摘要:
An electric motor control apparatus includes an electrical current control apparatus which is operable to limit current to an electric motor. When the electric motor is a three-phase motor, three current limiting switch assemblies are provided in the electric current control apparatus. A single stack of laminations concentrates magnetic fields emanating from conductors in all three current limiting switch assemblies. Each of the current limiting switch assemblies includes two movable contacts which are mounted on contact arms. The contact arms are movable in slots in the stack of laminations. A first series of splitter plates is disposed in an array along a path of movement of the contact on the first movable contact arm and a second series of splitter plates is disposed along a path of movement of the contact on the second contact arm for each of the current limiting switch assemblies. A short circuit splitter plate conducts electrical current between the two series of splitter plates. A bypass splitter plate is connected in a bypass circuit which conducts excessive current around a motor starter to protect the motor starter.
摘要:
A remote control residential and commercial lighting and appliance branch circuit breaker provides both overload current protection and load management. Structure is provided enabling packaging in a three-quarter inch width case, including a first set of contacts in the case provided by a pair of separable overload breaker contacts, trip structure in the case for causing separation of the overload breaker contacts in response to overload currents therethrough, a second set of contacts in the case provided by a pair of switching relay contacts having open and closed conditions and electrically connected in series with the overload breaker contacts, and an actuator in the case energizable to mechanically actuate the switching relay contacts. Feedback circuitry is included providing status indication of the condition of the switching relay contacts. Structure is provided for reducing actuator and spring requirements and sizes.
摘要:
A U-shaped or O-shaped metal strap (20, 30-32, 34) is attached in a belt-like manner around the insulating housing (2, 2') of a DC speed control switch to provide an external heat sink for a FET (22, 36) attached to the heat sink. Bosses (2f, 2h, 2g) on the switch housing project into holes (20e, 20b-32b, 34h, 34g) in the heat sink to position the heat sink on the housing. Formed terminal conductors on the FET plug into press-in terminations on the switch. A pair of mirror image battery clips (16) are trapped against opposite sides of the switch housing by the heat sink and an interposed insulator (18), the clips having cooperatively aligned depending legs (16e) forming battery terminal clips, and formed prongs (16c) that plug into press-in wire terminations on the switch. Holes (16d) in body portions of the battery clips surround bosses (2e) on the sides of the switch housing to interlock the clips against lateral movement.
摘要:
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 the movable contact carrier and an internal member (18) of the trigger operator, the internal member having a shaft (18a) projecting through an opening (2b) in an end wall of the housing which has a seal retaining cage (2c) formed thereon around the opening (26) the internal member being retractible to position the end of the shaft (18a) flush with the end wall for permitting a seal (22) and seal retaining cap (24) to be inserted to said cage, and an exterior trigger operator member (4) affixed to the end of the shaft.
摘要:
A formed pivot structure for a pivotally operable lever mounted in a bushing such as a toggle switch lever bushing. The pivot is provided by a suitable through-hole, opposite blind holes or circular groove in the enlarged portion of the lever into which thin portions of the bushing, either perforated or unperforated, are punched from opposite sides of the bushing. This provides a pair of aligned pivots affording free pivoting of the toggle lever in one plane while retaining it snugly from wobbling out of said plane. The pivot is formed by the method of forming opposite thin sections in the bushing, forming notches in the toggle lever such as the through-hole, opposite blind holes counter-sunk if desired, or circular beveled groove in the enlarged, partial-spherical portion of the toggle lever, inserting the toggle lever within the bushing and retaining it therein in position while two punches are actuated to form the thin sections of the bushing into the corresponding notches in the toggle lever for a close fit while allowing free pivoting of the toggle lever in one plane.
摘要:
A trigger speed control switch for use on portable tools having double-pole contacts with wiping action, larger contact opening gaps, screw-clamp terminals for connection of the power line conductors, a printed circuit board for mounting the speed control circuit, an adjustable trigger lock mechanism with detenting to hold it in adjusted position, and terminals for connecting a load device such as a motor as well as an external filter capacitor. A small version having all of these features is small enough for direct substitution for an on-off trigger switch as well as for universal portable tool application. A larger version having all of these features is adapted for substitution for present wired-components types of trigger speed control switches. In either case, modification of a given tool is not required to receive the double-pole trigger speed control switch.
摘要:
The snap-in mounting means includes a snap-in grommet carried on the shank of a bushing which extends from a switch frame mounted on a switch base of an electrical toggle switch assembly and pivotally supports a toggle lever for actuating switch contacts housed in the switch base. The snap-in grommet includes a radially yieldable sleeve slidably mounted on the lower end portion of the bushing shank, a tapered locking collar carried on the outer end of the sleeve and having a radially extending shoulder which engages the front of the panel around the panel mounting hole, after the collar has been squeezed through the hole during mounting, and a pair of opposed resilient back-up elements which are biased against the back of the panel to keep the locking collar shoulder in tight engagement with the front side of the panel. The bushing is pulled back after the locking collar has been squeezed through the panel mounting hole. As the bushing is moved axially relative to the grommet, a camming section on the outer end portion of the bushing having the shape of an inverted truncated cone cams the grommet sleeve radially outwardly into tight engagement with the inner wall of the hole to firmly lock the switch assembly to the panel. The bushing shank preferably includes a portion of reduced diameter between the lower end portion and the camming section so that, as the bushing is pulled back, the grommet sleeve slides onto the reduced portion with an audible snap, thereby providing a positive indication of the proper positioning of the grommet on the bushing.
摘要:
The snap-in mounting means includes a garter spring retained in an annular groove provided near the outer end of a bushing which extends from a switch frame on a switch base of an electrical toggle switch assembly and pivotally supports a toggle lever for actuating switch contacts housed in the switch. The garter spring has a helical diameter and an outermost toroidal diameter which is larger than the diameter of the mounting hole in a support panel on which the switch assembly is to be mounted. The bushing groove has an upper portion for retaining the garter spring in its normally expanded state, a lower portion of sufficient radial depth to receive the garter spring, when squeezed radially inwardly to a compressed state of reduced toroidal diameter without reducing the helical diameter, wherein the garter spring/bushing subassembly can pass through the panel mounting hole, and a tapered inner wall extending between the upper and lower portions.As the subassembly is pushed as a unit through the mounting hole from the rear of the panel, the garter spring engages the back rim of the hole and is squeezed into the compressed state in the lower portion of the bushing groove. The garter spring subsequently returns to its normally expanded state in the upper portion of the groove where a portion of the outer helical surface engages a front end of the mounting hole to retain the switch on the panel.
摘要:
A cam disc has a dual row of ratchet teeth on the periphery for dual rate of advancement by either of two oscillating motorized advance pawls. The disc has alternating high and low concentric cam tracks formed on one face. A plate is registered on the cam disc hub and has integrally formed plural resilient cam follower arms with each arm having a plastic cam track follower tip molded over the tip. The molded tips make contact with a stationary portion of the plate to limit follower travel when the cam is retracted by user movement of the shaft for setting the cam position. The high and low cam tracks engage adjacent follower arm pairs to effect a drop-to-make and drop-to-break action to each of a plurality of SPDT switches disposed for actuation by the cam followers.
摘要:
A two-pole switch for DC current has a housing formed by a pair of open shells abutting each other to enclose components of the apparatus. Each shell rigidly holds a stationary contact, and an actuator is pivotally coupled to the shells. A pair of movable contacts are pivotally attached to the actuator so that each movable contact touches one stationary contact when the actuator is in a first position and the contacts are separated when the actuator is in a second position. A spine plate is between the shells and electrically separates the two stationary contacts and arc extinguishing chambers. A solenoid is within the housing aligned with the contacts and drives the actuator between the second and first positions to close the contacts.