US2116983A - Switch construction - Google Patents

Description

May 1938- w. o. SCHULTZ SWITCH CONSTRUCTION Filed Oct. 2, 1955 3 Sheets-Sheet l INV ENT OR.

A ORNEY.

, May 10, 1938. w. o. SCHULTZ SWITCH CONSTRUCTION 3 Sheets-Sheet 2 Filed Oct. 2, 1935 I NVENT OR. M%m MM A ORNEY.

y 0, 1938. w. o. SCHULTZ 2,116,983

SWITCH CONSTRUCTION Filed Oct. 2, 1935 5 Sheet's-Sheet 3 unmmmm IN VENTOR.

Patented May '10, 1938 UNITED STATES PATENT FFICE 2,116,983 swrrcn CONSTRUCTION Application October 2, 1935, Serial No. 43,207

5 Claims.

This invention relates to a switch construction and is particularly directed to a high voltage switch, such as a disconnecting switch, for instance, although the invention is not limited to this type of switch.

Objects of this invention are to provide a construction in which a multiple switch may be em ployed, that is to say, one having a plurality of switch arms which are simultaneously actuated.

Further objects are to provide a switch of the above outlined type in which although the arms oi the switch may be relatively long, inaccuracies due to machining and other work do not cause lack of proper alignment between the movable and stationary contacts when the switch is in closed position, means being provided for automatically guiding the movable contacts into position so that they will engage the stationary contacts in the proper manner.

Further objects are to provide a switch construction in which means are provided for first breaking the contact between the movable and stationary contacts and thereafter raising the switch arm, such means insuring the breaking of any seal that may have occurred between the movable and stationary contacts without imposing severe stresses on the mechanism, the sep- "aration of the movable and stationary contacts occurring prior'to the actual rocking motion of the switch arms.

Further objects are to provide a construction in which a relatively light load is imposed during the lifting of the switch arms, as there are no dragging contacts to be separated during this motion, the separation of the movable and stationary contacts having been made automatically and prior to the lifting of the main switch arms, and to provide an auxiliary switch arm or guiding member which cooperates with are horns to maintain the electrical circuit after the separation of the movable and stationary contacts for the initial opening motion of the switch arms, so that, any arcing that might occur, will occur between the guide member and the arc horns, such are horns and guide member being removable and easily renewed and of relatively simple construction, the arc horns and guide member additionally acting'as guiding means for guiding the movable contacts into position for engagement with the stationary contacts, and the guide member itself also constituting a stopcoopersting with a portion of the stationary contact structure to arrest closing motion of the main switch arms at theappropriate point, thereby avoiding any inaccuracies due to machining and other work.

In greater detail, objects of this invention are to provide a construction in which either a single or a plurality of main switch arms may be emplayed, in which a tubular body portion is provided and a movable reciprocatory rod or contact member is carried within the tubular body portion, the reciprmatory rod constituting the movable contact and being projected into a yielding .tubular stationary contact which may be slotted and which is springy and afiords a secure and extensive engagement between the movable and stationary contacts.

Further objects are to provide a switch construction in which a very simple and easily produced and easily renewable stationary contact is provided which is housed and protected from the weather, and in which the actual contacting portion is easily renewable without dismantling the switch.

Further objects are to provide a switch construction in which the current does not pass through any of the bearing members or any of the joints, but is conducted directly from the movable and stationary contacts to the terminal members.

Further objects are to provide a novel form of switch construction in which the main switch arm is locked against rocking motion until after withdrawal of the movable contact from the stationary contact, and in which relative motion between the stationary contact and the switch arm is prevented until the switch arm is again returned to its closed. position.

Further objects are to provide a switch construction which is relatively simple, which is cheap to produce, which is eminently practical, and which is easy to operate.

A11 embodiment of the invention is shown in the accompanying drawings, in which:

Figure 1 is a side elevation of the switch construction with parts broken away, the counterbalancing spring being omitted for clearness.

Figure 2 is a plan view of the structure shown in Figure 1.

Figure 3 is a sectional detail of the movable and stationary contacts and adjacent portion.

Figure 4 is a transverse sectional view on theline 4-4 of Figure 3.

Figure 5 is a horizontal sectional view on the line 5-5 of Figure 1.

Figure 6 is a fragmentary view of the joint portion or hinge portion of one of the main switch arms, such view having parts broken away and in section, such section being taken on the line 6-6 of Figure 2, the counter-balancing spring being omitted for clearness.

Figure 7 is a fragmentary plan view of the structure shown in Figure 6, with-parts broken away and in section, such parts as are in section being taken on the line '|-1 of Figure 6.

Referring to the drawings, it will be seen that the multiple switch is carried upon a supporting frame indicated generally by the reference character I and formed of channel iron or r-frame members, or other structural steel work.

A plurality of switch units aresimultaneously operated and the operating mechanism for the switch units may take the form of a crank or similar member indicated by the reference character 2 in Figure 5 and coupled to the individual rock levers 3 for the several switch units, as indicated in Figure 5, by means of a series of connecting rods or links 4, 5, 3,1, and 8. The shaft 9 carrying the crank 2, see Figure 5, may be operated by hand or automatically as desired and may be spaced as far away from the main switch mechanism as desired, to thereby provide for remote operation of the switch. For example, the switch may be externally located with reference to a power house, substation, or similar shelter, whereas the operating mechanism may be located interiorly thereof, if so desired.

Theswitch units are duplicates and, as will be seen from Figure 1, an insulator stack I0 is provided for the stationary contacts and a. widely spaced insulator stack II is provided for the pivoted end of the main switch arm I2, a rotary insulator stack I3 being supported from each of the levers 3 so that rotation of the crank 2 or operating mechanism rotates the insulator stack The insulator stack l3 carries a shaft i4 which projects through the connector [5. The-connector l5 in reality forms a conducting member from the pivoted end of the main switch arm I2 to the terminal lug or member l6. However, a flexible connector hereinafter described connects the active movable contact portion of the switch arm directly with the connector I5. If, however, the connector I5 is formed of a metal having a low conductivity, the flexible connector may be extended to the terminal member IS in an obvious manner. A'crank I! is rigidly secured to the shaft l4 in any suitable manner and is connected by means of a universal joint indicated generally at l8 to the link orconnecting rod l9.

The outer end of the link or connecting rod I9 is joined by means of a universal joint 20 with a crosshead 2|. The crosshead 2| has the upwardly projecting ears, as shown most clearly in .Figures 2 and '1, between which the universal joint is pivotally carried. This crosshead extends downwardly and has a reduced or narrowed portion 22 into which the movable contact member or rod 23 is firmly screwed. This rod or movable contact member 23 forms a portion of the main switch arm I2.

In reality this main switch arm is of tubular construction, as very clearly shown in Figures 1, 2, 6, and 7. The inner end of the tubular arm I2 is screwed into the pivot yoke 24, the tubular member l2 being preferably provided with a bushing and guide l2, see Figures 1,2, and 3, screwed on to the end of the tubular arm l2.

The yoke 24 is pivotally carried on pivot pins 25 screwed into ears 26 formed integrally with the member I5. This yoke 24 also includes a pair of inwardly spaced parallel arms 21. provided with slots 28. The slots 29 register with slots 23 formed in upwardly projecting webs 39 formed integrally with the member i5, as most clearly shown in Figures 6 and 7.

The portion 22 of the crosshead, see Figure 6, is provided with a pin 3| that extends completely through the crosshead and into each of the pairs of slots 28 and 29, thus normally locking the members 21 to the stationary members 39 and consequently locking the movable switch arm against rocking motion.

However, when the cross head is retracted,

due to the operation of the crank H, the link l9 transmitting motion to the crosshead, it will be seen that the pin 3| slides rearwardly within the slots 28 and 29 and finally when the pin is in alignment with the pivot pin 25, allows the continued pull on the link H! to rock the movable switch arm upwardly about the pivot pins 25, the slots 28 being then turned at an angle to the slots 29.

When, however, the crank is reversely rotated to rock the switch arm downwardly, no relative motion can occur between the movable member 23 and the tubular portion I2 of the main switch arm, as the pin 3| is locked against motion due to the fact that the slots 28 are now turned at an angle to the slots 29. No relative motion between these parts can occur until the main switch arm is in its lowermost or closed position, as indicated in Figure 1. Y i

If desired, a. counterbalancing spring 32, see

Figure '7, may be employed to offset the weight of the main switch arm. The spring has been omitted in Figures 1 and 6 for the sake of clearness.

The insulator stack It) carries the stationary contact member which consists of a tubular contact portion 33 provided with a plurality of saw-cuts 34 so as to split it into a plurality of fingers, as shown in Figures 3 and 4. .These fingers have outwardly turned ends 35 and the extreme inner end of the movable contact rod or member 23 is slightly bevelled to facilitate entry of this movable contact member into the stationary contact member. If desired, the resilient gripping of the tongues may be increased by encircling spring clips 36. have been shown flat in Figures 3 and 4. but very obviously they may be formed in-each instance with a. helix of spring wire with its ends joined. Any suitable encircling spring member can be used.

The contact member 33 is screwed into an end cap 31 which in turn is screwed into the tubular These spring clips I portion 38 of the terminal casting 39. This ter- 1 vided with outwardly projecting apertured ears 4| which receive the portions 42 of the arc horns, such are horns being provided with downwardly turned inner portions 43. These arc horns are readily removable and are held in place by means of set screws 44 so that they may be renewed when they are worn.

A stop 45 in the form of a switch blade is carried by a split collar 49 clamped around the tubular switch arm l2.- This stop when the switch is in closed position, contacts with the stationary terminal member 39 and holds the movable switch arm in its lowermost position. Further, this stop 45 passes into the space between the arms 43, see Figure 4, of the arc horns, preferably bevelled portions 43 being provided 2, 1 1 6,983 to assist in guiding the arm or stop 55 into place.

Thus it will be seen that the stop member 45 is guided by the arc horns and is arrested in its lowermost position by the stationary terminal member 39 and this serves to align the movable contact member 23 with the stationary contact member 33. Any inaccuracies in machining will not interfere with the automatic and correct aligning of the stationary and movable contact members, as this is done in the manner hereinabove described.

It is to be noted particularly from Figures 6 and 7 that a flexible connector 41 is bolted securely to the crosshead 2! and to the connector or bearing member l5. Inasmuch as the slidable or movable contact member 23 is tightly screwed into the crosshead, it is at once evident that a very good electrical connection is aiiorded directly from the terminal member Hi to the movable contact member 23.

The operation of the switch is as follows:

Assuming that the switch is closed, it is apparent that rotation of the crank or operating member 2 rotates the insulator stack l3 and consequently the cranks I! of each of the switch units. Inasmuch as the switch units are duplicates, adescription of the operation of one will, of course, suffice. As the crank l'l rotates, it draws the link l9 rearwardly and consequently slides the movable contact rod or member 23 rearwardly out of engagement with the stationary contact 33. After the movable contact has cleared the stationary contact, the pin ill, see Figures 6 and 7, is in alignment with the pivot pins 25 and consequently the yoke 2t and the movable switch arm B2 are now free to rise upon continued pull of the link 89.

When it is desired to close the switch, reverse rotation of the crank rocks the switch arm downwardly to closedposition. Motion of the movable contact member is prevented as the slots 28 and 2a are not in alignment until the movable switch arm 52 has arrived at switch closed position. Thereafter continued forward motion of the link l9 causes the movable contact rod or member 23 to pass into and engage the stationary contact 33.

It will be seen that there is no lifting motion required or permitted until the movable contact has been withdrawn from the stationary contact and consequently there are no dragging loads imposed on the main switch arm during its upward motion.

Further, it will be seen that after the movable contact member has been withdrawn from the stationary contact member, that electrical contact is still maintained through the auxiliary switch blade or stop member 45 and the arc horns, and further that these members are the last ones in contact and any arcing that occurs, occurs between these members. They are readily renewable and may be easily replaced without dismantling the switch. Also they are of inexpensive and simple construction.

The stationary contact for each switch unit is housed in its own hood or casing and is thus protected from the weather. Any seal that may,

form between the movable contact and the stationary contact is broken by the direct longitudinal motion of the movable contact member without imposing any strains on the main switch arm.

Itwill be seen further that if wear should occur on the stationary contact members, they may be readily renewed as the end cap 31, see

Figure 3, may be unscrewed and a new stationary contact member may then be substituted for the old one. Further than this, the movable contact member 23 can easily be renewed, as it is merely necessary to unscrew it from the yoke, see Figure 6.

Further it will be seen that a very reliable,

serviceable and simple type of switch has been providedby this invention which is cheap to manufacture and which is relatively easy to operate. 1"

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. A switch comprising a stationary main portion, a switch arm pivotally mounted on said main portion, a reciprocatory movable contact guided and carried by said switch arm, a crosshead connected to the rear portion of said movable contact and reciprocable relative to said switch arm, a stationary contact adapted to receive the outer end of said movable contact, said stationary main portion and said movable switch arm having co-related aligning parts, means independent of said contacts and actuated by said crosshead for locking said co-related parts in alignment until said movable contact has been withdrawn from said stationary contact, and means for moving said crosshead to reciprocate said movable contact and rock said switch arm.

2. A switch comprising a stationary main portion, a switch arm pivotally mounted on said main portion, a reciprocatory movable contact guided and carried by said switch arm, a crosshead connected to the rear portion of said movable contact and reciprocable relative to said switch arm, a stationary contact adapted to receive the outer end of said movable contact, said stationary main portion and said movable switch arm having corelated aligning parts, means independent of said contacts and actuated by said crosshead for locking said co-related parts in alignment until said movable contact has been withdrawn from said stationary contact, and means including a crank and link mechanism joining said crank and said crosshead for reciprocating said crosshead and for rocking said switch arm.

3. A switch comprising a stationary main portion having a stationary member provided with an elongated slot, a switch arm pivotally mounted on said main portion, a reciprocatory movable contact guided and carried by said switch arm, a crosshead connected to the rear portion of said movable contact, a stationary contact adapted to receive the outer end of said movable contact, said switch arm having a portion adjacent the pivotal end thereof provided with an elongated slot aligning with said first mentioned elongated slot when said switch is in closed position, said crosshead having a projecting portion fitting within both of said slots to normallylock said switch arm to said stationary main portion while said switch is in closed position, said crosshead being free to reciprocate while said slots are in alignment to thereby cause relative motion between said movable contact and said switch arm, and means for drawing said crosshead rearwardly to place said projecting portion in alignment with the pivot point of said switch'arm, said means thereafter rocking said switch arm, the portion of said switch arm havingthe slot rocking at an angle to the first mentioned slot.

i 4. A switch comprising a stationary main portion having a rigidly mounted stationary member provided with an elongated slot, a switch arm having a yoke pivoted to, said stationary member and having a slotted portion rigid with said yoke with the slot normally aligning with said first mentioned slot when said switch is in closed position, an arm projecting from said yoke and forming a portion oi! said switch arm, a stationary contact, a movable contact member movably carried by said arm and adapted to engage said stationary contact, a crosshead operatively coupled to said movable contact for withdrawing said movable contact irom said stationary contact and provided with a pin fitting within both of said slots, and means for drawing said crosshead rearwardly to withdraw said movable contact from said stationary contact, said means when said crosshead is in its final retracted position aligning the pin thereof with the pivot point of said yoke, said means thereafter rocking said switch arm to switch open position.

5. A switch comprising a main stationary mema,11s,oss

be:- provided with a pair of spaced webs rigid therewith and provided with elongated slots, said stationary member having a pair 01' spaced pivot pins, a switch arm having a yoke pivotaliy carried by said pivot pins, said yoke having elongated slots aligning with the elongated slots in said webs when said switch arm is in switch closed position, 'a stationary contact, a movable contact adapted to engage said stationary contact, and movable with respect to said switch arm, a yoke operatively connected to said movable contact

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