IMPROVE- MENTS IN PUMPS OR APPARATUS FOR DRAWING AND FORCING FLUIDS, PARTICULARLY APPLICABLE TO THE VENTILATION OF MINES
Year: 1868

page_text: LETTERS PATENT to John Snape, of Mountain Ash, near Aberdare,
South Wales, Mechanical Engineer, for the Invention of "IMPROVE-
MENTS IN PUMPS OR APPARATUS FOR DRAWING AND FORCING FLUIDS,
PARTICULARLY APPLICABLE TO THE VENTILATION OF MINES."
Sealed the 18th June 1869, and dated the 22nd December 1868.
PROVISIONAL SPECIFICATION left by the said John Snape at the
Office of the Commissioners of Patents, with his Petition, on the
22nd December 1868.
I, JOHN SNAPE, of Mountain Ash, near Aberdare, South Wales,
Mechanical Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN PUMPS OR APPARATUS FOR DRAWING AND FORCING
FLUIDS, PARTICULARLY APPLICABLE TO THE VENTILATION OF MINES," to be as
follows:-
My Invention consists in an improved construction of pump or
apparatus for drawing and forcing fluids; it is primarily intended for
the purpose of ventilating mines by exhausting the ordinary air shaft,
but it also applies to drawing and forcing fluids generally.

page_text: The characteristic feature of the Invention lies in the employment of
two drums, one of which is formed with six or other convenient number
of convex surfaces, and the other with corresponding concave surfaces.
These two drums revolve in opposite directions, and in their revolution
the convex portions of one fit into the concave portions of the other.
The drums when applied to ventilating mines are fitted at the upper
end of the air shaft, and their respective convex and concave portions in
their revolution move round in segments of circles. In the revolution
of the convex drum air from the shaft is drawn into the space between
each successive pair of convex surfaces, and is carried off in this space
round the segment until it reaches the open air; in the revolution of the
concave drum air is in like manner drawn into cach successive concave
or recess and carried off in the same manner. For the purpose of
imparting rotation to the drums without the employment of gearing,
I prefer to adopt the following arrangement :-I employ an engine, the
piston rod of which extends through both ends of the cylinder; the two
ends of the piston rod are respectively connected by rods with cranks on
the two drums, the cranks being reverse, so that the drums revolve in
contrary directions. When it is required to force as well as to draw the
air or other fluid the drums are enclosed by a casing provided with a
suitable outlet.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Snape in the Great Seal Patent Office on
the 22nd June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SNAPE, of Mountain Ash, near Aberdare, South Wales, Mechanical
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of December, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Snape, Her special
licence that I, the said John Snape, my executors, administrators, and
assigns, or such others as I, the said John Snape, my executors, adminis-

page_text: trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein.
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN PUMPS OR
APPARATUS FOR DRAWING AND FORCING FLUIDS, PARTICULARLY APPLICABLE TO THE
VENTILATION OF MINES," upon the condition (amongst others) that I,
the said John Snape, my executors or administrators, by an instru-
ment in writing under , or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-
tion, 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 Snape, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the Drawings
hereunto annexed, that is to say :-
My Invention consists in an improved construction of pumps or
apparatus for drawing and forcing fluids; it is primilary intended for
the purpose of ventilating mines by exhausting from the ordinary air
shaft, but it also applies to drawing and forcing fluids generally.
The characteristic feature of the Invention lies in the employment of
two drums, one of which is formed with six or other convenient number
of convex surfaces, and the other with corresponding concave surfaces.
These two drums revolve in opposite directions, and in their revolution
the convex portions of one fit into the concave portions of the other.
These drums when applied to ventilating mines are fitted at the upper
end of the air shaft, and their respective convex and concave portions in
their revolution move round in segments of circles. In the revolution
of the convex drum air from the shaft is drawn into the space between
each successive pair of convex surfaces, and is carried off in this space
round the segment until it reaches the open air; in the revolution of the
concave drum air is in the like manner drawn into each successive
concave or recess and carried off in the same manner.
For the purpose
of imparting rotation to the drums without the employment of gearing,
I prefer to adopt the following arrangement:-I employ an engine, the.
piston rod of which extends through both ends of the cylinder; the two

page_text: thus of the piston you are
two drums, the cranks being reverse, so that the drums revolve in
contrary directions. When it is required to force as well as to draw
the air or other fluid the drums are enclosed by a casing provided with
a suitable outlet.
Figure I. of the accompanying Drawings is a side elevation of a pump
or apparatus constructed according to my Invention, and Figure 2 is
a plan of the same.
A, B, are the two drums, one of which is formed with six convex
surfaces, a, b, c, d, e, f, and the other six concave surfaces g, h, i, j, k, l,
the projecting ends or edges of which take into the spaces between the
convex surfaces of the other drum. Both the drums are mounted upon
suitable bearings above the air shaft or opening leading from the mine
or other place required to be ventilated. In order to drive the two
drums in a contrary direction, and to make the projecting edges of the
concave one take into the spaces of the convex one I provide each axle
with a crank C, D, to which the ends of the piston rods E, F, are con-
nected. The rods E, F, are attached to one piston of an oscillating
cylinder mounted upon a framework at one side of the drums, and mid-
distance between them; this allows a perfect control to be had over the
drums, and insures their working in regular order without drag or
friction. In some cases I employ an engine on the slot-link principle
for effecting the rotation of the drums in the manner before explained.
In the Drawings the drums are shewn as being mounted over an opening
and working in an enclosed casing at the lower part only. The air is
drawn up the opening G by the rotation of the drums, as shewn by the
arrows, where it becomes divided by the concavo surfaces of one drum
and the spaces of the other drum, and is carried into the atmosphere.
If the apparatus is required for forcing as well as for suction the upper
parts are covered in, so that the drums work in a complete casing, a pipe
or pipes leading from the upper part of the casing forming the outlet
therefrom. In some cases where the drums are large and heavy I
propose to employ two engines, one on each side thereof, as shewn in
Figure 2, in order that the drums may be worked without any sway or
side motion. The drums may be made of any material, either as
skeleton frames or in solid bodies. The surfaces may be composed of
the same or any other material and covered or not.

page_text: Although I have described my Invention as being applied to drawing
and forcing air from mines for ventilating purposes, it may be employed
for drawing and forcing fluids generally.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim, con-
structing pumps or apparatus for drawing and forcing fluids, in the
manner herein-before described and represented in the accompanying
Drawings.
In witness whereof, I, the said John Snape, have hereunto set
my hand and seal, this Seventeenth day of June, One thousand
eight hundred and sixty-nine.
JOHN SNAPE. (L.S.)