Isometric engineering sketch of a white square desktop device for inserting pencil lead into a mechanical pencil, showing internal mechanism.

A clean 3D isometric engineering sketch of a small desktop device that automatically inserts pencil lead into a mechanical pencil. The device is the size of a pencil sharpener. The design is minimal and modern, with a square box shape. On the top, there is a small circular hole where a mechanical pencil is inserted vertically. On the front side, there is a simple button. The drawing shows a semi-transparent cutaway view revealing the internal mechanism: - a funnel-shaped lead storage container at the top - a rotating disk mechanism with a single small slot that holds exactly one lead - a thin spring-loaded pusher that gently pushes the lead into the pencil Include arrows showing motion: - downward arrow for pencil insertion - circular arrow for disk rotation - forward arrow for lead movement Style: clean product design sketch, isometric perspective, soft pencil lines, light shading, minimalistic, white background, professional industrial design drawing, no colors, grayscale Mehr sehen