US1736746A - Pendant switch - Google Patents

Description

P. MCSHANE PENDANT SWITCH Nov. 19, 1929.

Filed July 18, 1928 ATORN EY Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE PHELAN MCSHANE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC MANUFACTURING COMPANY, A CORPORATION 0F PENNSYLVANIA' PENDANT SWITCH Application led July 18, 1928. Serial No. 293,764.

My invention relates, generally, to switches, and more particularly to switches of the pendant type which may be utilized for controlling the operation of machine tools and the like.

The object of my invention, generally stated, is to provide a switch that shall be simple and eflicient in operation and economical to manufacture.

A more specific object of the invention is to provide means for controlling the operation of a switch whereby its contact members may be separated in response to movement of the switch-actuating lever in any direction from its normal central position and be automatically engaged when the actuating lever is released.

Other objects of the invention will become evident from the following description, taken in conjunction with the drawing in which:

Fig. 1 is a front view, partly in section, and partly in elevation,'of a pendant switch embodying the features of my invention;

Fig. 2 is a sectional side view of the switch shown in Fig. 1;

Fig. 3 is a sectional side view of the switch shown in Fig. 1, showing a preferred form of stop switch in one of its open positions and Fig. 4 is a sectional view, taken along the line IV-IV of Fig. 2, showing'the stationary plate element of the switch and the relative positions of the contact members and setscrew pivot, members.

Referring to the drawing, 1 designates, generally, a switch of the pendant type that may be utilized .in connection with planercontrol systems and the like.

As shown, the switch 1 comprises a casing composed of a front or face member 2 and a removable back member 3.

In accordance with the usual practice, the pendant switch is provided with a pluralit of push- button switches 4, 5, 6 and 7 which may be utilized to eil'ect different control operations incident to the operation of a machine tool. Since push-button switches of this type are'well known and form no part of the present invention, further description of them is unnecessary.

In the operation of machine tools, it is usual to employ a stop switch in the control circuit, whereby the main motor may be stopped instantly by a very simple operation of the switch, which may be readily performed by the operator in the event of the occurrence of an emergency condition. A preferred form of stop switch, shown, generally, at 8, constitutes a part of the pendant switch 1. It will be observed that the switch 8 comprises only two main elements, a stationary element 9 and a movable element 10. l

In this embodiment of the invention, the stationary element 9 is supported from the front member 2 by means of a plurality of set screws, as shown, and is provided wlth oppositely disposed current-carrying contact members 11 and 12, having terminal members 13 and 14, respectively, which may be connected into any electric circuit.

The movable element 1010ie the switch 8 is provided with a current-carrying plate member 15, provided with contact members 16 and 17 disposed to engage contact members 11 and 12 on the stationary element 9.

In order to effect the operation of the switch, the movable element 10 is provided with an Aactuating lever 18 that is secured to a head member 19 which is disposed to support the current-carrying plate member 15. As shown, the actuating lever 18 extends downwardly through a suitable opening 20 provided in the bottom of` the. front casingA member 2.

In order to support the movable element 10 in operative relation to the stationary switch element 9, a suitable coil spring 21 is provided., As shown, thecoil spring 21 is disposed in concentric relation to the head member 19 of. the movable element and rests upon an annular flange 22, formed in the bottom part of the front member 2. The top coil of the spring 21 is disposed to bear against the head member 19 to actuate the contact members 16 and 17 of the switch into engagement with the contact members 11 and 12, respectively.

It will be readily understood that the sprin 21 serves as a pivot mounting for the mova le element 10 which permits the actuating lever l@ .t0 be moved dewewerdly Q1* in any direction from its normal vertical position, to effect disengagement of one or both of the contact members.

Referring to Fig. 2, it will be readily understood that the disengagement of either pair of contact members 11 and 16 or 12 and 17 may be effected by moving the actuating lever 18 slightly in any direction. It will be observed that, when the lever is moved to the left, as viewed in the drawing, the contact members 11 and 16 are utilized as a fulcrum, and' the plate member 15 is moved from its position parallel to the stationary element 9 to effect disengagement of the contact members 12 and 17. Likewise, the contact members, 11 and 16, are disengaged when the actuating lever 18 is moved towards the right, as viewed in the drawing.

In order that disengagement of either pair of contact members may be effected in response to movement of the actuated lever 18 to the right or to the left from its normal position, as shown in Figs. 2 and 3, provision is made for utilizing the contact members as fulcrum points for the plate member 15.

In this particular embodiment of the invention, the stationary element 9 is provided with set-screws, 23 and 24, interposed between the contact members 11 and 12. The contact members 11 and 12 and the set screws 23 and 24 of the stationary element 9 are, preferably, arranged, as shown in Fig. 4, so that when the actuating lever 18 is moved to the right or to the left from its normal position, as shown in Fig. 1, a fulcrum point for the plate member 15 will be provided by its engagement with the one or the other of the set screws 23 and 24.

Referring to Fig. 1, it is evident that, when the actuating lever 18 is moved to tbe right or to the left, the spring 21 permits the movable element 10 to pivot on its contact members 16 and 17 until the plate member 15 engages the one or the other of the said screws 2.3 and 24, depending upon the direction of movement of the lever. Further movement of the actuating lever effects the simultaneous disengagement of both pairs of contact members, since the engagement of the plate member 15 with a set screw provides a fulcrum point about which it may be tilted further from its normal position.

It will be readily understood that the disengagement of the contact members may also be effected by moving the actuating lever 18 in such direction as to cause the plate member 15 to flcrnm at two points, upon one of the set screws 23 and 24 and upon either of the contact members 11 and 12. It is evident of both airs of contact melnbers may also be effected y pulling downward on the actuating lever, thereby compressing the spring to permit separation of the stationary and movable contact members.

Since the spring 21 is constantly urging the movable element 10 toward the stationary element 9, it is evident that, when the actuating lever 18 is released from any of its operative positions, the movable element 10 will immediately assume its normal position to effect engagement of the contact terminals.

From the foregoing description, it will be readily understood that, by using a switch of this type for controlling the stopping operation ot' a main drive motor on a planer or other machine tool, the operator is enabled to shut down the machine in an emergency by manual operation of the switch-actuating lever in any direction.

It may be stated, in conclusion, that, while the illustrated example constitutes a practical embodiment of my invention, I do not wish to limit myself strictly to the exact details herein illustrated, since modifications of the vsame may be made without departing from the spirit of the invention as defined in the appended claims.

I claim as my invention:

1. In a switch, in combination, a casing, a stationary contact element mounted Within the casing, a cooperative movable contact element, an actuating lever secured'to the movable element and extending through the casing, resilient means for holding the contact elements in engagement, and means carried by the stationary contact element to engage the movable contact element when the latter is moved by the actuating lever to effect disengagement of the contact elements.

2. In a' switch, in combination, a casing, a stationary contact element mounted within the casing, a cooperative movable contact element, an actuating lever secured to the movable element and extending through the casing, means for biasing the contact elements. toward engagement, and means carried by the stationary contact element to effect the opening of the switch in response to a rocking movement of the actuating lever.

3. In a switch, in combination, a stationary element provided with contact members, a`

second element provided with a plurality of contact members, an actuating lever provided on the second element, and means for maintaining the contact members in engagement, said means being disposed to permit movement of the actuating lever in any direction to effect the disengagement of the contact members.

4. In a switch, in combination, a stationary switch member,a second switch member cooperative with the stationary member,`said second switch member being disposed for movement relative to the stationary switch llt) lll)

member, means for biasing the movable switch member upwardly toward engagement with the stationary -switch member, and means carried by the stationary member to engage the movable member to efect a tilting movement of the latter, when said movable fect the simultaneous disengagement of the contact members.

6. In a pendant switch, in combination, casing for enclosing the switch, a plate member stationarily` mounted within the casing, contact members carried by the plate member, a movably mounted plate member disposed beneath the' stationary plate member, contact members carried by said movable plate member, means for maintaining the contact members in en agement, and means for actuating said mova le late member to effect the disengagement o the contact members.

7. A switch comprising a stationary contact element, a movable Contact element' disposed in cooperative relation to the stationary contact element, means for supporting the movable element in engagement With'the stationary contact element, said supporting means being adapted to permit separation of the said elements, and a lever for effectin movement of the movable element to'cause the separation of the contact elements.

8. In a pendant switch, in combination, a

casing, a stationary switch element mounted in the casing, a movably mounted switch e ement cooperatlve with the stationary switch element, said movable element being provided with an actuating lever extending throughthe casing, and means carried by the stationary element to engage the movable element in `response to transverse movements of theV actuating lever to eiectthe opening of the switch. 9. A switch comprising a pair of contact carrying elements normally disposed imparallel relation, one otv said contact elements being stationary and the other movable, contact members carried by each element, means engaging the movable contact-carrying element to bias it toward-engagement with the stationary element, and means carried by-the stationary element for pivotally engaging the movable element in response to its being moved out of parallel relation with the c0- operating stationary element to eiiect a tilting movement of the movable element, thereby` to causegthe disengagement of the contact members.

10. In a switch, in combination, a casing provided with an opening in the bottom thereof, stationary and movable switch elements provided with equal numbers of contact members mounted in the casing, an actuating lever extending through the bottom of the casing, a spring supported by the bottom ,of the-casing and disposed to bias the mov- -able element toward the stationary element to cause the engagement of the contact memmaintain said movable and stationary element to engage said lmovable element in response to predeterminedv movements of the actuating lever to cause the contact members to become disengaged.

11, A switchfcomprising, in combination, a stationary element having a plurality of contact members, a movable element provided with a plurality of -contact members disposed to engage said stationary contact' members, a lever for` actuating theA movable element, and a resilient member disposed to maintain said movablel and stationary elements in an engaging osition, thereby to permit the movement o vthe actuating rlever into a plurality of positions to effect separation of the switch contacts.

12. A switch comprising a plurality of stationary contact elements, a plurality of cofil operating movable contact elements, 'means for supporting said movable elements in operative relation to the stationarytelements, said means comprising aagesilient/ member -disf posed to maintain the`contact elements in engaging relation, and an" actuating lever for effecting a movement of the movable contactelement-supporting means.

In'testimony whereof, x ave hereunto s ubscribed my name this '12tlif. ay of July, 1928.

" PHELAN MoSI-IANE.

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