IMPROVEMENTS IN STREET AND OTHER LAMPS
Year: 1881

page_text: LETTERS PATENT to Arthur Wood Calvert, of Leeds, in the County of York,
Tin, Iron, and Copper Plate Worker, for an Invention of "IMPROVEMENTS
IN STREET AND OTHER LAMPS."
PROVISIONAL SPECIFICATION left by the said Arthur Wood Calvert at the
Office of the Commissioners of Patents on the 5th October 1881.
ARTHUR WOOD CALVERT, of Leeds, in the County of York, Tin, Iron, and
Copper Plate Worker. "IMPROVEMENTS IN STREET AND OTHER LAMPS."
My Invention has for object improvements in street and other lamps.
In a lamp according to my Invention I provide around and above the bottom a
double row of perforated plates of metal or other suitable substance for the
admission of an atmospheric current or currents to supply air to the flame, the
inner row having finer or smaller perforations than the outer row, and place
around the inside thereof wire gauze in order that the air may on entering the
lamp be subdivided into small jets or streams.
In order that the air may not approach the illuminating flame in a large
volume, I place a cup or baffler on and around the supply pipe below the burner
to conduct or direct air to the flame as required, thereby feeding the flame regularly
and insuring the steady burning thereof. The bottom of the lamp I prefer to be
in one piece of glass or other transparent material, so as not to impede the
distribution of the light downwards. The staves of the lamp frame I make
hollow, the lower end of each being open so as to admit a small current of air, and
near the top of each stave I form an opening in communication with the interior
of the lamp, so that such current of air will enter the lamp, mix with the products
of combustion, and assist in expelling theun through the usual ventilator provided
at the top of the lamp.
The sides, the lower part, and the upper part or roof I form of clear glass, and
above and outside the glass of the upper part or roof I provide reflectors in sections,
having either corrugated or plain surfaces on their under sides, and with darkened
upper surfaces so as to prevent light passing upwards. These reflectors may be of

page_text: any suitable material, and being outside the glazing of the lamp are not so liable
to become smoked or tarnished as those which of themselves form the upper part
of the lamp. The reflectors may project down beyond the sides of the lamp in an
eaves-like form or otherwise as desired. The space between them and the glass of
the upper part of the lamp is open to the interior of the lamp near the apex, thus
forming an additional means of supplying air to the interior to keep in motion
and assist in expelling the products of combustion and vitiated air.
The reflectors are hinged at their upper ends to the lamp frame and around the
ventilator, and are secured at their lower parts to the frame work to prevent their
being moved about by the wind.
When it is required to clean the upper part of the lamp and the reflectors, the
latter may be easily lifted up around the hinge joints for the purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Arthur Wood Calvert in the Great Seal Patent Office on the
3rd April 1882.
ARTHUR WOOD CALVERT, of Leeds, in the County of York, Tin, Iron, and
Copper-plate Worker. "IMPROVEMENTS IN STREET AND OTHER LAMPS."
My Invention has for its object improvements in street and other lamps.
In a lamp according to my Invention I provido around and above the bottom a
double row of perforated plates or sides of metal or other suitable substanco, the
perforations being for the admission of atmospheric currents to supply a necessary
amount of air to the flame, the inner row having finer or smaller perforations than
the outer row, and I place around the inside thereof wire gauze in order that the
air entering the lamp may be subdivided into small jets or streams.
In order that the air may not approach the illuminating flame in a large volume,
I place a transparent cup, baffler, or deflector on and around the supply pipe below
the burner or burners, of such form as to conduct, direct, or deflect the said air to
the flame as required, thereby feeding the flame regularly and ensuring the steady
burning thereof. The bottom of the lamp I prefer to make in one piece of glass or
other transparent material so as not to impede the distribution of the light down-
wards. The staves of the lamp frame I make hollow, the lower end of each being
open so as to admit a small current of air, and near the top of each stave I form
an opening in communication with the interior of the lamp, so that such current of
air will enter the lamp, mix with the products of combustion, and assist in
expelling or removing them through the usual ventilator provided at the top of
the lamp. The sides, the lower part, and the upper part or roof I form of clear
glass, and above and outside the glass of the upper part or roof I provide reflectors
in sections, having either corrugated or plain surfaces on their under or reflecting
sides, and darkened or opaque upper surfaces so as to prevent light passing upwards.

page_text: These reflectors may be of any suitable material, and being outside the glazing of
the lamp are not liable to become smoked or tarnished, as arc those which of
themselves form the upper part or roof of the lamp. The reflectors may project
down beyond the sides of the lamp in an caves-like form or otherwise as desired,
the space between them and the glass of the upper part of the lamp is in commu-
nication with the interior of the lamp near the apex, thus constituting an additional
means of supplying air to the interior to keep in motion and assist in expelling or
removing the products of combustion and vitiated air. The reflectors are hinged
at their upper ends to the lamp frame and around the ventilator, and are secured
at their lower parts to the framework to prevent their being moved about by the
wind. When it is required to clean the upper part of the lamp on the outside and
the surface of the reflectors, the latter may be easily lifted up around the hinge
joints for the purpose.
Referring to the accompanying Sheet of explanatory Drawings, in which similar
letters represent similar parts, Fig. 1 is an elevation; Fig. 2 is a vertical section on
the line 1, 1, Fig. 4; Fig. 3 is a vertical section on the line 2, 2, Fig. 4, shewing
one half of the lamp; Fig. 4 is a plan of the bottom frame; Fig. 5 is an enlarged
vertical section of the same showing the outer and inner perforated plates or sides,
and the wire gauze in position. Figs. 6 and 7 are elevations shewing portions
respectively of the outer and of the inner perforated plates; Fig. 8 is an enlarged
cross section of one of my improved hollow staves shewing the attachment of the
glass thereto. a is the bottom frame of the lamp; b, b, are the outer perforated
plates around the same, the perforations being for the admission of air in a hori-
zontal direction immediately above the glazed bottom, as indicated by the arrows,
which air passes on through perforations of the inner plates c, which perforations.
are smaller than those in b. d is wire gauze with fine meshes that is fixed
around the inside of the said inner plate c. The said perforations of the inner
plate and the wire gauze are for the purpose of dividing the volume of air passing
into the lamp into small currents which in their course impinge against the outer
surface of the cup, baffler, or deflector e, Figs. 2, 3, and 4; this has the effect of
diverting the said currents upwards, as indicated by the arrows fand ƒ³, and in so
gentle a manner as to ensure a steady burning of the gas flame; the cup, baffler, or
deflector e being of glass offers no impediment to the light in a downward
direction. The products of combustion pass out in the usual manner through the
ventilator or chimney which may be such as is generally provided for the purpose,
and as shewn by the arrows g. h, h, are the staves or framework of the lamp, the
interiors of these staves are formed of metallic tubes, as shewn clearly in Fig. 8, an
enlarged cross-section thereof, where 3 is the metal tube, and 4 is the metal
(preferably copper) surrounding the same. Through each of the said tubes of the
staves a current of air passes upwards and (through a slit or opening h' provided
in the covering of the tubes) into the interior of the lamp; this air acts as an
auxiliary in removing the products of combustion, as indicated by the arrows j.
i are the side sheets of glass. The roof of the lamp is glazed with clear glass k.
I are reflectors of silvered glass or other suitable material which are placed outside
of or over the whole glazed portion of the roof; the frames for carrying the said
reflectors are formed of metal, and hinged at their upper parts to a fixed portion of
the framework at m, and when in position for use are secured by hasps n to loops
or staples in the framework. Through the space between the glass roof and the
said reflectors air passes, part of which enters the interior of the lamp at o, and
aids in the removal of the aforesaid products of combustion, the other part passes
on through conductors p provided for the purpose, and as shewn by the double
arrow and arrows ; this air tends to keep the upper part of the lamp cool, and
the isolation of the said reflectors from the products of combustion prevents them
from becoming fouled therewith, and when by the action of the atmosphere their
brilliancy becomes affected they may be turned up, as shewn by the dotted lines
at q, for the purpose of being cleaned.
Having described the nature of the said Invention, and the manner of carrying

page_text: the same into practical effect, I would have it understood that what I consider to
be novel and original, and therefore claim as secured to me by the Letters Patent
herein before in part recited is,-
1. In a lamp, providing for admission of air by constructing the lower part of
the lamp above the bottom thereof with outer and inner perforated plates or sides,
the perforations of the inner plate or plates being smaller than those of the outer
plate or plates, substantially as and for the purpose hereinabove described and set
forth.
2. In a lamp, the use in combination of perforated plates or sides at the lower
part of the lamp above the bottom thereof, and wire gauze of fine mesh, such
gauze being arranged within the said perforated plates or sides so as to further
divide the air on its way to the flame, substantially as and for the purpose herein-
above described and set forth.
3. In a lamp, the use in combination, of perforated plates or sides and wire
gauze, as referred to in Claim 2, and a transparent cup, baffler, or deflector, as and
for the purpose heroin-before described and set forth.
4. In a lamp, the use of staves constructed with metallic tubes therein, and so
as to conduct air into the interior of the lamp, as herein-before described and
shewn.
5. Providing a lamp with reflectors arranged above and outside of the glazed
roof of such lamp, substantially in the manner and for the purpose hereinbefore
described and set forth.
6. The method of mounting and securing the metallic frames of the reflectors
outside the roof of the lamp, as and for the purposes hereinbefore described and set
forth.
7. The improved lamp, constructed, arranged, and operating as shewn in the
Drawings, and hereinabove described.
In witness whereof, I, the said Arthur Wood Calvert, have hereunto set my
hand and seal, this Twenty eighth day of March, in the year of our Lord
One thousand eight hundred and eighty two.
Witness to the signature of the
said Arthur Wood Calvert,
THOS. E. CRAVEN, C.E.,
Patent Agent,
24, Victoria Chambers,
South Parade,
Leeds.
ARTHUR WOOD CALVERT. (L.S.)