US 4,281,430 A · Method and apparatus for machining pipe collars

Abstract

A method and apparatus for machining pipe collars having internally tapered coaxial threads is accomplished by providing a thread cutting tool having defined thereon a single thread groove forming tooth with first and second thread topping forming portions defined on opposite sides of the thread groove forming tooth. The first and second thread toppings are so designed and oriented with respect to the thread groove forming tooth that the first thread topping forms the top configuration of the first tapered threaded surface simultaneously with cutting the thread groove of the first tapered threaded surface. The second thread topping is so oriented with respect to the threaded groove cutting to that it remains clear of the first thread as the first threaded surface is being formed. While cutting the second tapered threaded surface during completion of a thread cutting path, the second thread topping forms the top configuration of the second thread simultaneously with cutting of the groove of the second thread by the single thread groove cutting tooth. The first thread topping is so oriented with respect to the thread groove cutting tooth as to remain clear of the second thread as the second thread is being cut. The first and second oppositely tapered internal threads of the pipe collar are formed during movement of the thread cutting tool through the pipe collar in a single thread cutting pass.

Claims6

Dependent claims

A method of machining a cylindrical workpiece having coaxial opposed first and second tapered internal surfaces to form an internally threaded pipe collar having coaxial, oppositely tapered first and second threaded surfaces, said method comprising:

providing a threading tool having a single thread cutting tooth and having a first thread topping disposed on one side of said thread cutting tooth and a second thread topping disposed on the opposite side of said thread cutting tooth, said first and second thread toppings defining a line tangential thereto;
continuously rotating said pipe collar to be internally threaded about the longitudinal axis thereof;
moving said threading tool in one linear direction along said first tapered internal surface of said collar in thread cutting manner with said tangential line parallel to the axis of said collar and with said tooth cutting the thread groove and said first thread topping forming the topping of said first tapered thread, and with said second thread topping remaining clear of said topping of said first tapered thread;
and
moving said threading tool in said one linear direction along said second tapered internal surface of said collar in thread cutting manner with said tangential line parallel to the axis of said collar and with said tooth cutting the thread groove and said second thread topping forming the topping of said second tapered thread, and with said first thread topping remaining clear of said topping of said second tapered thread.

2 more elements

A thread cutting tool for cutting threads along a work piece having first and second oppositely tapered internal surfaces, said thread cutting tool comprising:

a tool body adapted to be supported in immovable manner by a tool support bar of a threading machine;
a single thread groove cutting tooth being defined on said body and being oriented to cut the grooves of both of said tapered threaded surfaces;
a first thread topping being defined on said body as one side of said thread groove cutting tooth;
a second thread topping being defined on said body on the opposite side of said thread groove cutting tooth;
said first thread topping being oriented to form the top configuration of the threads of said first tapered threaded surface during cutting of the grooves of said first tapered threads and said second thread topping being oriented to maintain non-cutting clearance during cutting of said first tapered threaded surface;
and
said second thread topping being oriented to form the top configuration of the threads of said second tapered threaded surface during cutting of the grooves of said tapered threaded surface and said first thread topping being oriented to maintain non-cutting clearance during cutting of said second tapered threading surface.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for machining pipe collars

Life of this patent

Method and apparatus for machining pipe collars

Life of this patent

Abstract

Claims6