A New or Improved Oscillating Steam or other Fluid Motor.
Year: 1894

page_text: Date of Application, 24th Oct., 1894-Accepted, 6th July, 1895
COMPLETE SPECIFICATION.
A New or Improved Oscillating Steam or other Fluid Motor.
I, JOHN SMITH MC ANDREW, of 18 Royal Crescent, Glasgow, W., in the
County of Lanark, North Britain, Gentleman, 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 a new or improved oscillating steam or other fluid
motor, for marine and other purposes.
In accordance with my invention I employ an oscillating cylinder having two
side faces and trunnions which work in suitable brackets formed with the steam or
other fluid inlet and outlet chambers or chests; said brackets being formed with
suitable internal faces so as to enable suitable port plates being operated between
the same and the side faces of the cylinder for reversing purposes, suitable means
being provided for operating the said port plates.
My invention is particularly applicable for driving twin screws or propellers for
the propulsion of boats, though it may also be applied for driving single screws,
paddles and other marine and land machines or machinery.
But in order that my said invention may be more readily understood and easily
carried into effect I will describe it with reference to the accompanying drawings
which illustrate my invention for driving a single shaft, by means of steam.
Figure 1 is an elevation, Figure 2, a plan and Figures 3, 4, 5 and 6 detail views
of my improved motor.
Referring to the said drawings, 1 employ an oscillating metal cylinder A having
two flat side faces B. B', trunnions and covers D with stuffing boxes and
glands d. The said cylinder A is carried by means of its trunnions C in two side
brackets or standards E, E', which are formed or provided with the necessary
inlet and outlet chambers or chests and ports hereafter described.
The inner faces of the standards E, E' and the side faces B, B' of the cylinder
are so formed as to enable movable port or reversing plates or discs F, F being
mounted between the said faces as shown, one of the said disc F being shown in
detail views Figures 4 and 5, and the said discs F, F1 are mounted on the
trunnions C of the cylinder A, and formed with spur segments f,f', on their
peripheries into which gear spur segments or pinions f³, f³, for reversing purposes.
The said spur segments f, f, being carried by a horizontal shaft G and suitably
connected to their respective operating handles or levers G' and G' as shown.
Inside the said cylinder A, I mount an ordinary piston, to both sides of which
I suitably attach a piston rod which thus provides a very efficiently balanced
piston, though in the example shown, one of the said piston rods H' only acts as
a guide rod, while the outer or front end of the rod H is attached, in the usual
manner, to the crank or crank pin J of the shaft that is to be driven.
The arrangement of the inlet and exhaust chests in the brackets and the inlet
and outlet ports and passages in the brackets, port plates and cylinder is such that
there is always a certain amount of lead so as to enable the motor to go at a
smooth and steady rate of speed, and the action of the motor is as follows:-
Supposing the motor is desired to go in the direction of the arrow, the lever k
of the regulating or supply valve K is operated so as to supply steam to the inlet
chest in the bracket E and the port plate F brought into the position shown in
Figures 3, 4 and 5 by means of the lever G', so as to open the inlet ports e of the
said bracket E, and also the inlet ports f* and outlet ports of the port plate F

page_text: as shown in. Figure 3 that is to say, the inlet ports e and ft of the bracket E and
port plate F are brought in direct communication with the steam chest L, as at 1
and 2 while the outlet or exhaust ports f of the port plate F are brought in
direct communication with the exhaust chest M, as at 3 and 4. Then as shown
in detail, Figure 4, the inlet port a of the cylinder A is brought into communication
with the inlet port f, which is acting (as at 1) when the engine is going in the
direction of the arrow and when the crank pin J is in the position shown in Figure 3,
also the exhaust port a¹ of the cylinder is in communication with the acting exhaust
port (as at 4): The said ports are then gradually closed by the oscillation of
the engine's cylinder in such a manner as to have a slight lead on the next pair of
acting inlet and outlet ports, (as at 5 & 6 Fig. 5,) when. the crank pin. J is on the
dead centre, as indicated by the arrow 7, and so on. The other port plate F¹ is in
the closed position as shown in Fig. 6, that is to say, the ports in the port plate F
which are cross sectioned are close to both the inlet and outlet chests, of the
bracket E. When it is desired to stop the said engine all that is necessary is to
pull back the lever G¹ and so bring the ports. in the port plate F into a similar
position as shown in Figure 6, so as to cut off the supply of steam to the cylinder.
When it is desired to reverse the engine so as to go.in the opposite direction from
that shown, the lever G¹ is brought back,, steam valve K operated to supply steam
to the bracket, E³, and the lever G³ pushed forward so as, to open the port plate F
and so drive the engine in the opposite direction.
As a modification when not required for reversing purposes I. may dispense with
one of the port plates, steam and exhaust bracket and. sets of ports and in, lieu
thereof simply employ a plain bracket, on the one side of the cylinder.
When my improved motor is employed. for driving twin screws or propellers
simultaneously, I provide or form, both piston rods. H, H with means whereby they
may, be attached direct to the cranks or crank pins of the respective shafts..
It is, to be understood, that the said, engine is provided with the necessary
means for lubricating the working parts and with blow off.cocks &c. as hitherto.
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 :-
1st. The general arrangement, combination and construction of the various parts
constituting my improved, oscillating steam or other fluid motor, substantially as
and for the purposes, herein before described, and shown, in the accompanying
drawings.
2nd. In oscillating, motors, the arrangement, of, an; oscillating cylinder having
flat sides, port plates and, side brackets. having inlet, and exhaust chests,, whereby
the said motor. may, be-reversed, substantially as hereinbefore described and: shown
in the accompanying drawings.
3rd. In oscillating, motors having movable port plates,, the means for operating
the said, plates so as to reverse the motor, substantially as herein before, described
and shown in the accompanying: drawings,
Dated this 18th day of October 1894.
JOHNSONS,
115 St. Vincent Street, Glasgow, Applicants' Agents.