Improvements in Engine Indicators.
Year: 1893

page_text: Date of Application, 24th Apr., 1893
Complete Specification Left, 22nd Jan., 1894-Accepted, 14th Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements in Engine Indicators.
I, MOSES JOHN WAYNE, of 3 Louisa Cottages, East Street Prittlewell, in the
County of Essex, Engineer, do hereby declare the nature of this invention to be
as follows:
The invention relates to that class of indicator in which a small reciprocating
rotary motor is used to give motion to the diagram tracing point.
Heretofore such reciprocating rotary motor has been formed of a cylinder, two
fixed abutments diametrically opposite to each other within the cylinder, a double
piston fitting against the sides and periphery of the spaces in said cylinder and an
inlet and outlet passage to each of said spaces. These inlets have however been in
communication with a way or passage extending fully half round the cylinder and
connected with a single centrally situated passage or way; the consequence has
been that the half cylinder forming one side of the half circular passage has been
subject to different degrees of expansion to the other half of the cylinder; it has
consequently warped out of shape and thereby impaired the action of the motor.
According to my invention I place the inlet passages to the cylinder in communi-
cation with two passages separated from each other at their connection with the
cylinder and joined together at their opposite ends by which means I support that
side of the cylinder and thereby prevent warping and secure a correct action of the
motor. I also, instead of allowing the outlet passages to communicate at once with
the open air, attach to one end of the cylinder an enclosing cap forming a chamber
into which the outlets open, and I make an outlet opening at the lower side of such
cap. The piston axle passes through both ends of the cylinder and in one end it
has a cross cut and a screw thread formed in an axial recess. The corresponding
cylinder end has two studs fixed therein, a cylindrical doubly coiled wire spring is
attached at one end to a plate formed with two perforations to fit the said studs and
the other end of such spring has the wire passing diametrically across it to fit the
cross cut in the end of the piston axle ; a screw screwed into the piston end retains
the spring in position. The ends of the spring may however be otherwise fitted.
The spring will thus act in one direction on the piston axle and the motive force
will act thereon in the reverse direction.
In one form of the indicator I fix on the opposite end of the piston axis a tracer
pointer of any suitable construction, but I prefer to form it of a conical tube
having an enlargement to fit over the axle and divided rear extension or jaws
with clamping screw to adjustably fix it on the axle; the pointer tracer proper
fits within such tube, is held from rotation but is pressed forward by a suitable
spring.
In this form of indicator I employ a sheet of record paper mounted in a carrier
consisting of a slide mounted in guides which may consist of friction rollers carried
by a bracket and having at each end a clip consisting of fixed segmentally curved
jaws and correspondingly curved spring jaws fitting shallow recesses in the face of
the fixed jaws.
The paper, by being placed between the said fixed and spring jaws, is held
stretched in the form of a segment of a cylinder struck from the piston axis.
A narrow segmentally curved supporting table is fixed to the bracket or frame to
support the record paper at the part where the tracer presses thereon.
The slide bracket is mounted on a stud passing through the indicator frame
and it has fixed thereto a finger-piece, and a corresponding finger-piece is fixed

page_text: to the frame, a spring acting to keep such finger-pieces normally separated so
as to keep the record paper out of reach of the tracer until, by pressing the
said finger-pieces towards each other, the paper is brought within reach of the
tracer.
The indicator is fixed on a stop cock by means of a ball and socket joint to
facilitate adaptation of the same to any peculiarities of position.
The paper carrying slide is moved to and fro as follows:-
To co cnil of the elide is connected a card which passes partly round a drum
having a hollow shaft mounted on a hollow spindle fixed in the indicator frame;
the cord then passes between guide pulleys carried by an arm adjustably mounted
on the hollow spindle, and its opposite end is connected to a moving part of the
engine. One end of a cord, wire or steel band is fixed to the opposite end of the
slide and it is passed around the drum in the opposite direction to the first cord and
is fixed at its other end to such drum. A cylindrically coiled wire spring is
enclosed within the hollow spindle and it is connected at one end to the outer end
of the hollow shaft of the drum and at the other end to the opposite end of the
hollow spindle. The said spring has at one end a fitting having studs fitting in slots
in the end of the drum shaft, and the other end of said spring has a fitting with
studs passing into pairs of slots formed in the end of the hollow spindle, so as to
enable the strength of the spring to be regulated. This spring may however be
otherwise mounted.
If desired, instead of employing the above arrangement of bands and spring
for operating the slide, I may dispense with the spring and attach a cord to
each end of the slide and carry said cords around the drum in opposite directions
and connect the same to any suitable oscillating instrument operated by the
engine.
also attach to the indicator an apparatus whereby each motion of the tracer
is limited to a small portion of the range the limiting motion controlling the
tracer over the entire range so that the diagram is taken in small parts.
For this purpose I use a worm gearing into a worm wheel or into a segment of a
worm wheel concentric with the piston axis; on the axis of the worm I fix a handle
by which it can be rotated.
The worm wheel or segment is provided with means for readily but loosely con-
necting it with the piston axis and for readily disconnecting it therefrom. Thus,
when the worm wheel or segment is connected with the piston axis and the steam or
other motive force is allowed to act upon the piston, the latter can move only
through part of its range, but as the worm is caused to give motion to the worm
wheel or segment, the loosely connected parts will move through the entire range
and allow the tracer to trace the diagram piece by piece.
Instead of employing the paper slide above described, a horizontal paper
carrying drum may be used, in which case the tracer would be caused simply to
rise and fall on to the surface of the drum, and in such case the tracer limiting
mechanism would be attached to or operate one end of the piston spring. In this
case the limiting mechanism may be connected with the drum by suitable gearing
and connections so as to cause the drum to be moved gradually in the direction of
its axis while it is being oscillated by the engine.
If desired the worm may be driven automatically and in lieu of employing
worm gear for the limiting mechanism, other suitable gearing or connections
may be used.
Instead of attaching the tracer directly to the end of the piston axis it may
be operated as follows:-
:-
On one end of the piston axis is fixed a pulley around which a band, preferably
steel, is passed which carries the tracer; this band is passed around another pulley
mounted on an axis carried by a fixed support and at such a distance as to enable
the straight part of the band between such pulleys to extend from one end to the
other of a cylinder carrying the recording chart. The tracer is guided truly in a
straight course by resting on the straight edge of a plate, frame or guide, thereby

page_text: ensuring a steady motion of the tracer and consequently more exact action thereof.
I preferably arrange the pulleys and tracer band between two plates, which form a
frame to carry the second pulley and I cause the tracer to rest on and across the
upper edges of said plates.
The tracer band is preferably endless, but to prevent slip it is fixed to one or
both of the carrying pulleys, but if desired it may be a length of band whose ends
are fixed to the pulleys, in which case the second pulley would be acted upon in one
direction by a spring or weight.
The recording cylinder is mounted and driven in any suitable manner.
Thus, as the motive force acts upon the piston, the piston axis will twist or wind
the spring and partially rotate the band pulley, thereby moving the tracer in a
straight line, the spring is put under strain and, when the pressure diminishes, the
spring will bring the piston and tracer back and thereby complete the tracing of
the diagram.
As another modification the recording cylinder might be carried by the piston
axis and the tracer be moved to and fro by connections from a moving part of the
engine.
Also the counteracting spring and the first named band pulley may be fixed to
the same end of the piston axis.
COMPLETE SPECIFICATION.
Improvements in Engine Indicators.
I, MOSES JOHN WAYNE, of 3 Louisa Cottages, East Street, Prittlewell, in the
County of Essex, Engineer, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
The invention relates to that class of engine indicator in which a small
reciprocating rotary motor is used to give motion to the diagram tracing point.
Heretofore such reciprocating rotary motor has been formed of a cylinder, two
fixed abutments diametrically opposite to each other within the cylinder, a double
piston fitting against the sides and periphery of the spaces in said cylinder, and an
inlet and outlet passage to each of such spaces. These inlets have however been
in communication with a way or passage extending fully half round the cylinder
and connected with a single centrally situated passage or way; the consequence
has been that that part of the wall of the cylinder forming one side of the half
circular passage, has been subject to different degrees of expansion as compared
with the other part of the cylinder; it has consequently warped out of shape and
thereby impaired the action of the motor.
According to my invention I remedy this evil and generally improve the
construction of the indicator.
My improved indicator is represented in the accompanying drawings, in
which:-
Fig. 1 is a front view, Fig. 2 a left hand end view, and Fig. 3 a plan, of the
indicator complete.
Fig. 4 is an end view of the motor cylinder and other parts.
Fig. 5 is a vertical section on the line 1-1 of Fig. 4.
Fig. 6 is a vertical section on the line 2-2 of Fig. 5.
Fig. 7 is an elevation, partly in section, showing the piston axle and the loose
end of the cylinder on such axle.

page_text: Fig. 8 is an end view of the parts shown in Fig. 7.
Fig. 9 is a side view and Fig. 10 an end view of a slotted cap screwing on to
piston axis.
Fig. 11 is a vertical section through the axis of the drum connected with the
paper carrying slide.
Figs. 12 and 13 are respectively cross sections of parts drawn on the lines 3–3
and 4-4 of Fig. 3.
Figs. 14 and 15 are elevations drawn at right angles to each other of the tracer
pointer.
Fig. 16 is an end view thereof.
Fig. 17 is an elevation, partly in section, of the spring tracer apart from its
carrier.
Fig. 18 is a sectional side view and Fig. 19 is a plan of the manually operated
limiting mechanism, and
Fig. 20 is a plan of part thereof separately.
Fig. 21 is a perspective view of the indicator with the manually operated limiting
mechanism, showing it in operation.
Fig. 22 is a perspective view of the instrument in operation without the limiting
mechanism.
Fig. 23 is a side view and Fig. 24 is a cross section of the automatically operated
limiting mechanism.
a is the cylinder, which is fixed in the casting A; the cylinder has two inlet
ports a', two fixed abutments a², and two outlets a³.
According to my invention I place the inlet passages a¹ in communication with
two passages a, separated from each other at their connection with the cylinder,
by which means I solidly support the lower side of the cylinder a and thereby
prevent warping of the cylinder and consequent binding of the piston, and thus
secure a correct action of the motor. I also, instead of allowing the outlet
passages a³ to communicate at once with the open air, attach to one end of the
cylinder an enclosing cap a forming a chamber, into which the outlets a³ open, and
I make an outlet opening at the lower side of such cap and attach thereto a tube a
to conduct the water of condensation away from the indicator.
b is a double piston fitting the cross section of the space within the cylinder, the
axle of which passes through both ends a' as of the cylinder; the part b¹ has
a cross cut b³ in its outer end and a screw thread 6 around it. The cylinder end a
is a fixture but the cylinder end as is removable; this latter fits accurately within
a recess a¹ on the cylinder a and is provided with a stud a³ which fits a recess a¹³
to prevent any rotary movement of the end a³, and it is held in position by a screw
cap a3. This end as has two studs a fixed therein; a cylindrical doubly coiled
wire spring c is attached at one end to a plate c¹ formed with a central hole to pass
loosely over the part 6 of the axle and with two perforations to fit the studs a
The other end of the spring c has the wire passing diametrically across it to fit the
cross cut b³.
A screw cap d screwed on to the thread 64 retains the spring c in
position by means of helical slots in its two opposite sides acting against the
cross wire of the spring e; a cross slot d in the outer end of such cap d com-
municates with such helical slots d¹ to enable the cross wire of the spring c to enter
and leave the same. The ends of the spring may however be otherwise fitted.
The spring will thus act on the piston axle in a contrary direction to the motive
force.
I fix on the part 6 of the piston axis, a tracer pointer of any suitable construction,
but I prefer to form it of a conical tube e having a socket e to fit over the part 6°
of the axle and a divided rear extension or jaws with clamping screw e to
adjustably fix it on the axle.
The tracer point et is passed through a sleeve e*, which is split and sprung
inwards at its lower end, so as to facilitate adjustment and hold the point et firmly
enough during its action on the record paper. The sleeve e* passes through a
screw plug e, which is screwed into a collar e at the larger end of the tube e, and

page_text: a spring e, located between a collar eª and the inner end of the plug e, presses the
point forwards but permits slight endway motion when in use. The internally
threaded collar e is cut partly through at eo and the parts forced towards each
other so as to form a kind of lock nut to securely hold the plug e against becoming
loose by vibration when in use. The socket e¹ is fitted with a stud e' which enters
a slot in the end of the part 6 of the piston axle to secure the tracer in correct
position.
I employ a sheet of record paper X, see Figs. 21 and 22, mounted in a carrier
consisting of a slide f mounted between guides 9 carried by a bracket g and having
at each end a clip consisting of fixed segmentally curved jaws f¹ and corre-
spondingly curved spring jaws ƒ fitting shallow recesses along the faces of the
fixed jaws.
The paper, by being placed between the jaws f¹ƒ³, is held stretched in the form
of a segment of a cylinder struck from the piston axis.
A narrow segmentally curved supporting table g², having a slightly recessed face,
is fixed to the bracket or frame g to support the record paper at each side of the
part where the tracer e presses thereon.
The slide bracket 9 is mounted on a stud or axis g3 passing through the indicator
frame B, and it has fixed thereto a finger piece g, a corresponding finger piece 9°
being fixed to the frame B, whilst a spring 9 acts to keep such finger pieces
normally separated from each other and the slide f in the position shown by full
lines in Fig. 3, thereby keeping the record paper out of reach of the tracer e until,
by pressing the said finger pieces g*g* towards each other the paper carrier is caused
to turn on its axis g³ and so bring the paper within reach of the tracer e.
The indicator is fixed on a stop cock h by means of a ball and socket joint to
facilitate adaptation of the same to any peculiarities of position, and, in order to
facilitate connection of the same, I fit a spring h² under the union collar A' to keep
the same raised, thereby enabling the engineer to connect the indicator by simply
turning the union collar without having at the same time to press it upwards.
The slide is moved to and fro as follows. To the right end of the slide f is
connected one end of a cord i which passes partly round a drum j having a hollow
shaft mounted on a hollow spindle & fixed in the indicator frame B; the cord
then passes through a guide collar and between a pair of guide rollers j³, and its
other end is connected to a moving part of the engine. The collar j² is adjustably
mounted in a bearing made in the end of an arm, which latter is adjustably
mounted on the hollow spindle k. By these means the cord i can be led from the
indicator in any desired direction.
One end of a cord, wire or steel band is fixed to the left end of the slide f
and it is passed around the drum jin the opposite direction to the cord i and is
fixed at its outer end to such drum. A cylindrically coiled wire spring m is enclosed
within the hollow spindle k and it is connected at one end to the upper end of
the hollow shaft of the drum, and at the other end to the opposite end of the
hollow spindle k. The spring m has, at its upper end, a fitting m having studs m³
fitting in slots in the end of the shaft j', and the lower end of said spring has a
fitting m³ provided with studs m passing into pairs of slots ¹ formed in the lower
end of the hollow spindle k whereby the strength of the spring m can be regulated.
This spring may however be otherwise mounted.
If desired instead of employing the above arrangement of bands and spring for
operating the slide f I may dispense with the spring and attach a cord to each end
of the slide and carry said cord around the drum in opposite directions and
connect the same to any suitable oscillating instrument operated by the engine.
I also removably attach to the indicator, an apparatus whereby each motion of
the tracer is limited to a small portion of the range, the limiting motion controlling
the tracer over the entire range so that the diagram is taken in small parts, as
represented at Fig. 21.
This limiting mechanism can be worked by hand, see Figs. 1 to 21, or auto-
matically by the means shown at Figs. 23 and 24.

page_text: For this purpose, and when operating the limiting mechanism by haud, I use a
worm n gearing into a segment of a worm or toothed wheel o concentric with the
piston axis; on the axis of the worm n I fix a handle n' by which it can be
rotated:
The segment o has pinjointed thereto a pin o¹ which loosely fits a transverse
hole 6* formed in the part 6 of the piston axis, thereby permitting of only a slight
motion of the piston, and consequently of the tracer, at each action. Thus, when
the segment o is connected with the piston axis and the steam or other motive
force is allowed to act upon the piston, the latter can move only through part of
its range, but as the worm n is caused to give motion to the segment o, the loosely
connected parts will move through the entire range and allow the tracer to trace
the diagram picsa by pissa. The worm nis mounted in a fromo pand the segment o
is mounted in a segmental bearing p' in said frame; the latter is shaped to fit over
the top of the cap as, and it is provided with a screw stud p² which passes between
horns A' on the top of the casting A and, by the aid of a binding nut p³ screwing
thereon and provided with a conical face to screw against a correspondingly shaped
seat in the horns A¹, enables the said limiting mechanism to be readily connected
and disconnected with the indicator. The nut p³ is at the end of a spindle provided
with a button p by which it can be readily rotated.
The automatically operated limiting mechanism represented at Figs. 23 and 24
is constructed and fixed in position on the indicator in a similar manner to that
above described, with the exception that the worm n and operating handle n' are
dispensed with, and in lieu thereof the toothed segment o receives a slight impulse
at each action of the piston, the extent of motion being limited, by the escape and
Pawl
stop pawls 99', to a single tooth of the segment o.
is mounted on a pin g³,
whilst pawl q is pivotted at q to pawl q and is acted upon by a spring 2 which acts
to keep the pawls normally in, and to return them to, the position shown in the
drawings. Thus, when the toothed segment o is moved forward by the action of
the piston, it raises the pawl 9 out of the teeth and depresses the pawl g₁ into
them, so as to release only one tooth at a time. The pawls q q' are carried by a
plate g, which is connected to the frame p at one end by a pin 9°, and is pressed
down at the other end by a screw to keep the pawls q g' in position to act on the
toothed segment o when such limiting mechanism is required to operate, but when
it is not required to work, the screw r is turned back, when the springs will act
to raise the plate go with the pawls q q¹ away from the toothed segment o, or the
frame P and parts carried thereby may be entirely removed from the indicator by
the means hereinbefore described.
Without the limiting mechanism the indicator will produce a diagram in the
ordinary manner, as indicated by Fig. 22.
The diagram may be taken on the ordinary diagram paper by means of a brass
tracer, but I prefer to use a dull unglazed soft-faced paper and a tracer of steel or
other hard material not liable to wear, by which means I produce a diagram by
means of a line burnished on the said paper.
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 an engine indicator having a reciprocating rotary motor consisting of a
cylinder a provided with two inlet ports a¹, two fixed abutments a², two outlets a³
and a double piston b, the combination with the inlet ports a', of two passages a
communicating with the inlets a¹ but separated from each other by a solid part
giving support to the cylinder between the ports a', substantially as herein shown
and described.
2. In an engine indicator, the combination of a reciprocating rotary motor of
the character herein described, with a cap a enclosing the outlet ports and provided
with an outlet at the lower end, and a cylindrically coiled reaction spring c
surrounding the piston axis and adjustably connected at one end therewith and

page_text: at the other end with a plate c¹ guided by fixed pins a¹, substantially as herein
shown and described.
3. In an engine indicator, the combination with a rotary motor and reaction
spring of the character above described, of a diagram tracer e fixed on one end of
piston axis, a pivotted bracket g carrying guides g¹, a paper carrying slide f
working in such guides, segmentally curved jaws f' and spring jaws f fixed to the
slide, a narrow segmentally curved table 9² to support the record paper, means for
connecting the slide f to a moving part of the engine, and a reaction spring acting
upon the slide, substantially as herein shown and described.
4. In an engine indicator of the character above described, the combination with
the pivotted bracket of a finger piece g* fixed thereto, a finger piece 9° fixed to
the indicator frame B, and a spring 96 acting to keep the record paper out of
contact with the tracer e, except when the finger pieces 94 95 are pressed toward
each other, substantially as herein shown and described.
5. In an engine indicator of the character above described, the combination with
the slide f, of a drum j having a hollow axis j', a hollow spindle k carrying such
drum, a coiled spring m within the spindle k connected at the upper end with the
hollow axis j and adjustably connected at the lower end with the hollow spindle k,
a cord i passing around the drum j and connected at one end to one end of the
slide f and at the other to a moving part of the engine, and a cord I passing round
the drum j and connected at one end to the opposite end of the slide f and at the
other to said drum j, substantially as herein shown and described and for the
purpose stated.
6. In an engine indicator of the character above described, the combination with
the motor, of mechanism limiting the action of the piston and consisting of a
pivotted pin o' loosely fitting a transverse hole 6* in the piston axis, a worm or
tooth segment o carrying said pin o¹, and means for operating said limiting
mechanism automatically or manually, substantially as herein shown and described
purpose stated.
and for the
7. In an engine indicator provided with mechanism for limiting the motion of
the piston axis, the combination therewith of means for removably attaching such
mechanism to the motor, substantially as herein shown and described.
Dated this 22nd day of January 1804.
M. J. WAYNE,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.