IMPROVEMENTS IN ROOF LAMPS OF RAILWAY AND OTHER CARRIAGES
Year: 1864

page_text: LETTERS PATENT to John Strafford, of Waddington Place, Stratford,
in the County of Essex, Lamp Manufacturer, for the Invention of
"IMPROVEMENTS IN ROOF LAMPS OF RAILWAY AND OTHER CARRIAGES."
Sealed the 16th September 1864, and dated the 23rd March 1864.
PROVISIONAL SPECIFICATION left by the said John Strafford at the
Office of the Commissioners of Patents, with his Petition, on the
23rd March 1864.
I, JOHN STRAFFORD, of Waddington Place, Stratford, in the County of
Essex, Lamp Manufacturer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN ROOF LAMPS OF RAILWAY AND OTHER CARRIAGES," to be as
follows:-
The improvements in roof lamps of railway and other carriages relate, first,
to holding the glass in position by spring pressure. For this purpose the
rim of the glass rests on a flange of the inner case of the lamp. India-rubber
or other elastic material being placed to enclose or surround the glass rim
and within the inner case of the lamp. Springs with india-rubber or other

page_text: elastic material are applied to the inner case of the lamp to rest endways on
the rim of the glass. By these means facility is obtained for the replacement
of glasses.
Secondly, the improvements relate to means of controlling the passage of
the air admitted into the lamp for the purpose of supporting combustion and
for keeping the oil cool. For this purpose the annular space between the
inner and outer cases of the lamp is provided with partitions, which are by
preference placed horizontally and serve to divert the air and prevent it from
passing direct to the interior of the lamp, by which flickening of the light is
avoided. The openings in the inner case for the passage of the air serve also
to admit the springs for holding the glass. The rim supporting the interior
reflector is formed with long vertical slits or openings to admit air between
the reflector, the chimney, and the oil vessel to keep the oil cool; or this rim
may be reduced so that the reflector and chimney are supported from the oil
vessel by stays. Increase of reflecting power-is also obtained by silvering or
enamelling the under edge of the metal rim attached to the outer case of the
lamp for the purpose of strengthening-it at.its.lower edge.
The improvements also relate to forming the interior surface of the glass of
such, lamps inclined or:.conical from the bottom to the side surface thereof,
leaving the exterior curved or, of other desired figure..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Strafford in- the Great Seal Patent Office on the
23rd September 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
STRAFFORD, of Waddington Place, Stratford, in the County of Essex, Lamp
Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of March, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Strafford, Her special licence that I, the said John
Strafford, my executors, administrators, and assigns, or such others as I, the
said John Strafford, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,

page_text: use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN ROOF LAMPS OF RAILWAY AND OTHER CARRIAGES," upon the condition
(amongst others) that I, the said John Strafford, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Strafford, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
!י
The improvements in roof lamps of railway and other carriages relate, first,
to holding the glass in position by elastic pressure. For this purpose the rim
of the glass rests on a flange of the inner case of the lamp. India-rubber or
other elastic material being placed to enclose or surround the glass rim and
within the inner case of the lamp. Springs with india-rubber or other elastic
material are applied to the inner case of the lamp to rest end ways on the rim
of the glass. By these means facility is obtained for the replacement of
glasses.
こ
4
Secondly, the improvements relate to means of controlling the passage of
the air admitted into lamp for the purpose of supporting combustion and for
keeping the oil cool. For this purpose the annular space between the inner
and outer cases of the lamp is provided with partitions which are by preference
placed horizontally, and serve to divert the air and prevent it from passing
direct to the interior of the lamp, by which flickering of the light is avoided.
The openings in the inner case for the passage of the air serve also to admit
the springs for holding the glass. The rim supporting the interior reflector is
formed with long vertical slits or openings to admit air between the reflector,
the chimney, and the oil vessel to keep the oil cool, or this rim may be reduced
so that the reflector and chimney are supported from the oil vessel by stays.
Increase of reflecting power is also obtained by silvering or enamelling the
under edge of the metal rim attached to the outer case of the lamp for the
purpose of strengthening it at its lower edge.
J.
.:.
In order that the improvements may be fully understood I will by the
aid of the accompanying Drawing proceed to describe the same more in
detail.

page_text: DESCRIPTION OF THE DRAWING.
Figure 1 shows a section and Figure 2 an external view of a roof lamp
with my improvements applied to it; Figures 3 and 4 are horizontal sections
taken respectively through the line A, A, and B, B, of Figure 1.
a, a, is the outer case or frame of the lamp; b is the glass which is formed
with a flange 6', which when the glass is passed downwards through the inner
case a rests on the rim a¹ of that case, but with india-rubber c or other suitable
material at intervals between the rim 6 of the glass and the flange or rim a
to prevent injury to the glass and to allow of its expansion and contraction, as
well as to obtain a firmer holding of it. These pieces of india-rubber c are
attached to and hang from the metallic springs d, the lower ends of which
have applied to them other pieces of india-rubber d', adapted to come over and
rest upon the upper edge or rim 6 of the glass b to prevent it from being
pushed upwards out of its place from the under side when in use, whilst they
admit of the glass being removed and replaced when those springs are acted
upon by pressure on them from the inside of the case. These springs d are
applied to the inner case a³ of the lamp. Air from the exterior of the lamp
in passing into the interior thereof for the purpose of supporting combustion,
as well as for keeping the oil in the oil vessel e cool, passes first under the
screen thence through a series of smaller holes g to the annular space
between the outer case a and the inner case a³, and this space is provided with
horizontal partitions as serving to divert the air and prevent it from passing
too freely direct to the interior of the lamp. The air passes these partitions
at the spaces between them a, a, a', and thence from the lower part of this
space between the outer case a and the inner case a³ it passes by the openings a³
formed in the inner case a² to admit of the free action of the springs d. The
air thence passes partly downwards to the flame without causing flickering, and
partly through the long vertical slits or openings h between the reflector i, the
chimney j, and the oil vessel e, with a tendency to- keep the oil vessel cool.
In order to obtain increase of reflecting power I silver or enamel the under
side of the metal rim a'. Figure 5 shows by a separate view of parts the
reflector i formed with a narrow rim , and it is supported by stays i² from the
under side of the oil vessel e.
Having thus described my said improvements, and means by which I carry
the same into effect, I would have it understood that what I claim is, first
the holding the glasses of roof lamps of railway and other carriages by elastic
pressure substantially as explained.

page_text: Secondly, I claim the means of controlling the passage of the air to the
interior of the lamp so as to prevent flickering of the light, and keep the oil in
the oil vessel cool, substantially as explained.
Also I claim the application of the rim a¹ for strengthening the lower edge
of the case of the lamp and by its being silvered or enamelled of obtaining
increased reflecting power, substantially as explained.
In witness whereof, I, the said John Strafford, have hereunto set my
hand and seal, this Twenty-third day of September, in the year of
our Lord One thousand eight hundred and sixty-four.
JOHN STRAFFORD. (L.S.)