US3632033A

US3632033A - Ram mechanism for a snap fastener attaching machine

Info

Publication number: US3632033A
Application number: US33421A
Authority: US
Inventors: Erich A Schmidt
Original assignee: Tertron Inc
Current assignee: UNIVERSAL FASTENERS Inc A CORP OF; Tertron Inc
Priority date: 1970-04-30
Filing date: 1970-04-30
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04
Also published as: ES386513A1; BE760673A; CH564919A5; IE34741B1; IE34741L; DE2059121B2; DE2059121C3; ZA707758B; NL150320B; JPS503707B1; DE2059121A1; CA960617A; FR2074082A5; NL7017126A; GB1332164A

Abstract

A ram mechanism in a machine for attaching the components of a snap fastener to a material, wherein the snap fastener components are fed from strips in spaced relation to each other, are separately cut from the fed strips and are clamped together with the material therebetween by the ram mechanism; automatically operated gripping means on a ram plunger retains and releases a fastener component in accordance with particular movements of the ram plunger.

Description

References Cited UNITED STATES PATENTS 6/1960 Lundeberg...................

United States Patent Erich A. Schmidt Lexington, Ky. Appl No. 33,421

[72] Inventor 1,509,658 9/1924 Lewis Primary Examiner-Granville Y. Custer, Jr. Att0rneyMeech & Field [22] Filed Apr.30,1970

[45] Patented Jan. 4, 1972 [73] Assignee Tertron lnc.

Providence, RJ. a part interest ePoe m. t ma a m n I g de n Mf nh th 6 n .m mwm m m n mm mm P wWd l fi a Pm ABSTRACT: A ram mechanism in a machine for attachin components of a snap fastener to a materi fastener componentsare fed from flri each other, are separately cut from clamped together with the material therebetween automatically operated gripping means on a ram nger retains and releases a fastener com cordance with particular movements of the ram m s m m m mP umm m mmnms 2 R 2 27 E B2 N 2 E m mm T u u S m mm P u n A m mm RE m mm 0mm m I H m MC m mm Am m I M m mm M M m m ND m mr. C17 n EH5 m NS Mmm LM MT wm ATC S mk RA9 U IF U H N 5 5 U5 Pmmmm 41912 3,632,033

SHEET 1 OF 2 INVENTOR ERICH A. SCHMIDT A TTORNE Y6 PATENIEU JAN 4 asrz SHEET 2 BF 2 INVENTOR. ER/CH A. SCHMIDT A T TORNEYJ RAM MECHANISM FOR A SNAP FASTENER ATTACIIING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ram mechanism in a machine for attaching snap fastener elements to a material, and in particular, to such a mechanism having automatic clamping and releasing operations for the elements to be fastened.

2. Description of the Prior Art Conventional snap fastener attaching machines for attaching plastic snap fastener elements to garments or fabric material take a wide variety of forms as exemplified by U.S. Pat. Nos. 2,614,714, 2,735,567, 3,049,462 and 3,238,082. The known prior art machines have not been capable of performing satisfactory clamping operations with respect to snap fastener elements that are made of plastic. For this reason some of the prior art machines have used heating means to facilitate clinching or clamping of the snap fastener elements; while not all of the conventional machines have utilized heating means, of necessity they have required extremely complicated ram devices operating with such force that the assembled fastener was often deformed. Furthermore, all of the conventional machinery used for attaching snap fasteners have been extremely complicated in their sequence of operation and have utilized a complex arrangement of operating components in association with their ram mechanisms.

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to construct a ram mechanism for a snap fastener attaching machine that is operable in a simple manner with enough force to effect proper clamping of snap fastener elements.

The present invention is summarized in that a snap fastener attaching machine is provided with a ram mechanism including a ram plunger having a stroke movement on a longitudinal axis between rest and actuated positions, a fastener element gripping device on the ram plunger having latched and released positions, spring means normally biasing the gripper device towards the latched position, a lost motion connection between the gripping device and the ram plunger permitting unitary movement therebetween during initial stroke movement of the ram plunger and permitting relative movement therebetween during final stroke movement of the ram plunger, and means on the ram plunger in engagement with the gripping device when the same is in the latched position and being movable relative to the gripping device during final stroke movement of the ram plunger.

Another object of the present invention is to retain and release automatically a snap fastener element in accordance with the movement of a ram plunger in a machine for attaching snap fastener elements to a material.

The present invention has another object in that a lost motion device connects a ram plunger to a gripping device that holds a snap fastener element.

A further object of the present invention is to permit relative movement between the ram head and jaws of a gripping device in the ram mechanism for a snap fastener attaching machine.

Other objects and advantages of the present invention will become apparent from the following description of a preferred embodiment, taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a snap fastener attaching machine having a ram mechanism embodying the present invention;

FIG. 2 is an enlarged side view of a lower casing of FIG. 1 with parts in section and with a sidewall removed to illustrate the operating mechanisms;

FIG. 3 is an enlarged, partial side elevation view of a detail of FIG. 2;

FIG. 4 is an enlarged isometric view of the ram mechanism of FIG. 3;

FIG. 5 is an exploded perspective view of FIG. 4;

FIG. 6 is a partial elevation showing the ram mechanism of FIG. 5 during its initial stroke movement; and

FIG. 7 is a partial elevation similar to FIG. 6 but showing the ram mechanism during its final stroke movement.

DESCRIPTION OF THE PREFERRED EMBODIMENT As is illustrated in FIG. I of the drawings, a snap fastener attaching machine is indicated generally at 10, having a generally rectangular boxlike configuration formed of relatively thin upper and lower hollow casings. The upper casing I2 has an open top wall to receive a pair of reels l4 and 16 disposed in side-by-side relation to each other. The reel I4 includes a continuous strip of plastic snap fastener backing elements 18 joined together by severable links; similarly, the reel 16 includes a continuous strip of plastic snap fastener socket elements 20 (or stud elements) joined together by severable links. The plastic snap fasteners utilized in the present invention are of the type adapted to close the opening in material, such as an article of clothing. This type of snap fastener has a fastener backing element joined to a fastenersocket element with a piece of the material clamped therebetween. A mating part of the snap fastener is attached to a cooperating piece of the material and includes the same fastener backing element 18 whereas the part clamped thereto would be a stud element.

The lower casing 22 of the machine is supported on a horizontal rod 24 adjacent its front lower edge by any suitable means such as a clamping mount 26, while the lower rear edge of the casing 22 merely rests on any suitable support such as a tabletop (not shown). The casing 22 includes a front wall 28 which is bolted or otherwise secured to spaced

sidewalls

30 and 32; in order to illustrate the operating mechanism, the sidewall 32 is removed from FIG. 2. The upper casing 12 rests on the top of lower casing 22; the two casings I2 and 22 are pivotally connected by a pivot axle 23 at their adjacent front edges whereby the casing 12 may be pivoted outwardly for reel replacement purposes.

As is illustrated in FIG. 2, the operating mechanism for the machine 10 includes an air cylinder 34 having a shaft 36 integral with and projecting from the left end of cylinder 34 so that the cylinder 34 and shafi 36 will always move as a unit. The left end of cylinder 34 is supported on the

sidewalls

30 and 32 by means of a trunnion block 38 which encircles the shaft 36 and which has pivot pins 40 rotatably carried in suitable apertures of the

casing sidewalls

30 and 32. Adjacent its free end, the shaft 36 has a spring retainer block 42 secured thereto; a coil spring 44 surrounds the shaft 36 and is mounted in compression between the trunnion block 38 and the retainer 42.

A piston shaft 46 projects from the right end of the cylinder 34 and is secured to a clamping block 48 which is pivoted at 50 to the center of a toggle linkage. As is shown in FIG. 2, the pivot pin 50 defines a pivotal connection with one end of the toggle link 52, the other end of which is provided with an opening 54 which receives an eccentric pin 56 mounted in aligned apertures in the

sidewalls

30 and 32. The opening 54 and the eccentric pin 56 cooperate with each other to define a support for the suspension of the right hand of the piston shaft 46 as well as the attachments thereto. An adjustment lever 60 is threaded to eccentric pin 56in a direction perpendicular to the axis of pin 56 and extends through the front wall 28 and is locked in place by screws 62. Adjacent its inner end, the toggle link 50 has a pivot pin 64 which carries one end of a lower toggle link 66; the other end of the link 66 is pivotally connected to a pivot pin 68 for a purpose to be described more fully hereinafter.

The right end of the air cylinder 34 is secured to a bar 70 for unitary movement therewith. The bar 70 is disposed transversely to the longitudinal axis of the cylinder 34 and a second bar 72 is fixed intermediate its end to the free end of bar 70; the bar 72 is disposed in spaced parallel relation to the cylinder 34 and because of its rigid connection with the the bar 70, the bar 72 will always move in the same direction as the cylinder 34. As will be explained hereinafter, the cylinder 34 has an initial linear movement along its longitudinal axis as well as being pivoted about the trunnion axis 40. A pivot pin 74 connects the free end of a lever 76 to the left end of the bar 72. The other end of lever 76 is connected by means of a pivot screw 78 to the end of a lever arm 80 which is disposed generally transversely to the lever 76. The opposite end of the leverarm 80 is fixed to an intermediate portion of a lever 82 at that point where it is pivotally connected to the sidewall 30 by means of a pivot pin 84. The upper end of lever 82 is connected to a return spring 86 which is mounted in tension between lever 82 and a retainer 88 fixed to the casing wall 30. A stop member 85 is fixed to the casing sidewall 30 to limit the pivot movement of the lever arm 80 in a downward direction as viewed in FIG. 2.

At its lower end the lever 82 is pivotally connected to the end of a lower feed arm 90, the forward end of which is slidably disposed in a channel box 92 that receives the strip of fastener elements 18 from a guide or chute 94 fixed to the casing sidewall 30 by brackets 96. The forward end of the feed arm 90 is provided with multiple spaced-apart prongs 98-98 which project upwardly between the connecting strips of fastener elements 18. The forward edge pushes the element to the right as viewed in FIG. 2 during pivotal movement of the arm 90 and lever 82 about the pivot point 84. Although the prongs 9898 are only shown on one side of the fastener elements 18, it is to be understood that similar spaced-apart prongs 98-98 may be placed on the opposite side of feed arm 90 to project upwardly therefrom to engage the opposite side of the fastener elements 18. A flat ribbon-type spring 100 engages the undersurface of the feed arm 90 to normally bias the same in an upward direction.

The above described lever system is operated by the bar 72 to cause advancement of the lower strip of fastener elements 18. The same bar 72 is also utilized to advance the upper strip of fastener elements 20. As is shown in FIG. 2, the right end of the bar 72 engages the end of an adjustment pin 102 transversely carried on one end of a lever 104 which is pivotally mounted intermediate its ends by means of a pivot pin 106 carried by the casing sidewall 30. The lower end of the lever 104 pivotally carries an upper feed arm 108 intermediate its ends. A coil spring 110 is mounted in tension between an upper portion of the lever 104 and one end of the upper feed arm 108 which is accordingly biased normally in a clockwise direction. A stop member 11 1 is fixed to the casing sidewall 30 to limit the counterclockwise movement of the lever 104.

The forward end of the feed arm 108 is slidably disposed in an upper channel box 112 which receives the strip of fastener elements 20 from a guide or chute 114 fixed to the casing sidewall 30 by brackets 116. The forward end of the feed arm 108 is provided with multiple spaced-apart prongs 118 on each side similar to the lower feed arm 90. Each of the prongs 118 project downwardly and has a straight forward edge.

A coil spring 120 is mounted in tension between a retainer 122 on the casing wall 30 and an intermediate part of the lever 104, which part is located between the pivot pin 106 and the lower end of lever 104 so that the lever 104 is normally biased in a counterclockwise direction about the pivot pin 106. A second coil spring 124 is mounted in tension between the retainer 122 and an intermediate portion of a manually operated knife arm 126 which has one end mounted on a pivot 128 carried by the casing wall 30 so that the arm 126 is normally biased in a counterclockwise direction about the pivot 128. The other end of the arm 126 extends through a slotted opening 130 in the casing front wall 28; the upper and lower edges of the slot 130 define the limits of movement for the knife arm 126.

During manual operation of the knife arm 126 a knife blade 132 is depressed to sever the connections between the upper strip of fastener elements 20. A projecting lug 134 on the side of the knife blade 132 is engaged by the end of a flat spring 136 which causes the return of the knife blade in an upward direction upon release of the force applied thereto. The knife blade 132 is slidably mounted in a cover plate 138 that is attached to the casing sidewall 30 and cooperates therewith to define a channel for the knife blade 132 as well as a channel for a ram plunger 250 to be described more fully hereinafter; the upper end of plunger 250 to be described more fully hereinafter; the upper end of plunger 250 carries the pivot pin 68 so that the ram is pivotally connected to the link 66 of the toggle mechanism. A stop element 142 projects upwardly beyond the pivot pin 68 and cooperates with a stop 144 secured to the inner surface of the casing front wall 28. An actuating stem 146 for the knife blade 132 is also carried by the upper portion of the plunger 250 in spaced parallel relation thereto for unitary movement therewith. The stem 146 carries a compression coil spring 148 to absorb shock and to provide override compensation at the end of the plunger stroke.

A lower die or anvil 156 is fixed on one end of an anvil arm 158 that is pivotally mounted intermediate its ends on a pivot pin 160 carried by the casing sidewall 30. Between the pivot pin 160 and its free end, the anvil arm 158 carries an adjustable spring retainer 162; a preloaded, heavy duty compression spring 164 is mounted in compression between a retainer 162 and a fixed block 166 secured to the casing sidewall 30. Between the pivot pin 160 and the retainer 162 the anvil arm 158 is pivoted to a connecting link 168 which has a loosefitting connection with a pivot pin 170 intermediately carried between the ends of a lower knife arm 172. One end of the knife arm 172 is pivoted to the fixed block 166 by a pivot pin 174; the other end of the knife arm 172 projects through a suitable slot 176 in the casing front wall 28. Between the pivot pin 170 and the free end of the knive arm 172, the knife arm 172 carries a knife blade which projects upwardly to sever the connections between adjacent fastener elements 18 as will be explained more fully hereinafter. The free end of the anvil arm 158 carries an adjustable actuating stem 178 so that clockwise movement of the anvil arm 158 about its pivot pin 160 will cause operation of a control device by the actuating stem 178.

The control system for operating the mechanisms of the snap fastener attaching machine may be of any suitable type such as electric, electromechanical, hydraulic or pneumatic systems. The present embodiment of this invention utilizes a pneumatic control system and only those parts necessary for an understanding of the invention are being described for the sake of brevity. For example, a pneumatic source of air pressure is supplied through inlet 200 to a pneumatic relay control, indicated generally at 202. While the system may be in itiated automatically as in any other type of automated machinery, it may be also started manually as by a linkage 204 leading to a foot pedal (not shown). The relay control 202 is provided with a pair of fittings, having

flexible tubes

206 and 208 connected to opposite ends of the air cylinder 34 for actuation thereof. A second pair of

fittings

210 and 212 from the pneumatic relay 202 are connected to a pneumatic switch 214 which functions as a control device for terminating operation at the end of the cycle. This end of cycle relay 214 has a pivoted operator 216 which is actuated by the stem 178 on the anvil arm 158 as it is pivoted clockwise at the end of each cycle.

The actuating lever 206 may also be operated manually at any time by means of a plate 221, having a ledge 225, which will actuate lever 216. Plate 221 is slidably carried between casing sidewalls 30 and bearing plate 220. A coil spring 224 is mounted in tension with one end attached to pin 222 and its opposite end attached to retainer 226 intermediately disposed between the ends of a roller bar 228. One end of the roller bar 228 is pivotally mounted on plate 221 by means of a pivot pin 230 while its other end carries a roller element 232 which rests in valley 223 of the cam surface in plate 220, which determines the neutral position. Movement is imparted to the plate 221 and the roller 232 by the terminus 234 of a manual lever which has a push-type handle 236 on its other end extending through the casing front wall 28.

As best illustrated in FIGS. 3-6, the ram mechanism according to the present invention includes the ram plunger 250, the lower portion of which has a generally square configuration in cross section having a perimeter slightly less than that of the fastener element 20. One surface of the ram plunger 250 is drilled or formed with a blind bore 252 providing a mounting for one end of a coil compression spring 254. Slightly spaced from its lower end, the ram plunger 250 is machined with an elongated slot 256 extending through the ram plunger. A central blind bore 258 is drilled or formed in the bottom wall of the ram plunger 250 along the longitudinal axis thereof so as to be perpendicular to the elongated slot 256; the bore 258 intersects the slot 256 and has a depth to house a coil compression spring 260 and retainer stud 262. A transverse recess 264 is machined out of the bottom surface which defines a ram head 266; the recess 264 is perpendicular to both the elongated slot 256 and the longitudinal bore 258. With such a recess 264, the ram force is not applied to the center of the fastener elements but rather to the sides and comers thereof whereby the stud and socket structure of such elements are not subject to any deformation force.

A fastener element is held adjacent the ram head 266 by gripping means in the form of a pair of plates disposed on opposite surfaces of the ram plunger 250. As is shown in FIG. 5, one plate 270 has a transverse projection 272 along one edge to abut the ram plunger 250 on two sides. A threaded bore 274 is located in the lower portion of the plate 270, the lower edge of which defines an edge tooth or jaw 276 fon'ned by an edge recess having a triangular shape in cross section, (see FIGS. 6 and 7). The other plate 280 is similarly constructed with a transverse projection 282 along one edge extending toward the projection 272, a smooth wall bore 284 axially aligned with the threaded bore 274, and a bottom edge tooth or jaw 286 in opposed facing relation to the jaw 276. Spaced from its top edge, the inner surface of plate 280 has a recessed slot 288 that is substantially the same linear dimension as the slot 256; in assembled relation, the coil spring 254 is mounted in compression between the bottom wall of the blind bore 252 and the bottom wall of the recessed slot 288.

A fastening shaft 290 having the general configuration of a capscrew includes an unthreaded portion loosely received in the smooth bore 284, an intermediate portion 292 of reduced diameter disposed at the intersection of the elongated slot 256 and longitudinal bore 258, and a threaded end portion 294 which is threadedly received in the threaded bore 274. A nut 296 is threaded onto the free end of the threaded end 294 to act as a locknut for the assembled plate 270.

As is illustrated in FIG. 5 the surface of ram plunger 250 which is engaged by the plate 280, is provided with a cammed or inclined portion 268 adjacent its lower edge. This lower surface 268 is inclined or tapered inwardly from a line-adjacent the elongated slot 256 to the ram head 266. Thus, in its normal assembled relationship, the plate 280 is biased by the coil spring 254 away from the rain plunger 250; the plate 280 thus assumes an inclined position against the tapered surface 268 on the ram plunger 250 with the head of the fastener shaft 290 limiting the outward biased position of the plate (see FIG. 6). The jaw 286 thus cooperates with the other plate jaw 276 to retain one of the fastener elements therebetween. During the final stroke movement of the ram plunger 250, the plate 280 will be pivoted slightly against the bias of the coil spring 254 whereby the fastener element 20 is released from the

jaws

276 and 286 and the ram head 266 completes the attaching operation as will be described more fully hereinafter.

It is to be understood that various types of plastic snap fastener elements may be utilized with the machine of the present invention. Accordingly, while the present description relates to snap fastener elements comprising a base 18 and a socket 20 with the material clamped therebetween, the cooperating part of such a snap fastener device would be attached by a second machine and would include the same common base 18 but the socket 20 would be replaced with a snap fastener stud (not shown). Thus, a complete snap fastener device includes a base element 18 joined to a socket element 20 as the first unit, and a base element 18 joined to a stud element as the second unit. In such an arrangement, the base 18 and the socket 20 form the female unit while the base 18 and the stud form the male unit of the complete fastener device. For a more complete description of the type of fastener elements that may be utilized in the present invention by way of example, reference is made to similar snap fasteners found in U.S. Pat. No. 3,401,434.

For a detailed description of the general sequence of operation of the snap fastening machine, attention is directed to my copending application Ser. No. 875,688 filed Nov. 12, I969, which is incorporated herein by reference. However, a description of the sequence of operation is being set forth below in conjunction with the operation of the ram mechanism. In the ready condition of the machine as represented in FIG. 2, the cylinder 34 is displaced from the trunnion block 38 and the coil spring 44 on the shaft 36 is compressed. The piston shaft 46 extending from the other end of the air cylinder 34 is at its minimum extension whereby the toggle mechanism is in its unactuated condition with the ram plunger 250 located in its uppermost condition. In addition, the cylinder 34 has not yet been moved so the bar 72 is in engagement with the pin 102 which retains the lever 104 in its extreme clockwise position; the upper feed arm 108 is thus placed in a ready condition. At this time the condition of the ram mechanism is illustrated in FIG. 6 wherein the gripping means is biased to its latched position so that the fastener element 20 is retained between the

plate jaws

276 and 286. The ram mechanism will remain in this condition during its initial stroke movement so that the fastener element 20 will move with the ram plunger 250 until the final stroke thereof.

After placing the material between the ram head 266 and the anvil 156, operation is commenced with movement of the linkage 204 as by a foot pedal, whereupon the pneumatic relay supplies pressurized air to the cylinder 34 which is initially moved along its longitudinal axis against the trunnion block 38. The subsequent longitudinal movement of cylinder 34 and its bar 72 permits counterclockwise movement of the lever 104 by the tension spring 120 until the lever I04 engages the stop member 111. The feed arm 108, which is normally biased by its tension spring 110 in such a manner that its prongs 1 18 (FIG. 3) are disposed against the edges of snap fastener elements 18, causes the fastener elements 18 to be advanced. A spring ratchet member (not shown) prevents withdrawal of fastener elements 18 and aids in orienting element 18 in its proper position.

As the pneumatic relay 202 increases the air flow in the cylinder 34, the piston shaft 46 commences its extending movement and since the upper toggle link 52 is fixed on pivot pin 56, the toggle mechanism begins its downward movement. The rear end 50 is thus moving downwardly and the cylinder 34 is pivoting clockwise about the trunnion pin 40. The operation of the lower feeding mechanism is now commenced by the downward movement of bar 72 causing lever 76 and lever arm 80 to likewise move downward in a counterclockwise direction about the pivot 84; such movement continues until lever arm 80 engages the stop member 85. During such movement, the lever 82 is permitted to pivot counterclockwise about the pivot 84 because of the tension spring 86. As a result, the lower feed arm moves in the channel box 92 causing the teeth 98 to advance the snap fastener strip 20.

Full extension of the piston shaft 46 fully extends the toggle links 52 and 66 causing completion of the stroke of the ram plunger 250. At this time the stem 146 moves the upper knife blade 132 to sever completely the connections between adjacent snap fasteners 20. During its final stroke movement, the ram plunger 250 moves relative to the

plates

270 and 280 because of the lost motion connection therebetween. For example, the slot 256 permits continued downward movement of the ram plunger 250 without downward movement of the

plates

270 and 280; during such downward movement, the shaft 290 is relatively displaced from the bottom to the top of elongated slot 256. The camming surface 268 is similarly dispivoted inwardly against the bias of its coil spring 254. The

plate 280 is thus moved to its released position so that there can be no binding as the ram head 266 is moved passed the

jaws

276 and 286. Since the fastener shaft 290 is not rigidly connected to the ram plunger 250, the shaft 290 may move slightly on its longitudinal axis so that the other plate 270 may also be slightly displaced to preclude any binding between its jaw 276 and the ram head 266. With the gripping means in its released position, the ram head 266 carries the fastener against the fastener 18 on the anvil 156 whereby the two fastener elements are cinched together with the material therebetween. Upon initial impact by the rain head 266, the prongs (FIG. 3) on the fastener element 20 are squeezed through the material without destroying the material. This effect is obtained by the preloaded anvil arm 158 which is then pivoted by the impact force against the coil spring 164. As soon as the impact force overcomes the preload spring force, the four prongs of the fastener element 20 are deformed or cold flowed in aligned bores on the fastener element 18.

The pivot movement of the anvil arm 158 causes the link 168 and the knife am 172 to move upward whereby the lower knife blade 175 severs the connections between adjacent fastener elements 18. This pivotal movement also causes the actuator stem 178 to pivot the lever 216 whereby the pneumatic switch 214 ends the cycle and exhausts the air cylinder 34. The cylinder 34 then returns to its initial position as shown in FIG. 2. During such return movement the upper and lower feed arms 108 and 90 are retracted and slightly pivoted permitting the sloping edges of the

prongs

118 and 98, respectively, to ride over the

fastener elements

20 and 18, respectively.

Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A ram mechanism for a snap fastener element attaching machine comprising a ram plunger having a stroke movement on a longitudinal axis between rest and actuated positions,

gripping means on said ram plunger having latched and released positions and being adapted to hold a fastener element when in said latched position,

lost motion connection means between said gripping means and said ram plunger permitting unitary movement therebetween during initial stroke movement of said ram plunger and permitting relative movement therebetween during final stroke movement of said ram plunger,

said gripping means including a pair of oppositely disposed plates with one of said plates being movable relative to the other of said plates between the latched and released positions,

biasing means normally biasing said one plate to the latched position, and

camming means between said ram plunger and said one plate positioning said one plate in the latched position and causing movement of said one plate to the released position during final stroke movement of said ram plunger whereby a fastener element may be released therefrom.

2. The ram mechanism as recited in claim 1 wherein said lost motion connection means includes an elongated slot extending through said ram plunger transversely to its longitudinal axis and a fastening stud element extends through said elongated slot.

3.- The ram mechanism as recited in claim 2 wherein said fastening stud element has a smooth end portion loosely received in a smooth bore on one of said plates and a threaded end portion extending through a threaded bore on the other of said plates.

4. The ram mechanism as recited in claim 3 wherein said ram plunger has a longitudinal bore intersecting said elongated slot and spring means in said bore engages an intermediate portion of said fastening stud element whereby the fastening stud element is normally biased toward the bottom of said elongated slot.

5. A ram mechanism for a snap fastener attaching machine comprising a ram plunger having a stroke movement on a longitudinal axis between rest and actuated positions,

gripping means including a pair of oppositely disposed plates mounted on said ram plunger and having a latched position and a released position,

biasing means normally biasing said gripping means toward the latched position,

said lost motion connection means including an elongated slot extending through said ram plunger transversely to said longitudinal axis and a fastening stud element extending through said elongated slot,

said fastening stud element having a smooth end portion loosely received in a smooth bore on one of said plates and a threaded end portion extending through a threaded bore on the other of said plates,

a longitudinal bore in said ram plunger intersecting said elongated slot,

spring means in said longitudinal bore acting on an intermediate portion of said fastening stud element for normally biasing the same toward a bottom part of said elongated slot,

said ram plunger having a tapered surface normally engaged by the said one plate to define the said latched position and being movable relative to said one plate during final stroke movement of said ram plunger, and

said biasing means comprising a coil spring mounted in compression between said ram plunger and said one plate. 6. The ram mechanism as recited in claim 5 wherein said ram plunger has a blind bore receiving one end of said coil spring, and wherein said one plate has an elongated slot receiving the other end of said coil spring.

7. The ram mechanism as recited in claim 5 wherein each of said plates has a jaw on its lower end, said jaws being in opposed relation to each other to retain a fastener element therebetween.

8. A ram mechanism for a snap fastener attaching machine comprising a ram plunger having a stroke movement on a longitudinal axis between rest and actuated positions,

biasing means normally biasing said gripping means toward the latched position,

means on said ram plunger in engagement with said gripping means when the same is in the latched position and being movable relative to said gripping means during final stroke movement of said ram plunger,

a longitudinal bore in said ram plunger intersecting said each of said plates having a transverse projection along one elongated slot, edge in engagement with said ram plunger to guide the spring means in said longitudinal bore acting on an inter- Same during relative movement between said plates and mediate portion of said fastening stud element for nor Said ram Plungel mally biasing the same toward a bottom part of aid l 5 9. The ram mechanism as recited in claim 1 wherein said gated Slot, camming means comprises an inclined surface on said ram each of Said oppositely disposed plates having a jaw on its plungerand said one plate a portion engaging said inclined lower end, said jaws being in opposed relation to each Surfacem thelatched posmo thereof other to retain a fastener element therebetween, and 0

Claims

1. A ram mechanism for a snap fastener element attaching machine comprising a ram plunger having a stroke movement on a longitudinal axis between rest and actuated positions, gripping means on said ram plunger having latched and released positions and being adapted to hold a fastener element when in said latched position, lost motion connection means between said gripping means and said ram plunger permitting unitary movement therebetween during initial stroke movement of said ram plunger and permitting relative movement therebetween during final stroke movement of said ram plunger, said gripping means including a pair of oppositely disposed plates with one of said plates being movable relative to the other of said plates between the latched and released positions, biasing means normally biasing said one plate to the latched position, and camming means between said ram plunger and said one plate positioning said one plate in the latched position and causing movement of said one plate to the released position during final stroke movement of said ram plunger whereby a fastener element may be released therefrom.

3. The ram mechanism as recited in claim 2 wherein said fastening stud element has a smooth end portion loosely received in a smooth bore on one of said plates and a threaded end portion extending through a threaded bore on the other of said plates.

5. A ram mechanism for a snap fastener attaching machine comprising a ram plunger having a stroke movement on a longitudinal axis between rest and actuated positions, gripping means including a pair of oppositely disposed plates mounted on said ram plunger and having a latched position and a released position, biasing means normally biasing said gripping means toward the latched position, lost motion connection means between said gripping means and said ram plunger permitting unitary movement therebetween during initial stroke movement of said ram plunger and permitting relative movement therebetween during final stroke movement of said ram plunger, said lost motion connection means including an elongated slot extending through said ram plunger transversely to said longitudinal axis and a fastening stud element extending through said elongated slot, said fastening stud element having a smooth end portion loosely received in a smooth bore on one of said plates and a threaded end portion extending through a threaded bore on the other of said plates, a longitudinal bore in said ram plunger intersecting said elongated slot, spring means in said longitudinal bore acting on an intermediate portion of said fastening stud element for normally biasing the same toward a bottom part of said elongated slot, said ram plunger having a tapered surface normally engaged by the said one plate to define the said latched position and being movable relative to said one plate during final stroke movement of said ram plunger, and said biasing means comprising a coil spring mounted in compression between said ram plunger and said one plate.

6. The ram mechanism as recited in claim 5 wherein said ram plunger has a blind bore receiving one end of said coil spring, and wherein said one plate has an elongated slot receiving the other end of said coil spring.

8. A ram mechanism for a snap fastener attaching machine comprising a ram plunger having a stroke movement on a longitudinal axis between rest and actuated positions, gripping means including a pair of oppositely disposed plates mounted on said ram plunger and having a latched position and a released position, biasing means normally biasing said gripping means toward the latched position, lost motion connection means between said gripping means and said ram plunger permitting unitary movement therebetween during initial stroke movement of said ram plunger and permitting relative movement therebetween during final stroke movement of said ram plunger, means on said ram plunger in engagement with said gripping means when the same is in the latched position and being movable relative to said gripping means during final stroke movement of said ram plunger, said lost motion connection means including an elongated slot extending through said ram plunger transversely to said longitudinal axis and a fastening stud element extending through said elongated slot, said fastening stud element having a smooth end portion loosely received in a smooth bore on one of said plates and a threaded end portion extending through a threaded bore on the other of said plates, a longitudinal bore in said ram plunger intersecting said elongated slot, spring means in said longitudinal bore acting on an intermediate portion of said fastening stud element for normally biasing the same toward a bottom part of said elongated slot, each of said oppositely disposed plates having a jaw on its lower end, said jaws being in opposed relation to each other to retain a fastener element therebetween, and each of said plates having a transverse projection along one edge in engagement with said ram plunger to guide the same during relative movement between said plates and said ram plunger.

9. The ram mechanism as recited in claim 1 wherein said camming means comprises an inclined surface on said ram plunger and said one plate has a portion engaging said inclined surface in the latched position thereof.