Medical or dental handpiece
AssigneeJ. Morita Mfg. Corp.
InventorsHitoshi Tanaka, Shozo Nakayama
Life of this patent
Estimating the term…
Abstract
A medical or dental handpiece has a grip. The grip includes first to third rotation shafts. The first and second shafts are connected through a first gear mechanism and the second and third shafts are connected through a second gear mechanism so that a rotation is transmitted from the first shaft through the first gear mechanism to the second shaft and then from the second shaft through the second gear mechanism to the third shaft. The first or second gear mechanism has an internal gear secured on one shaft and an external gear secured on the other shaft, the internal and the external gears being engaged with each other. The external gear is substantially enclosed within a cylindrical plane extending along a peripheral edge of the internal gear.
Claims11
A handpiece having a contra-angled grip and a head, the handpiece comprising:
- first, second, and third shafts mounted for rotation about respective longitudinal axes thereof within an internal cavity defined in the grip;
- a first gear pair for transmitting a rotation from the first shaft to the second shaft;
- and
- a second gear pair for transmitting the rotation from the second shaft to the third shaft;
- the first gear pair having a first internal gear mounted on the first shaft and a first external gear mounted on the second shaft and engaged with the first internal gear;
- and
- the second gear pair having a second internal gear mounted on the second shaft and a second external gear mounted on the third shaft and engaged with the second internal gear;
- wherein the first internal gear is defined by a first pitch cone having a first cone angle and a first apex;
- wherein the first external gear is defined by a second pitch cone having a second cone angle and a second apex;
- wherein the first cone angle is greater than the second cone angle;
- and
- wherein the first apex and the second apex take the same position.
Dependencies are inferred from the claim text.