An Improved Rotary Pump.
Year: 1899

page_text: Date of Application, 6th July, 1899-Accepted, 10th Feb., 1900
COMPLETE SPECIFICATION.
An Improved Rotary Pump.
I, ALFRED ERNEST LUTTRELL, of Launceston, in the Colony of Tasmania,
Engineer, do hereby declare the nature of this invention and in what manner the
saine is to be performed, to be particularly described and ascertained in and by
the following statement:-
The object of this invention is to provide a pump which working on the rotary
principle and consisting of the fewest possible number of working parts com-
vines the actions of lifting and forcing and gives a steady and uniformi flow.
To obtain these results I construct a pump which consists of a circular chamber,
having an outlet and inlet in which revolves a helical disc or blade working in
conjunction with a sliding stop as hereinafter described.
In order that my invention may be more clearly understood I will at once refer
to the accompanying drawings.
Figure 1 shows the interior of the pump when one of the side covers is lifted
off and the movable parts removed.
a is the circular chamber.
b is the circular recess provided in the inside of each of the side covers to form
a bearing for each end of the drum on which the helical disc or blade is formed.
c is flange to which the side cover is bolted.
dd are the bolt holes.
e is a rectangular chamber provided in each of the side covers into which fits
one end of the sliding stop.
fis the inlet connection.
9 is the outlet connection.
Figure 2 is a vertical cross section through pump.
is the drum on which is formed the helical disc or blade k. The form of this
blade may be described as a half section of a right hand screw thread joined to a
half section of a left hand screw thread, thus forming a continuous helical disc
or blade, which at all points stands at right angles to the drum h on which it is
formed as shown in elevation in Figure 3.
is the spindle or shaft on which is keyed the drum h and by means of which
the drum and helical disc arc revolved in the chamber a.
mm are the bearings formed on the side covers nn; these bearings are pro-
vided with stuffing boxes.
p is the sliding stop which consists of a plate of metal or other suitable sub-
stance in which is cut a rectangular slot Fig. 4 through which passes the revolv-
ing disc. This stop always maintains a position across the course of the disc slid-
ing backwards and forwards into the chambers ee in either side cover as the disc
revolves thus forming a continuous stop.
This stop may be provided with expansion pieces rr and set screws ss in order
to take up any wear that may be caused by the friction of the disc on the sides
of the slot t.
v is the circumferential edge of the helical disc which is so constructed as

page_text: to form a joint with the inside periphery of the chamber a.
expansion rings may be provided.
If found desirable
keyed to shaft or
Figure 3 is elevation showing drum h and helical disc
spindle with sliding stop 7 in position. Figure 4 shows sliding stop p; t being
rectangular slot or aperture through which passes helical disc k as shown in
Figures 2 and 3.
The method in which my invention works is as follows:-
The helical disc k divides the circular chamber into two compartments for as
before stated the circumferential edge of the disc forms a joint with the inside
periphery of the pump chamber; thus two compartments are formed one on each
side of the disc.
P
The sliding stop p fits over and forms a joint with the helical disc and main-
tains a position across its course and the lower edge w of stop rests on and forms
a joint with the drum h on either side of the disc. This joint inay be maintained
by means of adjustable tension screws if found desirable. A portion (marked y)
of each side of the helical dise is always in contact with the side cover contiguous
thereto forming a joint therewith as shown in Figure 2, consequently (the sliding
stop being a continuous stop) the two compartments formed by the helical disc
are subdivided and four separate compartments formed, two on each side of the
disc, except at each half revolution when the portions yy are alternately passing
through the slot : At these positions of the dise the chamber is divided into
only three compartments and both inlet and outlet ports are closed on one side
of the disc alternately. The shape and position of the inlet and outlet ports is
determined as follows:-When the portions yy are alternately in the slot of the
sliding stop on their respective sides of the chamber a the shape of the inlet
and outlet ports is determined by marking the position of the outer edges of the
helical blade on the periphery of the chamber in eacli position. When the disc
is. revolved a partial vacuum is formed and the water enters through the inlet
pipe and fills one of the compartments one side of the helical disc and imme-
diately afterwards the corresponding compartment on the opposite side is filled
and carried round so that the revolution of the disc causes a continuous series
of discliarges and intakes thus giving a uniform flow from the outlet.
By dispensing with the sliding stop, my invention may be thus converted into
a highly effective centrifugal pump; as when the stop is removed the pump con-
sists of a disc revolving in a closed chamber, which will only have the action of a
centrifugal pump. In this case it will be necessary to alter the position of the
ports.
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 a rotary pump, a helical disc or circular blade, of the form and construc-
tion substantially as herein fully described and as illustrated in the drawings.
2. In a rotary pump, a sliding stop (such as ) of the nature and for the pur-
pose herein set forth and as illustrated in the drawings.
3. In a rotary pump, the combination of a helical disc or circular blade revolv
ing in a circular chamber with a sliding stop having a rectangular passage-way
therethrough substantially as herein fully described and as illustrated in the
drawings.
Dated this 41
1000
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.