Abstract: The field of the present invention is parking meters and more particularly to the use of electronically operated parking meters coupled with a sensor for positively sensing unobtrusively the presence or absence of a vehicle in a specified parking space controlled by the sensor and electronically operated parking meter. An induction coil mounted below the surface of the parking area is used to provide positive signals to the electronically operated parking meter and a cpu upon both the entrance of a vehicle into the parking space and the movement of the vehicle from the parking space. Moreover, the detecting system is battery operated and the battery life is extended by duty cycle operation of the detector system, whereby only a small portion of a detecting cycle is actually employed for detecting the status of the parking space.

Abstract: The field of the present invention is parking meters and more particularly to the use of electronically operated parking meters coupled with a sensor for positively sensing unobtrusively the presence or absence of a vehicle in a specified parking space controlled by the sensor and electronically operated parking meter. An induction coil mounted below the surface of the parking area is used to provide positive signals to the electronically operated parking meter and a cpu upon both the entrance of a vehicle into the parking space and the movement of the vehicle from the parking space. Moreover, the detecting system is battery operated and the battery life is extended by duty cycle operation of the detector system, whereby only a small portion of a detecting cycle is actually employed for detecting the status of the parking space.

Abstract: Apparatus for cutting a circular trough in a roadway whereby a traffic detection loop can be embedded with an advantageous round configuration. A frame for rotatably mounting a circular drill bit is pivotally engaged to a movable platform such as a single axle chassis. Hydraulic rams and hand-operated jacks engaged to the frame are provided for precise levelling and positioning of the circular drill bit. A hydraulically actuated motor drives the bit while a hydraulic ram adjusts downward cutting pressure. The unit is easily transported from location to location and the advantageous round shape is reliably and repeatedly achieved with great efficiency and speed.