A NEW OR IMPROVED METHOD OF AND MEANS FOR DISTRIBUTING STEAM, WATER OR GAS, IN STEAM ENGINES AND PUMPS.
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, ERNEST DE PASS, of 68, Fleet Street, in the City of London, Fellow of the
Institute of Patent Agents, do hereby declare the naturo of said Invention for
A NEW OR IMPROVED METHOD OF AND MEANS FOR DISTRIBUTING STEAM, WATER
OR GAS, IN STEAM ENGINES AND PUMPS. Communicated to me from abroad by.
Henri Tenting and Francis Salomon, both of 17, Boulevard Saint-Martin, Paris,
France, to be as follows:-
'
This Invention has for its object a novel method of distribution, by a movement
of lateral displacement of the piston in combination with its ordinary reciprocating
longitudinal movement, said method being applicable to steam engines, and to
water and gas pumps of all kinds.
I proceed to describe the invention as applied, by way of example, to a single
cylinder horizontal engine.
For purposes of description, let it be supposed that the piston is at half stroke
within the cylinder, and that between its faces, and the ends of the cylinder, are
free spaces.
The piston is provided with longitudinal passages, forming conduits, each of
which is freely open at one end, the other ends of the same communicating through
two rectangular orifices in the piston, with orifices formed in the cylinder, and
corresponding with the steam and exhaust pipes, in the manner about to be described.
If steam be now admitted through the steam pipe, it will traverse one of the
orifices in the cylinder, and passing through one of the rectangular orifices of the
piston, will enter into one of the interior longitudinal conduits, whence it will pass
into the free space at the right hand end of the cylinder, where it will impel the
piston, say from right to left. In this movement, the piston carries with it a
plate, termed a motion-plate (plaque de mouvement) and consequently a guide, and
its slide block, whereby the crank pin of the crank keyed on the shaft is caused to
travel, and thus a rotary movement of this shaft is effected.
By reason of this rotary movement of the shaft, a cam or eccentric, turning with
this shaft, in an opening formed in the piston, will communicate to this latter a slight
movement on its axis, so as to bring the second rectangular orifice in front of the
steam inlet orifice, and the first orifice in front of the exhaust steam outlet. Then
the steam entering through the other longitudinal conduit, will pass into the space
Pin d71

page_text: at the left hand end of the cylinder, and will impel the piston, the guide and the
crank pin of the crank, from left to right, which will cause the crank, the shaft
and the eccentric, to continue turning in the same direction; the steam, which has
acted in the right hand space, will pass out through the first named rectangular
orifice, which is then in communication with the exhaust steam outlet, and
consequently with the exhaust steam pipe.
When the piston is at the end of its stroke, the cam will again displace this
piston in a lateral direction; the first named rectangular orifice will again be in
front of the steam inlet orifice, and the second rectangular orifice, and consequently
the second named conduit, will correspond with the exhaust orifice.
It will thus be understood that the movement is caused to take place con-
tinuously by the alternating admission of steam, on the one or on the other face of
the piston.
To insure a perfect fit of the lateral surface of the piston, against the inside of
the cylinder, so as to prevent leakage, two screws are fitted to the two ends of the
piston, the ends of which screws are conical and tangential to the inner side of two
small bow springs, which have their ends let into the motion-plate. When, owing
to wear, the piston no longer bears against the inside of the cylinder, the screws are
screwed in further, thus tending, by reason of their conicalness, to displace the springs
from their former position. But, as the ends of these springs are held by the
motion-plate, it is the screws and consequently the piston to which they are fitted
which become laterally displaced, until the lateral surface of the piston is brought
to bear against the interior surface of the cylinder corresponding to it.
To allow of the crank being keyed on the middle of the shaft, a groove is
contrived at the centre of the guide; this arrangement avoids the use of a bent
shaft.
The method of distribution hereinbefore described, with reference to a single
cylinder horizontal engine, may also be employed for horizontal or vertical engines
with one or more cylinders, as for example, to compound engines.
In applying this invention to a water pump, the shaft being actuated by any
suitable motor, the steam pipe would serve as the suction pipe, and the exhaust
pipe as the delivery pipe.
"

page_text: Fig. 3, a longitudinal section, through the axis of the piston, and
Fig. 4, a transverse section on the line X Y, of Fig, 3, of an engine constructed
in accordance with this invention.
Let it be supposed that the piston D, is at half stroke in the cylinder P, and that
between its faces and the ends Q and Q, of the cylinder, are free spaces V and V¹
This piston is provided with longitudinal passages C and C', forming conduits,
each of which is open at one end, the other ends of the same communicating,
through two rectangular orifices c and c¹ in the piston, with orifices A, B and B¹,
formed in the cylinder and corresponding with the inlet and outlet steam pipes, in
the manner about to be described. If steam be now admitted through the pipe S,
(Fig. 4) it will traverse the orifice A, in the cylinder, and passing through the
rectangular orifice c, of the piston, will enter the interior longitudinal conduit C,
which will bring it into the space V (Fig. 3) where it will impel the piston from
V to V, in the direction of the arrow U. In this movement, the piston carries
with it a plate F, termed a motion plate (Fig. 4) and consequently a slide guide G
and its slide block H, whereby the crank pin i, of the crank I, keyed on the shaft J,
is caused to travel, and thus a rotary movement of this shaft is effected in the
direction of the arrow Z (Fig. 3).
By reason of this rotary movement of the shaft, a cam or eccentric K, (Fig. 4)
turning with this shaft in an opening formed in the piston, will impart to this
latter a slight movement on its axis, in the direction of the arrow (fig. 4) so as to
bring the rectangular orifice c¹, in front of the steam inlet orifice A, and the
orifice c, in front of the exhaust steam outlet B. Then the steam entering through
the longitudinal conduit C¹, will pass into the space V', of the cylinder and will
impel the piston, the slide guide and the crank pin of the crank from V¹ to V,
which will continue to cause the crank, the shaft and the eccentric to turn in the
same direction; the steam which has acted in the space V will pass out through
the orifice c, which is then in communication with the exhaust steam orifice B, and
consequently with the exhaust steam pipe T.
When the piston is at the end of its stroke, the cam will again displace this
piston in a lateral direction; the orifice c, will again be in front of the steam inlet
orifice, and the orifice c', and consequently the conduit C³ will correspond with the
exhaust orifice B¹ (Fig. 4). ·

page_text: It will now be seen how the movement is caused to take place continuously by
the alternating admission of steam on the one or on the other face of the piston.
To ensure a perfect fit of the lateral surface m, n, of the piston D (Fig. 4) against
the inside of the cylinder so as to prevent escape of steam, two screws W, W¹, are
fitted to the two ends of the piston, the ends of which, w, w², are conical and
tangential to the inner side of two small bow springs r, r³, (Figs. 3 and 4) whose
ends are let into the motion plate F. When, owing to wear, the piston no longer
bears against the inside of the cylinder, the screws W, W', are screwed in further,
thus tending by reason of their conicalness to displace the springs from their former
position, but as the ends of these springs are held by the motion plate F, it is the
screws, and consequently the piston to which they are fitted, which become laterally
displaced, until the lateral surface m, n, of the piston is brought to bear against
the interior surface of the cylinder corresponding to it.
To allow of the crank being keyed at the middle of the shaft, a groove 0 (fig. 3)
is contrived at the centre of the slide guide; this arrangement avoids the use of a
bent shaft.
The method of distribution herein before described with reference to a single
cylinder horizontal engine, may also be employed for horizontal or vertical engines
with one or more cylinders as, for example, to compound engines.
In applying this invention to a water pump the shaft J being actuated by any
suitable motor; the steam pipe S would serve as the suction pipe and the pipe T as
the delivery pipe. It is not necessary to refer to the retaining valves and other
accessory parts of pumps.
•
In the specification no reference is made to the other details of construction such
as segments, governors blow through cocks, fly-wheel, etc: which however can be
applied to these engines.
.
•
I now proceed to describe the application of these improvements to a compound
engine, in which the motion of the piston is transmitted to the shaft by means of
a connecting rod, and the improved means by which this result is obtained.
• Fig. 5, is a longitudinal section on the axis; Fig. 6, a horizontal section on the
axis, and Fig. 7, a cross section of a compound engine constructed according to
this novel method of distribution by a movement of lateral displacement of the piston.
D, is the piston working in the cylinder P, in which the boring at V, is larger
than at V. Therefore the diameter of the piston is greater on the side of V than
on that of V. The steam operates in V¹ under full pressure, then it passes into V
through the longitudinal conduit of the piston and then operates by expansion.
I thus obtain a compound engine with one cylinder only.
It is not necessary to make any special reference to the details of construction,
I shall only point out that the slide guide is replaced by a connecting rod E which,
when the speed is great, gives a much more regular motion.
The longitudinal passages forming the conduits may be effected by boring, but
it is preferable to cast them in, they then have the shape shewn in the drawings
at C and C (Figs. 7 and 9).
These two figures shew, in detail, the respective positions of the orifices in the
two extreme positions of the piston in the cylinder.
In (Fig. 7) the orifice C communicates with the steam inlet a. Fig. 8 is a plan
of the steam chest shewing the manner in which the steam operates in the
cylinder; the steam passes from the sinall cylinder through the orifice b and along
the conduit of the steam chest b', enters the main cylinder through the orifice 6"
The steam finally escapes into the open air through the conduit c.
•
Figs 10 and 11 represent the arrangement adopted for an engine working at
great speed.
A, is the cylinder.
'
4

page_text: F, F, F, the escape outlet; F and F1 are in communication through G; and
F and F are in communication through H.
For ordinary engines there is only one steam chest containing three orifices; one
for the admission to the centre and the two others for the escape.
In engines working at great speed which necessitate one of the orifices being
much larger, the escape, and the admission are separated and there is on the one
end of the cylinder an admission chest with one orifice and on the other end of the
cylinder another escape chest with two orifices.
The two chests for the admission and the escape are connected together by the
channels E and G.
Having now particularly described and ascertained the nature of the invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. The new or improved method of distribution by means of a piston formed
with interior conduits, to which is communicated in addition to its ordinary
longitudinal movement, a slight movement of rotation around its axis, said
movement causing each face of the piston to alternately correspond with inlet or'
outlet orifices through two longitudinal conduits formed in the piston and
respectively opening out on each of its faces, substantially as described and shewn
in the drawings.
2. The novel application of the improved method of distribution, by a movement
of lateral displacement of the piston herein above claimed; to steam engines, and
water and gas pumps of all kinds, substantially as set forth.
3. The special arrangement of steam motor, with distribution by a movement of
lateral displacement of the piston, substantially as hereinabove described, and
represented, in the accompanying drawings.
4. Constructing the piston with an opening, for the purpose of allowing the
passage of the shaft carrying the fly wheel and pulley, as herein described.
5. The special form of slide guide, herein described and shewn in the drawings
for allowing of the keying of the crank at the middle of the shaft.
6. The special arrangement of cam or eccentric for bringing about the lateral
displacement of the piston, as described.
Dated this 30th day of October 1884