Patent ID: 11937989
Assignee: W&H DENTALWERK BüRMOOS GMBH
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 13:
14. A dental prophylactic treatment device comprising:
a prophylactic contra-angle handpiece having
a handle part extending along a longitudinal axis,
a head part adjoining the handle part,
a tool holder rotatably disposed in the head part and extending along an axis of rotation, wherein the longitudinal axis of the handle part and the axis of rotation of the head part are disposed at an angle to one another, and the tool holder being configured to releasably hold a dental tool having a tool shaft and a prophylactic treatment section connected to the tool shaft so that the dental tool together with the tool holder can rotate about the axis of rotation, wherein
the tool holder comprises a positive-locking chucking device configured to fix the tool shaft of the dental tool in a positive-locking manner, wherein
the positive-locking chucking device comprises at least one holding element radially displaceable with respect to the axis of rotation of the tool holder and configured to engage a recess of the tool shaft of the dental tool to axially retain the dental tool in the tool holder, and wherein the holding element comprises a ring-shaped, spring biased slide having an inner wall and an inner pass-through opening defined by the inner wall, wherein a wedge-shaped protrusion extends from the inner wall into the inner pass-through opening, wherein
the wedge-shaped protrusion is configured to engage in the recess on the tool shaft of the dental tool in order to secure the dental tool axially in the chucking device, and wherein
the wedge-shaped protrusion comprises a first inclined plane on the upper side thereof facing away from a tool-receiving opening of the prophylactic contra-angle handpiece and a second inclined plane on its underside facing the tool-receiving opening of the prophylactic contra-angle handpiece, wherein
wherein the first and second inclined planes are arranged non-orthogonally relative to the axis of rotation, and wherein
the prophylactic contra-angle handpiece has no manually operated pushing device on the outside of the prophylactic contra-angle handpiece for moving the holding element for releasing the dental tool from the tool holder.