US3662132A

US3662132A - Electrical switch construction

Info

Publication number: US3662132A
Application number: US5710A
Authority: US
Inventors: Arthur L Good
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1970-01-26
Filing date: 1970-01-26
Publication date: 1972-05-09
Anticipated expiration: 1989-05-09

Abstract

An electrical switch construction having a support means carrying a first blade and a second blade, the blades respectively having projections extending toward each other with a rolling C-shaped spring having opposite ends provided with openings respectively receiving the projections of the blades therein. The blades each has a pair of tabs on opposite sides of its respective projection and being bent relative to the spring to provide knife edges bearing against the rolling spring in aligned relation with the respective slot of the rolling spring.

Description

[ 1 May9,1972

United States Patent Good ....200/83 P UX ....200/67 DA UX ......200/67 A UX Good...................................200/67 D a m ymm mcm m MMP 957 5667 9999 wmmm nwmm 6886 0757 9 ,3 2333 m m a T M MN 0 S L Ln m AC M U A m S 0 E m L0 v EC m m .4 D r 1 [73] Assignee: Robertshaw Controls Company,

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[21] Appl. No.: 5,710

400/ 200/83 P An electrical switch construction having a support means carl'mlh 13/36 rying a first blade and a second blade, the blades respectively 200/67 67 83 83 MN; having projections extending toward each other with a rolling C-shaped spring having opposite ends provided with openings respectively receiving the projections of the blades therein.

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References Cited The blades each has a pair of tabs on opposite sides of its UNITED STATES PATENTS respective projection and being bent relative to the spring to provide knife edges bearing against the rolling spring in 2,170,767 8/1939 Riche....................... 2,458,518 1/1949 2,584,460 2/1952 v minnow 3.682.132

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INVENTOR. ARTHUR L. GOOD HIS ATTORNEYS PATENTEBMM 9 1912 SHEET 2 0F 3 INVENTOR.

ARTHUR L. GOOD M,M77ms HIS ATTORNEYS PATENTEDMAY 9 I972 3.662.132

' sum 3 OF 3 BIA F G. 6

- 84 9 IOB 248 5 IIB 69B 0 8 27B 34B SIB HIS ATTORNEYS ELECTRICAL SWITCH CONSTRUCTION This invention is related to the electrical switch construction of applicants co-p'ending patent application, Ser. No. 781,307, filed Dec. 5, 1968, and assigned to the same assignee to whom this application is assigned.

This application relates to an improved electrical switch construction as well as to improved parts for such a switch construction or the like.

It is well known from applicants aforementioned co-pending patent application that an electrical switch can be provided wherein a snap blade arrangement is provided by a rolling spring interconnected between a first movable blade and a second movable blade, the second movable blade carrying the electrical contact that is moved during the switching function.

However, it is a feature of this invention to improve upon the switch construction disclosed in applicants aforementioned co-pending patent application by providing improved engagement between the respective switch blades and the rolling spring.

Another feature of this invention is to provide improved engagement between various operating parts of the switch construction and one of the switch blades thereof.

Another feature of this invention is to provide an improved switch blade for such a switch construction or the like.

In particular, one embodiment of this invention provides a support means carrying the first and second switch blades with the blades respectively having projections extending toward each other and being respectively received in longitudinal slots provided in the opposed ends of a rolling, C-shaped spring. Each blade has a pair of tabs on opposite sides of its projection with the tabs being bent relative to the blade to provide knife edges engaging against the spring in aligned relation with the respective longitudinal slot thereof. One of the blades has various areas thereof formed into a partial cylindrical configuration to be respectively engaged by operating members of the switch construction, such as the actuating plunger, the adjusting member, etc.

Also, such switch blade is formed with a substantially rectangular section having an opening passing therethrough to define two pairs of opposed sides of the section, a first tongue being integrally interconnected to one of the sides and extending away from the section and a second tongue being integrally interconnected to that one side and extending in spanning relation over the opening of the section. The first tongue providing the interconnection to the rolling spring and the second tongue providing the engagement portion for the adjusting member to adjust the snap condition of the electrical switch construction.

Accordingly, it is an object of this invention to provide an improved electrical switch construction having one or more of the novel features set forth above or hereinafter shown or described.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. I is a perspective view of the improved switch construction of this invention.

FIG. 2 is an enlarged cross-sectional view of the switch construction of FIG. 1 and is taken on line 2-2 thereof.

FIG. 3 is a cross-sectional view taken on line 3--3 of FIG. 2.

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 2.

FIG. 5 is an exploded perspective view of certain of the operating parts of the switch construction of FIG. 2.

F IG. 6 is a view similar to FIG. 2 illustrating another switch construction of this invention.

FIG. 7 is a view similar to FIG. 2 and illustrates another switch construction of this invention.

While the various features of this invention are hereinafter described and illustrated as being particularly adapted to provide a snap acting switch construction, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide other types of electrical switch constructions as desired.

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate some of the wide variety of uses of this invention.

Referring now to FIGS. 1 and 2, the improved electrical switch construction of this invention is generally indicated by the reference numeral 10 and comprises a housing means 11 formed from a pair of

housing members

12 and 13 suitably secured together by fastening means 14 to define a chamber 15 therein. A blade means 16 is carried by the housing or support means 11 and comprises a first blade 17 having one end 18 thereof fastened to a terminal 19 carried by the housing means 11 and being provided with a terminal screw 20 for attaching an external lead thereto in a conventional manner, the other end 21 of the blade 17 carrying contact means 22 and 23 on opposed sides thereof to respectively cooperate with an adjustable, fixed contact 24 and an opposed fixed and spaced contact 25 interconnected to another terminal 26.

The blade means 16 also includes another blade 27 having a substantially rectangular section 28 provided with an opening means 29 passing therethrough and defining two pairs of

opposed sides

30, 31 and 32, 33 with the side having integrally interconnected thereto oppositely directed

tongues

34 and 35 respectively being provided with

free ends

36 and 37. The medial portion 38 of the side 30 of the blade 27 is raised out of the plane of the

sides

32 and 33 whereas the medial portion 39 of the side 31 is lowered out of the plane of the

legs

32 and 33 with the

legs

32 and 33 being downwardly bowed at points 40 and 41 so that the

comers

42 and 43 of the

sides

32 and 33 of the blade 27 can rest on abutment means 44 and 45 of the

housing members

12 and 13 to mount the blade 27 in the chamber 15.

The tongue 35 of the blade 27 is suitably shaped to reinforce the same with a central ridge 46 extending longitudinally thereof whereas the free end 37 of the tongue 35 is bent or formed to define part of a cylindrical configuration which is engaged by an adjusting screw 47 threadedly carried by an adjusting member 48 itself being threadedly carried by the housing means 1 l.

Similarly, the medial part 38 of the side 30 of the blade 27 is provided with a downwardly formed part 49 that defines part of a cylindrical configuration and is adapted to be engaged by an end 50 of an actuating plunger 51 movably carried by the housing means 1 1.

Another adjusting screw 52 is threadedly carried by another adjusting member 53 threadedly carried by the housing means 11, the adjusting screw 52 engaging against an abutment 54 at the free end 55 of a blade 56 having its other end 57 fastened to a terminal 58 carried by the housing means 11, the fixed contact 24 being carried on the other side of the end 55 of the blade 56 whereby the natural bias of the blade 56 is upwardly and tends to hold the abutment 54 against the adjusting screw 52. In this manner, the position of the fixed contact 24 relative to the other fixed contact 25 can be adjusted by the

parts

52, 53.

The blade 17 is provided with two parallel and substantially

straight legs

59 and 60 joined at the left hand ends in FIG. 5 to a cross section 61 having a tongue portion 62 carrying the contact means 22 and 23 on the opposed sides thereof.

, The

tongues

34 and 62 of the

blades

27 and 17 respectively have substantially rectangularly

shaped projections

63 and 64 directed 17, other in the assembled relation illustrated in FIG. 2 to be respectively received in substantially rectangular slots 65 and 66 formed in the

opposed ends

67 and 68 of a C- shaped rolling spring 69 as illustrated in FIGS. 2 and 5.

In order to support and stabilize the rolling spring 69 on the

projections

63 and 64 of the

blades

27 and 17 the

tongues

34 and 62 respectively have a pair of tabs 70 disposed on opposite sides of the

respective projection

63 and 64 and being bent with a substantially arcuate transverse cross-sectional configuration to provide a straight line knife edge 71 at the free end of the respective tab 70 which will engage against the rolling spring 69 in longitudinally aligned relation with the longitudinal axis of the particular slot 65 or 66 receiving the

respective projection

63 or 64.

In this manner, it has been found that knife edges 71 provided by the tab 70 obtain the maximum efiective force from the rolling spring 69 as a reasonably obtainable consistency is provided in the switch performance and avoids a pivoting action of the

blades

17 and 34 against the rolling spring 69 that would ordinarily produce a high stress on the rolling spring 69.

Also, the switch construction 10, through the configuration of the blade 27, provides a desired operating or actuating pin return force to insure a biasing force to move the rolling spring 69 through the required actuation thereof. In particular, this feature is provided by the containing

means

44 and 45 holding the end portion 31 of the blade 27 so that the

sides

32 and 33 provide two cantilevered springs which are relatively independent of the position of the operating pin or actuator 51 and the calibrating means 47. Accordingly, by providing the adjusting screw 47 and the temperature selector screw 48, the final calibration of the electrical switch 10 can be made without a force applied to the temperature sensing mechanism, thus making it a one shot adjustment if the main arm calibration is within tolerable limits.

Normally, the

switch blades

17 and 27 are held in the position illustrated in FIG. 2 when no force is being applied to the operating pin 51 in moving the same upwardly in FIG. 2 whereby the contact 22 is in electrical contact with the contact 24 so the current flow can be provided between the

terminals

19 and 58.

However, when the actuating pin 51 is moved upwardly in FIG. 2 either manually or by a condition responsive means sensing a certain condition, the same moves the blade 27 upwardly in opposition to the force of the spring leg or tongue 35 until the end 36 of the tongue 34 has rolled the spring 69 in such a manner that the same snaps the blade 17 downwardly in FIG. 2 to move the contact 22 out of electrical contact with the contact 24 and into electrical contact with the contact 25 to now place the

terminals

19 and 26 together, the

blades

17 and 27 now remaining in this new position by the rolling spring 69 even though the plunger or actuating pin 51 is permitted to move back downwardly to the position illustrated in FIG. 2.

Therefore, in order to reset the

switch blades

17 and 27 back to the position illustrated in FIG. 2 after the actuation of the switch 10 in the manner previously described, a rotatable reset member 72 is carried by the housing means 11 and has a pair of tongues 73 for straddling the tongue 34 of the blade 27 and being engageable with the

sides

59 and 60 of the blade 17 when the reset member 72 is rotated in a counterclockwise direction in FIGS. 2 and by a lever member 74 operatively interconnected to the reset member 72 by a rectangular slot 75 thereof receiving a rectangular similarly shaped projection 76 of the reset member 72. Thus, movement of the

legs

59 and 60 of the blade 17 upwardly will cause the tongue 62 of the blade 17 to roll the spring 69 in such a manner that the same will snap the contact 23 away from the contact 25 and place the contact 22 against the contact 24 as illustrated in FIG. 2.

Therefore, it can be seen that by changing the configuration of the

blades

17 and 27 over the configuration provided in the aforementioned co-pending patent application, not only is knife edge contact provided between the

blades

17 and 27 with the rolling spring 69, but also

cylindrical surfaces

49 and 37 are being engaged by the

operators

51 and 47 to increase the bearing contact areas therebetween so as to reduce wear and reduce shift in the actuating pin 51 actuating position.

Such switch construction of this invention can be modified to provide for changing the actuating pin position by means other than the manual adjusting means 48.

For example, reference is now made to FIG. 6 wherein another switch construction of this invention is generally indicated by the reference numeral 10A and parts thereof similar to the switch construction 10 previously described are indicated by like reference numerals followed by the reference letter A."

As illustrated in FIG. 6, the adjusting member 48 has been removed from the housing means 11A and a retainer 77 has been threadedly disposed in the cooperating opening with such retainer 77 carrying an expansible and contractible element 78 having its interior interconnected to a temperature sensing bulb 79 by a capillary tube 80. A movable wall 81 of the power element 78 carries an operating pin 82 that projects through the retainer 77 and bears against the contoured free end 37A of the blade 27A to produce new actuating pin positions of the actuating pin 51A for snapping over the rolling spring 69A in the manner previously described for the condition sensed by the bulb 79. For example, the arrangement 10A of FIG. 6 could be a temperature set point change for a limit control to compensate for outdoor temperature as sensed by the bulb 79. I

As illustrated in FIG. 7, another electrical switch construction of this invention is generally indicated by the reference numeral 103 and parts thereof similar to the switch construction 10 previously described are indicated by like reference numerals followed by the reference letter B.

As illustrated in FIG. 7, the terminal 58 and its associated blade 56 of the switch construction 10 has been removed and the contact 24B is now carried on a terminal 83 fixed to the housing means 11A.

The reset means 72 of the switch construction 10 has been eliminated and another reset means 84 has been added to the housing means 118 and comprises a retainer 85 carried by the housing means 118 and having a plunger 86 passing therethrough with an enlarged end 87 thereof adapted to bottom out against the end 88 of the retainer 85 by the force of a compression spring 89 disposed within the retainer 85 and bearing against an opposed large end 90 of the plunger 86.

The end 87 of the plunger 86 carries a compression spring 91 having one end 92 fixed to the end 87 of the plunger 86 while the other end 93 thereof is disposed remote therefrom and is adapted to project through the opening of the blade 17B and engage against the tongue 34B of the blade 27B so as to move the blade 27B downwardly relative to the blade 178 when the operating pin 51B has previously caused the rolling spring 69B to move the blade 17B downwardly in the manner previously described.

Thus, the operator can push downwardly on the upper end 94 of the plunger 86 in opposition to the force of the compression spring 89 to move the spring 91 downwardly against the blade 27B to snap the

blades

27B and 17B back to the position illustrated in FIG. 7. When the operator releases the end 94 of the plunger 86, the compression spring 89 returns the same to the position illustrated in FIG. 7.

Therefore, it can be seen that this invention not only provides an improved electrical switch construction, but also this invention provides improved parts for such a switch construction or the like.

While the form of the invention now preferred has been disclosed as required by the statute, other forms may be used, all coming within the scope of the claims which follow.

What is claimed is:

1. In an electrical switch construction having support means and switch blade means carried by said support means for providing a switching function upon movement of said blade means relative to said support means a certain amount, the improvement wherein said blade means comprises a single blade having a generally rectangular section provided with an opening therethrough whereby two pairs of opposed sides of said section border said opening, said blade having a first integral tongue extending from one side of said section in cantilevered fashion away from said section, said blade having a second integral tongue extending from said one side of said section in cantilevered fashion to partially span said opening, adjusting means carried by said support means engaging said second tongue for adjusting said blade means, the side opposite to said one side being the only part of said blade engaging against said support means to position said blade relative to said support means, said blade means including another blade that carries a movable contact of said electrical switch construction, and means interconnected to said other blade and to the first-named blade to provide for movement of said other blade upon a certain movement of said first-named blade.

2. In an electrical switch as set forth in claim 1, the further improvement wherein said second tongue has a free end, said free end being formed to define part of a cylindrical configuration, said adjusting means engaging said formed free end of said second tongue.

3. In an electrical switch as set forth in claim 1, the further I improvement wherein an actuator is carried by said support means and is engageable with said one side of said section of said first-named blade.

4. In an electrical switch as set forth in claim 3, the further improvement wherein said one side of said section of said firstnamed blade is formed to define part of a cylindrical configuration, said actuator being engageable with said cylindrical configuration part of said one side of said section.

5. In an electrical switch construction having support means and switch blade means carried by said support means for providing a switching function upon movement of said blade means relative to said support means a certain amount, the improvement wherein said blade means comprises a single blade having a generally rectangular section provided with an opening therethrough whereby two pairs of opposed sides of said section border said opening, said blade having a first integral tongue extending from one side of said section in cantilevered fashion away from said section, said blade having a second integral tongue extending from said one side of said section in cantilevered fashion to partially span said opening, and adjusting means carried by said support means engaging said second tongue for adjusting said blade means, the side opposite to said one side engaging against said support means to position said blade relative to said support means, said blade means including another blade, a rolling spring interconnected to said other blade and the first-named blade to provide a snap acting arrangement.

6. In an electrical switch as set forth in claim 5, the further improvement wherein said first tongue of the first-named blade has a free end interconnected to said rolling spring.

Claims

3. In an electrical switch as set forth in claim 1, the further improvement wherein an actuator is carried by said support means and is engageable with said one side of said section of said first-named blade.

4. In an electrical switch as set forth in claim 3, the further improvement wherein said one side of said section of said first-named blade is formed to define part of a cylindrical configuration, said actuator being engageable with said cylindrical configuration part of said one side of said section.