Abstract: A changeover switch comprising first and second substrates assembled in spaced relation to each other, a plurality of reed switches disposed in a circle having predetermined angular intervals on the substrates, a permanent magnet pivotally mounted on a revolving disc so as to lie in the same plane as the first and second substrates for causing the reed switches to switch on and off alternately as it is revolved between the first and second substrates, and a means for intermittently rotating the permanent magnet at an angle of every 90.degree. around its pivotal axis.

Abstract: A thermo-magnetically operated switch having lower and higher operating points is maintained open below the lower operating point and above the higher operating point and is maintained closed between the two different operating points, and comprises a reed switch, two permanent magnets disposed alongside the reed switch over the respective reeds, a first ferromagnetic body having a Curie point corresponding to the higher operating point and disposed between the two magnets, and a second ferromagnetic body or bodies having a Curie point corresponding to the lower operating point and disposed along the two magnets. In order to improve reliability of the switch, two third ferromagnetic bodies having Curie points at or above the lower operating point are disposed to engage axial opposite ends of the second ferromagnetic body or bodies and the other pole faces of the magnets opposite the pole faces engage the first ferromagnetic body.

Abstract: A multi-part actuating mechanism formed of at least two correlated individual actuating elements contained within a housing. The actuating elements being arranged to move relative to each other and each being equipped with differently poled magnetic fields so that the fields are moved from a position in which identically poled magnetic fields oppose each other to one in which differently poled magnetic fields are opposite each other.

Abstract: A two position rotary type magnetically actuated reed switch (10) having magnetic detents is disclosed. The preferred switch includes a housing (12) having confronting magnetizable side walls (13, 14), a shaft (22) secured to the housing (12) for rotation relative thereto and means (30) at one end of the shaft (22) for effecting manual rotation thereof, a magnetic member (36) secured to the shaft (22) for rotation therewith between the confronting walls (13, 14) whereby the member (36) is in magnetic detented contact with one wall (14) when the shaft (22) is rotated to a first position and in magnetic detented contact with the other wall (13) when the shaft (22) is rotated to a second position, and a magnetic reed switch (60) supported in the housing (12) in the vicinity of the wall (14) such that the switch (60) is activated when the shaft (22) is in its first position and deactivated when the shaft (22) is in its second position.

Abstract: An electrical switching device for use on machinery to prevent machine operation unless safety guards or the like are correctly positioned comprises two separate parts one part including at least two Hall effect devices which respond to magnetic poles of opposite polarity and electronic switching means which is actuated only when all the Hall effect devices are triggered simultaneously, and the other part including a corresponding number of magnets positioned to actuate the respective Hall effect devices when the two switch parts are placed in close proximity and predetermined orientation. The switch is substantially tamper proof and a control circuit can detect any unauthorized attempt to override the switch.

Abstract: An improved magnetic proximity switch which comprises an auxiliary permanent magnet for retaining normal closing and a yoke arranged so that the magnetic path of said auxiliary permanent magnet and the magnetic path formed by the magnetic flux from outside are added each other. Thus, the switch has such merits that the contact pressure at the time of normal closing is raised, the working sensitivity is enhanced, with a small external magnet, without mis-working due to shock or vibration from outside and the like.

Abstract: There is provided an alarm, which includes a mounting base, and means for securing the mounting base to an item whose movement is to be signalled by the alarm. A magnetic reed switch constitutes a first element, and a magnet constitutes a second element. One of these elements is mounted on a pivotal member capable of pivoting with respect to the mounting base, while the other of the elements is capable of retaining a given position with respect to the mounting base.

Abstract: A float operated electrical switch assembly has a housing (10) fitted to an opening in a container wall (14). A float (19) follows the liquid level and is pivoted with a primary magnet (18) about a pivot axis (17). A pivotal secondary magnet (21) acts in repulsion with the primary magnet (18) through a non-magnetic wall (20) of the housing (10). The movement of the secondary magnet (21) causes at least one control rod (48) to reciprocate. A switch contact (32) is normally held under the resilience of its carrier leaf spring (38) in engagement with a fixed switch contact (33). The contacts are opened by movement of the control rod (48) moving the switch contact (32) against the resilience of its carrier.

Abstract: An anti-theft device for a vehicle having an internal combustion engine provided with an electrical circuit constituting an ignition or engine-heating circuit. The device includes a first circuit member having an output, a second circuit member having an input, the first and second circuit members being parts of the electrical circuit. A plurality of magnetic switches are disposed in a housing. One or more of the magnetic switches are electrically connected in series between the output of the first circuit member and the input of the second circuit member, all remaining ones of magnetic switches are connected between the input of said second circuit member or the output of the first circuit member and ground of the electrical circuit. One or more magnets are carried on a support in the form of a key which can be inserted into a slot in the housing.

Abstract: A low liquid level float control apparatus particularly adapted for use in vessels or tanks containing a fluid of the type utilized in liquid vending machines is disclosed. An electronic control unit has a probe section extending downwardly therefrom containing a reed switch, which is activated by the passage of an annular magnet vertically along the probe section. A second magnet is secured about the lower most portion of the probe section and is adjustable along the probe section thereby increasing the switch delay time, thus reducing the possibility of intermittent on-off operation of associated pump elements.

Abstract: A thermo-magnetically operated switch having two different and predetermined lower and higher operating points on a temperature scale so that it may be maintained open below the lower operating point and above the higher operating point and be maintained closed between the two different operating points comprises two permanent magnets, and two kinds of temperature sensitive ferromagnetic members in proximity to a reed switch. The two permanent magnets are disposed over respective reeds of the reed switch in a similar polar direction and with an axial space therebetween. Two temperature sensitive ferromagnetic members having a higher Curie point are disposed at opposite outer sides of both permanent magnets or at opposite ends of the reed switch, and are in contact with respective permanent magnets.

Abstract: A protective encasement for machine tools comprises a fixed part and a movable part composed of profiles assembled to form uprights and cross-pieces, bearing components controlling safety circuits activated by action of the movable part. The fixed part is composed of a single profile with a closed central cell, surrounded by several open cells which can receive windows and fixing and activating means and can be closed, and which contain the safety components and circuits. The movable part comprises a L-shaped profile connected to the fixed part and protecting contacts which cooperate with the components of the fixed part.

Abstract: An electric switch magnetically activatable including a Hall Effect sensor with a permanent magnet fixed on one side of the sensor and magnetic shielding interposed between the sensor and fixed magnet to direct flux away from the sensor, such that an operating magnet upon movement toward and away from the other side of the sensor cooperates with fixed magnet to produce an increased magnetic field through the sensor to activate the latter.

Abstract: A magnetic switching device comprising a drive member and a slave member having magnetically attractive surfaces, the two members move angularly with respect to one another so as to bring the magnetic surfaces in and out of contact with one another.

Abstract: A Hall effect switch device converted to a latching relay by having a reversible bias magnet attached thereto adjacent the Hall sensor so as to operate the switch circuit in one polarity of the bias magnet, and release the switch circuit in the other polarity of the bias magnet.

Abstract: A magnetic sensing device for sensing the proximity of a gas lift plunger up from the bottom of an oil or gas producing well is used to initiate the off cycle of the well and which comprises only one moving component, a magnet which is attracted to the plunger, completing an electrical circuit to a unit for controlling the operation of the well. The magnet is returned to its resting position by a ferrous set screw adjacent the magnet which attracts the magnet once the gas lift plunger has passed the field of the magnet sensor. The magnet and electrical contacts for the sensing device are enclosed in a molded plastic housing which can be easily opened to repair or replace any worn components.

Abstract: A moving element is held without contacts in a relatively stable holding position, out of which it is released by the application of an external force. The relatively stable holding position is obtained by superimposing a potential field of magnet edges by a further potential field based on a mechanical bias of the moving element or a magnet in such a manner that the curve of the total potential has a trough corresponding to the holding position. By applying an external force, the moving element is moved to a peak position of the total potential curve, whence it is subject to accelerating forces. Preferably rare earth magnets are used to form the potential field of magnet edges. In a print hammer actuator the moving element includes a moving coil.

Abstract: An automatic magnetic switch comprising an over-load or short-circuit protection means and a manual magnetic switch installed in the switch casing. A magnetic control means is contained in a sub-casing of the switch. The manual magnetic switch has a conductive plate with an electrical contact fixedly mounted in its casing and another conductive plate, generally rigid and inflexible, has an electrical contact mounted thereon for pivoting or sliding movement. Permanent magnets, one on the movable plate, and one outside the casing urge the movable plate to a contact engaging position when the outside magnetic member is brought proximate to the casing, and a spring is used to restore the movable plate to its non-engaging position when the outside magnetic member is moved away from the casing.

Abstract: A proximity detector has permanent magnets positioned within a chassis so that the axis and poles of the flux field of the permanent magnet are substantially normal to the front of the chassis. A switch is positioned along the front of the chassis proximate the magnet. The switch has contacts operable by the magnetic flux field of the magnet. A shield is positioned between the magnet and the rear of the chassis and between the switch and the rear of the chassis. The shield acts to inhibit extraneous magnetic fields from interferring with the detector operation and as a magnetic conductor to focus the magnetic flux field. The flux field of the permanent magnet is modified by a ferromagnetic object positioned at a predetermined distance from the front of the chassis to cause the contacts of the switch to operate in relation to the positioning thereof and in turn send an operate signal indicative of the positioning of the ferromagnetic object at the front of the switch to an external circuit.

Abstract: In an alarm control system for protecting a premises, a four conductor bus line leading from a master control station is extended about the interior perimeter of the premises. Sensors positioned near each port of entry to be monitored are connected in parallel relationship to the bus line, as is at least one remote station for manually arming, disarming or activating the system. Each sensor comprises a biased reel carrying line secured to window, door, screen, or the like. Disturbance of a sensor causes a magnetically responsive switch therein to generate a pulse triggering circuitry within the control station to activate the desired alarm device for a predetermined period of time. The system then resets automatically to an armed or ready condition to continue protecting the premises against subsequent intrusions. Preferably, the lines in the sensors are of a thermoplastic material so that the system is also activated by abnormally high temperature in the event of fire.

Abstract: An electric connector including, a female socket having at least one jack, a male plug assembly for coupling with the female socket and having a plug element thereby electrically engageable with the jack, a movable contact electrically connected to a terminal of the socket, the movable contact being mounted in the socket for movement between an operative position wherein the contact is electrically connected with the jack and an inoperative position wherein the contact is spaced from the jack and thereby not in electrical contact therewith, a magnetic actuator for moving the contact to the operative position upon the coupling of the male plug assembly to the female socket and a biasing magnet located in the socket for moving the contact to the inoperative position upon the uncoupling of the male plug assembly from the socket.

Abstract: A photographic copying machine wherein any one of a series of masks, each having a differently dimensioned light-transmitting opening, can be placed onto a locating plate which supports a battery of fixedly mounted or mobile magnetic actuators for discrete electric switching elements. Each mask carries a different array of soft magnets which displace or otherwise influence a group of actuators so that the thus influenced actuators open or close the associated switching elements which adjust the exposure controls and/or another system of the copying machine in dependency on the size and/or shape of the opening in the selected mask. The soft magnets on each mask influence a different group (e.g., a different number) of actuators each of which is an H-shaped permanent magnet.

Abstract: A spa construction for use by humans comprising a shell for containing water and having a well for receiving the feet of the user. A seat is provided adjacent the well upon which the user can sit. A side wall is provided against which the user can rest his back. A first pump is provided having an inlet coupled into the bottom portion of the shell for withdrawing water from within the shell and an outlet coupled to the shell above the seat for introducing jets of water into the shell. An air inlet is provided for mixing air into the jets of water introduced into the shell. A filter and heater housing is carried by the shell and has disposed therein filter and heater elements. An additional pump is provided having an inlet coupled to the shell for drawing water from the shell into the filter and heater housing and discharging the same through an outlet coupled to the shell.

Abstract: A magnetically actuated proximity device or switch is provided with an armature formed as a shallow U that is pivoted at its center and arranged with the legs of the U directed toward the pole faces of a pair of permanent magnets. The particular shape increases the sensitivity of the device and the force available for operating contacts or other output devices in response to the diversion of flux from an end of the armature.

Abstract: A magnetically operated reed switch device for use in physical security monitoring systems, machinery control systems, and the like, having a biasing permanent magnet associated therewith for providing adjustable sensitivity to the proximity of an actuating permanent magnet. The reed switch is enclosed in a cylindrical glass capsule and the biasing magnet is mounted near the capsule, with its axis of magnetic polarity parallel to an elongate reed of the reed switch, in a position adjustable along the longitudinal axis of the reed by an adjustment screw for controlling the sensitivity of the reed switch. The biasing magnet may be mounted on a screw-driven carriage or on the end of a screw moving within a tube parallel to the reed. The device is actuated by increased magnetic flux density provided by the actuating magnet, which is attached to the movable object whose position is being monitored. The switch device and its actuating magnet are fixed in protective housings having mounting means.

Abstract: Magnet-controlled switch comprising in a case at least one flexible-strip interruptor (FSI) placed between two magnetic plates, one being movable with respect to the other under the action of a manipulatable element, and at least one permanent magnet near each end of the FSI, in such a manner that the magnets exhibit poles of opposite polarities and produce a magnetic field perpendicular to the plates.

Abstract: A hinge is secured to the jamb of a door frame and to a door in the frame. Behind the jamb leaf of the hinge the jamb is provided with a hole that is concealed by the hinge. The back of the jamb leaf is provided with a recess facing the hole. An electric switch and its operating magnet are mounted in a housing that is held in the jamb hole and projects into the jamb leaf recess. The housing is not attached to the hinge. In case the hinge leaves are substantially parallel when the door is closed, a ferrous area of the door leaf will activate the switch. If the hinge leaves are at right angles to each other when the door is closed, a ferrous metal area of the edge of the door itself activates the switch.

Abstract: A magnetically operated proximity switch for use in physical security monitoring systems, machinery control systems, and the like, comprising a magnetic reed switch having permanent magnet biasing means associated therewith for controlling the sensitivity of the switch to the proximity of an external magnetic field. The reed switch is enclosed in an elongate glass capsule and the magnet of the biasing means is attached to the capsule with its axis of polarity parallel to the reed of the reed switch by means of either a slidable carrier or heat shrinkable tubing. The means of attachment of the biasing magnet to the reed switch capsule allows adjustment of the position of the biasing magnet to control sensitivity of the reed switch. Protective mounting means is provided for attaching the switch and biasing magnet to an object.

Abstract: A magnetically-actuated sensing device for use in security monitoring systems. A switch unit having a plurality of electrically interconnected magnetic reed switches disposed in a predetermined physical relationship is provided for controlling electrical circuits. Each reed switch is biased in a magnetically-actuated state by permanent biasing magnet in close proximity thereto, the biasing magnets being arranged in a predetermined combination of polarity orientations. A corresponding number of permanent actuating magnets with polarity orientators opposing those of the biasing magnets are disposed within an actuating unit so that they overcome the effect of the biasing magnets when the switch unit and actuating unit are in a predetermined physical relationship with each other. The polarity of at least one of the biasing magnets opposes the polarity of other biasing magnets of the device, providing a sensing device which cannot be deceived using only a single permanent magnet to simulate the actuating magnets.

Abstract: A keyboard which has support frame, or several rows of key units. Each key is movable out of an initial inoperative position by the tip of the index finger. The key of each key unit of a guide key row has a key rod and a top face on one end of the key rod. The tip of a finger rests at random pressure on each top face as, at the opposite end of the key rod, a non-depressable mounting is articulatedly lodged in the support frame and prevents downward depression of the key while permitting tilting toward one or more operational positions.Each key unit of the guide key row has a magnetic pole to exercise a determined initial attraction on the top face-bearing end of the key rod an doppose tilting movement of the key away from the attracting means, when this movement is initiated by a finger tip.

Abstract: A rotary switch comprising a stationary body provided with longitudinal bores in each of which a core of magnetic material is movable, switching means located at one end of said bores, and adapted to be actuated by the said cores and magnetic elements adapted to be brought successively opposite the ends of said bores to either displace or hold the said cores in the said bores for actuating the said switching means.

Abstract: A switch employing such magneto-sensitive switching element as, for example, reed switch or the like and generally used for crime prevention purpose with a high reliability, wherein the switching element is initially set in either one of its ON and OFF states by a permanent magnet disposed adjacent the element and rotatably about its central axis perpendicular to its longitudinal axis and such initially set state of the element is turned to the other state to actuate an alarm device when another permanent magnet mounted, for example, to a door approaches the rotatable magnet and magnetically varies initial relationship of the rotatable magnet to the element.

Abstract: A magnetically-actuated switch has a stationary mounting base to which a plurality of magnetically-actuated reed-type switches are secured in a layer parallel to the base. A moveable portion of the switch is pivotably mounted to the mounting base, and contains a plurality of magnets positioned to actuate the reed-type switches in any desired sequence. A second layer of magnetically-actuated, reed-type switches is positioned, parallel to the mounting base, below the above-mentioned layer, and additional magnets are added to the moveable portion, to supplement the existing magnets, and increases the magnetic field in certain portions of the moveable portion to effect the lower layer of reed-type switches.

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 differential float control is provided by a single switch and a single float wherein a vertical guide tube contains a magnetically operated switch, and a free float surrounds the tube and rises and falls with the liquid level and carries two magnets. As the float moves in one direction the switch is magnetically latched closed by one magnet and remains closed until unlatched by the other magnet as the float returns in the opposite direction. The switch may be normally open, or normally closed, so that movement of the float may provide any desired circuit sequence for operating a liquid level controlling pump or the like for maintaining the liquid level within prescribed limits.

Abstract: A magnetic proximity sensing apparatus for sensing ferro-magnetic objects is especially well adapted for use with fluid cylinders having pistons formed from magnetically attracted material. The apparatus includes a magnetic actuator responsive to the proximity of the fluid cylinder piston or other ferro-magnetic object which closes a switch and enables electrical circuitry for controlling fluid valves or other apparatus. A reed switch mounted within a hollow, cylindrical, permanent magnet has a separate pole piece secured at one end of the reed switch. The proximity of a ferro-magnetic object changes the flux within the magnet, closing the reed switch. The circuitry is solid state and includes a silicon controlled rectifier acting as a gated switch for completing the circuit.

Abstract: A magnetic proximity sensing apparatus for sensing ferro-magnetic objects is especially well adapted for use with fluid cylinders having pistons formed from magnetically attracted material. The apparatus includes a magnetic actuator responsive to the proximity of the fluid cylinder piston or other ferro-magnetic object which closes a switch and enables electrical circuitry for controlling fluid valves or other apparatus. A reed switch mounted within a hollow, cylindrical, permanent magnet has a separate pole piece secured at one end of the reed switch. The proximity of a ferro-magnetic object changes the flux within the magnet, closing the reed switch. The circuitry is solid state and includes a silicon controlled rectifier acting as a gated switch for completing the circuit.

Abstract: The drawings illustrate a switch and latch arrangement responsive to vehicular odometer movement and including means formed at a predetermined location on one of the odometer number wheels, indicative of a predetermined cumulative vehicle travel, for pivoting suitable magnetic shunt means from a first position out of the path of lines of flux extending from a permanent magnet to a magnetically actuated reed switch to a second position in the path of the lines of flux, in order to selectively control an external device electrically connected to the reed switch.

Abstract: The invention contemplates remotely operable lifting mechanism for selectively displacing a liquid-level float in a sealed tank, to permit checking of the operational status of the float throughout its displaceable range, and to permit check-out of magnetically operated electrical means actuated by the float at a predetermined float level within its displaceable range. The lifting force is coupled magnetically to the float without interference with the path of float movement and without interference with the magnetically operated electrical means.

Abstract: Operation of a push button, operates an advancement mechanism to index one of a plurality of magnets adjacent to a fixed polarity magnet coupled to electrical switch contacts to thereby actuate the same. Such plurality of magnets are alternately south and north pole magnets for successively attracting and repelling the fixed polarity magnet on the switch plate upon successive operations of the push button. Indicating lamps may be provided on the push button, the lamps being protected and accessible beneath a transparent lid pivoted on the push button.

Abstract: A proximity device comprises a pair of connected magnets that are movable with respect to a magnetizable member located intermediate the magnets and secured in a housing. The magnets are arranged to provide a high rate of change of force between the magnets and the member as the magnets are moved by the approach or retreat of a magnetizable operator to or from an area adjacent one of the magnets and remote from the magnetizable member between the magnets.

Abstract: A tactile feel device which provides a characteristic resistance to movement, and breakaway feel to signal the operator that movement and accompanying function, such as switching, has been accomplished. Resistance to movement is provided by spring biasing means for the initial stroke of the device, by spring biasing means plus magnetic force at the end of the initial stroke, and by spring biasing means only, after magnetic breakaway at the end of the initial stroke, to provide a characteristic breakaway feel. The device is shown and described in connection with a light pen which generates a signal when pressed against a cathode-ray-tube faceplate. The characteristic breakaway feel signals the operator that the tip or probe of the pen has been sufficiently pressed against the cathode-ray-tube to generate the appropriate signal in the light pen.

Abstract: A magnetically-actuated switch has a stationary mounting base to which a plurality of magnetically-actuated reed-type switches are secured in a layer parallel to the base. A moveable portion of the switch is pivotably mounted to the mounting base, and contains a plurality of magnets positioned to actuate the reed-type switches in any desired sequence. A second layer of magnetically-actuated, reed-type switches may be positioned, parallel to the mounting base, below the above-mentioned layer, and additional magnets may be added to the moveable portion, to supplement the existing magnets, and increases the magnetic field in certain portions of the moveable portion to effect the lower layer of reed-type switches.

Abstract: An endless-conveyor monitoring switch assembly includes an elongated frame having a shaft journaled for rotation therein and extending longitudinally therealong. A drive wheel is attached to and rotatable with the shaft at a first end of the elongated frame and a detecting switch is attached to the shaft at the opposite end of the elongated frame. A seesaw, U-shaped, mounting member is attached to the elongated frame at a point intermediate the drive wheel and the detecting switch for mounting the elongated frame on an endless-conveyor cable support. The mounting member allows the weight of the elongated frame and its attachments to pivot the frame in a seesaw manner to bring the drive wheel into contact with the endless conveyor. The detecting switch includes a conductive disc mounted on the shaft adjacent to a pendulum having permanent magnets and mercury switches mounted thereon.

Abstract: An apparatus for switching an alarm-signalling device connectable to a protective circuit so as to signal an alarm when a door or the like is displaced from its closed position in a jamb or the like by an intruder, in which the switching apparatus is mounted in the door and jamb or the like. The switching apparatus includes a switch connectable to the protective circuit, mounted in a housing installable so as to be recessed in the jamb, and a metal plate installable so as to be recessed in the side of the door and disposed opposite the switch when the door is closed in the jamb.

Abstract: Discloses a switch for use with a circuit board for simultaneously closing one or more circuits. A switch cover mounts therein a reciprocable member whose permanent strip magnet carries one or more contact elements for circuit completion. The circuit board carries another permanent strip magnet. The strip magnets have consecutive, alternating polarities such that, in the closed position of the switch, the strip magnets have opposite attracting polarities, and such that, in the open position of the switch, the strip magnets have the same and repelling polarities.

Abstract: A finger operated switching device includes a key assemblage having a key and a key magnet which moves relative to a biasing magnet wherein the magnets are so dimensioned and mutually positioned so that the key assemblage is biased to a retracted position and when the key assemblage is pushed to an extended position the force required first increases to a peak and then rapidly decreases.

Abstract: The following specification describes a magnetically operated lock for a coaxial switch in which slide member is operated in opposite directions by a slide magnet in a key to connect an incoming coax line to either another coax line or to ground through a characteristic impedance termination.The key has a configuration corresponding to the lock housing and when associated with the lock housing, automatically positions a plurality of spaced magnets in the key to operate a plurality of pins in opposite directions to unlock the slide. Removal or disengagement of the key from the lock housing enables the pins in the lock to engage the slide and lock the switch in either position to which it is operated.

Abstract: A conveyor comprising a trolley movable along a track and having at least one elongate member of ferromagnetic material which is settable in a position selected according to a code to convey information concerning the destination of the trolley. At a reading station on the track, there is a row of magnetically-operated switches with magnetic shields between them. With each switch there is associated a pair of magnets disposed on opposite sides of the switch with one magnet of the pair between the switch and the path followed by the elongate member through the reading station. When aligned with the magnets of a switch, the elongate member operates the switch as the member passes through the reading station.

Abstract: An endless-conveyor monitoring switch assembly includes an elongated frame having a shaft journaled for rotation therein and extending longitudinally therealong. A drive wheel is attached to and rotatable with the shaft at a first end of the elongated frame and a detecting switch is attached to the shaft at the opposite end of the elongated frame. A seesaw, U-shaped, mounting member is attached to the elongated frame at a point intermediate the drive wheel and the detecting switch for mounting the elongated frame on an endless-conveyor cable support. The mounting member allows the weight of the elongated frame and its attachments to pivot the frame in a seesaw manner to bring the drive wheel into contact with the endless conveyor. The detecting switch includes a conductive disc mounted on the shaft adjacent to a pendulum having permanent magnets and mercury switches mounted thereon.