IMPROVEMENTS IN GAS PUMPS
Year: 1886

page_text: I, WILLIAM JOHN FERGUSON, of the City of Baltimore and State of Maryland,
United States of America, Engineer, do hereby declare the nature of my invention
for "IMPROVEMENTS IN GAS PUMPS," and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
This invention relates to certain improvements in pumps to be employed in the
pumping of gases in refrigerating apparatus; and it consists in certain details of
construction of the said pump, in devices for closing the stuffing box gland around
the piston rod, at the lower end of the cylinder, and in means for lubricating the
said piston rod, as will hereinafter fully appear.
The drawing is a section of the improved pump cylinder.
In the drawing, A. represents the cylinder of the pump which stands in a vertical
or upright position, and is supported on a frame, B. C is the piston which is
hollow; and its hub, a, to which the piston rod, D, is attached is connected to the
body or rim, b, by means of the radial ribs c. The piston C is provided with a
valve E adapted to have a vertical movement on the upper end of the piston rod D
which projects through the hub a, of the piston. This valve is recessed to receive
the nut, d, and the recess in the valve is closed by means of the plate e, which is
ground in place to make a tight joint. The plate, e, is secured by means of
screws. The nut d, is split, and has lugs through which is passed a screw, g,
which is tightened after the nut is properly adjusted. The valve E is yieldingly
supported from the hub of the piston C by means of a spiral spring h, in order that
the valve shall have practically no weight and therefore be easily opened by the
gases when they become much attenuated in the exhausting operation. By the
piston and valve having together a flat upper surface the piston may be made to
come very close to the valve F in the upper end of the cylinder and which valve is
the full diameter of the said cylinder, consequently all the gas is discharged from
the cylinder at each upward stroke of the piston. The valve F has a stem i,
adapted to slide in the support j, which is formed as a part of the discharge
nozzle G, and a spring k serves to keep the valve in a seated position. The gas
enters the cylinder through the opening H and is discharged through the aperture I.
The cylinder proper is surrounded by a water jacket J after the manner of air and
gas compressors. K is the stuffing box around the piston rod D.
In this stuffing

page_text: box are confined the packing rings m and n the former being at the outer end of
the stuffing box, and the latter about midway of the same. The packing which is
not shown is situated between the packing rings. Oil chambers o and t are formed
around the packing rings m and n and these chambers are supplied with oil through
pipes L with its branch q. Holes r and s admit oil from the chambers o and t to
the surface of the piston rod.
The gland M which is screwed on the end of the stuffing box K is turned by
means of the ratchet N which needs no description herein as it is of ordinary
construction.
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 combination with a hollow piston a rod secured to one end of the piston,
having a nut wholly within the piston and upwardly opening valve with its upper
face flush with the upper end of the piston when said valve is closed, and arranged
to slide upon the end of the rod and be guided and limited in its motion, substan-
tially as specified.
.
2. The combination of the hollow piston C, and the rod D, secured to one end of
the piston, and having a nut at its end the valve E, having its upper face, when
closed, flush with the piston and guided upon, the end of the piston rod, and the
detachable plate-cap or plate e, secured to the valve flush with the same, substan-
tially as specified.
3. In combination with the stuffing box K and the piston rod D, the packing
rings m and n having oil chambers o and p which are in communication with the
surface of the said piston rod by means of the holes r and s, and oil pipes to supply
the said oil chambers, substantially as specified.