AN IMPROVED DOUBLE- ACTING SUPERLATIVE SCREW THROTTLE VALVE
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by William Leatham at the Office
of the Commissioners of Patents, with his Petition, on the 16th August
1859.
I, WILLIAM LEATHAM, of Leeds, in the County of York, Engineer, do
hereby declare the nature of the said Invention for "AN IMPROVED DOUBLE-
ACTING SUPERLATIVE SCREW THROTTLE VALVE," to be as follows:-
In place of all throttle valves now in use, I propose to introduce my
improved valve. Firstly, the advantage of this valve or cone consist in
its being worked by a screw, in consequence of which a more regular
supply or diminution of steam, water, or other fluids is given in its operation.
Secondly, the equalibrum arrangement of the valve or cone possesses more
advantages than can be found in any other valve now in use, on account of
its being entirely free from the frictional irregularities to which all other
valves at present in use are subject, all other valves being dependant upon
single action, and not being assisted with the screw the spindle is allowed to
corrode, which retards its motion, and thereby effectually prevents the free action
of all valves now in use. Thirdly, the provisional adjustment of the compound
lever or arm, which being attached to the governors acting on the valve, offers
inestimable advantages in governing the steam engine, thereby saving a great
amount of fuel and expense now incurred by the irregularity of speed of the
steam engine, which the valves at present in use are entirely inadequate to
govern.

page_text: The following is a description of the Drawings:-Figure 1 is a sectional
plan of the valve; Figure 2 is an end elevation of the same; Figure 8 is a
front elevation of the same. The same letters and figures refers to the same
parts in each Figure. A is a spindle of brass or other metals; B is a screw
cut on spindle A; C is a female busto of gun or other metal for the reception
of the screw B; D, D, are two brass valves or cones; E, E, are the seats of
brass or other metal to receive D, D; F is a continuation of seats E, E; G is
a stuffing box; H is a gland bushed with gun or other metal, and keeps the
spindle A steam-tight; G 1 is a faced flange bolted or screwed on the outer
shell or casing I, I, I, I, is the shell or casing for the valve; J, J, are the
two faced flanges cast on the shell or cover, and about the same size as the
steam or other pipes attached thereto, and the continuation of the same;
K, K1, K2, are bridges cast in the shell or casing to form or receive the valve
seats E, E 1, or the seats may be formed in the bridges irrespective of the
brass seats or other metal; L is the inlet for steam, water, or other fluids;
M is the outlet for the same; N is a boss keyed on spindle A, with two
circular slots in the same; O is a arm with two corresponding slots in the
same, and forced to the boss N; P is an universal swivel joint working on
stud Q; Qis provided with a long slot, in which the stud Q is made to slide
for the adjustable motion for governors; R is a lubricator for spindle A.
The arrows, Figure 1, shew the direction which the steam or other fluids tako
after entering the inlet E.