US1971392A - High pressure contact switch - Google Patents

Description

Aug. 28, 1934. G. L. CARLISLE HIGH PRESSURE CONTACT SWITCH Filed Feb. 11, 1933 Patented Aug. 28, 1934 UNITED STATES PATENT OFFICE HIGH PRESSURE CONTACT SWITCH Application February 11, 1933, Serial No. 656,345

23 Claims.

This invention relates to a high pressure contact switch, and particularly to a hook type disconnecting switch.

Until quite recently, it had been the customary practice to employ knife switches, of the tongue or clip type, in which the blade or blades and the jaw had the form of flat plates that engaged with full surface contact. The design practice was to so relate the area of the surfaces in contact to the maximum current capacity of the switch that the current density per square inch was of a low order. It has been demonstrated, however, that heavy currents may be carried by switches which employ line or point contacts under high unit pressures, such as of the order of 10,000 pounds per square inch, and upward.

An object of the invention is to provide an exceedingly simple, rugged and efficient disconnecting switch of the high pressure contact type. An object is to provide a high pressure contact switch having resilient blades that engage the jaw and the hinge member of the switch with contact areas of the order of point or line contacts. A further object is to provide a switch blade in the form of a plurality of resilient rods whose jaw ends are spaced apart by and secured to a bridge member, the hinge ends of the blade being pressed outward, by the resiliency 'of the rods, and into firm engagement with the hinge member. Another and specific object is to provide, in a switch of the type stated, a jaw member in the form of a post having short parallel side edges for engagement by the rods of the blade, the side edges terminating in stop shoulders against which the blade rests when the switch is closed.

Another specific object is to provide, in a switch of the type stated, a hinge member having the form of parallel side members which are apertured to receive the ends of the blade rods, the faces of said side members adjacent the blade rods being provided with beads or projecting flanges which restrict the contact area of the adjacent portions of the blade and hinge member.

These and other objects and advantages of the invention will be apparent from the following specification, when taken with the accompanying drawing, in which:

Fig. 1 is a perspective view, with parts broken away, of a disconnecting switch embodying the invention; i

Fig. 2 is a bottom plan view, of the jaw member, the bars of the switch blade being shown in section in switch-closed position;

terminal clamping bolt, and a post 14 which pro- Fig. 3 is a horizontal sectional view partly in section of the hinge member, with the .blade shown in openposition;

Fig. 4 is a sectional view of the hinge member, as taken on line 44 of Fig. 3; and

Fig. 5 is an elevation of another form of blade member.

In the drawing, the reference numeral 1 identifies the parallel rod members of the switch blade, the rods being resilient and, preferably, consisting of a steel core 1a and a sheath 1b of a ductile metal of high electrical conductivity, such as copper. At the outer or jaw end of the blade, the rods are secured to and accurately spaced by a bridging member 2 which is provided with a ring 3 for receiving the hooked end of the usual switch puller.

The opposite ends 4 of the rods are bent at right angles to provide the hinge pins or journals for mounting the blade on the hinge member. The hinge member of the switch may take the form of a casting having parallel side members 5 which are apertured, as at 6, to receive the bent ends 4 of the blade rods, The edges of side members 5 slope upwardly to a narrow top 7 and the opposed faces of the side members are provided with projecting rounded flanges 8 which extend around the periphery of the side members except at the top, the gap 9 which is thus left in the flanges being of a width and shape to receive the adjacent rod 1 of the blade when it is turned from closed position. As shown in Fig. 3, the upper portions of the contact flanges 8 flare away from each other, thus providing an increasing contact pressure between the hinge and blade members as the latter is turned upwardly into closed position. The bottom flange of the hinge member is apertured to receive a bolt for clamping the hinge member to a support, and the flange extends rearwardly to terminate in a lug 11 for receiving a clamp for attaching a line terminal.

The central portion of jaw terminal casting 12 is apertured to receive a bolt for securing the jaw to a support, and comprises a lug 13 for a jects above stop shoulders 15 against which the blade rods 1 rest when the switch is closed. The lower portion of the post 14 has side edges 16, preferably flat and parallel to each other, which are normal to the pivotal axis of the blade and which form the contact surfaces for engagement with the cylindrical surfaces of the blade rods 1.

The post 14 preferably flares outwardly just above the contact surfaces 16, as indicated at 17, and then tapers upwardly to provide sloping surfaces for guiding the blade. The spacing of the contact surfaces 16 is somewhat less than the normal distance between the blade rods 1, and the wider portions 17 therefore act as a yielding latch for retaining the switch in closed position.

The spacing of the outer ends of the rods 1 by the bridge member 2, the spacing of the contact surfaces 16 and the distance between the opposed contact flanges 8 of the hinge member are so related to each other that the rods 1 of the blade are pressed very tightly against the jaw and hinge member. The contact areas are of the order of line or point contacts, and the sliding of the contact portions over each other during the closing of the switch insures a clean metallic contact.

It will be noted that the contact flanges 8 of the hinge member extend along both edges of the side members 5, thus permitting the blade to be closed upon a jaw member positioned below, as viewed in Fig. 1, the hinge member. When closed, the blade is resiliently retained in that position by the shoulders 1'7 and, when opened, the rods 1 snap into the recesses 9 to retain the blade in open position, as shown in Figs. 3 and 4.

In this particular embodiment of the invention, the blade rods 1 have line contacts with the flat surfaces 16;of the jaw, and the blade rods have substantially point contacts with the rounded flanges of the hinge members.

The exact form of the restricted contact areas may be varied by appropriate changes in the geometry of the jaw member and the contact flanges of the hinge member. which may be more or less than two, are preferably of circular cross-section, but this is not essential as journals may be attached to the ends of square or oval rods, or the rod ends may be stamped or pressed into a circular cross-section.

In place of separate rods 1 joined by a rigid bridge 'member 2, the blade comprises a single rod 1' having an intermediate portion constituting the bridge member, as shown in Fig. 5. This intermediate portion may be, and preferably is, looped to form a ring 3' for receiving the hook of a switch puller. With either the composite or the single rod type of blade, the pressure exerted- 'upon' the jaw and hinge may be increased by a spacer 18 between the side members at an intermediate portion of the blade and/or by a spring 19 between the side members adjacent their pivoted ends.

The desired high pressure contactmay be obtained for any given switch by appropriate choice of the rods, their normal spacing, and the distance between and design of the jaw and hinge members. If desired, the jaw member may have the form of a yoke which engages the outer surfaces of the blade members, and the hinge member may be a single post having ribs at its opposite surfaces for engagement with the inner edges of the rods."

It will be apparent that the invention is not restricted to the particular construction hereindescribed and illustrated, as various changes may be made in the several parts, and in their relative size, shape and relationship without departure from the spirit of the invention as set forth in the following claims.

I claim:

1. In a disconnecting switch, a resilient current-carrying blade comprising a substantially straight rod of resilient metal, means pivotally supporting said rod about an axis substantially normal to the longitudinal axis of the blade, and

The rod or rods,

a pair of spaced contacts having contact surfaces adapted to be bridged across by said rod when the switch is closed, said contacts being stationary and with the contact surface of the contact adjacent the pivoted end of said rod projecting into the normal path of pivotal movement of said rod to flex the same into high pressure contact engagement with both contact surfaces.

2. The invention as claimed in claim 1, wherein said blade is a rod having a core of resilient metal and an outer sheath of ductile metal of high electrical conductivity.

3. The invention as set forth in claim 1, wherein said blade is of circular cross-section, and one end is bent over at right angles for pivotal engagement with said supporting means.

4. The invention as set forth in claim 1, wherein said blade is of circular cross-section, and one of said spaced contacts has a plane surface for engagement therewith when said switch is closed.

5. In a disconnecting switch, a hinge member, a blade member comprising a resilient rod and means pivotally supporting the same on said hinge member, a contact 'member spaced from said hinge member, and contact means adjacent the pivotal supporting means providing a second contact area engaged by said rod blade member when the latter engages said contact member, said contact surface of the contact means being inclined to a plane normal to the pivotal axis of said resilient rod to flex the said rod as the latter is pivotally moved from open position into a position bridging the said contact member and contact means.

6. The invention as set forth in claim 5, wherein the rod blade member and said contact member have cooperating contact surfaces of plane and of rounded contour, thereby limiting the contact area to not more than line contact.

"I. In a disconnecting switch, a blade comprising a pair of resilient rod members, a hinge member on which said blade is pivoted, a jaw member having a pair of contact surfaces for engagement by the respective rod members, and fixed means adjacent the pivotal axis of said blade providing a second pair of contact surfaces for engagement by said rods when the switch is closed, said second pair of contact surfaces being inclined with respect to a plane normal to the pivotal axis of said blade to flex said resilient rod members .when the blade is moved from switch-open to switch-closed position.

8. The invention as set forth in claim 7, wherein said contact means is integral with said hinge member.

9. In a switch, a blade comprising spaced resilient rods rigidly joined at their outer ends, the inner or hinge ends of the rods being bent to provide pivots, a hinge member on which said blade is pivoted, and a jaw member having a pair of contact surfaces for engagement with said rods.

10. The invention as set forth in claim 9, wherein the pivot ends of said blade rods are turned outwardly, and said hinge member comprises spaced side members between which said rods are located, said side members being apertured to receive the pivot ends of said rods.

11. The invention as set forth in claim 9, wherein said hinge member comprises side members apertured to receive said pivot ends of said rods, and contact flanges are provided on said side members for high pressure engagement with said rods when the switch is closed.

12. An electrical switch comprising a hinge member, a pair of cylindrical blade members I pivotallv supported upon said hinge member, a

stationary contact member engaged by the cylindrical surfaces of said blade members when the switch is closed, and means including a pair of flaring contact surfaces adjacent the pivotal axis of blade members for forcing the adjacent portions of said blade members laterally to establish high contact pressure engagement with said contact surfaces and contact member when the switch is closed.

13. The invention as set forth in claim 12, wherein said blade members are resilient, and said means includes a bridge member secured to the outer ends of said blade members and normally spacing the same apart by a predetermined distance difierent from the spacing of the contact surfaces of said contact member.

14. In an electrical switch, a blade comprising a pair of resilient cylindrical rods, a stationary hinge member having journal openings therein, one adjacent pair of ends of said rods being bent at right angles to the axis of said blade and seated in said openings for pivotally supporting said' blade, and a stationary jaw member.

15. An electrical swltchcomprising a hinge member, a pair of resilient cylindrical blade members having the ends thereof pivoted on said hinge member to support said blade members for pivotal movement and to support the said ends of said blade members for lateral movement towards and away from each other, a jaw member having flat contact surfaces for engagement by said cylindrical blade members, and flaring contact means for pressing said blade members into flrm engagement with said jaw member in the closed position of said switch.

16.-The invention as set forth in claim 15, wherein the jaw member comprises a post having a transverse thickness in excess of the normal spacing of opposed surfaces of said blade members.

17. In a disconnecting switch, a blade ha resilient side members of circular cross-section, adjacent ends of the side members being bent outwardly at right angles to provide pivots, bridge means connecting the opposite ends of said side members, a hinge having spaced side members apertured to receive said pivot ends of said blade members, a contact member having spaced contact surfaces for engagement with the respective side members of said blade, and contact flanges on said hinge having not more than line contact with the said blade members, the normal spacing of said blade members being such that the blade members are flexed into high pressure contact with said contact surfaces and contact flanges when said switch is closed.

18. The invention as set forth in claim 1'1, wherein said contact member comprises a post, the blade members being located on opposite sides of said post when the switch is closed.

19. In a switch, the combination with a hinge member and contactmember, of a switch blade, said blade comprising spaced resilient rods having one pair of adjacent ends of approximately circular cross-section laterally bent and pivoted upon said hinge member, means bridging the opposite pair of ends of said rod to space the same apart by a predetermined distance, and a second member connected between said rods intermediate the ends thereof.

20. The invention as set forth in claim 19, wherein said second member is a substantially rigid spacer secured to the respective rods.

21. The invention as set forth in claim 19, wherein said second member is a spring tending to increase the transverse pressure exerted upon said hinge and contact member by said rods.

22. In a switch, a jaw member, a hinge member, and a blade pivoted upon said hinge and adapted to be engaged with said jaw; said blade comprising a single resilient rod bent to form parallel side members, the ends of said rod being normal to said side members and providing pivots for mounting said blade upon said hinge member.

23. The switch as claimed in claim 22, wherein the portion of said rod joining said parallel side members is looped to form a ring for receiving the hook of a switch puller.

GEORGE L. CARL-181E.

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