IMPROVEMENTS IN STEAM ENGINES
Year: 1865

page_text: LETTERS PATENT to Joseph Stocker, of Amersham Vale Road, New
Cross, in the County of Kent, for the Invention of "IMPROVEMENTS IN
STEAM ENGINES."
Sealed the 29th May 1866, and dated the 12th December 1865.
PROVISIONAL SPECIFICATION left by the said Joseph Stocker at the
Office of the Commissioners of Patents, with his Petition, on the
12th December 1865.
I, JOSEPH STOCKER, of Amersham Vale Road, New Cross, in the County
of Kent, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN STEAM ENGINES," to be as follows:-
My Invention relates to a means applied in lieu of the crank for converting
or transmitting the reciprocating motion of the piston of a steam engine to the
main rotary shaft, through the intervention of which such power is to be
utilized; it is more particularly adapted for screw propeller engines and for such
engines as are known as trunk engines, but it is also applicable to engines
used for other purposes.
By the application of this Invention to trunk engines the engines can-be-
condensed into the smallest possible space. In the trunk engine I dispose the

page_text: steam cylinder concentric with the shaft, and I fix on the shaft a solid cylinder
nearly fitting the internal diameter of the trunk. In this solid block I cut
a kind of cam groove, which for the one half turn round the solid cylinder is
in the form of a thread of a right-hand screw or incline, while in the other
half it is a left-hand thread, and of course returning to the point of departure,
and so forming an endless groove. The incline of this groove in the half turn
equals the length of the stroke of the engine. A projecting stud furnished
with a truck roller is disposed inside the trunk, which roller is received in the
groove or cam, so that on reciprocating motion being given to the trunk by
the steam piston the thrust in the one direction is transmitted by the roller
to the solid cylinder fixed on the shaft through the intervention of the grooves,
which causes it to rotate a half revolution, and the thrust in the opposite
direction (the return stroke) taking effect in the part of the groove oppositely
inclined continues the rotation of the shaft in the same direction. There
may, of course, be two or more steam cylinders placed on the same shaft
which passes through the trunks or hollow piston rods, and is fitted in
suitable bearings for its support and thrust. The valves and other parts of
the engine may be worked from the shaft by any of the ordinary arrange-
ments.
This double-inclined groove solid cylinder may be applied to other engines
than trunk engines by disposing it on the shaft and placing it in communica-
tion with the piston rod of the steam cylinder by a stud, pin, or truck roller
fixed to such piston, a rigid connection being of course maintained between
the steam cylinder and the bearings of the shaft to resist the end thrust
produced.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Stocker in the Great Seal Patent Office on the
12th June 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
STOCKER, of Amersham Vale Road, New Cross, in the County of Kent, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of December, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the

page_text: said Joseph Stocker, Her special licence that I, the said Joseph Stocker,
my executors, administrators, and assigns, or such others as I, the said Joseph
Stocker, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN STEAM
ENGINES," upon the condition (amongst others) that I, the said Joseph
Stocker, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of
the said Letters Patent.
NOW KNOW YE, that I, the said Joseph Stocker, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-.
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Sheet of Drawings hereunto annexed,
and to the letters and figures marked thereon (tbat is to say) :—
:-
My Invention relates to a means applied in lieu of the crank for converting
and transmitting the reciprocating motion of the piston of a steam engine to
the main rotating shaft, through the intervention of which such power is to
be utilized; it is more particularly adapted for screw propeller engines and
for such engines as are known as trunk engines, but it is also applicable to
engines used for other purposes.
By the application of this Invention to trunk engines the engines can be
condensed to the smallest possible space. In a trunk engine I dispose the
steam cylinder concentric with the shaft, and I fix or form on the shaft a
solid cylinder nearly fitting the internal diameter of the trunk, it may be the
size of the shaft itself. In this solid piece I cut a kind of cam groove, which
for the one half turn round the solid cylinder is in the form of a thread of
a right-hand screw or incline, while on the other half it is a left-hand thread,
of course returning to the point of departure, and so forming an endless
groove. The incline of this groove on the half turn equals the length of the
stroke of the engine. A projecting stud furnished with a truck roller is
disposed inside the trunk, which roller is received in the groove or cam, so
that on reciprocating motion being given to the trunk by the steam piston the
thrust in the one direction is transmitted by the roller to the solid cylinder

page_text: formed or fixed on the shaft through the intervention of the groove, which
causes it to rotate a half revolution, the thrust in the opposite direction
(the return stroke) taking effect in the part of the groove oppositely inclined
continues the rotation of the shaft in the same direction. There may, of
course, be two or more steam cylinders placed on the same shaft which passes
through the trunks or hollow piston rods, and is fitted in suitable bearings for
its support and thrust. The valves and other parts of the engines. may be
worked from the shaft by any of the ordinary arrangements.
This double-incline grooved solid cylinder may be applied to other engines by
disposing it on the shaft and placing it in communication with the piston rod-of
the steam cylinder by a stud, pin, or truck roller fixed to such piston, a rigid
connection by a bed plate or framing being of course maintained between the
steam cylinders and other bearings of the shaft to resist the end thrust
produced. Instead of a cam groove in the cylinder or shaft it may be a pro-
jection thereon and following the same course, and embraced by a fork or
two truck rollers to transmit the motion.
DESCRIPTION OF DRAWINGS.
Figure 1 represents a part of a horizontal trunk engine constructed
according to my Invention, the one half being in elevation and the other half
in central vertical section, the arrangement being well adapted for screw
propulsion, as the engines may be disposed in the line of the keel and the
power taken from either end of the shaft. A pair of engines so coupled may
of course be used for any driving purpose, or one such only may be used,
and the shaft be furnished with a fly wheel to carry it over the dead point
as usual.
a, a, are the steam cylinders fitted with pistons 6 mounted on hollow
trunks C, which are disposed in line with each other and receive the shaft
D, D, which passes right through and is supported by bearings e, e, at either
end and by a mid-bearing f. G, G, are cylinders fixed on or they may be
enlargements of the shaft, fitting somewhat closely the interior of the trunks
C, C. In parts G, G, are formed cam grooves 9, 9, inclined and in the form
of a regular screw thread on the one side of G (say a right-hand thread),
while on the other side of the shaft it is reversed (a left-hand thread), the two
oppositely inclined parts of the groove 9 being united in a curve suitable
for the traverse of the stud or truck roller travelling therein, and so as to
conduce to the free and easy transition of motion from the one direction to
the other. The shaft part G and groove g are separately represented at

page_text: Figures 2 and 3, the one view being taken at right angles to the other..
Figure 4 is a cross section on line 1, 2, Figures 2 and 3. F, F, are what
may be termed the cross heads of the trunk piston rods, which are formed on
the trunks or fixed thereto, one of these is separately represented at Figure 5:;
a screwed bolt is passed through the socket in F and fixed by a check nut,
the point of said bolt projects into the groove g, and is furnished with a truck
roller h fitting said groove from side to side, or nearly so. From the foregoing
it will be evident that as the trunk C is propelled to and fro by the action of
the steam, as well understood, the truck roller h bearing on the groove g will
impart a rotary motion to the shaft D throughout its stroke, the rotary
motion of the shaft being continued in the same direction by the other
cylinder, or it may be by a fly wheel; the trunk and truck roller which has
completed its stroke will pass the dead point and proceed in the opposite
direction by the other limb of the cam groove 9, and so keep up the continuous
motion and revolution of the shaft. The one groove g is disposed on the
shaft D-at right angles to the other g', so that the one engine may be at mid-
stroke while the other is turning the dead point, as usual in coupling a pair of
engines. The valves and valve gearing may be of the ordinary character and
as shown in Figure 1. Figure 6 represents a cross section of Figure 1,
showing the eccentrics l, m, and the rods p, q, (two for each engine are
required as usual for reversing the motion), which are connected to a slot
link r shackled to a bell-crank levers, which transmit the motion by links t
to the valve rods u and valve v, seen in the sectional part of Figure 1. The
crank levers s are pivotted at w to an overhead frame x.
The arins y, z, on
the cross head F may be employed for working the pumps by rods direct, or
the pumps may be operated by the rotating motion of the shaft. This means.
of transmitting and converting the reciprocating motion of a piston directly
into rotary motion in a shaft may be variously applied besides as in the trunk
engines represented in the Drawings annexed, as will be readily understood
without other illustration; for instance, the thrusting motion of a single piston
and its solid rod may be transmitted to a shaft placed in line therewith, the
piston rod having fixed on it the bolt carrying the truck roller taking into the
endless cam groove formed in the interior of a solid cylinder fixed on or an
enlargement of the shaft, the two parts being held in proper position by
suitable bearings and parts such as may be necessary.
Having described the nature of my Invention, and the manner of per-
forming the same, I declare that what I claim as my Invention to be protected
by the herein-before in part recited Letters Patent is, the disposition and

page_text: arrangement of an endless cam groove or projection round a shaft or cylinder
for the purpose of transmitting rotary motion thereto from the reciprocating
motion of a steam piston, substantially in the manner herein-before described
and illustrated in the Drawings annexed.
In witness whereof, I, the said Joseph Stocker, have hereunto set my
hand and seal, this Eleventh day of June, in the year of our Lord One
thousand eight hundred and sixty-six.
Witness,
W. CLARK,
Patent Agent,
53, Chancery Lane,
London.
JOSEPH STOCKER. (L.S.)