Improvements in Pistons.
Year: 1898

page_text: Date of Application, 12th Nov., 1898-Accepted, 17th Dec., 1898
COMPLETE SPECIFICATION.
Improvements in Pistons.
I, JOSEPH IMLER, of Kendallville, County of Noble, Indiana, U.S.A., Mechanic,
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:-
-
This invention has for objects to make pistons lighter; to prevent undue wear
and obtain greater power by reducing friction; to obtain balanced piston rings;
to produce an adjustable slide for introducing as much or as little steam, gas,
or air into the piston as desired; and to enhance generally the effectiveness of
the same.
These objects are attained by the mechanism shewn in the accompanying draw-
ing in which Fig. 1 shews the piston of the invention in cross section. Fig. 2
is an end view as seen from the direction of the arrow 13 and with the cylinder
in section, and Fig. 3 is a detail view of a portion of the face of the central part
of diaphragm 2.
A is the cylinder, 1 the piston rod on which the piston is mounted and which
may be attached to a crank or other means of transmitting power to turn wheels
or otherwise, outside the cylinder.
In the central part of the piston is a diaphragm or partition 2 which separates
the two heads 3 and through which latter are openings 5 for the admission of
steam, gas, or air into chambers 4 which in turn are connected with small pas-
sages 11 around the head between the rings 8 by the openings 9, 10.
Slides or gates 6 are mounted upon the piston rod and these with the central
diaphragm 2 and heads 3 are firmly bound together upon the piston rod by lock
nuts 7.
In operation the steam or gas upon entering the cylinder A through port holes
of the usual kind, acts alternately upon each head of the piston by a suitably
provided valve in the steam chest or other receptacle and drives the piston from
one end of the cylinder A to the other and back again. Supposing the piston to
be driven in the direction 12 (to the right), the steam or gas with also enter the
ports 5 on that side of the piston and fill the chamber 4 and pass through the
apertures 9 into the space 11. This likewise occurs whether 9 is an aperture us
in Fig. 3 or a rough seam as 10, because the elastic force of the steam or gas in 4
forces the seam apart sufficiently to fill the space 11.
The latter is the preferable mode of construction and in practice supplies a
sufficient quantity of steam or gas.
The object of introducing steam into space 11 is twofold; to form a cushion
and thus secure an easier motion and also to balance the piston ring 8 by placing
the same force on both sides 14, 15 when the piston is moving before the live
.steam. When the steam or piston is travelling to the right or direction 12, in

page_text: the ordinary method of construction the great force is upon side 15 of the ring
forcing it tightly against shoulder 14. While the exhaust is taking place upon
the opposite side of the piston there is practically no pressure of steam in the
chamber 4 upon the exhaust side and the live steam then simply serves to press
the ring 8 through the chamber 11 tightly against the outer side of the groove
in which it is placed thus bringing practically all the work upon a single ring
at a time. The great pressure of the steam is thus brought to bear alternately
upon the rings, and as only one ring at a time is brought into use a much less
amount of friction is brought to bear upon the inner side of the cylinder. So
long as one of the rings does not allow the steam to pass around it, one ring at
a time receiving the full pressure of the steam answers every purpose.
By the invention the rings are put in equilibrium, the same force being on
both sides especially when the cylinder becomes worn or is untrue, the rings
playing up and down in the grooves and all engineers are aware that it takes
several pounds of steam to move the piston because of the friction created. By
balancing the rings as in the invention and providing a cushion between them
the friction is reduced to a minimum and much power saved which by the old
way is spent in overcoming the resistance of the cylinder.
Again, as balancing the valve in the steam chest relieves the friction so it does
by balancing the rings 8 and further by reducing the friction the wear is equally
reduced both on the rings and the internal surface of the cylinder. Actual
experimental tests have made this conclusive but it has been found necessary in
order to secure the best results to regulate the introduction of steam, gas, or air,
through the openings 5 by means of an adjustable slide 6. This is accomplished
by liberating lock nuts 7 and then rotating slide 6 upon piston rod 1 until open-
ing 5 is sufficiently large or small to secure best results, then locking nuts again.
By this method of construction another beneficial result is obtained, viz., the
piston is kept much hotter and proportionately condensation of steam in particular
is prevented by a hollow piston head, actual experiment has proven that the
chamber 4 is always dry and any condensation that may take place is in the open
space 11 which being filled with steam and water acts as a lubricator for the
rings as well as a cushion or balance to the rings.
The above is the preferable mode of construction and there may be any number
of rings 8 or any number or size of openings 5.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a piston, two grooved heads, packing rings placed in said grooves; the
piston rod to which the heads are secured, and a diaphragm which is located
between the two heads which are recessed upon their inner sides so as to formų
steam chambers, combined with a valve which is secured to the piston rod, and
which valve has a slightly turning movement so as to adjust the amount of steam.
admitted to the chambers; there being suitable openings or passages for the
outward passage of steam between the heads and the central diaphragm so as to
permit the space or chamber formed between the cylinder and diaphragm and
the heads to be filled with steam, substantially as described and shewn.
2. In a piston, two grooved internally chambered heads of less diameter than
the cylinder, suitable packing rings placed in the grooves, and the diaphragm
placed between the two heads and also of less diameter than the cylinder there
being suitable openings between the heads and the diaphragm to permit of the 5
outward passage of steam from the chamber that is formed between the heads
and the diaphragm and the cylinder combined with suitable valves for controlling
the openings leading into the chambers formed inside of the head, substantially
as described and shewn.
3. The combination with the heads having annular grooves for packing rings, 5

page_text: of covers 6, of the passages 5, the chambers 4, the passages 9 the space 11 the
central diaphragm 2 the rod 1 and means for holding all of said parts fixidly
together in proper position, substantially as described and shewn.
Dated the 12th day of November 1898.
THOMAS R. SHILLITO,
15, Tooks Court, London, E.C., Agent for the Applicant.