IMPROVEMENTS IN PISTONS OR PLUNGERS
Year: 1878

page_text: LETTERS PATENT to William Gibb, of Jarrow-on-Tyne, Engineer, for the
Invention of "IMPROVEMENTS IN PISTONS OR PLUNGERS."
Sealed the 26th November 1878, and dated the 6th June 1878.
PROVISIONAL SPECIFICATION left by the said William Gibb at the Office of
the Commissioners of Patents on the 6th June 1878.
WILLIAM GIBB, of Jarrow-on-Tyne, Engineer. "IMPROVEMENTS IN PISTONS OR
PLUNGERS,'
My Invention relates to improvements in pistons or plungers whereby a more
effective packing is obtained than heretofore, and it consists in the use in substitu-
tion for the springs ordinarily employed of oval helical springs, that is to say, springs
composed of wire coiled helically, but so as to form an oval or elongated in lieu of
a circular contour. These springs are fitted in recesses in the body of the piston or
plunger, so as to exercise pressure upon the packing rings after the manner of the
springs of the ordinary construction employed for a like purpose.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Gibb in the Great Seal Patent Office on the 4th December
1878.
#
WILLIAM GIBB, of Jarrow-on-Tyne, Engineer. IMPROVEMENTS IN PISTONS OR
PLUNGERS."
My said Invention relates to improvements in piston's or plungers whereby a more
effective packing is obtained than heretofore, and it consists in the use in substitu-
tion for the springs ordinarily employed of oval helical springs, that is to say, springs
composed of wire coiled helically, but so as to form an oval or elongated in lieu of
a circular contour. These springs are fitted in recesses in the body of the piston or
plunger, so as to exercise pressure upon the packing rings after the manner of the
springs of the ordinary construction employed for a like purpose.
And in order that my said Invention may be fully understood I shall now pro-
ceed more particularly do describe' the same, and for that purpose shall refer to the.
several Figures on the annexed Sheet of Drawing, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of my Drawings represents a half transverse section and half elevation
of a piston with my said Invention applied thereto; Figure 2 is a plan of the same
with one half of the annular cover removed; and Figure 3 is an elevation of one of
the springs detached.
A is the body of the piston, B is the packing ring, and C are recesses formed in
the piston body for the reception of the springs which act upon the internal peril
phery of the packing ring B; as in the ordinary manner, the said recesses being
closed on their upper side by an annular cover D.
According to my said Invention I substitute for the spring ordinarily employed
oval helical springs, as shewn at E, that is to say, springs composed of wire coiled
helically, but so as to form an oval or elongated in lieu of a circular contour, whereby
I obtain a more effective packing than is attainable by the use of springs of the
ordinary construction.
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 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 employment in pistóns or plungers of helical springs
of an oval or clongated contour, for exercising pressure upon the packing rings,
substantially as herein-before described.
2.
In witness whereof, I, the said William Gibb, have to this my Specification
set my hand and seal, this Fourth day of November, One thousand eight
hundred and seventy-eight.
WILLIAM GIBB..(LS.)