Improvements in Motors or Pumps with Tandem Cylinders and an Intermediate Shaft.
Year: 1897

page_text: Date of Application, 15th Apr., 1897-Accepted, 9th Apr., 1898
COMPLETE SPECIFICATION.
Improvements in Motors or Pumps with Tandem Cylinders and an
Intermediate Shaft.
I, CAMILLE BIRAULT, of 40, Rue Lecourbe, Paris, France, Engineer, do hereby
declare the nature of this invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
The invention forming the object of the present application for patent relates to
an arrangement of tandem cylinders on opposite sides of the same shaft, the con-
nection between the pin of the crank shaft and the pistons of the cylinders being
effected without connecting rods.
In order to enable the invention to be clearly understood I will take the special
case of a horizontal steam engine with two cylinders.
In the drawings accompanying the present description Fig. 1 represents a
vertical section of this machine through the axis of the cylinders, and Fig. 2 is
a vertical transverse section through the plane X Y of Fig. 1.
The two steam cylinders C C¹ are arranged on opposite sides of the horizontal
shaft A. The pistons P and P¹ of these cylinders act upon the same crank A B
to which they transmit the total power of the steam in the two cylinders.
The transformation of the alternating rectilinear movement of the pistons into
the circular movement of the shaft is obtained by the arrangement of parts which
is called the "longitudinal travelling frame with transverse guiding."
Under the name of longitudinal direction I include any direction parallel to
the displacement of the pistons, and under the name of transverse direction any
direction perpendicular to the latter.
In the special case taken the travelling frame is composed of four longitudinal
bars D, D, E, E¹, four bars G, G¹, connecting between them the extremities of
the previous bars, and of two transverse pieces F, F¹.
The piston rods are rigidly connected to the travelling frame, being fixed to the
parts F, F¹ of the frame.
A collar surrounds the pin B of the crank shaft. Its outer rim is turned to a
diameter slightly less than the horizontal space included between the parts F, F.
This circular piece, called the crank collar, is loose on the pin B of the crank.
The travelling frame is guided in its longitudinal displacement. An inspection
of Fig. 1 will show that by this arrangement the transformation of the alternating
rectilinear movement of the pistons to the circular movement of the shaft is
obtained.
In the rotary movement of the shaft the pin B of the crank turns within the
collar and the rim of the latter travels by rolling alternately on one and then on
the other of the guide surfaces F, F, and thus secures the transverse guiding of
the crank pin, whilst a longitudinal travelling movement is imparted thereto by the
frame.
When the crank AB is in a given position the force of the steam is applied on
the collar of the crank outside the axis of the cylinders.

page_text: The longitudinal bars D, D, E, E¹, of the frame towards their extremities carry
sliding surfaces d², d³, e², e³; the fixed slide blocks are shown at d, d¹, e, e¹.
The unequalness of the force produces a rubbing on these blocks. By this
guiding of the frame at its extremities, between the blocks d, d, e, e', the trans-
verse guide surfaces f, f¹ are kept vertical.
This distinguishes the arrangement described from all those where this result
is obtained by the rigidity of the connection of the piston rods with the parts F, F¹
and by resistance of the two pieces F, F¹ themselves.
On the contrary in the present case the connection of the pieces F and F with
the piston rods is not relied upon nor their resistance to flection; they form an
integral part of the frame the whole of the parts of which assist in resistance; the
piston rods may even be fixed to the pieces F, F¹ by articulated connections.
The crank collar is composed essentially:
Of an exterior ring, in one or several parts, of which the exterior surface is
turned;
Of a central part forming the hub composed of pieces which are of brass provided
with antifriction surfaces at their contact with the crank pin;
Of an arrangement for tightening and centreing situated between the ring and
the hub. It is composed of wedges or keys taking their bearing by one of their
faces on the interior part of the ring and by their opposite face on the exterior part
of the hub. These wedges or keys are actuated by any mechanical means, such as
articulated levers, screws, etc., and generally by any means permitting of obtain-
ing power without subsequent loosening.
This mode of tightening also permits of centreing the collar, seeing that it
produces displacements of the hub relative to the exterior ring. The collar might
be surrounded by a rim the surface of which rolls against the transverse guiding
surfaces of the frame.
Fig. 3 of the drawings represents a vertical section of a crank collar. The parts
previously described will be readily seen. The outer ring is in two parts H, H',
bolted together. The hub is composed of two pieces I, I', the central part of
which is of brass furnished with antifriction surfaces. The keys J and J¹ which
are replaced by keys of less thickness as the bearings I, II wear, permit of the
perfect tightening no matter what the wear may be.
The system of tightening and centreing is composed of four wedges L, L, L', L',
actuated two by two by means of levers to which the necessary power for tightening
the wedges is communicated by causing the nuts M, M³, to descend along the fixed
screws V, VI
Fig. 4 is a horizontal section of a guide surface f¹, f¹, of the rim of the collar H
when these two parts are in contact.
Figs. 3 and 5 show the method of lubricating adopted for the collar just
described.
Circular groove h is formed in the exterior surface of the crank collar. Four
copper tubes a permit of the entrance of the oil received in this groove h to the
hub; the oil passes by the passages 1, m, to the pin of the crank B and lubricates
the contact surfaces.
The tubes a contain inside a retaining valve shown at b, Fig. 5. This Fig. 5 is
a section of the crank collar in a diametrical plane passing through the axis of
the pin B.
In this figure the tube is supposed to be in one of its lower positions, when
the oil will flow out by the action of its weight. The valve b closes all exit; it is
applied to its seat by its weight, increased by that of an additional mass p, and by
the force of a springo also acting in the direction which closes the valve."
The power of this spring o is inferior to the weight of the valve proper and of
the mass p; its effect is to close the valve when the tubes a are near the horizontal
and the oil could run out.
The oil is distributed to the tubes a when they occupy an upper position near to

page_text: the vertical; the weight then opens the valves b and the oil descends within the
tubes.
By varying the mass p the valve can be charged so as to obtain its opening and
closing the desired moments.
In Fig. 3 I have shown a vertical section of an oil distributing apparatus. The
whole of this apparatus follows the vertical displacement of the collar between the
guide surfaces f, f. It is guided in this movement by wings K, K' which slide
in ways k, ; and it remains in contact with the exterior surface of the collar
through the bearing surfaces p¹, p². The oil is supplied to the centre of the
reservoir N whence it passes immediately by the tubes c, c¹, into the distributing
reservoirs, 0, 0¹
The oil only runs out of these reservoirs 0, 0¹ when the tubes g, g¹, are raised by
the inclines arranged in the groove h at the places where the tubes a are
situated.
At this moment the lateral openings formed in the tubes 9,g³, are brought
above the bottom of the reservoirs 0, 01; the oil flows down and passes into the
tubes a.
It then passes little by little to the hub remaining stored in the
spaces l, m, until it is consumed.
In cases where the effects of the compression of the steam at the end of the travel
of the pistons, and those of the advance to the admission are not judged sufficient
to annul the force of the inertia of the parts in movement, and to take up without
shock the play between the crank collar and the guide surface with which it is to
come in contact, use will be made of brakes with auxiliary resistances. These
brakes may be of any type and their resistance will be applied to the frame, or
to any part rigidly connected to the frame.
In Fig. 1 I have represented an arrangement of brake with a progressive and
adjustable resistance, where the force absorbed is recuperated.
This resistance is obtained by compressing air at the end of the travel in the
fixed cylinders Q, Q. In these cylinders travel small pistons fixed to the
extremities of the tail rods of the steam pistons.
The resistance thus obtained increases progressively as the motor pistons arrive
at the end of their travel; it is adjustable by imprisoning a variable initial volume
of air, according to which of the orifices i is left in communication with the
atmosphere. A circulation of water round the cylinders Q, Q' prevents the
temperature of the air from rising excessively by the effect of the compression.
The longitudinal travelling frame with transverse guiding described in the
special case shown in the drawings, Figs. 1 and 2, is naturally capable of being
varied in its form, in its arrangement, and the number of parts of which it is
composed. But in all cases it will comprise:
1. Longitudinal bars carrying near their extremities (except in the case herein-
before described) sliding surfaces or revolving rollers which guide the frame in
its longitudinal movement.
2. Transverse bars connected to the former in a rigid manner and between which
the transverse guiding of the crank collar is effected.
3. Supplementary bars serving to strengthen the whole or to connect at one or
several points the rods of the pistons to the frame.
They may when their position at the ends of the frame permits of it carry the
sliding surfaces or rollers described as applied to the longitudinal bars.
The pistons, of the cylinders are rigidly connected to the frame; in Fig. 1 a
rigid arrangement is indicated between the piston rods and the transverse pieces F
of the frame. The connection between the pistons and the frame may be effected
in any manner at several points if judged necessary, as for example by fixing
the extremities of the tail rods to the frame as well as the piston rods.
The frame of the steam motor with two cylinders previously described comprises:
Four longitudinal bars D, D¹, E, E; two transverse bars F, F, and four
auxiliary bars G, G₁. The longitudinal guiding is effected by friction and the

page_text: sliding surfaces d², d³, e², e³, are fixed to the extremities of the longitudinal
bars.
I will now complete the detailed description of the horizontal steam engine with
two cylinders which I have taken as a type by adding a description of a system of
valve distribution with variable expansion and reversing gear without either
connecting rod or eccentric, and which is particularly applicable to the special case
under consideration.
The valves T, T, (Fig. 1) of the two cylinders have their rods t, t¹, in the same
line and connected together by a stirrup through which passes the crank of crank
shaft parallel to the motor shaft A.
The valves T, T, are operated by the angular displacements of the shaft j.
Fig. 6 shows a transverse section of the distribution through the axis of the
motor shaft; Figs. 7, 8, 9 and 10 relate to details of this distribution.
The shaft receives its angular displacements through one of its extremities
during the forward movement of the pistons and through the other extremity
during the return movement.
On the parts F, F, of the frame are fixed two pieces with vertical wings S, S¹,
carrying guides n, n, n³, n¹, shown in longitudinal section, Fig. 10. During a
single travel of the pistons one of these guides raises a roller u connected to the
shaft so that the vertical movement of the roller produces a horizontal displace-
ment of the crank of shaft j; and consequently a longitudinal displacement of
the valves. The form of the guides n enables the phases of the distribution to be
effected as in a distribution by eccentric.
Two other pieces q, q', fixed to the parts F, F¹, of the frame carry stops v,
(Fig. 9).
At the end of the travel of the pistons during the period of the advance to
the admission these stops come in contact with blocks a connected to the shaft j.
They move them so as to obtain a complete opening of the valves when the
pistons arrive at the end of their travel.
The valves do not commence their movement in the reverse direction under the
action of the guides n and of the rollers u, until the return movement of the pistons
has attained the desired point according to the expansion adopted.
Variation of the expansion is obtained by modifying the profile of the guides n, n¹.
The part n (Fig. 10) of these guides can turn round the fixed pivot y. It is raised
by the horizontal displacements of the support z.
These displacements of z are produced from the outside, by imparting to the
shaft R (Fig. 6) a given angular displacement.
This rotation is transmitted by the intermediary of toothed sectors and pinions
(Figs. 7 and 8) to the stops s, s¹, which are displaced equally in opposite directions.
The travelling frame arriving at the end of its course strikes these stops through
the bars U, U. These bars can slide longitudinally and they are therefore carried
along as well as the supports 2, 21, which are fixed to them laterally.
For reversing the travel it is necessary to impart to the valves a sudden displace-
ment bringing them to the end of their travel or by determining between the
rollers u, u, and the guides n, n¹, a reverse contact to that which existed at the
moment when the travel was reversed. If for example the roller u is in contact
with the guide n, it is necessary to bring the roller u' into contact with the guide n¹
at the opposite extremity of the shaft j
This sudden movement is effected in the desired direction by admitting the
steam by a special valve to the face of one of the secondary pistons 1, 1ª, shown
in Fig. 1, and on a larger scale in Fig. 14.
These pistons are displaced in the cylinders 2, 2ª which are in constant communi-
cation with each other by the orifices w, w¹.
These pistons are displaced in the cylinders 2, 2" which are in constant communi-
During the normal travel the spaces 3, 3, are in communication with the con-
denser and the pressure is that of the condenser on the outer faces of the

page_text: pistons 1, 1. The diameters of these two pistons are equal; the whole is in
equilibrium.
The tail rods of the pistons 1, 1ª actuate by the articulated levers 4, 4ª, the
supplementary valves 5, 5º. These supplementary valves are pierced with a
vertical channel 6, 6" in which a cylindrical valve 8, 8" pressed to its seat by a
spring 7, 7 can rise and descend.
If the difference of pressure from the bottom to top becomes sufficient at a given
moment to raise the valve 8, 8ª the part of the channel 6, 6ª which is situated
beneath is placed into direct communication with the space 3, 3ª through the
lateral passages.
At the end of the travel of the valves T, T, the supplementary valves 5, 5ª are
displaced so as to be caused to occupy during the whole course of the steam pistons
which is about to commence the position giving the reversal of motion at any
moment of this travel.
Suppose that the supplementary valves 5, 5ª, occupy the position indicated
in Fig. 1. If at this moment steam is admitted simultaneously to the spaces 3, 3",
it will be seen that it will only act on the piston 1, at the right of the figure; on
the left hand, the valve 8" will remain forced to its seat by the effect of the steam
admitted at 3" and of the spring 7°.
The arrangement of the pistons 1 and 1ª is therefore no longer in equilibrium,
there is a force which displaces the whole system from the right towards the left,
and the movement will only stop when the valves T, T, arrive at the end of their
left travel, or until the contact is established between the roller u and the corre-
sponding guide n, this contact will then be the reverse of that which existed
before.
Consequently the travel of the motor is reversed and the movement of the
pistons and frame continue in the reverse travel, actuating the valves by this new
travel, which thus follows on as soon as it is set by the preceding arrangement.
The valves T, T¹, having arrived at the end of the left travel it will be seen in
Fig. 1 that the supplementary valves 5, 5" are brought back to their prior sym-
metrical position. The steam then acts also on the piston 1º and the whole system is
in equilibrium.
By the distributing apparatus of the reversing mechanism the spaces 3 and 3ª
are thus put into communication with the condenser. The steam which acts upon
the pistons 1, 1ª escapes on both sides at the same time, directly from one of the
pistons and in raising the valve 8 for the other; this valve afterwards falls back
to its seat by the effect of its spring 7.
The whole apparatus therefore remains still in equilibrium and the reversing
mechanism is back in its original condition, ready to operate for a subsequent
reversal of the same.
The spaces 3 and 3ª are alternately placed into communication with the steam or
with the condenser by a distributing apparatus which may consist of a simple
ordinary valve or a set of any valves."
It will be understood that this system of distribution which forms one of the
principal elements of my invention is susceptible of being modified according to
power of the motor or the application which one has in view.
the
The machine which I have described above is a horizontal steam engine with
two cylinders and a single crank. The whole of the preceding description is
equally applicable to vertical engines operated by any motive fluid.
Further this arrangement is also applicable with any number of cylinders
and several cranks, these cylinders being grouped on opposite sides of the shaft
so as to act several at a time on the same crank.
Figs. 11, 12 and 13 show an arrangement of cylinders for a horizontal engine
with five cylinders and two cranks at 90°. Figs. 11 and 12 are vertical sections
through the axis of the groups of cylinders acting through the same frame on the
same crank. Fig. 13 shows the arrangement of these cylinders in plan.

page_text: Finally the arrangement described may be applied if the shaft is actuated by
any special motor and that the force is transmitted to the pistons of the cylinders
as in the case of pumps and any kind of receptive machines. This arrangement is
also applicable when certain cylinders are motor cylinders and the others are
receivers.
-The result obtained by this arrangement is, by the suppression of the connecting
rod, to reduce the space included between the shaft and the piston, and of being
able to transmit to the same crank the power of several pistons, or to inversely
actuate through a single crank several pistons at the same time.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a motor or receptive machine (such as pumps) the arrangement in groups
of cylinders having the same axis and placed on opposite sides of the shaft, in
combination with the crank shaft, the crank collar, the travelling frame and
the auxiliary resistance brakes, all substantially as described and shown in the
accompanying drawings.
2. In the machines specified the construction and employment of the crank
collar, adjustable in position and provided with means of lubrication, all sub-
stantially as described and as shown in Figs. 3, 4 and 5 of the accompanying
drawings.
3. The application to motors or receptive machines of the system of variable
expansion distribution and reversal of travel described in connection with
Figs. 7, 8, 9 and 10 of the accompanying drawings.
Dated this 15th day of April 1897.
ALLISON BROS.,
Agents for the Applicant.
ALLISON BROS.,
Agents for the Applicant.