Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Having separate expander means – Frangible member
Reexamination Certificate
1999-12-16
2001-03-06
Wilson, Neill (Department: 3627)
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Having separate expander means
Frangible member
C411S055000, C411S060200, C411S080100
Reexamination Certificate
active
06196778
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a screw fixing plug used to mount instruments or the like to a construction article of concrete or mortar using a combination of the plug and a screw.
Heretofore, in mounting an instrument or the like to a construction article of concrete or mortar using screws, after forming a starting hole by drilling in the concrete or mortar, a cylindrical plug is inserted into the starting hole, a screw is inserted through an instrument superposed on the concrete or mortar, and the screw is tightened into the plug in the starting hole. The screw thus expands the plug, so that the instrument can be tightened to the concrete or mortar.
The conventional plug aims to obtain tightening force by pressing the plug against the inner wall of the starting hole by uniformly expanding the plug by the screw, thus preventing development of a gap between the screw and the starting hole. But since the plug is structured so as to prevent slip between the plug and concrete or mortar by the friction between the outer surface of the expanded plug and the inner wall of the hole in the concrete or mortar, slipping of the plug tends to occur relative to concrete or mortar, because the concrete or mortar is a material that is brittle and easily broken.
An object of this invention is to provide a screw fixing plug which can ensure biting of threads into concrete or mortar, when the plug is unevenly deformed and moved. The threads bite directly into both the concrete or mortar and the plug when the screw is tightened into the plug that is inserted into the starting hole. This increases the tightening force of the plug, and provides a combination of such a plug and a screw.
SUMMARY OF THE INVENTION
According to this invention, there is provided a screw fixing plug comprising a trunk made of a flexible material and having a first end and a second end, with a head at the first end. The trunk is split into a pair of leg portions by a slit extending longitudinally from the first end to the second end. The head at least partially protrudes radially outwardly from the outer periphery of the trunk and is formed with a through hole to receive a screw therein. And, the leg portions have opposed inner surfaces which are convex in section so that the slit narrows toward a diametrical center thereof.
Other features and objects of the present invention will become apparent from the following description made with reference to the accompanying drawings, in which:
REFERENCES:
patent: 805037 (1905-11-01), Stulz
patent: 1248008 (1917-11-01), Pleister
patent: 4223586 (1980-09-01), Miller
patent: 5688090 (1997-11-01), Miyamoto
patent: 5749688 (1998-05-01), Wakai
patent: 507155 (1930-09-01), None
Wakai & Co., Ltd.
Wenderoth , Lind & Ponack, L.L.P.
Wilson Neill
LandOfFree
Screw fixing plug and combination of the same with a 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 Screw fixing plug and combination of the same with a screw, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Screw fixing plug and combination of the same with a screw will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2451014