Year: 1897

page_text: Date of Application, 19th June, 1897
Complete Specification Left, 21st Mar., 1898-Accepted, 7th May, 1898
1, JAMES MCALLISTER, of 7, Rupert Street, Glasgow, Engineer, do hereby declare
the nature of this invention to be as follows:-
This invention relates to rotary motors and it has for its object to improve their
The motor can be driven by steam or other pressure fluid.
construction.
If steam is used its expansive action is taken full advantage of owing to the
special construction of the motor.
I will now describe the motor as adapted to be driven by steam with two
expansions.
There are three cylinders, casings, or chambers, arranged side by side one cylinder
being the high or initial pressure cylinder and the other two the low pressure or
expansion cylinders. The cylinders or chambers are divided from each other by
means of partitions, walls, or their equivalent. A shaft runs centrally through
the cylinders from end to end and fixed to the shaft are three motor wheels one
within each chamber or cylinder. The shaft is passed through stuffing boxes in
the cylinders and at its outer ends has fitted on it the usual fly wheel, driving
pulleys, or other gearing, etc. The steam or other pressure fluid enters the high
pressure cylinder through a reduced inlet port which directs the steam in a jet in
or against a series of buckets, paddles, or vanes, arranged around the circumference
of the high pressure motor wheel. At intervals apart around the inner circum-
ference of the cylinder are or may be fitted a number of retarding or baffling ribs
or plates which prevent the steam flying round freely over the edges of the buckets,
paddles, or vanes.
From the high pressure cylinder the live steam passes through narrow ports or
slots, of which there may be two, preferably at diametrically opposite points, made
in the dividing wall or partition, into the second or low pressure cylinder where the
exhaust steam, in the form of jets, strikes against or in the buckets, paddles, or
vanes, of the second or low press motor wheel and causes it to revolve. In order
to direct the steam passing through the exhaust ports into the low press cylinder the
ports are provided with bent or curved delivery pipes of any suitable section.
The steam after performing its work in the second cylinder is allowed to expand
through exhaust ports of an increased area into the third cylinder or chamber and
there to act upon the buckets, paddles, or vanes of the motor wheel therein.
All the wheels may be of the same construction or they may be varied in con-
struction as desired.
Each cylinder would preferably be provided with retarders or baffles.
From the third cylinder the steam is exhausted by a port of any suitable con-
struction arranged preferably at the lower part of the cylinder if the cylinders are
arranged horizontally.
In order to arrange for the reversal of the motor when necessary. two steam
inlets may be provided so that the steam may be directed against one side or other
of the high pressure motor wheel.

page_text: More than two expansions can if desired be made with this motor.
The vanes, paddles, or buckets may be of any suitable and well known shape.
I prefer to make the buckets of Z or L shape.
The chambers or cylinders are preferably enclosed in a single casing made in two
or more parts bolted together steam tight.
The motor may be used for driving all classes of machinery for light work such as
centrifugals, washing machines, lathes, etc., etc. The motor can also be used for
heavy work.
The motor may in some cases be driven by water or other fluid pressure and in
this case the expansion chambers may be done away with.
Any well known and suitable reversing gear may be used for the motor.
Doted this 18th day of Tuno 1807
I, JAMES MCALLISTER, of 7, Rupert Street, Glasgow, Engineer, 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 rotary motors and it has for its object to improve their
construction. The motor can be driven by steam or other pressure fluid.
If steam is used its expansive action is taken full advantage of owing to the
special construction of the motor.
And in order that my said invention may be properly understood I have hereunto
appended an explanatory sheet of drawings which shows, by way of example, a
rotary motor constructed and arranged for three expansions.
Fig. 1 is a longitudinal section of the motor.
Fig. 2 is a cross section on the line X-X Fig. 1.
Fig. 3 is an enlarged detail view showing part of the chamber b in section and
the motor wheel h in part section.
Referring to the drawings:
a, b, c, d, are four chambers, arranged side by side within the cylindrical casing p,
the chamber a being the high or initial pressure chamber and the other three low
pressure or expansion chambers. The chambers are divided from each other by
means of partitions or walls e, c¹, c² 3, 4, are the ends of the casing. A shaft f
runs centrally through the chambers from end to end and fixed to the shaft are four
motor wheels g, h, i, j, one within each chamber. The shaft is passed through
stuffing boxes k, l, and at its outer ends, has fitted on it the usual fly wheel, driving
pulleys, or other gearing, etc.
The steam or other pressure fluid from the supply pipe m¹ enters the high pressure
chamber a through a reduced inlet port or nozzle m which directs the steam in a
jet in or against a series of buckets o, or paddles, or vanes, arranged around
the circumference of the high pressure motor wheel 9 and causes the wheel and the
shaft to revolve. A part of the steam then escapes through the port r in the
partition e into the chamber b and drives the second wheel h, whilst the remainder
of the steam passes round until it escapes through the second port rl in the
partition e into the chamber 6 where it assists in driving the wheel h. In like
manner the steam in the second chamber b, after driving the wheel h, escapes, by the
ports and 3, into the third chamber c and so on, the steam continuously expanding
from chamber to chamber until it reaches the last one of the series when it escapes

page_text: by the exhaust pipe s. The ports r, r, etc. which may be made in the form shown.
in section at Fig. 3 have bent delivery nozzles or openings t arranged so as to
direct the steam into the buckets o. The ports gradually increase in size from the
first port r to the last or exhaust port leading to the pipe s.
As will be seen at Fig. 2 the ports r, r, etc., are arranged at the top and bottom
of the casing and alternately to the right or left of a central vertical line.
At intervals apart around the inner surface of each chamber are a number of
retarding or baffling ribs or plates 9 which prevent the steam flying round_over_the
edges of the buckets, paddles, or vanes of the motor wheels.
The motor wheels are, by preference, each made with a thin centre part or disc
and an enlarged rim provided with the buckets o.
The motor can be provided with more than four expansion chambers and motor
wheels if so desired.
The vanes, paddles, or buckets, may be of any suitable and well known shape.
When buckets are used I prefer to make them of L shape, as shown or of a Z
shape.
As will be seen the partitions e, e¹, etc. are preferably cast in one with the seg-
ments of the casing, and, as a consequence, they, like the casing itself, are in halves.
The motor may be used for driving all classes of machinery adapted for light
work such as centrifugals, washing machines, steam launches, lathes, etc., etc. The
motor can also be used for heavy work.
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
consider novel and desire to claim is:-
The construction or arrangement and combination of parts of the rotary motor
substantially as herein before described with reference to the drawings annexed.
Dated this 18th day of March 1898.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.