AN IMPROVED COMBINED GAUGE COCK, SURFACE BLOW-OFF COCK, AND ATMO- SPHERIC VALVE
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by William Clark at the Office of tho
Commissioners of Patents on the 10th July 1878. A communication from
abroad by John J. Tonkin and John Newton Van Lew, both of Richmond, in
the County of Henrico, State of Virginia, United States of America.
WILLIAM CLARK, of Chancery Lane, in the County of Middlesex, Patent. Agent.
"AN IMPROVED COMBINED GAUGE COCK, SURFACE BLOW-OFF COCK, AND ATMO-
SPHERIC VALVE." [A communication from abroad by John J. Tonkin and Johu
Newton Van Lew, both of Richmond, in the County of Henrico, State of Virginia,
United States of America.]
This Invention relates to an improved gauge cock for determining the water
level in steam boilers, the same being applicable to other uses, as hereafter
described. Ordinarily several cocks are employed for this purpose arranged at
different levels, and the height of the water in the boiler is determined by the
issuing of steam or water, as the case might be, from these several cocks when
successively tried.
Among the efforts to dispense with the multiplicity of these cocks is a single
axially turning tube having a right angular branch, which, when the tube is turned
axially moves laterally and dips from the steam space into the water space, the
water level being indicated by the degree of deflection. In this case, however, an
independent valve was arranged to be opened by independent devices to permit the
water or steam to issue.
The present Invention is an improvement upon this form of gauge cock, and it
consists in constructing the axial portion of the cock in such form that it shall fulfil
itself the function of a valve by longitudinal movement, so that in trying the water.
level, all that is necessary is to grasp the handle of the tube and force it
longitudinally in, and then turn the tube axially until its right angular arm shall
dip into the water, the pressure of the steam within serving to force back the tube
and seat its valve upon the valve seat.
When the hand wheel is forced into open communication with the boiler to try
the water, a gum ring on the stem fits against the end of the screw plug and forms

page_text: a steam-tight joint to prevent the steam from escaping at this point and burning
the fingers. At the same time also the valve is forced against a rear valve seat to
prevent leakage of steam at this point. ⚫
In the place of the gum ring referred to, a stuffing box may be employed.
In addition to the use of the Invention as a gauge cock, it is proposed also to
increase its dimensions and employ it for a surface blower for blowing off the
impurities from the surface of the water in marine and other engines, to which
point the impurities are lifted by the boiling action.
The difficulty with fixed blow-off cocks is, that they can only be used at times
when the water is at a certain level, whereas it will be seen this device can be made
to follow the level of the water and blow off as long as necessary.
The device may be also used to advantage as an air cock for determining where
the air line is in pumps employing an air chamber.
Upon the stem or hand wheel is located an index finger of the same length as the
dip pipe in the boiler, and pointing in the same direction, so that the end of the
index finger will always locate the end of the dip pipe.
One of the incidental advantages of the Invention is, that it is capable of opening
inwardly automatically to prevent a vacuum in the boiler whenever the pressure in
the boiler falls from condensation below the atmospheric pressure. The valve seat
moreover is never cut by the closing of the valve, as is the case frequently in screw
stem valves.