MENTS IN BALANCED SLIDE VALVES
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Henry Mantey at the Office of the
Commissioners of Patents on the 26th May 1877.
HENRY MANTEY, of Victoria Street, in the City of Westminster.
MENTS IN BALANCED SLIDE VALVES."
" IMPROVE-
This Invention has reference to balanced slide valves which have opposite faces
or sides arranged to slide between seats on both sides of the valve, and in which
the faces of the valve are adjustable as required to form close but free contact with
the seats.
My improved valve is composed of two outer sections of equal thickness, forming
the two valve faces, and of a central intermediate section of wedge or slightly
tapered form, situated between the two outer sections, which are slightly inclined
on their inner surface to correspond with the inclination or taper of the said inter-
mediate section. The three sections are all formed with an opening through them,
extending from face to face of the valve, and they are placed in a frame to which
the valve stem is connected. The valve thus composed of sections held in a frame
reciprocates between opposite valve seats in the valve chest. The valve seats are
formed of cheeks, each of which has 3 ports, the ports in the one cheek being
opposite to, and corresponding with, those in the other cheek. One pair of ports
are in connection with a passage, which admits steam to and from one end of the engine
cylinder; another pair are in connection with a similar passage, communicating
with the other end of the engine cylinder; while the third pair, being the central
pair, communicate with the exhaust, the steam being exhausted through the opening
in the valve when the same is brought over either of the outer pairs of ports, and
the steam passing through either of these pairs of ports accordingly as the same are
uncovered by the valve. In this way a balance of pressure on the valve is obtained
both laterally and around the outer or exposed edges of the valve within the valve
chest, to which steam is freely admitted at any suitable point. In order to adjust
the valve so that it may work in close but free contact with the seats, the central
intermediate wedge-formed section is pushed in to the required extent between the
two outer sections so as to bring their faces against the seats. The pushing in of
the wedge-formed section is effected by making a horizontal groove therein, and an
inclined dovetail groove in the valve frame, and by inserting into the said grooves

page_text: a double piece of corresponding sectional form, the further this double piece is
inserted the further is the wedge-shaped section pushed in between the outer
sections (owing to the inclination of the groove in the frame), and the further are
the outer sections separated. The double piece may be secured in the required
position by one or more set screws.
To prevent the outer edges of the cheeks which form the valve seats from being
forced towards each other by the steam pressure, or otherwise, I connect theni
together by an arch, or I form them with flanges, to which I bolt or fix a stay or
cross piece.
The novel features in my improved valve are, the central intermediate wedge-
shaped section between the two outer sections of the valve; the mode or means of
adjusting the said intermediate section between the outer sections; the mode of
preventing the cheeks or valve seats being forced towards each other; and the
general arrangement or combination of parts of the valve; all as herein-before
described.