Abstract: A door panel position sensor assembly for a transit vehicle is provided which comprises a door mounted actuator device and a vehicle mounted switch operating mechanism which is mounted adjacent to the path of travel of the door and is actuated by the door-mounted actuator device during movement of the door between open and closed positions. The switch operating mechanism comprises a signalling switch whose switching state indicates the position of the door and a single actuator lever which is movable by the door mounted actuator device between first and second positions to control actuation and de-actuation of the switch. A spring arrangement is located between actuator arm and the signalling switch which assists in toggling of the actuator lever and which, under the control of the actuator lever, engages the switch to provide actuation thereof.

Abstract: A reversible electric motor supported on a sub-base acts through a reduction gear train to rotate an output shaft supported by a main mounting base, the sub-base being capable of turning through a limited range relative to the main base about the axis of the output shaft. When the output shaft encounters excessive resistance torque in either direction, the sub-base automatically turns relative to the main base and effects the opening of switch means to de-energize the motor.

Abstract: A switch assembly comprises a push-button switch and a switch operating mechanism including an actuator and a plunger for transmitting the movement of the actuator to the push button to operate the push-button switch. While one end of the plunger is operatively associated with the actuator, the other end of the plunger is rotatably and removably, but axially non-movably, coupled to the free end of the push button. For this purpose, the other end of the plunger is formed with a radially outwardly extending anchor flange while the free end of the push button is formed with a generally U-shaped anchor recess for receiving the anchor flange therein.

Abstract: A sensor assembly on a crane apparatus includes a multi-pole switch such as a wobble switch mounted adjacent the head of a crane boom. The switch is carried by a pendulum arm and is activated by an actuating member engageable by the crane lift cable whenever the cable is out of plumb. Activation of any one of the switch contacts completes a specific circuit to illuminate a particular signal element in the crane cab thereby advising the operator in which of four directions the lift cable is out of plumb so the crane may be manipulated to obtain a plumb relationship prior to lifting of a load.

Abstract: Multiple limit switch comprising telescope plungers (16), each of which has a U-shaped anti-rotation element (62) engaging over the inner end of the plunger, this anti-rotation element comprising a hole (68) for the inner portion (44) of the plunger to pass through and forming an abutment for the plunger return spring (70). The outer portion (40) of the plunger has a collar (56; 56'), behind which projections (64) of the anti-rotation element (62) engage, this outer portion (40) having lateral flattened portions (58; 58') to secure the outer portion (40) of the plunger against relative rotation. The flattened portions abut against slide guide surfaces (60) of the anti-rotation element (62) or edges (64') of the latter. The anti-rotation element (62) is non-rotatably held in an inner groove (30) of the limit switch housing (10).

Abstract: This control device for an electric motor-reduction unit is designed to permit the accurate adjustment of the point at which it is desired to stop the rotation of the unit. For this purpose, it comprises a slide controlling during its movement in one direction and during a first time period the movement of beaks of a rocker in a direction in order to open the motor control switch when said beaks are engaged in notches of cam means. In a second time period, the slide causes a two-armed sliding lever supporting the notched-cam shaft to pivot in a direction, each notched cam being rigidly associated with a heart-shaped cam and with a toothed wheel adapted, when inoperative, to mesh with toothed drive pinions. In a third time period, the slide causes the beaks of the aligning lever to bear against the heart-shaped cams in order to align the notches with the beaks. The pinions remain radially fixed.

Abstract: A limit switch mechanism includes a limit switch disposed in confronting relation to a cam mounted on a switch drive shaft. The limit switch is actuatable by the cam when the switch drive shaft is angularly moved about its own axis through a predetermined angle. The limit switch has a longitudinal axis extending substantially parallel to the axis of the switch drive shaft, and is disposed in the vicinity of the switch drive shaft. The limit switch is actuated by being pushed by a limit switch arm extending from a cam arm actuatable by the cam and located more closely than the cam arm to the switch drive shaft.

Abstract: This disclosure depicts a novel apparatus for use with an electric limit switch. The apparatus is a neutral position limit switch lever head, or multiple position off-center to center movement translator, for use with an operator having first and second movable elements and a receiver having a movable member. The apparatus comprises a support cover, a linear actuator in contact with the movable member of the receiver and a tri-lobe roller follower in contact with the linear actuator and the two movable elements of the operator. The support cover retains the linear actuator in the center of the support cover and also holds the tri-lobe roller follower in position. The novel apparatus converts the off-center movement of the movable elements of the operator to a linear center movement of the linear actuator.

Abstract: A rotary switch comprises a control shaft rotatable clockwise from a neutral position to a first switch actuating position and beyond it to an overtravel position, and counter-clockwise to a second switch actuating position and beyond it to another overtravel position; a centering arrangement for biasing the control shaft to its neutral position; first and second switch mechanisms; a housing enclosing the switch mechanisms; and a switch actuating arrangement. The latter arrangement includes a pair of cams mounted on the control shaft, a pivotally-mounted blade for actuating the first and second switch mechanisms, and first and second cam followers formed on the blade for slidably contacting respective ones of the cams. The cams are preferably formed as plate cams each having a cam finger that is bendable in the circumferential direction, in relation to the control shaft, to adjust the contact position thereof on the respective cam follower.

Abstract: The invention relates to a hazard switch arrangement for flame-cutting and welding units. As the feeler for detecting mechanical obstacles (14) in the path of the torch nozzle (1), a plurality of feeler rods (7) is provided here. The feeler rods (7) are connected in each case to a plurality of movement switches (holder ring (5), contact ring (11) and feeler rods (7)). The multiplicity of feeler rods and movement switch arrangements guarantees prompt and reliable hazard warning in operation. In a preferred embodiment of the invention, the feeler rods themselves serve as the movement switches.

Abstract: The self-adjusting limit switch assembly of this invention has two switches mounted on a slide for sliding movement on a bracket. A transverse slot in the slide has two facing surfaces. The switches are mounted on each side of the slot with their operating members extending slightly past the slot. The actuator is positioned to extend into the slot. When the brakes are first moved to the brake released position the actuator engages not only the operating member of the switch on that side, but also a wall of the slot and moves the slide to a brake released position thereby correctly adjusting the position of the switches. When the brakes require adjustment due to wear, the actuator engages the operating member of the second switch, as before, causing an indicator to function.

Abstract: A limit switch wherein a switch mechanism and plunger for operating the mechanism are assembled together to a switch body having pull-out terminals to form an integral switch assembly which is housed in a housing from its open bottom inserting the plunger through a guide cylinder on the top of the housing. The plunger biased normally outward is operably coupled through an actuator to a movable contactor against a contactor turning spring force biasing the actuator normally inward. The switch assembly is fixed to the housing with the plunger retreated inward by a predetermined amount where the contactor is once turned over, the amount thus determining a retreating stroke of the plunger for the mechanism operation through the actuator to turn over the movable contactor.

Abstract: A safety arrangement for systems with parts freely movable spatially, in ticular for manipulation devices and driverless transportation devices, includes electric switch elements which upon collision of moved parts with persons or objects cause a control signal which shuts down the moved parts or initiates an emergency operation program which causes for instance a sequence of movements opposite to the direction of collision. Each of the electric switch elements is constituted by a per se known initially electrically insulating plastic layer which turns electrically conductive upon being pressure strained and which is provided planarly between two electrode layers at those locations of the moved parts which as a result of their shapes and motion energy represent a risk upon collision.

Abstract: For use with a vehicle tailgate lift that has a platform which when substantially level moves in an up and down movement, and which near and at its upper limit can also be moved in a folding mode, a circuit which enables the platform to be moved up, down or folded but which frustrates inadvertent folding of the platform by the provision of a safety circuit.

Abstract: A limit switch gauge positioner for a machine ram supporting a forming tool or the like. The ram, supported for reciprocal movement relative to a head, has a lineal distance gauging rod thereon formed with a plurality of longitudinally graduated reference indents. The rod has a body member slidable thereon including a detent coupling plunger adapted for engaging a selected one of the indents allowing an operator to initially locate the body member relative to the ram. A micrometer is supported on the body member with its spindle being settable at graduations along the spindle axis parallel to the path of travel of the ram. The head supports a housing including a microswitch with its actuator aligned on the spindle axis. An operating member is pivoted on the housing intermediate the switch actuator and spindle and gravitationally biases an arm section into arresting contact with the actuator in its extended switch closed position.

Abstract: A switching mechanism can be utilized in conjunction with an electrically driven actuator, for example, either a linear or rotary operated actuator. The switching mechanism can be utilized to either control the extent of operation of the actuator, thereby operating as a limit switch, and also can be used for controlling other electrical devices that are to be operated in dependence upon the position of the driven member of the actuator. For this purpose, the switching mechanism is provided with a plurality of electrical switches, each of which can be controlled so as to be switched at different points in the operation of the actuator. Associated with each of the electrical switches is a separate counting mechanism. All the counting mechanisms are driven by a common drive gear which is coupled to the drive mechanism of the actuator.

Abstract: An explosion-proof limit switch having an explosion proof housing that mounts to the side of a rotary control device with actuation pins extending through annular seals to be driven by a cam on the rotary shaft of the control device. Switching units mounted inside the explosion-proof housing are mounted on a fixed pivot at a first mounting point and held resiliently at a second mounting point in a double acting adjustable spring assembly which acts both to adjusting the switching point and to absorbing excessive impact or actuating throw so as to reduce possibility of damage.

Abstract: A method and apparatus for sensing a drill pipe joint is characterized by an arm pivotally moveable with respect to a drill pipe from a first, normal, position. The arm deflects a predetermined angular distance from the normal position when it comes into contact with a predetermined distended location on a drill pipe. An electrical signal is generated by a signal arrangement associated with the arm to indicate that the predetermined distended location is reached.

Abstract: This control device for electric motor-reduction units comprises two cams rotating at different speeds about a common shaft, each cam having only one notch formed in its outer periphery, the cam notches being adapted to cooperate with catch-forming portions of a rocker controlling the motor switch. The first cam is rigid and coaxial with a toothed wheel meshing with a driving toothed pinion pivoted on a shaft parallel to the cam shaft, and comprises two drive teeth adapted, during each revolution, to mesh with a reversing pinion pivoted to the driving pinion shaft and rigid with another pinion meshing with a second toothed wheel rigid with the second cam.

Abstract: A cover including switching chambers and housing contact carriers is associated with a base supporting two slides which act by the intermediary of frames either directly on the contacts, or through the intermediary of springs.

Abstract: This control device for electric motor-reduction unit intended for driving rolling shutters, roller-blinds or the like, and permitting an accidental overstepping of the electrical stop point without causing any damage in, or putting out of order, the control device, comprises a cam having a notch formed in its contour, adapted to be engaged by a follower portion of a lever so as to open a switch controlling the supply of drive current to the motor-reduction unit. The notch has a rear portion inclined laterally and rearwardly which opens into an extension of the cam contour which is level with the bottom of the notch, or located at a lower level than this bottom. When the cam rotating in a given direction oversteps the normal electrical stop point the inclined portion moves the follower laterally and the lever is moved laterally along its pivot axis against the force of spring means, but held at the same level.

Abstract: A linear actuator for providing a thrust force for actuating various movable members, such as, for example lever arms, cranks, slides and valve flaps. The thrust force is applied by an extension rod that is arranged within a housing so as to extend in an axial direction along the housing and out from the housing. The extension rod has a load connector mounted on the end outside of the housing for connection to the movable member to which the thrust force is to be applied. A drive screw is attached to the extension rod so that rotation of the drive screw is translated into an axial displacement of the extension rod. A drive motor serves to rotate the drive screw. Either when a blockage of the movable member occurs or when the extension rod has reached the end of its path of travel, any attempt for continued movement of the extension rod significantly increases the thrust force applied to the rod.

Abstract: Apparatus is provided for the positive activation of a switching device operated to function after a predetermined number of revolutions of a drive shaft to deactivate a drive prior to the apparatus reaching a stopping point, such as in finishing machines. Two camshafts are provided, with one driven slowly and one driven rapidly through appropriate gearing from the drive shaft of the apparatus. One or more cams are spaced on each camshaft with the slow cams having a short actuating surface and the fast cams having a long activating surface. Each slow and fast activating surface engages, respectively, one end of a toggle lever, which in turn moves a thrust rod to open the switch. Each toggle lever must be engaged simultaneously with a short and a long activating surface to activate the switch.

Abstract: A limit switch mechanism is disclosed which may be easily moved along a guide channel and actuated by a carriage movable along the guide channel. The limit switch is constructed of only three or four parts for simple and economical manufacture and assembly. The base of the switch is of resilient insulating material to permit the switch base to be snapped onto the guide channel to be resiliently secured in an adjustable position. A bent wire has actuator, actuating, pivot, and retention portions, with the actuating portion actuating the two contacts between closed and open condition. The retention portion retains the bent wire longitudinally of the pivot axis and acts on the guide channel rather than on the base to permit ready assembly of the bent wire onto the base.

Abstract: A pair of electrical switches are arranged to be engaged by a respective pivoted carriage member, to indicate the end of tape in correlation with the diameter of a tape reel mounted on each carriage member. Each switch is generally contained within a housing having a longitudinal axis. A pair of electrical contacts, each interconnected to the circuitry of the system, are positioned within the housing adjacent to the axis. A plunger is adapted to be operable along the longitudinal axis between the two contacts and has one end extending from the housing to act as an actuator. A yoke has a base threadedly secured to the plunger and has a body extending parallel with the plunger within the housing. An elastic shorting member is partially compressed and positioned within the body of the yoke. The elastic shorting member is adapted to engage the electrical contacts to conduct electricity through the switch.

Abstract: An automatic resetting anti 2-BLOCK condition crane warning system gives audible and visual warning of an imminent 2-BLOCK condition and prevents occurrence of an actual 2-BLOCK condition by means of a control output signal. The warning system is further operable to permit override of the indication of and control against the 2-BLOCK condition. Three distinct audible and visual indications are provided for NORMAL, 2-BLOCK, and OVERRIDE system states. The system is further operative to automatically reset to a NORMAL state from either a 2-BLOCK or OVERRIDE state upon sensing a transition from a 2-BLOCK condition to a NORMAL condition.

Abstract: A limit switch wherein a first spring means for actuating a push-button of selfcontained micro-switch and a second spring means only which engages an operating means for absorbing an over-travelling stroke of the operating means which receives an external operating force are both disposed inside a limit switch housing. In normal non-actuating position, respective biasing forces of the both spring means are balanced so that the second spring means restrains the first spring means from engaging the push-button but, upon application of the operating force through the operating means to the second spring means, the restraint of the first spring means is released due to a resilient bowing of the second spring means so as to have the push-button actuated by the biasing force of the first spring means, and the second spring means continues to further bow for absorbing the over-travelling.

Abstract: A dual snap-action electric switch is used in an electric motor antenna drive to stop antenna movement when predetermined force levels to longitudinal movement are encountered. The switch has two actuator arms operated by actuator tabs maintained in spaced relation by a primary spring. A secondary spring urges one actuator tab against the primary spring. The actuator tabs are movable longitudinally in response to longitudinal movement of an electric motor driven worm shaft to open one switch at a predetermined force level and the other switch at a higher predetermined force level, to stop the motor, such as when respective full extension or retraction of the antenna is reached.

Abstract: Apparatus for spirally slicing a cut of meat such as a ham or the like. The meat is retained in a substantially vertical position by means of upper and lower skewers. The lower skewers are powered thus providing for rotation of the cut of meat along a substantially vertical axis. A rotary circular cutting blade is supported by an arm which is generally movable about a vertical axis. A carriage imparts vertical movement to the arm and blade. When the rotary blade is brought into contact with the rotating cut of meat it is caused to be advanced along the axis of rotation of the meat thereby to form a continuous spiral slice in the meat. Sensing and control means are provided limiting both the horizontal and vertical movement of the blade to enable the cut of meat to be sliced about an internal bone.

Abstract: A lifting jack has its upward and downward traveling distance controlled by means of a limit switch. The lifting jack has a base, an upright outer member rigidly connected to the base and an upright inner member movable coaxially within the outer member. An up stop and an adjustable down stop are rigidly attached to and move with the inner member. An adjustable mount is mounted in a fixed position on the outer member, and the limit switch is mounted in fixed position on the mount. A guide shoe assembly is pivotally connected to the mount and is oriented generally perpendicular to the direction of travel of the inner member. A stop engaging member at one end of the guide is positioned to engage the up stop and the down stop, and an arm guiding portion at the opposite end engages and guides an actuating arm of the limit switch.

Abstract: An automatic electric downrigger shut-off switch comprises a pair of spaced electrical contacts mounted as to be in continuous physical contact with the downrigger's metal cable, which forms an electrically conductive path between the contacts. The switch includes a relay device that allows the downrigger motor to be operated through its main control switch so long as the cable provides electrical conductivity between the contacts. However, when a nonconductive sleeve mounted on the cable near the weighted end thereof comes into physical contact with one of the electrical contacts and disrupts the conductivity between them, the downrigger motor is automatically shut off to prevent the weight at the end of the cable from colliding with the end of the downrigger rod. An override switch is provided for reeling in the cable after the weight has been removed.

Abstract: A load position sensing device for load carriers, such as the fork lift of a fork lift truck, wherein the load carrier includes vertical support means and horizontal load-carrying means extending forwardly therefrom, comprising a plate mounted pivotally onto the vertical support means of said load carrier and movable toward and away from the vertical support means in the direction in which the horizontal load-carrying means extends, spring means biasing the plate away from the vertical support means, position sensing means to detect when the load is within a proper range or too close to the vertical support means, and indicator means to communicate the position sensed to an operator of the load carrier whereby potential damage to loads of frangible goods is minimized.

Abstract: An adjustable contact portion is detachably secured to the mast of an implement such as a snow plow blade and the other contact is secured to the fluid operator in the mast which raises and lowers the blade. These contacts are operatively connected to the battery of the implement and to an indicator adjacent the operator. The operator sets the adjustable contact portion and when the blade is lowered to the desired degree, the two contacts engage thus completing the circuit and operating the indicator so that the operator is informed that the blade is at the lowermost position desired. The device may also be used on agricultural implements such as discers or the like in order to indicate when a preset depth is reached or digressed from.

Abstract: A limit switch comprises a frame having an elongated extruded metallic base, a lead screw shaft supported on the frame and coupled with a drive source for rotation, and a pair of control discs threadably engaged upon the lead screw shaft and restrained from rotation therewith, such that rotation of the lead screw shaft causes the control discs to axially advance along the shaft. Switch assemblies are carried by the base and located in the path of axial advancement of the control discs for operation in repsonse to selective engagement with and disengagement from the control discs. The control discs are individually adjustable along the lead screw shaft, and the switch assemblies are individually adjustable along the base, to thereby permit a wide range of operation for the limit switch.

Abstract: A limit switch comprises a snap action switch component and an actuator, said actuator being constructed so as to selectively actuate the snap action switch component with respect to the rotating direction of a rotating shaft of the actuator. A rotational motion of the rotating shaft is transmitted to the snap action switch component through a pair of levers and a driving plunger member. The pair of levers are pivotally secured under the rotating shaft and the driving plunger member is rotatably and reciprocatingly secured under said pair of levers. Free ends of the levers are selectively engageable with the top surface of the driving plunger member, an upper portion of which is partially cut out. By setting the driving plunger member in a predetermined rotating angular position, one of said free lever ends is disengaged from said driving plunger member.

Abstract: An overhead door cable safety device for suspending adjacent a cable drum on an overhead door assembly and monitoring the condition and location of the cable on the drum. The cable when becoming loose on the cable drum or frayed contacting the cable safety device, which in turn closes an electrical switch for signalling the operator of the overhead door that the cable on the cable drum is in need of repair.

Abstract: The invention relates to a mechanism for actuating the carburetor throttle or fuel injection pump rack of an internal combustion engine. The mechanism comprises a ball screw device including an axially fixed nut rotatable by a reversible electric motor to axially reciprocate a screw concentrically within the nut and connected to the engine throttle or rack. Within and axially fixed relative to the nut is a caged ball arrangement which, when the cage is allowed to rotate, couples the nut to the screw to produce said axial displacement, but when the cage is blocked against rotation, causes the nut to freewheel. Stops carried by the screw are provided to engage and block the cage at each end of the axial travel of the screw to determine the stroke length thereof, and limit switches are provided actuated at each end of the stroke, to reverse the motor.

Abstract: A control device includes a magnetically actuated responder and an actuator. The responder is fixed to a relatively stationary portion of an apparatus and the actuator is fixed to a portion of the apparatus which is movable relative to the fixed portion. The fixed portion includes a housing for constraining the second, movable portion to linear movement. The actuator is located so that its outer surface is recessed into the surface of the movable portion flush with the surface of the movable portion of the apparatus thus providing an actuator for the responder which does not interfere with the movement of the movable portion. An alternate embodiment contemplates the use of a plurality of flush-mounted actuators axially spaced along the movable member with each actuator occupying only a portion of the circumference of the movable portion.

Abstract: A limit switch consisting of a driven member connected to a rotary driver member the operation of which is controlled by the limit switch, so as to turn therewith, one or more poles geared to the driven member so as to be rotated thereby, one or more fingers extending laterally from each of the poles, and one or more electric switches mounted adjacent each pole so as to be engaged and operated by one of the fingers at one position in the angular movement of the pole. The gear connection between the driven member and the poles is disengageable by manual means and readily adjustable to provide a coarse setting of the relative angular positions of the driver and poles, and the extension of the fingers from the poles is continuously adjustable to provide a fine setting. The ratio of the gears is such that the poles turn faster than the driver. This multiplies the motion of the fingers and hence provides greater accuracy in the operation of the switches.

Abstract: A device for terminating the rotary movement of a driven shaft following an adjustable predetermined number of revolutions, with one or more switch disks arranged coaxially adjacent and provided with notches of their outer circumference, said disks being driveable by the shaft, with a plurality of switch disks with different rotational speeds, and with a switch arm resting on the outer circumference of the switch disk(s), said arm dropping into the notch and/or (in the case of a plurality of switch disks) notches, when the latter correspond in their angular position, thus shutting off the drive to the shaft.

Abstract: A limit switch comprising a switch enclosure, a snap action switch, and an operating head. An actuator slidably mounted in the operating head is provided with a wing which prevents the rotation of the actuator.

Abstract: A dual snap-action electric switch is used in an antenna drive to stop antenna movement when a predetermined resistance to longitudinal movement is encountered. The switch has two actuator arms operated by actuator tabs maintained in spaced relation by a spring. The actuator tabs are movable longitudinally in response to longitudinal movement of an electric motor driven worm shaft to open one or the other of the switches to stop the motor, such as when full extension or retraction of the antenna is reached.

Abstract: A programmable, reciprocating, multiple electrical switch assembly contained within a waterproof housing. The assembly includes a plurality of discrete electrical switches arranged in a predetermined pattern on a fixed frame. The switches are triggered by projections strategically arranged on a sliding key-like finger which mates with the interior of the frame.

Abstract: A manufacturing machine such as an automatic assembly machine is disclosed which includes a work station which can include linear motion devices and rotary motion devices. A conveyor system is disclosed for transporting a workpiece to and from the work station, and positioning means are disclosed for precisely positioning the workpiece to the work station.

Abstract: A motion detecting limit switch minimized in size and still easy to assemble respective parts and to connect lead wires to contactor terminals is provided. The switch comprises a switch unit including switch over contactors and a head unit including a rotatable actuator arm for converting actuator displacements into switch actuating movements. The switch unit is accommodated in a housing comprising a base body widely opened with side walls of reduced height allowing free access to the contactor terminals of the switch unit secured in the base body, except an end wall of larger height to which the head unit is mounted, and a lid formed with an electrically insulative material in a shape complementary to the reduced height side walls of the base body for fitting over the switch unit.

Abstract: A motor driven plotter has a plotting head which is translated in two coordinate directions over the work surface of a plotting table. The plotting head is mounted on a first carriage which moves in one coordinate direction and a second carriage is mounted on the first for movement in the second coordinate direction. The limits of both carriages in each coordinate direction are directed by means of a pull cord suspended in a rectangular pattern from the first carriage. A cord portion or segment is intersected and extended by a contact at each limit of travel in the coordinate directions. A switch connected to the cord produces a limit signal when the cord is extended.

Abstract: A position sensor disposed on an elevator car has a first rotatable shaft connected to a secondary winding of a transformer or a switch actuating member, and a second rotatable shaft coaxial with the first shaft and connected to a primary transformer winding or to a switch position changing member. A first roller engages a rod-shaped cam mounted at an angle to a guide rail for the car toward the end of the path of travel of the car to rotate the first shaft in a direction to decrease the voltage across the secondary winding or successively actuate the switches. If the car moves horizontally, the first shaft is rotated to change the voltage and a second roller engaging the rail rotates a second shaft to compensate for this change in voltage.

Abstract: A switching bearing assembly for a motor-driven spindle, e.g. a leadscrew adapted to drive a nut axially along the leadscrew, is provided with a bearing housing disposed between two fixed plates and biased centrally thereof by a plurality of compression springs. The housing is positioned to actuate switches which turn off the motor when the spindle bearing is overloaded, e.g. when the nut reaches the end of its travel or is otherwise impeded in its first axial movement. The housing is also provided with a spring-biased pin which bears upon an eccentric carried by the shaft to frictionally retard further rotation thereof once the motor has been turned off.

Abstract: A rotatable cam limit switch with a switch operating cam mounted directly on a continuously rotating drive shaft and axially shiftable relative to the shaft. The drive shaft is also provided with a "fast thread" for adjustable axial positioning of a timing element in slidable engagement with the cam. Manual axially adjustable yoke elements respectively engage the cam and timing element for establishing preselected switch dwell time and phase relationship between said switch and said shaft.

Abstract: A hydraulic cylinder with heads on each end of a cylinder body utilizes a tie rod of hexagonal cross section to positively prevent relative rotation with an attached magnetic switch. The switch is engaged along the tie rod about a section in which the diametral dimension is at a relative minimum and has mated flattened portions which cooperate with flattened surfaces on the tie rod.