An Improved Draw-off Valve.
Year: 1889

page_text: Date of Application, 5th Feb., 1889
Complete Specification Left, 5th Nov., 1889-Accepted, 7th Dec., 1889
PROVISIONAL SPECIFICATION.
An Improved Draw-off Valve.
I SAMUEL WILKERSON of Bassingbourn in the County of Cambridge, Agricultural
Engineer do hereby declare the nature of this invention to be as follows:-
My Invention relates to draw-off valves for water-carts and other receptacles or for
controlling the flow of liquids or semi-liquids from, or into, any vessel. The valve
is a tightly hinged flap faced with india-rubber and seated over the orifice of the
pipe to be controlled. It is of square or rectangular form and is pivoted and
works tightly between projecting side cheeks connecting the end of the said pipe
with a discharge nozzle and forming a casing for the valve. The valve when open
or raised from its seat works through and closes the front of the casing and the
hinge joint of the valve is packed whilst the opposite or free end of the valve is in
the form of a segment curved to the arc struck from the pivotal centre and works
against a correspondingly faced part of the casing, so that all escape of liquid except
at the discharge nozzle is prevented. The valve is operated by a lever pivoted by
its end to the back of the valve and fulcrumed at an intermediate point to the ends
of a pair of radius links pivoted at their other ends to either side of the valve casing,
the links and the shorter arm of the lever together constituting a sort of toggle
whereby the valve is forcibly held to its seat when the centres of the links and lever
are brought into a straight line, the motion being limited by a stop when the parts
have passed just beyond the dead point or line of centres whereby the valvo is
effectually hold closed against internal pressure. The lever is elbow-shaped and to
the other member is jointed, upon an axis at right angles to the fulcrum of the
lever, a handle portion which, when the valve is closed, may be turned backwards
and secured to the valve casing in order to lock the valve in the closed position.
For this purpose, the handle portion may bo formed with a tubular socket at right
anglos to its length, suid socket fitting, and turning, upon the cylindrical outer
member of the elbow lever, the handle portion, when used for operating the valve,
being turned outwards approximately into line with the inner or toggle-like member
of the lever.
DL: FIL J10011
COMPLETE
SPECIFICATION.
An Improved Draw-off Valve.
I, SAMUEL WILKERSON, of Bassingbourn, in the County of Cambridge, Agricultural
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
My Invention relates to draw-off valves for water-carts, liquid-manure carts, and
other receptacles, or for controlling the flow of liquids or semi-liquids from, or into,
any vessel, applicable also as a mud-valve or blow-off cock for steam boilers and for
other purposes.
My Invention consists of a flap valve seated over the orifice of the pipe to be
controlled and tightly hinged between projecting side cheeks which are in one with,
and connect, the end of the pipe with a discharge nozzle, the said valve when in its

page_text: open position constituting with the cheeks an elbow of which the valve itself forms
the outer wall leaving an unobstructed passage for the liquid.
The Invention will be described with reference to the accompanying drawings
forming part of this specification, wherein figure 1 is a central vertical section,
figure 2 is a plan (partly broken away) figure 3 is an end elevation (also partly
broken away) while figure 4 is a similar view to figure 1, shewing the valve in its
two positions. The same lettors of reference indicate like parts in all the figures.
A is the valve which is faced with indin rubber or other equivalont material A'.
This valve is seated over the orifice B' of the pipe B to he controlled and pivoted
at a between the cheeks (which are cast in one with, and connect, the pipe B with
the discharge nozzle 1). The valve is of rectangular form and fits tightly between
the side checks which form a casing for the valve which is packed at both sides at a'
to prevent leakage. The valve when open or raised from its sent, as shown in
figure 4, closes the front of the casing and forms the outer wall of the elbow
connecting the pipe B with nozzle D. The hinge joint of the valve is packed at b
whilst the opposite or free end of the valve is in the form of a segment a curved
to the arc struck from the pivotal centre and works against a correspondingly faced
part of the casing which is also packed at d so that all escape of liquid except at the
lischarge nozzle is prevented. The valve is operated by a lover E, E', pivoted at a²
to the back of the valve A and fulerumed at an intermediate point c to the ends of
a pair of radius links F which are pivoted at their other ends to either side of tho
pipe B, the links F and the shorter arm E of the lever together constituting a sort
of toggle whereby the valve is forcibly held to its seat when the contres of the links
and lever are brought into a straight line, the motion being limited by the casing
nd when the parts have passed just beyond the dead point or line of centres,
whereby the valve is effectnally held closed against internal pressure.
In order that the handle portion E of the lover may be thrown out of the way,
as seen in dotted lines in figure 1, when the valve is in its closed position, the
portion E is elbow-shaped and the handle portion E' is formed with a tabular socket ³,
at right angles to its length, which fits and turns upon the pin e' of the lever E, the
handle portion when used for operating the valve being turned outwards approximately
into line with the inner or toggle-like member of the lever, as in full lines in figure 1.
The valve may be thrown completely back, as shewn in dotted linos in figure 4,
when desired, as, for instance, when the pipe B is to be cleaned out. In order to
provide against the bursting of the pipe B by frost, the bore B' is made slightly
conical.
The radius links F may, if necessary, be made of steel so that they may have the
necossury spring to allow the centres of the lovers to pass for the purpose of locking
the valve in its closed position, as described. The falcrum pin which connects lover E
with links F is made with a square body portion upon which the lever E fits.
This square portion is eccentric to the end portion of the fulcrum pin upon which
the links are fitted, so that any looseness of the parts from wear may be compensated
for by giving the pin a quarter turn in the lover E.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is;
1st. The herein described construction of draw-off valve consisting of the tightly
hinged flap seated over the orifice of the pipe to be controlled and within side chocks
which project from the end of the pipe, and unite the latter with the discharge nozzle,
the said flap being provided with means for locking it in the closed position, sub-
stantially as specified.
2nd. A valve consisting of a tightly hinged flap fitted between side cheeks
projecting from the end of a pipe and forming a casing for the valve said Hap boing
provided with means for locking the same in its closed position, as specified.

page_text: 3rd. The combination, with a valve constructed as herein described, of the locking
lever adapted to be turned out of the way when the valve is closed, substantially as
specified.
4th. In a valve constructed as herein described, the connection of the radius links
with the lever by means of the eccentric pin to enable the wear of the joints to be
compensated for, as specified.
Dated this Sun day or November 1889.
S. WILKERSON.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.