US3848212A - Snap-action switch assembly - Google Patents

Snap-action switch assembly Download PDF

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Publication number
US3848212A
US3848212A US00416474A US41647473A US3848212A US 3848212 A US3848212 A US 3848212A US 00416474 A US00416474 A US 00416474A US 41647473 A US41647473 A US 41647473A US 3848212 A US3848212 A US 3848212A
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United States
Prior art keywords
arm
spring
assembly
end portion
elongate
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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
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US00416474A
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English (en)
Inventor
H Schwarm
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.)
Eberle Werke KG
Original Assignee
Eberle Werke KG
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Filing date
Publication date
Priority claimed from DE19722261039 external-priority patent/DE2261039C3/de
Application filed by Eberle Werke KG filed Critical Eberle Werke KG
Application granted granted Critical
Publication of US3848212A publication Critical patent/US3848212A/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
    • H01H5/18—Energy stored by deformation of elastic members by flexing of blade springs

Definitions

  • a snap-action switch assembly comprises an arm projecting from a first support and having a first end portion thereof supported by the first support, a spring interconnecting a second support andth arm to exert acompressive force on the arm, a spring adjuster supported on asubstantially central portion of the spring and selectably presettable 'to vary the magnitude of the compressive force, and
  • an electrical contact mounted on the end portion of the arm opposite the first end portion and actuatable by angular displacement of the arm.
  • spring adjuster is arranged symmetrically in the middle of the spring, since the effectiveness of the setting is then at its greatest.
  • the spring adjuster directly varies the characteristic of the spring and is attached to the spring itself, so that a very compact form of construction results.
  • the present invention relates to a snap-action switch assembly of the kind comprising an arm having one end supported and the respective other end angularly displaceable between, for example, two alternative positions.
  • Snap-action switch assemblies are provided with electrical contact means which are actuated in response to the displacement of the free end of the arm.
  • Such snap-action switches may be employed, for example, either in the construction of micro switch devices or in the construction of temperature regulating devices.
  • the arm of the switch normally includes a bimetal element which is responsive to changes of temperature to initiate the opening or closing of the contact means.
  • the arm may be either a rigid or a resilient elongate member which is displaced by mechanical means in order to initiate the I switching action.
  • a temperature regulating device is dscribed in Swiss Pat. Specification No. 251,432.
  • the arm of the snapaction switch disclosed in the aforementioned Swiss Patent Specification is a bimetal leaf spring, on the free end of which acts a U-shaped spreading spring.
  • the distance between the limbs of this U-shaped spring may be adjusted by rotating a regulator screw mounted in a threaded bore in th housing of the device and acting upon only one limb of the U-shaped spring.
  • Particular disadvantages of this known device are that the pressure exerted by the spring on the arm is not settable with sufficient accuracy and the setting range is unduly restricted.
  • a snap-action switch assembly comprising a first support member, an elongated arm projecting from the first support member and having a first end portion thereof supported by the first support member, a second support member, an elongated spring member interconnecting the second support member and the arm to exert a compressive force on the arm, spring adjuster means supported on a substantially central portion of the elongate spring member and selectably presettable to vary the magnitude of the compressive force, and electrical contact means mounted next adjacent a portion of the arm spaced from the first end portion and actuatable by angular displacement of the end portion of the arm opposite the first end portion.
  • the spring adjuster means is arranged symmetrically in the middle of the elongate spring member, since the effectiveness of the setting is then at its greatest.
  • the spring adjuster means directly varies the characteristics of the elongate spring.
  • the spring adjuster means is attached to the spring itself and, thereby, a very compact form of construction results.
  • the spring adjuster means comprises a tensioning screw passing through the elongate spring member and provided with a clamping nut.
  • the stiffness of the elongate spring member, and hence the magnitude of the compressive force exerted on the arm, may be increased by tightening the screw of clamp the spring more firmly between the head of the screw and the cooperating clamping nut.
  • the resilient bias exerted by the spring on the arm can also be varied by exchanging one tensioning screw for another one with a different sized head.
  • FIG. 1 shows in side elevation a snap-action switch provided with a resiliently biassed contact carrying arm having one end provided with a knife edge and resiliently urged into contact with walls of recess in a sup porting wall;
  • FIG. 2 shows another view of the switch shown in FIG. 1, with the contact carrying arm in a different switching position and having one end firmly clamped to a supporting wall;
  • FIG. 3 shows a modified embodiment of the invention
  • FIG 4 shows a detail of the embodiment illustrated in FIG. 1.
  • a snap-action switch embodying the invention may be employed in the construction of a micro-switch or, particularly when the lever arm 1 is a bimetal leaf spring, in the construction of a temperature dependent switch.
  • An end portion 2 of a lever arm 1 is supported in a recess in the wall 4 of a housing.
  • the extremity of the lever arm 1 contacting the housing is provided with a knife edge 3.
  • the lever arm 1 carries a switch contact 5, which, when in the contact position shown in FIG. 1, cooperates with a locally fixed counter-contact 6.
  • the counter-contact 6 is rigidly supported by any suitable means which, in the interest of clarity have not been shown in the drawing.
  • FIG. 2 shows the switch with its contacts 5 and 6 spaced apart. In this condition, the movable contact 5 rests against a stop 7. As indicated in FIG. 2, the end portion 2 of the arm 1 is firmly clamped to a rigid wall.
  • the means by which the end portion 2 of the arm 1 is firmly clamped to the wall have not been shown in FIG. 2, but may comprise a socket in the wall into which the end portion of the arm is firmly wedged.
  • the free end of the arm 1 is provided with a knife edge bearing 8, which receives one end of a leaf spring 9.
  • the opposite end of the leaf spring 9 is supported in a recess 10 in a support 12.
  • the snap-action switch is actuated mechanically by displacement of a pin 11 to vary the laterally directed pressure exerted by the pin 11 on the arm 1.
  • Such a snap-action switch may also be mehanically actuated by displacement of the support 12 in the direction indicated by the double-headed arrow in FIG. 2.
  • the arm 1 comprises a bimetal leaf spring element and, in these circumstances, the switch is actuated when the tension in such a bimetal element is increased as a result of changes in temperature to such an extent that the bias force exerted thereon by the spring 9 is exceeded.
  • the temperature responsive characteristic of the arm I (which is then constructed as a bimetal leaf spring) can be adjusted by varying the position of a threaded pin 11 to change the contact pressure between the pin and the bimetal element.
  • a tensioning screw 13 which passes through a corresponding bore in the spring 9 and is screwed up relative to a clamping nut provides means for varying the bias exerted by the spring 9 on the arm 1.
  • the spring 9 is provided with a rectangularly shaped portion 18. Screwed into a threaded bore in one limb 19 of this portion 18 is a tensioning screw 20, and an end portion 21 of the screw is pressed against a further limb 22 of the portion 18.
  • the resilient bias exerted by the spring 9 on the arm 1 in FIG. 3 may be adjusted by rotating the screw 20 to vary the pressure which it exerts on the two limbs 19 and 22. As this pressure is increased, the limbs are forced further apart and, consequently, the resilient bias exerted by the spring 9 is increased.
  • the electrical contact means comprise one contact element mounted on an end portion of the arm and another mounted next adjacent the first.
  • the contact means may comprise two spring contact elements, neither of which is supported on the arm, but which are so mounted next adjacent the de flectable end portion of the arm that when the arm is deflected such spring contact elements are urged together to contact one another in response to the movement transmitted to one of the contact elements by the displacement of the arm.
  • a snap-action switch assembly comprising, in combination:
  • spring adjuster means supported on a substantially central portion of said elongate spring member and being selectably presettable to vary the magnitude of said compressive force
  • electrical contact means mounted next adjacent a portion of said arm spaced from said first end portion and actuatable by angular displacement of the end portion of said arm opposite said first end portion.
  • said adjuster means comprises a headed member having a threaded shank passing through said elongate spring member to engage a cooperating thread on a clamping member, said clamping member cooperating with the head of said headed member to clamp a substantially central portion of said elongate spring member therebetween.
  • clamping member comprises means to restrain said clamping member against rotation relative to said elongate spring member.
  • said restraining means comprises, at least, one lug projecting from said clamping member to enter a respective recess in said spring member.
  • said elongate spring member comprises a central portion having two mutually facing limbs, one of said limbs having a threaded passage, and wherein said adjuster means comprises a threaded .member extending through said threaded passage to contact the respective other one of said limbs.
  • said electrical contact means comprises at least one contact element supported on said arm.

Landscapes

  • Thermally Actuated Switches (AREA)
  • Push-Button Switches (AREA)
  • Mechanisms For Operating Contacts (AREA)
  • Springs (AREA)
US00416474A 1972-12-14 1973-11-16 Snap-action switch assembly Expired - Lifetime US3848212A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19722261039 DE2261039C3 (de) 1972-12-14 Vorrichtung zum Auslösen der Schaltbewegung eines Schnappschalters

Publications (1)

Publication Number Publication Date
US3848212A true US3848212A (en) 1974-11-12

Family

ID=5864323

Family Applications (1)

Application Number Title Priority Date Filing Date
US00416474A Expired - Lifetime US3848212A (en) 1972-12-14 1973-11-16 Snap-action switch assembly

Country Status (5)

Country Link
US (1) US3848212A (enrdf_load_html_response)
JP (1) JPS4989173A (enrdf_load_html_response)
FR (1) FR2210812B1 (enrdf_load_html_response)
GB (1) GB1418522A (enrdf_load_html_response)
NO (1) NO134574C (enrdf_load_html_response)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3887734T2 (de) * 1987-11-23 1994-05-19 Otter Controls Ltd., Buxton, Derbyshire Temperatur emfindliche elektrische Schalter.
GB2248519B (en) * 1987-11-23 1992-06-24 Otter Controls Ltd Improvements relating to thermally responsive controls for water boiling vessels

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1869610A (en) * 1928-01-19 1932-08-02 Western Clock Co Electric switch
US2611845A (en) * 1951-03-31 1952-09-23 Hotpoint Inc Temperature control device
US3733571A (en) * 1971-12-27 1973-05-15 Gen Electric Switch control

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1869610A (en) * 1928-01-19 1932-08-02 Western Clock Co Electric switch
US2611845A (en) * 1951-03-31 1952-09-23 Hotpoint Inc Temperature control device
US3733571A (en) * 1971-12-27 1973-05-15 Gen Electric Switch control

Also Published As

Publication number Publication date
NO134574C (enrdf_load_html_response) 1976-11-03
FR2210812B1 (enrdf_load_html_response) 1977-09-16
NO134574B (enrdf_load_html_response) 1976-07-26
JPS4989173A (enrdf_load_html_response) 1974-08-26
GB1418522A (en) 1975-12-24
DE2261039A1 (de) 1974-06-27
FR2210812A1 (enrdf_load_html_response) 1974-07-12
DE2261039B2 (de) 1976-10-14

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