US1722452A - Electrical switch - Google Patents

Description

July 30, 1929. c. BoLLlNGl-:R 1,722,452

ELECTRICAL SWITCH Filed April 4, 1924 2 sheets-sheet July 30, 1929. Q BOLLINGER 1,722,452

ELECTRICAL SWITCH Filed April 4. 1924 2 Sheets-Sheet 2 i p hllullll Patented July 3o, 1929.

' UNITED vSTATI-:s

PATENT 'oi-"Flo,

CHARLES IBOLLINGER, OF CHICAGO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

VELECTRICAL swrrcn.

Application tiled April 4, 1924.` Serial No. 704,099.

This invention relates to electrical switches, and more particularly to the operating mechanisms of switches.

The primary object of the invention is to provide improved o erating mechanism for bringing the movab e contact or contacts of a switch into and out of engagement with the fixed or stationary contact or contacts thereof.

Other objects of the invention are to provide a switch wherein the movable contact must be brought into a certain one of its positions before it can be brought into the othergj to provide operating mechanism which insures that the movable contact of a switchwill be moved from its intermediate position to a certain one of its extreme positions before it is moved to the other extreme position; to provide a switch wherein the movable contact'is locked against -displacement in one direction when it is in an intermediate position; to provide a switch wherein the movable contact isstopped in an intermediate position if it does nottravel at a predetermined rate of speed when moving from one of its extreme positions -to another;. to provide improved quick make and break mechanism for ay switch, and to provide means for equalizing the force with which several contacts of a switch press upon other contacts of theswitch. f

To facilitate the disclosure of this invention, ay switch embodying a preferred form of the invention is shown in connection with the starting and running circuits of an alternating current motor. In the switch, a plurality of movable contacts are loosely mounted upon an insulating membery which is rigidly secured to a shaft carrying a' sition being the position wherein they close the running circuit. The intermediate position inthis case is a neutral position wherein the contacts do not close a circuit or circuits. To insure against improper manipulation of the switch, a latch locks the lever against direct displacement from the yintermediate position to the running position, but if the lever is iirst moved to the starting position, it'may be moved quickly to the running position as a cam surface on the lever Will then render the latch ineffective.

In this embodiment of the invention if the lever. is released while in the starting position, is returned to the intermediate position by a spring which is compressed whenever the lever is moved from the intermediate position to the starting position. The spring has not sutiicient strength to drive the lever through the intermediate position.

The quick makev and break mechanism comprises` an arm rigidl secured to the shaft and adapted to sidably journal a plate, which together with the arm, slidably journals a latch bar adapted to engage a plurality of stops which correspond to the above described positions of the actuating lever. A spring tends to hold the plate in alignment with the actuating lever and a second spring tends to hold the latch bar in an extended position with respect to the arm. The actuating lever, when displaced, causes the plate to Withdraw the latch from its extended position wherein it engages a stop, and when the latch is disengaged from the stop, the arm springs' into alignment with the actuating lever, the arm being heldy stationary during the initial movement of the lever as it moves from one position to another. This construction allows the quick make and' break mechanism to function when the movable contacts are brought from the intermediate position to the starting position, as well as when they are brought from the starting position to the running position or from the running position to the intermediate position.

Further objects of the invention will become apparent as the detailed description progresses, reference being had to the accompanying drawings wherein,

Fig. 1 is a central longitudinal section taken through a switch embodying the 1nvention;

Fig. 2 is an elevation of the switch looking from the ri ht in Fig. 1;

Fig. 3 is a section taken on ofv Fig.v 1;

Fig. 4 is a fragmentary view showing a changed position of the mechanism shown in Fig. 2;

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

Fig. 6 is an elevation of the switchlook.- ing from the left in Fig. 1;

Fig. 7 is a section taken on the line 7-7 of Fig. 1;

Fig. 8 is a section taken on the line 8 8 of Fig. 2; n

Fig. 9 is a detail perspectlve of oneof the movable contacts which form parts of the improved switch; y

Fig. 10 is a detail perspect1ve of an actuating lever which forms a part of the improved switch, and

Fig. 11 is a diagram of the starting and running circuits of an alternatingcurrent motor, the switch being shownin connect1on therewith.

Referring to the drawings wherein like reference characters designate like, parts throughout the several visws, the reference character 15 designates in its entirety a. housing vupon and in which the mechanism of the improved switch is preferably mounted.

. The housing comprises an apertured boss 16 contacts 21, 22, and 23 into and out-of eny gagement with various combinations ofthe stationary contacts 17. The movable contacts 21, 22, and 23 are loosely mounted upon pins 24 carriedv by an insulating disk 25 which is rigidly secured to the. shaft section 20. It will be noted that the several pins 24 are disposed parallel to the axis of' the shaft section 20 and that the movable contacts 21, 22, and 23 may be moved away from or toward the stationary contacts 17. How.- ever, yielding means are provided for holding the movable contacts in engagement".

with the stationary contacts, the yielding means comprising a spiral spring 26 which 1s interposed between a nut 27 threaded upon the shaft section 20 andfan insulating disk 28 loosely mounted upon the shaft section 20; the shaft section :may be termed a supthe 1in@ 343.

port for the insulating disk 28.` The spiral spring 26 forces the insulating disk 28 against the movable contacts, the disk being adapted to engage arcuate surfaces 29 formed upon the contacts. Each of the movable contacts is adapted to be brought into aposition wherein it rests upon two adjacent stationary contacts and it is apparent that the spring pressed insulating disk 28 operating upon the` arcuate surfaces 29 of the contacts will cause the movable contacts to press against each of the two stationary contacts with equal force. 26 is common to the several movable contacts 21, 22, and 23 and is centrally disposed with respect to them, it follows that the s ring will equalize the force with.l which hese contacts press against the stationary .con-

tacts.

Referring now to Figs. 7 and 11, each of the movable contacts 21, 22, and 23 is shown associated with three of the stationary con- \tacts 17 Thus in Figs. 7 and 11 each of the movable contacts Aisshown in engagement with a stationary contact 30 disposed midway between a pair of stationary contacts 31 As the spiral spring vand 32. Fig. 11 illustrates the manner in X which the switch Imay be employed to con# trol the starting and running-circuits of a three-phase alternating current motor 33.'

Each contact 30 vis shown-connected to one of the three mains. The contacts 31 are local to the starting circuit of the motor and the contacts 32 are local to the running circuit of the motor, the running circuit of the motor beinoj provided with a plurality of fuses 34. ll`he movable contacts may be moved into positionsl wherein each will bridge a pair of adjacent contacts 30 and 31 or into positions Where each will bridge a pair of adjacent contacts 30 vand 32. It is oted upon a shaft section 36 rotatably jour,` Analed 1n the housing 15. The shaft section 36 seat-s in a socket 37 formed in one end of the shaft section 20 and has its axis disposed coincident with the axis of the shaft section 20. A pin 38 projecting'from the shaft section 36 and eccentrically disposed with respect to the axis' thereof is adapted to enter a recess 39 formed in the shaft section 20.`

The pin 38 insures that the shaft sections will be assembled in predetermined positions relative to each other. A pin 40 projecting through the shaft section 36 and engaging slots 41 in the shaft section 20 provides means whereby the shaft section 36 may an,-y

` ina bushing 42 mounted in the insulating base plate 18. y

The actuating lever is operatively connected to the shaft section 36 by quick make and break mechanism comprising an arm 43 rigidly secured to the shaft sectionl 36 (Figs. 1 to 4 inclusive). The arm 43 slidably journals a plate 44, the arm and the plate being provided with guides 45 and 46 respectively. The plate 44 has an outstanding lug 47 carrying a pin 48, the axis of which is disposed normalto the axis of the shaft section 36.v The in 48 is secured to the lug 47 by means ot a cotter pin 49 and the upper end of the pin (Fig. l) is slidably Vjournaled in an outstanding lug 50 formed upon the arm 43. A helical compression spring 51 wound around the pin 48 and disposed between the outstanding lugs 47 and 50 is adapted to hold the plate 44 in' a position wherein a pair of rearwardly extending lugs 52 `formed integral with the plate 44will bear upon a pair of forwardly extending lugs 53 formed integral with the actuating lever 35. When theplate 44 is in this position it is said to be in alignment with the actuating lever. The arm. 43 and the plate 44 together slidably journal a latch member 54- which rides upon the lower end of thepin 48 and is adapted to engage a plurality of stops 55 and 56. A helical` cornpression spring 57 tends to hold the latch member 1n engagement with either of the stops, the spring being wound around the pin 48 and beingdisposed between the out? standing lug 47 and the latch member 54. The latch member 54 mayv be withdrawn from the stops by means ofl the plate 44 which has an integral bar 58 engaging the latch member. As shown in", 4, if the actuating member 35 is angularly disposed in atcounter-clockwise direction, the righthand lug 53 of the actuatin 4lever will displace the plate 44 against t e action of the Aspring 51 and the bar 58 of the plate 44 will in turn displace the latch member 54. If the actuating member is displaced in a counter-clockwise direction from the position wherein it is shown in Fi 4, the latch member 54 will be disengage entirely from the left-hand side of the stop 56 and the compression spring 51 will act to bring the plate 44 into alignment with the actuating lever. The latch member 54 will then be driven in a position wherein it engages the right-hand side of the stop 56. If the actuatlng lever is now an ularly displaced in a clockwise direction (lig. 4) the plate 44 will again la Abehind the actuating lever until the latc the left-hand side of the stop 56 or the lefthand side of the stop 55, from which latter position it may be brought again to the position wherein it engages the left-hand side of the stop 56. As the movable contacts 2l, 22, and 23 are constrained to move with the arm 43 and as angular displacement of the1 arm relative to the common axis of the shaft sections 20 and 36 is controlled by the plate 44, it is readily understood that .the angular movements of the plate are transmitted to the movable contacts. Therefore the movable contacts will not move in unison with the actuatin lever 35 but will be moved from one position to another position at a speed determined mainly by the helical compression spring 51.

Returning now to Fig. 11, it will benoted that if the actuating lever has been displaced in a counter-clockwise direction, the several movable contacts will bridge each pair of adjacent stationary contacts 30 and 31 to close lthe starting circuit of the motor 33.

The movable contacts may then be moved in a clockwise direction (Fig. 11) to positions wherein they will bridge the several pairs of adjacent stationary contacts 30 and 32 to close the running circuit of the motor. It is of course importantthat the movable contacts be moved into positions wherein they close the starting circuit before they are moved into positions wherein the close the running circuit, as otherwise t 1e several fuses 34 might be destroyed. The invention contemplates means for controlling the actuating mechanism of the switch so that the movable 'contacts must be brought as a unit into a certain one of their extreme positions before they can be brought into the other of their extreme positions. Or to state it 6() depending from a slotted post 61 which projects from the housing 15. A cotter pin 62 closes the outer'end of the slot in the post 61 and prevents the latch 60 from being displaced therefrom (Figs. 2, 4,and 5). The latch 60 may be said to be pivotally mounted in the post and as best shown in Fig. 5, it is adapted toengage a lug 63, formed on the actuating lever 35, when the actuating lever is in its intermediate position. The latch 60 permits the lever 35 to be displaced in a counter-clockwise direction (Figs. 2 and 4) .but will not permit the actuating lever to be displaced directly from its yintermediate position to the position wherein it causes/the? lug 63 when the actuating lever 35 is moved` quickly in a clockwise direction (Figs. 2 and 4) from one of its extreme positions to the other. It is apparent that the actuating lever `may be returned to its intermediate.

position at any time.

Means are preferably provided for insuring that the actuating lever will not be left in the starting position. This means in-` cludes a spring 67 which has one of its ends secured to the housing 15, the otherend of the spring being adapted to bear upon a pin 68 when the actuating lever is in its intermediate position. The pin 68 is fixed in the housing 15 and simply serves as a stop for the free end of the spring. A shouldered pin 69 projecting from the actuating lever 35 also engages the free end of the spring and, when the actuating lever is angularly displaced in a counter-clockwise direction (Figs. 2 and 4) compresses the spring. The spring 67 is of sufficient strength so that 1f the operator releases the actuating f lever while it is in the starting position, the spring will drive the lever to the intermediate position.

In the operation of the switch, the operator first moves the actuating lever to the right (Fig. 2), thus causing the right-hand lug 53 of the actuating lever to displace the plate 44 against the action of the spring 51.

The latch in turn withdraws the latch meinbcr 54 from engagement with the left-hand side of the stop 56, which action permits the spring 51 to drive the plate 44 into alignnient with the actuating lever and to bring the movable contacts into positions wherein they close the starting circuit of the motor. As soon as the motor has picked up its load the operator throws the actuating lever `35 to its other extreme position wherein it closes the running circuit. When the running circuit is to be opened the actuating lever is moved to its intermediate position.

An advantage attending the improved vswitch is the ability of the quick make and break mechanism to operate when the actuating lever 1s brought from any one of its several positions to another of its positions.

For instance, the quick make and break h mechanism is effective when, the actuating lever is brought from its intermediate position to the starting position, and it is also effective when the lever is brought from the starting position to the running position, or when the lever is brought from the running position to the intermediate position. In addition, the latch member 54 of .this mechanism serves to lock the actuating member in the running position, a function whichit would also perform when the lever is in the starting position if the spring 67 were omitted from the switch.

As best shown in Fig. 1, the movable and stationary contacts of the switch are disposed in a chamber 70 formed by the housing 15 and a cover 71, the cover being detacliably secured to the housing by screws 72. In practice, the chamber 70 is preferably filled with oil or any other compound or mixture which would prevent or reduce arcing between the contacts. The actuating mechanism of the switch is protected by a cover plate 73 secured to the housing by screws 74. i

What is claimed is:

1. Ina switch, a ,plurality of contacts, a pluralityof contact members, an arcuate surface projecting from each contact member, an insulating plate contacting with all of the arcuate surfaces, and resilient means engaging the plate to cause a uniform pressure between the contacts and contact meinbers.

2. In a switch, a plurality of contacts, a plurality of contact members, disk for carrying the contact members provided with a slot for each contact member, a pin in each of said slots upon which the contact member is mounted permitting axial movement of the contact member, and means for resiliently urging the contact members in an axial direction to cause a firm engagement with the contacts.

3. In a switch, a'plurality of contacts, a plurality of contact members, a supporting element for said contact member, a shaft operatively connected to said supporting'element, means fastened to the opposite end of said shaft having oppositely disposed proj ectingA portions,

an insulatingl a lever loosely mounted` on Licc said shaftl and provided with members'cooperating with the projecting portions of said means for causing the rotation thereof to effect the movement of said supporting element, means secured to said lever, and a latch engaging said last recited means for preventing the movement of said lever in one direction. 1

4. In a switch, a plurality of contacts, a plurality of contact members, a supporting element therefor, a shaft operatively connected to vsaid supporting element, means fastened to the opposite end of said shaft aving oppositely disposed projectin tions, a lever loosely mounted on sai shaft and provided with members cooperating,...-

with the projecting portions of said means por- forecausing the rotation thereofto effect the movement of said supporting element, means secured to said 1ever,'a latch engaging said last recited means for preventing the move- 5 ment of said lever in one direction, and a cam surface formed on tive when said lever is moved from one exsaid lever and efectreme position to the other for rendering said latch ineffective.

In Witness whereof, I hereunto subscribe 10 my name this 27th day of March, A. D. 1924. v

CHARLES BOLLIN GER.

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