Year: 1885

page_text: I BENJAMIN CLAYTON WAITE of 68 North First Street, Brooklyn in the County
of Kings and State of New York, United States of America Machinist do hereby
declare the nature of this invention to be as follows:-
The Invention consists in certain features of construction and arrangement
having the object to obtain simplicity and durability of construction and
economical operation of that type of engine whether the power in use is the full or
only the partial capacity of the engine, all as hereinafter described.
My improvements relate to the employment in steam engines of two pistons in
one cylinder the movement of the pistons to be in opposite directions, and both
connected to the same crank shaft.
The crank shaft has three cranks the middle one being diametrically opposite
and between the other two and the one piston rod is tubular and its cross head is
connected to the two outer cranks whilst the other piston rod passes through the
tubular rod and its cross head and is connected to another cross head which is
connected to the middle crank. The cross-head of the tubular piston rod is
provided with a stuffing box for the inner rod and the two cross-heads move in
different slideways.
The cylinder is formed with steam passages from its ends, uniting at a common
opening in the valve seat. There is also a steam passage from the mid length of
the cylinder opening to a separate part in the valve seat, and between these two
steam ports there is an exhaust port in the seat. The valve is of D form and has
a transverse movement in relation to the cylinder for connecting either steam
passage with the exhaust.
For operating the valve and reversing the movement the following mechanism is
employed: a rock shaft is fitted transversely of the bed plate and beneath the
cylinder. On one end of this shaft is a crank arm that takes the slot of a T piece
on the valve rod the T piece being adjustable for setting the valve. On the other
end of the rock shaft is a disc provided with crank pins at opposite sides with one
or other of which engages by a gab one or other of a pair of connected roda. The
engagement of the rods is controlled by a handing lever which may be locked in
one position by a hand wheel and in the other by a nut and quadrant. The rods
may be operated by an ordinary eccentric on the shaft.
On the engine shaft is a straight grooved disc having lengthwise of the groove a
Borew carrying a nut that is formed with a crank pin to which the two rods are

page_text: connected, the construction being such as to allow adjustment to regulate the
length of movements of the valve, and by shifting the rods so as to release one and
engage the other with the other crank pin on the rock shaft disc the movement of
the valve is reversed.
The valve rod is connected to the valve by means of flanged collars engaging
logs on the valve and secured by nuts which allow their adjustment; and in case
of wear the outer collar can be taken off, filed down, to bring the flanges nearer
together, and then replaced and screwed up to the lugs.
In the operation of the engine steam entering between the two pistons forces
them apart and to the opposite ends of the cylinder, and they are again forced to
the middle position by the steam entering at the ends. Each piston thus has a
stroke half the length of the cylinder, and the momentum of their movement is
balanced by their motion in reverse of each other. The strain is also balanced by
the reverse cranks on the shaft so that the engine runs without jar or tendency to
oscillate.
When the full capacity of the engine is not required, one cross head may be
made fast with the piston head at the centre of the cylinder and the shaft driven
by the movement of the other head alone, thereby obtaining full power from a
small amount of steam.
The details of construction specified may be varied within the scope of my
invention. In place of the reversing mechanism described the ordinary link
motion may be used with single eccentric rod.
By passing one piston rod through the other only one additional stuffing box is
needed, and that being on the cross head is readily accessible.
I, BENJAMIN CLAYTON WAITE, of Brooklyn, in the County of Kings, and State 3
of New York, United States of America; Machinist, 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 improvements relate to the employment in steam-engines of two pistons in
one cylinder, the movement of the pistons to be in opposite directions, and both 3
connected to the crank shaft.
The Invention consists in certain features of construction and arrangement
having for their object to obtain simplicity and durability of construction and

page_text: economical operation or that type of engine wh
or only the partial capacity of the engine, all as hereinafter described and claimed.
Reference is to be had to the accompanying drawings forming a part of this,
specification in which similar letters of reference indicate corresponding parts in all,
the Figures.
Figure 1 is a sectional plan view of an engine of the improved construction.
Figure 2. is a side elevation of the same.
Figure 3. is a longitudinal section of the cylinder in a plane at right angles to
Figure 1.
Figure 4 is a side view of the cylinder in reverse of Figure 2 and with the
steam-chest cover removed. Figure 5. is an end view of the cylinder with the head
removed and steam-chest in section.
Figures 6. 7. and 8 are detail views.
Figure 9. is a side elevation of the ordinary link-motion.
The engine shown is horizontal. A is the bed plate; B the cylinder; C the
steam-chest at one side of the cylinder; and D the shaft provided with three
cranks ff g two being at one side, and the third crank g diametrically opposite
and between the other two. The rod a of the piston b is tubular, and is attached
to a cross-head c fitted to move on slideways d and connected by rods e e to the
cranks ff. The rod h of piston i passes through the rod a and cross head c and is
attached to a cross-head k working on slideways and connected by a rod m with
crank g. The cross head c is provided with a stuffing-box d around rod h. The
cylinder is formed with steam passages n n from its ends, uniting at a common
opening in the valve-seat. There is also a steam-passage o from the mid-length of
the cylinder-opening to a separate part in the valve seat, and between these two
steam ports there is an exhaust-port in the seat connecting to the exhaust pipe p.
The valve p¹ is of D form, and has a transverse movement in relation to the
cylinder for connecting either steam passage with the exhaust. For operating the
valve, and reversing the movement the following mechanism is employed;-q is a
rock shaft fitted transversely of the bed-plate and beneath the cylinder. On one
end of this shaft is an arm q¹ (see Figure 4.) having a crank pin q³ that takes
the slot of a T-piece r on the valve-rod s, the piece r being adjustable for setting
the valve. On the other end of shaft q is a disc r¹ provided with crank pins r² at
opposite sides. t t are rods connected together having gabs for engaging pins
t is a nut and hand-wheel on shaft 4. 8 is a lever that connects by a link 8' with
one rod t and the longer arm of the lever has a bolt at t entering a slot in a fixed
segment u so that the lever can be secured by a nut on the bolt t. The lever 8¹,
as shown in Figure 8, lies between the hand-wheel t¹ and bub of disc r¹ so as to be
clamped by the hand wheel when the rod t engages the upper pin. When the
engine is reversed and rod t engages the lower pin the lever is to be locked to the
segment u The rods may be operated by an ordinary eccentric on the shaft;
but I prefer the device shown. On the engine shaft D is a straight grooved disc v
(shown most clearly in Figure 7) having lengthwise of the groove a screw u
carrying a nut v that is formed with a crank pin receiving the head-piece w to
which the two rods are connected. The piece w has a slot receiving a collar on
the crank pin and on the pins are washers w³ at opposite sides of piece w, while a
nut w¹ on the end of the pin clamps the inner collar to the disc thereby holding
the parts firmly together. This construction allows adjustment to regulate the
length of movements of the valve, and by shifting the rods t so as to release one
and engage the other with disc 1 the movement of the valve is reversed.
shown most clearly in Figure 6, the rod s is connected to valve p¹ by means of
flanged collars a¹ engaging lugs b¹ on the valve. The collars a¹ are held on the rod
by nuts c¹ which allow their adjustment; and in case of wear the outer collar can
be taken off, filed down to bring the flanges nearer together, and then replaced and
screwed up to the lugs. In the operation of the engine, steam entering between
the two pistons by the passage o forces them apart and to the opposite ends of the
cylinder, and they are again forced to the middle position by the steam entering
As

page_text: by passages n. Each piston thus has a stroke half the length of the cylinder, and
the momentum of their movement is balanced by their motion in reverse of each
other. The strain is also balanced by the reverse cranks on the shaft, so that the
engine runs without jar, or tendency to oscillate. When the full capacity of the
engine is not required, one cross head made be made fast with the piston at
the centre of the cylinder, and the shaft driven by the movement of the other head
alone, thereby obtaining full power from a small amount of steam.
The details of construction specified may be varied within the scope of the
Invention. In place of the reversing mechanism shown, the ordinary link-motion
may be used with a single eccentric rod t as shown in Figure 9. By passing one
piston rod through the other only one additional stuffing-box is needed, and that
being on the cross-head is readily accessible.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a steam-engine, the combination of cylinder B having steam passages no,
pistons bi, piston-rods a h, stuffing box d³, and cross-heads c k substantially as
shown and described.
2. The combination of valve p¹ fitted for movement transversely of the cylinder,
with a cylinder formed with steam passages n n o, and intermediate exhaust-port,
and the two pistons bi substantially as described.
3. The reversing mechanism consisting of disc 71 having pins r³, the lever 8¹,
eccentric rods and gabs t, link 83, hand wheel t¹, and slotted segment u, combined
with the operating shaft 9 of the valve, substantially as described.
4. The slotted disc v, screw v³, nut and crank-pin v³ and the slotted head piece w
combined with the crank shaft D and valve-operating rods t substantially as
described.