US3266286A

US3266286A - Compressing device

Info

Publication number: US3266286A
Application number: US317373A
Authority: US
Inventors: Stuart L Parsons; Henkel Werner Otto Peter; Over William Roderick
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1963-10-18
Filing date: 1963-10-18
Publication date: 1966-08-16
Anticipated expiration: 1983-08-16
Also published as: GB1022508A; US3283558A; NL140372B; BE654334A; NL6411836A; DE1502213B2; CH414351A; DE1502213A1

Description

Aug. 16, 1966 s. PARSONS ETAL 3,266,286

COMPRES SING DEVI CE 6 Sheets-Sheet 1 Filed Oct. 18, 1963 Aug 15, 1966 s. L. PARSONS ETAL 3,266,286

COMPRESSING DEVICE 6 Sheets-Sheet 2 Filed Oct. 18, 1963 Aug- 15, 1956 s.`| PARSONS ETAL 3,266,286

` COMPRESSING DEVICE Filed OCI.. 18, 1965 6 SheetsSheet 3 Allg- 16, 1966 s L. PARSONS ETAL 3,266,286

COMPRESSING DEVICE Filed Oct. 18, 1965 6 Sheets-Sheet 4 Aug. 16, 1966 s. L. PARSONS ETAL 3,255,286

COMPRESSING DEVICE Filed om. 18, 1963 6 SheeS-She t 5 [les f i' [1]/ Y ug- 16, 1966 s. L. PARSONS ETAL 3,266,286

COMPRESS ING DEVICE Filed oct. 18, 1965 6 Sheets-Sheet G United States Patent O Filed tiet. 18, 1963, Ser. No. 317,373 5 Claims. (Cl. 'i2- 413) This invention relates to compressing devices, and is herein disclosed in an embodiment comprising a conventional bench press. It will be obvious, however, that the principles of the invention are applicable to other types of compressing devices such as hand tools or relatively larger presses.

An object of the invention is to provide an improved press or the like having a high capacity relative to its weight and size. A further object is to provide an irnproved mounting and guiding system for the dies of a press or the like. A still further object is to provide a press or the like which is of relatively simple construction and which achieves :a high degree of `accuracy as regards the movement of the press dies relatively towards and away from each other. A still further object is to provide a press having the advantage of low frictional losses so that most of the force developed by the power source of the press is applied directly to the work piece. A still further object is to provide a press having a guiding means for the press dies which is not subject to deterioration as a result of wear.

These and other objects of the invention are achieved in a preferred embodiment co-mprising a pair of coextensive cantilever plates which are rigidly mounted at one end and rigidly connected to each other at their free ends. The press die or other work engaging piece is rigidly mounted on the free ends of the cantilever plates and rmeans are provided for applying a force to this die which is directed towards the fixed die of the press so that the cantilever plates are flexed and guide the movable die relatively towards and away from the fixed die. The plates may be of spring temper steel and are relatively long with respect to their thickness so that only a relatively low force is required to deflect the plates when a force is applied to the movable die. The force applied is thus utilized almost entirely for the compressing operation being carried out and is not partially lost in friction. The plates are also relatively wide with respect to their thickness so that while they will deflect in a direction extending normally of their planes, they will not readily deflect in the transverse direction, that is in a direction parallel to their planes. The dies mounted on the ends of the plates are thus prevented from moving laterally and are guided along a path extending substantially normally of planes of the plates.

In the drawing:

FIGURE 1 is a sectional side view, taken along the lines 1--1 of FIGURE 3, o-f a preferred form of electrical terminal crimping press in accordance with the invention, this View showing the relative positions of the parts when the dies are separated.

FIGURE 2 is a view similar to FIGURE 1 but showing the relative positions of the parts when the dies are in their closed positions.

FIGURE 3 is a view looking obliquely towards the front of the press as indicated by the arrows 3 3 of FIG- URE 2.

FIGURE 4 is a side view of the forward portion of the press looking from the left of FIGURE 3 and showing the actuating linkage for the terminal strip feed mechanism.

FIGURE 5 is a side view similar to FIGURE 4 but looking from the right in FIGURE 3 and showing the means for adjusting the shut height of the crimping dies.

FIGURE 6 is a sectional frontal view of the strip feed mechanism.

FIGURE 7 is View taken along the lines 7-7 of FIG- URE 2 and showing the cam rollers which apply the actuating thrust to the movable die and which actuate the strip feed mechanism.

FIGURE 8 is aview taken along the lines 8--8 of FIGURE 1.

FIGURE 9 is a perspective view of a `short section of uncrimped terminals in side-by-side strip form.

Referring rst to FIGURES 1 and 3i, the attached drawing shows a crimping press for electrical Contact terrninals in side-by-side strip form incorporating the principles of the instant invention. The press frame comprises a base plate 2 having a pair of upstanding

parallel side plates

4, 6 between which the crimping dies, the suspending and guiding system for the dies, and the actuating mechanism are contained. Plates 4,` 6 are secured by means of suitable fasteners to a spacer 8 integral with the base plate and to a mounting block 10 which is Icontained between the side plates at their rearward ends and suitably fastened to the base plate.

Mounting block it) is cut away at its righthand side as viewed in FIGURE 1 to provide a seat 12 on which a pair of relatively wide and

thin cantilever springs

14, 16 are mounted. The mounting means for these cantilever springs may comprise a spacer block 18, a clamping bar 19, and suitable fasteners 2t), the spacer block being clamped between the cantilever springs by means of the fasteners which extend through the bar 19, both of the springs, and into the block lll.

The forward ends of the

cantilever springs

14, 16 are rigidly connected together by means of a spacer block 22 and fasteners 26. The spacer block 22 is clamped between the forward ends of the cantilevers and the fasteners extend through a die mounting block 24, through the spacer 22, and are threaded into a clamping bar 25 which is mounted on the underside of the lower spring 16. A movable crimping` die 28 is mounted on the underside of the block 24 and in front of the ends of the cantilever springs. Die 28 is secured by means of a fastener 30 to a shank 32 having flanges (not shown) extending from its upper sides. Shank 32 is positioned behind depending flanges 31 on the front of block 24 and is held in position on one side by a clamping bar 34, and on the other side by a pin 36. The clamping bar 34 is secured by fasteners to the underside of block 24 and overlaps the flanges on the shank. The pin 36 extends through, and is locked to, a leaf spring 38y secured to the side of the die block 24 with the end of the pin extending inwardly beyond the flange on the die shank. The arrangement is such that the entire upper die can be quickly removed by merely pulling the pin rightwardly in FIGURE 3 against the biasing force of the spring 38 and swinging the .die` and the mounting shank in a clockwise direction about its lefthand side to remove the die from engagement with the clamping bar 34.

Die mounting block 24 is connected by' means of a link 42 to a spacer block 44 which is contained between and secured by suitable fasteners to a pair of actuator plates or

cam support plates

46, 48 which are parallel to, and positioned between the opposing faces of, the

frame plates

4, 6. As shown in FIGURES 1 and 3, the link 42 is pivoted within a central recess in the actuator plate spacer block 44 and is pivotally connected in a similar recess in the spacer block 44. It should be mentioned at this point that the weight of the die mounting block 24 and the die 28 is borne by the link 42 rather than by the

springs

14, 16. In the preferred embodiment, these springs are relatively thin and would be incapable of supporting the weight of the block 24 without exure. These springs thus function only as a guiding means for the die.

The actuator plates 46, 4S each have rearwardly extending arms 50 which extend beside the

cantilever springs

14, 16 and which are pivotally mounted on a common pivot pin 52 in the mounting block 10. It will be apparent that the arrangement is such that upon clockwise movement of the

plates

46, 48 about their pivotal axis 52 as viewed in FIGURE 1, a downward force will be applied to the die mounting block 24 thus causing downward movement of the movable die 23 with concomitant exure -of the suspending and guiding system including the

cantilever springs

14, 16.

The pivotal motion of the

actuator plates

46, 48 is achieved by means of a pair of superimposed cam rollers 60, `62 whch are movable rightwardly from the position of FIGURE 1 to the position of FIGURE 2. The lower roller 60 moves over a `cam surface 56 on a cam block 54 which is positioned between and secured to the opposed sides of the

pivoted plates

46, 48. The upper roller 62, which is in tangential contact on its underside with the lower roller, moves over a cam surface 58 on the underside of a fixed camming block which extends between, and is secured to the opposed faces of, the

frame plates

4, 6. Cam surface 56 is convergent with respect to cam surface 58 when the parts are in the positions of FIGURE 1 so that upon the rightward movement of the cam rollers, the two cam plates will be forced downwardly in a clockwise swinging motion about their pivotal axis 52.

Referring now to FIGURE 7,

cam rollers

60, 62 are mounted on

shafts

64, 66 which extend between a pair of parallel arms 68, 70 described more fully below. The shaft 66 extends through suitable bearings in the roller 62 and has its ends mounted in the arms 68, 70. The lower shaft 64 extends through bearings in the roller 60, through bushings 61 in each of the arms 68, 7th, through guide rollers 114 in each of the

plates

46, 48, and through guide rollers 112 in each of the

frame plates

4, 6. The rolls 114 are confined in elongated slots 116 in the cam plates and the rolls 112 are confined in slots 117 in the frame plates to permit movement of the

cam rolls

60, 62 and the arms 68, 70' from the position of FIGURE 1 to the position of FIGURE 2.

The arms 68, 70 extend leftwardly as viewed in FIG- URE 1 beyond the support plates and the

frame plates

4, 6. The ends of these arms are secured by fasteners 72 to an extension '74 on the upper side of a block 76 which straddles, and is pivotally secured to, a nut 78 threadedly mounted on a power screw 80. The nut 78 may be of conventional design or, advantageously, may have suitable roller bearings or ball bearings therein to reduce the frictional .losses between the nut and the power screw when the screw is rotated in the manner described below. One suitable type of commercially available nut has planetary bearings interposed between the nut and the threads of the power screw thereby to reduce the frictional losses when the nut moves relatively over the power screw during operation.

The power screw 80 has an Unthreaded end 82 which extends rearwardly through a suitable bearing in the upper end of the block and is coupled as shown at 84 to the output shaft 86 of an electric mot-or 88. This motor vshould advantageously be of a type which can be readily reversed and should have an armature having a relatively .low inertia since the motor must be reversed during each complete operating cycle of the press. A suitable type of motor, for example, is a printed circuit armature motor of the type produced by Printed Motors Incorporated of Glen Cove, New York.

It will be apparent from the foregoing description that rotation of the power screw causes movement of the

cam rollers

60, 62 along a straightline path extending parallel to the axis of the power screw, the direction of movement of the cam rollers being dependent upon the direction of rotation of the power screw. The inclination of the cam surface 56 with respect to the fixed cam surface 58 is such that upon rightward movement of the `cam rollers from the position of FIGURE 1 to the position of FIGURE 2,

actuator plates

46, 48 are swung in a clockwise direction about their pivotal axis 52 thereby to move the die 28 relatively towards the xed die. The slots 117 in the frame plates, in which the rolls 112 are contained, extend parallel to the path of reciprocation of the cam rollers since these frame plates are fixed. The slots 116 in the cam support plates, in which the rollers 114 are contained, extend Iparallel to the cam surface 56. It will be noted that the slots 116 extend rearwardly beyond the cam surface 56 as indicated at 119 so that when the cam rollers move leftwardly from the position of FIGURE 2 to the position of FIGURE 1, the rollers and the shaft 64 are permitted to move leftwardly after the rollers have moved olf of the cam surface 56 and the upward stroke of the die 28 has been completed. This final portion of the return stroke of the rollers is utilized to actuate the terminal strip feeding mechanism as described below.

The operation of the press is controlled by a control circuit including a switch which is' engaged by an extension on the block 76 (not shown) during leftward movement of the nut over the power screw to stop the motor at the end of an operating cycle. Starting of the motor may be accomplished by a foot switch or by a switch which is mounted behind the dies and which is closed upon positioning a wire end between the crimping dies. Reversal of the motor at the end of the downward stroke of the movable die is controlled by means of a photoelectric cell 94 (FIGURE 5) mounted in a block 92 adjustably secured to the external surface of the frame plate 4. The beam of the photoelectric cell is directed transversely across a slot 95 in the block 94 and a shutter 97, mounted on the projecting end of the shaft 64, enters this slot during forward motion of the rolls 61), 62. When the shutter passes through and interrupts photoelectric cell beam, a suitable control circuit (not shown specifically) is energized to bring about reversal of the drive motor 8S.

The shut height of the crimping dies can be changed by merely adjusting the location of the photoelectric cell 94 along the path of movement of the shaft 64. In order to lpermit such adjustment, the block 92. is secured to a boss 96 by means of screws which extend through elongated slots in the boss. An adjusting screw which is threaded through this boss is journalled in a pair of spaced apart plates 11B@ and has a forwardly projecting end on which a linger piece 102. is provided so that rotation of the finger piece has the effect of moving the boss and, therefore, the photoelectric cell 94 rightwardly or leftwardly as viewed in FIGURE 5. Advantageously, a lock nut 104 is provided on the forwardly projecting end of the screw 98 so that the block 92 can be securely locked in a given position of adjustment.

FIGURES 4 and 6 show the actuating means for the terminal strip feed mechanism and the terminal strip feed mechanism respectively. It should be mentioned that the terminal strip feed mechanism and its actuating linkage are not lshown in FIGURES 1, 2 and 3 in the interest of presenting a clearer view of the press and the suspension system.

Referring now to FIGURE 4, the actuating mechanism for the terminal strip feeding means comprises a pair of bell cranks 122, 124 which `are pivotally mounted on the external surface of the frame plate 6. Bell crank 124 has an upper arm 125 which extends alongside the slot 117 of frame plate 6 and has a contoured cam surface on its upper edge which is engaged by a roller 120 on a projecting end of the shaft 64. The arm 12S extends beyond an upwardly directed arm 123 of the bell crank 122 and has a roller 126 on its end which is in engagement with the rearwardly facing edge of the arm 123. A downwardly directed arm 132 of bell crank 124 is connected by means of a tension spring 134 with arm 123 at a location adjacent to the pivotal axis of bell crank 122. The forwardly directed arm 128 of bell crank 122 has a notched end 130 which is coupled to the feed mechanism as described below.

Upon rightward movement of `the roller 120 from the position of FIGURE 4, the bell crank 124 is swung counterclockwise about its pivotal axis causing the roller 126 to ride downwardly over the edge of arm 123 thereby to swing the bell crank 122 in -a clockwise direction and move the end 130 of arm 128 downwardly. The contour of the upper edge of arm 125 is such that this motion of the end of .arm 130 takes place during a first portion of the rightward stroke of the roller 120 so that arm 128 dwells in its lowered position during the final portion of the fonward stroke. During rearward movement of the shaft 64 and roller 120, the two bell cranks lare held stationary by the spring 134 until the shaft approaches the limit of its rearward movement at which time a roller 118 on the shaft engages the forwardly facing edge of the arm 123 and swings the bell crank 122 in a counterclockwise direction to raise the end 130 of the arm 128. The r-oller 118 engages arm 123 after the

cam rollers

60, 62 have moved off of the cam surface 56, that is, when the shaft moves into the end portions 119 of the slots 116. By virtue of this arrangement, feeding of `the terminal strip takes place after the movable die has completed its upward travel as will be apparent from the description given below of the strip feed mechanism. In the disclosed embodiment, la spring biased plunger 131 is mounted on the side of the frame plate at a location such that it is engaged by the edge of arm 123 of bell crank 122 during the final portion of counterclockwise movement of this bell crank. This plunger functions as a damping device to bring the bell crank 128 to a smooth and even stop.

The terminal strip (FIGURE 9) is provided with spaced 'apart pilot holes which are entered by the ends of feed pawls 136, 138 (FIGURE 6) and which .advance the strip rightwardly as viewed in FIGURE 6 to position the leading terminal thereof at a location between the two feed pawls and directly beneath the movable crimping die. The feed pawls 136, 138 are pivotally mounted at 140 and 142 on the upper ends of a pair of pivoted

levers

139, 141. These levers are pivoted intermediate their ends as shown at 146 and are connected by means of a link 148 at their lower ends, this link being pivotally -mounted on pins received in the lower ends of the levers so that the two levers move as a unit about their pivotal axis. Motion is imparted to the levers by means of an arm 152 which extends laterally past the frame plate 6 and into a notch in the end 130 of the arm 128 of bell crank 122. The feed pawls are normally biased to the positions Ishown in FIGURE 6 by means of flat springs 144 which bear against the sides of the levers of the pawls. However, the pawls can be swung in a clockwise direction about their pivotal axes 140, 142 when they are moved leftwardly from the position of FIGURE 6 thereby to permit indexing of lthe feed system in a manner described Y below.

An L-shaped mounting plate 156 is secured to the press frame and has an arm which extends beside the levers 139, 144 and downstream therefrom with respect to the crimping station. A block 158 is adjustably mounted on the plate 156 by means of a guide pin 160 which extends into block 158 and an adjusting screw 162 which extends through an opening in the plate 156 and into a threaded opening in the block 158. On its upper end, the block 158 has a feed pawl 164 mounted thereon which is similar to the

feed pawls

136, 138. The block 156 however, does not move, excepting for purposes of Iadjustment and functions as a stop in a manner described below.

The

levers

139, 141 are normally spring biased in a counterclockwise direction with respect to their pivotal axes 146 by means of compressing springs 168 which are CFI ' the strip can take place if the 6 interposed between the side of the block 158 and the side of the lever 139.

Adv-antageously, -a drag block 166 is provided on the upper side of the feeding mechanism which resiliently bears against the surface of the strip downstream from the crimping station. The function of this drag bar is to maintain the carrier st-rip from which the contact terminals have been removed in the same plane as the incoming strip and thereby to assist in properly positioning the leading terminal of the strip in the crimping ystation between the two

feed pawls

136, 138.

In operation, the parts will normally tions shown in FIGURE 6 at the beginning of the operating cycle. Upon downward movement of the end of the arm 130, the two

levers

139, 141 are swung in a counter-clockwise direction about their pivotal axes 146 so that the upper ends of these levers and the

feed pawl

136, 138 are moved leftwardly with respect to the strip. The feed pawls are permitted to swing about their pivotal axes 140, 142 so that the ends of the pawls move out -of engagement with the pilot holes in the strip although these feed pawls will initially pull the strip slightly leftwardly as viewed in FIGURE 6 until the pilot hole in which the end of the pawl 164 is received is positioned against the right hand end of the hole. This slight leftward movement of the strip positions the leading terminal of the strip in precise alignment with the two crimping dies. The exact position of the leading terminal of the strip after retraction can be changed by means of the adjusting screw 162 which, when rotated, has the effect of moving the pawl 164 rightwardly or leftwardly las viewed in FIGURE 6.

When the actuating lever or bell crank arm 128 reaches the limit of its downward motion as viewed in FIGURE 6, the

feed pawls

136, 138 will enter a pair of adjacent pilot holes of the terminal strip at a location upstream from the crimping station. Upton upward movement of the bell crank arm 128, which takes place at the end of the operating cycle of the press, the

levers

139, 141 are moved in a clockwise direction about their pivotal axes 146 to advance the strip and to position the next adjacent contact terminal in alignment with the dies.

A salient feature of the disclosed feeding mechanism is that the terminal strip is 'both pushed and pulled during the feeding operation; the strip is pulled by the leading feed pawl 138 and is at the same time pushed by theV trailing feed pawl 136 during relative rightward movement of these pawls as viewed in FIGURE 6. Furthermore, at the end of the feeding stroke, the strip is held Iby the two feed pawls on each side of the crimping yStation so that misalignment of the leading terminal which is being crimped onto a `wire does not take place. These features of the feeding system shown are of particular importance with `relatively small sized terminals since -buckling `of strip is simply pushed by a single feed pawl having its end received in one pilot hole.

In operation, the motor 83 is first energized to drive the shaft 86 and the power screw 80 in a direction such that the

cam rollers

60, 62 move rightwardly from the position of FIGURE 1 to the position of FIGURE 2 thereby to swing the

actuator plates

46, 48 in a clockwise direction and to move the die downwardly. The precise path of movement of the movable die is determined by the two

plates

14, 16 which, -as explained above, undergo flexure as a unit. During return movement of the cam rollers, the die is moved upwardly and the

spring plates

14, 16 return to their normal positions.

The upward movement of the

actuator plates

46, 48 is not brought about by the cantilever springs 14, 16 but is controlled by the slots 116, in which the rollers 114 on the shaft 64 are movable. As shown in FIGURES l and 2, these slots curve relatively downwardly on their lefthand end so that leftward movement of the rollers 114 from the positions shown in FIGURE 2 has the effect of raising the two actuator plates and the movable crimpbe in the posispaanse 'i' ing die. The

springs

14, 16 thus perform only a guiding function for the movable die and are not required to bear the weight of the actuating system for the die.

While the dimensions of the springs and the materials used are not critical, some dimensional limitations should be observed for best results. The springs can be made of ordinary high carbon steel having a spring temper so that they will be capable of undergoing virtually an infinite number of fiexure cycles without fatigue failure.

The exact dimensions of the centilever springs will, of course, depend upon the size of the press and the amplitude required in its stroke but in general it can be stated that the springs should be relatively long and relatively wide in relation to their thickness. For example, where the press is required to have a capacity in the range of about 150G-2000 pounds, and a stroke of about l, the springs may have a thickness of 0.022, a length of about 8, and a width of about 1".

As is evident from a comparison of FIGURES l and 2, the cantilever springs 14, 16 assume a slight S-shape when the springs are flexed upon rightward movement of the

cam rollers

60, 62. Flexure of the springs in this manner results from the fact that the ends of the springs are connected by the block 22 which is rigidly clamped to the ends of both springs. Since the springs are forced to deliect in this manner and since the iiexure of the springs controls the path of movement of the die 28, this die moves diagonally towards the fixed die but the vertical axis of the die 28 is always parallel to the position it occupies when the die is in its raised position. The lateral component of this movement is, however, slight and does not interfere with good crimping practice.

A salient advantage of the invention is that an extremely simple guiding system is provided for the movable die which is not subject to wear, does not involve substantial lubrication problems, and does not involve frictional losses of any magnitude. For example, in a press constituted in accordance with the approximate dimensions `given above, the force required to bring about deflection of the guiding system including the springs is -only about two or three pounds although the maximum thrust developed during a crimping operation will be about 1,500- 2,000 pounds.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

We claim:

1. A press comprising a pair of coextensive cantilevers having corresponding fixed ends and corresponding free ends, means rigidly connecting said free ends to each other, a first die mounted on said free ends, a second die mounted for cooperation with said first die upon movement of said first die towards said second die along a predetermined path, means for iiexing said cantilevers to cause movement of said first die towards said second die comprising, actuator lplate means extending beside said cantilevers, said plate means being pivotally mounted on an axis extending transversely of said cantilevers adjacent to said fixed ends, a link having one of its ends pivotally connected to said free ends of said cantilevers and having its other end pivotally connected to said actuator plate, and means for swinging said actuator plate means about said pivotal axis thereby to flex said cantilevers and move said first die towards said second die along said predetermined path.

2. A press as set forth in claim 1 wherein said means for swinging said actuator plate means comprises a pair of cam surfaces, one of said cam surfaces being on said actuator plate means and the other of said cam surfaces being fixed and extending beside said first cam surface, said one cam surface being disposed proximate to the free ends of said cantilevers, and means movable be.- tween said cam surfaces to swing said actuator plate means about its pivotal axis.

3. A press as set forth in claim 1 wherein said actuator plate means comprises a pair of plates, one of said plates being disposed on each side of said cantilevers, said means for swinging said actuator plate means comprising a pair of cam surfaces, one of said cam surfaces being secured to, and contained between, said actuator plates, the other of said cam surfaces being fixed and extending beside said one cam surface, and means movable between said cam surfaces to swing said plates about said pivotal axis.

4. A device as set forth in claim 3 wherein said means movable between said cam surfaces comprises a pair of superimposed rollers.

5. A device as set forth in claim 3 wherein said means movable between said cam surfaces comprises a pair of superimposed rollers, said rollers being Wound as an actuator arm extending beside said cantilevers, and means for reciprocating said actuator arm.

References Cited by the Examiner UNITED STATES PATENTS 1,354,770 10/1920 Little 72-452 3,214,957 11/1965 Leonard 72-412 CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner.

Claims

1. A PRESS COMPRISING A PAIR OF COEXTENSIVE CANTILEVER HAVING CORRESPONDING FIXED ENDS AND CORRESPONDING FREE ENDS, MEANS RIGIDLY CONNECTING SAID FREE ENDS TO EACH OTHER, A FIRST DIE MOUNTED ON SAID FREE ENDS, A SECOND DIE MOUNTED FOR COOPERATION WITH SAID FIRST DIE UPON MOVEMENT OF SAID FIRST DIE TOWARDS SAID SECOND DIE ALONG A PREDETERMINED PATH, MEANS FOR FLEXING SAID CANTILEVERS TO CAUSE MOVEMENT OF SAID FIRST DIE TOWARDS SAID SECOND DIE COMPRISING, ACTUATOR PLATE MEANS EXTENDING BESIDE SAID CANTILEVERS, SAID PLATE MEANS BEING PIVOTALLY MOUNT-