US2934593A

US2934593A - High voltage bushing

Info

Publication number: US2934593A
Application number: US567664A
Authority: US
Inventors: Henry F Kollinger
Original assignee: Kuhlman Electric Co
Current assignee: Kuhlman Electric Co
Priority date: 1956-02-24
Filing date: 1956-02-24
Publication date: 1960-04-26
Anticipated expiration: 1977-04-26

Description

April 26, 1960 H. F. KOLLINGER HIGH VOLTAGE BUSHING Filed Feb. 24, 1956 INKENTOR. l eflz glfa/fin aen ATTORNEY;

United States Patent O i HIGH VOLTAGE BUSHING Henry F. Kollinger, Bay City, Mich., assignor to Kuhlman Electric Company, Bay City, Mich, a corporation of Michigan Application February 24, 1956, Serial No. 567,664 4 Claims. (Cl. 174-145) This invention relates to transformer bushings and the like, and more particularly to a high voltage bushing provided with means for covering and shielding the live parts against short circuits and a consequent disruption of service.

One of the prime objects of the invention is to design a high voltage bushing which permits all live connections to be made without the use of tools of any kind.

Another of the prime objects of the invention is to design a high voltage bushing provided with an enclosed conductor clamp with a cap serving as a shield to completely shield and cover electrically charged parts of the clamp from accidental contact by the operator, animals of all kinds, birds, falling branches and similar hazards which could cause grounds and short circuits causing service interruptions on a distributing system.

A further object is to design a high voltage bushing which affords safety, convenience and speed in handling high voltage connections on transformers, and which can be easily and quickly mounted in position.

Still a further object is to provide a bushing including an insulated knob or cap resistant to weather and shock and which forms a rain-shed over the upper end of the bushing body in open, closed, or intermediate position of the conductor clamp.

A further object still is to design a high voltage bushing provided with a plurality of circumferentially spaced radial openings to accommodate live wires from either side, and also to permit excess voltage sparkover to a lightning arrestor or other external device.

With the above and other objects in view, the present invention consists in the combination and arrangement of parts, hereinafter more fully described, illustrated in the accompanying drawing, and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportion and minor details of construction without departing from the spirit, or sacrificing any of the advantages of the invention.

In the drawings:

Fig. 1 is a part sectional side elevational view showing my high voltage bushing.

Fig. 2 is a transverse sectional View taken on the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary side elevational view showing the bushing mounted on a transformer tank cover.

Fig. 4 is a top plan view of the bushing.

Fig. 5 is a fragmentary part sectional side elevational view taken on line 5-5 of Fig. 2.

Referring now more specifically to the drawing in which I have shown the preferred embodiment of my invention. The letter B indicates the bushing proper which comprises a bushing body 8 formed of porcelain or other insulating material, provided with a plurality of corrugations 9 to provide for creepage and centrally cored as at 10 to accommodate a cable terminal 11 which bears on a washer 12, and a lead wire 13 leads from the trans- 2,934,593 Patented Apr. 26,1960

ice

former (not shown), housed in tank T, to the threaded cable terminal 11 above referred to.

The upper end of the bushing B terminates in an open top, generally cup-shaped housing section 14 in which a suitable terminal clamp mechanism C is mounted, the clamp body being formed with an enlarged flange or face section 15 intermediate its length, with a cylindrical depending section 16 extending into the core 10, said section being bored and threaded as at 17 to accommodate a screw 18 extending through terminal 11 to secure the upper end of the lead wire 13 in the usual manner, and a corprene gasket 19 is provided between the flange 15 and the upper end of the cored passage 10 i.e. at the bottom of the housing 14, to prevent oil leakage at this point.

The terminal clamp includes a laterally projecting leg or terminal 20 and a centrally disposed vertical opening or slot 21, the upper end of said clamp being bored and threaded as at 22, and a centrally bored pressure screw 23 is threaded therein, said bore terminating in a reduced opening 24 adapted to revolubly accommodate the hub 25 of a follow bar or jaw I, the face of the bar being preferably knurled to provide a firm gripping surface.

The upper end of the pressure screw is slotted as at 26, and a rubber insulated knob or clamping head 27 is molded thereon, this knob being substantially spherical in shape with a depending skirt 27a of a size to telescope over the upper open end of the housing and form a rainshed for same in open, closed, or intermediate position, and in closed position the lower edge of the skirt clears the line conductor L entering the housing.

A plurality of flutes 28 are formed in the knob 27 to provide a secure grip, and it will be obvious that by turning the knob the follow bar of the clamping mechanism will be raised or lowered thus freeing or securing the line connection L therein.

Oppositely disposed openings or gaps 2929 are cored in the side wall of the housing section 14, these gaps accommodating a live wire L from either side. An opening 30 is also formed in the side wall and accommodates the laterally projecting terminal 20 above referred to for establishing a fixed or adjustable gap to an external device such as a lightning arrestor terminal or ground terminal (not shown).

I also wish to direct attention to the fact that the upper surface of the base part 15 is preferably crowned or pitched from the center towards the openings 29, 30, to provide natural drainage of water through the openings and the adjacent surface of the jaw J is complementally shaped as is shown in Figures 1 and 5.

The lower end or shank of the bushing body B extends into the tank T through opening 31, said body including a shouldered section 32 which bears on the cover 33 of tank T, and a preferably stamped plate 34 fits over tl e shoulder 32 and bolts 36 are provided for securing the assembly to the cover 33 of the tank.

From the foregoing description it will be obvious that I have perfected a very simple, safe, and convenient high voltage bushing for connecting line leads to transformers; which shields all live parts from animals, birds, etc., and which also permits line connections to be made without use of tools.

What I claim is:

1. A high voltage bushing comprising a cored body member formed of insulating material and terminating at one end in an open-top, generally cup-shaped housing having a bottom and having at least one opening through a side thereof; an electrically conductive clamp body member having a base seated on the bottom of said housing and having an opening therein in register with said opening in said housing to receive an electrical conductor, said base having a crowned surface sloping from its center towards the bottom of said housing; current conducting means connected to the base of said clamp body member and extending into the cored body member to form a cable terminal; a knob member formed of insulating material threadedly mounted for movement on one of said body members; an electrically conductive clamp element located in said opening of said clamp body member and having a clamping surface complementary to the crowned surface of said base; and means connecting said clamp element to said knob member, said clamp element being movable with said knob member towards and away from said base so as selectively to clamp and unclamp an electrical conductor between said clamp element and said base, said knob member forming a closure and rain shed for the open top of said housing.

2. The construction set forth in claim 1 wherein said knob member is mounted on said clamp body member.

3. A high voltage bushing comprising a cored body member formed of insulating material and terminating at one end in an open-top, generally cup-shaped housing having a bottom and having aligned openings through opposite sides; an electrically conductive clamp body member having a base seated in said housing and having an opening therein in alignment with said openings in said housing to enable an electrical conductor to be received in the opening in said clamp body member from either side of said housing, said base having a crowned surface sloping from its center towards the bottom of said housing; electrically conductive means connected to the base of said clamp body member and extending into said cored body member to form a cable terminal; a hemispherical knob member formed of insulating material threadedly mounted for movement on one of said body members and having a depending skirt portion adapted to telescope over the top of said housing; an electrically conductive clamp element located in the opening of said clamp body member and having a clamping surface complementary to said crowned surface; and means connecting said clamp element to said knob member, said clamp element being movable with said knob member towards and away from said base so as selectively to clamp and unclamp an electrical conductor between said clamp element and said base, said knob member forming a closure and rain shed for the open top of said housing.

4. The construction set forth in claim 3 wherein said knob member is mounted on said clamp body member.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Publication: Pennsylvania Transformer Company advertisement, Electrical World, May 12, 1952, page 14.