Year: 1890

page_text: Date of Application, 6th May, 1890-Accepted 28th June, 1890
Engineer, ALPHONSE EDOUARD TAVERNIER, of 17, Colencarne, og
in the County of London, Civil Engineer, and EDWARD CASPER, of 11, Queen Victoria
Strest, in the City of London, Gentleman, 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:-
Our invention relates to an indicator for steam and other engines, and it comprises
the improvements hereinafter described.
In the accompanying drawings-
Figure 1 is a front elevation of our improved indicator; and,
Figure 2 is a section on the line figure 1.
a is the base of the indicator which is made hollow so as to form a chamber b, the
said chamber communicating by means of a channel b¹ with the passage b² in a nozzle
at the lower part of the said base.
c is a nut by means of which the apparatus is secured to the cock upon the cylinder
of an engine.
d is a disc fitted upon the flange a¹ of the base a, and having at its centro an
enlargement containing a chamber d' which communicates by means of a passage d²
with the chamber in the base.
e is a cylinder which rests upon the disc d and which at its upper end is closed
by a cap e secured by screws e².
fis au india-rubber or other flexible diaphragm arranged between the disc and the
flange of the cylinder e; g is a piston working within the cylinder e and connected
with the rod g by a ball-joint g²; and his a spring surrounding the rod g², and
secured at its upper end to the block screwed onto a correspondingly screw-
threaded projection on the cover e¹, and at its lower end to a block bearing upon
the piston g. The piston g is pressed against the diaphragm f by this spring, so that
any pressure acting against the said diaphragm upon the underside is transmitted
through the diaphragm to the piston.
i is a socket projecting from the base-piece a and adapted to receive the shank i¹ of
a bearing, in which is arranged a shaft carrying two pinions *, * for a purpose
hereinafter described.
Upon the exterior of the cylinder e and adapted to rotate thereon is mounted a
drum j, having at its lower part a pulley ¹ designed to work in connection with the
pulley on the shaft. Within the drum j is a helical spring ³, one end of which
is fixed to the interior of the said drum, while the other end is connected to a movable
sleeve adapted to be adjusted in any required position upon the cylinder e by means
of the set screws . It is obvious that by means of this sleeve the power which the
spring exerts upon the drum j can be regulated. The object of the said spring is to
return the drum to its normal position after it has been rotated by means of the
pulley in the manner hereinafter described. is the indicator-paper carrying
cylinder which is adapted to fit onto the drum j, as shown, and which is provided
with the metal strips or fingers k¹, k¹ of ordinary construction with which the paper
is engaged to hold it in position, the said carrying cylinder & being adapted to follow
the drum in all its movements.
1. I are two series of crossed levers arranged in the same manner as lazy tongs,
the free ends of which are connected by links, to the cover e'. These two series
of levers are connected together by rods m, m³, m² so that they act simultaneously.

page_text: The rods m³, m³ project into slots formed in two guides n secured to the cover e¹ at
their lower ends and connected by the cross-bar at their upper ends, and the upper
rod m projects quite through the said slotted guides and has jointed to its ends two
vertical rods o, o. These rods o, o at their lower ends are secured to a frame Pr and
to the latter are also secured two guide-rods p² sliding in sockets p² carried by
arms p projecting from the base-pioco a. The frame p serves to carry the pencil-
holder 9.
This pencil-holder comprises a small cylinder through which slides a small tube »
for carrying the pencil and having on its outer ond a head or knob. A spring
surrounding the tube tends to hold the pencil in contact with the paper on the
cylinder k, but in order that the said pencil may be held out of contact with the paper
when desired, a small lug or projection is formed upon the tube and a corre
sponding slot is formed in the cover of the cylinder r. By drawing the tube
backwards and slightly rotating the same it is obvious that the pin thereon can be
caused to hear against the solid part of the cover and so hold back the said tube and
also the pencil carried theroby against the pressure of the spring.
In order that the motion of the piston shall be imparted to the levers / and thence
to the pencil-holder, the piston rol g' is connected to a blocks on the lowermost
rod m², so that the motion imparted to the lowermost levers I, I will be transmitted
through all the other lovers and so considerably increased or multiplied. It will thus
be obvious that the very slight movement of the piston can be amplified to such an
extent as to give the required amount of vertical movement to the pencil.
To permit of the adjustment of the pencil-holler relatively to the paper cylinder k,
we provide for increasing or decreasing the length of the rod g' and for this purpose
the said rod is formed in two parts which are connected together by a screw nut or
socket having right and left hand screw-threads.
To impart the motion of the engine piston to the paper carrying cylinder k, a cord
wound around the pulley is attached to some moving part of the engine, and a
second cord is wound partly upon the pulley and partly upon the pulley j of the
cylinder k, in such a manner that during the out-stroke of the engine piston, the cord
will be unwound from the drum so as to rotate the latter. This rotation being
transmitted to the pulley causes the winding of the second cord upon the last
named pulley and the corresponding unwinding of the same from the pulley j
whereby the latter with the drum & is rotated against the power of the spring
During the in-stroke of the engine piston the reaction of the spring causes the
unwinding of the cord from the pulley and the consequent rotation of the latter and
of the pulley upon which the cord is rewound.
u is a bar upon which is fixed a small guide pulley for the cord upon the pulley.
In order to work the apparatus the chamber in the base a is filled with glycerine,
oil, water or other desirable fluid, through the opening shown in the drawing as
closed by the screw r, which fluid serves as a cushion botween the steam or othur Huid
from the engine cylinder and the diaphragm f.
When the indicator is applied to an engine cylinder and communication is opened
between the interior of the latter and the chamber b, the said fluid will be forced into
the chamber d' through the passage d' and there press upon the diaphragm, which
in its turn presses upon the piston and more or less raises the same against the
pressure of the spring h, the upward movement being communicated by the piston
rod to the crossed levers 1, 2 and thence to the pencil-holdor as hereinbufore
described.
By varying the relative diameters of the pulleys j', ^, bereinbefore described, I
provide for regulating the rotation of the paper carrying cylinder to the stroke of the
engine to which the indicator is applied, so that the said paper carrying cylinder shall
not make more than a complete rotation during each in-stroke and cach out-stroke.
It is thus possible to connect the conl on the pulley directly to the piston rod or
connecting rod without the intervention of levers as heretofore.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In an engine indicator, mounting the paper carrying cylinder upon a drum
which is adapted to rotate around the working cylinder which serves as a pivot,
substantially as described.
2. An engine indicator in which the pressure acts upon the piston through the
medium of an elastic diaphragm, substantially as described.
3. In an indicator of the kind referred to in the preceding claiming clause, the use
of a liquid cushion in connection with the diaphragm, substantially as described.
4. An engine indicator having a series of crossed levers acting in the same manner
as lazy tongs for amplifying a slight movement imparted to the piston, substantially
as described.
5. An engine indicator having the chambers 6 and d² for containing a liquid for
transmitting pressure, substantially as described.
6. In an engine indicator the employment of pulleys, such as is, ³, for enabling the
indicator to be directly operated from the connecting rod or the piston rod of the
engine to be indicated whatever may be the stroke thereof, substantially as
described.
7. The manufacture and use of the improved engine indicator hereinbefore
described and illustrated in the accompanying drawings.
Dated the 6th Jan SM-100/
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.