Adjustable cycling switch for electric range

• US 5,191,310 A
• Filed: 07/09/1992
• Issued: 03/02/1993
• Est. Priority Date: 07/09/1992
• Status: Expired due to Term

• Current Assignee: Ranco Incorporated of Delaware (Schneider Electric SE)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Tuma, Paul H., Joyce, Ronald S., Obermann, George
• Primary Examiner(s): Broome, Harold
• Application Number:
  US07/911,234
• Time in Patent Office: 236 Days
• Field of Search: 337/102, 337/103, 337/105, 337/107, 337/82, 337/93, 337/94, 337/51, 337/52, 337/53, 337/57, 219/507, 219/514, 219/511
• US Class Current: 337/105
• CPC Class Codes: H01H 37/18 by varying bias on the thermal element due to a separate spring
• CPC Class Codes: H01H 89/04 Combination of a thermally actuated switch with a manually operated switch

Abstract

A thermally responsive load cycling switch assembly user adjustable for varying the time of cycling current to load connecting terminals and having a contact blade cantilevered from an insulator block pivoted in the switch housing. A bimetal blade actuator means is also cantilevered from the block and includes heater means to cause the bimetal to effect movement of the contact blade. A separate blade spring cantilevered from the block enables the block to be pivotably preloaded. A spring blade is cantilevered from the actuator means to enable separate preloading of the bi-metal for temperature calibration. A flexible jumper blade connects the contact blade to one of two load terminal connectors for series and parallel operation. A manually operated arming switch is series connected between one powerline terminal and one of the load terminals. A stationary contact disposed for closing a circuit with the contact blade is connected to the opposite powerline terminal. The block, contact blade, actuator means including bi-metal, heater, and the calibration spring jumper are assembled as a unit and pivoted in the housing. The terminal connectors are integrally formed with offset tabs for insertion and snap locking in grooves in the housing.

Claims

1. A thermally actuated switch assembly for heater load connection comprising:

(a) housing structure defining a first and a second power line connector terminal and a third and fourth heater load connector terminal and circuit means connecting said second and third connector terminal;

(b) a stationary contact electrically connected to said first connector terminal;

(c) a thermally responsive cycling mechanism, including a member mounted for pivotal movement on said housing structure, said mechanism including a contact blade having a movable contact thereon disposed upon movement for making and breaking a circuit with said stationary contact, and including a resistance member electrically connected in circuit with at least one of said third and fourth connector terminals, said resistance member operable upon a certain wattage of current flow therethrough to become heated and effect movement of said contact blade to break the circuit with said stationary contact, whereupon said current ceases to flow through said resistance member, which thereupon cools and effects remaking of said circuit with said movable contact thereby cycling current to the load; and

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(d) adjustable means operable upon user actuation to adjust the initial position of said cycling mechanism.

2. The terminally actuated switch assembly defined in claim 1, wherein said cycling mechanism includes a snap action device for effecting said movement of said blade member.

3. The assembly defined in claim 1, wherein said adjustable means includes a user rotatable cam with a resilient cam follower.

4. The assembly defined in claim 1, wherein said circuit means includes a user actuated switch series connected between said second and third connector terminals.

5. The assembly defined in claim 1, wherein said circuit means includes a user operated switch series connected between said second and third connector terminals;

and, said adjustment means is operable for effecting actuation and deactuation of said user actuated switch.

6. The switch assembly defined in claim 1, wherein said cycling mechanics comprises a subassembly of a resilient cam follower member mounted on said pivoted member, for operably contacting said adjustable means, a contact blade member and a bi-metal member heat warped by said resistance member.

7. The assembly defined in claim 1, wherein said cycling mechanism comprises a subassembly having a resilient preload arm operably contacting said adjustable means and with said conductive member formed integrally with said contact blade.

8. The assembly defined in claim 1, wherein said housing includes a fifth connector terminal electrically connected to said circuit means and adapted for connection to an indicator.

9. The assembly defined in claim 1, wherein said cycling mechanism includes an elongated support member, a calibration spring arm attached to one end thereof with said contact blade attached to the opposite end thereof, and including a snap acting spring with said calibration spring applying a preload to said snap acting spring.

10. A cycling mechanism for a thermally actuated load switch comprising:

(a) a pivot block means adapted for being pivotably mounted on said switch;

(b) as adjustment arm having one end thereof rigidly anchored to said block means and extending therefrom in cantilever;

(c) a resilient contact blade having one end anchored to said block means and extending in cantilever therefrom, said contact blade having an electrical contact provided on the free end thereof;

(d) electrical heater means associated with said pivot block means and movable therewith, said heater means operable, upon flow of a certain wattage of current therethrough, to effect movement of said electrical contact with respect to said pivot block means; and

(e) electrical terminal means connected with said contact blade and said heater means and adapted for external circuit connection therewith.

11. The cycling mechanism defined in claim 10, further comprising a support member mounted on said blade member with said heater means mounted thereon.

12. The cycling mechanism defined in claim 10, wherein said contact blade includes a snap action spring member.

13. The cycling mechanism defined in claim 10, wherein contact blade includes a snap action spring member;

and, said heater means includes a support member with a heater thereon, said member having one reaction end of said snap action spring registered thereon for effecting over-center movement thereof upon flow of said certain wattage of current.

14. The cycling mechanism defined in claim 10, wherein said heater means includes a support member with a heater thereon, said support member having one reaction end of a calibration spring in contact therewith, with the opposite reaction end adapted for contacting an adjustment means.

15. The cycling mechanism defined in claim 10, wherein said contact blade includes said heater means.

16. The cycling mechanism defined in claim 10, wherein said contact blade includes a spring portion movable over-center for effecting a snap action movement;

and, said heater means includes a member operable to move said spring portion in said over-center movement.

18. The switch assembly defined in claim 10, wherein said contact blade is formed of bi-metal material.

19. The switch assembly defined in claim 10, wherein means adjustably applying said preload to said block means includes ambient temperature compensation means.

20. The switch assembly defined in claim 10, wherein said contact blade arm means includes snap acting means for effecting movement of said movable contact.

17. A thermally actuated switch assembly for cycling current to a load comprising:

(a) housing means;

(b) a swing switch means adapted for connection to one side of a power line and operable upon user actuation to make connection with a first load connecting terminal;

(c) a second load connecting terminal isolated from said first terminal;

(d) insulated block means mounted for pivotal movement on said housing means;

(e) user adjustable means operable to apply a reload torque in one direction on said block means;

(f) a stationary electrical switch contact mounted on said housing means and adapted for connection to the side of a power line opposite said one side;

(g) a first resilient flexible electrically conductive lead means connected between one of said first and second load terminals and said block means;

(h) a switch contact blade having one end thereof anchored to said block means with a movable contact thereon said one end and disposed adjacent said stationary contact;

(i) thermally responsive actuator means operable upon being heated and cooled to cycle said contact blade between a position making and a position breaking circuit with said movable and stationary contacts;

(j) heater means connected in circuit with said flexible lead means and said movable contact means and operable upon making of said movable and stationary contact means and current flow therethrough to effect heating of said actuator means;

(k) calibration means operable for adjustably biasing said contact blade; and

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(l) second electrically conductive means connecting said first lead means with one of said second and first load terminals and said blade means,

wherein said block means, said contact blade, movable contact, said first and second means, said calibration means, and said user adjustable preload means are assembled as a subassembly for said pivotal mounting on said housing means.

21. An electrical control assembly comprising:

(a) housing defining a wall portion;

(b) circuit means mounted in solid housing means including a set of electrical contacts operable to perform an electrical control function;

(c) a plurality of apertures formed in said wall means;

(d) detent means formed in said housing means adjacent said aperture;

(e) a connector terminal formed from generally thin flat stock and having

(i) a first resilient tab formed integrally therewith and offset therefrom;

(ii) a second tab spaced from said first tab formed integrally therewith and offset therefrom;

(iii) a guide portion received in said aperture;

(iv) a blade portion extending externally through said aperture;

(f) said housing means defining a channel having a detent surface formed therein and a stop surface spaced from said detent surface, wherein said detent surface and said stop surface are generally aligned with said aperture;

(g) said terminal assembled to said housing means by deflecting said first tab over said stop surface to engages said detent surface wherein said second stab is biased against said stop surface retaining said terminal in said housing means with said blade portion extending outwardly therefrom and said guide portion received in said aperture; and

(h) lead means connecting said connector terminal to said switch means.

22. The assembly defined in claim 21, wherein said guide portion forms a portion of said blade portion.

23. The assembly defined in claim 21, wherein said guide portion and said blade portion are disposed generally at right angles.

24. The assembly defined in claim 21, wherein said circuit means includes switching means operable to make and break a circuit through said connector terminal.

25. The assembly defined in claim 21, wherein said circuit means includes means operable upon current flow therethrough to cyclically make and break a set of contacts.