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

Claim 0:
1. 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 rotational axis of the head part are disposed at an angle to one another,
a dental tool having
a tool shaft, and
a prophylactic treatment section connected to the tool shaft,
wherein said tool shaft extends from a handpiece end of the dental tool over a length up to the prophylactic treatment section, wherein
at least a section of said tool shaft is detachably receivable in the tool holder, so that the dental tool together with the tool holder can be rotated about the axis of rotation, wherein
the tool holder comprises a positive-locking chucking device configured to retain the tool shaft of the dental tool in a positive-locking manner, wherein
the positive-locking chucking device is radially displaceable with respect to the axis of rotation of the tool holder and comprises a ring-shaped slider having an inner wall and an inner pass-through opening defined by said inner wall, wherein a wedge-shaped protrusion extends from said inner wall into said inner pass-through opening, 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 the first inclined plane and the second inclined plane extend toward one another in the direction of the axis of rotation to form a taper having a plurality of outer faces which engage a recess on the tool shaft to axially retain the dental tool in the positive-locking chucking device when the tool shaft is arranged in the inner pass-through opening of the ring-shaped slider, wherein
the wedge-shaped protrusion is formed only by non-orthogonal outer faces arranged non-orthogonally relative to the axis of rotation,
a spring element which moves the ring-shaped slider with the wedge-shaped protrusion radially with respect to the axis of rotation of the tool holder; and wherein the prophylactic contra-angle handpiece has no user-operated pushing device for moving the ring-shaped slider for releasing the dental tool from the tool holder.