Improvements in Ratchet Driving Gear.
Year: 1897

page_text: COMPLETE SPECIFICATION.
Improvements in Ratchet Driving Gear.
I, HERMANN GANSWINDT, of 10 Herberstrasse, Schöneberg, in the German
Empire, Manufacturer, 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 :-
The
This invention relates to intermittently-acting driving gear for shaits, actuated
by a belt, rope, or chain, and pawl and ratchet arrangements, and one of the objects
of the improvements is to reduce to a minimum the friction which acts
detrimentally to the rotation of the driven shaft, or, in the case of a long shaft, to
so arrange several driving discs or pulleys that those of such pulleys as are inactive
are ineffective only as to a part of the ratchet and pawl arrangement.
invention is also intended to allow the motion of the driving pulley, effected by
treadles, or other motive power, to continue so that the pulling device connected
with the pulley is completely unwound therefrom, and also that in case the strokes
do not follow each other immediately the firmly held driving pulley does not
produce power-absorbing friction on the driven shaft.
This object is effected according to my invention as follows:-The pulley serving
as a point of attachment for the belt or other pulling appliance, and ratchet and
pawl mechanism by means of which the gearing is actuated, as well as the spring
by which the return motion is secured, are arranged on a firmly secured sleeve,
or (in the case of shafts which are not continuous) on a fixed pin. whilst the sleeve
carrying the ratchet wheel is keyed on the driven shaft. In this way, when the
driving pulley makes a backward movement or comes to a standstill, the driven
shaft is not affected by friction. The arrangement can of course be reversed so
that the ratchet-wheel is arranged on the fixed sleeve or pin, and the means by
which the gear is actuated arranged on the driven shaft. A further essential
arrangement of the gear is that the pawl after its effective action in engagement
with the ratchet-wheel, is automatically disengaged therefrom either by the spring
producing the return movement of the driving pulley or by a spring specially
provided for that purpose.
Another advantage and object of this arrangement is the prevention of the
friction produced by the sliding of the pawl on the ratchet wheel, during the
backward stroke of the pulley and the prevention of the clicking noise generally
caused thereby. The backward movement of the driving pulley is facilitated by
this prevention of friction.
In another method of carrying out the invention the necessity for employing
special appliances for disengaging the pawls is obviated: for this purpose these
latter are unequally distributed at the circumference of the ratchet wheel, being
arranged in one of the spokes of the actuating pulley in such a manner that they

page_text: are automatically put out of engagement by their own weight when the pulley
device has been completely unwound from the driving pulley.
In the accompanying two sheets of Drawings:-Figure 1 is a vertical sectional
elevation of a driving gear constructed in accordance with my invention; Figure 2
a cross sectional elevation of same, the upper half being a partial section taken on
the line of Figure 1, and the lower half a section taken on the line, 2-2 of
the same figure; Figure 3 a longitudinal sectional elevation of a slightly modified
arrangement. Figure 4 is partly an elevation and partly a longitudinal sectional
elevation, and Figure 5 a cross sectional elevation of an arrangement of the gear
in which the disengagement is effected by means of a special spring. Figures 6
and 7 are respectively longitudinal and cross sectional elevations of a further
modification of the gear.
In the arrangement shown in Figures 1 and 2 the driven shaft a passes freely
through a sleeve b, which is firmly secured to a hanger c or other fixed part of the
machinery. The ratchet wheel d provided with teeth is fixed to or formed with
a sleeve e which is keyed to the shaft a. In the ball bearing f, screwed into the
wheel d, are friction balls g which bear on the end of the fixed sleeve band support
the wheel d thereon without opposing any material friction to the motion thereof.
The driving pulley encloses the sleeve and the ratchet wheel with part of
the sleeve c. The belt i is connected to the pulley by a bolt passing through tho
loop of a flap of the belt and through eyes on the pulley and is wound on and off
the pulley alternately.
The pulley has on the inside spoke-like arms k, the nave or boss of which is
adapted to receive ball-bearings, for friction balls m, which bear against the
sleeve b. The arms are bored out, and serve as guides for the pawls o which
bear on springs n. The tops or heads of the pawls o fit the teeth of the ratchet-
wheel, and engage therewith when the pulley h makes a forward movement,
thereby causing the rotation of the shaft a in the direction of the arrow (Figure 1).
The return or backward movement of the pulley with the pawls is caused by a
springs, which is attached at one end to a fixed ring p on the sleeve band at the
other end to the inside of the pulley h.
In order that the pawls o may be kept out of engagement with the teeth of the
ratchet wheel d when the shaft comes to a stand-still between the forward and
backward strokes, which stationary period ordinarily occupies a considerably longer
time than the actual stroke, pins are provided on the pawls o; these pins pass
through slots in the arms & and the coil s' of the springs is so extended laterally
that after the complete winding up of the spring by the rotation of the pulley
the broader coils of the spring acts against the pins g and disengages the paw 30
from the teeth, so that while the pulley remains stationary no friction whatever
is produced on the shaft, the backward movement of the pawls is not interfered
with and the backward movement of the pulley h and of the parts connected there-
with is effected, to a certain extent, without noise or friction.
The arrangement shown in Figure 3, which is only made use of in cases where
a short driving shaft with a single driving pulley is employed (for sewing
machines, velocipedes, and the like), for example, is only distinguishable from that
above described in that the shaft terminates in the boss e of the ratchet wheel
and that the sleeve is replaced by a solid pin 6' which is secured in the hanger el.
The arrangement can also be altered, as already mentioned, in such a manner
that the position of the ratchet wheel d can be exchanged, for that of the driving
pulley and the parts connected therewith.
In the arrangement shown in Figures 4 and 5 the springs serves exclusively
for effecting the backward movement of the driving pulley h after the strap i, or
other pulling device, has been unwound from the said driving pulley,, whilst the
automatic disengagement of the pawlso provided with the side-pins 7 is effected
by a special springs, which is likewise fastened at one end to the fixed ring p of
the sleeve bor to the fixed pin b', as the case may be, and at the other end to the
driving pulley h. According to Figure 5 the spring is so bent or cranked at 53,

page_text: that a broader space is left between the adjoining coils of the spring for the pins q
of the pawl o, which allows of the forward or effective stroke of the pulley h when
the pawls are engaged, and the releasing or disengaging of the pawls only occurs
at the end of the stroke before the return movement, or the coming to a standstill
of the driving pulley. The springs s may or may not be separated by means of
a partition connected with the palley or with the ring p. If the spring be
strong enough to effect the backward movement of the pulley h at the end of the
forward stroke, the spring s specially provided for this purpose may be dispensed
with.
The arrangement shown in Figures 6 and 7 is distinguished from those above
described by the fact that the pawls are not evenly distributed round the
circumference of the ratchet-wheel but are placed together in one arm or spoke k¹
of the wheel h.
These pawls can either move quite freely in their respective holes, or they may
bear on springs, which are subjected to tension by the weight of their freely moving
pawls, and which, when the pawls are carried beyond their upper vertical position
effect the forward movement of such pawls, whilst in the absence of the springs
the pawls fall into the position for engaging with the ratchet teeth, just as, at
the end of the forward stroke of the driving pulley, when the strap or other
pulling device is completely unwound. the said pawls being in the corresponding
vertical upwardly directed position of the spoke arm &³, are put out of engagement
with the ratchet-wheel dy falling down in the holes in which they are located.
In this case no spezial arrangement is required for taking the pawls out of gear:
this operation, as well as that of putting them in gear, being effected automatically
when the driving pulley is changing from the forward to the backward stroke.
In this case the springs has no other function to perform than that of bringing
back the pulley when the forward stroke is completed. This spiral spring may,
however, be employed, as above described, for the purpose of effecting the automatic
| disengagement or taking out of gear of the pawls.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
First. Intermittently-acting driving gear for shafts in which the driving
pulley to which the belt or other actuating device is fastened, the devices k, n, o,
by which the ratchet and pawl mechanism is operated, and the spring $ by means
of which the backward or return movement of the driving pulley is secured, are
arranged on a fixed sleeve bor on a fixed pin b. whilst the boss e carrying the
ratchet wheel d is keyed on the driven shaft, so that when the driving pulley h
comes to rest at the end of each forward movement the driven shaft a is relieved
of friction, and the backward movement of the said driving pulley is facilitated,
substantially as described.
Second. In driving gear of the kind herein described the arrangement in
which the pawls o with the parts supporting them, the boss e fixed on the shaft a.
the ratchet wheel d, and the fixed part 6 or b³, are combined and operate
substantially as described.
Third. In driving gear of the kind herein described the arrangement in which
the automatic disengagement of the pawls o is effected by the springs at the
change from the forward to the backward stroke, which spring is for that purpose
either extended laterally at (Figures 1 and 3) so as to operate upon pins q
extending from the pawls, or is bent at (Figure 5) to form a suitable path for
the said pins to work in, substantially as described.
Fourth. In driving gear of the kind herein described the arrangement in
which the pawls are placed all together in an arm or spoke of the driving pulley h
and are adapted to move freely, with or without springs, in holes formed in such
arm or spoke, so that their disengagement from the ratchet teeth takes place
automatically at the end of the forward stroke of the driving pulley, and their

page_text: engagement with the ratchet teeth takes place automatically at the end of the
backward stroke of the driving pulley, substantially as described.
Dated this 2-1 1
190
H. GANSWINDT,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.
H. GANSWINDT,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.