A piezoelectric energy hunting device and a voltage signal application system thereof are disclosed. The piezoelectric energy hunting device includes a plurality of curved piezoelectric elements, a plurality of rigid foams, and a flexible foam structure. The plurality of curved piezoelectric elements are arranged side by side with one another, wherein each curved piezoelectric element is attached to one of the rigid foams. The flexible foam structure includes a top foam and a bottom foam covering the outer surface of the plurality of curved piezoelectric elements and the plurality of rigid foams; when the flexible foam structure is compressed, the plurality of curved piezoelectric elements are simultaneously deformed, thereby generating a voltage signal. When the flexible foam structure is not compressed, the flexible foam structure and the plurality of rigid foams provide an elastic force to restore the plurality of curved piezoelectric elements.

A vehicle includes a body having a first part and a second part, which is moveably coupled to the first part. The vehicle further includes a pedal assembly having a first component coupled to the first part and a wheel assembly having a second component coupled to the second part. The vehicle further includes an extendable drive shaft having a first member and a second member. The first member is coupled to the first component and the second member is coupled to the second component. The vehicle further includes a locking mechanism having a locking member coupled to the first part and the second part of the body. The locking member, in an unlocked position, unlocks the second part from the first part to allow the second part to move over the first part, which may cause a change in a length of the extendable drive shaft.

A vehicle includes a body having a first part and a second part, which is moveably coupled to the first part. The vehicle further includes a pedal assembly having a first component coupled to the first part and a wheel assembly having a second component coupled to the second part. The vehicle further includes an extendable drive shaft having a first member and a second member. The first member is coupled to the first component and the second member is coupled to the second component. The vehicle further includes a locking mechanism having a locking member coupled to the first part and the second part of the body. The locking member, in an unlocked position, unlocks the second part from the first part to allow the second part to move over the first part, which may cause a change in a length of the extendable drive shaft.

A bicycle crankarm provided with an electric/electronic system, including a battery power unit, a processor having a standby mode and a running mode, and a wake unit that emits a wake signal of the processor, wherein the wake unit is completely supported by or in the crankarm.

A bicycle pedal cover system for covering and protecting footwear from inclement weather, mostly rain. The water proof device simply clips on to the cycle pedals, covering the footwear and protecting the shoe from getting wet while cycling. The device is slightly larger than the footwear and allows the foot of a user to be easily inserted without impeding any movement whatsoever. Further, the device is able to collapse into a flat object and be mounted to a seat post of a bike for convenient storage and portability.

A crank assembly for a pedal-driven vehicle includes a first member, a second member, and a rotary sensor. The first member rotates about a crank axis of the pedal-driven vehicle. The second member is rotationally coupled to the first member and is configured to pivot about the first member via a member pivot. The second member also is configured to receive a pedal at a pedal interface. The rotary sensor is coupled to the first member and configured to measure rotation of the second member relative to the first member.

A crank assembly for a pedal-driven vehicle includes a first member, a second member, and a rotary sensor. The first member rotates about a crank axis of the pedal-driven vehicle. The second member is rotationally coupled to the first member and is configured to pivot about the first member via a member pivot. The second member also is configured to receive a pedal at a pedal interface. The rotary sensor is coupled to the first member and configured to measure rotation of the second member relative to the first member.

An adhesively coupled power-meter measures one or more of force, torque, power, and velocity of a mechanical arm. The power meter includes a plate with a first surface prepared for adhesively coupling to the mechanical arm. At least one strain gauge is physically coupled with a second surface, opposite the first, of the plate and with an orientation corresponding to an orientation of the adhesively coupled power meter such that mechanical forces are transferred from mechanical arm to the at least one strain gauge when the plate is adhesively coupled to the mechanical arm. The power meter also includes electronics for receiving a signal from the at least one strain gauge and for determining one or more of force, torque, power and velocity from the signal, and a wireless transmitter for transmitting one or more of force, torque, power and velocity to a receiving device.

An adhesively coupled power-meter measures one or more of force, torque, power, and velocity of a mechanical arm. The power meter includes a plate with a first surface prepared for adhesively coupling to the mechanical arm. At least one strain gauge is physically coupled with a second surface, opposite the first, of the plate and with an orientation corresponding to an orientation of the adhesively coupled power meter such that mechanical forces are transferred from mechanical arm to the at least one strain gauge when the plate is adhesively coupled to the mechanical arm. The power meter also includes electronics for receiving a signal from the at least one strain gauge and for determining one or more of force, torque, power and velocity from the signal, and a wireless transmitter for transmitting one or more of force, torque, power and velocity to a receiving device.

A bicycle electrical unit is provided for a bicycle crank assembly. The bicycle electrical unit includes a housing, a wireless communication unit and a charge receiver port. The housing is mounted on a crank arm. The wireless communication unit is enclosed in the housing. The charge receiver port is provided on the housing.