US2625629A - Over and under actuator for electric switches - Google Patents

Description

Jan. 13, 1953 J. s. COLDWELI. 2,625,629

OVER AND UNDER ACTUATOR FOR ELECTRIC SWITCHES Filed Aug. 28, 1950 2 SHEETSSHEET 1 SULAr/U/V 34 INVENTOR. Jok 72 ,8; f'aZawaZZ.

ATTORNEY Jan. 13, 1953 J. 5. COLDWELL 2,625,629

OVER AND UNDER ACTUATOR FOR ELECTRIC SWITCHES Filed Aug. 28, 1950 2 SHEET$-SHEET 2 INVENTOR. J07? Sf Cldzoeil MKQ W ATTORNEY Patented Jan. 13, 1953 OVER AND UNDER ACTUATOR FOR ELECTRIC SWITCHES John S. Coldwell, Milwaukee, Wis., assignor to Globe-Union Inc., Milwaukee, Wis., a corporation of Delaware Application August 28, 1950, Serial No. 181,904

'This invention relates to improvements in elec- I trical switches and particularly to such switches of the quick-make and quick-break type.

'Switches of this type are frequently used in connection with other control components, such as radio rheostats and the like, and are operated by the same control member as such component. Heretcfore such switches have been added as a complete unit to the other component with an associated mechanism to form the inter-operative connection. The combined unit so made is comparatively bulky and expensive and not easily used in such applications as miniature radio sets, hearing aids, and the like.

One object of this invention, therefore, is to provide a switch of this type which may be simply and inexpensively built into another control com" ponent to create a small compact unit.

Quick-make and quick-break actions have been accomplished by toggle mechanisms, hill and valley constructions, ball and detent mechanisms,

garter springs, and other like devices. Each type is particularly adapted for a special application. Most of them are complicated and costly to make. Some of them do not have true snap action, slow operation of the control member eliminating the snap action.

Another object of this invention, therefore, is to provide a switch of this type which: has positive and reliable quick-make and quick-break action no matter how slowly the control shaft is operated; may be utilized for both single and multiple pole and throw; and may be operated by either angular or linear motion of a control mem ber. i

In accomplishing the foregoing objects, a spring contact having an insulator-striking block is moved from a normally biased position (either switch closed or open) to a controlled position (either switch open or closed) by the force of a spring-actuator engaging such block. The application of the force of the spring-actuator is controlled by the movement of such actuator relative to a fixed cam. As the actuator moves ei ther into or out of juxtaposition with respect to such block the cam flexes the actuator out of its normal position so that upon release from the cam the actuator snaps either against or away from such block to quickly move the spring contact with a snap action. In one direction of travel of the actuator it will move over said cam and. in the opposite direction of travel it will move under said cam to effect the desired quick application or quick withdrawal of actuating force. This principle of quickly applying and re- '11 Claims. (Cl. 200-154) gaeement with fixed contacts.

or make of switch contact.

moving a force to and from the spring contact may be utilized in various ways. The spring contact may carry one or a multiplicity of contacts. It may be biased either into or out of en- It may be normally in contact with one set of contacts and biased into contact with another set of contacts. Thus a single or multiple pole or single and -double throw switching action may be obtained. No matter how slowly the control member moves the actuator the release of the latter from the cam is always instantaneous and complete so that the stored force is suddenly applied or removed to provide a sure and dependable snap action break The length of engagement between cam and actuator is relatively short so that only a minimum movement of the actuator is required to effect switching action. The actuator may be carried by a movable ele- *nent of the other control component, the fixed cam may be positioned on the housing of such component, and the fixed contacts and spring contacts mounted on the cover for such housing. Thus a relatively small number of parts is em- 'oloyed and such parts incorporated with the elemerits of the other control component to make a compact inexpensive unit. As any type of relative movement between cam and actuator will control such actuator the movement of the control member may be linear or angular thus making the switch applicable for use with a large variety of other components. However, a switch embodying these principles may be constructed and used as a separate individual unit.

The novel features which are considered char acteristic of the invention are set forth with particularity in the app-ended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings, in which:

Fig. l is a View partly in elevation and partly in cross section on the meandering section line |l in Fig. 2 of a switch embodying the present invention incorporated with a variable resistor,

in the position assumed as the switch is being actuated toward on position;

Fig. 5 is a view similar to Fig. 3 with such parts shown with the switch in on position;

Fig. 6 is a view similar to Fig. 3 with such parts shown as the switch is being actuated toward 01? position;

Fig. 7 Ba top plan View of another modification of the switch embodying the present invention and operated by lineal movement of the control member; and

Fig. 8 is a view in side elevation of the .switch viewed in Fig. '7.

In Figs. 1 to 6, inclusive, theswitch embodying the present invention is combinedwith another control component such as a variable resistor. As the variable resistor. is. of well-known construction it will not be fully described herein. The switch and variable resistor are mounted-in a metal shell or case ld'to which is secured a mountingbushing 5'2 rotatably carrying a control member .orshaft 5- 3. Thevariablerresistonis adjusted by-therotation of-such control member as it 'movesp'an insula-ted-rcontact shoe 4,6 stakedto the inner end thereof. The variable resistorlshas customary electrical terminals, one of"which,isindicatedat l8. Thecontact shoe l6,'together with the innerend of-shaft 1 3, comprise the mounting support for a spring-actuator 2D staked con and rotatable -with*such shaft. A cam follower-22 carried by the'spring-actuator 20 is biased thereby'to a neutral position spaced laterally from the "body of-suchspring-actuator. The follower 22 may thusbe flexed to either side of its neutral position. enough so that the follower while in substantially'neutral position will be able to assert enoughforce to counteractthe inherent force in the rspring contact. Because of the inherent characteristics of the variable resistor :there .is oneportion of the totalmovement of'theshaft l 4 :at which. it is desirable to accomplishswitching operation. A fixedcam 24 is stationed near such portion in the normal path of travelf the'follower '22 to engage'the follower and cooperate in eiiectingswitch operation. The cam 2d may be made, as is shown inFigs. 1'.and'2,.by cuttingand' forming out a portionofthewall of the housing Iii, or any other way of so'fixedly positioning thecam in the path' of the 'follower will be satisfactory. It is only essential that thefollower bemomentarily flexed fromnormal position and suddenly. releasedso thattheforce so stored therein by suchflexingcan beutilized to open or close the: switch contact. In theparticular embodiment shown in .Figs. 1 to 6, .the cam 24 is sloped rearwardly and upwardly (as viewed inzF-ig. 1). As viewed in Figs..3. to 6,:inclusive,up"is down'.on the sheet, top is bottom on the sheet,*and vice versa, because such views were'taken on-a-sectional viewof Fig. 2 and Fig.2 'is-an inverted view. I-Iencepas the follower 22 is "moved angularly clockwise .(as viewed inFig. 2) from-the switch oif position shown in Fig. 2'it will strike against thetop of the cam z'andbe flexed upwardly. When the follower gz'clears the upper edge of thecam 24 it will forcibly spring to its normal .unfiexed position. When the follower 22 isreturned angularly counterclockwise it will engage the bottom ofcam 24 and be flexed downwardly until-it clears the lower edge of such cam. The follower willthen again spring to its normal unflexed position.

.The controlled. movement :ofthe follower. 22: is

The actuator is stiff used to operate a spring contact 26 mounted within the casing ID on a terminal 28. In this embodiment spring contact 26 is inherently biased toward engagement with a fixed contact 30 also mounted within the casing It by a terminal 32. However, the inherent force in the spring contact "26 is HOt-"SIlmCiGHttO "overcome the inherent stiffness-in spring-actuator 20'and cause it to have any substantial movement from normal position. Operative engagement between the follower 22 and the spring contact 25 is accomplishedthroughan insulating block 34 secured to the'end'of the spring contact 2'5 by suitable means. An-example of such means consists of a p'ortion'saticutfrom the body of the spring contact ilfi and bentitoward the end of such spring contact so as topass through an opening in the block as. The end'of such portion is clinched againsti'thelblock to hold it in place, as shown. The width (vertical dimension as viewed in Figs. 3 to-;6) -of the-block iszsuihcient-so that when itis engaged by thefollower 22 the spring: contact 26 will be raised fromengagement with fixed contactSi]. This is the position shown inFigsal,

.2, and 3. In order to permit thefollowerZZ-to be fiexedupwardly by the cam. 24 without letting the. spring-actuator 26 make .contact with .the fixedcontact .36, alower corner of theblock-34 is out ofi, as indicated at'33, to provide a sloping :edge substantially .parallel with .the surfaceof the canrz l. Thus as the follower22 is moved clockwise, as viewed inFig. 2, and engageson the top of cam .24, it will slide upwardly along the sloping surface 38 atthesame-ratethatit *slidesupwardlyalong the cam 24. This'relationship, as shown in Fig. 4, will notpermit the block 34 to change its position until .the follower 22 leaves the cam-24. When .the 'follower leaves the cam .24... and springs.to;its normal position, the inherent resilience. in .the spring contact. 26 will. cause. it .tosnap. to .theclosed or on positionofj'ig. 5. :Thespring-actuator-20- is then free to move with the control member I 4 :as it regulates. or operates the other component. :Upon reversemovement of the member I l-the follower 22 will..ride. down. the bottom of thecam- 24' (see Fig. 6) and not contact the block until .it clears the end of.such cam. Atsuchtime the followerwillriseand strike the spring arm 22.breaking the .contact with asnap.

In. Figs. 7 and Bthere is shown -a-modification in which the switch embodying-.thepresent. inventionis. not. combined with any. other control component. .In this modification theswitching action results from a lineal movement of the control member. The control memberconstitutes a push bar 46 whichis slidably smountedin-=a pair-of. spaced bracketsJi i and- 36 carried..by.-.a frame .42. .A leg .48 .on such .framedorms the supportjoran insulating platefiii. on whichis mounted the switch contacts. The fixed contact 52 iscarried on abracket 54 so as'to bespace'd from .the plate. A terminal t5 issecured to such bracket. Thespring contact 58. is secured-tothe plate'fiii and underlies the fixedcontact 52being biased soastobe normally in engagement therewith. .Aterminalfiilis connected with the spring contacted The springcontact '58 is1snapped open in a manner similar .to thatpreviously describedi-n connection with therfirstmodification by the controlledaction of a springeactuator 52 .mounted on the-push'bar as. 'This'springactuatorhas'a'cam follower 6 3 in linealialinement'with a fixed cam. 86 carried on the frame 42. The spring :contact- .58 carries an insulating block 68 with a sloping edge 1!! substantially parallel to and slightly spaced from the cam 66 in the normal position as shown in Fig. 8. When the push bar 46 is moved in a lineal path inwardly or to the right as viewed in the figures, the follower 65 will ride up on th cam 65 and bias the spring-actuator 52 from its normal position. When the follower 84 clears the cam 66 the actuator 62 will cause it to spring down on the top of the block 68 and snap the contacts to open position. When in this position lineal movement of the push bar as to the left will cause the follower 64 to ride down the underside of cam 66. During such movement the follower will be in engagement with the sloping surface and thus still' keep the contacts open. However, when the follower 64 clears the cam 66 it will spring to its normal position shown in Fig. 8 permitting the contacts to snap closed.

The principle herein described of actuating single pole throw switches can also be used to operate multiple pole single throw switches or multiple pole double throw switches. The switches may be operated from either normally open to closed or normally closed to open positions. Any number of fixed contacts may be employed and engaged by a number of movable contacts operated by a single actuator. In the case of a double throw switch the fixed contacts are positioned on opposite sides of the spring contact member. In both the modifications disclosed herein, the follower, the fixed cam, and the insulating block all have sloping surfaces which are substantially parallel. lhe purpose of this is to provide smoother action. However, as previously explained, the essence of the invention is to momentarily force the spring-actuator out of a normal position. This may be done by a follower which is sloped and a fixed cam which is not sloped at all. The same result may b accomplished by a follower which has no slope and a a cam which has the desired slope. It is not necessary in all cases to provide a sloping surface on the striker block except to provide necessary clearance to permit the spring contact to go to completely normally closed position. It does not make any difference in the desired switching action if the spring contact is moved farther away from off position during the return movement of the spring-actuator.

Although only several embodiments of the invention are shown and described herein, it will 'be understood that this application is intended to cover such other changes or modifications as come within the spirit of the invention or scope of the following claims.

I claim:

1. In an electric switch having relatively movof said contacts to control the movement of said contacts, and cam means in said path for flexing said actuator from said normal path, said actuator upon release from said cam means controlling the movement of said contacts with a snap action.

2. An electric switch as claimed in claim 1 in which said actuator rides up and snaps down from said cam means in one direction of travel and rides under and snaps up from said cam means in the opposite direction of travel to effectuate operation of said contacts.

3. In an electric switch having relatively movable contacts, one of said contacts having an actuator engaging portion, a spring actuator hav- 6 ing a normal path of travel in alinement with said portion, an actuator flexing member in said path, and camming means operative between said member and said actuator to temporarily flex said actuator out of said path and suddenly release said actuator for return to said path while in juxtaposition with said portion to operate said contacts.

4. An electric switch as claimed in claim 3 in which said portion and said camming means have related sloping surfaces permitting said actuator to be flexed while traveling from said portion toward said member without operating said contacts.

5. An electric switch including a spring contact biased toward one position, a relatively stiff member having a normal place in which said member holds said spring contact away from said one position, cam means for temporarily deflecting said member from said normal place and permitting said member to snap back to said normal place upon release of said cam means consisting of a flat sloped camming surface and a movable follower one of which is relatively fixed and the other of which is moved by a control member, and a control member for said cam means.

6. An electric switch including a spring contact biased toward one position, a relatively stiff member having a normal place in which said member holds said spring contact away from said one position, cam means for temporarily deflecting said member from said normal place and permitting said member to snap back to said normal place upon release of said cam means consisting of upper and lower fiat sloped camming surfaces and a movable follower, one of said follower or said surfaces being relatively fixed and the other being movable by a control member, and a control member for said cam means, said follower riding up said upper surface in one direction of movement of said control member and riding down said lower surface in the opposite return direction of movement of said control member.

7. An electric switch as claimed in claim 5 in which said control member consists of a rotating shaft.

8. An electric switch as claimed in claim 5 in which said control member consists of a slidable bar.

9. An electric switch comprising relatively movable contacts, a rotating member movable in a normal path to actuate the contacts, a stationary obstruction in said path, said member riding over one side of said obstruction and being deflected from its normal path and snapping back to its normal path as it leaves said obstruction when operated in one direction, said member riding over the other side of the obstruction and being deflected in the opposite direction from its normal path and snapping back to its normal path as it leaves said obstruction when operated in the opposite direction, the snap in opposite directions as it passes alternate ends of said obstruction operating said contacts.

10. An electric switch having relatively movable contacts, an actuating member consisting of a flat spring, a flat cam in the path of said spring and set at an angle to said path so that said spring engages and rides over one side of the cam when it approaches it from one direction and engages and rides over the opposite Side of the cam when it approaches from the opposite direction, departure from the cam at each end effecting movement of said switch contacts.

11. In an electric switch having movable con- 7 tacts, a movable.- actuating member, a stationary cam .for temporarily biasing -said memher, :a striker block ,on .one. of :.said contacts having ."a portion beneath said :cam engageable .by said member as said membersnaps off saidocam in one direction of travel thereof tooperate'said contacts, said block having -a 'taperalong which said member slides in the return opposite direction of travel so that as saidmember is biased byrsaid cam said block Will not be moved sufiiciently to operate said contacts until said member-clears'said cam.

JOHNS. COLDWELL.

8 .REEERENCES CITED 'The"fo11owing references are of x.record:.ini'the file'ofthis patent:

UNITED STATES PATENTS Number Name 'Date 2,014,474 Hopkins Sept. 17,1935 2,431,197 Platt Nov. 18, .1947

FOREIGN PATENTS Number Country Date #396,270 Germany May 31, 1924

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