IMPROVEMENTS IN STEAM AND OTHER MOTIVE ENGINES
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by Christopher Brakell, William
Hoehl, and William Gunther, at the Office of the Commissioners of
Patents, with their Petition, on the 26th May 1862.
We, CHRISTOPHER BRAKELL, WILLIAM HOEHL, and WILLIAM. GUNTHER,
Engineers, all of "The North Moor Foundry Company," Oldham, in the
County of Lancaster, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN STEAM AND OTHER MOTIVE ENGINES," to be as follows:-
Our improvements relate, firstly, to valve gear for reciprocating engines,
and to a mode or arrangement and combination of mechanism for actuating
valves for admitting and cutting off the supply of steam, so as to work it at
various degrees of expansion. According to this part of our Invention, our
improved mechanism opens the valve, and only permits it to be closed at the
proper time by the pressure of the steam upon the valve (if a lift valve), or by
the force or the assistance of the force of a weight or spring, which will keep
the valve closed at all times, except when acted upon by the valve gear. The
motion for working the valve gear is obtained from the crank shaft of the
engine, by means of a crank, excentric, or other known means, and is transmitted
to a slotted lever, carrying a movable die, to which one end of a connecting rod
is jointed, the other end being jointed with an arm fixed on a "rocking shaft,"
which receives a varying amount of oscillatory motion according to the position
of the sliding die in the slotted lever. An arm is fixed on the rocking shaft,
having tappet projections upon it, which act upon levers connected with the

page_text: spindle of the valve, in such manner as to open the valve when moved in the
right direction, but not to act upon the valve when moved in the opposite
direction. The valve gear will open the valve, or admit the steam under all
circumstances at the same point, but will permit the valve to close at various
times (thus cutting off the steam), depending upon the extent of tappet surface
acting upon the levers in connection with the valve spindle, and the length of the
oscillations of the rocking shaft. When there is the least amount of oscillation
in the rocking shaft, the end of the lever operated upon is the greatest time in
travelling over, and thus getting released from the tappet surface, and vise
versa, and as the tappet surface is fixed in length it forms a smaller fraction
of the greater than the lesser oscillation of the "rocking shaft," consequently
the greater the oscillation, the sooner, in relation to the piston, will the valve
be permitted to close and cut off the supply of steam. The die in the slotted
lever may be moved either by hand, or by a governor, or other regulating
mechanism, by suitable levers and connecting rods.
The second part of our Invention relates to improvements upon rotatory
steam engines or wheels, acting by the momentum of the motive power
employed, such as those for which Letters Patent were granted to
Mr. Christian Schiele, respectively numbered 13,965, in the year of our Lord
one thousand eight hundred and fifty-two, and 1698, in the year of our Lord
one thousand eight hundred and fifty-five. In this class of engines, in order
to obtain the greatest efficiency and economy, the turbine wheel should have a
velocity bearing a certain proportion to the velocity of the entering steam or
other motive power.
There are some velocities of high-pressure steam or
other motive power which are inconveniently great. The object of our
Invention is to be able to use high-pressure steam or other motive power
giving great velocities, with a moderate speed in the turbine wheel, and this
part of our Invention consists in passing the steam or other motive power
through a series of turbine wheels, working the second by the steam or other
fluid from the first, and the third from the second, and so on, and thus a
portion of the momentum of the motive power is given off to each turbine
wheel.