Abstract: Apparatus for and methods of bonding electrical components or semiconductor chips to a substrate or lead frame is disclosed. According to the present invention, a sawn semiconductor wafer is held upside down in a first substantially horizontal plane and the substrate or lead frame to which it is to be bound is held in a second plane which is below and substantially parallel to the first plane. A die eject head located above the sawn wafer cooperates with a die bond head located between the wafer and the substrate to remove an individual die from the sawn wafer. The die bond head then rotates about an axis which is parallel to both planes and places the die on the lead frame. Also included is a transducer means which is responsive to electrical stimulus for actuating the die eject head and the die bond head such that the interactive force between the heads and the component may be precisely controlled.

Abstract: A device is provided for centering components intended to be implanted in the flat condition and having at least one preformed pin for implantation thereof, the device including two pairs of jaws perpendicular to each other and having recesses for centering the components without damaging the pin during clamping of the jaws.

Abstract: A method of optical recognition of a component suction-gripped by a suction nozzle, wherein, when a small component (P) is illuminated by a first illuminator (23), from cone-shaped reflector provided on the base part of a sucking nozzle (3), thereby making a silhouette image of the small component, and when a large component (P') is suction-gripped, a second illuminator, having two-piece movable translucent sheets (25a+25b, which are opened to pass the large component (P') through a thus-opened gap, illuminates the large component (P') to make its silhouette image. By using a lightweight nozzle, a silhouette of the large component is obtainable, assuring high speed mounting of components.

Abstract: An article picking up mechanism for picking up articles placed in a container one by one for assembling the articles on works. The mechanism includes a tiltable table for receiving the container and tilting it to thereby shift the articles to one side of the container leaving a space in the other side. A manipulator robot is provided to shift one of the articles toward the space and grip the article to take out of the container.

Abstract: An electrical connector assembly machine for loading an insulating housing having a plurality of parallel apertures with a plurality of contacts. It consists of a housing support for supporting the insulating housing; a table having a plurality of parallel channels at equal intervals and in registration with the parallel apertures for receiving the contacts; a pusher disposed over the table so as to be movable vertically and laterally along the parallel channels and having a plurality of grooves for receiving conductor sections of the contacts when the pusher is lowered. The grooves each have at the front edge a jaw portion for pushing forward crimped strain relief tabs of the contact.

Abstract: A contact on the end of a wire is inserted into an aperture of a multi-pin connector by a traveling insertion head that moves in three dimensions to fetch the wire from a wire holder, pull it from the holder and drive it into a selected aperture of the connector. The head moves back toward a wire to insert the wire end contact between a pair of rotating wire drive rollers which grasp the contact and wire to position the contact wholly within a protective insertion quill. The insertion head is then driven into alignment with a selected connector aperture, slightly inserts the quill into the aperture while the contact is fully protected, and the wire drive rollers are rotated to drive the contact and wire through the quill into the connector. A pull test is provided by pivotally retracting the rollers which still grasp the wire. The rollers and quill are withdrawn and opened to enable the rollers and quill to move laterally off the now connected wire to prepare for fetching the next wire.

Abstract: A wire inserting ram (3) is reciprocably mounted in a tool frame (1) which defines a guideway for a connector (7) extending transversely of the ram path. Spring biased wire-grippers (20) are mounted above a wire pusher (27, 28) at a forward end of the ram (7) to support a wire (22) against displacement on trimming between a pusher part (29) and a shear plate (18) on the frame, on forward movement of the ram (7). A bore (36) in the frame allows passage of trimmed wire. Cam means (26) on the frame (1) is arranged to engage the wire grippers (20) on withdrawal of the ram (7) to urge them against the spring bias to an open condition.

Abstract: A lead frame having opposite rows of leads to be connected to the edges of a semi-conductor device and heads on one end of the leads provided with similar angularly related legs between which the edges of the device are received for ultimate soldered connection thereto, the leads and corresponding heads respectively extending from opposite sides of an elongated supporting strip connected at the ends thereof to the lead frame adjacent recesses in the frame to permit bending of the rows of leads substantially along the axis of the supporting strip and thereby extend the heads of the leads upwardly to cause the uppermost legs of the heads of opposite rows thereof to be spaced apart a distance greater than the width of the device to be connected thereto while the ends of the rows of lowermost legs of the heads are spaced a distance less than the width of the device to be supported thereon prior to the rows of leads being reversely bent to restore the bent leads and heads thereon to the plane of the frame and ther

Abstract: A method and apparatus for placing a ferrite core in the slot of a pad of a ferrite head. A circular magnet is mounted below a non magnetic table on a slider slidable along a line. The pad is clamped on the table with its slot exposed and aligned along the line and the center of the magnet. When the ferrite core is placed on the table near the magnet, it stands on edge, aligned along a radial line of flux from the magnet. As the magnet is slid towards the slot, the core follows the center of the magnet, aligned along the centerline of the slot following the radial line of flux. The core slides into the slot and is thereafter bonded to the pad.

Abstract: A head assembly for a burn-in board loader and unloader comprises a mounting block having a generally vertical track. A main body is mounted on the mounting block and afforded vertical movement along the track. The main body has a vertical bore through which a vertically movable plunger extends. The main body also comprises at least three vertical mounting wire holes spaced-apart around the bore. A floating crown having a vertical bore through which the plunger extends is mounted on the upper end of the main body by mounting wires which are fixedly attached at their upper ends to the crown and extend downwardly into the mounting wire holes. The mounting wires are fixedly attached at their lower ends to the main body at the lower ends of the mounting wire holes. The crown is preferably mounted to provide a gap between the crown and main body of about 0.005 inch.

Abstract: An end effector, which is adapted to be disposed on a movable industrial manipulator arm, is capable of placing a holed object having an opening therethrough onto a stud member. The end effector includes a tool adapted to centrally releasably support the holed object and a support mount slidingly connected to the tool for mounting the tool to the industrial manipulator arm. A first sensing system is utilized for sensing when the holed object has been aligned with, and is disposed about, the stud member, and a second sensing system is used for sensing when the holed object is misaligned with the stud member. A third sensing system is provided for determining the amount of misalignment between the holed object and the stud member in one of two planar directions, and a fourth sensing system is included for determining the amount of misalignment between the holed object and the stud member in the other of the two planar directions.

Abstract: An apparatus for processing the end portion of a shielded cable comprises at least one cable-holding means for holding the shielded cable, a transport means for moving the cable-holding means through various stations, the shielded cable being removed of a predetermined length of its outer insulation jacket beforehand and being clamped in the cable-holding means at a first station such that the exposed portion thereof projects forward compressed air means provided opposite the position at which the exposed portion of the shielded cable stops at the second station for blowing air onto exposed shielding wires so as to separate them into upper and lower rows, a wire-bending means provided opposite the position at which the exposed portion of the shielded cable stops at the third station for straightening and aligning the shielding wires separated by the compressed means and bending the same back over the cable-holding means, and a wire-cutting means provided opposite the position at which the exposed portion of t

Abstract: Terminal inserting apparatus comprises first and second sets of closable jaws, the second set of jaws being between the first set of jaws and the cavity in the connector into which the terminal is to be inserted. The jaws are normally aligned and are juxtaposed and are movable relative to each other to spaced-apart positions. In use, the first set of jaws is closed onto the wire adjacent to the end thereof and adjacent to the terminal. The second set of jaws is then moved towards the cavity and closed into surrounding and confining relationship with the terminal on the wire. The second set of jaws does not grip the wire so that the terminal can move relative thereto. The first set of jaws then moves towards the second set of jaws thereby moving the terminal, into the cavity. The actuating mechanism swings the jaws between a lead pick-up station and a lead insertion station.

Abstract: This invention concerns a process for changing electric lines, especially for cutting a line to length and equipping cut line segments with electric connectors especially in an automatic cable finishing machine with lateral transport of the cut line segments with endless belts, where several different lines each unwound from a cable drum are stored on an arc of a circle, so they are parallel to each other with a certain distance apart and they are pivoted together on the arc of the circle for the purpose of changing the lines until a predetermined line is positioned at the culmination point of the arc. This invention also concerns a device for carrying out this process, characterized by a line storage device with support points for lines arranged on an arc extending across the transport direction of a line that is to be cut and arranged so they are spaced a certain distance apart, where the storage device is mounted so it can be pivoted back and forth in the direction of the arc.

Abstract: A feeder assembly comprising a feeder tube having metal rails mounted therein along which IC's can slide on the parts of their leads next to their body and at one end an adapter for guiding the IC's from a transport tube onto the rails. An opening in the feeder tube is provided for permitting pulses of gas to flow through the tube toward the end of the tube remote from the adapter so as to move the IC's to a pick-up pad at said remote end one at a time.

Abstract: A wafer transfer mechanism used for transferring wafers between cassettes and a boat uses sensors to detect and to measure any offset of the actual center of each wafer being transferred with respect to the expected or precalibrated center of that wafer. An appropriate adjustment is made to effectively eliminate such offset so that each wafer can be transferred throughout the system without any edge contact between a wafer and the boat or the cassette. The system also includes a boat exchange unit having a rotatable turntable which is used in association with two boats. The boat exchange unit permits a continuous mode operation in which one boat can be undergoing a loading or unloading of wafers at one station on the turntable while another boat is at or is moving to or from a heating chamber loading or unloading station on the turntable.

Abstract: In a device for transferring a pallet-mounted electric motor armature to an armature winding formation station, the armature is made rigid with the pallet by members which enable it to be released therefrom, and the frame carrying the winding arms comprises a vertical gripper for gripping the armature and connected to drive means which cause it to rotate about its axis between said winding arms; means are also provided for vertically transferring either the armature alone or the armature rigid with the pallet from the conveyor belt to the winding arm zone in which the armature becomes released from the pallet and secured to the vertical gripper.

Abstract: A tool for mounting cable end sleeves on the ends of cables, the tool having two profiled clamping jaws which can be pressed against a cable end sleeve by means of two pliers arms via a toggle joint. The sleeves to be mounted form an end sleeve magazine together with a carrier which, at the time of the opening of the tool, is transported along by means of a jump feed device.

Abstract: The invention concerns a wiring tool to be employed in the cutter-terminal technique for wiring multipole electric connectors, contact strips, and similar structures, with a support and a retainer for the connector that accommodates the conductors that are to be connected and with the support capable of being displaced parallel to itself and to the retainer or vice versa, wherein the support and retainer constitute an interchangeable head that adapts to an extremely wide range of applications and that can be mounted on and dismounted from a transmission, characterized in that the transmission consists of a device that is driven by an electric motor.

Abstract: In an electronic chip placement machine with test function, there is provided a suction nozzle for holding a chip, a chip-regulation device for regulating the attitude of the chip by clamping the chip at portions having no electrodes probes for testing electrical characteristics of the chip. The tip portion of the suction nozzle is made of an insulating material such as a ceramic or a synthetic resin in order to avoid a short-circuit between electrodes of the chip through the nozzle. Therefore, the electrical characteristics of the chip can be tested without the separation between the nozzle and the chip. Furthermore, since one cycle of the operational process according to the present invention is shorter than that of the conventional operational process, it is possible to provide chip-test and placement machines whose structure is simple. As a result, productivity and durability can also be increased.

Abstract: Apparatus for installing connectors onto flat conductor cables. An improved installation station including the apparatus includes magazines for supporting a plurality of connector portions and a transport station to sequentially move the includes magazines for supporting a plurality of connector portions and a transport station to sequentially move the connectors from the magazines to the installation station. The installation station includes a surface for retaining cables in a horizontal plane and a press having an avil and ram for coupling connector portions to the cable and to each other. The installation station also includes means to retain connector portions on the ram during the coupling.

Abstract: An apparatus for preparing stacks of armature disks, which comprises a guide track receiving and guiding successive disks in a direction perpendicular thereto to form a stack, a drive arranged to push against one of the stack ends to advance the stack in this direction along the guide track, an abutment arranged to stop the opposite end of the stack driven thereagainst by the drive, and a device for removing a predetermined portion of the stack adjacent the opposite end.

Abstract: A pick and place machine having an electronic component feed device is described. The feed device feeds electronic components to various pick up locations with such high positional accuracy that alignment jaws on the pick up head are not necessary. Elevated tracks run parallel to a printed circuit board conveyor belt. These elevated tracks support an arm which in turn supports the electronic component pick up head. The feed device is positioned under the elevated tracks so that an operator can replenish the supply of electronic components in the feed device without reaching over the tract.

Abstract: A robotic pick up head for use in picking up electrical connectors (25 and 27) having top actuated rivets (176) and being of different lengths, placing them on a circuit board (19) and setting the rivets (176) to secure the connectors (25 or 27) to the board (19), comprises a body (28) having a top plate (30) for connection to the Z axis shaft (18) of a pick and place robot (2). Opposed piston and cylinder drive units (70 and 72) in the body (28) drive a toggle linkage (50, 54) to drive plungers (142) of riveting tools (26), first to cause the tools (26) to grip the rivets (176) when a connector (25 or 27) is to be picked up and then to set the rivets (176) when they have been inserted into holes (H) in the board (19), to secure the connector thereto.

Abstract: An apparatus for use as an alignment and centering tool for providing a fixed spatial alignment between a rotor and a stator, including a base member and at least one finger member fixedly secured to the base member and extending generally therefrom. The finger member is adapted to be positioned between the rotor and the stator that are to be aligned and centered. A first releasable coupling is provided for operatively connecting the rotor and the finger member to hold the tool and the rotor in a selectively releasable, fixed spatial relationship. A second releasable coupling is also provided for operatively connecting the stator and the finger member to hold the tool and the stator in a selectively releasable, fixed spatial relationship. An alternative user-adjustable embodiment is also provided.

Abstract: The device for testing or processing small electrical component parts having end face contacts includes an endless conveyor belt having a plurality of holes therein that are sized to fit the electrical components. The belt also includes a second parallel row of positioning holes. A component container maneuvers a single component into a complementary hole in the belt. A measurement and/or processing station includes a swing arm which extends across and above the belt and which moves towards the belt. On the swing arm is a pin-like positioning element that depends vertically from the swing arm and has a conical or spherical point. The diameter of the pin is slightly greater than the diameter of the positioning hole on the belt thereby providing an air cushioning effect when the pin approaches the belt. The swing arm also includes a contact element that contacts the end face contacts of the electrical component located in the component hole.

Abstract: A combination electrical component sequencing and inserting machine having a conveyor for receiving components from a source, a verifier for determining acceptability of the component, a blow out station for removing unacceptable components, a transfer station for accepting components from the sequencer, an inspection station for indicating to the machine control the absence of components from the sequence and a repair station adjacent an insertion head for replacing missing components from the sequence. The repair station also functions to test the replacement component prior to placement into the sequence.

Abstract: An apparatus for automatically fixing a printed circuit board to a predetermined position on a worktable of an automatic electronic components insertion machine having a non-shiftably arranged reference positioning pin and a shiftable positioning pin which is automatically shifted by an automatic shifting unit, including a numerically controlled rotary drive unit and a feed screw mechanism. The shiftable positioning pin is arranged so as to be always shifted from a predetermined origin position toward or away from the reference positioning pin in response to a change in the size of printed circuit boards to be fed onto the worktable.

Abstract: A cable core self-aligning apparatus comprises core feeding means for holding a plurality of cores, drawn out of an end of a cable, in a line and sequentially feeding the cores; rotational conveyor means having a conveying rotor for holding and rotationally conveying each of the cores to a core extracting position; and core identifying means for identifying the number of each core while that core is being conveyed to the core extracting position by the rotational conveyor means.

Abstract: An alignment sensing device for use with an article and an apparatus requiring alignment of the article in relation to the apparatus. The alignment sensing device has a first lever and a second lever with an aperture corresponding to a portion of an outer contour of the article. The first lever is pivotally mounted to the second lever, allowing rotation of the first lever relative to the second lever from a normal rest position to an engaged position. The alignment sensing device is movable toward the article, thereby initiating contact between the first lever and the article. The first lever begins to rotate from the normal rest position toward the engaged position, while the alignment sensing device continues to move toward the article. Subsequently, if the article is aligned with the apparatus, the aperture of the second lever matingly encompasses a portion of the outer contour of the article, while the first lever simultaneously reaches the engaged position which is sensed by the alignment sensing device.

Abstract: A tool for aligning contacts of an electrical connector with conductive areas of a circuit board comprises a clamp for clamping the connector therein, a slide is movably mounted on the clamp and includes a comb between the teeth of which the contacts are disposed, and adjustment means moves the slide and comb thereby causing the comb teeth to move the contacts so that they are positioned in alignment with the conductive areas.

Abstract: A method and apparatus are disclosed for providing a crimp seal pleated filter assembly having a two piece housing with a filter media disposed within the housing and having a plurality of alternating pleats. The apparatus includes a first and second jig for supporting the housing halves and an odd number of at least three or more movable pleat forming blades on one side of the apparatus. The odd number of blades are movable through one of the supporting jigs with blade edges opposing the other supporting jig. The odd number of blades includes an independently movable center blade and a first pair of outer blades with opposing surfaces of adjacent blades defining a first plurality of pleat forming spaces. An even number of pleat forming blades are positioned with blade edges opposing the first plurality of pleat forming spaces and are spaced apart from and in alignment with the opposing pleat forming blades.

Abstract: An assembly tool for applying multi-terminal electrical connectors to multi-conductor flat electrical cable having sequentially operated sliding plates which locate and hold the flat cable against a bottom plate with the conductors precisely located in grooves in the plates.

Abstract: An apparatus for positioning circuit components such as flat package IC's at predetermined positions of a printed circuit board and a method therefor are disclosed. In the apparatus, a guide body is provided on the printed circuit board and a positioning member is installed on a retainer plate which holds one of the circuit components. The guide portion guides the positioning member to a point where the component coincides with the predetermined position.

Abstract: An electronic part insertion apparatus which includes an inclined portion inclined by a predetermined inclination angle and having at least one inclined surface on which electronic parts having leads slide to descend under their own weight. An intermittent feeding mechanism is arranged in the middle of the inclined portion to feed intermittently the electronic parts, and a positioning mechanism is provided at a lower portion of the inclined portion to stop and position the electronic parts on the inclined surface. A hand portion is arranged to be pivotable to hold the positioned electronic part at a first position and to insert the held electronic part into a printed circuit board at a second position.

Abstract: In a feeder for carrying electronic components in a predetermined sequence such as ICs packed in a cassette, stick or the like in an electronic insertion machine, part of a carrying path is made movable between the two positions; a component passing position in a usual state and a waiting position outside the carrying path, whereby in the case of incorrect insertion of an electronic component, a new identical component can be supplied by leaving behind the components of the sequential order.

Abstract: The invention relates to an apparatus for surface mounting of components (201) on a support (106). The arrangement comprises a positioning device )102, 103, 104) for holding and moving the components to a mounting position relative to the support. A centering arrangement of two components (203, 204) movable towards and from each other and disposed to center the component from opposite sides concurrently with its movement to the mounting position is provided. The centering arrangement (203, 204) comprises two centering electrodes (300, 310) which are designed with recesses (301, 302, 305, 306) which are adapted to the form and the size of the different component types to be mounted. The centering electrodes moreover comprise electric contact members (307, 308, 706) which are intended to connect the component to an equipment for measuring its electrical properties.

Abstract: An improved apparatus for terminating single conductors to an electrical connector having two rows of terminals, one on top of the other. The rows are staggered so that the terminals of one row are located between the terminals of the other row. An improved terminator is used to terminate wires to both upper and lower connector rows with an actuator of constant predetermined downward deflection.The apparatus also includes an improved index means for advancing a succession of terminals to a termination station.

Abstract: A method for assembling terminal cup-shaped end caps over the ends of cartridge-type electrical subminiature fuses during the assembly thereof has for its novel feature the provision of a centered axially extending handling wire attached to the outer face of each end cap prior to the assembly process. By configuring the lengths of the handling wires substantially longer than the dimensions of the cap itself, the use of an alignment fixture employing the wires for handling and alignment purposes allows for precise orientation of the end caps during the press-on assembly process over the ends of the fuse body. After assembly the wires are removed from their respective end caps. A shearing station suitable for mass production lead removal has upwardly extending sheraing blades with the fuses passed sequentially past the blades with their leads extending slightly over the top of the blade cutting edges.

Abstract: Machine for tipping by pressing cable leads (KE) with end sleeves (AD) or other similar connection elements with a female connector, which may be clamped, respectively pressed, closed or opened at the surface of the envelope, particularly crimp contact elements; the machine comprises a container for storing conductor end sleeves, a supply unit (200) for supplying the conductor end sleeves, which supply unit is provided with a conductor end sleeve unpairing unit (203) for unpairing the conductor end sleeves (A) or similar connection elements received from the storage container, a cable conductor insertion unit (20) and a clamping-fitting unit.

Abstract: A pick-up head (20) for a robot (2), comprises a body (28) having a plate (30) for attachment to the Z-axis shaft (18) of the robot (2). Two pick-up arms (34), pivotally attached to the body (2) each carry a riveting tool (26). The tools (26) are driven through a working stroke by a piston and cylinder drive unit (52) on the body (2), against the action of return springs (82). The tools (26) are inserted by the robot (2) lowering the pick-up head (20), into rivets at the ends of the leading electrical connector (25') at a pick-up station (21) and are arranged to be releasably secured to the rivets to allow the robot (2) to transfer the connector (24') to a circuit board (19) and to insert projecting ends of the rivets into holes in the board (10). The drive unit (52) is then actuated to cause the tools (26) to expand the projecting ends of the rivets, the tools (26) are released from the rivets, and the pick-up head (20) is raised by the robot (2).

Abstract: In a production line for electric motor stators, the stators are rigidly fixed individually, onto respective individual pallets which advance along conveyor belts, in proximity to which the necessary stator-working stations are located; mechanical means are also provided for removing the pallets from the belts and handling them so that the respective stators become disposed in positions corresponding with the working stations located along the line, and in proximity to which said mechanical means are provided.

Abstract: An improved machine for applying electrical connectors to electrically conductive cable, such as multi-conductor flat cable. The machine includes a pair of opposed tool members, each of which include a shelf-like recess for receiving a connector portion. The cable is positioned between the tool members which are advanced toward each other for staking the connector body portion to the cable and receiving the connector cap to the connector body, and thus securing the connector to the cable.In each tool member the shelf-like recess is formed from a shelf which is slidably mounted to the tool member and biased to an outward position. When the shelf engages the cable and other tool member, it retracts and the tool member urges the connector onto the cable. Upon retraction of the tool member, the shelf is biased to its extended position.

Abstract: A compact spindle assembly for surface mounting and insertion of electrical components comprises a unitary casing in which electric rotary and linear displacement motors are housed in order to provide for actuation of a vacuum nozzle and easily interchangeable tool assemblies such that components may be picked from a supply, squared and/or centered during transfer to a placement station, and placed at a particular position on a circuit board or the like.

Abstract: The disclosed wafer handling system includes an input port, an input queue, and output port, and an output queue. The input and output queue each include a vertical elevator assembly capable of storing plural carriers representing multiple tube-loads of wafers input in the input port and into the output queue. A ferriswheel having multiple tube-load storage means is cooperative with an input waling beam and the input queue for arraying the plural carriers therein in multiple tube-loads of wafers each at different intermediate storage locations. A vertical transfer sub-assembly is cooperative with the ferriswheel and with a computer-controlled robot arm for transferring the wafers from each tube-load of carries to quartzware maintained by an inclinable transfer pad defining an elevator-transport access port.

Abstract: There is herein described an improved surface mounted component (SMC) transport mechanism which accepts a multiple number of such components from a plurality of carrier media and transports them to a desired location, for example, adjacent a printed circuit board (PCB) prior to the mounting of the SMC onto the PCB.

Abstract: A device usable in the manufacture of stators for dynamo-electric machines for fixing end portions of the coils of a stator to a support member carried by the stator comprises means for disposing the end portions of the stator coils in directions parallel to a plane substantially perpendicular to the axis of a stator and facing an end surface of the stator so as to make the end portions project outwardly from the stator, means for moving the end portions in the plane substantiallyperpendicular to the axis of the stator until they are brought into a zone of the end surface of the stator in which the support member is disposed, and means for thrusting the end portions downwardly to fit them into corresponding grooves provided in the support member.

Abstract: An apparatus for positioning the spool in the valve body and setting the armature air gap with respect to the core assembly of a compound, spool type valve driven electro-mechanically by a pair of face type opposing solenoids.

Abstract: A technique for moving and presenting an article to a work station is described. A plurality of articles, loaded onto a conveyor system, are moved so that a leading article is positioned at a pick-up and elevating station (46). A separating mechanism (44) is activated to lift (via 90, 91) from the conveyor system (42) all of the articles which trail the leading article, and to move them a predetermined distance behind and away from the elevating station (46). Next, the leading article is elevated above the plane of the conveyor system in order to facilitate its removal therefrom (FIG. 3).

Abstract: Apparatus has a support, and means is associated with the support for reciprocal movement. Resilient means is operable for opposing the movement in one direction of the reciprocal movement means, and wedge means conjointly movable with the reciprocal movement means is also arranged for pivotal movement with respect thereto. Means is associated with the wedge means and the reciprocal movement means for accommodating both the pivotal movement and the conjoint movement of the wedge means with the reciprocal movement means.