KoⱭs in Tandem Steam Engines.
Year: 1885

page_text: KoⱭs in Tandem Steam Engines..
I, WALTER BROCK, of the firm of Denny and Company of Dumbarton, in the
County of Dumbarton, North Britain, 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, that is to say:—
My said Invention relates to what are known as tandem steam engines and in
which two cylinders are placed in the same line and have their pistons fixed on
the same rod; and my improved apparatus is applicable (although not exclusively
so) in cases in which the two cylinders are far enough apart to allow of access to
the larger cylinder and valve casing through their covers or through manholes.
formed in their covers. In such cases it has been usual to fit stuffing boxes for the
rods in the ends of each cylinder and each valve casing, making two independent
stuffing boxes for the piston rod and two for the valve rod. In order to avoid the
inconveniences of this arrangement I arrange the parts so as to have only one
working stuffing box for each rod and so that the packing shall be conveniently
accessible from the outside. This working stuffing box is in each case in the cover
of one cylinder or valve casing and the gland is in the form of a tube which
extends to the other cylinder or valve casing where it is made tight by an ordinary
stuffing box (in which however the rod does not work).
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append an explanatory drawing comprising
a vertical section of parts of a pair of tandem cylinders and their valve casings
and showing one mode of applying my improvements.
In the accompanying drawing the smaller upper cylinder, 1, is shown as far
enough apart from the larger lower cylinder, 2, to allow of access from between
them to the larger cylinder. The piston rod, 3, of the two pistons, passes through
a stuffing box, 6, formed in the cover of the lower cylinder, 2, and the gland of
this stuffing box is formed at the lower end of a pipe, 7, which extends up to the
bottom of the upper cylinder, 1, and encloses the part of the piston rod, 3, which
is between the two cylinders. The upper end of the pipe, 7, is entered into a
stuffing box, 8, formed on the bottom of the upper cylinder; the packing of this
upper stuffing box bearing on the outside of the pipe, 7, and not on the piston

page_text: rod, 3. The pipe or elongated gland, 7, is held in position in the stuffing box, 6,
by means of nuts on screw studs, 9; and nuts on the same studs but on the
undersides of the lugs of the gland, 7, serve for lifting the gland the upper end of
its pipe, 7, then passing through the upper stuffing box, 8, up into the upper
cylinder, 1, and free access being thereby obtained to the interior of the stuffing
box, 6. This stuffing box, 6, may be packed in the ordinary way; but I prefer to
use metallic packing in it.
The packing apparatus for the valve rod, 13, is the same as that for the piston
rod, 3, and the corresponding parts are marked with the same reference numerals
increased by 10.
I do not restrict myself to the precise details shown in the accompanying
drawing provided the essential features of my Invention are retained.
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
The packing of the piston rod or valve rod between the cylinders or valve casings
of a pair of tandem cylinders by means of one working stuffing box for each rod
formed in the end of either cylinder and valve casing and provided with an
elongated gland extending to and capable of being slid into the other cylinder or
valve casing all substantially as and for the purposes herein before described.
Dated this thirty-first day of October 1885.