IMPROVEMENTS IN MECHANICAL FOG HORNS
Year: 1881

page_text: LETTERS PATENT to Joseph Sturge, of Birmingham, in the County of
Warwick, Lamp Manufacturer, and John Grubb, of Birmingham aforesaid,
Manufacturer, for an Invention of "IMPROVEMENTS IN MECHANICAL FOG
HORNS."
PROVISIONAL SPECIFICATION left by the said Joseph Sturge and John
Grubb at the Office of the Commissioners of Patents on the 3rd June 1881.
JOSEPH STURGE, of Birmingham, in the County of Warwick, Lamp Manufac-
turer, and JOHN GRUBB, of Birmingham aforesaid, Manufacturer. "IMPROVEMENTS
IN MECHANICAL FOG HORNS."
Our Invention consists of the combination or arrangement herein after described
of the parts of mechanical foghorns, whereby a continuous sound is produced in the
said foghorns.
In constructing a foghorn according to our Invention wo take two hollow
cylinders of different diameters, and we fix the smaller one concentrically within
the larger one. The diameter of the larger cylinder is by preference about three
times that of the inner cylinder. The said larger cylinder constitutes a compressed
air chamber or reservoir, and the smaller one forms a pump cylinder in which a
piston works, the said piston being actuated by a lever or by other convenient
means. The large hollow cylinder, besides serving as a compressed air chamber
or reservoir, also serves to protect the pump cylinder from injury. The ends of the
two cylinders are closed, but the inner or pump cylinder is provided with valves.
In the top and bottom of the pump cylinder are valves opening inwards for the
entrance of air from the atmosphere to opposite ends of the pump cylinder, and in
the sides of the pump cylinder, and near the first mentioned valves, are other
valves opening outwards, that is, into the compressed air chamber, for the passage
of the compressed air from the pump cylinder to the said air chamber. The pump
is a double acting one, that is, while the air on one side of the piston is being forced

page_text: into the compressed air chamber or reservoir, air is being drawn from the atmosphero
into the pump cylinder on the other side of the said piston. By the reciprocating
motion of the pump piston in its cylinder the air is alternately forced out of the
pump cylinder at its upper and lower ends into the outer compressed air chamber
or reservoir, where it is stored, and the compressed air supplied to the horn so as to
produce a continuous sound in the said horn.
The fog horn may consist of an ordinary reeded fog horn, and is attached to the
compressed air chamber or reservoir. The horn may be turned in any direction,
and have a plain or trumpet mouth, and thỏ blast may be regulated or stopped by
means of a stop cock.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Sturge and John Grubb in the Great Seal Patent Office on
the 18th November 1881.
JOSEPH STURGE, of Birmingham, in the County of Warwick, Lamp Manufac-
turer, and JOHN GRUBB, of Birmingham aforesaid, Manufacturer. "IMPROVEMENTS
IN MECHANICAL FOG HORNS."
Our Invention consists of the combination or arrangement herein after described
of the parts of mechanical foghorns, whereby a continuous sound is produced in the
said foghorns.
In constructing a foghorn according to our Invention we take two hollow
cylinders of different diameters, and we fix the smaller one concentrically within
the larger one. The diameter of the larger cylinder is by preference about three
times that of the inner cylinder. The said larger cylinder constitutes a compressed
air chamber or reservoir, and the smaller one forms a pump cylinder in which a
piston works, the said piston being actuated by a lever or by other convenient
means.
The larger hollow cylinder, besides serving as a compressed air chamber or
reservoir, also serves to protect the pump cylinder from injury. The ends of the
two cylinders are closed, but the inner or pump cylinder is provided with valves.
In the top and bottom of the pump cylinder are valves opening inwards for the
entrance of air from the atmosphere to opposite ends of the pump cylinder, and in
the sides of the pump cylinder, and near the first mentioned valves, are other
valves opening outwards, that is, into the compressed air chamber, for the passage
of the compressed air from the pump cylinder to the said air chamber. The pump
is a double acting one, that is, while the air on one side of the piston is being
forced into the compressed air chamber or reservoir, air is being drawn from the
atmosphere into the pump cylinder on the other side of the pump piston.
By the reciprocating motion of the pump piston in its cylinder the air is
alternately forced out of the pump cylinder at its upper and lower ends into the
outer compressed air chamber or reservoir, where it is stored, and the compressed
air supplied to the horn so as to produce a continuous sound in the said horn.
The fog horn may consist of an ordinary reeded foghorn, and is attached to the
compressed air chamber or reservoir. The horn may be turned in any direction,
and have a plain or trumpet mouth, and the blast may be regulated or stopped by
means of a stopcock.
The accompanying Drawing represents in vertical section a mechanical fog horn,
the parts of which are combined or arranged according to our Invention.
a is the large hollow cylinder constituting the compressed air chamber or
reservoir of the fog horn, and also serving to protect the inner or pump cylinder b
of the double acting pump. At the base of the compressed air chamber a is a
strong rim, foot, or stand c, by which the apparatus is supported; d is the piston
working in the pump cylinder b, the said piston being raised and lowered in the
said cylinder by the lever c to which the piston rod is jointed. The said lever e is
jointed to the link f, and the latter turns on the fixed arm or bracket g secured
at g to the outside of the compressed air chamber a. The pump cylinder 6 has a
valve h at top and a valve i at bottom, the said valves h, i, opening inwards for the
entrance of the air from the atmosphere.
In the side of the pump cylinder 6 are valves k, l, opening outwards into the
compressed air chamber a for permitting of the passage of the compressed air from
the pump cylinder b to the compressed air chamber a; m is the fog horn attached
to the side of the air chamber a by the joint piece n, by means of which the fog

page_text: horn m may be turned in any direction. The joint pièce n may be furnished with
a stop cock to regulate the blast passing from the air chamber a to the said fog
horn m.
The operation of the double acting pump b, d, is as follows:-In the Drawing
the piston & is represented in the act of making its up stroke, as indicated by the
large arrow on the said piston.
As the piston rises in the cylinder b the valve h is closed and the valve k is
opened, and the air abovo the piston is forced through the open valve into the
compressed air chamber a. The valve i at the bottom of the cylinder bis at the
same time opened, and air enters the spaco below the piston, the side valve opening
into the compressed air chamber being closed, as represented. As the piston d
makes its descending stroke the valve k is closed and the valve h is opened, the
bottom valve i being at the same time closed and the side valve opened, and the
air below the piston is forced into the compressed air chamber through the open
valve l, atmospheric air entering above the piston by the open valve h.
In this way the reciprocating motion of the pump piston d in its cylinder b,
produced by the lever c, alternately forces air out of the upper and lower ends of
the pump cylinder into the compressed air chamber or reservoir a, where it is
stored, and the compressed air supplied to the horn m so as to produce a
continuous sound in the said horn, as will be understood by an examination of the
Drawing.
"
Instead of working the piston of the double acting pump by a lever, as described
and represented, the piston rod may be connected to a crank on a shaft, and the
Intter be rotated by a winch or hand wheel.
Having now described the nature of our Invention, and the manner in which
the same is to be performed, we wish it to be understood that we claim as our
Invention, the improvements in mechanical fog horns for producing a continuous
sound, herein before described and illustrated in the accompanying Drawing, that is
to say, the combination of the double acting pump b, d, and the valves h, i, k, l, with
the concentric outer compressed air chamber or reservoir a, the latter receiving
compressed air from the pump cylinder and delivering it to the reeded or other
fog horn of the apparatus, substantially as described and illustratod.
In witness whereof, I, the said Joseph Sturgo, have hereunto set my hand
and scal, this Fifteenth day of November, in the year of our Lord One
thousand eight hundred and eighty one.
Witness,
RICHARD SKERRETT,
37, Temple Street,
Birmingham.
JOSEPH STURGE. (L.S.)