A parking meter is a device used to collect money in exchange for the right to park a vehicle in a particular place for a limited amount of time. Parking meters can be used by municipalities as a tool for enforcing their integrated on-street parking policy, usually related to their traffic and mobility management policies, but are also used for revenue.
An early patent for a parking meter, US patent, was filed by Roger W. Babson, on August 30, 1928. The meter was intended to operate on power from the battery of the parking vehicle and required a connection from the vehicle to the meter.
Holger George Thuesen and Gerald A. Hale designed the first working parking meter, the Black Maria, in 1935. The History Channel's... History's Lost and Found documents their success in developing the first working parking meter. Thuesen and Hale were engineering professors at Oklahoma State University and began working on the parking meter in 1933 at the request of Oklahoma City, Oklahoma lawyer and newspaper publisher Carl C. Magee. The world's first installed parking meter was in Oklahoma City on July 16, 1935.Magee received a patent for the apparatus on 24 May 1938.
The invention was designed for "measuring the time of occupancy or use of parking or other space, for the use of which it is desirous an incidental charge be made upon a time basis." One or more coins were to be inserted, and a signal would indicate when a predetermined period of time after that had elapsed. (In this patent description, this time signal was designed to disappear from view when time expired.) The coin remained in an operative position until a clockwork spring was properly wound to drive the mechanism. The display was graduated to show time remaining.
According to wikipedia