Abstract: The present invention relates to a fail-safe automatic sliding operation control apparatus for a press. The entrance and withdrawal behaviors of an operator's hand relative to danger zones (D, D.sub.N) on a bolster of the press are detected by an output generation configuration of two optical curtains. A signal for permitting a lowering operation of the slide is generated when the operator's hand is withdrawn from the danger zones (D, D.sub.N).

Abstract: A manual tool is driven by an electric motor, and has a primary handle and a secondary handle arranged at a distance from each other. A switch is situated in the manual tool and can only be switched on by the simultaneous actuation of two contact mechanisms, one arranged in each handle, the motor being switched off when grip on either handle is released. The tool further comprises an initiating device in the form of a safety interlock mechanism which is adapted to prevent actuation of the switch, unless the safety interlock mechanism is actuated prior to actuation of the contact mechanism arranged in the primary handle. The switching mechanism is particularly suitable for a hedge clipper or chainsaw, especially a cordless tool.

Abstract: The present invent provides an improvement in the handling and operation of portable working machines, particularly in a loop front handle and an operation lever adjacent to the handle for easy operation. An operation lever mechanism for a handle according to the present invention includes: a rotatably supported body; a swingable operation lever pivotally supported by the rotatably supported body; and an operating portion movable in a direction along an axis X--X of the rotatably supported body, the operating portion connected to a swinging end of the operation lever, wherein the rotation axis X--X of the rotatably supported body is situated so as to encompass a virtual center X of a loop handle or a point adjacent to the center X, and the grip portions of second swinging end of the swingable operation lever rotate and move along an arc of the loop handle.

Abstract: A control panel (24) of an industrial truck is provided, on two sides, with combination control grips (2a, 2b), which can both be rotated in the circumferential direction and deflected vertically, and on which control levers (45a, 45b) are arranged. Signal transmitters (51, 52), which can be operated by the fingers, and by means of which various types of movements of an internal load pickup means of the truck can be selected and can be preset as a set value for the control lever (45) of the respective opposite combination control grip (2), are integrated within the control levers (45a, 45b).

Abstract: A machine operator control station circuit which uses capacitive proximity switches to replicate the function of mechanical switches used in prior art control stations. A monitoring circuit for monitoring the "on" state of the capacitive proximity switches used in a two hand industrial machine control station is disclosed. The circuit also reduces the chance of unintended operation of the machine being controlled as a result of emitted or conducted radio frequency interference which might be detected by the capacitive proximity switches. An isolation transformer provides an isolated power supply for the monitoring circuit. The monitoring circuit includes a first capacitive proximity switch for detecting the presence of one of the machine operator's hands, and a second capacitive proximity switch for detecting the presence of the other of the machine operator's hands. Each proximity switch has a monitoring circuit for monitoring the length of time the proximity switch remains in the activated or "on" state.

Abstract: A two-hand operator's control station mounted on a common enclosure detects an operator's hands and provides output signals without requiring the operator to push buttons. Such control stations, called pushless run bars, are for use with automatic machinery which requires the simultaneous use of two hands to initiate operation of the machinery. In each embodiment of the present invention, two hand-sensing mechanisms are provided on or near the cover of an elongated enclosure, one for sensing each hand. The sensing mechanisms are located sufficiently far apart, near opposite ends of the run bar enclosure, to prevent accidental operation by one hand. Suitable anti-tie-down circuitry, an electrical cover interlock, indicator lights, and physical barriers to prevent access from certain directions may also be provided as part of the apparatus. A first embodiment of the run-bar apparatus employs two separate photo-transceiver units for detecting the operator's two hands.

Abstract: A safety control system for power operated equipment which ensures operator safety by immediately disconnecting the power drive from a power driven rotating member, such as a toothed feed shaft of a meat skinning machine or a moving blade of a band saw, and then positively stops and then reverses the direction of movement of the rotating member, upon a metal conductive glove worn by the operator, contacting the blade or toothed shaft. The operator's glove is electrically connected to a safety mechanism and upon the glove completing a circuit upon contact with the rotating member or equipment immediately disconnects the power drive from the rotating member by actuating a clutch or tensioning cylinder. A trigger mechanism then is actuated and permits a positive stopping element to engage and stop the moving element.

Abstract: In a preferred embodiment, a capacitive switch system including two capacitive switches which must be activated nearly simultaneously to operate a piece of equipment. When one switch is touched, a timing function is activated. If a predetermined length of time lapses before the other switch is touched, the other switch will be locked out. Both switches must then be released before the activation procedure is re-initiated. The components providing timed and anti-tie-down features, are integral to the circuitry of the switches and these as well as output relays are compactly housed in the switch housings to prevent tampering and circumvention of the safety features. The sensitivity of the switches is such that they cannot be activated by liquids.

Abstract: A control station for a machine is equipped with capacitive proximity sensors in two locations for sensing the presence of operator's hands at the locations. The sensors are enclosed in a protective housing behind exterior target surfaces forming exterior wall surfaces of the enclosure and are supplied by a voltage source. A relay in series with each sensor and the voltage source is actuated when the operators hands are both sensed. Each sensor generates an electrical field extending outwardly a predetermined distance forwardly beyond each target surface for sensing an operators hands which are outside the enclosure within the field and need not be in tactile contact with the target surfaces. Only when both hands are sensed do the relays indicate operation of the machine.

Abstract: A control and safety system for electrically operated devices with a cutting tool (9) connected to a reversible electric motor (88), and control means for halting and reversing the movement of said motor comprises a pair of electrically conducting gloves (A) and (B) adapted to be worn by the operator and connected by a conducting wire (2,3) to a box (4) fixed to the operator's body containing a rechargeable battery and an electronic sensor-transmitter circuit (120) arranged to emit a light pulse when the golves are both worn by the operator and to interrupt the light pulse when one of the two gloves or part of the operator's body accidentally makes contact with any metal part of the device (10). An optical fiber (12) connects said box (4) to the base of the device where it is connected to a receiving control circuit (121) located thereat.

Abstract: A two-hand operator's control station mounted on a common enclosure detects an operator's hands and provides output signals without requiring the operator to push buttons. Such control stations, called pushless run bars, are for use with automatic machinery which requires the simultaneous use of two hands to initiate operation of the machinery. In each embodiment of the present invention, two hand-sensing mechanisms are provided on or near the cover of an elongated enclosure, one for sensing each hand. The sensing mechanisms are located sufficiently far apart, near opposite ends of the run bar enclosure, to prevent accidental operation by one hand. Suitable anti-tie-down circuitry, an electrical cover interlock, indicator lights, and physical barriers to prevent access from certain directions may also be provided as part of the apparatus. A first embodiment of the run-bar apparatus employs two separate photo-transceiver units for detecting the operator's two hands.

Abstract: The invention relates to a two-handle arrangement for a handheld portable tool having a drive motor and equipped with forward and rearward handles for two-handed operation. Each of these handles includes respective actuating elements which can be actuated only in a specific sequence. First, force must be applied to the actuating element on the forward handle and only when a corresponding actuation of the throttle lever takes place is there an increase in the speed of the drive motor. The invention is especially suited for handheld portable tools equipped with an internal combustion engine such as motor-driven chain saws, hedge trimmers and the like.

Abstract: This invention utilizes a conventional meat skinning machine having a frame, an elongated skinning blade, a rotatable gripping roll closely positioned adjacent the blade, an electrical motor operatively connected to the gripping roll and to a source of electrical power, and a danger zone defined by the area approximate to the gripping roll closely adjacent the blade. The motor is a braking motor which has a normally inoperative braking means adapted to stop the motor substantially instantaneously when becoming operative. A safety circuit is electrically connected to the braking motor, the blade and the gripping roll. The safety circuit is normally open and is adapted to be closed when the blade and gripping roll are electrically connected by any electroconducting means, such as an operator's glove made of electroconducting material, that simultaneously comes into electrical contact with the blade and the gripping roll.

Abstract: In a method of operating a press machine having a servomotor (20) and a servo controller therefor, the tool stays substantially still immediately after the completion of working a workpiece for a period of from 0.05 to 2 seconds and also the speed of the tool applying an impact to the workpiece for working is decelerated immediately before the tool strikes against the workpiece in order to reduce the noise generated when the impact is applied. The speed and positional locus of the ram (36) are set for each step using respective setting switches provided on a panel. The servomotor (20) is program-controlled according to the data input through the respective setting switches.

Abstract: The invention relates to a two-handle arrangement for a handheld portable tool having a drive motor and equipped with forward and rearward handles for two-handled operation. Each of these handles includes respective actuating elements which can be actuated only in a specific sequence. First, force must be applied to the actuating element on the forward handle and only when a corresponding actuation of the throttle lever takes place is there an increase in the speed of the drive motor. The invention is especially suited for handheld portable tools equipped with an internal combustion engine such as motor-driven chain saws, hedge trimmers and the like.

Abstract: A safety control system for power operated equipment ensures operator safety by immediately disconnecting or reversing the power drive from a power driven rotating member such as a circular blade of a meat trimming knife or a toothed feed shaft of a meat skinning machine, upon a metal conductive glove worn by the operator, contacting the blade or toothed shaft or other electrically isolated portion of the equipment. The operator's glove is electrically connected to a safety switch which immediately disconnects or reverses the power drive from the rotating member upon the glove completing a circuit upon contact with the electrically isolated portion of the equipment. A moisture impervious dielectric plastic glove preferably is worn by the operator to prevent the moisture in the meat from conducting current between the metal glove and isolated machine portion until the plastic glove is cut and contact made with the metal glove.

Abstract: A safety device for an apparatus to be manipulated by an operator. The apparatus is connected via a supply line for a supply means to a supply means source. A handgrip is provided to be grasped by the operator for controlling the operation of the apparatus. An operating sensor is actuated by the operator and is connected to the control device. The operating sensor may be an electric proximity switch provided so that it is possible to shut off the apparatus when the operator ceases to actuate the operating sensor. The operating sensor, or at least one indiciator element of the operating sensor, is disposed on the hand of the operator, particularly integrated into a protective glove for the hand of the operator.

Abstract: A throttle lever holding mechanism is disclosed in which an intermediate locking member is provided for at least one of first and second throttle levers. The throttle lever is moved in an operational direction so that the throttle lever is kept under a predetermined operational condition by the intermediate locking member. The throttle lever is further moved in the operational direction so that the locking of the throttle lever by the intermediate locking member is released.

Abstract: A compact, versatile lawnmower control is provided which is especially useful for holding and releasing ground drive and blade clutch cables and which allow connection and removal of the cable end without dismantling the control, allows the optional inclusion of a releasable handle lock, and allow the use of a deadman handle to release two cables at differing release distances. The preferred control includes an operating handle having a tubular body rotatably mounted within a housing; a coupling element rotatably mounted coaxially with the handle body for coupling with a deadman handle; and a holding and releasing means intercoupling the element and the body for holding the handle in a second position when the element is in the operating position and for releasing the handle for shifting to a first position when the element shifts to a relaxed position.

Abstract: A safety device for an apparatus to be manipulated by an operator. The apparatus is connected via a supply line for a supply means to a supply means source. A handgrip is provided to be grasped by the operator for controlling the operation of the apparatus. An operating sensor is actuated by the operator and is connected to the control device. The operating sensor may be an electric proximity switch provided so that it is possible to shut off the apparatus when the operator ceases to actuate the operating sensor. The operating sensor, or at least one indicator element of the operating sensor, is disposed on the hand of the operator, particularly integrated into a protective glove for the hand of the operator.

Abstract: An electronic ON/OFF control system for use on a powered hand tool to ensure operator safety and ease of operation. The hand tool is driven either by an electric motor driven, flexible drive shaft or a source of pressurized air supplied to the hand tool through a supply line. A low power frequency is applied alternately to the hand tool and power supply line. Appropriate circuitry detects changes in the frequency of the applied signal caused by an operator grasping the hand tool and power supply line and the sequence in which the two components are grasped. If the hand tool is being grasped when the drive shaft or supply line is subsequently grasped a signal is supplied to a power control unit which actuates the power source for the hand tool. The power control unit maintains the hand tool energized after releasing of the operator's grasp on the on the power supply line and automatically de-energizes the hand tool upon the operator releasing his grasp on the hand tool.

Abstract: This safety monitoring system for punch press operators is designed to prevent the operators from being injured by such presses or other factory equipment. Primarily, it consists of a pair of wrist units which are strapped to the wrists of the operators, and which include optical fiber cables and a latching assembly, and the optical fiber cables are used in cooperation with a pair of identical electronic circuits employing LED's, a light sensitive transistor, a pair of other transistors, a zener diode, and a relay, for instantly shutting a punch press on or off.

Abstract: A control for a treadle activated machine tool having a driving power and a mechanical treadle linkage connecting the treadle to the driving power. The control comprises at least one sensor for sensing the presence of an operator's hand remote from a work area of the machine tool and an interrupt for selectively interrupting the treadle linkage in response to a signal indicating the absence of the operator's hand from the sensor.

Abstract: A dual hand control actuation mechanism for a manually actuated device has a pair of opposed actuating rods that have wedge shaped ends defining forward and rearward camming surfaces to interact with forward and rearward cam surfaces on a cam member positioned between the actuating rods. If both of the actuating rods are pushed simultaneously, their forward cam surfaces engage the rearward cam surfaces of the cam member and move the cam member to cause it to engage a switch to actuate the device. If one of the actuating rods is pushed before the other, its forward camming surface engages the rearward camming surface on the cam member and pivots the cam member preventing the other actuating member from engaging the cam member in a manner that will move the cam member against the switch, thereby preventing actuation of the device.

Abstract: To permit operation of the power tool only if both hands of an operator are engaged, the tool is formed with a handle portion which has a sensing surface thereon, electrically coupled to a current flow sensing circuit, preferably including an opto-coupler or a field-effect transistor (FET) circuit which permits firing of a triac, thyristor, or the like only if current flows over the sensing surface by area contact therewith. The sensing surface is energized, preferably, from a resistive or capacitative voltage divider; the capacitative voltage divider has the advantage that the triac firing circuit can cause the triac to fire during null or zero crossings of ac supplied power. If a locking-type switch is used, two handles or touch-areas are needed; if a spring-loaded switch is provided, it can function as one safety element, and a touch-area sensing surface as the other.

Abstract: A guard for protecting the hand or hands of an operator to limit the extension thereof and prevent entry into a hazardous or danger zone of a machine, such as a stamping press or the like, includes a shield in the form of a transparent or partially transparent rigid plate member which is fixed in spaced relation to the throat or nip point or hazardous region of the press. The plate has an aperture through which the operator may extend a portion of a protective glove in loading and unloading articles into and out of the hazardous region. The glove has a rigid, radially extending cuff or collar surrounding the glove at the wrist portion and having an outer dimension which exceeds that of the aperture formed in the plate. The position of the collar on the glove is related to the position of the plate and the maximum extension of the fingers such that when the glove is inserted through the opening, no part of the hand may enter a predetermined danger zone.

Abstract: The trimming apparatus and fixture for holding a PC board prior to and during trimming of an upper surface of the PC board utilizes a trimming blade rotated by a variable speed motor. This apparatus includes X and Y motion mechanism moved by hand grips that are spaced apart and cooperate with push button switches providing a safety control circuit. The X and Y motion mechanism employs linear ball bushings mounted and movable on hardened steel shafts. Removable holding fixtures are employed to hold and retain the PC boards during trimming. One holding fixture is used for PC boards that are not warped and not likely to warp. This fixture holds the PC board on three sides and a quick acting cam clamp is actuated to retain and release a PC board. Another fixture is adapted to hold and retain a PC board that is warped or likely to warp. Vacuum is used with a plurality of standoffs to establish the desired holding plane of this PC board.

Abstract: A cylindrical chamber full of oil, without any valves or inlet/exit ports for this oil. A piston travels in said sealed cylindrical chamber with a rod on either side, assembled with sealing rings and provided with a series of peripheral axial holes all of the same diameter and equidistant from the piston axis. On the rod anchored to the ram slides a plunger disc supported directly under the piston assembly by two diametrically opposed threaded studs with large heads. Said studs are first threaded through the piston assembly and then screwed through the two holes found on the plunger disc. The upward travel of this disc which stops under and against the piston holes, is prevented each time the dual push-button control is operated since, when operating, these buttons, besides starting the movement of the ram, prevents the upward travel of the plunger disc simultaneously.

Abstract: The specification discloses a safety device for presses and other similar machines in which stock material is manually inserted between converging machine parts. A ram and sleeve arrangement cooperates with a collar mounted on the moving portion of the machine to insure that the operator's hands are drawn completely back to the safety position prior to the commencement of the machine stroke. In the event that the ram does not operate at the commencement of the press cycle, the collar abuts the sleeve on the downward stroke of the press, and moves the pull-back mechanism therewith to the safety position.

Abstract: A control circuit for a press can perform various control functions simply by electrically detecting two modes of change, i.e. from OFF to ON and from ON to OFF, of a single rotary cam switch mounted on a press. Until reaching a first slide stroke angle at which the first change of the rotary cam switch takes place, operation of the press depends upon an ON or OFF state of a push button and thereafter the operation continues regardless of the ON-OFF state of the push button. After reaching a second slide stroke angle at which the second change of the rotary cam switch takes place, the operation of the press is stopped with the slide being stopped at a top dead center regardless of depression or non-depression of the push button and restarting of the press function is prevented in case the push button is kept depressed.

Abstract: A manual stock feeder apparatus for feeding stock to a machine for processing said stock, said manual stock feeder having a moveable carriage capable of engaging a length of linear stock and capable of sliding along a plurality of parallel linear guide members toward said machine while engaging such length of linear stock and thereby feeding such linear stock into the machine for processing said stock. The apparatus further includes a second stock engagement means for engaging and securing the stock while the carriage 4 is being repositioned to its initial starting place to resume the feeding of stock to the machine for processing said stock.

Abstract: A mechanism for controlling either momentary or maintained, continuous operation of devices such as valves, presses, machines and other devices which require simultaneous use of two hands by an operator to prevent accidents and injury. The mechanism includes a moveable linkage formed from rigid links pivotally connected in a closed polygon, preferably a parallelogram. A pair of hand-controlled plungers, which are biased to return the linkage to its rest position when released, enable movement of the linkage to momentarily or continuously operate an electrical switch, pneumatic valve or other contact control device only when both plungers are depressed simultaneously. A raised surface for guiding movement of the linkage is included to prevent unintended or single-handed operation. Constant depression of one plunger with intermittent operation of the other, or sequential operation of the plungers, will not engage the contact or control device.

Abstract: A safety device for a mechanical cam press having a ram attached to a vertically extending shaft arranged for reciprocating movement and utilizing a brake and clutch for controlling the reciprocating strokes of the cam, the shaft including a stepped edge engageable by a pair of retractable slides arrange for horizontally reciprocating movement to retain the shaft and therefore the ram in the top, dead center position against downward movement toward with switch means actuated by a tripping device responsive to an inadvertent downward movement of the shaft from the top, dead center position to thereby engage the brake and disengage the clutch for avoiding injury to the operator.

Abstract: The application discloses a control system for a mechanical press in which two separate control circuits must simultaneously produce control signals to operate the ram through its ram cycle. If either of the control circuits produces a spurious output or intermediate signal or fails to produce a proper output or intermediate signal, circuitry will detect such occurrences and stop or prevent operation of the ram. A plurality of checking circuits constantly monitor input signals, intermediate signals, and output signals to insure that the press is not activated by spurious signals. A circuit is provided to allow the run buttons to be used to initiate an upstroke of the ram of the press, and an indicator transmits information to the operator of the press to indicate operational status of the press.

Abstract: A two-hand safety system utilizing an operator's skin resistance is provided to control the operation of a work fabricating tool. An operator must place both hands on a pair of spaced electrodes in order to initiate operation of a radio digital signal generator which transmits a digital signal to a receiver. The receipt of the digital signal in conjunction with a predetermined positioning of a freely slidable work holder energize a circuit to control the operation of the work fabricating tool.

Abstract: A circuit interconnecting a source of electrical energy with a power operated machine. The circuit comprises an interlock device including a motion switch which is adapted to be removably attached to the machine operator's body. The motion switch is movable between a normally deactivated position to prevent the flow of electrical energy from the source to the machine and an activated position to permit the flow of electrical energy from the source to the machine for operating the machine. The motion switch is operable to be moved to the activated position in response to movement of the operator's body.

Abstract: A drive arrangement for a mechanically driven press with the press including at least one drive shaft mounted in a press frame and at least one eccentric or crank arranged on the drive shaft with a clutch being operatively connected to the drive shaft for permitting a press stroke operation upon engagement of the clutch. At least two hydraulic brakes are provided for braking the press between press strokes and a two system hydraulic circuit is provided for controlling the operation of the clutch and the at least two brakes.

Abstract: A safety device to be used with a machine so as to have the operator keep both hands occupied during operation of the machine. The device includes a solenoid member having a core extension which blocks a first control element of the machine when the solenoid member is energized. The operator pushes a hand-operable switch and a hand-operable actuation member which in turn actuates a second control element.

Abstract: Logic circuitry in combination with a limit switch on a press automatically controls the operation of the press during the press cycle without visual monitoring of the cycle by an operator.

Abstract: A control in which an active member is momentarily actuated by a moving member only when both members move toward each other and pass each other, the active member being actuated by the moving member as it passes said active member from one direction only, when said members meet and pass in the opposite direction said active member will not be activated, the movement of either member being limited so that the two members can pass each other only when both members move towards each other along parallel paths.

Abstract: A single cycle control system for a press or the like in which interrupted stroke protection is combined with novel interconnections of the control components in the system such that the failure of any single control component cannot endanger the operator of the machine. Relay failure (even a simultaneous failure of two) is completely eliminated as a possible source of an unexpected repeat stroke of the machine. The solenoids for operating the air valves that control the operation of the machine are energized initially through the usual run switches for the machine, after which these solenoids are kept energized through separate holding circuits which include limit switches operated by the machine and switches operated by the respective air valves.

Abstract: A pneumatic control system for a press which includes a pair of start switches. The system is constructed so that the press can only be started if both of the start switches are actuated within a predetermined time interval. If one of the start switches is released during a down stroke of the press, the press is stopped. A cam operated switch permits continued operation of the press after the press has reached its bottom position even though start switches are released after the press has passed full down position. A brake cam operated switch prevents operation of the press if the press fails to stop at its full up position.

Abstract: A stamping press system, the press having a ram, a driving means for the ram, and an electrically energizable ram control device for causing the driving means to drive the ram through a stamping cycle. The press is guarded by a barrier movable between an open position permitting operator access to the point of stamping operation and a closed position barring such access. A press trip control for the system has a pair of actuators, one for each hand of the operator. Upon their concurrent actuation, the actuators cause movement of the barrier to the closed position and energization of the ram control device initiating a stamping cycle. Provision is included for preventing such energization thereby preventing a stamping cycle if the barrier is not closed. Circuitry of the system prevents re-energization of the ram control device, thus preventing a further cycle until the operator has removed both hands from the actuators.

Abstract: Safety apparatus attachable to a punch press for providing a time delay between the starting of the drive-brake motor which drives the flywheel and the engagement of the clutch which couples the flywheel to the drive shaft. The time delay allows the flywheel to be brought up to sufficient speed by the drive motor prior to its engagement with the crankshaft such that it imparts sufficient momentum to the crankshaft to perform the task intended for the crankshaft ram. A safety shut-off switch is utilized in combination with the time delay mechanism to totally shut down the drive-brake motor at the end of a pressing cycle of the drive shaft by shutting off motor power, causing the braking function of the motor to stop the flywheel. The start of the drive motor and the initiation of the time delay for engaging the clutch are simultaneously initiated by the downward movement of a safety shield which may be attached to the press to shield the work area during movement of the flywheel.

Abstract: The press blocking and air logic control system of this invention embodies a press ram blocking apparatus and air logic circuitry and control means in combination for moving a ram blocking member into ram stopping position thereunder upon the occurrence of one or more events justifying blocking of the press ram, to prevent injury or damage to personnel or equipment which would expectedly result from inadvertence, error or accident. The air logic control circuitry for the blocking device is connected to and in association with conventional press circuitry for the press ram actuating mechanism. For normal press operation, the ram blocking member is retained in retracted position by its air logic control circuitry.

Abstract: A circuit is provided for apparatus of the type in which a member is reciprocated through a work stroke relative to a support on which work is placed and from which it is removed by the operator. Typical operations are cutting and forming. The circuit includes two parallel leads and a pair of switches in control of both leads, one switch for each hand of the operator. The switches are normally closed with reference to the first lead. The second, normally open lead includes a device which, when energized, initiates the work stroke and the first lead includes means enabling the second lead to be closed relative to the device if the operator actuates both switches but the means of the first lead cannot again be operated unless and until both switches are in their normal position.

Abstract: The press blocking and control system of this invention embodies a press ram blocking apparatus and circuitry and control means for moving a ram blocking member into ram stopping position thereunder upon the occurrence of one or more events justifying blocking of the pressed ram, to prevent injury or damage to personnel and equipment which would expectedly result from inadvertence, error or accident. The control circuitry for the blocking device is connected to and in association with conventional press control circuitry for the press ram actuating mechanism. For normal press operation, the ram blocking member is retained in retracted position by its actuating apparatus and control circuitry.

Abstract: Safety apparatus for a press or the like having dies which are movable relative to each other and which define an open area therebetween for receiving an article includes a gate that is pivotable about a primary pivot axis from an open position to expose the open area to a closed position to shield the open area, and a secondary pivot axis that is parallel to and spaced from the primary axis. In the closed position, the gate engages a normally closed switch means and thereby enable the dies to move towards each other. When the gate is in the closed position and an obstruction is aligned with the gate, movement of the dies causes the obstruction to contact the gate which is pivoted about the secondary pivot axis, whereby the switch means closes and movement of the dies is interrupted.

Abstract: A press control includes a pair of pushbuttons each operating a pneumatic pump means to form a pair of signal pulses and an integrated valve to form a pair of binary logic pressure signals. A press position sensor provides a binary pressure signal related to the press position. The pushbutton and sensor signals are connected to fluidic logic gate means to compare and detect the actuation of the pushbuttons as well as the status of such pushbuttons and the press cycle. The logic output is connected by a plurality of logic gates to actuate a flip-flop output unit to generate an extend output or a retract output. The flip-flop output unit has an input connected to a latch input control to provide automatic reset to the retract output if release of the button signal sources occurs during a hazardous portion of the extend cycle. Once the non-hazardous portion of the extend cycle is reached, the latch is complete for the terminal portion of the extend cycle.