Improvements in Candle Lamps for use in Photographic Dark Rooms and for other uses.
Year: 1891

page_text: Date of Application, 10th Mar., 1891
Complete Specification Left, 19th June, 1891-Accepted, 25th July, 1891
PROVISIONAL SPECIFICATION.
Improvements in Candle Lamps for use in Photographic Dark Rooms
and for other uses.
We, HERBERT AUGUSTUS BENHAM and WILLIAM HOPKINS TOмSON both
Managing Directors of Benham and Froud Limited of Chandos Metal Works
Chandos Street Strand in the County of Middlesex Art Metal Workers and
Manufacturers do hereby declare the nature of this invention to be as follows:-
:-
The invention relates to improvements in that class of lamp consisting of a
"reflecting reading lamp" closed at the front with a disc of suitably coloured glass
in order to adapt it to the requirements of the photographic dark room and to other
uses wherein a non actinic or screened light is desirable and the objects of the
present invention are to simplify some of the constructive details of and therefore to
cheapen the lamp, to provide an efficient means for freely admitting a supply of air
in excess of that actually required to support combustion, in order to keep cool the
parts adjacent to the candle whilst obstructing the passage of any rays of light
issuing from the lamp and to render the lamp capable of compression into a
comparatively small compass for transport.
For this purpose we cover the front of the reflecting hood with a disc of ruby or
other non actinic glass as heretofore proposed but we fit this disc of glass into the
front of the hood against a bead or shoulder and hold it in its place by means of an
annular ring or cap of U shaped section which fits tightly upon the rim of the hood
and when the lamp is not in use we in order to protect the glass cover the front
thereof with a metal cap which at other times constitutes the foot or base of the
lamp as hereinafter described.
The foot or base of the lamp is formed hollow to fit upon the ring or cap of the
hood and with a central apertured rise constituting a socket to receive and hold the
lower end of the candle tube which constitutes the stem of the lamp and is formed
with a rim or shoulder adapted to rest upon the wall of the socket.
We provide the upper part of the candle tube with a candle cone or burner
consisting of a flat ring supported upon short studs or projections from the candle
tube or stem as we find that such arrangement materially assists the steady burning
of the flame of the candle.
The hood is formed with a downwardly extending short tube of a diameter con-
siderably larger than the candle tube and which at its upper part extends into the
hood in the manner well understood whilst at its lower part its diameter is increased
so as to form an annular chamber.
Into this annular chamber we insert a ring or fitting formed like an annular
trough the inner wall of which is prolonged and adapted to fit and slide upon the
candle tube whilst the outer wall is formed shorter than the depth of the annular
chamber and of slightly smaller diameter than the wall thereof so as to leave an
air passage between the parts and the outer wall of the ring or fitting is provided
with several ribs or distance pieces disposed vertically around the exterior thereof
and shaped to tightly fit the annular chamber but so that the ring or fitting will be
easily separable therefrom.
By this arrangement of parts an air passage of large area is provided between the
ring or fitting and the annular chamber and a current of air of considerable volume
is thus caused to pass upward between the candle tube and the short descending
tube of the hood and those parts are thus efficiently maintained in the cool condition
necessary to prevent the candle becoming unduly softened whilst any rays of light
from the flame of the candle will strike down into the annular trough of the ring
or fitting which presents a very extended surface blackened in the manner well

page_text: understood and in order to escape the rays would then require to rise over the outer
wall of the trough and descend between that wall and the wall of the annular
chamber.
Any suitable form of chimney may be employed which will allow a free exit to
the products of combustion and obstruct any rays of light from the flame but we
prefer to employ a short chimney having somewhat the shape of an inverted
truncated cone and we fit the top of this chimney with a dwarf cap provided with a
central aperture therein and we insert within the chimney a loose ring to support a
notched deflector or screen.
When a white light is required the rim or cap and glass may be removed from
the front of the hood or the hood may be removed bodily from the candle tube.
When it is desired to compact the lamp for transport the candle tube is telescoped
within the hood when the height of the lamp will be much reduced whilst the foot
or base may be detached and placed over the front of the hood as a cap or cover to
protect the glass.
Dated this 10th day of March 1891.
WHITE & WOODINGTON,
27, Southampton Buildings, London, Agents.
COMPLETE SPECIFICATION.
Improvements in Candle Lamps for use in Photographic Dark Rooms
and for other uses.
We, HERBERT AUGUSTUS BENHAM and WILLIAM HOPKINS TOMSON both
Managing Directors of Benham and Froud Limited of Chandos Metal Works
Chandos Street Strand in the County of Middlesex Art Metal Workers and
Manufacturers 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 that class of lamp consisting of a
"reflecting reading lamp" closed at the front with a disc of suitably coloured glass
in order to adapt it to the requirements of the photographic dark room and to other
uses wherein a non-actinic or screened light is desirable and the objects of the
present invention are to simplify some of the constructive details of and therefore to
cheapen the lamp to provide an efficient means for freely admitting a supply of air
in excess of that actually required to support combustion in order to keep cool the
parts adjacent to the candle whilst obstructing the passage of any rays of light
issuing from the lamp and to render the lamp capable of compression into a
comparatively small compass for transport.
For this purpose we cover the front of the reflecting hood with a disc of ruby or
other non-actinic glass as heretofore proposed but we fit this disc of glass into the
front of the hood against a bead or shoulder and hold it in its place by means of an
annular ring or cap of U shaped or equivalent section which fits tightly upon the
rim of the hood and when the lamp is not in use we in order to protect the glass
cover the front thereof with a metal cap which at other times constitutes the foot or
base of the lamp as hereinafter described.
The foot or base of the lamp is formed hollow to fit upon the ring or cap of the
hood and with a central apertured rise constituting a socket to receive and hold the
lower end of the candle tube which constitutes the stem of the lamp and is formed
with a rim or shoulder adapted to rest upon the wall of the socket.
We provide the upper part of the candle tube with a candle cone or burner
consisting of a flat ring supported upon short studs or projections from the candle tube
or stem as we find that such arrangement materially assists the steady burning of
the flame of the candle.
The hood is formed with a downwardly extending short tube of a diameter con-
siderably larger than the candle tube and which at its upper part extends into the

page_text: and hold the lower end of the candle tube b which constitutes the stem of the
lamp and is formed with a bead or shoulder b' adapted to rest upon the wall of the
socket a².
The candle 69 is inserted into the candle tube 6 from the lower end thereof and
is forced upward by means of a spring 62 held in place by a screw plug 63 as is well
understood and the upper part of the candle tube b is provided with a candle_cone
or burner consisting of a flat or cupped ring 6 supported upon short studs or
projections 6 from the candle tube or stem b as it is found in practice that such
arrangement materially assists the steady burning of the flame of the candle.
The hood c is formed with a downwardly extending short tube ³ of a diameter
considerably larger than the candle tube band which at its upper part extends into
the hood c in the manner well understood whilst at its lower part its diameter is
increased so as to form an annular chamber c¹.
Into this annular chamber c is inserted a ring or fitting e formed like an annular
trough the inner wall e¹ of which is prolonged and furnished with a split ring el*
and is thus adapted to fit and slide upon the candle tube b whilst the outer wall e³ is
formed shorter than the depth of the annular chamber and of slightly smaller
diameter than the wall * thereof so as to leave an air passage between the parts
and the outer wall e' of the ring or fitting e is provided with several distance pieces e³
formed of strips of metal which are at one end fixed to the outer wall e2 of the ring
or fitting e and the other ends of which are turned over to form springs and shaped
to tightly fit the annular chamber whilst they are slightly bent outwards at their
ends e* to engage an annular groove or depression *** formed in the wall c✶ of
the annular chamber c so that the ring or fitting e will be securely held in place
but with capability of easy removal.
By this arrangement of parts an air passage of large area is provided between the
ring or fitting e and the wall of the annular chamber e and a current of air of
considerable volume is thus caused to pass upward between the candle tube b and
the short descending tube 3 of the hood c and those parts are thus efficiently main-
tained in the cool condition necessary to prevent the candle becoming unduly
softened whilst any rays of light from the flame of the candle will strike down into
the annular trough of the fitting or ring e which presents a very extended surface
blackened in the manner well understood and will thus be efficiently trapped as in
order to escape the rays would require to rise over the outer wall of the trough
and then descend between that wall and the wall c* of the annular chamber c*.
Any suitable form of chimney may be employed which will allow a free exit to
the products of combustion and obstruct any rays of light from the flame of the
candle but in the course of our experiments we have found the following simple
arrangement of parts to answer well.
represents a short tube of large diameter rising from the upper part of the
hood c and formed with an enlargement or shoulder c at its upper part upon which
is loosely placed a deflector or screen c' shaped like an inverted cone and formed
with a downwardly projecting notched or scalloped ring c* which rests upon the
shoulder c and whilst supporting the cone shaped deflector or screen c' also affords
a free passage to the current of air and products of combustion passing through the
tube or chimney c³.
The top of the chimney c is fitted with a dwarf cap e8 provided with a central
aperture therein which occupies a position over the hollow or depression of the
cone shaped deflector c' and thus affords an efficient egress for the air and products
of combustion whilst at the same time it assists to obstruct the passage of any rays
of light from the flame of the candle.
When a white light is required the ring or cap d and glass do may be removed
from the front of the hood c or the hood may be removed bodily from the candle
tube b.
When it is desired to compact the lamp for transport the candle tube b is telescoped
within the hood c as represented at Figure 2 when the height of the lamp will be
much reduced whilst the foot or base a may be detached from the candle tube b and

page_text: placed over the front of the hood c as a cap or cover to protect the glass d* as
herein before described.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what
we claim is :-
1. In a candle lamp of the character herein described a base or foot formed
detachable from the candle tube or stem and adapted to fit upon the front of the
hood substantially as herein shown and described.
2. In a candle lamp of the character herein described the combination of a foot
or base formed with a socket and a candle tube formed at its lower end with a flange
or bead or its equivalent and adapted to fit the socket substantially as herein shown
and described.
3. In a candle lamp of the character herein described an annular ring or cap
Ushaped or equivalent section adapted to fit upon the rim of the hood and over-
lap the edge of the glass disc substantially as herein shown and described and for
the purpose stated.
4. In a candle lamp of the character herein described the combination of a hood
provided with a screened chimney or out-let for the products of combustion a short
descending tube of large diameter carried by such hood and formed with an enlarge-
ment at its lower end, a candle tube and a fitting formed to slide upon the candle
tube and removably fit such enlargement leaving an air space between the parts
but so as to obstruct the passage of any rays of light from the flame substantially
as herein shown and described and for the purpose stated.
5. In a candle lamp of the character herein described the combination with the
hood of a short descending tube of large diameter formed with an enlargement
constituting an annular chamber at its lower end, a cardle tube and a fitting formed
like an annular trough the inner wall of which is adapted to fit and slide upon the
candle tube whilst the outer wall is formed shorter than the depth of the annular
chamber and of less diameter and is fitted with ribs or distance pieces substantially
as herein shown and described and for the purpose stated.
6. The general combination and arrangement of parts constituting a candle lamp
substantially as herein shown and described.
Dated this 19th day of June 1891.
WHITE & WOODINGTON,
27, Southampton Buildings, London, Agents.