Improvement in Air-compressing Pumps.
Year: 1888

page_text: Date of Application, 7th Aug., 1888
Specification Accepted, 7th Sept., 1888
Improvement in Air-compressing Pumps.
We, ERNEST CHARLES FASOLDT, Optician, and EZRA WILLMARTH SMITH, Engineer,
both of No. 30 North Pearl Street, Albany, New York, United States of America,
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 tho
following statement :—
Figure 1 is a side elevation of our air-compressing pump.
Figure 2 is a vertical section of the outer cylinder of our pump, showing the inner
cylinder in elevation.
Figure 3 is a central vertical section of the outer and inner cylinders when the
parts are at the highest point of their movements.
Figure 4 is a like section showing the parts in an intermediate position during an
upward movement of the outer cylinder: and
Figure 5 is a horizontal section of Fig. 3 at the line X X.
This invention relates to improvements in air-compressing pumps; and it consists
of a stationary cylinder and a movable cylinder which are arranged concentrically to
cach other; the stationary cylinder having a piston-head which fits the bore of the
movable cylinder, and the latter being provided with a piston-head which fits the
bore of the stationary cylinder.
As represented in the drawing, A is the inner cylinder, which is preferably retained
in a stationary position and is provided with a piston-head, B, which snugly fits the
bore of the outer cylinder of the pump; said piston-head is provided with an
upwardly-opening inlet-valve, 1-which closes the opening through which air is
admitted into the outer cylinder-a downwardly-opening valve, 2-which closes the
opening through which the air passes from the outer cylinder into the inner cylinder→
and an upwardly-opening valve, 3-which closes the discharge-opening from the
inner cylinder; said discharge-opening leads into a passage, 4, from which a discharge-
pipe,, extends to the exterior of the apparatus so that a suitable tube-either
flexible or inflexible-may be attached thereto to convey the compressed air to any
required point of delivery.

page_text: B is the outer cylinder and is preferably made movable, under the latter con-
dition it is provided with a cross-handle, 6, or other suitable means, for the purpose
of giving to it a reciprocating movement; the bore of said outer cylinder is adapted
to form an air-tight joint with the perimeter of the piston-head B; the upper end of
said outer cylinder is closed by a head, D, from the center of which depends a rod, 7,
which passes through a stuffing-box, 8, formed on the upper side of the piston-
head B, and thereby provision is made for the reciprocating movement of the
movable cylinder while an air-tight joint is maintained around said rod. The lower
end of the rod 7 is provided with a piston-head, E, which is fitted to form an air-
tight joint with the bore of the inner cylinder.
the
The operation of this air-compressing pump is as follows: On moving the
cylinder C, and its attached piston-head E, upwardly as indicated by the outer
arrow on Fig. 4-the air will enter said cylinder through the inlet air-opening that
is governed by the valve 1; simultaneously therewith the air contained in the inner
cylinder A which air has received its primary compression by being forced into the
inner cylinder by a downward stroke of the outer cylinder is forced out of the
inner cylinder-through the discharge-opening governed by the valve 3-and from
thence is conveyed, through the discharge-pipe 5 and its connections to the required
point of delivery; on reversing the direction of the movement of the cylinder
air that is contained in said cylinder is compressed and forced to pass-through the
opening governed by the valve 2-into the cylinder A, the valves 1 and 3 closing
instantly, on the reversal of the movement of the cylinder C, to prevent the air from
passing through the openings governed by said valves. The direction of movement
of the air during an upward stroke of the cylinder C is indicated by the full arrows
inside of the cylinders in Fig. 4, and the movement of the air during a downward
stroke of said cylinder is indicated by the dotted arrows in the same figure. It will
be readily understood that a primary compression of the air is effected by forcing the
air contained in the larger cylinder Cinto the small inner cylinder A, and a second
compression of the air is produced by forcing it out of the latter cylinder.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what wo
claim is-
An air-compressing pump consisting of an inner cylinder and an outer cylinder
that is arranged concentrically to said inner cylinder; the said inner cylinder having
a piston-head which fits the bore of the outer cylinder and is provided with valved
inlet and outlet air-openings, and the said outer cylinder being provided with a
piston-head which is fitted to the bore of the inner cylinder, as and for the purpose
herein specified.
Dated this 22nd dos of Tu1 1000