US1685665A - Mechanism for operating electric switches - Google Patents

Description

Sept 2.5., 1928.

... W. BOND MECHANISM FOR OPERATING ELECTRIC SWITCHES s mi Filed Nov. 25, 1927 Figa.

Patented Sept. 25, 1928.

UNITED STATES PATENT oFFicE.

LESLIE W. BOND, OF SCHIENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORK.

IECHANISM FOB OPERATING ELECTRIC SWITCHES.

Application led November 25, 1827. Serial No. 235,412.

My invention relates to mechanisms for operating electric switches, which are adapted 'for both manual and automatic operation, and more particularly for electric switches of large current carrying capacity wherein it is desirable to move the switch to opencircuit position with a minimum amount of energy. My invention lies in a novel arrangement of parts which constitutes an improvement upon similar devices heretofore known in the art.

According to my invention, I providean operating mechanism embodying a compound toggle mechanism for latching the switch to closed circuit position whereby it is possible for the switch to be quickly moved to 'open circuit position by the expenditure of a minimum amount of elort. Provision is also made 'for manually operating the switch to either closed circuit or open circuit position.

The novel features which I believe to be characteristic of m invention 'will be definitely indicated in the appended claims while the features of construction and mode of operation will be more clearly understood by reference to the following description taken in connection with the accompanying drawing which shows the preferred embodiments of my invention.

Referring to the drawing, Figure 1 is a perspective view of a switch embodying my invention, partly cut away, to more clearly illustrate the arrangement of parts; Fig. 2 is a side elevation showing the operating mechanism in open circuit position; Fig. 3 is aside elevation showing the operating mechanism in closed circuit position as actuated by the closing solenoid; Fig. 4 is a side elevation showing the operating mechanism tripped to open circuit position by means'oi the manually operated trip; Fig. 5 is a similar side elevation showing the operating mechanism moved into closed circuit position by means of the manually operating means, 'and Fig. 6 is a side elevation of the manual operating means.

Automatic closing of the switch is accom'- plished as follows: Referrin tothe drawing, 1 represents a base or Stan ard upon whicli are mounted the operating mechanism and the stationary contacts-2. Cooperating with these contacts, are the movable contacts d carried on an operating crank 4 comprising a shaft 5 covered with an insulating covering 6, upon which is rigidly secured the dog 7. r

The shaft 5 is rotatably mounted in suitable pro3ect1ons 8 of the base 1 (only one being shown in the drawing).4 The dog 7 is connected to the base by means of a toggle mochanism comprising the links 9 and V10. This toggle mechanism 9-10 is actuated by the links 11, one end of each being connected to the toggle by the pin 12 and the other being pivotally connected to the plunger 13 of the solenoid 14. The movement of the plunger 13 is so ixed that the pin 12 is always below dead center ot the toggle mechanism, so that the spring pressure of the contacts will always tend-to buckle the toggle and open the switch. Energization ot this solenoid lifts the plunger 13 which straightens the toggle 9-10 to rotate the crank 4 clockwise and bring the movable contacts 8 into engagement with the stationary contacts 2.

IThe pin 12 extends beyond the toggle mechanism and engages with a crank 15 pivotally mounted on a shaft 16 suitably joui-nailed in projections (not shown) on the base 1. This shaft 16 also serves as a pivot for link y10 ot the toggle mechanism. A compression spring 17 is interposed between the crank 15 and the projection 8 ot the base and exerts a 'force additive to that ot the spring pres* surepotythe contacts tending to torce the pin 12 downward, buckling the toggle 9-10 to open the switch.

Link 9 has a projection 18 carrying a roller 19 (best shown in Figure 2) which engages the surface 20 of the lever 21. This lever 21 is lalso pivoted on the shaft 16 and is biased to move in a clockwise direction by means of the spring 22. The other end oi' lever 21 is connected to the projections 23 of the base by means of a second toggle mechanism comprisi ng the links 24-Q5- This toggle 24-25 is connected through a link 26, having a lost i motion slot 27, to the plunger 28 of `the tripping solenoid 29.

The operation ot the latchin mechanism is as follows: When the movab e contacts 3 have been moved to circuit closedlposition as described above, the roller 19 on the projection 18 of link 9 rides up the surface 20 of iever 21 and allows the biasing spring Q2 to turn the lever 21 in a clockwise direction about the shaft 16. As the upper end of lever 21 moves to the right, the toggle 24--25 is straightened and falls slightly past dead center by its own weight, latching the lever 21 in this position. The surface 2O of this lever in turn engages the roller on the projection 18 of link 9 and preventsthe toggle 9-10 from buckling, whereby the switch is latched in closed position.

After the breaker is latched closed, it is 'desirable that the closing solenoid should be fle-energized; This de-energization of the closing solenoid is accomplished by means ot an auxiliary contactor 30 whose coil circuit is broken when the switch is closed, by means of the interlock 31, actuated by a pin 32 secured to the lever 21. This expedient is well known in the art and forms no part of this invention.

Energization of the tripping solenoid 29 draws up the plunger 28 connected to the link 26 which buckles the toggle 24-25 upward slightly past dead center. The spring pressure of the contacts, and torque exerted by spring 17 then turns lever 21 in a counterclockwisedirection to open the switch and complete the buckling of toggle 24-25, which is accomplished by its' pivot pinsliding upward in the lost motion slot 27 of link 26. This lost motion slot enables the tripping plunger 28 to have a very limited motion, so that the open circuit air gap of the solenoid 29 is very small, and a maximum electromagnetic pull is obtained on the plunger 28 for a given energy consumption by the tripping solenoid. l

Provision is made for manually operating the switch at t-he will of the operator. This manual operating means comprises a handle 33 rigidly secured to a hub 34 which is pivotally mounted on the shaft 16. Hub 34 has a shoulder 35 adapted to engage the crank 15 when the handle 33 is rotated in a clockwise direct-ion, shown in Fig. 6, as position A, and' close the switch.' The operation of the mechanism in closing and latching is the same as previously described under automatic operation. This is shown in Fig. 5.

The hub 34 also has an ear 36 which is pin connected to the link mechanism 37-38-39-40-4 1. Upon a movement of the handle 33 to position B, Fig. 6, the ear 36 is moved in a counterclockwise direction raising the link 37 which in turn, through the link 38, turns the links 39-40, which are rigidly secured together, in a counter-'clockwise direction about the pivot 43. The link 40 is adapted to engage one end oa lever 41 pivoted freely on the pin 44. The other end of the lever 41 engages the center pin of the auxiliary toggle 24-25, and the counterclockwise movement of the link 40 causes a clockwise movement ot the lever 41 which buckles the toggle 24--25 and allows the Leganes switch mechanism to open as described above in connection with automatic operation. The link 37 has a lost motion slot 45 in which moves the pin 46 connected to the link 38. This allows the switch mechanism to open trip free of the handle, whereby the opening of the switch is more rapid and more certain. The corresponding position of the elements is now as shown in Fig. 4. The handle 33 is now returned to position C which is the neutral position maintained for electrical operation and the apparatus is in readiness toV be closed automatically in response to energization of the closing solenoid, or manually by moving the operating handle 33 to position A. i

In accordance with the provisions of the patent statutes I have described the preferred embodiment of my invention, but I do not wish to be limited to the particular construction shown and described, as it will be apparent to those skilled in the art that many modifications therein may be made without departing from the scope of the invention as set forth in the appended claims.

What 1 cla-im as new and desire to secure by Letters Patent of the United States, is

1. A switch operating mechanism comprising a base, an operating crank pivotally mounted on said base, a toggle mechanism between said crank and said base biased to open circuit position, a solenoid having a plunger, a1 link connection between said plunger and said toggle for actuating the same, an eXtension on one link of said toggle carrying a roller, a lever pivotally connected to said base and biased to the position corresponding to closcd circuit, one end of said lever being adapted to engage said roller and the other end being connected to said base through a second toggle mechanism whereby the switch is latched in closed circuit position, a tripping solenoid having a plunger and a link connection between said last mentioned plunger and said second toggle mechanism whereby the lever and crank are released to open the switch when the tripping solenoid is energized. n 2. In combination, an electric switch having a stationary contact mounted on a base, a cooperating movable contact carried by an operating crank pivota-lly mounted on said base, a toggle mechanism between said crank and said base biased to open circuit posit-ion, a closing solenoid having a. plunger', a link connection between said plunger and said toggle for actuating said toggle to close the switch, an extension on one link of said toggle carrying a roller, a lever pivotally connectcd to said base and biased to the position corresponding to closed circuit, one rnd of said lever being adapted to engage said roller and the other end beingconnectcd to said base through a second toggle mechanism whereby the switch is mechanically latched in closed circuit position, a tripping solenoid having a moved in one direction, and to break said secplunger and a link connection between said 0nd toggle through a link mechanism when l0 last mentioned plunger and said second toggle moved in the opposite direction, to open the mechanism whereby the lever and crank are switch.

5 released to open theswitch when the tripping In witness whereof I have hereunto set my solenoid is energized, and manually operable hand this 23d day of November, 1927. means pivotall -mounted on said base adapted to rotate sai crank to close the switch when LESLIE W. BOND. v

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