Improvements in Pistons for Engines and Pumps.
Year: 1890

page_text: Date of Application, 29th Apr., 1890-Accepted, 31st May, 1890
COMPLETE SPECIFICATION.
Improvements in Pistons for Engines and Pumps.
I WALTER MARTIN MUSGRAVE Mechanical Engineer of Globo Iron Works
Bolton Lancashire 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:-
The object of my invention is to enable the pistons of horizontal engines or pumps
to be adjusted so that the pistons rods may always work in the centre of the stuffing
boxes. The friction of the pistons will also be much reduced. To accomplish my
intention I turn the piston & junk ring slightly smaller than the cylinder or working
barrel & support the weight of same upon the rings in the manner shown upon the
Drawings accompanying this specification.
Referring to the drawings Fig. 1 sheet one clearly shows the method of supporting
the piston.. It will be noticed that the spring A employed to expand the rings is
not carried completely round the inside of the latter as is usual but is cut away on
the under side to admit a block B against the ends of which, the spring presses.
Fig. 2 sheet one gives a cross section through the block & rings showing how the
former bears against the latter forcing them against the sides of the piston & junk
plate. The wedges C Care placed between the block B & the body of the piston & are
made adjustable by means of the right & left hand screw D. By this means as the
rings wear the piston & piston rod can be raised & kept in the centre of the cylinder
or working barrel. A hand hole closed by the cover J is provided for obtaining
access to the screw.
It will be seen that with the arrangement described the whole of the wear is
transferred to the rings as the piston & junk ring do not touch the cylinder the rings
are thickened upon the underside to allow for wear.
With pistons of the ordinary construction the friction is increased by the pressure
of the steam forcing the piston down upon the bottom of the cylinder. With the
arrangement described this friction is entirely removed.
Figs. 5 & 6 sheet 2 shows a modified form of the device suited for pistons fitted
with rings the inner faces of which form right angles. The block B is made in
two parts the wedges C C being formed so as to press the divided block against
the sides of the rings thus keeping the latter pressed against the sides of the
piston & junk ring. A small peg E is fitted into the cover J & engages with
the right & left hand screw so that no alteration in the position of the screw can
take place.
Any suitable form of spring may be employed for expanding the rings but we
prefer the form used by Messrs. William Buckley & Co. of Sheffield for their well
known patent pistons.
Figs. 3 & 4 sheet
shows an arrangement by which the right & left hand
screw can be adjusted without the employment of a moveable cover. A bevil
wheel F is fitted upon the right & left hand screw & gears with a pinion H the
spindle of which passes through the side of the piston or junk ring.
Figs. 7 & 8 sheet 2 show a modified arrangement, a worm & wheel being
employed instead of bevil gear.
Although I prefer to actuate the wedges simultaneously by means of a right &
left hand screw it will be obvious that separate screws may be employed for each
wedge such screws may also be actuated by bevil gear separate wheels being
secured upon each screw & gearing into one pinion.

page_text: Having now particularly described & ascertained the nature of my said inven-
tion & in what manner the same is to be performed I declare that what I
claim is.
{"
The arrangement for supporting the pistons of engines & pumps by means of
wedges & screws as described in 'the above specification & shown upon the plans,
or any mere modification of same.
• Datal this th dove of Annil 1900.
WALTER M. MUSGRAVE