Year: 1885

page_text: I, HERBERT JOHN HADDAN, of 67 Strand, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention, a communication to
me from abroad by George Delagneau and John H Graham, both of Hastings,
Nebraska, United States of America, Manufacturers, 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 an improved device for packing pistons, and it consists
in the peculiar construction and combination of devices set forth more fully
hereinafter.
In the accompanying drawings:-
--
Fig. 1 is a vertical longitudinal sectional view of a piston and rod with the
improved devices attached thereto.
Fig. 2 is a rear view of the piston, the rear piston-plate being removed.
Fig. 3 is a front elevation showing the indicator and the set-screw for controlling
the packing, and
Fig. 4 is a detailed view.
A represents the piston of a steam engine, and B the piston-rod. From the rear
side of the piston projects an annular flange C, which is of smaller diameter than
the piston and is arranged concentrically therewith.
A plate D, which corresponds in diameter to the piston, is bolted to the rear
side thereof, in the ordinary way. E represents a metallic packing-ring that is cut,
as at e, and is thereby rendered expansible. This packing-ring is placed between
the piston and the plate D and is concentric with the flange C. The piston-rod is
hollow, as shown, and through it extends a rod F, to the rear end of which is
fixed a cam-wheel G, having the inclines g. A series of openings corresponding to
the number of inclines on the cam-wheel, is made through the flange C, and in
these openings are placed push-pins H, the inner ends of which pins bear against
the cams or inclines g, and the outer ends of which are pointed. Flat springs I are
arranged around the flange C and bear between said flange and the inner side of
PinAd1

page_text: the packing-ring, and these springs serve to keep said packing-ring expanded
against the inner side of the cylinder and thereby pack the piston therein. Each
of the springs is provided with a central seat i, in which the pointed end of one
of the pins H enters, as shown in detail in Fig. 4.
By this construction it follows that when the rod F and cam-wheel are turned in
the direction indicated by the arrow in Fig. 2, that the pins will be forced out-
wardly by the inclines g, and the pressure of the springs against the inner side of
the packing-ring be increased so as to further expand said packing-ring, and
tighten it in the cylinder.
To the outer end of the hollow piston-rod is attached a plate K, from the upper
right hand corner of which projects a lug k through which is passed a vertical set-
screw L. To the outer end of the arm F is screwed an arm f, on the outer end of
which arm bears the lower end of the set-screw.
By turning the set-screw, the rod F and cam Ġ can be partly rotated and thus
expand the packing-ring to any desired degree. In order to indicate exactly to
what extent the packing-ring is expanded in the cylinder, I provide an indicator
hand or pointer Ò, that is secured to the rod F, and sweeps over a graduated
scale P, that is inscribed on the plate K.
By means of a packing-device thus constructed, I am enabled to keep the piston
steam-tight in the cylinder without the necessity of stopping the engine and
removing the cylinder-head, which is now necessary in steam-engines of the
common construction, and thus I can effect a great saving of time and labor.
Having now particularly described and ascertained the nature of said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The combination of the piston having the annular flange and the hollow
piston-rod, the expansible packing-ring, the rod passing through the hollow piston,
the cam affixed thereto, the push-pins bearing on the inclines of the cain, and
extending through the annular flange, the springs bearing between the inner side
of the packing-ring, and the push-pins, the arm secured to the outer end of the
cam-rod, and a screw bearing on the free end of the said arm, substantially us
described.
2. The combination of the piston having the annular flange, and the hollow
piston-rod, the expansible packing-ring, the rod passing through the hollow piston-
rod, the cam affixed thereto, push-pins bearing on the inclines of the cam and
extending through the annular flange, the spring bearing between the inner sides
of the packing-ring and the push-pins, the arm secured to the outer end of the cam-
rod, the plate having the scale and the bearing-screw, said plate being secured to
the hollow piston-rod, and the indicator hand on the cam-rod, for the purpose set
forth, substantially as described..
3. The piston, and the hollow piston-rod, in combination with the expansible
packing-ring, the rod passing through the hollow piston-rod and carrying the cam,
the spring-actuated push-pins operated by the cam, and arranged to expand the
packing-ring, and the screw bearing against the free end of the cam-rod, as set
forth.