US3111565A - Electrical snap-action switch - Google Patents

Electrical snap-action switch Download PDF

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Publication number
US3111565A
US3111565A US135098A US13509861A US3111565A US 3111565 A US3111565 A US 3111565A US 135098 A US135098 A US 135098A US 13509861 A US13509861 A US 13509861A US 3111565 A US3111565 A US 3111565A
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US
United States
Prior art keywords
switch
shift lever
contact
action
moving member
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
US135098A
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English (en)
Inventor
Bunke Horst
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Individual
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Individual
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Filing date
Publication date
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Publication of US3111565A publication Critical patent/US3111565A/en
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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
    • H01H35/34—Switches operated by change of fluid pressure, by fluid pressure waves, or by change of fluid flow actuated by diaphragm
    • 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
    • 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
    • H01H5/06—Energy stored by deformation of elastic members by compression or extension of coil springs

Definitions

  • This invention relates to an electrical snap-action switch, in particular for electrically heated apparatus such as continuous-flow heaters.
  • Snap-action switches are well known in various modifications, wherein a shift lever can be moved through its dead center position and is connected with a contact arm by means of a snap-action spring. In such switches, the snap-action spring changes its direction of operation and suddenly moves the contact arm into its make or break direction, as soon as the shift lever passes through its dead center position.
  • the shift lever In many cases, in particular in power switches for electrically heated apparatus, the shift lever must be actuated nonpositively by a moving member such as the push rod of a diaphragm exposed to water pressure or by the expansion member'of a thermostat. If such a moving member makes a slow movement and this is the case as a rule, the shift lever is approached to its dead center slowly. As a consequence, the contact pressure depending on the snap-action spring is decreased during the switching-off operation and reaches the value of zero in the dead center position before the contact arm is lifted from the counter-contact by the snap-action spring after the dead center position has been passed through. This means that with such a snap-action switch, an uncertain contact tending to freezing together is obtained in the neighborhood of the dead center, if the shift lever is actuated non-positively by a slowly moved member.
  • a moving member such as the push rod of a diaphragm exposed to water pressure or by the expansion member'of a thermostat. If such a moving member makes a slow movement and this is
  • the invention has for its object to maintain the full contact pressure in such a snap-action switch up to the moment of breaking, even with slow actuation of the shift lever.
  • the shift lever is prevented by the locking device from following the slow moving member during the switching-off movement, and is released only in that moment when the moving member has already moved backwards to such an extent that [a sudden breaking is effected.
  • such an arrangement comprising a. locking device for maintaining the full contact pressure can be employed in all possible embodiments of such dead center switches.
  • the locking device comprises a spring loaded pawl, which can be released by a cam provided on the moving member.
  • a shift lever 1 designed as a flexible blade and a contact arm 2 also designed as a flexible blade of an inte gnal stamping is fixed at 3 to the switch casing (not shown).
  • a compression spring 4 is fixed between the free end of the shift lever 1 and the contact arm 2.
  • a push rod. 6 acts on the shift lever -1 against the action of a return spring 5.
  • a spring loaded locking pawl 7 is pivotally mounted in the switch casing. Pawl 7 blocks the shift lever in the position shown. The locking pawl can be released at a certain position of the push rod 6 by means of a cam 8 provided on the push rod.
  • Reference numeral 9 designates a stop for the contact arm ice 2.
  • the stationary counter contact 10 cooperates with a contact 2' of the contact arm 2 to close the electric circuit.
  • the switch is actuated by the Water deficiency safety device of an electrically heated continuous-flow heater. It will, of course, be understood that the invention is not limited to such or similar applications.
  • the continuous-flow heater comprises a main body 11 provided with a U-shaped heating channel 12.
  • a heating coil 13 is arranged in the heating channel 12. This coil is supplied with current from an A.C. current source 14 through the contacts 2', 10 of the switch described.
  • Channels 15 and 16 are provided in series with theheating channel 12 at the inlet and at the outlet side thereof.
  • the heating coil is not insulated and arranged in the water how, and the water columns in the channels 15 and 16 constitute electric resistors which limit the leakage currents and make it possible to ground the inlet and the outlet of the apparatus. This principle of an electric continuous-flow heater is well known per se and forms no part of the present invention.
  • a throttle screw 17 is provided between channels 15 and 12.
  • a bell-shaped diaphragm casing 18 is placed on the main body 11.
  • the main body 11 is provided with a recess 19 on its top face.
  • the recess is connected with the channel 15 through a bore 20.
  • a diaphragm 21 is clamped between the main body 11 and the diaphragm casing 18.
  • the space 22 above the diaphragm 21 is connected to the channel 16 through a channel 2.3 passing through the outer rim of the diaphragm 21.
  • the push rod 6 is passed through the diaphragm casing 16 by means of a stuiiing box .24, and, at its lower end, carries a diaphragm plate which comes into contact with the diaphragm 21 under the influence of a spring 26, if the diaphragm makes a stroke.
  • the push rod 6 is provided with a shoulder stop 27 and is enclosed by the fork-shaped end of a leaf spring 28 which rests on the shoulder 27 and is fixed at 29.
  • a screw 30 presses on the spring 28. By means of screw 30 the spring 28 may be more or less pre-tensioned.
  • the switch stop 9 is conducting part of the circuit and is connected with the contact 2 by a [flexible conductor 31.
  • a dynamic pressure drop at the throttle 17 is obtained in well known manner, which becomes effective on the diaphragm in the spaces 19 and v22 through channels 20 and 23, respectively.
  • the diaphragm makes a stroke and lifts the push rod :6 against the action of the springs 26 and 28.
  • the pressure to which the deviceresponds can be varied in order to permit an accommodation to the local conditions.
  • the pressure drop is decreased and the push rod 6 is moved downwards under the influence of the springs 26 and 28.
  • an electrical snap-action switch having a contact arm movable between switch-on and switch-off positions, a shift lever operatively connected to the contact arm and movable across a center position for over-the-center actuation of the contact arm, a moving member contacting the shift lever for positive action to the switch-on position and movable between switch-on and switch-off positions through a point corresponding to the center position of the shift lever, and means urging the shift lever towards the switch-off position
  • the improvement comprising: a releasable latch engaging the shift lever in the switch-on position; and actuating means connected to the moving member to release the latch after the moving member has moved from the switch-on position to beyond said point.
  • said latch comprises a pivotally mounted pawl movable between a latched and an unlatohed position and having a portion blocking the shift lever in the switch-on position, and means connected to the pawl and urging the pawl to said latched position; and said actuating means comprises a cam connected to the moving member and contacting said latch when in the latched position to move the latch to the unlatched position.
  • An electrical snap-action switch including: a flexible contact arm having a supported and an unsupported end; a flexible shift lever having a supported and an unsupported end and having its supporttd end integral with the supported end of the contact .arm; means fixedly mounting the supported end of each of the arm and the lever with the unsupported ends extending in a common direction; resilient means interconnecting unsupported portions of the lever and arm, whereby as the lever is moved across center from one side to the other side, the arm will move from a switch-on to a switch-01f position and vice versa; a contact contacting the arm when the arm is in the switch-on position; means operatively connected to the lever to urge the lever from said one side towards the other; an operating member positioned at the other side of the lever, said operating member being movable toward said one side to contact and move the lever to said one side against said urging and to retract beyond the center; a pivoted latch engaging the lever when the lever is at said one side; and a cam attached to the operating member to contact said latch and disengage it

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)
  • Control Of Combustion (AREA)
  • Control Of Transmission Device (AREA)
US135098A 1960-08-20 1961-08-21 Electrical snap-action switch Expired - Lifetime US3111565A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEE19806A DE1131297B (de) 1960-08-20 1960-08-20 Elektrischer Schnappschalter, insbesondere fuer elektrisch beheizte Geraete

Publications (1)

Publication Number Publication Date
US3111565A true US3111565A (en) 1963-11-19

Family

ID=7070110

Family Applications (1)

Application Number Title Priority Date Filing Date
US135098A Expired - Lifetime US3111565A (en) 1960-08-20 1961-08-21 Electrical snap-action switch

Country Status (6)

Country Link
US (1) US3111565A (de)
CH (1) CH387132A (de)
DE (1) DE1131297B (de)
FR (1) FR1297554A (de)
GB (1) GB925434A (de)
NL (1) NL268370A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3356803A (en) * 1966-02-21 1967-12-05 Perkin Elmer Corp Pressure switch having means for increasing the stroke of a bellows pressure sensing element
US4877928A (en) * 1987-07-22 1989-10-31 Bbc Brown Boveri Ltd. Release mechanism for a high speed circuit breaker

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1236051B (de) * 1962-11-02 1967-03-09 Rowenta Metallwarenfab Gmbh Moment-Einschalter

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1275200A (en) * 1914-12-15 1918-08-13 Cutler Hammer Mfg Co Electric switch.
US1284930A (en) * 1915-08-17 1918-11-12 Reciprocating Electric Tool Company Electrical hammer and stone-cutter.
US2284940A (en) * 1939-08-04 1942-06-02 Honeywell Regulator Co Snap action device
US2376634A (en) * 1943-03-01 1945-05-22 Allen Bradley Co Edge-wound tubular expansible member
US2720564A (en) * 1952-07-14 1955-10-11 Soreng Products Corp Fluid pressure responsive switch

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH251997A (de) * 1944-11-07 1947-11-30 Spiess Paul Momentschalter mit Tastkontakten für elektrische Apparate.
US2740857A (en) * 1952-01-15 1956-04-03 Porland Kjeld Electric switch with tilting movement
US2748215A (en) * 1954-06-01 1956-05-29 Allen V C Davis Electric switch

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1275200A (en) * 1914-12-15 1918-08-13 Cutler Hammer Mfg Co Electric switch.
US1284930A (en) * 1915-08-17 1918-11-12 Reciprocating Electric Tool Company Electrical hammer and stone-cutter.
US2284940A (en) * 1939-08-04 1942-06-02 Honeywell Regulator Co Snap action device
US2376634A (en) * 1943-03-01 1945-05-22 Allen Bradley Co Edge-wound tubular expansible member
US2720564A (en) * 1952-07-14 1955-10-11 Soreng Products Corp Fluid pressure responsive switch

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3356803A (en) * 1966-02-21 1967-12-05 Perkin Elmer Corp Pressure switch having means for increasing the stroke of a bellows pressure sensing element
US4877928A (en) * 1987-07-22 1989-10-31 Bbc Brown Boveri Ltd. Release mechanism for a high speed circuit breaker

Also Published As

Publication number Publication date
NL268370A (de)
DE1131297B (de) 1962-06-14
GB925434A (en) 1963-05-08
FR1297554A (fr) 1962-06-29
CH387132A (de) 1965-01-31

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