Improved Piston for Gas or Oil Motor Engine Cylinders.
Year: 1899

page_text: Date of Application, 22nd Feb., 1899-Accepted, 29th Apr., 1899
COMPLETE SPECIFICATION.
Improved Piston for Gas or Oil Motor Engine Cylinders.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
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 Koeln-Deutz, in the Empire of Germany,
Manufacturers), and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:
-
With gas or oil motor engines of the usual single acting kind in which the con-
necting rod is directly pivotted to the piston and there is no crosshead and guides,
the piston itself is made to act as crosshead working in the cylinder as a guide.
The packing is generally effected by means of spring rings in the rear part of
the piston, while in the front part thereof are formed the eyes for the pivots or
trunnions of the connecting rod.
In the construction heretofore employed, as shewn in cross section and longitu-
dinal section at Figs. 1 and 2, the entire piston is made to constitute the cross-
head, the cylindrical surface of the piston being made to fit the cylinder and to
transmit along its entire length the pressure due to the angular positions of the
connecting rod to the cylinder surface.
This arrangement, though suitable for small engines, has the disadvantage when
applied to larger engines that the piston is subject to detrimental abrasion because
it is not possible to insure such a perfect fit of the whole of the large cylindrical
surfaces, and also to insure such a uniform distribution of the lubricant between
them as is required in the case of the unfavorable frictional conditions of cast iron
working upon cast iron.
as to fit
The present invention has for its object to overcome 'this disadvantage, and
consists in making the piston of smaller diameter than the internal
diameter of the cylinder, and in providing the
front part n, o of
the piston with rings 6b of antifriction metal as shewn at Figs. 3
and 4 such rings projecting beyond the surface of the piston so
accurately against the surface of the cylinder and thus prevent the body of the
piston from coming in contact therewith. Such rings are preferably cast in. suit-
able grooves formed in the cylinder as shewn. The rear part of the piston
body mn, which is thus maintained entirely out of contact with the cylinder, con-
tains the ordinary spring packing rings a.
By this construction the functions of the piston are separated in such manner
that the rear part mn thereof operates solely as a packing device, while the front
part no operates as sliding crosshead, and thus, owing to the employment of anti-
friction metal working upon cast iron, no detrimental abrasion of the piston and
cylinder can take place.
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:
A piston for gas and oil motor engines consisting of the combination of a front

page_text: part no acting as sliding crosshead provided externally with a coating of antifric-
tion metal, and a rear part men working free in the cylinder and provided with
packing rings so as to act solely as a packing device, substantially as and for the
purpose described."
D001 J
Th
1000