Abstract: A caliper type device is provided for identifying the cranial midline on a patient. The device includes a pair of arms have first ends for receipt in a patients ears, and opposite, pivotally connected second ends which allow the arms to open and close to fit to different sized heads of various patients. A housing at the second end of the arms holds a laser pointer or other tool for identifying the cranial midline after the device is positioned on the patients head.

Abstract: A drive mechanism for a motorized vehicle is disclosed which is reliable and requires less maintenance. The drive mechanism includes a differential having at least one rotatable shaft extending outward therefrom and having a first gear mounted thereon. A drive shaft having a first end and a second end with a gear mounted to each of the first and second ends rotatably meshes with the first gear on the rotatable shaft. The first gear also provides a pivot point for the drive shaft. The drive mechanism further includes a hub capable of supporting a rotatable member. The hub has a second gear mounted thereto which rotatably meshes with the gear mounted to the second end of the drive shaft. Lastly, the drive mechanism includes a hollow support arm extending between the pivot point and the hub. The hollow support arm has a vertical vector and completely encloses the drive shaft.