AUTOMATIC GEAR CUTTING MACHINES
Year: 1885

page_text: COMPLETE SPECIFICATION.
I, AMOS HALE BRAINARD of Hyde Park in the County of Norfolk and State
of Massachusetts, United States of America, Mechanical Engineer, do hereby
declare the nature of my invention for AUTOMATIC GEAR CUTTING MACHINES,
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 improvements in gear cutting machines, of that class
in which the functions are entirely automatic. The improvements consist essentially
of means for maintaining a self-acting feed, with a quick return motion and of
means for driving and operating the dividing mechanism.
On the drawings Fig 1 represents a general front view of the improved machine;
Fig 2 shows a detail plan view of the cutter slide, the feed and reversing motions,
and part of the means employed for operating the dividing mechanism; Fig 3
represents a rear side view of the machine; Fig 4 represents a detail rear view of
the worm dividing wheel, its worm shaft and adjustable bracket, with a sectional
view of the mechanism for operating the change gears, by which the movement of
the dividing wheel is controlled; Fig 5 represents an enlarged side view of the
latch mechanism shown in Fig 3; Fig 6 represents an enlarged view of the feed
shaft shown in Figs 1 and 2; Fig 7 represents an enlarged front view of the latch
mechanism shown in Fig 3; Fig 8 represents a sectional view of the mechanism
for controlling the belt, by which the dividing mechanism is operated, such view
being an enlarged section on the line Y-Z shown in Fig 3; Fig 9 represents an
enlarged section of the feed tripping latch on line W-X in Fig 2. Similar letters
refer to similar parts wherever they occur.
.
a (Figs 1, 2 and 3) is the standard or frame of the machine, having in its upper
end a bearing a³, for the spindle b, to the forward of which is secured the wheel b
to be cut. A cutter is secured on the cutter spindle c, which is mounted in a
slide c. On the outer end of the spindle c, is secured the driving pulley c", and
feed pulley Power is communicated from the feed pulley c, by means of a
swinging arm and intermediate pulley and cone, to the feed cone d, as shown in
Figs 2 and 3. The feed cone d, (Fig 2) is mounted loosely on the hollow feed
shaft d', and carries with it a pinion d", mounted loosely on a stud d. This
pinion engages with two gears d, d, of the same diameter, but dr, has one tooth

page_text: more than d. The gear d' is fastened securely to a bearing block f, screwed to
the cutter slide bed c, while the gear d, is mounted loosely on the feed shaft d
and has its hub extending through the gear d', and block f. This mechanism is
such, that, when the cone pulley d, moves in either direction, the gear div moves
in the opposite direction and at a much slower velocity, moving only one tooth
for each revolution of the cone pulley. To the hub of the gear d, is secured
a ratchet clutch f, while to the hub of the cone pulley d, is fastened a ratchet
clutch f f f are two clutches engaging alternately in f' and f" and connected
rigidly to a clutch rod g, (Figs 2 and 6) by the pins g. This clutch rod g, is free
to move in the feed shaft d', by means of the slots g
iii
To the end of the feed shaft di is secured a bevel pinion h, engaging with a bevel
wheel, mounted loosely upon the feed screw h", to which it communicates motion
by the clutch, and thus to the cutter slide c¹. On the clutch f, is placed a
ring, which is pivoted to a shipping lever k, and this in turn is pivoted to the
slide bed civ
This lever at its outer end is attached to the shipper rod ", by means of a
screw playing in a slot , formed in the shipper rod". The object of the
slot in the shipper rod will be hereinafter explained. The shipper rod k", carries
the dogs and , which are adjustable to the length of stroke required and are
operated by a stop 1, screwed to the cutter slide c. To the shipper rod k", is
fastened the wedge piece m, moving on the anti-friction roll m³, supported in the
block m, which is rigidly connected to the cutter slide bed c. The wedge m,
engages with the feed tripping latch n, (Figs 2 and 9) operated by the spring n'
The latch n, is held back by a set screw 22", whenever it is desired to prevent the
automatic shipping of the feed motion.
To the rear end of the spindle b, is fastened the worm wheel o, (Figs 3 and 4)
protected by the guard o¹. o" (Fig 4) is the worm and the worm shaft, by means
of which the worm wheel is operated. o is a shaft mounted in the same block or
bracket O as the shaft ot, and to one end of which is secured a graduated disc p,
while on the other end is placed one of the compound system of change gears pi
which communicates motion to the worm shaft o. This arrangement of gearing
requires but one revolution of the shaft ow, which is of especial advantage as will
be further explained. p is a gear disc mounted loosely on the shaft o, and secured
to the disc p, by bolts p, held in a circular T slot in the gear disc p". The gear
disc p, has a notch p (Fig 7) cut in one side to receive a latch q. This construction
of discs allows the shaft or to be moved while the latch q is seated in the notch p
by loosening the bolts p and is used for obtaining the "set over" required in bevel
gear cutting. The gear disc p is operated by a pinion v, cut on the hub of a
pulley, which with the pulley ", is mounted loosely on a stud, secured to the
bracket O. These pulleys are driven by a belt from the countershaft. The latch
is mounted in a block q', (Figa 5 and 7) which is secured to the standard a, of the
machine. q is a lever mounted loosely on a stud q, which is secured to the block q';
the lever q is pivoted to the latch q. The latch q is held in its seat by the
spring qq is a cam which is secured to the stud q. s is a disc mounted loosely
on the hub of the lever q. A pawl & is pivoted to the disc s near its rim,
by a studs, and is actuated by a spring 8. This pawl engages with the
lever q in such a way that when the disc s', is revolved the latch q is with-
drawn from its seat in the notch p. For the purpose of tripping the lever q, from
engagement with the disc 8, a roll 8, (Figs 5 and 7) is placed on the pawl s¹, in
such a way as to engage, at the proper time with the cam q', thus lifting the pawl
out of engagement with the lever q. A spring 8 is placed on the hub of the
cam g, which engages with a studs, projecting from the disc s, in such a way as
to return the disc with its pawl si to engagement with the lever q". Attached to
the standard a, is a stud t (Figs 3 and 8). Upon this stud is placed a sleeve t¹,
which is adjustable on the stud, by means of a screw t", tapped into it and operated
by a milled knob t. The sleeve t¹, carries two studs tv, and upon them are
'mounted two flanged guide rolls t", between which runs the belt t, which drives the

page_text: dividing mechanism. This construction is made to adjust the belt upon the
pulleys,, in such a way, that it shall have just tension enough, to drive the
dividing mechanism freely, when the latch q is withdrawn from the notch p.
Attached to the disc s (Figs 3 and 7) is a ribbon u This ribbon leads to one of a
pair of wrist plates u, u" (Figs 2 and 3) which are mounted loosely upon a shaft u¹",
extending from the cutter slide bed c. The plate u' is adjustable upon u, by means
of bolts u held in a circular T slot cut in the plate u", and is made thus adjustable
for the purpose of taking up the slack in the ribbon u, to suit any required position
of the cutter slide bed cv To the plate u, is pivoted a rod v, by means of a crank
pin v. This rod moves freely in a bearing on the under side of the cutter slide c¹,
and has upon it an adjustable dog v", which engages with the cutter slide cand
thus causes a movement of the plates u, u" and of the ribbon u.
The operation of the machine is as follows:
A gear blank is placed upon the dividing spindle b, and a cutter upon the cutter
spindle c, and the parts arranged for depth of cut and the dogs land (Fig 1
and 2) arranged for the length of stroke, when the machine can be started. The
feed is thrown in by the clutch h, on the feed screw h". When the cutter has
passed through the work, the stop 7", engages with the dog 1, thus moving the
shipper rod. This at first causes no motion in the shipping lever k, owing to the
slot in the shipper rod . This slot is made of such length that when the shipper
rod has been moved sufficiently to carry the wedge piece m, up to the apex point
of the tripping latch n (Figs 2 and 9) the shipping lever will have been moved
sufficiently to nearly disengage the ratchet clutches f, fi, and, the forward motion
still continuing, the spring n', will cause the wedge m and rod k to be quickly
moved still farther forward, thus disengaging the clutches f, fi and engaging f","
This causes the cutter slide to be returned at a rapid rate. Just before the stop li
reverses the action of the clutches, after the return motion, the cutter slide e¹ will
engage with the dog ", thus moving the rod v, and with it the plates u, u". This
action pulls the ribbon u, which moves the disc 8, and by reason of the pawl s¹, the
lever q is moved and with it the latch q. As soon as the latch q is withdrawn
from the notch p, the belt t rotates the dividing mechanism, and at the same
time the roll & engages with the cam q", lifting the pawl s from contact with the
lever and releasing the latch q, which seats itself in its notch p, on the
completion of a single revolution of the gear p". On the next forward motion of
the cutter slide, the spring 8' will act against the stud si to revolve the disc & in
the opposite direction, until the pawl & becomes again engaged with the lever q".
The arrangement of latch and compound gearing herein described is of especial
advantage because it insures the accuracy of division whenever the latch is seated
in its notch even though the gearing should make more than one complete turn,
and also allows the operator to withhold the latch and allow the gear blank to be
revolved for examination when the latch can be again seated, without the necessity
of finding the exact place for the cutter to start in.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The combination of the ratchet clutches f', f, ƒ ƒ", with the differential
gears d, d, pinion d and cone pulley d as shown.
2. The combination of the ratchet clutches fi, fƒ ƒ ƒ, with the hollow shaft ď³,
lever, clutch rod g, pins g' and the gears dv, d, pinion d" and cone pulley das
set forth.
3. The combination of the slotted shipper rod, wedge block m, latch n and
spring n' as shown.
4. The combination of the index shipper rod v, with the adjustable plates u', u".
5. The combination of the adjustable plates u, u", ribbon u and discs, with the
pawls, cam q, roll 8, lever q" and index latch q as shown.
6. The combination of the disc 8, pawl 8', cam q", roll 8, spring 8", lever q" and
latch
q, adapted to lock into a recess in the gear disc p", located on the shaft of and

page_text: connecting gears to worm shaft ou, for the purpose of obtaining any desired amount
of division on the wheel o by one complete revolution of the gear disc p" as set
forth.
7. A friction gearing for driving the dividing mechanism of a gear cutting
machine, composed of a tight and loose pulley and means substantially as described
for constantly retaining a portion of the driving belt on the loose pulley and
adjusting such portion only of the belt upon the tight pulley as may be required
for operating the dividing mechanism as herein set forth and described.
8. In a gear cutting machine, the adjustable sleeve t carrying the rolls tv, tv, for
regulating the width of belt necessary to drive the dividing mechanism substantially
as set forth.