US3882440A - Thermostat and method of adjusting the same - Google Patents

Thermostat and method of adjusting the same Download PDF

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Publication number
US3882440A
US3882440A US384506A US38450673A US3882440A US 3882440 A US3882440 A US 3882440A US 384506 A US384506 A US 384506A US 38450673 A US38450673 A US 38450673A US 3882440 A US3882440 A US 3882440A
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US
United States
Prior art keywords
thermostat
housing portions
housing portion
housing
faces
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
US384506A
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English (en)
Inventor
Walter Hollweck
Karlheinz Eberl
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.)
INTER CONTROL Hermann Koehler Electrik GmbH and Co KG
Original Assignee
INTER CONTROL Hermann Koehler Electrik GmbH and Co KG
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 INTER CONTROL Hermann Koehler Electrik GmbH and Co KG filed Critical INTER CONTROL Hermann Koehler Electrik GmbH and Co KG
Application granted granted Critical
Publication of US3882440A publication Critical patent/US3882440A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K5/00—Measuring temperature based on the expansion or contraction of a material
    • G01K5/48—Measuring temperature based on the expansion or contraction of a material the material being a solid
    • G01K5/56—Measuring temperature based on the expansion or contraction of a material the material being a solid constrained so that expansion or contraction causes a deformation of the solid
    • G01K5/62—Measuring temperature based on the expansion or contraction of a material the material being a solid constrained so that expansion or contraction causes a deformation of the solid the solid body being formed of compounded strips or plates, e.g. bimetallic strip
    • 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
    • H01H37/52—Thermally-sensitive members actuated due to deflection of bimetallic element
    • H01H37/54—Thermally-sensitive members actuated due to deflection of bimetallic element wherein the bimetallic element is inherently snap acting
    • 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
    • H01H37/52—Thermally-sensitive members actuated due to deflection of bimetallic element
    • H01H37/54—Thermally-sensitive members actuated due to deflection of bimetallic element wherein the bimetallic element is inherently snap acting
    • H01H2037/5445—Thermally-sensitive members actuated due to deflection of bimetallic element wherein the bimetallic element is inherently snap acting with measures for avoiding slow break of contacts during the creep phase of the snap bimetal

Definitions

  • a thermostat which comprises a first housing portion accommodating a circuit breaker and a second [30] Foreign Apphcanon Prmmy Data housing portion accommodating a snap action temper- Aug. 1, 1972 Germany .i 2237815 ature Sensor coupled to the circuit breaker by an actw ating member, the two housing portions have mutually [52] US. Cl. 337/354; 337/360 contacting camming faces Shaped and arranged in [51] hit. Cl.
  • This invention relates to a thermostat which includes a snap action bimetal temperature sensor coupled by means of an insulating actuating member with the contact system of, for example, an electric circuit breaker.
  • the temperature sensor, on the one hand, and the contact system, on the other hand, are arranged in two separate housing portions which have common contacting faces.
  • the invention further relates to a method of adjusting a thermostat of the afore-outlined type.
  • a bimetal temperature sensor of the snap action type generally comprises a circular, arcuate bimetal disc which first undergoes a so-called creeping expansion (or contraction) within a predetermined temperature interval and then, upon reaching a predetermined temperature, snaps in an impact-like manner from one position into another with a simultaneous reversal of the orientation of its curvature. During this snapping movement the disc executes a relatively large working stroke which, with the aid of an insulating actuating member, is used for the opening or closing of electric contacts.
  • the latter may comprise, for example, a leaf spring contact and a stationary contact.
  • Such snap action temperature sensor may also be formed of a bimetal strip corrugated over a portion of its width. Snap action temperature sensors find wide-range application since they make possible a simple and inexpensive manufacture of thermostats, particularly temperature regulators having a predetermined fixed switching point.
  • the thermostat be accurately adjusted, that is, the distance between the snap action temperature sensor and the contact system be set with respect to the dimensions of the insulating actuating member in such a manner that during the creeping deformation of the temperature sensor, the contacts cannot be actuated.
  • the distance between the contact system and the snap action body must be selected with respect to the length of the actuating member in such a manner that there is provided a sufficient clearance for the dimensional changes of the snap action body during its creeping deformation and that, during the snap action proper, the magnitude of the executed large work stroke is sufficient to open or close the contact system with the aid of the actuating member.
  • FIG. 1 is a diagram illustrating the displacement of a selected point on the snap action bimetal temperature sensor as a function of temperature.
  • FIG. 2 is a sectional side elevational view of a preferred embodiment of the invention.
  • FIG. 3 is an exploded perspective view of two components incorporated in the embodiment illustrated in FIG. 2.
  • FIG. 4 is a side elevational view, partially in section, of another preferred embodiment of the invention.
  • FIG. 5 is a perspective view of still another preferred embodiment of the invention.
  • FIG. 1 there is shown a diagram illustrating the displacement (ordinate) of a selected point on a snap action bimetal temperature sensor as a function of temperature (abscissa). More specifically, the diagram illustrates the path of deformation of a snap action disc in a predetermined temperature zone which includes that temperature at which the snapping movement proper takes place. It is noted that the diagram is qualitative only, since actual temperature and distance values vary from case to case.
  • the diagram which, regarding illustration and information conveyed, is known to persons skilled in the art and which may be supplied, for example, by the manufacturer, shows in the temperature zone from T to but excluding T the creeping expansion (in the lower portion of the ordinate) and in the temperature zone from T to but excluding T the creeping contraction (in the upper part of the ordinate) of the snap action disc.
  • the temperature T in case of increasing temperatures and the temperature T in case of dropping temperature are the snap action temperatures at which the disc snaps in an impact-like manner in a direction opposite to the orientation of the previously assumed curved shape. During this occurrence, as it may be observed from FIG.
  • Such an adjustment is accomplished by setting the distance between the snap action disc and the contact system with respect to the length of the actuating member disposed therebetween in such a manner that in the zone of the creeping dimensional change, such a change does not yet cause an actuation of the contact system; such an actuation occurs only during the much more substantial dimensional change to which the disc is submitted during the snap action proper.
  • the thermostat is adjusted to utilize the work stroke portion s s which lies within the maximum available work stroke zone s
  • the adjustment of the thermostat according to the invention is effected by coaxially rotating the two housing portions with respect to one another until a relative position between the two housing portions is reached in which the snap action disc opens or closes the contacts, for example, at room temperatures.
  • the setting to the higher or lower desired value at which the thermostat according to the invention, should in fact switch is then effected according to the disc characteristic represented by a diagram such as shown in FIG. 1. From this diagram, one may then read the distance through which the disc will move between room temperature and desired switching temperature. Assuming that a snap action disc, having the characteristics as shown in the diagram of FIG. 1, should switch, for example, at temperature T then after adjusting the thermostat to the room temperature T the distance between the snap action disc and the contact system has to be extended by the path from s to s, in order to ensure that in the temperature zone between T and up to and excluding T no contact actuation takes place, since in this temperature range the movement of the snap action disc from s to s is in fact the creeping deformation.
  • FIG. 2 there is shown a preferred embodiment of the invention which comprises a first housing portion 1 accommodating two stationary contacts 2 and 3 connected, respectively, to electric conductors 4 and 5. There is further provided a reciprocable movable contact in the form of a bridge member 6 which, dependent on its position, electrically connects the contacts 2 and 3 to, or disconnects them from, one another. The bridge 6 is urged into engagement with the contacts 2, 3 by a compression spring 1 1.
  • a second housing portion 7 which is connected to the first housing portion 1 by means of a crimped cap 8, there is disposed a bimetal snap action disc 9 which, in its condition depicted in FIG. 2, is downwardly convex.
  • the cap 8 is preferably made of a good heat conducting material to ensure rapid and true temperaturetransmission from the surrounding medium to the disc 9.
  • the coupling between the snap action disc 9 and the movable contact bridge 6 is effected by means of an insulating actuating or force transmitting member 10, which is arranged in the housing portion 7 in such a manner that when the bridge 6 is in engagement with the L-shaped lower bent portions of the contacts 2 and 3, the upper end of the actuating member 10 is at a predetermined distance from the bridge 6.
  • This distance which is well observable in FIG. 2, corresponds, for example, to the path extending from s to s in the diagram of FIG.
  • the contacting housing faces 12 and 13 of the two respective housing portions 1 and 7 constitute a pair of camming faces and are of wedge-shaped configuration as it may be better observed from the perspective FIG. 3 to be described later.
  • the distance between the contact system in the housing portion 1 and the temperature sensor 9 in the housing portion 7 may be varied in a simple manner by a coaxial rotation of the housing portions 1 and 7 with respect to one another. Such a relative rotary motion will cause, due to the camming action of the cooperating faces 12 and 13, a shift in the axial distance between the two housing portions 1 and 7 and thus, as a result, a distance between the temperature sensor 9 and the movable contact 6 will vary.
  • the cap 8 is crimped, whereby the housing portions 1 and 7 are tightened together. By appropriate means it is ensured that subsequent to the tightening together of the two housing portions 1 and 7 no further relative displacement therebetween can take place.
  • the two housing portions 1 and 7 have a cylindrical configuration at least in the zone of their mutually contacting faces 12 and 13, respectively.
  • the wedge-shaped or stepped zones are arranged on the radial annular zones of the contacting faces and have oppositely oriented pitches with respect to the axes of the housing portions.
  • FIG. 4 there is illustrated a further embodiment of the invention in which the wedge-shaped zones of the contacting faces 12 and 13 are formed as immediately successive wedge-shaped parts 12', 12", 12", and 13,
  • FIG. 4 corresponds to that illustrated in FIG. 2.
  • FIG. 5 there is illustrated in a schematic perspective view still another embodiment of the invention.
  • the mutually contacting cooperating faces of the two housing portions 1 and 7 have a stepped shape and have oppositely oriented pitches.
  • the height of each step corresponds to the smallest possible adjustment step (increment).
  • the housing protions are axially pulled apart and then, for example, the housing portion 7 is held stationary and the housing portion 1 is turned counterclockwise through an angle corresponding to two steps. Thereafter the two housing portions are secured together by the cap 8 (not shown in FIG. 5) as in the embodiment described in connection with FIG. 2.
  • the axial distance therebetween may be increased by as many as three steps, or it may be decreased by one step.
  • thermostat and the method of its assembly according to the invention, that the adjustment of the thermostat may be effected as a one step operation during and part of the assembly and thus no additional adjusting operation subsequent to the completion of the assembly operation is required.
  • a thermostat having a first and a second housing portion each having an axis, securing means for holding the two housing portions together, a circuit breaker held in the first housing portion, a snap action temperature sensor held in the second housing portion, an insulating actuating member coupling the temperature sensor to the circuit breaker, the improvement comprising at least one pair of camming faces, said pair being formed of two mutually engaging cooperating faces, one belonging to the one housing portion and the other belonging to the other housing portion, said camming faces being arranged for varying the axial spacing of the two housing portions and the distance between said circuit breaker and said temperature sensor upon coaxial rotation of the two housing portions with respect to one another.
  • each housing portion has a plurality of wedge-shaped camming faces to form a plurality of said pairs.
  • a thermostat as defined in claim 1 wherein said camming faces have a stepped configuration and the cooperating stepped faces have a mutually oppositely 7 8 b. mounting a snap action temperature sensor in a two housing portions for connecting them together second housing portion; and for immobilizing them with respect to one anc. connecting the two housing portions to one another for preventing furtherrelative rotation thereother whereby camming faces on one and the other between. housing portion are brought into engagement with 8.
  • step (c) rotating the two housing said cap accommodating one of said housing portions portions coaxially with respect to one another for and being crimped firmly onto the other of said housing adjusting the distance between said temperature portions for connecting the housing portions together sensor and said circuit breaker to a predetermined 10 and immobilizing them in their predetermined angular value; and relationship with respect to one another.

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  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Thermally Actuated Switches (AREA)
US384506A 1972-08-01 1973-08-01 Thermostat and method of adjusting the same Expired - Lifetime US3882440A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2237815A DE2237815C3 (de) 1972-08-01 1972-08-01 Thermische Schaltvorrichtung

Publications (1)

Publication Number Publication Date
US3882440A true US3882440A (en) 1975-05-06

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ID=5852359

Family Applications (1)

Application Number Title Priority Date Filing Date
US384506A Expired - Lifetime US3882440A (en) 1972-08-01 1973-08-01 Thermostat and method of adjusting the same

Country Status (12)

Country Link
US (1) US3882440A (hu)
AT (1) AT331535B (hu)
CA (1) CA987280A (hu)
CH (1) CH568650A5 (hu)
CS (1) CS176245B2 (hu)
DE (1) DE2237815C3 (hu)
FR (1) FR2195052B1 (hu)
GB (1) GB1433418A (hu)
HU (1) HU168241B (hu)
IT (1) IT990979B (hu)
NL (1) NL7310674A (hu)
SE (1) SE391030B (hu)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0051474A2 (en) * 1980-11-03 1982-05-12 Texas Instruments Incorporated Thermostatic switch
US4827096A (en) * 1985-11-05 1989-05-02 Bruno Martinetti Universal switch with integral contact tabs
CN107921873A (zh) * 2015-10-29 2018-04-17 宝马股份公司 操作元件

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4079348A (en) * 1976-05-27 1978-03-14 Texas Instruments Incorporated Thermally responsive electrical switch
FR2618597A1 (fr) * 1987-07-22 1989-01-27 Jaeger Contacteur electrique thermostatique
DE102017000808B4 (de) 2017-01-28 2023-07-27 Wolfgang Hamm Piezothermische Schalteinrichtung

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2230770A (en) * 1939-12-09 1941-02-04 Cons Car Heating Co Inc Circuit controller
US2753421A (en) * 1953-03-11 1956-07-03 Stevens Mfg Co Inc Thermostatic switches
US3668594A (en) * 1970-10-21 1972-06-06 Ranco Inc Room wall thermostat

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3418617A (en) * 1966-03-21 1968-12-24 George W. Crise Snap-acting, cycling, thermostatic switch

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2230770A (en) * 1939-12-09 1941-02-04 Cons Car Heating Co Inc Circuit controller
US2753421A (en) * 1953-03-11 1956-07-03 Stevens Mfg Co Inc Thermostatic switches
US3668594A (en) * 1970-10-21 1972-06-06 Ranco Inc Room wall thermostat

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0051474A2 (en) * 1980-11-03 1982-05-12 Texas Instruments Incorporated Thermostatic switch
EP0051474A3 (en) * 1980-11-03 1983-02-23 Texas Instruments Incorporated Thermostatic switch and method of making
US4827096A (en) * 1985-11-05 1989-05-02 Bruno Martinetti Universal switch with integral contact tabs
CN107921873A (zh) * 2015-10-29 2018-04-17 宝马股份公司 操作元件
US11046146B2 (en) * 2015-10-29 2021-06-29 Bayerische Motoren Werke Aktiengesellschaft Control element

Also Published As

Publication number Publication date
FR2195052A1 (hu) 1974-03-01
FR2195052B1 (hu) 1977-08-19
DE2237815B2 (de) 1978-03-23
IT990979B (it) 1975-07-10
CS176245B2 (hu) 1977-06-30
ATA655873A (de) 1975-11-15
HU168241B (hu) 1976-03-28
NL7310674A (hu) 1974-02-05
AT331535B (de) 1976-08-25
SE391030B (sv) 1977-01-31
GB1433418A (en) 1976-04-28
DE2237815C3 (de) 1978-11-23
CH568650A5 (hu) 1975-10-31
CA987280A (en) 1976-04-13
DE2237815A1 (de) 1974-02-07

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