IMPROVEMENTS IN VIBRATING ENGINES
Year: 1885

page_text: COMPLETE SPECIFICATION.
"
I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, of 52 Chancery
Lane, London, in the County of Middlesex, Patent Agents, do hereby declare the
nature of said invention for IMPROVEMENTS IN VIBRATING ENGINES," a com.
munication to me from abroad by William Edward Crist, of the City, County and
State of New York, in the United States of America, Mechanical Engineer, 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 that class of engines wherein a vibrating piston or
diaphragm is secured upon an oscillating shaft to work within a sector-shaped
chamber whose converging walls radiate from the shaft.
The principal object of the invention is to provide a simple, compact, well
balanced, direct-acting, compound engine, wherein the pressure of steam or air
shall be utilized successively in two chambers of unequal capacity, first in a small
high-pressure chamber, and second in a larger low-pressure chamber, into which
the exhaust from the first is carried; or wherein air may be compressed by a
reverse movement, forcing air from the larger into the smaller chamber; many
features of the invention being equally applicable to a single acting engine.
The improvement consists primarily, in forming within a suitable casing and on
diametrically opposite sides of a central, oscillating shaft supported by the casing,
two sector-shaped chambers of unequal capacity because of unequal radial section
or unequal length and within each of which is fitted a piston secured to the rock-
shaft as its pivotal support; and in combining therewith means for admitting
steam or air alternately upon opposite sides of the piston in the smaller chamber,
to exhaust therefrom into the larger chamber upon the opposite sides alternately of
its piston, and thence pass out freely from the engine, the oscillating movement of
the rock-shaft thus obtained being converted into a continuous rotary movement by
well known devices.
i

page_text: The improvement further consists in a novel construction of steam exhaust and
cut-off valves; and self-adjusting valve-seats, and in details of construction
hereinafter particularly specified.
In the accompanying drawings:-
Figure 1 is an end elevation of the engine with the end-plate removed, showing
the valve and crank-gearing.
Figure 2, a vertical, longitudinal, sectional elevation in the line x, x, of
Figure 1.
Figure 3, a transverse, sectional elevation in the line z, z, of Figure 2.
Figure 4, a vertical, transverse, sectional elevation in the line 2, 2, of Figure 2,
showing a separate cut-off valve and means for operating it.
Figure 5, a longitudinal, sectional elevation of the piston in the line w, w, of
Figure 6.
Figure 6, a transverse section of one of the pistons and part of its hollow
rock-shaft in the line v, v, of Figure 5.
Figure 7, a transverse, sectional elevation through the working-chamber, steam
chamber, and valve and exhaust chambers, showing a modification in the form of
valves adapted to this form of engine.
The casing of the engine herein described is preferably made in four
divisions, A, A1, A2, and A³, embracing four distinct chambers (see Figures 2
and 3), viz: the steam chamber, B, working-chambers C, C¹, exhaust cham-
bers D, D¹, and crank chamber, E. The working and exhaust chambers
communicate with each other through suitable ports and passages which are
controlled by an oscillating valve, F, of peculiar construction, to admit the steam
from the chamber, B, to the chamber, C, then to chamber, C, at a reduced
pressure and in an increased volume, and finally to the exhaust chambers, D, D¹,
from which it escapes into the atmosphere.
In the construction shown in the drawings the working-chambers, C, C¹, (see
Figure 3) are sector-shaped and arranged diametrically opposite each other to
radiate from an intermediate cylindrical casing through which they communicate
freely with each other. This free opening between the chambers is closed, and
their communication controlled, by means of a tubular shaft, G, fitted within the
cylindrical casing to oscillate freely therein. The chambers, C, C', thus located on
opposite sides of the rock-shaft, G, are of unequal radial section, the piston area of
the lower chamber, C³, being illustrated as about three times greater than that of
the upper chamber, C.
Flat wings or plates, H, H¹, are secured radially to project from diametrically
opposite sides of the hollow rock-shaft, G, respectively into the chambers, C, C¹, and
are made to fit and move closely against the walls thereof so as to serve as the
vibrating pistons of the engine. The open end, g (Figures 2 and 4) of the hollow
shaft serves as an exhaust port, and communication is established between the
working-chambers and the interior of the shaft by ports, g¹ and g², g³ and g',
(Figure 3) cut on each side of the base of each piston, and by central ports, g³ and g³,
cut diametrically opposite each other at a right angle with said pistons.
Within the hollow shaft, G, is fitted the cylindrical valve, F. The outer
cylindrical-face of this valve is flattened or cut away sufficiently at opposite points
to form passages, f¹ and ƒ2, (Figure 3) to connect alternately in the oscillating
movement of the valve, the ports, g¹ or g³, with the port, g³, on one side, and the
ports, g or g, with the port go, on the opposite side when properly brought into
register therewith. A central recess, f, in the valve communicates constantly
through the open end, g, of the hollow shaft, G, with an exhaust chamber, D, and
ultimately by a lateral opening with the ports, g³ and g. A three-way passage is
also formed in the body of the valve, to encircle partially the central recess, f,
therein and to open outwardly through the face of the valve between the proximate
edges of the outer channels, f¹, and f³, and between the opposite edges of said
channels and the intermediate central port, f, so that communication shall be

page_text: constantly established through the same by means of the diverging passages, fa
and f, therein, either between the port, g¹ and the port 9, on the one side, or
between the port, gå and the port g³, on the other side of the two pistons, H, H.
The side-walls of the cylindrical casing enclosing the rock-shaft, G+, between the
working-chambers, are made movable so as to become self-adjusting against the
rock-shaft to serve as valve-faces or seats and are made to constitute the inner
walls of hollow boxes, I, I', which are borne and held against the shaft with a
constant pressure to form a steam-tight joint therewith, by means of springs
enclosed between the outer face of each and a steam-chest, I, within which the box
is fitted. Ports m, m, are cut through these valve-faces or inner walls of the
boxes, I, I, to establish communication between the ports, gs and go, in the hollow
rock-shaft, G, and the interior of the boxes, I, I, as hereinafter set forth. The
valve-boxes, I, I, and the enclosing steam-chests I, I, are left open at the top and
bottom to admit of a free passage thereinto of steam from the enclosing steam-
chamber, B, as shown in Figures 3 and 4.
Live steam being freely admitted from the steam pipe, B¹³, into the steam-
chamber, B, will pass freely into the steam-chests I, I, and valve-boxes, I, I¹. If
now the port, g6, on one side of the hollow rock-shaft, G, in register for the time
being with the passage, f, of the valve, F, is brought into register with the port, m,
in the face of the valve-box, I, on that side, the steam will pass through said
port, g, and passage, f, to the port, g³, in the hollow rock-shaft and through the
same into the smaller or high-pressure working-chamber, C, of the engine, as shown
in Figure 3, and will drive its piston, H, over, the steam' in front of said piston
meantime escaping into the larger, low-pressure working-chamber, C¹, (to bear
against its piston and drive it forward), through the exhaust-way opened through
the port, g¹, on that side of the piston, the three-way passage in the central
valve, F, and the port, g, opening into the chamber, C', the steam in front of the
low-pressure piston, H¹, being left free to exhaust through the port, g³, into the
central exhaust-passage, f, in the valve, F, and out through the open end, g,
(Figure 2) of the rock-shaft, G.
In the drawings, the radial section, or piston-area of the small high-pressure
chamber, C, is represented as about one-third that of the larger low-pressure
chamber, C, although any other relative proportions may be employed.
The connection of the several ports is changed to produce the alternate pressure
and exhaust upon opposite sides of each piston required to cause its vibration, by
means of the oscillating movement of the valve, F, within the hollow rock-shaft, G.
The valve, F, moves with the rock-shaft, G, during the principal part of each
stroke of the pistons, the admission of steam during the stroke being determined
by the relation of the supply port g³ or go, in the rock-shaft to the stationary
supply port, m, in the valve-box, I', and governed by the length of the said port, m.
When the high-pressure piston is sufficiently near the end of the stroke in either
direction to require its reversal and yet allow sufficient steam in front of it to serve
as a cushion therefor in completing its movement, the valve, F, is arrested and
reversed in its movement by means of an arm, K, (see Figure 1) fixed to a crank-
pin, L, on the end of the main shaft, L, of the engine, or by an eccentric on said
shaft, which said arm or eccentric is coupled with a crank-arm, M, on the end of
the valve-shaft, F, by a coupling-rod, N, pivoted thereto so that the revolution of
the main shaft, L, will produce an oscillation of the valve, F. The continued
movement of the rock-shaft, G, as the piston finishes its stroke after the valve, F,
is arrested, operates to change the relative positions of its ports with reference to
those in the valve and thus change the direction of the currents of live and exhaust
steam.
The crank-pin, L¹, and arm, K, on the end of the shaft, L, revolve in a crank-
chamber, E, which may be closed by a detachable face-plate, A³, (see Figure 2)..
The lower part of the chamber, E, may be filled with oil which being constantly
agitated by the movement of the crank will distribute itself thoroughly 'over the
bearings and journals-projecting into said chamber.

page_text: The open end, g, (Figure 2) of the hollow rock-shaft, G, may be made to
communicate by means of a passage, D, (see Figure 2) with a chamber, D¹, formed
within the base or pedestal of the engine to receive the exhaust steam.
A feed-water pipe, O, may be arranged in a coil in this lower exhaust-
chamber, D, and being therein surrounded by the exhaust-steam, will furnish
in a simple, compact form means for heating the feed-water without additional
expense.
A cut-off, or combined cut-off and throttle-valve, may be applied and used
in connection with the hollow rock-shaft, G, in the following manner. The self-
adjusting valve-faces or seats in the boxes, I, I, are formed with recesses, P, P,
into which segmental valves, R, R, (see Figure 4) are fitted to bear and move freely
upon the outer surface of the hollow shaft, G, with a steam-tight joint. The
valves, R, are actuated and adjusted upon the shaft, G, by means of vertically-
moving rods, R¹, and serve by their adjustment to increase or decrease the size of
the steam supply openings through the valve-faces and to determine thereby the
point at which the steam will be cut off from the ports, g³ and 96, in the oscillation
of the rock-shaft. The valves, R, may be opened to full width to admit steam
during nearly the entire stroke of the piston, as shown upon the right in Figure 4,
or may be partially opened, as shown upon the left in the same Figure. Or the
valves may be dropped so far as to entirely close the ports in the valve-faces and
thereby serve as a throttle to completely cut off the admission of steam to the
engine. The valve-rods, R¹, may be actuated by any suitable mechanical devices,
and I contemplate connecting them to the governor of the engine in any well
known or desired manner to secure their movement by its action and thereby
regulate the point of cut-off in conformity to the requirements of the engine.
The pistons, H, H¹, are packed by means of side strips, h, end strips, h¹, and
corner pieces, h², (see Figure 6) adapted to fit snugly into a groove or channel, l,
(see Figure 5) in the edges of the pistons. The side and end strips are forced
outward against the walls of the working-chamber by the pressure of springs, S, S,
interposed between the strips and the bottom of the channels. The angular,
corner pieces, h³, are fitted against the ends of the side and end strips with a
beveled joint (see Figure 5) adapted to produce an outward movement of the
corner pieces simultaneously with the outward movement of the spring-actuated
strips. The packing strips may be of phosphor-bronze, steel or other metal which
preserves its edge truly. The corner pieces being acted upon with a pressure
corresponding to that upon the side and end strips, are held with equal force
against the inner surface of the working-chambers, and thereby preveut unequal
friction and consequently unequal wear at any one point.
Various changes may be made in the details of construction of the engine
without departing from my invention, and many well known devices may be
substituted for certain of the novel devices peculiarly adapted to my invention
without departing from its general scope; as for instance, two or more steam-valves
may be employed to govern the supply and exhaust ports of the working-chambers,
to be operated according to well known systems of valve movement.
In Figure 7, an example is given of the use of four oscillating-valves, T, T¹,
T2, T3, in combination with the remaining features of my compound engine. The
valves, T, T¹, control the admission of the high-pressure steam from the steam
supply chamber, B, to the upper working-chamber, C, through the ports, W, W,
and W, W, and its subsequent exhaust through the ports, W₁, WI, and valves, T²
and T3, from the high-pressure chamber, C, to the low-pressure chamber, C¹. The
valves, T, Ts, operate synchronously with the valves, T, T¹, so as to admit steam
from the high-pressure chamber, C, through the ports, W₁, W¹, and valves T, T¹, to
the ports, W2, W2, and into the low-pressure chamber, C¹, and by means of the
ports, W2, W2, and W³, W³, allow its exhaust into the chamber, D', surrounding
the lower or low-pressure working-chamber.
Where separate valves of the above described arrangement are employed, the
rock-shaft. Š. to which the pistons. H. H¹. are connected may be made solid and

page_text: the pistons bolted thereto instead of being cast thereon. The self-adjusting steam-
balanced valve-faces of the boxes, I, I, described in connection with the remaining
Figures of the drawings may also be dispensed with in this case, as a simple,
spring-actuated packing-strip, Y, (Figure 4) may be employed in lieu thereof.
I do not limit myself to the exact arrangement of ports herein shown, as my
invention includes any arrangement or method of connecting two sector-shaped
chambers of unequal capacity, when in combination with vibrating pistons of
unequal area operating, or to be operated upon, by air, gas, or steam contained.
alternately in the chambers and expanded from high-pressure to low-pressure or
compressed from low-pressure to high-pressure.
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
1st A compound, vibrating-piston engine, constructed with two sector-shaped
working-chambers of unequal piston area; pistons vibrating therein about a
common axis; a communicating channel adapted and arranged to conduct the
steam or air expelled from one chamber by the forward movement of its piston,
into the second chamber against its moving piston, substantially in the manner and
for the purpose herein set forth.
2nd In a vibrating-piston engine, the combination with communicating chambers
of unequal piston area, of vibrating pistons working within said chambers and
secured to and radiating from a common axial shaft to be subjected jointly and
successively to unequal pressure upon their opposite faces, substantially in the
manner and for the purpose herein set forth.
3rd The combination with the two piston-chambers of a compound-engine and
with its exhaust and supply pipes and ports, of an oscillating valve interposed.
between said chambers and adapted to connect in its movements said exhaust and
supply pipes and the supply and exhaust ports of said chambers and to establish
communication between the latter, substantially in the manner and for the purpose
herein set forth.
4th The combination in a compound vibrating-piston engine, with its working-
chambers and with a hollow oscillating shaft; ports therein communicating with
the supply and exhaust pipe of the engine and with said chambers; and an
oscillating-valve fitted within the shaft to participate in its movement and yet be
free to oscillate independently thereof; of a valve-lever pivoted to said shaft and
devices for reversing the lever and valve in the movement of the shaft and pistons,
substantially in the manner and for the purpose herein set forth.
5th The combination in a vibrating-piston engine with its steam chest, working-
chamber and with a vibrating-piston secured to a hollow rock-shaft through which
are formed the ports adapted to establish, in the movements of the shaft and piston,
communicating passages between the steam-chest and working-chamber and the
working-chamber and exhaust pipes, of an automatic cut-off valve fitted upon the
outer side of the shaft and adapted, in the movement of the latter, to cut off
the admission of steam to its supply ports, substantially in the manner and for the
purpose herein set forth.
Gth In a vibrating-piston engine the combination with two working-chambers
arranged on either side of a common centre, of two steam-chests placed opposite
each other on either side of said centre, intermediate the working-chamber, and
adapted to enclose self-adjusting, balanced valve-seats supporting a central,
oscillating, bollow piston-shaft, substantially in the manner and for the purpose
herein set forth.
7th The combination in a vibrating-piston engine with its working-chamber; its
hollow, oscillating piston-shaft and pistons; the steam supply ports in the shaft ;
and a steam-supply-chamber or jacket enclosing the same, of self-adjusting,
balanced valve-faces or seats adjusted to the oscillating-shaft on opposite sides

page_text: thereof, and fitted with ports for the admission of steam to the shaft, substantially
in the manner and for the purpose herein set forth.
8th The combination with an angular piston in a piston-engine and with packing
strips fitted longitudinally to the sides and outer edges of the piston, of corner
pieces whose ends are inwardly beveled to rest each upon, and against, the
counterpart beveled ends of the adjacent edge and side strip, and be forced
outwardly by the outward movement of said strips, substantially in the manner
and for the purpose herein set forth.