Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said James Wavish at the Office
of the Commissioners of Patents on the 13th December 1880.
JAMES WAVISH, of Leytonstone, in the County of Essex.
IN PISTONS,"
"IMPROVEMENTS
My Invention relating to improvements in the pistons of cylinders has for its
object enabling the pistons to be more easily and accurately adjusted in position in
cylinders, whereby the pressure of the packing ring is equalized over the inner
circumference of the cylinder, and the piston is materially reduced.
In carrying out my Invention I prepare recesses, or slots, or chambers in the
piston running from the circumference towards the centre, into each of which
I place a spiral spring with a plate on the end nearest the circumference which
bears against the inner surface of the packing ring. A plate is also placed at the
inner end of the spiral spring to which is connected a bolt with set nuts, by means
of which each spring can be readily and accurately adjusted, so that an equal
pressure can be brought to bear on or by each spring, and the piston and piston rod
are kept in their position..
SPECIFICATION n pursuance of the conditions of the Letters Patent and of
an Order of the Lord Chancellor filed by the said James Wavish in the Great
Seal Patent Office on the 24th June 1881.
JAMES WAVISH, of Leytonstone, in the County of Essex.
IN PISTONS."
"IMPROVEMENTS
My said Invention relating to improvements in the pistons of cylinders has for
its object enabling the pistons to be more easily and accurately adjusted in position

page_text: in their cylinders, whereby the pressure of the packing ring is equalised over the
inner circumference of the cylinder, and the friction is materially reduced.
In carrying out my said Invention, in order to effect this object, I prepare
recesses or slots or chambers in the piston running from the circumferance towards
the centre, into each of which I place a helical spring with a plate on the end
nearest the circumference, which bears against the inner surface of the packing
ring, and a washer or plate at the inner end of the helical spring to which is
connected a bolt with set nuts, by means of which each spring can be readily and
accurately adjusted, so that an equal pressure can be brought to bear on and by
the whole of the springs, and the piston and piston rod are kept in their position.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in both the Figures.
Figure 1 of the accompanying Drawings represents a vertical section of a piston
constructed according to my said Invention, and Figure 2 is a horizontal section of
the same corresponding to Figure 1. A is the body of the piston; B are the usual
split packing rings, and c is the junk ring. In the body A I provide a series of
chambers D in each of which I place the following parts, videlicit :-A helical
spring a arranged radially, a V. shaped plate b, which bears against the inner
surface of the packing rings B, and on which plate the spring a exercises its
pressure, and a washer or plate C which bears against the inner end of the spring a
and through which passes a screw bolt d having set nuts e, by means of which the
tension of each spring can be adjusted, the head f of the bolt being located in a
suitable recess formed in the body A of the piston.
It will be obvious that as the whole of the springs can be accurately and
uniformly adjusted, the pressure of the packing rings may be equalized over the
inner circumference of the cylinder with a corresponding reduction in the friction
of the rubbing surfaces.
-
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that I am aware that it has previously been
proposed to employ helical springs arranged radially in the body of a piston, and
therefore to this in itself I lay no claim, but what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-before
in part recited Letters Patent is,―
The combination in a piston of the springs a, plates b, washers c, and adjusting
devices, the whole arranged and combined together and with the packing ring or
rings so as to operate, substantially in the manner and for the purposes herein-
before described and as illustrated in the accompanying Drawings.
In witness whereof, I, the said James Wavish, have to this my Specification
set my hand and seal, this Eleventh day of June, in the year of our Lord
One thousand eight hundred and eighty one.
JAMES WAVISH. (L.S.)