US2814685A - Snap action device - Google Patents

Snap action device Download PDF

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Publication number
US2814685A
US2814685A US542985A US54298555A US2814685A US 2814685 A US2814685 A US 2814685A US 542985 A US542985 A US 542985A US 54298555 A US54298555 A US 54298555A US 2814685 A US2814685 A US 2814685A
Authority
US
United States
Prior art keywords
sheet
edge
snap action
movement
corrugations
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
US542985A
Other languages
English (en)
Inventor
Theodore N Flight
Arthur J Chinn
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.)
Rheostatic Co Ltd
Original Assignee
Rheostatic Co Ltd
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 Rheostatic Co Ltd filed Critical Rheostatic Co Ltd
Application granted granted Critical
Publication of US2814685A publication Critical patent/US2814685A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/19—Control of temperature characterised by the use of electric means
    • G05D23/275—Control of temperature characterised by the use of electric means with sensing element expanding, contracting, or fusing in response to changes of temperature
    • G05D23/27535—Details of the sensing element
    • G05D23/27541—Details of the sensing element using expansible solid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H35/00—Gearings or mechanisms with other special functional features
    • F16H35/14—Mechanisms with only two stable positions, e.g. acting at definite angular positions
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/01—Control of temperature without auxiliary power
    • G05D23/02—Control of temperature without auxiliary power with sensing element expanding and contracting in response to changes of temperature
    • G05D23/024—Control of temperature without auxiliary power with sensing element expanding and contracting in response to changes of temperature the sensing element being of the rod type, tube type, or of a similar type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/02—Details
    • H01H13/26—Snap-action arrangements depending upon deformation of elastic members
    • H01H13/36—Snap-action arrangements depending upon deformation of elastic members using flexing of blade springs
    • 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
    • Y10T74/18—Mechanical movements
    • Y10T74/18856—Oscillating to oscillating
    • Y10T74/18864—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
    • Y10T74/18—Mechanical movements
    • Y10T74/18856—Oscillating to oscillating
    • Y10T74/18864—Snap action
    • Y10T74/18872—Plate spring

Definitions

  • This invention is concerned with snap action devices comprising an internally stressed metal sheet in which a snap movement of one part of the sheet is derived from the sudden release of stress imposed by the gradual movement of an actuator applied to another part of the sheet.
  • Such snap action devices have been made from a sheet of metal by cutting slots adjacent to two parallel edges and corrugating or twisting the edge limbs so formed to place these limbs in tension and the centre limb in compression. They have also been made by forming a sheet with two parallel slots originating at one edge of the strip and terminating before reaching the opposite edge so as to form three parallel limbs. The two outer limbs are then placed in tension and the middle limb in compression with its free end pressing against a pivot support. Alternatively the outer limbs of such a sheet have been fixed to a base in such manner as to deform the slots from parallel to tapering thus putting the sheet in an unstable condition.
  • an internally stressed metal sheet or strip is made from a metal sheet without slotting or cutting but by forming intermediate the length of the sheet several corrugations running from side to side of the sheet and flattening the corrugations slightly where they meet the edge of the sheet, thus putting the two parallel corrugated edges in compression compared with the centre corrugated portion.
  • This extra length of metal at the edges resulting from the slight flattening of the corrugations is accommodated by a twisting action on the sheet, the two sides concerned twisting in opposite directions causing the edges of the sheet parallel to the corrugations to lie at an angle to one another.
  • Fig. 1 is a plan view of a rectangular sheet formed in the manner described while Fig. 2 is a side elevation of such a formed sheet, the twist being accentuated in the drawing to make the action clear.
  • Figs. 3 and 4 are side elevation and plan views respectively, of a simple snap action switch in which the formed sheet is supported at one end the opposite end, of the sheet carrying one contact on an extension of one corner while the initiating force or movement is applied to the sheet at .a point at the same end.
  • Figs. 5, 6 and 7 are end view, side view and plan view respectively, of a construction in which the snap action is self-returning on the removal of the initiating force.
  • Fig. 8 is an elevational view partly in section which illustrates the application of the device to a gas control thermostat.
  • A indicates the formed sheet of metal.
  • four corrugations are indicated at 1, 2, 3, 4, the variation of shading indicating the reduction of the depth of corrugation at the edges of the strip which produces the stress within the strip to cause it to take the form shown in Fig. 2.
  • the sheet A is supported across its width at one end while a contact 5 carried by the sheet presses against a contact 6 which is so positioned as to arrest the movement of contact 5 before the sheet has moved to its position of final equilibrium thus producing pressure between the contacts 5 and 6.
  • An actuator indicated by the arrows 7 engages the sheet at a point at the same end of the sheet as the contact. As this actuator 7 is moved slowly up and down, the corner carrying contact 5 of the sheet passes with a snap action from pressing on contact 6 to pressing against a backstop 8 which is in turn positioned to arrest the sheet before it has passed to its second equilibrium position.
  • both corners of one end of the sheet A are extended as indicated clearly in Fig. 7 to carry contacts 9 and 10 co-acting alternately with contacts 11 and 12 mounted on a base B.
  • the centre point of the width of the sheet between the contacts 11 and 12 is supported at 13 from the base B and is held in contact at this centre point by a spring tongue 14 extending from a plate C supported from the base B, the tongue pressing on the top of the sheet A.
  • the formed sheet A is shown as supported at one corner 17 of the sheet by a post 18 rising from the instrument base 19. Pressure is applied to the sheet near support point 17 by a tongue as indicated at 20. Extending from the base 19 is a tube 21 of relatively high expansion metal joined at its end remote from the base to a relatively non-expanding rod 22 which is brought through the base to press the sheet A at a point 23 intermediate the pressure point at and the edge of the sheet and in opposition to pressure at point 20. A valve disc 24 is attached to the sheet A at the diagonal corner from that at which the rod 22 presses on the sheet. The valve seat is shown at 25 and the gas inlet and outlet ports are indicated at 26--27.
  • pressure at point 20 is so set that as the pressure of rod 22 is reduced due to the heating of the expanding tube 21 the corrugated sheet A takes up the position shown in the drawing in which the corner of the sheet carrying the valve 24 has moved towards the base and closed the inlet port 26. A gradual fall in temperature of the tube 21 moves the rod 22 to press on the sheet until the opposite end carrying the valve 24 moves with snap action to open the valve.
  • the initiating movement applied to the sheet is generated by diflerential expansion of metals with temperature change
  • the initiating movement may be generated by the expansion of a capsule or bellows with pressure change associated with the capsule or bellows, or may be applied by a manual operation.
  • this invention concerns the formation of a snap action device from a metal sheet without cuts or slots but by the differential stressing of the sheet in the manner described it does not exclude the shaping of the sheet to provide contact carrying parts or parts for alternative fixing positions. It is not intended to limit the operating force to the pressure or movement of an actuator applied to one point on the sheet. A snap action of one part of the sheet may be obtained from a twisting action applied to the opposite end of the sheet.
  • a sheet of metal formed initially with at least one corrugation running transversely of the sheet from one edge to the opposite edge of the sheet, said corrugation being thereafter deformed by at least partial flattening of the corrugation near the said two edges of the sheet so as to place each such corrugated edge in compression relative to the body of the sheet between the deformed edge portions.
  • a strip of metal formed with a plurality of corrugations running transversely of the strip from one edge to the opposite edge of the strip, said corrugations being deformed by partial flattening of the corrugations near the two edges of the strip so as to place each such corrugated edge in compression relative to the body of the strip between the deformed edge portions.
  • a snap action device comprising a sheet of metal formed with corrugations running transversely of the sheet from one edge to the opposite edge of the sheet, said corrugations being deformed by partial flattening of the corrugations near the two edges of the sheet so as to place each such corrugated edge in compression relative to the body of the sheet, a base supporting said sheet at one corner thereof, and means for applying an initiating movement to the sheet between the support point and the corner of the sheet on the same uncorrugated side.
  • a self-returning snap action device comprising a sheet of metal formed with corrugations running transversely of the sheet from one edge to the opposite edge of the sheet, said corrugations being deformed by partial flattening of the corrugations near the two edges of the sheet so as to place each such corrugated edge in compression relative to the body of the sheet, means for applying an initiating movement to the sheet between the support point and the corner of the sheet on the same uncorrugated side, and means for applying pressure to the sheet on the same uncorrugated side intermediate the fixing and the point of application of said initiating movement and in opposition to said initiating movement.
  • a prestressed snap acting metal sheet initially corrugated from one edge to an opposite edge, the corrugated portions of the sheet along said edges being thereafter deformed to have less corrugation depth relative to the corrugation depth of the intervening corrugated portion of the sheet, whereby said corrugated portions of less depth along said edges of the sheet are in compression relative to said intervening corrugated portion of the metal sheet.
  • a snap action device comprising a sheet or strip of metal which is neither slotted or cut but is formed with one or more corrugations passing from one edge of the sheet to the other, which corrugations are partially flattened near each edge of the sheet to produce internal stresses within the sheet which twists in such manner that the two uncorrugated sides of the sheet lie at an angle to one another in the plane of the sheet.
  • a snap action device as claimed in claim 6, including means for supporting the sheet along one uncorrugated side, and an initiator applied to a point on the other uncorrugated side of the sheet the gradual movement of which produces a snap movement of the unsupported side of the sheet causing it to assume a reversed position relative to the plane of the sheet.
  • a snap action device as claimed in claim 6, including means for supporting the sheet at one corner, and an initiator applied to the uncorrugated supported side of the sheet the movement of which produces a snap movement of the unsupported uncorrugated side of the sheet causing the unsupported side to assume a reversed position relative to the plane of the sheet.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Clamps And Clips (AREA)
  • Advancing Webs (AREA)
  • Making Paper Articles (AREA)
  • Separation, Sorting, Adjustment, Or Bending Of Sheets To Be Conveyed (AREA)
  • Springs (AREA)
  • Safety Valves (AREA)
US542985A 1954-10-28 1955-10-26 Snap action device Expired - Lifetime US2814685A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB339652X 1954-10-28
GB2661/57A GB799728A (en) 1954-10-28 1957-01-24 Snap action device

Publications (1)

Publication Number Publication Date
US2814685A true US2814685A (en) 1957-11-26

Family

ID=62529294

Family Applications (1)

Application Number Title Priority Date Filing Date
US542985A Expired - Lifetime US2814685A (en) 1954-10-28 1955-10-26 Snap action device

Country Status (6)

Country Link
US (1) US2814685A (xx)
CH (1) CH339652A (xx)
DE (1) DE1152862B (xx)
FR (1) FR1134222A (xx)
GB (2) GB774219A (xx)
NL (2) NL99035C (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2954447A (en) * 1958-12-18 1960-09-27 Therm O Disc Inc Thermostatic switch
DE1106394B (de) * 1958-12-03 1961-05-10 Saia A G Schaltkontaktanordnung
EP0790208A1 (de) * 1996-02-16 1997-08-20 Iro Ab Vorrichtung zum Umlenken eines Fadens

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE311101B (xx) * 1967-09-11 1969-05-27 Mach Ind Ets
GB2355509A (en) * 1999-10-21 2001-04-25 Teddington Controls Ltd Snap action shut-off valve

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US725220A (en) * 1902-03-11 1903-04-14 Claude A Contant Method of forming gib-seats on spring-leaves.
US1331677A (en) * 1918-02-11 1920-02-24 Schachter Nathan Method of manufacturing shock-absorber springs
US1678407A (en) * 1923-11-10 1928-07-24 Spencer Thermostat Co Thermostat
US1895592A (en) * 1930-09-08 1933-01-31 Gen Plate Co Snap acting device
US2084982A (en) * 1935-05-28 1937-06-29 Oscar W Anderson Thermostatic valve mechanism
US2102656A (en) * 1936-02-08 1937-12-21 Sidney P Vaughn Thermostatic device
US2204792A (en) * 1940-06-18 Movement producing device
US2230720A (en) * 1939-06-09 1941-02-04 Gen Electric Snap action device
US2332883A (en) * 1942-06-09 1943-10-26 Abrahamson Robert Snap action switch
US2469217A (en) * 1946-04-17 1949-05-03 Gen Electric Snap-action thermostatic switch
US2469686A (en) * 1946-05-06 1949-05-10 First Ind Corp Gauging switch
US2511526A (en) * 1946-07-01 1950-06-13 Erling P Bugge Snap switch
US2613874A (en) * 1950-03-17 1952-10-14 Metals & Controls Corp Relief valve
US2700079A (en) * 1950-09-16 1955-01-18 Haydon Switch Inc Snap action switch
US2706226A (en) * 1953-08-18 1955-04-12 Signal Stat Corp Snap-action vane

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2402312A (en) * 1942-07-31 1946-06-18 Wilcolator Co Snap-acting apparatus
US2415473A (en) * 1943-05-21 1947-02-11 Chace Co W M Snap acting thermostat
US2629791A (en) * 1951-06-16 1953-02-24 Tourneau Robert G Le Snap switch
DE937712C (de) * 1951-10-28 1956-01-12 Kloeckner Moeller Elek Zitaets Schnappschalter
DE951646C (de) * 1952-08-30 1956-10-31 Landis & Gyr Ag Kipporgan fuer Regelschalter

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2204792A (en) * 1940-06-18 Movement producing device
US725220A (en) * 1902-03-11 1903-04-14 Claude A Contant Method of forming gib-seats on spring-leaves.
US1331677A (en) * 1918-02-11 1920-02-24 Schachter Nathan Method of manufacturing shock-absorber springs
US1678407A (en) * 1923-11-10 1928-07-24 Spencer Thermostat Co Thermostat
US1895592A (en) * 1930-09-08 1933-01-31 Gen Plate Co Snap acting device
US2084982A (en) * 1935-05-28 1937-06-29 Oscar W Anderson Thermostatic valve mechanism
US2102656A (en) * 1936-02-08 1937-12-21 Sidney P Vaughn Thermostatic device
US2230720A (en) * 1939-06-09 1941-02-04 Gen Electric Snap action device
US2332883A (en) * 1942-06-09 1943-10-26 Abrahamson Robert Snap action switch
US2469217A (en) * 1946-04-17 1949-05-03 Gen Electric Snap-action thermostatic switch
US2469686A (en) * 1946-05-06 1949-05-10 First Ind Corp Gauging switch
US2511526A (en) * 1946-07-01 1950-06-13 Erling P Bugge Snap switch
US2613874A (en) * 1950-03-17 1952-10-14 Metals & Controls Corp Relief valve
US2700079A (en) * 1950-09-16 1955-01-18 Haydon Switch Inc Snap action switch
US2706226A (en) * 1953-08-18 1955-04-12 Signal Stat Corp Snap-action vane

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1106394B (de) * 1958-12-03 1961-05-10 Saia A G Schaltkontaktanordnung
US2954447A (en) * 1958-12-18 1960-09-27 Therm O Disc Inc Thermostatic switch
EP0790208A1 (de) * 1996-02-16 1997-08-20 Iro Ab Vorrichtung zum Umlenken eines Fadens

Also Published As

Publication number Publication date
GB799728A (en) 1958-08-13
NL99035C (xx) 1900-01-01
DE1152862B (de) 1963-08-14
CH339652A (de) 1959-07-15
GB774219A (en) 1957-05-08
FR1134222A (fr) 1957-04-09
NL201520A (xx) 1900-01-01

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