US1406171A - Electric switch - Google Patents

Description

W. A. CHRYST.

ELECTRIC SWITCH.

APPLICATION FILED MAY 22. 1916.

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UNITED s'r 'rss PATENT OFFICE.

LABORATORIES COMPANY, A CORPORATION OF OHIO.

ELECTRIC s'wIToH.

Specification of lLetters Patent. Patented Feb. 14 1922 Applicationfiled May 22, 1916. Serial No. 99,131.

To all whom it may concern Be it known that I, IVILLIA'M A. CHRYs'r,

' a citizen of the United States of America,

residing at Dayton, county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Electric Switches, of which the following is a full, clear, and exact description.

This invention relates to improvements in electrical switches.

It is among the objects of the present invention to provide a switch for electrical circuits, which is compact-in construction and which maybe manufactured at a relatively small cost, but which will operate efficiently to efi'ect the opening and closing of the circuits with which it is associated.

Further objects and advantages of the present invention will be clearly apparent from the following description, with reference to the accompanying drawings, wherein a preferred form of embodiment of the present invention is clearly illustrated.

Fig. 1 is a view in elevation of the switch.

Fig. 2 is a sectional view of the switch with its controlling parts shown in normal or inoperative position, certain of the parts of said switch being shown in elevation for the sake of clearness. I

Fig. 3 is a view similar to Fig. 2, showlng the operating member or pedal partially depressed and the contacts of the switch in closed position.

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 1.

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 1, illustrating the switch casin and its associated parts, certain parts being omitted for the sake of clearness.

By referring to the drawings, and more particularly to Figs. 2 and 3, the switch 1s shown comprising a casing 28, which is lined with insulating material 29.

A pair of stationary contacts 24 and 26 are mounted within the insulating lining 29 and are so formed that the upper portions of these respective contacts provide a beveled face to insure a more perfect contact with a movable contact element 25, as will be described in detail hereinafter.

These stationary contacts are held in place sembled position,

tric circuit which is to be made and broken by the operation of the switch.

In order to maintain the respective stationary contacts 24 and 26 in a determined position, a plurality of lugs or projections 21 are formed on each of said contacts and when the elements of the switch are in asthese projections prevent the turmng of the terminal bolts and thereby also prevent any movement of the stationary contacts. The terminal bolts 30 and 31 are formed with square heads so as to more readily permit of their being held in a determined position.

A suitable piece of insulation 22 passes diametrically across the bottom of the switch casing and tends to space or separate the stationary contacts.

In order to facilitate the assembling of the stationary contacts in the switch casing, together with the terminal bolts and also to decrease the weight and stock of the stationary contacts, a longitudinal portion of said contacts is cut away as at 23.

The switch casing 28 is provided with a cover 33, which rigidly supports a collar 34. This collar forms a bearing for the contact carrying element 35, upon which is mounted the movable contact 25, insulated therefrom in any suitable manner.

The movable contact 25 is cup-shaped, being formed in contour to correspond with the interior faces of the two stationary contacts 24 and 26. In order to insure eflicient engagement between the movable contact 25 and the stationar contacts 24 and 26, the movable contact 1s slotted as at 36, which increases the resiliency of this element.

The contact carrying element or sleeve 35 includes a hollow or shell portion 37 which is in alinement with a stud 32 rigidly fastened to the casing 28. A spring 38 is located within the hollow portion 37, one end of said spring abutting against the end of the stud 32. This spring normally tends to hold the movable contact 25 out of engagement with the stationary contacts 24 and 26, and forms the sole means for maintaining the separation of the movable and stationary contacts.

The collar 34 not only forms a bearing for the contact carrying sleeve 35, but also for the operating pedal 40. This operating pedal may be provided with a head portion 41, which acts as a stop, when the pedal DAYTON menianame is depressed to a determined point, thereby in any suitable manner, such as by a threaded connectlon, as at 45, see Figs. 2 and 3. This stud projects through the center of the spring 43 and the portion 46 of the contact carrying sleeve 35, and is formed with an enlarged head portion 47 which fits wlthin said sleeve 35. By virtue of the head engaging a stop 48, formed in the portion 46, displacement of the operating pedal 40 by the spring 43 is prevented. By connecting the stud 44 with the pedal 40, in the manner shown, the assembly of the various elements heretofore referred to is greatly facilitated.

By the above described arrangement and construction of the parts, it will be noted that when the operator desires to close the main circuit, the operating pedal 40 is depressed. Upon depression of the operating pedal, downward motion is transmitted through spring 43, which is much stronger than spring 38, to contact sleeve 35, causing.

the compression of the spring 38' to continue until the movable contact 25 is firmly compressed into contact with the stationary contact plates 24 and 26. Further compression of the spring 38 cannot occur, since the stationary contact plates are of substantially rigid stock, and the movable contact element is resilient only to a slight degree, and element 35 can have no further downward movement. Therefore, after the movable and stationary contacts have been brought into position, and the operating pedal 40 is still further depressed, all of the downward pressure on 40 will cause the compression of spring 43, and the compressive force in spring 43 will be transmitted to the sleeve 35, causing increased pressure between elements 24 and 25, without having any further effect on the spring 38. g

It will therefore be seen that if the operator tends to slightly release the pressure on the pedal 40, during the interval that the, circuit is supposed to be closed, the pedal must first move upwardly until the head 47 of stud 44 is limited by the stop 48, formed in the portion 46 of element 35, before the separation of the contacts will be effected. The reason for this is that until the compressive force of spring 43 is taken up by the pressure between head 47 and stop 48, the downward pressure of spring 43 acting upon sleeve 35, will always overcome spring 38 and maintain the contacts in engagement. After spring 43 is allowed to expand to its initial, shape, then the spring 38 will become effective to'open the contacts;

It will further be obvious that the proportioning of the various parts and their respective locations, will be such as to prevent the injurious operation of the switch; that is, for instance, the space between the element 41 and the collar 34 is substantially less than the normal distance between the pedal 40 and the portion 46 of the contact carrying element 35. Therefore, the pressure on the switch elements cannot exceed a certain amount which can be safely applied.

While the form of mechanism herein shown and described constitutes a preferred form of embodiment of the invention, it is to be understood that other forms might be adopted, all coming within the scope of the v claims which follow.

What I claim is as follows:

1. In a switch, the combination with a casing having a plurality of stationary contacts mounted therein, and a movable contact slidably mounted within said casing co-opcrating with the stationary contacts; a spring of determined strength positioned between the casing and the movable contact, and adapted to maintain said movable con tact in disengaged position relatively to the stationary contacts; an operating member movably mounted upon the casing; a second spring of greater strength than the first mentioned spring, interposed between the movable contact and the operating member. for maintaining'the operating member in normalposition with respect to the movable contact, when the switch is inoperative, and for transmitting motion from the operating member to bring the contacts together against the pressure of the first spring and to maintain said contacts in engaged position under pressure; and means for limiting the pressure applied to the contacts.

2. In a switch, the combination with a plurality of stationary contacts mounted in the casing and insulated therefrom and from each other; of a stud mounted in the casing; a movable contact adapted to be brought into engagement with the stationary contacts; a cover plate for the casing; a collar carried by the cover plate; a movable sleeve slidably mounted in the collar, and adapted to carry the movable contact; an operating member extending outside of the aforementioned collar and having a portion extending the-reinto a stud rigidly connected to the operating member and slidably associated with the movable sleeve-and provided with a stop cooperating with the stop on the sleeve, to limit the distance to which. said operating member and sleeve may be separated; a spring of determined strength interposed between the sleeve and operating member and adapted to hold same apart; another spring of lesser strength than the aforementioned spring, in-

. ing member toward the casing.

3. In a switch, the, combination with a switch contact housing and a hollow collar portion-supported thereby; of stationary contacts mounted in said housing; a movable contact mounted on a hub portion which is slidably supported within said collar portion; a pedal slidably supported within said collar portion; a spring between the pedal and hub portion; a stud secured to the pedal and extending through the hub ortion, and having provisions engaging the iiub whereb to limit the separation of the pedal and uh by said spring; and other spring means for separating the contacts when the pedal is released.

- 4. In a switch, the combination with a switch contact housing and a hollow collar portion supported thereby; of stationary contacts mounted in said housing; a movable contact mounted on a hub portion which is slidably supported within said collar portion; a pedal slidably supported within said collar portion; a'spring between the pedal and hub portion; a stud securedto the pedal and extending throu h the hub portion; a

second stud supporte by the housin and a spring located between the secon stud and the hub portion for separating the contacts when the pedal is released.

'5. In a switch, the combination with a switch contact housing and a hollow collar portion supported thereby; of stationary contacts mounted in said housing; a movable contact mounted on a hub portion which is slidably supported within said collar portion; a pedal; a spring transmitting motion from the pedal to the hub portion; means cooperatin with the pedal and hub portion to limit t e movement of the pedal away from the hub portion; and-a spring cooperating with the casing and the hub portion for separating the contacts when the pedal is released.

6. In a switch, the combination with a stationary contact and a movable contact; of a movable contact carrying element; means for slidably supporting said carrying element; a pedal also slidably sup orted by said means and by said carrying e ement; a spring motion transmitting member between said pedal and said carrying element; andmeans for separating the contacts when the pedal is released.

7 In a switch, the combination with a stationary contact and a movable contact; of a movable contact carrying element; means for "slidably supporting said carrying element; a pedal also'slidably supported by said means; a member connected with said pedal and slidably supported by said carrymg element and having provisions cooperating with said carrying element whereb to limit the separation of said element rom said pedal; a sprin motion transmitting member between sai pedal and saidcarrying element; and means for separating the contacts whenv the pedal is released.

- In testimony whereof I aflix my signature in the presence of two subscribing witnesses.

WILLIAM A. CHRYST.

Witnesses:

J. W. MCDONALD, O. D. Mownr.

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