US918969A - Insulating-bushing for electrical service-boxes. - Google Patents

Description

R. C. COLE.

INSULATING BUSHING FOR ELECTRICAL SERVICE BOXES.

APPLICATION FILED D3011, 1908.

Patented Apr. 20, 1909.

UNITED STATES PATENT OFFICE.

ROBERT C. COLE, OF WEST HARTFORD, CONNECTICUT, ASSIGNOR TO THE JOHNS-PRATT COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

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Spebification Letters Patent.

Patented April 20, 1909.

Application filedDecomber 11, 1909. semi'no. 460,964.

To all whom it may concern:

Be it known that I, ROBERT C. UOLE, a

- citizen of the United States, residing at 'for Electrical Service-Boxes, of which the following is a full, true, and concise specification. i The invention is an improvement in the inclosures of electrical apparatus such as are generally known as fuse or service-boxes, and consists of a new means for fastening the insulating bushings within the a er'tures in the walls of such boxes, the sai apertures and bushings being for the accommodation of the electric circuit wires which lead to the apparatus within the box.

he object of the invention is to improve the security with which said bushings are held in dues, to render the connection substantial y moisture and water proof, and to rovide a mode of attachment that will not e liable to deterioration under vibration or other conditions of severe service and also to reduce the cost and facilitate the'assemblalge of the parts.

he drawings forming a part hereof show,

in Figure 1, a perspective view of an ordinary fuse or service box of the kind herein referred to. Fig. 2 is an enlarged lon 'tudinal section of the front wall of said ox, showing a bushing also in section, secured therein according to my invention. Fig. 3 is a similar view with the several arts separated as before assemblage the bushing in this figure being shown in elevation.

The box shown in Fig. 1 is rovided with the usual hinged cover 1 and ocking nut' 2, and is intended to contain electrical fuses or other apparatus which for known reasons rest against the marginal portion of the box wall, immediately adjacent to the aperture, and with a barrel portion 5 occupying the aperture and protruding more or less beyond it as desired. The exterior formation of the said barrel portion is coordinated with the formation of the inner wall of the aperture so as to provide 0 posing abutments respectively thereon an within the annular crevice between the two parts; for example, the barrel portion 5, just behind the head or flange 4, is provided with a groove or recesswhich forms an abutment ledge, indicated at the point marked 6, and the aperture in-the box wall is convergingly tapered'toward the head of the flange, so that its most contracted end affords a similar ledge or abutment, indicated at the point marked 7, the two abutments being disposed in opposition to each other so as to withstand thrust in a longitudinal direction or parallel with the axes of the bushing and aperture. Other coordinated formations may be provided, how- I ever,that will produce opposing abutments of similar function, but the form described is of advantage in that it provides a tapered or somewhat funnel-shaped entrance to the interior of the crevice or annular space between the bushing and the wall, this being due to the taper of the a erture. Into this entrance it is intendedt rat a plastic interlocking and sealin member shall be forced for the urpose o 'filling up the space between t e abutments w1th a more or less rigid pressure transmitting medium, and thus locking the bushing in lace.

The sealing member, as in 'cated in Fi 3,

consists of a ring 8 of plastic metal suc as soft lead or otherdense plastic or semi-plastic material capable of accommodating its shape to the s ape of the crevice under it conforms in size and she e to the shape of the creviceand is inten ed to be pressed or crowded into the latter by means of any suitable pressure instrument, so that it flows suitable pressure. Before insertion, the ring ments in the crevice there .etween, said havin a flange abutments being disposed to withstand thrust parallel with and in the direction to remove said bushing and a plastic metal looking ring crowded into the space between said crevice abutments and serving as an. in-

terloeking thrust-transmitting medium between the same. 1

2. The combination, with the box or mclosure of electric fuses or other electrical apparatus, having an'a erture tlirough the wall thereof for the intro notion of a circuit wire, of an insulatin bushing for said apeature 5 head thrusting against the wall 0 said inclosure, and behind said head an abutment dis )osed in opposition to an abutment forms in said aperture, and a plastic metal ring crowded into the space between said abutments to moval of the bushing.

33. The combination, with the inclosure for electric fuses or other electric apparatus hav prevent the reing a flared or tapered aperture through the eiaeee wall'thereof for the introduction of a circuit wire, of an insulating bushing for said aperture having a flange thrusting against the margin of t e smaller and of said tapered aperture, and having behind said flange and said smaller end an opposing abutment within the aperture and a plastic ring crowdedinto the crevice between said abutment and the tapered end of the aperture.

4. The combination, with the inclosure of electric fuses or other apparatus having a tiered or ta ered aperture through the wall th reof for t e introduction of a circuit wire, of an insulating bushing -for saidaperture having a rooved exterior formation disposed within said aperture and a plastic ring ressed through the larger and of said aperure into interlocking engagement with said grooved formation and said tapered aperture to revent removal of said bushin n testimony whereof, I have signed presence of 50 name to this specification in the two subscribing witnesses.

ROBERT (3. COLE.

Witnesses ARTHUR B. PEoK ALVAN WALDO IlYnE.

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