Claims
- 1. In a condition responsive electrical switch construction having frame means carrying an electrical switch and a condition responsive device having a movable wall for causing movement of a lever that is pivotally carried by said frame means and is operatively associated with said switch to operate the same as said lever is moved by said wall to a certain position in opposition to the force of a range spring carried by said frame means, the improvement comprising a cradle-like member having a base operatively associated with said range spring so as to be held thereby against said wall to be moved in unison with said wall and having arm means engaging said lever to cause said lever to move in relation to movement of said wall.
- 2. A condition responsive electrical switch construction as set forth in claim 1 wherein said range spring engages against said base of said cradle-like member.
- 3. A condition responsive electrical switch construction as set forth in claim 2 wherein said range spring comprises a coiled compression spring having opposed ends, one of said opposed ends of said spring engaging against said base of said cradle-like member.
- 4. A condition responsive electrical switch construction as set forth in claim 3 wherein said frame means has adjustable means for adjusting the position of the other of said opposed ends of said spring to thereby set the force of said range spring acting on said cradle-like member.
- 5. A condition responsive electrical switch construction as set forth in claim 4 wherein said adjustable means comprises an internally threaded tubular member carried by said other end of said spring, an externally threaded member threadedly disposed in said tubular member and having an end projecting out of said other end of said spring, said end of said externally threaded member being slotted for receiving a tool to threadedly adjust said threaded members, and a cam operated lever pivotally carried by said frame means and engaging said end of said externally threaded member to position said other end of said spring at the desired set position thereof.
- 6. A condition responsive electrical switch construction as set forth in claim 1 wherein said arm means of said cradle-like member comprises two arms extending substantially transverse to said base and each engaging said lever.
- 7. A condition responsive electrical switch construction as set forth in claim 6 wherein each arm has an outwardly turned end that engages said lever.
- 8. A condition responsive electrical switch construction as set forth in claim 1 wherein said base has a substantially flat surface, said wall having a substantially flat surface engaging said flat surface of said base.
- 9. A condition responsive electrical switch construction as set forth in claim 8 wherein said flat surface of sid base is annular.
- 10. A condition responsive electrical switch construction as set forth in claim 9 wherein said base has a raised central portion inboard of said annular flat surface thereof, said range spring comprising a coiled compression spring having opposed ends, one of said opposed ends of said spring telescopically receiving said raised central portion of said base and engaging said base on the side thereof opposite to said annular surface thereof.
- 11. In an actuator arrangement for a condition responsive control unit and having frame means carrying a condition responsive device provided with a movable wall for causing movement of a lever that is pivotally carried by said frame means and is adapted to be operatively associated with an actuatable device to operate the same as said lever is moved by said wall to a certain position in opposition to the force of a range spring carried by said frame means, the improvement comprising a cradle-like member having a base operatively associated with said range spring so as to be held thereby against said wall to be moved in unison with said wall and having arm means engaging said lever to cause said lever to move in relation to movement of said wall.
- 12. An actuator arrangement as set forth in claim 11 wherein said range spring engages against said base of said cradle-like member.
- 13. An actuator arrangement as set forth in claim 12 wherein said range spring comprises a coiled compression spring having opposed end, one of said opposed ends of said spring engaging against said base of said cradle-like member.
- 14. An actuator arrangement as set forth in claim 13 wherein said frame means has adjustable means for adjusting the position of the other of said opposed ends of said spring to thereby set the force of said range spring acting on said cradle-like member.
- 15. An actuator arrangement as set forth in claim 14 wherein said adjustable means comprises an internally threaded tubular member carried by said other end of said spring, an externally threaded member threadedly disposed in said tubular member and having an end projecting out of said other end of said spring, said end of said externally theaded member being slotted for receiving a tool to threadedly adjust said threaded members, and a cam operated lever pivotally carried by said frame means and engaging said end of said externally threaded member to position said other end of said spring at the desired set position thereof.
- 16. An actuator arrangement as set forth in claim 11 wherein said arm means of said cradle-like member comprises two arms extending substantially transverse to said base and each engaging said lever.
- 17. An actuator arrangement as set forth in claim 16 wherein each arm has an outwardly turned end that engages said lever.
- 18. An actuator arrangement as set forth in claim 11 wherein said base has a substantially flat surface, said wall having a substantially flat surface engaging said flat surface of said base.
- 19. An actuator arrangement as set forth in claim 18 wherein said flat surface of said base is annular.
- 20. An actuator arrangement as set forth in claim 19 wherein said base has a raised central portion inboard of said annular flat surface thereof, said range spring comprising a coiled compression spring having opposed ends, one of said opposed ends of said spring telescopically receiving said raised central portion of said base and engaging said base on the side thereof opposite to said annular surface thereof.
- 21. In a condition responsive electrical switch construction having frame means carrying an electrical switch and a condition responsive device having a movable wall for causing movement of a lever that is pivotally carried by said frame means and is operatively associated with said switch to operate the same as said lever is moved by said wall to a certain position in opposition to the force of a range spring carried by said frame means, the improvement comprising a one-piece hardened metallic insert carried by said frame means and having a plurality of fulcrum surfaces against which said lever pivots.
- 22. A condition responsive electrical switch construction as set forth in claim 21 wherein said insert is substantially U-shaped and thereby has a cross member and a pair of legs extending therefrom, said legs each having one of said fulcrum surfaces thereon.
- 23. A condition responsive electrical switch construction as set forth in claim 22 wherein each said fulcrum surface comprises a substantially L-shaped surface, said lever having a pair of projections extending in opposite directions therefrom and respectively bearing against the elbows of said L-shaped surfaces of said legs of said insert.
- 24. A condition responsive electrical switch construction as set forth in claim 22 wherein said frame means includes a casing having opposed surfaces, said insert having said fulcrum surfaces thereof disposed adjacent and inboard of said opposed surfaces of said casing.
- 25. A condition responsive electrical switch construction as set forth in claim 24 wherein said opposed surfaces have openings therethrough adjacent said fulcrum surfaces of said insert, said lever having a pair of projections extending in opposite directions therefrom and respectively bearing against said fulcrum surfaces and extending out of said openings adjacent thereto.
- 26. A condition responsive electrical switch construction as set forth in claim 25 wherein said frame means includes another casing secured to the first mentioned casing, said casings clamping part of said insert therebetween to hold said insert to said frame means.
- 27. A condition responsive electrical switch construction as set forth in claim 26 wherein each leg of said insert has a tang means extending outwardly therefrom and comprising said part that is clamped between said casings.
- 28. A condition responsive electrical switch construction as set forth in claim 27 wherein one of said casings has an end surface, said tang means hooking around said end surface.
- 29. A condition responsive electrical switch construction as set forth in claim 26 wherein said other casing has sections thereof respectively disposed adjacent and outboard of said openings to cover and project said projections of said lever that project out of said openings.
- 30. A condition responsive electrical switch construction as set forth in claim 26 wherein said other casing holds said condition responsive device to said frame means.
- 31. An insert for a condition responsive electrical switch construction having frame means carrying an electrical switch and a condition responsive device having a movable wall for causing movement of a lever that is pivotally carried by said frame means and is operatively associated with said switch to operate the same as said lever is moved by said wall to a certain position in opposition to the force of a range spring carried by said frame means, said insert comprising a one-piece hardened metallic member adapted to be carried by said frame means and having a plurality of fulcrum surfaces against which said lever is adapted to pivot.
- 32. An insert as set forth in claim 31 wherein said insert is substantially U-shaped and thereby has a cross member and a pair of legs extending therefrom, said legs each having one of said fulcrum surfaces thereon.
- 33. An insert as set forth in claim 32 wherein each said fulcrum surface comprises a substantially L-shaped surface for receiving in the elbow thereof a projection of said lever.
- 34. An insert as set forth in claim 32 wherein each leg has a tang means extending outwardly therefrom and being adapted to be clamped between a pair of casings of said frame means.
- 35. An insert as set forth in claim 34 wherein each said tang means has hook means adapted for hooking with an end surface of one of said casings.
- 36. In a condition responsive electrical switch construction having frame means carrying an electrical switch and a condition responsive device having a movable wall for causing movement of a lever that is pivotally carried by said frame means and is operatively associated with said switch to operate the same as said lever is moved by said wall to a certain position in opposition to the force of a range spring carried by said frame means, said constrution having a movable selector means that is operatively associated with an abutment means of said lever to move said lever against a stop when said selector means is moved to an off position thereof, the improvement comprising biasing means disposed between said selector means and said abutment means to transmit motion of said selector means to said abutment means and to take up further movement of said selector means after said lever has been moved thereby against said stop.
- 37. A condition responsive electrical switch construction as set forth in claim 36 wherein said biasing means comprises a leaf-like spring member having a loop therein disposed between said selector means and said abutment means.
- 38. A condition responsive electrical switch construction as set forth in claim 37 wherein said selector means comprises a rotatable cam that cams against said loop as said selector means moves to said off position thereof.
- 39. A condition responsive electrical switch construction as set forth in claim 38 wherein said leaf-like spring member has opposed ends, one of said opposed ends of said spring member being secured to said frame means and the other of said opposed ends of said spring member being looped to define said loop thereof and being engageable by said cam.
- 40. A condition responsive electrical switch construction as set forth in claim 38 wherein said one end of said spring member is offset relative to said other end thereof.
BACKGROUND OF THE INVENTION
This application is a divisional patent application of its copending parent patent application, Ser. No. 865,594 filed Dec. 29, 1977, now U.S. Pat. No. 4,194,102.
1. Field of the Invention
This invention relates to an improved condition responsive electrical swhich construction as well as to improved parts therefor and/or for other devices and methods of making such parts.
2. Prior Art Statement
It is well known that condition responsive electrical switch constructions have been provided to each act as a "cold control" wherein the same is utilized to control the operation of a refrigerator or the like so that when the temperature in the refrigerator rises to a certain temperature, the control will operate an electrical switch to turn on the refrigerant compressor and continue to operate the refrigerant compressor until the temperature in the refrigerator has fallen a certain differential below the previously described high turn-on temperature whereby the control will cause the switch to turn off the compressor.
For example see the following four items:
(1) U.S. Pat. No. 3,065,323 to Grimshaw,
(2) U.S. Pat. No. 3,096,419 to Howell,
(3) U.S. Pat. No. 4,045,635 to Pursnani et al,
(4) Robertshaw Controls Company publication M D 12-C (Rev. 5/75) entitled "Robertshaw R C Series Narrow Differential Cold Controls"
The prior known condition responsive electrical switch construction of item (4) above has a pivotally mounted lever for operating the electrical switch with the lever being pivotally moved by a movable wall of a condition responsive device that is opposed in the expanding direction thereof by a suitable range spring. The range spring includes a pin-like member that passes through a slot in the switch actuating lever so as to have its free end received in a complimentary recess formed in the movable wall of the condition responsive device, the lever being biased against an annular shoulder of the pin member so as to follow movement thereof.
The condition responsive electrical switch construction of items (1) and (2) above each appears to have a cradle-like member to transmit movement of the pin member of the range spring to the switch actuator lever.
The switch housing of item (4) above has two pairs of opposed locating ears received respectively in aligned slots of a housing casing and are held in place by a staking of the casing to deform side edges of the casing slots against adjacent side edges of the ears of the switch housing.
Each of the switch housings of items (1) and (2) above appears to have a single pair of opposed locating ears received respectively in aligned slots of a housing casing and each being wedged between an angled edge of its respective slot and a cooperating flat edge opposed thereto as a cover member is being pivoted into place on the housing casing and thereby camming against the switch housing and causing the switch housing and housing casing to move into the final assembled position thereof.
The electrical switches of items (1), (2) and (4) above each appears to have a single movable contact moved by a kicker of the aforementioned actuating lever relative to a single fixed contact whereas the electrical switch of item (3) above has a single movable contact disposed between a pair of spaced fixed contacts whereby the movable contact is moved between the fixed contacts by the aforementioned actuator lever.
It is also known to have two movable contacts disposed between the two fixed contacts of a similar electrical switch with the two movable contacts respectively being engageable with the fixed contacts and being controlled by the kicker of the aforementioned actuator lever.
It is also known to have a pair of movable contacts disposed on opposite sides of a fixed contact with an actuator member disposed between the movable contacts to respectively move one of the movable contacts away from the fixed contact while the other movable contact remains in contact with the fixed contact.
For example, see the following six United States patents:
(5) U.S. Pat. No. 3,609,270 to Jorgensen et al,
(6) U.S. Pat. No. 3,656,081 to John,
(7) U.S. Pat. No. 3,735,069 to Andresen,
(8) U.S. Pat. No. 3,735,080 to Andresen,
(9) U.S. Pat. No. 3,819,896 to Aidn, et al,
(10) U.S. Pat. No. 4,027,131 to Aidn, et al,
It is also known to loop a switch blade to provide for a wiping action of the contact thereof with a fixed contact when the looped switch blade is moved by an actuator member in order to break a weld between the movable contact member and the fixed contact member.
For example, see the following two items:
(11) U.S. Pat. No. 3,548,181 to Piber,
(12) German Pat. No. 1,266,387 to Lorsbach,
Each of the condition responsive electrical switch constructions of items (1), (2) and (4) above appears to have the selector shaft thereof provided with a cam surface that engages against an abutment of the actuator lever to force the actuator lever against a stop when the selector shaft is rotated to an "off" position thereof.
Each of the condition responsive electrical switch constructions of items (1), (2) and (4) above appears to have the actuator lever thereof be provided with knife-edges which pivot against "vee" edges formed in the casing of the housing means thereof, item (2) appearing to have an additional lever cooperating with the actuating lever to reduce the bearing load on the "vee" edges of the casing.
It was found according to the teachings of this invention that if misalignment occurred between the range spring arrangement and the pivotally mounted actuator lever during the manufacture of the aforementioned condition responsive electrical switch construction of item (4) above, the range spring pin engages one of the side edges of the slot in the switch actuator lever to thereby provide interference to the free movement therebetween and, thus, an inaccuracy in the operation of the electrical switch so that the control device would turn on the refrigerant compressor at temperatures other than the selected set temperature of the control device.
The cradle-like member of items (1) and (2) above tends to eliminate the adverse effect of misalignment between the switch actuator lever and the range spring arrangement therefor because the cradle-like member transmits movement of the pin member of the range spring to the switch actuator lever.
However, it was found, according to the teachings of this invention, that a high wear area is provided between such cradle-like member and the pin member of the range spring.
Accordingly, it is a feature of this invention to provide a condition responsive electrical switch construction wherein the pin member of the range spring is eliminated.
In particular, one embodiment of this invention provides a condition responsive electrical switch construction having frame means carrying an electrical switch and a condition responsive device having a movable wall for causing movement of a lever that is pivotally carried by the frame means and is operatively associated with the switch to operate the same as the lever is moved by the wall to a certain position in opposition to the force of a range spring also carried by the frame means. A cradle-like member has a base operatively associated with the range spring so as to be held thereby against the wall of the condition responsive device to be moved in unison with the wall and has arm means engaging the lever to cause the lever to move in relation to movement of the wall whereby the range spring does not have a projecting pin member carried thereby to engage the wall of the condition responsive device as in the prior known condition responsive electrical switch constructions.
It was also found according to the teachings of this invention that the electrical switch for such a condition responsive electrical switch construction could be improved because some means must be provided for overshoot movement of the movable contact.
Thus, it was found according to the teachings of this invention that such an electrical switch could be formed with a single fixed contact and a pair of movable contact means.
In particular, one embodiment of this invention provides an electrical switch construction having frame means carrying fixed contact means and movable contact means to be moved relative to the fixed contact means by a kicker-type actuator member, the fixed contact means comprising a single contact member and the movable contact means comprising a pair of movable contact members disposed on opposite sides of the fixed contact member and each being biased in a direction to tend to place the same in contact with the fixed contact member. The actuator member is disposed between the pair of movable members and is movable in opposite direction sto engage and move the respective movable contact member out of contact with the fixed contact member. Each movable contact member comprises a conductive blade having two legs joined together by a loop at adjacent ends of the legs, one of the legs being substantially straight and having the loop offset therein at the end thereof to cause that leg to tend to elongate between the fixed contact member and the outside edge of the loop should a weld exist between that leg and the fixed contact member when the actuator member is attempting to move that conductive blade out of contact with the fixed contact member. Each conductive blade has the one leg thereof engageable with the actuator member and adapted to make contact with the fixed contact member intermediate the offset loop thereof and where the actuator member is engageable with that one, leg.
It was found, according to the teachings of this invention, that as a matter of convenience each of the casings of such condition responsive electrical switch constructions is normally constructed with tabs to be folded over as a fastening means for the cover and power element thereof and thereby creates the need for a ductile casing. However, such casing is normally constructed with "vee" pivot seats for one or more pivoting levers. While it is common practice to harden the knife-edges of the actuator lever, to minimize wear thereon, little can be done to protect the "vee" casing seats because the casing must be kept soft for the aforementioned ease of assembly purposes.
Thus, an additional lever in item (2) above was provided to reduce bearing load, particularly, for a high temperature differential control.
However, it is a feature of this invention to provide hardened "vee" seats for the hardened knife-edges of the actuator lever.
In particular, one embodiment of this invention provides a one-piece hardened metallic insert carried by the frame means of the condition responsive electrical switch construction and having a plurality of fulcrum surfaces against which the actuator lever pivots.
It was also a feature of this invention to provide improved assembly alignment between the electrical switch housing and the remaining casing of the housing means for any of the aforementioned condition responsive electrical switch construction or other constructions, as desired.
In particular, one embodiment of this invention provides a housing construction for an electrical switch construction or the like having one housing member partially telescoped inside another housing member to have a pair of opposed ear means of the one housing member respectively project through a pair of opposed slot means in the other housing member together with a cover member secured to one of the housing members to hold the same in their assembled and telescoped relation, each of the slot means of the other housing member being defined in part by a pair of opposed surface means of the other housing member one of which comprises a biasing section. Each ear has opposed edge means respectively press-fitted between the surface means of its respective slot means whereby the biasing sections hold one of the edge means of the ears against the other surfaces means of the slot means.
It was also found according to the teachings of this invention that when the selector means of any of the aforementioned condition responsive electrical switch constructions was turned to the "off" condition thereof, there was a tendency to cause the actuator lever to move out of its pivoted position should there be any over travel between the engaged abutment means of the actuator lever and the cam surface of the selector means.
Accordingly, it is a feature of this invention to provide an improved selector arrangement for such a condition responsive electrical switch construction for holding the actuator lever in its "off" position.
In particular, one embodiment of this invention provides a condition responsive electrical switch construction having a movable selector means that is operatively associated with an abutment means of an actuator lever to move the lever against a stop when the selector means is moved to an "off" position thereof, the selector means including a biasing means disposed between a cam surface of the selector means and the abutment means to transmit motion of the cam surface to the abutment means and to take up over travel movement of the cam surface after the lever has been moved against its "off" stop.
Accordingly, it is an object of this invention to provide an improved condition responsive electrical switch construction having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Another object of this invention is to provide an improved part for such an electrical switch construction or the like, the improved part of this invention having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Another object of this invention is to provide an improved method of making such an improved part of this invention, the method of this invention having one or more of the novel features set forth above or hereinafter shown or described.
US Referenced Citations (10)
Foreign Referenced Citations (1)
| Number |
Date |
Country |
| 1266387 |
Apr 1968 |
DEX |
Divisions (1)
|
Number |
Date |
Country |
| Parent |
865594 |
Dec 1977 |
|
Patent Grant
4363015
