US3011376A - Wire cutting knife assembly with spring biased pivoted arm return means - Google Patents

Description

Dec. 5 1961 Original Filed June 15 J. WIRE CUTTING KNIFE ASSEMBLY WITH SPRING BIASED PIVOTED ARM RETURN MEANS G. WRIGHT ET AL 1956 5 Sheets-Sheet 1 r- 9 1:- L -zay .1 1 1 17 Z03 INVENTORS z I .TAMES M. CHAFIN & 0 GEORGE M. wr/v Y 1951 J. G. WRIGHT ETAL 3,011,376

WIRE CUTTING KNIFE ASSEMBLY WITH SPRING BIASED PIVOTED ARM RETURN MEANS Original Filed June 15, 1956 3 Sheets-Sheet 2 IN V EN TORS 10.! 70 G. WING/1'7;

JAMES M. (IMF/IV t; BGEORGE M. WVN/V Dec. 5, 1961 J. G. WRIGHT ET AL WIRE CUTTING KNIFE ASSEMBLY WITH SPRING BIASED PIVOTED ARM RETURN MEANS 3 Sheets-Sheet 3 Original Filed June 15, 1956 m M N 0 E l H T MZM .WWME 4 6 5 u n {MG Y W 2/ United States Patent SPRING Original application June 15, 1956, Ser. No. 591,680, now

Patent No. 2,944,758, dated July 12, 1960. Divided and this application Apr. 14, 1958. Ser. No. 733,221

1 Claim. (Cl. 83199) 7 This invention relates in general to fastener forming and inserting machines of the type arranged for forming fasteners from a continuous length of wire and inserting the fasteners formed in material to be secured, and more specifically to a machine of this sort arranged to particular advantage for handling relatively heavy wire, and for forming therefrom and inserting relatively heavy fasteners.

For this purpose, the present invention provides an improved means for following the fastener forming motion and actuating the return of the heavy duty fastener forming means required for the heavy wire being handled. This application is a division of copending application Serial No. 591,680, filed June 15, 1956, now U.S. Patent No. 2,944,758, issued July 12, 1960.

These and other features of the present invention are described in detail below in connection with the accompanying drawings, in which: a

FIG. 1 is a front elevation of a fastener forming and inserting machine arranged in accordance with the present invention;

FIG. 2 is a generally corresponding right side elevation;

FIG.' 3 is a detail of the operating head showing the arrangement of the fastener forming knife assembly as disposed at fastener forming position;

FIG. 4 is a corresponding detail showing the fastener forming knife assembly at fastener inserting position; and

FIG. 5 is a sectional detail taken substantially on the line 5-5 in FIG. 3.

The fastener forming and inserting machine shown in the drawings, for purposes of illustration, is a machine arranged especially for nailing in wood Working operations and the like and follows generally the form of the machine disclosed for this purpose in U.S. Patent No. 2,636,168, but is particularly adapted according to the present invention, as noted above, for handling relatively heavy wire of the order of 13 gauge and for forming therefrom and inserting fasteners in alength of as much as 2% inches. i 7 I Referring first to FIGS. 1 and2 of the drawings, the nailing machine shown comprises generally a frame structure 10 arranged With a base portion 11 adapted to support the machine on a floor or similar surface, a column portion 12 on which a work table structure 13 is carried in the manner disclosed by the above noted prior U.S. Patent No. 2,636,168, and an upper arm portion 14 on which an operating head is mounted at 15 above the work table structure 13, together with an operating shaft 16 therefor. Means 100 is arranged at the base portion 11 according to the present invention for dispensing wire W from a coiled supply S so that it may be delivered effectively to a fastener forming and inserting knife assembly 200 carried by the operating head 15 by the action of wire feeding means also arranged in the opera-ting head as indicated generally at 300. The machine is operated from a foot pedal 17 at the frame structure base portion 11 connected through a suitable linkage (not shown), as in the previously noted U.S. Patent No. 2,636,168, to control a clutch mechanism at 18 on the operating shaft 16 so that a cycle of operation is initiated by each depression of the foot pedal 17.

The wire dispensing means 100, which is disclosed in detail and claimed in the previously noted U.S. Patent r 3,011,376 Patented Dec; 5, 1961 2 No. 2,944,758, comprises a vertical spindle 101 attached at its lower end to the frame structure baseportion 11 by means of a bracket arm 102. This vertical spindle 101 is shouldered intermediate its length to carry aturntable 103 for supporting the supply of coiled wire Sconcentrically with respect to the spindle 101, and has a guide member 104 fixed at its upper extending end for directing the withdrawal of wire Wfrom the inside windings of the coiled supply S.

The supply of coiled wire S is arranged according to the present invention in a packaging car-ton 105 having both side panels thereof formed with openings 106 and 107, that are substantially concentric with the axis of the wire supply S contained therein, and that are proportioned with a diameter not greater than the inner diameter of the wire supply S. The previously mentioned turntable 103 is in turn formed at its top face with a circular boss portion 108 proportioned in diameter for a positioning fit within one of the carton side panel openings 106, so as to locate the coiled wire supply S more or less concentrically with respect to the spindle-101, with the other carton side panel opening 107 affording clearance for withdrawalof the wire W through the guide member 104 from the'inside windings of the coiled supply S.

, Provision for training the wireW from the guide mem ber 10 4 of the dispensing means 100 to the fastener forming knife assembly 200 in the operating head 15 is made by means of a wire guide tube 109 carried on the frame structure column portion 12 at 110. This wire guide tube 109 is fitted at its entrance end with a length of flexible wire tubing 111 to provide for receiving the wire W readily therein, and is angled toward its discharge end for allowing the wire W to be further trained through a shock absorber unit 112 before being delivered to the fastener forming knife assembly 200 by the Wire feed means 300, which incorporates a stationary block member 301 and a movable block member 302 arranged inthe operating head 15 for sliding reciprocable movement to and from: the stationary block member 30 1 by means of a pivoted lever 306 biased at 304 for actuation through a plunger element 305 from a follower arm structure 306 at a cam The fastener forming knife assembly 200, as shown in FIGS. 3, 4 and 5, is also of the type disclosed in the above noted U.S. Patent No. 2,636,168, and comprises a stationary blade member 201 .and ama-tched movable blade member 202 assembled therewith for pivoting movement between fastener forming and fastener inserting positions, as indicated in FIGS. 3 and 4, respectively. The movable blade member 202 is formed with an extending cam arm portion 203 through which the pivoting movement thereof from fastener forming to fastener inserting position is actuated by a plunger member 204 reciprocated from a crank mechanism 205 carried at the forward end of the operating shaft 16 (see FIGS. 1 and 2). Each downward stroke of the plunger member 204 moves it initially into contact with the cam arm portion 203 for effecting the shift of the movable blade member 202to fastener inserting position so that a driving tip 206 carried at the lower end of the plunger member 204 may drive a fastener formed by the knife assembly 200 into the material to be secured.

During the shift of the movable blade member 202 to fastener inserting position, the cam arm portion 203 is held in operating relation with respect to the plunger member 204 by the following action of a trip lever 207 pivoted on the operating head 15 and yieldably biased for following the motion of the cam armportion 203 to member 202 to fastener forming position. This trip lever 207 is fixed on a pivot shaft 268 to extend oppositely with respect to the cam arm portion 293 and to pivot so that the bias thereof is exerted on the cam portion 203 through a follower roll 209 at its extending end in a direction angled greater than 99 with respect to its pivoted extending length, thereby providing the greatest mechanical advantage of the cam arm portion 293 on the trip lever 207 during the initial portion of its shifting movement from fastener forming to fastener inserting position soas to facilitate the initial shifting action of the plunger member 204 on the cam arm portion 233.

That is, with the trip lever 297 extending from its pivot shaft 208 to hold the knife assembly cam arm portion 263 in fastener forming position as seen in FIG. 6, the lengthwise axis of the trip lever 267 is disposed to intersect the lengthwise axis of the cam arm portion 283, and the positioning bias exerted through the follower roll 209 is directed perpendicularly at the contacting face of the cam arm portion 263, so that the direction of this positioning bias necessarily forms an angle of greater than 90 with the lengthwise axis of the trip lever 26-7 as measured clockwise therefrom with the follower roll 299 as a center. As a consequence, when the cam arm portion 293 is shifted to fastener inserting position as seen in FIG. 7, its mechanical advantage against the positioning bias of the trip lever 267 will increase until the respective lengthwise axes of the cam arm portion 2133 and trip lever 2B7 become parallel, and will thereafter decrease in reaching the FIG. 7 position. Accordingly, the cam arm portion 203 will have its greatest mechanical advantage when needed most during its initial shifting phase actuated from the plunger 2%; while the trip lever 267 will conversely have its greatest mechanical advantage when needed most in initiating the return of the cam arm portion 263 from the FIG. 7 to the FIG. 6 position.

The bias on the trip lever 297 is provided by means of a torsion spring 21% disposed about the pivot shaft 208 with one end fixed at an anchor pin 2-11 carried at the back of the operating head 15 and the other end secured at an anchor pin 212 carried by a manipulating lever213 that is also fixed on the pivot shaft 268 adjacent the end thereof opposite the end at which the trip lever 297 is fixed, and that provides for manually displacing the trip lever 207 from the cam arm portion 203 whenever necessary in adjusting the knife assembly 266" or relieving a jammed condition therein. In this connection, it should also be noted that the arrangement of the trip lever 2&7 eliminates entirely the necessity for any shear pin or release motion such as is usually provided to guard against damage to the knife assembly 2013 upon jamming. Jamming of the knife assembly 200 almost always occurs through breaking of the plunger driving tip 206 in the knife assembly .200 at fastener inserting position so that the movable blade 202 is locked at this position and cannot be returned to fastener forming position upon withdrawal of the plunger member 294. When this happens, the trip lever 207 simply remains in its shifted position with the cam arm portion 203 until the jammed condition is relieved.

The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise except as delined in the appended claim.

We claim:

In a fastener forming and inserting machine adapted for forming fasteners from a continuous length of wire and inserting said fasteners in material to be secured, a fastener forming knife assembly comprising a stationary blade member and a matched movable blade member assembled therewith for movement between fastener forming and fastener inserting positions, said movable blade member being formed with an extending cam arm portion, means operable at said cam arm portion for shifting said movable blade member from fastener forming to fastener inserting position, and a rigid trip lever fixed on a pivot shaft and yieldably biased by a torsion spring disposed about said pivot shaft for releasably following the motion of said cam arm portion upon shifting of said movable blade member to fastener inserting position and for returning said blade member to fastener forming position by reason of the pivot shaft bias thereon independently of the operation of said cyclic shifting means otherwise, said pivoted trip lever being carried by said pivot shaft to extend oppositely with respect to said cam arm portion and to pivot about the axis of said shaft so that the bias thereon is exerted on said cam arm portion at an angle greater than with respect to the pivoted extending length of said lever when said movable blade member is at fastener forming position, whereby the mechanical advantage of said cam arm portion on said lever is greatest during the initial portion of its shifting movement from fastener forming position, and said pivot shaft also having a manipulating lever fixed thereon for manually displacing said trip lever from said cam arm portion whenever desired.

References Cited in the file of this patent UNITED STATES PATENTS 97,191 Goddu Nov. 23, 1869 2,520,521 Wright et al Aug. 29, 1950 2,566,104 Wright Aug. 24, 1951 2,606,613 Junkunc Aug. 12, 1952 2,703,894 Goldberg Mar. 15, 1955 2,712,692 Ross July, 12, 1955 2,766,823 Purmal Oct. 16, 1956

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