Buckles – buttons – clasps – etc. – Independent – headed – aperture pass-through fastener
Reexamination Certificate
1998-02-05
2001-12-04
Sakran, Victor N. (Department: 3626)
Buckles, buttons, clasps, etc.
Independent, headed, aperture pass-through fastener
C024S297000, C024S573110, C024S607000, C411S046000
Reexamination Certificate
active
06324731
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a fastener for joining two parts, and more particularly, to a plastic fastener comprising a pin and an isolator grommet for joining the housing of a computer cooling fan to the chassis of the computer. The isolator grommet is preinstalled in the fan housing. Insertion of the pin through the chassis and into the isolator grommet completes the mounting.
2. Description of the Prior Art
Fasteners for joining apertured work pieces are well known in the prior art, and are usually manufactured of metal or plastic. The nut and bolt and the screw are examples of common metallic fasteners, while examples of plastic fasteners are shown in U.S. Pat. Nos. 2,882,780 and 2,941,439.
When joining the cooling fan housing of a computer to the chassis of the computer, however, many prior art fasteners have proven unsatisfactory. With regard to metallic fasteners, they generally have a high elastic modulus, making them poor isolators of the vibrations caused by the operation of the fan, often resulting in bothersome and unacceptable noise. Second, metallic fasteners are relatively more difficult to install than plastic fasteners, often requiring use of a tool, such as a wrench or a screwdriver. Third, metallic fasteners are conductive and thus could prove hazardous if lost inside the computer.
With respect to plastic fasteners, many plastic fasteners have proven unsatisfactory in that they, as with metallic fasteners, insufficiently isolate the vibrations caused by the operation of the fan. Other plastic fasteners are difficult to install and/or remove, and yet other fasteners provide a weak coupling between the fan housing and the chassis.
It is therefore an object of the present invention to provide a plastic fastener for securing a fan housing to the chassis of a computer which results in a quieter mounting than that achieved by currently used fasteners. Another object of the present invention is to provide a plastic fastener which provides a secure connection between the housing and the chassis. Yet another object of the present invention is to provide a fastener which can be easily installed and removed. Other objects will become apparent from the discussion below.
SUMMARY OF THE INVENTION
An isolator fan fastener in accordance with the present invention achieves the above and other beneficial objects by providing a plastic fastener having a pin and a separate isolator grommet with an axial bore extending therethrough. The pin has a head and a shank. The shank has a first engaging portion, a second engaging portion, a third engaging portion and a fourth engaging portion. The four engaging portions have varying diameters and, as discussed below, are frictionally engageable with corresponding portions of the interior walls of the isolator grommet.
The isolator grommet has a head, a shank, a circumferential lip, and an axial bore of varying dimension extending therethrough for receiving the pin. The bore forms a first interior wall portion for receiving the first engaging portion of the pin shank in releasable frictional engagement, a second interior wall portion for receiving the second engaging portion of the pin shank in releasable frictional engagement, a third interior wall portion for receiving the third engaging portion of the pin shank in releasable frictional engagement, and a fourth interior wall portion for receiving the fourth engaging portion of the pin shank in releasable frictional engagement.
In operation the shank of the isolator grommet is inserted into a hole in the fan housing such that the wall of the fan housing is situated between the head and lip of the isolator grommet and the head and lip bear against the outer and inner surfaces of the housing, respectively. The isolator grommet is dimensioned in the manufacturing process to mate with a fan housing of predefined thickness, i.e. the thickness of the fan housing corresponds to the distance between the head and lip on the grommet.
The bore in the grommet is then aligned with the hole on the computer chassis with the isolator grommet head bearing against the inside of the chassis. The pin is inserted into the grommet until the pin head bears against the outside surface of the chassis. The pin is dimensioned in the manufacturing process for use with a computer chassis of predefined thickness. When the pin is fully inserted into the chassis the first engaging portion on the pin shank is in releasable frictional engagement with the first interior wall portion of the grommet, the second engaging portion on the pin shank is in releasable frictional engagement with the second interior wall portion of the grommet, the third engaging portion on the pin shank is in releasable frictional engagement with the third interior wall portion of the grommet, and the fourth engaging portion of the pin shank is in releasable frictional engagement with the fourth interior wall portion of the grommet.
At that point the fan housing is firmly and releasably fastened to the chassis. The isolator grommet is manufactured of a soft plastic such that it isolates a large portion of the vibration of the fan, thereby reducing the noise level. The pin, on the other hand, is manufactured of a hard plastic to ensure secure coupling with the isolator grommet, thereby securely fastening the fan housing to the chassis.
An isolator fan fastener in accordance with the present invention offers numerous advantages over the prior art. First, the noise caused by the operation of the fan is reduced as compared to many prior art fasteners. Second, the frictional engagement of the pin and the isolator grommet ensures a secure fastening. Third, the fan housing may be attached or detached to the computer chassis by simple insertion or extraction of the pin into or out of the isolator grommet without use of excessive force or a special tool. Other advantages will become apparent from the discussion below.
REFERENCES:
patent: 4457050 (1984-07-01), Kanzaka
patent: 4579473 (1986-04-01), Brugger
patent: 4757664 (1988-07-01), Freissle
patent: 5214826 (1993-06-01), Fortune
patent: 5568675 (1996-10-01), Asami et al.
patent: 5775860 (1998-07-01), Meyer
patent: 1220181 (1960-05-01), None
patent: 0676355 (1964-11-01), None
Illinois Tool Works Inc.
Pitney Hardin Kipp & Szuch LLP
Sakran Victor N.
LandOfFree
Isolator fan fastener does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Isolator fan fastener, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Isolator fan fastener will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2594571