US2264862A - Electric switch - Google Patents

Description

Dec. 2, 1941. SCHEUERMEYER I 2,264,862

ELECTRIC SWITCH Filed Jan. 10, 1940 2 Shets-Sheet l Inventor" I Emil Scheuermeyer;

is Att; 01' Hey.

2, 194 1. E. SCHEUERMEYER 2,264,862

ELECTRIC SWITCH Filed Jan. 10, 41940 2 Sheets-Sheet 2 Inve. nb or: Emil S'ch eue-rme /e Hls -Att orney Patented Dec. 2, 1941 anac'rnrc swrrcn Emil Scheuermeyer, Upper Darby, Pa., assignor'to General Electric Company, a corporation of New York Application January 10, 1940, Serial No. 313,208 8 Claims. (01. 200-48) My invention relates to improvements in electric switches and more particularly switches ofv the type wherein successive translatory and rotary movements of a movable circuit controlling member are efiected by a continuo movement of an operating member. v

-In pillar insulator mounted disconnecting switches of the rotatable blade andcooperating stationary jaw contact type especially for high voltages and high contact pressures, the engagement and separation of the blade and jaw contact particularly when there is any tendency for them to stick because of corrosion, current welding, sleet and ice formations, etc.,' are likely to impose on the insulators, usually of ceramic material, bending and torsional stresses which they are inherently ill adapted to sustain. In order to reduce the severity of the duty on the insulators as well as other parts of such switches; it has been proposed that in the circuit-opening operation of the switch the blade be first withdrawn from its cooperating stationary contact in.' a substantially straight line motion and then rotated to provide the clear break necessary for the voltage of the circuit. The circuitclosing operation is in the reverse order; that blade rotation and then translation.

One object of my invention is to provide an improved and simplified electric switch mechanism for obtaining such translatory and rotary blade actuations with one continuous movement of an operating member.

Another object of my invention is to provide an electric switch mechanism for obtaining a positive and definite transition between the. two movements whereby to insure that the blade is correctly aligned with the stationary contact prior to engagement therewith.'

A further object of my invention is to provide an improved electric switch mechanism with means for simply and readily adjusting the transition point between the rotary and transiatory movements.

These and other objects of my invention will appear in more detail hereinafter. I

My invention will be better understood from the following description when considered in connection with the accompanying two sheets of drawings, and its scope will be pointed out in the appended claims.

In the accompanying drawings Fig. 1 is a side elevation of a blade and jaw type of electric switch embodying my invention;

Fig. 2 is a top plan view to an enlarged scale with parts 'broken away illustrating the jaw contact with the blade positioned therein;

Fig. 3 is a view similar to Fig. 2 with the blade withdrawn from the jaw contact;

Fig. 4 is a vertical elevation of that portion of the switch mechanism mounted on the middle insulator of the switch shown in Fig. l as viewed from the left-hand insulator-in Fig. 1;

Fig. 5 is an elevation partly in section on line 5-5 of Fig- 4 showing the parts in the switch-closed condition;

' Fig. 6 is an elevation similar to Fig. 5 show- I ing the parts in position at the end of the translatory opening movement or the beginning of the translatory closing movement of the blade;

contact element l2 and indicated generally by l8, l9 and 20 are mounted on a suitable base.

I5. and interconnecting means, such as a link it, between the parallel motion mechanism l5 and the crank it. As shown, the contact means Ill is mounted on a terminal insulator bracket I! attached to a stationary supporting insulator It. The rest of the switch mechanism is supported by a stationary insulator i9 and a rotatable insulator 20. At their upper ends these insulators are interconnected by a strut 2|,

which serves to keep them in alignment, sup-- ports the parallel motion mechanism i5, and carries a suitable bearing for the upper end of the rotatable insulator to which the'crank I4 is suitably secured. The outer end portion of the strut 2| may also serve as the other terminal of the switch. The supporting insulators which is not shown but which, as will be apparent to those skilled in the art, may include a bearing for the lower end of the insulator 20. In order to insure a good conductive path between the strut !l and the contact element l2,

9. suitable flexible connection 22 may be provided between these members. In those cases where the switch may be used to interrupt relatively small currents, such as magnetizing our the rents oi transformer banks, arcing horns 23 may be provided.

As shown in Figs. 2 and 3, the stationary contact means It is of the full floating line pressure contact type comprising two opposed cylindrical contacts I I respectively mounted in hood or shroud members 24. These house resilient means, such as springs 25, bias the contacts toward each other. In order to insure a good conductive connection between, the terminal bracket l1 and each of the contacts they are interconnected by suitable flexible connections 26. In order to provide a guided entry of the blade portion l3 into the contacts ii, each of the hoods 24 may be provided with flanges 21 arranged to provide a V-shaped entering notch.

In accordance with my invention, I so construct the parallel motion mechanism that it can function as a parallel motion device during a part of the movement of the operating member l4, but during the remainder of the movement of this member, it is effectively operative as a rigid member. Thus during that part of the movement of the operating member H in which the parallel motion mechanism If! is operative, as such, translatory movement of the contact element I2 is efiected but during that part of the movement of the operating member l4 in which the parallel motion mechanism is operative as a rigid member, the rotary movement of the contact element I2 is efl'ected,

As will be more readily apparent from" Figs. 4-6, inclusive, the parallel motion mechanism l5 comprises a plurality of relatively movable interconnected links 30, 3|, 32 and 33. These may be pivotally interconnected by bearing pins 34, 35, 36 and 31, as shown. Also, as illustrated, the contact element-l2 is suitably mounted, as by a clamping means 33, on one of the links 35 which may also be connected to the operating move as a unit about the axis after the translatory movement of the blade has been completed in the circuit-opening operation of the switch, the center-to-center distance of the bearing pins 42 and 44 is made equal to the center-to-center distance of the bearing pins 40 and 42. Also, in order to obtain the desired relative and rigid movement of the parallel motion links, the cam member 4| has two cam portions or faces and 46 providing a reversely curved configuration or outline against which the pin 38 bears. Thus, the cam face 45 is circular with its center in the axis of the pin 42. The radius of curvature of the cam face 45 is such as to engage the pin 36 and thereby prevent rotation of the link 32 as long as the cam face 45 is over the pin 33; in other words, during the translatory movement of the contact element 2. However, when the cam member 4| is rotated clockwise sufliciently for the pin 36 to move by the point of curvature reversal so-as to engage the cam'surface 46, as shown inFig. 6, then, in accordance with my invention, the parallel motion mechanism can retate as a rigid unitabout the axis 40. At this point in the movement of the cam member 4| the bearingpin 44 is in line with the bearing pin 40, and the bearing boss 41 of the cam 4| enmember l4 by the link It through universal Joint means 39, as shown. v

In order to secure the desired translatory and rotary movements of the contact element 2 by the parallel motion mechanism I5, I rotatably support one of the links 32 for angular movement gages orabuts stops 43 on the link 32 whereby to prevent further relative movement of this link and the cam member, the parts being positioned as shown in Fig. 6. Further movement of the operating member l4 now results in rotary movein the plane of the mechanism. Thus, as shown, the link 32 is supported on a bearing pin or pivot 40 which is intermediate its pivotal connections 35 and 36 to the mechanism and which is supported by the strut 2]. Further, in accordance with my invention, I so arrange to prevent movement of the link 32 during a part of the movement of the operating member 4 as to effect relative movement of the links of the mechanism,

but on further movement of the operating member, to prevent relative movement of the links of the mechanism, Thus, for example, in the illustrated embodiment of my invention during that portion of the motion of the operating member in which translatory movement of the contact element I2 is desired, I provide means for preventing rotation of the link 32 about its bearing pin 40. Upon further movement of the operating member, however, during which rotary movement of the'contact element I2 is to be effected, I provide means which prevents relative movement of the links of the parallel motion mechanism I5 but allows rotary movement of this mechanism as a unit about an axis, such, for example, as the pivot pin 40 on which the link 32 is mounted.

The means which I have shown for obtaining the desired relative and rigid movementsof the ment of the contact element l2 as the pin 36 travels along or engagesthe cam surface 46 since the parallel motion mechanism is now locked and can move only as a unit about the axis 40. Such unitary motion continues until the parts come to the position shown in Fig. 7 wherein the motion is limited by the end 49 of the link 32 abutting suitable means, such as a stop 50 on the strut 2|. In the switch-closing movement the operation just described is, of course, in reverse order from the position shown in Fig. '7 to Fig. 6, where the translatory movement starts, to the position shown in Fig. 5, where the translatory movement ends on the switch-closing movement.

Since it is important that the blade end l3 of the contact element |2 be rotated to the desired alignment with the stationary contact jaws before the translatory movement is started; it is preferable to have a stop for limiting the counterclockwise rotation of the parallel motion mechalinks 3I-33, inclusive, is a cam member 4| which nism as a unit. This may be'accomplished by placing a stop 5| in' the path of movement of the end 52 of the link 32. In order to allow for manufacturing tolerances and lost motion, espe- I and suitably secured against relative movement of said other link whereby to efiect relative movethereto by a lock'nut 53 as more clearly appears in Fig. 4,.

While the parallel motion mechanism may be thought of theoretically as comprising elements which have only one dimension, that is, length,

and operating in the same plane it is, of course,

obviously impossible to make these elements without thickness so that to a certain extent they have to be ofiset from each other. In order to maintain symmetry of structure with better distribution of loads so as to avoid cramping and undue friction, certain parts of the mechanism may be duplicated, as shown in Fig. 4. However, for practical purposes I have found that it is not necessary to duplicate the cam portions on the member 4|. Thus, as shown in Fig. 4, while the cam member 4| is shown as comprising two interconnected portions 4|, 4 l only the portion 4| is provided with the cam faces 45 and 46. In order to limit the translatory movement in switch closing direction, the portion 4|" of the cam member 4| may be provided as shown more clearly in Fig. 4, with a tail or stop portion 54 which abuts the strut 2| in the closed position of the switch. The stop position of this cam member can readily be varied by means of suitable shims, such as washers 55, mounted under the head of one of the cap screws 56 which secures the strut 2| to thecap of the insulator 49.

While I have shown and described my invention in considerable detail, I do not desire to be limited to the exact arrangements shown, but seek to cover in the appended claims all those modifications that fall within the true spirit and scope of my invention.

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

1. An electric switch comprising a movable contact element, anoperating member, and means for effecting successive rotary and translatory movements of said contact element by a continuous movement of said operating member comprising a parallel motion mechanism having a plurality of relatively movable interconnected links, means for preventing relative movement of said links during a predetermined portion of the movement of said operating member subsequently operative during further predetermined movement of the operating member to permit relative movement of the links of the mechanism, including means actuated in dependence on the movement of one of saidlinks, and means for changing the point in the movement of the operating member at which transition from rotary to translatory movement of the contactelement occurs.

2. An electric switch comprising relatively movable cooperating contact elements, an operating member, and means for efiecting successive translatory and rotary movements of one of said contact elements by a continuous movement of said operating member to cause a change in the circuit controlling condition of said contact elements comprising a parallel motion mechanism having four pivotally interconnected links to one of which said operating member is connected, means pivotally supporting another of said links at a point intermediate its pivotal connections in.

the mechanism for angular movement in the plane of the mechanism, a rotatably mounted member having a reversely curved cam, said cam of said operating member to prevent movement ment of the links or the mechanism and on further movement of said operating member to prevent relative movement of the links of the mechanism.

3. An electric switch, comprising a movable contact element, an operating member, and means for effecting successive translatory and rotary movements of said contact element by a continuous movement of said operating member comprising a parallel motion mechanism havin a plurality of relatively movable interconnected links to one of which said operating member is connected, means rotatably supporting another of said links for angular movement in the plane of the mechanism, a rotatably mounted memher having a reversely curved cam engageable with said mechanism, said cam member being coupled to said mechanism and movable thereby during a part of the movement of said operating member to prevent movement of said other link whereby to effect relative movement of the links of the mechanism and on further movement of said operating member to prevent relative movement of the links of the mechanism, and means for controlling the point in the movement of the operating member at which the curvature engagement of the cam with the mechanism is reversed.

4. An electric switch comprising relatively movable cooperating contact elements, an operating member, and means for eifecting successive translatory and rotary movements of one of said contact elements by a continuous movement of said operating member to cause a change in the circuit controlling condition of said contact elements comprising a four link parallel motion mechanism which supports said one contact element and to which said operating member is connected, means supporting one of the links of said mechanism at .a point intermediate its connections in the mechanism for angular movement in the plane of the mechanism, and means for preventing movement of said one linkiduring a part of the movement of said operating member whereby to efiect relative movement of the links of the mechanism operative on'further movement of the operating member to prevent said relative movement of the links of the mechanism.

5. An electric switch comprising relatively movable cooperating contact elements, an operating member, and means for effecting successive translatory and rotary movements of one of said contact elements by a continuous movement of said operating member to cause a change in the circuit controlling condition of said contact elements comprising a parallel motion mechanism having four pivotally interconnected links to one of which said operating member is connected, means pivotally supporting another of said links at a point intermediate its pivotal connections in the mechanism for angular movement in the .plane of the mechanism, arotatably mounted member having a reversely curved cam engageaxis of support of said other link, said coupling link being pivotally connected to said mechanism.

6. An electric switch comprising a movable contact element, an operating member, and means for effecting successive translatory and rotary movements of said contact element by a continuous movement of said operating member comprising a parallel motion mechanismhaving a plurality of relatively movable interconnected links to one of which said operating member is connected, means rotatably supporting another of said links for angular movement in the plane of the mechanism, a rotatably mounted member having a reversely curved cam engageable with said mechanism, said cam member being coupled to said mechanism and movable thereby during a part of the movement of said operating member to prevent movement of said other link whereby to efiect relative movement of the links of the mechanism and on'further movement of said operating member to prevent relative movement of the links of the mechanism.

7. An electric switch comprising a movable contact element, an operating member, and means for effecting successive translatory and rotary movements of said contact element by a continuous movement of said operating member comprising a parallel motion mechanism having a plurality of relatively movable interconnected links to one of which said operating member is connected, means rotatably supporting another of said links for angular movement in the plane of the mechanism, a rotatably mounted member having a reversely curved cam engageable with said mechanism, said cam member being coupled to said mechanism and movable thereby during a part of the movement of said operating member to prevent movement of said other link whereby to efiect relative movement of the links of th mechanism and on further movement of said operating member to permit rotation of said other link about its support whereby to prevent relative movement of the links of the mechanism, and means for adjustably positioning said other link to control th point in the movement of the operating member at which rotation of said other link becomes possible.

8. An electric switch comprising a movable contact element, an operating member, and means for effecting successive translatory and rotary movements of said contact element by a continuous movement of said operating member comprising a parallel motion mechanism having a plurality of relatively movabl interconnected links to one of which said operating member is connected, means rotatably supporting another of said links at a point intermediate its connections in the mechanism for angular movement in the plane of the mechanism, means for preventing relative movement of the links of said mechanism during a part of the movement of said operating member, means for permitting during the remainder of the movement of the operating member relative movement of the links of the mechanism including means for holding said other link against movement, and means for changing the point in the movement of the operating member at which said other link is held.

EMIL SCHEUERMEYER.

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