Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUNp ~F THE INVENTION
The present invention is concerned with the
automatic changing of~cutting inserts on toolholders when
they become damaged or worn during a machining cycle.
In the machining of materials utilizing toolholders
with replaceable cutting inserts, a great deal of work
has been done in trying to make the machining process a
very efficient one. One of the inefficiencies of the
machining system concerned the changing of the cutting
insert when it became dull or worn, and even more
importantly, the changing of the cutting insert when it
fractured during the machining cycle.
When the insert can no longer be used in the cut, it
is necessary to back the toolholder out from the
workpiece and either index the cutting insert to another
cutting edge or replace it in its ent.irety. This is
usually done by the operator coming in and unclamping the
insert with regular or special tooling, picking up the
hot insert, utilizing gloves or other special equipment,
and indexing or replacing the insert without introducing
too much contamination, dirt or debris to the insert
seat.
The insert can then be clamped by the operator and
the toolholder returned to the workpiece for a test cut
to determine if the new cutting edge has the same
dimensional cutting ability as the previous cutting edge.
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If not, the machine tool must be readjusted so as to make
up for any tolerancing differences.
In addition to the insert becoming dull and worn,
the more catastrophic situation, and the most
inefficient, from the standpoint of machining systems,
occurs when the end of the life of the insert happens
through breakage while the insert is still involved in
the cutting of the workpiece. This situation can lead to
severe damage, which may cause the scrapping of the
workpiece, in addition to the lost time and other things
associated with the changing of the insert.
More recently, studies have indicated that there are
systems which may measure when a cutting inse.rt is
reaching the end of its useful life. When this occurs, a
signal ma~ be generated, indicating that the insert
should be ~hanged rather than risk any further machining
operations.
It is an obj ect of the present invention to provide
an automatic insert changer whenever a signal has been
generated indicating that the cutting insert has
completed its useful life.
~ is a further ob~ect of the present invention to
more efficiently replace the cutting insert than when
completed by a machine operator.
It is a further object of the present invention to
provide a toolholder and insert cartridge to provide for
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long periods of unattended machining operations.
BRI EF SUMMARY OF THE I NVENTI ON
According to the present invention, an insert
cartridge mechanism has been designed which comprises an
insert storage chamber for holding multiple similarly-
shaped cutting inserts in a face-to-face and stacked
relation. One end of the storage chamber is open on at
least one side so that inserts may, one at a time, be
slid in or out of the chamber.
On the open end of the storage chamber, there is a
longitudinal abutment surface to hold the stacked
inserts longitudinally in the storage chamber. On the
other end of the storage chamber, from the abutment
surface, is a spring arrangement for urging the inserts
toward said abutment surface.
Preferably, a central rod extends through the
storage chamber and engages central holes in the inserts
stored therein. A rod means is connected to the spring
means and has longitudinal reciprocal movement with one
end of the rod extendin~ to the open end of the storage
chamber and engaging the central hole in the endmost
insert.
Also, according to the present invention, is a
toolholder which comprises a shank with one end having an
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insert pocket with at least a bottom wall and a side
wall. Located within the insert pocket is a movable seat
with a central pin extending upwardly from the insert
seat for engagement with a central hole in an insert. A
drawbar extends through the shank of the toolholder and
is connected with a means for moving the insert seat
forwardly and rearwardly in the insert pocket. When the
seat is moved rearwardly in the insert pocket, the pin
engaging the center hole of the insert will clamp the
insert between the pin and the side wall of the insert
pocket.
In addition to clamping the insert against one side
wall of said pocket, an additional pivotal clamp has been
furnished along another side wall of the pocket, with the
clamp having an insert side wall contact portion and an
insert top wall contact portion. As the insert is moved
into the insert pocket, a side wall of the insert
contacts the insert side wall contact portion of the
abutment clamp, causing it to pivot downwardly with the
insert top wall contact portion firmly pressing down on
the insert.
Preferably, the drawbar mechanism comprises a
movable rod extending through the shank of the insert,
and the rod connects with a rack and pinion arrangement
to move the insert seat so that, when the drawbar is
pulled or pushed rearwardly on the toolholder, the insert
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seat is moved forwardly out of the insert pocket. The
movable rod means in the shank of the toolholder also,
preferably, has means urging it to its forwardmost
position within the toolholder.
Also, according to the present invention, is the
method of replacing a used or worn cutting insert on the
toolholder described above. The method comprises
unclamping the used insert on the toolholder by moving
the insert seat forwardly in the toolholder pocket and
removing the insert from the insert seat. The insert
mechanism is then positioned in proper alignment with the
insert seat and further engaged with the insert seat so
that the upstanding pin on the insert seat mates with the
center hole of the insert in the open end of the storage
chamber and pushes the central rod rearwardly in the
storage chamber.
The method then comprises pushing the drawbar and
the toolholder shank inwardly so that the insert seat
moves into its clamping position in the toolholder
pocket, thereby taking with it the insert formerly
located in the endmost position of the storage area of
the insert mechanism. The insert mechanism is then moved
back to its original position out of the way of the
machining efforts.
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~RIEF DESCRIPTION OF THE DRAWINGS
The exact nature of the present invention will
become more clearly apparent upon reference to the
following detailed specification taken in connection with
the accompanying drawings in which:
Figure 1 shows a side view of the toolholder
according to the present invention.
Figure 2 shows a side view with a partial cut-away
of the insert cartridge according to the present
invention.
Figure 3 shows a top view with a partial cut-away of
the toolholder according to the present invention with
the insert in its clamped position.
Figure 4 shows a top view with a partial cut-away of
the toolholder according to the present invention with
the insert in its unclamped position.
Figure 5 is a front view of the toolholder of the
present invention ,with the insert in its clamped
position.
Figure 6 is a front view of the toolholder of the
present invention with the insert in its unclamped
position.
Figure 7 is a toolholder of the present invention
with the insert cartridge in proper alignment above the
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toolholder of the present invention.
Figure 8 is a cut away top view of the toolholder
according to the present invention.
Figure 9 is a cut away top view of the toolholder
according to the present invention.
DETAI LED DESCRI PTI ON OF THE I N~7ENTI ON
Referring to the drawings somewhat more in detail,
what is shown in Figure 1 is a toolholder 10 having a
movable insert seat 12 with an insert 14 seated thereon.
The movable insert seat 12 and the insert 14 are located
in an insert pocket having a bottom wall 16 and a side
wall 18. The insert seat 12 is connected to means 20 and
engages pinion 22 so as to be reciprocably movable in a
forwardly manner.
A reciprocably movable rod means 24 extends there-
through the shank 26 of the toolholder 10 and has a
spring means 28 urging the rod means 24 to its
forwardmost position in the shank 26 of the toolholder 10
so that the insert` seat 12 is firmly held in its
rearward-most position in the insert pocket of the
toolholder. The movable rod means 24 may have threaded
means 30 on one end so as to be connected to a machine
tool.
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Also shown in Figure 1 is a shoulder-type screw 5
having a spring means 6 associated therewith that is
connected to the bottom portion of the insert seat 12.
Shoulder screw 5 and spring 6 hold the insert seat 12
against the shelf 7 of the toolholder as it slides in and
out of the toolholder pocket. The shoulder screw 5
provides a positive stop against abutment 8 when the
insert seat is moved to its outermost position.
What is shown in Figure 2 is an insert storage
mechanism 32 having an insert storage area 34 for storing
multiple, similarly-shaped inserts 36 in a stacked, face-
to-face relationship. Inserts 36 are normally
polygonally shaped whèn viewed in plan and have a central
hole therethrough to aid in clamping the insert against
the bottom wall 16 and the side wall 18 of the insert
in the pockst of the toolholder 10.
The insert storage area 34 has an open end 38 that
has at least one side open so that the inserts 36 may be
removed from the insert storage area 34. The open end 38
has an abutment surface 40 that holds the endmost insert
42 frorn any longitudinal movement. Rod means 44 extends
throughout the approximate center line of the insert
storage area 34, extending through the center holes in
the inserts 36 and engaging the central hole of insert 42
so as to prevent any lateral movement of insert 42~
Spring 45 and cap 46 provide a means for urging the
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stack of inserts 36 into engagement with the abutment
surface 40. Reciprocal movable rod means 44 is also
urged toward the abutment end 40, but may be pulled back
by handle 46 so that insert 42 may be laterally removed
from the insert mechanism through the open end 38.
What is shown in Figure 3 is a plan view of the
toolholder 10 having reciprocably movable rod means 24
with engagement means 36 on the end of the rod 24.
Insert seat 12, shown in Figure 1, has a tongue 48 which
connects with means 20 so as to engage the pinion 22.
Rod 24 also engages the pinion 22, and it can be seen
that the insert 14 is being firmly held against the side
wall 18 of the insert pocket. The pivotal clamp means 50
is shown in the clamped position with a top wall insert
contact portion 52 pressing downwardly on the top of the
insert 14. Spring means 54 urges the pivotal arm 50 to
pivot upwardly when the insert 14 is not engaged with
the pivotal clamp 50.
What is shown in Figure 4 is that the rod means 24
has been actuated rearwardly with engagement with end 36,
thereby rotating the pinion 22 and causing rod 20 to
move the tongue 48 and push the insert eat 12 out of the
insert poc~et 13. The insert 14 is still seated on the
insert seat, and when in this position, may be removed so
as to be replaced by another insert 42, shown in Figure
2. The pivotal arm 50 now has the top insert contact
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portion 52 rotated to its uppermost position by spring
54
What is shown in Figure 5 is a front view of the
toolholder 10, showing the insert seat 12 having a
lowermost portion 15 and an uppermost portion 17. The
insert 14 is seated on the uppermost portion 17 while
portion 15 sits on the bottom wall 16 of the insert
pocket. The toolholder is now in its clamped position,
showing the pivotal arm 50 having contact portion 52
engaging the top of the insert 14 and pressing downwardly
and also having a side finger 53 engaging the side wall
portion of insert 14.
When in the clamped position, the insert 14 will be
clamped and located between the bottom and side walls of
the insert pocket and, also, will abut the side wall
contact portion 53 of pivotal arm 50 while being pressed
down by the top wall contact portion 52 of pivotal arm
50.
What is shown in Figure 6 is, again, an end view of
the toolholder 10 showing the insert 14 in an unclamped
position having the insert seat 12 moved out of the
insert pocket and showing the pivotal arm 50 rotated to
its uppermost position such that the top wall contact
portion 52 does not engage insert 14. Further, the side
wall contact portion~53 is also not engaging insert 14
and insert 14 may be removed from the toolholder.
What is shown in Figure 7 is the insert cartridge 32
and the toolholder 10 being held by appropriate means so
that the automatic changing of the insert 14 may be
accomplished. With the insert cartridge 32 properly
positioned above the toolholder 10, the insert 14 may be
automatically changed. Proper positioning means that the
movable rod 44 is positioned so that when it is lowered
it will engage the central pin 31 on insert seat 12.
The central pin 31 on insert seat 12 serves to clamp
the insert 14 against the side wall 18 in the insert
pocket of toolholder 10. When the insert cartridge 32 is
lowered into engagement with the insert seat, pin 31 will
push movable rod means 44 upward in the insert storage
chamber 24 so that it no longer engages the innermost
central hole of the ihsert 42.
Shown in Figure 8 is toolholder 10, showing the
drawbar 24 with the insert 14 in the clamped position.
The drawbar 24 has a front end portion 101 that sits in a
through hole that extends to the front part of the
toolholder 10.
Through the through hole 103, the drawbar 24 may be
actuated as is shown in Figure 9, such that the insert 14
is moved to the unclamped position. In this manner it
may not be necessary for the toolholder to be actuated
from the rear. Rather, the insert may be clamped and
unclamped from the front of the toolholder 10.
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Modifications may be n~ade within the scope of the
appended cl aims .
