Improvements in or relating to Rotary Pumps.
Year: 1897

page_text: Date of Application, 7th July, 1897-Accepted, 28th Aug.,
1897
COMPLETE SPECIFICATION.
Improvements in or relating to Rotary Pumps.
I, RICHARD LLOYD GURDEN, at present residing at Bedford Hotel, Southampton
Row, in the county of Middlesex, Land Surveyor, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
cescribed and ascertained in and by the following statement:-
66
"
drum
This invention relates to rotary pumps of particularly the construction in which
a cylindrical body hereinafter termed the
rotates eccentrically within a
chamber or casing hereinafter termed the casing" which is preferably of nearly
but not quite circular form in cross section and the invention has among its
objects to provide means for overcoming the difficulty hitherto experienced in pro-
viding the "casing" with a satisfactorily true and even surface.
In the accompanying drawings
Figures 1 and 2 are sectional views showing one manner of constructing the
"casing."
Figs. 3 and 4 are respectively a transverse and a longitudinal section of a rotary
pump showing a second construction of the "casing.”
Fig. 5 is a section of the drum and
Fig. 6 is a section of the piston.
"
Like letters indicate like parts throughout the drawings.
The casing represented diagrammatically in Figs. 1 and 2 is formed in two
halves A A¹ each of which is of slightly less than half a cylinder. These parts A A¹
are provided with flanges a by which they may be bolted or otherwise secured
together. When the parts A A¹ are turned or bored they are bolted together with
distance strips B between the flanges as shown in Fig. 1 these strips B being of
such thickness that when the parts A A¹ are subsequently secured, together as
shown in Fig. 2 without the said strips being interposed between them the "casing'
will be of the required non-circular form.
"
In the apparatus shown in Figs. 3 and 4 I form the portion A² of the casing
which has the non-circular sweep larger than would be necessary to present the
finished. face and preferably with dovetail or similar recesses a¹ and then bore or
After this I
turn out the circular portion of the interior in the ordinary manner.
"
place within the recessed " casing a blank or core occupying a space corre-
sponding in shape and size to the space occupied or swept through by the drum C
piston D and packing strips E. I then pour in suitable molten metal say for
example gun metal or Babbitts metal so as to fill the recesses a¹ and the space
between the casing" and core, the smooth surface of which latter imparts the
necessary smooth surface to the metal thus cast without rendering it necessary
subsequently to tool" or finish the said surface.
"
"
If desired the whole of the interior surface of the "casing" may be formed in
the last described manner so as to save the expense of boring or turning.
The drum C is hollow and rotates in recesses formed in the covers A³ which close
in the ends of the casing and it is provided with diametrically opposite slots C¹

page_text: in which is fitted and free to slide the piston D whose opposite edges are provided
with the packing strips E which are constantly pressed outwards by springs El
Fig. 6 so as to maintain them in the necessary tight contact with the surrounding
wall of the "casing.".
The arrangement in the casing of inlet and outlet is such that while both are
never simultaneously in communication with that side of the piston which 18
remote from the point of contact of the drum with the casing, the range of motion
throughout which the volume of water on the said remote side is not in communi-
cation with either inlet or outlet is as small as is possible compatibly with cheapness
and convenience of construction, the opening and closing of communication being
effected solely by the rotation of the piston by means of its edges E without the
use of valves of any description, although I may use a foot valve in the suction
and non-return valve in the delivery if desired, to save priming and prevent the
pumps being driven as a motor respectively:
At the angles formed between the surface of the cylinder and those of the suction
and delivery pipes I remove some of the material as at A in Figure 3 thus forming
relief passages.
In this way I reduce a two-fold wasteful resistance which is
caused on the one hand by the creation of a partial vacuum, behind-the piston as
it removes from the top point of contact with the casing towards the suction pipe,
and on the other by the pressure generated as the edge of the piston moves across
and gradually closes the opening from the casing to delivery pipe.
The shaft or shafts F is or are, secured to the drum C or may be cast in one
piece with it. A bearing or bearings A a stuffing box A being provided in the
casing of the pump. I do not confine myself to a casing non-circular or of any
particular outline but may make it as described or circular or of amy curves to
which the piston can adapt itself. I may also form the casing of one casting or
shape. the interior to any desired form by tools if preferred.
Where it is desired to use these pumps for high lifts, in which case
the irregularity of delivery gives rise to undesirable pulsations, I use
two or three
are rigidly connected
or more pumps whose spindles
or made in one piece and all of whose delivery, branches or ports
communicate with one common main delivery, and whose suction branches
or ports are similarly arranged, and I arrange the pistons so that these
To effect this in the case of two
pulsations are partially or entirely eliminated.
pumps so connected, the pistons are arranged at. right ankles to each other,' and
in the case of three pumps at angles of 60° of four pumps at 45° and so on,' the
180 where n is the number
angle of advance of each piston on that next to it being -
of pumps thus connected.
:
•
n
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is:
I
1. In a rotary pump of the kind described the, combination with a casing of
non-circular internal outline of an inlet, and outlet arranged,,substantially as
described and illustrated in the accompanying drawings.
2. In a rotary pump of the kind described a casing the whole or part, of whose
internal surface and conformation is formed by pouring molten metal into the
space between the wall of the casing and an internal core or chill of any desired
outline substantially as and for the purpose described. .
597
3. In a rotary pump of the-kind-described a. casing whose internal contour is
that obtained by first turning or horing it as a true cylinder whilst distance pieces
such as B are inserted between the two halves and then securing the two halves
together after such-distance pieces have been removed substantially as described
and illustrated in the accompanying drawings..
T
4. In a rotary nump the combination with a branch or port, opening, from or into
the casing of an extension such as A7 substantially as and for the purpose described.

page_text: 5. The combination of two or more pumps of the kind described having their
pistons disposed and constantly maintained at a definite angle with one another
their delivery pipes communicating with one common outlet, their suction pipes
being also similarly arranged substantially as and for the purpose described.
R. L. GURDEN.
Boult & Wade,
Agents for the Applicant.
Dated this day of y
HOST.
R. L. GURDEN.
Boult & Wade,
Agents for the Applicant.