What’s cooler than a pair of lighted shoes? A pair of shoes that blink without batteries!
In a nutshell, this is what the Stride Rite® patent US2007020122 is all about: addressing the issue of battery depletion so that a small child's lighted shoes will blink without exhaustion.
Prior art lighted shoes have attempted to address the issue of battery depletion by resorting to various strategies. Among these strategies, increases in battery life, pressure sensitive switches that turn the lights on only under the pressure of a jump, a skip or walking, the use of less blinking lights, or of light-blinking sequences so that not all the lights go on at the same time. But none of these lighted shoes were batteryless. Indeed, none had ever operated without switches or a controller!
Accordingly, US2007020122 offers to resolve the issue of battery life in children’s lighted shoes with a light and power-generating device “configured as a magnetic field induction element that operates in accordance with Faraday's law of electromagnetic induction:. .”
The shoe upper contains LED lights in a desirable configuration. The lights are connected with wires to a printed circuit board that is part of a lighting module, located in a cavity, inside the shoe heel or elsewhere inside the sole.
The power-generating device, consisting of a permanent magnetic rod measuring less than ½ an inch in length, and less than 1/8 of an inch in diameter, inside a tube, configured as a magnetic field -operating according to Faraday’s law of electromagnetic induction, then has the capacity to induce voltage on a coil, coiled around the tube, and thus to generate sufficient voltage to make a small LED light blink, every time the magnetic field is disturbed.
Accordingly every time there is erratic movement (skipping, jumping, walking), the magnetic rod will move, creating a disturbance in a magnetic field that induces voltage on a coil, which in turn will make the lights blink!
Thus, not only does the shoe no longer need a battery to operate the LED lights of the little shoe, it also no longer needs a pressure-activated switch, since the movement of the magnetic field is enough to induce voltage. In turn, the reduction in the number of components of the invention also makes the little shoe more cost efficient.
The patent further recites the specific design details of this dynamic magnetic motor or “dynamo” that generates energy inside the shoe, using the relative motion of a magnetic field and stationary coiled inductor or stator, the various circuit configurations to actuate the lights, and those that will bypass the use of a controller, thus further reducing the number of parts, components and cost associated with the invention.
Stride Rite® lighted shoes may thrill little kids with their blinking lights, and they may also fascinate parents with such an ingenious patent stored in their soles and uppers!
The Abstract for US2007020122 titled Lighted shoes is included below with one of the patent drawings and a marketed Stride Rite® StarWars lighted model.
A lighted shoe including, but not limited to, a component including, but not limited to, at least one light source (e.g., a light emitting diode or "LED"), and a power generating element (e.g., a magnetic dynamic motor or "dynamo") used to generate power to illuminate the at least one light source. The lighted shoe need not incorporate a battery to operate the at least one light source.[Abstract US2007020122]