Turning – Portable lathe for pipe turning
Reexamination Certificate
1999-10-13
2001-02-20
Tsai, Henry (Department: 3722)
Turning
Portable lathe for pipe turning
C082S128000, C082S131000, C082S136000
Reexamination Certificate
active
06189425
ABSTRACT:
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates generally to apparatus for refurbishing pipes, valves, flanges and the like in industrial plants, such as power generation facilities, petroleum pipeline facilities and the like, and more particularly to a portable lathe machine that can be rapidly set up and used in the field to accurately machine flat or beveled surfaces on pipe flanges, valve, fittings and pipe ends within close tolerance ranges.
II. Discussion of the Prior Art
Various portable machines for performing different machining operations are known in the art. In the refurbishment of industrial tubing, such as is found in refineries, pipelines, steam power plants and the like, it is often necessary to cut through a pipe and then perform one or more end prep operations, such as beveling, facing, threading, etc. to thereby facilitate the joining of pipe ends or flanges. The Wachs et al. U.S. Pat. No. 4,411,178 describes a typical prior art machine for end prepping pipes and piping components. In that machine, separate drive motors are required for causing radial and axial feed of the tool. The feed rates are controlled by controlling the speed of the two motors. Moreover, the design reflected in the Wachs et al. '178 patent precludes the tool slide and tool supported thereby to be placed at an angle to the base plate
30
, thus making it more difficult to accurately bevel the end of a pipe workpiece.
The present invention also comprises an improvement over my earlier portable end prep machine described in U.S. Pat. No. 4,799,409. For example, in that earlier design, no provision is made for an adjustable radial feed rate of the cutting tool, nor is any provision made for tilting the tool slide at a desired angle to the axis of the pipe to facilitate mitering or beveling of the pipe end being machined. Further, no provision is made for accurately gauging movement in the axial feed direction as an operator manually attempts to adjust axial displacement of the housing on which the tool head is mounted.
SUMMARY OF THE INVENTION
The present invention comprises a portable rapid end prep lathe for machining piping components. It comprises an elongated mandrel having radially adjustable legs proximate one end thereof which are adapted to cooperate with the internal diameter of a pipe or pipe component to be worked on so as to concentrically mount the mandrel relative to the axis of that workpiece. An annular housing is concentrically mounted on the portion of the mandrel that projects outward from the end of the tubular workpiece. The annular housing member is longitudinally displaceable along the mandrel. Contained within it is a plurality of regularly spaced bearings that project outwardly from one face of the housing member proximate an outer periphery thereof. A gear ring is also concentrically disposed on and journaled for rotation about the mandrel. The gear ring has first and second faces where the first face includes an annular groove into which fits the plurality of regularly spaced bearings. At least one, and preferably two, slide assemblies are mounted on a second face of the gear ring. The slide assemblies include a base member with a threaded feed screw journaled for rotation therein, the feed screw carrying a threaded feed nut. A tool block is slidably mounted on the base and engaged by the feed nut such that rotation of the feed screw affects displacement of the tool block relative to the base. A motor is affixed to the annular housing and arranged to drive the gear ring. A drive mechanism is operatively coupled between the gear ring and the feed screw for rotating the feed screw to thereby radially reposition the tool block that carries the cutting bit therein.
In accordance with a further feature of the invention, the drive means includes a gear box assembly having a forward, reverse and neutral position as well as a novel mechanism for varying the speed of rotation of the feed screw in the tool slide assembly. This mechanism includes a plurality of ramps pivotally joined to a face of the annular housing member. A mechanism is provided for manually setting the slope angle of these ramps. The input shaft to the gear box has a one-way ratchet clutch affixed to it and a cam is provided that is adapted to traverse the plurality of ramps as the gear ring is driven where the cam rotates the one-way ratchet clutch by an amount determined by the slope angle of the ramps. A manual adjustment is provided for setting the slope angle of the ramps and, therefore, the speed at which the input shaft to the gear box operates.
REFERENCES:
patent: 4411178 (1983-10-01), Wachs et al.
patent: 4493232 (1985-01-01), Nall
patent: 4677884 (1987-07-01), Kwech et al.
patent: 4799409 (1989-01-01), Ricci
patent: 5189933 (1993-03-01), Ricci
patent: 5549024 (1996-08-01), Ricci
patent: 5887501 (1999-03-01), Ricci
Place Brent
Ricci Donato L.
Nikolai Mersereau & Dietz, P.A.
Ricci Donato L.
Tsai Henry
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