US3174448A - Stringing machines - Google Patents

Description

H. A. 'IMHOF STRINGING MACHINES March 23, 1965 6 Sheets-Sheet l Filed June 14, 1962 Invent@ Herman/4 Imhof /z/sfomey March 23, 1965 H. A. :MHOF 3,174,448

STRINGNG MACHINES Filed June 14. 1962 6 Sheets-Sheet 2 March 23, 1965 H. A. IMI-10F STRINGING MACH INES 6 Sheets-Sheet 3 Filed June 14, 1962 v H. A. IMHoF STRINGNG MACHINES March 23, 1965 6 Sheets-Sheet 4 Filed June 14, 1962 March 23, 1965 Filed June 14, 1962 March 23, 1965 H. A. IMHOF sTRmGNG MACHINES 6 Sheets-Sheet 6 Filed June 14, 1962 United States Patent O 3,174,443 srnrnorne Macs This invention relates generally to article stringing machines and more particularly to devices useful in such machines for controlling the movement of Vthe flexible strand and for clamping the articles to be threaded in strand receiving position.

In a machine such as that disclosed in application for United States Letters Patent Serial No. 117,219, tiled .lune l5, 1961, in the name of Charles P. Cardani et al., now Patent No. 3,142,896, a single article or a pair of articles are clamped in position and the leading end of a flexible strand is passed through the article or articles, a quantity of the strand is measured and then severed from the supply and the two ends of the severed length are looped about an eyeleting spindle. An eyelet is then clinched to connect the two ends together in tell-tale relationship so that any tampering with the loop may be readily detected.

In the accomplishment of the operation an eye-pointed needle carries the leading end of the strand through the article and is then withdrawn to yform an enlargement or bulge in the strand which is gripped by a piucer before the needle is fully withdrawn. Another pincer is employed for gripping the strand between the needle and a device which severs the length from the supply. The two pincers are then actuated through orbital movements about an eyeleting spindle to form bights which are connected together by the clinching of an eyelet.

It has been found in the machine of the application that articles of certain materials such as relatively stiif leather or plastic tend to be excessively damaged by the puncture of the needle which carries the strand. In addition the pincers are not completely reliable for retaining the ends of certain strands so that the machine fails to carry out its intended function during an operating cycle and the operation must then be repeated.

It is accordingly an object of the present invention to provide, for holding articles to be strung, clamps adapted to minimize puncture damage to the articles.

Another important object is to improve the reliability of operation of pincers for stringing machines.

A related object is to improve the uniformity of bulge formation, particularly when operating upon materials which do not grip the strand with sufficient tightness about the needle to prevent return movement of the strand without bulging.

Another object is to improve the article clamping and strand manipulation without increasing the time required to position articles in Stringing position and also without increasing the duration of the operating cycle of the machine.

In the achievement of the foregoing objects a feature of the invention relates to a vnovel construction for a first pincer which grips the bulge of the strand with greater certainty. Mounted on the rst pincer is a strand controller which assists in applying friction to the strand to assure the formation of the bulge and is effective even under conditions when the needle passes through an opening in the article being strung so that no bulge for-ming friction is provided by the article.

The first pincer achieves greater reliability in seizing the bulge in the strand by being brought into closer proximity with the needle and also by including two movable jaws so that the space for entry of the bulge is greater. According to anotherimportant feature of the invention the first 3,174,443 Patented Mar. 23, 1965 pincer is constructed to Iresist withdrawal of the strand from its grip after it has closed upon-the strand. For-this purpose one ofthe strand gripping surfaces of thepincer is Vhollowed outandthe other sur-face is Vformed with a-snubbing stud about -which the strand is Wrapped `in being l gripped by ,the jaws. 'In addition, in order to resist escape ofthe strand at a time in the operating cycle of the machine when the strand is under greater tension 1a depending post is formed on one of the jaws in a -position .to receive a partial wrap of the strand so vthat the frictional engagement of the strand against the post cooperates with the grip of the jaws to -prevent the Withdrawal ofthe strand.

According to still another feature Aofthe -invention the clamps which hold the articles 'in Stringing yposition are formed to cooperate with the pincers inthe manipulation of the strand during the operation of the machine. Both clamps are lformed withperforations which offer a limited clearance for the passage ofthe needle and also provide strand engaging surfaces which restrict the movement of thestrand to minimize any possible tearing-of the article being threaded. The clamp nearer to the first pincer is additionally formed with ,a strand retaining notch which assists in the placement of a bight from the leading end of the strand about an eyeleting spindle preparatory to joining the two ends of the Strand together to form a closedloop.

The foregoing objects and features and additional advantages of the present invention will be better understood from the following detailed description of an illustrative embodiment taken in connection with the accompanying drawings in which FIG. l is a View in left side elevation of an artice Stringing machine embodying the features of the present invention; l

FIG. 2 is a fragmentary View in left side elevation and partly Vin cross section of a portion of the machine shown in FIG. l, and more particularly depicting a clamp for an article to be str-ung and clamp operating connections;

FlG. 3 is a fragmentary View in front elevation of that portion of the machine shown in FIG. 2, and also including p incers employed for manipulating a flexible strand in the machine;

FIG. 4 is a fragmentary plan View of that part of the machine depicted in FIGS. 2 and 3 and also showing orbits defined by the pincers in forming bights about an eyeleting spindle; i

FG. 5 is a sectional detail view of clamp operating connections taken along the line V-V of FIG. 2;

FG. 6 is a detail perspective View on an enlarged Scale showing a pincer which is employed for manipulating the trailing end of the strand in forming a loop;

FIG. 7 is a fragmentary view in side elevation of a pincer for manipulating the leading end of the strand;

FIG, 8 is a plan view of the pincer of FIG. 7 on an enlarged scale and partially in cross section for showing internal pincer construction;

FIG. 9 is la sectional view taken along the line IX--IX of FIG. 8 showing the opening of the pincet jaws to grip the bulging strand;

FlG. l0 is a View in cross section taken along the line X-X of FIG. 8 and on a greatly enlarged scale illustrating the gripping of la bulge formed in the leading end of the strand and subsequent movement of the pincet after the bulge has been gripped;

FIG. 1l is fa fragmentary view showing the position of the leading end of the strand after the pincer of FIG. l0 has traveled through an orbit for laying a bight about an eyeletin g spindle;

PEG. 12 is a fragmentary view in side elevation of a portion of the pincer of FIG. 10, showing the placement of the strand at the end of the orbital motion; and,

FIG. 13 is a View in left side elevation depicting strand contacting instrumentalities and the position of the strand at the completion of the spindle looping motion of the pincer of FIG. 7.

The general organization of the present machine, as 'seen in FIGS. 1 to 3 inclusive, is similar to that of the 'above-identied Cardani et al. application and that disclosed in application for United States Letters Patent Serial No. 184,804, filed in my name on April 3, 1962-. The present machine includes a frame of a modiied eyeleting machine mounted on a base plate 12 and sup- 'porting a box-like subframe 14 in which is journaled a main shaft 16 which is driven a single revolution during the operation of the machine. The shaft 16 carries a complement of cams for actuating the various machine instrumentalities which include a curved eye pointed needle 18 and a strand measuring drum 20 more particularly disclosed in my copending application. Before the strand indicated at 22 is carried through the work pieces illustrated in FIG. 4 as a pair of shoes 24, 26, the work pieces :are held in position against the sides of a post or pedestal 28 by clamps indicated generally at 38 and 32. The clamps 30 and 32 are of novel and advantageous construction and not only minimize damage caused to the articles by the puncture of the needle 18 but also cooperate respectively with novel pincers indicated generally at 34 and 36 for manipulating the strand.

The clamps 30, 32 are opened by depressing a treadle 38 which also lowers the post 28 upon which is mounted an eyeleting spindle 40. The connections between the post 28 and the treadle 38 are the same as those disclosed in the Cardani et al. application and include a pair of spaced apart triangular plates 42 pivoted on the frame at 44. As shown in FIG. 1, interposed between the plates 42 and the treadle is a lever 46 pivotally supported on the frame at 48 and having a pivotal connection at 50 with a link 52 which connects the lever to the triangular plates. Also pivotally connected to the lever 46 at 50 is the lower ed of a short vertical link 54 for operating the clamps 30, 32 when the treadle 38 is depressed. The link 54 is urged downwardly by a tension spring 56 stretched between an anchor 58 on the frame and a pivot pin 60 forming the connection between the link 52 and the triangular plates 42. The treadle 38 is connected to the lever 46 by a vertical link rod 62 the lower end of which is pivoted at 64 to the treadle and the upper end of which is p-ivoted at 66 to the lever.

In the Cardani et al. machine there is provided a clamping arrangement designed to equalize clamping force on two articles received in the machine. However, there is no provision for assuring an adequate area of contact between the clamps and the work piece under conditions of different work piece thickness'. The Cardani et al. clamps are not adapted to minimize the enlargement of needle puncture attributable to movement of the strand nor to cooperate with the pincers in the placement of the strand during the operating cycle of the machine. Also the equalizing clamp biasing arrangement is complex and includes parts which are subject to being restricted in their motion by the introduction of lint or other foreign matter.

The clamp 30 in the present machine comprises a pad 70 pivoted at 72 to the lower end of a depending arm 74 which in turn is pivotally supported concentrically with the needle 18. The arm 74 is integral with a rearwardly extending body 76 spaced by an arm 78 from a sleeve portion 80 which is joumaled on a rearward extension of a shaft 82 defining the axis of the needle 18. The body 76 extends rearwardly past the arm 78 and receives at its rearward end a tension spring 84 for urging the pad 70 toward the pedestal 28. The clamp 32 is similarly arranged and includes a pad 86 pivoted at 88 to a depending arm 9) formed integral with :a body 92. The pad 86 also pivots about the axis of the shaft 82 and for this purpose the body 92 is formed on the distal end of an arm 94 which is integral with a sleeve 96 journallcd on the sleeve for the clamp 30. The sleeves Si) and 96 are retained against endwise movement on the shaft 82 by a shoulder at the forward end and by a snap ring 98 entering a groove in the shaft behind the sleeves. YThe body 92 extends rearwardly to receive a springltl' stretched between the body and a fixed anchor pin 102 to urge the pad 36 toward the pedestal 28.

To facilitate the removal of work pieces, particularly those tied together in pairs, it is desirable, especially when the two articles of the pair are tied together closely by a flexible strand, that the pedestal 28 be depressed before the clamps 3S and 32 are opened. For this purpose a T-shaped lifter 184 (FlGS. 2 and 5) is connected to the link 54 by means of a pin 196 in the link 54 passing through a slot 188 cut in the lower end of the lifter to form a lost motion connection. The lifter 184 is guided in a slide block 118 secured to the subframe 14 and the cross bar forming the top of the lifter engages the bodies .76 and 92 of the clamps. When the treadle 38 is depressed to raise the link 54 the triangular plates 42 are immediately pivoted in a clockwise direction as seen in FIG. l causing the spindle 48 to be lowered and the pin 186 rises in the slot 188 with no effect until the pin reaches the top of the slot. The lifter 184 then rises causing the bodies 76 and 92 to swing outwardly against the bias of their respective springs 84 and 180. After one or more articles such as a pair of shoes 24, 26 have been placed beneath the pads 70 and 86 respectively the treadle is released and as the lifter 104 is retracted downwardly the pads 70 and 86 close to hold the articles under the force of the springs 84 and 160. Because the pads 70 and 86 are pivotally supported, each adapts to the individual thickness or even downwardly tapering thickness of the articles which it clamps and because the clamps are urged into clamping position by separate springs there is no reaction from one clamp to the other in the absence of an article under one of the clamping pads.

In the Cardani et al. machine a needle actuating mechanism comprising a stub shaft formed integral with a driven pinion is journaled in the subframe. In the present machine, however, the shaft 82 upon which the needle 18 is pivoted is stationary, being formed with an enlargement 112 which is tightened against a surface of the subframe 14 by a nut 114. A needle carrier 116 to which the needle 18 is clamped is formed integral with a pinion 118 and both the pinion and carrier are free to rotate on the stationary shaft 82. The pinion 118 is engaged by a driving sector 127 operated as in the Cardani et al. machine. For stiffening the needle against deflection as it penetrates work pieces, a needle guide 122 is also journaled on the shaft 82 and is urged away from the carrier 116 by a torsion spring 124. As in the machine of my copending application, a quantity of strand is measured by being laid on the oscillated drum 20 which carries at its periphery a strand engaging pin 128. The drum 20 is oscillated through connections with a cam on the shaft 16 which include a driven pinion 132 and a driving gear sector 134.

As in the machines of the prior applications, before the quantity of strand is measured for the formation of a closed loop of strand passing through the articles, the leading end of the strand is gripped by the rst pincer. For this purpose the needle 18 is retracted slightly to cause a bulge such as that shown at 136 in FIG. 10 to form in the leading end of the strand and to be gripped by the first pincer 34 which in the present machine has been materially improved over the corresponding member of the prior applications in order to insure reliability of gripping and retention of the leading end of the strand against the tension encountered during subsequent manipulation. As in the Cardani et al. machine, the pincer 34 is opened to receive the leading end of the strand and is thereafter closed to grip the strand and moved bodily upwardly and in an orbit 138 shown in FIG. 4 to lay a iirst' bight about the eyeleting spindle 40. In the present machine the raising and lowering of the pincer 34 ,and its orbital movement about the path 138 are the same as in the Cardani et al. machine, but the strand engaging members of the pincers have been the subject of improvement. As in the Cardani et al. machine the opening and closing oi the pincel' 34 is under the control of a lever 140 corresponding to the lever 354 of the Cardani et al. application and urged by a tension spring (not shown) in a clockwise direction as seen in FIG. 7 to cause closure of the pincer. The open-ing of the pineer is effected by imparting a counterclockwise movement' to the lever 14d through a shoe 14,2 corresponding to that identified `as 382 in the Cardani et al. application.

The lever 140 is pivoted at 144 on the forward end of a slide 145 guided in a trunnion block 148. In the present machine movement is imparted to the rearward end of the slide 146 and the trunnion block 14S is raised and lowered in exactly the same manner as that disclosed in the Cardani et al. application. Since the support of the slide 146 and the mounting of the block 148 form no part of the present invention they will not be described in further detail.

For gripping the strand there are pivoted on the forward end of the slide 146 an inner jaw 150 and an outer jaw 152, the pivot being provided by a pin 154 retained in place by a snap ring 156. The inner jaw 1561 is hollowed out at S to receive a portion of a snubbing stud 160 formed integral with the -outer jaw 152. The inner jaw 159 is formed with a rearwardly and upwardly extending integral operating arm 162 slotted at 154 to receive a pin 166 which also serves as a pivotal connection .between the jaw operating lever 1d@ and a 1in`k163 connected at its forward end to the jaw 152 above the pivot 15d, the pivotal connection between the jaw 152 and the link 16S being in the form of a pin 179.

The strand engaging surfaces ofthe jaws 15% and 152 are arranged to grip the bulging portion 13d of the strand between surfaces which, while the pincer is opened, are

generally -parallel to the plane of the needle 13, indicated ,depicted in FIG. 7 under the bias of its associated spring,

the jaws '150 and 152 assume the relative positions for clamping the strand as shown in FIG. `8. Under these circumstances a clamping pressure is exerted in a broad area 173 of the strand ,above and to the left of the snubbing stud 16? as shown in FIG, 10 and also in a smaller area identied 'oy the reference numeral 174 in FIG. l0. The yclamping area 174 is important to assist the snubhing stud 160 to resist tension on the strand Z2 in the direction indicated by an arrow 176, as the pincer 34 is raised from its solid line position to its dash line position of FIG. lO and during subsequent manipulations in the operating cyclefof the machine.

It has been found Vin the .operation of the machines of the prior applications that work pieces of .certainnonresistive materials apply insutiicient friction .to the leading end portion of the strand about the needle `to cause the formation of a bulge 136 with reliability. As shown in FIG. 10, for example, the eXtreme leading end surface of the strand is shown havingiescaped from the body of the shoe 24 at the time that the needle penetrated .to its` cxtreme position shown in dashed lines. It is accordingly chines there is mounted on the forward face of the jaw 152 a strand controller 178 positioned to engage the leading end of the strand extending beyond the eye of the needle. The controller 173 which Ais formed of spring wire and is readily adjustable and replaceable has a straight, generally vertical shank terminating in a closed eye through which passes a screw 179 for securing the controller to the jaw 152,. At its lower end the controller 178vhas a generally semi-circular presser 180 which surrounds the upper half of the needle cross section, as seen particularly in FIG. 9, and by so doing prevents the escape of the strand A 22p from a groove 18,2, also shown in FIG. l0 `and formed on the inside or" the needle radius of curvature, to maintain the leading end of the strand in proper position to assure `formation of the bulge 136. It is to be noted also that the needle 18 is formed with an outside groove 184 for facilitating the passage of the threaded needle through the work piece and also for retaining in position the active portion of ,the strand, that is, that portion .extending rearwardly toward the supply from the needle eye.

In operation, the presser lies in the path of the needle 18, the needle having penetrated through the A shoe 24 and advanced beyond the pad 70 to a position in which the eye of the needle is beneath the pincer 34. vAt this time .the presser 180, having been .deilected slightly in an upwardly direction by the point of the needle, begins to apply a small downward pressure upon the vstrand r22, As shown in FIG. 9 the jaws of the pincer 34 are at this time open and since the needle 18 is moving forward the strand is relatively tight in the groove `182. The formation of the bulge 136 occurs as the needle is retracted from the dash line position of FIG. l0 to its solid line position. Formation of the bulge is assured because the presser 180 remains .stationary in .engagement with the strand as the needle is retracted so that it is not necessary in the present machine to rely upon the frictional engagement provided by the work piece which, assuming a normally wide range of work piece characteristics may be at times insufficient to provide reliable bulging. After the needle is retracted to the solid line position of FIG. l0, the jaws of the pincer are closed to grip the bulge 13,6. It will be appreciated lthat the jaw 152, in closing, turns in a clockwise direction about the pivot 154, as seen in FIG. 7, thus bringing the presser 180 closer to the eye of the needle and thus tending to increase the size of the bulge 136, as the jaws are approaching a position of gripping engagement with the strand.

In the solid line position of the pincer 34 depicted in FIG. 10 there is no tension upon the active portion of the strand and hence the bulge 136 initially lies out Vof engagement with the snubbing stud 160, being clamped in the area 173 shown deflected and of enlarged width in FIG. 10 and in the area 174 to the right of the stud. After the jaws have closed the needle 18 is retracted and the pincer 34 is raised from the solid line position to the dashed line position depicted in FIG. l0 and shortly afterward when the point of the needle has retracted to the right of the pin 12S on the drum 2d, as sho-wn in FIG. 3, the drum is set in motion to measure -a quantity of strand to be used in the formation of the closed loop passing through the work piece. Retraction or the needle and movement of the drum both tend to apply tension to the active portion of the strand 22 and when the strand is a hard twisted one of such a material as nylon for eX- ample, there is a tendency for the strand to slip from its spaced relationship with the stud 1611 into the embracing position depicted in the dashed showing of FIG. l0. ln the stud-embracing position which is attained after a slight slippage of the strand between the jaws, the tendency of the strand to be pulled `further out of the jaws is resisted by the grip imposed upon it in the area 174, the snubbing action about the stud as well as by the grip in the area 173 to the left of the stud.

Cooperating with the pincer 34 in positioning the active portion of the strand 22 during the formation of a iirst bight about the eyeleting spindle 40 are a keyhole-shaped aperture 188 and a slot 190 in the pad 70. The pad 86 is also formedl with a similar aperture 191 as seen in FIG. 3; AAsthe pincer 34 rises to its dash line position in FIG. 10 the tearing di die snee 24 by the reerientaaon and newly acquired tension on the active pr't of the strand 22 is prevented by the confinement offered by the aperture 188 and during the rise of the pincer the portion of the strand at the pad 70 enters the slot 190 and is thereafter retained in position as the relative orientation of the pincer 34 and the aperture 188 is continuously changed during the movement of the pincer about its orbit 138. Because the clamp pad 70 has a limited movement about its pivot 72 which in turn pivots about the axis of the needle it is possible to minimize clearance between the needle and the aperture 188 and thus the aperture is much more effective for strand control than would otherwise be possible., I

In order t assist the grip of the jaws `150 and 152 and the snubbing action of the stud 160 in resisting withdrawal of the strand under further tension applied to` the strand as the pincer 34 reaches the position of FIG. l1 there is provided on the jaw 150 a depending post 192. The orbital movement of the pincer 34 after, the strand has rst been placed in Contact with the spindle 40 causes the strand to be wrapped about the post 192 and the resulting frictional engagement is of material assistance in preventing withdrawal of the strand from the pincer 34 under the increased strand tension.

As in the machines of the above-identified applications, as the needle in being withdrawn approaches the position shown in FIG. 3, the pincer 36 grips the strand between the eye of the needle and the pad 86 and a severing device indicated generally at 194 (FIG. 4) is actuated to cut the strand between the pincer and the needle. In the prior machines difficulty has been experienced in the escape of the trailing end of the strand from the right pincer during the orbital movement of the pincers about the eyeleting spindle. The pincer 36 has accordingly been improved to assure a greater strand holding reliability than has heretofore been possible.

As best seen in FIGS. 4 and 6, the pincer 36 comprises a lfixed jaw 196 formed integral with a generally horizontal slide 19S, and a movable jaw 200 pivoted at 202 on the slide. The jaw 200 is connected by a pivot pin 204 to a generally horizontal short link 206 which is pivoted at 208 at its rearward end to the forward end of a fragmentarily depicted three-armed lever 210. The slide 198 and the lever 210 correspond respectively to members 596 and 620 of the Cardani et al. application, and are operated in the same manner. The lever 210 is pivoted at 212 on the slide 198 and is spring urged to depress the pivot pin 208 causing the jaw 200 to grip the strand 22 against the stationary jaw 196. The pin 208 is raised against the spring bias for opening the jaw 200 to release the strand 22 and for thereafter capturing the next length of strand in a succeeding machine cycle.

In order to prevent escape of the strand from between the distal ends of the jaws 196 and 200 as the pincer 36 is propelled about its bight forming orbit 214 the movable jaw 200 is formed with a horn 216 which bars the escape of the strand from between the jaws .as the strand is first being gripped and later in the cycle when the strand is under tension.

In summary, the operation of the machine after one yor more articles herein represented as a pair of shoes y24, 26 have been clamped in Stringing position by the pads 70 and 86, the shaft 16 is rotated through a single revolution by depressing a treadle 218, seen in FIG 1. At

the beginning of the machine cycle the needle 18 is propelled from the position of FIG. 3 to the dash line position of FIG. 10. As the needle is advancing the pincer 34 is lowered and opened to bring the presser 180 into vengagement with the leading end of the strand lying in the groove 18,2 and the needle is thereafter retracted to naar;

the solid line position in FIG. l() to cause the formation of the bulge 136 with the assistance of the presser 180. The pincer 34 is closed on the bulge 136 and the needle withdrawn back to the position of FIG. 3 as the pincer 34 rises to the dash line position of FIG. 10. After the point of the needle has passed to the right of the pin 12S `as shown in FIG. 3, the drum 20 is oscillated in a clockwise direction, as seen in FIG. l, so that its pin 128 engages the strand for measuring the length to be included in the closed loop connected to the Work piece, the strand being then reaved from the supply through the eye of the needle. During the retraction of the needle back to the position of FIG. 3 the pincer 34 travels about the orbit 133 to form a rst bight about the eyeleting spindle 40. After the needle has reached the position of FIG. 3 the pincer 36 grips the strand ahead of the needle eye and the strand is cut between pincer 36 and the needle eye by the strand severing device 194. The pincer 36 is then propelled about the orbit 214 to lay a second bight from the trailing end of the strand about the eyeleting spindle 40. After the two bights, one from the leading end and the other from the trailing end of the length of strand have been laid about the spindle 40 as shown in FIG. 6 an eyeleting tool 220 (FIG. 2) is lowered to pick up an eyelet from a raceway 222 (FIG. 1) and to clinch .the eyelet on the spindle 40 thereby securing together the two ends of the strand in tell-tale relationship and typically connecting the strand in the same operation to a tag 224 shown in FIG. 13.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. In a. machine for Stringing articles, the combination of a curved eye-pointed needle for carrying the leading end of a ilexible strand through an article, a clamp mounted for pivotal movement about the axis of needle movement and having an apertured pad adapted to engage the article, the aperture of which closely surrounds the needle for minimizing the size of puncture from the needle in the article and for thereafter assisting in the control of the strand, a rst pincer having a pair of movable jaws for gripping the leading end of the strand near the needle eye, one of the jaws having a recess in its strand engaging surface and the other having a snubbing stud extending into the recess, a second pincer for gripping the strand between the needle eye in retracted position and the article, means for severing the strand between the second pincer and the needle eye, means for imparting orbital movements to the pincers for forming bights from the end portions of the severed strand about a spindle, and means for thereafter securing the two bights together.

2. In a machine for Stringing articles having a curved eye-pointed needle for carrying the leading end of a exible strand through an article, and means for receiving the article in Stringing position, the combination of a pincer comprising a pair of movable jaws mounted to be opened generally parallel to the path of the needle, one of the jaws having a recess in its strand engaging surface and the other jaw having a snubbing stud extending into the recess, a strand controller mounted on one of the pincer jaws for frictionally engaging the leading end of the strand beyond the needle, means for retracting the needle while the strand is engaged by the controller to form a bulge in the strand partially surrounding the stud, and means for drawing the controller while in contact with the strand nearer to the needle eye to assist in enlarging the bulge as the pincer jaws are being closed.

3. Ina machine for Stringing articles, having a curved eye-pointed needle for carrying the leading end of a flexible strand from a supply through an article means for receiving the article in Stringing position, and means for severing from the supply a length of strand passing through the article, the combination of a pincer comprising a pair of movable jaws mounted to be opened generally parallel to the path of the needle, one of the jaws having a recess in its strand engaging surface and the other having a snubbing stud extending into the recess, a spindle about which bights from the leading and trailing end of the strand are formed, a post depending from one of the jaws, and means for imparting to the pincer an orbital movement about the spindle during which the strand is wrapped about the post to assist the grip of the jaws and the snubbing engagement about the stud in resisting Withdrawal of the leading end of the strand from the pincer under increased tension.

4. In a machine for Stringing articles having a curved eye-pointed needle mounted for oscillatory movement about an axis to carry the leading end of a flexible strand from a supply through an article, the combination of a clamp arm mounted for pivotal movement about the axis of needle movement, a pedestal against which the article is secured, a spring urging the 'arm toward the pedestal, an apertured pad pivoted on the arm and adapted to clamp the article in Stringing position, the aperture of the pad closely surrounding the needle for minimizing puncture damage to the article and for controlling the strand, the pad being additionally formed with a slot in which a portion of the strand is trapped for a part of the operating cycle of the machine.

5. In a machine for Stringing together pairs of articles having a curved eye-pointed needle mounted for oscillatory movement about an axis to carry the leading end of a flexible strand from a supply through a pair of articles, a pair of clamp arms mounted for pivotal movement about the axis of needle movement, a pedestal against which the articles are secured, a spring urging each arm toward the pedestal, an apertured pad pivoted on each arm to clamp one of the articles in Stringing position, the apertures of the pads closely surrounding the needle for controlling the strand to minimize tearing ol' the articles by the strand as the orientation of the strand is changed relative to the articles during the operating cycle of the machine.

6. In a machine for Stringing `articles having acurved eye-pointed needle, means for imparting an article penetrating motion to the needle for carrying the leading end of a flexible strand from a supply through an article and for thereafter retracting the needle lirst to form a bulge in the leading end of the strand and then to withdraw the needle completely from the article, and means for receiving the article in Stringing position, the combination of a pincer comprising a pair of movable jaws mounted to be opened generally parallel to the path of the needle, a strand controller mounted on one of the pincer jaws for frictionally engaging the leading end of the strand beyond the needle eye to cooperate with the bulge forming retraction of the needle for causing a bulge of the leading end of the Strand to enter between the open pincer jaws, and means for drawing the controller nearer to the needle l@ eye to assist in enlarging the bulge as the pincer jaws are closed.

7. In a machine for Stringing articles having a curved eye-pointed needle, means for imparting an article penetrating motion to the needle for carrying the leading end of a liexible strand from a supply through an article and for thereafter rst retractng the needle to form a bulge in the str-and and then to withdraw the needle completely from the article, and means for receiving the article in Stringing position, the combination of a pincer comprising pair of movable jaws mounted to be opened generally parallel to the path of the needle, a thread controller mounted on one of the pincers for frictionally engaging the leading end of the strand beyond the needle eye to cooperate with the bulge forming retraction of the needle for causing a bulge or" the leading end of the strand to enter between the open pincer jaws, means for drawing the thread controller nearer to the needle eye to assist in enlarging the bulge as the pincer jaws are closed, a depending post on one of the jaws, a spindle, and means for imparting an orbital bight-forming movement to the pincer about the spindle during which movement the strand is wrapped about the post to assist in resisting escape of the strand from between the jaws while the strand is under tension.

8. ln a machine for Stringing article having a curved eye-pointed needle, means for imparting an article penetrating motion for carrying the leading end of a flexible strand from a supply through an article `and for thereafter retracting the needle lirst to form a bulge in the leading end of the strand and then to withdraw the needle completely from the article, means for severing from the supply a length of strand passing through the article, and means for receiving the article in Stringing position, the combination of a irst pincer comprising a pair of movable jaws mounted to be opened generally parallel to the path of the needle to receive and grip the bulge in the leading end of the strand, a thread controller mounted on one of the jaws of the first pincer for frictionally engaging the leading end of the strand beyond the needle eye to assist in forming the bulge, and a second pincer comprising a pair or" jaws one of which is movable and one of which is formed with a horn extending across the space between the jaws while gripping the trailing end of the strand to prevent escape of the strand from the pincer under strand tension.

References Cited inthe file of this patent UNITED STATES PATENTS 1,293,554 Rosenthal et al Feb. 4, 1919 2,503,809 Eastman Apr. 1l, 1950 2,911,928 Burke Nov. 10, 1959

Claims (1)

1. IN A MACHINE FOR STRINGING ARTICLES, THE COMBINATION OF A CURVED EYE-POINTED NEEDLE FOR CARRYING THE LEADING END OF A FLEXIBLE STRAND THROUGH AN ARTICLE, A CLAMP MOUNTED FOR PIVOTAL MOVEMENT ABOUT THE AXIS OF NEEDLE MOVEMENT AND HAVING AN APERTURED PAD ADAPTED TO ENGAGE THE ARTICLE, THE APERTURE OF WHICH CLOSELY SURROUNDS THE NEEDLE FOR MINIMIZING THE SIZE OF PUNCTURE FROM THE NEEDLE IN THE ARTICLE AND FOR THEREAFTER ASSISTING IN THE CONTROL OF THE STRAND, A FIRST PINCER HAVING A PAIR OF MOVABLE JAWS FOR GRIPPING THE LEADING END OF THE STRAND NEAR THE NEEDLE EYE, ONE OF THE JAWS HAVING A RECESS IN ITS STRAND ENGAGING SURFACE AND THE OTHER HAVING A SNUBBING STUD EXTENDING INTO THE RECESS, A SECOND PINCER FOR GRIPPING THE STRAND BETWEEN THE NEEDLE EYE IN RETRACTED POSITION AND THE ARTICLE, MEANS FOR SEVERING THE STRAND BETWEEN THE SECOND PINCER AND THE NEEDLE EYE, MEANS FOR IMPARTING ORBITIAL MOVEMENTS TO THE PINCERS FOR FORMING BIGHTS FORM THE END PORTIONS OF THE SEVERED STRAND ABOUT

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