IMPROVE- MENTS IN VALVES FOR STEAM ENGINES
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by James Gillies at the Office of the
Commissioners of Patents, with his Petition, on the 8th Noveinber
1860.
I, JAMES GILLIES, of Glasgow, in the County of Lanark, North Britain,
Turner, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN VALVES FOR STEAM ENGINES," to be as follows, that is to say:-
This Invention relates to an improved mode of regulating the action of the
throttle or other valve of steam engines by the agency of the governor or
regulator of such prime movers. The practical details may be carried out in
various ways in practice, but according to one practicable and convenient
arrangement the valve is worked from a continuously revolving horizontal
shaft driven by the engine. The free end of this shaft is placed in close
contiguity with the vertical spindle of the steam valve to be regulated, such
valve being upon the steam supply pipe of the engine. The governor itself,
which may be of any convenient and useful kind, is connected to the actually
operating parts or details by means of a bell crank or lever arm and shaft
arrangement. This bell crank operates upon an annularly grooved ring or
boss upon the continuously revolving shaft of the engine, so as to be capable
of traversing the boss longitudinally upon the shaft whilst the latter revolves.
The shaft is tubular, and at the part where the ring or boss is fitted on it is
slotted longitudinally to afford the means of connecting the boss with an
internal solid shaft contained in the external tubular shaft. It is this solid
internal shaft which carries the actual operating parts working the valves.

page_text: The solid shaft projects beyond the end of the tubular shaft, and upon it is
fitted a boss carrying or formed with inclined disc faces, single or double. At
the base or starting point of each inclined face there is a square or flat end
piece of the full width or length of the disc, and this tapers gradually down
laterally or upon the face until it dies off in the plain or simple annular portion
of the operating piece. The vertical spindle is fitted with a lateral concave
piece of metal within range of the rotatory action of the inclined disc. The
operation is this:-When the square end or base of the incline comes round,
it catches upon the square end of the concave piece on the valve spindle;
this causes the depression of the valve, opening it for the passage of the steam.
The onward revolution of the inclined disc then causes the base piece to
traverse inside the concavity of the piece carried by the valve spindle, and
the incline upon the disc face clears it at an earlier or later period from the
valve spindle, when the latter, by means of a spring or springs, rises and
closes the valve. When the engine goes too fast, the governor, operating
upon the bell crank, herein-before described, draws the inclined disc piece
more or less away from the valve spindle, and hence the inclined face slips off
and clears itself from the valve spindle at an early period; on the other hand,
when the engine goes too slow, the governor pushes the inclined disc forward,
and the latter thus retains the valve open for a longer period. The valve
spindle is fitted with a cross head working in guides, which cross head abuts
in its upward movement against caoutchouc rings or buffer pieces. A screw
spindle and hand wheel are also fitted on for setting the valve as may be
required.