Improvements in Mechanical Counters.
Year: 1888

page_text: Date of Application, 17th Nov., 1888
Complete Specification Left, 10th Aug., 1889-Accepted, 14th Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in Mechanical Counters.
I WILLIAM SNELGROVE of Bankwood, Church Road Moseley in the County of
Worcestershire, Engineer, do hereby declare the nature of this invention to be as
follows:-
:-
My invention has for its object to improve and simplify the mechanism of mechanical
counters for indicating and registering the number of revolutions or reciprocations
performed by any part of a machine or moving object.
In counters as at present constructed the mechanical arrangements are somewhat
complicated and expensive; by my invention I dispense with complications such as
toothed wheels gearing into each other and use only simple ratchet wheels and pawls.
As in many other counters I use movable discs, upon the edges of which are marked
the numerals, these discs move on a common axis and indicate by the figures brought
opposite apertures in a containing case the required numbers. The counter may be
constructed to register any required number of reciprocations or revolutions depending
on the number of discs used. In a counter containing four discs hereinafter described
the greatest number registered is 99999. The four discs have marked upon each of
their edges the figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, and cach disc has on one side a
portion forming a ratchet wheel with ten teeth, into which teeth, fall flat springs or
holding pawls so as to prevent movement except in one direction and also driving
pawls engaging at the proper times, and each disc has also on the other side a portion
forming a ratchet wheel with one tooth. A lever at one end of the case pivoted on
the same axis as the discs, connects to a lever at the other end, also on the disc axis,
by a long spindle between the extremities, and this spindle carries four pawls pressed
upon parts of the discs by springs or by their own weight. This lever is moved to
and fro by the object, the reciprocations of which are to be counted, and the spindle
carries the ends of the four pawls over the edges of the four discs at each movement.
The disc registering units has ten ratchet teeth into which the first driving pawl falls
and the disc is moved one tooth at each forward movement of the driving pawl,
during the backward movement the holding pawl prevents shifting. The units disc
therefore moves one revolution for ten reciprocations of the lever. The second disc
which indicates tens has also ten ratchet teeth as already mentioned, but the pawl
driving it is kept out of the teeth by resting upon the smooth edge of the one toothed
ratchet wheel of the units disc adjoining until it has come round to 9, where the
notch or tooth is so, that the second pawl is allowed to fall into that notch and there-
fore also into a tooth in the second disc; and the stroke which brings round 0 on the
first disc moves the second disc (tens) one tooth.
If all discs stood at zero to start with 10 would now be indicated. The next eighty
movements brings the indications up to 90 when a notch upon the smooth edge of
the second disc or that portion of it forming a one toothed ratchet wheel permits the
third pawl to seize a tooth in the third disc, but this would cause the next stroke to
move the third disc one tooth and therefore 100 would appear as succeeding 91, to
prevent the third pawl seizing thus prematurely, a stop is arranged from the second
pawl so that the third pawl is held up by the second till the second falls in, so that
although the number nine appears on the second disc, the third pawl cannot act until 99
has appeared, the second pawl then falls in and with it the third causing the third
disc to move one tooth.
The fourth pawl is in the same manner held up by the third, so that the third
and fourth depend upon the second falling into a tooth to seize their respective

page_text: That is the first and second pawls act independently but the third and fourth
depend upon the action of the second to bring them into action as well as the notches
in their preceding discs; they do not act every time the second acts but only when
the second acts and at the same time their notches are also free to allow them to fall
in. Any greater number of discs may be arranged precisely the same way all awls
depending on the preceding up to the second as well as notches in the smooth edges
of each preceding disc for their power of falling in and moving a tooth.
The lever moving the driving pawls may be connected to the reciprocating piece
whose motions are to be counted in any convenient manner, provided the lever
receives the full necessary stroke.
When revolutions are to be counted, the counter is provided with a small spindle
having an eccentric which gives the necessary to and fro movement to the lever or
any convenient mechanical equivalent for effecting the same purpose.
Dated this 16th day of November 1888
MARKS & CLERK,
Agents for Applicant.
COMPLETE SPECIFICATION.
Improvements in Mechanical Counters.
I, WILLIAM SNELGROVE of The "Nest" King's Norton, in the County of Worcester,
Engineer, 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 :—
My invention has for its object to improve and simplify the mechanism of mechanical
counters for indicating and registering the number of revolutions or reciprocations
performed by any part of a machine, or moving object.
In counters as at present constructed the mechanical arrangements are somewhat
complicated and expensive; by my invention I dispense with complications such as
toothed wheels gearing into each other and use only simple ratchet wheels and pawls.
As in many other counters I use movable discs, upon the edges of which are marked
the numerals these discs move on a common axis and indicate by the figures brought
opposite apertures in a containing case the required numbers. The counters may be
constructed to register any required number of reciprocations or revolutions depending
on the number of discs used.
In a
counter containing four discs hereinafter
described the greatest number registered is 9999. The four discs have marked upon
each of their edges the figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, and oach disc has on one
side a portion forming a ratchet wheol with ten teeth into which teeth fall flat springs
or holding pawls so as to prevent movement except in one direction and also driving
pawls engaging at the proper times and each disc has also on the other side a portion
forming a ratchet wheel with one tooth. A lever at one end of the case pivoted on
the same axis as the discs connects to a lever at the other end also on the disc
axis by a long spindle between the extremities and this spindle carries four pawls
pressed upon parts of the discs by springs or by their own weight. This lever is
moved to and fro by the object, the reciprocations of which are to be counted, and
the spindle carries the ends of the four pawls over the edges of the four discs at each
movement. The disc registering units has ten ratchet teeth into which the first
driving pawl falls and the disc is moved one tooth at each forward movement, of the
driving pawl, during the backward movement the holding pawl prevents shifting.
The units disc therefore moves one revolution for ten reciprocations of the lever. The
second disc which indicates tens has also ten ratchet teeth as already mentioned but
the pawl driving it is kept out of the teeth by resting upon the smooth edge of the
one toothed ratchet wheel of the units disc adjoining until it has come round to 9
where the notch or tooth is so that the second pawl is allowed to face into that notch
and therefore also into a tooth in the second disc and the stroke which brings round 0
on the first disc moves the second disc (tens) one tooth. If all discs stood at zero to

page_text: start with 10 would now be indicated. The next eighty movements brings the
indications up to 90 when a notch upon the smooth edge of the second disc or that
portion of it forming a one toothed ratchet wheel permits the third pawl to seize a
tooth in the third disc, but this would cause the next stroke to move the third disc
one tooth and therefore 101 would appear as succeeding 90, to prevent the third
pawl seizing thus prematurely, a stop is arranged from the second pawl so that the
third pawl is held up by the second till the second falls in, so that although the
number 9 appears on the second disc the third pawl cannot act until 99 has appeared,
the second pawl then falls in and with it the third, causing the third disc to move one
tooth.
The fourth pawl is in the same manner held up by the third, so that the third
and fourth depend upon the second falling into a tooth to seize their respective
discs.
That is the first and second pawls act independently but the third and fourth
depend upon the action of the second to bring them into action as well as the
notches in their preceding discs, they do not act every time the second acts but
only when the second acts and at the same time their notches are also free to allow
them to fall in. Any greater number of discs may be arranged precisely the same
way all pawls depending on the preceding up to the second as well as notches in
the smooth edges of each preceding disc for their power of falling in and moving a
tooth.
The lover moving the driving pawls may be connected to the reciprocating piece
whose motions are to be counted in any convenient manner, provided the lever
receives the full necessary stroke.
When revolutions are to be counted, the counter is provided with a small spindle
having an eccentric which gives the necessary to and fro movement to the lever or
any convenient mechanical equivalent.
In order that my invention may be fully understood and readily carried into
effect 1 hereunto append an explanatory sheet of drawings which I will now
describe.
Figure 1 is an external plan. Figure 2 is a plan with the outer case removed in
order to show the disc, ratchet wheels and other parts. Figure 3 is an elevation
with the case removed. Figure 4 is an end elevation partly in section and Figures 5
to 11 are separate views of details.
A base A carries a main spindle B upon which the four discs C, D, E F, are
mounted respectively registering units, tens, hundreds, thousands, two slot levers G, G₁,
are pivotted at H, H¹ and connect to each other by the spindle I, the main spindle B
rotates freely within the discs and carries eccentrics J J¹ working within the slots and
levers G, G².
Four pawls C, D, E, F¹ are pivotted on I and moved to and fro over the
surface of the ratchet wheels when the spindle B is rotated. Figures 9, 10, and 11
show different views of one disc, each disc has on one side a ratchet wheel with ten
teeth a as in figures 10 and 11 and on the other side a smooth wheel with one
ratchet tooth b as in figures 9 and 10. Figure 10 is an end elevation showing
both ratchet wheels a and b and the central portion of the disc, upon the periphery
of which the numbers are marked. Four springs, K, K, K, K, Figures 3 and 4 act
as pawls on the four ratchet wheels having ten teeth each and prevent the disc moving
except in a forward direction. The bosses c, d, e, f of the pawls C, D, E, F₁, are
recessed as shown in Figure 2. Figures 6 and 8 are views of opposite sides of the
pawl D and figure 7 is an end elevation. The bosses d, e, fare so arranged that the
pawls E, F cannot fall into and engage the teeth of their respective ratchet wheels
unless D₁ also falls in and F is dependent on E' falling in. When the spindle B is
reciprocated or rotated by the lever L or any other convenient attachment to a
sufficient extent to give the pawls the necessary travel and assuming that the indicator
discs are all set to begin with at zero, for each revolution or reciprocation the pawl C¹
moves the 10 tooth ratchet wheel on the disc Coue tooth and thus indicates units up
to and inclusive of 9; when the figure 9 comes up, the tooth on the single tooth side

page_text: of C comes round, and upon the next movement of the levers the pawl D¹ is no
longer held out of the 10 teeth ratchet in D; it therefore falls into both teeth and
the next movement brings up 0 upon Cand 1 upon the disc D. The single tooth
wheels of the discs C, D, E are placed next to 10 tooth wheels of the discs D, E, F
so that the pawls D₁, E¹, F', cannot seize the ten tooth ratchet wheels of the
discs D, E, F unless the single tooth is in position. Figure 5 shows the single tooth
ratchot 6 in position to allow the pawl D¹ to fall into a tooth in the 10 tooth ratchet a.
The pawl then on the next movement moves a one tooth and as by doing so it has also
moved a tooth, the end now travels upon the smooth surface of b for the next nine
movements until the tooth in 6 again comes round. When nine revolutions or recipro-
cations have been registered the pawl E would be free to fall into the ten tooth
ratchet upon E because the single tooth upon D next to it would have come into the
position shown in Figure 5 but this would cause the 100 disc to move one and thereby
register 101 as immediately succeeding 90 instead of 91; to prevent this the pawl ¹
cannot fall into the ratchet teeth until D¹ is free to fall in. When the number 9
comes up on the disc the pawl D' falls in and allows E¹ also to fall in and it is then
prevented from falling in again until the disc D is again moved through 9 te.th
and through 99 teeth. The pawl F', is dependent in like manner upon the falling
in of the pawl E' as well as upon the position of the adjoining single tooth ratchet
wheel. The action of the pawl C¹ upon the disc C is to cause a movement of one
tooth for each revolution or reciprocation and thus to bring the single tooth in the
side B Figures 9 and 10 in position shown in Figure. 5 at every ten revolutions or
reciprocations. In the same way the single tooth of the ratchets b, b, b, of the
dises C, D, E, comes in position Figure 5 for each ten teeth moved upon C, D, E,
but in the case of the pawls E and F it is necessary not only that a and b of each
pair of discs over which they move should be in a position shown in Figure 5 but that
a and b of the discs C and D should also be in that position. In this way the
pawls E and F can only move their respective discs one tooth at such times as the
preceding pawl D' and in the case of F the pawl E' as well as D¹ fulls in and seizes
a tooth. This dependence of the pawls upon each preceding one is secured by the
use of the recess bosses c, d, e, f shown on Figures 5 and 6 for the pawl D'. The
disc F has only the ten toothed ratchet wheel A upon it but if a fifth disc were to be
added to indicate five figures instead of four then it would require a smooth ratchet b
as well on the other side.
The pawls C, D'E' F' are pressed into position by springs M, N, O, P Figure 2
of which M, N, O are shown broken so as to allow of a view of the mechanism
beneath.
Although I have shown one construction of my improved counter in the manner
I have hereinbefore described yet the arrangements may be altered without departing
from my invention, for instance I may pivot the levers G, G¹ upon the spindle B and
cause the springs M, N O P to move with it as shown in Figure 12 and instead of
recossing the bosses D, E, F, I may cause the pawls D', E F to depend upon each
other by means of pins c, d e, f projecting from the one to the other as shown in
Figure 13 in which case the figured edge of the discs C, D, E, F, may be recessed
below the general surface to form the ratchet wheels A and B instead of projecting as
shown in Figures 2, 3, and 4. When used for counting revolutions the revolving
eccentric J may have an axis away from the axis B or a small crank may be useri to
cause the reciprocation of the lever G.
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 :-
I. The improved construction of mechanical counters in which the actions are
entirely performed by pawls and ratchet wheels substantially as and for the purpose
hereinbefore described.
II. The arrangement of pawls D', E¹, F¹ and ratchets such as a, b so that each
succeeding pawl depends upon the preceding one for power to seize a tooth as well

page_text: as upon the position of the single tooth ratchet b on the ten tooth ratchet a, as herein-
before described and illustrated in the accompanying drawings.
III. In a mechanical counter the use of projecting pieces g, h, i, j, such as is shown
at Figure 13 to prevent the pawls F' and E from falling in before the pawl D¹ can
5 fall in and the recessed bosses C, D, E, F, Figure 2 substantially as and for the
purposes herein before described and illustrated in the accompanying drawings.
Dated this 9th day of August 1889.
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for Applicant.