U.S. patent application number 11/546105 was filed with the patent office on 2008-04-17 for tool for milling tapered threads with blunt start.
Invention is credited to Laszlo Frecska, James T. Hartford.
Application Number | 20080090666 11/546105 |
Document ID | / |
Family ID | 39321455 |
Filed Date | 2008-04-17 |
United States Patent
Application |
20080090666 |
Kind Code |
A1 |
Frecska; Laszlo ; et
al. |
April 17, 2008 |
Tool for milling tapered threads with blunt start
Abstract
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.
Inventors: |
Frecska; Laszlo; (Spring
Grove, IL) ; Hartford; James T.; (Silverlake,
WI) |
Correspondence
Address: |
Leo J. Aubel
111 Rivershire Lane
Lincolnshire
IL
60069
US
|
Family ID: |
39321455 |
Appl. No.: |
11/546105 |
Filed: |
October 11, 2006 |
Current U.S.
Class: |
470/10 |
Current CPC
Class: |
B23G 2210/48 20130101;
B23G 1/34 20130101; B23G 2210/08 20130101 |
Class at
Publication: |
470/10 |
International
Class: |
B21H 3/02 20060101
B21H003/02 |
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.
Description
BACKGROUND OF THE INVENTION
[0001] 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 INVENTION
[0002] A 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.
[0003] 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.
DRAWINGS
[0004] FIG. 1 is a side view of the thread milling tool of the
invention;
[0005] FIG. 2 is an end view of the thread milling tool of FIG.
1;
[0006] FIG. 3 is a view of the inventive tool mounted on a tool
holder for operation; and
[0007] FIG. 4 is a view of tapered threaded connector with a blunt
end made such as by the inventive tool.
DESCRIPTION OF THE INVENTION
[0008] FIG. 1 is a view of a preferred embodiment of the inventive
tool 11 for forming tapered threads with a blunt end all within the
purview of a single or same operation. Tool 11 comprises an
elongated shank or rod 12 having an end 14 that, in operation, is
secured in a tool holder 25, as will be described with reference to
FIG. 2., hereafter. Cutting teeth 15 are formed on the other or
non-secured end 17 of tool 11. An end view of the tool 11 is shown
in FIG. 2. The teeth structure 15 includes side rakes 17 formed
adjacent the teeth which rake angles or fades onto the periphery of
the rod 12. A smooth cylindrical section 19 is formed above the
teeth 15. A cutting shoulder or tooth 21 is formed above the smooth
section 19; shoulder 21 cuts and blunts the end of the thread
formed by the tool 11, as will be discussed further.
[0009] FIG. 3 shows the tool 11 mounted in a tool holder 25 which
is, in turn, mounted on a spindle 22 of a milling CNC machine. Tool
holder 25 includes a drive collar 26 and a threaded locking collar
27, as is known in the art, that enable the tool 11 to be quickly
mounted on or removed from the tool holder 25.
[0010] 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 FIG. 4, in a number of automotive
applications a tapered connection 28 provides a convenient means of
connection in tight or confined spaces. Again as mentioned above a
problem arises when using tapered connectors 28 due to the fact
that the end of a conventional tapered thread is thin and
susceptible to damage and also susceptible to stripping of the
threads as the threads are screwed together. This is often due to
the fact that there is an initial large spacing between the male
and female threads at the entry point that often causes
misalignment. Accordingly, one of the ways to minimize or solve the
problem is to provide a blunt end 30 for the tapered threads as
indicated in FIG. 4. Previously, this required at least one
additional step after milling the tapered thread. The present
inventive tool provides a tool that mills the tapered threads and
in the same CNC operation mills a blunt end on the threads during
the same machining procedure or program. As shown in FIG. 1, tool
11 includes a cutting tooth or shoulder 21. In the same CNC
operation, the tapered threads are cut and the shoulder 21 is
caused to engage and cut the thin end of the threads to provide a
blunt end 30 as indicated in FIG. 4. That is, the feathered end of
the tapered thread is cut off or blunted. The advantages of a
tapered thread are retained while including a stronger blunt
end.
[0011] 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.
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