Year: 1887

page_text: Date of Application, 13th May, 1887
Complete Left, 13th Feb., 1888
Complete Accepted, 11th May, 1888
We JAMES THORNE, Merchant and EBENEZER BANTON BURB, Engineer, both of
85 Gracechurch Street, in the City of London, do hereby declare the nature of this
invention to be as follows:-
Our invention relates to lenses and reflectors for lamps, and comprises improvements
whereby we provide for greatly increasing the illuminating power of a lamp.
It has been customary heretofore to use spherical lenses and spherical reflectors in
lamps for railway and other purposes, and to make and arrange the lens and reflector
without any special regard to the relative proportions thereof.
Now the object of our invention is to make the lens and reflector of such relative
proportions and to arrange them relatively to each other in such a manner as to obtain
much better results than heretofore with respect to both the intensity and the concen-
tration of the light.
In carrying our said invention into practice, we employ a parabolic, elliptic or other
lens or
bulls eye
in combination with a reflector of corresponding form and
dimensions, and we arrange the said lens and reflector relatively to each other in such
a manner that their foci correspond or coincide with each other, and the rays of light
concentrated by the reflector will pass through the lens and extend therefrom in a
direction parallel or nearly parallel to its axis.
We prefer to use a parabolic reflector and to make the lens in the shape of a para-
boloid, the height or abscissa of which is equal to that of the reflector minus the distance
from the light to the apex of the reflector. When the proportions of the lens and
reflector are determined upon this basis, it is evident that the greater the distance
between the light and the apex of the reflector, the less will be the height or abscissa
of the lens, or, in other words, the less acute will be the curvature of the lens.
When we use other forms of lenses and reflectors we proceed in substantially the
same manner

page_text: By reason of the peculiar formation and arrangement of our lens and reflector, we
are enabled to place the light and reflector nearer the lens than heretofore, and thus
economize space. Moreover, instead of the flame of the lamp being visible through
the lens as in lamps heretofore constructed, a lamp provided with our improved lens
and reflector presents the appearance of an illumined disc, the light appearing to have
substantially the same brilliancy over the entire compass or area of the lens; and the
said lamp throws out a beam of intense light which can be seen at a great distance
from the lamp.
Our improvements are applicable to all kinds of lamps which require lenses and
reflectors, whether oil, gas, electricity or other illuminating agent is used.
101
1
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements relating to Lenses and Reflectors for Lamps.
We, JAMES THORNE, Merchant, and EBENEZER BANTON BURR, Engineer, both of
85 Gracechurch Street, in the City 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 ascertained in and by the following statement:-
Our invention relates to lenses and reflectors for lamps for railway and other
purposes, and comprises improvements whereby we provide for greatly increasing
the illuminating power of such lamps.
It has been customary heretofore to employ spherical lenses and spherical
reflectors in signal-lamps for railway and other purposes, to increase their illu-
minating power; and such lenses and reflectors have usually been made and
arranged without any special regard to the relative proportions thereof.
Now the object of our invention is to make the lens and reflector of a lamp of
such form and relative proportions and to so arrange them relatively to each other
and to the light as to obtain much better results than heretofore with respect to
the intensity of the beam projected from the lamp.
In carrying our said invention into practice, we employ a parabolic or parabo-
loid lens and a reflector of corresponding form (or of other suitable form or shape)
and we
so arrange the said lens and reflector relatively to each other and to the
light that their foci correspond or coincide with each other, and the rays of light
concentrated by the reflector will pass through the lens and extend therefrom in
a more or less divergent beam.
We find it advantageous to make the lens in the form of a parabola or parabo-
loid the height or abscissa of which is equal to that of the reflector minus the
distance from the centre of the light to the apex of the reflector. When the
proportions of the lens and reflector are determined upon this basis, it is evident
that the greater the distance between the light and the apex of the reflector, the
less will be the height or abscissa of the lens, or, in other words, the less acute
will be the curvature of the lens.
By reason of the peculiar formation and arrangement of our lens and reflector,
we are enabled to place the light and reflector nearer the lens than heretofore,
and thus economize space in the lamp. Moreover, in a lamp provided with our
improved lens and reflector, instead of the shape of the light or flame of the lamp
being visible through the lens as in lamps heretofore constructed, the lens presents
the appearance of an illumined disc, the light having substantially the same
brilliancy over the entire area of the lens, and the lamp throws out a beam of
intense light which can be seen at a great distance from the lamp.
Our improvements are applicable to all kinds of lamps which require lenses and
reflectors, whether oil, gas, electricity or other illuminating agent be used therein.
The form of reflector used for oil or gas lamps should, however, be different

page_text: from that used for electric lamps on account of the orange rays produced by oil
A spherical reflector may, in some instances, be advantageously used in
combination with a parabolic or paraboloid lens for the purpose of our invention.
or gas.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we wish it understood that
we make no claim in this application for Letters Patent to a lamp provided with
a parabolic or paraboloid lens when such lens is used without a reflector, but we
claim :-
The employment of a parabolic or paraboloid lens and a reflector of corresponding
or other suitable form arranged substantially as hereinbefore described for the
purpose specified.
Dated this 11th day of February 1888.
JAMES THORNE.
E. B. BURR.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.

page_text: This Specification was, upon the 20th day of August 1888, Amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
PROVISIONAL DI EUITIVATION,
Improvements relating to Lenses and Reflectors for Lamps.
We JAMES THORNE, Merchant and EBENEZER BANTON BURR, Engineer, both of
85 Gracechurch Street, in the City of London, do hereby declare the nature of this
invention to be as follows:-
Our invention relates to lenses and reflectors for lamps, and comprises improvements
whereby we provide for greatly increasing the illuminating power of a lamp.
It has been customary heretofore to use spherical lenses and spherical reflectors in
lamps for railway and other purposes, and to make and arrange the lens and reflector
without any special regard to the relative proportions thereof.
Now the object of our invention is to make the lens and reflector of such relative
proportions and to arrange them relatively to each other in such a manner as to obtain
much better results than heretofore with respect to both the intensity ani the concen-
tration of the light.
In carrying our said invention into practice, we employ a parabolic, elliptic or other
lens or
bulls eye
in combination with a reflector of corresponding form and
dimensions, and we arrange the said lens and reflector relatively to each other in such
a manner that their foci correspond or coincide with each other, and the rays of light
concentrated by the reflector will pass through the lens and extend therefrom in a
direction parallel or nearly parallel to its axis.
We prefer to use a parabolic reflector and to make the lens in the shape of a para-
boloid, the height or abscissa of which is equal to that of the reflector minus the distance
from the light to the apex of the reflector. When the proportions of the lens and
reflector are determined upon this basis, it is evident that the greater the distanco
between the light and the apex of the reflector, the less will be the height or abscissa
of the lens, or, in other words, the less acute will be the curvature of the lens.
When we use other forins of lenses and reflectors we proceed in substantially the
same manner.

page_text: By reason of the peculiar formation and arrangement of our lens and reflector, we
are enabled to place the light and reflector nearer the lens than heretofore, and thus
economize space. Moreover, instead of the flame of the lamp being visible through
the lens as in lamps heretofore constructed, a lamp provided with our improved lens
and reflector presents the appearance of an illumined dise, the light appearing to have
substantially the same brilliancy over the entire compass or area of the lens; and the
said lamp throws out a beam of intense light which can be seen at a great distance
from the lamp.
Our improvements are applicable to all kinds of lamps which require lenses and
reflectors, whether oil, gas, electricity or other illuminating agent is used.
Dated this 13th day of Mov 1887
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION (AMENDED).
Improvements relating to Lenses and Reflectors for Lamps.
We, JAMES THORNE, Merchant, and EBENEZER BANTON BURB, Engineer, both of
85 Gracechurch Street, in the City 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 ascertained in and by the following statement :-
Our invention relates to lenses and reflectors such as are hereinafter mentioned and
intended for lamps for railway and other purposes, and comprises improvements
whereby we provide for greatly increasing the illuminating power of such lamps.
It has been customary heretofore to employ spherical lenses and spherical
reflectors in signal-lamps for railway and other purposes, to increase their illu-
minating power; and such lenses and reflectors have usually been made and
arranged without any special regard to the relative proportions thereof.
Now the object of our invention is to make the lens and reflector of a lamp of
such form and relative proportions and to so arrange them relatively to each other
and to the light as to obtain much better results than heretofore with respect to
the intensity of the beam projected from the lamp.
In carrying our said invention into practice, we employ a parabolic or parabo-
loid lens and a reflector of corresponding form (or of other suitable form or shape)
and we so arrange the said lens and reflector relatively to each other and to the
light that their foci correspond or coincide with each other, that is lie in the axial
line common to both lens and reflector and the rays of light concentrated by the
reflector will pass through the lens and extend therefrom in a more or less
divergent-beam
We find it advantageous to make the lens in the form of a parabola or parabo-
loid-the-height or abseissa of which is equal to that of the reflector minus the
distance from the centre of the light to the apex of the reflector. When the
proportions of the lens and reflector are determined upon this basis, it is evident
that the greater the distance between the light and the apex of the reflector, the
less will be the height or abseissa of the lens, or, in other words, the less cente
will be the curvature of the lens.
By reason of the peculiar formation and arrangement of our lens and reflector,
we are enabled to place the light and reflector nearer the lens than heretofore,
and thus economize space in the lamp. Moreover, in a lamp provided with our
improved lens and reflector, instead of the shape of the light or flame of the lamp
being visible through the lens as in lamps heretofore constructed, the lens presents
the appearance of un illumined disc, the light having substantially the same
brilliancy over the entire area of the lens, and the lamp throws out a beam of
intense light which can be seen at a great distance from the lamp.

page_text: but we make no claim under this Patent to the use of a parabolic lens or a parabolic
reflector, in combination with an electric light as such a combination forms part of our
invention for which we applied for Letters Patent dated February 12th 1887, No. 2262
and is described in the Specification of that Patent.
The form of reflector used for oil or gas lamps should, ho vever, be different
from that used for electric lamps on account of the orange rays produced by oil
A spherical reflector may, in some instances, be advantageously used in
combination with a parabolic or paraboloid lens for the purpose of our invention.
or gas.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we wish it understood that
we make no claim in this application for Letters Patent to a lamp provided with
a parabolic or paraboloid lens when such lens is used without a reflector, as such
lamps form the subject of our application for Letters Patent made on January 14th
1888 No. 631 and will be found described in the Specification thereof but we claim :-
The employment of a parabolic or paraboloid lens and a reflector of corresponding
or other suitable form arranged substantially as hereinbefore described for the
purpose specified.
Dated this 11th day of February 1888.
JAMES THORNE.
E. B. BURR.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.