IMPROVEMENTS IN INDICATORS FOR PRIME MOVERS
Year: 1880

page_text: LETTERS PATENT to Joseph Casartelli, of Manchester, in the County of
Lancaster, Mathematical Instrument Maker, and William Potter, of Lower
Broughton, in the same County, Manager, for an Invention of "IMPROVEMENTS
IN INDICATORS FOR PRIME MOVERS."
PROVISIONAL SPECIFICATION left by the said Joseph Casartelli and William
Potter at the Office of the Commissioners of Patents on the 16th April 1880.
JOSEPH CASARTELLI, of Manchester, in the County of Lancaster, Mathematical
Instrument Maker, and WILLIAM POTTER, of Lower Broughton, in the same
County, Manager. "IMPROVEMENTS IN INDICATORS FOR PRIME MOVERS."
Our Invention relates principally, and in the first place to steam engine indicators
of the "Richards" type wherein the movement of the tracer is multiplied or
increased in relation to the movement of the piston. The principal object of the
first part of our Invention is to render more accurate the parallelism of movement
of the tracer. To this end we mount the tracer upon the outer end of a lever
which is jointed to the outer end of a multiplying lever, and connect the piston rod
with the last named lever by means of a lever which is connected with the tracer
lever by means of a link or of links either directly or through an intermediato
lever, or through intermediate levers, or we effect the connection of the piston rod
with the multiplying and tracing levers by means of radius arms and links. The
parts are so proportioned as that the movement of the tracer around the centre of
connection with the multiplying lever, as compared with the movement of the
centre of connection with the piston rod head around the centro of connection with
the said multiplying lever, is multiplied in the same proportion as the vertical 'or
acting movement of the tracer. We prefer to make the multiplying lever of the
Richards" indicator, partly in
same proportions as the corresponding part in the "
order that such indicator inay be more readily altered to correspond with our
Invention. According to a second part of our Invention we arrange for the part
upon which the fulcrum arm swivels to screw to the cylinder. When it is necessary
to withdraw the piston this part is unscrewed and the part carrying the piston and
rod as well as the said arm and the connected levers is disconnected from the
A third part
cylinder without interfering with the connection of the other parts.

page_text: of our Invention consists of improvements in an Invention for which Letters
Patent, dated October 25th in the year 1875, and numbered 3702, were granted to
Edward Thomas Darke. In the said Invention ratchet teeth were cut in the
bottom flanch of the paper barrel, and a pawl was caused to engage with tho said
toeth when it was desirable to arrest the rotation of the said barrel. In order that
the action of the pawl may be more conveniently controlled we form the ratchet
teeth in a part which is attached to the upper part of the barrel, and we throw tho
pawl into gear by means of a spindle which is mounted in a fixed part and is
provided with a milled head, or is otherwise formed to be readily acted upon. In
one arrangement a cam upon the inner end of the said spindle acts upon the tail
of a spring which when so acted upon presses the pawl into position to engage
with the ratchet teeth. A remaining part of our Invention also relates to the
arresting of the barrel. We employ a lever, cam, excentric, or gripping appliance
to hold the actuating cord when the movement of the barrel is to be arrested. In
ono arrangement the cord passes between a pulley and a milled excentric which
can be partially rotated by means of a suitable handle or by any suitable means,
and when so rotated forces the cord against the said pulley, and thereby holds the
cord and prevents the return movement of the barrel.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joseph Casartelli and William Potter in the Great Seal Patent
Office on the 16th October 1880.
JOSEPH CASARTELLI, of Manchester, in the County of Lancaster, Mathematical
Instrument Maker, and WILLIAM POTTER, of Lower Broughton, in the saine
County, Manager. "IMPROVEMENTS IN INDICATORS FOR PRIME MOVERS."
of the
"
Our Invention relates principally and in the first place to steam engine indicators
17
Richards type, wherein the movement of the tracer is multiplied or
increased in relation to the movement of the piston. The principal object of the
first part of our Invention is to render more accurate the parallelism of movement
of the tracer. To this end we mount the tracer upon the outer end of a lever
which is jointed to the outer end of the multiplying lever, and connect the piston
rod with the last named lever by means of a lever which is connected with the
tracer lever by means of a link. The parts are so proportioned as that the
movement of the tracer around the centre of connection with the multiplying lever,
as compared with the movement of the centre of connection with the piston rod
head around the centre of connection with the said multiplying lever, is multiplied
in the same proportion as the vertical or acting movement of the tracer. According
to a second part of our Invention we arrange for the part upon which the fulcrum
arm swivels to screw to the cylinder. When it is necessary to withdraw the piston
this part is unscrewed and the part carrying the piston and rod, as well as the said

page_text: arm and the connected levers, is disconnected from the cylinder without interfering
with the connection of the other parts. A third part of our Invention relates to
the arresting of the movement of the barrel. We employ a lever, cain, excentric, or
gripping appliance to hold the actuating cord when the movement of the barrel is
to be arrested. In one arrangement the cord passes between a pulley and a milled
excentric which can be partially rotated by means of a suitable handle, or by any
suitable means, and when so rotated forces the cord against the said pulley and
A
thereby holds the cord and prevents the return movement of the barrel.
remaining part of our Invention consists of an improvement in an Invention for
which Letters Patent dated October 25th, in the year 1875, and numbered 5702,
were granted to Edward Thomas Darke. In the said Invention ratchet teeth were
cut in the bottom flanch of the paper barrel, and a pawl was caused to engage with
the said teeth when it was desirable to arrest the rotation of the said barrel. In
order that the action of the pawl may be more conveniently controlled we form
the ratchet teeth in a part which is attached to the upper part of the barrel, and
wo throw the pawl into gear by means of a spindle which is mounted in a fixed
part, and is provided with a milled head or is otherwise formed to be readily acted
upon.
.4
And in order that our Invention may be fully understood we have attached
hereunto a Sheet of Drawings to which we will refer in this place. In the said
Drawings Fig. 1, partly in section, represents an indicator which is fitted in
accordance with the first, second, and third parts of our Invention ; Fig. being
a plan of the parts represented in Fig. 1. In the said Figs., A is the arrangement
of levers and links which we employ to give motion to the tracer in accordance
with the first part of our Invention, a being the multiplying lever and b'the tracer
lever. A diagram of the arrangement is represented at Fig. 4. The leve a is
connected by the short lever c with the head of the piston rod d. The uppe. ad
the upper
end of the
of the lever c is extended above the joint with the lever a,:
lever b is also correspondingly extended, and the ends of the two levers are connected
by means of a link e. The lower end of the lever b carries the tracer f. The said
lever and links are. or may be in pairs, as is usual, each lever consisting of two
levers connected together at the joints. The outer end of the shorter arm of the
lever a is mounted upon a fixed fulcrum gas is usual. We prefer to make the
lever a of about the same proportions as the corresponding part in the ordinary
"Richards" indicator. The said ordinary indicator can readily be altered to
correspond with our Invention. The length of the lever b from the joint centres 1
to 2 in Fig. 4 bears the same proportion to the length from 1 to 3 as the length
4 to 5 bears to the length 4 to 3. The cylinder cover is formed in two parts h
and h', the latter corresponding to the ordinary cover. The part h is adapted to
screw upon the upper end of the cylinder, and is formed with a cylindrical part
upon which the boss formed upon the fulcrum arm g is fitted to swivel. A milled
collar is formed upon the part h, and the boss of g is retained in position between
the said collar and the projecting edge of the part h'. When the cover or part / is
unscrewed and removed the piston and rod, together with the fulcrum
attached parts, are removed and remain connected so that access is obtained to tho
piston for changing the spring, or for other purposes, without disconnecting any of
the parts with the exception of the screwed connection of the part h with the
cylinder. The third part of our Invention is illustrated by Figs. 1 and 2 and also
by Fig. 3. The actuating cord passes between two grooved guide pulleys and l
which are mounted in a forked arm which is formed upon a swivel plate n which
can be fixed in the required position by means of the nut o. In the said forked armı
are formed bearings for the axle pin of an excentric gripper p which is or may
be formed with a milled edge in order that it may have a better hold upon the cord.
Upon the axle of the said gripper is fixed or formed a handle r. The gripper can
be quickly turned by means of the said handle into position to force the cord
against the pulley 1, as indicated in Fig. 3, whereby the cord is firmly held. When
the cord is gripped at the time when it has completed its outward movement in the
and all

page_text: direction indicated in Fig. 1, the return movement of the barrel is prevented, and it
remains stationary until the cord is released by turning the gripper in the proper
direction. The form and arrangements of the parts for gripping the cord may be
varied. Figs. 5 and 6 illustrate the remaining part of our Invention. In Fig. 5,
8 represents in section the upper end of the cylinder which receives the paper barrel,
and is a cap which is secured to the upper end of the spindle upon which the
cylinder rotates. In the cylinder aro cut ratchet teeth, as indicated by dotted lines
in Fig. 6. A pawl u engages with the said teeth when forced into action by a
spring v. A cam upon the lower end of a spindle w is formed to act upon the tail
of the said spring. When the spindle w is turned in one direction by means of its
anilled head the said cam by bearing upon the tail of the spring causes the other
end of the spring to move the pawl into gear with the ratchet teeth. When the
spindle is turned in a contrary direction the pressure upon the spring is relieved
and the pawl withdraws from the ratchet teeth. The arrangements for controlling
the pawl by the aid of the spindle w may be varied to some extent.
Having now fully set forth and indicated the nature of our said Invention and
the methods whereby we carry the same into practical effect, we would have it to
be understood that we claim,—
First. The combination of levers and links for transmitting motion to the tracer,
substantially as set forth and indicated hereiubefore, and in and by the accompanying
Drawings.
Secondly. Mounting the fulcrum arm to swivel upon the part h which forms the
cylinder cover, substantially as set forth and indicated.
Thirdly. The arrangement for gripping the cord, substantially as set forth and
indicated.
Fourthly. The employment of a gripping apparatus to bold the cord when it is
desirable to arrest the movement of the paper barrel.
And, Lastly. The spindle w mounted in the cap t and acting to move a pawl into
and out of gear with ratchet teeth in the upper end of the cylinder, substantially as
set forth and indicated.
In witness whereof, we, the said Joseph Casartelli and William Potter, have
hereunto set our hands and seals, this Fifteenth day of October, in the
year of our Lord One thousand eight hundred and eighty.
Signed, sealed, and delivered by
the said Joseph Casartelli and
William Potter, the day and
year last above written, in
presence of
ARTHUR LEDGER,
(Clerk to Edward K. Dutton),
41, John Dalton St.,
Manchester,
(Agent for the Patentecs).
JOSEPH CASARTELLI. (L.S.)
WILLIAM POTTER. (L.S.)