US2810799A - Electric switch - Google Patents

Description

Oct. 22, 1957 R. D. CARMICHAEL ETAL 2,810,799

ELECTRIC SWITCH Filed Feb. 6, 1956 2 Sheets-Sheet 1 INVENTORS Roberf 0 Carmichael ATTORNEY Thomas A. Buros w WJ/ Z 1957 R. D. CARMICHAEL ETAL 2,810,799

ELECTRIC SWITCH 2 Sheets-Sheet 2 Filed Feb. 6, 1956 INVENTORS Roberi D. Carm/chae/ Thomas A; Buroesh w 5% 7K ATTORNEY United States Patent 9 ELECTRIC SWITCH Robert D. Carmichael, Hampton, and Thomas A. Burdeshaw, Griifin, Ga., assigners to Southern States Equipment Corporation, a corporation of Georgia Appiication February 6, 1956, Serial No. 563,719

9 Claims. (Cl. 200-48) This invention relates to electric switches and more particularly to switches having a fixed jaw contact and a blade mounted for bodily swinging movement relative to the jaw contact and arranged to be rotated about its longitudinal axis when the tip thereof is disposed between the jaws of the fixed contact thereby to engage and disengage the jaw.

In switches of this type it is customary to provide an operating mechanism which swings the blade during a switch closing operation and which also thereafter rotates the blade about its longitudinal axis, such rotation being initiated in response to the engagement of the blade with a fixed stop on the jaw contact. Sometimes in large high voltage switches particularly, the inertia of the blade is sufliciently high enough and the operating mechanism is suficiently powerful to cause the blade to rotate about its longitudinal axis prematurely during a switch closing operation, i. e., before the blade tip engages its stop. In such an event it may be impossible to close the switch since the space between the jaws of the fixed'contact is slightly less than the width of the contact tip in the direction of its larger dimension.

A principal object of this invention is to provide an electric switch of the above described type in which the blade is virtually incapable of rotating prematurely about its longitudinal axis during a switch closing operation.

Another object of this invention is the provision of means for preventing premature blade rotation during a closing operation in a switch of the type described above and to arrange such means so that its mechanical advantage practically eliminates the possibility of premature blade rotation during closing of the switch but which does not materially interfere with smooth and easy rotation 'of the blade when applying contact pressure.

The invention in one form as applied to a switch having a blade mounted on bearing means and arranged for rotation about its longitudinal axis in response to movement of an operating means comprises a linkage which interrelates the bearing means and the operating means. The linkage is biased into engagement with a stop when the switch is open so as to cause the operating means and the switch blade to move in unison with the bearing means during a closing operation until the blade engages a stop on a fixed jaw contact. Thereafter the linkage collapses to allow the blade and its operating means to rotate relative to the bearing means thereby to establish high pressure engagement with the jaw contact.

For a better understanding of the invention reference may be had to the following detailed description taken in conjunction with the accompanying drawings in which Figure 1 is a side view of a two-break type switch embodying the invention; Figure 2 is an enlarged side view partially in section of the center portion of a switch such as is shown in Figure 1; Figure 3 is a plan view of the elements shown in Figure 2 with a part of the cover removed showing the parts in the positions they occupy when the switch is open; Figure 4 is a view similar to Figure 3 but show- Patented Oct. 22, 1957 ing the parts in the positions which they occupy when the switch is closed; Figure 5 is a cross-sectional view along the line 5-5 as indicated in Figure 2; Figure 6 is a crosssectional view along the line 66 as indicated in Figure 3; and Figure 7 is a cross-sectional View along the line 77 as indicated in Figure 4.

With refernce to Figure 1 the numeral 1 designates a switch base which may be in one of several forms. The numerals 2 and 3 designate fixed insulator stacks which are respectively mounted on the base 1 by bolts designated by the numerals 4 and 5. Aflixed atop the insulator stack 2 is a fixed jaw contact designated by the numeral 6 while a similar jaw contact designated by the numeral 7 is afl'ixed atop the fixed insulator stack 3. A rotatable operating means in the form of an insulator stack 3 which is mounted on bearing means generally designated by the numeral 9 is provided with an operating crank designated by the numeral 10. Supported on the operating means comprising elements 8, 9, and 10 is a bearing means 11 in which a switch blade 12 is rotatably supported. As will be explained in detail hereinafter an operating force applied to crank 1d imparts rotation to insulator stack 8 and causes bearing 11 to rotate about a vertical axis and thereby swings the blade 12 into and out of engagement with the contacts 6 and 7. Suitable means amounted within the housing of bearing 11 causes the switch blade 12 to swing bodily relative to contacts 6 and 7 and also irnparts rotary motion to blade 12 about its longitudinal axis so that in performing a closing operation the insulator stack is rotated so as to move the switch blade 12 into engagement with the contacts 6 and 7 with the tips 12;; thereof disposed between the spaced horizontal jaws of the fixed contacts. Thereafter continued force applied to crank it? causes the blade 12 to rotate about its longitudinal axis thereby to establish pressure engagement when the parts occupy the position indicated in Figure 1, i. e., with the major dimension of blade tip 12a disposed vertically with the edges thereof in high pressure engagement with the jaws 7a and 7b and with the opposite end of the blade similarly disposed relative to jaw 6.

With reference to Figure 2 it is apparent that a spindle 13 extends upwardly from a base 14 affixed by bolts 15 to insulator stack 8. Rigidly secured by bob. 16 to the upper end of spindle 13 is an operating element 17 provided with teeth 18. Teeth 18 cooperate with teeth 19 formed on element 29 secured by clamp 29:; and by bolts 21 to switch blade 12. Thus it is obvious that rotation of insulator stack 8 about its vertical axis causes the element 17 to rotate and due to the cooperation between gear teeth 18 and 19 results in rotation of switch blade 12 about its longitudinal axis.

For rotatably mounting the switch blade 12 within the bearing means 11 suitable bearing elements generally designated by the numerals 22 and 23 are provided. Bearings 22 and 23 are similar and as is best shown in Figure 2 may comprise a bearing ring such as is designated by the numeral 22a, ball bearings such as are designated by the numeral 22b, and a bearing race affixed to the bearing housing 11 such as is designated by the numeral 22c. A clamping collar such as is designated by the numerals 2 3 and 24a may be secured to the switch blade 12 by bolts such as 25 in order to maintain the bearing elements in their proper relative positions. Furthermore, as is apparent from Figures 2, 3 and 4, the bearing means A. may comprise a lower portion 11a and an upper portion 111), the upper or cover portion lib being held in position by suitable means such as screws 25a which threadedly engage the fixed bearing race element 220.

For operably relating the bearing means as above described with the operating means comprising insulator stack 8, upstanding spindle 13, and base 1 5, the lower por- 7 shown in Figure 3.

tion of the bearing means designated by the numeral 11c is provided with openings 26 and 27 through which the spindle 13 extends. As is best shown in Figure 2 the upper center portion of th'e'base 14 is provided with a conically shaped portion 14a. which supports ball bearings 28 and in turn the lower internally flanged part 11d of the lower part 11c of bearing '11, the part 11d definingiopening 27.. '"l'hreadedly. secured to the spindle i3 is an in With the switch in the open position the parts occupy V 'the positions depicted in Figure 3.

Thus when it is desired to swing the switch blade. 12 bodily relative to the fixed contacts ,6 and 7 so as to close the switch, a counterclockwise operating force must be imparted to the spindle 13 as viewed in Figure 3 by applying a suitable force to the crank 1t Premature rotation of blade 12 about its longitudinal axis would obviously cause the major dimeusionof the biade tips 12a to be disposed vertically and would therefore prevent the tips from is maintained closed due to the friction of, the parts,

particularly of the jaw elements of the fixed contacts 6 and 7 and the blade tips 12a.

Figure 6 shows the position of the blade and the gear teeth 19 when the switch is in the open position while Figure 7 represents the position of the blade and the gear teeth 19 after the blade 12 has been rotated about its longitudinal axis to establish a high pressure contact when;

the switch is in the closed position.

Figure 5 shows the parts with the switch in the open a position. From Figure 5. it can be seen that the lower portion 110 of the bearing means 1I'is provided at one point along its periphery with a cutaway-portion 11 It will also be observed from Figure S that a projecting element 14/) is mounted on the base 14. Thus when it 1 is desired to close the switch and withthe parts occupying moving into the space between the jaws of the fixed. cone tacts 'and7. Therefore, according to a feature of the invention means are provided to force the bearing means 11 to move in unison with the operating means com-prising insulator stack 8 during the initial counterclockwise swinging movement of blade 12. 7. Such means comprises a first link'32 which is pivoted by a pin 33 to a crank 34 formed integrally with the operating member '17 and a second link '35 pivoted to bearing 11 by pin 36 and pivotally connected with link '32 by pin 37.. The links 32 and '35 are maintained in the position shown in Figure 3 by means of a tension spring 33 which at .oneend thereof is in engagement with a pin 39 and at the other end thereof -is in engagement with the pin 37 to bias the linkage 32,

35 into engagement with a stop formedjon the botto portion 11a of the bearing means 11'.

From'Figure 3 it will be obvious that a counterclockwise force applied to the spindle 13 causes the crank 34' to exert a force to the left on the linkage 32-35. It will also be observed that the crank 34 is substantially normal relative to the link 32. Since the parts when in the position shown in Figure 3 are disposed so that'the pivot pins 33, 37, and 36 are substantially in a straight line very little opportunity is afforded the linkage 32-35 to collapse, i. e., to allow the pin37 to move away from the. stop. 4% by extending the tension spring 38. Thus according to a feature of the invention the parts are virtually locked in the position shown in Figure 3 at. the beginning of a switch closing operation. Stated otherwiseithe operating means comprising insulator stack 8 is incapable of moving'relative to the bearing-means 11 at the beginnin of a switch closing operation at normal switch closing acceleration. Upon engagement with a stop member mounted betweenthe jaws ofthefixed contacts 5' and7 (which stop members are not shown in the the open position as depicted in Figures 2 and 5 the insulator stack 8 is'rotated in a counterclockwise direction and all the parts shown in Figures 2 and 5 move inunison until the blade '12 engages the stop members mounted on the fixed contacts 6 and 7. Upon engagement of the blade 12 with the fixed stops. the operating means com prising stack 8 and base 14 and projection 14b continue to rotate for a limited angular movement with the projection 14b riding along the cut-away portion-11f of the hearing means 11-. It will be understood that when the switch is opened the reverse movement occurs and that the maximum relative movement between the bearing means and the operating means is determined bythe length of the cut-away portion 11f in a' peripheral direction. V V r 1 The invention as-described above and as showniin the drawings is applied to a switch of the two-break type; that is, one in which the ends of a blade such as'12cooperate with a pair of fixed contacts such as are designated 1 by the numeralslfi and 7. a It will bra-understood that-one of the contacts such as; 6"or7 could be eliminated desired and the invention would be equally applicable:

While I have shown and'described a particular em-g bodiment of the invention it will be obvious to those skilledin the art that various changes and modifications drawings) bodily swinging movement of the blade 12 is arrested. Thereafter countenclockwise rotation of spindle l3and other elements of the operating means causes the crank 34 to shift the positions of the links 32 and 35 to the positions shown in Figure 4. This shifting movement is possible because the position of pi'n 37 is slightly above an imaginary line connecting pins 33 and 36 as Once the parts assume the positions 7 'shown in Figure/ r the bias of spring 38 has very little tendency to twist the blade 12 since the pin 37 and the pin 33 are virtually aligned with the spindle 13 so that a 7 little if any turning movement isappliedto switch blade l2 through the gear teethlS and 19 and associated parts I due to the bias, of spring 33. In this manner the switch may be made without departing from the invention in its broader aspects and it is therefore intended in therap pended claims to cover all such changes and modifications V as fa ll within the true spirit and scope of theinvention.

What weclaim as new and desire to secureby Letters Patent of the United States isz 7 1. An electric switch comprising operating means,

bearing means mounted on said operating means and arranged for movement relative to said operating means,

a switch blade mounted on said bearing -means and I0- tatable relative thereto aboutv its longitudinal axis and arranged for bodily swinging movement in coordination with movement ofsaid bearingmeans, and yieldable holding means directly interrelating said operating means and said bearing means and tending to. prevent relative -movernent therebetwe'en;

2. An electric switch comprising operating means,

bearing means mounted on said operating means and arranged for movement relative to said operating means, a switch blade mounted on said bearing meansand 'rotatable relative thereto'about itsdongitudinal axis and arranged for bodily swinging movement in coordination with movement of said bearing means, means inter? relating' said operating means and said switch blade for rotating said blade about its longitudinal axis in co ordination with relative movement between said operat- I ing means and said bearing means, and yieldable holding means interconnecting said operating means and said bearing means and tending to prevent relative movement andarrangedfor limited rotation relative to said operat-' ing means, a switch blade mounted on said bearing means and rotatable relative thereto about its longitudinal axis in coordination with relative movement between said bearing means and said operating means, said blade being arranged for bodily swinging movement in response to rotation of said operating means in unison with rotation of said bearing means, and yieldable holding means directly interrelating said operating means and said bearing means and tending to prevent relative movement therebetween.

4. An electric switch comprising operating means, bearing means operably related with said operating means and arranged for movement relative to said operating means, a switch blade mounted on said bearing means and rotatable relative thereto about its longitudinal axis and arranged for bodily swinging movement in coordination with movement of said bearing means, a linkage interconnecting said operating means and said bearing means and normally effective to prevent relative movement between said operating means and said bearing means, said linkage being collapsible to accommodate relative movement between said operating means and said bearing means, and biasing means tending to prevent collapse of said linkage.

5. An electric switch comprising operating means, bearing means operably related with said operating means and arranged for movement relative to said operating means, a switch blade mounted on said bearing means and rotatable relative thereto about its longitudinal axis and arranged for bodily swinging movement in coordination with movement of said bearing means, means interrelating said operating means and said switch blade for rotating said blade about its longitudinal axis in coordination with relative movement between said operating means and said bearing means, a collapsible linkage interconnecting said operating means and said bearing means and normally efiective to prevent relative movement between said operating means and said bearing means and between said blade and said bearing means, said linkage being collapsible to accommodate relative movement between said operating means and said bearing means and between said blade and said bearing means, and yieldable biasing means tending to prevent collapse of said linkage.

6. An electric switch comprising operating means, bearing means mounted on said operating means and arranged for movement relative to said operating means, a fixed contact, a switch blade mounted on said bearing means and arranged for bodily swinging movement with said bearing means to engage and disengage said fixed contact in response to movement of said operating means, said blade being rotatable about its longitudinal axis in coordination with engagement of said blade with said fixed contact and relative movement between said operating means and said bearing means, and yieldable holding means directly interrelating said operating means and said bearing means and tending to prevent relative movement therebetween and rotation of said blade about its longitudinal axis.

7. An electric switch comprising operating means, hearing means operably related with said operating means and arranged for movement relative to said operating means, a first link pivotally connected near one end thereof to said operating means, a second link pivotally connected at one end thereof to said bearing means, a pivot means interconnecting the other ends of said links, a stop positioned adjacent said links, and yieldable means biasing said links toward a position determined by said stop.

8. An electric switch comprising operating means, bearing means operably related with said operating means and arranged for movement relative to said operating means, a first link pivotally connected near one end thereof to said operating means, a second link pivotally connected at one end thereof to said bearing means, pivot means interconnecting the other ends of said links, a stop positioned adjacent said links, and yieldable means biasing said links toward a position determined by said stop, the position of said pivot means being closely adjacent to but not coinciding with an imaginary line connecting the pivotal connections at the said one end of each of said links when said switch is open and said pivot means being movable to a position more remote from said imaginary line when said switch is closed.

9. An electric switch comprising operating means having an operating crank, bearing means operably related with said operating means and arranged for movement relative to said operating means, a first link having one end thereof pivotally connected with said crank, a second link having one end thereof pivotally connected with said bearing means and having the other end thereof pivotally connected with the other end of said first link, said crank and first link being substantially normal to each other when the switch is open and being disposed approximately in-line when the switch is closed, and means including biasing means tending to hold said first link in a position approximately normal to said crank.

References Cited in the file of this patent UNITED STATES PATENTS

Images