Year: 1894

page_text: Date of Application, 13th Sept., 1894
Complete Specification Left, 13th June, 1895-Accepted, 3rd Aug., 1895
I, GEORGE FINNEY, of 100 Ryland Street, in the City of Birmingham,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in pistons for steam, gas, and other
engines.
The object of my invention is to construct a durable piston having its springs
and expanding segments or rings so arranged as to effectually prevent escape of the
steam or other working gas or fluid, and to enable the piston to be readily placed
within the cylinder.
In carrying my invention into effect I construct the block or body of the piston
from cast iron, steel, or other metal, having a circular base or bottom plate turned
to suit the cylinder and a central boss for the reception of the piston rod.
Radiating from the boss I provide a number of arms or ribs, having their outer ends
enlarged and bolt or stud holes formed therein for the junk ring bolts or studs
hereinafter described. Over the extremities of the radiating arms or ribs I place a
solid ring, the underside of such ring resting or seating, when in position, upon the
inner face of the base or bottom plate of the piston block, while the upper side of
the ring is preferably arranged to be flush with the top of the radiating arms or
ribs. At suitable positions around the interior of this solid ring I provide pockets,
preferably formed in one with the ring, for the reception of spiral or other springs
acting upon the stems of the cones or wedges for expanding the segments or split
rings against the sides or wall of the cylinder. I preferably employ two such
seginental or split rings and so arrange them that the splits or divisions in the rings
The combined width of the
do not come immediately above and below each other.
rings is rather less than the space provided for their reception between the inner or
upper face of the base or bottom plate of the piston block and the underside of the
junk ring or plate, but the rings are pressed tightly against the bottom plate and
the junk ring by the action of spiral or other springs carried in suitable recesses
formed in the rings. The junk ring or plate is of the ordinary type, and is secured
to the piston block by bolts or studs passing into or through the holes formed at the
outer ends of the radiating arms or ribs.
In the construction of small pistons having the junk ring or plate secured by
means of the nut or other fastening on the end of the piston rod, I preferably fix
the pocketed ring over the boss of the piston and arrange the spring pockets to
project from the exterior of the ring.
I do not limit myself to any particular form of the cones or wedges which I
employ in conjunction with the springs contained by the pockets formed with or
attached to the solid inner ring, but modify such cones or wedges and the con-
struction and arrangement of the pocketed ring and other parts of my improved
piston to suit varying requirements.
Dated this 10th day of Santamber 1801
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicant.

page_text: TOCOL am and other Engines.
I, GEORGE FINNEY, of 100 Ryland Street, in the City of Birmingham,
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 :-
This invention relates to improvements in pistons for steam, gas and' other
engines.
The object of my invention is to construct a durable piston having springs and
expanding segments or rings so arranged as to effectually prevent escape of the
steam or other working gas or fluid, and to enable the piston to be readily placed
and freely worked within the cylinder of the engine.
In the accompanying sheet of explanatory drawings to be hereinafter
referred to,-
Figure 1 is a plan of one form of my improved piston with the junk plate
removed.
Figure 2 is a sectional elevation of the piston.
Figures 3 and 4 are similar views to Figures 1 and 2 representing another form
of my piston.
The same reference letters in the different views indicate the same parts.
In carrying my invention into effect I construct the block or body A of the
piston from cast iron; steel, or other metal having a circular base or bottom-plate
turned to suit the cylinder and a central boss for the reception of the piston rod.
Radiating from the boss I provide a number of arms or ribs such as 13 having their
outer ends enlarged and bolt or stud holes formed therein for the junk ring bolts or
studs hereinafter described. Over the extremities of the radiating arms or ribs I
place a solid ring C the underside of such ring resting or seating, when in position,
upon the inner face of the base or bottom plate of the piston block, while the upper
side of the ring' is preferably arranged to be flush with the top of the radiating arms
or ribs: A't suitable positions' around the interior of this solid ring I provide
pockets or chambers D, preferably formed in one with the ring, for the reception of
the steins of the cones or wedges E and spiral or other springs such as F which act
upon the wedges E for expanding the segments or split rings G against the sides or
wall of the cylinder. I preferably employ two such segmental or split rings and so
arrange them that the splits or divisions in the rings do not come immediately above
and below each other. The combined width of the rings is rather less than the
space provided for their reception between the inner or upper face of the base or
bottom plate of the piston block and the underside of the junk ring or plate, but the
rings are pressed tightly against the bottom plate and the junk ring by the action
of the spiral or other springs H carried in suitable recesses formed in the rings.
The junk ring or plate J is of the ordinary type, and is secured to the piston block
by bolts or studs passing into or through the holes K formed at the outer ends of
the radiating arms or ribs.
In the construction of small pistons having the junk ring or plate secured by
means of the nut or other fastening on the end of the piston rod, I preferably fix
the pocketed ring over the boss of the piston and arrange the spring pockets to
project from the exterior of the ring as illustrated at Figures 3 and 4.
I do not limit myself to any particular form of the cones or wedges which I
employ in conjunction with the springs contained by the pockets formed with or
attached to the solid inner ring, but modify such cones or wedges and the con-
struction and arrangement of the pocketed ring and other parts of my improved
piston to suit varying requirements.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In pistons for steam and other engines, the method of expanding the
segmental packing rings by menus of springs and wedges substantially as and for
the purposes herein before described and as illustrated in the accompanying
drawings.
2. In pistons for steam and other engines, the use of an independent ring within
the piston having pockets or chambers for the reception of springs substantially as
and for the purposes herein before described and as illustrated in the accompanying
drawings.
3. In pistons for steam and other engines, the combination of an internal ring
having pockets or chambers for the reception of springs, with external segmental
rings having interposed springs, substantially as and for the purposes hereinbefore
described and as illustrated in the accompanying drawings.
4. The improved general construction and arrangement of parts forming the
improved piston substantially as herein described and illustrated."
Dated this 12th day of June 1895.
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicant.