Tool for milling tapered threads with blunt start
A tool for cutting tapered threads, said tool being mountable on a tool holder that is in turn positioned onto a spindle of a milling machine controlled by a CNC. The CNC rotates and moves the tool in a pattern to cut a tapered thread on a male connector. The tool includes a step or projection of slightly greater dimension than the threads, and at a position slightly above the threads. During the same operation that the threads are being cut, the tool severs the thin end of the tapered threaded connector to form a blunt end.
This invention relates to tools for milling threads for connectors wherein the threaded connecting member may be of tapered design. Many different designs and methods have been used for securing connectors or male tapered thread into a threaded opening or female receptor. One of these tapered designs is the so-called Higbee thread. In many of these connectors there is a problem of providing a tight secure fit between the parts. Further the threaded connector has a tapered or feathered end which upon initial entry to the female counterpart is quite a loose fit which tends to cause a stripping problem: also the tapered end is generally thinner than the other part of the thread and tends to be damaged and to break more readily. Accordingly, one of the solutions to the problem is to form a blunt end on the entering male tapered thread. Another solution such as disclosed in U.S. Pat. No. 4,722,694, the end of the tapered threaded has special hardened surface or piece formed on the end which of course requires addition material and extra production effort. The present invention is directed to providing a milling tool that conveniently forms a tapered thread and in the same operation forms a blunt end for the tapered thread and without requiring reinforcing material.
SUMMARY OF THE INVENTIONA tool mountable on a tool holder that is in turn positioned onto a spindle of a milling machine controlled by a CNC. The tool includes an elongated shank or rod and has milling teeth formed at the free or non-secured end. The CNC control rotates and moves the tool in a pattern to cut a tapered thread on a male connector. The tool includes a cutting shoulder or projection of slightly greater diameter than the threads that is positioned slightly above the threads and, during the same operation that the threads are cut, the thin end of the tapered connector is severed to form a blunt end.
The foregoing features and advantages of the present invention will be apparent from the following more particular description of the invention. The accompanying drawings, listed herein below, are useful in explaining the invention.
As alluded to above, the tool 11 is particularly useful for forming the threads of a tapered screw thread. In many applications including electrical connections utilizing bushings, tapered connectors are employed to assure convenient and fast connections. Also, as indicated in
While the invention has been particularly shown and described with reference to a particular embodiment thereof it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
Claims
1-3. (canceled)
4. A tool having a cylindrical shank or rod adapted to have one end of said rod mounted onto a milling machine,
- a) milling teeth formed on the other end of said rod;
- b) side rakes formed adjacent said teeth which rakes fade or angle into the periphery of said rod to form tapered threads;
- c) said rod including a cylindrical section above said teeth and in adjacent relation to said teeth; and
- d) a cutting shoulder formed on said cylindrical section to cut and blunt the end of said tapered thread formed by said tool as the terminal part of the same operation.
5. A method of forming blunt ends for tapered thread connector consisting of the steps of:
- a) cutting tapered threads tapering from a first thickness to a feathered or thin end; and
- b) cutting the thin end of the tapered threads in the same operation as the cutting operation for forming said blunt ends.
6. A tool for mounting on a milling machine to form tapered threads on a male connector comprising,
- a) an elongated rod having one end mountable on a tool holder of a CNC machine;
- b) tapered thread cutting teeth formed at the other end of the rod, said teeth cutting said thread from a first thickness to a feathered or thin end; and
- c) a cutting shoulder formed on said rod in adjacent relation to said teeth for cutting said thin end of the formed tapered thread during the same operation as the thread cutting operation to provide a blunt end to said tapered thread.
Type: Application
Filed: Oct 11, 2006
Publication Date: Apr 17, 2008
Inventors: Laszlo Frecska (Spring Grove, IL), James T. Hartford (Silverlake, WI)
Application Number: 11/546,105