Improvements in Springs for Pistons.
Year: 1894

page_text: Date of Application, 11th June, 1894
Complete Specification Left, 17th Dec., 1894-Accepted, 2nd Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in Springs for Pistons.
1. WILLIAM ELGIE FRITH of No. 3, The Gardens, Leadmill Road, in the City
of Sheffield, Engineer, do hereby declare the nature of my invention to be as
follows:-
My invention has for its object to obtain a perfect combination of lateral and
vertical spring pressure, by a coiled spring of the most simple construction, and
which will even when broken still retain and exert the two above named pressures.
In carrying out my invention, I coil a length of wire or rod as follows, namely,
so that it shall consist of a series of small coils with, at regular intervals, a number
of larger or longer coils so constructed that they will project alternately above and
below what I have called the "small" coils.
I prefer that all the coils both large and small shall be formed oblong and not
circular, and that the non-projecting ends of the longer coils shall be level with
the small coils.
In practice I make the small coils to slope away from the projecting side of
the longer coils, which gives a slight zigzag form to the spring.
The piston rings are not made.with the usual bevelled or inclined faces for the
spring to act against, but are recessed square or thereabouts.
When the spring is placed in position the rings bear against the ends or bends
of the longer coils which project alternately upwards and downwards as before
described.
The compression of the spring when forced into position by screwing down the
coverplate causes it to exert a radial expansive pressure and this is aided by its
zigzag formation which becomes straightened when compressed between the cover
and the piston block.
I do not bind myself to the number of coils to form the varying parts of the
small and the long coils as these may be varied.
Dated the 7th day of June 1894.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.
I, WILLIAM ELGIE FRITH of No. 3 The Gardens, Leadmill Road in the City
of Sheffield, 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 :-
My invention has for its object to obtain a perfect combiuation of lateral and
vertical spring pressure for piston rings by means of a coiled spring of the most
simple coiled form, and which will even when broken still retain and exert the two
above named pressures.
The spring is illustrated in the annexed drawings in which:
Fig. 1, represents a short length of the spring coiled according to my invention.

page_text: Fig. 2, the same spring permanently bent to a slight zigzag or wayed form, in
position.
Fig. 3, end view of same.
In carrying out my invention I coil a length of wire (or rod) as follows, namely,
so that it shall consist of or be formed into a series of small coils A, and at
intervals a number of larger or longer coils B, which are constructed so that they
project beyond the small coils, above and below alternately.
I prefer for the purpose named that all the coils both small and large shall
be of an oblong configuration, and that the non-projecting ends of the longer
coils B, shall be level with the small coils A.
In practice I permanently bend the small coils so that they slope at an angle
from the projecting side of the longer coils as seen in Fig. 2, which gives a
-slight zigzag form or waved configuration to the spring, which is of advantage.
When the spring is placed in position, the rings C, bear against the ends or
bends of the longer coils B, which as before described, project beyond the smaller
coils, alternately upwards and downwards as seen in Fig. 2.
The compression of the spring, when forced into position by screwing down the
coverplate of piston causes it to exert a radial expansive pressure and this is aided
by its zigzag formation which becomes straightened under such pressure.
I do not bind myself to the number of coils either small or large, which form
the several parts of either coils, nor to the proportions shown as these require to
be varied in springs of different diameters, and possibly for springs working under
-different pressures.
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:
An improved spring for pistons coiled and constructed as hereinbefore described
and s
substantially AS SHOWN TH the drawings.
Ustauranty as shown the drawings.
pated the 21st day of November 1894.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.