Threaded – headed fastener – or washer making: process and apparat – Process – Making internally threaded fastener – e.g. – nut
Reexamination Certificate
2001-11-02
2003-05-06
Tolan, Ed (Department: 3725)
Threaded, headed fastener, or washer making: process and apparat
Process
Making internally threaded fastener, e.g., nut
C470S018000, C470S025000
Reexamination Certificate
active
06558263
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a forging method of producing a hollow part from a cylinder blank.
BACKGROUND OF THE INVENTION
A conventional method for forging a nut contains the following steps as illustrated in
FIGS. 5A-J
. A blank
101
is cut so that a diameter D of the blank
101
may be smaller than the width B across the flat portions of the nut by approximately 0.4 mm and also have a large flat cross section. In a first process, the blank
101
are chamfered to produce a cylindrical semi-manufactured product
102
. In a second process, a semi-manufactured product
103
having its outer shape preformed to be hexagonal is obtained. In a third process, dents
104
a
and
104
b
to be used for forming a female thread are created on a semi-manufactured product
104
. In a fourth process, the semi-manufactured product
104
having the dents
104
a
and
104
b
is further extruded to form a semi-manufactured product
105
having deeper dents
105
a
and
105
b
. Then in a fifth process, piercing is performed to the remaining portion between the dents
105
a
and
105
b
, and a final product
106
having a pierced hole
106
a
is obtained. In the next process, a female thread is formed in the pierced hole
106
a.
However, such a conventional method requires a large number of processes like chamfering and preforming to forge a hollow part, and the processes are complicated.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a forging method which enables forging of a hollow part by simplified processes.
In order to attain the above object, the present invention provides a forging method of a hollow part comprising steps of upsetting a cylinder blank having the upsetting ratio of 1.5-2.0 so that the blank has the smaller outer shape and the lower height than those of the part to be formed, forming dents on both sides of the blank in the direction of the height of the part; and piercing the bottom portion of the dents to create a pierced hole in the blank.
It is preferable that the depth of the dents are made different. Also, if the part is selected from the group consisting of a nut, a hub nut and a flange nut, it is preferable to form a female thread after a pierced hole is created. The part could be a bush collar.
REFERENCES:
patent: 2542023 (1951-02-01), Friedman
patent: 4253323 (1981-03-01), Murakami et al.
patent: 4299000 (1981-11-01), Koch
patent: 4422196 (1983-12-01), Skinner
patent: 5524471 (1996-06-01), Nielson
Davis & Bufold, P.L.L.C.
Tolan Ed
LandOfFree
Forging method of a hollow part does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Forging method of a hollow part, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Forging method of a hollow part will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3065422