US761745A - Switch for electric circuits. - Google Patents

Description

- PATENTED JUNE 7, 1904.

G. WRIGHT. ,SWITGH FOR. ELECTRIC GIRGUITS.

APPLIOATION FILED NOV a0 1903 N0 MODEL.

INVENTOR. GiIber bWri WITNESSES:

ATTORNEY.

I UNITED STATES Patented June 7, 1904.

PATENT OFFICE.

' GILBERT WRIGHT, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO STANLEY ELECTRIC MANUFACTURING COMPANY, OF PITTSFIELD, MASSACHUSETTS, A CORPORATION OF NEW JERSEY.

SWITCH FOR. ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 761,745, dated June '7, 1904.

Application filed November 30, 1903. Serial No. 183,139. (No model.)

To Z7, whom it may concern.-

Be it known that I, GILBERT VVEIGIIT, a citizen of the United States, and a resident of Pittsfield, Massachusetts, have invented certain new and useful Improvements in Switches for Electric Circuits, of which the following is a specification.

My invention relates to switches adapted to break electric circuits carrying large currents at high potentials. It has been the custom for several years to construct such switches with the contacts submerged in oil, since this practice reduces the arcing which occurs upon opening the circuit. Such switches as have been heretofore constructed are open to a number of objections. In the first place highcurrent capacity demands perfect contact be tween the stationary contacts and the movable member, and the perfect alinement which is necessary for providing such contact has not been suitably provided for in the majority of switches heretofore built. Moreover, breaking acurrent at high potential produces some arcing even in oil, and this arcing isinjurious to the contact-surfaces between which the arcs spring. In many switches as heretofore constructed the are forms between the surfaces which are in engagement when the switch is closed, and for this reason the contactsurfaces rapidly deteriorate. Furthermore, switches having their contacts immersed in oil and their operating mechanism outside of the oil tank or reservoir have been cumbrous or complicated in structure, and therefore eX- pensive to build, unwieldly in operation, and liable to excessive wear in the moving parts.

The object of my invention is to provide a structure for oil switches which shall be simple and durable in structure and efiicient in action.

A further object of my invention is to provide an arrangement of contacts in such a switch which shall be perfectly self-alining, so as to secure a maximum contact-surface when the switch is closed, and which shall receive the are upon opening the switch between surfaces which form no part of the contact- Surface when the switch is closed.

In the accompanying drawings, Figure 1 shows an end elevation in cross-section of a switch constructed in accordance with my invention, and Fig. 2 shows a side elevation in cross-section of the same.

In the drawings, A represents a tank or reservoir which is adapted to contain oil or other insulating fluid and which is supported by the frame B.

C C C are insulators mounted in frame B and carrying stationary contacts D, which are provided with theterminals (Z.

E is a longitudinally reciprocating rod which slides through guides F on frame B. Rigidlysecured to rod E by the bolts Cr are the two pieces of wood or other insulating material HH, placed one above the other. The lower piece H is cut out, as shown in the drawings, to receive the movable contacts I and the springs J. Springs J when the switch is open, as shown in Fig. 2, press movable contacts I against the lower surface of upper piece H. Movable contacts I are provided with the lugs or cars 2', loosely engaging upper piece H, as shown in Fig. 1, and preventing all horizontal movement of the movable contacts relatively to the member-H. It will be seen from the drawings that both stationedges of contacts D and are pressed down, so

that the movable contact slides under the stationary contact. The movable contacts I are accordingly pressed down away from the upper piece H and are free to aline themselves perfectly under the pressure of springs J with the stationary contacts D D, which are bridged. Thus the maximum contact-surface is secured when the switch is closed, since if each pair of stationary contacts D D is machined off evenly after mounting in frame B perfect alinement is always secured. It will be understood that the particular switch shown in the drawings is designed for double-throw. It is evident that for a single-throw switch half of the stationary contacts shown would be omitted. The operating-handle for red E is shown broken ofi' at its front end. It will be understood that the operating-handle may be of any well-known and suitable type. When the switch is opened, the curved edges or extensions of the stationary and movable contacts are pressed into engagement by the springs J after the flat bearing-surfaces have separated. All arcing consequently takes place between the curved edges, and the bearing-surfaces of the contacts are in no way affected thereby.

It will be seen from the above description that I have provided a switch in which the maximum bearing-surface is always obtained and in which the arcing that must necessarily occur can produce no deleterious effects. There is not a pivot or joint of any kind in the structure which I have provided nor unnecessary parts which must increase the cost of construction as well as the complication and wear of the switch. It will be evident that a number of changes may be made in the structure which I have described which will in no way depart from the spirit of my invention. For instance, the guides F F may be omitted, the rod E sliding directly upon the top of frame B and guided by the bolts G, passing through their slots in frame B. The friction of the moving parts is, however, reduced by the structure which I have shown. Other similar alterations in detail may be made, and accordinglyI do not desire to limit myself to the particular construction'and arrangement of parts here shown, since changes therein which do not depart from the spirit of my invention and which are within the scope of the appended claims will be obvious to those skilled in the art.

Having thus fully described my invention, Iclaim as new and desire to protect by Letters Patent 1. In a switch for electric circuits, an oiltank, stationary contacts submerged therein, a longitudinally-reciprocating rod, a member rigidly secured to and supported by said rod, and self-alining contacts secured to said member. 2. In a switch for electric circuits, an oiltank, stationary contacts submerged therein, a longitudinally-reciprocating rod, a member rigidly secured to said rod, and bridging contacts let into and extending through said member.

3. In a switch for electric circuits, an oiltank, stationary contacts submerged therein, a longitudinally-reciprocating rod, a member rigidly secured to said rod,and spring-pressed contacts secured to said member.

4. In a switch for electric circuits, a supporting-frame, an oil-tank supported below said frame, stationary contacts submerged in said tank, a longitudinally-reciprocating rod supported above said tank, a member submerged in said tank and supported from said rod, and self-alining contacts secured to said member.

5. In a switch for electric circuits, an oiltank, stationary contacts submerged therein, a horizontal longitudinally-reciprocating rod, and spring-pressed contacts supported from said rod and, restrained from horizontal movement relative to said rod.

6. In a switch for electric circuits, a supporting-frame, an oil-tank supported below said frame, stationary contacts submerged in said tank, a longitudinally-reciprocating rod supported above said tank,and spring-pressed contacts supported within said tank from said rod and restrained from horizontal movement relative to said rod.

7. In a switch for electric circuits, a supporting-frame, an oil-tank supported below said frame, stationary contacts submerged in said tank, a longitudinally-reciproeating rod supported above said frame. a member submerged in said tank and rigidly supported from said rod, and bridging contacts secured to said member.

8. In a switch for electric circuits, stationary contacts, a reciprocating member, and a self-alining contact let into and extending through said member.

9. In a switch for electric circuits, stationary contacts having inclined edges, a reciprocating member, and a spring-pressed bridging contact having an inclined edge and extending through said member.

10. In aswiteh for electric circuits, stationary contacts,a reciprocating member,a bridging contact extending through said member and provided with ears loosely engaging said member, and a spring arranged to press said bridging contact in a direction at right angles to the direction of movement of said member.

11. In a switch for electric circuits, a supporting-frame, an oil-tank supported below said frame, stationary contacts submerged in said tank, a horizontally-reciprocating member supported above said tank, asecond member submerged in said tank and rigidly supported from the first member, and a bridging contact secured to said second member.

12. In a switch for electric circuits, a supporting-frame, an oil-tank supported below said frame, stationary contacts submerged in said tank, a reciprocating member supported above said tank, a second member submerged in said tank and rigidly supported from the first member, and a self-alining contact secured to said second member.

Signed at Pittslield,h Iassachusettathis 27th day of November, 1903.

GILBERT I/VRIG-HI.

Witnesses L. A. HAWKINs, R. E. I'IAYNES.

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