US1913309A - Disconnecting switch - Google Patents

Description

June 6, 1933. J. KUTSCHKE ET AL DISCONNECTING SWITCH Filed July 15, 1932- Patented June 6, 1933 T umran STATES PATENT OFFICE JULIUS IU'I'SCHIE, mNEEII, AND FRITZ MULLER, O! HEDDENHEIK L. D. 3.. I

GERMANY, ASBIGNOBS TO AKTIEHGESELLSCHAFT BROWN BOVERI & G13, 0] mm. SWITZERLAND, A. JOINT-STOCK COMPANY 01' SWITZERLAND DIBOONNECTING SWITCH Application am my 1:, 1m, Serial Io. 02am, and in Germany m 14.1931. 7

" Thisinvention relates to improvements in switches for. disconnecting electric circuits when the circuit is without current, i. e. after an interrupting circuit breaker has operated. The usual construction of such switches includes a stationary member and a member movable into and out of engagement with the stationary member by suitable means. The stationary member generally is 'in-the form of resilient jaws or jaws pressed toward each otherby springs between which jaws the movable member in the form of a blade is held under sufiicient pressure to permit current flow through the switch without material resistance at the contact surfaces thereof. Repeated movement of the blade into and out of such jaws-,however, causes abrasion of the jaws and the blade which eventually reduces the area of the surfaces v in good contact and increases the resistance to flow of current toa point at which flow of I high currents through the circuit heats the jaws orthe pressure springs ing loss of resiliency, or such heating may cause welding of the jaws Disconnecting switches of the character above described are also generally provided with means such as latches for preventing the undesired opening of the switch due to the electro dynamic forces produced. upon the flow of high currents such as short circuit currents throughthe circuit including the switch. Such latching device, however undesirably complicates the construction of the switch and prevents the ready operation thereof. It has been found in practice that 'proper' operation of such switches is frequently im ossible due to failure of the jaws as above escribed or failure of the latch which permits undesired opening or prevents opening of the switch -when such operation is required.

thereby cans and the bladewhich renders the switch inoperative.

Among the disadvant a es of a switch of the character above descri ed should also be noted the fact that the use of resilient jaws or contact pressure sprin roduces a switch .in which the friction o t e jaws and the blade must be overcome during the opening and closing operation of the switch and' also the fact t at, in the closed osition of the switch, the position of the b ade relative to the jaws varies. a

It is therefore among the objects of the present invention to provide a disconnecting switch for electric circuits in which the movable and the stationary portions thereof are operable without frictional engagement of the several ortions thereof which are however firmly c amped together in the closed position. I

Another object of the invention is to provide a disconnecting switch'for electric circuits in which the movable and the stationary portions thereof are held together under ressure in the closed position of the switc by mechanical means as opposed to the use of resilient jaws or other resilient constructions.

Another object of the invention is to provide a disconnecting .switch for electric circuits in which the movable and the stationary portions thereof are locked in the closed position by the same means as are used to cause Another object of the is to promovement of one portion of the switch into and .out of engagement withother portions thereof. Y

vide a disconnecting switch for electric-circuits in which the movable-and the stationary portions thereof are locked .in the closed position by a positive mechanical latch and by clamping of the several elements of the stationary and movable portions thereof; the positivelatching and the clamping being interconneeted and operated by the switch op-' eratingljrmeans.

Objects and advantages other thanthose above set forth will be apparent from the following description when readin connection with the which:

Fig. 1 is an elevation of one embodiment of accompanying drawing in' 1 the invention showing the switch in the of Fig. 2,

hereinafter.

Fig. 5 is a section taken on the line V--V of Fig. 2,

Fig. 6 is a fragment of one of the stationary conductors of the switch at the end at which the blades of the switch are pivotally connected therewith, and

Fig. 7 is afragment of one of the blades of the switch.

Referring more particularly to the drawing by characters of reference, the reference numeral 11 designates one end of a bus bar formed from a plurality of bars or conductors spaced from each other by spacers 12. The bus bar end 11 is supported on an insulator 13 and is attached thereto by suitable means 14. The other end of the bus bar is designated at 16 and is supported in spaced relation with the end 11 on an insulator 17 to which it is attached by suitable means 18. The several bars of the bus bar end 16 are spaced from each other by suitable spacers '19. The'bars of thebus bar 16 are each formed with a slot 21 as illustrated in Fig. 6 for a purpose which will appear hereinafter. The two ends of the bus bar are connected, when the electric circuit including the bus bar is closed, by means of blades 26 interleaved between the several bars 16 and mounted on a shaft 27 extending through the bars 16 and the blades 26. Each of the blades 26 is formed with a cam shaped slot 28 as shown in Fig. 7 for a purpose which will appear The blades 26 are each notched as at 29 to engage a shaft 31 having mounted thereon cranks 32, 33 each having a hub portion 34 or 35 respectively formed with screw threads in the periphery thereof. The screw threads are so cut that one of the threads is right handed and the other is left handed. The threads engage with nuts 37 and 38 respectively which are pinned as at 39 to the outer bars 11. Thus when the cranks are rotated as will be described hereinafter, the nuts 37 and 38 are moved toward or away from each other and clamp together or release the interleaved bars 11 and the engagingends of the blades 26 thus, in the first instance, securing such pressure between the bars and the movable blades as to minimize the contact resistancetherebetweenQ When the switch is opened and the nuts move away from each other the pressure is released and the ends of the blades 26 may move from between the bars 11 with'the minimum of friction.

Cranks 41 and 42 are mounted on the ends of shaft 27 extending through blades 26 and beyond bars 16. Each of the cranks isformed with a slot as at 43 in Fig. 2. A

pin 44 extends through the slots 43 in the cranks, the slots 21 in the bars 16 and the slots 28 in the blades 26. The ends of the tween the outer bars 16 and the cranks 41- and 42 to receive nuts 46 and 47 which are severally pinned as at 49 to the outer bars 16. The threads on the shaft 27 are left handed and right handed respectively so that rotation of the shaft causes the nuts to move toward or away from each other thus securmg a tight clamping together of the ends of blades 26 and bars 16 or a releasing of such pressure dependent on the direction of rotation of the shaft 27 which is obtained by any suitable means. One means by which such rotation may be secured comprises a gear 51 mounted on the end of the shaft 27 and engaging with a gear 52 mounted on and driven by a shaft 53 which may be rotated manually'or by any desired means.

The cranks 41 and 42 have pivotally attached thereto rods 54 and 55 respectively at one of the ends thereof. he rods are supported for longitudinal movement at substantially their central portion on arms 57 or 58 attached to a spindle 59 extending through the blades 26 adjacent the central portion thereof. The free ends of the rods, i. e. the ends of the rods not connected with the cranks 41 and 42, are each provided with hooked ends 61 or 62 arranged to engage pins extending outwardly from the cranks 32 and 33 respectively when the blades 26 are being moved into the closed or engaging position with the bars 11 forming the jaws of the switch.

Consideration of Fig. 1 of the drawing will show the relative positions of the. sev-- eral portions of the structure when the switch is in the opened position. It will be seen from Fig. 1 that cranks 32 and 33 have been rotated in a clockwise direction from the position shown in Fig. 2 which illustrates the relative positions of the several portions of the structure when the switch is in the closed position. Rods 54 and 55 have released the pins of the cranks 32 and 33 and have moved longitudinally to the right, due to the clockwise rotation of shaft 27 andcra'nks 41 and 42, from the position shown in Fig. 2. Such rotation of cranks 41 and 42 has caused movement of pin 44 to the end of slot 28 in blades 26 and has caused movement of pin 44 upwardly to the end of slot 21 in bars 16.

away from each other :thus releasing the clamping action of the pairs of nuts on the bars 11 and blades 26 and on the bars 16 and blades 26 respectively. Due to the release of such clamping action the movement of the blades into the open position shown 5 in Fig. 1 has been obtained without thenccessity for overcoming more than a minimum of friction between the contacting surfaces of the'switch. y I

When the switch is to be closed, i. 0. moved into the osition shown in Fig. 2 from the position s own in Fig. 1, shaft 27 and cranks 41 .and 42 are rotated in a counterclockwise direction by causing gear 51 to rotate in a counter-clockwise direction. Such movement U, of the cranks first causes counterclockwise movement of blades 26 between" the ends of the jaws 11 and causes engagement of hooks 61, 62 with the pins of cranks 32, 33 respectively. During this movement pin 44 is rem tained in the transverse portion of slot 43 and the arcuate portion of slot 21. Continued movement of shaft 27 causes pin 44 to slide to the right hand end of the transverse slot portion of slot 21 thereby permitting further counterclockwise movement of cranks 41, 42 and of cranks 32, 33. During the latter counterclockwise movement of the two pairs of cranks, the nuts 46, 47 and 37, 38 are moved toward each other due to the action of the right and left handed threads until, in the position shown in Fig. 2, the pairs of nuts clamp the ends of the blades etween the conductors forming the 'aws 11 and the stationary conductors 16 85 one end of an electric circuit.

It will be seen from consideration of Fig. 2 that, in addition to the clamping pressure on the blades, the cranks and rods cooperate to produce-a positive mechanical interlock between. the several portions of the switch which prevents undesired opening of the switch under all conditions and by an means other than deliberate rotation of sha t 53. The same means are employed to secure closin movement of theswitch blades and clamping of the several portions of theswitch thereby permitting frictionless operation with the product-ion of any predetermined contact pressure between the stationary and so the movable portions "of the switch; Due

orming to the absence of any resiliently formed or" resiliently controlled. portions the end positions of the switch are'always exactly deter minable. and exactly the same.

' ent inventionbas been illustrated an adescribed, it will be apparent to those skilled in the art that various changes and .modia fications may be made thereinq-without de- 00 parting from the s irit'of the invention or from the scope of t e appended claims.

It is claimed and desired to secure by Letters Patent:

1. A busscctionalizing switch-comprisin two bus bar sections having laminated on r ing devices carried by said end portions respectively, said devices each comprising a pair of cranks a pair of clamp actuating rods carried by sai switch blade, each rod havin one end thereof operatively connected wi the cranks associated with the end rtion which carries said switch blade, and aving the other end thereof provided with means for engaging the clamping cranks associated with sai other end portion only when said switch blade bridges said end portions; and means operable by a continuous movement thereof to first move said switch blade to bridge said end portions and then to simultaneously actuate all of said clamping devices.

2. A bus sectionalizing switch comprisin' two bus bar sections having laminated on portions arranged in spaced alinement, a switch blade having lamlnations adapted to interlard with the laminations of said end portions respectively, a bin e connection for rotatably securin one en of said switch blade to one of sald end portions, two clamping devices carried by said end portions respectively, said devices each comprising a pair of cranks, a pair of clamp actuating rods carried by said switch blade, each rod havin one end thereof operatively connected with the cranks associated with the end ortion which carries said switch blade, and aving provided with means the other end'thereof for enga in the clamping cranks associated with sai ot er end portion only when said switch blade bridges said end portions, and means operable by a continuous movement thereof to first move said switch blade to bridgesaid end portions, then to simultaneously actuate both of said clamping devices, said means comprising a mechanism operable only during the final portion of said'clamping movement to positively lock said switch blade in its bridging position.

3. A switch for sectionalizing a bus, comrising in combination, two bus bar sections aving laminated end portions arranged in alined' spaced relation, a shaft. extending y V throu h .each' of said bus bar sections adja- Although but oneembodiment of the. res-w cent' t eends thereof, a laminated switch blade having one. end thereof rotatively mounted on one'of said shafts .and having each end thereof interlarded with the laminations of said end portions respectively, clampv ing mechanism mounted on each end portion each comprising a clamp actuating. crank, means operable to simultaneously reaction of each clampin lease the clampin mechanism and t on disconnect one end 0 said switch blade from one of said end portions, said means comprisin a link member connected at one end wi the crank associated with said one of said shafts and detachably associated at the other end thereof with the other of said cranks.

4. A switch for sectionalizing a bus, comprising in combination, two bus bar sections having laminated end portions arranged in ralined spaced relation, a laminated switch blade normally bridging said end portions.

and interlarded therewith, a shaft extending through each of the interlarded portions of said switch blades and said end portions, one

of said shafts being arranged to serve as a pivot for one end of said switch blade, the

other end of said switch blade having an open slot therein permitting disen agement thereof with the end portion normfily interlarded therewith, means associated with each shaft for clamping each end portion and the switch blade interlarded therewith, 'said means comprising clampin cranks secured to said shafts, means 0 ra 1e to simultaneously actuate the cran s of said clamping means to release the clamping action thereof and'then to disconnect the slotted end of said switch blade from the respective end portion, said last mentioned means comprising a pin and slot connection between said switch blade, one of said end portions and certain of said cranks.

In testimony whereof, the signatures of the inventors are aflixed hereto.

JULIUS KUTSGHKE.

FRITZ MULLER.

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