Improvements in Electric Are Lamps and their Connections.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in Electric Are Lamps and their Connections.
I ROOKES EVELYN BELL CROMPTON, Engineer, of Arc Works, Chelmsford
do hereby declare the nature of this invention to be as follows:-
The invention relates to improvements in the method of and means or apparatus
for connecting electric arc lamps to their supports and sources of electrical energy.
My invention has for its object mainly to effect improvements in the method of
attaching are lamps to brackets, crutches or similar supports so that a strong and
effective joint may be made which shall insulate the lamp from its bracket, crutch
or other support and shall at the same time allow the cables, conveying current to
and from the lamp to pass through it so that they are neatly enclosed and
protected.
In carrying out my invention I arrange to provide the top of the arc lamp case,
which is usually a casting of disc or dome form, with a hole with or without a neck.
Into this hole I fit two cylindrical flanged bushes preferably one being put in from
the outside and the other from the inside of the arc lamp case. These bushes are
made of stoneware, glass, porcelaiu or other reliable insulating material which will
not be affected by moisture or heat.
Through the central hole in these insulating bushes is passed a central tube o£
metal screwed and fitted with a nut at each end. These nuts are screwed together
so as to hold tightly between them the two insulating bushes and the top of the arc
lamp case this top being between the two insulating bushes. The insulating bushes
keep the top of the arc lamp case from electrical contact with the central tube.
The central tube may be left projecting beyond the nut outside the arc lamp
case so that the arc lamp may be attached by means of this central tube to the
bracket or other support, or this attachment may be made to the outside nut
instead of to the central tube. Instead of providing two nuts one at each end of
the central tube I may provide a flange at one end and a nut at the other the
flange being inside the lamp case and the nut outside or vice versa. The nut on the
outside of the arc lamp case if used also may instead of being a separate piece,
form part of the bracket or other support to which the arc lamp is attached. The
two insulating bushes may be fixed to the top of the arc lamp case by cement or
similar material or they may lie loose therefrom and only kept in position by means
of the central tube with its nuts or flanges. The flanges of the insulating bushes
I prefer to extend all round to form what is known as a "shed" in ordinary
telegraph line insulators the object of this shed being to increase the exposed surface
of the insulating bush and so reduce the surface leakage of electricity. Instead
of two insulating bushes with flanges as above described one may be used in
conjunction with an insulating disc, and other modifications embodying the same
principle may be made..
Through the central tube the conductors conveying the current to and from the
lamp may be passed.

page_text: Improvements in Electric Arc Lamps and their Connections.
I ROOKES EVELYN BELL CROMPTON, Engineer, of Arc Works, Chelmsford,
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
The invention relates to improvements in the method of and means or apparatus
for connecting electric are lamps to their supports and sources of electrical energy.
My invention has for its object mainly to effect improvements in the method of
attaching arc lamps to brackets, crutches, or similar supports, so that a strong and
effective joint may be made which shall insulate the lamp from its bracket, crutch,
or other support and shall at the same time allow the cables, conveying current
to and from the lamp, to pass through it so that they are neatly enclosed and
protected.
In carrying out my invention I arrange to provide the top of the arc lamp case,
which is usually a casting of disc or dome form, with a hole with or without a
neck.
Into this hole I fit two cylindrical flanged bushes B₁ B" see Fig. 1-one being
put in from the outside and the other from the inside of the arc lamp case.
These
bushes are made of stoneware, glass, porcelain or other reliable insulating material
which will not be affected by moisture or heat.
Fig. 1 shows the apparatus by a sectional view and Fig. 2 by a plan view.
Through the central hole of these insulating bushes is passed a central tube of
metal C screwed and fitted with a nut d' d at each end.
These nuts are screwed together so as to hold tightly between them the two
insulating bushes B₁ B" and the top of the arc lamp case a this top being between
the two insulating bushes. The insulating bashes keep the top of the arc lamp
case from electrical contact with the central tube C. The central tube may be
left projecting beyond the nut d outside the arc lamp case so that the arc lamp may
be attached by means of this central tube to the bracket or other support, or this
attachment may be made to the outside nut instead of to the central tube.
Instead of providing two nuts one at each end of the central tube I may provide
a flange at one end and a nut at the other the flange being inside the lamp case and
the nut outside or vice versa.
The nut on the outside of the are lamp case if used also may instead of being a
separate piece, form part of the bracket or other support to which the arc lamp is
attached.
The two insulating bushes may be fixed to the top of the are lamp case by
cement e or similar material or they may lie loose therefrom and only kept in
position by means of the central tube with its nuts or flanges. The flanges of
the insulating bushes I prefer to extend all round to form what is known as a
"shed" in ordinary telegraph line insulators, the object of this shed being to
increase the exposed surface of the insulating bush and so reduce the surface
leakage of electricity. Instead of two insulating bushes with flanges as above
described one may be used in conjunction with an insulating disc, and other
modifications embodying the same principle may be made. Through the central
tube the conductors conveying the current to and from the lamp. may be passed.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is: :―
1. The improvements in the method of attaching are lamps to brackets, crutches,
or similar supports, so that a strong and effective joint may be made which shall

page_text: insulate the lamp from its bracket, crutch, or other support, and shall at the same
time allow the cables, conveying current to and from the lamp to pass through
it so that they are neatly enclosed and effectively protected substantially as
set forth.
2. In insulating are lamps the combination of an internal and external insulating
washer formed and arranged substantially as herein described.
Dated the 6th day of November 1895.
WM. BROOKES & SON,
55 & 56 Chancery Lane, London, Agents for the Applicant.