IMPROVE- MENTS IN SINGLE CYLINDER, STEAM, OR OTHER MOTIVE-POWER ENGINES
Year: 1870

page_text: LETTERS PATENT to James Shand, of 75, Upper Ground Street,
Blackfriars, in the County of Surrey, for the Invention of "IMPROVE-
MENTS IN SINGLE CYLINDER, STEAM, OR OTHER MOTIVE-POWER ENGINES."
Sealed the 31st March 1871, and dated the 11th October 1870.
PROVISIONAL SPECIFICATION left by the said James Shand at the
Office of the Commissioners of Patents, with his Petition, on the
11th October 1870.
I, JAMES SHAND, of 75, Upper Ground Street, Blackfriars, in the
County of Surrey, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SINGLE CYLINDER, STEAM, OR OTHER MOTIVE-POWER
ENGINES," to be as follows:-
By my improvements I obtain a continuous rotary motion of the crank
shaft by assisting it past the neutral points of its path, usually called
the dead centres, and for which purpose a fly wheel has hitherto been
employed, but with the disadvantage that the engine could not be started
when the crank was at either of the dead centres.

page_text: On the crank shaft of engines in which the steam supply is regulated
by a slide valve is fixed an eccentric for the purpose of giving motion to
the said slide valve. The position of this eccentric on the crank shaft
is considerably in advance of the crank, depending on the length of the
eccentric rod, and usually above ninety degrees, therefore, when the
crank is at either of the dead centres (or I may say at zero) the eccentric
is in a favourable position for assisting the crank if auxilliary power was
supplied to the slide when in this position; it (the slide) would then
become the motor of the crank shaft, the eccentric would act as the
crank (which I prefer to an eccentric for this purpose), and the eccentric
rod would act as a connecting rod; thus, when the engine crank is on
either of its dead centres the slide auxilliary would be in full action,
and when the slide eccentric (or crank) was on either of its dead centres
the engine crank would be in full action. By these means I obtain a
continuous rotary motion of the crank shaft, not requiring the moving
of the crank past its dead centres for starting, nor the momentum of a
fly wheel while in motion, as there are no dead points on which the
engine would stop, and no part of its revolution at which it would not
start. To obtain this auxilliary power I prolong the slide rod through
the steam chest into a small cylinder placed on top or end of said steam
chest, and on the prolonged slide rod and in the small cylinder is fitted
a piston that by my Invention becomes its own slide valve, automatically
admitting and exhausting steam or other power as required for assisting
the engine crank over the dead centres before named.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Shand in the Great Seal Patent Office on
the 5th April 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
SHAND, of 75, Upper Ground Street, Blackfriars, in the County of Surrey,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of October, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Shand, Her special licence a

page_text: that I, the said James Shand, my executors, administrators, and assigns,
or such others as I, the said James Shand, 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 SINGLE CYLINDER,
STEAM, OR OTHER MOTIVE-POWER ENGINES," upon the condition (amongst
others) that I, the said James Shand, 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 James Shand, do hereby declare the
nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement:-
By my improvements I obtain a continuous rotary motion of the crank
shaft by assisting it past the neutral points of its path, usually called
the dead centres, and for which purpose a fly wheel has hitherto been
employed, but with the disadvantage that the engine could not be started
when the crank was at either of the said dead centres.
On the crank shaft of engines in which the steam supply is regulated
by a slide valve is fixed an eccentric for the purpose of giving motion to
the said slide valve. The position of this eccentric on the crank shaft
is considerably in advance of the crank (depending on the lap of valve
and length of the eccentric rod), and usually above ninety degrees, there-
fore when the crank is at either of the dead centres (or I may say at
zero) the eccentric is in a favorable position for assisting the crank if
auxiliary power was supplied to the slide when in this position; it (the
slide) would then become the motor of the crank shaft, the eccentric
would act as the crank (which I prefer to an eccentric for this purpose),
and the cccentric rod would act as a connecting rod; thus, when the
engine crank is on either of its dead centres the slide auxiliary would
be in full action, and when the slide eccentric (or crank) was on either
of its dead centres the engine crank would be in full action. By these

page_text: means I obtain a continuous rotary motion of the crank shaft, not
requiring the moving of the crank past its dead centres for starting, nor
the momentum of a fly wheel while in motion, as there are no dead
points on which the engine would stop, and no part of its revolution at
which it would not start. To obtain this auxiliary power I prolong the
slide rod through the steam chest into a small cylinder placed on top
or either end of said steam chest. On the slide rod and in the small
cylinder is fitted a piston that by my Invention becomes its own slide
valve, automatically admitting and exhausting steam as required for
assisting the engine crank over the dead centres before named; or, as a
more compact arrangement, I fit a-small auxiliary slide in the steam
chest actuated by a projection from the slide valve frame striking against
a similar projection at either end of said auxiliary slide, and moving it
so as to open the port for admission of steam to either end of the before-
named small cylinder on end of steam chest, and exhausting into the
main exhaust port, thus actuating a small ordinary piston fixed to the
slide rod, and through the slide connecting rod or cross head conveying
motion to the small crank, thus applying power for assisting the main
crank over its dead centres as before named.
The accompanying Drawings will better explain my improvements :-
Figs. 1, 2, and 3 shew the arrangement first mentioned. A, the
slide valve; B, the slide rod; C, the steam chest; D, the auxiliary
cylinder; E, its piston. The slide valve A is shewn at the end of its
stroke with its small crank F on its dead centre, and with the piston G
and its crank H about the middle of its stroke. When the piston G was
at the beginning of its stroke, and its crank H on the centre Q, and
travelling in the direction of arrows, the steam would impel the piston E
(also in direction of arrow) and press against the shoulder I, and assist
the crank H considerably past its centre; the travel of the piston E
would be arrested by coming in contact with the end J of small cylinder;
here its action would cease, but the piston G would by this time get into
full action, and the crank H would then turn the crank F, and thrust
the hollow piston rod K through the piston E, changing its ports, and
bring the shoulder L in contact as shewn. The steam will now issue
through the hollow rod M into the annular passage N, and through the
holes O to the other end of small cylinder, and force the piston E through
its stroke, and thus assist the crank H over the other centre to be again
arrested by contact with the end P of small cylinder; the crank H will

page_text: then be in full action, and will draw the hollow rod K through the
piston E, and change its ports as before, the exhaust steam escaping in
like manner through the hollow rod either in the air or in connexion
with the exhaust of main cylinder. Figure 2 is an end view of the hollow
rod and the piston E shewing the holes through which the steam issues
from and the exhaust escapes into the annular passages of piston E;
and the hollow rod, Fig. 3, shews the small crank F and the crank H in
the position corresponding to the slide A and small piston E, as shewn
in Fig. 1.
Figs. 4, 5, and 6 shew a more compact arrangement for obtaining the
before-mentioned result. A is the steam valve; B, a sling or frame to
same; C, a small auxiliary valve; D, the steam chest; E, a small
auxiliary cylinder; F, its piston; G, the small crank for actuating
slide; H, the engine crank, which in this case is shewn working in a
cross head, but it may work through a connecting rod; I, the engine
cylinder; J, the piston of same. The engine piston J is shewn at the
beginning of its stroke, the crank H on the dead centre, the small
crank G in position for opening steam port K, and at about one hundred
degrees in advance of crank H, during the time the crank H is on the
centre (as shewn) the steam is passing through the small port L and
along the pipe M to end of auxiliary cylinder E, and pressing the
piston F in the direction of arrow will move the crank H by the crank G
past its dead centre into a position in which it has power; the crank H
will then carry the crank G to its dead centre and the slide A to the end
of its stroke; but meanwhile the projection N on the sling B will touch
the projection O on the slide C and push it across the port L, opening
the same to the exhaust, and opening the port S at the other end of the
auxiliary slide, and admitting steam to the other side of the small
piston to repeat the action on the opposite dead centres, the two
cranks thus continuing to assist cach other, and maintaining a con-
tinuous rotation of crank shaft P. The small cranks F in Fig. 1, and
G in Figs. 4 and 5, represent the usual eccentric for working the slide
valve, its action being the same, but to avoid friction I have reduced
its diameter and call it a crank. In thus describing its action I have
assumed that steam is the motive power in order to avoid confusion, but
the arrangement is equally applicable with water or gas.
My claim is the fitting a piston on the slide rod, and by the means I
have here shewn making the slide rod perform the duties alternately of

page_text: a slide and connecting rod, that is to say, as a slide rod being impelled
by, and as a connecting rod by impelling the crank shaft.
In witness whereof, I, the said James Shand, have hereunto set my
hand and seal, this First day of April, in the year of our Lord
One thousand eight hundred and seventy-one.