US1832721A - Electric switch - Google Patents

Description

Nov. 17, 1931.

- H. 1;. MILLER ELECTRIC SWITCH Filed Ju1y 26, 1928 Fig.2. 0

Inventor: H arr ElMiller; by Y LZZm/ His Attorney.

. which are used Patented Nov. 17, 1931 HARRY E. MILLER, OF I BAIII'IMORE, MARYIAND,

ASSIGNOR 'ro GENERAL Emo'rmc comm, A 'conronArIoN or NEW YORK ELECTRIC swn'on Application filed July 26,

My invention electric switches, and more particularly to improvements in disconnecting switches to isolate electric apparatus and portions'of an electric circuit.

Switches of this type are operated so infrequently that the blades and contacts usually become corroded which causes them to stick. If the switches are out-of-doors sticking due to corrosion is quite troublesome, and in winter formation of ice on may make it quite difiicult to open them.

The object of my invention is to provide a switch of this character which can be readily closed and o ened even if the contacts or joints thereof are corroded or covered with ice, and in which the portions of the movable member of the switch adapted to engage the gontacts of the switch cannot interfere with closing of the switch. I accomplish this by providing a switch having a relatively fixed contact and a movable switch member capable of being moved so as to bring one end thereof in proximity to the contact and then having the end of the switch member forced against the contact, the switch member being positively prevented from being forced against the contact until the end of the switch member is in proximity to the contact.

My invention will be more fully set forth in the following description referring to the accompanying drawings and the features of novelty which characterize my invention will .be pointed, out with particularity in the claims annexed to and forming a part of this specification.

In the drawings, Fig. 1 is a side elevation of a switch embodying my invention showing the same in open circuit position; Fig. 2 is a front elevation of the switch shown in Fig. 1 with the movable member moved inproximity to the contacts but not in close contact? therewith; Fig. 3 is a fragmentary front elevation of the switch shown in'Fig. 1 with the movable member in close contact with the' jaws of the contacts, and Fig. 4 is a side elevation, partly broken away, of the resilient link connecting the switch operating mechanism with the movable member of the switch.

Referring relates to improvements in the switches tact 10 so that the free .an operating yoke or to the drawings, the electric 1928. Serial No. 295,574.

switch in connection with which I have shown my invention comprises two stationary contacts 10 and 11, which are mounted on insulators-12 and 13 attached to a suitable supporting framework 14, and a movable member 15 which is arranged to bridge the contacts 10 and 11 in closing the switch. The contacts 10 and 11 are provided with integral terminal portions 16 and 17 respectively for connecting the switch in the circuit in which it is used, and the terminal portion 16 of the contact 10 is carried by an extension 18 thereof for supporting the switch operating mechanism. The contacts 10' and 11 are formed with projecting portions, such as jaws 19 and 20 respectively arranged to be engaged by the movable member 15 in closing the switch, and the contact 11 is provided with a hood 21 for shielding the jaws of the same. The movable member of the switch may be mounted in any suitable manner so that it can be swung into position to bridge the contacts 10 and 11. In the particular construction shown this movable member is pivotally mounted at 22 between the jaws 19 of the conend thereof can be swung toward and away from the contact 11 in closing and opening the switch. In order possibility of the movable thereon, the movable member is made so that the ends thereof are forced into close contact with the jaws of the contacts after the 1 member is in position to bridge the contacts. The construction of the movable member 15 shown for forcing the ends of the movable, member into engagement wlth the jaws of the contacts comprises separate blades 23 and 24 having tapered blocks 25 and 26 secured to the ends thereof whichoverlapat 27 to keep the ends of the blades in proper alignment. Wedges 28 which are arranged between the tapered surfaces of the blocks 25 and 26, taper in' the same direction, and are connected by arod 29 and yokes 30 and 31 which are pivotally secured at 32 to lever 33, so that the Wedges can be moved simultaneously toward the free end of the movable member to force the blades 23 and 24 into close contact with the jaws of the contacts 10 and 11 when the movable member is swung about its pivotal support to a position bridging the contacts. The operatin yoke or lever 33 is also pivotally connecte to the blades 23 and 24 at 34 so that swinging of the lever 33 about this pivotal connection in one direction will move the wedges 28 so as to spread the blades apart and force them into engagement with the jaws of the contacts '10 and 11 and swinging the lever in the other direction will retract the wedges toward the contact 10 to relieve the pressure exerted by the blades 23 and 24 on the jaws of the contacts.

In switches of this character heretofore proposed, the means for moving the ends of movable member 15 relative thereto could be actuated before the movable member was swung to a position bridging the contacts so that the end of the movable member 15 was sometimes moved relative thereto so as to prevent the switch being properly closed. In accordance with my invention this is avoided by providing means for positively preventin the end of the movable member 15 of the switch from being moved relative thereto in the direction whichit is moved to force the end thereof into engagement with the contact until the movable member is brought into proximity therewith. In the construction which I have shown for convenience in illustration, I do this by arranging a stationary abutment or cam 35 formed with a surface engaging a roller 36 carried by the end of an arm of the operating yoke or lever and extending over an arc of a circle having the center on the axis of the pivotal support 22 of the movable member 15. This cam engages the roller 36 throughout the movement of the member 15 from open position of the switch as shown in 1, to a position in which the member bridges the contacts 10 and 11, shown in Fig. 2. It will be observed that in closing the switch by means of the operating lever 33 the force tending to swing the movable member 15 to closed osition tends to turn the lever 33 about its pivotal connecthe cam when the blades 23 and 24 of the mov- V able member bridge thejcontacts 10 and 11 between the jaws thereof, as shown in Fig. 2. In this way after the blades 23 and 24 have been swung to a position bridging the contacts 10 and 11, and the roller 36 runs off the cam 35, furthermovement of the operating lever swings the same about the pivotal support 34 connecting it to the blades 23 and 24,

, in bearings 39, and 40 on the extension 18 and frame work 14 respectively, having an operating crank 41 which is connected by a bracket to a bar 42 adapted to connect several such operating mechanisms together for operating the switches simultaneously. The end of the insulator 38 supported on the extension 18 is also provided with a crank 43 which is connected to the operating lever 33 of the movable member 15 by yokes 44 and 45 carried by the threaded rod 46. In order to allow for any inaccuracy in the length of the links of the switch operating mechanism, I connect the yoke 45, which slidably fits the rod 46 to the latter, as shown in Fig. 4, by two spaced nuts 47 and 48 having a spring 49 engaging the nut 47 for retaining the yoke 45 against the nut 48. The yoke 45 is connected to the operating lever 33 of the switch,

compression of the spring 49 without sub jecting the switch or theoperating mechanism to any excessive stresses. The' movement of the operatin mechanism in closing the switch is limited liy a stop 50 carried by the crank 43 and arranged to engage a stop 51 on the extension 18 when the switch is closed.

The switch which I have described is opened and closed by means of the switch opcrating mechanism connected to the bar 42. When it is desired to move the switch from the open osition, shown in Fig. 1, to the closed position shown in Fig. 3, the bar 42 is moved longitudinally to the right, as viewed in Fig. 2, which turns the insulator 38 and the crank 43 counterclockwise asviewed in Fig. 2, and swings the movable member 15 about its pivotal support 22 until the movable member bridges the contacts 10 and 11 between the jaws thereof. During this movement of the member 15 the yoke or lever 33 is positively prevented from turning about its pivotal connection to the blades 23 and 1 nism is taken up by are. As the roller 36 on the the jaws Upon further movement of the crank 43 in opening the switch, the blades 23 and 24 of vmove from the sure between the blades 23 and 24 an 24 and moving the wedges 28 by the abutment or cam 35 which engagesthe roller 36 on endof the lever 33-, so that the blades 23 and 24 cannot be spread apart until both ends thereof are between the jaws of the contacts and 11. When the free ends of the blades of the movable member move between the jaws of the contact 11, as shown in Fig. 2, the roller 36 runs off the end of the cam at 37 which permits the force exerted by the operating mechanism to turn the yoke or le-- about its pivotal connection with the ver 33 blades at 34 and move the wedges 28 toward the free ends of the blades. This forces both ends of the blades into close contact with the jaws of the contacts 10 and 1.1, as shown in Fig. 3, and completes the closing of the switch. In the closing operation, the movement of the crank 43 is limited by the stops and 51 and any inaccuracy in the length of the links of the switch operating mechathe sprin 49 4).

In opening the switch the bar 42 is moved to the left, as viewed in Fig. 2, which turns the crank 43 clockwise as viewed in this figor lever 33 is not in engagement wit-h the cam 35, the initial movement of the crank 43 in this direction swings thelever 33 about the pivotal connection 34 with the blades 23 and 24 and retracts the wedges 28 toward the ends of the blades pivoted at 22. During this movement of the crank 43 the wedges 28 position shown in Fig. 3'in which they force the blades 23' and 24 against of the contacts to the position shown in Fig. 2 in which the contact pressure between the blades 23 and 24 and the. jaws of the contacts is relieved. In order to indicate clearly in Fig. 2 that this contact resthe jaws of the contacts is relieved,.the blades are shown spaced the contacts, although the blades may not actually move clear of the jaws of the contacts in this initial operation of the switch.

the movable member 15 are swung to the position shown in Fig. 1. This is not prevented by the roller 36 as-the initial move,- ment retracting the wedges 28 swings the yoke or lever 33 so that the roller 36 can move over the arcuate surface of the cam 35.

, It will be apparent that as the initial moment of the operating mechanism relieves the contact pressure between the blades of the switch and the jaws of the contacts, swinging the movable member 15 from the position shown in Fig. 2 to that shown in Fig. 1 to openthe switch will be resisted only by corrosion or ice formed on the jaws of the contactsvso that the switch can be opened without subjecting the parts to excessive stresses.

the.

end of the yoke.

slightly from the jaws of Although I have shown my invention in connection with I desire it to be understood that my invention is not to be limited thereto, except as defined in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is 1. A switch having a contact and a cooperating movable switch contact member, actuating means operative in one continuous movement for moving said-switch contact member to bring one end thereof in proximity to said contact and for forcing the end of said switch contact member against said contact, and means including a lever pivotimity to said contact and for forcing the end of said switch contact member against said contact, and means including a lever pivotally connected to said switch contact member and an abutment engaging said lever for positively preventing said forcing action until the end of said switch contact member is in proximity to said contact.

a. particular form of switch,

3. A switch having a contact and a coopcrating movable switch contact member, ac-

tuating means operative in one continuous movement for moving said switch contact member to bring one end thereof in proximity to said contact and for forcing the end of said switch contact member against said contact, and means including a lever pivotally connected intermediate the ends thereof to said switch contact member and a fixed abutment acting on said lever for positively preventing said forcing action until the end of said switch contact member is in proximity to said contact.

4. A switch having a pair of contacts spaced apart, a movable switch member including two blade elements, means for moving said switch member to bring the ends of said blade elements into proximity to sand contacts, means for forcing the ends of said blade elements against said contacts, and I'means including a lever pivotally connected to said switch member for positively preventing operation of said forcing means until the ends ofsaid blade elements are in proximity to said contacts.

5. A switch havinga pair of spaced contacts each provided with a projecting portion, a cooperating movable switch contact member, means for moving said switch contact inember to bring the ends thereof opposite the projecting portions of said contacts, means for forcing the ends of said switch contact member laterally against said contively preventing actuation of said forcing means until the ends of said switch contact member are opposite the projecting portions of said contacts.

6. A switch having a pair of jaw contacts spaced apart, a movable switch member including two blade elements, means for moving said switch member to bring. the ends of said blade elements between the jaws of said contacts, means for forcing the ends of said blade elements against the jaws of said contacts, and means including a lever pivotally connected intermediate the ends thereof to said switch member and a fixed abutment acting on one end of said lever for positively preventing actuation of said forcing means until the ends of said blade elements are between the jaws of said contacts.

7. A switch having a pair of contacts spaced apart, a movable switch member pivotally connected to one of said contacts, means for rotating said switch member to bring the free end thereof in proximity to the other of said contacts, means for forcing both ends of said switch member laterally against said contacts after said switch member has been rotated to bring the free end thereof in proximity to the other of said contacts, and means including a lever pivotally connected intermediate the ends thereof to said switch member and a fixed abutment acting on one end of said lever for positively preventing actuation of said forcing means Lgtlkthe free ends of said switch member e in proximity to the other of said contacts.

8. A switch having a pair of spaced stationary jaw contacts, a movable switch member including two blades, means for actuating said switch member to bring the ends of said blades between the jaws of said contacts, means mounted between said blades for forcing the ends thereof laterally against the jaws of said contacts after the member has been actuated to bring the blade ends be tween the contact jaws and means for positively preventing the operation of said forcing means until the switch member has been actuated to bring the blade ends between the jaws of the stationary contacts.

9. A switch having a pair of spaced stationary jaw contacts, a pivotally mounted switch member including two spaced blades, means for rotatin said switch member to bring the ends of said blades between the jaws of said contacts, wed ing means mounted between said blades For forcing the ends thereof laterally against the jaws of said conoperation of said wedging means until the switch member has been rotated to bring the blade ends between the jaws of the stationary contacts. 7

10. A switch having a pair of spaced stationary jaw contacts, a pivotally mounted switch member including two substantially parallel spaced blades, means for rotating said switch member to bring the ends of said blades between the jaws of said contacts, wedging means mounted between said blades for forcing the ends thereof laterally against the jaws of said contacts after said member has been rotated to bring the blade ends between the contact jaws and means for positively preventing the operation of said wedging means until the switch member has been rotated to bring the blade ends between the jaws of the stationary contacts including a lever pivotally mounted on said member and a fixed abutment for controlling the movement of said lever relatively to said member.

In witness whereof, I have hereunto set my hand this 24th day of July, 1928.

' HARRY E. MILLER.

tacts after said member has been rotated to bring the blade ends between the contact jaws and means including a lever mounted on said member for positively preventing the

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