US3747825A

US3747825A - Stitching head apparatus

Info

Publication number: US3747825A
Application number: US00154418A
Authority: US
Inventors: L Barland
Original assignee: Precision Industries Inc
Current assignee: Molins Machine Co Inc
Priority date: 1970-05-14
Filing date: 1971-06-18
Publication date: 1973-07-24
Anticipated expiration: 1990-07-24

Abstract

A wire stitching head is disclosed for successively producing a series of uniformly shaped and sized stitches from a continuous length of wire and includes a reciprocating stitch forming bar and a relatively shiftable stitch driving bar operated by a rotating cam wheel provided with an arcuate feeding cam which coacts with a guide roller to feed a predetermined length of wire into stitch forming position upon each rotation of the cam wheel. The stitch forming bar and stitch driving bar are guided in their reciprocating paths of motion by a guide member having a channelway into which the preselected length of wire is positioned for the forming and driving operation. The preselected length of wire, determined by the arcuate length of the aforementioned feeding cam, is just slightly less than the width of the channelway in the guide member whereby such length of wire does not reach the opposite wall in the channelway at any time during the stitch forming or stich driving operation thereby avoiding deflection and bending of the wire which otherwise occurs especially at high speed operation. To more precisely regulate the length of wire fed into stitch forming position, the aforementioned guide roller is mounted on the frame of the apparatus for rotation with the cam wheel and preferably by being geared thereto. Also to aid in positioning the wire in the stitch forming apparatus, a novel wire check structure, comprising a pair of unidirectional clutches between which the wire passes, is mounted immediately adjacent the aforementioned guide member to minimize the distance between the wire check and a passageway in the guide member through which the wire passes to reach the stitch forming position. Additionally, wire guide means are provided which include a hollow tube, a portion thereof being disposed in a curvilinear path which is opposite the direction of the bias established by the supply of wire. In this manner, the natural bias of the wire in the direction of the coil rolls from which it was stored is reversed and the wire is straightened out prior to being fed to the stitch forming portion of the apparatus. Finally, after a stitching cycle has been completed, the deenergization of the driving mechanism of the stitching head apparatus is arranged to take place when the moving parts thereof approach a condition of zero momentum thereby substantially reducing the stresses which must be withstood by such elements as the clutch-brake utilized to halt the motion of the apparatus.

Description

United States Patent [191 Barland STITCHING HEAD APPARATUS [75] Inventor: Lauri C. Barland, West Chester, Pa.

Related US. Application Data [631 Continuation-impart of Ser. No. 37,190, May 14,

1970, Pat. No. 3,642,187.

[52] US. Cl. 227/90 [51] Int. Cl. B27! 7/02 [58] Field of Search 227/82, 83, 84, 85,

[56] I References Cited UNITED STATES PATENTS 5/1951 Zeruneith 227/84 6/1939 Robinson. 227/82 1,246,455 11/1917 Niskanen. 227/91 2,226,916 12/1940 Zeruneith 227/89 3,173,592 3/1965, l-lerbst 227/7 Primary Examiner-Granville Y. Custer, Jr. Attorney-Lawrence l. Lerner et al.

[57] ABSTRACT A wire stitching head is disclosed for successively producing a series of uniformly shaped and sized stitches from a continuous length of wire and includes a reciprocating stitch forming bar and a relatively shiftable stitch driving bar operated by a rotating cam wheel provided with an arcuate feeding cam which coacts with a guide roller to feed a predetermined length of wire into stitch forming position upon each rotation of the cam wheel. The stitch forming bar and stitch driving bar are guided in'their reciprocating paths of motion by a guide July 24, 1973 member having'a channelway into which the preselected length of wire is positioned for the forming and driving operation. The preselected length of wire, determined by the arcuate length of the aforementioned feeding cam, is just slightly less than the width of the channelway in the guide member whereby such length of wire does not reach the opposite wall in the channelway at any time during the stitch forming or stich driving operation thereby avoiding deflection and bending of the wire which otherwise occurs especially at high speed operation. To more precisely regulate the length of wire fed into stitch forming position, the aforementioned guide roller is mounted on the frame of the apparatus for rotation with the cam wheel and preferably by'being geared thereto. Also to aid in positioning the wire in the stitch forming apparatus, a novel wire check structure, comprising a pair of unidirectional clutchesbetween which the wire passes, is mounted immediately adjacent the aforementioned guide member to minimize the distance between the wire check and a passageway in the guide member through which the wire passes to reach the stitch forming position. Additionally, wire guide means are provided which include a hollow tube, a portion thereof being disposed in a curvilinear path which is opposite the direction of the bias established by the supply of wire. In this manner, the natural bias of the wire in the direction of the coil rolls from which it was stored is reversed and the wire is straightened out prior to being fed to the stitch forming portion of the apparatus; Finally, after a stitching cycle has been completed, the deenergization of the driving mechanism of the stitching head apparatus is arranged to take place when the moving parts thereof approach a condition of zero momentum thereby substantially reducing the stresses which must be withstood by such elements as the clutch-brake utilized to halt the motion of the apparatus.

'8 Claims, 3 Drawing Figures 1 July 24, 1973 PAIENIEDJuLzmn SHEET 1 0F 3 uvvzxvron LAURI c. BARLAND LERNER, DAVID 8 LITTENBERG A TTORNEYS CLUTCH- M BRAKE PATENTEDJULZWB 3.747. 825

STITCHING HEAD APPARATUS CROSS REFERENCES TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. Pat. application Ser. No. 37,190 filed May 14, 1970 in the name of Lauri C. Barland and entitled Stitching Head Apparatus, now U.S. Pat. 3,642,187, assigned to the assignee of the instant application.

FIELD OF THE INVENTION This invention relates to wire stitching heads, more particularly wire stitching heads capable of successively producing a series of uniformed shaped and sized stitches from a continuous length of wire, and more particularly to such a wire stitching head having significant improvements which make possible wire stitching at extremely high rates of speed.

BACKGROUND OF THE INVENTION In U.S. Pat. application Ser. No. 37,190 filed May 14, l970 in the name of Lauri C. Barland, and assigned to the assignee of the instant invention, there is disclosed a wire stitching head of the type to which the instant invention is directed. Thus the stitching head of the aforementioned Harland application includes, as the heart of its mechanism, a motor driven earn wheel which performs a number of functions which may be briefly summarized as follows.

First, the cam wheel carries along its periphery an arcuate feeding cam which, together with a cooperating guide roller, functions to intermittently feed preselected lengths of wire into the stitch forming position upon each revolution of the cam wheel. Secondly the cam wheel pivotally carries on a forward surface thereof a pair of links one of which is pivotally connected to a reciprocating stitch forming bar and the other of which is pivotally connected to a stitch driving bar which functions to drive a stitch into the work piece after the stitch has been formed by the aforementioned stitch forming bar. The stitch forming bar and stitch drivingbar are guided in their reciprocating paths of travel by a guide member having a channelway into which each preselected length of wire is successively fed prior to being formed and driven into the work piece positioned therebeneath. This basic machine, although now enjoying wide spread popularity in the industry, has been found to encounter certain difficulties when the speed of operation thereof is substantially increased.

For example, at extremely high rates of stitching speed, for example 1500 stitches per minute, the stitches being produced by the stitching head tend to become non-uniformly shaped, leading sometimes to improper stitch placement or even worse, sometimes to ajamming ofthe stitching head. Also, at extremely high rates of stitching speed, the momentum of the moving parts becomes extremely high and attempts to deactivate the stitching head, for example by applying a braking force to the rotating cam wheel to which the stitch forming bar and stitch driving bar are attached, sometimes applies such stresses that the braking mechanism completely fails (i.e., is physically destroyed). Moreover, at high rates of stitching speed, such problems as controlling the feeding of the wire and preventing back-slip during the interval between feeds, becomes especially acute creating unacceptable deviations in the form, shape and placement of the stitches produced by the stitching head apparatus.

SUMMARY OF THE INVENTION The instant invention is directed to a wire stitching head of the general arrangement discussed above, but is provided with significant improvements which have simply, inexpensively, and effectively eliminated the aforementioned problems associated with operating the wire stitching head at increased rates of speed.

Specifically, applicant has discovered that one of the reasons the wire stitches become deformed or otherwise improperly shaped, is because when a length of wire is fed into the channelway of the aforementioned guide member at an extremely high rate of speed, it must absorb a proportionally greater amount of energy from the shock it receives when its leading end bangs into the far wall of the channelway. Of course, the energy it absorbs is dissipated by the undesirable bending and deflection of the wire mentioned previously. In the instant invention, this problem is completely eliminated by providing that the preselected length of wire being fed into the aforementioned guide member for subsequent forming and driving is less than the width of the channelway such that the leading end of the wire never quite reaches the far wall of the channelway when it is fed into stitch forming and driving position. As will be described in greater detail, such result is accomplished by preselectively selecting the arcuate length of the aforementioned feeding cam to correspond to the preselected length of wire which is just less than the width of the aforementioned channelway. In addition, and in a manner to be further described, controlled accuracy is assured by providing a direct power drive for the aforementioned guide roller and by providing a novel wire check, comprising a pair of unidirectional clutches which prevents wire slippage back toward the supply roll in between periods of wire feed. Also, novel wire straightening means are provided adjacent the wire check such that the length of wire finally fed into the aforementioned channelway will be transversely oriented with respect to the direction of travel of the formet and driving bars and not curved in the direction of its storage position on a supply roll.

With respect to the problem of clutch-brake failure at high speeds, the instant invention includes a system for deactivating the driving means associated with the aforementioned multifunction cam wheel at a point in time when the stitch forming means and stitch driving means are approaching a condition of zero momentum (at the point where the reciprocating forming and driving bars reverse their direction of travel). In this manner, the braking mechanism has virtually no-momentum to absorb regardless of the speed at which the stitching head is operating.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 1 FIG. 1 is a front elevational view of the stitching head of the present invention with the front cover plate thereof removed to show the operative parts of the mechanism;

FIG. 2 is a side elevational view of the stitching head of the present invention; and

FIG. 3 is a schematic representation of the certain aspects of the instant invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Turning to the Figures, wherein like numerals are employed to designate like elements, it will be observed from FIGS. 1 and 2 that the wire stitching head of the present invention is in the form of a compact motor driven organization which is adapted to be suitably mounted at the upper end of a main support frame (not shown), which is provided with a horizontally disposed work supporting surface 12 fitted with a clenching member 14 for clenching the wire stitches as the same are successively formed in the stitching head and driven thereby through the work W to be stitched.

As mentioned previously, the instant invention represents improvements to the stitching head of the aforementioned Barland application Ser. No. 37,190, and as such includes: top and bottom

channel guide members

28, 30 secured on the front surface 18 of a frame 16 for guiding a reciprocating stitch forming bar 32 which has a bifurcated lower end 34, a driving bar 36 mounted for reciprocal motion within guideways 38 provided on the confronting inner surface 39 of the bifurcated lower end 34 of the forming bar 32; a multi-function cam wheel 40 rigidly secured to one end 42 of a driven shaft 44 suitably journalled by

ball bearings

46 and 48 in the front and rear surfaces 18 and of the frame 16; an electric motor 50 the output shaft 52 of which is selectively connectable to the driven shaft 44 by a clutch mechanism 54; and a pivoting anvil 56 the nose portion 58 of which is utilized in the stitch forming operation in a manner more fully set forth in the aforementioned Barland application, the contents of which are hereby incorporated herein by specific reference thereto.

In order to understand the manner in which the improvements of the instant invention function in a wire stitching machine of the type set forth in the Barland application, it is perhaps worthwhile to begin a description of the instant invention by providing a short description of the overall operation of a stitching head of the type described in said Barland application Ser. No. 37,190.

Initially it should be pointed out that the cam wheel 40 carries an arcuate feeding cam 60 which projects slightly into the path of travel 62 defined by the periphery of the cam wheel 40 and a guide roller 64 the specific construction of which is set out in great detail in the aforementioned Barland application. Thus for each revolution of the cam wheel 40 (affected when the clutch 54 interconnects the continuously rotating output shaft 52 of the motor 50 with the driven shaft 44), a preselected length of wire, corresponding to the arcuate length of the feeding cam 60 will be advanced from a supply reel (not shown) through

tubular wire guides

68, 70, through a wire check 71 forming a part of the instant invention, and a passageway 72 provided in the lower guide member 30, into channelway 74 provided in the lower guide member 30.

It will be appreciated that the clearance between the guide roller 64 and the periphery of the cam wheel 40 is such that the wire 66 fits freely therebetween under normal circumstances. It is only when the projecting feed cam 60 enters the path of travel 62 that the wire is "sandwiched and thereby advanced. Of course, during intervals of non-feed, when the wire 66 is free with respect to the feeding mechanism, the wire check 71 to be described in greater detail, prevents the wire from being pulled back toward its supply roll, not shown. Also, it will be appreciated that the arcuate or peripheral length of the feeding cam 60 is preselectively choosen to correspond to the overall length of the ultimately desired stitch. Yet to be described in connection with an improvement of the instant invention is the manner in which the preselected length of wire corresponding to the arcuate length of the feed cam 60, is chosen with respect to the width of the channelway 74 in the lower guide member 30.

Provided on the rearward side of the cam wheel 40 (as viewed in FIG. 1) is a second cam surface 76 which, as best seen in FIG. 2, cooperates with a following rod 78 to maintain the pivotally mounted anvil 56 in the wire supporting position illustrated in FIG. 2. It will be appreciated, that when the cam 76 rotates free of the following rod 78, a spring biased plunger 80 will rotate the anvil 56 in a clockwise direction as viewed in FIG. 2 and out of the path of travel of the driver bar 36 as will be described below. It should be pointed out, that the placement of the

cams

60 and 76 relative to one another, and the arcuate length of the cam 76, are chosen such that the anvil 56 and its wire supporting nose 58, will be in the proper wire supporting position illustrated in FIG. 2, as the wire 66 is being advanced into the channelway 74 in the manner previously described.

Finally, the front surface 82 of the cam wheel 40 carries an outstanding pin 84 to which is pivotally connected to one end of a pair of

links

86, 88 respectively. The opposite end of the link 86 is pivotally connected to the pin outstanding from the forming bar 32, and the opposite end of the link 88 is pivotally connected to pin 92 provided on the driver bar 36. It will be noted that the pin 90 joining the link 86 to the former bar 32 is mounted off center and to the right (as viewed in FIG. 1) with respect to the location of the pin 92 which joins the link 88 to the driving bar 36. This mounting is intentionally chosen, such that the length of the reciprocating stroke of the driver bar 36 is greater than the length of the reciprocating stroke of the bifurcated forming bar 32 which together function in the following manner.

Assuming that the feeding cam 60 has positioned the next length of wire in the channelway 74 (appropriately supported by the anvil 56 by virtue of the cam surface 76 and the follower rod 78), continued rotation of the cam wheel 40 causes the

links

86 and 88 to begin the downward strokes of the former bar 32 and the driver bar 36 respectively. Because the lower end of the former bar 32 is initially lower than the bottom edge 94 of the driver bar 36, the wedge like surfaces 96 of the bifurcated end 34 of the former bar 32 quickly engage the opposite ends of the wire length positioned in the channel 74 and bend them downward around the anvil nose 58 to form the desired U shaped stitch illustrated at 98 in FIG. 2. Immediately thereafter, the lower end 94 of the driving bar 36 reaches the bight portion of the U shaped stitch and continues to drive the stitch (within the confines of the confronting faces 39 of the bifurcated forming bar) through the work piece W and into engagement with the clenching member 14. It should be pointed out that the wire is initially cut from the continuous supply running through the passageway 72 by the side edge 100 of the bifurcated forming bar 32. Additionally, it should be pointed out that the positioning and length of the second cam 76 provided on the cam wheel 40 is such that just as the driving bar 36 engages the bight portion of the U shaped stitch, the cam 76 leaves the following rod 78 and the spring biased plunger 80 quickly rotates the anvil 56 out of the path of travel of the driving bar 36.

Thus the stitch is fed, formed, driven, and clenched in one quick continuous operation, all motions of which are generated by the single multi-function cam wheel 40. During the second half cycle of cam wheel rotation, the motions are reversed with the driving bar 36 being lifted before the forming bar 32.

With respect to FIG. 3, the actual initiation of a stitching cycle begins when anappropriate photoelectric sensing means 97 functions to sense the leading edge of the work piece 14 as it advances past the stitching head 10. When the photocell detects the presence of the leading edge, it energizes a conventional timer 99 which is set to time out upon the expiration of a predetermined amount of time corresponding to the length of the front flaps of the carton to be constructed from the box blank 14 being stitched by the machine. When the timer 99 is timed out, it generates a signal applied to the gate 101 of a semiconductor controlled rectifier 103 which is thereby turned on to complete a circuit comprising voltage source 106, clutch coil 148 (FIG. 2), the SCR 103, and to ground. Once clutch coil 148 is energized, then in a manner described in further detail in the aforementioned Barland application, the clutch 54 is activated to interconnect the outputof the motor 50 with the cam wheel 40. It is to be understood, however, that any suitable clutch or clutch brake combination may be used in the instant invention and not just the clutch brake described in detail in the aforementioned Barland application.

To control the deactivation of the stitching operation, sensing contacts 105 are positioned in the path of travel of the reciprocating stitch former bar 32. A counter 107 responsive to the pulses produced by the contacts 105 is utilized to preset the number of stitches desired. When the preset number of stitches have been sensed by contacts 105 and accumulated by counter 107; a signal is applied on the line 109 which the capacitor-resistive network 111 converts to a pulse appearing on the line 113 which is applied to the base 115 of a transistor 117 which turns on to thereby momentarily make a low impedance bypass circuit around the SCR 103 which is thereby extinguished. Thus coil 148 is deenergized, the clutch 54 is braked, and the stitching head ceases operation.

Turning to the specific contributions of the instant invention, it was previously mentioned that at extremely high rates of speed, there is a tendency for the leading end 119 of the wire to bang against the far wall 121 of the passageway 74 thereby bending and deforming the wire and the subsequent stitch formed thereby. To avoid this problem, the arcuate length A of the feeding cam 60 of the cam wheel 40, corresponding to the length of wire which will be fed into the channelway 74, is preselectively chosen to be slightly less than the width of the channelway 74 designated B in FIG. 3. In this manner, the end 119 of the wire never reaches the far wall 121 and the aforementioned problem is completely eliminated.

Since the preselected length of wire fed into the channelway 74 isan important factor in eliminating the tendency of the wire to bang against the far wall thereof, it will be appreciated that the wire feeding operations described previously must be especially accurate. To this end, and to avoid any possibility of slippage during the feeding operation, the instant invention provides that the guide roller 64 be positively driven for rotation with the cam wheel 40 during the feeding operation. Specifically and as seen perhaps most clearly in FIG. 2, the guide roller 64 (the details of which are disclosed and claimed in the aforementioned Barland application), is fixedly mounted by a key way 123 to the reduced diameter end 125 of a shaft 127. The shaft 127 is provided with a gear 129 the teeth 131 of which mesh with gear teeth 133 provided around the periphery of the cam wheel 40. In this manner, the guide roller 64 is driven synchronously with the cam wheel 40 thereby materially increasing the control and accuracy of the feeding operation.

At the other end of the feeding operation, the novel wire check means 71 is provided to prevent backup of the wire 66 toward its supply (not shown) during the intervals between positive wire feed. Before describing the wire check 71 in detail, it is to be appreciated, and considered one of the improvements of the instant invention, that the wire check 71 is secured to the frame 16 immediately adjacent the lower guide member to thereby minimize the distance between the wire check and the passageway 72 through which the wire passes on its way to the channelway 74.

In accordance with one aspect of the invention, the wire check 71 includes a pair of

shafts

135, 137 supported between

end plates

139 and 141 respectively. Mounted on each shaft is a

roller

143, 145 spaced apart from one another to define a feed path for wire passing therethrough. Each of the rollers is rotatable in only one direction, that corresponding to the direction of feed of the wire toward the stitch forming channelway 74. To accomplish such unidirectional rotation, the rollers may comprise for example the type of unidirectional clutches manufactured by the Torrington Company of Torrington, Connecticut but of course, any other suitable unidirectional roller arrangement may be provided to establish the direction of rotation desired.

To facilitate the insertion of the wire during an initial loading operation, the shaft 137 may be rotated in a counterclockwise direction about pivot 147. A spring 149 wrapped around the pivot 147 and having one end connected to the arm upon which the shaft 137 is mounted and the other end connected to a fixed pin 151 normally biases the roller 145 toward the roller 143.

To further help in properly aligning the length of wire within the channelway 74, it is desirable that the length of wire in the channelway remain in a position transverse with respect to the reciprocating path of travel of the forming bar 32 and the driving bar 36. To this end, the wire guiding tube terminates in a portion 153 which is disposed in a curvilinear path which is opposite to the direction of bias established on the supply of wire by virtue of its storage on a roll (not shown). Thus by the time the wire emerges from the passageway 72 in the lower guide member 30 it has been straightened out and no longer attempts to return to the direction of curvature in which it was stored on the supply roll.

Finally, as was mentioned previously, when operating at extremely high rates of stitching speed, it sometimes happens that the clutch mechanism such as S4 physically fails in its attempt to apply a braking action to the moving parts of the stitching head which of course gather increasingly high momentum with higher operating speeds. To eliminate this problem, the instant invention provides that the sensing contacts 105 are positioned in the reciprocating path of motion of the forming bar 32 adjacent the uppermost point of travel designated 155 in FIG. 3 of the forming bars 32. Of course it will be appreciated that the point 155 represents the point of reversal of travel of the reciprocating forming bar 32, such that this point 155 corresponds to a condition of zero momentum for the reciprocating parts. Therefore, and in accordance with this aspect of the instant invention, location of the contacts 105 adjacent the point of zero momentum, guarantees that the clutch 54 will be subjected to a minimum, virtually zero, momentum when it applies a braking force to the moving parts of the stitching head. Thus, regardless of what speeds are attained, the clutch 54 never sees" the high momentums involved when it applies the braking force and the aforementioned failure thereof is completely eliminated. Preferably, the contacts 105 are spaced from the uppermost point of travel 155 by a distance designated C in FIG. 3 corresponding to the time required for the circuitry to deenergize the coil 148 (and the mechanism responsive thereto, described in the aforementioned Barland application, to actually disengage the clutch and apply the braking action) whereby the stitch forming means and stitch driving means will just reach their zero momentum position when the brake is actually applied to the shaft 44.

Although this invention has been described with re spect to its preferred embodiments, it should be understood that many variations and modifications will now be obvious to those skilled in the art, and it is preferred, therefore, that the scope of the invention be limited, not by the specific disclosure herein, only by the appended claims.

I claim: 1. A wire stitching head comprising; a frame; stitch forming means mounted on said frame for forming a preselectively shaped stitch from a preselected length of wire which has been supplied thereto; stitch driving means movably mounted with respect to said stitch forming means for driving the stitch formed by said stitch forming means into a work piece positioned in predetermined relationship with respect to said stitching head; and wire feeding means for intermittently supplying said preselected length of wire to said stitch forming means from a supply of said wire; said wire feeding means including;

a cam wheel mounted on said frame, driving means for selectively rotating said cam wheel,

a guide roller mounted on said frame, said guide roller mounted on said frame in proximity to said cam wheel to define a path of travel for said supply of wire therebetween,

said cam wheel having an arcuate feeding cam of said preselected length, said arcuate feeding cam projecting into said path of travel each time said cam wheel is rotated a revolution by said driving means; and further including linking means connected between said cam wheel and said stitch forming means and said stitch driving means for operating said stitch forming means and said stitch driving means in reciprocating paths of motion in response to rotation of said cam wheel by said driving means; and further including start means for initiating the energization of said driving means; and

stop means for deenergizing said driving means; said stop means including sensing means for deenergizing said driving means when said stitch forming means and said stitch driving means approach a condition of zero momentum.

2. The wire stitching head of claim 1 wherein said sensing means includes switching means positioned ih said reciprocating path of motion adjacent the uppermost point of travel of said stitch forming means.

3. The wire stitching head of claim 2 wherein said switching means is spaced from said uppermost point of travel of said stitch forming means by a distance corresponding to the time required for said stop means to deenergize said driving means; whereby said stitch forming means and stitch driving means will just reach their zero momentum position when said driving means is deactivated.

4. A wire stitching head comprising:

a frame,

stitch forming means mounted on said frame for forming a preselectively shaped stitch from a prese lected length of wire which has been supplied thereto;

stitch driving means movably mounted with respect to said stitch forming means for driving the stitch formed by said stitch forming means into a work piece positioned in predetermined relationship with respect to said stitching head,

wire feeding means for intermittently supplying said preselected length of wire to said stitch forming means from a supply of said wire;

driving means for operating at least said stitch forming means and said stitch driving means; and further including start means for initiating the energization of said driving means;

stop means for deenergizing said driving means;

said stop means including sensing means for deenergizing said driving means when said stitch forming means and said stitch driving means approach a condition of zero momentum.

5. The wire stitching head of claim 4 wherein sai stitch forming means and said stitch driving means move with respect to said frame in reciprocating paths of motion; and

wherein said sensing means includes switching means positioned in said reciprocating path of motion adjacent the uppermost point of travel of said stitch forming means.

6. The wire stitching head of claim 5 wherein said switching means is spaced from said uppermost point of travel of said stitch forming means by a distance corresponding to the time required for said stop means to deenergize said driving means; whereby said stitch forming means and stitch driving means will just reach their zero momentum position when said driving means is deactivated.

7. The wire stitching head of claim 4 and further including a guide member secured to said frame for guiding the movement of said stitch forming means, said guide member including a channelway into which said preselected length of wire is fed by said wire feeding means and within which said stitch forming means rehaving an arcuate feeding cam of said preselected length projecting into said path of travel each time said cam wheel is rotated a revolution by said driving means; and

wherein the arcuate length of said feeding cam corresponds to said preselected length of wire.

I II

Claims

1. A wire stitching head comprising; a frame; stitch forming means mounted on said frame for forming a preselectively shaped stitch from a preselected length of wire which has been supplied thereto; stitch driving means movably mounted with respect to said stitch forming means for driving the stitch formed by said stitch forming means into a work piece positioned in predetermined relationship with respect to said stitching head; and wire feeding means for intermittently supplying said preselected length of wire to said stitch forming means from a supply of said wire; said wire feeding means including; a cam wheel mounted on said frame, driving means for selectively rotating said cam wheel, a guide roller mounted on said frame, said guide roller mounted on said frame in proximity to said cam wheel to define a path of travel for said supply of wire therebetween, said cam wheel having an arcuate feeding cam of said preselected length, said arcuate feeding cam projecting into said path of travel each time said cam wheel is rotated a revolution by said driving means; and further including linking means connected between said cam wheel and said stitch forming means and said stitch driving means for operating said stitch forming means and said stitch driving means in reciprocating paths of motion in response to rotation of said cam wheel by said driving means; and further including start means for initiating the energization of said driving means; and stop means for deenergizing said driving means; said stop means including sensing means for deenergizing said driving means when said stitch forming means and said stitch driving means approach a condition of zero momentum.

2. The wire stitching head of claim 1 wherein said sensing means includes switching means positioned in said reciprocating path of motion adjacent the uppermost point of travel of said stitch forming means.

4. A wire stitching head comprising: a frame, stitch Forming means mounted on said frame for forming a preselectively shaped stitch from a preselected length of wire which has been supplied thereto; stitch driving means movably mounted with respect to said stitch forming means for driving the stitch formed by said stitch forming means into a work piece positioned in predetermined relationship with respect to said stitching head, wire feeding means for intermittently supplying said preselected length of wire to said stitch forming means from a supply of said wire; driving means for operating at least said stitch forming means and said stitch driving means; and further including start means for initiating the energization of said driving means; stop means for deenergizing said driving means; said stop means including sensing means for deenergizing said driving means when said stitch forming means and said stitch driving means approach a condition of zero momentum.

5. The wire stitching head of claim 4 wherein said stitch forming means and said stitch driving means move with respect to said frame in reciprocating paths of motion; and wherein said sensing means includes switching means positioned in said reciprocating path of motion adjacent the uppermost point of travel of said stitch forming means.

7. The wire stitching head of claim 4 and further including a guide member secured to said frame for guiding the movement of said stitch forming means, said guide member including a channelway into which said preselected length of wire is fed by said wire feeding means and within which said stitch forming means reciprocates; said preselected length of wire being less than the width of said channelway.

8. The wire stitching head of claim 7 wherein said wire feeding means includes a cam wheel mounted on said frame, said driving means rotating said cam wheel upon activation thereof; a guide roller mounted on said frame in proximity to said cam wheel to define a path of travel for said wire therebetween; said cam wheel having an arcuate feeding cam of said preselected length projecting into said path of travel each time said cam wheel is rotated a revolution by said driving means; and wherein the arcuate length of said feeding cam corresponds to said preselected length of wire.