US2870291A - Snap action device - Google Patents

Snap action device Download PDF

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Publication number
US2870291A
US2870291A US663925A US66392557A US2870291A US 2870291 A US2870291 A US 2870291A US 663925 A US663925 A US 663925A US 66392557 A US66392557 A US 66392557A US 2870291 A US2870291 A US 2870291A
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US
United States
Prior art keywords
vane
body section
strip
deformations
snap action
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
US663925A
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English (en)
Inventor
James W Welsh
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.)
HODA Corp
Original Assignee
HODA 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
Application filed by HODA CORP filed Critical HODA CORP
Priority to US663925A priority Critical patent/US2870291A/en
Priority to GB17222/58A priority patent/GB889761A/en
Priority to FR1209183D priority patent/FR1209183A/fr
Priority to DES27266U priority patent/DE1872037U/de
Application granted granted Critical
Publication of US2870291A publication Critical patent/US2870291A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H37/00—Thermally-actuated switches
    • H01H37/02—Details
    • H01H37/32—Thermally-sensitive members
    • H01H37/46—Thermally-sensitive members actuated due to expansion or contraction of a solid
    • H01H37/48—Thermally-sensitive members actuated due to expansion or contraction of a solid with extensible rigid rods or tubes
    • 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
    • H01H5/30—Energy stored by deformation of elastic members by buckling of disc springs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H61/00—Electrothermal relays
    • H01H61/06—Self-interrupters, i.e. with periodic or other repetitive opening and closing of contacts

Definitions

  • This invention relates'to snap actionvanes for use in thermostatically or thermodynamically operated electric circuit controllers, such as tor'th'e type of circuit areal;- ing and/or reversing switch, one form of which is known asa flasher. More particularly, the invention is directed to such vanes having a'thermostatic operator integral therewith, such as the type forming the subject matter of my copending application Serial No. 664,034, filed June 6, 1957, for Snap Action Device.
  • the vane is pre-stressed to bend about the other diagonal by attaching a thermostatic wire or ribbon to the corners at the ends of the first diagonal, the wire or ribbon being attached in the cold, contracted condition with the vane bent about the second diagonal.
  • a thermostatic wire or ribbon to the corners at the ends of the first diagonal, the wire or ribbon being attached in the cold, contracted condition with the vane bent about the second diagonal.
  • a pieceaof preferably electrically conductive spring metal is used, the. metal'being selected for high elasticity and resistance to creep understatic or dynamic stresses.
  • isss tion of the metal areits specific temperature resistance, coeflicient of resistance, and coetficientof expansion, all of which factors must be considered with particular reference to external or ambient operating conditions.
  • the metal piece it formed with a closed-end slot extending alongand parallel to an edge so as to provide a narrow strip of metal along such edge integral at each end with the much larger body section of the vane.
  • This narrow strip forms the thermostatic strip or wire for snapping the vane between two conformations. Due to its smaller cross-section as compared with that of the main body of the vane, the strip heats and expands at a faster rate than does the main bodywhen there is a flow of electric current through the vane.
  • the vane is so designed as to form an automatic breaking or storage point to build up kinetic energy.
  • the vane is so formed as to provide controllable pressure points or areas within the vane.
  • This is eitected by thinning the vane metal along a pair of rectilinear zones to form a pairof ridges or embossed sections which are rectilinear and extend inwardly toward each other but have their inner ends separated.
  • This embossing accomplishes several purposes.
  • the thinning of the vane material sets up substantial external pressures along the general line of the embossments.
  • the spacing of the inner ends of the embossments creates a focal point or area toward the center of the vane so that the vane, when operating, will break down at a predetermined point or area.
  • the central area betweenthe innerrends of the embossments is kept unmarred as most oithe flexing will occur in this area.
  • the bending stresses are also kept away from this central area. it has been found that keeping this central area free of' stresses results in stable operation of the vane being effectively maintained over a long period of time.
  • the depth of the embossments and the consequent thinning of the vane material is dependent upon the desired operating parameters of the vane.
  • the deformation of 'themain body section results in an initial set being impaired to the vane along a bending line determined by the direction of the deformations.
  • the thermostatic strip is then foreshortened by forming an offset therein ator adjacent its center. This foreshortening of the strip, which latter is integral at each end with the main body section, results in stressing the main body section to bend about a line normal to the strip and at an angle to the initial bending-line of the body section.
  • the strip heats and expands much faster than'the mainbody section.
  • the differential expansion of the strip relative to the main body section progressively decreases the stress holding the main body section bent about a line normal to the strip, and the main body section fiattens'to a point where it snaps to a position bent about itsinitial bending line as determined by the direction of the deformations therein.
  • Figs. 1 through 4 are plan views of various forms which the vane may assume in practice
  • Fig. 5 is a plan view of the vane of Fig. 1 after deformation of the strip;
  • Fig. 6 is a schematic wiring diagram of the vane of Fig. 5 as incorporated in an electric heating circuit
  • Fig. 7 is a side elevation view of the vane of Fig. 5 in the unheated condition.
  • Pig. 8 is a side elevation view of the vane of Fig. 5 after snapping to its stressed position due to heating by the circuit of Fig. 6
  • a vane 10, of suitable high electrical resistance material which is resilient in nature, such as thin spring steel is formed with an elongated slot or cutout 11 extending along and parallel to one edge. Slot 11 divides vane 10 into a main body section 12 and a much narrower strip integral at each end with body section 12. Due to the difference in crosssectional area between body section 12 and strip 15, when an electric current is caused to flow through vane 10, strip 15 will heat and expand at a'much greater rate than will body section 12. Thus, strip 15 will expand differentially relative to body section 12 causing relative bending of the body section 12 and strip 15.
  • the bending stresses are directed toward a relatively central area 13 of body section 12 by thinning or otherwise deforming the metal of section 12 along a pair of rectilinear lines, extending inwardly toward each other, to form bosses, ridges, or depressions 20. It will be noted that the inner ends of the deformations are spaced from each other, leaving the central area 13 therebetween substantially undeformed. Deformation of body section 12 causes the vane to have an initial set or bend about a bending line or axis aligned with deformations 20.
  • Fig. 1 shows a vane 10 of rectangular form, and this shape is preferred in many practical applications of the invention. However, this vane may take other configurations, in plan, Without effect on its operation.
  • vane 16A is shown as substantially square, with slot 11A extending in closely spaced parallel relation to one edge to define body section 12A and strip 15A, bosses or ridges 249A being formed in section 12A, in the same manner as in Fig. 1, to leave unmarred central area 13A.
  • vane 10B is generally semi-circular, with slot 11B extending parallel to a diameter. Deformations 2 B of body section 1213.
  • a circular shape vane 10C is desired, as shown in Fig. 4.
  • slot 11C extends parallel to the circumference of the vane.
  • Ridges 26C are formed in section 12C and are spaced from and diverge outwardly from slot 11C.
  • Fig. 5 shows the vane 14 of Fig. l as further deformed by imposing an offset bend 16 in strip 15.
  • the consequent shortening of the distance be- P tween the ends of strip 15' results in a bend being imparted to body section 12 about an axis perpendicular to deformations 21?.
  • Fig. 6 schematically illustrates a typical electric circuit incorporating vane 10.
  • the ungrounded terminal of a grounded battery 21 is connected through switch 22 to one side of vane 10, such as to the center of strip 15. he other side of vane 10 is connected to ground through a lead 23.
  • Alternative connections are shown in broken lines.
  • a snap action vane comprising a substantially flat piece of a single resilient metal having a relatively elongated closed-end slot extending along and adjacent an edge thereof to divide the vane into a main body section and a strip separated from said body section by said slot and integral with the body section at each end, with the strip having a cross-sectional area only a fraction of that of the body section; said body section having a pair of substantially rectilinear deformations therein extending toward a central area of the body section; the inner endsof the deformations terminating short of each other to leave said central area free of deformation; whereby, upon heating of said vane, the strip will expand relative to the body section to induce bending stresses in the body section with the bending stresses directed by said deformations.
  • a snap action vane comprising a substantially flat piece of a single resilient metal having a relatively elongated closed-end slot extending along and adjacent an edge thereof to divide the vane into a main body section and a strip separated from said body section by said slot and integral with the body section at each end, with the strip having a cross-sectional area.
  • said body section having a pair of substantially rectilinear deformations therein extending toward a central area of the body section; the inner ends of the deformations terminating short of each other to leave said central area free of deformation; said strip having an offset bend intermediate its ends to bend said body section to a stress-deformed position bent about a zone perpendicular to said strip; whereby, upon heating of said vane, the strip will expand relative to the body section to flatten said body section and to induce bending stresses in the body section to snap said vane to a restored position with the bending stresses directed by said deformations.
  • a snap action vane for use in an electrothcrrnically actuated switch comprising a substantially flat piece of a single resilient metal of relatively high electrical resistance having a relatively elongated closed-end slot extending along and adjacent an edge thereof to divide the vane into a main body section and a strip separated from said body section by said slot and integral with the body section at each end, with the strip having a cross-sectional area only a fraction of that of the body section; said body section having a pair of substantially rectilinear deformations therein extending toward a central area of the body section; the inner ends of the deformations terminating short of each other to leave said central area free of deformation; whereby, upon how of electric current through the vane, the strip will heat and expand relative to the body section to induce bendingstresses in the body section with the bending stresses directed by said deformations;
  • a snap action vane for use in an electrothermically actuated switch comprising a substantially flat piece of a single resilient metal of relatively high electrical resistance having a relatively elongated closed-end slot extending along and adjacent an edge thereof to divide the vane into a main body section and a strip separated from said body section by said slot and integral with the body section at each end, with the strip having a crosssectional area only a fraction or that of the body section; said body section having a pair of substantially rectilinear deformations therein extending toward a central area of the body section; the inner ends of the deformations terminating short of each other to leave said central area free of deformation; said strip having an otfset bend intermediate its ends to bend said body section to a stress-deformed position bent about a zone perpendicular to said strip; whereby, upon flow of electric current through the vane, the strip will heat and expand relative to the body section to flatten said body section and to induce sending stresses in the body section to snap said vane to a restored position with the

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  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Catalysts (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Surgical Instruments (AREA)
  • Push-Button Switches (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
US663925A 1957-06-06 1957-06-06 Snap action device Expired - Lifetime US2870291A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US663925A US2870291A (en) 1957-06-06 1957-06-06 Snap action device
GB17222/58A GB889761A (en) 1957-06-06 1958-05-29 Improvements in snap action device
FR1209183D FR1209183A (fr) 1957-06-06 1958-05-30 Dispositif rupteur à action brusque
DES27266U DE1872037U (de) 1957-06-06 1958-06-03 Auf temperaturaenderung ansprechender elektrischer kleinschalter mit dehnungsstreifen, insbesondere zur verwendung fuer blinker.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US663925A US2870291A (en) 1957-06-06 1957-06-06 Snap action device

Publications (1)

Publication Number Publication Date
US2870291A true US2870291A (en) 1959-01-20

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Family Applications (1)

Application Number Title Priority Date Filing Date
US663925A Expired - Lifetime US2870291A (en) 1957-06-06 1957-06-06 Snap action device

Country Status (4)

Country Link
US (1) US2870291A (fr)
DE (1) DE1872037U (fr)
FR (1) FR1209183A (fr)
GB (1) GB889761A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3080464A (en) * 1959-08-06 1963-03-05 Tung Sol Electric Inc Snap acting switch blade
US3110788A (en) * 1959-11-17 1963-11-12 Signal Stat Corp Automatic re-set thermostatic circuit breaker
DE1162915B (de) * 1960-03-10 1964-02-13 Otto Mueller Einseitig eingespannter, am freien Ende Kontakte tragender umschnappbarer Bimetallstreifen
DE1201727B (de) * 1959-10-20 1965-09-23 James W Welsh Thermisch wirkende Blinkeinrichtung
US3218411A (en) * 1961-12-21 1965-11-16 Tung Sol Electric Inc Compensated shunt type snap action device
US3970294A (en) * 1973-08-21 1976-07-20 Nissan Motor Co., Ltd. Synchronous ring in a synchronous device
FR2728813A1 (fr) * 1995-01-04 1996-07-05 Nicomatic Procede de fabrication de pieces plates, et pieces plates formees par sa mise en oeuvre

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2363280A (en) * 1941-05-14 1944-11-21 Westinghouse Electric & Mfg Co Circuit controller
US2533274A (en) * 1944-11-28 1950-12-12 Fasco Industries Bimetallic thermostatic element
US2708697A (en) * 1953-08-18 1955-05-17 Signal Stat Corp Snap-action device
US2716682A (en) * 1953-09-02 1955-08-30 Gen Mills Inc Positive opening and closing switch with wiping action
US2720568A (en) * 1953-01-27 1955-10-11 Stevens Mfg Co Inc Snap-acting bimetallic thermostat

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2363280A (en) * 1941-05-14 1944-11-21 Westinghouse Electric & Mfg Co Circuit controller
US2533274A (en) * 1944-11-28 1950-12-12 Fasco Industries Bimetallic thermostatic element
US2720568A (en) * 1953-01-27 1955-10-11 Stevens Mfg Co Inc Snap-acting bimetallic thermostat
US2708697A (en) * 1953-08-18 1955-05-17 Signal Stat Corp Snap-action device
US2716682A (en) * 1953-09-02 1955-08-30 Gen Mills Inc Positive opening and closing switch with wiping action

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3080464A (en) * 1959-08-06 1963-03-05 Tung Sol Electric Inc Snap acting switch blade
DE1201727B (de) * 1959-10-20 1965-09-23 James W Welsh Thermisch wirkende Blinkeinrichtung
US3110788A (en) * 1959-11-17 1963-11-12 Signal Stat Corp Automatic re-set thermostatic circuit breaker
DE1162915B (de) * 1960-03-10 1964-02-13 Otto Mueller Einseitig eingespannter, am freien Ende Kontakte tragender umschnappbarer Bimetallstreifen
US3218411A (en) * 1961-12-21 1965-11-16 Tung Sol Electric Inc Compensated shunt type snap action device
US3970294A (en) * 1973-08-21 1976-07-20 Nissan Motor Co., Ltd. Synchronous ring in a synchronous device
FR2728813A1 (fr) * 1995-01-04 1996-07-05 Nicomatic Procede de fabrication de pieces plates, et pieces plates formees par sa mise en oeuvre
WO1996020799A1 (fr) * 1995-01-04 1996-07-11 Nicomatic Procede de fabrication de pieces plates, et pieces plates formees par sa mise en ×uvre
CN1090545C (zh) * 1995-01-04 2002-09-11 尼科梅蒂克公司 制造扁平零件的方法和通过实施该方法制造的扁平零件

Also Published As

Publication number Publication date
DE1872037U (de) 1963-05-16
FR1209183A (fr) 1960-02-29
GB889761A (en) 1962-02-21

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