This invention is related to a chuck for connecting an end mill to a drive spindle. The chucking structure includes a cone that is received in a rotating spindle, a shank that is telescopically received in the cone and threadably received in a tool holder body. A retention knob joins the cone to the tool holder body by expanding a collar on the cone into an opening in the tool holder body as the retention knob is rotated.
Several forms of chucking structures are known for connecting an end mill to a rotating spindle, generally using a tapered body that is received in a tapered opening in the spindle.
Art that has addressed this problem include U.S. Pat. No. 6,394,466 issued May 28, 2002 to Masakazu Matsumoto et al. for an End Mill Chucking Structure, and U.S. Pat. No. 6,923,451 issued Aug. 2, 2005 to Masahiro Taguchi et al. for a Tool Holder.
The broad purpose of the present invention is to provide a tool holder chucking structure comprising a minimal number of components, and usable with a variety of commercially available spindles.
Still further objects and advantages of the invention will become readily apparent to those skilled in the art to which the invention pertains upon reference to the following detailed description.
The description refers to the accompanying drawings in which like reference characters refer to like parts throughout the several views, and in which
Tool holder 10 comprises a retention knob 16, a cone 18, a shank 20 and a tool holder body 22.
Referring to
The upper end of body 22, as viewed in
Bore 30 has a cylindrical wall 38 between shoulder 32 and seat 34. Bore 30 has a cylindrical wall 40 between shoulder 32 and an annular flange 42. Flange 42 abuts the lower surface 44 of spindle 14, when the tool is being rotated.
Shank 20 has a lower threaded end 46 that engages threaded section 36. Threaded end 46 joins an annular collar 48. Collar 48 has a lower face 49 that abuts seat 34 when the shank is fully joined to body 22. The outer cylindrical surface 49a of collar 48 is slidably received in cylindrical wall 38.
Referring to
Cone 18 has an upper bearing surface 62 for seating the retention knob, and a frustoconical wall 64 which progressively enlarges in diameter to a gage line 66. The outer cylindrical surface 68 of the cone extends from gage line 66 to a lower annular flat face 70. Cylindrical surface 68 slidably engages cylindrical wall 40 of the body. The cone has an axial bore 71.
Referring to
The arrangement is such that as the cone is biased toward the shank collar, neck 74 is expanded by the tapered section of the shank in the direction of arrows 82 and 84, wedging the neck between the shank and the body. In this seated position, a small clearance exists between lower flat face 85 of the neck and the upper face 51 of the collar. Further, a clearance exists between flat face 70 of the cone and the upper shoulder 32 of the body.
Referring to