Brakes – Internal-resistance motion retarder – Using a rotary-type fluid damper
Reexamination Certificate
2000-05-30
2001-10-09
Butler, Douglas C. (Department: 3613)
Brakes
Internal-resistance motion retarder
Using a rotary-type fluid damper
C188S322500
Reexamination Certificate
active
06298960
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a small viscous precision damper wherein the cap is attached by a tongue and groove joint which is ultrasonically welded.
2. Description of the Prior Art
Viscous dampers are known in the prior art. However, typically the cap includes a cylindrical rim which is inserted over the body of the damper and fastened thereto so as to create a shear connection between the cap and the body. However, such a design, particularly as smaller and smaller dampers are desired to be manufactured, can result in degraded repeatability in manufacturing, sealing and torque aspects. More specifically, some prior art damper designs result in both weld and torque variations due to the outward pressure applied to the cap during welding. This outward pressure decreases the weld penetration and varies the overall height of the damper which creates variations in the damper torque and may further result in silicone leakage. Similarly, some prior art damper designs have decreased weld encapsulation which decreases weld strength and sealing and creates undesired minute strings of plastic which affect customer applications.
An example of a prior art damper using a snap-together design is disclosed in U.S. Pat. No. 4,614,004 entitled “Oil Filled Rotary Damper Having a Symmetrically Shaped Flexible Membrane” issued on Sep. 30, 1986 to Oshida.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a damper design, particularly an improved seal therefor, for applications requiring a reduced size of damper.
It is therefore a further object of the present invention to provide a damper design with increased repeatability with respect to manufacturing, sealing and torque.
It is therefore a still further object of the present invention to provide a damper design which minimizes weld and torque variation resulting from outward pressure applied to the cap.
It is therefore a still further object of the present invention to provide a damper design which provides sufficient weld penetration.
It is therefore a still further object of the present invention to provide a damper design which provides a uniform damper height.
It is therefore a final object of the present invention to provide a damper design with sufficient weld encapsulation and minimization or reduction of undesired minute strings of plastic.
These and other objects are attained by providing a small or miniature rotary damper typically including a cap, rotor, O-ring, optional gear, viscous fluid (or other damping media) and a housing. The cap and the housing include a tongue and groove joint specifically adapted to ultrasonic welding. As the cap is generally disk-shaped and placed directly on the edge of the housing and ultrasonically welded thereto, the damper height can be precisely maintained.
REFERENCES:
patent: 4527675 (1985-07-01), Omata et al.
patent: 4571773 (1986-02-01), Yuda
patent: 4614004 (1986-09-01), Oshida
patent: 4638528 (1987-01-01), Omata et al.
patent: 4691811 (1987-09-01), Arakawa et al.
patent: 4701229 (1987-10-01), Arakawa et al.
patent: 4796733 (1989-01-01), Nakayama
patent: 4830151 (1989-05-01), Numata
patent: 4833938 (1989-05-01), Reinwall et al.
patent: 4840083 (1989-06-01), Hagan et al.
patent: 4869125 (1989-09-01), Saigura
patent: 4893522 (1990-01-01), Arakawa
patent: 5211267 (1993-05-01), Clark
patent: 5269397 (1993-12-01), Kawamoto et al.
patent: 5301775 (1994-04-01), Nedbal et al.
patent: 5718309 (1998-02-01), Kariya
Butler Douglas C.
Illinois Tool Works Inc.
Pitney Hardin Kipp & Szuch LLP
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