Year: 1887

page_text: Date of Application, 15th Nov., 1887
Specification Accepted, 16th Dec., 1887
I, DEXTER D. HARDY, of Chicago, in the United States of America, Manufacturer,
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 :-
My invention relates to improvements in direct-acting steam-engines, and the
objects of my improvements are to simplify the construction of such engines, and to
so construct them that the moving parts balance each other, rendering them capable
of high speed.
Reference being had to the accompanying drawing:
Fig. 1 is a vertical cross-section on a plane passing through the axis of one of the
cylinders.
Fig. 2 is an oblique vertical section through the axes of both cylinders.
In the drawing A is the casing of the engine, B B are steam-cylinders, CC the
pistons, D the main shaft, E E the main-shaft cranks, F F sliding plates carrying the
standards G G which enter, at their upper ends, sockets in the cylinders B B, and act
against springs H H in said sockets.
J is the steam-valve, which governs the admission and discharge of steam to and
from the cylinders, and which may be of any desired form. Steam is admitted to
the valve-chamber at K and exhausted from the cylinders at L. M is an eccentric
operating the valve in the usual way. The pistons CC take hold of the cranks
directly, without the use of any connecting-rod. They are journalled to the crank-
pins in an usual manner, except that the caps N¹ N¹ contain springs 0 0, to force the
lower half of the journal-box up against its journal, to take up lost motion.
Each piston carries a cylinder or guide P at its lower end, which is fitted to slide
on the standard or upright Q. While the pistons are reciprocating vertically, the
steam-cylinders reciprocate in a horizontal direction. This admits of and through
the action of the steam on the pistons, produces-a circular movement of the cranks.
The springs H H acting on the cylinders on one side, and on the standards G.G on
the other, and through them on the sliding plates F F-tend to force said plates and
cylinders away from each other. This causes the cylinders, which are open at
their tops, to bear firmly against the inside surface of the top of the casing,

page_text: watch is prepared for them, inaintaining a steam-tight joint between cylinders and
casing.
In addition to this, shoulders R are formed in the top of the cylinders, which
reduce the area of opening of the cylinders at their ends, thereby producing an
upward pressure, when steam is in the cylinders, tending to force the cylinders still
harder against their seat. This upward pressure is that due to the difference between
the area of the main bore of the cylinders and that of their end openings. The
pistons are shouldered at S to agree with the shoulders R so as to reduce clearance
space.
The springs O in the caps N¹ cause the boxes to hug the crank-pins or journals
constantly, to prevent "pounding" of the pistons on said journals at high speeds.
The cranks E E are placed 180 degrees apart, which causes the weights of the pistons
to balance each other in all positions. The piston guides P are fitted to slide on the
uprights in order to relieve pistons and cylinders from side wear.
I do not confine myself to two cylinders and pistons for any number above two may
be used, and a similar balance of parts produced, if the cranks be placed at equal
angular distances apart. The cylinders may be located below or beside the shaft, or
in any radial direction therefrom, in any case being beside each other and
corresponding to separate cranks E.
I make the weights of the pistons alike, and the weights of the cylinders also alike ;
moreover, I make that part of each piston which is above its crank-pin exactly to
balance, in static balance, that part which is below; and considering the
plates F and rods G as parts of the cylinders I apply the same principle to the
cylinders.
This is in order that the inertia of the rapidly moving parts shall be the same on
each side of the crank-pins, to destroy any tendency of these parts to revolve about
their crank-pins. Placing the crank-pins 180 degrees apart makes the running
balance complete, for the inertia of the equal weight cylinders and equal-weight
pistons is equal, and acts in opposite directions on the shaft.
The exhaust ports L open directly into the cylinders and are closed by the sliding
faces of the cylinders, while the steam-ports N are opened and closed by the valve J.
This construction enables the admission of steam to be adjusted or automatically
governed while the exhaust is not affected thereby.
I enclose pistons and cylinders within the tight casing A and partly fill the latter
with oil or other lubricant, which being splashed about by the running parts is thrown
onto all the interior rubbing surfaces.
W is a central support for the shaft, which may or may not be used. X X are
bearings for the shaft, formed in the sides of the casing.
When preferred the exhaust may be operated by a separate valve.
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. A direct-acting steam-engine, consisting of two or more single-acting recti-
linear-vibrating cylinders, in combination with their pistons journalled directly to
separate cranks, situated at equal angular distances apart, on the same shaft, together
with their connecting parts, substantially as and for the purpose herein before set
forth.
2. The combination of the rods G G springs H H, plate F, and rectilinear-
vibrating cylinder B, substantially as and for the purpose hereinbefore set forth.
3. The piston C journalled directly to the crank E in combination with the cap N',
spring O, and vibrating-cylinder B, substantially as set forth.
4. The shoulder R formed by reducing the size of the cylinder at its end, in com-
bination with open-end rectilinear vibrating cylinder B, and casing A, having a
suitable surface for the cylinder to slide against, substantially as set forth.
5. The combination of two or more rectilinear-vibrating cylinders B, with pistons
journalled directly to separate cranks E; the crank-shaft D having two or more

page_text: cranks at equal angular distances apart; the casing A having exhaust-ports leading
directly into the cylinders B, and the steam-ports N, operated by the valve T,
substantially as herein set forth.
.
6. The combination of the rectilinear-vibrating cylinders B; the single-acting
pistons C, journalled directly to separate cranks E; the casing A enclosing said
cylinders, pistons and cranks; the rods G, springs H, and plates F; and the guide-
cylinders P and posts Q, substantially as and for the purpose herein set forth.
3443
D. D. HARDY.
By Herbert & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents to Applicant.