Abstract: An electromagnetic operator for a contactor (2) having a housing (4,34) including an insulating upper part (4) and a snap-in lower part (34), a magnetic armature (24) movable in the upper part (4), and a magnetic core (30), molded coil (28), return spring (36) and shock pad (32) in the lower part (34). The molded coil (28) is clamped immovably by the lower part (34) against the upper part (4) of the housing. The shock pad (32) has a flat base (32a) with a thin spherical segment (32b) between the magnet core (30) and the lower part (34) and four tabs (32c-f) at its corners supporting the four legs (28c-d) of the molded coil (28) to press the latter securely against the upper part (4) of the housing, these legs (28c-d) having reduced sections (28e-f) that sink into those tabs (32c-f). The shock pad (32) also has two pairs of resilient strips (32g,h,j,k) that extend from the opposite edges of the base (32a) up and toward one another between the yoke portions (32c,d) of the magnetic core (30) and the coil (28).

Abstract: Four different versions of multi-position selector switches can be assembled from a kit of parts by selecting various combinations of the parts and assembling them into a housing consisting of an insulating case and cover. Inventory of parts is reduced by mutual use of some parts in two or more versions. The possible selector switch versions are a three position selector switch having three momentary pushbuttons for selectively closing two normally open contacts and opening a normally closed contact a two-position slector switch having two momentary pushbuttons for selectably closing a normally open contact or opening a normally closed contact, a three-position selector switch having three maintainable pushbuttons for selectively closing two normally open contacts and opening the same, and a three-position selector switch having three pushbuttons including a momentary pushbutton and two maintainable pushbuttons for selectively closing two normally open contacts and for opening the maintained contact.

Abstract: A pair of insulating base halves (26,28) are adapted for mutual engagement along respective open sides, one base half (26) containing stationary contacts (30,32,34) and an electrical bussing element (30) structurally interlocked with the base half and the other base half containing a speed control circuit board (40) and electrical connectors (56,58) biased into electrical engagement with the circuit board and forming push-in lead connectors with the stationary contacts and bussing element, a movable contact carrier (38) disposed between the base halves for sliding movement and having a movable contactor (64) engaging the stationary contacts and a wiping contact (66) engaging variable resistance (44,46) elements on the printed circuit board, the two base halves being interlocked (26k,28e) together along a lower edge and retained together along an upper edge by inserting them into a hollow housing (2) containing a depressible trigger operator (4,18) the insertion effecting a driving connection (18d,38k) between

Abstract: A solid state switching circuit for energizing a lamp (L) is connected around a fuse (12) across an AC supply for detecting a voltage differential at the opposite sides of a blown fuse and applying that differential across the control (g) and switching (c) electrodes of the solid state switch (SCR) to render the same conductive. Current limiting resistors (RL1 and RL2) are placed in the ends of wire conductors which are to be connected at opposite sides of the fuse, thereby to limit current flowing in the conductors over the entire length of the conductor, minimizing electrical shock hazard upon damage to the conductor.

Abstract: A refill unit for a negative pressure type implanted infusion device includes a hollow cylindrical housing member which is adapted to receive at one end a bottle of vacuum conditioned medication. As the bottle is inserted first and second needles or tubes penetrate the closure member of the bottle, the shorter one of these needles being positioned to receive medication inside the bottle and the longer one extends into the ullage space of the bottle when it is inserted and held vertically. The shorter needle communicates with a refill needle, which extends downwardly from the other end of the cylindrical member, through a membrane type filter which is hydrophilic to the medication and has a micron rating such that the filter once it is wetted can pass air bubbles but only at a differential pressure substantially greater than the negative pressure differential of the implanted device.

Abstract: A motor overload protection system (OL) that has a speed of operation fast enough so that it will always trip before the power switch (MC) has had time to operate if the turn-on control means (ON) is operated under overload conditions. In one version, modules (OL1,OL2) are provided having PTC thermistor sensors (PTC1,PTC2) bonded to resistance heaters (H1,H2) connected in the motor power circuit (L1,L2,L3), these sensors being supplied from a current source (CT) and being effective to shunt current to a protective trip device (TR) upon occurrence of an overload condition, there being an ambient temperature compensating PTC themistor (PTC3) in series in the sensor circuit (OLC).

Abstract: A plurality of wide flat bus bars (A,B,C,N) stacked in flat face-to-face relation are clamped against separation forces of short circuit currents in the bus bars by U-shaped reinforcement channels (6,14) disposed over opposite edges of the bus bars with bight portions (6a,14a) of said channels abutting the edges of the bus bars and leg portions (6b,14b) thereof extending along flat surfaces of outer ones of said bus bars. A plurality of bolts (8) through aligned holes in outwardly directed flanges (6c,14c) formed on the free ends of the legs of the channels and are threadably tightened to draw the channels together and to exert a clamping force against the flat faces of the bus bars. A flat sided housing (16,24) is attached to the channels (6,14) and may be provided with access openings (16a) at intervals therealong for making plug-in connections with the bus bars.

Abstract: A protective shroud (22) for a flexible electrical cable (20) at the location where it emerges coaxially from the rear end (14) of an electrical device, such as an inductive proximity or photoelectric sensor (2), serving as a strain relief and protection from being bumped as well as retaining such electrical cable (20) at a gradual right-angle bend from a horizontally-mounted sensor (2) to keep it out of the way, such as from the aisle adjacent a conveyer on which the sensor is mounted. Snap-in means including an annular groove (18) on the rear end of the sensor (2) and a constricted-opening (22f) slot (22e) in the inner side wall (22d) of the shroud (22) afford snap-in mounting of the latter onto the rear end (14) of the sensor (2) with the shroud (22) being rotatable thereon to allow the electrical cable (20) to be oriented in any desired direction. Another version of protective shroud (24) adapted for a vertically-mounted sensor ( 2) in FIG.

Abstract: A front mounted rectangular pushbutton switch is clamped within a hole in the panel by screws accessible through a front opening of the switch housing which drive an external clamping assembly against the rear of the panel at the midpoints of four sides of the switch housing. The clamping assembly employs two screws at diagonally opposed corners of the housing, each of which controls movement of a clamp on two adjacent sides of the switch.

Abstract: A pushbutton switch having a rectangular opening in a forward end of its housing substantially filled by a single rectangular pushbutton has a rectangular resilient seal attached to the housing at the forward end, the seal further having cylindrical shape disposed within the rectangular shape attached to a cylindrical surface at the rear of the pushbutton, the rectangular and cylindrical shapes being joined together by a reflex bend to provide a rolling movement of the seal upon depresion of the pushbutton.

Abstract: An L-shaped member (20) is secured adjacent a fuse clip (12) to extend forwardly along one side of a fuse (F) received in that fuse clip. A flexible insulating strap (24) is secured to the outer end of the forwardly projecting post (20a) to lie within a groove (20e) in the post and extend rearwardly around the back side of the fuse and then forwardly along an opposite lateral side of the fuse. Pulling the free end of the strap (24) upwardly or forwardly causes that end of the fuse to be rolled forwardly of the fuse clip with a mechanical advantage.

Abstract: A bimetal operated latch subassembly (600) for an electrical device such as an overload/switch device which is a self-contained unit that can be mounted into operative position relative to the trippable member (012) of the electrical device. A bimetal assembly (660) and a pair of terminals (604,621) electrically connected thereto are mounted on a main insulating base (601). A vibration and shockproof latch assembly (610) is preassembled on a stainless steel sub-base (611) which is then secured by a single screw (605) to the main base (601) at the same time coupling the bimetal assembly (660) to the latch (610) in operative relationship. The latch (610) is rendered shockproof by providing a spring-biased linear slider (650) that latches to a transversely pivoted latch lever (613). The latch friction that must be overcome by the bimetal (608) is reduced to a minimum by providing the latch lever (613) with an adjustable bias (614,615) that almost balances the tripping force (Y) of the trippable member (012 ).

Abstract: A pair of insulating base halves (26,28) are adapted for mutual engagement along respective open sides, one base half (26) containing stationary contacts (30,32,34) and an electrical bussing element (30) structurally interlocked with that base half upright against an interior wall and the other base half containing a speed control circuit board (40) disposed in an upright position along an opposite interior wall and electrical connectors (56,58) biased into electrical engagement with the circuit board and forming push-in lead connectors with the stationary contacts and bussing element, a movable contact carrier (38) disposed between the base halves for sliding movement and having a movable contactor (64) engaging the stationary contacts and a wiping contact (66) engaging variable resistance (44,46) elements on the printed circuit board, the two base halves being interlocked (26k,28e) together along a lower edge and retained together along an upper edge by inserting them into a hollow housing (2) containing a

Abstract: A motor (M) supplied by AC full-wave voltage is controlled by a triac (Q2) under the control of a double-time constant triggering circuit which has a speed setting branch (R3-C2) connected at the triac (Q2) side of the motor (M) and the other time constant branch (R1-C1) connected at the supply side of the motor (M) to provide a feedback function as well as a first time constant. A unidirectional diode (D1) is incorporated in the feedback sensing time constant branch for rendering feedback signals only on alternate half cycles to prevent oscillation and overcompensation of motor speed due to the feedback signal. A soft-start circuit, usable also in half-wave applications, is incorporated in the branch containing adjustable speed setting resistor and comprises a transistor (Q3) having its collector-emitter circuit connected in series with the adjustable resistor (R3).

Abstract: Stationary contacts (12) of a multi-pole disconnect or safety switch are arranged to be engaged by one of a rotatably movable bridging contact (2) before engagement of the other end thereof with a second set of stationary contacts (10). Stationary contacts (12) of adjacent switch poles are positioned on alternate ends for increasing the phase-to-phase failure distance, and one stationary contact (10a) may be arranged to close one or two milliseconds late to produce single phasing for a short time under fault current conditions during which time current limiting fuses (14) begin to open the circuit.

Abstract: A heater strip (12) is disposed in spaced relation to a temperature responsive actuator element (20) for indirectly heating that element in response to current flow in the heater (12). An adjustable heat sink (22) is disposed in spaced proximity to the actuator element (20) for removing heat from the actuator element by radiation therefrom through air to the heat sink in a first position and adjustable to be in thermally conductive engagement with the actuator in a second position for increasing the efficiency of heat transfer from the actuator to the heat sink. Increased current flow in the protected branch circuit is required to cause the actuator (20) to attain its predetermined actuation temperature as the heat sink is adjusted to increase the efficiency of heat transfer between the actuator (20) and the heat sink.

Abstract: A silicon substrate (2,22) having a SiO.sub.2 layer (4,24) grown on its upper surface and a metallization layer (6,26) of magnetic material subsequently deposited on the upper surface of the SiO.sub.2 layer is etched to define a cantilever beam (8,38) extending over a recess (12,32) in the substrate (2,22) having a magnetic layer (6,26) along the top surface thereof. The resulting structure is subsequently masked with a photoresist layer to enable a second layer (14,34) of magnetic material to be deposited on the first layer. The photoresist layer is stripped forming a second magnetic layer (14,34) projecting from the unsupported end of the cantilever beam over and spaced from a fixed stop (10,30) of magnetic material adjacent the unsupported end of the cantilever beam. In one version the magnetic material (6,14) serves as electrical current carrying contacts which close upon application of a magnetic field to the switching device.

Abstract: A pair of heaters (16,18) are mounted within a breaker housing (2) in spaced relation to a temperature responsive actuator element (30) for indirectly heating that element in response to current flow in the heaters. Each heater is provided with a wiring terminal member (6,8) for selectively individually connecting one or the other heater in circuit with a branch circuit to be protected. One heater (16) is selected to generate greater amounts of heat than the other heater (18) when subjected to the same current levels.

Abstract: A molded insulating switch housing (2) has a rectangular opening (2a) in an end wall thereof through which an actuator (4) having a rectangular cross-sectional shape extends for linear reciprocable movement and is biased to an extended position with respect to the housing. A trigger operator member (6) is affixed to the outer end of the actuator (4) and has a recess (6b) open toward the end wall of the housing (2). A continuous rectangular flange (2b) surrounds the opening (2a) in the end wall and is telescopically received within the recess (6b) of the trigger operator (6) to form a dust and foreign contaminant material seal for the switch.

Abstract: A cylindrical contact carrier (4) is journaled for rotational movement about an axis extending in the direction of linear movement of a depressible trigger operator (2). Spiral grooves (4d) formed in the carrier (4) cooperably receive cam elements (10g) which are disposed in fixed planes with respect to the axis of rotation and depression of the trigger operator (2) effects relative linear movement of the cam elements (10g) with respect to the spiral grooves (4d) to cause rotation of the carrier (4) for moving contacts (18) positioned on the carrier (4) into and out of engagement with stationary contacts (22) disposed around the periphery of the carrier (4).