This invention relates to a brake operating device adapted to be mounted to a bicycle handle bar, and more particularly to a brake operating device adapted to be mounted to a bicycle drop type handle bar comprising a straight rod section and substantially U-shaped bent rod sections extending forwardly and downwardly from both ends of the straight rod section.
Generally, this kind of brake operating device is provided with a bracket member mounted to the bent rod section of the handle bar, the bracket member carrying a main lever substantially parallel to the bent rod section and an auxiliary lever substantially parallel to the straight rod section and bent rod section, so that a rider may operate the brake by hands gripping the handle bar at the position of either the straight rod section or the bent rod section.
The main lever supports one end of a control wire connected at the other end thereof to the bicycle brake and the auxiliary lever is made operable in association with the main lever. Such means for associating the levers are, as is well-known, disclosed in the British Pat. No. 778,809, and the U.S. Pat. No. 3,403,577 and No. 3,915,028. Namely, the first Patent discloses an auxiliary lever fixed to one side of a main lever through a screw bolt, the second discloses an auxiliary lever supported to an axial end of a pivot swingably supporting a main lever, the auxiliary lever extending for insertion at its head portion between the foremost end face of the main lever and a bracket member and being operable in association with the main lever, and the third discloses an auxiliary lever fixed at its head to a main lever through a single pin.
However, in the first case of using the screw bolt, there is a defect such that the junction of both levers becomes weak. Also the main lever is subjected to the eccentric force of the brake operation of the auxiliary lever to thereby cause torsion on the pivot of the main lever, resulting in a brake action which is not smooth. In the second case, the defect is such that the main lever changes its position in the direction of the swinging motion whether or not the auxiliary lever is mounted to the bracket member, thereby considerably changing the distance between the handle bar and the grip of the main lever, and further the auxiliary lever is likely to be loose and unstable due to its one-point-support. In the third case, the problem is that the auxiliary lever is not easily removable and also unstable due to its one-point-support.
In order to overcome the aforesaid porblems, this invention has been designed. A main object of the invention is to provide a brake operating device capable of easily mounting or dismounting an auxiliary lever and of holding it in a stable manner. Another object of the invention is to provide a brake operating device in which the auxiliary lever is mounted at the rider's choice and which is available by the main lever without the auxiliary lever, and notwithstanding, the mounting of the auxiliary lever, the main lever position is kept constant in the swinging motion direction.
The brake operating device of the invention is so constructed that a hollow shaft is provided at the foremost end of the main lever supported swingably to a bracket member. The hollow shaft carries a retaining member holding one terminal of a control wire, the other terminal of which is connected to the bicycle brake. The auxiliary lever is mounted to the bracket member swingably around a pivot coaxial with a pivot through which the main lever swings and is provided at the head and with an engaging shaft parallel to the common axis of the pivots and insertable into the hollow shaft. The engaging shaft engages with the hollow shaft to thereby operate the auxiliary lever in association with the main lever.
The auxiliary lever is pivoted at its pivoting portion to the bracket member through the second pivot coaxial with the first pivot carrying the main lever, and is supported at the head insertably into the hollow shaft through the engaging shaft, thus being stable through a two-point-support.
Furthermore, the auxiliary lever, which is in association with the main lever through insertion of the engaging shaft into the hollow shaft, is easily mountable or removable to or from the bracket member, and also usable at the rider's choice. Furthermore, the auxiliary lever, when in use, is inserted at its head not between the bracket member and the front end face of the main lever as in the aforesaid prior art, but into the hollow shaft for operation in association with the main lever, resulting in the position of the main lever in the swinging motion direction being kept constant regardless of the existence of the auxiliary lever.
These and other objects and novel features of the invention will be apparent from the following description of an embodiment of the invention in accordance with the accompanying drawings.