Year: 1885

page_text: I HENRY EDWARD NEWTON of the Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of Middlesex, Civil 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 :—
This invention relates to a means for packing piston or plunger rods, by which
the friction due to the passage of the rod through the packing, is to a great extent
avoided, and the movement of the rod made more easy.
The present invention may be applied with good effect in any case where it
is necessary to form a tight joint around a piston or plunger rod, but is more
particularly useful in that class of compound engines, in which the same rod is
connected to the pistons or plungers of two or more cylinders, which are arranged
end to end, and in comparatively close proximity to each other.
In such cases, it is of course necessary that the rod should pass through the
adjacent ends or heads of the cylinders, and that the cylinder heads should be
provided with suitable means for forming tight joints around the rod. If stuffing
boxes of the ordinary construction, in which the packing material is pressed directly
around the rod, are employed for this purpose, the friction between the packing
and the rod is sufficient to cause a considerable loss of power, and this it is highly
desirable to avoid.
It is the object of the present invention to, as nearly as possible, overcome this
difficulty, and to provide a means by which a tight, or practically tight joint, can
be formed around a piston or plunger rod, with less friction than is occasioned by
the employment of ordinary stuffing boxes.
As a full understanding of the invention can be best imparted by a detailed
description of the manner in which it is applied, such description will now be given,
reference being had to the accompanying drawings, in which:-
Figure 1 is a horizontal section of the two cylinders of a compound, engine, the
outer end or head of the smaller cylinder, and the adjacent ends or heads of the
two cylinders, being provided with packing devices constructed according the present
Invention
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page_text: Figure 2 is a similar view, showing the adjacent ends or heads of the two
cylinders provided with packing devices embodying the invention in a slightly
modified form.
Referring to said figures, it is to be understood that A, B, are the two cylinders
of an ordinary compound engine, their two pistons CD being attached to the same
rod E, which passes through the outer end or head c of the smaller cylinder, and
the adjacent ends or heads a b of the two cylinders, which are, as is frequently the
case, placed a short distance from each other. This shows both applications of the
invention in a single structure.
In order to avoid the friction occasioned by the passage of the piston rod E
through two packings between the cylinders, I provide the rod with a rigid sleeve 9,
which surrounds the rod between the two cylinders, with its opposite ends extending
into two ordinary stuffing boxes 7-8, with which the adjacent cylinder heads a b
are provided.
In the construction shown in Fig. 1, the sleeve 9 extends through the glands 2-4,
of the two stuffing boxes 7 and 8. These glands press the packings 5-6, with which
the boxes are provided, around the sleeve, so as to form perfectly tight joints. The
glands 2-4 may be arranged to screw into the boxes to compress the packings, or
this may be done by means of bolts passing through the flanges of the glands and
the flanges of the boxes.
By this means it will be seen, that the pressure of the packings 5-6, instead of
being exerted directly against the rod E, is exerted against the sleeve which
surrounds the rod, thereby relieving the rod from the friction of the packings.
The sleeve 9 will be made to fit the rod, leaving it free to slide therein, with but
little friction, against the rod E. The glands 2-4 will be made to fit loosely, as
indicated, so that the sleeve may be capable of a slight lateral movement against
the yielding packings, so as to accommodate itself to any spring in the rod E, and
thus prevent the rod from cutting or wearing, as would be the case if the sleeve
were rigidly supported.
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•
In order to prevent the sleeve 9 from having any endway, movement, it is
provided with a flange, as 3, which rests between one of the cylinder heads and
the packing at that end of the sleeve, as shown in the drawing. If preferred, the
sleeve 9 may be provided with two of the flanges 3, one for each stuffing box.
Should any slight leak take place through the sleeve, it being simply from one
cylinder to the other, and not to the open air, it will in most cases be found
unobjectionable, and the possibility of any such leak can be still further reduced
by providing the interior of the sleeve with a series of annular grooves, as 1, in
which water will accumulate, so as to not only lubricate the rod E, but also provide
a water packing.
The invention is also applicable where the rod to be packed passes through one
cylinder head only. This application of the invention is illustrated at the outer
end of the cylinder B, in which the sleeve 9 simply surrounds the rod E in the
stuffing box 10, and is provided with a gland 11, which compresses the packing 12
around it. In this case, the sleeve 9 is provided with the grooves 1 and flange 3,
and the gland 11 is made to fit loosely around the sleeve, the same as in the
arrangement first described, and for the same purpose.
In the construction shown in fig. 2, the packing devices of the head c, at the
outer, end of the smaller cylinder, are the same as already described, but the
sleeve 9 which surrounds the rod E between the adjacent cylinders, instead of
extending through both of the stuffing boxes 7-8, is arranged to extend through
only one of the stuffing boxes (the box 7 of the cylinder A, as shown in the present
case), while its other end simply enters the other of the stuffing-boxes, and forms
the gland for pressing the packing 5 contained in that box around the rod E.
The sleeve 9 is provided with a flange 2, by which the sleeve can be bolted to
the flange of the stuffing box 8, so as to compress the packing 5 in the usual
manner. The gland 4, bolted to the flange of the stuffing box 7, compresses the
packing 6 contained in that box around the sleeve, as before explained.
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page_text: With the packing device thus constructed, the operation of packing the rod E is
as follows:-The gland 4, having been backed out of the box 7, and the gland end
of the sleeve 9 out of the box S, the packing 5 can readily be inserted around the
rod E, and the packing 6 around the sleeve 9. By then forcing the end of the
sleeve 9 into the box 8, and the gland 4 into box 7, the packing 5 will be com-
pressed, so as to form a tight joint around the rod, and the packing 6 will be
compressed so as to form a tight joint around the sleeve.
It will be seen that by this means perfectly tight joints are formed around the
rod, so as to prevent the escape of steam from either of the cylinders, and that this
is done by bringing only one packing (the packing 5) into contact with the rod,
thus relieving the rod of the friction of one packing...
In this case, the-rod E is not so fully relieved of friction as in the construction
first described, but a more perfect packing is provided, which may be preferable in
some cases.
The sleeve 9 is constructed the same in this case as in the case first described,
and is capable of yielding slightly to accommodate itself to deflections of the rod E,
as before stated.
It is also to be understood that the sleeve 9 and gland 4, instead of being secured
to the boxes 7-8 by means of bolts, may be secured by being screwed into the
boxes, or in any other convenient or suitable manner.
Although for the purpose of illustration, the invention is herein shown as applied
to the cylinders and piston rod of a compound engine, it is to be understood that
it is not limited in its application to the cylinders and rod of such an engine, but
can be applied with equally good results in any case where it is necessary to form
a tight joint or joints around a rod which passes through a single wall, or through
two walls which are located in close or comparatively close proximity to each other.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my Foreign Correspondent, I declare that what I claim is
The application to a stuffing box or stuffing boxes, of a rigid sleeve or sleeves for
receiving a piston or plunger rod, such sleeve or sleeves taking the pressure of the
packing wholly or partially from the rod, in the manner and for the purpose above
set forth.