Patent ID: 8253572

Claim:
A vehicle-mountable tethering mechanism with automatic vehicle braking control features comprising: a retractable spool mountable to a vehicle and having a tether that pays out when a pulling force is applied to the tether, and retracts when the pulling force is removed; the tether that includes a plurality of counting indications disposed at predetermined positions on the tether, said tether having a free end configured to detachably attach to a dog collar or dog harness; a counter that counts the counting indicators as the counting indicators pass by the counter when the tether is paying out or retracting; a rate of change detector that determines rate of change of the tether as a pay out rate or retraction rate of the end portion of the tether relative to a moving vehicle, a time period between counting indicators passing by the counter being indicative of a rate of change; an electrical power source; a brake actuator configured to actuate brakes on the vehicle to controllable slow the vehicle by predetermined amount; a computer readable storage device that has stored therein braking levels that correspond with and a tether deployment amount and rate of change; and a processor configured to retrieve from the storage device a braking level corresponding to the tether deployment amount and the rate of change, and control the breaking actuator to apply the breaking level to the brakes if the determined tether deployment is less than a predetermined amount and the rate of change is greater than a predetermined amount.