Machine element or mechanism – Control lever and linkage systems – Hand operated
Reexamination Certificate
2002-05-22
2003-06-17
Kim, Chong H. (Department: 3682)
Machine element or mechanism
Control lever and linkage systems
Hand operated
C074S524000
Reexamination Certificate
active
06578445
ABSTRACT:
FIELD OF THE INVENTION
The present application relates to control levers for vehicles. More particularly, the present invention relates to a collapsible control lever suitable for use on motorcycles.
DESCRIPTION OF THE RELATED ART AND SUMMARY OF THE INVENTION
In many motorcycles the brake and/or clutch is operated by a manual lever that is mounted to the handlebar. A bowden wire or hydraulic hose, depending on whether the brake or clutch is mechanical or hydraulic, extends from the lever to a structure that is to be operated, i.e. the brake or clutch.
Typically, the manual lever is located alongside the handgrip on the handlebar. To operate the lever the rider places one or more fingers around the handgrip and lever; the rider then applies a squeezing force to the lever to rotate the lever toward the handgrip. The lever movement produces a pulling force on the bowden wire, or a pushing force on a hydraulic plunger, again depending on the type of brake or clutch to be actuated.
One problem with conventional levers is that, due to the handlebar generally being the most outwardly disposed portion of the motorcycle, in the event of the motorcycle falling over the end of the lever may forcibly strike the ground causing the lever, or its mounting structure, to break. This could occur from the motorcycle being tipped from its kickstand or work stand. In another situation, the motorcycle could be subject to a crash while in motion. A manual transmission motorcycle is inoperable without a functioning clutch, therefore if the clutch lever is broken during a motorcycle race the rider will not be able to finish. In many racing events the rider must finish the race in order to score points; if a rider does not complete the race the rider is given a DNF (Did Not Finish) and is awarded zero points. A single DNF may cost a rider enough points to lose the championship in a series made up of individual races.
An attempted solution to this problem is illustrated in U.S. Pat. No. 6,047,611 to Warren et al. The Warren et al. control lever assembly uses a modified lever section having two pivots. The first pivot allows substantially fore and aft rotation about an axis, while the second pivot allows substantially up and down rotation about an axis. The purpose of the two pivots is to allow the lever to fold away such that the handlebar absorbs any impact from the ground as a result of the motorcycle falling over. Such a construction, however, has many drawbacks preventing it from being widely used. The multi-pivot construction of Warren et al. is complex, heavy and does not perform adequately in comparison with a conventional lever.
Another solution, used especially by motorcycle racers, is to modify the lever to provide a hole or notch on an outward portion of the lever. The purpose is to weaken the lever so that in the event of a crash the lever will break at the weakened area. The hole or notch is positioned such that a portion of the lever will remain intact to allow the rider to finish the race, however it must also be located far enough inward from the end of the handlebar so that the remaining portion of the lever is not in contact with the ground when the motorcycle is on its side. Otherwise, the lever would be subject to damage in a similar manner to a conventional lever. As a result, after a crash in which the lever is severed at the weakened area, the intact portion provides little space for the rider's fingers to actuate the lever. Therefore, with this approach the lever must be replaced after the race. As crashes are a frequent occurrence in motorcycle races, this method becomes quite impractical.
An aspect of the present invention involves the realization of several inherent disadvantages in a multi-pivot control lever, such as that illustrated in Warren et al. The disadvantages with respect to a conventional control lever include reduced cable pull (or plunger movement), reduced finger grip area, and unwanted motion of the lever.
Providing multiple pivots in a control lever takes up a significant amount of space, forcing the rider's fingers to be positioned further from the lever's axis of rotation (pivot) than a conventional lever. A control lever can only be positioned so far from the handlebar and still be comfortable for the rider to reach with his fingers. Therefore, the available rotational motion is limited and moving farther from the pivot reduces the amount the wire is moved relative to its sheath in a bowden wire arrangement, or the amount the hydraulic plunger is moved in a hydraulic arrangement (generically referred to as “cable pull”). As it is desirable to keep the rotational movement required at a minimum, increasing the distance of the lever input of the rider's fingers from the pivot of the lever presents a disadvantage.
An additional disadvantage to the multi-pivot construction is that the space taken up by the pivot assembly reduces the lever area available for the rider's fingers. As. most riders use their inner one or two fingers to control the lever, the multiple pivots illustrated in Warren et al. decrease the most valuable portion of the lever.
The multi-pivot design as in Warren et al. includes a horizontal axis of rotation that allows substantially vertical movement of the lever. In order to be useful, the resistive element in the horizontal pivot of a multi-pivot lever construction must be flexible enough to allow the lever to move if the motorcycle were to fall over while at very low speeds or even while standing still. This is a disadvantage because most of the forces imparted on an off-road motorcycle are vertically oriented, such as from rough surfaces or the motorcycle landing from jumps. As a result, substantial vertical forces may cause undesired movement of the lever while the motorcycle is in use.
Accordingly, preferred embodiments of the present invention provide a collapsible control lever that inhibits breakage, avoids problems of the prior art and performs control functions as well as a conventional lever.
One aspect of the invention is a manual lever assembly for mounting on a handlebar including a handgrip. The lever assembly includes a handlebar mount defining a gripping surface for contacting a handlebar wherein the gripping surface defines a handlebar axis. The handlebar mount defines a first axis of rotation. The lever assembly additionally. includes an intermediate section connected to the handlebar mount so as to be rotatable about the first axis between a relaxed position and an actuated position. The intermediate section defines a second axis of rotation and an actuator retaining portion. A lever section defining a finger grip portion and having a distal end and a pivot portion is connected to the intermediate section so as to be rotatable about the second axis of rotation. The lever section further has a normal position and a fully deflected position at least approximately 120° from the normal position. The distal end of the finger grip portion of the lever section defines a first perpendicular distance from the handlebar axis when the intermediate section is in a relaxed position. The distal end of the finger grip portion of the mount further defines a second perpendicular distance from the mount when the intermediate section is in an actuated position, the first distance being longer than the second distance.
A further aspect of the invention is a manual lever assembly for mounting on a handlebar including a handgrip. The lever assembly includes a handlebar mount defining a gripping surface for contacting a handlebar wherein the gripping surface defines a handlebar axis. The handlebar mount defines a first axis of rotation. The lever assembly additionally includes an intermediate section connected to the handlebar mount so as to be rotatable about the first axis between a relaxed position and an actuated position. The intermediate section defines a second axis of rotation and an actuator retaining portion. A lever section defining a finger grip portion and having a distal end and a pivot portion is connecte
Barnett Robert L.
Kim Chong H.
Knobbe Martens Olson & Bear LLP
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