US Patent 9352064 Wearable chemical dispenser

Wearable devices for dispensing insect repellents, fragrances, and/or other chemicals along the outside of the clothing of a human are disclosed. They are of the type that are clipped onto a belt or the like, and use a powered fan to dispense active. They are configured with a first timer to account for a passive release rate of the active and a second timer to account for an active release rate of the active. The first time and second timer are in communication with a useful life indicator to provide a signal to a user of the device to indicate when the substrate in the device for containing the active should be replaced.