An Improvement in Pistons for Gas or Oil Motor Engine Cylinders.
Year: 1899

page_text: Date of Application, 9th Aug., 1899-Accepted, 9th Sept., 1899
COMPLETE SPECIFICATION.
An Improvement in Pistons for Gas or Oil Motor Engine Cylinders.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Build-
ings, in the County of London, Consulting Engineer and Chartered Patent Agent,
do hereby declare the nature of this invention (as communicated to me from
abroad by The Gasmotoren Fabrik Deutz, of Köeln-Deutz, in the Empire of
Germany, Manufacturers,) and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
This invention relates to a construction of piston described in the Specification
to Patent No. 3948 of 1899 wherein the front part of the piston is made to act
only as sliding crosshead and is provided with external rings of antifriction metal
which support the piston while the rear part thereof which works free in the
cylinder is provided with spring packing rings so as to act solely as a packing
device. With such a construction the piston requires in many cases, to be
provided with so many packing rings, that on account of the consequent great
length of the rear part of the piston, which works free in the cylinder, the
centre of gravity of the piston becomes shifted too far away from the middle part
of the front supporting part of the piston.
Thus referring to Figs. 1 and 2 of the accompanying drawing, which shew
respectively a cross section and longitudinal section of such a piston, this is
provided with seven packing rings a and four rings of antifriction metal b, the
centre of gravity being situated nearly in line with the rear end n of the anti-
friction metal covering b. In consequence hereof, the rear edge of the lower
part of the antifriction metal covering becomes worn to a greater extent than
at the front end, at o, so that the piston gradually assumes an inclined position
to the cylinder axis, and becomes leaky.
The present improvement has for its object to prevent this disadvantage by
multiplying, as it were, the arrangement of the piston described in the prior
specification, that is to say, providing several supporting parts and several parts
with packing arranged alternately one behind the other. Figs. 3 and 4 shew a
cross section and longitudinal section of such a construction of the piston, in
which there are two parts m n and op provided with packing rings, arranged
alternately with two supporting parts n o and provided with antifriction
metal Figs. 5 and 6 shew similar views of a modification in which there are
three parts with packing rings m n, o p, q, and three supporting parts no,
Prs, arranged alternately.
In both arrangements the centre of gravity is brought more towards the middle
of the supporting parts, that is, in the middle between n and 9 or n and s, thus
more or less preventing the unequal wear of the antifriction metal covering.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:
In pistons of the kind referred to in Patent No, 3948 of 1899 the arrangement

page_text: whereby several parts of the piston having spring packing rings are made to
alternate with several supporting parts having rings of antifriction metal, for
the purpose of reducing friction and preventing unequal wear of the supporting
surfaces, substantially as described.
11
1. 1000
ABEL & IMRAY,
Agents for the Applicant.