US2734955A - Electric switches - Google Patents

Description

Feb. 14, 1956 J. B. OWENS ELECTRIC SWITCHES Filed Feb. 26, 1953 INVENTOR James B. Owens.

WlTN ESSESZ /1%%M United States PatentO ELECTRIC SWITCHES James B. Owens, East McKeesport, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of Pennsylvania Application February 26, 1953, Serial N 0. 339,090

7 Claims. (Cl. 200-48) My invention relates, generally, to electric switches and, more particularly, to disconnecting switches and the like.

One of the most troublesome problems in building a disconnecting, or similar, switch having a blade which is both rotated and oscillated is that of conducting current from the blade to the hinge end terminal. In one prior method a bridging member makes high-pressure contact with the end of the blade and one hinge pin. This method is satisfactory for current ratings up through 600 amperes, but is not economical for switches rated 1200 amperes and above.

An object of my invention, generally stated, is to provide a switch of the rotating and oscillating blade type which shall be simple and efiicient in operation and which may be economically manufactured and installed.

A more specific object of my invention is to provide for conducting current through mechanical supporting members of an electric switch which are movable relative to each other.

Another object of my invention is to provide electrically conducting hinge members for an electric switch.

A further object of my invention is to provide for conducting current through a bearing for the rotatable blade of a disconnect or similar switch.

Other objects of my invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of my invention, a plurality of contact segments or fingers are disposed on a sleeve to make contact with a hinge pin or a round switch blade rotatably mounted in the sleeve. The fingers are bound together with a garter spring which applies pressure on each finger. The fingers are so shaped and the spring is so located that substantially equal pressure is applied on the sleeve and the pin or switch blade.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a view, in perspective, of a portion of a dis connecting switch embodying the principal features of the invention, portions being cut away for clearness;

Fig. 2 is an enlarged view, in section, showing a contact bearing for the switch blade;

' Fig. 3 is an enlarged and exploded view, in perspective, of the contact bearing for a hinge pin;

Fig. 4 is an enlarged view, in section, of the contact bearing for the hinge pin, and

Fig. 5 is an enlarged view, in perspective, of one of the contact fingers or segments for the contact bearing.

Referring to the drawing, and particularly to Fig. l, the structure shown therein comprises a portion of a disconnecting switch assembly which may be of the type described in Patent No. 2,373,360, issued November 21, 1944, to H. L. Rawlins, and assigned to the same assignee as this application.

The portion of the switch structure shown comprises spaced insulators 11 and 12 which are mounted on a base 2,734,955 Patented Feb. 14, 1956 13. The base 13 is preferably a metal channel having flanges 14 extending outwardly from the sides of the channel. As described in the aforesaid patent, the insulator 11 is rotatably mounted upon the base 13 for the purpose of operating the switch actuating mechanism.

A disconnecting switch blade '15 is rotatably mounted in a substantially enclosed housing 16, which, in turn, is pivotally mounted on a combined support and terminal member 17. The blade 15 is shown in the closed position in which one end of the blade engages spaced contact jaws 18 and 19. The contact jaws are mounted upon a terminal member 21, which, in turn, is mounted upon the insulator 12. When the switch is closed, a circuit is established between the terminal member 21 and a similar terminal member which may be formed integrally with the support member 17.

As previously explained,'the operating mechanism for the switch is of the typedescribed in the aforesaid patent. Briefly, the mechanism comprises a crank arm 22 which may be formed integrally with a shaft 23 which is rotated by the insulator 11. A roller (not shown) on the end of the crank 22 is disposed in a track 24 on the housing 16. A fork 25, which'is secured to the end of the blade 15 inside the housing 16, engages the crank arm 22. The mechanism is so constructed that during opening of the switch, the blade 15 is first rotated to reduce the pressure between the contact jaws 18 and 19 and the blade 15, after which the housing 16 is pivotally actuated about its hinge members 26 to swing the blade in a vertical plane to a substantially vertical position. During closing of the switch, the blade is first oscillated about its pivotal supports to lower it to a horizontal position between the contact jaws 18 and 19, and then rotated to increase the contact pressure between the end of the blade and the contact jaws.

As explained hereinbefore, one of the difiicult problems in building a switch of this type is that of conducting current from the movable switch blade to the fixed terminal member 17. The current must first be conducted from the blade 15 to the housing 16 and then from the housing 16 to the terminal member 17.

As shown in Fig. 2, I have provided for conducting current from the blade 15 to the housing 16 through a contact bearing 27 in which the blade 15 is rotatably mounted. The bearing 27 comprises a bearing sleeve 28 which may be pressed into an opening 29 in the end of the housing 16, a plurality of contact segments or fingers 31 which are disposed around the sleeve 28 in contiguous relation and a garter spring 32 which binds the contact fingers together on the sleeve 28. As shown, the sleeve 28 has a ridge or shoulder 33 around its outer periphery which functions to retain the fingers on the sleeve. Each one of the fingers 31 has a curved surface 34 for receiving the shoulder 33. Each finger or segment 31 has a notch 35 therein for receiving the spring 32.

The spring is so disposed on the segments 31 that the pressure between the ends of the segments which engage the blade 15 and the pressure between the segments and the sleeve 23 are substantially equal. Thus, the spring 32 functions to retain the segments in position around the sleeve 28 and to apply the desired contact pressure to conduct current between the blade 15 and the sleeve 28 and thence to the housing 16.

In order to conduct current between the housing 16 and the terminal member 17, I have provided the hinge 26 which is somewhat similar in construction to the bearing 27. As shown in Figs. 3 and 4, the hinge 26 comprises a hinge pin 36 which may be threaded into an opening37 in the member 17, a sleeve 38 which may be pressed into an opening 39 in the housing 16, a plurality of contact segments 31 and a garter spring 32.

The hinge pin 36 is disposed in. the sleeve 38'ancl the ends ofthe contact segments 31 are pressed against the Pinbythespring 3zinthe'samemanner in'which' thecontact segments are pressed against the blade as previously..-described. ,Thus, current is conducted from the housingllti through'the sleevej38 andthe contact'segments 31 tolthe fpinf36 and thence to the terminal member 17. In, this manner, current is coriductedbetween the switch blade- 15 and the terminal member*17"withoutthe useof flexible'shunts or. bridging members between the relatively movable members of the switch structure.

,IOneof the-advantages of the current conducting bearings herein described is the'relatively small amount of space requiredfor the conducting members. The current capacity .ofthe' conducting bearingidepends upon the size offthe bearing members aridjthe contact pressure'between themembers. For switches havinga high current rating, arelatively largeflbearing maybe provided in the end of the1housing16 for the blade15 and a smaller bearing may be provided for each one of the hinge pins 36 which support the housing 16 On the member 17. Thus, the current flow is divided between the two hinge pins 36.

Another advantage of the present bearing structure is itheease of assembly of'the bearing members. The con tact segments or fingers are. so shaped that they may be assembled and held togetherby the spring 32 prior to being placed on the bearing sleeve. The contact assembly may then be handled as a unit and snapped in place on the :bearing sleeve. The blade or the hinge pin, as the case may be, may then be inserted through the bearing sleeve. The hingev pin or the blade may be removed at any time without disturbingthe contact assembly.

Stillanother advantage of the present structure is that full contact pressure is maintained in any blade position. Longitudinal movement of the switch blade in the contact bearing or endwise movement of the housing'16 along the hinge, pins-36 does not affect the contact pressure. In view of thisfeatureof the bearing structure, it may be utilized for conducting current between members which .movelongitudinally as well as rotatably.

A further advantage of the present structure is that g'the currentconducting bearings are substantially enclosed byithe-housing 16. Thus, they are protected against ice andasleet forming -on the bearing members while the switch is in service.

From the foregoing'description, it is apparentthat I "have provided current conducting bearing members which maybe utilized for conducting current between-relatively movable'members of'a switch or other structure. IThe bearing'members are relativelysimple in structure and maybe readily assembled.

"Sin'ce numerous changes maybe made in the abovedescribed construction, and different embodiments of the invention may be'rnade .without departing from the spirit and scope'thereof, it is intended that all matter contained .in the foreg'oing'description or shown inthe accompany- .ing drawing-- shall be interpreted as illustrative and not in a limiting sense.

vI claim as my invention:

:L-Jn a switch, in combination, a switch blade, sup- ;portingmeans for the switch blade, bearing means in saidxsupporting. .means rotatably Y supportingv one. end of sthe switch blade,.said blade extendingrthrough saidlbearing means, current conducting contactsegments encircling said bearing means and engaging substantially the entire periphery of the blade for conducting current from the blade to said supporting means, a terminal member, a "hinge' pin in said member pivotally supporting said supporting means, additional bearing means in said support- -ingmeans for the-hinge pin,,said pin extending through said additional bearing means, and additional current conducting contact. segments encircling saidadditional bearing means and engagingsubstantially the entire-penriphery df the :hinge pin for conducting current :from the supporting means to the hinge pin and thence to said terminalmember.

2. In a switch, in combination, a switch blade, blade supporting means, a bearing sleeve in said means rotatably supporting one end of the switch blade, said blade extending through said sleeve, current conducting contact segments encircling the bearing sleeve and engaging substantially the entire periphery of the blade for conducting current between the blade and saidsupporting means, a terminal member,'pivotal supporting :means for said blade supporting means, bearing-means for said pivotal means, said pivotal means extending through thebearing means, and additional current conductingcontact segments encircling said bearing means and engaging the pivotal means forwconducting current; between the blade supporting means and the terminal member.

3. In a switch, in combination, a switch blade, a bearing housing, a bearing. sleeve in the housing rotatably supportingone end of the switch blade, said blade extending through said "sleeve, a'pluralityof contact fingers disposedon the bearing sleeve in contiguous relationiand engaging the. switch blade, resilient imeans biasing "the fingers towards the blade, a terminal member, a pivot pin in the terminal member supporting'the housing, an additional sleeve in the housing for the pivot pin, said' pin extending through said additional sleeve, apluralityof 'contact'fingers disposed on the additionally bearing sleeve ing housing,

in contiguous relation and engaging the pivot pin, and resilient means' biasing thecontact fingers towards the pivot pin, whereby. current is conducted from the' blade through the housing to the terminal member.

4. In a switch, in combination, a switch blade, a beara-bearing-sleeve in the housing rotatably supporting one end of theswitch blade, said blade extending through the bearing sleeve, a plurality of contact 'fingers' disposed on the bearing sleeve'in contiguous relation and engaging the switchblade, resilient means biasing the fingers towards the blade, a terminal member, a pivot pin in'the terminal member supporting the housing, a second bearing sleeve in the housing'for the pivot pin, said-pin extending through saidsecond bearingsleeve -a pluralityof' contact segments disposed around the second bearing sleeve in contiguous relation and engaging the pivotpin; and a spring surrounding-the contact segments -to bias them towards the pivot pin, whereby current is conducted from the blade through the housing to the terminal member.

5.' In aswitch, in combination, a support member, a substantiallyenclosed housingpivotally mounted on'the support member, a switch blade'rotatably mounted in the housing-and extending through an opening in the housing, bearing means inside the housing around'the-switch blade, said blade extending through the bearing means, and current conducting contact members surrounding the "bearing means inside the housing for conducting current between the 'blade and the housing, each' contact member having one end engaging the blade and-the other end engaging 'the bearing means.

6. In a switch, in combination, a-substantiallyenclosed housing, a switch blade rotatably mounted in thehousing, a support member, pivot-means dispo'sed'in' the support member and extending inside the housing'for supporting the housing on .the support -member, bearing means extending .inside 'the"housing-:around the spivot means, said pivot meansextending through the bearing means, and current conducting-1 contact "memberssurrounding said bearing means inside thehousing' for conducting current between the housing and the support'member, each contact member having one end engaging the pivot .means and the other end engaging the bearing means.

'71 In a switch, incombination, a substantially enclosed housing, a switch blade rotatably mounted .in'thehousing-and. extending through-an. opening in.=the..h.o1ising,

bearing means'insidethe housing around the switch blade,

said blade extending through the bearing means, current conducting contact members surrounding the bearing means inside the housing and engaging the blade and the bearing means for conducting current between the blade and the housing, a support member, pivot means disposed in the support member and extending inside the housing for supporting the housing on the support member, additional hearing means extending inside the housing around the pivot means, said pivot means extending through the additional bearing means, and additional current conducting member surrounding said additional hearing means inside the housing and engaging the pivot means and the additional bearing means for conducting current between the housing and the support member.

References Cited inthe file of this patent UNITED STATES PATENTS

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