GB476276A - Improvements in or relating to thermally-controlled electric circuit-breakers - Google Patents

Improvements in or relating to thermally-controlled electric circuit-breakers

Info

Publication number
GB476276A
GB476276A GB941/37A GB94137A GB476276A GB 476276 A GB476276 A GB 476276A GB 941/37 A GB941/37 A GB 941/37A GB 94137 A GB94137 A GB 94137A GB 476276 A GB476276 A GB 476276A
Authority
GB
United Kingdom
Prior art keywords
circuit
support
contacts
resetting
motor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB941/37A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Leland Electric Co
Original Assignee
Leland Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Leland Electric Co filed Critical Leland Electric Co
Publication of GB476276A publication Critical patent/GB476276A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10Operating or release mechanisms
    • H01H71/12Automatic release mechanisms with or without manual release
    • H01H71/14Electrothermal mechanisms
    • H01H71/20Electrothermal mechanisms with fusible mass
    • H01H71/205Electrothermal mechanisms with fusible mass using a ratchet wheel kept against rotation by solder
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10Operating or release mechanisms

Landscapes

  • Thermally Actuated Switches (AREA)
  • Protection Of Generators And Motors (AREA)
  • Fuses (AREA)

Abstract

476,276. Thermal switches; automatic circuit breakers ; protective cut - out systems. LELAND ELECTRIC CO. Jan. 12, 1937, No. 941. Convention date, Feb. 13, 1936. [Class 38 (v)] An automatic circuit-breaker for protecting a motor or similar device from injury by excessive heat comprises a contactor 17 biassed to circuit-opening position, a controlling member 22 adapted to move the contactor to circuit-closing position and to be moved in the other direction by the contactor when the circuit opens, a support 20 for the member 22, means such as a one-way clutch interposed between the member and the support to permit movement of the member in the circuitclosing direction and normally prevent the movement of the member in the other direction and a thermal element adapted to release the controlling member for movement in the circuit-opening direction when subjected to abnormal temperature. In the arrangement shown, the circuit-breaker is mounted on an insulating base 15 inside the casing 10 of a motor to be protected, and comprises a pair of movable contactors 17, 17a co-operating with normally stationary but yieldable contacts 16, 16a, both movable contactors being under the control of the controlling member 22. The support 20 is mounted on a stud 18 which forms one end of a heat conducting rod 19, and is normally secured to the stud by a fusible binder 21 of solder of low melting point. The one-way clutch between the member 22 and its support 20 comprises a spring 24 coiled about and attached to a reduced portion 23 of the support 20, the spring being in frictional engagement with the inner surface of the member 22, so that the tendency of the member to rotate in the circuit-opening direction will expand the spring and cause it to act as a clutch. The contactors 17, 17a are in the form of curved springs secured at one end to studs 25, 27, while the other ends of the springs engage lugs 28 on the controlling member 22, as shown in Fig. 5, and tend to rotate the member to the circuit-opening position. If the temperature rises to a point sufficient to meet the binder 21, the support 20 is released and the contactors together with the controlling member rotate to the open position. When the temperature falls, the binder resets, and the controlling member can be rotated in the opposite direction to reclose the circuit. For this purpose a resetting member 29 is rotatably mounted on the outer end of the controlling member 22, and is provided with radial lugs 30 adapted to engage lugs 31 on the controlling member, which extend outwardly beyond the lugs 28. The resetting member also carries curved insulating flanges 32 which are moved between the stationary and movable contacts when the resetting member is rotated in the closing direction, so that the circuit does not close until the resetting member has been retracted into its inoperative position and it is impossible to hold the circuit closed by hand. The resetting member may be used to open the circuit at any time by rotating it to its operative position, in which it is held by the friction between the flanges and the stationary contacts until it is positively withdrawn. The resetting member may be arranged to project through the casing of the motor so as to be directly operable by hand, but in the construction shown, a separate actuating member 33 is provided, having a knob 35 outside the casing and a tongue and groove connection with the resetting member. In a modification, Fig. 10 (not shown), the stationary and movable contacts of each pair are formed in one piece and supported by a single terminal stud. The application of the circuit-breaker to a motor having a main winding 48 and an auxiliary starting winding 54 is shown in Fig. 11. In this application, the contacts 16, 17 are connected in the starting circuit, which circuit also includes a heating coil 36 mounted on the rod 19. The contacts 16a, 17a are in the circuit of the main winding 48. When the motor has run up to speed, a centrifugal switch 37 automatically interrupts the starting circuit.
GB941/37A 1936-02-13 1937-01-12 Improvements in or relating to thermally-controlled electric circuit-breakers Expired GB476276A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US476276XA 1936-02-13 1936-02-13

Publications (1)

Publication Number Publication Date
GB476276A true GB476276A (en) 1937-12-06

Family

ID=21950021

Family Applications (1)

Application Number Title Priority Date Filing Date
GB941/37A Expired GB476276A (en) 1936-02-13 1937-01-12 Improvements in or relating to thermally-controlled electric circuit-breakers

Country Status (2)

Country Link
FR (1) FR476276A (en)
GB (1) GB476276A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3626770A1 (en) * 1986-08-07 1988-02-11 Braun Ag FUSE PROTECTION, ESPECIALLY FOR ELECTRIC MOTORS

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3626770A1 (en) * 1986-08-07 1988-02-11 Braun Ag FUSE PROTECTION, ESPECIALLY FOR ELECTRIC MOTORS
US4789800A (en) * 1986-08-07 1988-12-06 Braun Aktiengesellschaft Fuse, in particular for electric motors

Also Published As

Publication number Publication date
FR476276A (en) 1915-07-22

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