US3118196A

US3118196A - Die casting apparatus

Info

Publication number: US3118196A
Application number: US76843A
Authority: US
Inventors: Fred T Hall; Reino H Mustonen
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1960-12-19
Filing date: 1960-12-19
Publication date: 1964-01-21
Anticipated expiration: 1981-01-21

Description

Jan. 21, 1964 F. T. HALL ETAL 3,118,196

DIE CASTING APPARATUS Filed Dec. 19. 1960 s Sheets-Sheet 1 alluunamun INVENTORS 1964 F. T. HALL ETAL DIE CASTING APPARATUS 3 Sheets-Sheet 2 Filed Dec. 19, .1960

ATTO/PA/L'Y Jan. 21, 1964 F. T. HALL ETAL 3,118,195

DIE CASTING APPARATUS Filed Dec. 19. 1960 5 Sheets-Sheet 5 w? w W k A?! i h W67 75 r [362: 5 T a V415 k 7 12! INV EN TORS jka Z/VQ/Z 6 BY @1220 fluid/rev;

A from/5y United States Patent Ofi ice Patented Jan. 21, 1964 3,118,196 DEE CASTING APPARATUS Fred T. Hall, Clawson, and Reine H. lvlustonen, Wixom,

Mich, assignors to General lvlotors Corporation, Dctroit, Mich, a corporation of Delaware Filed Dec. 19, 1960, Ser. No. 76,843 9 Claims. (Cl. 22-64) This invention relates to the art of die casting and more particularly to apparatus by which the cast article is automatically transferred sequentially from the die cavity after the casting process to a plurality of processing operations such as trimming, drilling, etc.

In conventional die casting practice, the cast article is loosened from the die cavity by ejection pins usually associated with the movable die and the operator removes the casting from the machine by manual means and places it on a conveyor belt, a cart or the like for removal to a subsequent processing station for an operation such as trimming, drilling and the like.

it is a principal object of this invention to provide apparatus whereby the die cast article are cast directly onto a supporting arm attached to a belt, conveyor or the like and thereafter the conveyor is operative to carry the casting through a plurality of work stations at which a variety of operations are performed on the casting such as drilling, trimming and the like. A more specific object of the invention is to provide means for accurately and automatically locating or positioning the cast article in a predetermined position at a particular work station whereby the work is correctly and efficiently performed preferably by automatic means.

In general, these and other objects are accomplished by the provision of apparatus including an endless conveyor disposed between a die casting machine and a series of work stations; a plurality of support arms attached to the conveyor to which the articles to be cast are cast directly; and ball-like enlarged portions inte rally associated with support members which may be clamped at the various work stations between locating members having a cavity corresponding to the configuration of the ball-like portions of the supports whereby the castings are readily positioned for a processing operation.

Other objects of this invention will become more apparent from the following detailed description, reference being had to the accompanying drawings in which:

FlGURE 1 is an elevation view of die casting apparatus including a plurality of work stations and a conveyor means for transferring castings from the die casting apparatus to the various work stations;

FIGURE 2 is a top view of the apparatus shown in FlGURE l;

FEGURE 3 is a side view taken along line 33 of FlGURE l;

PEGURE 4 is a partially cross-sectional view taken through e l4 of FIGURE 3;

FEGURE 5 is a top view taken along line 55 of FIGURE 1; and

FIGURE 6 is a cross-sectional view taken along line 66 of Z 'EGURE 5.

The basic objective of the present invention is to provide a mechanism for automatically moving a casting from the cavity of the die casting apparatus sequentially through a variety of work stations whereby a casting may be cast and processed in an economical and efficient manner. FIGURES l and 2 show in a general way apparatus elfecting this objective in accordance with this invention.

The apparatus shown in FEGURES 1 and 2 of the drawings illustrates the invention in a general way. It includes .a die casting machine 10, a casting quenching station 12,

a drilling station 14, a trimming station 15, a conveyor apparatus 18 for transferring a casting from the die casting machine ill to the work stations i2, 14 and 16 and a final work station 20 for removing residual casting metal from the conveyor line casting support members.

The conveyor apparatus 38 consists of a pair of horizontally disposed endless tracks 22 and 24 in the form of angle irons as is best shown in FIGURE 3 on which the endless link chains 26 and 28, respectively, travel. The link chains 26 and 28 carry pairs of relatively closely spaced cross bars 31? and 32, respectively, at equally spaced intervals about the endless chains. The cross bars 3%) and 32 in turn carry a pair of

support arms

34 and 36, respectively, having ball-like enlarged portions 38- and 4d. The particular manner in which the

carrier arms

34 and 36 are attached to the

cross bars

30 and 32 involves an important aspect of this invention as will be described more fully hereinafter. Since each of the cross bars 3% and 32 and the support arms are of identical construction, these will hereinafter be described in terms of the cross bar 3%, carri r arms 34 and the ball-like member 3?; for the sake of convenience.

The link chain members 26 and 23 travel on sprockets 42 and 44 journaled on the shaft 46 on one end of the conveyor assembly. At the opposite end of the conveyor apparatus, the link chains similarly travel on the sprockets and 58 journaled onto the shaft 52. A driven sprocket 54 fixed to the shaft 52 is drivingly connected to the drive sprocket 56 journaled to a shaft 58 by means of the link chain 69. The drive sprocket 56 is preferably driven by electric motor means (not shown).

The manner in which the conveyor apparatus 18 conveys the casting from the die casting apparatus is most clearly shown in connection with FIGURE 3 of the draw- The movable and stationary die platens are indicated generally at 62. and 64, respectively, and are shown to carry the movable die 66 and the stationary die 68, respectively. The movable die platen 62 is adapted to be reciprocably moved on the tie rods 76 by hydraulic means in a manner well known in the art. The principal die cavity 72 is shown in each of the

dies

66 and 68 in broken lines. The die cavity also includes a vertically disposed tubular portion 74 adapted to snugly receive the carrier arm 34 and an enlarged ball-like cavity portion 76 adapted to snugly receive the ball-like portion 38 of the carrier arm. The die cavity, of course, includes a sprue opening (not shown) through the stationary die 63 and platen and suitable gating (not shown) leading from the sprue opening to various portions of the die cavity. These are not shown in the drawings for sake of clarity, although it will be understood that these are provided in accordance with foundry practice and do not affect the character of this invention. Although only a single tubular and ball-like portion 74 and 7:5 is shown associated with the cavity '72 for receiving a single support arm 34, it will be understood that in a typical die arrangement the die cavity proper, in this instance the cavity 72, may be relatively large or elongated and several support arms may be used in connection with each casting to insure a satisfactory support for the casting. in the embodiment shown, two

support arms

34 and 36, respectively, are used to support a casting which is elongated and oval in shape as indicated by the numeral 73 of FlGURE 1 in connection with the quenching station 12.

The movable die as is provided with the usual ejector pins 89 which, as will be apparent to those skilled in the art, are attached to an ejector plate within the body of the die 66 which in turn is connected through connecting rods to a means which is operative to retract the ejector pins 8% so that the ends thereof are flush with the die cavity surface when the dies are in a closed position and in forcing the pins outwardly toward the movable die when the dies are in a fully open position as shown in FlGURE 3.

The carrier arm 34 is attached to the cross bar 3% by the mechanism 32 shown in FIGURE 4. This mechanism consists of a Wedge-like block 84 journaled onto the cross bar 3@ for longitudinal movement therealong. A ball bushing as is provided which enables the block 84 to travel longitudinally of the bar 3% with minimum friction andwear and with the elimination of binding, chatter and the like. The carrier arm 34 is threaded onto a plate which in turn is suspended from the top or widest portion of the block 84 by means of the vertical plates 3% and 91. It will be apparent that by reason of the

slopin'g sides

85 and 87 of the block 34-, the supporting arm 34 may be translated transversely to a limited extent with respect to the cross bar as determined by the slope of the sides of the block 84 and it may be moved along the length of the cross bar 39. The cross bar 3b which, of course, carries the block 3-4 is carried by the link chains 26 and 2-3 which, as will be apparent from FIGURE 3, may also be raised vertically to a limited extent. It will thus be apparent from the construction above described that the locating ball 38 of the carrier arm 34 may readily be moved vertically, horizontally and transversely.

In performing a die casting operation in accordance with the invention, a pair of

carrier arms

34 and 36 are indexed or moved into place between the open dies 66 and in a position such that the ball portion 38 of the support 34 is approximately in position to be received in the cavity '76 when the dies are closed. As shown in PTGURE 4, the pairs of

carrier arms

34 and 36 are preferably linked together by means of a connecting plate 92 so that the two arms will tend to operate as a unit. When the carrier arms 34 are moved in position as above indicated, the

dies

66 and 68 are caused to close whereby the carrier arms 3-; are moved into an accurately aligned position by the locating balls 38 which, due to their partially spherical character, will readily slide into position within the portion76 of the die cavity. Any misalign- 'ment or mislocation incident to the natural limitation of non-precision mechanical equipment will be readily compensated for by the horizontally, vertically and transversely movable character of the carrier arm 34. After the dies are closed and the casting operation has been completed, the movable platen s2 is caused to move away from the stationary platen 64 whereby the dies are opened and the ejector pins 8-9 force the casting 78 which has been cast onto the supporting arm 34 as shown, out of the die cavity. As the movable die 66 is moved to an open position, the carrier mechanism 32 is pulled along with it until the ejector pins 3Q eject the casting from the die cavity as shown in FIGURE 3.

A device is preferably provided for moving the carrier mechanism 82 and the casting 78 to a point between the open dies as and from which position the casting may be eificiently moved to subsequent work stations. This device includes an 'L-shaped bracket 94 attached to longitudinal'channel bars 95 and 93 between which the carrier mechanism 82 at the upper level of the conveyor travels.

mechanism also includes a lever pivotally attached by a pin 1492 to the bracket as. The upper end of the lever Ebb connected to the bracket by a tenn coil spring res. The lower end or" the lever loll is mechanism 32 when it is in a die casting position. A transversely positioned rod res rigidly attached to the movable platen 62 by a bracket means 1&3 and reciprocably connected to the stationary platen 64 by a slidable bearing connection ill? carries a collar 112 adjustably held in place by a set screw 114. The rod res is located'adjacentthe lever lot} so that when the collar 112 is moved across the location of the lever 1%, the collar 112 engages the lever causing the'lower portion of the lever to engage the supporting mechanism 82.

The operation of this mechanism is as follows. At the onset of the casting operation, the carrier mechanism 82 ti the normal horizontal line of travel of the p 93 is located in a suitable position to begin the casting operation. The movable die 66 is thereupon moved to the left into a die closed position. In this movement the ejector pins 8% are moved to a position flush with the die cavity and the supporting mechanism 82 is carried to the right toward the stationary die 6 As described above, the substantially universal movement of which the supporting ball 38 is capable permits the carrier arm 34 to be accurately located within the cavity portion 74, the dies are closed and molten metal is ejected into the die cavity. As a consequence of the metal casting operation, a portion of the casting is cast around the end of the support arm 34- and attached thereto. The movable die is then causec to move to its open position. As a consequence of this movement as previously described, the supporting mechanism 84 is carried to the left. This also causes the collar 112 on the rod 1% to be likewise moved to the left. in the course or" its travel, the collar M2 engages the lever 1% thereby subjecting the carrier mechanism to a horizontal force to return it to its original intermediate position after being released from the die cavity by the ejector pins 8%.

The conveyor is next indexed to move the casting over a quenching tank 12 as shown in PGURE 1. After the casting 78 comes to rest over the quenching tank, the

elevator mechanism 13 raises the quenching tank 12 so that the quenching water therein envelops the casting 78. The machine is then indexed and the casting 73 is advanced to the drilling station 14.

The drilling station 14 consists basically of clamping means for holding the casting a pre etermined position and a drilling device 116 driven by the electric motor 118 which may be advanced against the casting to perform the required drilling operation. The nature of this work station will be apparent from the description of the subsequent trimming station 16 which is shown in greater detail in FIGURES 5 and 6. The means for supporting the casting in the proper position within the drilling station 14 may be identical with that to be described hereinafter in connection with the trirmning station 16.

As shown in FIGURLS 5 and 6, the trimming station includes a horizontally movable platen 120 and a stationary platen 122. The stationary platen 122 is mounted on a vertical support 124 which in turn is mounted on a horizontal base 126 having an opening 1'23 through which trimmed castings may drop to a suitable receptacle after the trimming operation. A cutting trim die 13%) is bolted to the stationary platen 122 in a vertical operating position. A locating plate 13-2 connected to a rod 134 having a collar 136 is journaled for longitudinal movement within the U-shaped bracket 133 attached to the vertical support 124- in a manner such that the collar 136 functions to limit the movement of the rod 134 between the legs of the U-shaped member 138. A compression coil spring 14s normally urges the locating plate 132 toward the movable platen 12b.

The movable platen lit has attached thereto a die supporting plate 3A2 which in turn supports the complementary anvil portion 144 of the die. The movable die platen 12b rides on the horizontal tie rods 145 and is power driven reciprocably by hydraulic piston means attached to the connecting rod 148. A second complementary locating plate or block is mounted on the movable platen 12% by means of the horizontal plate 152. The locating plate 154 has a partially cylindrical and partially spherical depression 151 adapted to snugly receive the locating ball 38 and support arm 34. The locating block 132 is provided with a partially cylindrical, horizontally disposed channel 133. V V

The operation of the trimming station is as follows. When the casting is indexed from the drilling station 14, the locating ball 33 glides into the channel 133 in the locating block 132. To this end, the collar 136' is adjusted to permit the block 132 to extend a distance toward the line of travel of the support arm 34 such that the locating ball 3-8 will glide into the groove 13-3. Next, the movable platen 132 is caused to move toward the stationary platen 122. This causes the locating block 150 to engage the locating ball 38. As the movement to the left is continued, the coil spring 140 is compressed and the casting is moved toward the trimming die 130. At the instant or just prior to the time when the dies 13% and 144 engage the casting in the cutting operation, the cating ball 33 has been snugly positioned between the partially spherical depression 151 of the moving locating plate 15% and the groove of the locating plate 132 which has become stationary due to the collar 1% abutting against the opposite leg of the bracket 138. It will be obvious that the locating blocks 15% and 132 cooperate with the locating ball 38 to locate the casting accurately for the trimming operation.

After the trimming operation, the platen 120 is moved to an open position and the coil spring 140 is effective to move the support arm 34 to its centered position from whence it may be moved to the next station. in the embodiment of the invention shown, the casting has now been out free of the gating and the castin offal by which it is attached to the support arm 38 and the casting is now moved to the final station 20. This station consists merely of gas jets 154 which are arranged in a position suitable to play a hot flame on the remaining casting offal so as to expand and strip all of the casting metal from the support arms 34 into the receptacle 156.

It will, of course, be understood by those skilled in the art that the particular work stations illustrated herein are intended for illustrative purposes. More work stations may be added to the apparatus and some of the work stations may, if desired, be omitted. Various portions or the apparatus may be adapted for casting other plastic materials such as synthetic resins and the like. It will also be understood that the particular operations including the quenching, drilling and trimming operations may be operated automatically in response to suitable electrical control mechanisms as is wel known in the art.

Although the invention has been described with speciiic reference to a particular embodiment, it is not intended to be so limited since changes and alterations may be made therein which are Within the full intended scope of the invention as deiined by the appended claims.

We claim:

1. Forming apparatus comprising a die casting machine and carrier means for carrying a casting from the cavity of said die casting machine to a plurality of work stations, said die casting machine comprising complementary movable and stationary dies defining a cavity thereoetween said dies including a tubular passage at the interface thereof extending from said cavity to a point outside said dies, said passage havin an enlarged hallshaped portion between said cavity and said point, said carrier means including a conveyor mechanism and a carrier arm attached thereto adapted to extend snugly through the tubular passage of said dies and into said cavity in one position of said conveyor mechanism, said carrier arm having a ball-shaped enlarged portion adapted to be snugly received and urged within the enlarged portion of said passage when said dies are closed, said carrier means including support means permitting said carrier arm sutlicient movement in all planes whereby said carrier ball shaped portion is snugly received in said enlarged portion of said passage as said dies are closed.

2. Metal forming apparatus including a die casting machine, a conveyor means for conveying castings from the cavity of said die casting machine to a plurality of Work stations, said die casting machine including stationary and movable dies defining a cavity therebetwe-en, said dies including a tubular passage at the interface of said dies extending vertically from said die cavity to a point outside of said dies, said tubular passage having an enlarged portion therein, flexible endless carrier means mounted over said dies adapted to move in a plane perpendicular to the plan in which said movable die moves, a transverse bar mounted on said carrier means adapted to be moved to a predetermined position over said dies and being capable of limited vertical motion due to the flexibility of said carrier means, a support arm slidably mounted on said bar and adapted to be moved along said bar and snugly received Within said passage and to extend into said cavity when the dies are closed, said support arm having an enlarged ball-like portion adapted to be snugly received and urged within said enlarged portion of said passage when said dies are closed, said support arm being mounted on said bar by means permitting movement of said ball portion relative to said bar in a direction transverse to the longitudinal axis of said bar.

3. Metal forming apparatus including a die casting machine, a conveyor means for carrying castings from the cavity of said die casting machine to a plurality of work stations, said die casting machine including stationary and movable dies defining a cavity therebetween, said dies including a tubular passage at the interface of said dies extending vertically from said die cavity to a point outside of said dies, said tubular passage having an enlarged portion therein, flexible endless carrier means mounted over said dies for movement in a direction transverse to the direction of movement of said movable die, a bar mounted on said carrier means adapted to be carried over said dies and to be stopped in a predetermined position over said dies and perpendicular to the plane in which said movable die moves, a support arm adapted to be snugly received within said passage and to extend into said cavity and having an enlarged ball-like portion adapted to be snugly received within said enlarged portion of said passage, and means for mounting said support on said bar permitting the said support to slide therealong and to move relative to said bar in a direction transversely to the longitudinal axis thereof said carrier arm having limited vertical movement due to the flexibility of said carrier means.

4. Metal forming apparatus including a die casting machine, a conveyor means for carrying cast'ngs from the cavity of said die casting machine to a plurality of work stations, said die casting machine including stationary and movable dies defining a cavity therebetween, said dies including a tubular passage at the interface of said dies extending vertically from said die cavity to a point outside of said dies, said tubular passage having an enlarged portion therein, flexible endless carrier means mounted over said dies for movement transverse to the direction of movement of said movable die, a plurality of bars mounted on said carrier means in spaced relation and in a position perpendicular to the plane of movement or" said movable die and a support arm slidably mounted on each of said bars, said support arm being adapted to be snugly received within said passage and to extend into said cavity, said support arm having a locating enlarged ball-like portion adapted to he received Within said enlarged portion of said tubular passage when one of said bars is moved to a die operating position and said dies are moved into a closed position, the mounting of said support arm on said carrier means including means for permitting said support arm to move transversely relative to the longitudinal axis of said bar, said support arm being capable of limited vertical movement due to the flexibility of said carrier means.

5. Metal forming apparatus including a die casting machine, a conveyor means for conveying castings from the cavity of said die casting machine to a plurality of work stations, said die casting machine including sta 7O tionary and movable dies defining a cavity therebetween,

direction of movement of said movable die, a bar mounted on said carrier means adapted to be positioned over said dies in a position perpendicular to the direction of movement or" said movable die, a support arm having an enlarged ball-like portion adapted to be snugly received within said passage and to extend into said cavity when said ball-like portion is received Within said enlarged portion, means for mounting said support arm on said bar which permits slidable movement thereof along said bar and movement of said carrier arm in a direction transverse to the longitudinal axis of said bar, said carrier arm being capable of vertical movement when said dies are moved into a closed position due to the flexibil y of said carrier means whereby said balllike portion may be urged within said enlarged portion of said dies by said movable die as it is moved into a closed position.

6. Metal forming apparatus including a die casting machine, a conveyor means for carrying castings from the cavity of said die casting machine to a plurality of work stations, said die casting machine including stationary and movable dies defining a cavity thcrehetween, said dies including a tubular passage having an enlarged portion therein extending vertically from said die cavity at the interface of said dies to a point outside of said ies, a flexible endless chain carrier means mounted over said dies for movement transverse to the direction of the movement of said movable die, a bar attached to said endless chain means adapted to be supported over said die cavity in one position of said carrier means, a support arm having an enlarged ball-like portion adapted to be snugly received Within said tubular passage and to extend into said cavity when said ball-like portion is reeive'd within said enlarged portion, and means for mounting said support arm on said oar permitting slidable movement of the support arm along said bar and movement thereof relative to the longitudinal axis of said bar in a direction transverse of said bar.

7. Metal forming apparatus including a die casting machine, a conveyor means for carrying castings from the cavity of said die casting machine to a pl ality of Work stations, said die casting machine including stationary and movable dies defining a cavity therebetween, said dies including a tubular passage having an enlarged portion therein extending vertically from said die cavity at the interface of said dies to a point outside of said dies, an endless flexible carrier means comprising a pair of spaced endless chains slidahly mounted on spaced tracks mounted over said dies for movement transverse to the direction of the movement of said movable die, a transverse bar mounted across said chains adapted to be supported'over said die cavity in one position of said carrier means, a support having an enlarged balllilte portion adapted to be snugly received within said passage and to extend into said cavity when said balllike portion is received Within said enlarged portion, means for mounting said support arm on said bar permitting slidahle movement of the support arm along said bar and movement thereof relative to said bar in a direction transverse to the longitudinal axis of said bar,

horizontal plate and said blocl; v /hereby 8 said support arm is capable of movement transverse to the longitudinal axis of said bar.

8. Metal forming apparatus including a die casting machine, a conveyor means for carrying castings from the cavity of said die casting machine to a plurality of work stations, said die casting machine including stationary and movable dies defining a cavity therebetween, said dies including a plurality of tubular passages each having an enlarged portion therein extending vertically from said die cavity at the interface of said dies to a point outside of said dies, an endless flexible carrier means mounted over said dies for movement transverse to the direction of the movement of said movable die, a bar mounted on said carrier means in a position transverse to the direction of movement of said carrier means adapted to be supported over said die cavity in one position of said carrier means, a plurality of support arms having enlarged ball-like portions adapted to he snugly received within said passages and to extend into said cavity when said ball-like portions are received within said enlarged portions, means for mounting said support arms on said bar permitting slidable movement of the support arms along said bar and movement thereof relative to said bar in a direction transverse to the longitudinal axis of said bar, and connector means coupling said support arm.

9. Metal forming apparatus including a die casting machine, a conveyor means for carrying castings from the cavity of said die casting machine to a plurality of work stations, said die casting machine including stationary and movable dies defining a cavity thercbetween, said dies including a tubular passage having an enlarged portion therein extending vertically from said die cavity at the interface of said dies to a point outside of said dies, a flexible endess chain carrier means mounted over said dies for movement transverse to the direction of the movement of said movable die, a bar attached to said endless chain means in a position transverse to the direction of movement of said carrier means adapted to be supported over said die cavity in one position of said carrier means, a support arm having an enlarged ball-like portion adapted to be snugly received within said tubular passage and to extend into said cavity when said ball-like portion is received Within said enlarged portion, means for mounting said support arm on said bar permitting slidable movement of the support arm along said bar and movement thereof in a planeperpendicular to the longitudinal axis of said bar, a work station positioned below said conveyor means adapted to perform a finishing operation on a casting formed on said support arms when said casting is located in a predetermined position, said Work station including a vertical abutment having a ball-like depression therein, a,

movable ram adapted to move said ball-like enlarged portion snugly into said ball-like depression, said support arm being operative to position a casting attached thereto in said predetermined position when said ram moves said ball-like portion against thedepression of said abutment.

References Tired in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ll8 l96 January 21 1964 Fred T. Hall et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8 line 26 for "arm" read arms Signed and sealed this 9th day of June 1964,

SEAL) Affe'st:

ERNEST w; SWIDER EDWARD J. BRENNER Ai'tes'ting Officer Commissioner of Patents

Claims

8. METAL FORMING APPARATUS INCLUDING A DIE CASTING MACHINE, A CONVEYOR MEANS FOR CARRYING CASTINGS FROM THE CAVITY OF SAID DIE CASTING MACHINE TO A PLURALITY OF WORK STATIONS, SAID DIE CASTING MACHINE INCLUDING STATIONARY AND MOVABLE DIES DEFINING A CAVITY THEREBETWEEN, SAID DIES INCLUDING A PLURALITY OF TUBULAR PASSAGES EACH HAVING AN ENLARGED PORTION THEREIN EXTENDING VERTICALLY FROM SAID DIE CAVITY AT THE INTERFACE OF SAID DIES TO A POINT OUTSIDE OF SAID DIES, AN ENDLESS FLEXIBLE CARRIER MEANS MOUNTED OVER SAID DIES FOR MOVEMENT TRANSVERSE TO THE DIRECTION OF THE MOVEMENT OF SAID MOVABLE DIE, A BAR MOUNTED ON SAID CARRIER MEANS IN A POSITION TRANSVERSE TO THE DIRECTION OF MOVEMENT OF SAID CARRIER MEANS ADAPTED TO BE SUPPORTED OVER SAID DIE CAVITY IN ONE POSITION OF SAID CARRIER MEANS, A PLURALITY OF SUPPORT ARMS HAVING ENLARGED BALL-LIKE PORTIONS ADAPTED TO BE SNUGLY RECEIVED WITHIN SAID PASSAGES AND TO EXTEND INTO SAID CAVITY WHEN SAID BALL-LIKE PORTIONS ARE RECEIVED WITHIN SAID ENLARGED PORTIONS, MEANS FOR MOUNTING SAID SUPPORT ARMS ON SAID BAR PERMITTING SLIDABLE MOVEMENT OF THE SUPPORT ARMS ALONG SAID BAR AND MOVEMENT THEREOF RELATIVE TO SAID BAR IN A DIRECTION TRANSVERSE TO THE LONGITUDINAL AXIS OF SAID BAR, AND CONNECTOR MEANS COUPLING SAID SUPPORT ARM.