US2022964A - Mounting for electrical devices - Google Patents

Description

Dec. 3, 1935. E. H. JONES MOUNTING FOR ELECTRICAL DEVICES Filed Aug. 2, 1933 INVENTOR E. H. JONES 8V A T TORNE Y Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE Telephone Laboratories,

Incorporated, New

York, N. Y., a corporation 01' New York Application August 2. 1933, Serial No. 683,245

1 Claim.

This invention relates to mountings for electrical devices and more particularly to sockets for electron discharge devices.

In some sockets for electron discharge devices of the type having external prongs extending from the base thereof, the contact members for engaging the prongs are either exposed through a relatively large aperture for receiving the base of the device or are disposed ad'acent an insulating member having apertures f r receiving the terminal prongs. It sometimes occurs that the contacts are connected in a circuit even when no device is in the socket and there is danger, therefore, of accidental short-circuiting of the contact members by a tool or other piece of metal. There is danger also, particularly in those cases in which devices'utllizing relatively high potentials are employed, of injury to a person who accidentally comes in contact with the contact members.

One object of this invention is to prevent accidental short-circuiting and contact with the contact members of a socket for electron discharge deviccs or similar apparatus.

In one embodiment of this invention, a socket comprises a base portion and a tubular portion extending therefrom and adapted to receive the base of an electron discharge device or the like, and provided with a groove or slot for accommodating a bayonet pin projecting from the base of the device. Contact members are mounted on the base portion of the socket and are spaced to engage terminal prongs on the device when the latter is inserted in the tubular portion of the socket.

In accordance with a feature of this invention, a rotatable shield of insulating material is mounted within the tubular portion of the socket and adjacent the contact members, and is provided with a plurality of apertures disposed in the same geometrical relation as the contact members and the terminal prongs of the device. The shield member is normally positioned so that the apertures therein are misaligned with the contact members, thereby preventing accidental contact with the contact members. When a device is inserted in the tubular portion of the socket, the terminal prongs on the device enter into the apertures in the shield member. As the device is rotated to lock the bayonet pin in the slOt or groove therefor, the shield likewise is rotated so that the apertures therein are brought into alignment with the contact members and the latter engage the terminal prongs. When the device is removed from the socket, the shield is rotated by the rotation of the device to misalign the apertures and the contact members. Stop members may be provided to limit the rotation of the shield to the angle of rotation of the device during its insertion in or withdrawal from 5 the socket. The shield may be locked in position when the device is in the socket, by a pawl or the like cooperating with a groove or notch in the shield member. In order to prevent accidental rotation of the shield member, friction pads, such 10 as of felt, may be provided adjacent and in contact with the peripheral portion of the shield member.

The invention will be understood more clearly and fully from the following detailed description 15 with reference to the accompanying drawing in which:

Fig. 1 is an exploded View in perspective of a mounting constructed in accordance with this invention, and partly broken away to show the 20 insulating shield more clearly;

Fig. 2 is a side view in cross-section of the mounting shown in Fig. 1; and

Fig. 3 is a fragmentary view showing a stop arrangement for limiting rotation of the shield 25 and for preventing accidental rotation thereof.

Referring now to the drawing, the mounting comprises a hollow elbow-shaped member III, which may be of metal, having an integral flange or supporting plate portion ll provided with 30 apertures l2 for receiving screws for securing the mounting to a. suitable support, and provided also with an aperture l3. An insulating block it is secured to the rear wall of the flange or plate II, as by screws l5, and has secured thereto by 35 bolts I 6 an insulating plate I! which extends through the apertures l3 into the interior of the elbow-shaped member l0. A plurality of conductive members are mounted upon the plate l1, each of the members including an elongated strip portion l8 having a terminal portion l9 extending outwardly beyond the insulating block l4 and secured to the block M as by screws 20, only one of which is shown. Each of the conducting members includes also an integral upstanding 45 contact portion 2| for engaging terminal prongs 4| extending from the base 42 of an electron discharge device or thelike, and provided with a guiding and positioning groove 22.

Another insulating block 23 is secured to the rear wall of the flange or supporting plate H, as by screws 24, and has secured thereto by a bolt 25 a conducting member including a terminal portion 26, a contact portion 21 and an inter- 55 mediate reversely bent portion 28 secured to the insulating plate H as by a bolt 29.

The contacts 2| and 21 are disposed in the same geometrical relation as the terminal prongs 4| of the device to be supported in the mounting. If the device to be supported is an electron discharge device, the contacts 2| preferably are adapted to engage the low potential terminals 01' the device and the contact 21 is adapted to engage the high potential terminal. The plate l1, therefore, provides a high insulation between the low and high potential contacts and prevents arcing therebetween.

The elbow-shaped member I0 is provided with an annular recess at one end, in which the peripheral portion of a rotatable insulating disc or shield 30 is seated, the disc or shield being provided with apertures 3| disposed in the same geometrical relation as the contacts 2|I and 21. A tubular shell 32 is secured to the elbow-shaped member III as by screws 33, together with a friction pad 34 of felt or similar material which engages the disc 30 and prevents accidental rotation thereof. The shell is provided with an L-shaped groove or slot 35 for receiving a bayonet pin 43 on the device to be supported in the mounting.

The elbow-shaped member l0 may be provided with an integral inwardly projecting flange 36 which underlies the disc or shield 30 and has embedded therein a pinlr31 extending into an elongated aperture or guide slot 33 in the disc or shield. The slot is so positioned that for one extreme position thereof relative to the pin 31 the apertures 3| are in alignment with the contacts 2| and 21 and is of a length substantially equal to the travel of the bayonet pin 43 in the lateral arm of the groove or slot 35.

In an alternative arrangement tor limiting the rotation of the disc or shield 30, shown in Fig. 3, the disc or shield may be provided with suitably spaced and positioned notches 39 for receiving a spring or pawl 43 mounted on the elbowshaped member I0.

Normally, that is, when the mounting is not in use, the disc or shield 30 is positioned so that the apertures 3| are misaligned with the contacts 2| and 21, and thereby prevents accidental contact from the exterior of the mounting with the contacts. When a device is placed in the mounting, the base 42 thereof is inserted into the tubular sleeve 32 with the bayonet pin 43 on the base in the vertical arm of the groove or slot 35 and the terminal prongs 4| on the base extending through the apertures 3|. As the device is rotated to lock the bayonet pin in the lateral arm of the groove or slot 35, the disc 30 is rotated until the terminal prongs 4| on the device engage the contacts 2| and 21 and are held in the grooves 22 in the contacts. 4

When the device is to'be withdrawn from the socket, it is rotated in-accordance with the travel of the bayonet pin in the lateral arm of the 5 groove or slot 35 and the disc or shield 33 is likewise rotated so that the apertures 3| therein are misaligned with the contacts 2| and 21. The rotation of the disc or shield and of the device is limited by the pin 31 and guide slot 33 arrangement (Figs. 1 and 2) or by the pawl and notch 39 arrangement (Fig. 3) and by the travel of the bayonet pin in the lateral arm or the groove or slot 35, so that at one end of the travel the bayonet pin is in alignment with the vertical arm of the groove or slot and the base of the device may be withdrawn from the shell 32.

It will be apparent, particularly from Fig. 2, that the disc or shield 30 may be made relatively thin and that the contacts 2| and 21 may be posi- 2 tioned immediately adjacent the disc or shield. As a result, a large portion of the terminal prongs, which are usually of a standard length, on 1. devices such as electron discharge devices, is engageable by the contacts 2| and 21 so that a 25 large surface and low resistance contact is established.

Although a specific embodiment of the invention has been shown and described, it will be understood, of course, that modifications may be made therein without departing from the scope and spirit of the invention as defined in the appended claim.

What is claimed is:

A mounting for an electrical device having a base, terminal prongs extending from said base,

and a bayonet pin projecting from a wall of said base, said mounting comprising a hollow member having a tubular portion for receiving the base of said device and provided with a guide slot having a lateral part for receiving said bayonet pin,

a plurality of contacts within said hollow memher and disposed in the same geometrical relation as said prongs, an insulating shield within said hollow member, having apertures for receiving said prongs and having also an elongated aperture adjacent its periphery, said shield being rotatable in accordance with the travel of said bayonet pin in said lateral part of said guide slot to align said apertures with said contacts, 50. and a pin fixed to said hollow member and extending into said elongated aperture, said elon gated aperture being of a length commensurate with the lateral travel of said bayonet pin in said lateral part of said guide slot. 5

EDWARD H. JONES.

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