Machines for Making Milling-cutters.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Machines for Making Milling-cutters.
I, CHARLES C. TYLER, of No. 15 Chestnut Avonue, in the City of Waterbury,
County of New Haven, State of Connecticut, one of the United States of America,
Watch-tool Maker, do hereby declare the nature of my invention for MACHINES FOR
MAKING MILLING-CUTTERS, 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 machines for making milling-cutters by means of a tooth-
forming compressor-tool, whereby the periphery of a cutter-blank is toothed by
successive compressions thereof, the surplus metal being displaced laterally without
romoval thereof.
In the drawings accompanying this Specification are shown machines embodying my
improvements.
Fig. 1 is a side olevation of a hand-power cutter-making machine embodying the
principal features of my invention.
Fig. 2 is a front elevation of the same, in which some minor details are shown in
section.
Fig. 3 is a plan view, partially in section, of an automatic machine for making the
cutiers.
Fig. 4 is an elevation of the front side of the machine shown in Fig. 3.
Fig. 5 is a rear elevation of the automatic machine.
Fig. 6 is a detail drawn on an enlarged scale, illustrative of the operation of the
machine.
The two machines shown in the drawings are the same in respect of the more
essential and leading features thereof, but differ in minor particulars; and the auto-
matic machine has feeling mechanism not shown in the drawings of the hand-power
machine, Figs. 1 and 2.
For the manufacture of milling-cutters by means of my improved machines, I form
the teeth by a compressor-tool, T, after the manner described in the Specification
accompanying my application for British Patent No. 13933, of even date herewith.
According to said method, I ordinarily use an over-size blank, B, only approximately
shaped, and reduce the same to the required size simultaneously with, and by, the
forming of the teeth on said blank. By this means, when making small cutters, (for
which my said improvement is more particularly adapted,) the blanks may be first cut
out by means of cutting-dies from sheet-metal of suitable quality, and afterward cut,
or "toothed," without any other intermediate preparation than forming therein the
usual central hole for the cutter-carrying arbor. Consequently, by the said method
and my improved machine, I am able to produce the milling-cutters of a high quality
and precision, at a very low cost, and of a very uniform size and shape.
The instrumentality by means of which I ordinarily practise my invention, consists
of a tooth-forming compressor-tool, T, having on its working face, 20, a conformation
coinciding with the form of tooth to be made. This tool, when making circular
cutters of a required size, is limited in its working stroke to stop at a certain precise
distance from the centre of the cutter, said cutter being, for this purpose, carried by
some suitable guide or carrier, as, for instance, the slide herein shown and described.
The tool T has its front face, 42, substantially in the plane of its working stroke;
while its lower or working face, 20, is cross-wise to said front face and has formed
therein the tooth-shaping groove 47; which groove has a cross-sectional shape
corresponding to that of the cutter-tooth which, in any particular instance, is to be
made by the said tool. The working face of the tool is also preferably made at an
angle of less than 90 degrees from the said front face, so that the tool acts as a wedge
to throw the metal under compression away from the cutting face of the tooth forming;
the junction of said working and front faces constituting a sharply defined metal-
Din S71

page_text: dividing edgo for dividing off that portion of the metal of the cutter-blank which is to
be compressed by the said grooved working face. This mode of operation may be
readily understood from this description and drawings taken in connection with my
aforesaid Letters Patent.
Having thus referred to the art in a general way, and to the principal instrumentality
employed, I will next describe in detail the hand-power machine shown in Figs. 1
and 2.
The blank B is carried on an arbor, D, which is curried in a closely fitted bearing
in the bed or frame A. Said blank is or may be allixed to its arbor by the tight and
loosa flanges 3, 4, respectively, and the nut 3. The arbur D) is held in plaes longi
tudinally of its bearings by collars or otherwise, and is or may be revolved intermittingly
by a suitable feed-mechanism substantially as follows: A worm-wheel, W, is fixed on
said arbor, by check-nut 7 or otherwise, and its teeth, 8, mesh with the corresponding
teeth on the worm 23, that is formed or fixed on the shaft R; which shaft is carried
in bearings 26 and 28 on said frame. An index disk or plate, 31, is carried by its
hub 33, in said hearing 26, being held in place by a set-screw, 34, or otherwise, and
forming the immediate fearing for the outer end, 36, of said shaft 1. This shaft is
turned by a crank-arm, 35, fixed thereon by the pin 46, and having the handle 27,
whose point, 88, forms a stop-pin fitting the index-holes 19 that are formed in said
disk 31. A spring, 37, contained within the hub, 61, of the arm 35, serves to hold
said index-pin in engagement with said index-holes. By making a suitable number
of said index-holes equally spaced, and by turning said handle 27 through the required
number of said spaces or divisions, any desired angular-advance may be given tō said
cutter-artor and the blank thereon.
The tooth-forming tool T is carried by a slide E, which moves in ways 17, on the
forward side of the frame A. The tool is conveniently supported on sail carrier by
placing the same in a slot or channel, 18, under the set-screws 19, and forward
of the adjusting-screw 29, whereby said tool may be forced out toward the bank B, to
obtain the required adjustment thereof for properly forming cutting-teeth on suid blank.
For netuating said carrier and tooth-forming tool. I employ any well-known mechanical
device adapted thereto. One of the most su’table said devices is, in my opinion, the
toggle-joint shown in the drawings. The shaft 50 carried in the bearing 54 on the
frame A, is readily turned by means of the handle 35 which is fixed to one end thereof hy
the pin 56. At the forward end thereol, said shaft carries thereon the arm or “link” 57,
whose lower end is connected by pin 58 to the upper end of the lower Enk 59, that is
connected by pin 60 to the said carrier-slide E. Stops 51 and 52 are provided to
properly limit the movement of said links. In Fig. 1, the slide or cartier E is shown
raised, but by raising the handle 55, the links 57 and 59 are brought into alignment,
and the tool T forced down to form the tooth-space 43, immediately underneath the said
tool, by a movement parallel to the free of the tooth forming. The tool being now
retracted by an opposite movement of the handle and links, to the position shown in
Fig. 1, the blank may be fed forward as before described, and the tooth-forming opern-
tion repeated.
In the automatic machine shown in Figs. 3, 4, 5 and 6, the blank B is carried on
an arbor, 1, which is supported in a closely fitted hearing in the bed or frame A, sub-
stantially the same as in the case of the machine above described; said blank being
fixed to its arbor by the tight and loose flanges 3 and 4, respectively, and the nut 5.
The arbor is held in place by collars, 6, or otherwise, and is revolved intermittingly
by a suitable feed-mechanism substantially as follows: A ratchet-wheel, W, is fixed
on said arbor, by a nut, 7, or otherwise, and has a series of teeth, 8, corresponding to
the teeth to be made on the cutter-blank B. A feed-slide, S, (carried in ways 9, on
one side of bed A,) carries a feed-pawl, 10, which is pivoted thereto at 11, and is hold
normally in contact with said teeth 8, by a spring, 13. Said slide S is usually
furnished with an ordinary anti-friction roller, 12, bearing against the feal-cam 16, on
the driving-sluft II. A spring, 15, (shown in dotted lines in Fig. 1) is laid in a
recess in the slide S, and reacts against the stop 14 to drive said slide toward shaft H
and keep the roller 12 in contact with cam 16.

page_text: The tooth-forming tool T is carried by a slide, E, which moves in ways, 17, on the
forward side of the bed-plate A. The tool is placed in a slot or channel, 18, under the
set-screws 19, and forward of the adjusting-screw 29, whereby said tool may be forced
out toward the blank B, (see Figs. 1 and 2,) to obtain the required adjustment for
properly forming cutting-teeth on said blank. A spring, 21, (similar to spring 15,)
reacts against the pin or stop 22, to retract the slide E and to hold the anti-friction
roller 24, with which said slide is or may be provided, against the compressing-cam 25,
that is fixed on slimft H. This cam 25 imparts a reciprocating, or advancing and
retracting, movement to the reciprocatable tooth-forming tool T, and while the slide E
is retracted the cam 16 feeds forward the arbor D and blank thereon, ready for the
next tooth-forming operation. It will be noticed that the bevel or inclination of the
face 20 is such that it tends, on entering the metal of blank B, to turn the arbor in
the direction of arrow 30. To overcome that tendency and insure accurate results,
one portion, 32, of the cam 16 is made circular, to serve as a stop to prevent any
retrograde movement of the pawl 10 or wheel W during the tooth-forming operation.
For this purpose said cam 16 is set in such relation (substantially as shown) to cam 25
that the wheel W is fully fed forward toward the point of the tool T, before said tool
comes against the blank, and so that said portion 32 stands against the roller 12
throughout the whole duration of the action of said tool on said blank.
The collars 3 and 4 form side-dies or gauges, limiting the displacement of the metal
radially to the axis of the cutter, and co-operate with the tool T to force the surplus
metal in a forward direction, and thus avoid any displacement of the preceding tooth.
To properly effect this important result, I find it advisable to construct the said
collars or dies of such diameter as to approach the line 39 of the bases of the teeth,
by a distance not greater than the thickness of said blank; but this feature is more
important when working some kinds of steel and with some sizes or shapes of cutters,
than with other kinds and sizes. In Fig. 6, the darkor shading at 48 illustrates the
condensation of the metal between the tool T and said flanges, and shows how the
main portion of the blank or plate B is protected by said flanges from distortion.
In each of the machines above described, the operation of forming a milling-cutter
tooth consists in the compression of the blank, (which may be unheated and in its
natural condition,) by a suitable instrumentality, as for instance, tool T, operating in a
direction cross-wise to the line of the points of the cutting teeth, and at such an angle
thereto as is proper to form the required relief or "backing-off" for the tooth by a
movement of the said tool in a direction parallel to the cutting-face of the tooth
formed by said movement. This having been done once, the blank is advanced
(relative to such instrumentality) and anothor compression similarly effected.
In Fig. 6 is illustrated on a small scale the manner of forming the teeth on the
blank B, and the effect of the tool T thereon; for a more particular description
of which reference is made to said British Patent Specification, No. 13933, of 1890.
The final compression extends on the lines 45 from the root, 39, of the tooth 40,
upward and forward to the intersection, 41, with the line, 43, of the points of the
cutting-teeth; and beyond point 41 to the periphery, 44, of the blank. The blank
now advanced through the arc (or space) from point 39 to point 44, Fig. 4, and
the operation repeated. It will thus be seen that the true size of the cutter is a line
extending through the points, 41, of the cutting-teeth; and that the position of
these points is determined by the angle of said line 45, and by the distance through
which the blank is advanced between the successive compressions.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In a machine for making milling-cutters, the combination with the blank-
carrying arbor, of the reciprocatable tooth-forming compressing-tool supported and
operating substantially as described to have a movement toward the blank parallel to
the cutting-face of the tooth forming, all substantially as described.
2. In a machine for making milling-cutters, the combination with the blank-

page_text: carrying arbor, of the reciprocatable tooth-forming compressing-tool T, having its
movement in directions toward and from the blank on said arbor, the slide carrying
said tool, and slide-actuating devices substantially as described advancing said slide
to a fixed point, and arbor-rotating devices substantially as described for advancing
the arbor while the tool is retracted, all substantially as described.
3. The improved tooth-forming compressor-tool herein described, it consisting in a
tool which lins a front face, together with a lower or working face crosswise to
said front face and having therein the tooth-shaping groove, and the junction of said
faces constituting a metal-dividing edge, all substantially as described.
4. The improved tooth-forming compressor-tool herein described, it consisting in
a tool which has a front face, together with a lower or working face crosswise to
said front face and having therein the tooth-forming groove, said lower or working
face being made at an angle of less than ninety degrees from said front face, and
the junction of said faces constituting a motal-dividing edge, all substantially as
described.
5. In a muchino for making milling-cutters, the combination with the blank-
carrying arbor, of the reciprocatable tooth-forming compressing-tool, having its
movement in directions toward and from the blank on said arbor, and parallel to
the cutting-face of the tooth forming, and means substantially as described
automatically advancing and retracting said tool, and intermittingly revolving said
arbor while the tool is retracted, all substantially as described.
6. In a machine for making milling-enters, the combination with the blank-
carrying arbor, of the reciprocatable tooth-forming compressing-tool, laving its
movement in directions toward and from the blank on said arbor and parallel to tho
cutting-face of the tooth-forming, the slide carrying said tool, the cam netuating said
slide, and means intermittingly revolving the arbor while the tool and slide are
retracted, substantially as described.
7. In a machine for making milling-cutters, the combination with the blank-
carrying arbor, of the reciprocatable tooth-forming compressing-tool, having its
movement in directions toward and from the blank on said arbor, and means
substantially as described intermittingly revolving the arbor while the tool is
retracted, the face of said tool being inclined to its line of movement, and the arbor
being revolved in the direction toward the cutting-point of said tool, all substantially
as described.
8. In a machine for making milling-cutters, the combination with the blank-
carrying arbor, of the reciprocatable tooth-forming compressing-tool, the slide
carrying said tool, means advancing and retracting said slide and fool, the ratchet-
wheel, the pawl, and the cam 16 having the circular part 32, the arbor being revolved
in a direction toward the point of the tool, and the circular part 32 serving as a stop
to provent retrograde movement of the arbor during the tooth-forming operation, all
substantially as described.
9. In a machine for making milling-cutters, the combination with the arbor, having
the gauge flanges, of the reciprocatable compressing-tool having the inclined tooth-
forming face, and means intermittingly revolving said arhor, substantially as
described.
10. In a machine for making milling-cutters, the combination with the boil-plato,
and the blank-carrying arbor, of the slide E, the compressing-tool T adjustably fixed
to said slide, the cam 25 advancing, and a spring retracting said slide, substantially
as described.
11. In a machine for making milling-cutters, the combination with the bad-plate,
of the arbor D, having ratchet-wheel W, the slide E carrying tool T, slido S carrying
a pawl actuating said wheel, the driving shaft, a cam-netuating slide B, and a cam-
actuating slide to feed the wheel while the slide E is retracted, all substantially as
described.