US1784669A - Electric switch - Google Patents

Description

Dec; 9, 1930.

J. D. HILLIARD 1,784,669

ELECTRIC SWITCH Filed Aug. 26, 1925 I I l I I I l E i -40 I I I I I I I I I I I I 2 I I I f- I I I 1 I I|UIJ I I 8 4 I L- 3 I 2/ I I 6 /5 /9 I 17 l9 2/ la /7 49 m 19 Inventor.

John D.HLLLLClIfd,

HLs Attorney 0 oil switches.

Patented Dec. 9, 1930 UNITED STATES PATENT OFFICE JOHN D. HILLIARD, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEV YORK ELECTRIC SWITCH Application filed August 26, 1925.

My invention relates to electric switches and particularly to switchesofthe fluid break type having explosion chambers in which are arranged auxiliary or arcing contacts.

One object of my invention is the provision of an improved construction of switch of this type by which a higher speed of separation of the arcing contacts is obtainable. Another object of my invention is the provision of an improved connection between the movable arcing contact and the supporting member therefor.

In accordance with my invention I obtain this higher speed of separation by providing alost motion connection between the movable main contacts and the movable arcing con tacts so that in the opening movement of the switch the movable main contacts are enabled to acquire considerable speed before the arcing contacts are started on their opening movement. The movable arcing contacts not only thereby have an initially higher speed but, by reason of the expulsive force of the gases in the explosion chambers and the aforesaid lost motion connection, rapidly acquire still greater speed.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Referring to the drawing, Figure 1 illustrates in a more or less diagrammatic manner one embodiment of my invention and Fig. 2 illustrates a modification thereof.

In the drawing, Fig. 1, I have shown by way of example the lower ends of two insulator bushings 1, such as are commonly employed to support the stationary contacts of Attached to the end of each bushing I have shown the main stationary contact 2 and the explosion chamber 3. The contact bridge t, when the switch is closed, connects the contacts 2 and forms the main current carrying path therebetween. Within the explosion chambers are the stationary arcing contacts 5 with which cooperate the movable arcing contact rods 6. Bridging member 7 supports the two contact rods 6 and has secured thereto at its middle portion the Serial No. 52,670.

operating rod 8. This rod terminates at its upper end in a head 9 and loosely fitting it is the sleeve 10, to the upper end of which is pivoted the operating lever 11 and to the lowor end of which is secured the contact bridge 4. It will be noted that the length of the sleeve 10 including the contact bridge is somewhat shorter than the length of the rod 8 between the bridge 7 and thehead 9. The pur pose of this difference is to enable the sleeve 10, the contact bridge 4 and the operating mechanism therefor to gain speed in the opening movement of theswitch before the bridge 7 carrying the arcing contacts is engaged. The arcing contact rods 6 are thereby givena relatively high initial velocity. This high velocity moreover is further increased due to the gas pressure within the explosion chamber formed by the are drawn therein, and because of the lost motion connection between rods 8 and sleeves 10 the contact rods 6 are more easily accelerated than would be the case were the sleeves 10 and operating mechanism therefor fixed to the arcing contact rods.

In Fig. 2 I have shown a construction similar to Fig. 1 but with a further lost motion connection arranged between the arcing contactrods 14 and the bridging member 15 which corresponds with member 7 of Fig. 1. The rods 14 are longer than rods 6 and have two limiting flanges 16. Each end of the bridging member 15 carries a pair of opposed plates 17 having inturned flanges 18 at the ends thereof and between the plates and the rod 1 1 are rollers 19. Coil springs 20 mounted on guide pins 21 provide the necessary pressure between the bridge and the contact rods for good conductivity.

Referring to Fig. 2 the initial opening movement of the switch comprises downward movement of the sleeve 10 on the rod 8 opening the main current path through the bridge 4-, the arcing contact rods 14: remaining in frictional engagement with their co0perating stationary contacts 5. The moving parts rapidly gain speed and when the bridging member 15 is reached and the lost motion at this point is taken up, this member is given an initial relatively high velocity. However,

by reason of the lost motion connection between the arcing contact rods 14 and the bridging member 15, further acceleration of the moving parts which now include the bridging member 15 takes place. At length the lower flanges 16 of the arcing rods are reached and the arcing contacts are quickly separated. The explosive force of the arc gases formed in the explosion chambers moreover expels the arcing rods from the explosion chambers with still greater speed, the mass of the rods being relatively small, thus again taking up the lost motion provided. A, quick final break in the circuit may thus be obtained even though the switch and the operating mechanism therefor be of massive construction for controlling circuits of large capacity.

lVhat I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric switch comprising a pair of spaced contact members, an explosion chamber surrounding each member, an operating rod, a. bridging member secured thereto, a pair of contact rods, and a lost motion connection between each of said contact rods and said bridging member comprising a spring pressed plate carried by the bridging member and a plurality of rollers arranged between the plate and the contact rod.

2. An electric switch comprising stationary main and arcing contacts, explosion chambers enclosing the arcing contacts, movable main contacts, a sleeve connected to said main contacts, movable arcing contacts, a bridging member connecting said movable arcing contacts, an operating member for both of said movable main and arcing con tacts and a lost motion connection between the movable main and arcing contacts comprising a rod connected to the bridging member slidable in said sleeve whereby in the open circuiting movement of the switch the bridging member and the arcing contacts may attain a greater initial velocity than that of the movable main contacts.

3. An electric switch comprising a pair of explosion chambers each having a socket contact therein, a contact rOd arranged to engage each of said socket cont-acts, a bridging member supporting and connecting said contact rods, an operating rod connected with said bridging member, plates secured to the bridging member on opposite sides of each contact rod, a plurality of rollers bet-ween the rod and each plate, and springs pressing together the plates, rollers and contact rods.

4. In, an electric switch, a socket contact member, a cooperating contact rod, a transverse supporting member therefor, and means comprising a spring pressed roller forming a lost motion connection between the contact rod and the supporting member therefor.

5. In an electric switch, an explosion chamher having a socket contact member, a movable contact rod adapted to project therein, a support for said rod having a lost motion connection therewith and rolling contact means between the support and the contact member.

6. In an electric switch, a pair ofexplosion chambers each having a socket contact therein, a pair of cooperating contact rods each adapted to project into one of the explosion chambers, a bridging member joining the contact rods, an operating member secured thereto, a spring pressed pressure plate carried by the bridging member at each end thereof, and a plurality of rollers arranged between each pressure plate and one of the contact rods.

In witness whereof, I have hereunto set my hand this 12th day of August, 1925.

JOHN D. HILLIARD.

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