Improvements in connection with Dividing Apparatus suitable for Gear Cutting Machines and the like.
Year: 1898

page_text: Date of Application, 16th June, 1898
Complete Specification Left, 16th Mar., 1899-Accepted, 6th May, 1899
Improvements in connection with Dividing Apparatus suitable for
Gear Cutting Machines and the like.
We, JOHN WILLIAM DARLING and HERBERT SELLERS, of the firm of Darling and
Sellers Limited, Airedale Works, Keighley, in the County of York, Engineers' Tool
Makers, do hereby declare the nature of this invention to be as follows:-
This invention relates to certain mechanism and the combination of the same with
the dividing motion such as is used in machines for cutting teeth in wheels or racks
and with other machines in which similar automatic dividing gear is used; and has
for its object, the prevention of the cutter, drill or the like being brought into
cutting operation before the spacing is completed, that is to say, before the requisite
change from one tooth space or hole to another is completed.
The improved mechanism is applicable to gear cutting and other machines in
which the change wheel shifting gear is operated by friction, and in which the
automatic feed of the slide or head stock carrying the cutter, drill or the like may be
put into operation by a sliding clutch.
In carrying out our invention say in connection with a gear cutting machine, the
revolving cutter is mounted to the feed slide or head stock, and connections made
with a clutch box in the usual manner, as are also the levers in connection with the
continuously rotating portion of the clutch. At one end of the lever connected to
the sliding portion of the clutch, is a projection which at intervals engages with a
weighted lever for keeping the revolving sliding clutch out of gear until liberated by
the improved mechanism.
To the frame of the machine we mount a pair of friction discs, one disc is
continuously rotating, and the other connected by a train of gearing to a wheel on
one of the shafts of the dividing mechanism, arranged to make exactly one revolution
for each spacing change, the said wheel being provided with a sliding pin for retain-
ing the wheel in position when required, and arresting the rotation of the said wheel
when one complete revolution has been made, and at a time when the cutter head
liberated in the usual manner has or is returning to its original position.
Secured on the before mentioned shaft; is a disc plate provided with an adjustable
tappet bar having a wedge shaped end, and when the sliding pin is depressed clear of
a stop notch, the wheel is liberated, and the train put in motion by the rotating
friction discs, and on the end of the wedge shaped tappet bar coming in contact with
a pawl having a wedge shaped extension, the pawl and a rod connected therewith are
raised such a distance that, the before mentioned weighted lever is moved clear of
the projection on the sliding clutch lever, thereby allowing the sliding portion of the
clutch to be moved into gear with that portion of the clutch in connection with
the cutter slide, when the cutting operation is repeated; provision being made for
retaining the sliding clutch box in a position that, on the teeth coming into gear they
do not override.
It will be obvious to persons having a knowledge of the dividing motions applied
to gear cutting machines, and to drilling and like machines in which the dividing
nechanism is automatically operated at intervals by friction, that the hereinbefore

page_text: described apparatus for regulating the completion of the spacing is equally applicable,
on securing one of the train of wheels provided with a sliding pin and connected
with the friction disc on one of the dividing shafts turning one revolution for each
change, and securing on the said shaft, a disc plate provided with a tappet bar to
operate upon a pawl in the manner as herein before described.
Improvements in connection with Dividing Apparatus suitable for
Gear Cutting Machines and the like.
We, JOHN WILLIAM DARLING and HERBERT SELLERS, of the Firm of Darling and
Sellers Limited, Airedale Works, Keighley, in the County of York, Engineers' Tool
Makers, 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
This invention relates to certain mechanism and the combination of same with a
dividing motion such as is used with machines for cutting teeth in wheels or racks,
and with other machines in which similar automatic dividing gear is used, and has
for its object, the prevention of the cutter, drill or the like being brought into
cutting operation before the spacing is completed, that is to say, before the requisite
change from one toothed space or hole to another is completed.
The improved mechanism is applicable to gear cutting and other machines in which
the change wheel shifting gear is operated by friction, or other drive not absolutely
positive, and in which the automatic feed of the slide or head stock carrying the
cutter, drill or the like may be put into operation by a sliding clutch.
In describing our invention in detail reference is made to the accompanying sheet
of drawings in which Fig. 1 represents a side elevation of certain and well known
portions of a dividing apparatus to which our improvement is added, as it may
be applied to a wheel cutting machine, and Fig. 2 is an elevation of the arrangement
at right angles to that shown by Fig. 1.
In carrying out our invention when applied to a wheel cutting machine, the revolving
cutter A is mounted on an ordinary feed slide-block B arranged to throw the sliding
portion C of the feed clutch, out of gear at the end of the downward stroke of said
feed slide-block, by the operation of the bell crank lever S in the usual manner; the
feed slide-block returning automatically to the starting point without re-engaging
with the sliding portion C of the feed clutch.
The clutch lever D is mounted on a suitable fulcrum, one end of the said lever
engaged with the sliding portion C of clutch, and at the other end is formed a side
projection E shown by dotted line which engages with a notch F, (shown by dotted
lines) of the weighted lever G when the sliding portion C of clutch is out of gear; the
said lever being disengaged, as shown, on restarting the feed, when the weighted
lever is raised automatically by our improved mechanism.
The dividing or spacing motion is driven by a pair of friction discs, or other
nonpositive drive, through a train of change gearing in the ordinary manner, one disc
rotating continuously, the other being attached to the first wheel of the before
mentioned train. One of the intermediate wheels W is secured on shaft H which
is arranged to make exactly one revolution for each spacing change, and on the said
wheel is a stop pin J which when automatically depressed clear of the stop K by
the action of the feed slide operating the rod J' permits the dividing gear to rotate,

page_text: and arrests the rotation as soon as a complete revolution has been made, a compressed
spiral spring forcing the stop pin J outward as soon as clear of the stop K in the
ordinary manner. So far the apparatus is old and forms no part of our invention.
Our invention utilizes the revolving shaft H to re-engage the feed just at the
completion of a revolution, which registers also the completion of the spacing change;
effected in the manner as hereinafter described.
Secured on the before mentioned shaft H is a disc L provided with an adjustable
tappet M, having a wedge shaped end, and during the terminal portion of the
revolution of the said shaft and disc, the tappet M on coming in contact with a wedge
ended pawl N connected to a rod 0, raises the rod, the upper end of which bears
against the weighted lever G, thus raising the lever until it is clear of the side
projection E on clutch lever D as shown, upon which the latter is free, thereby
allowing the clutch C to move into gear for restarting the feed under the action of a
spring, weight or other customary device.
Further, when the weighted lever G has been raised in the manner as hereinbefore
described, it is prevented from dropping again and relocking the clutch lever D in
case of the clutch teeth meeting point to point at the instant of release, thereby
blocking the movement of the sliding portion C of the clutch from properly gearing
with the other half of the clutch.
This is effected as follows. On the rod O which lifts the weighted lever G is a
projection P, which so long as it engages with one arm Q of bell crank lever cannot
drop, and therefore continues to hold the weighted lever G clear of the side
projection E until such time as the arm Q is drawn clear of the projection P. This is
effected by connecting the other arın Q¹ of bell crank lever with a rod R acted upon
by the feed slide-block B in its self acting downward movement when near the
completion of the said movement, by a portion of the said feed slide-block B coming
in contact with the adjustable nuts R¹ on rod R, thereby operating the said rod and
ensuring the re-engagement of the feed before the release of the rod O, which holds up
the weighted lever G.
On the withdrawal of the arm Q of bell crank lever clear of the projection P the
rod O and pawl N descend to the position to be acted upon by the revolving tappet M
at the next revolution of shaft H and disc L; the notch F of weighted lever G
engaging with the side projection E, thus retaining the sliding portion C of clutch
out of gear, until the weighted lever G is again raised by the tappet M to the position
shown, on the said tappet making a revolution; the rod R being moved back to its
original position in the ordinary manner on the return of the feed slide-block B to the
top of its stroke.
It will be obvious to persons having a knowledge of dividing motions applied to
gear cutting machines, and to drilling and like machines in which the dividing
mechanism is automatically operated at intervals by friction or other drive not
absolutely positive, that the herein before described apparatus for regulating the
completion of spacing is equally applicable to either, on securing one of the
intermediate wheels, such as wheel W, on a shaft arranged to make exactly one
revolution for each spacing change, and providing the said wheel with a sliding stop
pin similar to J, which when depressed in any convenient manner clear of a stop such
as K, the frictional device or other nonpositive drive, rotates the said shaft and
dividing gear, and operates a pawl similar to N to which suitable connections are
made for operating a weighted lever, which is combined with a lever and sliding
portion of a clutch, substantially in the manner as hereinbefore described.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. A friction or other not absolutely positive driven dividing apparatus in which
tappet M and pawl N are combined with a sliding clutch C by intermediary
connections and attachments, arranged substantially in the manner and for the
purpose as hereinbefore set forth.

page_text: 2. A dividing apparatus in which a rod
provided with a projection P is combined
with a bell crank lever connected to rod R. Arranged substantially in the manner
as herein before described and illustrated for the purpose of retaining the weighted
lever G clear of projection E on lever D until the clutch teeth are in position to
engage.