Note: Descriptions are shown in the official language in which they were submitted.
~06426~
SPECIFICATION
The present invention relate~ to certain aspects
of our earlier co-pending application Serial No. 257,077
which are not broadly claimed therein.
The present invention relates to a machine for
shaving or honing work gears by rotating them in tight mesh
with either a gear shaving tool or a gear honing tool.
A gear shaving tool is in the form of a gear con-
jugate to the required form of a work gear, but with its teeth
at a helix angle such that the work gear and tool mesh with
their axes crossed in space, as for example at an angle of
3-30. It is made of tool steel, having serrations or grooves ~ ;
in its teeth, the corners of which constitute cutting or shav- -
ing edges capable of removing chips or shavings from the gear
teeth. In operation, the gear and shaving cutter are placed
in tight mesh, and either the gear or tool is rotated, thereby
driving the meshing member. In order to distribute the shaving
action from end to end of the gear teeth, a relative traverse
is provided between the gear and tool. This may be parallel
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to the axis of the gear or oblique or diagonal with respect
thereto. The traverse strokes are back and forth, and between
traverse strokes, an incremental feeding motion is made, in a
direction parallel to a line perpendicular to and intersecting ~
the axes of both gear and tool. - '! ' '
A gear honing tool is also in the form of a gear
conjugate to the required form of the work gear, but its teeth
are formed of slightly resilient abrasive material. The gear
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and honing tool are meshed in tight mesh at cros~ed axes,
as in shaving, and either the gear or honing tool is driven
in rotation. The gear and tool are relatively traversed as
in shaving, but in this case the direction of relative traverse
is parallel to the axis of the gear. Instead of providing
- incremental feed, a relatively small yieldable pressure is
applied in a direction having at least a substantial component
radial of the gear so that as material is removed from the
gear teeth, pressure is maintained.
In accordance with the present inventian, the machine
comprises a frame, a tool head on the frame, a work slide
movable on the frame toward and away from the tool head,
a rotary work gear support on the slide with its axis per-
pendicular to the direction of slide movement, and means
for moving the rotary work gear support in back and forth
traverse strokes on the slide in a plane perpendicular to
the direction of slide movement. The tool head comprises
a fixed mounting member, a pivot support angularly adjustable
on the mounting member about an axis parallel to the direction
of slide movement. A tool carrier is pivoted to said pivot
support for pivotal movement about an axis perpendicular to
the direction of slide movement, and has a rotary tool support
thereon having an axis of rotation parallel to the pivot axis
of said carrier. The pivot axis of the carrier is located
laterally from the axis of the rotary tool support. Means
are provided for driving one of the rotary supports in rotation.
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For a better understanding of the invention, one
example of a combined gear shaving and honing machine embody-
ing the invention will now be described with reference to the
accompanying drawingQ in which:
Figure 1 is a side elevation of the tool head with
parts broken away;
Figure 2 is a sectional view on the line 2-2, figure
,
Figure 3 is a fragmentary elevational view in the
dire~tion of the arrows 3-3, figure 1;
Figure 4 is a sectional view on the line 4-4,
figure 3;
Figure 5 is a fragmentary sectional view on the
line 5-5, figure 1;
Figure 6 is a diagrammatic view illustrating the
relationship of the tool head shown in the previous figures,
with the remainder of a gear finishing machine.
Referring first to figure 6, the tool head in its
entirety is illustrated at 10 and includes a tool carrier
12 pivotally mounted at 16 on an angularly adjustable pivot ~`
support 14. The support 14 is mounted for angular adjustment
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on a fixed base 18 which carries a slide 20 mounted for hori-
zontal movement. The slide 20 carries a support 22 including
, a rotary support or arbor for mounting a work gear W in mesh
-1 with a gear-like tool T carried by the tool carrier 12. Means
are provided for moving the slide 20 horizontally to the right
, and left as seen in figure 6 to bring the work gear into and
out of tight mesh with the tool.
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In addition, support 22 is mounted on ~lide 20 for
slow back and forth traverse movement in a direction parallel
to the axis of the gear W, by suitable mechani~m, which as
usual in this art i9 screw mechanism, not illustrated.
The pivot support 14 is angularly adjustable on a
fixed mounting member about a horizontal axis as will sub-
sequently appear, so that the work gear W and tool T may be
br~ught into mesh at crossed axes. One of the rotary supports
is provided with means (not shown) for driving one of the
meshed members in rotation. In addition, means are provided
for effecting a relative traverse movement between the gear
W and the tool T in a direction parallel to the rotation axis
of the work gear W as well as for effecting meshing relation-
ship and depth feed where required by movement of the slide
20 horizontally toward and away from the tool head 10.
This may comprise a traverse mechanism for traversing
support 22 on slide 20 in a direction paralle' to the axis of
gear W.
Referring now to Figures 1-5 the tool support structure
comprises stationary mounting member in the form of a column 26
to which the pivot support 14 is mounted for angular adjustment
by a cylindrical projectian 28 received in a tubular flanged
portion 30 of the column 26. The pivot support 14 is retained
in its angularly adjusted position by clamping heads 31 fixed
to threaded studs 32 which in turn carry clamping nuts 34.
The pivot 16 connecting the pivoted tool carrier
12 to the pivot support 14 is preferably in the position best
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illustrated in Figure 1, where it ~111 be noted that it is
displaced to the left from the vertical plane passing through
the rotation axis of the tool T and is located well above the
horizontal plane passing through the rotation axic of the
tool T.
A gear shaving operation requires that the relative
motions between a gear shaving cutter and a work gear in mesh
therewith shall consist of meshed rotation in crossed axes
relationship, and a relative traverse between the gear and
tool in a plane which is parallel to the axes of both the
gear and shaving cutter. The specific direction of traverse
may be parallel to the axis of the gear or it may be diagonal
or oblique with respect thereto. During each traverse stroke,
the radial spacing between the gear and tool axes is maintained -
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by blocking carrier 12 against pivotal movement. In addition,
a depth feed is provided between traverse strokes and of course ~ -
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a reverse feed or withdrawing motion is provided following
termination of the shaving cycle. ~ -
On the contrary, a gear honing operation is one in
which the gear is rotated under relatively light pressure con- -
ditions but in full mesh with an abrasive gear-like honing
, tool. Light pressure is maintained between the gear and hone
throughout the operation and relative back and forth traverse
is provided in a direction parallel to the axis of the gear G.
In order to maintain constant light pressure contact between
the teeth of the gear and hone, it is necessary for the hone
to float and this condition is met by pivotally mounting the
tool carrier 12 which carries the honing tool.
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The tool carrier 12 as illustrated in Figure 1, is
connected through a pivot link 36 connected internally of a
cylinder 38 to a piston (not shown), the link extending beyond
the cylinder and carrying an adjusting nut 40 constituting a
spring stop for a counterbalance spring 42 which counterbalances
the weight of the tool carrier 12. Air pressure i~ supplied to
the cylinder, an air connection thereto being indicated at 44.
With this arrangement a relatively light clockwise bias may be
applied to the pivoted carrier 12 to maintain a predetermined
pressure contact between the teeth of a tool, diagrammatically
indicated at T, and a work gear in mesh therewith, a portion ~ .
of which is indicated diagrammatically at W. ~,
n order to ensure suitable lateral control of the
motion of the tool carrier 12, it is provided with a tongue 50
having flat sides in contact with corresponding flat sides of
wear plates 52, the position of each of which is adjusted by
a plurality of adjusting screws 54. The screws 54 are adjusted ;~
to remove all play but to permit free sliding movement of the ~`
tongue 50 so that its movement about the axis of the pivot 16
is freely permitted.
Since under other conditions, such as gear shaving,
it is desired to eliminate pivotal or rocking movement of the
tool carrier 12, means are provided for locking the tool car- ~ -
rier 12 in a fixed position and this means comprises screws -
56 extending through enlarged openings or slots 5~ and having
threaded engagement at their lower ends as indicated at 60.
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In addition, slotted blocks or plates 62 are provided, pivoted
as indicated at 64 and having laterally extending arcuate
slots 66 to receive the screws 56. When the block~ 62 are
in the position illustrated in Figure 4 and the screws 56
are tightened down, it will of course be apparent that the
tool carrier 12 is firmly locked against movement about the
axis of the pivot 16. On the other hand, when the ~crews are
loosened and the blocks 62 swung into clearance positions, the
tool carrier 12 is freely movable.
In addition to the blocking of the tool carrier 12
against movement about the axis of its pivot 16, preferably
additional clamping means are provided which take the form of
a pair of clamping levers 70 pivoted as indicated at 72 to a
bracket 73 connected to the support 14 and having abutment
extensions 74 adapted to engage opposite sides of a rigidly
fixed abutment plate 76 carried by pivoted carrier 12. One of
; the levers 70 carries an air cylinder 78 having a piston therein
connected to an adjustable abutment screw 80 engageable with the
end of the other lever 70, in a relationship best illustrated
in Figure 5. When pressure is applied to the piston within the ~~
cylinder 78, the upper ends of the lever 70 are forced apart
and the forces exerted by the extensions 74 are thus equalized
on opposite sides of the plate 76, thus additionally supporting
the tool carrier 12 in fixed position during the gear shaving
operation.
Referring now to Figure 2, details of the connection
between the support 14 and the tool carrier 12 are illustrated.
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As seen in thiC Figure, the pivot 16 is shown as comprising a
pin 82 fixed in the tool carrier 12 and preferably journaled
at its ends as indicated at 84 in ears 86 on the support 14.
Means for suitably rotatably mounting a tool T is
provided in the tool carrier 12 and takes the form of bearings
88 supporting a shaft 90 for rotation about an axis indicated
at 91.
Inasmuch as the particular tool head illustrated
herein is designed for supporting relatively large tools,
- 10 special means are provided for effecting limited angular move-
ment of a tool T so as to bring the teeth thereof into proper
alignment with the teeth of a work gear. This means comprises
a bevel gear 92 fixed to the shaft 90 and a bevel gear 94 fixed
to a vertically movable shaft 96 in housing 97 normally retained
in clearance relation as illustrated in Figure 2 with respect
to the gear 92 by a compression spring 98. A pivot cam 100 is
pivoted as indicated at 102 between ears 104 and an operating
shaft 106 is slidably movable through an opening 108 provided
in an upward extension 110 on the cam 100. The shaft 106 has
. 20 an operating knob 112 by means of which the operator may move
~: the knob to the right as illustrated in Figure 2 and thereafter,
swing it upwardly to depress the nose of the cam and thereby
depress shaft 96 to bring about meshing engagement between the
bevel gears 92 and 94. Thereafter, limited rotational movement
of the shaft 106 in a hori~ontal plane results in rotation of
the shaft 96 and corresponding rotation of the tool support
shaft 90.
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Referring now again to the location of the pivot
indicated generally at 16 in Figure 1 and constituted by the
pin 82, it has been found that the precise location of this
shaft controls the action resulting from rotation of the gear
and a honing tool in mesh. At this time, as previously noted,
the tool carrier 12 is mounted for pivotal movement about the
axis of pivot 82 forming the pivot support 16 and is urged
into pressure engagement with the work gear only by a relatively ~light air pressure applied to the cylinder 38. In practice ~-
the total force exerted between the gear and honing tool may
be only a few pounds.
In the past it was believed desirable to provide
for pivot mounting of the tool carrier which provided for
approach and separation between the gear and tool in a position
r such that the relative approach took place substantially in
a direction parallel to the line joining and perpendicular to
the axes of the gear and tool. This corresponded to the direction
of movement where the approach and separation was accomplished,
not by means of a pivot mounting, but by means of a suitable
slide. However, it is much preferred to provide for the re-
quired relative movement by means of a pivot mounting.
It was found that when the honing operation was carried
out by rotating either the gear or hone in one direction under
a given predetermined relatively light radial loading, a smooth
hon~ng action took place. However, when the direction or rotation
was reversed, the smooth honing action did not take place and
it appeared that the difference was attributable to a variation
in the sum ofthe forces tending to pivot the pivoted carrier to
apply pressure between the tool and gear.
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It appears that advantages are obtained by locating
the pivot mounting for the pivoted carrier within the acute
angle between the lines of action and as close as is reasonably
possible to the line perpendicular to the line of centers pa~s-
ing through the pitch point.
This i8 the subject matter of prior application
Serial No. 257,077, and i9 not claimed herein. The only re-
quirement of the structure disclosed herein is that pivot
movement of carrier 12 results in movement of the tool in
a direction whose major component is parallel to the direction
of movement of slide 20.
Referring again to the specific machine design
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illustrated in Figure 1, it will be ob~erved that the axis i-
of pivot support 16 is located substantially within the acute
angle between lineæ of action 124 and 126, and could be located ~ -
on the bi~ector of this angle, if found to be neces~ary. ~ -
In the actual machine illustratea the pivot mounting ~-
for the pivoted carrier 12 is located above its axis, at a
position such that pivotal movement of the carrier moves the
tool in a direction having a major component radial of the
gear. However, ~o far as the principles of the invention are
concerned, the pivot mounting 16 might be mounted generally
below the pivoted carrier. As a matter of fact, the principles
of the present invention would apply if the swinging movement
of the pivoted member took place in a horizontally di~posed
plane or an oblique plane.
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