US2039493A - Sealing means for electric switch ground boxes - Google Patents

Description

May 5, 19367'. s. T. QUILLIAM 2,039,493

SEALING MEANS FOR ELECTRIC SWTCH GROUND BOXES Filed Feb. l5, 1933 Samuel Thomas Qm'uam` Cil Patented May 1936 UNIT-ED STATES PATENT OFFICE SEALING MEANS FOR ELECTRIC SWITCH GROUND BOXES ration of Kentucky Application February 13, 1933, Serial No. 656,573 In Great Britain March 2, 1932 3 Claims.

The invention relates 'to Vimproved means for application to boxes for electrical mechanism or like appliances wherewith mercury sealing means of circular or endless forms are provided.

Such-like sealing means are, for example, made use of in 'boxesor containers of mechanism employed for electrically operating tramway or railway points, and electrical switches, to which mechanism my present invention is particularly applicable.

With regard to boxes of this type, an example of which is illustrated, in part, in the specication of my British Patent No. 305,447, led March 2, 1932, it is very essential to keep said mechanism free from moistureior which purpose operating shafts ofthe apparatus are formed with circular depending lips or iianges, which dip into a mercury seal in the lid or cover, the reservoir or container of said mercury being also circular in form, to suit.

When a lid or cover of this type of apparatus with its operating shaft and depending flange thereof is removed for inspection, repairs or cleaning operations, the mercury in the reservoir named is liable to be spilled, and unless the amount so lost is replaced to a suicient extent, Water or moisture may subsequently enter the box below the lid or cover concerned, eventually resulting in damage to the parts within, such as the ultimate burning out of the solenoidal coils or motors or electrical apparatus with which said boxes are provided.

The object of my invention is to provide an improved form of reservoir of the kind herein named, from which the mercury cannot escape on the tilting or displacement of the lid or cover referred to, taking place.

For this purpose, I provide for the lid or cover a reservoir for mercury which consists oi a circumferentially formed cavity adapted for containing mercury of the required quantity at a lower portion thereof, but provided at an upper part with a continuous outer wall and a discontinuous inner wall, or maybe Walls, in a depending position, the discontinuity of the inner Wall leaving a communication between said upper and lower portions of the cavity. The cavity or chamber is so formed or adapted as to permit of the depending flange of the operating shaft concerned, in the case of a box or container named herein, diping into the contained mercury to the necessary extent to form a water or moisture proof seal, when said shaft is in position.

'I'he circular form of the reservoir in the lid or cover enables the said reservoir to be situated about the shaft referred to, which shaft is Aemployed for transmitting motion from internal solenoid coils, or a motor or electrical apparatus, to the point or like mechanism operated by said appliance.

But the invention is applicable to electrical switches of the kind provided with shafts or -handles which are, or may be formed with depending lips of circular character, parallel to a horizontal plane, or thereabouts.

In the accompanying drawing, Fig. 1 is a sectional elevation along the end of a box of the type according to my patent herein named, 'and provided with means arranged in accordance with one form of my present invention.

Fig. 2 is a modification of Fig. 1, and in both figures only so much of the interior of a box is shown to make the application of my said invention thereto sufciently clear.

The outer casing of the box is shown at I, a revoluble shaft for the same, and operated by the solenoidal or other mechanism (not shown) being indicated at 2.

The outer part of said shaft is marked 3, while an inner cover for the solenoidal parts is indicated at 4.

The shaft 2 is formed as usual with a circular depending lip 5, and external of said shaft, which lip or ange dips into a mercury seal indicated at 1. A larger lip 6 is shown provided for the cover 4.

According to my invention, the reservoir containing the mercury at 1, at its lower part, is of circumferential form here for passing around the position of the shaft 2, and above the level of the mercury l aforesaid the cover is provided with a cavity part having a continuous outer wall such as at 8, and a discontinuous inner wall of a depending character, such as 9 in Fig. 1.

In Fig. 2, a pair of discontinuous depending Walls are employed passing around the reservoir. In the last-named example a further wall is provided adjacent to the shaft 2, but in the case of Fig. 1 the usual bearing for said shaft forms a continuous Wall for completing the reservoir.

It will be observed that, in the examples given, there is a sloping surface leading from the trough containing mercury to the outer wall, or walls, 8, and it will be obvious on account of the principle made use of in the manner shown, that should the cover 4', for example, with the shaft in position, be removed, and the said cover 4 be tilted, the mercury will ow into the cavity marked IU, according to the direction of tilting, and will be prevented from escape by the inner wall 9.

I prefer that the sectional area of the cavity I0 shall be suicient to accomodate the area lof mercury in the same plane when the cover, such as 4, with the shaft 2 in position, is tilted in the said plane through an angle of degrees from the vertical.

In the present example, the reservoir described is formed as part of the cover 4, in Fig. 1, but this is not at all essential.

Although Fig. 2 here relates more particularly to Fig. 1, or to a type of electrical street box, it is clear that the device shown in said Fig. 2 could be applicable to a switch, part 3 being a portion or continuation of the shaft or handle of said switch.

The dimensions and shapes of the parts ernployed for the improved reservoir would obviously be capable of alteration to suit different mechanisms or appliances, Without altering the principle involved.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. Sealing means for a rotatable shaft extending through a cover of a fluid tight housing, comprising a cup-shaped member fixed to the shaft and projecting into a liquid disposed in a Well in said cover, an inverted trough having inner and outer annular Walls surrounding said cupshaped member, said outer wall being fixed to said cover, said inner Wall providing an aperture having a diameter greater than the outside diameter of said cup-shaped member and constructed and arranged to retain said liquid irrespective of the position of the cover.

2. Sealing means for a rotatable shaft extending through a lid of a fluid tight housing, comprising a cup-shaped member fixed to the shaft and projecting into a liquid normally disposed in a Well fashioned in said lid, an inverted trough surrounding said cup-shaped member and serving as a reservoir for said liquid Whenever the lid is moved from a normal position, said trough having an outer Wall fixed to said lid and an inner Wall encircling said cup-shaped member, said inner wall providing an aperture having a diameter greater than the outside diameter of said cup-shaped member so as to permit removal of said cup-shaped member while said trough is xed to said lid.

3. Sealing means for a rotatable shaft extending through a horizontal cover of a fiuid tight housing, comprising an inverted cup-shaped member fixed to the shaft and projecting into a liquid normally disposed in a Well in said cover, an inverted trough encirclingsaid cup shaped member and serving as a reservoir to prevent escape of said liquid Whenever said cover is moved from the horizontal position, said trough having an outer Wall fixed to said cover and an inner Wall loosely disposed about said cup-shaped member, said inner Wall providing an opening larger than the outside diameter of said cup-shaped member so as to permit removal of said cupshaped member and shaft While said trough is fixed to said lid, and thereby prevent escape of said liquid while in said disassembled condition.

SAMUEL THOMAS QUILLIAM.

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