Year: 1888

page_text: Date of Application, 13th Apr., 1888
Complete Specification Left,. 10th Jan., 1889
Complete Specification Accepted, 12th Feb., 188
1, WILLIAM HAVIE of 222 Broomielaw, Glasgow, in the County of Lanark, North
Britain, Lamp Mantcturer do hereby declare the nature of this invention to be as
follows:-
This Invention, which relates to improvements in that class of lights commonly
known amongst naval and sea-faring men as "search lights," is also applicable to other
lights of an analogous kind.
"
It is here explained that "search lights are lights of a class used for the finding
of floating er fixed objects at night at sea or on river banks, quays, harbours,
docks, and other places, to enable the navigation of ships to be safely performed
in the dark, such lights being also used for the purpose of discovering lookout boats,
launches, torpedo boats and other crafts that may be sent out by an enemy or an
enemy's ships. Such lights may also be used for searching or other purposes on
land.
The object of this Invention is to enable the anterior luminous rays in such light
to be either instantaneously condensed into a cylinder of light or to be instantaneously
diffused into a cone of light at will.
This object is effected by mounting at the required distance in front of the focus
of the reflector of such lights a dioptric lens or an equivalent lens which, when its
axis is in line with the focus of the reflector, will condense the anterior rays of light
falling upon it into a parallel beam and which when turned at right angles to that
position ceases to interfere with or influence the said rays, so that they are diffused
into a cone of light.
To enable this variation of the rays of light to be effected the dioptric or equivalent
lens is mounted on a vertical axis carried in or upon the casing of the light. This
axis is so mounted in a tubular vertical bearing that by means of a projection attached

page_text: to it at the outside of the casing it can be turned instantaneously against one of two
stops which determine the two positions of the lens within the light. A spring or a
set-screw may be applied for holding the lens in either position.
It is to be understood that in place of mounting the dioptric lens upon a vertical
axis, it may be mounted upon a horizontal axis, or the axis may be in any suitable
position between the horizontal and vertical.
The dioptric lens hereinbefore referred to may also be employed in that class of lights
wherein an opaque screen is sometimes used to intercept the cone of light.
Dated this 12th day of April 1888.
ST. JOHN V. DAY,
115, St. Vincent Street, Glasgow,
Petitioner's Agent.

page_text: COMPLETE SPECIFICATION.
66
Improvements in that Class of Lights known as Search Lights,"
the same being Applicable to other Lights of an Analogous
kind.
I, WILLIAM HARVIE of 222 Broomielaw, Glasgow, in the County of Lanark, North
Britain, Lamp Manufacturer 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 :-
My Invention, which relates to improvements in that class of lights commonly
known amongst naval and sea faring men as search lights," is also applicable to other
lights of an analogous kind.
It is here explained that "search lights" are lights of a class used for the finding
of floating or fixed objects at night at sea or on river banks, quays, harbours, docks
and other places to enable the navigation of ships to be safely performed in the dark,
such lights being also used for the purpose of discovering lookout boats, launches,
torpedo boats and other crafts that may be sent out by an enemy or an enemy's ships.
Such lights may also be used for searching or other purposes on land.
The object of my Invention is to enable the anterior luminous rays in such lights
to be either instantaneously condensed into a cylinder of light or to be instantaneously
diffused into a cone of light at will.
This object is effected by mounting at the required distance in front of the focus of
the reflector of such lights a dioptric lens or an equivalent lens, which, when its
axis is in line with the focus of the reflector, will condense the anterior rays of light
falling upon it into a parallel beam and which when turned at right angles to that
position ceases to interfere with or influence the said rays, so that they are diffused
into a cone of light. The dioptric lens hereinbefore referred to may also be employed
in that class of lights wherein an opaque screen is sometimes used to intercept the
cone of light.
In order that my Invention may be properly understood and readily carried into
effect, I have hereunto appended two explanatory sheets of drawings in the several
Figures of which corresponding parts are marked with similar letters of reference.
Figure 1, is a horizontal section of a catadioptric holophotal reflector having its
lens A, so mounted in it that the entire apparatus constitutes the improved "search
light" of which my present Invention consists. As the centre of the lens A, there
is shewn a small circle b, this being a vertical axis upon which the lens A, is held at
the underpart of its periphery, the lens being in a ring attached thereto. The axis
is carried in a vertical tube attached to the lamp casing in which it is capable of being
turned into two positions at right angles to each other. For the purpose of so turning
the lens A, into either of these two positions the axis in the aforesaid tube is made to
project a short distance below the bottom of that tube and is fitted with a button or
thumb and finger piece so that by applying the thumb and finger thereto the lens A,

page_text: is at once turned into either of the two positions required. The outside of the casing
in the neighbourhood of the said button or thumb and finger piece is provided with
stops for determining with exactitude the two positions of the lens, namely the position
shewn in Figure 1, wherein the whole of the anterior rays of light B, emanating from
the focus C, which are not intercepted by the paraboloid reflector D, are intercepted by
the said lens A, and thrown forward as parallel rays. When it is desired to withdraw
the influence of the lens A, for to condense the rays of light into parallel rays and
to cause them to be diffused into a cone of light, this is instantly effected by turning
the lens A, into the position shewn. at Figure 2, that is to say, at right angles to
the position hereinbefore described and shewn in Figure 1, in which position it
ceases to condense the anterior rays and allows them to diverge as indicated by the
cone E.
It is to be understood that in place of mounting the dioptric lens upon a vertical
axis, it may be mounted upon a horizontal axis, or the axis may be in any suitable
position between the horizontal and vertical.
It has sometimes been the practice hitherto to employ an opaque screen in search
lights and under the present improvements in such lights I place a dioptric, annular
cr equivalent lens A, as shewn in the diagram Figure 3. The effect of substituting
such lens is to condense into a parallel beam of light the rays which fall upon it,
instead of allowing the rays which fall upon the opaque screen to be lost as hitherto.
The lens A, may be carried on an axis as in Figures 1 and 2, or it may be fixed.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
1. In search lights or equivalent lights the improvement consisting in mounting
the lens A, upon an axis either vertical or horizontal or which axis may be at any
angle between the vertical and horizontal and so that it may be turned into one
position which condenses the anterior rays of light passing through it into parallel
rays and when turned into the opposite position allows the said anterior rays to be
diffused as a cone of light, substantially as hereinbefore described and shewn at
Figures 1 and 2 of the annexed drawings.
2. In search lights or equivalent lights the substitution of the lens A, for the
opaque screen sometimes used in such lights as hereinbefore described and shewn at
Figure 3, of the annexed drawings..
Dated this 25th day of October 1888.
ST. JOHN V. DAY,
115, St. Vincent Street, Glasgow,
Applicant's Agent.

page_text: 1, WILLIAM HARVIE of 222 Broomielaw, Glasgow, in the County of Lanark, North
Britain, Lamp Manufacturer do hereby declare the nature of this invention to be as
follows:-
This Invention, which relates to improvements in that class of lights commonly
known amongst naval and sea-faring men as "search lights," is also applicable to other
lights of an analogous kind.
22
It is here explained that "search lights are lights of a class used for the finding
of floating or fixed objects at night at sea or on river banks, quays,, harbours,
docks, and other places, to enable the navigation of ships to be safely performed
in the dark, such lights being also used for the purpose of discovering lookout boats,
launches, torpedo boats and other crafts that may be sent out by an enemy or an
enemy's ships. Such lights may also be used for searching or other purposes on
land.
The object of this Invention is to enable the anterior luminous rays in such light
to be either instantaneously condensed into a cylinder of light or to be instantaneously
diffused into a cone of light at will.
This object is effected by mounting at the required distance in front of the focus
of the reflector of such lights a dioptric lens or an equivalent lens which, when its
axis is in line with the focus of the reflector, will condense the anterior rays of light
falling upon it into a parallel beam and which when turned at right angles to that
position ceases to interfere with or influence the said rays, so that they are diffused
into a cone of light.
To enable this variation of the rays of light to be effected the dioptric or equivalent
lens is mounted on a vertical axis carried in or upon the casing of the light. This
axis is so mounted in a tubular vertical hearing that by means of a projection attached

page_text: to it at the outside of the casing it can be turned instantaneously against one of two
stops which determine the two positions of the lens within the light. A spring or a
set-screw may be applied for holding the lens in either position.
It is to be understood that in place of mounting the dioptric lens upon a vertical
axis, it may be mounted upon a horizontal axis, or the axis may be in any suitable
position between the horizontal and vertical.
The dioptric lens hereinbefore referred to may also be employed in that class of lights
wherein an opaque screen is sometimes used to intercept the cone of light.
Dated this 12th day of April 1888.
ST. JOHN V. DAY,
115, St. Vincent Street, Glasgow,
Petitioner's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in that Class of Lights known as "Search Lights,"
the same being Applicable to other Lights of an Analogous
kind.
1, WILLIAM HARVIE of 222 Broomielaw, Glasgow, in the County of Lanark, North
Britain, Lamp Manufacturer 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 :—
My Invention, which relates to improvements in that class of lights commonly
known amongst naval and sea faring men as "search lights," is also applicable to other
lights of an analogous kind.
22
It is here explained that "search lights are lights of a class used for the finding
of floating or fixed objects at night at sea or on river banks, quays, harbours, docks
and other places to enable the navigation of ships to be safely performed in the dark,
such lights being also used for the purpose of discovering lookout boats, launches,
torpedo boats and other crafts that may be sent out by an enemy or an enemy's ships.
Such lights may also be used for searching or other purposes on land.
The object of my Invention is to enable the anterior luminous rays in such lights
to be either instantaneously condensed into a cylinder of light or to be instantaneously
diffused into a cone of light at will.
This object is effected by mounting at the required distance in front of the focus of
the reflector of such lights a dioptric lens or an equivalent lens, which, when its
axis is in line with the focus of the reflector, will condense the anterior rays of light
falling upon it into a parallel beam and which when turned at right angles to that
position ceases to interfere with or influence the said rays, so that they are diffused
into a cone of light. The dioptric lens hereinbefore referred to may also be employed
in that class of lights wherein an opaque screen is sometimes used to intercept the
cone of light.
In order that my Invention may be properly understood and readily carried into
effect, I have hereunto appended two explanatory sheets of drawings in the several
Figures of which corresponding parts are marked with similar letters of reference.
Figure 1, is a horizontal section of a catadioptric holophotal reflector having its
lens A, so mounted in it that the entire apparatus constitutes the improved "search
light" of which my present Invention consists. As the centre of the lens A, there
is shewn a small circle b, this being a vertical axis upon which the lens A, is held at
the underpart of its periphery, the lens being in a ring attached thereto. The axis
is carried in a vertical tube attached to the lamp casing in which it is capable of being
turned into two positions at right angles to each other. For the purpose of so turning
the lens A, into either of these two positions the axis in the aforesaid tube is made to
project a short distance below the bottom of that tube and is fitted with a button or
thumb and finger piece so that by applying the thumb and finger thereto the lens A,

page_text: is at once turned into either of the two positions required. The outside of the casing
in the neighbourhood of the said button or thumb and finger piece is provided with
stops for determining with exactitude the two positions of the lens, namely the position
shewn in Figure 1, wherein the whole of the anterior rays of light B, emanating from
the focus C, which are not intercepted by the paraboloid reflector D, are intercepted by
the said lens A, and thrown forward as parallel rays. When it is desired to withdraw
the influence of the lens A, for to condense the rays of light into parallel rays and
to cause them to be diffused into a cone of light, this is instantly effected by turning
the lens A, into the position shewn. at Figure 2, that is to say, at right angles to
the position hereinbefore described and shewn in Figure 1, in which position it
ceases to condense the anterior rays and allows them to diverge as indicated by the
cone E.
It is to be understood that- in place of mounting the dioptric lens upon a vertical
axis, it may be mounted upon a horizontal axis, or the axis may be in any suitable
position between the horizontal and vertical.
It has sometimes been the practice hitherto to employ an opaque screen in search
lights and under the present improvements in such lights I place a dioptric, annular
er equivalent lens A, as shewn in the diagram Figure 3. The effect of substituting
such lens is to condense into a parallel beam of light the rays which fall upon it,
instead of allowing the rays which fall upon the opaque screen to be lost as hitherto.
The lens A, may be carried on an axis as in Figures 1 and 2, or it may be fixed.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
1. In search lights or equivalent lights the improvement consisting in mounting
the lens A, upon an axis either vertical or horizontal or which axis may be at any
angle between the vertical and horizontal and so that it may be turned into one
position which condenses the anterior rays of light passing through it into parallel
rays and when turned into the opposite position allows the said anterior rays to be
diffused as a cone of light, substantially as hereinbefore described and shewn at
Figures 1 and 2 of the annexed drawings.
2. In search lights or equivalent lights the substitution of the lens A, for the
opaque screen sometimes used in such lights as hereinbefore described and shewn at
Figure 3, of the annexed drawings. .
Dated this 25th day of October 1888.
ST. JOHN V. DAY,
115, St. Vincent Street, Glasgow,
Applicant's Agent.