Year: 1888

page_text: piston passes.
The construction of these parts is as follows: The piston B, consists of a hollow,
annular outer part which carries any suitable packing, as in the ordinary piston, and
of an inner part, which is movably secured therein, by a ball and socket joint, the
socket bearing being formed upon the inner face of the outer part, and the ball bearing
upon the inner part, as shown, the latter being also hollowed out to fit, against the
inwardly projecting head E, of the cylinder. The piston rod C, is secured to this
inner part in the usual rigid manner, so that the inner part rocks within the outer
part, in accordance with the angular position of the piston rod, during the travel of
the piston.
The stuffing box forms a ball and socket joint with the head E of the cylinder, and
by means of a suitable nut G, which forms a ball and socket joint on the inner end of
the stuffing box the latter is secured to the cylinder head, free to follow the angular

page_text: movement of the piston rod. The stuffing box is suitably packed, at its outer end,
and from there towards its inner end its bore is enlarged for the purpose of forming a
sufficient clearance for the piston rod to assume its angular position without binding,
or producing any lateral pressure.
In practico, it will be seen that with this construction and arrangement of parts, the
usual connecting rod is entirely dispensed with, as the piston rod is entirely free to
assume an angular position.
The steam pressure keeps the ball and socket joint of the stuffing box steam tight,
and would naturally keep the latter in position, without securing it by the nut G, but
the latter will prevent any accidental displacement of such stuffing box, in case no
steam is on, and the piston is removed to the rear.
The peculiar conical form of the inwardly projecting portion of the head E, is
provided, to afford a free play for the stuffing box; and in accordance therewith I
form the piston to fit against the inner face of the head, to the exclusion of all undue
clearance.
The object of projecting the head E, of the cylinder so far inwardly is to form the
center of movement of the ball and socket joint of the stuffing box, as near as possible
toward the middle of the cylinder, for the purpose of reducing the necessary
dimensions of the ball and socket joint of the stuffing box, by reducing the relative
angular play of the piston rod, within the stuffing box. This is an advantago as it
reduces the friction of the ball and socket joint between the stuffing box and the
cylinder head, to a minimum.
The difference in the relative amount of angular play of the piston rod and stuffing
box, evidently depends also on the length of the stuffing box, and if it is desired to
decrease this amount of play, it can be done by lengthening the stuffing box.
To prevent all binding or injurious friction of the stuffing box with the piston rod,
the packing should form the only point of contact between the two.
The point of greatest relative angularity between the piston rod and stuffing box, is
not at the quarter, but near the beginning or end of the stroke, as shown in
Figure two. This is on account of the rapid approach to each other of the center of
angular motion of the piston rod (which is the center of the ball and socket joint of
the piston) and the center of the ball and socket joint of the stuffing box ; and the
advantage of constructing the engine in such manner that these two points are at a
relatively short distance from oach other in the positions of the parts in Figures 1
and 3, therefore will be easily understood. This consideration combined with the one
which locates the center of the ball and socket joint of the stuffing box, preferably at
or near the middle of the cylinder, determines the relative shape of the head E, and of
the piston.
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. In an engine of the kind described, the combination with the oscillating piston
rod, of an oscillating stuffing box, provided with an enlarged boro for the lateral.
play of the piston rod, and a ball and socket joint between the inner end of the stuffing
box, and the cylinder head, the center of motion of said ball and socket joint being
located inside the cylinder, substantially as described.
2. In an engine of the kind described, the combination of the stuffing box, termi-
nating in a ball and socket bearing at its inner end, the cylinder head provided with a
conical inward projection, terminating in a socket bearing at its inner end, and the
enlarged bore in the stuffing box to provide for relative angular play between the
stuffing box and piston rod, substantially as described.
3. In an engine of the kind described, the combination with the oscillating stuffing
box, of the cylinder head provided with a conical inward projection, and of a ball and
socket joint between the inner end of the stuffing box and the cylinder head, said
joint having its center of motion located at or near the center of the cylinder,
anhotantially as desenihed

page_text: 4. In an engine of the kind described, the combination of the cylinder, provided
with the inwardly projecting head, the stuffing box, forming a ball and socket joint
therewith, and provided with the enlarged bore, and the two part piston head, provided
with a ball and socket joint between its parts, substantially as described.
5. In an engine of the kind described, the combination of the inwardly projecting
conical head E, the stuffing box F, having a ball and socket joint therewith the nut G,
having a ball and socket joint with the stuffing box, and the piston head D, consisting
of an annular outer part, and an inner, conical recessed part, secured to the
piston rod, and having a ball and socket joint with said outer part, substantially as
described.
In witness whereof I, the said Samuel Esler Jarvis, have hereunto set my hand
and seal, this twenty-eighth day of December, A.D. eighteen hundred and
SAMUEL ESLER JARVIS.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.