MACHINERY FOR INDICATING THE NUMBER OF of
Year: 1875

page_text: LETTERS PATENT to Alfred Barlow, of Packenham Street, Gray's
Inn Road, in the County of Middlesex, Engineer, for the Invention
MACHINERY FOR INDICATING THE NUMBER OF
of "IMPROVEMENTS IN
ROTATIONS OR OTHER MOVEMENTS PER MINUTE OR OTHER PORTION OF TIME OF
SHAFTS OR OTHER BODIES."
Sealed the 18th January 1876, and dated the 21st August 1875.
PROVISIONAL SPECIFICATION left by the said Alfred Barlow at the
Office of the Commissioners of Patents, with his Petition, on the
21st August 1875.
I, ALFRED BARLOW, of Pakenham Street, Gray's Inn Road, in the
County of Middlesex, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MACHINERY FOR INDICATING THE
NUMBER OF ROTATIONS OR OTHER MOVEMENTS PER MINUTE OR OTHER PORTION OF
TIME OF SHAFTS OR OTHER BODIES," to be as follows:-

page_text: other portion of time of shafts or other bodies, and relates to apparatus
in which a finger is moved through the medium of a friction coupling
or clutch by means of apparatus receiving motion primarily from the
shaft or body to be indicated, and having its action governed by clock
mechanism.
In one arrangement the finger or pointer is actuated through the
medium of the friction coupling or clutch directly from a primary lever
or rocking shaft, the needle being released at proper intervals by the
clock mechanism operating a brake.
In another arrangement the needle is moved through the medium of
the friction coupling or clutch directly from the clock mechanism, the
needle being released at proper intervals by the primary lever or rocking
shaft, causing the disengagement of the friction coupling or clutch.
In the first-mentioned arrangement the shaft or body whose rotations
or movements are to be indicated is caused to operate a primary lever,
which by its movements effects the winding of the clock mechanism
forming a component of the machine, and also through a ratchet wheel,
worm, worm wheel, and friction coupling or clutch moves a finger or
pointer over a dial. This finger or pointer moves freely on the axis of
the worm wheel, and has a projecting pin or part against which bears a
projection carried by the loose part of the friction coupling or clutch
centred on the same axis. The finger is provided with a spring or other
means tending to move it into and hold it in its normal position, and a
brake.serves to retain the finger in any other position to which it may
be moved through the operation of the worm wheel and friction coupling
or clutch.
F
The spindle of the escapement wheel of the clock mechanism carries
a projection, which at the end of each minute or other predetermined
portion of time for which it is set causes the primary lever to momen-
tarily remove the brake from the finger, thus allowing of its automatic
return movement until arrested by the projection of the coupling or
clutch. As the primary lever continues its movement the brake again
takes hold of the finger, the friction coupling or clutch is drawn out of
gear, its free part automatically turning back to its normal position to
commence a fresh turn. If during the minute or portion of time thus
commenced the movements of the body to be indicated shall exceed the
number made during the preceding minute or portion of time the finger

page_text: will on its projection being reached by that of the coupling or clutch be
moved from where it (the finger) was left on the termination of the
preceding minute or portion of time into a position corresponding to the
extended space moved through by the periphery of the coupling or clutch.
On the other hand, should the movements of the body to be indicated be
fewer than during the preceding minute or portion of time the projection
of the coupling or clutch will not get round to that of the needle, which
therefore during the temporary withdrawal of the brake will automati-
cally return towards its normal position until arrested by the projection
of the coupling or clutch, thus indicating the space last moved through
by the latter. Immediately after each return to the finger of the brake
the loose part of the clutch is released, and returns to its normal
position.
In constructing the apparatus, so that the indicating finger or pointer
shall receive its motion from the clock mechanism (which may be
wound up as before by the action of the primary lever), I arrange the
primary lever so as towards the conclusion of each stroke to operate a
part of the friction coupling or clutch, and thus to break the contact of
the coupling or clutch, so that the finger of the indicator being set free
shall automatically return to its normal position at the conclusion of
each revolution or movement of the body to be indicated. The parts
are so arranged as unless the clutch be operated to carry the finger once
round the dial in each minute or other predetermined portion of time for
which the apparatus is set, it follows that the point of the dial reached
by the finger during each minute or portion of time will depend upon the
frequency with which the primary lever is actuated from the body to be
indicated. Thus assuming that the apparatus be set to move the finger
round the dial at the rate of once in a minute if the rotations or move-
ments of the body to be indicated be at the rate of four per minute, the
finger will be released by the coupling or clutch when it has moved
through only one-fourth of the circumference of the dial, and being
caused to return to its normal position will forthwith commence a fresh
revolution, and so on.
In order to extend the range of the instrument it may be arranged
to allow of the finger making more than one entire revolution of the
dial.
Ti will be arrident that indination

page_text: moving a finger_or_pointer through the medium of a friction coupling
or clutch may be constructed in various forms, according to require-
ments.
· The clock mechanism may be provided with either a pendulum,
balance wheel, or other kind of escapement or a fan.
The finger may be arranged to record upon paper in the .usuai
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred Barlow in the Great Seal Patent Office
on the 21st February 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
BARLOW, of Pakenham Street, Gray's Inn Road, in the County of
Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of August, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alfred Barlow, Her special
licence that I, the said Alfred Barlow, my executors, administrators,
and assigns, or such others as I, the said Alfred Barlow, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
MACHINERY FOR INDICATING THE NUMBER OF ROTATIONS OR OTHER MOVEMENTS PER
MINUTE OR OTHER PORTION OF TIME OF SHAFTS OR OTHER BODIES," upon the con-
dition (amongst others) that I, the said Alfred Barlow, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain
the nature of the said Invention and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal

page_text: Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alfred Barlow, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, and the accompanying Sheets of
Drawings therein referred to (that is to say) :-
-:
This Invention has for its object improvements in machinery for
indicating the number of rotations or other movements per minute or
other portion of time of shafts or other bodies, and relates to apparatus
in which a finger is moved through the medium of a friction coupling
or clutch by means of apparatus receiving motion primarily from the
shaft or body to be indicated, and having its action governed by clock
mechanism.
In one arrangement the finger needle or pointer is actuated through
the medium of the friction coupling or clutch directly from a primary
lever or rocking shaft, the finger or needle being released at proper
intervals by the clock mechanism operating a brake.
In another arrangement the finger or needle is moved through the
medium of the friction coupling or clutch directly from the clock
mechanism, the finger or needle being released at proper intervals by
the primary lever or rocking shaft, causing the disengagement of the
friction coupling or clutch.
In the first-mentioned arrangement the shaft or body whose rotations
or movements are to be indicated is caused to operate a primary lever
which by its movements effects the winding of the clock mechanism
forming a component of the machine, and also through a ratchet wheel,
worm, worm wheel, and friction coupling or clutch moves a finger or
pointer over a dial. This finger or pointer moves freely on the axis of
the worm wheel and has a projecting pin or part against which bears a
projection carried by the loose part of the friction coupling or clutch
centred on the same axis. The finger is provided with a spring or other
means tending to move it into and hold it in its normal position, and a
brake serves to retain the finger in any other position to which it may
be moved through the operation of the worm wheel and friction coupling
or clutch.

page_text: The spindle of the escapement wheel of the clock mechanism carries
a projection which at the end of each minute or other predetermined
portion of time for which it is arranged causes the primary lever to
momentarily remove the brake from the finger, thus allowing of its
automatic return movement until arrested by the projection of the
coupling or clutch. As the primary lever continues its movement the
brake again takes hold of the finger, the friction coupling or clutch is
drawn out of gear, its free part automatically turning back to its normal
position to commence a fresh turn. If during the minute or portion of
time thus commenced the movements of the body to be indicated shall
exceed the number made during the preceding minute or portion of
time the finger will on its projection being reached by that of the
coupling or clutch be moved from where it (the finger) was left on the
termination of the preceding minute or portion of time into a position
corresponding to the extended space moved through by the periphery of
the coupling or clutch. On the other hand should the movements of the
body to be indicated be fewer than during the preceding minute or portion.
of time the projection of the coupling or clutch will not get round to
that of the needle, which therefore during the temporary withdrawal of
the brake will automatically return towards its normal position until
arrested by the projection of the coupling or clutch, thus indicating the.
space last moved through by the latter: Immediately after each return
to the finger of the brake the loose part of the clutch is released and
returns to its normal position.
In constructing the apparatus so that the indicating finger or pointer
shall receive its motion from the clock mechanism (which may be
wound up as before by the action of the primary lever) I arrange the
primary lever so as towards the conclusion of each stroke to operate a
part of the friction coupling or clutch, and thus to break the contact
of the coupling or clutch so that the fin of the indicator being set
free shall automatically return to its normal position at the conclusion
of each revolution or movement of the body to be indicated. The
parts are so arranged as unless the clutch be operated to carry the
finger once round the dial in each minute or other predetermined
portion of time for which the apparatus is arranged it follows that the
point of the dial reached by the finger during each minute or portion of
time will depend upon the frequency with which the primary lever is
actuated from the body to be indicated. Thus, assuming that the
apparatus be arranged to move the finger round the dial at the rate of

page_text: once in a minute if the rotations or movements of the body to be
indicated be at the rate of four per minute the finger will be released
by the coupling or clutch when it has moved through only one-fourth
of the circumference of the dial, and being caused to, return to its
normal position will forthwith commence a fresh revolution and so on.
In order to extend the range of the instrument it may be arranged to
allow of the finger making more than one entire revolution of the
dial.
It will be evident that indicating machines wherein a primary lever or
rocking shaft is combined with clock mechanism and apparatus for
moving a finger or pointer through the medium of a friction coupling or
clutch may be constructed in various forms according to requirements.
The clock mechanism may be provided with either a pendulum,
balance wheel, or other kind of escapement, or a fan.
The finger may be arranged to record upon paper in the usual way.
The connection with the body to be indicated may be made in various
ways.
Fig. 1 is a front view, with a portion of the dial plate removed, of a
machine in which a finger, needle, or pointer is actuated through the
medium of a friction coupling or clutch directly from a primary lever or
rocking shaft, the finger or needle being released at proper intervals by
clock mechanism operating a brake. Fig. 2 is a sectional plan in the
line A, B, of Fig. 1; Fig. 3 is a vertical section at right angles to Fig. 1,
but in different planes.
Figs. 4 to 13 inclusive represent to enlarged and various scales the
three pulleys and the spindle which form part of the friction apparatus,
whereby the finger or pointer is moved, as herein-after. described.
a is the framework of the machine; and b, the dial; c is the primary
lever which by its movements effects the winding of the clock
mechanism, as herein-after described, and also by a spring hook or
catch d (or a hook or catch pressed towards the ratchet wheel by a
spring) operates a ratchet wheel a fixed on the shaft f. On the same
shaft is a worm f'. Fixed on the axis is the finger or pointer e.
The finger e is fixed to a boss which I will call pulley e¹, this pulley is
free to turn on the axis g, and has a projecting pin or part e³ against
which bears a projection ¹ carried by the loose part (herein-after called

page_text: '
pulley h) of the friction coupling or clutch centred on the same axis.
e³ is a cord attached at one end to the pulley e¹ and at its other end to a
spring e, the opposite end of which spring is held by a hook e, the
tendency of the spring is to move the pulley e¹ with the finger into and
hold them in the normal position. A brake (herein-after called the
brake ) consisting of a lever / having its fulcrum at k¹ in the frame of the
'machine formed at ³ to fit against the periphery of the pulley e¹; and
having attached to its end 4* one end of a spring ', whose other end
is attached to the frame a serves to retain the pulley e¹ and finger in
any position to which they may be moved through the operation of the
worm wheel and friction coupling or clutch. 2 is a cord attached at
one end to the pulley / and at the other end to one end of a spring ³,
whose opposite end is held by the pin eº. The spring tends to turn the
pulley over from right to left, but the projection ¹ of the pulley
coming in contact with a stop j affixed to the framing a prevents the
pulley from being drawn back beyond its normal position corre-
sponding to the zero position of the finger pulley. The fixed portion of
the friction coupling consists of a part i (herein-after called the pulley i)
which is free to move endwise on the axis or shaft g, but by a pin
taking into its slot, as shewn, is prevented from turning independently
of the said axis or shaft. Between this pulley i and the boss of the
worm wheelf is interposed a spiral spring surrounding the shaft g,
and tending to force the pulley i against the pulley h. m is the spindle
of the escapement wheel m¹ of the clock mechanism; m² is a projection
carried by said spindle, which projection at the end of each minute or
other predetermined portion of time for which the apparatus is arranged
comes in contact with the end of an arm n guided by a pin n³ fixed to
part of the framing, which pin passes through a slot n² in the arm,
'whose other end is attached to a depending lever o having its fulcrum
at o'. This depending lever is formed or provided with two projections
and o". When the slotted arm and the depending lever bave been
moved forward by the projection of the escapement wheel the pro-
jection o* will be under a pin or projection c* of the lever c, and the
projection o" will overlap the projection p' of a lever p, having its
fulcrum at p (in the framing) and carrying an antifriction wheel p³,
which when the free end of the lever is moved downward bears against
an incline q' on the lever q which has its fulcrum at q³, and has its
upper end forked to embrace the grooved portion of the pulley i. The
free end of the lever p is normally held up by a spring p', and carries a

page_text: hook p which projects over a projection * of the brake lever k. From
this arrangement it results that when the projection of the escapement
wheel has pushed forward the slotted arm and lever o, the lever p will
by the subsequent movement of the lever c be moved downward by
means of its catch or hook, thus momentarily removing the brake from
the pulley e¹, and so allowing said pulley with its finger to be returned
towards the normal position by the action of the spring e' until arrested
by the projection of the pulley h, and as the lever c continues its
downward movement the brake will return to the pulley e¹, and the
lever P still moving downward will by the operation of its antifriction
wheel p³ against the incline q¹ of the lever q push back the forked upper
end of that lever, thereby moving the pulley i out of contact or gear
with the pulley h, which latter will then be moved back by its spring h
into the normal position in readiness to commence a fresh turn.
The clock is wound up by the following arrangement:- is a winding
lever guided in a slot in the upper part of the framing. The lower end
of this lever is formed with a projection, shoulder, or bent 11. The lever
carries a pawl kept by a spring ³ in gear with the ratchet wheels of
the clock; this ratchet wheel is fixed on the arbor s¹: The lever r is
provided with a strong spiral spring * to draw it upward, and thus cause
the pawl to operate upon the train of wheels and keep the clock in
motion. When the lever arrives at its highest point its projection or
shoulder comes under the pin or projection co of the lever c, and the
result is that by. the next downward movement of the latter lever the
lever and its pawl are drawn down and the pawl takes into the
lower part of the ratchet wheel, thus winding up the clock and keeping
the lower end of the lever beyond the range of the projection of the
lever c until the clock has again nearly run down, when the operation
of winding will be automatically repeated as before; t is a spring by
which the lever c is held up in its normal position.
""
The object of the apparatus is, as before stated, to show by means of
the dial and pointer or finger the number of revolutions or intermittent
motions that has been performed during the preceding minute or other
unit of time by the shaft or body to be indicated.
The dial may be
divided into any convenient number of spaces that may be desired, but
in the example just described and shewn in Figs. 1, 2, and 3, is divided
into 432 spaces.
In the modification hereinafter described with reference to Figs. 14-to

page_text: 35 inclusive the dial is shewn divided into 130 spaces only, which
number is suitable to the usual number of revolutions made by steam
engines per minute.
In the arrangement already described with reference to Figs. 1, 2,
and 3, at each revolution or motion to be shewn the finger is moved one
space on the dial, i.e., if it commences at zero. At the termination of
the unit of time, which I will suppose to be one minute, the finger stops
and shews the number of revolutions made until at the end of the next
minute when the finger has either advanced or retreated to shew the
number of revolutions made during the last minute, and so the operation
is repeated. This operation is carried out by means of the three pulleys
placed upon the one shaft and constituting the main portions of what is
herein called the friction apparatus, and which is so arranged that when
the second pulley (h) is advanced by means of the first (i) it pushes
forward the third (e¹) also, but when the second pulley (/) is released as
before described, the third (e¹) does not return with it, being held in the
position it has been brought to by means of the brake which is of
sufficient power to hold the pulley (e¹) in position only, but not so strong
as to prevent the second pulley (7) in its motion when the studs are in
'contact overcoming the brake and carrying forward the finger or third
pulley.
The pulleys may be made of brass, wood, or other suitable material.
Fig. 14 is a front view of a modification of the arrangement last
above described.
Fig. 15 is a front view with the dial removed, various portions being
broken in the Drawing to shew the mechanism more distinctly.
Fig. 16 is a diagram illustrating the clockwork arrangement; and
Fig. 17 is a vertical section of the apparatus representing the principal
portions in the line M*, M*, of Fig. 15.
Figs. 18 to 22 inclusive are diagrams shewing the action of the stops
on the second and third pulleys.
In all these Figures the same letters and marks refer to the same
parts.
Motion is given to the machine by means of a cord or wire attached
to the lever A (whose fulcrum, is at A²), by means of which cord the

page_text: lever is drawn downward at each revolution or motion to be indicated.
This lever A has three offices to fulfil, namely, first, to wind up the
clockwork; secondly, to actuate the finger or pointer through suitable
mechanism; and thirdly, through other mechanism to release at the
proper times the brake and the friction apparatus through which motion
is communicated to the finger or pointer.
The three pulleys which form part of the friction apparatus which
moves the finger or. pointer are shewn at X, Y, Z, (Fig. 17), and
separately in section in Fig. 23, also to an enlarged scale with their
shaft in Figs. 24 to 33 inclusive.
There is a barrel or pulley X, upon which is placed a spiral spring, as
shewn. A slot is made in the barrel, through which and the shaft is
passed the pin a, and it is through this pin that the pulley is moved by
the shaft. Pulley Y fits loosely on the shaft next to pulley X, and the
two pulleys are pressed together by the action of the spiral spring, for
the spring presses against the pin a and against the side of the
pulley X, which in its turn presses the pulley Y against the collar b,
which is pinned fast upon the shaft. The fork B fits into the groove
formed in pulley X, and this fork when pressed by the downward move-
ment of the lever C through the medium of the adjusting screw e sliding
on the surface of the inclined plane & pushes back the spring of the
pulley, and releases the pressure and friction on pulley Y. Thus, if
pulley Y has been carried any portion of a revolution by X it will,
immediately it is released, fly back to its normal position by means of
the cord fand spring, which turns back the pulley until the stud i is
brought into contact with the stop 9 (Fig. 35). The pulley Z, which
carries the finger or pointer, has a stud k (Fig. 34) fixed in its side
corresponding to the stud i on pulley Y. The pulley Z is provided with
a friction brake m operated as herein-after described, also with a cord
and spring p.
+
The motion of the pulleys will be perhaps more clearly shewn by the
diagrams, Figs. 18 to 22. In Fig. 18 the pulley Y is shewn with the
stud pressing against the stop g attached to the framing, and the
stud is shewn pressing against i. When the pulley Y is advanced by
the friction pulley X it carries along with it the pulley Z by means of
the stud, as shewn in Fig. 19, where k has been moved about one-fifth
of a revolution. Fig. 20 shews the position of the parts when the stop i
having reached the position shewn in Fig. 19, the friction on the

page_text: pulley Y has been released, and the pulley has gone back to its normal
position, but has left the pulley Z with its stop in the position shewn
at %, where it has been (during the return of Y) and still is retained by
the brake m. If the brake m were released then the pulley Z would run
back until its stud assumed the position shewn at k in Fig. 18, but
assuming that the pulley Z had not been released its stud would have
been overtaken by the stud kat n, and have been carried further on, as
shewn at Fig. 21.
By releasing the friction on the pulley Y it again returns to its normal
position, and immediately the pressure is again applied it advances.
Now Fig. 22 shews the position of the parts when the pulley Y, having
been moved a short distance only, and the brake m having been then
taken off the pulley Z, the stud k of Z has returned to the stud i, and
remains in the position at which it has so been arrested, for the brakes are
put into action at the termination of each minute or other predetermined
unit of time for which the apparatus is set or constructed, and what
thien takes place is as follows:-First, the brake m is raised and lowered,
then the fork B presses back the pulley X; thus the pulley Y runs back
to its normal position at the termination of each minute or other unit of
time, but leaves the pulley Z at the spot reached, and the finger or pointer
being attached to the pulley Z shews on the dial the position and the
number of the revolutions made.
In order that the friction pulley arrangement may be thoroughly
understood I have illustrated the same detached in section in Fig. 23,
and to a larger scale in Figs. 24 to 33, and in Figs. 34 and 35 I have
shewn back and front views respectively of the pulley Z and of the
pulley Y, and some parts connected thereto.
In Fig. 23 60 represents the shaft. The pulley Z is fitted loosely on
to the shaft 60 so as to be capable of rotating thereon, but is by the
shoulder on the shaft and by the pin and washer 61 prevented from'
moving lengthwise of the shaft. 62 is the finger or pointer; 63, the
friction surface for the brake m; k, the stud. Between pulleys Z and Y
a collar 70 is secured to the shaft as shewn. This collar receives the
pressure of the pulley Y so as not to throw any pressure upon the
pulley Z; 71 is the groove for the cord in the pulley Z; 64 is the groove
for the cord in the pulley Y.
The stud of the pulley Y is shewn at i, but the stop g, Fig. 17, is

page_text: works, and 66 shews the slotted barrel forming part of the pulley and
the spring; 72 is a washer, which the spring presses against the pin 67.
The pulley can be pushed back by the fork B against the pressure of
the spring into the position indicated by the dotted lines 73, thereby
relieving the surface of the pulley Y from the pressure of the pulley X
at 74.
The back view, Fig. 34, of the pulley Z shews the position of the
stud when the finger or pointer is in its normal or zero position, and
the cord 68, which is attached to the spring shewn at p, Fig. 15.
The front view, Fig. 35, of the pulley Y shews the position of the
stud i when the pulley is in the position corresponding to the normal
position of the finger or pointer (sce also Fig. 18), and pressing against
the stop shewn in dotted lines. The cord 69 is also shewn, which is.
attached to a spring, as at f, Fig. 17.
The remainder of the mechanism of the machine is merely for the
purpose of moving the pulley X and for the throwing in and out of
action of the brake and friction apparatus, and motion for these.
operations is as already stated derived from the lever A. To the lever A
a catch bar L is jointed at h, and at each depression of the shorter arm
of the lever A the catch draws down one tooth of the ratchet wheel R.
This ratchet wheel is fixed on the end of a spindle, upon which is fixed
a pinion t geared into a wheel w. The wheel w therefore being fixed
upon the same shaft as the pulleys X, Y, Z, causes their motion, and in
the apparatus now under description (Figs. 14 to 35 of the Drawings)
makes a complete revolution to every 140 draws of the catch bar L;
but as this machine is not arranged to indicate a speed greater than 130
revolutions per minute the pulleys Y and Z are thrown out of gear
before that number is reached, and that is done in the following manner:
The machine is divided into two sections G and H, the latter being
simply a train of clockwork with an ordinary escapement. In this
instance it is a common house clock lever escapement terminating at
onc end with the minute hand shaft Q. Upon the end of this shaft
(Fig. 15) is fixed a cam or tappet q, which at the termination of each
minute presses and pushes forward the lever V. Now this lever V throws
into gear the mechanism which releases the brake m and the friction
pulley X. There is an L shaped slot at s in the lever V, through which
protrudes its fulcrum pin, upon which pin the lever rests and slides.
The lever V slides in the forked pieces o, o. Its right hand end has attached

page_text: •
to it a spring u, and when the lever is pushed forward in the direction
_of_the_arrow, Fig. 15, by the cam Q, the spring-suddenly--pulls-the-
lever upwards, and the pin s enters the lower part of the slot, and also
brings the pin into contact with the curved part of the catch
lever N. There is also on the bar N a stud r, which when the bar is
depressed carries with it the lever V to its normal position after being
raised by the spring u and the slot s. By this motion the lever 'N' is.
forced forward towards the right hand, and the hook 2 at its lower end
is brought underneath the stud 3 fixed in the lever A. Thus when that
arm of the lever A is depressed it draws down the catch lever N, which
by means of the studs v, v¹, carries with it the lever C; whose fulcrum
is at 4, and this lever operates the brake and clutch apparatus as follows:-
The hook bar 5 fixed on the pin 6 hooks at 5* upon a pin 7 fixed in
the brake lever m. The brake lever turns on the fulcrum pin 8, and as
the pin 7 and its end of the lever are drawn downward the hook and
pin are thrown out of contact by the operation of the inclined upper end
of the hook bar upon the pin 9. Thus in the downward motion of the
lever C and catch bar 5 the brake m is released only momentarily, and
recovers its position before the friction apparatus is operated upon.
The movement of the lever, C having released the brake m before the
right-hand arm of the lever A has descended through about half the
space it has to move or from 10 to 11, Fig. 15%; the lever A continues
its motion to 12. In this last part of the motion the adjusting screw e
of the lever C slides down the inclined plane d of the fork B, which is
consequently pressed backwards, and with it the pulley X. Thus the
pulley Y is released from the grip, and by the cord f and spring f¹ is
returned to its normal position, leaving the pulley Z and finger or pointer
retained by the brake m in the position they had attained at the moment
of the pulley Y commencing its return movement.
It will now be seen that the motions must be properly timed in order
to assure the correct working of the finger or pointer.
I would here remark that the apparatus may be modified by dis-
pensing with the pulley Z, and fixing the finger or pointer on the
pulley Y; but this plan would be imperfect, for the finger would travel
back to zero at the conclusion of each minute or other predetermined
unit of time, and at the termination of the minute or other unit of time
only would the speed be ascertainable.

page_text: The clockwork, as before stated, is an ordinary train of wheels, as
shewn in Fig. 16, in which 13 is the escapement, and 14 the minute
arbor upon which the cam Q, Fig. 15, is fixed; but there is a self-
acting winding-up apparatus which during the motion of the lever A
constantly keeps the clock going without any further attention. This
is performed by means of the winding lever D, Fig. 15, which carries
upon it a small pawl 15 taking into the ratchet wheel 16. This ratchet
wheel is fixed on the end of the arbor 15*, Fig. 16, in the present
instance, but any other arbor of the train may be employed that may
be suitable for the purpose. The winding lever D is provided with a
strong spiral spring 20 to draw it downward, and thus cause the pawl 15
to operate upon the train of wheels and keep the clock in motion.
When the winding lever D arrives at its lowest point its shoulder 19
rests upon the pin 18, one of the pins (17 and 18) which constitutes a
slot-like guide, and the result is that the .catch 120 is carried forward
and over the stud 21 of the lever A. On the ascent of that end of the
lever A the winding lever D is carried up, and consequently the clock
is thereby wound up.
It will be observed that so long as the shoulder 19 of the winding
lever D does not rest upon the pin 18, the force of the small spring 23
keeps the pawl 15 in gear with the ratchet wheel; this is indicated by
the respective positions of the parts shewn dotted at 22 and 24, Fig. 15.
The catch lever N is held in its normal position (Fig. 15) by the
spring 25, and by means of the shoulder 26 the book or shoulder 2 is
kept clear of the pin 3 until pushed into gear by the lever V, as before
stated. In like manner each of the levers is held in its normal position
by means of a spring, as the Drawing shews, thus the lever C is held
up by the spring 27, and the hook bar 5 is held in position by the
spring 28, and the lever A by the spring 29.
In the machines above described the pulleys X, Y, Z, receive motion
through mechanism from the engine or shaft to be indicated without
the intervention of the clock, whose duty is confined to setting in
motion the apparatus for operating the brake and friction apparatus
on the termination of the unit of time for which the apparatus is
arranged; but sometimes I modify the apparatus so that this order is
reversed. Such a modification is shewn in Figs. 36 and 37, representing
an apparatus in which motion is given to the pulleys through the
medium of clockwork, and the friction brakes are released by the engine

page_text: or shaft to be indicated, setting in motion the apparatus for operating
the-brake-and-friction apparatus-on the termination of the unit of time
for which the apparatus is arranged without the intervention of clock-
work for that. purpose. This plan is more especially designed for
indicating the time within. which one, two, or more revolutions shall
have been made; in other words, the finger while being moved forward
by the clock indicates time, and the commencement of its return to its
normal or zero position indicates the conclusion of the revolution or
movement, or revolutions or movements, be the number one, or five,
or ten, or otherwise, which the apparatus is arranged to indicate.
Hence the position whence the finger commences its return stroke
will shew within what time the shaft or body to be indicated has made
the revolution or movement, or revolutions or movements for which the
apparatus is arranged.
It will be evident that this arrangement though well adapted for
indicating slow revolutions or movements is not suitable for indicating
single revolutions or movements of great speed; but by arranging the
apparatus so that the finger or pointer shall return to its normal position
only at every tenth, or twentieth, or other suitable number of revolu-
tions or movements, high speeds may be indicated.
It will be observed that the dial is divided differently to that of the
apparatus already described. In this case the pulleys X, Y, Z, are
placed upon an arbor of the clock, revolving once in a minute, and the
finger or pointer would consequently make a whole revolution of the
dial if it were not released by the operation of the friction apparatus.
Now supposing the finger or pointer to be carried over half of the
circumference of the dial and then released it would stop in that position
until the next time the friction pulleys X, Y, were drawn apart, as
described with reference to the preceding machine. Thus if the finger
or pointer stopped at half a revolution it would stop opposite the
Figure 2, shewing that the speed had been for that revolution at the
rate of two per minute. Again, if it stopped at a fourth part of the
circumference it would point to the Figure 4, which would be the rate
per minute of the revolution. For slow working shafts each revolution
may by these means be shewn, but by making the minute hand revolve,
say ten times per minute, then the figures on the dial would be increased
and become tens instead of units. Thus 2 would be 20, and 4 would
become 40. If very fast speeds are to be recorded a ratchet wheel with
J

page_text: a stud may be used so that at every 5, 10, or 20 revolutions the speed
may be indicated. It will thus be evident that many modifications may
be made without affecting the principle of the action.
In the sectional view, Fig. 37, the clockwork may be driven by
winding up the lever marked A. through a lever like that at D, Fig. 15,
or it may be done as in ordinary clocks, and in this case, as in the
previously described machine, the self-winding arrangement may be
dispensed.with.
The brake and friction apparatus resemble those described with
reference to Figs. 14 to 35, and the same numbers and letters are used
to denote like parts.
The framework of the machine may be made as shewn in Fig. 17,
where 30 and 31 are two circular plates enclosed in a drum 34. The
front plate 32 may be cut away as required, as shewn in Figs. 15 and 17.
The dial 33 may be in any form desired.
:
In the Drawings several portions of the working parts, such, for
example, as the train of clockwork in Fig. 37, &c., have been omitted
to avoid complication.
It will be obvious that the connection between the primary lever of
the machine and the shaft or body to be indicated may be made in
various ways, as by pneumatic, magnetic, or mechanical means.
It will also be evident that a recording register may be connected with
the machine. The dial may be arranged to represent miles or other
measurements, as desired, for locomotives, ship's logs, and other bodies
and measuring machines.
In cases of very slow speeds, or when desired, the machine may be
arranged to indicate not only each revolution, but portions of revolu-
tions by adapting the attachment for that purpose.
Having described the nature of my said Invention, and the mode of
carrying the same into practical effect, I desire to have it understood
that save and except as herein-after mentioned I do not intend to claim
any of the mechanical parts of the apparatus herein-before shewn and
described when taken separately and apart from the combination or
application thereof, in manner and for the purposes herein described,
but what I consider to be novel and original, and therefore claim as
secured to me by the herein-before in part recited Letters Patent is,―
B

page_text: .
First. In a machine for indicating rotations or other movements the
combination with a dial of a finger or pointer carried by a pulley or
boss mounted freely on a driven shaft or axis, means for rotating said
, pulley or boss on the said shaft or axis, a brake for arresting the pulley
or. boss as required, and a spring and cord, or the equivalent thereof, for
'moving back the pulley or boss when released by the brake so as to
return the finger or pointer to its normal position, substantially as
described.
Secondly. The combination with the finger or pointer, its pulley or
boss and the brake operating in conjunction therewith of an intermediate
pulley provided with a stud arranged to operate in conjunction with a
stud on the finger pulley or boss and a driving pulley provided with a
spring for pressing it against the intermediate pulley, and with dis-
engaging apparatus for moving it out of contact or gear with the
intermediate pulley at the proper times, substantially as herein described
and shewn for the purpose specified.
Thirdly. The combination of parts constituting the improved indi-
cating machine constructed, arranged, and operating, substantially as
shewn in and described with reference to Figs. 1 to 13, inclusive of the
accompanying Drawings.
Fourthly. The combination of parts constituting the improved
indicating machine constructed, arranged, and operating, substantially
as shewn in and described with reference to Figs. 14 to 35, inclusive of
the accompanying Drawings.
.
Fifthly. The combination of parts constituting the improved indi-
cating machine, constructed, arranged, and operating, substantially as
shewn in and described with reference to Figs. 36 and 37 of the
accompanying Drawings.
In witness whereof, I, the said Alfred Barlow, have hereunto
set my hand and seal, this Nineteenth day of February, in the
year of our Lord One thousand eight hundred and seventy-six.