A spring part, in particular for a driving device, includes a spring body extending around a central axis. The spring body comprises several spring windings which run radially around a spring axis and are made of at least a base material. The base material is surrounded at least by a first protective layer, and the spring body is at least partially covered on the outside by a lubricant. A method for manufacturing a spring part includes the steps of providing a spring body with several spring windings made of a base material and coating the base material at least with a first protective layer. The method includes the step of applying a lubricant formed as a silicone-based lubricant to the outside of the coated spring body.

The invention comprises a double roller garage door panel hinge and method for same. The hinge comprises a first hinge half and a second hinge half that are removably and pivotally connected to each other by a clasp formed by the second hinge half; the first hinge half further comprises a first half hinge base that supports a first roller support tube up and away from a first half hinge base, the first roller support tube rotatably supports a first garage door roller; the second hinge half further comprises a second half hinge base that supports a second roller support tube up and over the second half hinge base, the second roller support tube rotatably supports a second garage door roller; wherein the first hinge half is attached to first garage door panel and the second half hinge is attached to an adjacent garage door panel.

An electric tailgate strut includes telescopic rod, gas spring, driving unit and tailgate connection assembly. Telescopic rod comprises outer tube and inner tube, wherein the outer tube can move along the axial direction of inner tube. Gas spring is arranged inside telescopic rod and includes thread tube with thread on inner wall, piston and piston rod. Driving unit is fixedly arranged in the outer tube and serves to drive piston rod in the rotation so that piston rod drives outer tube to move along axial direction of inner tube. Tailgate connection assembly is located at both ends of telescopic rod and is used for connection between telescopic rod and tailgate. Piston rod is driven to rotate by motor, so that outer tube can move along axial direction of inner tube to achieve rise or fall of strut. Thread tube itself, piston rod and piston form a gas spring.

A door control system is provided. The control system includes a controller configured to control a door via a motor. The motor is powered by a battery and bypasses the controller via relays and/or switches when power to the controller is disconnected. The current of the motor may be monitored and/or displayed to confirm that the door is balanced.