Improvements in or connected with Enclosed Are Lamps.
Year: 1899

page_text: Date of Application, 4th Jan., 1899
Complete Specification Left, 3rd Oct., 1899-Accepted, 18th Nov., 1899
Improvements in or connected with Enclosed Are Lamps.
I, GEORGE THOMAS-DAVIES, of 53, Primrose Mansions, Battersea Park, in the
County of London, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention for improvements in or connected with enclosed arc lamps
has for its object to provide an improved means for fixing the enclosing bell
in position and in forming a valve for the escape of excessive pressure in the
enclosing bell.
In carrying out this invention, the glass bell is provided at its upper end
with a flange and is secured to a coned bush by a screw cap. The coned bush
fits in or around an annular conical extension of the crown plate and is drawn
up against the extension by bolts that are drawn upwards through the crown plate
by springs bearing against the crown plate. Eyes on the bolts engage below
lugs on the coned bush, in which lugs are formed slots for the accommodation
of the bolts, so that the bush and bell can readily be removed without removing
the bolts from the crown plate after disengaging them from the lugs. The conical
surfaces form an efficient valve that is practically air tight and that ensures the
bell shall resume the proper position.
1000
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.
Improvements in or connected with Enclosed Arc Lamps.
I, GEORGE THOMAS-DAVIES, Engineer, of 53, Primrose Mansions, Battersea Park,
in the County of London, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
This invention for improvements in or connected with enclosed arc lamps
has for its objects to provide an improved means for fixing the enclosing bell
in position and for facilitating the escape of excessive pressure in the enclosing
bell.
In carrying out this invention, the glass bell is provided at its upper end
with a flange and is secured to a coned bush by a screw cap. The coned bush
fits in or around an annular conical extension of the crown plate and is drawn

page_text: up against the extension by bolts that are drawn upwards through the crown plate
by springs bearing against the crown plate. Eyes on the bolts engage below
lugs on the coned bush, in which lugs are formed slots for the accommodation
of the bolts, so that the bush and bell can readily be removed without removing
the bolts from the crown plate after disengaging them from the lugs. The conical
surfaces form an efficient valve that is practically air tight and that ensures the
bell shall resume the proper position.
In the accompanying sheet of illustrative drawings, Figs. 1 and 2 are respec-
tively section and elevation of a part of an are lamp showing the enclosing
globe and its fittings constructed according to this invention.
The glass bell d is provided at its upper end with a flange d' and is secured
to the coned bush by a screw cap d. The coned bush fits on a conical
extension a¹ of the crown plate a and is drawn up against the extension a¹ by
the hooks that act on the lugs d and are drawn upwards by the springs de
bearing against the crown plate a. It will readily be seen that the conical
extension a¹, bush and spring hooks d form a valve that will allow any excess
pressure within the bell d to be relieved but that effectually prevents any ingress
of fresh air.
Each hook is formed with an eye on the lower end which hooks on to a
lug on the side of the screw cap d or as shown grips below and between two
luga d³ to facilitate unhooking and hooking the vessel in place as the finger, can
pass through the eye to remove the hook. Two hooks are shown one on either
side of the vessel at opposite ends of a diameter.
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. In an electric arc lamp, a bell surrounding the are, a conical metal bush
connected to the bell, a crown plate, a conical metal extension on the crown
plate adapted to fit in or on the conical metal bush, and springs drawing the
bush and extension together.
2. The improved fixing for the enclosing bell. of an electric arc lamp sub-
stantially as described with reference to the drawings.
Dated this 28th day of September 1899
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents,