Abstract: An optical alignment device for aligning the pulleys of a belt drive system in three planes. The device includes first and second members releasably attachable to each pulley. The first member mounts a target device having horizontal and vertical alignment markings corresponding to the centerline of the pulley. The second member mounts a viewing device having horizontal and vertical alignment markings corresponding to the centerline of the other pulley. The target is seen in the viewing device, when the horizontal and vertical markings of the viewing device and the target are superimposed, the pulleys will be in alignment in the horizontal, vertical and angular planes. A projector may be used in place of the viewing device to project a beam of light on the target in a second preferred embodiment of the invention.

Abstract: An alignment tool for aligning the pulleys of a belt drive in three planes. The device includes a clamp releasably attached to each pulley which mounts a member extending normally to the face of each pulley. Each member has a universal joint at each end and an adjustable link joins the universal joints. Slidable guides oppositely disposed on each side of the universal joints indicate alignment of the pulleys in two planes when the faces of the guides are parallel. The device may also be used to determine if the pulleys have become angularly misaligned.