Year: 1897

page_text: Date of Application, 17th Nov., 1897-Accepted, 29th Jan., 1898
I, OSSIAN ALBERT RINGBOM, of Lahtis, Finland, 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:--
The present invention relates to improvements in steam engines having differ-
ential piston as hereinafter described.
In the accompanying drawing I have shown a steam motor provided with
centrally arranged slide valve.
a is the small cylinder and the large cylinder, c is the large piston and c¹
the small one, d is the slide or central valve, dan inner chamber in the piston,
e are orifices in the piston-rod head f; indicates orifices in the middle part
or trunk of the piston leading to the steam outlet or exhaust i, k is a rod arranged
on the small cylinder and passing through the valve having at one end a collar
or washer ¹, m is a spring for actuating the slide d and p is the steam-inlet.
The openings are for the lubricating substance and s the outlet or blow off
aperture for the condensed steam.
The inner part of the slide d is by means of side-openings t placed in permanent
communication with the smaller steam-chamber and the steam-inlet, while the
open end of the slide, that is turned towards the piston rod, is provided with a
flange u, for closing the inner chamber of the piston, as soon as the slide has
been displaced to the right, while when the slide is in its other or left hand
position its open end is tightly closed by a projection or valve v on the piston
rod-head.
With this arrangement of the slide it is of course necessary for the rod k
to pass loosely through the end of the said slide. The annular space between
the slide and the inner chamber of the piston communicates by means of
a narrow channel ¹ with the interior of the slide and with the steam. inlet.
This slide is operated in the following manner :-
The steam entering through the inlet p acts upon the smaller piston c¹ and
by means of the openings t fills the interior of the slide d. In the drawing the
slide is shown in the position it occupies, when the piston is moving from right
to left. In this position the large steam cylinder is, by means of the projection v
fitting into the open end of the slide, shut off from the small steam cylinder and the
eteam inlet, while the said large cylinder by the annular space or inner chamber d¹
around the slide and the openings h communicates with the steam outlet i.
During this motion of the piston, the slide is retained in the same position with
respect to the piston by the pressure of the steam acting partly on its end and
partly on the enlarged part of the said slide which fits into the inner circular
chamber of the piston. When the piston c has arrived near the end of the
large cylinder b, the end of the slide strikes the washer or collar k¹ on the rod k
and the slide is then thrown over to its other extreme position so that the flange u
closes the outlet from the large cylinder, while the projection or valve v leaves
open
end of the slide, so that the steam chambers of the large and the small
cylinders are put in connection with each other and the piston is moved in the
the

page_text: opposite direction. When the end of the slide strikes the buffer spring m, the
slide resumes the position illustrated in the drawing and the above described
motion is repeated.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what 1
claim is:-
The hereindescribed improvements in steam engines having differential pistons,
consisting of a projection (v), arranged in front of the hollow slide (d) and firmly
connected with the piston, the said projection serving as a valve for closing the
open end of the slide when the piston is moving in one direction, while a circular
flange around the open end of the slide serves as a valve, which, when the
piston is moving in opposite direction closes the opening between the large steam
cylinder and the inner chamber d¹ of the piston leading to the steam outlet,
the said slide being provided at its opposite end with side opening t by which
the interior of the slide is in permanent communication with the small steam
chamber and the steam-inlet.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.