Abstract: A safety power assist for a manual press is provided. In another aspect, a press includes a tool, a manual actuator, a switch and an automatically powered actuator. A further aspect of the present press employs a spring which must be compressed beyond a predetermined pinching force before a switch is activated, where switch activation causes an automatically powered actuator to advance a workpiece-contacting punch or tool.

Abstract: A pneumatic riveter may include a jaw assembly (110) configured to extend around a portion of an object through which a fastener is to be driven, a lever (222) configured to be actuated to initiate rivet driving, a valve assembly portion (230) comprising a piston configured to enable progressive control of rivet driving responsive to actuation of the lever, and an unlocking assembly. The unlocking assembly may be configured to selectively inhibit operation of the lever responsive to positioning of a button (240) of the unlocking assembly in a locked position, and enable operation of the lever responsive to positioning of the button in an unlocked position.

Abstract: A method for controlled peening includes forming a surface layer on a workpiece by impacting a surface with a tool wherein the tool is under control to form compressive residual stresses in the surface layer. A system for peening a workpiece includes a tool configured to vibrate and an effector operatively connected to control the tool. The tool includes a peening surface. The tool is configured to cause controlled impact between the peening surface and a surface of a workpiece to form a surface layer of the workpiece with compressive residual stresses. The effector is configured to move the tool in multiple axes.

Abstract: Certain embodiments of the invention may include systems for providing stator bar shape tooling. According to an example embodiment of the invention, a system for shaping an element is provided. The system includes tooling that having at least one constraining surface that is fabricated at least in part by selective laser sintering, where the at least one constraining surface includes at least one curved element section to facilitate bending of at least a portion of an element around the at least one curved element section.

Abstract: An apparatus and method are provided for changing physical characteristics of a workpiece which may have been pre-loaded before being further processed. The workpiece is supported in a fixed position during processing. A driven member applies multiple impacts to one surface of the workpiece. The driven member is operated within adjustable parameters. A controller, having the adjustable parameters, is operatively connected to the driven member for causing the driven member to apply multiple impacts against a surface of the workpiece while under the control of the pre-adjustable parameters for changing physical characteristics of the workpiece.

Abstract: A wire stop assembly is provided for a terminal crimping machine that crimps a terminal to a wire. The terminal crimping machine includes a crimping zone. The wire stop assembly includes a wire stop member having a stop surface configured to engage the wire to limit an amount of travel of the wire in the crimping zone. The wire stop member is movable relative to the crimping zone in a floating direction. A biasing mechanism is configured to exert a biasing force on the wire stop. The biasing force provides a resistance to the movement of the wire stop member in the floating direction.

Abstract: A multi-tool having a plurality of tool-receipt openings adapted to receive respective tools. The multi-tool can be used on turret presses, single-station presses, other industrial presses, or other fabrication equipment.

Abstract: A plate workpiece processing tool including a workpiece support defining a support plane for supporting a workpiece, a tool punch, a tool die, and a control unit configured to control movements of the tool punch and the tool die along a stroke axis. The tool punch and the tool die are displaceable, along the stroke axis, to a processing position above the support plane of the workpiece support such that the tool punch and the tool die are capable of processing a region of a workpiece having a formed shape that extends upwardly from the workpiece support.

Abstract: An applicator ram includes a ram body configured to hold crimp tooling, and a ram adaptor coupled to the ram body. The ram adaptor is configured to be coupled to a terminator ram. The ram adaptor includes an adaptor hub having a hub chamber configured to receive a ram post of the terminator ram. A latch mechanism is movably received in the hub chamber. The latch mechanism is movable between a latched position and an unlatched position. The latch mechanism is configured to engage the ram post in the latched position. The latch mechanism allows the ram post to be released from the hub chamber in the unlatched position. An adaptor stud extends from the adaptor hub and is configured to be coupled to the applicator ram.

Abstract: A forging press includes a slide configured to have a die attached thereto; a drive shaft configured to cause the slide to rise and lower by rotating; a flywheel connected to the drive shaft via a clutch; a servomotor connected to the drive shaft; and a control part configured to control respective operations of the clutch and the servomotor, wherein the control part is configured to perform such control as to cause the drive shaft to rotate with the driving of the flywheel in at least one of a rising process, in which the slide is caused to rise, to cause the slide to rise and a lowering process, in which the slide is caused to lower, to cause the slide to lower.

Abstract: A servo-press machine determining whether or not a drive power supply voltage between a positive power supply path and a negative power supply path that connect a power supply device and a motor rotation control section is lower than an induced voltage of a servomotor, and correcting speed-related data based on slide motion information when the servo-press machine has determined that the drive power supply voltage is lower than the induced voltage.

Abstract: A multi-tool having a plurality of tool-receipt openings adapted to receive respective tools. The multi-tool can be used on turret presses, single-station presses, other industrial presses, or other fabrication equipment.

Abstract: The invention relates to a novel design of hydraulic processing pincers for processing workpieces, with a tool which, in a first tool part, has an axially displaceable tool plunger which, with a first end or with a tool provided there and an opposite work rest, forms a working region or a working gap and can be moved with the first end towards and away from the work rest, and made up of a hydraulic actuating device for applying a force to the tool plunger via a movable pressure-transmitting element, said force moving said tool plunger in the direction of the work rest. The piston and/or the piston rod are/is designed with a cavity in which the tool plunger is accommodated in its initial position at least over part of its length.

Abstract: A robot for the shaping of lingual archwires, including an anterior plate arced according to an anterior portion of a patient's teeth, wherein the anterior plate is capable of accepting an anterior portion of a lingual wire; a plurality of movable posterior bending units positioned posterior to the anterior plate, each bending unit capable of accepting a posterior portion of the lingual wire; a plurality of motors capable of selectively actuating each of the posterior bending units independently along at least one axis to bend the lingual wire along the at least one axis at a plurality of positions; a mother board in electrical communication with the plurality of motors and capable of receiving and executing instructions for desired dimensions of a lingual archwire; and a power source.

Abstract: A conduit bender having a unitary frame is mounted to a wheeled base which provides for transportation of the bender. A braking assembly provides for simplified locking of the wheels to secure the bender in a location. The bender is mounted to the base through a pivoting assembly which allows for bending of conduit in either a horizontal or vertical plane. A circuit is provided for controlling the bending operation. An auto-sensing portion of the circuit receives information regarding the characteristics of the conduit to be bent upon placement of the conduit in the bender. A feed back portion of the circuit is used to provide a precise bending operation.

Abstract: A multi-tool having a plurality of tool-receipt openings adapted to receive respective tools. The multi-tool can be used on turret presses, single-station presses, other industrial presses, or other fabrication equipment.

Abstract: The present invention relates to an apparatus for machining a variable trim line of a panel, which can machine the variable trim line through a simple manipulation within a single process at the time of machining a trunk lid panel. The apparatus includes: an upper die unit disposed at an upper die steel and including a select retainer adapted to selectively punch the variable trim line of the panel, and an upper punch adapted to be moved forward and backward; and a lower die unit disposed at a lower die steel in such a fashion as to be directed opposite to the upper die unit in a row and adapted to push a strap caught in the lower die steel while cooperating with punching operation of the upper punch of the upper die unit. With the apparatus, a die manufacturing cost can be reduced, productivity can be increased and default rate can be reduced.

Abstract: The invention involves a multi-drive tool for use on a fabricating press having a table with multiple stations. Each station can include a mount opening passing through the table. The multi-drive tool can have a bridge member relating to at least two drive members such that a ram stroke of the press simultaneously moves the drive members or components thereof in a direction toward the workpiece. The invention also involves a die shoe adapted for use on a press. A die-mounting recess configured to receive a die is formed in the top of the die shoe. The invention also provides a fabricating press in combination with a multi-drive tool, as well as methods of fabricating a workpiece.

Abstract: The invention is a multi-mode hammering machine that operates in a rigid mode, a flexible power hammer mode and a machine press mode to contour, shape and form sheet metal products. In all three modes, a ram is linearly stroked toward and away from a fixed die by a common ram drive assembly that includes a lever drive assembly and a reciprocating lever. The lever drive assembly moves in a rigid non-flexing manner. The reciprocating lever includes a rigid mode and a flexible mode. A conversion pin is used to engage one and simultaneously disengage the other. The lever drive assembly includes a control link that interfaces with a stroke adjustment mechanism. The gap adjustment mechanism is located at the fulcrum of the reciprocating lever. Both stroke length and gap are adjusted independently during the operation while the ram is cycling.

Abstract: A method and apparatus for detecting a turned blank at a workstation in a progressive forging machine comprising simultaneously monitoring both the force on a tool in the workstation and the crank angle of the machine, determining a reference crank angle when the tool is subjected to a force at the workstation about to deliver a blow and a blank in the workstation is properly angularly aligned, operating the machine to forge blanks in a normal manner when a force on the tool at the workstation occurs substantially at the reference crank angle, and interrupting said normal manner when the force on the tool at the workstation occurs before said reference crankshaft angle to enable the blank being formed at the workstation to be separated from remaining blanks being forged in the machine.

Abstract: Press driving modules are provided to permit a standardized press design. The presses of a press line are equipped with always identical press driving modules, and the pressing force of the presses is varied only by the adaptation of the number of press driving modules. The press driving modules each contain two driving devices, respectively, that interact parallel or in series and have different characteristic curves. In particular, they have different maximal traveling speeds and different maximal forces. They can also have a different design with respect to their positioning capability and path resolution. This concept permits not only a standardization of presses of different performance classes within a press line but, beyond that, the largely free definition of characteristic path-time curves of the slides, and thereby finally also a freer design of workpieces, particularly of vehicle body parts.

Abstract: A calibration tool for fabricating disk springs. The tool includes a circular cylindrical tool body having an insertion bevel at its face end portion for receiving and centering a workpiece within an inner circumferential enveloping surface of the tool body. A tool surface at the inner circumferential enveloping surface aligns the workpiece relative to a forming tool disposed within the inner circumferential enveloping surface. The tool surface includes a first portion having an inner diameter that increases in size along the axial longitudinal direction of the tool body, and a second portion with an inner diameter that decreases in size along the axial longitudinal direction of the tool body.

Abstract: The invention is a multi-mode hammering machine that operates in a rigid mode, a flexible power hammer mode and a machine press mode to contour, shape and form sheet metal products. In all three modes, a ram is linearly stroked toward and away from a fixed die by a common ram drive assembly that includes a lever drive assembly and a reciprocating lever. The lever drive assembly moves in a rigid non-flexing manner. The reciprocating lever includes a rigid mode and a flexible mode. A conversion pin is used to engage one and simultaneously disengage the other. The lever drive assembly includes a control link that interfaces with a stroke adjustment mechanism. The gap adjustment mechanism is located at the fulcrum of the reciprocating lever. Both stroke length and gap are adjusted independently during the operation while the ram is cycling.

Abstract: A plurality of workpiece holders 52 are attached on a slide plate 71 on a bar 14 and connected to a movable plate 72 by a plate connecting portion 73. The plate connecting portion 73 includes an engaging portion 731 that is provided on the movable plate 72 and an engaged portion 732 that is provided on the slide plate 71 and engaged with the engaging portion 731. By moving a fixed bar 141 downward relative to a movable bar 142, the movable bar 142 is detached and the engagement of the engaging portion 731 with the engaged portion 732 is released. Since both of the movable bar 142 and the slide plate 71 can be detached by a single downward movement of the fixed bar 141, no actuator is required, thereby simplifying the structure.

Abstract: A method of operating a safety system for an industrial press having a moveable section and a stationary section, the safety system providing a plurality of continuous planar laser beams having a generally constant lateral width, each laser beam being spaced at varying distances from the moveable section, the method including moving the moveable section towards the stationary section at a relatively high speed; starting deceleration of the moveable section when one said laser beam reaches a speed control point located immediately adjacent the stationary section, moving the moveable section at a final crawl speed when a second said laser beam reaches the speed control point, the moveable section continuing to move at said final crawl speed towards said stationary section.

Abstract: A power hammer assembly providing forming capabilities while remaining economical with respect to performance, vibration, footprint size and acquisition costs. The power hammer assembly can provide for a single stroke speed and/or a single set stroke with respect to the striking of die assemblies against a piece of metal. The power hammer assembly can provide for a large throat area and/or a larger die gap for ease of use. The power hammer assembly can include adjustment features allowing for the use of die sets of varying configurations such as, for example, shank size, shank length or alternatively, die sets fabricated for use with other machinery. In addition, the power hammer assembly can include a belt transmission assembly designed to slip in the event of die interference during set-up or operation so as to avoid damaging the power hammer assembly.

Abstract: A control device for a die cushion mechanism, for carrying out force control with high accuracy and at a high speed. The control device for controlling the force generated by the die cushion mechanism utilizes a press working cycle which is repeatedly carried out. A correcting part of the control device corrects each deviation in one working cycle based on a time-series of deviation data in the just before press working cycle. By repeating this operation, the deviation between the detected value and the commanded value may be converged toward zero. Therefore, the deviation may become smaller than that of the conventional feedback control, whereby it is possible to respond to a change in the commanded value in a short time.

Abstract: The present invention provides a mechanical press with a low height. A sliding guide mechanism and a position adjusting mechanism are provided on the upper and lower sides of an adjustor member, respectively. The sliding guide mechanism converts the rotating motion of an eccentric part of a crankshaft into a reciprocating linear motion and is provided above the adjustor member. The position adjusting mechanism adjusts the position of the slide and is provided below the adjustor member.

Abstract: The invention metal working machine includes a stationary frame and a moving frame. Both the stationary frame and the moving frame carry opposite corresponding tool dies that perform metal working operations when the moving frame translates relative to the stationary frame. The moving frame is arranged so that one end can move while the other end remains stationary. Hydraulic cylinders on each end of the metal working machine are connected by pivot joints between the stationary frame and moving frame. When both of the hydraulic cylinders are activated in the same direction, the entire moving frame moves up or down relative to the stationary frame. If only one of the hydraulic cylinders is activated, only one side of the moving frame translates while the other side of the moving frame moves only slightly.

Abstract: Tool units (400) are slid by crank mechanisms (409) which are arranged on the respective sides of a table (200), convert rotational motions into translational motions, and use servo motors as drive sources, and are supported to swing on the rear end portions of the tool units.

Abstract: An apparatus for drawing a strand has a frame extending in a longitudinal direction, a pair of substantially identical linear motors each having a primary fixed on the frame, and a movable secondary slidable along the respective primary in the direction. The primaries extend parallel to the direction and are transversely spaced on a plane extending in the direction. A strand clamp capable of gripping the strand is fixed between the secondaries. Electricity is supplied to the primaries to longitudinally displace the secondaries and clamp in the frame so that the clamp and any strand held by it are advanced longitudinally through the frame.

Abstract: A positive lock for infinite adjustable stroke alignment mechanism for a mechanical press with an eccentric bushing disposed within a press connection member with a second eccentric member disposed within the eccentric bushing. A rotatable crankshaft is connected to the second eccentric member. A positive lock alignment mechanism is included for aligning the press connection member with the eccentric bushing to prevent rotation therebetween and permitting rotation of the second eccentric member with the eccentric bushing for infinite stroke adjustment whereby rotation of the crankshaft, when the mechanism is activated causes a press stroke adjustment.

Abstract: On a turntable are disposed a plurality of applicators and their respective terminal reels holding strings of terminals. A rail and a shank holder guide are provided between a press for operating one of the applicators and a waiting position on the turntable. One of the applicators alone moves between a set position in the press and the waiting position on the turntable.

Abstract: A bottom dead center correction device for a servo press machine which can correct the bottom dead center with a high precision not achieved by a bottom dead center correction by a slide position detection device provided on a frame includes a bottom dead center sensor (11) and a temperature sensor (12) on a lower mold (10B) of a die (10). The bottom dead center of a set slide motion of slide (3) is corrected by the bottom dead center measurement value of bottom dead center detection sensor (11) and by the temperature drift of bottom dead center detection sensor (11) resulting from the temperature rise of die (10) due to molding and detected by temperature sensor (12). A bottom dead center correction of one micron unit not previously achieved becomes possible. The bottom dead center correction device also can be provided as one which corrects for the fluctuations in the bottom dead center resulting from deformations in all of the construction parts and the die of the servo press.

Abstract: A method of adjusting the stroke of a press brake having a movable beam (1) supporting a punch (2), a fixed beam (3) supporting a die (4), means of displacing (5, 5′) the movable beam with respect to the fixed beam, said displacement means resting on side frames (6, 6′) immovably attached to the fixed beam, linear encoders (9, 9′) for measuring the displacement of the movable beam with respect to the side frames, at least one sensor (8, 8′) measuring a physical parameter (p) varying with the force exerted by said punch on a metal sheet placed on said die, and an electronic device for controlling (7) the bending movement controlling the speed of said displacement movement between top dead center and bottom dead center (BDC), provided with a calculation means for correcting the value of said bottom dead center depending on the measurement of said displacement and said physical parameter.

Abstract: A press with a press lock includes a press frame, a press ram slidably connected with the press frame, a rack fixedly connected with the frame, a pinion block connected with the ram, a pinion actuator operatively interconnected between the ram and the pinion block, and a control operatively connected with the pinion actuator. The press frame defines a stroke length and the press ram slides along the stroke length. The rack also extends along the stroke length, and the pinion block slides generally perpendicular to the stroke length, between open and closed positions of the press lock. The pinion block is also substantially fixed with the ram, relative to movement in a direction along the stroke length. The pinion block further engages the rack in the closed position, fixing the ram at a predetermined location along the stroke length, and disengages the rack in the open position, not inhibiting sliding of the ram along the stroke length.

Abstract: A machine for corrugating a metal foil strip includes a form gear having identical cavities along its perimeter that is driven intermittently by an electronically controlled rotary servomotor to index successive cavities to a forming station. During each dwell of the form gear, a form tooth of a punch unit at the forming station is driven by an electronically-controlled linear servomotor into the cavity to at least partly form a corrugation in the strip. During each operating stroke of the punch unit, a hold finger clamps the immediately outgoing node of the corrugation that just left the forming station against the immediately outgoing tooth of the form gear, thus preventing any part of the outgoing corrugation from being pulled back into the cavity and ensuring that the next corrugation is formed solely from a segment drawn in from the incoming foil.

Abstract: A slide drive apparatus and a slide drive method for a pressing machine capable of enhancing positioning precision at the time of adjustment of die height, and responding to pressing work at high stroke per minute. For this purpose, the drive apparatus includes a slide (4), a servo motor (21) for controlling slide motion, a mechanical power transmission mechanism (3, 5, 6) for converting rotational power of the servo motor for controlling slide motion into reciprocating motion of the slide, and a servo motor (31) for adjusting die height, which performs die height adjustment of the slide by a position control.

Abstract: A vertical position of a ram (5U) is directly detected by a ram position detecting means (11), and a first speed arithmetic operating portion (65) determines a first ram moving speed on the basis of a change of the detected position. At the same time, a second speed arithmetic operating portion (67) determines a second ram moving speed on the basis of a rotational number of a servo motor (39) which is determined by a servo motor rotational number detecting means (40). A comparing portion (69) compares the first ram speed with the second ram speed, and in the case that a difference is equal to or more than a predetermined amount, a judging portion (71) judges that an abnormality exists so as to immediately stop the servo motor (39) and stop a working.

Abstract: A crimping press provides increased accuracy and precision. Both a rotative measuring system, such as an encoder arranged at a motor shaft, and a linear measuring system such as, for example, a measuring head and a glass scale, are provided. The linear measuring system may be coupled between a tool holder and the fixed press stand. The measurement values generated by the rotative measuring system and the measuring values of the linear measuring system are fed to a regulating circuit for regulation of crimping height.

Abstract: An infinite variable slide motion for a mechanical power press is achieved by use of a differential located on the press drive system. Differential movement means are employed to rotate the differential relative to the drive system so that the output of the differential may be increased or decreased relative to the drive system.

Abstract: A crimping including a stand at which a motor and a transmission are arranged. Moreover, first guides, at which a crimping bar is guided, are arranged at the stand. A shaft driven by the transmission has an eccentric pin at one end, and a resolver for detection of rotational angle is coupled to the other end. The crimping bar includes of a slide member guided in the first guides and of a tool holder with a retaining fork. The slide member stands in loose connection with the eccentric pin, wherein the rotational movement of the eccentric pin is converted into a linear movement of the slide member. The tool holder actuates a tool, which together with an anvil produces the crimp connection. An operator terminal is provided as an interface between the operator and the crimping press. The operator terminal includes a rotary knob and a keypad for input of operating data and commands into a control. A display is provided for visualization of data.

Abstract: A sheet fabrication machine includes a direction convert mechanism that converts the movement of the driving mechanism along one direction to drive the tool for fabricating a worksheet in another direction. The direction conversion mechanism includes a carriage plate whereon a plurality of direction convert units may be mounted. Each of the direction convert units may be configured in the form of a cam that has a number of contact surfaces each having a preset angle. The carriage plate is interposed between a drive contact, such as for example a rotating mechanism, and the ram that presses against the tool of the machine. When one of the cams in the carriage plate is positioned into alignment with the rotating mechanism and the ram, the rotating mechanism is moved along the one direction so that it applies a biasing force against the cam.

Abstract: A crimping press provides increased accuracy and precision. Both a rotative measuring system, such as an encoder arranged at a motor shaft, and a linear measuring system such as, for example, a measuring head and a glass scale, are provided. The linear measuring system may be coupled between a tool holder and the fixed press stand. The measurement values generated by the rotative measuring system and the measuring values of the linear measuring system are fed to a regulating circuit for regulation of crimping height.

Abstract: A crimping tool for crimping crimp contacts, in particular crimp contacts in the form of a strip, and which includes a base body (3) which mounts a pressing device (2), and a table (4) associated with the base body for guiding the crimp contacts to a crimping position. The crimp contacts are fed to the crimping position via the table (4), and the position of the table (4) is adjustable relative to the base body along a guideway (5) so as to permit a precise and variable positioning of the crimp contacts. Also, an adjusting mechanism (6) is provided for an infinitely variable positioning of the table (4) along the guideway (5). The table (4) further includes a positioning device (20) for a functional positioning of the crimp contacts (1) relative to the table (4).

Abstract: Damage to the dies due to a die collision caused by an input error of bending data etc. is avoided without use of a specialized device for pressure detection. A die interference checking mode is provided for setting the pressure of the ram, which supports the movable die, to a value that does not cause damage in the event that the movable die and the fixed die interfere with each other and for driving the ram so as to create the set pressure. A die interference determining step is further provided in which it is determined whether the movable die and the fixed die have interfered with each other in the die interference checking step, and if it is determined that the dies have interfered, the movement of the ram is stopped, and if it is determined that the dies have not interfered, the die interference checking step is cancelled and the operation of the press brake proceeds to an ordinary bending step.

Abstract: A drawing apparatus in a press or similar forming system has a blank holder which can be acted upon by one or optionally several pressure cylinders. Blocking devices are provided which act, in one case, directly upon a pressure cheek supporting the blank holder and, in another case, indirectly upon the pressure cheek by way of an articulated train or transmission train. Thereby, an unintentional lifting or lowering of the blank holder is prevented when the press is inoperative.

Abstract: A terminal applicator (10) is disclosed having a shut height adjustment mechanism (60) for controlling the shut height (160) of the terminal barrel crimping bar (26). The mechanism includes upper and lower adjusting members (66, 64) having opposed ramp surfaces (110, 80), the lower adjusting member being attached to the tooling ram (36) and the upper adjusting member being rotationally coupled to the ram. By incrementally rotating the upper adjusting member (66), the relative spacing between a press ram (148) and the tooling ram assembly (18) can be adjusted, thereby changing the shut height (160) of the barrel crimping bar (26). The upper adjusting member includes an inner cylindrical surface (120) having serrations (122) formed therein that are engaged by resilient projections (98) that extend from an outer cylindrical surface (90) of the lower adjusting member (64).

Abstract: A method of controlling a terminal press attaching device by providing a elevating crimper for crimping terminals onto exposed conductors of the cables, setting an anvil opposite to the crimper, and elevating the drive means including a servo motor. More specifically, the crimp height for press attached terminals is monitored, a detected height and the predetermined set value are compared to control said drive means such that the detected height is made equal to the set value. Thus, the crimp height of the terminal to be attached (or the crimper height) is automatically and easily adjusted.

Abstract: A terminal applicator (10) is disclosed having a shut height adjustment mechanisms (68, 120) for controlling the shut height (102, 220) of both the terminal barrel crimping bar (26) and the insulation crimping bar (28). The mechanism includes upper and lower ramp members (126, 128) having opposed ramp surfaces (140), the lower ramp member being attached to the tooling ram (40) and the upper ramp member being rotationally coupled to the ram. By incrementally rotating the upper ramp member (128), the relative spacing between a press ram (222) and the tooling ram (40) can be adjusted, thereby changing the shut height (220) of the barrel crimping bar (26). A cam (72) is rotationally coupled to the tooling ram (40) at right angles to the axis (24) of the upper and lower ramp members (126, 128). The cam has a series of flat surfaces (98), each of which is a different distance from its center of rotation (79).