US2734959A - immel - Google Patents

Description

Feb. 14, 1956 R. B. IMMEL SNAP-ACTION SWITCH 3 Sheets-Sheet 1 Filed Nov. 28, 1951 INVENTOR Rcllph B. Immel. W

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ATTORNEY Feb. 14, 1956 R. B. IMMEL 2,734,959

SNAP-ACTION SWITCH Filed Ncv. 28, 1951 3Sheets-Sheet 3 ff F' .II. Fig.7. 0

WITNESSES:

INVENTOR W Ralph B. Ir n mel. 2 m, MM

ATTORNEY United States Patent SN AP-ACTION SWITCH Ralph B. Immel, Williamsville, N. Y., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 28, 1951, Serial No. 258,656 25 Claims. (Cl. Zea-s7 My invention relates, generally, to electric switches and, more particularly, to switches which operate with a snap action.

An object of my invention is to provide a switch having a precise and positive action.

Another object of my invention is to provide a multiposition snap-action switch.

A further object of my invention is to provide a snapacting switch of the tubular type having a pivotally mounted operating handle.

Still another object of my invention is to reduce friction between the members of a switch of the snap-acting type.

A still further object of my invention is to provide a switch having a bridging contact member which is spring supported within the switch.

A more general object of my invention is to provide a snap-acting switch which is simple and reliable in operation and which may be economically manufactured.

Other objects of my invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with my invention, the bridging contact member of a snap-action switch is connected through a lost-motion means to an operating handle by toggle springs which cooperate with a spring arm or arms formed integrally with the bridging member to maintain contact pressure and to actuate the bridging member from one position to another with a snap-action when the handle is operated.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawings in which:

Figure 1 is a view, in side elevation, of a switch embodying the principal features of the invention, the cover being removed;

Fig. 2 is an enlarged and exploded view of certain parts of the switch, the parts being shown in perspective;

Fig. 3 is a view, in section, of a modified switch;

Fig. 4 is a view, similar to Fig. 2, of parts of the switch shown in Fig. 3;

Fig. 5 is a view, partly in side elevation and partly in section, of another modified form of switch;

Fig. 6 is a view, similar to Fig. 2, of parts of the switch shown in Fig. 5;

Fig. 7 is a view, partly in side elevation and partly in section, of still another modified form of switch;

Figs. 8 and 9 are views, in side elevation, of the switch shown in Fig. 7, the operating handle and the contact members being in difierent positions;

Fig. 10 is a bottom plan view of the switch shown in Fig. 7 with the cover in place, and

Fig. 11 is a view, similar to Fig. 2, of parts of the switch shown in Fig. 7.

Referring to the drawings, and particularly to Figs. 1 and 2, the switch shown therein comprises a base 10 having holes 11 therein for attaching a cover (not shown) to the base 10 by means of rivets or bolts. The base 10 and the cover are preferably molded from a suitable insulating material. An opening 12 is provided in the base 10 for an operating handle 13 which is utilized to actuate the switch mechanism in a manner which will be more fully described hereinafter.

Upper stationary contacts 14 and lower stationary contacts 15 are mounted on the base 10. Each upper contact 14 is supported by a generally U-shaped bracket 16 which is attached to a terminal 17, which may be molded into the base 10. Each lower contact 15 is supported by a generally Z-shaped bracket 18 which is attached to a terminal 17. Terminal screws 19 are provided for making electrical connections to the terminal members.

A generally rectangular bridging contact member 21 is movably disposed between the upper contacts 14 and the lower contacts 15. The member 21 carries upper contacts 22 and lower contacts 23, which are disposed to engage the upper contacts 14 and the lower contacts 15, respectively, under predetermined conditions. The bridging contact member 21 may be stamped from a relatively thin sheet of a resilient good electrical conducting material, such as Phosphor bronze or beryllium copper. The contacts 14, 15, 22 and 23 are composed of a good electrical conducting material, such as silver or a silver alloy.

As shown most clearly in Fig. 2, the bridging contact member 21 has two pairs of integrally formed spring arms 24. The arms 24 are arranged in oppositely disposed pairs with the ends of each pair spaced a predetermined distance apart. The end of each arm 24 has a projection 25 extending therefrom. A semi-cylindrical portion 26 is formed in the center leg of the member 21. A similarly formed strap 27, which may be attached to the member 21 by rivets 28, clamps a bearing bushing 29 to the member 21. A bearing pin or shaft 31 is mounted in the bearing bushing 29. The ends of the shaft 31 are disposed in openings provided in the base 10 and the cover for the switch, thereby supporting the bridging contact member 21.

The actuating mechanism for the switch comprises the handle 13, an operating lever 32 and a pair of generally U-shaped toggle springs 33 which are joined together by an integrally formed bar 34. The handle 13 may he threaded into an opening 35 in the operating lever 32. The lever 32 has spaced integrally formed legs 36 having openings 37 therein through which the ends of the shaft 31 are inserted. The lever 32 also has downwardly extending projections 38 which straddle the tie bar 34 for the toggle springs 33. The distance between the projections 38 is considerably greater than the width of the tie bar 34, thereby providing a lost-motion connection be tween the operating lever 32 and the toggle springs 33. The toggle springs 33 have integrally formed spaced legs 39 with openings 41 therein through which the ends of the shaft 31 are also inserted. Thus, the bridging contact member 21, toggle springs 33 and the operating lever 32 are movable about the same axis 31 when the switch is assembled.

As shown in Fig. 2, the ends of the arms of the U- sh'aped toggle springs 33 are generally V-shaped with an opening 42 in each arm. The parts of the switch may be assembled by inserting the projections 25 on the spring arms 24 into the openings 42 in the toggle springs 33 and inserting the ends of the shaft 31 into the openings 41 in the legs 39 of the toggle springs. The operating lever 32 may then be placed in position over the toggle springs 33 and the ends of the shaft 31 inserted into the openings 37 in the legs 36 of the operating lever 32. The entire movable assembly may then be placed in the casing with the handle 13 extending through the opening 12. The cover may then be attached to the casing.

In order to obtain the desired snap action of the switch, the distance between the V-shaped ends of the toggle jections 25 011 the spring arms 24' into the openings 42 in the spring toggle 61. The bearing pin 64 may then be inserted through the openings 63 in the legs 62 of the spring toggle and through an opening 72 in the bearing block 65, thereby supporting the spring toggle 61 and the bridging contact member 21. The operating lever 68 may then be placed in position with the handle 13 extending through the opening 12 in the base, after which the cover for the casing may be attached.

When the switch is assembled, the spring toggle 61 and the operating lever 68 are movable about the same axis since the pins 71, which support the operating lever 68, are in alignment with the bearing pin 64 for the spring toggle 61. The switch is operated in the same manner as the ones shown in Figs. 1 and 3 by actuating the operating handle 13'. However, in the present structure the bridging contact member 21 is self-aligning, since it is supported by the toggle spring 61 and not on a fixed axis, as in the structure shown in Figs. 1. and 2. Accordingly, quick movement of the bridging contact member is assured when the toggle spring passes overcenter as the handle is actuated. Slow action, caused by misalignment of the parts of the switch, is eliminated.

The switch shown in Figs. 7 to 11 inclusive is of the 3-position type, that is, the handle 13 may be actuated from an off or intermediate position toward the left to one closed position or toward the right to another closed position, thereby providing the equivalent of a single-pole double-throw switch. The upper stationary contacts 14 are mounted on an integrally formed cornbined bearing bracket and contact supporting member 73. The member 73 has a generally U-shaped bearing bracket 74 having openings 75 therein for receiving a bearing pin 76. The member 73 also has integrally formed L-shaped arms 77 to which the contacts 14 are attached. The member 73 is mounted on a middle terminal A and is electrically connected to the terminal A. One of the lower stationary contacts is mounted on a terminal B and the other is mounted on a terminal C.

The bridging Contact member 2i has two integrally formed spring arms 24 which function in the manner previously described. A left-hand toggle spring 78 and a right-hand toggle spring 79 are provided. These toggle springs are independently operable and each one operates only the spring arm 24' which it engages. The V-shaped end of each toggle spring has an opening 42 for receiving the projection on one of the spring arms 24'. The spring toggle 78 has spaced legs 81 having openings 82 therein for receiving the bearing pin 76. Likewise, the spring toggle 79 has legs 83 with openings 84 therein for receiving the bearing pin 76. The legs 83 of the toggle 79 are spaced further apart than the legs 81 of the toggle 78 to permit the legs 83 to straddle the legs 81 when assembled. The toggle 78 has an upwardly extending pin 85 which is disposed in a slot 86 in an operating lever 8'7. Likewise the toggle 79 has a pin 88 which is disposed in a slot 89 in the operating lever 87.

The switch may be assembled by inserting the projections 25 on the spring arms 24 into the openings 42 in the spring toggles 78 and 79. The bearing pin 76 may then be inserted through the opening 75 in the hearing bracket 74, the openings 84 and 82 in the toggles 78 and 79 through an opening 91 in a bearing bushing 92. The handle 13 may be inserted through an opening 93 in the operating lever 87 and threaded into an opening 94 in the bearing bushing 92, and drawn tightly against the bearing pin 76 to'retain the bearing pin in position. The handle 13" and the toggle springs 78 and 79 are movable about the bearing pin 76.

Since the distance between the ends of the spring arms 24 is less than twice the distance between the V-shaped ends of the toggle springs and their bearing axis, the toggle springs and the spring arms are under stress when assembled in the switch. Thus, the assembly is un- 6 stable unless the operating handle 13" is in one of its three definite positions.

When the operating handle 13" is in the off position, as shown in Fig. 7, the contact members 22 carried by the bridging contact member 21 engage the upper contacts 14, and the contact members 23 are disengaged from both of the lower stationary contacts 15. If the handle 13" is moved in a counterclockwise direction, the right-hand end of the bridging contact member 21' will not move until the knife-edge bearing of the toggle spring 79 is substantially in alignment with the sides of the bridging contact member. At this point a condition of unstable equilibrium is attained and the right-hand end of the bridging contact member 21' will snap downward to cause the contact 23 to engage the hight-hand lower stationary contact 14 as shown in Fig. 8.

Once the toggle spring 79 starts to move over-center, it will go all the way, as there is suflicient play in the lost-motion connection to prevent the operating handle from holding it. The length of each of the slots 86 and 89 in the operating lever 87 is considerably greater than the diameters of the pins and 88, thereby providing the lost-motion connection between the operating lever and the toggle springs. It will be noted that the position of the toggle springs 78 and the left-hand end of the bridging contact member 21 is not changed by moving the handle 13" to the left because of the lost-motion connection between the toggle spring 78 and the operating lever 87.

When the switch is in the position shown in Fig. 8, an electrical circuit is established between the terminals A and C through the right-hand lower stationary contact 15, the contact 23 on the right-hand end of the bridging contact member 21', the upper contact 22 on the left-hand end of the bridging contact member 21, the contact 14 on the left-hand end of the member 73, and the bearing bracket 74 to the terminal A.

If the handle 13" is actuated to the right or in a clockwise direction from the position shown in Fig. 7, the bridging contact member is actuated to the position shown in Fig. 9. When in this position, an electrical circuit is established between the terminals A and B through the left-hand stationary contact 15, the left-hand contact 23 on the bridging contact member 21', the righthand contact 22 on the bridging contact member 21, the right-hand stationary contact 14 on the member 73, and the bearing bracket 74 to the terminal A. The lostmotion connections beween the spring toggles 78 and 79 and the operating lever 87 permit the desired snap action to be attained for either direction of operation of the handle 13".

As in the switch structure previously described, the spring toggle members and the spring arms of the bridging contact member cooperate to provide the force for maintaining contact pressure between the contacts of the switch. As in the previously described structure, the force increases as the operating handle is moved, thereby securing the snap action which prevents the contact from burning. a

The operating handle 13" is stopped by the sides of the opening 12 in the base 10' in either one of the on positions of the switch. The handle 13" is retained in the OE position by the contacts 22 on the bridging contact member engaging both upper stationary contacts 14 and the stresses on both toggle springs being substantially equal, thereby obtaining a condition of stable equilibrium.

From the foregoing description, it is apparent that I have provided snap-acting switches which are relatively simple in structure and precise and positive in operation. The parts of the switch do not require extremely close manufacturing tolerances in order to obtain the desired operation of the switch. Therefore, the switch may be economically manufactured and assembled.

Since numerous changes may be made in the above described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all the matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. An electric switch comprising, a stationary contact, a contact member movable into and out of engagement with said stationary contact, a spring arm formed integrally with the contact member, said spring arm being free to move at both ends, a pivotally mounted operating handle, spring toggle means engaging the spring arm, said spring toggle means being pivotally mounted independently of said operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said spring arm and said spring toggle means cooperating to bias the contact member in a predetermined direction, and said spring toggle means being stressed when the operating handle is actuated to actuate the contact member.

2. An electric switch comprising, a stationary contact, a contact member movable into and out of engagement with said stationary contact, a spring arm formed integrally with the contact member, a pivotally mounted operating handle, generally U-shaped spring toggle means engaging the spring arm, pivotal means supporting said toggle means independently of the operating handle, lostmotion means operatively connecting the operating handle and the spring toggle means, said spring arm and said spring toggle means cooperating to bias the contact member in a predetermined direction, and said spring toggle means being stressed when the operating handle is actuated to actuate the contact member.

3. An electric switch comprising, spaced stationary contacts, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, said spring arm being free to move at both ends, a pivotally mounted operating handle, spring toggle means engaging the spring arm, said spring toggle means being pivotally mounted independently of said operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said spring arm and said spring toggle means cooperating to bias the bridging contact member in a predetermined direction, said spring toggle means being stressed when the operating handle is actuated to actuate the bridging contact member, and said spring arm and said spring toggle cooperating through the lost-motion means to retain the operating handle in the position to which it was last actuated.

4. An electric switch comprising, spaced stationary contacts, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, a pivotally mounted operating handle, generally U-shaped spring toggle means engaging the spring arm, pivotal means supporting said toggle means independently of the operating handle, lost-motion means operatively connecting the operating handle and the spring toggie means, said spring arm and said spring toggle means cooperating to bias the bridging contact member in a predetermined direction and said spring toggle means being stressed when the operating handle is actuated to actuate the bridging contact member, and said spring arm and said spring toggle cooperating through the lostmotion means to retain the operating handle in the position to which it was last actuated.

5. An electric switch comprising, a stationary contact, a contact member movable into and out of engagement with said stationary contact, a spring arm formed integrally with the contact member, said spring arm being free to move at both ends, a pivotally mounted operating handle, spring toggle means engaging the spring arm, said spring toggle means being pivotally mounted independently of said operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said contact member having an opening therein for receiving the spring toggle means, said spring arm and said spring toggle means cooperating to bias the contact member in a predetermined direction, and said spring toggle means being stressed when the operating handle is actuated to actuate the contact member.

6. An electric switch comprising, a stationary contact, a contact member movable into and out of engagement with said stationary contact, a spring arm formed integrally with the contact member, a pivotally mounted operating handle, generally U-shaped spring toggle means engaging the spring arm, pivotal means supporting said toggle means independently of the operating handle, lostmotion means operatively connecting the operating handle and the spring toggle means, said contact member having an opening therein for receiving the spring toggle means, said spring arm and said spring toggle means cooperating to bias the contact member in a predetermined direction, and said spring toggle means being stressed when the operating handle is actuated to actuate the contact member.

7. An electric switch comprising, spaced stationary contacts, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, said spring arm being free to move at both ends, a pivotally mounted operating handle, spring toggle means engaging the spring arm, said spring toggle means being pivotally mounted independently of said operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said bridging contact member having an opening therein for receiving the spring toggle means, said spring arm and said spring toggle means cooperating to bias the bridging contact member in a predetermined direction, said spring toggle means being stressed when the operating handle is actuated to actuate the bridging contact member, and said spring arm and said spring toggle cooperating through the lost-motion means to retain the operating handle in the position to which it was last actuated.

8. An electric switch comprising, spaced stationary contacts, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, a pivotally mounted operating handle, generally U-shaped spring toggle means engaging the spring arm, pivotal means supporting said toggle means independently of the operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said bridging contact member having an opening therein for receiving the spring toggle means, said spring arm and said spring toggle means cooperating to bias the bridging contact member in a predetermined direction, said spring toggle means being stressed when the operating handle is actuated to actuate the bridging contact member, and said spring arm and said spring toggle cooperating through the lost-motion means to retain the operating handle in the position to which it was last actuated.

9. An electric switch comprising, spaced stationary contacts, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, said spring arm being free to move at both ends, a pivotally mounted operating handle, spring toggle means engaging the spring arm, said spring toggle means being pivotally mounted independently of said operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said spring arm and said spring toggle means cooperating to bias the bridging contact member in a predetermined direction, said spring toggle means being stressed when the operating handle is actuated to actuate the bridging contact member, said spring arm and said spring toggle cooperating through 9 the lost-motion means to retain the operating handle in the position to which it was last actuated, and said operating handle and said spring ti ggle means being movable about the same axis.

10. An electric switch comprising, spaced stationary contacts, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, a pivotally mounted operating handle, generally U-shaped spring toggle means engaging the spring arm, pivotal means supporting said toggle means independently of the operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said spring arm and said spring toggle means cooperating to bias the bridging contact member in a predetermined direction, said spring toggle means being stressed when the operating handle is actuated to actuate the bridging contact member, said spring arm and said spring toggle cooperating through the lost-motion means to retain the operating handle in the position to which it was last actuated, and said operating handle and said spring toggle means being movable about the same axis.

11. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, at least one spring arm formed integrally with the bridging member, said spring arm being free to move at both ends, an operating handle pivotally mounted in the casing, spring toggle means engaging the spring arm, said spring toggle means being pivotally mounted independently of said operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said spring arm and said springtoggle means cooperating to bias the bridging contact member against certain of the stationary contacts, and said spring toggle means being stressed when the operating handle is actuated to actuate the bridging contact member.

12. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, at least one spring arm formed intergrally with the bridging member, an operating handle pivotally mounted in the casing, generally U-shaped spring toggle means engaging the spring arm, pivotal means supporting said toggle means independently of the operating handle, lostmotion means operatively connecting the operating handle and the spring toggle means, said spring arm and said spring toggle means cooperating to bias the bridging contact member against certain of the stationary contacts, and said spring toggle means being stressed when the operating handle is actuated to actuate the bridging contact member.

13. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, oppositely disposed spring arms formed integrally with the bridging member, an operating handle pivotally mounted in the casing, pivotally mounted spring toggle means engaging the spring arms to support the bridging member, a pivotally mounted operating lever operatively connecting the operating handle and the spring toggle means with a lost-motion connection, said spring arms and said spring toggle means cooperating to bias the bridging contact member against certain of the stationary contacts, and said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member.

14. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, two pairs of oppositely disposed spring arms formed integrally with the bridging member, an operating handle pivotally mounted in the casing, pivotally mounted spring toggle means engaging the spring arms, a pivotally mounted operating lever operatively connecting the operating handle and the spring toggle means with a lost-motion connection, said spring arms and said spring toggle means cooperating to bias the bridging contact member against certain of the stationary contacts, and said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member.

15. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, two pairs of oppositely disposed spring arms formed integrally with the bridging member, an operating handle pivotally mounted in the casing, pivotally mounted spring toggle means engaging the spring arms, a pivotally mounted operating lever operatively connecting the operating handle and the spring toggle means with a lost-motion connection, said spring arms and said spring toggle means cooperating to bias the bridging contact member against certain of the stationary contacts, said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member, and said operating handle and said spring toggle means and said bridging contact member being movable about the same axis.

16. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, said spring arm being free to move at both ends, spring toggle means engaging the spring arm, bearing supporting means mounted in the casing, an operating handle pivotally mounted in said supporting means, said spring toggle means being pivotally mounted in the casing independently of the operating handle, lost-motion means operatively connecting the operating handle and the spring toggle means, said spring means cooperating to bias the bridging contact member against certain of the stationary contacts, and said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member.

17. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, spring toggle means engaging the spring arm, bearing supporting means mounted in the casing, said spring toggle means having integrally formed legs pivotally mounted on said bearing supporting means, an operating handle pivotally mounted in said suporting means, lostmotion means operatively connecting the operating handle and the spring toggle means, said spring arm and said spring toggle means cooperating to bias the bridging contact member against certain of the stationary contacts, and said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member.

18. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, a spring arm formed integrally with the bridging member, spring toggle means engaging the spring arm, bearing supporting means mounted in the casing, said spring toggle means having integrally formed legs pivotally mounted on said bearing supporting means, an operating handle pivotally mounted in said supporting means, lostmotion means operatively connecting the operating handle and the spring toggle means, said spring arm and said spring toggle means cooperating to bias the bridging contact member against certain of the stationary conarm and said spring toggle.

tacts, said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member, and said operating handle and said spring toggle means being movable about the same axis.

19. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts,

oppositely disposed spring arms formed integrally with the bridging member, spring toggle means engaging the spring arms to support the bridging member, bearing supporting means mounted in the casing, said spring toggle means having integrally formed legs pivotally mounted on said bearing supporting means, an operating handle pivotally mounted in the casing, pivotally mounted lost-motion means connecting the handle and the spring toggle means, and said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member.

20. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, oppositely disposed spring arms formed integrally with the bridging member, spring toggle means engaging the spring arms, bearing supporting means mounted in the casing, said spring toggle means having integrally formed legs pivotally mounted on said bearing supporting means, an operating lever pivotally mounted in the casing and engaging the spring toggle means with a lost-motion connection, an operating handle secured to the operating lever, and said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member.

21. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, oppositely disposed spring arms formed integrally with the bridging member, spring toggle means engaging the spring arms to support the bridging member, bearing supporting means mounted in the casing, said spring toggle means having integrally formed legs pivotally mounted on said bearing supporting means, an operating lever pivotally mounted in the casing and engaging the spring toggle means with a lost-motion connection, an operating handle secured to the operating lever, said spring toggle means being stressed by actuating the operating handle to actuate the bridging contact member, and said operating lever and said spring toggle means being movable about the same axis.

22. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, oppositely disposed spring arms formed integrally with the bridging member, toggle springs engaging the spring arms to support the bridging member, bearing supporting means mounted in the casing, said toggle springs having integrally formed legs pivotally mounted on said bearing supporting means, an operating handle pivotally mounted in the casing, a pivotally mounted operating lever connecting the handle and the toggle springs with a lost-motion connection, and said toggle springs being stressed by actuating the operating handle to actuate the bridging contact member.

23. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, oppositely disposed spring arms formed integrally with the bridging member, separately operable toggle springs engaging the spring arms, bearing supporting means mounted in the casing, said toggle springs having integrally formed legs pivotally mounted on said bearing supporting means, an operating handle pivotally mounted in the casing, a pivotally mounted operating lever connecting the handle and the toggle springs with a lost-motion connection, and said toggle springs being stressed by actuating the operating handle to actuate the bridging contact member.

24. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, oppositely disposed spring arms formed integrally with the bridging member, separately operable toggle springs engaging the spring arms, bearing supporting means mounted in the casing, said toggle springs having integrally formed legs pivotally mounted on said bearing supporting means, a three-position operating handle pivotally mounted in the casing, a pivotally mounted operating lever connecting the handle and the toggle springs with a lost-motion connection, and said toggle springs being stressed by actuating the operating handle to actuate the bridging contact member.

25. In an electric switch in combination, a casing, stationary contacts disposed in the casing in spaced relation, a bridging contact member movable into and out of bridging engagement with said stationary contacts, oppositely disposed spring arms formed integrally with the bridging member, separately operable toggle springs engaging the spring arms, integrally formed contact and bearing supporting means mounted in the casing, said toggle springs having integrally formed legs pivotally mounted on said bearing supporting means, a threeposition operating handle pivotally mounted in the casing, a pivotally mounted operating lever connecting the handle and the toggle springs with a lost-motion connection, and said toggle springs being stressed by actuating the operating handle to actuate the bridging contact member.

References Cited in the file of this patent UNITED STATES PATENTS 1,650,348 Hanny Nov. 22, 1927 1,797,466 DeHufi Mar. 24, 1931 2,129,151 Raney Sept. 6, 1938 2,135,864 Weber Nov. 8, 1938 2,574,429 Wood Nov. 6, 1951 2,608,628 Dietrich Aug. 26, 1952 FOREIGN PATENTS 929,963 France July 28, 1947 614,812 Great Britain Dec. 23, 1948 985,619 France Mar. 14, 1951 Feb. 14, 1956 c, Y S 2,734,960

SAFETY SIGNAL DEVICE FOR HYDRAULIC BRAKE SYSTEMS Filed Oct. 5, 1953 V {IIIIIIIIIIIIIQVIIIIIIIIIIIIIIIII INVENTOR Charles G. Reynolds WM 6 [MM ATTVJ

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