Improvements in Devices for Making Milling and similar Cutters.
Year: 1895

page_text: Date of Application, 5th Mar., 1895-Accepted, 20th Apr., 1895
COMPLETE SPECIFICATION.
Improvements in Devices for Making Milling and similar Cutters.
I, STEPHEN MARION BALZER, Mechanical Expert, of 386 Pleasant Avenue,
New York City, County and State of New York, United States of America, do
hereby declare the nature of this invention, and in what manner the same is to
be performed, to be particularly described aud ascertained in and by the following
statement:--
The object of my invention is to provide a simple, cheap and effective device
capable of use in an ordinary lathe by means of which milling-cutters or similar
tools may be readily made.
The invention consists in a device having an intermittently rotative spindle or
sleeve adapted to carry a cutter-blauk in such position that it can be operated upon
by a suitable tool carried by the tool rest of the lathe, whereby the teeth of the
cutter can be formed and "backed-off," through the medium of the intermittent
motion given to said spindlo. The "backing-off" of the teeth of the cutter is
accomplished through the medium of an eccentric motion given to said spindle
during its rotation, so that the back of the teeth of the cutter will be operated ou
more fully than the forward cutting edge of said teeth.
The invention further consists in the combination with said intermittently
rotative spindle or sleeve, of suitable gear wheels provided with differential gears
and a pinion that meshes with said gears and is carried around by the face plate or
equivalent part of the lathe, so that at certain times during the revolution of said
pinion the gear wheel connected with said spindle or sleeve will be turned a distance
equal to a few of its teeth, whereby the cutter-blank will be presented at different
points to the cutting tool.
The invention also consists in the novel details of improvement and the
combinations of parts that will be more fully hereinafter described and then pointed
out in the claims.
Reference is to be had to the accompanying drawings forming part hereof,
wherein,
Figure 1 is a detail side elevation of my improved cutter-making device; Figure 2
is a central longitudinal section thereof, showing it supported in position between
the face plate and the tail stock of a lathe;
Figure 3 is a face view of the differential gear wheel; Figure 4 is a similar
view of the accompanying gear, having all its teeth corresponding, and
Figuro 5 is a detail view of a cutter that may be produced by my improved
device.
In the accompanying drawings, in which similar numerals of reference indicate
corresponding parts in the several views, the numeral 1 indicates a hollow spindle
or sleeve adapted to carry a cutter-blank 2. The spindle or sleeve 1 is shown
reduced at one end to receive said cuttor-blank and provided with clamping
rings 3, 4, and a clamping nut 5, threaded on the spindle 1, so as to securely lock
the cutter-blank upoù said spindle. Before said cutter-blank is placed on the
spindle 1, it will be suitably shaped aud provided with the desired number of
teeth 2. The spindle 1 is mounted to turn on a spindle 6, which is shown in
Figure 2 as passing through a bore 7 in the spindle or sleeve 1. The spindle 6 is
shown at one part as having a straight surface 6, and a tapered surface 6º, the
bore 7 being correspondingly shaped to receive said spindle. By this means the

page_text: spindle I is conveniently centered on the spindle 6 and held from end wise movement
thereon. The outer end of the spindle 6 may be threaded at 8 to receive a nut 9,
against which the outer end of the spindle or sleeve 1 may bear whereby said
spindle may be held in proper relative position to cause the cutter-blank 2 to
properly turn on the spindle 6. The ends of the spindle 6 are provided with
recesses or sockets 10, to receive the centering spindles 11, 12, of the face-plate 13,
and tail stock (not shown) respectively of a lathe. The recesses or sockets 10 in
the ends of the spinille 6 are placed eccentric to the longitudinal axis of said
spindle, as seen by following the dotted line 14 in Figure 2, the dotted line 15
indicating the true longitudinal axis of the spindle 0. By this means as the spindle 6
is turned it will move in an eccentric path described around the centering
spindles 11, 12, by which means the cutter-blauk 2 will be given a lateral motion,
to be presented to the cutting tool 16. Or in other words the cutter-blank is
moved toward and from the tool 16 in order that said tool may operate on said
cutter-blank, in contradistinction to having the tool moved against the cutter-blank.
The tool 16 may be carried by a tool rest of the lathe (not shown).
The spindle or sleeve 1 and thereby the cutter-blank are given an intermittent
rotary motion as follows:-17 is a spur wheel secured to the spindlo or sleeve 1, as
by locking pins 18, or otherwise, and 19 is another spar wheel, of the same diameter
as the wheel 17, but mounted on the spindle 1 so that the latter can turn therein.
The wheel 19 may be kept from turning by suitable means, an arm 20 being shown
secured to said wheel and having an extension or pin 21, that may bear on the
tool 16, or on any other part of the lathe or machine. The extension 21 is shown
provided with a roller or sleeve 22 that may bear on the tool 16 to reduce friction
as the arm 20 moves back and forth under the eccentric rotary motion of the
spindle 6. The spur wheel 17 is shown provided with a series of teeth 17" all
corresponding in pitch and size, sixty of said teeth being shown on said wheel. The
wheel 19 has differential teeth, that is to say, for a part of the circumference of
said wheel there are thirty teeth 23 corresponding to the teeth on the wheel 17, and
for the rest of the circumference of said wheel 19, there are twenty-six teeth 24,
of a larger size or at a greater distance apart than the teeth 23. The wheels 17
and 19 are placed side by side so that their teeth can align as in Figure 1. 25 is a
pinion meshing with the teeth on wheels 17 and 19, and said pinion is shown
journaled on a pivot pin 26, secured to au arm 27, that is rigidly carried by the
spindle 6, being shown secured thereto by a pin 28. The pin 20 is adapted to
engage the face plate 13 of the lathe, so that as said plate rotates the arm 27, and
consequently the pinion 25, will be carried around. As the arm 27 is thus carried
around the spindle 6 will be turned and in consequence of its eccentric bearing
at 10, 11, 12, it will move in an eccentric path as before stated. As the pinion 25
is carried around by the arm 27, it will rotate on its pin 26, while it is in engage-
ment with the teeth 17, on wheel 17 aud the teeth 23 on wheel 19, without causing
said wheels to turn, but as soon as said pinion engages the teeth 24 on wheel 19
(being also in engagement with the teeth 17*) it will cause the wheel 17 to turn
a short distance consequent upon the difference between the quantity of the teeth 24
and 17, that are side by side, and the different spacing between the teeth 24 and 17*.
The intermittent motion given the wheel 17 is caused by the teeth of the pinion 25,
as the fatter is carried around by the arm 27, endeavouring to pass between the
teeth 24 and 17, and as all of said teeth cannot be aligned simultaneously the
teeth of the pinion 25 will press upon certain of the teeth of wheel 17, and thus
cause said wheel to turn slightly. In the example shown, the wheel 17 will be
turned a distance equal to four teeth 24, which will correspond to the size of a
tooth 2, of cutter-blank 2, and when the pinion 25 has passed from the teeth 24,
the wheel 17 and consequently the spindle 1 will come to rest until said pinion
again encounters the teeth 24. Thus, for each revolution of the arın 27, the
spindle 1 will be given a rotary movement equal to the size of a tooth 2 of cutter-
blank 2, and during said turning of said spindle 1, the tool 16 will operate on a
tooth 2, of the cutter-blank to cut it to the desired shape. In consequence of the

page_text: eccentric motion of the spindle 1, (the lateral motion thus given said spindle) the
cutter will be brought to bear against the tool 16, and the tool will thus act to cut
the tooth 2*, from the point 2 back toward the point 2, whereby the "backing-
off" of the tooth 2 is accomplished. The eccentric or lateral movement of the
cutter-blank 2 and the intermittent rotary motion thereof are so timed and
proportioned, with relation to the position of the tool 16, that at about the moment
the cutter-blank is to be turned it will also be moved toward and in contact withi
the tool 16, the movement of said blank gradually increasing under the eccentric
action, to back of the teeth 2 of the cutter-blank. When the tooth 2 has passed
from the tool 16 it will come to rest to enable it to recede from the tool so that the
front edge 2, of the tooth 2 of the cutter will 'clear the tool 16 when the cutter-
blank next turns, yet will engage the tool at the desired point to cut or back off
the teeth 2ª
The amount of movement given the cutter-blank 2 for each intermittent rotary
action will be governed by the difference in ratio between teeth 23 and 24 on
wheel 19.
The cutter-blauk 2 will be given more or less movement for each intermittent
movement according to the number of its teeth. Thus, by dividing the number of
teeth on wheel 17, by the number of teeth on the cutter-blank, the quotient will
show the number of teeth to deduct from the part of wheel 19 having teeth 24.
Thus, in the example shown the whoel 17 has sixty teeth and the cutter-blank 2
has fifteen teeth, the quotient, therefore, being 4, shows how many teeth to
eliminate from the part of wheel 19 having the teeth 24. Thus, there aro usod
twenty-six teeth 24, the number of teeth 23 corresponding to the teeth 17 where
they align.
The device will be found simple in construction, rapid in operation and effective
The cutter-blank 2 can be cut to shape and "backed-off" by my device in
a very short time, as the action is continuous and automatic.
in use.
I do not limit my invention to the precise details of improvement shown and
described as they may be varied without departing from the spirit of my invention.
The tool 16 will of course be given the desired shape to produce the desired shape
of tooth 2".
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what 1
claim is :-
1. In a cutter-making device, a rotative spindle or sleeve having eccentric
motion, and means for imparting to said spindle or sleeve an intermittent rotary
motion, substantially as described.
2. In a cutter-making device, a rotative spindle or sleeve having incans to carry
a cutter-blauk, incans for giving said spindle or sleeve an eccentric motion,
and means for intermittently rotating said spindle or sleeve, substantially as
described.
3. In a outter-making device, an eccentrically supported rotative spindle, a
hollow spindle or sleeve mounted thereou, and means for giving said hollow spindle
or sleeve an intermittent rotary motion, substantially as described.
4. In a cutter-making device, an eccentrically rotative spindle, a bollow spindle
or sleeve mounted thereon, and differential gears for giving said hollow spindle or
sleeve an intermittent rotary motion, substantially as described.
5. In a cuttor-making device, the combination of a spindle adapted to carry a
cutter-blank, a stationary differential gear wheel, another gear wheel connected
with said spindle and having an even series of teeth, and a pinion mesling with
both of said gear wheels and adapted to be carried around said wheels to give an
intermittent rotary motion to said spindle, substantially as described.
6. In a cutter-making device, the combination of a spindle adapted to be turned
eccentrically, a hollow spindle or sleeve mounted thereon, a gear wheel connected
with said hollow spindle or sleeve, another gear wheel loosely mounted on said
-

page_text: hollow spindle or elecve, said gear wheels having differential teeth, an arm carried
by said eccentric spindle, and a pinion carried by said arm and meshing with said
gear wheels, and adapted to move said hollow spindle or sleeve intermittently as it
is carried around said wheels, substantially as described.
7. In a cutter making device, the combination of a spindle having eccentric
hearings, an arm connected therewith, and a pinion carried by said arm, said arm
being adapted to be turned by the face-plate of a lathe, with a hollow spindle or
sleeve mounted on said eccentric spindle, a gear wheel carried by Baid hollow
spindle or sleeve, a differential gear wheel loosely mounted on said hollow spindle
or sleeve and means for holding Enid differential gear wheel from turning, said
pinion meshing with said gear wheels, substantially as described.
8. In a cutter-making device, an eccentrically rotative spindle having a straight
portion and a tapered portion, combined with a hollow spindle or sleeve having a
bore corresponding to the circumference of said eccentric spindle, and differential
gearing for rotating said hollow spindle or sleeve intermittently, substantially as
described.
9. In a cutter-making device, au eccentrically rotative spindle having a tapered
portion, combined with a hollow spindle or sleeve having a corresponding taper in
its bore, an adjusting nut on said eccentric spindle for holding the hollow spindle
or sleeve in position, and differential gearing for giving said hollow spindle or sleeve
an intermittent rotary motion, substantially as described.
10. In a cutter-making device, the combination of an eccentrically rotative
spindle carrying an arm, with a hollow spindle or sleeve mounted to turn on said
eccentric spindle, a gear wheel connected with said hollow spindle or sleeve, a
differential gear wheel loosely mounted on said hollow spindle or sleeve, an arm
projecting from said differential gear wheel, a roller .22 carried by said arm to
engage a tool, a pivot pin carried by the first mentioned arm and adapted to engage
the face-plate of a lathe, and a pinion carried by said pivot and meshing with the
said gear-wheel, all arranged for operation substantially as set forth.
Dated this 5th day of March 1895.
ALLISON BROS.,
Agents for the Applicant.