Improvements in the Packing of Piston Rods and Plungers Subject to Heat and Pressure.
Year: 1899

page_text: Date of Application, 22nd Nov., 1899
Complete Specification Left. 16th Aug., 1900-Accepted, 29th Sept., 1900
PROVISIONAL SPECIFICATION.
Improvements in the Packing of Piston Rods and Plungers Subject
to Heat and Pressure.
I, FREDERICK WILLIAM LANCHESTER, of 53, Hagley Road, Edgbaston, in the
City of Birmingham, Engineer, do hereby declare the nature of this invention to
be as follows:
-
This invention relates to the packing of piston rods for gas and oil motor engines
and like purposes and has for its object to provide a packing which will success-
fully resist the heat of combustion and remain pressure tight, thereby facilitating
the construction of tandem engines and the like.
In one mode of carrying this invention into effect as applied to the construction
of a tandem "Otto" cycle engine I arrange a packing consisting of a number of
rings bored to the diameter of the piston rod and of about a quarter to half its
diameter in thickness. These rings are turned on the outside and the alternate
ones have the bore concentric to the outside, the remaining alternate ones having
a certain amount of eccentricity. The packing consisting of a number of rings
constructed and arranged as above described is enclosed in a spiral spring which
neatly fits it on its exterior. The back cover of the compression chamber is made
It is
sufficiently thin to yield somewhat under the pressure of the explosion.
preferably quite flat or even of corrugated form to facilitate as far as possible
such yielding: the centre of the back cover is bored to allow the piston rod to
pass through and is prevented from bulging by the packing which has a space
allotted to it between the back cover and a more rigid abutment provided in the
rear. It will be understood, that the rings constituting the packing are accurately
faced as also the central portions of the back cover and rear abutment between
which it takes up its position.
A taper is provided on the end of the piston rod so that when threaded through
its packing it will automatically adjust the packing discs stretching somewhat
their containing spring.
It will be seen that when the engine is at work a packing constructed as
herein before described is free to follow any irregularities either of position or
form possessed by the piston rod and at all times forms substantially a mechani-
cally fitting busli. When the pressure rises within the cylinder considerable end
pressure comes on to the rod packing and leakage between its component parts
thereby becomes impossible. The packing may therefore be regarded as a bush
which automatically adjusts itself between every working stroke of the engine.
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1
Sambar 1800
MARKS & CLERK.
18. Southampton Buildings. London, W.C.,
13. Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents,

page_text: Improvements in the Packing of Piston Rods and Plungers Subject
to Heat and Pressure.
Q
I, FREDERICK WILLIAM LANCHESTER, of 53, Hagley Road, Edgbaston, in the
City of Birmingham, Engineer, de 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:.
}
:
This invention relates to packing for piston rods and the like, and more
especially to piston rods for gas and oil motor engines, and has for its object to
provide a packing which will successfully resist the heat of combustion and
remain pressure tight thereby facilitating the construction of tandem engines
and the like.
This invention consists in packing piston rods and the like by means of, rings
which are embraced by a helical spring in such a manner that they form in com-
bination an efficient and automatically adjusting packing. The invention further
consists in causing the packing rings to be pinched during periods of pressure in
the cylinder, between a flexible cylinder end and a rigid abutment so that the
packing is specially secure from leakage during periods of high pressure in the
cylinder.
In carrying my invention into effect as illustrated in the accompanying draw-
ings and as applied to the construction of a tandem Otto-cycle engine.
Figure 1 is a sectional elevation of one of the cylinders of the tandem engine
showing in section the packing and packing spring in position on the piston rod.
Figure 2 is an end elevation of the packing before it is placed on the piston rod.
Figure 3 is an end elevation of the packing when in position on the piston rod.
I arrange a packing a consisting of a number of rings 1, 2, 3, etc. bored to the
diameter of the piston rod, and of about a quarter to half its diameter in thick-
ness. These rings are turned outside, and the alternate ones, 1, 3, etc. have their
inside and outside circumferences concentric, the remaining alternate one have
their inside and outside circumferences eccentric. The packing consists of a
number of rings constructed and arranged as above described, and enclosed in a
helical spring b which neatly fits on its exterior. The back cover c of the com-
pression chamber is made sufficiently thin to yield somewhat under the pressure
of the explosion and is preferably flat or corrugated in form, to facilitate as far
as possible such yielding. In the centre of the cover a hole d is bored through
which the piston rod passes. Beyond the back cover c is provided a more rigid
abutment e between which and the cover c is placed the packing, which thus pre-
vents the back cover from bulging. It will be understood that the rings con-
stituting the packing, and the central portions of the back cover and rear abutment
are accurately faced.
A taper is provided on the end of the piston rod so that when threaded through
its packing it will automatically adjust the packing discs, stretching somewhat
their containing spring. Figure 2 shows the aspect and relative position" of the
packing discs before the insertion of the piston rod, under these conditions the
exteriors of the discs are held true to one another by the spring, when, however.
the rod is inserted the internal circumferences of the discs become concentric
and the spring b is distended, this condition is shewn in Figure 3.
It will be seen that when the engine is at work, a packing constructed as
herein before described is free to follow any irregularities either of position or form
possessed by the rod, and 'at all times form a mechanically fitting bush. When
the pressuré rises within the cylinder considerable end pressure comes on the

page_text: rod packing and leakage between its component parts thereby becomes impossible.
The packing may therefore be regarded as a bush which automatically adjusts
itself between every working stroke of the engine.
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. A packing for piston rods and the like, consisting of rings embraced by a
helical spring in such a manner that they form an efficient and automatically
adjusting sliding joint substantially as described.
2. Causing packing for piston rods and the like, to be pinched during periods
of pressure in the cylinder, between a flexible cylinder end and a rigid abutment,
so that the packing is specially secure from leakage during periods of high pres-
sure in the cylinder, substantially as described.
3. A packing for piston rods and the like consisting of rings embraced by a
helical spring, said packing being pinched during the periods of pressure in the
cylinder, between a flexible cylinder end and a rigid abutment; so that the pack-
ing is specially secure from leakage during periods of high pressure in the cylin-
der, substantially as described.
4. A packing for piston rods and the like consisting of a number of annular
discs embraced by a helical spring the discs having equal internal and external
diameters; the internal circumference of each alternate disc being eccentric,
while the remaining dises are concentric so that when the inner circumferences
are made concentric by means of a piston rod the containing spring will be dis-
tended and its reaction will press the thickest portions of the discs against the
rod, thus forming an efficient and automatically adjusting sliding joint, substan-
tially as described.
5. In reciprocating engines, pumps and the like a flexible cylinder cover and
an external rigid abutment between which is placed the piston packing so that
the pressure in the cylinder will cause the flexible cover to pinch the packing
against the rigid abutment thus preventing leakage of the packing especially
during periods of high pressure in the cylinder, substantially as described.
6. The improved piston rod packing herein before described with reference to
the accompanying drawings.
Doted thi
1
MÁRKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.
MÁRKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.