US2831081A

US2831081A - Electric switch

Info

Publication number: US2831081A
Application number: US526908A
Authority: US
Inventors: Howard F Mason
Original assignee: MASON ELECTRIC CORP
Current assignee: MASON ELECTRIC CORP
Priority date: 1955-08-08
Filing date: 1955-08-08
Publication date: 1958-04-15
Anticipated expiration: 1975-04-15

Description

3 Sheets-Sheet 1 April 15, 1958 H. F. MASON ELECTRIC SWITCH Filed Aug. s, 1955 Jil-e. 1. Jzr@ April 15, 1958 H, F, MASON 2,831,081

- 1=JLEGTRICv SWITCH April 15, 1958 v H, F, MASON 2,831,081

ELECTRIC SWITCH Fild Aug. 8, 1955 f2 254 252 3 Shfaets-Sheet 5 United States Patent Ottice 2,831,081 Patented Apu 15, 1958 ELECTRIC SWITCH Howard F. Mason, Los Angeles, Calif., assignor to Mason Electric Corporation, Los Angeles, Calif., a corporntiozi of California Application August 8, 1955, Serial No. 526,908

14 Claims. (Cl. 20D- 67) The present invention relates in general to electric switches, and a general object of the invention is to provide a switch which operates with a snap action to provide a fast make and break to minimize arcing, which operates in a positive manner in the sense that the able contact snaps from one operative position to another without any possibility of pausing between the two operative positions, which operates in the foregoing manner irrespective of how the switch is manipulated manually by the operator, which provides a positive feel i so that the operator can readily tell that the switch `has advanced from one operative position to another, and the like.

Another general object of the invention is to provide a switch which in some respects constitutes an improvement on that disclosed and claimed in my copending application Ser. No. 325,401, led December ll, i952, of which this application is a continuation in part. However, various features of the switch of the present invention are independent of that disclosed and claimed in my said copending application, and it will be understood that such features are not to be regarded as limited thereto except insofar as may be required by the patent claims forming part hereof.

Considering the switch of the present invention generally, it includes a contact path having two or more recesses therein which dene operative positions ot a movable contact, the latter preferably being a roller contact adapted to roll along the contact path. More particularly, the invention contemplates switch wherein the contact path is arcuate, deilning either part ot s, circle, or a complete circle, and wherein stationary contacts located at at least some of the recesses in the arcuate contact path. Thus, the roller contact engages stationary contacts in one or more of its operative positions wherein t it is received in one of the recesses, the Contact path being formed of electrically insulating material intermediate the stationary contacts. The switch of the invention also includes an actuating means for moving the roller contact along the Contact path and into and out of each of the recesses therein.

With the foregoing general background, a primary object of the invention is to bias the roller contact into engagement with the contact path with a biasing means which applies a maximum bias to the roller Contact when it is being moved into or out ot each of the recesses, and which applies lesser biases to the roller contact when it is in engagement with the contact path intermediate the recesses and when it is in each ofthe recesses. ln this connection, a related object is to providefmeans which applies a minimum bias to the roller contact when it is in engagement with the Contact path intermediate the recesses therein.

With the foregoing construction, by applying a maximum bias to the roller Contact when it is being moved into or out of each of the recesses, resistance to movenicht out of each recess is a maximum to provide a posi- Contact path intermediate the recesses, resistance to movement from one recess to another is minimized to provide ease of action, which are important features of the invention. Preferably, an intermediate bias, intermediate the maximum and lminimum biases mentioned, is applied to the roller contact when it is in each of the recesses, which provides a feel advising the operator that the roller contact is indeed in one of the recesses.

To accomplish the foregoing, it is an object of the present invention to provide `means for applying a minimum bias to the roller Contact when it is in engagement with the contact path yintermediate the recesses therein, for applying an intermediate bias to the roller contact when it is in each of the recesses, and for applying a maximum bias to the roller contact when it is being kmoved into or out of each ofthe recesses.

Still vmore particularly, an important objectof the invention is -to provide snap-acting means connecting the roller contact and the actuating means therefor for biasing the roller contact into engagement with the contact path in thel manner indicated above. A related object is to provide a snap-acting means for the-purpose mentioned which operates with a snap action as the roller Contact moves vinto and out of each of the recesses, whereby the force acting between the roller Contact and the contact path is the maximum roller-contact-biasing force applied to the roller Contact as it moves into and out of each of the recesses in the manner hereinbetore discussed. Still another object in this connection is to provide a snap-acting means which applies a minimum bias to the roller contact when it is in engagement with the contactpath between the recesses, and whichk applies to the roller contact when it is in each of the recesses an intermediate bias less than the maximum bias but'greater than the minimum bias.

Although various snap-acting means capable of applying a variable bias to-the roller Contact in the foregoing mannermay be utilized within the scope of the present invention, I prefer to employ as such snap-acting means the leaf-spring detent means disclosed and claimed in my Patent Number 2,684,843, granted July 27, 1954,-to which reference is hereby made for a detailed description of the structure and operation of such leaf-spring detent means. In general, such detent means assumes either of two configurations with a snap action, and is capable of exerting a maximum biasing force in opposition to an applied force causing it to snap from one configuration to the other. When such detent means is in said one configuration, it is capable of exerting the intermediate biasing force hereinbefore mentioned, and when it is snapped into said other configuration, it is capable of exerting the minimum biasing force hereinbefore mentioned, the detent means being in what might be termed a ,relatively4 accid condition under the latter circumstances.

Another important object is to provide a switch wherein the roller contact is mounted on a carrier which is connected to the actuating means and which is connected to the roller contact through the snap-acting means men'- tioned, the latter preferably being disposed between the carrier and the roller contact. Another object in this connection is to provide a switch wherein there is a resilient 10st-motion connection between the actuating means and the carrier, the lost-motion connection providing a range of relative movement between the carrier and the actuating means which is at least equal to the spacing between the recesses in the contact path so as toy providerfor movement of the roller contact from one recess to another with a snap action in the manner more fully discussed in my aforesaid copending application. Still another object in this connection is to provide stop means on the actuating means which engages the carrier, after the range of relative movement provided by the resilient lost-motion connection between the actuating means and the carrier has been taken up, for insuring displacement of the roller contact out of the particular i means and the carrier, becomes inoperative due to changes in characteristics, for example, or if the roller contact becomes welded to one of the stationary contacts, or the like. In general, upon application of a predetermined operating force to the actuating means, the snap-acting biasing means between the carrier and the roller contact will snap into its llaccid condition to permit the roller contact to move out of the particular recess in which it is disposed and to snap into the next recess due to the characteristic action of the resilient means incorporated in the resilient lost-motion connection between the actuating means and the carrier.

Another object of the invention of considerable importance is the provision of a roller contact which includes a magnet, or magnetic hub, having therearound a cylindrical jacket of nonmagnetic, electrically conductive, arc rupturing material, such as a silveralloy, a1- though it may be copper, brass, or a noble metal.

The foregoing construction provides magnetic arc quenching to minimize arcing between the roller contact and the stationary contacts as they are made and broken. By making the arc-quenching magnet movable with the movable conta-ct, only one such magnet is required for a plurality of stationary contacts and, by making the arcquenching magnet a part of the roller contact, specifically the hub thereof, a very compact magnetic arcquenching means results, which are important features of the invention.

One advantage of the snap-acting biasing means for urging the roller contact into engagement with the contact path which has not been mentioned heretofore is that it provides a very compact switch, particularly where the leaf-spring detent means of my aforementioned Patent Number 2,684,843 is employed as the snap-acting biasing means. Thus, by using such a snap-acting biasing means and/or the magnetic arc-quenching means incorporated in the roller contact, a very compact switch results, which is particularly desirable in installations wherein the space available for switches is at a premium, this being an important feature of the invention.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will become apparent hereinafter, may be attained with the exemplary embodiments of the invention which are illustrated in the accompanying drawings and which are described in detail hereinafter. Referring to the drawings:

Fig. l is a longitudinal sectional view of a three-position toggle switch which embodies the present invention;

Fig. 2 is a transverse sectional view of the toggle switch illustrated in Fig. l and is taken along the arrowed line 2 2 of Fig. l;

Figs. 3, 4 and 5 are enlarged, fragmentary sectional views illustrating the operation of a snap-acting biasing means of the invention for three different positions of a, roller contact on a contact path of the switch of the invention, the three positions to which Figs. 3, 4 and 5 correspond being indicated by the

broken lines

3, 4 and 5, respectively, of Fig. 2 of the drawings;

Fig. 6 is an enlarged, fragmentary sectional view cor 4 responding to Fig. 5 of the drawings and corresponding to the roller-contact position indicated by the broken line 5 of Fig. 2 of the drawings;

Fig. 7 is a longitudinal sectional View of a rotary switch which embodies the present invention;

Fig. 8 is a transverse sectional view of the rotary switch of Fig. 7 of the drawings which is taken along the arrowed line 8 8 of Fig. 7;

Fig. 9 is a longitudinal sectional view of a rotary switch which is presently regarded as the preferred embodiment of the invention;

Fig. l0 is a transverse sectional view on a reduced scale taken along the arrowed line 10-10 of Fig. 9;

Fig. ll is a `fragmentary sectional view taken along the arrowed line 11-11 of Fig. 9; and

Figs. l2, 13 and 14 are enlarged, fragmentary sectional views illustrating the operation of a snap-acting biasing means of the Vembodiment of Fig. 9 for three different positions of a roller contact on a contact path, and correspond to Figs. 3, 4 and 5, respectively.

Referring particularly to Figs. 1 and 2 of the drawings, the embodiment illustrated therein constitutes a toggle switch of the invention and is designated generally by the numeral 10. The switch 10 includes a case or housing 12 which is open on one side and which is provided in its opposite wall with an aperture 14 through which projects a tting 16. The latter is externally threaded to receive a nut, or the like, not shown, for mounting the switch 10 on a panel, not shown, with the panel clamped between such nut and the housing 12 in the conventional manner.

Within the housing 12 is a block 20 of electrically insulating material, such as a suitable plastic. The block 20 is provided with an arcuate cavity 22 therein and extending along the circumferential wall of this cavity are two arcuate grooves 24 separated by an arcuate rib 26. The radially inner wall 28 of this rib forms part of an arcuate contact path 30 for a roller Contact 32 to be described hereinafter.

Spaced apart along the contact path 30 and forming parts thereof are

contacts

34, 36 and 38, the contact path 30 being provided with

recesses

40, 42 and 44, for the roller contact 32, in the

respective contacts

34, 36 and 38. Preferably, and as more fully disclosed in my aforementioned copending application, each of the

contacts

34, 36 and 38 includes two contact elements respectively disposed in the grooves 24. The three contact elements in one of the grooves 24 are preferably electrically interconnected and are electrically connected to a terminal 46 projecting through the block 20 and the open side of the housing 12. The other contact element of the contact 36 is not provided with any terminal, while the other contact elements of the contacts 34 and 38 are respectively electrically connected to terminals 48 and 50 which also project from the open side of the housing 12 through the block 20. The contact elements of each of the

contacts

34, 36 and 38 are spaced apart, being separated by the rib 26, so that they are bridged by the roller contact 32. Thus, with this construction, which is illustrative only, the switch 10 is provided with an off position and two on positions, the switch being in the off position when the roller contact 32 is in the recess 42 in the contact 36, and the switch being in its on positions when the roller contact is in the

recesses

40 and 44 in the contacts 34 and 38.

As shown in Fig. l of the drawings, the arcuate ri Z6 is provided with recesses 52 therein which are aligned with and slightly deeper than the

recesses

40, 42 and 44 in the

contacts

34, 36 and 38, thereby avoiding engagement between the roller contact 32 and the rib 26 when the roller contact is in one of the

recesses

40, 42 and 44. Only one of the recesses 52 is visible in Fig. l of the drawings. Also, it will be noted that the

recesses

40, 42 and 44 in the

contacts

34, 36 and 38 are not quite as wide as the contacts themselves so that these contacts asenosr form parts of the intermediate sections of the contact path 30 beween the recesses r40, 42 yand 44. As pointed out in more detail in the copending application, this prevents arcing between the roller contact 32 and the

contacts

34, 36 and 38 Within the

recesses

40, 42 and 44 in these contacts.

The switch includes snap-acting means 58 for biasing the roller contact 32 into engagement with the contact path with a minimum force when the roller contact is in engagement with the contact path intermediate the

recesses

40, 42 and 44, with an intermediate force when the roller contact is in each of these recesses, and with a maximum force when the roller contact is being moved out of these recesses. The snap-acting means 5E, which will be described in more detail hereinafter, connects the roller Contact 32 to an actuatingy means ed through a carrier 62 for the roller contact, the snapacting means 53 connecting and being positioned between the roller contact and the carrier. A resilient lost-motion connection 64 is provided between the carrier 62 and the actuating means 60, the latter being provided with stop means 66 which limit the range of relative movement between the actuating means 6i) and the carrier 62 and which serve as kickers as hereinbefore outlined and as hereinafter described in more detail.

Considering the manner in which the roller contact 32 is mounted on the carrier 62 and connected thereto by the snap-acting means S8, the roller contact, which will be described in more detail hereinafter, is provided with an axle 68 rotatably mounted relative to ianges 70 of a cage 72, the flanges 70 being located at opposite ends of the roller contact and the cage 72 being provided with other flanges 74 on opposite sides of the roller contact. The cage 72 is loosely mounted in a cavity 76 in the carrier 62 so that the cage, and the roller contact 32, may move freely in this cavity in a direction toward and away from the contact path 30.

The cage 72 carries, on the side thereof opposite the roller contact 32, an element 78 having end iianges Si) and projections 82 inwardly of the respective flanges. Confined between the flanges 80 and engaging the projections S2 is a leaf-spring detent means 84 which is constructed as disclosed in my Patent Number 2,684,843 so that a detailed description herein is unnecessary. The projections S2 engage one side of the detent means S4, and the other side thereof is engaged by a projection 656 on the inner wall of the cavity 76, the projection 6 being located between the projections S2.

The actuating means 60 includes a lever 90 which projects through the fitting 16 into the housing 12, there being a ball-and-socket connection, indicated generally by the numeral 92, between the tting 16 and lever 90 to provide for universal movement therebetween. While the ball-and-socket connection 92 provides for universal movement to provide several degrees of freedom, as more fully discussed in my aforesaid copending application, it will be noted that movement of the carrier 62, to which the lever is connected in a manner to be described, is largely restricted to movement along the contact path 30 because of the fact that the carrier is disposed in the arcuate cavity 22 in the block 20. Thus, movement of the carrier laterally of the arcuate cavity 22 is limited to the clearance between the carrier 62 and the side walls of the arcuate cavity. The lever 90, at its inner end, is connected to a U-shaped spring 94 which embraces the carrier 62. This connection permits relative movement between the lever 90 and the carrier 62 in either direction along the arcuate contact path 30, and constitutes the resilient lost-motion connection 64 hereinbefore mentioned. The kickers 66 mentioned earlier herein are constituted by the ends of a yoke 96 which is also carried bythe inner end of the lever 90, the arms of the yoke being spaced outwardly from the respective arms of the U-shaped spring 94 to permit relative movement of the lever 90 and the carrier 62 throughout a limited range `as hereinbefore outlined and as hereinafter discussed in more detail.

Clamped between a flange 98 on the fitting 16 and the housing 12 is an eye or annulus 100 whichy carries a spring 102 engageable by one of the kickersy 66 for a purpose to be explained. The spring 102 may be omitted, or two such springs, not shown, one for each kicker 66, may be employed, depending on the mode of operation desired for the switch 10 as hereinafter discussed.

Turning now to a consideration of the over-all op eration of the switch 1), the manner in which the roller contact 32 is snapped from one of the

recesses

40, 42 and 44 to the next will be considered first for convenience. A detailed description of this snap-action herein is unnecessary, since it is fully described in my aforementioned copending application, and it will therefore be described only briefly. When the lever is moved in a direction to tend to move the roller contact 32 from one of the

recesses

40, 42 and 44 to another, the roller contact resists movement out of the recess in which it is disposed until the snap-acting means 58 snaps in a manner to be described hereinafter. Be* cause of this resistance to movement of the roller contact 32 out of the recess in which it is located, the resilient lost-motion connection 64 yields to permit move ment of the lever 90 relative to the carrier 62. In other words, the U-shaped spring 94 exes to permit the carrier 62 to rock relative to the yoke 96. Ultimately, the U-shaped spring 94 is stressed to such an ex tent that the snap-acting means 58 snaps, whereupon the roller contact 32 leaves the

recess

40, 42 or 44 in which it is located and moves to the next recess with a snap action. As hereinbefore mentioned, the total range of relative movement between the carrier 62 and the lever 90 which is provided by the resilient lost-motion connection 64 exceeds the spacing of the

recesses

40, 42 and 44 so that the roller contact 32 automatically moves to the next recess once it has been displaced out of the particular recess in which it is located. Consequently, once the operator applies to the lever sufficient force to displace the roller contact 32 out of the recess in which it is located, no manual manipulation of the lever can prevent the roller contact from moving to the next recess. This provides a very positive and reliable action, which is an important feature.

Considering now the operation of the snap-acting means 5S as the roller contact .32 is displaced out of one of the

recesses

40, 42 and 44 and moved to the next with the snap-action described, Figs. 3, 4 and 5 of the drawings best illustrate what happens to the snapacting means S8 as the foregoing occurs. Referring to Fig. 3, the ieaf-spring detent means d4 assumes the conguration shown therein when the roller contact 32 is in one of the recesses, e. g., the recess 42, with no force applied to the lever 9d. When the detent means S4 has this configuration, which may be termed its normal configuration, it applies an intermediate bias to the roller contact 32, urging it into the recess 42 to center it therein. Now, if an actuating torce is applied to the lever 90 sufiicient to move the roller contact 32 away from the center of the recess 42, as indicated by 'the broken line 4 in Fig. 2 of the drawings, the detent means 84 transiently assumes an intermediate, on-center, configuration as shown in Fig. 4 of the drawings. .lust before the detent means 34 attains the transient intermediate configuration illustrated in Fig. 4 of the drawings, it is on the verge of snapping over center into the configuration shown in Fig. 5 thereof hereinafter termed its second coniiguration, and, when the detent means is on the verge of snapping into such configuration, it applies a maximum bias to the roller contact 32 resisting its displacement out of the recess 42. However, when the actuating force applied to the lever 9@ reaches a sutlciently high value, the detent means 84 snaps through the intermediate configuration shown in Fig.

4 of the drawings into the coniiguration shown in Fig. 5 of the drawings, the detent means, under such conditions, being more or less flaccid and applying a minimum bias to the roller contact 32. Consequently, when the detent means 84 snaps into the configuration of Fig. 5 of the drawings, the roller contact 32 is free to leave the recess 42, whereupon the energy stored in the resilient lost-motion connection 64 snaps the roller contact into the recess 44 in the manner hereinbefore discussed.

Considering the advantages of the action of the detent means 84, since it applies an intermediate bias to the roller contact 32 when the latter is in one of the recesses. e. g., the recess 42, with no force applied to the lever 90, any force applied to the lever encounters increasing rcsistance as the coniiguration of the detent means 84 is changed to increase the bias applied to the roller contact 32 from the intermediate value to the maximum value. Thus, the operator is provided with a positive feel advising him that the roller contact is properly positioned within the recess 42, which is an important feature. Once a suiicient actuating force has been applied to the lever Swl to snap the detent means S4 from the configuration illustrated in Fig. 3 through the intermediate conguration illustrated in Fig. 4 into the conguration illustrated in Fig. 5, the detent means, in effect, suddenly goes limp to permit the roller contact to jump out of the recess 42 and to permit it to be snapped into the next recess 44 by the energy stored in the resilient lost-motion connection 64. The bias build-up from the intermediate value to the maximum value required to displace the roller contact 32 out of the recess 42 prevents inadvertent operation of the switch 10, while the minimum bias applied to the roller contact while it is on the contact path between the

recesses

42 and 44 minimizes friction and thus assures free rolling of the contact from the recess 42 to the recess 44. Thus, a still more positive action is attained.

As an example, for a switch 10 having a rating of in the neighborhood of from twenty to thirty amperes, the intermediate bias applied to the roller contact 32 by the detent means S4 when the roller contact is in the recess 42 may be of the order of magnitude of two pounds. The maximum bias developed just before the detent means 84 snaps into the configuration illustrated in Fig. 5 of the drawings may be of the order of magnitude of three pounds. The minimum bias occurring when the detent means S4 is between the

recesses

42 and 44 and is more or less flaccid, may be of the order of magnitude of one and one-half pounds. The latter is suthcient to cause the detent means titi to snap back into the contiguration illustrated in Fig. 3 of the drawings when the roller contact 32 enters the recess 44. It will be understood that the foregoing bias values are illustrative only and that the invention is not limited thereto.

The kickers 66 normally do not come into operation, and engage the carrier 62 to kick the roller contact 32 out of the recess in which it is disposed only when extraordinary rcsistance to displacement of the roller contact out of such recess is encountered, the switch thereafter operating as hereinbefore described, Such extraordinary resistance to displacement ot the roller contact may be due to the presence of foreign matter, welding of the roller contact 32 to one of the contacts 34, 3o and 3d, changes in the operating characteristics of the detent means tit with the passage of time, and the like.

It will be noted that when the roller contact is displaced into the recess 44 in the manner hereinbefore described, the yoke 96 engages the spring 102and stresses it. The characteristics and position of the spring 102 relative to the yoke 96 are such that, upon release of an actuating force applied to the lever 90, the spring 1&2 automatically returns the roller contact 32 from the recess 44 to the recess 42. Thus, the spring 102 might be termed a momentary return spring since it permits the roller contact 32 to remain in the recess 44 only so long as a sufficient actuating force is applied to the lever 90, the spring 102 thereby permitting momentary engagement between the roller Contact 32 and the contact 38. As hereinbefore pointed out, a similar spring, not shown, may be employed on the opposite side or" the yoke 96 to produce the same effect with respect to the contact 34. .alternatively the spring 102 may be omitted if the momentary return feature is not desired.

Considering the roller contact 32 in more detail, its axle 68 is made of a resilient material, such as spring wire, and the roller contact is provided with a hub 106 which engages the axle 68 throughout only a relatively portion of its length. Thus, as more fully described in my aforesaid copending application, the axle 68 may Een to permit the roller contact 32 to wobble or rock somewhat, thereby assuring proper engagement with the Contact elements of the

contacts

34, 36 and 38 even though the recess in one contact element of a particular pair may be deeper than the other, or may be offset circumferentially from the other, due to inaccuracies in manufacture, changes in the recess contours due to arcing, and the like.

An important feature of the invention resides in making the hub 106 of the roller Contact 32 a permanent magnet, such as an Alnico magnet, and by surrounding it with a cylindrical open-ended jacket 108 of non-magnetic, electrically conductive material. The jacket 108 is made nonmagnetic to prevent shunting of the magnet eld provided by the magnetic hub 106, and is made electrically conductive to carry current betweenthe contact elements of the

contacts

34, 36 and 38. As the roller contact 32 engages or disengages one of the

contacts

34, 36 and 38, the flux produced by the magnetic hub tends to quench any arc produced between the contacts, magnetic arc quenching being extremely effective as is well known in the art. By making the arc quenching magnet movable with the movable contact, only one such magnet is required for a plurality of stationary contacts, which is an important feature, and by incorporating the magnet as the hub 106 of the roller contact 32, a very compact magnetic arc-quenching means results, which is another important feature.

Turning now to Figs. 7 and 8 of the drawings, illustrated therein is a rotary switch 110 which, except for the fact that it embodies the present invention, is similar to a corresponding embodiment of my aforementioned application, so that only a relatively general description thereof herein will be required. The switch 110 includes a housing 112 comprising an annulus 114 of electrically insulating material clamped between two end plates 116 and 118, the latter being provided with a tubular fitting 120 corresponding to and externally threaded for the same purposes as the iitting 16 of the switch 10. The inner periphery of the annulus 114 provides an arcuate contact path 122 for a roller contact 124, the path 122 being a complete circle in this embodiment. The contact path 122 is provided with a plurality of recesses 126 therein which are formed in stationary, circumferentially spaced contacts 128 each shown as including two contact elements 130 adapted to be bridged by the roller contact 124 and provided with terminals 132 externally of the annulus 114. Thus, with this particular construction, any one of a plurality of circuits may be made by means of the roller contact 124 bridging the contact elements 130 of one of the contacts 128.

Projecting through the tting 120 into the interior of the housing 112 is an actuating means 136 comprising a shaft 138 connected at its inner end to a rotor 140 of electrically insulating material. The shaft 138 is Xedly connected to the rotor and is journaled in the fitting 120, the opposite end of the rotor being journaled in the end plate 118, whereby the rotor rotates with the shaft. The roller contact 124 is carried by a carrier 142 which is generally Ushaped andy which is mounted on a pin 144 the axis of which coincides Lwith axis of the rotor 14d, the carrier-142 being pivotable relative to the rotor about the axis of the pin 144. The roller contact 12d is mounted on a resilient axle 146, which may be formed of spring wire, and this axle extends through tlanges of a cage 161i into radial grooves 152 in the respective arms of the U-shaped carrier 142. Thus, the roller contact 124 may move radially toward and away from the contact path 122 to permit it to move into and out of tr es 1536, the roller contact being guided by virtue or ne fact that the ends of the axle 146 are disposed in the grooves 152 and being guided by virtue of the tact that the cage 150` is loosely contined between the arms of the U- shaped carrier 142. Further guiding of the cage l@ is accomplished in a manner to be described hereinafter.

The roller contact 124 is in engagement with the axle 146 throughout only a small portion of the length of the axleso that the roller contact may wobbie or roel; in the manner described in connection with the switch 1d to insure proper engagement with the contact elements 136 ofthe contacts 128. For arc quenching purposes, the roller contact 124 includes a magnetic hub 154 enclosed by asleeve or jacket 156 of nonmagnetic, electrically conductive material.

Thecage is provided with spaced, radially inwardly extending flanges 158 which embrace a seat member 160 for a snap-acting means 162, the seat member 161) being provided with flat sides 164 cooperating with the anges 158 to further guide the cage 15d, and thus the roller contact 124, for radially inward and outward movement relative to the rotor 146. The seat member 165i iS Pierced by the pin 144 and extends through a hole in the base of the U-shaped carrier 1412 so that the carrier and the seat member pivot as a unit about the axis of the pin 144.

Considering the snap-acting means 162, it includes at least two nested, leaf-spring detent means 166 each corresponding to the detent means of the switch 1d, two such detent means being nested in this embodiment to provide greater bias and longer life. The two detent means 166 are confined between anges 168 at the ends of an element 170 corresponding to the element 78 of the switch 10, one of the detent means 166 being seated on projections 172 spaced inwardly from the flanges 168, respectively. The center of the other detent means 166 is engaged by a projection 174 on the cage 150. The element 170 is carried by a platform 176 on the adjacent end of the seat member 16@ for the snap-acting means 162. Thus, it will be apparent that the snap-acting means 162 Vis similar to the snap-acting means 52S of the switch 10, its operation also being simiiar so that a detailed description is unnecessary.

Therey is a resilient lost-motion connection 17S between the `rotor 14) of the actuating means 136 and the carrier 142 for the roller Contact 124, this resilient lost- :notion` connection being similar to and serving the same functions as the resilient lost-motion 64 between the carrier 62 and the actuating means 661 of the switch 1d. The

connection 17S includes two, oppositeiy acting, torsion springs 181i` respectively encircling the pin 144 on opposite sides of the seat member 16@ and between it and the arms of the U-shaped carrier 142. Each spring 1811 has anend 182 engaging the base of the U-shaped carrier 142, and has an end 134 engaging an internal shoulder 186 on the rotor 14d. Thus, regardless of which direction the rotor 140 is rotated, relative motion of the actuating means 136 and the carrier 142. can occur until such` time as that one of the torsion springs 16@ which is being stressed by such relative movement is stressed to an extent sufcient to produce movement of the roller contact 124 out of the particular recess .126 from which itis disposed. The lost-motion provided by the connection 178 is at least equal to the spacing of the contacts 12S 1@ for the reasons hereinbefore indicated to insure that the roller contact 124 will move completely from one recess 126 to the next with a snap action.

The end 188 of the seat member 169 opposite the platform 176 is engageable with stop means or kickers lft) formed by internal shouidcs on the rotor 144. Thus, relative rotation of the carrier 1412 and the actuating means 136 is limited to the clearance between the end 18S of the seat member and the kickers 19d.

It will be quite apparent that the over-all operation ci the switch is very simila to that of the switch it@ so that a complete description is unnecessary. Brieiiy, on application to the actuating means 136 of a force tending to move the roller Contact 1211 from one recess 126 to the next, the detent means 166 are snapped from one configuration through an intermediate conguration to another coniiguration in much the same way as the detent means S4. initially, tie detent means 166 apply an intermediate bias to the rolier contact 124i, this bias increasing to a maximum as the detent means snap, and then decreasing to a minimum as the detent means be* come iiaccid while the roller contact is in engagement with the Contact path tift intermediate the recesses im. The resilient lost-motion connection 17; produces a snap action which snaps the roiler contact 124 from one recess 126 to the next as the stress built up in one of thev torsion springs 18h is released. The roller contact 124, due yto the provision of the magnetic hub 15d, acts as a compact arc-quenching means which is applicable to all of the stationary contacts in various other respects, what has been said hereinbefore in connection with the switch 1d is also applicable to the switch so that it does not need to be repeated.

Considering now the presently preferred embodiment ot the invention which is iilustrated in "53. 9 to 14 of the drawings, illustrated therein is a rotary switch El@ which is generally similar to 'the rotary sw hereinbefore described. The switch 21d includes a housing 212 comprising an annulus 214 ot electrically insulating material clamped between two end pistes 216 and 21S. Suitably secured to the latter is a cu? having connected thereto a tubular, externally threaded fitting 222 corresponding to and for the purpose as the tting 16 of the switch 1t. The inner periphery of the anu nulus 214 provides an

arcuate Contact path

22,4 for a roller contact 226, the Contact being a complete circle. Circurnterentially spaced aiong the contact path 224 are recesses 228 which are formed in stationary contacts each shown as including two contact elements E32 adapted to be bridged by the r r contact and provided with terminas mit externe ly of the annulus 214. As will be apparent, any one of a plnraiity of external circuits may be ciosed by moving roller contact 226 into bridging engagement with the contact eiements of one of the contacts "i:

Projecting through the sitting int-o the interior of the cup 22.@ or" the housing is an actuating means 236 comprising a shaft journaied in the fitting 222 and provided with a head Lidi@ at its inner end. A resilient lost-motion connection connects the actuating means 236 to a carrier Lt-4- for the relier contact For the reasons hereinbefore discussed, the resilient lost-motion connection 242 provides a range of relative movement between the actuar-ii means and the carrier 2;4 at least equai to the spacing of the recesses 228. stop means 22136 being provided for limiting this range of relative movement. stop means 24rd also act as kickers as hereinbefore outlined and as hereinafter described in more detail. A pn ig means interposed between the carrier 3- and the roiler contact 226 urges the roller contact into engagement with the contact path 224 with a variable bias as hereinbefore suggested. When this general description of the switch El@ in mind, it will now be considered in detail.

The carrier 244 is disposed within the annnlus 214 and is constituted by a rotor of electrically insulating niaterial xed on a shaft 256i which is journaled at one end in the end plate 2id and at its other end in the head 24d on the shaft In the particular construction illustrated, the carrier 244 is nxed on the shaft i250 by providing the carrier with a square opening therethrough which receives a square section 252 of the shaft 257%.

Considering now the resilient lost-motion connection between the actuating means and the carrier 24.4', fixed on the head of the shaft 238 is a disc 254- having an integral arm 256 projecting from a direction parallel to the axis of the switch 2 d, but spaced therefrom. At the outer end of the arm 256 are transverse lugs "M for a purpose to be described. The disc se 254 is provided with two circumferentially spaced, approximately radial edges 26d respectiveiy iocated on op posite sides of the arm 256 and respectively constituting the stop means or kickers Fixed on the carrier shaft 25d, as by being provided with a square opening receiving the square section of this shaft, is an element 262 having fixed thereon a disc which is provided with arm 266 parallel to but spaced radially outwardly from the arm 256 on the disc 254. The free end of the arm is provided with lugs 263 corresponding to the lugs 258 and for a purpose to be described.

Carried by he head on the shaft 238 is a torsion sprinC having arms22 and 274 which receive the arms and on the discs 254i and 264 therebetween. The lugs and on the

arms

256 and 266 prevent axial movement of the torsion spring 27d.

Considering the operation of the lost-motion connection 242, it will be apparent that, as the actuator shaft 238 is rotated in the clockwise direction, as viewed in Fig. 1l of the drawings, the arm 256 on the disc 254 rotates the arm 2 d of the spring 270, while the arm 266 on the disc 2nd prevents rotation ofthe arm 272 of the spring, thereby stressing the spring. When the spring 270 has been stressed sufciently, the snap-acting means 248 snaps in a manner to be described, to permit the roller contact 226 to leave the particular recess 228 in which it is disposed, whereupon the energy stored in the spring 270 snaps the roller contact into the next recess in the manner more fully discussed previously herein in connection with the description of the operation of the switch 10. Upon counterclockwise rotation of the actuator shaft 238, similar' events occur, but in a reversed sense.

it the spring 270 fails to snap the roller contact 226 from one recess 22E to the next in the foregoing manner for any reason, one or the other of the kickers 246 eventually engages the arm 266 on the disc 264 to force the roller con act out of the particular recess in which it is disposed, whereupon the spring 270 snaps the roller contact into the next recess. The range of the lost motion provided by the lost-motion connection 242 is determined by the circumferential spacing of the kickers 246 and is, as hereinbefore indicated, at least equal to the spacing of the recesses 22S. rIhis insures that the roller Contact 226 wili move to the next recess 228 after it has been displaced out of an adiacent recess, irrespective of any manual manipulations of the actuator shaft 238. Consequently, a positive and reliable action is provided, which is an important feature.

Considering now the manner in which the roller contact 226 is connected to the carrier 24d through the snap-acting means 24S, the carrier is provided in one side thereof with a recess 273 having a central projection 289 thereinto and having at its edges inwardly extending lugs 282. As will be described hereinafter, the roller contact 226 is carried by a cage which is conned in the recess 27S by the lugs 232 which cooperates with the snap-acting means the latter also being disposed in the recess. (In the particuiar construction illustrated, the carrier 244 is provided with another recess 286 which is identical to the recess 273 and which is adapted to receive another snapaeting means, not shown, and another roller-contact cage,

not shown, identical to the snap-acting means 248 and the roller-contact cage 284, respectively. With this construction, the switch 210 may be utilized in installations requiring the making of two external circuits simultaneously. lf desired, the carrier 244 may .be further modified to carry more than two roller contacts.)

Considering the roller-contact cage 284, it includes two spaced ilanges 23d in which is journaled an axle 290 carrying the roller contact 226. The latter is provided with a ma'ietic hub 292 and a jacket 294 of nonmaguetic, elecctive material on the hub. The axle 290 makes contact with the hub 292 throughout only a relatively small portion of the axle so that the roller contact 22d may wobble or rock for the reasons hereinbefore indicated. The cage 284 is provided with arms 296 which t under the lugs 232 on the carrier 244 to retain the cage in the recess, while still providing several degrees of freedom for the roller contact 226 relative to the carrier 244 for the purposes more fully discussed in my aforementioned copending application.

Considering the snap-acting means 248, it includes at least two nested, leaf-spring detent means 298 each corresponding to the detent means 84 of the switch 10, two such detent means being utilized in this switch to provide greater bias. The two detent means 298 are conned between the arms 296 of the cage 284 and one of them is seated on projections 300 spaced inwardly from the respective arms 296. The center of the other detent means 298 is engaged by the aforementioned projection 280 on the carrier 244.

The `operation of the snap-acting means 248 is again similar to that of the snap-acting means 58 of the switch 1i) so that only a general description of its operation is necessary. As shown in Fig. 12 ofthe drawings, when the roller contact 226 is in one of the recesses 228, the detent means 296 assume what might be termed their normal configurations, and apply an intermediate bias to the roller contact.

Referring to Fig. 13, when the actuator shaft 238 is.

tions shown in Fig. l2 to the configurations shown in Fig.`

14. This exing occurs with a snap-action, as hereinbefore discussed, the bias applied to the roller contact 226 by the detent means 298 being a maximum as, or just before, the detent means snap from their normal configurations to the configurations shown in Fig. 14. As soon as the detent means 298 snap, they become more or less flaccid and apply a minimum bias to the roller contact 226, whereupon the roller contact leaves the recess 228 in which it is disposed, as shown in Fig. 14 of the drawings, and moves to the next recess with a snap action due to the hereinbefore-discussed action of the torsion spring 270. This over-all action is similar to that of the switch 10 so that what has been said hereinbefore in connection with the switch 10 is equally applicable to the switch 210, as well as to the switch 110. Consequently, repetition is considered unnecessary.

Although I have disclosed exemplary embodiments of my invention herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments without departing from the spirit of the invention as hereinafter dened in the claims allowed to me.

I claim as my invention:

1. In a switch, the combination of: a contact path having a recess therein; a contact engaging and movable along said path and receivable in said recess; actuating means for moving said movable contact along said path and into and out of said recess; and snap-acting means connecting said movable contact and said actuating means for biasing said movable contact into engagement.

i3 with said bath, said snap-acting means comprising a spring having a normal configuration when said contact is in said recess and arranged to snap over center t-o a second conguration when said contact moves out of said recess.

2.v In a switch, the combination of: stationary contacts spaced -apart along a contact path having recesses therein at rsaid stationary contacts, respectively; a contact engaging and movable along said path into engagement with successive ones of said stationary contacts, said movable contact being receivable in each of said recesses; actuating means for moving said movable contact along said rpath and into and out of each of said recesses; and snap-acting means connecting said movable contact and said actuating means for biasing said movable contact into `engagement with said path, said snap-acting means comprisinga spring having a normal configuration when said contact is in any one of said recesses and arranged to snap over center to a second configuration when said contact moves out of a recess.

3. In a switch, the combination of: a contact path having spaced recesses therein and having a stationary contact in at least one of said recesses; a roller contact engaging and movabler along said path and receivable in each of said recesses; yan actuating means for moving said roller contact along said path and into and out of each of said recesses; and snap-acting means connecting said roller contact and said actuating means for vbiasing said roller contact into engagement with said path, said snapacting means comprising a spring having a normal con- `figuration when said roller contact is in yany one of said recesses and arranged to snap over center to a second configuration when said roller contact moves out of a recess.

4. In a switch, the combination of: stationary contacts spaced apart along an arcuate contact path having recesses therein at said stationary contacts, respectively; a roller contact engaging and movable along said path into engagement with successive ones of said stationary contacts, said roller contact being receivable in each of "A said recesses; an actuating means for moving said roller contact along said path and 'into and out of each of said recesses; and snap-acting means connecting said roller contact and said actuating meansfor 'biasing said roller contact into engagement with said path, said snap-acting means comprising a spring having a normal configuration when said roller contact is in any one of said recesses and arranged to snap over center to a second configuration when said roller contact moves out of a recess.

5. In a switch, the combination of: stationary contacts spaced apart along an arcuate contact path having recesses therein at said stationary contacts, respectively; a roller contact engaging and movable along said path into engagement with successive ones of said stationary contacts, said roller contact being receivable in each of said recesses; an actuating means for moving said roller contact along said path and into and out of each of said recesses; and snap-acting means connecting said roller contact and said actuating means for biasing said roller contact into engagement with said path, said snap-acting means operating with a snap action Ias said roller contact moves -into and out of each of said recesses, said snapacting means including means for applying a minimum bias to said roller contact when the latter is in engagement with said path intermediate said recesses, for applying an intermediate bias lto said roller contact when it is in each of said recesses, and for lapplying a maximum bias to said roller `Contact as it is 'being moved into or out of each of said recesses.

6. In a switch, the combination of: stationary contacts on an arcuate contact path having recesses therein at said stationary contacts, respectively; a roller contact engaging and movable along said path into engagement with each of said stationary contacts, said roller contact being receivable in each of said recesses; an actuating Cir means for moving said roller contact along said path'and into and out of each ot said recesses; and leaf-spring detent means intermediate said roller Contact and said actuating means for biasing said roller contact into engagement with said path with a variable force, said detent means comprising a spring having :a normal configuration when said roller contact is in any one of said re" cesses and arranged to snap over center to a second configuration when said roller contact moves out of a recess.

7. ln a switch, the combination of: stationary contacts on an arcuate contact path having recesses therein at said stationary contacts, respectively; a roller Contact engaging and movable lalong sai-d path into engagement with each of said stationary contacts, said roller Contact being receivable in each of said recesses; an actuating means for moving said roller contact along said path and into and out of each of said recesses; and leaf-spring detent means intermediate said roller Contact and said actuating means for biasing said roller contact into engagement with said path with a variable force, said detent means operating with a snap action as said roller contact moves into and out of each of said recesses, said -detent means including means for applying a minimum bias to said roller contact when the latter is in engagement with said path intermediate said recesses, for applying an intermediate bias to said rollercontact when it is in each of said recesses, and for applying a maximum bias to said roller contact when it is being moved into or out of said recesses.

8. In a switch, the combination of; stationary con tacts spaced apart along an arcuate contact path having recesses therein at said stationary contacts, respectively; a roller contact engaging and movable along said path into engagement with successive ones of said stationary contacts, said roller contact being receivable in each of said recesses; la carrier for said roller contact; snap-acting means connecting said roller contact and said carrier for biasing said roller contact into engagement with said path, said snap-acting means comprising a spring having a normal configuration when said roller contact is in any one of said recesses and arranged to snap over center to a second configuration when said roller contact moves out of a recess; and actuating means for moving said carrier so as to move said roller contact along said path and into and out of each of said recesses.

9. In a switch, the combination of: stationary contacts spaced apart along an arcuate contact path having recesses therein at said stationary contacts, respectively; a roller contact engaging and movable along said path into engagement with successive ones of said stationary contacts, said roller contact being receivable in each of said recesses; a carrier for lsaid roller contact; snap-acting means connecting said roller contact and said carrier for biasing said roller contact into engagement with said path, said snap-acting means comprising a spring having a normal configuration when said roller contact is in any one of said recesses and arranged to snap over center to a second configuration when said roller contact moves out of a recess; and actuating means for moving said carrier so as to move said roller contact along said path and into and out of each of said recesses, said actuating -means having a resilient, lost-motion connection with said carrier.

10. In a switch, the combination of: stationary contacts spaced apart along an arcuate contact path having recesses therein at said stationary contacts, respective- 1y; a roller contact engaging and movable along said path into engagement with successive ones of said stationlary contacts, said roller contact being receivable in each of said recesses; a carrier for said roller contact; snapacting means connecting said roller contact and said carrier for biasing said roller contact into engagement with said path, said snap-acting means comprising a spring having a normal configuration when said roller contact is in any one of said recesses and arranged to snap over center to a second configuration when said roller contact -moves out of a recess; and actuating means for moving said carrier so as to move said roller contact along said path and into and out of each of said recesses, said actuating means having a resilient, lost-motion connection with said carrier, said lost-motion connection providing a `range of movement between said carrier and said actuating means at least equal to the spacing of said stationary contacts.

l1. A switch as delined in claim 2 wherein said movable contact includes a magnet, and a jacket of nonmagnetic, electrically conductive material on said magnet.

12. A switch as defined in claim 3 wherein said roller Contact includes a magnet and a cylindrical jacket of nonrnagnetic, electrically conductive material around said magnet.

13. In a switch, the combination of: an arcuate, concave contact path having circumferentially spaced, radially inwardly facing, recesses therein and having thereon at least one stationary contact in which one of said recesses is formed; a freely rotatable roller contact engaging and movable along said contact path and receivable in each of said recesses; a contact carrier for said roller Contact located radially inwardly of and movable adjacent and parallel to said contact path; an axle carrying said roller contact and mounted on said Contact carrier and providing free rotation of said roller contact relative to said contact carrier; snap-acting means for biasing said rollerv contact into engagement with said contact path, said snap-acting means comprising a spring having a normal conliguration when said roller contact is in any one of said recesses and arranged to snap over center 'to a second configuration when said roller contact moves out of a recess; actuating means movable about the center of curvature of said contact path for moving said contact carrier adjacent and parallel to said Contact path; means providing a rockable lost-motion connection between said actuating means and said contact carrier; and means for limiting the range of rocking lost motion between said actuating means and said contact carrier.

14. A switch including: a contact carrier; a roller contact carried by said carrier; a contact path engaged by said roller contact and having spaced recesses therein; snap-acting means for biasing said roller contact into engagement with said contact path, said snap-acting means comprising a spring having a normal configuration when said roller contact is in any one of said recesses and arranged to snap over center to a second configuration when said roller contact moves out of a recess; an actuator; and a lost-motion connection between said actuator and said carrier and having means providing relative rocking movement between said actuator and said carrier.

References Cited in the tile of this patent UNlTED STATES PATENTS 1,667,965 Blauvelt May 1, 1928 1,812,410 Meuer June 30, 1931 2,015,399 Grothe Sept. 24, 1935 2,090,544 Michel Aug. 17, 1937 2,334,562 Latta Nov. 16, 1943 2,448,841 Taylor Sept. 7, 1948 2,521,468 Lodge Sept. 5, 1950 2,565,863 Linn Aug. 28, 1951 2,668,204 Tregoning Feb. 2, 1954 2,684,843 Mason July 27, 1954 FOREIGN PATENTS 107,336 Great Britain June 28, 1917 571,395 Great Britain Aug. 22, 1945 U. S. DEPARTMENT OF COMMERCE PATENT OFFI CE CERTIFICATE OF CORRECTION Patent No. 2,831,081 Howard F. Mason It ie hereby certified that error appears .in the printed specification of the above numbered patent requiring correction and that the said Lettere.

Patent should read as corrected below.

April l5, 1958 Column 6, line '70, after nFig. 5" insert a comme; same line, strike out "thereoi`"; column lO, line '73, for Whenn read '-f- With column 13, line 1, for "bath" read path column 14, line 31, after "of" change the semi-colon to a colon.

Signed and sealed this 27th day of May 1958.

(SEAL) Attest: t

KARL E; AXLINE ROBERT C. WATSON Comnssioner of Patents Attesting Officer U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,831,081 Howard F. Mason It is hereby certified that error appears .in the printed specification of the above numbered patent requiring correction and that the said Letters` Patent should read as corrected below.

Apri1 15, 1958 Column 6, line '70, after Wig. 5" insert a comme; same line, strike' out uthereo"; column 10, line '73, for "When" read f-' With co1umn 13, line 1, for "bath" read path column 14, line 31, after "of" change the semi-colon to a colon.

Signed and sealed this 27th day of May 1958.

(SEAL) Attest:

KARL H5 AXLINE ROBERT C. WATSON Comnssioner of Patents Attestng Officer