Improvements in and relating to the Distributing Mechanism of Steam and other Fluid Pressure Engines.
Year: 1899

page_text: Date of Application, 5th Aug., 1899-Accepted, 17th Feb., 1900
Improvements in and relating to the Distributing Mechanism of
Steam and other Fluid Pressure Engines.
I, CLAUDE BONJOUR, of 71, Rue Lafayette, Paris, in the Republic of France,
Engineer, 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 a mechanism having unified differential movements
intended for the actuation of distributing parts of any kind such as slide valves,
piston valves, valves, obturators and so forth, and which is applicable to any motor
operated by means of fluids under pressure whatever may be its type or system.
This mechanism is represented in the accompanying drawings, in which
Figure 1 shews the mechanism in question as a whole applied to the actuation
of the distributing mechanism of a vertical steam engine.
Figures 2, 3 and 4 are respectively a front elevation, a side elevation and a
plan view of the mechanism considered separately.
Figure 5 is a diagram of the movements of the various parts of the distributing
mechanism.
Figure is a diagram shewing the periods during which the distributing
mechanism is open.
Figure 7 shews a modification of the distributing mechanism and its application
to a horizontal steam engine.
Figure 8 is a section taken on the line A-B of Figure 7.
Figure 9 is a diagram relating to
Figures 10 and 11 represent a
mechanism.
the modification shewn in Figures 7 and 8.
further modification of the distributing
Figures 12 and 13 represent another modification of the distributing mechanism.
Figures 14, 15 and 16 represent a still further modification of the distributing
mechanism and its application to a horizontal steam engine.
Figures 17 and 18 represent still another modification of which the distributing
mechanism is capable.
The distributing mechanism, represented in Figures 1, 2, 3 and 4 comprises two
levers a and b pivoted respectively at c and d to the bars e and f of the excentrics
one of which is intended for distribution and the other for expansion. The
distribution excentric is rigidly fixed upon the driving shaft of the machine
and participates in all its movements; the expansion excentric, although con-
nected with the driving shaft, is connected with a governor which regulates its
angle of attachment, as in the case of all distributing mechanisms.
The lever a oscillates upon an axis g situated at a fixed point of the framework
of the machine; the lever b oscillates upon an axis h which is rigidly connected
with the lever a.
The extremity i of the lever 6 is connected, by means of a pin and a slide
block, to a slide way to which it transmits a reciprocating movement, as is here-
inafter explained. This slide way j is provided with an axis enabling its rotation
around the point k situated at the extremity of the lever a.

page_text: Upon the axis of oscillation k of this slide way j is keyed a crank which by
means of its stud and slide block m actuates another slide way n to which an
angular reciprocating motion is also imparted, such motion being around the
point o situated upon a lever p parallel with the lever a, with which it is rigidly
connected.
It is also this latter slide way n which, by means of the axis q rigidly con-
nected therewith, actuates the traction rod r of the distributing parts.
Referring to the diagram shewn in Figure 5, the paths described by the various
parts of the distributing mechanism above described may readily be followed.
The pivot c of the bar e of the distribution excentric describes the arc c² c².
The pivot d of the bar f of the expansion excentric describes the path represented
by the curve d', whilst the extremity of the lever describes the path represented
by the curve i¹.
Owing to the combination of the angular movements transmitted by the two
excentrics to their respective levers a and b, the pin m of the crank l, keyed upon
the axis of oscillation of the slide way.j, describes a path represented by the
curve m¹.
It follows from the combination of the movements as a whole, that the pin q,
forming a rigid whole with the slide way n, describes a path represented by the
curve ; this special curve, becoming modified in proportion as the governor
alters the angle of fixing of the expansion excentric, enables distributing parts
of any kind to be actuated by means of the pin q, as indicated by the regulating
curves represented in Figure 6.
The mechanism in question, which consists in the interposition and combination
of the slide ways j and, thus enables extremely eccentuated periods of retarda-
tion and also periods of acceleration to be obtained regarding the movements of
the pin g.
The periods of retardation serve, by reducing the action of the expansion
excentric during a considerable angle of the travel of the crank, to allow that of
the distribution excentric to preponderate.
The periods of acceleration, on the contrary, serve to increase the intensity of
the action of the expansion excentric in proportion to that of the distributing
excentric, this intensity of action taking place during a very small angle of the
travel of the crank,
The periods of retardation coincide with those of the opening of the orifices:
by the distributor or distributors and the periods of acceleration with those of the
closing of the said orifices; it will thus be readily understood that the com-
bination of the movement as a whole serves to effect the rapid closing of the
admission orifices and to maintain, between zero and 65% of the stroke of the
piston, constant advances and compressions, as will be seen from an examination
of the regulation curves represented in Figure 6 which shews a diagram of the
periods during which the distributor is open.
In this diagram the various elements of the slide valve and of the orifices are
represented by horizontal numbered lines, thus line XI represents the median
position of the slide valve, XII the inside lap upon the side N, XIII the inside 4
lap upon the side AR, XIV the outside lap upon the side AR. XV the outside
lap upon the side AV; the distance between the lines XIV and XVI represents
the width of the orifice of the cylinder upon the side AR, and that between the
lines XV and XVII the length of the orifice of the cylinder upon the side AV.
The vertical lines 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 95 represent the 5
various fractions of the stroke of the piston and all the elements of the distribution
being thus in juxtaposition, the curves 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, clearly
demonstrate the phases of the said distribution in accordance with the various
angular positions given respectively to the expansion excentric by the various
positions of the governor.
The dotted lines 1-1 represents the maximum stroke of the slide valve, 2–2

page_text: the admission; 3-3 the admission lap, 44 the exhaust; 5 the exhaust lap
on the side AR.
6-6 represents the minimum opening for admission; 7-7 the admission,
8-8 the admission lap; 9-9 the exhaust, and 9 the exhaust lap on the side AV.
For example, if the regulation resulting from the curve 40 be considered it will
be seen that the advance at the admission upon the side AR is 6 m/m 3, that the
slide valve attains its maximum aperture at 15%. that the closing of the orifice
takes place at 40%, that the closing of the exhaust takes place at S3% and that
consequently the compression is 17%; then examining the reverse travel of the
slide valve it will be seen that the advance at the exhaust AR takes place at 88%
of the stroke of the piston, the advance at the admission upon the side AV is
6 m/m 7, the slide valve attains its maximum aperture at 15%, the closing of the
admission orifice takes place at 39% and finally the closing of the exhaust
orifices AR takes place at 82% so that the compression is 18%, and by proceeding
in this manner for all curves of the regulation we are able to follow step by
step the travel and operation of the slide valve for all the angular positions
transmitted by the governor to the expansion excentric.
An examination of the said regulation curves will shew the essentially novel
result obtained by the employment of the pantographe mechanism with unified
differential movements which permits, with a nil distributor of causing the
duration of the admission to vary between zero and 65% of the stroke of the
piston whilst preserving constant advances and compressions, which result has
never been attained hitherto.
It should be understood that the distributing mechanism above described is
capable of numerous modifications which do not in any way change its method of
action, the said mechanism consisting of two movements connected together, one
of them taking place at invariable periods with respect to the position of the
driving crank and the other, on the other hand, at periods which are variable,
either at will or under the influence of the governor the two movements being
connected by means of any suitable unification mechanism which will produce
for the actuation of distributing parts of any kind, curves similar to those repre-
sented in Figure 6, whatever may be the mechanical combinations employed to
obtain this effect.
Figures 7 and 8 shew, in this connection, a modification of the distributing
mechanism. In this modification the levers a and b are retained, and they are
arranged in exactly the same manner as that above indicated. being connected with
the bars e and f respectively. The difference consists in the fact that the
mechanism comprises only one slide way, the slide way j, pivoted at k upon the
lever a and of which the pivot is provided with the crank which directly
actuates the distributing slide valve by means of the driving rod r. Nevertheless,
in order to still further improve the results obtained by the employment of the
distributing mechanism, instead of directly actuating the slide valve by means
of the said mechanism, there may be interposed between these two parts a second
mechanism upon the same principle, comprising periods of retardation and
acceleration and serving to reduce the total travel of the slide valve whilst at the
same time increasing the openings of the orifices for small admissions. This
mechanism consists of two special slide ways s and the slide blocks of which are
rigidly connected and thus couple the said slide ways; one of these slide ways s
is connected with the unification mechanism, whilst the other transmits its move-
ment to the slide valve either by means of its axis of oscillation u or by means
of a connecting rod of any suitable kind, having regard to the machine as a
whole and to the applications for which it is intended.
The law of the variations of the angular movements, and also that of the periods
of repose of the said mechanism, is illustrated by the diagram represented in
Figure 9. which represent a diagram of the mechanism having a varied movement;
in this diagram the connecting bar r, instead of actuating the slide valve directly,

page_text: actuates a slotted levers oscillating around the point 10. This lever, by means
of a combination of slide blocks and slide ways in its turn actuates a second lever t
oscillating around the point u, and it is this second lever which actuates the distri
buting slide valve according to circumstances either through the centre of oscilla-
tion u or by means of the traction bar 11 pivoted at 12.
In this diagram, the dotted lines 15-15 represents the maximum stroke of the
connecting rod. 16-16 the maximum stroke of slide valve, and 18 the maximum
opening for admission.
An examination of this diagram will shew that by the combination of the two
levers provided with slide ways, the slide valve experiences a progressive retarda-
tion attaining its maximum at the middle point of its travel since the axis of
assemblage of the slides comes proportionally nearer to the centre of oscilla-
tion 10; then, the lever t has reached the end of its stroke which is limited by a
buffer piston rigid with the slide valve, its experiences a stoppage whilst per-
mitting the lever s to continue its movement; at this moment the axis of
assemblage of the slide blocks, being displaced in the slide way of the lever t, then,
the inverse movement taking place, the parts again assume their respective
positions so as to continue symmetrically the movement in the inverse direction.
If the said mechanism is intended to actuate a fixed expansion distribution, it
may be greatly simplified; in this case the crank actuating the slide valve is
not provided with a slide way, but its pin m is rigidly fixed and then directly
attacks the slide block and the slide ways connected with the unification
mechanism.
In the modification represented in Figures 10 and 11, there are also retained
the lever a oscillating at g and connected at e to the bar e of the excentric, and
also the lever b oscillating at h upon the lever a and connected at d to the bar f
of the excentric. The extremity of the lever b is also connected by means
of a pin and a slide block to the slide way oscillating at k upon the lever a, with
this difference that the said slide way is combined with a toothed sector u in
engagement with a pinion v mounted loosely upon the axis of oscillation and
provided with a crank pin w acting upon the distributor by means of the
connecting rod r.
In the modification represented in Figures 12 and 13, the lever b oscillating
at upon the lever a is itself provided with the toothed sector u in engagement
with the pinion, the axis of which, situated at k upon the lever a, is provided a
with a crank a the pin of which engages in a slide way y oscillating at c upon
the lever a and upon which is adjusted the connecting rod serving to actuate the
distributor.
The Figures 14, 15 and 16 represent another modification in which the lever a is
omitted, whilst the lever b, connected at d with the bar f of the expansion
excentric, is arranged so as to oscillate upon a fixed axis z. At d the lever is
provided with a spindle engaged in a slide way 1 oscillating upon a fixed axis 2
and itself connected by means of a slide block, to a second slide way 3 oscillating
upon the fixed shaft and connected by means of its arm 4 with a connecting
rod 5 attached to a lever 6 rigidly connected with the rod 7 of the slide valve.
There is imparted to this slide valve a reciprocating rectilinear movement which
is transmitted to it by the bar e of the distributing excentric; here it is circular
and its admission edges terminate in a helicoidal section corresponding with that
of the admission orifices. The expansion excentric f, instead of acting upon the
said slide valve by modifying, as in the previous case, its reciprocating move- 5
ment, imparts to it, on the contrary, an angular movement, as will be understood
from the action of the parts described, the object of which is to effect the rapid
closing of the admission orifices.
In the last modification represented in Figures 17 and 18, the two levers a
and bare retained, the lever a oscillating upon a fixed point g and being con- 5
nected at c to the bare of the distributing excentric, whilst the other lever b
oscillates at the extremity of the lever a and is connected at d to the bar f of the

page_text: expansion excentric. The extremity of this lever b is in this case directly
connected with the rod r serving to actuate the distributor.
The difference consists, in this case, in the fact that the expansion excentric
properly so called is replaced by a plate 8 grooved upon its two faces in accordance
with an excentric curve. The free extremity of the bar f is forked and embraces
the edge of the said plate; this fork is provided with rollers engaged in the
grooves of the said plate. In addition to this it is maintained by means of a lever 9
oscillating around a fixed point. Under the influence of the rotation of the excen-
trically grooved plate 8, the bar f modifies the relative position of the levers a
and b and consequently modifies the periods of the travel imparted to the
distributor by the distributing excentric.
The various modifications above described only serve to demonstrate that the
mechanism above described having unified differential movements is capable of
undergoing numerous modifications of detail.
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 distributing mechanism for steam and other motors, consisting of two
movements, one of which is invariable with respect to the movements of the
driving crank, whilst the other, on the contrary, is submitted to a variation
serving to modify the duration of the admission, the said movements being con-
nected and coupled together by means of a unification mechanism enabling the
regulation curves illustrated in Figure 6 of the accompanying drawing to be
reproduced.
2. A distributing mechanism for steam and other motors comprising two levers,
one of which oscillates upon a fixed point and is connected with the bar of the
distribution excentric, whilst the other oscillates upon the first and is connected
with the bar of the expansion excentric, and a system of two slide ways and a
crank placed in operation by the second lever and which serve to act upon the
driving rod of the distributor.
3. A distributing mechanism for steam and other motors comprising two levers,
one of which oscillates upon a fixed point and is connected with the bar of the
distributing excentric, whilst the other oscillates upon the first and is connected
with the bar of the expansion excentric, and a system composed of a slide
way and a crank, this latter acting directly upon the rod actuating the distributor.
4. A distributing mechanism for steam and other motors such as described in
Claim 3, the said mechanism acting in combination with an intermediate
mechanism situated between the aforesaid mechanism and the distributor, com-
prising a system of two slide ways coupled one with the other, one of which
is connected with the distributing mechanism whilst the other is connected with
the rod acting upon the slide valve.
5. A distributing mechanism for steam and other motors, comprising, two
levers one of which oscillates upon a fixed point and is connected with the bar of
the distributing excentric, whilst the other oscillates upon the first and is con-
nected with the bar of the expansion excentric, and a slide way with which is
connected the second lever and which is combined with a toothed sector in
engagement with a pinion carrying a crank connected with the rod acting upon
the distributor.
6. A distributing mechanism for steam and other motors, comprising two
levers one of which oscillates upon a fixed point and is connected with the bar
of the distributing excentric whilst the other oscillates upon the first and is
connected with the bar of the expansion excentric, the said second lever being
provided with a toothed sector engaging with a pinion journalled upon the said
first lever and provided with a crank acting in combination with a slide way
oscillating upon the said first lever and connected with the rod acting upon
the distributor.

page_text: 7. A distributing mechanism for steam and other motors, comprising, a lever
oscillating upon a fixed point and connected with the bar of the expansion
excentric, a system of two slide ways connecting the said levers with the
rod acting upon the distributor, to which is imparted, by means of the said
mechanism, an angular movement, whilst on the other hand a reciprocating move-
ment is imparted to it by the distributing excentric.
8. A distributing mechanism for steam and other motors comprising, two
levers one of which oscillates upon a fixed point and is connected with the
bar of the distributing excentric, whilst the other oscillates upon the first and
is connected with the bar of the expansion excentric, the said expansion excen-
tric being formed of and excentrically grooved plate acting upon the said bar
which is also maintained by an oscillating lever.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.