US2276885A - Thermally operated electric switch - Google Patents

Thermally operated electric switch Download PDF

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Publication number
US2276885A
US2276885A US319520A US31952040A US2276885A US 2276885 A US2276885 A US 2276885A US 319520 A US319520 A US 319520A US 31952040 A US31952040 A US 31952040A US 2276885 A US2276885 A US 2276885A
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US
United States
Prior art keywords
spring
contacts
contact
plate
ramp
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
US319520A
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English (en)
Inventor
Sherlock John Edward
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Individual
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Individual
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Filing date
Publication date
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Application granted granted Critical
Publication of US2276885A publication Critical patent/US2276885A/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
    • H01H5/00—Snap-action arrangements, i.e. in which during a single opening operation or a single closing operation energy is first stored and then released to produce or assist the contact movement
    • H01H5/04—Energy stored by deformation of elastic members
    • H01H5/045—Energy stored by deformation of elastic members making use of cooperating spring loaded wedging or camming parts between operating member and contact structure
    • 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
    • H01H35/26—Details
    • H01H35/2607—Means for adjustment of "ON" or "OFF" operating pressure
    • H01H35/2614—Means for adjustment of "ON" or "OFF" operating pressure by varying the bias on the pressure sensitive element
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H37/00—Thermally-actuated switches
    • H01H37/02—Details
    • H01H37/12—Means for adjustment of "on" or "off" operating temperature
    • H01H37/26—Means for adjustment of "on" or "off" operating temperature by adjustment of abutment for "off" position of the movable contact
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H37/00—Thermally-actuated switches
    • H01H37/02—Details
    • H01H37/60—Means for producing snap action
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/20—Control lever and linkage systems
    • Y10T74/20576—Elements
    • Y10T74/20636—Detents

Definitions

  • This invention relates to thermally operated electrical switch devices and has for its object to provide an improved construction or arrangement thereof designed to enable the making or breaking of engagement of the contact members to be effected by a snap action and to avoid the disadvantage of a decrease in pressure on the contact members prior to the moment of breaking contact.
  • a thermally operated electrica1 switch device comprising a member having a double ramp thereon, a spring pressed component engaging said member and a thermostatic control element adapted to cause movement of the double ramp member or the spring pressed component whereby the recoil of the spring or springs compressed by the action of the first portion of the ramp is converted by the action of the second portion of the ramp into a sudden movement or snap action to open or close electrical contact elements.
  • a thermally operated electrical switch device comprising a thermostatic control element adapted to cause movement of a spindle having a double ramp formed thereon and a movable switch contact carrying member having elements in spring pressed engagement with said spindle and so arranged that the recoil of a spring compressed by the action of the first part of the ramp is converted by the action of the second part of the ramp into a sudden movement of the said contact carrying member to open or close the switch.
  • a thermally operated electrical switch device comprising fixed and movable contact members, a thermostatic control element adapted to operate the movable contact member by a snap action to open or close the switch and means associated with the operating mechanism to cause the pressure on the contact members to increase up to the moment of breaking contact.
  • Fig. 1 is a sectional plan
  • Fig. 2 is a section taken on the line A-B of Fig. 1.
  • control part consists of a slidable push rod a guided in a casing b and bearing at one end against a flexible metal bellows c and at the other end against a disc or plate 11 supporting a control spring e the pressure of which can be adjusted by means of a regulating screw I mounted co-axially with the push rod a and carrying a collar g bearing upon one end of the spring e, the said collar being prevented from turning by engagement with a rod h.
  • a snap action unit comprising a plate 1' supporting a housing 7 in which three plungers is set at angles of apart are arranged so that they press radially inwards (as shown in Fig. 2) against a double ramp 1 formed on the push rod (1.
  • the plungers k are pressed inwards by a common spring in the form of an endless tension spring m passing round all the plungers and bearing directly upon their outer ends.
  • the double ramp consists of two frustoconical surfaces set base to base so as to provide a ridge at the point of transition from one surface to the other as shown in Fig. l.
  • the aforesaid plate i may be guided by the push rod or by a part of the casing, but it is preferred to provide an odd number of spring-pressed plungers, say three as shown and to leave sufficient clearance between the plate 1 and the push rod a and surrounding parts to prevent any contact of the plate i with parts which might exert a frictional drag during the snap-action movement.
  • the movement of the aforesaid plate 1' is limited in one direction by the engagement of a number of electrical contacts 12 on one face of the plate with fixed contacts 0 mounted in an annular flange p in the casing and in the other direction by a stop which may consist of a flanged sleeve q slidably mounted in the casing co-axially with the push rod.
  • the sleeve q is controlled by a screw r accessible from the forward end s of the casing for the purpose of displacing the sleeve and thus adjusting the differential of the instrument.
  • any number of electrical contacts may be operated by the device but it is preferred to provide three contacts so as to ensure that all contacts can be closed simultaneously in spite of slight inaccuracies of adjustment of the fixed contacts 0 which might involve a slight tilting of the plate 1'. If two contacts only are desired, suitable stops may be provided to limit the tilting movement of the plate 1 about a line joining the two contacts proper. For a three phase switch in which three pairs of contacts may be required to be bridged simultaneously by three pairs of contacts on the plate z, the members of each pair of fixed contacts may be set close together so that the contact between the six fixed contacts and the plate 1' approximates to a three point contact.
  • the adjusting screw 1 which controls the pressure of the control spring 2 is operated by a hand wheel or knob 15 associated with a graduated scale.
  • the hand wheel t is attached to a sleeve u coupled to the adjusting screw f by means of a friction clutch 1) which can be released by pressing the screw 1 axially inwards against the pressure of the control spring 6.
  • the hand wheel t is attached to the sleeve u by means of an axial screw w which engages directly in the end of the adjusting screw and clamps the adjusting screw 1, the sleeve u and hand wheel t securely together.
  • the said axial screw to is accessible from the front of the hand wheel 75 and its removal permits the hand wheel to be detached so that access can be gained to the end of the adjusting screw f by means of a screw driver or other tool for causing a screw a: mounted within the adjusting screw to be caused to project more or less beyond the inner end of the adjusting screw for the purpose of adjusting the range of the instrument.
  • the aforesaid sleeve u may carry a cam or ramp 1/ adapted to co-operate with a part fixed to the casing and arranged to push the sleeve u inwards through a sufficient distance to cause the inner end of the adjusting screw 1 or a screw in to abut against the push rod 01. and to move the same to the off position.
  • This mechanism is arranged to come into action only when the hand wheel t is rotated to an extreme position.
  • a thermally operated electrical switch device comprising a thermostatic control element, a spindle responsive to the movements of said element, a double conical ramp formed on said spindle, a housing, fixed electrical switch contact elements within said housing, a ring freely mounted around said spindle, a plurality of plungers equidistantly spaced around and movable radially within said ring, spring means maintaining the inner ends of said plungers in contact with one or the other of the coned surfaces of said ramp and guiding said ring for movement axially of said spindle, movable electrical switch contact elements carried by said ring and movable thereby into and out of operative engagement with said fixed contacts, and means for varying the extent of movement of said ring in the direction which disengages said contacts to thereby adjust the temperature differential of the device.

Landscapes

  • Thermally Actuated Switches (AREA)
US319520A 1939-02-20 1940-02-17 Thermally operated electric switch Expired - Lifetime US2276885A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5623/39A GB525106A (en) 1939-02-20 1939-02-20 Improvements in or relating to thermally operated electric switches

Publications (1)

Publication Number Publication Date
US2276885A true US2276885A (en) 1942-03-17

Family

ID=9799560

Family Applications (1)

Application Number Title Priority Date Filing Date
US319520A Expired - Lifetime US2276885A (en) 1939-02-20 1940-02-17 Thermally operated electric switch

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US (1) US2276885A (en))
BE (1) BE463147A (en))
FR (1) FR921979A (en))
GB (1) GB525106A (en))

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2446355A (en) * 1944-07-20 1948-08-03 Jeffrey Mfg Co Detent mechanism for pressure regulators
US2511640A (en) * 1946-09-30 1950-06-13 Cutler Hammer Inc Circuit controlling device
US2591993A (en) * 1947-10-07 1952-04-08 Peterson Co Carl G Multipawl feed mechanism
US2716902A (en) * 1949-10-19 1955-09-06 Bingham Herbrand Corp Mechanism control
US3062071A (en) * 1959-12-29 1962-11-06 Warren P Morrow Actuator for triggering system
DE1153439B (de) * 1961-03-01 1963-08-29 Busch Jaeger Duerener Metall Temperaturabhaengiger elektrischer Schalter mit topffoermigem Isolierstoffgehaeuse und von aussen einsetzbarer Druckdose
US3295468A (en) * 1962-10-16 1967-01-03 Thomas E Belshaw Dough forming machine

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2446355A (en) * 1944-07-20 1948-08-03 Jeffrey Mfg Co Detent mechanism for pressure regulators
US2511640A (en) * 1946-09-30 1950-06-13 Cutler Hammer Inc Circuit controlling device
US2591993A (en) * 1947-10-07 1952-04-08 Peterson Co Carl G Multipawl feed mechanism
US2716902A (en) * 1949-10-19 1955-09-06 Bingham Herbrand Corp Mechanism control
US3062071A (en) * 1959-12-29 1962-11-06 Warren P Morrow Actuator for triggering system
DE1153439B (de) * 1961-03-01 1963-08-29 Busch Jaeger Duerener Metall Temperaturabhaengiger elektrischer Schalter mit topffoermigem Isolierstoffgehaeuse und von aussen einsetzbarer Druckdose
US3295468A (en) * 1962-10-16 1967-01-03 Thomas E Belshaw Dough forming machine

Also Published As

Publication number Publication date
FR921979A (fr) 1947-05-23
GB525106A (en) 1940-08-21
BE463147A (en))

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