Clocks, Watches, and Paper-drums of Steam Engine Indi- cators and the like
Year: 1886

page_text: Clocks, Watches, and Paper-drums of Steam Engine Indi-
cators and the like.
EDWARD THOMAS DARKE Engineer &c of 16 Rochester Terrace Camden Road
London N.W. do hereby declare the nature of my invention for IMPROVEMENTS
IN SPRINGS AND SPRING-BARRELS APPLICABLE TO CLOCKS WATCHES AND PAPER-
DRUMS OF STEAM-ENGINE INDICATORS AND THE LIKE to be as follows:-
By this invention the great difficulty in taking out replacing and adjusting
clock springs in thier barrels or drums more especially those used in steam-engine
indicators is avoided. I effect this by cutting a gate in the wall or side of the
spring-box the sides of which gate are parallel to the axis of the arbor and the
width as wide as the width of the spring and turn the end of the spring into
a book which engages the one side of the gate. On the other end of the spring
I form a similar hook which engages a hook formed out of the solid metal of the
hook-collar upon the fixed arbor and of the length of the width of the spring the
top of the hook-collar is elongated and there is a tommy-hole or other means, of
turning it upon its arbor and a means of fixing it in any, or certain parts, of a
revolution upon the arbor.
If such a spring barrel is placed on its arbor and a small portion of the inner
end of the spring made as described is projected through the gate in the wall of
the spring-barrel and the book of the described hook-collar made to engage the
corresponding hook of the inner end of the spring the hook-collar (being in
position on its arbor) can be turned by means of a tommy &c and the whole
spring drawn into its position in the spring-barrel and the tension of the spring
adjusted.
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page_text: Clocks, Watches, and Paper-drums of Steam-engine Indi-
cators and the like.
EDWARD THOMAS DARKE Engineer &c of 16 Rochester Terrace Camden Road
London N.W. do hereby declare the nature of my invention for IMPROVEMENTS
IN SPRINGS AND SPRING BARRELS APPLICABLE TO CLOCKS WATCHES AND PAPER-
DRUMS OF STEAM-ENGINE INDICATORS AND THE LIKE and in what manner the
same is to be performed, to be particularly described and ascertained in and by
.the following statement :-
By this invention the great difficulty in taking out replacing and adjusting
clock-springs in their barrels or drums more especially those used in steam-engine
indicators is avoided. I effect this by cutting a gate in the wall or side of the
spring-barrel the sides of which gate are parallel to the axis of the-arbor and the
width as wide as the width of the spring and turn the end of the spring into
a hook which, engages the one side of the gate On the other end of the spring
I form a similar hook which engages a hook formed out of the solid metal of the
hook-collar upon the fixed arbor and of the length of the width of the spring
The top of the hook-collar is elongated and there is a tommy-hole or other means
of turning it upon its arbor and a means of fixing it in any position or certain
part of the revolution upon the arbor.
If such a spring barrel is placed upon its arbor and a small portion of the inner
end of the spring made as described is projected through the gate in the wall of
the spring-barrel and the hook of the described hook collar be made to engage the
corresponding hook of the inner end of the spring (the hook collar being in
position on its arbor) can be turned by means of a tommy &c and the whole
spring drawn into its position in the spring barrel and the tension of the spring
adjusted.
I will now particularly describe my invention by the aid of the drawing herewith
which represents my improved spring barrel adapted to the paper drum of the
steam engine indicator described in my specification A.D. 1879, 28 Nov. No 4888
see figures 9 and 10 sheet 2 of that specification.
In that indicator and generally the paper drum turns freely upon its arbor
backward and forward but is prevented from turning through the entire revolution
by stops conveniently placed for that purpose and is actuated in one direction by
means of a clock spring and in the other direction by means of a cord led from
some part of the steam engine to be indicated having a motion proportionate to
that of the piston of the steam engine.
The drawing Fig. 1 is of the steam engine indicator in plan Fig. 2 is a side
elevation and Fig. 3 is an end elevation. In Fig. 1, w represents the wall of the
spring barrel of the paper drum g is the gate a is a fixed arbor on which both the
spring barrel and the hook collar moves c is the hook collar h is the hook formed
out of the metal of the hook collar t is the tommy hole for turning the hook collar

page_text: upon its arbor and p is a set screw by means of which the hook collar is fixed at
certain parts of its revolution upon the arbor.
In this figure the spring & is represented as being drawn into the spring barrel
through the gate g it being understood that the spring barrel is prevented from
further revolving upon its arbor in the direction of the arrow by the stop already
spoken of The inner end of the spring has been passed through the gate in such
a manner that the hook at h has engaged the hook in the hook collar o at h and
that a part of the spring a left out of the spring barrel has been allowed to take
the position represented. The tommy t and therefore the hook collar has been
revolved in the direction of the arrow until a portion of the spring has been drawn
into the spring barrel and if the hook collar is still revolved the whole of the
spring will be drawn into the spring barrel and the hook h¹ at the outer end of
the spring wiil engage the wall of the spring barrel at g¹.
By further revolving the hook-collar the desired amount of tension may be
given to the spring and the hook collar may be fixed upon the arbor by turning
the set screw p until its point enters one of the recesses r shown upon the arbor
by which the hook collar is prevented from turning upon the arbor and the spring
barrel is prevented from rising from its place upon the arbor.
In Figures 2 and 3 in which the spring is not shown a is the arbor c is the
hook collar t is the tommy w the wall of the spring barrel and g is the gate.
Figures 4 and 4¹ represents a plan and sectional elevation of the spring barrel
w is the wall g the gate and o the hole which receives the arbor.
Fig. 5 and.5¹ represents a plan and side elevation of the hook collar the outside
diameter of which is increased at the top to form a head by which a longer
bearing is given for the set screw p and the tommy the hole of which is shown at t.
The hook extends no further upwards than the under part of the head.
Figures 6 and 6¹ represent a plan and side elevation of part of the arbor
7 shows the recesses made to receive the point of the set screw (p see Fig. 5) and a
is that part on which the spring barrel and hook collar turns.
It will now be seen that the arrangements I have now described may be very
much modified For example instead of the spring barrel being made as drawn pins
of a suitable length placed in a circle of which the arbor is the centre and being
parallel to the axis of the arbor might be used instead of the walls of the spring
barrel in which case any space between the pins would serve as the gate. Again
the ordinary hooks might be used to engage the spring at either or both ends and
other means might be used both for revolving the hook collar and fixing it upon
its arbor.
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. I claim the spring barrel constructed with a gate as described or any equiva-
lent applied to steam engine indicators clocks watches and such like.
2. I claim the book collar and its parts as described or other equivalent as
a means of winding or drawing the spring through the gate into the spring barrel.
3. I claim the whole spring barrel and its parts described in this specification
and substantially as represented in the annexed drawing.
Dated this twentieth day of February 1886.-