Improvements in Semi-rotary Pumps.
Year: 1897

page_text: Date of Application, 1st Apr., 1897-Accepted, 19th June, 1897
Improvements in Semi-rotary Pumps.
I, DAVID MORELL of 37 Wilhelmshöher Allee, Cassel, in the German Empire,
Manufacturer, 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 pumps which may be employed for elevating liquids and
compressing and forcing air and gases and which are especially applicable for the
latter purposes. A pump constructed to embody my present improvements may,
because of its simplicity, be produced at a very low cost, and possesses a high.
efficiency. Its weight being relatively low, it may also bo very easily transported,
and it may be worked with great ease and be readily mounted for work." The
smaller sizes may conveniently be used for inflating pneumatic tyres and for other
similar purposes.
I will describe my improvements with reference to the accompanying drawings in
which :-
Figure 1 represents a plan of the pump with a cross section taken through one of
the pairs of pistons.
Figure 2, a section along the line -, Figure 1: and
Figure 3, a section of a modification of the piston as used for pumping
liquids.
The pump casing consists of two parts, one of which, a, is fixed, and the other, b,
rotary. The pistons are contained in an annular recess, which may be circular in cross
section or of any other suitable and convenient shape. The rotary part of the
casing, b, moves around a bolt or pin c, one end of which is screwed or fixed in
the part a, and the other end of which is provided with a washer and nuts. which
prevent lateral motion of the part b. A packing ring, is arranged between the
parts a, and b.
b
0
The annular recess between the parts a and b, may contain six pistons and h.
three of the pistons 9 being arrangod at equal distances apart on the part a, and
three h, being similarly arranged upon the part so as to come between the pistons .
Upon one part of the circumference of the part & there is a lug i, shewn in dotted
lines in Figure 1, to which there is pinned a connecting rod or the like, k, which
may be actuated by hand or by power. The pistons are hollow, and the walls of
those which are fixed upon the part a, are provided with the perforations 1. The
front surfaces of all the pistons are fitted with leather, indiarubber, or other similar
packing discs or rings, the outer edges of which are turned outwards from the
pistons as shewn. These are fixed upon the pistons by means of the metallic plates
and the set screws ". The packings m sorve also to act as valves with reference to
the openings 1, and to permit the full action of such valves the plates.o have their
contiguous parts cut away. This construction permits the use of the ordinary
distributing valves to be dispensed with. Passages p and q are arranged in the
central part of the casing a, close to the fixed pistons g. Three of these passages p,
communicate with the passager and the other three, g, with the passages.
passages r and open into a chamber at the end of the bolte which is divided by the
partition t, and this chamber is closed by the perforated screw plug v. On each side
of the partition, there is arranged a block, r, y, of indiarubber, by the movement
of which under the action of the pump, the openings of rands are alternately closed
and opened. On the outer face of the part of the casing a, there is formed an annular
Di 01
The

page_text: groove z, which is normally covered by the indiarubber ring or disc 2'. This groove
communicates by the passage with tho atmosphere, and by the passages ¹ with the
hollow interiors of the fixed pistons g.
Assuming the pump to be employed in forcing air or gases, its action is as follows:-
When the pistons are moved in the direction indicated by the arrow 1, the air in
front of the pistons is compressed and entering the passages q, passes the passage
and block which is forced outwards, and finally issues through w, to which a
pipe may be connected for conveying the compressod air where wanted.
In the meantime, the air at the backs of the pistons has become rarefiod and
consequently atmospheric air is drawn in through the passages, 2 and into the
spaces within the pistons y, whence it passes through the openings into the
increasing spaces between the pistons and h. It will be seen that in this
movement the atmospheric pressure lifts the packing over 1, to allow the air to pass.
At the end of the stroke the motion is reversed and the air which has just entered
becomes compressed, enters the passages p, r, moves the valve y, and issues through u
to the receiver.
This cycle of motions is repeated with every oscillation.
If the pump is intended to be used for liquids, it would be found that the openings l
as shewn by Figure 1, would bo inadequate, and it would be advantageous to arrange
a larger opening on each face of each piston g, as shewn by Figure 8, in the centre
of the face, and protect this opening by means of a back pressure valve a' or '.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In double acting pumps, a casing divided perpendicularly to its axis and
containing an annular recess, one part of the casing being fixed and the other capable
of oscillation, a number of radial pistons fixed in the fixed part of the casing, and an
equal number of pistons fixed in the oscillatory part, constructed arranged and
operated substantially as herein before described and as illustrated by the accompanying
drawings.
g
2. In pumps of the type set forth, the pistons 9 having the valves m ! and being
fixed relatively to the pump, in combination with pistons & oscillating between the
pistons ; constructed and arranged substantially as hereiubefore described with
reference to the accompanying drawings.
3. Double acting pumps constructed arranged and operated substantially as heroin-
before described with reference to the accompanying drawings.
Date this 31st day of March A 1) 1897
W. E. HEYS & SON,
Agents for the Applicant.