Improvements in Ratchet Mechanism suitable for Driving Lubricating Pumps and other Machines.
Year: 1892

page_text: Date of Application, 12th Nov., 1892
Complete Specification Left, 12th Aug., 1893-Accepted, 11th Nov.. 1893
PROVISIONAL SPECIFICATION.
Improvements in Ratchet Mechanism suitable for Driving
Lubricating Pumps and other Machines.
I, RUDOLPH JOHANNES WERNER, of Aarhus, Denmark, Civil Engineer, do
hereby declare the nature of this invention to be as follows :—
Ratchet mechanism according to this invention is specially suitable for driving
lubricating pumps in place of the ordinary ratchet wheels hitherto employed for
this purpose, which cannot be adjusted with sufficient exactness to allow of the
speed of the lubricating pumps being accurately regulated to suit requirement
even when the wheel is made as large and the pitch of its teeth made as small as
is practicable since the rate of rotation of the wheel can only be varied by causing
the pawl to move back over the same number of teeth along the entire periphery
of the wheel, each time when the pawl is to engage with the wheel.
Now with mechanism constructed according to this invention much smaller
gradations in the speed of the apparatus can be obtained as will be hereinafter
explained.
Although as already stated the mechanism is designed especially for driving
lubricating pumps, it can be applied with advantage to many other kinds of
machines, whether the said machines have been heretofore operated by the ordinary
ratchet apparatus or otherwise.
According to this invention the pitch of the teeth of the ratchet wheel is varied
at different places on the periphery of the wheel to suit requirement. The pitch
can be made to vary according to widely differing rules.
Usually however the pitch of the teeth will be made to vary in steps by making
the pitch smaller at every tooth, or at every second tooth, or at every third tooth
and so on.
Or the difference of pitch may be made to increase or to diminish
according to certain rules. The pitch of the teeth may be made to diminish from
a certain point of the periphery of the ratchet wheel back to the same point, or
merely over a certain portion of the periphery, as for instance a half, third, fourth
or other part of the circumference, the series of teeth either with increasing
or decreasing pitch being repeated on the successive parts of the periphery of the
wheel.
Or the pitch of the teeth may be made to increase or to decrease over one part
of the periphery of the ratchet wheel according to a certain rule, and over another
part according to another rule.
The various pitches of teeth in each case are such as to meet the desired
requirements of each particular application.
The distance travelled by the reciprocating pawl which drives the ratchet wheel
and always takes the same time to make a to and fro movement whether the
distance be small or large, must at least, be greater than the greatest pitch, so
that the pawl will project everywhere over at least one tooth of the ratchet wheel.
Starting with this length of stroke, the distance travelled by the wheel can be
increased by very small amounts, the result being a correspondingly quicker
rotation of the ratchet wheel, because the teeth will enable the pawl to advance
the ratchet wheel at one or more points of the periphery thereof to the extent
of two or more teeth at a time instead of only one tooth.
With this kind of ratchet wheel it is obvious that the ordinary detent cannot be
employed for preventing the ratchet wheel turning back during the return move-
ment of the pawl, since such a detent should be situated diametrically opposite to
the forward limit of the actual travel of the pawl in which case, to prevent any

page_text: return movement the teeth of the wheel need to be made of equal pitch on both
halves of the wheel.
For this purpose a friction device is preferably employed in ratchet mechanism
according to this invention for holding the wheel during the return movement of
the pawl.
In the accompanying drawings,
Fig. 1 is a side elevation; and
Fig. 2 a sectional plan on the line A A of Fig. 1 of ratchet mechanism
according to this invention.
a is a ratchet wheel operated by a pawl c, that is pivoted in a lever b oscillating
about the axis d of the ratchet wheel, and the engagement of which in the teeth
of the wheel is aided by a spring ffixed to said lever. The bar is as heretofore
moved to and fro at a predetermined rate by means of a suitable intermediate piece
or link and the length of travel is varied in the well known manner.
The fixing of the ratchet wheel a during the return of the pawl is effected by
means of a brake fork 9, shown separately in Fig. 3 which is a section taken on
the line B B of Fig. 1. This brake fork is connected at one end by a bolt i to the
frame h, whilst the other end is of fork shape and embraces the edge of the ratchet
wheel. In one of the prongs of the fork is inserted a screw j, which presses by
means of two steel springs & upon a disc I, that encircles the end of the screw i, and
thus clamps the ratchet wheel a in an elastic manner between the disc / and the
other prong of the fork.
k
In order that the connection of the brake fork to the frame shall not offer any
hindrance to this elastic movement, the guide for the bolt is slightly rounded at
the ends, so that the brake fork can move to a certain extent to and fro on the bolt,
without the bolt itself having any play.
A groove m is formed in the one side of the ratchet wheel into which the end of
the screw extends so that the fork retains its position with respect to the ratchet
wheel without adjustment. The bolt i must be arranged on the frame in such a
manner that the direction of the force exerted by the ratchet wheel on the brake
fork shall be as far as possible at right angles to its axis.
The worm
lubricating pump. In order to enable the invention to be more readily understood
the proportion of the teeth of the ratchet wheel is assumed to be rather simple, so
that only a relatively small number of variations are obtained in the time necessary
for the wheel to perform a complete revolution, and consequently a smaller decrease
or increase of the quantity of lubricant supplied during a determined period by the
lubricating pump.
The proportion of teeth upon the ratchet wheel may however
be so arranged that a far greater number of gradations within the same limits may
be obtained.
mounted on the axis of the ratchet wheel serves for driving the
Let it be assumed that the ratchet wheel has twenty-nine teeth the relative
proportion of the pitch of which is arranged in the order in which the teeth are
arranged on the wheel riz. 14, 14, 13, 13, 12, 12, 11, 11, 10, 10, 9, 9, 8, 8, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14. Then if the diameter of the ratchet
wheel be for example 80 min., the pitch of the biggest tooth will be :—
4 (14+13 + 12 + 11 + 10 + 9 +8) +
The pitch of the smallest tooth :—
7 π 80
4 (14+13+12+11 + 10 + 9 +8) + 7
and the difference between the teeth will be :-
11.17 min.
= 5.585 mm.

page_text: By adjusting the lengths of the bar within a peripheral length equal say to
61-64 mm. or by an angular ontstroke of say 87.26 mm. there can be obtained with
this wheel 37 gradations, whereby the wheel is compelled to revolve once for 29,
28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 15, 12, 12, 11, 11, 10, 10, 91, 9,
8, 8, 7, 7, 7, 63, 64, 61, 6, 5, 5, 5, 5, 43, 44 strokes of the bar.
Dated this 12th day of November 1892.
R. J. WERNER,
By L. W., per F. B.
COMPLETE SPECIFICATION.
Improvements in Ratchet Mechanism suitable for Driving
Lubricating Pumps and other Machines.
I, RUDOLPH JOHANNES WERNER of Aarhus, Denmark, Civil 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
stateinent :-
Ratchet mechanism according to this invention is specially suitable for driving
lubricating pumps in place of the ordinary ratchet wheels hitherto employed for
this purpose which cannot be adjusted with sufficient exactness to allow of the
speed of the lubricating pumps being accurately regulated to suit varying require-
ment even when the ratchet wheel is made as large and the pitch of its teeth is
made as small as is practicable because the pawl employed will always move
forward the same number of teeth of the ratchet wheel each time the pawl is moved
forward.
Now with mechanism constructed according to this invention small gradations in
the speed of the apparatus can be obtained as will be hereinafter explained.
Although as already stated the mechanism is designed especially for driving
lubricating pumps, it can be applied with advantage to many other kinds of
machines, whether the said machines have been heretofore operated by the ordinary
ratchet apparatus or otherwise.
According to this invention the pitch of the teeth of the ratchet wheel is varied
at different places on the periphery of the wheel to suit requirement. The pitch
can be made to vary according to widely differing rules. Usually however the
pitch of the teeth will be made to vary in steps by making the pitch smaller at
each successive tooth, or at every second tooth, or at every third tooth and so on.
Or the difference of pitch may be made to increase or to diminish according to
certain rules. The pitch of the teeth may be made to diminish from a certain
point of the periphery of the ratchet wheel back to the same point, or merely over
a certain portion of the periphery as for instance a half, third, fourth or other part
of the circumference, the series of teeth either with increasing or decreasing pitch
being repeated on the successive parts of the periphery of the wheel.
Or the pitch of the teeth may be made to increase or to decrease over one part
of the periphery of the ratchet wheel according to a certain rule, and over another
part according to another rule.
The various pitches of teeth in each case are such as to meet the desired
requirements of each particular application.
The distance travelled by the reciprocating pawl which drives the ratchet wheel,
and which always takes the same time to make a to and fro movement whether the
distance be small or large, must at least, be greater than the greatest pitch, so that
the pawl will always move back over at least one tooth of the ratchet wheel.
Starting with this length of stroke, the successive distances moved through by the
intermittently operated ratchet wheel can be increased by very small amounts, the
result being a correspondingly quicker rotation of the ratchet wheel, because

page_text: the teeth will enable the pawl to advance the ratchet wheel at one or more points
of the periphery thereof to the extent of two or more teeth at a time instead of
only one tooth.
With this kind of ratchet wheel it is obvious that the ordinary detent cannot be
employed for preventing it turning back during the return movement of the pawl,
since such a detent should be situated diametrically opposite to the forward limit
of the actual travel of the pawl in which case, to prevent any return movement, the
teeth of the wheel would need to be made of equal pitch on both halves of the
wheel. A friction device is therefore preferably employed in ratchet mechanism
according to this invention for holding the wheel during the return movement of
the pawl.
In the drawings left with my Provisional Specification,
Fig. 1 is a side elevation; and
Fig. 2 a sectional plan on the line A A of Fig. 1 of ratchet mechanism according
to this invention.
a is a ratchet wheel operated by a pawl c, that is pivoted in a lever boscillating
about the axis d of the ratchet wheel, and the engagement of which in the teeth of
the wheel is aided by a spring ffixed to said lever. The bar is, as heretofore,
moved to and fro at a predetermined rate, by means of a suitable intermediate
piece or link, and the length of travel can be varied in the well known manner.
The fixing of the ratchet wheel a during the return of the pawl is effected by
means of a brake fork g, shown separately in Fig. 3, which is a section taken on
the line B B of Fig. 1. This brake fork is connected at one end by a bolt i to the
frame h, whilst the other end is of fork shape and embraces the edge of the ratchet
wheel. In one of the prongs of the fork is inserted a screw j, which presses by
means of two steel springs k upon a disc 7 that encircles the end of the screw j, and
thus clamps the ratchet wheel a in an elastic manner between the disc and the
other prong of the fork. By adjusting the screw the tension of the spring can be
regulated.
In order that the connection of the brake fork to the frame shall not offer any
hindrance to this clastic movement, the guide for the bolt i is slightly rounded at
the ends, so that the brake fork can move to a certain extent to and fro on the bolt,
without the bolt itself having any play.
A groove m is formed in the one side of the ratchet wheel into which the end of
the screw extends so that the fork retains its position with respect to the ratchet
wheel without adjustment. The bolt i must be arranged on the frame h in such a
manner that the direction of the force exerted by the ratchet wheel on the brake
fork shall be as far as possible at right angles to its axis.
The worm p mounted on the axis of the ratchet wheel serves for driving the
lubricating pump or other machine to which the ratchet mechanism is applied. In
order to enable the invention to be more readily understood the proportion of the
teeth of the ratchet wheel is assumed to be rather simple, so that only a relatively
small number of variations are obtained in the time necessary for the wheel to
perform a complete revolution, and consequently a smaller decrease or increase of
the quantity of lubricant supplied during a determined period by the lubricating
pump. The proportion of teeth upon the ratchet wheel may however be so
arranged that a far greater number of gradations within the same limits may be
obtained.
Let it be assumed that the ratchet wheel has twenty-nine teeth the relative
proportion of the pitch of which is arranged in the order in which the teeth are
arranged on the wheel tiz. 14, 14, 13, 13, 12, 12, 11, 11, 10, 10, 9, 9, 8, 8, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14. Then if the diameter of the ratchet
wheel be for example 80 mm., the pitch of the biggest tooth will be:-

page_text: In the present case, where the diameter of the ratchet wheel is 80 mm., by
adjusting the stroke of the outer end of the bar carrying the pawl within a
peripheral length equal say to 61.04 mm., which corresponds to an angular outstroke
of 87° 26', there can be obtained with this wheel 37 gradations, whereby the wheel
is compelled to revolve once for 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 15,
12, 12, 11, 11, 101, 10, 91, 9, 81, 8, 7, 71, 7, 63, 64, 6, 6, 5, 5, 5, 5, 4, 4
strokes of the bar.
In
The accompanying table (Figs. 4, 44) shows how this result is arrived at.
the three left hand vertical columns are given the consecutive numbers of the teeth;
the proportions of pitches of the teeth hereinafter termed teeth proportions, in their
numerical order determined by the order on the wheel; and the distance of their
rear edges on the periphery of the wheel from the zero mirk on the wheel, which
distances are termned the "positions of the teeth" which are given according to the
same unit as the pitch of the teeth.
In the upper horizontal rows of figures there are
(1) The numbers of the variable values;
(2) The length of travel of the pawl, which corresponds exactly to the transition
between two variable values, because the pawl engages, at one or more points
around the wheel, just with the edge of a tooth; these lengths are also given in
the same unit and are termed "dead travels of the pawl.".
(3) The lengths of the travel of the pawl which allow of the most certain
engagement for the various variable values; these lengths are termed the "effective
travels of the pawl," and must obviously fall between the "dead travels of the
pawl" quoted under (2).
In the table a number is given for every "dead travel of the pawl" such number
being placed opposite the tooth with which the pawl engages, and between the
"dead travel of the pawl" considered in a determined case, and the next following
greater "dead travel of the pawl." This number indicates how far the pawl must
travel back on the periphery of the ratchet wheel with the "dead travel of the
pawl," until it engages with the aforesaid tooth.
"
This number must obviously always be smaller than the "position of the tooth
for the next tooth, as otherwise the pawl would engage with this tooth, and therefore
the number would relate to this tooth and not to the preceding one.
The following example will serve to explain the matter more clearly.
For the variable value No. 15 with "dead travel of the pawl" 29, the pawl will
travel from the point 6 on the periphery of the wheel first to 29 and then will
engage with the tooth No. 2 the "position of tooth" of which is 28. At the
next travel of the pawl, the pawl will travel back from 28 on the periphery of the
wheel to 28 + 29 57, and will then engage with the tooth No whose "position
of tooth" is 54.
=
At the third travel of the pawl, the pawl will travel back from 54 at the
periphery of the wheel to 4 + 29 = 83 on the same, before it engages with the
tooth No. 6 whose "position of the tooth" is 78 and so on. When the pawl has
acted on the tooth No. 28, the position of tooth" of which is 301 it will
move back to 301 + 29 - 315 = 15 on the periphery of the wheel, before it
engages with the tooth No. 1, whose position of tooth is 14.
66
At the termination of the second revolution of the wheel, the pawl engages
behind the tooth No. 29 the position of tooth of which is 315 or zero.

page_text: At the next travel of the pawl the pawl will therefore move back to 29 on the
periphery of the wheel and then engage with the tooth No. 2, exactly as at the
commencement of the first revolution, whereupon the just described order of
operations will be repeated.
"
At the bottom of the table is a horizontal row of figures giving the number of
strokes of the guide bar, which besides the "effective travels of the pawl
situated between the "dead travels of the pawl" is required for every complete
revolution of the wheel; these numbers are obtained by simply counting up the
engagements of the pawl and teeth given in the vertical columns above them.
With a wheel of the aforesaid diameter of 80 mm. but with the same teeth
heretofore employed, with a pitch nearly equal to the smallest pitch on the wheel
just described, that is to say, about 5 mm. and consequently with 50 teeth, then,
by varying the stroke of the bar or the travel of the pawl within the above
mentioned limits, only one revolution of the wheel could be obtained for each of
the following number of the strokes of the bar:-50, 25, 16, 12, 10, 8, 71, 61,
58 5, 4, 4, that is to say according as the pawl is allowed to move back
over 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 teeth on the wheel for each movement
thereof. Therefore only a far smaller number of variations can be obtained than
with a ratchet wheel having teeth of different pitch as herein before described.
Since the smallest length of the teeth can be even reduced to 2 mm. it is clear that
with the new differential ratchet teeth, when the pitch of the teeth is sufficiently
varied and calculated, as many variations can be obtained for one and the same
wheel as are required to meet any special circumstances, which cannot be done
with the ratchet wheels heretofore employed having teeth of one uniform pitch
over their entire periphery.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In ratchet mechanism a ratchet wheel having teeth of different pitch at
different parts of its periphery so that when the stroke of the pawl used for
actuating the said wheel is increased to an extent less than the pitch of the largest.
tooth a correspondingly quicker rotation of the ratchet wheel will result owing to
the pawl, at a certain point or points of the periphery of the wheel having a
greater effective travel substantially as described.
2. For the purpose of preventing backward rotation of the ratchet wheel
specified in the preceding claim during the return of the pawl used for actuating it,
the combination with such ratchet wheel of a friction device consisting of a pivoted
arm mounted on the frame carrying the ratchet mechanism and having a fork
shaped end within which the edge of the ratchet wheel is capable of being clamped
more or less firmly by means of a spring mounted on the fork and the tension of
which is capable of being regulated, whilst the fork is retained in position
relatively to the ratchet wheel, by means of a pin mounted on the fork and
engaging in an annular groove formed in the adjacent side of the ratchet wheel
substantially as described.
Dated this 12th day of August 1893.
R. J. WERNER,
By L. W., per F. B.