The invention concerns an actuator unit for a hydraulic brake on two-wheelers.
In recent years, certain high performance bicycles have included hydraulic brakes. The reach adjustment for the brake levers for these types of brakes are typically complicated and involve expensive components.
It is therefore a task of the invention to design an actuator unit of a hydraulic brake, so that adjustment of the reach occurs by simple, cost-effective parts that are easy to install.
The task is solved according to the invention in that the actuator unit for a hydraulic brake mechanism comprises a housing configured to be attached to the handlebar, a brake cylinder arranged to be configured substantially perpendicular to the handlebar in the housing, a piston configured to be moved in the brake cylinder, a brake lever configured to be pivotably attached to the housing to rotate about an axis of rotation, the brake lever being operatively associated with the piston to move the piston, and a reach adjustment mechanism configured to be operatively associated with the brake lever to move the brake lever for selecting a starting position of brake lever, wherein the axis of rotation of the brake lever is unchangeable in position respect to the housing, and wherein the reach adjustment mechanism moves the brake lever with respect to the axis of rotation of the brake lever.
As an example the brake lever may be mounted adjustably movable with respect to an axis substantially at an end of the lever, the axis being rotatably mounted to the housing, the adjustment option being provided for by the adjustment mechanism, wherein the lever, the adjustment mechanism and the axis rotate together relative to the housing.
Changing the relative position of the lever with respect to the fixed axis of rotation during operation of the brake lever is simpler than adjusting the moving linkage between the lever and the piston. Additionally, it has been found that movement of the lever is particularly improved in such a configuration where the lever is configured to be journaled at one end, to be operated substantially at an opposite end and acting onto the hydraulic braking mechanism between the two ends if reach adjustment is provided for at the end the lever is journaled with. The rotational axis is preferably the center axis of the journal, on which the brake lever is mounted to rotate. Preferably the brake lever is mounted adjustably relatively to the axis of rotation of the brake lever, in particular the mounting being adjustable substantially parallel to the center axis of the brake cylinder, when the brake lever is in a position corresponding to a half stroke.
In a preferred embodiment the reach adjustment mechanism comprises an adjustment bolt, a journal configured to be operatively associated with the adjustment bolt, wherein the journal has a through hole for receiving the adjustment bolt extending there through. Accordingly the lever is guided by the adjustment mechanism allowing for well defined positioning of the lever.
In a particular embodiment the axis of rotation is the center axis of the journal on which the brake lever is mounted to rotate.
The through hole is preferably provided with internal threads, such that reach adjustment can be easily obtained by a rotation of the adjustment mechanism. It is to be noted that other means could be provided for allowing setting of the relative position between the adjustment mechanism such as a bolt and the journal.
The lever may comprise at least one elongated recess or hole for receiving the journal in a guided manner, in particular the elongated hole(s) extending roughly parallel to the center axis of the brake cylinder when the lever is in a position corresponding to a half stroke or preferably to a position corresponding to an intermediate selected start position of the brake lever. Hence, the lever can be guided in a manner as to be guided commonly by the adjustment mechanism and the elongated hole or holes.
The elongated hole (s) can be configured as having ends formed in both directions as stops for the journal. Accordingly the journal can be guided on both sides in the lever in elongated holes that extend roughly parallel to the center axis of the brake cylinder when the lever is in a position corresponding to a half stroke and have ends designed in both directions as stops for the journal. Because of this, the adjustment range of the grip width is limited in simple fashion by design and surpassing of this range is not possible. The production of elongated holes by machining or in a deformation process is very simple.
In a preferred embodiment the adjustment mechanism is comprised of a bolt abutting with the lever on an upper and lower part thereof. This configuration allows for a well defined positioning of the lever substantially without any play, regardless of whether the lever is in an end position or an intermediate position with respect to it's adjustability.
In order to construct the inventive device small and having a nice appearance the lever may be provided with recesses forming abutment regions for the bolt. Accordingly, the heads of the bolt may be received substantially flush with the surrounding surface of the lever.
According to a preferred embodiment the adjustment mechanism comprises indexing means. Such indexing means could be corrugations between any of the heads of the bolt and the housing or other suitable well known means for indexing relative rotational positions.
The lever can comprise a recess of conical shape with rounded apex for engaging the piston. Thus in contrast to the prior art there is provided for uncomplicated actuation of the piston resulting from the fact that the inventive structure provides for adjustability substantially without impairing structural behaviour of the journal supporting the one end of the lever. Thus there is no substantial need for additional guiding of the lever at the place the piston is operated. Nevertheless it is to be noted that such additional guiding may be provided for.
As the reach adjustment is provided for at small distance from the interaction of the lever with the piston it is preferred that the piston is provided with a ball shaped end for engaging the brake lever. Thus easy engagement and operation can be guaranteed.
A preferred embodiment of the invention will now be explained below in detail, with reference to the drawings. The description is to be regarded as illustrative only and should not be understood to restrict the scope of protection as defined by the claims.
An actuator unit 2 is fastened to the handlebar 15 of a two-wheeler. It is connected by means of a line to a hydraulic brake (not shown) for braking of the vehicle. It can be a disk brake or a rimbrake. The housing 4 of the device 2 is fastened on the handlebar with a clamp fitting or other suitable fixation. A hole 6 in housing 4 extends essentially perpendicular to the handlebar 15. Its end on the handlebar side is closed, its end facing away from the handlebar 15 is open. The hole 6, in its internal part, forms the brake cylinder 7.
The actuator unit in an intermediate adjustment position is illustrated in detail in
The journal axle 12 is mounted rotatably in or to the housing 4 and extends through the elongated hole. The journal axle 12, which defines the pivot axis A1, is provided with a through hole to which an adjustment bolt formed of two parts 10 and 14 is arranged. By means of the adjustment bolt the position of the axle 12 within the elongated hole of the brake lever 1 can be secured in any number of possible positions such that the brake lever 1 is journaled pivotally to the housing 4.
In the position shown in
On the left hand side of
On the right hand side of
In summary, it is to be noted that the invention provides for very uncomplicated and inexpensive reach adjustment having the great advantage of not needing any intervention with respect to the hydraulic cylinder piston arrangement in a very easy and convenient manner. The pivot axle always remains in the same position of the housing solely being rotatable in this respect in order to allow in the respective reach adjustment positions common rotation of the axle, the brake lever and the adjusting mechanism.
The inventive configuration has also proven to be particularly beneficial in that, during the reach adjustment, the movement behaviour of the brake lever is slightly changed which change surprisingly copes well with the needs of a user in correspondence of the selected reach adjustment. Furthermore, the provision of the reach adjustment mechanism in a rotatable fashion together with the axle reduces any risks of inadvertent change of the adjustment position as it can occur with any reach adjustment known in the prior art.
Various changes and modifications could be envisaged such as to provide the respective heads of the bolt portions 10, 14 in matching recesses of the brake lever (as shown in
The embodiments described above are exemplary embodiments of the present invention. Those skilled in the art may now make numerous uses of, and departures from, the above-described embodiments without departing from the inventive concepts disclosed herein. Accordingly, the present invention is to be defined solely by the scope of the following claims.
Number | Date | Country | Kind |
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EP 05012773.7 | Jun 2005 | EP | regional |
This application is a divisional of U.S. patent application Ser. No. 11/400,969, filed Apr. 7, 2006, now U.S. Pat. No. 7,654,367, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
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Parent | 11400969 | Apr 2006 | US |
Child | 12695938 | US |