Year: 1888

page_text: I, THOMAS WILLIAM COLE, of No. 12, Grange Road, Leyton, in the county of
Essex, Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to steam and other engines.
In steam engines as heretofore constructed it is necessary in order to obtain the
full power of the steam upon the crank at its points of greatest leverage, that is to
say, at points at right angles to the axis of the cylinder, to allow the steam to
enter the cylinder at full pressure until the piston has completed at least half its
stroke. The result of this is that in high pressure-engines the full expansive power
of the steam is not utilized owing to the lack of space within the cylinder thus
causing a considerable waste of power.
The chief object of my invention is to obtain the full power of the steam or
other motive fluid upon the crank before the piston reaches the middle of its stroke,
so that the expansive power of the steam can be utilized much more effectually than
heretofore in a single cylinder.
.
According to my said invention the cylinder is caused to follow the piston until
the crank has performed a certain part of its revolution, the pressure being then
applied to the piston to complete the stroke. Or the length of the crank is made
variable in such a manner that for a certain part of the rotation of the crank shaft
the length of the crank will be increased thus allowing the piston to remain approxi-
mately stationary within the cylinder until the crank has reached the most favorable
position to receive the pressure.
A great advantage of this invention is that I am enabled to use a crank of much
longer throw relatively to a cylinder of a given length than can be used when a
fixed cylinder and a crank of unvariable throw are employed, so that, besides using
a smaller quantity of steam as hereinbefore described, I enable this steam to act
upon the crank shaft through a much longer leverage than heretofore.
My improvements are applicable to engines operated by compressed air, gas or
other motive fluid as well as to those operated by steam.
Dated the 18th day of February 1888
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant.

page_text: Improvements in Steam and other Engines.
I, THOMAS WILLIAM COLE, of No. 12 Grange Road, Leyton, in the County of
Essex, 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 :-
My invention relates to steam and other engines.
In steam engines as heretofore constructed it is necessary, in order to obtain the
full power of the steam upon the crank at its points of greatest leverage, that is to
say, at points at right angles to the axis of the cylinder, to allow the steam to
enter the cylinder at full pressure until the piston has completed at least half its
stroke. The result of this is that in high pressure engines the full expansive power
of the steam is not utilized owing to the lack of space within the cylinder thus
causing a considerable waste of power.
The chief object of my invention is to obtain the full power of the steam or other
motive fluid upon the crank before the piston reaches the middle of its stroke, so that
the expansive power of the steam can be utilized much more effectually than hereto-
fore in a single cylinder.
According to my said invention the cylinder is caused to follow the piston until the
crank has performed a certain part of its revolution, the pressure being then applied
to the piston to complete the stroke. Or the length of the crank is made variable in
such a manner that for a certain part of the rotation of the crank shaft the length of
the crank will be increased thus allowing the piston to remain approximately
stationary within the cylinder until the crank has reached the most favorable position
to receive the pressure.
A great advantage of this invention is that. I am enabled to use a crank of much
longer throw relatively to a cylinder of a given length than can be used when a fixed
cylinder and a crank of unvariable throw are employed, so that, besides using a
smaller quantity of steam as hereinbefore described, I enable this steam to act upon
the crank shaft through a much longer leverage than heretofore.
My improvements are applicable to engines operated by compressed air, gas or other
motive fluid, as well as to those operated by steam.
To enable my invention to be fully understood I will describe how it can be carried
into practice by reference to the accompanying drawing, in which Figures 1 and 2
are a side elevation and plan respectively of a steam engine constructed according to
my invention.
Figures 3 and 4 are a front elevation and vertical section respectively illustrating a
modification of my invention.
с
Referring to Figures 1 and 2, a is the engine cylinder, b the piston, c the crank,
d the crank shaft, e the bed-plate, and the slide valve.
The cylinder is constructed and arranged so as to slide in guides 9 on the bed-
plate e to enable it to follow or move with the piston b until the crank c has performed
a certain part of its revolution, the steam pressure being then applied to the said
piston to complete the stroke.

page_text: The friction existing between the piston and the cylinder will generally be sufficient
to cause the sliding movement of the cyclinder a, but in order to control the move-
ment of the said cylinder I provide on the crank shaft d a disc h, having two cam
projections ', against the underside of which disc bears a friction roller i at the short
end of a lever which is pivotted to the under side of the bed-plate e. The other or
long end of the lever j is connected by a link k to a frame / sliding vertically in
guides m, m.. This frame is provided with a horizontal slot n in which slides the crank
pin o of a crank p carried in a bearing on the bed-plate e. The crank pino also
extends into and slides in a slot q in a framer one end of which is attached to the
rear end of the cyclinder a, while the other end is provided with a rods which slides
in a supporting bracket t.
By this arrangement it will be seen that when the crank shaft d is rotated, one of
the cain projections h¹ on the disc h will depress the short end of the lever j and then
allow it to rise so as to cause the frame to rise and fall, thereby causing the crank p
to make a half revolution either backward or forward.
The drawing shows the cylinder a as having been driven to its extreme forward
position with the piston band crank c into the position shown, the said crank being at
about a right angle to the axis of the cylinder.
In order to admit steam to the cylinder a I cause the slide valve to be operated by
a lever u to one end of which it is connected. This lever is pivotted to a bracket v,
and as the cyclinder is caused to slide to and fro on the bed-plate e, the free end of
the lever u comes against stops to, and is thereby caused to operate the slide valve f.
For the purpose of cutting off the steam I employ a supplementary slide valve c
attached to the steam inlet pipe y, the said valve being operated, through the medium of a
lever a, by a cam on the crank shaft d.
t
The portion of the steam inlet pipe y to which the valve is attached, is provided
with a stuffing box and gland so as to form a steam tight joint with the other
part of the said inlet pipe y which is attached to the cylinder a as shown clearly in
Figure 2.
The operation of the engine is as follows; that is to say,-
Suppose the cylinder to be in the position shown in the drawing, and the slide
valves and open and admit steam to the cylinder a, the full power of the said
steam being exerted on the piston (which is in its most favorable position for receiving
the same) thereby rotating the crank.
After the crank has made say a sixth of a revolution the valve a is closed thereby
allowing the expansive force of the steam in the cylinder to complete the stroke.
The momentum of the fly-wheel operating through the disc, lever j, frame l,
crank p and frame r, moves back the cylinder a into position for the return stroke of
the piston which is performed in a similar manner to the forward stroke, after which
the cylinder is again moved forward, and so on.
Instead of the herein before described arrangement of sliding cylinder and ordinary
crank I can use a fixed cylinder in combination with the variable crank shown in
Figures 3 and 4.
This crank c is provided with a slot or opening a' by which it is enabled to slide on
a block 6' attached to the crank shaft d. The crank c is also provided with a friction
roller c¹ which works in a groove d' of the shape shown in Figure 3, the said groove
being formed in the bearing carrying the crank shaft d, and causing the crank-pin
when operated from the piston to describe the curve shown by the dotted line in the
same figure.
By this arrangement it will be seen that the length of the crank increasing will
keep the piston approximately stationary until the crank has reached the most favorable
position to receive the pressure from the said piston.
It will be obvious that this arrangement of variable crank is applicable to the pro-
duction of rotary motion in engines or machines driven by manual power.
Instead of the arrangements of sliding cylinder and variable crank herein before
described it will be obvious that I can, without departing from the principle of my

page_text: invention, use a connecting rod or piston rod so constructed as to automatically shorten
and lengthen every stroke in order to produce the same results.
I wish it understood that I do not limit my invention to the construction herein-
before described, as it is obvious that I may vary the construction very considerably
without departing from the nature of my invention.
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 ;
(1) A new kind of engine operated by steam, compressed air or other expansive
fluid, baving a crank the throw of which is greater than the length of the cylinder of
such engine, whereby the said crank may be at right angles or substantially at right
angles to the piston rod before the piston has commenced its stroke in the cylinder,
for the purposes specified.
(2) In an engine of the kind referred to in the preceding claiming clause, the
employment of a cylinder adapted to slide to and fro substantially in the manner set
forth with reference to Figures 1 and 2 of the drawing, and for the purpose
specified.
(3) The arrangement of my invention wherein I employ a fixed cylinder and a
crank of variable throw, substantially as described with reference to Figures 3
and 4 of the drawing.
(4) The use in an engine or machine driven by manual power of a variable crank
of the kind herein before described.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant.