Turning – Portable lathe for pipe turning
Reexamination Certificate
1996-07-29
2001-09-25
Tsai, Henry (Department: 3722)
Turning
Portable lathe for pipe turning
C082S123000, C082S128000, C082S160000
Reexamination Certificate
active
06293174
ABSTRACT:
This invention relates to internal drive core cutters.
More particularly, this invention relates to quick change drive assemblies for internal drive core cutters.
FIELD OF THE INVENTION
Still more particularly, this invention relates to the drive assemblies described above wherein the assemblies permit the quick changing of a core cutter drive assembly and associated components, so as to permit the cutting of cores of different diameters by means of changing the drive assemblies and their associated core cutting components.
Internal drive core cutters derive their names from the fact that they engage the inside of cores in order to rotate them during the cutting operation.
A typical internal drive core cutter mandrel has a non-rotating central pull rod, a drive unit that rotates on the pull rod and a non-rotating outer sleeve that encloses the drive unit except at parts of its proximal end where the drive unit engages a core drive train, and at its distal end where a drive plate engages a core drive assembly.
The core drive assembly is made up of a rotating component that engages the drive unit and carries expandable grippers that engage the inside of a core and a fixed component that is secured to the pull rod and a cone structure which urges the grippers into contact with a core when the pull rod is translated so as to cause the cone structure to force the grippers outward. The typical core drive has as a part thereof, a cutting pad against which a core cutting knife works to effect a core cut off. The core cutting knife is usually circular and may rotate or be fixed. The cutting pad may also rotate or be non-rotating.
Core stock is formed as long cylindrical tubes. The core stock is mounted on long mandrels which are a part of core cutting machines which perform the tasks associated with cutting cores to the desired lengths. On internal drive core cutters, the interior of the core stock is engaged by a core drive attached to the distal end of the mandrel, and the core is rotated past a core cutting knife which moves into the core stock to sever a core of the desired length from the core stock. In the past, it was common practice for a user to have a separate core cutting mandrel for each diameter of core to be cut in his work. In recent times, manufacturers of core cutting machinery have provided multiple mandrel core cutting machines which permit the employment of one machine to cut cores of more than one diameter on the same machine without requiring a time consuming change-over.
The art has long been in need of a quick and low cost means for converting a core cutting mandrel to accomodate to a range of diameters of cores to be cut.
The frequency of cycling of high stress loads, both static and dynamic, on internal core drives, and the limitations of space inside the core to be cut make it difficult to maintain the elements of the core drive in reliable operating condition. Therefore, it is common practice in the art to build the core drive onto the end of the mandrel so as to, in effect, make the core drive a part of the mandrel. Heretofore, the art has not provided an internal drive core drive that can be attached and removed from a core cutting mandrel as a unit.
It is, therefore, an object of this invention to provide quick change core drive mechanisms for internal drive core cutters.
It is further an object of this invention to provide the mechanisms described above wherein a drive mechanism of one diameter may be quickly exchanged for a drive mechanism of another diameter.
It is further an object of this invention to provide the mechanisms described above wherein components that need to be changed with a change in the core diameter, are maintained in association with the above described drive mechanisms so as to provide an assembled kit which facilitates the conversion of a core cutting mandrel from one core drive to another.
Other objects will become apparent from the following specifications, drawings and claims.
DESCRIPTION OF THE RELATED ART
The core cutting art is replete with drive mechanisms for internal drive core cutters. The inventor does not know of any such drives that can be characterized as quick change drive mechanisms. The cone mechanisms that are a part of this invention are found in the core cutter art and abound in the core gripper and roll handling and roll chuck art.
The prior art provides machines that have multiple mandrels of different sizes to facilitate the cutting of cores of different sizes.
It is known in the art to exchange a mandrel of one size on a machine for a mandrel of another size in order to facilitate the cutting of cores of different sizes. Typically the exchange requires the use of skilled tradesmen and typically requires about 45 minutes to accomplish.
It is further known in the art to rebuild the core drive of a mandrel to accept a core of a different size in order to facilitate the cutting of cores of different diameters. Typically the rebuilding of a core drive of a mandrel requires the services of a skilled tradesman and typically requires about 15 minutes to accomplish.
In counter-distinction, a quick change core drive unit of this invention can be exchanged for a similar quick change core drive of a different diameter in less than one minute by a machine operator.
SUMMARY OF THE INVENTION
This invention is a quick change core drive mechanism for internal drive core cutters having a fixed central pull rod and a drive unit that is rotatable around said pull rod and comprising: a core drive assembly having a rotating mechanism and a non-rotating mechanism, and the rotating mechanism is engageable with said drive unit and said non-rotating mechanism is engageable with said pull rod. The means for engaging the rotating mechanism is typically a male-female coupling which is engageable and disengageable by sliding the core drive assembly along the pull rod. The means for engaging the non-rotating mechanisms with the pull rod is typically a spring clip, or a pull pin, or a spring loaded “saber” style coupling.
A core pusher which supports the proximal end of a length of core stock and serves to advance the core stock to position the core stock for cut-off may be provided with a magnetic coupling element so that when the pusher comes in contact with the rotating element of the core drive mechanism, it becomes magnetically coupled therewith.
The core drive assembly and the pusher may be provided with an encasement that serves as a storage means for the core drive assembly and its associated pusher as well as serving as an aid to the quick assembly and disassembly of the core drive and pusher with a core cutter mandrel.
REFERENCES:
patent: 1012657 (1911-12-01), Kurschus
patent: 1345458 (1920-07-01), Pierce
patent: 1435511 (1922-11-01), Sutherland
patent: 1736700 (1929-11-01), Davis
patent: 2084801 (1937-06-01), Hall
patent: 2615644 (1952-10-01), Enz
patent: 3017207 (1962-01-01), Lloyd
patent: 3500976 (1970-03-01), Halley
patent: 3818797 (1974-06-01), Zettler
patent: 3951018 (1976-04-01), Gilmore
patent: 5026223 (1991-06-01), Hunt
patent: 5458031 (1995-10-01), Wolff
patent: 5555783 (1996-09-01), Pienta
patent: 000276245 (1990-02-01), None
Johnson Russell L.
Productive Solutions Inc.
Tsai Henry
LandOfFree
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