Improvements in Pistons and Piston Valves.
Year: 1891

page_text: Date of Application, 27th July, 1891
Complete Specification Left, 6th Nov., 1891-Accepted, 12th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in Pistons and Piston Valves.
SAMUEL SHELDRICK of 32 Eldon Road Riverside Cardiff in the County of
Glamorgan Engineer, do hereby declare the nature of this invention to be as
follows:-
女
This invention relates to pistons and piston valves and has for its object to so
improve the same that the packing rings and pistons may be more easily placed
within the cylinders or valve boxes and the said packing rings may be allowed to
expand from time to time as required by operating the said pistons or piston valves
from the outside of the cylinder or valve box without it being necessary to remove
the cylinder or valve box covers to attain which in the case of a piston slide valve
I fm a portion of the valve spindle conical upon which portion I place a loose
coll r which acts as an end cover to said piston valve then I place a suitable
nun er of rings which form distance pieces and annular grooves for the packing
rings to fit therein.
Where the piston valve is arranged with two or more pistons I also arrange a
sleev or sleeves to divide the same the said sleeve or sleeves fitting over the spindle
and having enlarged ends to form the ends of the pistons.
Extending from the washer forming the cover of piston valve opposite the washer
on the conical part of valve spindle I arrange another sleeve which passes through
the valve box or chest cover and through a stuffing box and gland and said sleeve
is ar. inged at its outer end so as to receive pressure from one or more nuts or
equivalent device for tightening or slacking said sleeve.
The said nuts may screw on to the valve spindle or on to a screwed ferrule
secure to said spindle.
The packing rings are of ordinary construction and are first fitted around the
smaller distance pieces forming the groove and are gripped laterally within said
grooves by means of the washers distance pieces and sleeve or sleeves. The packing
rings are thus held down to the same diameter as the valve box chest or cylinder
and the piston valve can be easily placed therein and as the said valve box or
cylinder becomes heated and expands so as to allow of a leakage of the motive
fluid over the packing rings the nuts aforesaid or equivalent pressing device are or
is released thereby allowing the said packing rings to immediately expand to the
walls of the valve box chest or cylinder after which the nuts or equivalent device
are or is tightened up so that the washers distance pieces and sleeves again grip
the packing rings laterally and prevent an undue pressure against said walls of
valve box or cylinder as will be well understood.
In the case of a separate piston one piston cover or washer. bears on a conically
formed part of the piston rod and then the distance pieces forming the grooves for
the reception of the packing rings are placed on the parallel part of said piston rod
and another washer forming the opposite cover or end of said piston and finally the
adjustable sleeve extends through the cylinder cover and a stuffing box and gland
and is pressed or released at its outer end by nuts or other equivalent means in the
manner and for the purpose hereinbefore described.
Dated this 25th day of July 1891.
H. F. BOUGHTON, M.I. Mech. E.,
London, Sheffield, and Barnsley, Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Pistons and Piston Valves.
I SAMUEL SHELDRICK of 32 Eldon Road Riverside Cardiff in the County of
Glamorgan 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 present invention relates to pistons and piston valves and has for its object to
so improve the same that the packing rings and pistons may be more easily placed
within the cylinders or valve boxes and the packing rings of said pistons or piston
valves may be allowed to expand to the walls of the said cylinders or valve boxes
from time to time as required by operating the pistons or piston valves from the
outside of the cylinders or valve boxes without it being necessary to remove the
cover or covers of said cylinders or valve boxes to attain which I construct my
improved piston and piston slide valve in the manner set forth in the accompanying
sheet of drawings in which
Fig. 1 is a longitudinal sectional elevation of my improved piston valve fitted
within a valve box or steam chest and
Fig. 2 is a longitudinal elevation of my improved piston fitted within a cylinder
the latter being in section.
Similar letters of reference denote corresponding parts in each figure.
Referring to Fig. 1 which as before stated represents my improved piston valve
I form a portion of the valve spindle A conical at a' upon which portion I place a
loose collar B which acts as an end cover to the piston valve.
Then I place a suitable number of rings C upon said piston rod A. which form
distance pieces and annular grooves for the packing rings D to fit in as shown.
Where my improved piston valve is arranged with two or more pistons I arrange
a sleeve E to divide the same. The said sleeve E fitting over the valve spindle A
and having enlarged ends e¹ in order to form the ends of the pistons.
Extending from the washer B forming the cover of the piston valve situated near
the valve cylinder cover J I arrange another sleeve G which passes through the
said valve box cover J and through the stuffing box and the sleeve G is arranged
at its outer end so as to receive pressure from one or more nuts H which are either
threaded on the spindle A or on a screwed sleeve or other similar device keyed or
otherwise secured thereto.
Or pressure may be applied to the end of the sleeve G in the manner shown at
Fig. 2 in which case a flange or washer g¹ is secured or placed at the end of the
sleeve G and a spiral spring S is arranged around the spindle A. between said flange g¹
and the boss of a hand wheel H¹ which screws on the threaded part of the spindle A
and receives at its back part a check or lock nut H having a padlock fitted thereto
arranged in a similar manner to the padlock of a safety valve.
Referring again to Fig. 1 the packing rings D may be of ordinary construction
such for instance as those known as Ramsbottom's rings. They are first fitted
within the grooves and are gripped within the same by means of the washers B
distance pieces C and sleeve E.
a smaller
The said packing rings D are thus held down to the same as or
diameter than the valve box or cylinder K so that the said piston valve can be
easily placed within the valve box or cylinder K as will be well understood and
when it is placed within the valve box the pressing device is released and the packing
rings D allowed to expand to the walls of the valve, box when the device is screwed
up and the rings gripped in the manner described.
When the valve box K becomes heated and its internal diameter gets larger
than the external diameter of the packing rings D thereby permitting a leakage
of the motive fluid over said packing rings D the hand wheel H' or nuts Hor
equivalent device are again released for the purpose of allowing the packing

page_text: rings D to spring out fully to the walls of said valve box when the hand wheel H'
or nuts H or equivalent device are again tightened up thus preventing_any
further expansion of the packing rings D until the hand wheel H₁ nuts H or
equivalent device are again released, and this operation may be performed as
often as it is found necessary to allow a further expansion of the packing
rings D.
Referring again to Fig. 2 which as before stated represents a single or
separate piston constructed in accordance with my present invention. One cover B
of the piston bears on the conically formed part a³ of the piston rod A and then
the distance pieces C forming the annular grooves for the reception of the
packing rings D are placed on the parallel part of said piston rod A and
another washer B forming the opposite cover or end of said piston is also
placed on said parallel part of piston rod A and finally the adjustable sleeve G
extends through the cylinder cover J and stuffing box and receives at its
outer end suitable pressure by means of the device already herein before described.
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. In pistons or piston valves the combination of washers B and distance pieces C
gripping packing rings D with a sleeve G arranged on the piston rod or spindle A
the said sleeve G receiving pressure at its outer end by means of nuts H or other
equivalent device substantially as described and illustrated and used for the purpose
set forth.
2. In pistons or piston valves the combination of washers or covers B distance
pieces Cand a sleeve or sleeves E gripping packing rings D with a sleeve Garranged
on the piston rod or valve spindle and receiving pressure at its outer end by means
of screw nuts H or other equivalent device substantially as described and employed
for the purpose stated.
Dated this 18th day of October 1891.
H. F. BOUGHTON, M.I. Mech. E.,
London, Sheffield, and Barnsley.