Improvements in Machines for Cutting the Teeth of Gear Wheels and for similar purposes.
Year: 1898

page_text: Date of Application, 20th Apr., 1898-Accepted, 16th July, 1898
COMPLETE SPECIFICATION.
Improvements in Machines for Cutting the Teeth of Gear Wheels
and for similar purposes.
I, EDWARD HARVEY PARKS, of the City and County of Providence. and State
of Rhode island, United States of America, Mechanical Engineer, 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 invention relates more especially to that class of machines for cutting
bevel-gears in which the gear blank is carried by a revoluble support which is
intermittently revolved at the proper time, and in which the blank is acted upon
by a revolving cutter carried in a reciprocating carriage, although it will be
understood that the invention may be embodied in other machines where it is
desirable to change the angular relation between the work and cutter between
successive cuts.
In bevel-gears the sides of the teeth converge and the angular relation between
the cutter and work must therefore be changed in forming the opposite sides of
the teeth. It has been customary heretofore to adjust the work and cutter in
proper relation to form one side of the teeth, and to maintain this adjustment
until one side of all the teeth has been cut, the work being indexed after each cut,
and the cutter acting upon the stock as the carriage moves forward and running
idly on the return movement of the carriage. The adjustment is then changed
to bring the cutter and work into proper relation to form the other side of the
tooth and the teeth finished in a similar manner. With this manner of cutting
the gears, the blank must be indexed through two revolutions, and the time
required for returning the cutter carriage after each cut is lost time.
With the present invention the gear is completed when the blank has been
indexed through a single revolution, and the cutter acts upon the stock during
both its forward and return movement thus increasing the rapidity with which
the gear is cut and correspondingly increasing the efficiency of the machine.
This is accomplished by changing the angular relation between the cutter and
work after the forward movement of the cutter so that the cutter will act upon
the stock during the return movement as well as during the forward movement.
In order that the same side of each tooth may be cut during the forward move-
ment of the cutter, it is preferred to change the angular relation of the cutter
after each return movement also, although this is not essential.
-
In embodying the invention in a bevel-gear cutting machine, it is preferred
to change the angle between the cutter and work by swinging the cutter carriage
about an axis after each forward movement and to swing the carriage back to its
former angular position after the return movement, the indexing of the gear
blank taking place after the return movement of the carriage. In embodying
the invention in some forms of machines, it may be found desirable to reciprocate
the work instead of the cutter or to change the angular relation of the cutter
and work by movement of the work support rather than the cutter support, and
it will be understood that such variations or other variations in the construction

page_text: could be made without departing from the invention which consists in a work
support and cutter support, either of which reciprocates, and mechanism for
changing the angle between the cutter and work between the forward movement
and the return movement of the reciprocating part.
The invention also consists in the further features and combinations herein-
after described and set forth in the claims.
Referring to the drawings:
Fig. 1 is a side elevation of a bevel-gear cutter embodying the present inven-
tion.
Fig. 2 is a detail elevation of the indexing mechanism.
Fig. 3 is a plan view of the machine.
Fig. 4 is a section on line 44, Fig. 5.
Fig. 5 is a longitudinal sectional view.
Fig. 6 is a section on line 6-6, Fig. 5, and
Fig. 7 is an end elevation.
Referring to Figs. 1 and 2, the work support consists of a spindle 1 mounted
in bearings secured to a standard 2 which is in turn mounted on the frame 3.
The gear blank 4 may be secured to the spindle by any suitable means, as by
an arbor 5, which passes through the spindle, and has mounted on its rear end
an internally threaded hand wheel 6 for drawing the gear blank against the
end of the spindle. The spindle is indexed by means of a ratchet wheel 7 secured
thereto which is engaged by a pawl 8 pivoted on an arm 9 loosely mounted on
the spindle. The pawl carrying arm 9 is provided with gear teeth 10 which
are engaged by a gear segment 11 formed on the end of a lever 12 pivoted at 13
and engaged by a cam 14 secured to a shaft 15. The lever is held in engagement
with the cam by means of a spring 16, and as the shaft 15 revolves the cam rocks
the lever, thus oscillating the pawl carrying arm and causing the pawl to inter-
mittently rotate the work carrying spindle. The pawl is held in engagement
with the ratchet wheel by a spring 17. The spindle is held in position by a
locking bolt 18, the upper end of which is forced into engagement with one of
the notches in the ratchet wheel by a spring 19. The bolt is withdrawn at the
proper time to allow the forward movement of the spindle by a cam 20 secured
to the shaft 15, which cam engages a shoulder 21 on the end of the bolt. The
shaft 15 is driven from a continuously revolving shaft 22 by means of bevel-
gears 23 and 24 mounted upon shafts 22 and 15 respectively.
The cutter 25 is secured to a shaft 26 mounted in a cutter carriage 27 guided
on ways 28 (Fig. 6). A spiral gear 29 is secured to the end of the cutter shaft 26
and is engaged by a spiral gear 30 secured to a short shaft 31 mounted in bear-
ings 32 on the side of the carriage. The shaft 31 is connected by means of a
universal joint 33 to a link 34, the other end of which is connected by a similar
joint 35 to the end of a shaft 36 mounted to slide in a bearing 37 on the frame 3.
The shaft 36 has a sliding connection with a spiral gear 38 which is engaged and
driven by a spiral gear 39 secured to the transverse driving shaft 40 (Fig. 7).
By these connections the cutter shaft is continuously driven without interfering
with the movements of the cutter carriage.
The ways 28 on which the cutter carriage is mounted are formed on a swivel-
bed 41 mounted upon the frame 3 and provided with a depending pivot post or
stud 42 which fits within a circular recess 43 in the frame, and is cut away to
allow the passage of shaft 22. The bed 41 is oscillated about its pivot as the
carriage reaches the limit of its movement in each direction by a reciprocating
slide 44 (Fig. 6) provided with a lug or projection 45 which lies between two
lugs 46 and 47 on the end of the bed 41. Screws 48 and 49 extend through the
lugs 46 and 47 respectively and form shoulders for engaging the lug 45, and by
adjusting these screws the amount of lost motion between the slide and bed may
be adjusted and the movement of the bed thus varied as desired. The slide 44
is guided upon two bars 50 projecting from the frame 3 and extending through
slots 51 formed in said slide. The slide is moved at the proper times first in

page_text: one direction and then in the other by two cams 52 and 53 secured to the shaft
and arranged to engage rolls 54 and 55 respectively, mounted on the slide.
During the forward movement of the cutter carriage the roll 54 rides on the
circular part of the cam 52 and the bed is rigidly clamped between the lug 45
and an adjustable screw 56 which is mounted in a lug 57, Fig. 6, on the frame
and engages the side of the bed. After the cutter has passed beyond the gear
blank, the cam 52 passes roll 54 and eam 53 engages roll 55 moving the slide 44
to the right in Fig. 6. This movement of the slide swings the bed on its pivot,
and as the roll 55 reaches the swell of the cam 53 the bed is clamped between
the lug 45 and an adjustable screw 58. During the return movement of the
carriage, the roll 55 rides on the circular part of cam 53 and holds the bed firmly
against the screw 58. After the cutter has passed the gear blank on the return
movement, the cam 52 engages the roll 54 and moves the bed back against the
screw 56.
Since the greater part of the stock is removed by the cutter during the forward
movement of the carriage, the return movement may be made at a more rapid
rate and therefore the cam 53 has a shorter circular part than cam 52.
The carriage is reciprocated by means of a cam 59 (Fig. 5) secured to shaft 22,
and provided with a cam groove 60 engaged by a roll 61 which is carried by a
stud 62 secured in a sliding bar 63. The bar 63 is guided in a groove 64 formed
in the frame 3 which projects up at both ends of the cam 59 through an open-
ing 65 formed in the bed 41 (Figs. 4 and 5).
A roll 66 is mounted on a stud 67 projecting from the upper face of the bar 63
and engaging a curved slot 68 in the cutter carriage. As the shaft revolves the
bar 63 is reciprocated and by reason of its connection with the carriage recipro-
cates said carriage without interfering with the swinging movement thereof.
The cam groove 60 is so shaped that the return movement of the carriage
rapid then the forward movement, since the cut is not so heavy on the return
movement.
more
The shaft 22 is continuously driven by means of a worm wheel 69 secured
thereto, which is engaged and driven by a worm 70 secured to the transverse
driving shaft 40. Power is applied to the driving shaft through a pulley 71
secured thereto.
During each revolution of the shaft 22 the cutter is advanced through the
blank to form one side of a tooth, the angular relation between the cutter and
blank is changed by swinging the swivel-bed about its pivot, the cutter is returned
and cuts the opposite side of a tooth, the swivel-bed is swung back and the blank
is indexed preparatory to cutting another space between the teeth. When the
blank has been indexed through a single revolution, the gear teeth have been
cut upon both sides and the machine is stopped and a fresh blank inserted.
Should the width of the cutter be the same as the width of the space between
the teeth at their inner ends, then the axis about which the cutter carriage
swings should be in line with the inner ends of the teeth, but should the cutter
be thinner than the space between the teeth however, then the line of the axis
should lie beyond the inner ends of the teeth. Means are therefore provided for
varying the relative position of the axis, and the work and this is preferably
done by adjusting the work support, although it will be understood that the same
result could be effected by adjusting the axis. In the drawings, the standard 2,
which carries the work supporting spindle 1, is mounted on ways on the frame 3,
and may be adjusted to vary the relative position of the pivot 42 and the work
by means of a screw 72 which is journalled in a bracket 73 secured to the stan-
dard 2 and engages a nut 74 on the frame 3.
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 ciaim is:
1The combination of a work sunport a cutter support
mechanism for re-

page_text: ciprocating one of said elements, and mechanism for changing the angular
relation between the work and cutter between the forward movement and the
eturn movement of the reciprocating element, substantially as described.
2. The combination of a work support, a cutter support, mechanism for re-
ciprocating one of said elements, and mechanism for changing the angular
relation between the cutter and work after the forward movement and also after
the return movement of the reciprocating element, substantially as described.
3—The combination of a work support, a cutter support, mechanism for re-
ciprocating one of said elements, mechanism for changing the angular relation
between the cutter and work after the forward movement of the reciprocating
element, and mechanism for indexing the work after the return movement of
the reciprocating element, substantially as described.
4 The combination of a revoluble work support, a rotary cutter shaft, mechan-
ism for reciprocating one of said elements, mechanism for indexing the work
support, and mechanism for changing the angular relation between the cutter
and work between the forward movement and the return movement of the recipro-
cating element, substantially as described.
5 The combination of a revoluble work support, a rotary cutter shaft, mechan-
ism for reciprocating one of said elements, mechanism for indexing the work
support after each return movement, and means for changing the angular rela-
tion between the cutter and work after each forward movement of the recipro-
cating element, substantially as described.
6 The combination of a work support, a cutter carriage, mechanism for re-
ciprocating said carriage, and mechanism for changing the angular relation
between the carriage and work between the forward movement of the carriage
and the return movement thereof, substantially as described.
7 The combination of a work support, a cutter carriage, mechanism for re-
ciprocating said carriage, mechanism for indexing the work support after each
return movement of the carriage, and means for changing the angular relation
between the carriage and work after each forward movement of the carriage,
substantially as described.
8 The combination of a work support, a cutter carriage, mechanism for re-
ciprocating said carriage, mechanism for indexing the work, and mechanism for
changing the angular relation between the carriage and work after each forward
movement and also after each return movement of the carriage, substantially as
described.
9 The combination of a work support, a cutter carriage, mechanism for
reciprocating said carriage and mechanism for swinging the carriage about an
axis after each forward movement of said carriage, substantially as described.
10 The combination of a work support, a cutter carriage mechanism for
reciprocating said carriage, and mechanism for swinging said carriage about an
axis in one direction after each forward movement and for swinging said carriage
in the opposite direction after each return movement, substantially as described.
11-The combination of a work support, a swivel-bed, a cutter carriage
mounted to reciprocate on said bed, and mechanism for moving said bed about
its axis after each forward movement of the cutter carriage, substantially as
described.
12 The combination of a work support, a swivel-bed, a cutter carriage
mounted to reciprocate thereon, mechanism for moving said bed about its axis
after each forward movement and in the opposite direction after each return
movement of the carriage, substantially as described.
°
13 The combination of a swivel-bed, a cutter carriage mounted to reciprocate
thereon, and mechanism for moving said bed about its axis between the forward
and return movements of the carriage, substantially as described.
14 The combination of a swivel-bed, a cutter carriage mounted to reciprocate
thereon, and mechanism for moving said bed about its axis between the forward

page_text: and return movements of the carriage and clamping said bed in position, sub-
stantially as described.
15 The combination of a swivel-bed, a carriage mounted to reciprocate there-
on, a transverse slide for swinging said bed about its axis, and cams for recipro-
cating said slide, substantially as described.
16 The combination of a swivel-bed, a carriage mounted to reciprocate there-
on, stops at the sides of said bed, and means for moving and holding said bed
against said stops alternately, substantially as described.
17 The combination of a swivel-bed, a carriage mounted to reciprocate there-
on, a transverse slide provided with a lug or projection, adjustable shoulders on
said bed for engaging said lug, and means for reciprocating said slide, substan-
tially as described.
18 The combination of a swivel-bed, a carriage mounted to reciprocate there-
on, a transverse slide provided with a lug or projection, shoulders on said bed
for engaging said lug, means for adjusting the lost motion between said lug and
shoulders, stops for engaging the bed, and means for operating said slide, sub-
stantially as described.
19 The combination of a swivel-bed, a carriage reciprocated thereon, mechan-
ism for oscillating said bed, a slide mounted in stationary guides, and connected
with said carriage, and means for reciprocating said slide, substantially as
described.
20 The combination of a swivel-bed, a carriage reciprocating thereon, mechan-
ism for reciprocating said bed, a slide mounted in stationary guides, a projection
on said slide engaging a slot in said carriage, and means for reciprocating said
slide, substantially as described.
21 The combination of a swivel-bed, of a carriage reciprocating thereon, a
rotary shaft, a cam secured thereto for reciprocating said carriage, connection
between said cam and carriage, cams on said shaft for oscillating said bed, and
connections between said cams and bed substantially as described.
22-The combination of a work support, a cutter support mechanism for recipro-
cating one of said elements, mechanism for swinging one of said elements about
an axis between the forward movement and the return movement of the recipro-
cating element, and means for varying the relative position of the axis and work,
substantially as described.
23-The combination of a work support, a cutter carriage mechanism for
reciprocating the cutter carriage, mechanism for swinging said carriage about
an axis after each forward movement of the carriage, and means for varying the
relative position of the axis and work, substantially as described.
24 The combination of a work support, a cutter carriage mechanism for
reciprocating the cutter carriage, mechanism for swinging the cutter carriage
about an axis after each forward movement, and means for adjusting the work
support relative to said axis, substantially as described.
יד
I
A 1808
EDWARD HARVEY PARKS.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.