CERTAIN IMPROVEMENTS IN PISTONS FOR STEAM ENGINES AND OTHER PURPOSES
Year: 1885

page_text: I, ALEXANDER HENRY REED, of 90 Cannon Street in the city of London,
Engineer do hereby declare the nature of the said invention for CERTAIN
IMPROVEMENTS IN PISTONS FOR STEAM ENGINES AND OTHER PURPOSES and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The invention relates to pistons for steam engines and other purposes and
consists in the novel features of construction hereinafter described whereby an
article of superior utility is obtained.
In the accompanying drawing
Figure 1 represents a longitudinal section of a piston embodying the invention.
Fig. 2 is a cross section in the plane x x fig 1.
Figs 3 and 4 are detail views of parts.
Similar letters indicate corresponding parts in all the figures.
The letter A designates the body of the piston and B the follower thereof, the
two parts being connected together by the axial screw bolt C, which is formed on
the end of the piston rod. The letters D D indicate packing rings intermediate of
the body A and the follower B and the letter F designates an expansion ring
arranged intermediate of the packing rings D D. Each of these rings D D and F
is cross cut as at S, S, S, fig. 3 and the packing rings are bevelled in an inward
direction on their inner edges which face each other whilst the expansion ring Fis
bevelled on both edges in an outward direction to engage the bevelled edges of the
packing ring.
Each of the rings moreover is made of steel or other elastic metal and con-
sequently if the bolt C, is adjusted to draw the body A and follower B together,
the packing rings D, D are expanded by the action of their bevelled edges upon
the bevelled edges of the expansion ring F, the latter forming so to speak a circular
wedge, whilst if the bolt is adjusted to free the head and follower, the packing
rings are permitted to contract by their inherent elasticity, so that the rings are
readily adjusted to the cylinder.

page_text: At a point opposite to its cross cut S each of the packing rings D is provided
with a recess G into which is fitted a tongue I, see figs 3 and 4 to break joints with
the rings, thereby preventing the passage of steam through the cut.
They are
A perspective view of one of these tongues is shown in fig. 4.
provided with flanges which extend up on the inner sides of the packing rings and
rivets a, a which pass through these flanges and through the rings, serve to hold
the tongues in position.
By referring to fig. 3 it will be seen that each tongue is retained by a single
rivet, so that it does not interfere with the expansion of the packing ring to which
it is attached. Instead of holding the tongues in position by means of rivets as
above described, they may be held in place by means of springs. In the body A
is a small channel b with two side channels c, c' (fig. 1) leading into the space
between the head and the follower. In the interior of the channel bare formed
two valve seats d, d, the side channels c, c¹ being intermediate between these seats
and into said channel b, is fitted a plunger e the ends of which form valves f, ƒ ¹.
If steam is admitted into the cylinder against the follower B the valve fis driven
to the seat d and steam passes through the channel b, and side channel c¹ into the
interior of the piston and if the steam acts on the piston in the opposite direction,
the valve fis sealed, and the side channel c is opened to admit the interior of the
piston.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The combination of the piston body A, the follower B, the axial screw bolt C
on the piston rod, the cross cut packing rings D, D, having their inner or adjacent
edges bevelled inwardly, the cross cut expansion ring F having its opposite edges
bevelled outwardly, the packing rings having recesses G opposite their cross cuts,
and the tongues I arranged in the recesses, the said axial screw bolt by its
adjustment serving to move the follower towards or from the head for expanding
and contracting the packing rings substantially as herein shown and described.
2. The combination substantially as herein shown and described with the piston
body A, the follower B, the cross cut packing rings D, D having their inner or
adjacent edges bevelled inwardly and the cross cut expansion ring F having its
opposite edges bevelled outwardly of a channel b formed in the head, the valve
seats formed in said channel, the side channels c, c' intermediate between the valve
seats and the valves f, f¹ formed at the opposite ends of the plunger e.
יד
funth day of February 1885