Motorized bicycle seatpost assembly

A motorized bicycle seatpost assembly is basically provided with a first tube, a second tube, a motor and a movement mechanism. The first tube has a first end and a second end. The second tube has a first end and a second end. The first end of the second tube is open such that the second end of the first tube is telescopically disposed in the first end of the second tube. The motor is arranged in at least one of the first tube and the second tube. The movement mechanism is connected to the motor to change a relative axial position between the first and second tubes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention generally relates to a seatpost that is adjustable to adjust the seat height of a bicycle seat. More specifically, the present invention relates to a motorized bicycle seatpost assembly to adjust the seat height of a bicycle seat.

2. Background Information

Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle.

A bicycle seat is normally supported on a bicycle frame by a seatpost that is telescopically disposed in the seat tube of the bicycle frame. The bicycle seat typically has a pair of parallel rails extending along the bottom of the seat. The rails of the bicycle seat are attached to the seatpost by a clamp at the top of the seatpost. The height of the bicycle seat with respect to the bicycle frame is typically adjusted by changing the insertion amount of the seatpost in the seat tube of the bicycle frame. The upper end of the seat tube is typically provided with a longitudinal slit and a clamping arrangement that adjusts the diameter of the upper end of the seat tube to squeeze the seatpost for securing the seatpost in the desired position with respect to the bicycle frame.

Recently, seatpost assemblies have been proposed that use motors in order to adjust the height of the seat. Examples of motorized seatpost assemblies are disclosed in Japanese Laid-Open Patent Application No. 2005-231567 and Japanese Laid-Open Patent Application No. 2005-262900. One drawback to these seatpost assemblies is that part of the seatpost assembly is fixed to the bicycle frame.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a motorized bicycle seatpost assembly that is simply to install in a seat tube of a bicycle frame and easy to operate.

The foregoing objects can basically be attained by providing a motorized bicycle seatpost assembly that mainly comprises a first tube, a second tube, a motor and a movement mechanism. The first tube has a first end and a second end. The second tube has a first end and a second end. The first end of the second tube is open such that the second end of the first tube is telescopically disposed in the first end of the second tube. The motor is arranged in at least one of the first tube and the second tube. The movement mechanism is connected to the motor to change a relative axial position between the first and second tubes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially toFIGS. 1 and 2, a bicycle10is illustrated that is equipped with a motorized bicycle seatpost assembly12in accordance with a first embodiment. The motorized bicycle seatpost assembly12is mounted to a seat tube14and a handlebar15. The seat tube14is a conventional portion of a bicycle frame16that includes a clamping arrangement (not shown) for securing the motorized bicycle seatpost assembly12to the bicycle frame16. The motorized bicycle seatpost assembly12adjusts a seat height of a bicycle seat18with respect to the bicycle frame16. In this embodiment, the length of the telescoping seatpost22is adjustable to three preset seatpost positions, e.g., a high preset seatpost position, a middle preset seatpost position and a low preset seatpost position. The motorized bicycle seatpost assembly12basically includes an inner (first) tube20, an outer (second) tube22, a height adjustment device24, a controller26and an operating switch28. In this embodiment, the length of the inner and outer tubes20and22is adjustable to three preset seatpost positions, e.g., a high preset seatpost position, a middle preset seatpost position and a low preset seatpost position.

In general, the inner and outer tubes20and22are telescopically arranged, with the amount of insertion of the inner tube20into the outer tube22being adjustable. The inner and outer tubes20and22are a separate unit from the bicycle frame16such that the outer tube22is easily installed into the seat tube14. The outer tube22is secured to the seat tube14by a conventional clamping arrangement (not shown) provided on the upper end of the seat tube14. In particular, the upper end of the seat tube14is provided with a longitudinal slit such that the clamping arrangement adjusts the diameter of the upper end of the seat tube to squeeze the outer tube22. The height adjustment device24is operatively connected to the inner and outer tubes20and22for selectively extending and retracting the inner tube20with respect to the outer tube22based on a motor control signal from the operating switch28via controller26. More specifically, the controller26operates the height adjustment device24by selectively supplying electricity to the height adjustment device24based on the signal from the operating switch28. When an operating lever28a(FIG. 2) of the operating switch28is moved in an upward direction relative to the bicycle10, the operating switch28outputs a first (up) motor control signal that extends the inner tube20with respect to the outer tube22for raising the seat18with respect to the bicycle frame16. On the other hand, when the operating lever28aof the operating switch28is moved in a downward direction relative to the bicycle10, the operating switch28outputs a second (down) motor control signal that retracts the inner tube20with respect to the outer tube22for lowering the seat18with respect to the bicycle frame16.

As seen inFIG. 3, the inner tube20has an interior bore30, a first end31and a second end32. The second end32of the inner tube20is open such that the interior bore30of the inner tube20extends longitudinally from the second end32of the inner tube20towards the first end31of the inner tube20. The first end31of the inner tube20includes a seat mounting member34that secures the bicycle seat18thereto. As seen inFIG. 4, the outer surface of the second end32of the inner tube20has a pair of anti-rotation keys36attached to the outer surface of the second end32of the inner tube20. The inner and outer tubes20and22are non-rotatably connected together by the anti-rotation keys36.

As seen inFIG. 3, the outer tube22has an interior bore40, a first end41and a second end42. The first end41of the outer tube22is open such that the interior bore40of the outer tube22extends longitudinally from the first end41of the outer tube22towards the second end42of the outer tube22. In other words, the first end41of the outer tube22is open such that the second end32of the inner tube20is telescopically disposed in the first end41of the outer tube22. As seen inFIG. 4, the interior bore40of the outer tube22has a pair of longitudinally extending slots40athat slidably receives the anti-rotation keys36of the second end32of the inner tube20to prevent relative rotation between the inner and outer tubes20and22.

The height adjustment device24basically includes a reversible electric motor44and a linear movement mechanism46. The motor44is arranged in at least one of the inner and outer tubes20and22. In this illustrated embodiment, the motor44is rigidly secured to the second end32of the inner tube20via the linear movement mechanism46by three screws48. The linear movement mechanism46is operatively disposed between the inner and outer tubes20and22. The linear movement mechanism46basically includes a gear unit50mounted to the inner tube20by the screws48and a female thread52formed on the interior bore40of the outer tube22.

The gear unit50includes a pinion gear54, a pair of idle gears56, a ring gear58, a first gear housing part60and a second gear housing part62. The pinion gear54is rigidly mounted on an output shaft44aof the motor44. The teeth of the idle gears56are rotatably engaged with the teeth of the pinion gear54. The internal teeth of the ring gear58are rotatably engaged with teeth of the idle gears56. The ring gear58also has a male thread58aon its outer surface that is threadedly engaged with the female thread52that is disposed on the interior bore40of the outer tube22. As seen inFIGS. 4 to 12, the first gear housing part60is secured to the inner tube20by the screws48, while the second gear housing part62is attached to the first gear housing part60by two screws64. The ring gear58is rotatably disposed between the first and second gear housing parts60and62. Preferably a plastic ring66is disposed between the ring gear58and the first gear housing part60so that the ring gear58smoothly can rotate relative to the first gear housing part60.

As seen inFIG. 4, the gear unit50of the linear movement mechanism46is operatively connected to the output shaft44aof the motor44to change a relative axial position between the inner and outer tubes20and22. In this illustrated embodiment, the linear movement mechanism46is partially attached to the second end32of the inner tube20and partially formed in the first end41of the outer tube22. In other words, the linear movement mechanism46is operatively connected to the output shaft44aof the motor44within the second end32of the inner tube20, and is partially disposed between the inner and outer tubes20and22to change insertion quantity of the inner tube20in the outer tube22.

Basically, the motor44receives electrical power (electricity) from a battery68via the controller26. In particular, the battery68is disposed completely inside the inner tube20and electrically connected to the motor44via the controller26. The motor44is also disposed completely inside the inner tube20. The motor44is operatively connected to the linear movement mechanism46to selectively extend or retract the inner tube20relative to the outer tube22.

As seen inFIG. 13, the controller26is operatively connected to the motor44with the controller26having three different preset seat position settings that selectively operate the motor44to move the inner tube20relative to the outer tube22. In this illustrated embodiment, the controller26includes among other things, a central processing unit or CPU70, an intermediate frequency (IF) circuit72, a motor driver74and a regulator76. The controller26is powered by the battery68that is mounted completely within the inner tube20.

The central processing unit70preferably includes a microcomputer. The central processing unit70can also include other conventional components such as an input interface circuit, an output interface circuit, and storage devices such as a ROM (Read Only Memory) device and a RAM (Random Access Memory) device. The intermediate frequency (IF) circuit72, the motor driver74and the regulator76are conventional components that are well known in the field. Thus, the components72,74and76will not be discussed in detail herein.

A position detecting device78is operatively connected to the controller26. The position detecting device78detects a relative position between the inner and outer tubes20and22. Preferably, the position detecting device78detects the relative position between the first inner and outer tubes20and22by detecting a rotation amount of the motor44when the controller26operates the motor44. In particular, in the illustrated embodiment, the position detecting device78includes an encoder that is mounted on the motor44completely within the inner tube20. The encoder of the position detecting device78determine the rotational amount of the motor44for determining the high, middle and low preset seat positions. The high seat position (shown inFIG. 2) is a riding position for when the bicycle10runs in the flat road or uphill. The middle position (shown inFIG. 14) is a riding position for when the bicycle10runs in the slightly rapid downhill. The low position (shown inFIG. 15) is a riding position for when the bicycle10runs in the considerably rapid downhill.

The operating switch28is operatively connected to the controller26, and thus operatively connected to the motor44. The operating switch28generates a motor control signal to operate the motor44in response to operation of the operating switch28. The electrical power from the battery68is supplied to the operating switch28via the controller26for generating the motor control signals.

General Interpretation of Terms