US3789643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double angle cutoff die and method for rolling screws
Assignee: REED ROLLED THREAD DIE CO
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Filing: 1972-02-10
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Granted: 1974-02-05
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Expires: 1992-02-10
Abstract
Abstract This invention relates to gimlet point screws and thread rolling dies for making such screws. A full precisely formed gimlet point is achieved by means of an extruding cutoff ramp having a high rate of penetration initially followed by a more gradual penetration to remove the extrusion slug.
Inventors
- 👤 J Dickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:45
CPC Classifications
B; B21; B21H; B21H3/00; B21H3/02; B21H3/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
138 words
A roll forming die for forming the circumference of a cylindrical workpiece and for pointing and severing the cylindrical workpiece wherein the die is provided with (a) a first surface for forming a body portion of a cylindrical workpiece, said first surface having a mean plane and (b) a cutoff ramp upstanding from said mean plane for pointing and severing the cylindrical workpiece, said cutoff ramp rising from said first surface of the die for forming the workpiece and having a first plane inclined at a first angle to said mean plane and a second plane inclined at a second angle to said mean plane, said second angle being different than said first angle, said cutoff ramp having a point threading surface on the side thereof between said mean plane and the uppermost portion of said cutoff ramp.
Claim 2
Dependent Claim
138 words
A roll forming die for forming the circumference of a cylindrical workpiece and for pointing and severing the cylindrical workpiece wherein the die is provided with (a) a first surface for forming a body portion of a cylindrical workpiece, said first surface having a mean plane and (b) a cutoff ramp upstanding from said mean plane for pointing and severing the cylindrical workpiece, said cutoff ramp rising from said first surface of the die for forming the workpiece and having a first plane inclined at a first angle to said mean plane and a second plane inclined at a second angle to said mean plane, said second angle being different than said first angle, said cutoff ramp having a point threading surface on the side thereof between said mean plane and the uppermost portion of said cutoff ramp.
Claim 3
Dependent Claim
18 words
A die as set forth in claim 1 wherein said first angle is greater than said second angle.
Claim 4
Dependent Claim
58 words
A roll forming die as set forth in claim 2 wherein a generally planar second surface extends between said first surface and said cutoff ramp, said second surface being obliquely disposed with respect to said mean plane to form a pointed surface on the workpiece adjacent to the end formed when said cutoff ramp severs the cylindrical workpiece.
Claim 5
Dependent Claim
33 words
A roll forming die as set forth in claim 3 wherein said first and said second surfaces are provided with a plurality of ridges for forming a continuous thread on the cylindrical workpiece.
Claim 6
Dependent Claim
46 words
A roll forming die as set forth in claim 4 wherein said first plane engages said workpiece before the second plane and said cutoff ramp penetrates into the workpiece three quarters of its total penetration in the first one-half of its length which contacts the workpiece.
Claim 7
Dependent Claim
50 words
A roll forming die as set forth in claim 4 wherein said first plane engages said workpiece before said second plane and said cutoff ramp penetrates seven-eights of its maximum penetration into the workpiece after three quarters of the length of the cutoff ramp has passed over the cylindrical workpiece.
Claim 8
Dependent Claim
140 words
A pair of roll forming dies for forming the circumference of a cylindrical workpiece and for pointing and severing the cylindrical workpiece wherein each die is provided with (a) a first surface for forming a body portion of a cylindrical workpiece, said first surface having a mean plane and (b) a cutoff ramp upstanding from said mean plane for pointing and severing the cylindrical workpiece, said cutoff ramp rising from said first surface of the die for forming the workpiece and having a first plane inclined at a first angle to said mean plane and a second plane inclined at a second angle to said mean plane, said second angle being different than said first angle, said cutoff ramp having a point threading surface on the side thereof between said mean plane and the uppermost portion of said cutoff ramp.
Claim 9
Dependent Claim
140 words
A pair of roll forming dies for forming the circumference of a cylindrical workpiece and for pointing and severing the cylindrical workpiece wherein each die is provided with (a) a first surface for forming a body portion of a cylindrical workpiece, said first surface having a mean plane and (b) a cutoff ramp upstanding from said mean plane for pointing and severing the cylindrical workpiece, said cutoff ramp rising from said first surface of the die for forming the workpiece and having a first plane inclined at a first angle to said mean plane and a second plane inclined at a second angle to said mean plane, said second angle being different than said first angle, said cutoff ramp having a point threading surface on the side thereof between said mean plane and the uppermost portion of said cutoff ramp.
Claim 10
Dependent Claim
20 words
A pair of dies as set forth in claim 7 wherein said first angle is greater than said second angle.
Claim 11
Dependent Claim
67 words
A pair of roll forming dies as set forth in claim 8 wherein each of said dies has a generally planar second surface extending between said first surface and said cutoff ramp, each of said second surfaces being obliquely disposed with respect to said mean plane to form a pointed surface on said workpiece adjacent to the end formed when said cutoff ramp severs the cylindrical workpiece.
Claim 12
Dependent Claim
36 words
A pair of roll forming dies as set forth in claim 9 wherein said first and said second surfaces are each provided with a plurality of ridges for forming a continuous thread on the cylindrical workpiece.
Claim 13
Dependent Claim
48 words
A pair of roll forming dies as set forth in claim 10 wherein said first plane engages said workpiece before said second plane and said cutoff ramp penetrates into the workpiece three quarters of its total penetration in the first one-half of its length which contacts the workpiece.
Claim 14
Dependent Claim
54 words
A pair of roll forming dies as set forth in claim 10 wherein said first plane of each die engages said workpiece before said second plane and said cutoff ramp penetrates seven-eighths of its maximum penetration into the workpiece after three quarters of the length of the cutoff ramp has passed over the workpiece.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |