CA1152307A

CA1152307A - Self-centering tool holder

Info

Publication number: CA1152307A
Application number: CA000365268A
Authority: CA
Inventors: Leonard R. Golick
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1979-12-05
Filing date: 1980-11-21
Publication date: 1983-08-23
Also published as: JPS5689452A; YU305980A; ES8202179A1; EP0030828A1; KR830004071A; ES497466A0; KR850000008B1

Abstract

13 48,388 ABSTRACT OF THE DISCLOSURE
The present invention provides a quick release tool holder mounted on the free end of a remotely con-trolled tool support and positioning arm in a manner that permits the tool to, upon guidance thereof by existing openings into which the tool must be inserted, become properly disposed and aligned for the particular operation accomplished by the tool. In addition, provision is made for coolant to be delivered to the tool through the tool holder for longer tool life.

Description

3~7 48, 388 SELF CENT13RIN~ TOOL HûI.DER
BACKGR~llND OF mE INV~TION
Field of the I~ention: .
Thls invention relates to a tool holding chuck and more particularly to a quick-release chuck mounted on 5 a remotely operated tool-positioning arm and having lim-ited sel~-centering and sel~-alignlng capability~
Description o~ the Prior Art:
Quick rel~ase tool holding chuck~ are well known in the prior art" Such chucks are generally solidly mounted in apparatus to provide defin~te9 repeatable pos~tioning o~ the tool. In the environment in which the chuck of the instant invent~on ~s to be used, namely within an irradiated ~uclear steam generator, manual guidance and position ad~ustment is not possible. m ere-~ore, the tools which are particularly adapted to performvarious operations ln a remote detubing/re~ubing proce-dure, are mounted on an apparatus such as discussed in Canadian Pa-tent No. 17090,991 lssued Decem~er 9~ 1980 in which they are automatically positioned from a re~ote control faci.llty as ~herein disrussed. For the most part the tool positioning ~s ~uf~ic~ntly accurate~ Howe~er, a~ sho~ ~n the above-identi~led applicatlon~ the tool ls mounted on the distal end of an arm ~hat ma~n~ s ~ny angular mi~ positioning of the ~rm. Al~o, t~e wei~ht o~
the arm and the wor~ing ~orce applied by the tool at ~he end may cause a de~lection in th~ support struoture.
Thus, particularly when an operatlon is being done wh~ch requlre~ the tool to ~ollow an exlstlng opening~ as in ..c~, .

. -': :

3~ ~

2 ~8,388 drilling out the tube, it would be preferable to permit the tool to assume the proper placement and alignmen-t to minimize stress on the various parts.
SUMMARY OF THE INVENTI~N
me present invention provides a qulck release tool holder mounted on the ~ree end of a remotely con-trolled tool ~upport and posltio~ing arm in a manner that permits the tool to, upon guidance thereo~ by existing openings i~t~ which the tool must be i~sertedl become properly dlsposed and aligned for the par~icu1ar operation accomplished by the tool. In addition, provision is made ~or coolant to be delivered ~o the tool through the tool holder ~or longer tool li~e.
DESCRIPTION OF THE DRAWINGS
_ Figure 1 is a partial sectional view o~ a nucle-ar steam generator head with remotely operated tool hold-ing and placement apparatu~ disposed therein ~or repairing the tube and tubesheet of the generator;
Figc 2 is an enlarged cross-sectional view o~ a portion o~ the ~ree end o~ the tool holding arm showing the tool holder o~ the present i~vention;
Fig. 3 is a view ~imilar to Flgo 2 with the tool holder rotated 90 from the position of Fig. 2; and Fig. 4 is an exploded isometric of the quick : 25 release tool holder of the present invention~

Referring inltially to Figure 1, the particular remotely controlled apparatus disposed in the channel head of a nuclear steam generator and which supports the tool holder o~ the present i~entlon is sho~O Such apparatus is more ~ully described and claimed in C~nadian Patent NoO
1,~907991 ~or the description of thi~ particular st~uGture~
However, i~ is su~icient to note the tool holding chuck (59 therein~ is suppor~ed on the d~stal end of a removably mounted cantilevered tool holder arm (57 ~herei~ supporting a tool generally in axial al~gnment with tub2s extending through a tube~heet (3 therein) o~

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3 ~8,3~8 the nuclear steam generator. It is apparent that proper disposition of -the tool so as to initially be disposed in axial alignment with each individual tube to be worked on and also in continued axial alignment as the tool is elevated within the tube are necessary for minimal stress on the -tool and the attendant suppor-t s-truc-ture. However, it is also apparent that due to manufact-uring tolerances and the inherent deflections in the cantilevered tool support arm, exact axial alignment and subsequent axial travel of the tool are not assured. Thus, the tool holder 59 of the present invention permi-ts, whenever such mis-alignment occurs, a self-centering of the tool as guided by the tool pilot as it enters the tube.
Thus referring to Figs. 2 through 4, -the tool chuck 59 is clearly shown as mounted on the distal end of the tool holding arm 57 of such an apparatus shown in Flg.
1. The chuck 59 is formed of an assembly of parts com-prising a rotatably driven base member 14 having a shank portion 16 vertically supported in a pair of bearings 18 in the arm 57 and a drive gear is keyed thereto for ro-tat-ing the base member 14 from a gear drive arrangemen-t described in the above-referenced copending application.
The upper end of base member 14 projects above the arm 57 and defines an enlarged cylindrical head 20 having a generally planar upper face 22 defining a groove or channel 24 (see Fig. 3) extending diametrically there-across. A pair of diametrically opposed roller members 26 are supported within appropriate openings 28 in the head 20 via hori~ontal axial roller shafts 30 received within a horizontal bore 32 in the head 20 perpendicular -to the channel 24. The rollers 26 extend upwardly through the surface 22 of the head 20 so that the peripheral rolling surface of the rollers 26 projects above the general plane of the upper surface, as is seen, and provides a rolling direction parallel to the channel 24.
The head 20 is also externally threaded as at 34 for threaded engagement of an upstanding internally threaded annular collar member 36, to be described later, 3 ~ ~
~1 ~18,388 and an internally threaded lock nut 38.
An intermediate cylindrical plate member 40 having a generally planar lower surface 42 rests on the opposed rollers 26 so that the plate 40 is elevated some-what from the surface 22 of the base member 14 and thus free to teeter or wobble thereon wi-th the roller members 26 forming the fulcrum. The lower sur-face 42 of the pla-te 40 defines a downwardly projec-ting diametrically extending tongue or rib 44 slidingly received in the channel 24 of the spindle member 14 to provide an indexed engagement therebetween which guides any translational movement of the plate 40 permitted by the rolling supports 26 so that both rotational and transla-tional movement permitted thereby is in a common vertical plane on the surface 22.
The upper surface 46 of the plate 40 is likewise generally planar except for a pair of diametrically ex-tending and opposed upwardly projecting -tongures or ribs 48 angularly off-set from the lower rib 44 90. A pair of diametrically opposed rollers 50 (similar -to the rollers 26 in the base member 14 and more clearly shown in Fig. 3) are supported in the plate 40 and have a peripheral sur-face projecting slightly the planar surface 46 of the plate. The rotational axis of the rollers 50 is likewise angularly offset from the axis of rollers 26 in -the base member 14 by 90.
I-t should be noted that the ou-ter diameter of the plate 40 is somewhat less than -the inner diameter of the collar 36 to provide an annular gap therebetween.
The tool-holding portion comprises a generally cup-like upper cylinder member 52 having an open upper end formed by a central cavity 53 and a planar lower surface 54 resting on the rollers 50 of the plate 40. The lower surface 5~1 defines a diametrically extending groove or channel 56 for receiving the ribs 48 of the plate 40 for indexed angular orientation of the cylinder member on the plate. This permits the cylinder member 52 to teeter or wobble about the rollers 50 in a vertical plane 90 off-set from the wobble plane of the plate 40 and the rollers .. , ' ' ' ~
.
: ' ' ' ~ ~
. - ~ - ~ .

~8,388 50 also permit the cylin~er member 52 translational mo-tion, as guided by the rib L~8 and channel 56 engagement, in a vertical plane 90 o~-se-t from the travel permitted by the plate ~0 on the base member 14 with both such pivotal movement and transla-tional movement on surface 46 being generally perpendicular to the respective movemen-t on surface 22.
The cylinder member 52 has an annular exterior flange 58 at its base with the upper surface 60 thereof lo angled outwardly downwardly. The upper end 62 of the collar member 36 has an internal complimentary annular shoulder 64 angled inwardly upwardly overlapping the flange 62 of the cylinder member 52. I-t is noted that the internal diameter of the collar 36 is likewise greater than the outer diameter of the cylinder member 52 to define a like annular gap therebetween.
To assemble the above-identified parts, it is apparent that the plate member 40 is axially aligned on the base member 14 with the respective ribs and channels properly engaged and the upper cylinder member 52 is likewise axially aligned on the plate 40 with the respec-tive ribs 48 and channels 56 engaged. The lock nu-t 38 is -threaded into a lowered position on -the spindle head 20 and the collar 36 is threaded onto -the spindle until initial abutment between the complimen-tary engaging sur-faces 60, 64 of the cylinder member 52 and the col~Lar 36.
(After this initial abutment the collar 36 is then slight-ly backed-off to permit generally free movement of the plate 40 and cylinder member 52 without in-terference of the complimentary surfaces 60, 64). And the lock nut is then tightened against the collar to maintain such assem-bly.
In the preferred embodiment the tool holder of the present invention includes an insert 68 that closely fits within the cavity 53 of the cup-like member 52 and which is securely attached to the shank 70 of the tool supported in the -tool holder. The insert 68 includes a set-screw 71 projecting through the sidewall thereof and . . . . .

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5~ ~ ~ 7 6 ~8,388 into the bore for enga~ement of the tool shank 70 to prevent relative rotation of the tool within -the inser-t, and a second set-screw 72 forming a vertically adjustable base for the insert to preset the depth of -the inser-tion of the tool within -the insert. By this struc-ture all tools can be pre-assembled with an inser-t to a uniform position before the tool and insert assembly is mounted within the member 52.
The cylindrical member 52 has a quick-release capability for engaging the insert 68 and to this end includes an upper annular camming ring 76 in close sliding engagement with the exterior of the member 52 and de~ining an upper surface 78 abutting a retaining ring 80 mo~mted in an annular groove adjacent the top of the member 52 and further defining a lower depending leg portion 8~ havin~
an internal diameter in sliding engagemen-t with the member 52. Between the upper surface 78 and the leg portion 84 the ring defines a generally concave surface 86 providing an annular space and including downwardly inwardly tapered area 88 extending to the sliding engaging leg portion 8~.
The cylindrical member 52 defines an elongated horizontal aperture 90 through the cylindrical wall in alignment with the lower portion 84 of the ring 76. A
locking pin 92 is slidingly housed within the slot 90 and extends into the inner area of the member 52 to engage a complimentary engaging groove 9~ in the inser-t 68 for locking engagemen-t between the member 52 and the insert.
A key 96 retains the locking pin 92 from sliding comp]ete-ly through the aperture 90 when the insert 68 is removed.
A tensile coil spring 98 encircles the cylin-drical member 52 with the opposite ends thereof received in appropriate facing notches 100 and 102 in the collar member 36 and the ring member 76 respectively, and -the normal biasing force of the spring retains the ring 76 in i-ts upward position wherein the leg portion 8~ prevents the locking pin 92 from sliding outwardly and thus locks the tool insert 68 within the cavity 90 of the cylindrical member 52. However, manually forcing the ring 76 down-' 1' : ;~ :-;::

, ~23~7 7 ~8,388 wardly moves the concave portion ~6 thereof into alignment wi-th -the pin ~2 and thus upward manual force on -the tool insert 68 will cam the locking pin 92 outwardly into the annular space 86 and ou-t of the way of fur-ther withdrawal of the insert permitting quick release of the tool and insert from -the cylinder member 52.
~ n annular outer skir-t 104 is attached to the ring 76 to enclose the spring 98 and provide a generally smooth outer surface for manual engagement, and also a guard to keep cutting chips from entering the internal mechanism.
The tool holder of the present invention also includes cooling fluid delivery to the -tool and to this end the base member 1~, pla-te 40, cylindrical member 52, and set screw 72, all have an axial oversized bore 106 for receiving therethrough a tube 108 containing both a lubri-cant delivery line (not shown) and a pressurized air delivery line (not shown) so that at the terminal end of the tube 108, which mates with an axial bore in the tool, pressurized cooling fluid is delivered -thereto for ~lowing through the -tool and out appropriate apertures thro-ugh the side of -the tool. A bearing member 16 is retained in -the bottom of the member 52 so as to be between the rotatable member 52 and the stationary tube 108 so that any movement of the member 52, whether the permit-ted translational movement or the rocking or teetering movement provided by these members being supported on the rollers, is trans-mitted to the flexible tube 108 to similarly move or flex it such that the tube 108 does no-t come into contact with any rotating part that would otherwise eventually wear the tube away.
Thus, it is seen that on those occasions where the upwardly projecting tool, as mounted within the holder of the present invention, is not exactly axially aligned with the opening in the -tubesheet, initial insertion of the tool within such opening will cause the tool holder to move by virtue of its ability to move in any direction parallel to the surface 22 and ~6 (in a first vertical 3 ~ 7 8 48,388 plane and in a second vertical plane perpendicular to the first plane such that any required resultant movement within the permitted limits can be obtained through these two right-angle planes of movement). Also, on occasions where the axis of rotation of the base member 52 is not in alignment with the axial direction of the opening receiv-ing the tool, the tool holder, through its ability -to also pivot or teeter in two vertical planes off-set 90 and about surface 22 can also permit the axls of the tool -to be in alignment with the axis of the opening and angularly off-set from the axis o~ the drive so that any stress on the tool, tool holder or drive mechanism due to slight misalignment is minimized.

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Claims

9 48,388 CLAIMS:

1. Tool holding apparatus for use with a tool support and positioning mechanism and comprising:
a base member having a keyed shank for rotatable mounting within said support mechanism and defining a first surface generally perpendicular to the axis of ro-tation of said member;
a tool holding member having a side-wall slot for slidably receiving a locking pin to engage a tool within a tool receiving cavity open at one end and having a second.
surface at the opposite end generally perpendicular to the axis of said cavity and in spaced facing relationship with said first surface with said members being generally coaxial;
an intermediate member disposed between said spaced first and second surfaces and defining generally parallel end surfaces, with one of said end surfaces in adjacent facing relationship with said first surface and the other of said end surfaces in adjacent facing relation-ship with said second surface;
said base member and said intermediate means de-fining first engaging means for rotational generally coaxial driving engagement therebetween, said first engag-ing means further permitting relative translational move-ment therebetween in a first axially extending plane;
said tool holding member and said intermediate member defining second engaging means for rotational general-ly coaxial driving engagement therebetween, said second 48,388 engaging means further permitting relative translational movement therebetween along a second axially extending plane generally perpendicular to said first plane;
first support means for supporting said inter-mediate member on said base member with said first surface and said one surface in spaced relationship and providing a fulcrum therebetween permitting pivotal movement of said one surface in one axially extending plane;
second support means for supporting said tool holder member on said intermediate member with said second and said other surface in spaced relationship and providing a fulcrum therebetween permitting pivotal move-ment of said second surface in another axially extending plane perpendicular to said one plane; and interconnecting means extending between said tool holding member and said base member for preventing axial disengagement of said first and second engaging means, whereby said axis of said tool holding member is permitted translational motion with respect to the axis of rotation of said base member and pivotal movement with respect to said base member.

2. Structure according to claim 1 wherein each said first and second engaging means comprises engaging tongue-and-groove structure on said facing adjacent sur-faces.

3. Structure according to claim 2 wherein each said first and second support means comprises:
a pair of diametrically opposed roller members disposed within diametrically opposed cavities in one surface of each pair of said facing adjacent surfaces and wherein the axis of said roller members is parallel to said surface, and an arcuate portion of the surface of said roller member projects above said surface providing said fulcrum support; and wherein, 11 48,388 said tongue-and-groove structure between said facing adjacent surfaces extends perpendicularly to the axis of said roller members separating said respective surfaces so that the rollers provide a rolling support in the direction of guided translational movement permitted by said tongue-and-groove structure.

Structure according to claim 3 wherein: said base member, said intermediate member and said tool hold-ing member are generally cylindrical; and, said tool holding member defines an outer annu-lar shoulder adjacent said second surface, with the outer diameter of both said shoulder and said intermediate member less than the outer diameter of said base member;
and wherein, said interconnecting means comprises a collar threaded to said base member and having an upper inner annular lip overlying said shoulder to retain said tool holding member and said intermediate member on said base member, whereby said collar provides an annular space between it and the outer peripheral walls of both said tool holding member and said intermediate member to permit at least limited translational movement of said members within said collar.

5. Structure according to claim 3 wherein said roller members are housed within cavities in said first surface and said other of said end surfaces respectively and wherein said one of said end surfaces and said other of said end surfaces each define the tongue portion of said tongue-and-groove engaging means,

6. Structure according to claim 4 wherein said lip and shoulder define complementary engaging surfaces angled outwardly downwardly, that is toward the base member, to permit relative pivotal movement of said shoul-der with respect to said lip.