Improvements in Rotary Pumping and Motive Power Engines.
Year: 1889

page_text: Date of Application, 20th Apr., 1889-Accepted, 15th June, 1889
COMPLETE SPECIFICATION.
Improvements in Rotary Pumping and Motive Power Engines.
I, EDWIN GOSSMAN Engineer Victoria Road, Gourock in the County of Renfrew,
North Britain 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 :-
My Invention, which relates to Improvements in Rotary pumping and motive power
engines, consists of a cylindrical chamber, inclosing three plates sliding in slots formed
in a drum, which drum is hung so as to rotate on an axis parallel to but excentric
from that of the inclosing cylinder: the plates and drum being arranged as fully
described hereinafter, so as to divide the inclosing cylinder into three compartments
which expand and contract as the drum rotates.
In order that my said Invention may be distinctly understood, and readily carried
into effect, I will now proceed to describe the drawings hereunto annexed.
Figure 1 (sheet I), is an end elevation of a Rotary pump or engine, showing
cylinder cover with inlet and exhaust ports.
Figures 2. 3 (Sheet I), are respectively a side elevation and a plan of same.
Figure 4. (Sheel II), is a transverse vertical section of Rotary pump or engine,
showing excentric drum carrying diaphragm, which with the drum, divide the
cylinder into three compartments.
Figure 5, (Sheet II), is a longitudinal vertical section of same, showing driving
shaft on drum, projecting through packed hearing in cylinder cover.
Figure 6 (Sheet 11), is a plan of drum, with the diaphragm plates, in the position
shown by Fig. 4.
Figure 7 (Sheet II.) is an end elevation of same showing arrangement of strips for
keeping ends of drum and plates, pressure tight against the cylinder covers.
Figure 8. (Sheet II), is an elevation of a portion of cylinder cover (inside) showing
inlet and exhaust ports.
Figures 9. 10. 11. (Sheet III), are respectively an elevation vertical section, and
horizontal section of cylinder cover, of Rotary motive power engine fitted with
reversing cock and expansion valve.
Figures, 12. 13. 14. 15, (Sheet III) are elevations of the port face of cylinder
cover, showing four different positions of expansion valve, viz. 12, full admission:
13, 2nd grade: 14, 3rd grade; 15, 4th grade, or earliest cut off.
Note No provision is made for expansive action while engine is reversed; the
position of the gridiron valve being then as in Fig. 12.
In my said Improvements in Rotary pumping and motive power engines, the cylinder
ends or covers 61, 611 (Figs. 1. 2. 3. 5. 9. 10. 11) are made, either or both removable from
the cylinder a. (Figs. 2. 3. 4. 5.): the drum c (Figs. 4. 5. 6. 7.) is hung with its axis
parallel to but excentric from the axis of the cylinder a, by having turned projections
or trunnions d¹, du, formed on its ends (Figs. 2. 3. 5. 6. 7), resting in bearings
formed in the cylinder covers 61, 61: one of these projections, di, is extended through
the cylinder cover b¹, and being made strong enough to transmit the work of the
pump or engine, is employed as the driving shaft: the other projection d", need not
project through the cylinder cover 6". The bearing in which the driving shaft runs
is made pressure tight, by the usual expedient of packing e, and gland ƒ (Fig. 5): the
drum is made in length, a close working fit between the faces of the cylinder covers.
An annular recess g (Figs. 4. 5), is formed at each end of the cylinder, by checking
down the cylinder covers, in each of which recesses are fitted three sliding blocks h. h. h.
(Figs. 4. 5.) which so far as they extend circumferentially, fill the recesses g.
Hush with the faces of the cylinder covers. Three diaphragm plates i¹, ",
(Figs. 4. 5. 6. 7.) are formed, each with its outer edge terminating in two turned

page_text: projections, which take into bearings, sunk in sliding blocks h. h. h., the same edge
of each diaphragm plate being shaped to such a radius as to allow of the plates
acting hingewise in the slipper pieces j¹, j", j¹¹ (Figs. 4. 5), which are thus held in
contact with the curved wall of the cylinder a, and present a suitable surface at
whatever angle the position of the plates necessitates. The plates,,, slide in
slots in the drum so disposed that the three faces on which the plates work form an
equilateral triangle, and the reciprocating motion of the plates,,, caused by
their passing over and under the axis of the inclosing cylinder, as the drum c revolves,
is tangential to the inscribed circle. The plates,,, like the drum c form a close
working fit between the faces of the cylinder covers 61, 61, they are kept by means of
the sliding blocks h. h. h. and the slipper pieces in communication with the
curved wall of the cylinder, and they each bear on the drum c, thus dividing the
inclosing cylinder into three compartments.
It will be seen on examining Fig. 4, that as each plate is furthest from the
axis of the inclosing cylinder, the compartment behind it is reduced to its
minimum capacity, that is, the necessary clearance; and that as it passes from this
position the compartment begins to expand it will likewise be seen that each com-
partment is at its maximum capacity when its relative plate is nearest to the axis of
the inclosing cylinder, and passing from that position begins to contract. On the end
of the drum c furthest from the driving shaft d' are formed three ports k¹, kll, kill,
(Figs. 4. 5.) with passages through part of the length of the drum c, and through and
round each plate to its relative compartment; two ports K', K" (Fig. 8.) are formed
on the face of the cylinder cover 6", one leading to the suction, when the engine
used as a pump, or to the boiler or other source of pressure when used as a motive
power engine; the other leading to delivery in the one case and to exhaust in the
other. These ports are placed in the path of those in the drum c, one on each side of
that position which each drum port fills, when its relative compartment is of minimum
capacity; they (K1, K") are separated by a bridge just so broad as to lap each drum
port, and they are carried round the path of the drum ports so far as to be separated
by a similar port diametrically opposite, the first. Each compartment begins to
receive so soon as it opens to the inlet port, on the cylinder cover, it receives until the
drum port has traversed the cylinder cover port, the compartiment has meanwhile
rotated one half revolution, has attained its maximum capacity, and begins to open to
outlet port, simultaneously with the beginning of its contraction.
When my said Invention is applied as a motive power engine requiring reversibility
of motion, I fit over the passages K', K" (Fig. 1) a four way cock (Fig. 9. 10. 11.)
actuated by a lever handle or other suitable gear: either K' or K" may thus be
opened to the boiler or other source of pressure, while the other is open to exhaust.
To render my said Invention applicable to a motive power engine working ex-
pansively by steam or other elastic gas or fluid, I modify as follows the arrangement
for distributing the pressure, viz. (Figs. 9. 10. 11. 12. 13. 14. 15), the passages leading
from ports K, K" are placed close to one of the bridges, (Figs. 12. 13. 14. 15) the
surface of the other bridge is depressed so much as allow the sector shaped plate p,
of sufficient thickness to afford the necessary rigidity, to lie on the said bridge and be
flush with the face of the cylinder cover 6"; the sector shaped plate is formed at one
radius with a flange bearing on the bottom of the port recess in the cylinder cover
(Figs. 10. 11.) and the surface of the plate is broken up by radial openings
(Figs. 12. 13. 14. 15) of such width that any two can be covered by the bridge over
which the sector shaped gridiron valve works, as much of the sector's surface being
left solid at the flanged edge as will lap the drum ports. The cut off is made earlier
by advancing the flanged edge of the sector shaped valve or plate so as to meet the
drum port at a reduced angle of its circuit, the sector being of such size that when the
flanged edge is in position for earliest cut-off (Fig. 15), the other edge exactly overlies
the remote edge of the bridge, this bridge besides being reduced in depth to admit the
thickness, has as much breadth cut off the side as is given to the flange of the sector
shaped plate or valve, so that the latter may be put into the position shown by
Fig. 12 this is necessary when the engine is to be run full steam, and to permit free

page_text: exhaust when reversed. In order that this expansion valve may be adjusted to various
positions while the engine is at work, it is formed with a spindle extending through
the centre of the reversing cock; (Figs. 9. 10. 11.) in this arrangement the stud d
projecting from the drum c is dispensed with, and instead thereof the spindle of the
plate or valve p. extends into the drum (Figs. 10. 11.). Figure 9. shows a lever
handle for adjusting the expansion valve p, but any of the well known high speed
governors may be applied to effect automatic expansive action. The method which I
adopt for holding the port face of the drum c pressure tight against the face of the
cylinder cover to prevent leakage from one compartment to another is shown by
Figs. 5. 7, s. s. s. and t. t. t being packing slips fitted into ends of diaphragm plates
and drum and held against the face of the cylinder cover by springs or other elastic
material.
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 1
claim is,
I. The Improvements in Rotary pumping and Motive power engines, consisting of
dividing a cylindrical chamber into three compartments, by the combination of a drum
rotating on an axis excentric to that of the inclosing cylinder, and carrying three
diaphragm plates, which while retaining their contact with the cylinder walls, slide in
slots in the said drum in a direction tangential to the circle about which they revolve
all substantially as described.
II. The Improvement in Reversing Rotary Engines, consisting of the employment
of the arrangement above claimed in combination with a four way cock for reversing
the current of pressure, in the manner substantially as described.
III. The Improvements in Rotary engines to be worked expansively, consisting of
the arrangements claimed above (claims I & II) in combination with the sector shaped
expansion valve applied between the ports in the drum and the ports in the cylinder
cover, and controlled by hand or by automatic governor, all substantially as
described.
Dated this Nineteenth day of April 1889