Improvements in or connected with Metallic Packings for Piston Rods and the like.
Year: 1898

page_text: Date of Application, 15th Dec., 1898-Accepted, 21st Jan.,
1899
COMPLETE SPECIFICATION.
Improvements in or connected with Metallic Packings for Piston
Rods and the like.
I, JOSEPH BUTTERWORTH, of 141, Station Road, Pendlebury, near Manchester,
in the County of Lancaster, Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement and accompanying drawings:
My said invention has reference to metallic packings for piston rods and the
like and has for its object to regulate or reduce the pressure of fluids upon the
back of the metallic blocks or rings so as to prevent undue wearing of the same.
For this purpose I have devised means whereby the pressure in the cylinder is
excluded, or almost entirely so, from the case in which are arranged the metallic
packings. To effect this I provide two sets of packing rings within the box and
dispose between the two sets of packing rings compressed springs exerting pres-
sure in a line parallel with the axis of the piston rod. This elastic pressure tends
to press the two sets of packing rings firmly against each end of the box and
thus isolate the box from the cylinder and the atmosphere.
In case of leakage from the cylinder the pressure thus gradually accumulating
within the packing box is regulated by means of a relief valve.
And in order that my invention may be more fully understood I will refer to
the accompanying drawings which clearly illustrates the same.
The fig. represents the packing box of a steam engine partly in section and
partly in outside view.
From an inspection of the upper portion of the fig. it will be seen that within
the box A are arranged two sets of metallic packings B and C. The set B, which
a arranged within
is nearest the cylinder, is composed of bevelled metallic rings
a case b.
The metallic packing C is formed of segmental rings d and encircling
springs e as described in the Specification of my former Letters Patent No. 2759
of 1898.
It will be understood that the position of the two sets of packings may be
reversed, or both sets may be alike of either type. Disposed between the two
sets of metallic packing B and C is fitted a bush E containing springs f under
compression which press the two sets of packings against each end of the case A.
Ball and socket rings F are provided as is usual to allow for oscillation of the
piston rod. At the end of the packing box A nearest the cylinder, an annular
lip or rim g is provided, and the case b, or the packing a, is ground to the annular
lip thus formed. In cases where the hole at this end of the box A is considerably
5 larger than the body of the rod a bush h represented in dotted lines, provided
with the annular projection is fitted tightly in the hole.
I attach the relief valve G to the lower part of the packing box A. This valve
is shown as loaded by means of a spring i, and a screwed spindle j is provided to
A dead
regulate the lift of the valve and the pressure at which it blows off.
weight or lever valve may however be used for the purpose.

page_text: By adjusting the load on the valve G the pressure behind the blocks of the
packings B and C, gradually accumulating by leakage from the cylinder, can be
regulated to any degree, and need be no more than is sufficient to maintain the
packing steam tight. I do not confine myself to the use of the relief valve to
cases where two sets of packings are placed in one box as described, as it is equally
applicable where two sets of packings are fitted in separate but ad-
joining chambers in which case the valve can be fitted to the
chamber furthest from the cylinder so that the pressure therein is regulated as
already described.
By placing the relief valve G at the lowest part of the box it will act to auto-
matically drain the box when the weight of liquid therein overcomes the load on
the valve.
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
1) As means for regulating the pressure of fluids upon metallic packing for
piston rods and the like, providing the packing box with two sets of packing
rings thrust apart against each end of the box by means of interposed springs,
and a relief valve adjusted to a pre-determined load to regulate the pressure
within the box, and to automatically drain the box of condensed water sub-
stantially as described and shown.
2) The employment of a relief valve in conjunction with a packing box or
boxes provided with two sets of packing rings for the purposes and substantially
as described and shown.
3) The combination of a packing box A formed or provided at its inner end
with an annular lip or fitting piece g. duplicate sets of metallic packing B, C,
interposed springs f, and the relief valve G all arranged and acting in the manner
for the purposes and substantially as described and illustrated.
Dated this 13th dox of Llanars kon 1809
Dotod thre R435
dax at Hanamkon 1809
For the Applicant,
E. K. DUTTON & Co.,
Chartered Patent Agents, 5, John Dalton Street, Manchester.