving as few as nine or fewer fasteners in the distal end of frame 12. It is time to reload the gun in accordance with the invented method illustrated below by reference to FIGS. 5A and 5B.

FIGS. 5A, 5B, 5C, 5D, 5C′ and 5D′ are fragmentary isometric views of gun 10 being used in various phases of its intended operation. Specifically, FIGS. 5A and 5B illustrate loading and ‘cocking’ of the gun adjacent its proximate end, and FIGS. 5C, 5D and 5C′ and 5D′ illustrate important intermediate phases of dispensing a rebar fastener therefrom adjacent its distal end respectively for application to a perpendicular and a parallel rebar junction.

FIG. 5A shows gate 40 in its open position that renders the rear surface of frame 12 unobstructed for the quick and easy loading of an interlocked train of plural rebar fasteners therein by sliding them into the open end with their guide pin pairs engaged within opposite races 14a, 14b. FIG. 5B shows gate 40 being swung back into its closed and stopped position that renders it stationary and capable of pushing the loaded train of plural rebar fasteners down the rear surface of frame 12 toward dispensing head 18. Loading is that easy.

FIG. 5C shows ultimate fastener FU poised immediately above a cross (perpendicular) rebar junction ready to be fastened, with transverse channels 42, 44 aligned thereabove, and with penultimate fastener FP trailing therebehind in the train and secured within the gun's magazine. FIG. 5D shows ultimate fastener a moment later securing the rebar junction after the gun is forced against the junction. By virtue of the spring clip action of fastener FU, the rebar junction is secure and the fastener FU snugly and securely fastened thereto. When the gun is retracted from the vicinity of the rebar junction, fastener FU remains securely fastened to the rebar junction and the guide pins and bushings 56a, 56b yield slightly and sufficiently to tug fastener FU free of the gun. Those of skill in the art will appreciate that a moment later the spring action of feed mechanism 16 advances fastener FP into position in the terminus of dispending head 18 to be dispensed and applied to the next rebar junction. The process is repeated until the magazine is substantially exhausted, the gun is reloaded as described and the next series of plural rebar fasteners is applied.

Those of skill in the art will appreciate that FIGS. 5C′ and 5D′ correspond identically to FIGS. 5C and 5D described above, except for the relative orientation of the rebar lengths being joined, wherein FIGS. 5C′ and 5D′ illustrate applying a fastener to form a parallel rebar junction or so-called ‘extension.’

It will be understood that the present invention is not limited to the method or detail of construction, fabrication, dimension, material, application or use described and illustrated herein. Indeed, any suitable variation of construction, fabrication, dimension, material, application or use is contemplated as an alternative embodiment, and thus is within the spirit and scope, of the invention.

From the foregoing, those of skill in the art will appreciate that several advantages of the present invention include the following.

The present invention provides a relatively inexpensive, semi-automatic means for conveying, dispensing and applying fasteners, for example to rebar junctions or the like, at increased speed, reduced labor cost and with less repetitive motion and potential stress-related injury. The invention provides a novel rebar fastener gun that is uniquely constructed for conveying a train of plural, interlocked rebar fasteners and for dispensing and applying them one at a time to form a rebar junction in parallel alignment in a so-called extension or in perpendicular alignment in a so-called cross. The gun includes a high-capacity magazine having a race, a spring-loaded feed mechanism, an angled dispensing head and one or more handles. In one embodiment, the gun includes a fixed and an adjustable handle and a relatively short magazine, for use in applying rebar fasteners, e.g. in a generally vertical concrete pillar or wall, with the gun in a generally horizontal orientation. In another embodiment, the gun includes a fixed and an adjustable handle and a relatively long magazine, for use in applying rebar fasteners, e.g. for a generally horizontal concrete slab, with the gun in a generally vertical orientation.

It is further intended that any other embodiments of the present invention that result from any changes in application or method of use or operation, method of manufacture, shape, size, or material which are not specified within the detailed written description or illustrations contained herein yet are considered apparent or obvious to one skilled in the art are within the scope of the present invention.

Accordingly, while the present invention has been shown and described with reference to the foregoing embodiments of the invented apparatus, it will be apparent to those skilled in the art that other changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.