Improvements in Lamps for Overhead Lighting.
Year: 1895

page_text: Date of Application, 7th Jan.,
1895
Complete Specification Left, 7th Oct., 1895-Accepted, 7th Feb.,
1896
Improvements in Lamps for Overhead Lighting.
I, THOMAS COOPER JOHN THOMAS, of 93 Manor Park Road, Harlesden, in
the County of Middlesex, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to a construction of overhead gas lamp that may
advantageously be used for burning oil-gas in railway carriages, whilst also
applicable for burning ordinary coal gas, in the same or other situations. According
thereto the reflector at the top of the lamp bowl is provided with one or more
inwardly projecting flat flame burners or nibs above which, or each of which, air
inlets are provided in the reflector, the arrangement being such that when the
lamp is burning, air will issue through the said air inlets and impinge upon the
upper surface of the flame extending from the gas burner or from each burner
when two or more are used, and impart a curved form to such flame and direct it
towards an exit opening or openings formed in the top or upper part of the
reflector. The air inlet openings are protected by a baffle or guard that may be of
truncated conical form and be secured to the reflector so as to carry the lamp
chimney, the arrangement being preferably such that the air supplied to the flame
will not be heated to any considerable extent. The burner, or each burner, is in
connection with a gas box that is or may be arranged to be cooled by the inflowing
air. The upper part of the reflector may be provided at the underside with one or
more baffles arranged to prevent or check air issuing through the air inlets in the
reflector, from passing direct to the chimney without impinging upon the upper
surface of the flame. Air inlet openings may be formed in the outer portion of
the reflector for supplying air to cool the lamp bowl and to the under surface of
the flame.
My invention may be applied in connection with reflectors of various forms and
having one or more gas exit openings arranged in various ways.
In one construction the outer portion of the reflector is of truncated conical
form, the central portion to which the burner or burners is or are secured and in
which the air inlet openings are provided, being made of pyramidal form and
terminating in an exit opening located at the bottom of the chimney.
In another arrangement the reflector which may be of conical shape is provided
in its central part which may be of dome, cone or dish-like form with an annular
row or rows of holes in lieu of a large central exit opening.
Dated this 7th day of January 1895.

page_text: Improvements in Lamp's for Overhead Lighting.
I, THOMAS COOPER JOHN THOMAS, of 93 Manor Park Road, Harlesden, in
the County of Middlesex, Engineer, 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 :-
This invention has reference to a construction of overhead gas lamp that may
advantageously be used for burning oil-gas in railway carriages, whilst also
applicable for burning ordinary coal gas in the same or other situations.
In the accompanying drawings,
Fig. 1 shews, in vertical section, a railway carriage roof lamp constructed
according to this invention; and
Fig. 2 is a plan of the reflector and attached parts used in such lamp;
Fig. 3 is a part vertical section of the lamp taken in a plane at right angles to
Fig. 1 and
Fig. 4 is a section on the line a x of Fig. 1.
The reflector 1 at the top of the lamp bowl 2 is provided with inwardly projecting
flat flame burners or nibs 3 above which air inlets 4, in the form of curved slots, are
provided. The outer portion of the reflector is of a flattened truncated conical form,
the central portion, to which the burners or nibs 3 are secured, and in which the
air inlet openings 4 are provided, being made of pyramidal form as shewn or of
equivalent form, for example conical, and terminating in an exit opening 5 located
at the bottom of the chimney 6.
The reflector may advantageously be made in two parts as shown, the upper
part being of cast metal and the lower part to which the enamel to form a
reflecting surface is applied, being of sheet metal stamped to shape and suitably
secured as by screws, to the upper part.
The air inlets 4, which may advantageously be each formed by a short pipe or
passage 4 of plano-convex form in cross section (see Fig. 4), are protected by a
baffle or guard 8 that may be of truncated conical form as shown, and be secured
to the chimney 6, and which is fitted upon the upward extension 1 of the reflector
in which the exit opening 5 is formed. To further aid in steadying the current of
air flowing through each opening 4, one or other side of the tube 4ª constituting
such opening may be perforated as shown, in which case the baffle or guard 8
may rest upon the end of the tube. Or both sides of the said tube may be thus
perforated. The perforated side or sides of the tube may be formed by a
separate detachable piece or pieces of perforated sheet metal that is or are
confined in place by the baffle or guard 8. As will be seen the arrangement is
such that the air supplied to the flames will not be heated to any considerable
extent. Each burner or nib 3, which is or may be of a form now commonly
used for burning oil gas, is in connection with.a gas box 9 that may, as shown,
be arranged to be cooled by the inflowing air, so that the lamp can be used for
burning oil gas. The gas box is connected with the main gas supply pipe 10
by a pipe 11 pivoted thereto, so as to allow of the reflector and attached parts
being swung out of the lamp casing for cleaning or other purposes as well
understood.
By the construction described, when the lamp is burning, air will issue through
the said air inlets and impinge upon the upper surface of the flame extending
from each burner, thereby imparting a curved form to such flame and directing
it towards the central exit opening 5. The air entering the hollow central or
pyramidal portion of the reflector also serves to prevent contact between this
portion of the reflector and the flames and thus prevent the reflector from being
blackened by smoke.

page_text: The upper central part of the reflector 1 may, as shown in dotted lines, be
provided at its underside with baffles 12 arranged to prevent or check air issuing
through the air inlets 4 in the reflector, from passing direct to the chimney 6
without impinging upon the upper surface of the flame. Usually however these
baffles will be found unnecessary. 13 are air inlet openings in the outer portion of
the reflector for supplying air to the underside of the flame and for cooling the lamp
bowl 2. 14 is a sliding ring for closing the annular opening between the reflector
and the lamp bowl, as described in the Specification of my Patent No. 5865
of 1893.
As will be obvious gas lamps according to my invention may be constructed with
only one burner or nib 3 and air inlet 4, or with more than two such burners or nibs
and air inlet openings.
Having now particularly described and ascertained the nature of the said inven-
tion I declare that I do not claim broadly supplying air through holes in the
reflector to the upper part of a flame but what I claim is :-
1. In a lamp of the kind referred to, constructing the reflector with a central
recessed portion of pyramidal or equivalent shape as set forth, with inlets or inlet
therethrough, and burners or burner below, the arrangement being such that a
curved form is imparted to the flame substantially as herein before described with
reference to the drawings.
2. My improved lamp as described and shewn.
Di 1
Ր
1007
W. Lloyd Wise,
T. C. J. THOMAS.
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.