Improvements in Rotary Pumps.
Year: 1892

page_text: Date of Application, 9th June, 1892-Accepted. 23rd July, 1892
COMPLETE SPECIFICATION.
[Communicated from abroad by BENJAMIN FRANKLIN TABER, of 429, Prospect
Avenue, in the City of Buffalo, in the County of Erie and State of New York,
United States of America, Manufacturer.]
Improvements in Rotary Pumps.
I, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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:-
This invention relates to an improvement in that class of pumps which are
provided with a revolving cylinder arranged eccentrically in an enclosing case, and
sliding pistons which revolve with the cylinder and run with their outer edges in
contact with the enclosing case.
Heretofore these pistons were usually arranged in pairs and extended through
the cylinder, so that when one of the pistons receded into the cylinder, the opposite
piston moved out from the cylinder. The receding of the pistons was caused
principally by the outer edge of the pistons bearing against the eccentric side of
the case, which produced excessive wear of the case. The column of water pressing
upon the receding piston of a pair, also caused the opposite projected piston to
grind heavily against the side of the case.
The object of my invention is to so construct the pistons that they will more
inwardly and outwardly in the cylinder principally by their own weight and thereby
reduce the wear against the case.
In the accompanying drawings:
Figure 1 is a longitudinal sectional elevation of my improved pump.
Figure 2 is a vertical cross section thereof.
Figure 3 is a longitudinal section, partly in elevation, of part of my improved
pump designed more particularly for pumping heavy liquids.
Figure 4 is a cross section on the linee Figure 3 looking toward the right.
Figure 5 is a perspective view of one of the heads of the pump.
Figure 6 is a fragmentary side elevation of one of the pistons.
Like letters of reference refer to like parts in the several figures.
A represents the enclosing case of the pump supported on a suitable base frame
and provided with a suction chamber B at its lower end and a discharge chamber C
at its upper end. D represents the piston cylinder arranged eccentrically in the
case with its periphery in contact with an abutment d formed by one side of the
case between the suction and discharge chambers. E represents the sliding pistons
arranged in grooves or ways e formed in the cylinder. Each of these pistons, which
are preferably four in number, consists of a segmental or arc-shaped plate having
concavo-convex sides, and the groove in the cylinder receiving said plate has the
same curvature as the plate, so that the latter can move freely in and out in
the groove.
The cylinder is formed of a solid casting with a separate or independent groove
or way for each piston. Each groove opens with its outer end through the
periphery of the cylinder and extends in a curved line from its outer end inwardly
toward the axis of the cylinder and then outwardly toward the periphery of the
cylinder, its inner end being closed by the periphery of the cylinder, as shown at e
Figure 2.
By this arrangement, the pistons rotate with their concave sides forwardly. As
soon as a piston has passed below the abutment d, it slides outward in its groove by
its own weight until it bears against the eccentric portion of the case formed

page_text: below the abutment. The pistons,, therefore,, move in contact with the case with
comparatively little friction, but are, at the same time held against the case, by
gravity, sufficiently snug to insure the proper working of the pump. The concentric
portion of the case limits the outward movements of the pistons and the latter
raise the water in moving, upwardly past that portion of the case.
When the piston has reached the upper end of the concentric portion of the
case, the piston and its groove stand at such an inclination as to cause the piston to
slide into its groove by gravity. By constructing and arranging the pistons as
described, the pressure of the outer ends of the pistons against the case is exerted
nearly in the direction or arc in which the pistons move, thereby facilitating the
entrance of the pistons into their grooves and reducing the wear upon the upper
portion of the case. The walls of the curved grooves, owing to the peculiar form
and arrangement of the latter, retard the outward movement of the segmental
pistons sufficiently to prevent the pistons from being heavily forced against the
surrounding case, but not. to such an extent as to interfere with the free operation
of the pistons.
When two connected pistons are arranged to slide diametrically. through the
cylinder, as heretofore constructed, the column of water in the discharge chamber
exerts a heavy pressure upon the receding piston, which pressure is transmitted to.
the outwardly moving piston on the opposite side of the cylinder, causing the latter
piston to grind unduly against the bottom or lower side of the case.
By, my
improved construction, the pistons are not acted upon by the water pressure in this
manner, but simply hear by gravity against the case, whereby the wear upon the
pistons and the case is materially reduced.
The outer edge of each piston is preferably chamfered on its rear side so as to
fit snugly against the inner side of the case when in its working position..
G represents the driving shaft formed on one end of the cylinder h¹ is the bearing
formed on the adjacent head H of the case and in which the driving shaft is
journalled.
K is a trunnion formed on the opposite end of. the cylinder and journalled in a
bearing K¹ formed on the opposite head L of the case.
When the pump is used for pumping liquids of a heavy consistency, such as
molasses or soap-makers' stock the viscous liquid entering the grooves of; the piston
is liable to retard their free action, and in order to cause the pistons to be positively
moved outward under such conditions, a cam or projection M is preferably
employed, which is so located relatively to the pistons, that as soon as the pistons
have passed below the abutment d, their inner portions strike the cam and are
projected from their grooves.
As represented in Figures 3, 4 and 5, the cam M is formed on the inner side of
the head L within the periphery of the piston-cylinder and the adjacent ends of the
pistons project beyond the end of the cylinder, and are provided near their inner
ends, with a shoulder n.. The cam M is arranged in the path of the shoulders of
the pistons, so that as the cylinder rotates, the pistons are successively projected
from the cylinder by their shoulders striking the cam.
. M..
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign.correspondent I declare that what I claim is :-
1. The combination with. the enclosing case, of a rotary cylinder arranged
eccentrically. in said. case and provided with independent curved grooves or pockets,
each extending in the arc of a circle no.. he periphery of the cylinder inwardly
toward the axis of the cylinder and outwardly, toward. the periphery thereof, and
segmental or arc-shaped pistons arranged loosely in said grooves and capable of
sliding: bodily in the same, the pistons having no attachment to the cylinder and
being, guided in their movements by the, walls of the grooves, substantially as set
forth.
2. The combination with the enclosing case, of a rotating cylinder arranged
1.
L

page_text: eccentrically in said case and provided with independent arc-shaped grooves each
arranged on one side of the axis of the cylinder and trending with both ends toward
the periphery of the cylinder and having one end terminating near the periphery of
the cylinder and the other opening through the periphery, and sliding arc-shaped
pistons arranged loosely in the grooves of the cylinder and guided by the walls of
said grooves, substantially as set forth.
3. The combination with the enclosing case, of a rotary cylinder arranged
eccentrically in said case and provided with independent curved grooves or pockets
each extending in the arc of a circle from the periphery of the cylinder inwardly
toward the axis of the cylinder and outwardly toward the periphery thereof,
segmental or arc-shaped pistons sliding in said grooves, and a cam or projection
whereby the pistons are moved outwardly in their grooves, substantially as set
forth.
Dated this 9th day of June 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.