IMPROVEMENTS IN WATER GAUGES, APPLICABLE ALSO TO GAUGE, STEAM, AND OTHER COCKS
Year: 1876

page_text: LETTERS PATENT to John Smith, of Bow, in the County of Middlesex, Engineer,
for the Invention of "IMPROVEMENTS IN WATER GAUGES, APPLICABLE ALSO TO
GAUGE, STEAM, AND OTHER COCKS."
Sealed the 3rd November 1876, and dated the 6th May 1876.
PROVISIONAL SPECIFICATION left by the said John Smith at the Office of
the Commissioners of Patents on the 6th May 1876.
JOHN SMITH, of Bow, in the County of Middlesex, Engineer.
"IMPROVEMENTS
IN WATER GAUGES, APPLICABLE ALSO TO GAUGE, STEAM, AND OTHER COCKS."
This Invention relates to improvements in water gauges, applicable also to gauge,
steam, and other cocks.
According to my Invention 1 construct the cocks with a double shell surrounding
the plug and forming an annular space between the two shells into which annular
space the steam or water is allowed to enter, thus protecting the inner shell or that
one in immediate contact with the plug from the outside atmosphere, and so
equalising the expansion of the plug and the said surrounding shell. The plug
governs the flow of the steam or water by passages formed either through it or on
its outer surface. When through they pass first in the direction of the plug and
then out at right angles, and when formed on the outside of the plug they are
stopped off at the upper end.
Behind the plug is a chamber to equalise the pressure of the steam on the plug,
and so keep it up to its face, the steam reaching said chamber by back pressure.
Behind this a gland for packing may also be provided.
The cock thus constructed is applicable for gauge, steam, and other cocks, and is
also the pattern used for the top cock of the water gauge. The bottom cock of
the water gauge is constructed with two ways through the plug one opening con-
nexion between the water in the boiler with the gauge glass, and the other between
the gauge glass and the chamber behind the plug and the tail cock, only one of which
ways can be open at a time. Thus when the water is shut off the steam passes
down the gauge glass through the top of the plug and out of the side steam chamber
at the back thereof to the tail cock, thus providing for a blow right through when
required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Smith in the Great Seal Patent Office on the 6th November
1876.
JOHN SMITH, of Bow, in the County of Middlesex, Engineer.
16
IMPROVEMENTS
IN WATER GAUGES, APPLICABLE ALSO TO GAUGE, STEAM, AND OTHER COCKS."
This Invention relates to improvements in water gauges, applicable also to gauge,
steam, and other cocks.
And in order that the same may be clearly understood and readily carried into
effect, I will proceed to describe it with the aid of the accompanying Drawings,
reference being had to the letters and figures marked thereon, and in which Fig. 1
is a front view of a water gauge constructed according to my Invention; Fig. 2 a
sectional view taken ou the centre line of Fig. 1; Fig. 3 a sectional view taken at
the line a, b; Fig. 2 and Fig. 4 a sectional plan view taken at the line c, d, Fig. 2.
The same letter of reference (lenotes the same part in all the several Figures.
I construct the cocks of the gauge each with a double shell A, B, surrounding
the plug, such double shell forming an annular space C between them and around
the plug D, into which annular space the steam or water from the boiler is allowed
to enter. The inner shell B, or that one immediately in contact with the plug D,
is thus protected from the varying temperature of the surrounding atmosphere, and
is maintained of the same (or nearly so) degree of heat as the plug, thus equalising
the expansion and contraction of the plug and surrounding shell. The plug of the
upper cock governs the flow of the steam or water by passago E formed either
through the plug or in its outer surface. When through the plug (as illustrated in
the Drawing) the direction of the passage is first in the direction of the plug for
about half way through, when it turns at right angles and passes thence out of the
side of the plug. The plug of the lower cock is constructed with two ways F, G,
either through it or on its outer surface.
In the Drawing one F is shewn passing through the plug, and the other G on its
outer surface. F opens connection between the water in the boiler and the annular
chamber C and the way G, which is on the outer surface of the plug at right
angles to F, opens communication between the annular chamber C and the blow off
passage K. The gauge glass communicates with chamber C of both cocks, and
this chamber C also communicates with a chamber H behind the plug. This
chamber H terminates in a cylinder in which works a piston J attached to the
spindle of the plug, and of the same area as the back or thick end of the plug. The
steam acting on this piston equalises or balances the pressure of steam on the plug,
and so prevents the plug being either jammed into or pressed away from its scat.
Behind piston J is a gland for packing, through which the spindle of the plug
passes.
The passage from the boiler to the plug can at any time be cleaned in a few
minutes, if required, when steam is down by removing the gland and plug.
In my Provisional Specification I describe my Invention as applicable to
ordinary steam cocks. This I have not found to answer my expectations in practice,
and I, therefore, abandon same.
In witness whereof, I, the said John Smith, have hereunto set my hand and
seal, this Sixth day of November, in the year of our Lord One thousand
cight hundred and seventy-six.
JOHN SMITH. (L.S.)