Chucks or sockets – Socket type – Spring biased jaws
Reexamination Certificate
1998-09-08
2001-07-17
Young, Lee (Department: 3729)
Chucks or sockets
Socket type
Spring biased jaws
C279S110000, C409S233000
Reexamination Certificate
active
06260855
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed workholding equipment. Specifically, the present invention discloses a workholding apparatus for securing a toothed workpiece in a machine tool in which the workholding apparatus is quickly secured in, and released from, the spindle of the machine tool by the movement of components of the workholding apparatus.
BACKGROUND OF THE INVENTION
In metalworking operations where a workpiece is machined, equipment of some type is necessary to hold the workpiece in position in a machine tool so the machining process can be successfully carried out. This type of equipment is known as “workholding” equipment. In the production of toothed articles, such as gears, workholding equipment can be generally categorized as two types, chucks and arbors.
Chucks hold a workpiece by contracting a component called a “collet” around the workpiece or a component thereof. For example, when a bevel or hypoid pinion with integral shaft is placed in a chuck, it is usually the shaft that is gripped by the collet which has been reduced in diameter to grip the shaft to hold the pinion in position. Examples of chucks for gripping pinion shanks can be found in U.S. Pat. No. 3,083,976 to Stark and U.S. Pat. No. 3,244,427 to Taschl.
Arbors grip a workpiece by expanding a collet into contact with a surface of the workpiece. As an example, a bevel ring gear is placed on an arbor and the collet is expanded until contact of sufficient force is established with the surface of the bore of the ring gear to hold the ring gear in position during machining. An example of an arbor for a ring gear can be found in U.S. Pat. No. 3,735,994 to Jaehn. An arbor for expanding into contact with the bore of a pinion can be found in U.S. Pat. No. 3,517,939 to Jaehn.
In either chucks or arbors, the force necessary to contract or expand the collet mechanism is provided by a draw bar in the machine tool. The draw bar is advanced and/or retracted usually with a hydraulically operated piston. Movement of the draw bar in the axial direction of the chuck or arbor usually causes opposed angled surfaces of components within the workholding equipment to slide relative to one another resulting in inward (contracting) or outward (expanding) movement of the collet to grip a workpiece or component part thereof. Generally, one angled surface is found on the collet and the other angled surface is found on an actuator attached to the draw bar or on the draw bar itself.
Chucks and arbors are mounted for rotation in the bore of a machine tool spindle. The spindle bore is usually tapered and a similar taper is usually found on the outer surface of the chuck or arbor. Once placed in the spindle bore, a plurality of bolts are extended through holes in a mounting flange located about the spindle and into engagement with corresponding threaded holes on the face of the machine spindle.
Securing a chuck or arbor to a machine tool spindle, or ejecting it from the machine tool spindle, are manually performed operations that are very time consuming since the many bolts must be tightened to specifications. When removing the chuck or arbor, aside from the time necessary to loosen and remove all of the bolts, ejector screws usually must be utilized to “break” the contact between the chuck/arbor outer tapered surface and the tapered inner surface of the spindle bore.
It is an object of the present invention to provide a means to reduce the amount of time needed to install a chuck or arbor in a machine spindle and/or remove it from the spindle.
It is a further object of the present invention to provide a chuck or arbor in which action of a draw bar not only results in a workpiece being gripped but also results in the chuck or arbor being positioned in the machine tool spindle.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus for holding a workpiece in a predetermined position in a machine tool. The apparatus has an axis of rotation and comprises an outer body having an outer surface, an inner bore, a first end and a second end with the second end being insertable into a tapered opening of a spindle of the machine tool. The outer body includes means projecting radially from the outer surface for abutment against a face of the spindle for stopping inward movement of the apparatus upon achieving a predetermined final position in the spindle. A portion of the outer surface adjacent the stop means and extending toward the second end is inwardly tapered by an amount whereby the taper of the outer surface is generally equal to the taper of the spindle opening.
The workholding apparatus includes a connector attached to the second end of the outer body, the connector having a first end insertable into the second end of the outer body and a second end comprising a plurality of spaced-apart lugs extending radially outward.
The inventive apparatus further comprises a collet located at the first end of the inner bore and a contractor located in the inner bore. The contractor is axially movable and comprises a first end having one or more angled surfaces in contact with respective angled surfaces on the collet whereby axial movement of the contractor expands or contracts the collet. The contractor has a second end comprising a plurality of spaced-apart lugs extending radially outward.
The present invention also includes an inventive draw rod having a first end located within a sleeve with both the first end of the draw rod and the end of the sleeve having spaced-apart lugs extending radially inward whereby lugs from the connector and contractor can pass through slots between the lugs on the draw rod and sleeve such that subsequent rotation of either set of lugs will result in all lugs attaining a face-to-face contact thereby coupling the contractor and connector to the draw rod and sleeve respectively.
REFERENCES:
patent: 2574754 (1951-11-01), Peters
patent: 3083976 (1963-04-01), Stark
patent: 3244427 (1966-04-01), Taschl
patent: 3517939 (1970-06-01), Jaehn
patent: 3612384 (1971-10-01), Loyd
patent: 3735994 (1973-05-01), Jaehn
patent: 3877329 (1975-04-01), Noa
patent: 4031810 (1977-06-01), Nattefort
patent: 4202102 (1980-05-01), Nakanishi
patent: 5354076 (1994-10-01), Yeo et al.
patent: 5806859 (1998-09-01), Saccomanno
McDowell Robert L.
Smith Sean
The Gleason Works
Young Lee
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