IMPROVEMENTS IN THE CONSTRUCTION OF ROTARY ENGINES TO BE WORKED BY STEAM OR OTHER POWER
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Bryce Grey Nichol at the Office
of the Commissioners of Patents, with his Petition, on the 15th May
1866.
I, BRYCE GREY NICHOL, of Spital Tongues, near Newcastle-on-Tyne, in the
County of Northumberland, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF ROTARY ENGINES TO BE WORKED BY
STEAM OR OTHER POWER," to be as follows:-
This Invention relates to certain improvements in the construction of rotary
engines, to be worked by steam, hot air, gases, or other motive power. I
propose to set on suitable standards and framing a narrow cylinder of a
diameter in accordance with the power required by the engine; through the
centre of this cylinder the driving shaft is placed horizontally and allowed to
rotate in suitable bearings. The shaft is connected to an internal cylinder of
such dimensions as to allow a space between the inner periphery of the large
cylinder and the outer surface of the internal cylinder. To the internal
cylinder a piston is fixed, consisting of a series of metallic pieces and packing
tightened together by screws. On each side of the engine or the large
cylinder a horizontal slide valve or stop is arranged, in order to admit and cut
off successively the steam and also to act as bearings between the steam and
the piston. These sliding valves are actuated by a cam or by a tappet motion
attached to the shaft of the engine. In the case of a cam motion being used
a helical spring is employed surrounding the rod of the valve to force it against

page_text: the periphery of the internal cylinder, the cam forcing the valve outwards free
of the passage of the piston, but in the case of the tappet motion a double
tappet must be used to effect the to-and-fro motion of both slides. These
motions must be so arranged by means of excentrics in accordance with the
inlet and exhaust ports of the steam, that the steam shall always act against
one or other of the slide valves and also that these valves shall continuously
recede and advance in order to allow the piston to traverse freely throughout
the circle. Reversing gear is applied according to the ordinary means, so that
the engine may be worked in either direction.
The action of the engine is as follows:-The inlet and exhaust valves being
properly arranged, the steam or other motive agent is allowed to enter, and
bearing upon one of the horizontal slides it acts upon the piston and forces
it round to the opposite slide, but just as it approaches that slide the excentric
or tappet forces back the slide and allows the opposite one to advance by the
action of its spring against the periphery of the internal cylinder; the steam
valves then change their position and allow the steam to act upon the advanced
valve, which forms a stop, and also upon the piston, so that a continuous
rotary motion of the piston is obtained and communicated to the driving shaft,
whereby power is obtained direct from the rotary movement of the engine,
dispensing with reciprocating motion. As the various rotating parts of the
internal cylinder and piston which are subject to friction become worn they
are to be tightened up or kept in position by means of springs in connection
or not with screws.