Improvements in Cylinders and Pistons therefor.
Year: 1899

page_text: COMPLETE SPECIFICATION.
Improvements in Cylinders and Pistons therefor.
We, WATSON SPENCE, of No. 800, Ellsworth Street, and JOHNSTON NOLAN, of
No. 3015, Poplar Street, both in the City and County of Philadelphia and State
of Pennsylvania, United States of America, Machinists, 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 pistons for steam, hydraulic, air and other cylinders,
and has for its object to provide a simple and efficient construction whereby the
undue wearing of the cylinder and the piston incident to the weight of the
latter, particularly in large horizontal steam engines, shall be materially
reduced.
To this end the invention, as generally stated, consists in the combination with
the cylinder, of a piston having therein a novel construction and arrangement
of supporting roller or rollers, together with certain adjuncts which will be
hereinafter particularly described and claimed.
In the drawings-
Figure 1 is a sectional elevation of a piston and a portion of a cylinder embody-
ing our invention.
Figure 2 is a full transverse section on the line 2-2 of Figure 1.
Figure 3 is a detail showing one of the adjustable bearing blocks for the
rollers.
Figure 4 is an elevation of one of the rollers detached.
A is a horizontal cylinder, and B the reciprocative piston therein. This piston
comprises the body, b, with circular end heads, 61, detachably bolted thereto.
The heads are peripherally grooved for the reception of appropriate packing
rings 62
The lower peripheral portion of the piston body is transversely
recessed, as at 63, for the reception of anti-friction rollers, b, that are suitably
mounted therein so as to bear upon the floor of the cylinder and thus afford a
rolling support for the piston in its traverse. These rollers are each preferably,
though not essentially, made up of a series of independently rotatable sections or
rings, as shown, so as to ensure a uniform contact thereof upon the bearing sur-
face.
One or more rollers may be employed, as the size and weight of the piston
may determine. In the present instance two rollers are illustrated. These rollers
are journaled in lateral bearing blocks, 5, which are fitted within the recess so
as to be vertically adjustable therein within limits; suitably-disposed set-
screws, 66, being provided to permit the vertical adjustment of said blocks and
the rollers in respect to the cylinder and piston, and thus ensure the efficient
working of the latter. In this case a bridge is formed within the piston,
directly above the rollers, and the set screws are fitted in the bridge in positions
to act upon the respective bearing blocks and serve as determine stops therefor.
These screws are provided with jam nuts 68 to lock the screws in their positions
of adjustment. The piston body is, of course, appropriately recessed above the
bridge, as at b, to permit the screws to be readily manipulated when one of the
heads is removed.

page_text: By the foregoing described construction it will be seen that the reciprocation
of the piston is attended with the minimum of friction between the same and the
cylinder, and that, therefore, the otherwise undue wearing action between the
piston and the floor of the cylinder is materially reduced, and the efficiency of
the engine correspondingly increased.
It will also be seen that the rollers are entirely concealed within the piston,
and, consequently, not subjected to the direct action or pressure of the steam
or other fluid within the cylinder. Further, that to apply, detach, or adjust the
rollers, it is not necessary to remove the piston from the cylinder, inasmuch as
one of the heads of the piston may be unbolted and detached while the piston
is within the cylinder, and access to the rollers and their adjuncts be thereby
readily effected.
We preferably arrange in the floor of the cylinder, and flush therewith, a
plate, a, of phosphor-bronze, or like metal upon which run the supporting rollers
on the piston; which plate, in the present instance, is dovetailed in the cylinder,
so that it (the plate) may be removed and replaced should need require.
We also preferably arrange upon the bridge 67 suitable oil cups 610, which
communicate by means of ducts b with the journals of the respective rollers and
effect the lubrication thereof.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. The combination with a cylinder, of a piston having a recess formed therein
and opening upon the working surface of said cylinder, detachable means for
closing said recess, and an anti-friction roller adjustably mounted within said
recess and adapted to bear upon the working surface of the cylinder, substantially
as described.
2. The combination with a cylinder, of a piston having a recess in its lower
portion and opening upon the noor of said cylinder, a detachable packing head
1or closing said recess, and an anti-friction roller adjustably mounted in said
recess and adapted to bear upon the floor of the cylinder, substantially as described.
3. The combination with a cylinder, of a piston having a recess in its lower
portion and opening upon the hoor of said cylinder, detachable means for closing
said 'recess, adjustable bearing blocks arranged in said recess and retained therein
by said closing means, an anti-friction roller journaled in said blocks, and means
for vertically adjusting said blocks, substantially as described.
4. The combination with a cylinder, of a piston having a recess in its lower
portion and opening upon the floor of said cylinder, detachable means for closing
said recess, bearing blocks arranged in said recess and retained therein by said
closing means, an anti-friction roller journaled in said blocks, and set screws
bearing upon the blocks for purpose of adjustment, substantially as described.
5. The combination with a cylinder, of a piston therein having a recess or
opening in its lower peripheral portion and having detachable packing heads
enclosing the ends of said recess or opening, adjustable bearing blocks in said
recess or opening, an anti-friction roller journaled in said blocks, and means for
vertically adjusting said blocks, substantially as described.
6. The combination with a cylinder, of a piston therein having in its lower
portion the recesses 63, 69, and the interposed bridge b', the bearing blocks fitted
within the recess 3, the roller or rollers journaled in said blocks, and the set
screws fitted in said bridge and adapted to act upon the respective blocks, sub-
stantially as described.
7. The combination with a cylinder having in and flush with the floor thereof
a longitudinal bearing plate, of a piston having a recess in its lower portion,
and an anti-friction roller adjustably mounted in said recess and adapted to roll
upon said bearing plate during the travel of the piston, substantially as described.
8. The combination with a cylinder having in and flush with the floor thereof

page_text: a longitudinal bearing plate, of a piston having a recess in its lower portion,
adjustable bearing blocks arranged in said recess, an anti-friction roller journaled
in said blocks and adapted to roll upon said bearing plate during the travel of
the piston, and means for adjusting said blocks, substantially as described.
Dated this 14th day of August 1800
WATSON SPENCE,
JOHNSTON NOLAN.
Wm. P. Thompson & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.