US2773146A - Pressure switch - Google Patents

Pressure switch Download PDF

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Publication number
US2773146A
US2773146A US470639A US47063954A US2773146A US 2773146 A US2773146 A US 2773146A US 470639 A US470639 A US 470639A US 47063954 A US47063954 A US 47063954A US 2773146 A US2773146 A US 2773146A
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US
United States
Prior art keywords
pressure
switch
transformer
movement
movable
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 - Lifetime
Application number
US470639A
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English (en)
Inventor
Louis E Sauer
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.)
Westinghouse Electric Corp
Original Assignee
Westinghouse Electric Corp
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
Priority to CA550139A priority Critical patent/CA550139A/en
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US470639A priority patent/US2773146A/en
Priority to DEW17900A priority patent/DE1052506B/de
Priority to JP3047754A priority patent/JPS321674B1/ja
Application granted granted Critical
Publication of US2773146A publication Critical patent/US2773146A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H35/00—Switches operated by change of a physical condition
    • H01H35/24—Switches operated by change of fluid pressure, by fluid pressure waves, or by change of fluid flow
    • H01H35/32—Switches operated by change of fluid pressure, by fluid pressure waves, or by change of fluid flow actuated by bellows
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/26—Means for detecting the presence of an arc or other discharge

Definitions

  • This invention relates to relays and, in particular, to pressure and/or rate of pressure change responsive relays for efiecting the disconnection of a transformer from a power source when a fault occurs within the transformer.
  • An object of this invention is to provide a new and improved relay that is responsive to two operating conditions.
  • Another object of this invention is to provide a pressure responsive relay which effects an operation in re sponse to both a sudden increase in pressure and to a predetermined pressure, but not to gradual increases in pressure.
  • a further object of this invention is to provide for increasing the speed of response of a pressure responsive relay.
  • Still another object of this invention is to provide a pressure responsive relay which has a high speed of response and yet a minimum of maintenance.
  • Another object of this invention is to provide a pres sure responsive relay which is so constructed and associated with a transformer tank that normal movement of the transformer tank wall, due to changes in pressure within the tank, has substantially no adverse effect on the operation of the pressure responsive relay.
  • a more specific object of this invention is to provide for so associating a pivoted arm member having a switch mounted thereon with pressure responsive means and with a stop member that the inertia of the pivoted arm mem' ber prevents its movement on sudden pressure changes to thus effect an actuation of the switch, and yet permits bodily movement of the switch in response to gradual changes in pressure until the stop member prevents its further movement and thus permits the pressure responsive means to effect an actuation of the switch.
  • Fig. 1 is a schematic diagram of a transformer embodying the teachings of this invention
  • Fig. 2 is a view partly in section taken along the line Ii-ll of Fig. 1;
  • FIG. 3 is a detail view of the microswitch shown in Fig. 1 with cover off.
  • the transformer 10 comprises a receptacle or transformer tank 12 within which is disposed a magnetic core member 14 having primary windings 16 and 17 disposed in inductive relationship therewith.
  • the transformer tank 12 is of the form-fit type, however, it is to be understood that other types of receptacles or tanks are equally applicable to this invention.
  • a dielectric fluid such as transformer oil 18, is disposed in the tank 12.
  • the pressure within the tank 12 may increase gradually due to for instance changes in ambient temperature or changes in the load on the transformer. This effects an increase in the total pressure within the tank 12.
  • a fault produces impulse changes in pressure of varying magnitude, but does not materially effect the total pressure within the tank 12.
  • a protective device or pressure responsive relay 20 is provided to effect a deenergization of the transformer Iii when the pressure of the transformer oil 18 suddenly increases, or when the pressure of the transformer oil 18 increases to a predetermined value under normal operating conditions.
  • the pressure responsive relay 21 does not immediately effect a deenergization of the transformer 10 when gradual increases in the magnitude of the pressure of the transformer oil 18 occur.
  • the transformer 16 is protected from faults of large or small magnitude and from gradual increases in pressure which continue for a relatively long period of time so as to increase the transformer oil pressure to a predetermined value.
  • Deenergization of the transformer 10 is effected by a circuit breaker 22 which is responsive to the operation of the pressure responsive relay 20.
  • the circuit breaker 22 is shown schematically and comprises movable and stationary contact members 24- and 26, respectively, a trip mechanism 28, and a handle 29 for effecting a manual resetting of the circuit breaker 22.
  • the trip mechanism 28 includes a magnetic core member 30, the positioning of which is determined by the energization of an operating coil 32.
  • a compression spring 34 is provided in order to effect a return of the magnetic core member 30 to its normal position after having been actuated as a result of current flow through the operating coil 32.
  • the pressure responsive relay 20 comprises pressure responsive means 44 responsive to changes in the pressure of the transformer oil 18, a movable switch 46 normally biased to a predetermined position by gravity, the pressure responsive means 44 being disposed to effect an actuation of the movable switch 46 in response to sudden changes in the pressure of the transformer oil. and effect a bodily movement of the movable switch 46. without actuating the switch 46, in response to gradual changes in the pressure of the transformer oil 18, and a stop member for limiting the bodily movement of the movable switch 46 so that the pressure responsive means 44 can effect an actuation of the movable switch 46.
  • the pressure responsive means 44 comprises a metallic Sylphon bellows Stl having a base member 52.
  • the end opposite the base member 52 is suitably secured to a plate member 54 which carries an ad justing-nutPSS having a passageway 56 for'receiving an actuating member or a switch operating rod 56' which is suitably secured to the base member 52 for movement therewith.
  • the passageway 56 is of such diameter that the interior of the Sylphon bellows 54 is exposed to atmospheric pressure and, thus, owing to a minimum of inertia, quickly responds to a change in the pressure of the transformer oil 18.
  • the exterior of the Sylphon bellows 56 is exposed only to the pressure of the transformer oil 18, the transformer tank 12 being sealed off to atmospheric pressure.
  • a compression spring 60 is disposed around the switch operating rod'Sti and between the adjusting nut 55 and the base member 52 of the Sylphon bellows 56.
  • the strength of the compression spring 60 determines the pressure range over which the pressure responsive relay 20 will effectively operate. That is, the higher the expected pressure of the transformer oil 18 at the relay location, the greater must be the resisting force of the compression spring 66.
  • the adjusting nut 55 is provided.
  • the nut 55 threadedly engages the plate 54 and bears against the end of the compression spring 64 The higher the head of oil 18 the further is the nut 55 screwed into the plate 54. Thus, irrespective of the magnitude of the head of oil 18, the positioning of the rod 58 with respect to the movable switch 46 is maintained.
  • the movable switch 46 is mounted for movement with a pivoted arm 62 which pivots about a pivot point 64. Also mounted for movement with the pivoted arm 62 is a mass or adjustable nut 65. Specifically, the adjustable nut 65 threadedly engages the end of the pivoted arm 62. Thus, the distance of the nut 65 from the pivot point 64 can be readily varied. in order toprevent movement of the adjustable nut 65 with respect to the pivoted arm 62 once the desired position of the nut 65 has been obtained, a lock nut 68 is provided.
  • the pivoted arm 62. the movable switch 46, the adjustable nut 65, and the lock nut 66 comprise an unbalanced mass whose inertia can be changed by varying the position of the adjustable nut 65 along the length of the pivoted arm 62-. For instance, if the distance between the adjustable nut 65 and the pivot point 64 is decreased, the inertia of the unbalanced mass is likewise decreased, to thereby require a more rapid rate of increase, or a more sudden increase in the pressure of the transformer oil 318. in order to effect an actuation of the movable switch 46. Thus, by adjusting the nut 65, the value of rate of increase of pressure at which the movable switch 46 is actuated under sudden increases in transformer oil. pressure can be varied. It is to be noted that due to the above-described structure, the operating pin 69 of the movable switch 46 remains in contact with the end of the rod 56 irrespective of the pressure of the oil 18 surrounding the bellows 44.
  • the reason that the switch operating rod 58 is able to effect an actuation of the movable switch 46 when sudden increases in the transformer oil pressure occur is that the inertia of the unbalanced mass, which includes the movable switch 46, is greater than the switch operating force needed to effect an actuation of the movable switch 46.
  • the switch operating force as effected by the switch operating rod 5
  • the switch operating force is not of sufiicient magnitude to effect an actuation of the movable switch 46 and as a result, the movable .witch 46 is bodily moved until its further movement is prevented by the stop member 425.
  • the movable switch 4: 46 is actuated by the switch operating rod 58, as will be explained more fully hereinafter.
  • the movable switch 46 is a microswitch and comprises a stationary contact member '70, a movable contact member 72 carried by a snap acting leaf spring 7d which in normal operation biases the movable contact member '72 to the open position with respect to the stationary Contact member 76, and the operating pin 69 which actuates the snap actin leaf spring 74 in response to the outward movement of the switch operating rod 56.
  • the stop member 43 comprises an L-shaped bracket 78, one end of which is suitably secured to the plate member 54, an adjustable screw fill carried by the bracket 78, and a lock nut 32 provided to prevent movement of the adjustable screw 8t) with respect to the bracket '78 once the screw 86 has been properly adjusted.
  • the position of the end of the screw 39 with respect to the movable switch 46 determines at what total transformer oil pressure the movable switch 46 will be actuated. For instance, the closer the end of the screw 80 to the movable switch 46, the lower will be the pressure of the transformer oil 18 at which the movable switch 46 is actuated.
  • the apparatus embodying the teachings of the invention has several advantages. For instance, even though a pressure wave front effects a slight movement of the transformer tank wall associated with the pressure responsive device 20 still owing to the inertia of the unbalanced mass, which includes the movable switch 46, there is substantially no movement of the switch 46.
  • the speed of response of the pressure responsive means 20 is maintained at a high value.
  • the pressure responsive means 20 comprises few components which can be readily manufactured and assembled. Further, the pressure responsive means 20 is readily adaptable to transformers of different power ratings.
  • a receptacle containing a fluid under pressure, an arm pivoted about a predetermined pivot point, a switch having operating means for effecting an actuation of the switch, the switch being mounted on the pivoted arm for movement therewith, a mass also mounted on the pivoted arm for movement therewith, said mass being adjustable so that its distance from the pivot point can be varied, pressure responsive means including an actuating member disposed to engage and effect an actuation of said switch operating means, said actauting member being responsive to the pressure of the fluid for actuating the switch in response to sudden changes in fluid pressure and for effecting bodily movement of the pivoted arm and switch, without actuating the switch, in response to gradual changes in the fluid pressure, and means for limiting the movement of the switch so that the said actuating member can effect an actuation of the switch when the fluid pressure reaches a predetermined value.
  • a receptacle containing a fluid under pressure, an arm pivoted about a predetermined pivot point and having threads on the end thereof opposite the pivot point, a nut disposed on the threaded end of the pivoted arm, the nut being adjustable so that its distance from the pivot point can be varied, a switch having operating means for effecting an actuation of the switch, the
  • pressure responsive means including an actuating member disposed to engage and effect an actuation of said switch operating means, said actuating member being responsive to the pressure of the fluid for actuating the switch in response to sudden changes in fluid pressure and for effecting bodily movement of the pivoted arm and switch, without actuating the switch, in response to gradual changes in the fluid pressure, and means for limiting the movement of the switch so that the said actuating member can effect an actuation of the switch when the fluid pressure reaches a predetermined value.
  • a receptacle containing a fluid under pressure, an arm pivoted about a predetermined pivot point and having threads on the end thereof opposite the pivot point, a nut disposed on the threaded end of the pivoted arm, the nut being adjustable so that its distance from the pivot point can be varied, a switch having operating means for eflecting an actuation of the switch, the switch being mounted on the pivoted arm for movement therewith, pressure responsive means including a Sylphon bellows having a base member and an actuating member carried by the base member and disposed to engage and effect an actuation of said switch operating means, said actuating member being responsive to the pressure of the fluid for actuating the switch in response to sudden changes in fluid pressure and for effecting bodily movement of the pivoted arm and switch, without actuating the switch, in response to gradual changes in the fluid pressure, and means for limiting the movement of the switch so that the said actuating member can effect an actuation of the switch when the fluid pressure reaches a predetermined value.

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  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
  • Housings And Mounting Of Transformers (AREA)
US470639A 1954-11-23 1954-11-23 Pressure switch Expired - Lifetime US2773146A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
CA550139A CA550139A (en) 1954-11-23 Pressure responsive relays
US470639A US2773146A (en) 1954-11-23 1954-11-23 Pressure switch
DEW17900A DE1052506B (de) 1954-11-23 1955-11-22 Auf schnellen Druckanstieg und/oder allmaehlich aber eine gewisse Druckhoehe uebersteigende Druckaenderungen ansprechende elektrische Schalt- und Schutzeinrichtung fuer fluessigkeitsgefuellte Behaelter
JP3047754A JPS321674B1 (en, 2012) 1954-11-23 1955-11-30

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US470639A US2773146A (en) 1954-11-23 1954-11-23 Pressure switch

Publications (1)

Publication Number Publication Date
US2773146A true US2773146A (en) 1956-12-04

Family

ID=54601531

Family Applications (1)

Application Number Title Priority Date Filing Date
US470639A Expired - Lifetime US2773146A (en) 1954-11-23 1954-11-23 Pressure switch

Country Status (4)

Country Link
US (1) US2773146A (en, 2012)
JP (1) JPS321674B1 (en, 2012)
CA (1) CA550139A (en, 2012)
DE (1) DE1052506B (en, 2012)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3277341A (en) * 1958-11-26 1966-10-04 Deutschmann Tobe Energy storage capacitors and associated circuitry
US3366838A (en) * 1964-11-03 1968-01-30 Messwandler Bau Gmbh Pressure and current responsive protection device for a cascaded transformer arrangement
US3816801A (en) * 1973-01-11 1974-06-11 Westinghouse Electric Corp Electrical transformer
US4001644A (en) * 1975-03-27 1977-01-04 Westinghouse Electric Corporation Sudden pressure relay having seismic protection
FR2402932A1 (fr) * 1977-09-09 1979-04-06 Westinghouse Electric Corp Protection contre les surpressions pour appareils electriques refroidis par vaporisation
US20100065261A1 (en) * 2008-09-17 2010-03-18 General Electric Company System with directional pressure venting
US20100065306A1 (en) * 2008-09-17 2010-03-18 General Electric Company Rupture resistant system
US9159482B2 (en) 2008-09-17 2015-10-13 General Electric Company Rupture resistant tank system
CN111326367A (zh) * 2018-12-17 2020-06-23 Abb瑞士股份有限公司 用于中压或高压开关设备的过压释放阀瓣装置

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL249491A (en, 2012) * 1959-03-26
FR2452175A1 (fr) * 1979-03-23 1980-10-17 Alsthom Unelec Sa Appareil electrique de coupure dans l'air muni d'un dispositif indicateur de court-circuit

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2094319A (en) * 1935-08-31 1937-09-28 Bristol Company Sanitary pressure operated device
US2357878A (en) * 1943-01-21 1944-09-12 Hotstream Heater Co Pressure control device
US2648741A (en) * 1950-06-09 1953-08-11 Meletron Corp Pressure operated temperature responsive switch
US2658122A (en) * 1950-01-27 1953-11-03 Cleveland Fuel Equipment Compa Pressure switch

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB698069A (en) * 1947-11-14 1953-10-07 Westinghouse Electric Int Co Improvements in or relating to pressure sensitive electrical apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2094319A (en) * 1935-08-31 1937-09-28 Bristol Company Sanitary pressure operated device
US2357878A (en) * 1943-01-21 1944-09-12 Hotstream Heater Co Pressure control device
US2658122A (en) * 1950-01-27 1953-11-03 Cleveland Fuel Equipment Compa Pressure switch
US2648741A (en) * 1950-06-09 1953-08-11 Meletron Corp Pressure operated temperature responsive switch

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3277341A (en) * 1958-11-26 1966-10-04 Deutschmann Tobe Energy storage capacitors and associated circuitry
US3366838A (en) * 1964-11-03 1968-01-30 Messwandler Bau Gmbh Pressure and current responsive protection device for a cascaded transformer arrangement
US3816801A (en) * 1973-01-11 1974-06-11 Westinghouse Electric Corp Electrical transformer
US4001644A (en) * 1975-03-27 1977-01-04 Westinghouse Electric Corporation Sudden pressure relay having seismic protection
FR2402932A1 (fr) * 1977-09-09 1979-04-06 Westinghouse Electric Corp Protection contre les surpressions pour appareils electriques refroidis par vaporisation
US20100065261A1 (en) * 2008-09-17 2010-03-18 General Electric Company System with directional pressure venting
US20100065306A1 (en) * 2008-09-17 2010-03-18 General Electric Company Rupture resistant system
US8710946B2 (en) * 2008-09-17 2014-04-29 General Electric Company Rupture resistant system
US8717134B2 (en) 2008-09-17 2014-05-06 General Electric Company System with directional pressure venting
US9159482B2 (en) 2008-09-17 2015-10-13 General Electric Company Rupture resistant tank system
CN111326367A (zh) * 2018-12-17 2020-06-23 Abb瑞士股份有限公司 用于中压或高压开关设备的过压释放阀瓣装置
EP3671788A1 (en) * 2018-12-17 2020-06-24 ABB Schweiz AG Overpressure relief flap apparatus for a medium or high voltage switchgear
EP4109481A1 (en) * 2018-12-17 2022-12-28 Abb Schweiz Ag Overpressure relief flap apparatus for a medium or high voltage switchgear

Also Published As

Publication number Publication date
CA550139A (en) 1957-12-10
JPS321674B1 (en, 2012) 1957-03-12
DE1052506B (de) 1959-03-12

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