Note: Descriptions are shown in the official language in which they were submitted.
l~8::~Lsa;~ !
BACXGROUND OF THE INVENTION
This invention relates to machine tools of the type used
to drill and/or tap holes in a workpiece. In such machine tools
there is a problem of removing chips from the bottom of the holes,
particularly after the holes are tapped, and this invention is
addressed to that problem.
In the past, machine tools of the above-noted type have been
manufactured in which coolant is introduced through the tool via
an axial duct in the spindle which mates with an axial duct in
the toolholder or via a rotary gland on the toolholder. This in-
vention is particularly adapted for use in combination with such
coolant-through-the-tool machine tools and uses the existing cool-
ant ducts for the additional function of blowing chips and coolant
out of holes drilled and/or tapped in a workpiece.
SUMMARY OF THE INVENTION
A conduit for compressed gas is mounted adjacent to a machine
tool spindle and is coupled to a duct in a toolholder when the tool-
holder is clamped in a toolholder socket on the end of the spindle.
A hollow probe projects axially from the toolholder and is coupled
to the toolholder duct. The outer end of the probe has a nozzle
Lhereon. Means is provided for forcing a compressed gas through
the duct in the toolholder and out the nozzle to blow chips and
coolant out of a hole in a workpiece adjacent to the nozzle.
DESCRIPTION OF THE DRAWINGS
Figure 1 is an axial sectional view of one preferred embodi-
men~ of the invention in combination with a coolant-through-the-
tool-type of machine tool;
Fig. 2 is an axial sectional view of one toolholder having
a hollow probe for blowing chips and coolant out of holes in a
workpiece;
.
; - 2 -
- ~.;
10815~)3
Fig. 3 is a fragmentary perspective view, partially cut away,
showing the probe of Fig. 2 being used to blow chips and coolant
out of a hole in a workpiece;
Fig. 4 is a plan view, partially cut away, of a second pre-
ferred embodiment of the invention in combination with a secondcoolant-through-the-tool-type of machine tool;
Fig. 5 is a cross-sectional view taken on the line 5-5 of
Fig. 41
Fig. 6 is a cross-sectional view taken on the line 6-6 of
Fig. 4; and
Fig. 7 is a side elevational view taken on the line 7-7 of
Fig. 4.
DESCRIPTION OF THE PREFERRED EMBQDIMENTS
Figure l is an axial sectional view of the spindle l0 of a
horizontal machining center. Spindle l0 is journalled within a
spindle head 12 by bearings 14, 16 and 18 and is rotated by motor
means tnot shown) through a drive gear 20 which is rigidly attach-
ed to spindle l0. Spindle head 12, which is represented by frag-
ments in Fig. l, is conventional in every respect, as are the re-
maining portions of the machining center which are not shown in
Fig. l. The outer portions of spindle l0 are conventional in
structure but the inner portions have been modified for the pur-
poses of this invention.
The inner portion of spindle l0 has an axial bore 22 which
extends the full length of spindle l0 and opens at one end into
a toolholder socket 24 which is shaped to receive conventional
toolholders. A toolholder 26 which has been modified for the
purposes of this invention is shown mounted in toolholder socket
24 and clamped therein by a draw in clamp 28 which engages a re-
tention knob 30 on the inner end of toolholder 26. The forward
portion of toolholder 26 is disclosed in Fig. 2 and will be de-
scribed after the inner portion of spindle l0 is described.
- 3 -
` 101~15~3
A cylindrical drawbolt 32 is axially slidably mounted within
spindle bore 22 for movement between a retracted position, shown
in Fig. 1, and an extended position, in which drawbolt 32 is moved
to the left in Fig. 1. Drawbolt 32 is spring biased to its re-
tracted position by a stack of selleville springs (not shown) which
urge drawbolt 32 to the right in Fig. 1. A hydraulic cylinder (not
shown)is provided for moving drawbolt 32 to its extended position
(to the left in Fig. 1) against the ~orce of the Belleville springs
by bumping against an adjustable sleeve 34 on the inner end of
drawbolt 32. Sleeve 34 can be adjusted and locked in place by
a setscrew 36 to regulate the extended position of drawbolt 32.
Clamp 28 is attached to the outer end of drawbolt 32.
Clamp 28 includes a slotted sleeve 38 which has internal screw
threads 40 on one end (to the right in Fig. 1) and jaw elements
42 on the other end. Slotted sleeve 38 is made of spring materi-
al and jaw elements 42 are spring biased thereby outwardly but
are moved inwardly when drawbolt 32 is moved to its retracted
position by interaction with a collar 44. The inner surface of
collar 44 and the outer surface o~ jaw elements 42 are shaped
to cam jaw elements 42 together when drawbolt 32 is moved to
its retracted position, shown in Fig. 1, thereby clamping jaw ele-
ments 42 onto retention knob 30. When drawbolt 32 i5 moved to its
extended position (to the left in Fig. 1) the cam surfaces allow
jaw elements 42 to open due to spring tension and release reten-
tion knob 30.
Drawbolt 32 has a central axial duct 46 extending there-
through and has an insertion tube 48 on the outer end thereof
which is coupled on one end to duct 46 and is positioned to be
; inserted on the other end into an opening 50 in the retention
, 30 knob 30 of toolholder 26. Insertion tube 48 is clamped to the
`- outer end of drawbolt 32 by a threaded sleeve 52 which is attached
- 4 -
~, . .. .
~0~5(~3
to the outer end of drawbolt 32 by screw threads 54. An 0-ring 56
on the inner end of insertion tube 48 seals the inner end of tube
48 and also provides a small amount of play to compensate ~or
small mismatches in the position Of insertion tube 48 and the
opening 50 in retention knob 30.
On the other end of drawbolt 32, a conventional rotary union
58 having two inlet conduits 60 and 62, one for compressed air and
the other for coolant, is coupled to drawbolt 32 and to duct 46
therein. Conduit 62 is coupled to a source of coolant fluid (not
shown) and to a conventional coolant-through-the-tool solenoid
valve 63. The coolant pump and distribution system is convention-
al in structure and function and hence is omitted from the draw-
ings. Conduit 60 is coupled to a compressed air tank 64 through
a conventional solenoid valve 66 When solenoid valve 66 is open-
ed, compressed air is admitted through conduit 60 and rotary union
58 into duct 46 and from duct 46 through insertion tube 48 into
the opening 50 in retention knob 30. This compressed air is used
to blow chips and coolant out of holes in a workpiece through a
modified toolholder shown in Figs. 2 and 3.
Referring to Fig. 2, toolholder 26 has an axial duct 68
which opens into opening 50 in retention knob 30 and extends
through toolholder 26. A hollow, elongated cylindrical probe
70 is mounted in the front end of duct 68 and is held therein by
a setscrew 72. Probe 70 has a slender front portion 74 which is
; 25 dimensioned to fit within the holes which are to be cleaned and
has a nozzle 75 on its outer end. Fig. 3 shows the front portion
74 of probe 70 inserted into a hole 76 in a workpiece 78 with
nozzle 75 being near the bottom o~ hole 76. With the probe 70 r
. in this position, compressed air is forced through probe 70 by
the means described above to blow chips and coolant out of hole
76. When the compressed air is initially applied to rotary union
....
~8~S~3
58, there may be some coolant in duct 46 from a preceding coolant-
through-the-tool operation, and this will be blown out of duct 46
and then out of hole 76 by the compressed air. Within a short
space of time, the compressed air will blow both ~oolant and chips
out o~ hole 76.
The modified toolholder 26 of this invention has a standard
outer configuration including an automatic toolchanger flange 80
and can be handled by a conventional automatic tool changer.
Other tools used in combination with modified toolholder 26 have
an opening 50 in their retention knob 30 to accommodate the end
of insertion tube 48. Positioning of probe front portion 74 into
the hole to be cleaned out is accomplished by the conventional
positioning controls for the machining center. This may be done
by moving spindle head 12 with respect to workpiece 78, or by mov-
ing workpiece 78 with respect to spindle head 12, or by a combina~
tion of both.
Figs. 4 through 7 show a second preferred embodiment for
use in combination with a coolant-through-the-tool-type of machine
tool in which the coolant is introduced through a rotary gland in
the toolholder rather than through an axial duct in the spindle.
Re~erring to Fig. 4, the toolholder 82 ~or this embodiment is
substantially cylindrical in shape and is shown clamped into a
spindle 84 which is rotatably mounted by conventional means not
shown in a spindle head 86. A spindle ring 88 is rigidly attached
2S to spindle head 86 by bolts 90 (Fig. 5). Spindle ring 88 surrounds
spi~dle 84 and serves as a support for the coolant conduit and sock-
et as described in later paragraphs. The portions of the machine
tool which support spindle 84 and spindle head 86 are conventional
; in structure and hence are not shown in the drawings.
A coolant and air supply block 92 having a coolant and air
- socket 94 therein is bolted to spindle ring 88 adjacent to spindle
-- 6 --
~81S03
84. A coolant and air supply conduit 96 is attached to supply
block 92 and is coupled to socket 94 by duct 98 (Fig. 7). Coolant
is supplied to conduit 96 from a conventional coolant supply (not
shown) which contains valves (not shown) for also routing compress-
ed air to conduit 96 which also serves as a compressed air conduit
~or the purposes of this invention. The coolant is introduced into
conduit 96 when a conventional coolant-through~the-tool toolholder
is used and the compressed air is introduced into conduit 96 when
a modified coolant-throught-the tool toolholder 82 (shown in Figs.
4-7) is used to blow chips and coolant out of a drilled and tapped
hole.
Toolholder 82 is modified by means of a rotary gland 100
which couples a fluid (either coolant or compressed air) to the
toolholder while it is rotating. Rotary gland 100 is seated in a
substantially rectangular gland block 102 which has a bore 104
therein (Fig. 4) for receiving toolholder 82. A pair of bushings
106 and 108 rotatably support toolholder 82 within bore 104. Bush-
ings 106 and 108 are spaced apart axially to form a gap 110 into
which coolant or compressed air is forced. 0-rings 112 and 114
on the interior surface of bushings 106 and 108 seal in the coolant
or compressed air at the rotary junction between bushings 106 and
108 and toolholder 82. Bushing 108 is held in place by a flange 116
on toolholder 82 and bushings 106 is held in place by a snap ring
118.
A radial opening 120 in toolholder 82 communicates between
annular gap 110 and an axial duct 122 in toolholder 82. Axial duct
122 is coupled to a radial duct 124 which in turn is coupled to a
central axial duct 126 in a probe 128 which is removably held in
toolholder 82 by a setscrew 130. Probe 128 has a slender elongated
outer end 132 which terminates in a nozzle 134. In the operation
of this embodiment, compressed air is forced from gap 110 through
-- 7
. .
S()3
opening 120 and through ducts 122, 124, and 126 out nozzle 134 to
blow chips and coolant out of a drilled and/or tapped hole into
which probe end 132 is inserted. However, with a coolant-through-
the-tool type of tool inserted into toolholder 82 in place of probe
128, coolant can be conducted from gap 110 through opening 120 and
ducts 122, 124 to the coolant-through-the-tool tool.
The connection between coolant socket 94 and gap 110 is
effected by a coupling tube 136 which is mounted in a block 138
attached to gland block 102 and is coupled to gap 110 through a
duct 140 in block 102. Coupling tube 136 has an 0-ring 142 which
interacts with bushing 144 to seal the connection between socket
94 and coupling tube 136. Either coolant or compressed air can
be conducted from socket 94 to gap 110 via tube 136 and duct 140.
To effect correct alignment between coupling tube 136 and
socket 94, an alignment pinl46 is moved into and out of a no~h 147 (Fig. 6)
in an adjacent flange 148 of toolholder 82 to lock toolholder 82
in a predetermined angular position with respect to gland block
102 when it is stored in the tool magazine (not shown) or is being
moved between the tool magazine and spindle 84. Alignment pin 146
is attached to plunger 150 which is slideable in an axial bore 152
in block 138 and is normally spring biased inwardly by a compression
spring 154. An abutment 156 opposite the inner end of plunger 150
bears thereagainst to move alignment pin 146 away from flange 148
when toolholder 82 is mounted in spindle 84. When toolholder 82
is removed from spindle 84, spring 154 forces plunger 150 inwardly
and causes alignment pin 146 to engage notch 147 in flange 1480
An annular splash shield 158 is attached to the front of
gland block 102 around toolholder 82 to limit the splashing of
chips and coolant regardless of whether coolant or compressed air
` 30 is being applied to toolholder 82.
~08~S03
Although the illustrative embodiments of the invention have
been described in considerable detail for the purpose of fully
disclosing a practical operative structure incorporating the
invention, it is to be understood that the particular apparatus
shown and described is intended to be illustrative only and that
the various novel features of the invention may be incorporated
in oth~r structural forms without departing from the spirit and
scope of the invention as defined in the subjoined claims.
_ g _
