A New or Improved Automatic Shut-off Cock.
Year: 1894

page_text: UT
Buckau-Magdebourg, in the German Empire, Engineers.]
A New or Improved Automatic Shut-off Cock.
I, WILLIAM EDWIN HEYS of 70 Market Street, Manchester in the County of
Lancaster, Patent Agent, 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:-
This invention relates to a new or improved automatic shut-off cock which may
be employed for general purposes, but which is more particularly intended for use
in cases where it is desirable that the cock should close automatically when a
sudden reduction of pressure takes place on one side. As a particular example of
a case in which the cock may serviceably be used, may be mentioned the case of a
water gauge of a boiler, in which it is a great advantage if the cock can close
automatically in the event of the accidental breakage of a glass.
The new or improved cock is particularly described hereinafter with reference
to the accompanying drawings, in which :-
Figure 1 is a longitudinal section shewing the cock open, and
Figure 2 a partial longitudinal section shewing it closed.
The cock, as constructed according to this invention, consists of the casing C
and the plug P p.
The bore of the casing and the cross section of the plug differ
from those of ordinary cocks in not being truly circular or cylindrical, but in being
bounded by concentric circular arcs of two different radii. Referring to the
drawings, one half of the plug and of the bore, a b c has a larger radius than the
other half, def. It is immaterial whether the plug and its seating be conical or
cylindrical.
The passage through the plug g is smaller than the inlet and outlet
passages A A¹
If, when the cock is in use, there is no reduction of pressure on the outlet side,
or if there be only a slight reduction of pressure there, no action will take place,
but, should there occur from any cause, such for example as the breakage of a
gauge glass, a sudden or material reduction of pressure on the outlet side, the
excess pressure will be exerted on the shoulder a of the plug and cause it to rotate
towards the position indicated in Figure 2. The plug is fitted with an external
handle, which indicates the position of the plug, and the momentum imparted to
the plug and handle will be sufficient to carry it into the closed position.
it
It is not necessary for the plug to be a tight fit in its seating, on the contrary,
is an advantage that it should be free, because it then responds more quickly, and
no steam or other fluid can escape in appreciable quantity when the cock is closed,
because the pressure forces the solid part of the plug against the outlet.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An automatic shut-off cock, constructed and arranged substantially as herein-
before described with reference to the accompanying drawings.
2. In an automatic shut-off cock, a plug and seating of which the cross section
is bounded by two concentric circular arcs of different radii, substantially as
hereinbefore described and as illustrated by the accompanying drawings.

page_text: 3. In an automatic shut-off cock having a plug composed of two sectors of
different radii, an opening through the plug of smaller area than the inlet and
outlet openings of the body of the cock, constructed substantially as hereinbefore
described with reference to the accompanying drawings.
Dated this 16th day of November A.D. 1894.
WILLIAM E. HEYS.