Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Headed fastener element with nut – washer – securing means or cap – Metallic resilient securing means
Reexamination Certificate
1998-12-17
2001-08-28
Wilson, Neill (Department: 3627)
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Headed fastener element with nut, washer, securing means or cap
Metallic resilient securing means
C411S107000, C411S396000, C411S552000
Reexamination Certificate
active
06280131
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to captive screws of the type generally used to attach a first panel to a second panel, frame or other surface wherein it is desired to keep the fastener in position on the first panel without loose items of hardware. The captive screw is mounted to the upper panel such that the screw stays attached to the panel even when the threads of the screw are fully disengaged from a threaded hole in the second panel to which the first panel is attached.
The present invention is directed toward a new and improved captive screw of a type which has a knob, a screw, and a ferrule. The captive screw is captivated on a panel by the ferrule and as the screw is screwed into a second panel the knob telescopically retracts over the ferrule. A spring may be used which urges the knob and integral screw to its fully retracted position when the captive screw is not attached to the second panel, thereby withdrawing the threads of the screw from the area of the lower panel.
Captive screws of the foregoing type in general are disclosed in, for example, Frattarola, U.S. Pat. No. 5,382,124 and French Patent 1,339,942. These patents depict captive screws of the general type herein but contain different configurations where the screw head mates integrally with the knob of the captive screw.
SUMMARY OF THE INVENTION
This invention relates to a low profile, retractable captive screw of the type wherein a first panel or other thin flat surface is to be mounted against another surface, such as a second panel or frame. The captive screw of the present invention has a unique configuration in the means by which the screw portion of the captive screw is mounted to the knob of the captive screw. The screw is attachable to the first panel, and is used for attaching the first panel to a lower surface, the lower surface having a threaded hole. The captive screw has a screw with or without an added flange surrounding the periphery of the head of the screw with protrusions integral to the outer perimeter of the screw head or flange, a thin-walled, cylindrical hollow knob that rigidly attaches to the screw, a ferrule that attaches to the upper panel and to the knob, and a spring. The flange with the protrusions or the screw head with the protrusions rigidly secures the screw head to the inner surface of the knob and provides a press-fit of the screw to the inner surface of the knob. The flange, if used, provides significant advantages in that it provides for a positive stop when the screw is pressed into the knob. Further, the screw head is installed into the knob from the bottom side of the knob rather than the top side of the knob as in similar prior art screws, providing further advantages as described below.
A second means for attachment of the screw to the knob allows for a press fit of the screw into the knob by filling in a chamfer on the periphery of the screw with material from the inner surface of the knob. This new construction provides significant structural advantages over prior art captive screws. The screw applies force directly through the ferrule rather than through a portion of the knob as in some similar prior art screws. The construction of the knob/screw interface allows for insertion of the screw into the bottom of the knob, rather than the top of the knob. In failure of the knob screw interface, the captive screw of the present invention still retains the panels to which the captive screw is attached. Even if the knob breaks free of the screw while the screw is in the open position, the knob is still retained on the screw, the screw is retained in the captive screw assembly, and the screw functions.
It is therefore an object of the present invention to provide a captive screw that provides for an improved, stronger knob/screw interface.
It is a further object of the present invention to provide a captive screw that provides for an improved, stronger knob/screw interface that provides for more surface area and therefore a stronger assembly, particularly when the captive screw is pressed onto a panel.
Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: D. 283591 (1986-04-01), Swanstrom
patent: D. 357176 (1995-04-01), Ernest et al.
patent: D. 388316 (1997-12-01), McDonough et al.
patent: 436523 (1890-09-01), Glover
patent: 748078 (1903-12-01), Kaisling
patent: 1166345 (1915-12-01), Gates
patent: 1188420 (1916-06-01), Eadie
patent: 1664820 (1928-04-01), Hughes
patent: 2006359 (1935-07-01), Lackner
patent: 2151255 (1939-03-01), Witchger
patent: 2331322 (1943-10-01), Heinick
patent: 2470927 (1949-05-01), Hale, Jr.
patent: 2553236 (1951-05-01), Bratfisch
patent: 2773574 (1956-12-01), Able
patent: 2831520 (1958-04-01), Clarke
patent: 2967557 (1961-01-01), Tait et al.
patent: 2987811 (1961-06-01), Acres
patent: 3033280 (1962-05-01), Snow
patent: 3052942 (1962-09-01), Mulvaney
patent: 3056197 (1962-10-01), Lawson
patent: 3059736 (1962-10-01), Boyd
patent: 3074292 (1963-01-01), Polman
patent: 3126935 (1964-03-01), Tuozzo
patent: 3137336 (1964-06-01), Wing
patent: 3180389 (1965-04-01), Frank
patent: 3195600 (1965-07-01), Middleton, Jr.
patent: 3204680 (1965-09-01), Barry
patent: 3209807 (1965-10-01), Ryner
patent: 3244212 (1966-04-01), Barry
patent: 3245450 (1966-04-01), Sauter
patent: 3250559 (1966-05-01), Sommerfeld
patent: 3263728 (1966-08-01), Lynch
patent: 3279302 (1966-10-01), Modrey
patent: 3343581 (1967-09-01), Martin et al.
patent: 3346032 (1967-10-01), Gulistan
patent: 3385341 (1968-05-01), Garstkiewicz
patent: 3437119 (1969-04-01), Dey
patent: 3465803 (1969-09-01), Ernest et al.
patent: 3502130 (1970-03-01), Gulistan
patent: 3564563 (1971-02-01), Trotter et al.
patent: 3571904 (1971-03-01), Gulistan
patent: 3718950 (1973-03-01), Engstrom
patent: 3912411 (1975-10-01), Moffat
patent: 3958308 (1976-05-01), Gooding
patent: 4007516 (1977-02-01), Coules
patent: 4047266 (1977-09-01), Bisbing
patent: 4078414 (1978-03-01), Orain
patent: 4367643 (1983-01-01), Hackett
patent: 4387497 (1983-06-01), Gulistan
patent: 4398322 (1983-08-01), Ewen
patent: 4399682 (1983-08-01), Hackett
patent: 4594040 (1986-06-01), Molina
patent: 4602903 (1986-07-01), Wilburn
patent: 4692075 (1987-09-01), Metz
patent: 4915557 (1990-04-01), Stafford
patent: 4952107 (1990-08-01), Dupree
patent: 4964773 (1990-10-01), Schmidt
patent: 4975007 (1990-12-01), Molina
patent: 5042880 (1991-08-01), Garuti et al.
patent: 5094579 (1992-03-01), Johnson
patent: 5146668 (1992-09-01), Gulistan
patent: 5209018 (1993-05-01), Heinrich
patent: 5336028 (1994-08-01), Yamamoto
patent: 5338139 (1994-08-01), Swanstrom
patent: 5382124 (1995-01-01), Frattarola
patent: 5544992 (1996-08-01), Ciobanu et al.
patent: 5642972 (1997-07-01), Ellis et al.
patent: 558456 (1958-06-01), None
patent: 1339942 (1962-11-01), None
patent: 2 268 977 (1975-04-01), None
patent: 2 579 009 (1986-02-01), None
patent: 2 626 384 (1988-09-01), None
patent: 626013 (1949-09-01), None
patent: 825877 (1959-12-01), None
patent: 1579730 (1980-01-01), None
Catalog-Huck International, Inc., Lakewood, CA. 90712 “Captive Fasteners and Rivetless and Rivetless Nut Plates”, Index Tag “Captive Screws, Press—in Type” Code ID #97928 “Deutschsert, Press-In Captive Screw, Floating, Retactable”, (one page), Jan. 1994.*
Penn Engineering & Manufacturing Corp., Fasteners For Use In or with PC Boards, Pem Bulletin K-488, (Danboro, PA 1980).
Penn Engineering & Manufacturing Corp., “Snap-Top Standoffs”, Pem Bulletin SSA-988 (Danboro, PA 1987).
Pem Engineering & Manufacturing Corp., “Type PF11 Self-Clinching Panel Fastener Assembly”, Pem Bulletin PF11-297, (Danboro, PA).
Camloc Fateners, “Captive Screws”, Catalog No. 3800, pp. 1-12 (Hasbrouch Heights, NJ).
Southco Fasteners Handbook 45, pp. C1-C11, C18-C27 (Pennsylvania, 1993).
Southco Fasteners Handbook 5, pp. C1-C44 (Pennsylvania, 1995).
American Society For Metals, Source Book on Cold Forming, pp. 83-87 (Ohio, 44073).
Huck International, Inc., “Captive Fasteners and Rivetless Nu
Dickerson Harry L.
Ellis Thomas J.
McCormack Edward A.
Paul & Paul
Southco Inc.
Wilson Neill
LandOfFree
Captive screw does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Captive screw, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Captive screw will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2545942