Endless belt power transmission systems or components – Control for variable input to output speed-ratio – Including belt shiftable axially from one to another surface...
Reexamination Certificate
1998-09-10
2001-09-25
Bucci, David A. (Department: 3682)
Endless belt power transmission systems or components
Control for variable input to output speed-ratio
Including belt shiftable axially from one to another surface...
C474S078000
Reexamination Certificate
active
06293883
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is directed to bicycle components and, more particularly, to a bicycle derailleur which can be quickly installed to and removed from a bicycle frame.
Conventional bicycle rear derailleurs comprise a base member, a movable member supporting a chain guide, and a linkage mechanism coupling the base member to the movable member so that the movable member moves relative to the base member. The movable member includes a guide pulley for guiding the chain to one of a plurality of sprockets attached to the rear wheel. A through bore is usually formed in the base member, and a fixing bolt is fitted within the through bore for screwing the base member either directly to the bicycle frame or to a separate fixing member which, in turn, is directly attached to the bicycle frame. The derailleur is usually positioned below the rear wheel axle.
In order to operate properly, the radial position of guide pulley relative to the plurality of sprockets should be properly set. For derailleurs which have the base member rigidly fixed to the bicycle frame, the radial position of the guide pulley is set by adjusting the rotational position of the base member until the guide pulley has the desired position, and then the fixing bolt is tightened using a wrench. If the radial position of the guide pulley is to be readjusted, then the fixing bolt is loosened with the wrench, the rotational position of the base member is readjusted until the guide pulley has the desired new position, and then the fixing bolt is retightened with the wrench. The adjustment operation thus requires substantial effort and requires special tools. Furthermore, since the base member is usually positioned offset from the wheel axle, rotation of the base member to adjust the radial position of the guide pulley does not produce an intuitively predictable positioning of the guide pulley. Additionally, different frame manufacturers have different configurations for the attachment location of the derailleur. Not only does this further complicate the adjustment operation, but the derailleur designer cannot design a single derailleur that will work properly for all frame designs.
Another problem resulting from mounting the base member to the frame offset from the wheel axle is that the derailleur interferes with easy removal of the wheel. More specifically, the derailleur must be manually rotated so that the wheel can clear the derailleur when the wheel is removed from the frame. The derailleur again must be rotated when the wheel is to be reinstalled. The entire procedure often heavily soils the rider's hands, which can be very bothersome if the wheel must be removed to fix a flat.
SUMMARY OF THE INVENTION
The present invention is directed to a bicycle rear derailleur that can be quickly adjusted, installed and removed without requiring special tools, and which can be designed to operate with all frame designs. The derailleur can be removed separately or as an integral unit with the rear wheel.
In one embodiment of the present invention, a quick-release bicycle derailleur includes a base member, a movable member supporting a chain guide, and a linkage mechanism coupling the base member to the movable member so that the movable member moves relative to the base member. A draw bar extends from the base member and has a cam follower at the base member. A rotary cam is supported by the base member and contacts the cam follower so that rotation of the rotary cam pulls the drawbar into the base member. A nut may be fitted to the other end of the draw bar so that, when the drawbar is pulled into the base member, the base member and the nut securely clamp the derailleur to a pair of fork ends on the bicycle frame. If desired, a control lever may be coupled to the rotary cam and may extend outward from the base member so that rotation of the control lever causes rotation of the rotary cam to facilitate pulling and releasing the draw bar. As a result, the derailleur can be installed, removed and adjusted very quickly by rotating the control lever. No special tools are required.
The draw bar typically extends through a hollow axle shaft, so the base member will be centered on the rotational axis of the rear wheel. This facilitates adjustment and allows the derailleur designer to design a derailleur that will not be affected by different frame configurations.
In another embodiment, a quick-release bicycle derailleur includes a base member having a threaded opening, a movable member supporting a chain guide, and a linkage mechanism coupling the base member to the movable member so that the movable member moves relative to the base member. The threaded opening in the base member allows the base member to be screwed directly to the hub axle, if desired, or to a draw bar. In any event, the base member again will be centered on the rotational axis of the rear wheel, thus facilitating the design of the derailleur by the designer and adjustment of the derailleur by the user.
In a more specific embodiment, a draw bar has a first end coupled to the threaded opening in the base member and a second end spaced apart from the base member. A cam follower is disposed at the second end of the drawbar, and a housing is fitted over the second end of the drawbar. A rotary cam is supported by the housing and contacts the cam follower so that rotation of the rotary cam pulls the drawbar into the housing. This, in turn, causes the housing and the base member to securely clamp the derailleur to a pair of fork ends on the bicycle frame.
If desired, the base member may include a fixing nut rotatably supported in an opening in the base member. The fixing nut may include an external flange with knurls or a projection on the outer peripheral surface to facilitate rotation of the fixing nut by hand, or else the fixing nut can include a polygonal opening to facilitate rotation using a tool.
REFERENCES:
patent: 2784758 (1957-03-01), Rohe
patent: 3854753 (1974-12-01), Hautier
patent: 4384864 (1983-05-01), Bonnard
patent: 4443208 (1984-04-01), Kozakae
patent: 4580670 (1986-04-01), Nagano
patent: 4624151 (1986-11-01), Huret
patent: 4637809 (1987-01-01), Nagano
patent: 4676118 (1987-06-01), Leiter
patent: 4724692 (1988-02-01), Turin et al.
patent: 4731046 (1988-03-01), Juy
patent: 4789379 (1988-12-01), Ozaki et al.
patent: 4820096 (1989-04-01), Knight
patent: 4842568 (1989-06-01), Marchigiano
patent: 4904110 (1990-02-01), Klein
patent: 5238458 (1993-08-01), Ishibashi
patent: 5257855 (1993-11-01), Nagano
patent: 5295916 (1994-03-01), Chattin
patent: 5380252 (1995-01-01), Iwasaki et al.
patent: 5397273 (1995-03-01), Ando
patent: 5597366 (1997-01-01), Ozaki
patent: 5622412 (1997-04-01), Yamane
patent: 5660407 (1997-08-01), Adams
patent: 5919106 (1999-07-01), Ichida
patent: 0 653 347 A1 (1995-05-01), None
patent: 97/07013 (1997-02-01), None
Bucci David A.
Charles Marcus
Deland James A.
Shimano Inc.
LandOfFree
Quick release derailleur does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Quick release derailleur, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quick release derailleur will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2452356