Year: 1888

page_text: J, FREDERICK WALKER, of 4 Little Moorfields, in the City of London, 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 object of my Invention is to provide packing rings for steam and other pistons,
the construction of which allows of the pressure being equal all round the circum-
ference of the piston and maintaining a tight, but perfectly elastic joint between said
piston and the interior of the cylinder.
In order that my Invention may be the better understood I have appended the
accompanying sheet of drawings, on which Figure 1 represents a plan view of a piston
constructed according to my Invention, and Figure 2 is a transverse section of same,
and Figures 3 and 4 shew the action of the plate pring upon the rings, hereinafter
to be fully described.
In carrying out my Invention I surround the piston body k by two rings a a,
which fit easily upon and around it. Said rings a a are preferably of cuneiform,
or wedge shaped, cross-section. Intervening between the flat surfaces of these rings
where they oppose each other, I arrange an annular flat plate spring f. I form lugs
or projections d upon the rings a a in such a manner that one lug of the upper ring
intervenes between two similar lugs upon the lower ring, as shewn by Figure 3.
This arrangement allows of the flat spring being compressed in a serpentine form
when the two rings a a are forced together by the junk ring or equivalent device.
The outer packing rings g g are formed either in segments, or simply divided, and
tongued, or the divisions may be opposed so as to prevent leakage. I provide lugs
or projections n around the inner circumference of the outer packing rings 9 g, said
lugs being suitably wedge shaped to correspond with the inner rings a a. The action
of the compressed plate spring, when the piston is put together, is that its tension
tends to open the rings a a apart from each other, and thus cause said rings to press

page_text: upon the wedge shaped lugs n upon the outer packing rings g and press them
radially against the interior surface of the cylinder. In this way I obtain an equal
lateral pressure between the piston body and the junk ring, and also an equal radial
pressure around the circumference of the outer packing rings, tending to keep the
piston air, steam, or fluid tight, and yet allow sufficient elasticity to allow said piston
to work freely within the cylinder.
As an alternative form, I may dispense with the lugs dd upon the rings a a, as
shown by Figure 4, in which case the flat annular spring f must previously be bent
so as to assume the required serpentine form.
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 I claim is,―
In metallic piston packing for steam or other pistons, the combination of two inner
rings with an annular flat spring, and opposing wedge shaped or cuneiform surfaces
on both the inner and outer packing rings as and for the purposes substantially as
herein described and set forth.
Dated this 14th day of May 1888.
FREDK. WALKER & HYDE,
4, Little Moorfields, E.C.,
Agents for Applicant.
FREDK. WALKER & HYDE,
4, Little Moorfields, E.C.,
Agents for Applicant.