US Patent 10236801 Door closer system

A door closer system is provided that includes a motor, a spring, a reduction gear set, and a rack and a pinion mechanism. The spring and pinion may be coupled to the rack, and the pinion may be selectively coupled to the gear set. The motor may be selectively mechanically coupled to the gear set. The pinion may rotate in a first direction via the rack as the spring is compressed in a second direction opposite the first direction as the spring is expanded. The motor is operable to rotate and act upon the pinion through the gear set, thereby rotating the pinion in the second pinion direction and assist the spring in closing the door.