Patent EA-001494-B1 (EA)
Title: Toothbrush
Inventor: HALM HANS
IPC: A46B5/00
Filed: 1998-09-22
Abstract: 1. A toothbrush with a head and a grip handle, with a neck in between the head and grip handle, all disposed along a longitudinal toothbrush axis, bristles projecting from the head in a direction generally perpendicular to the toothbrush axis, having a hinge located between its head and its handle, characterised in that the hinge is provided by a first hinge part extending from the head end of the toothbrush toward the handle end, and a second hinge part extending from the handle end toward the head end, the said first and second hinge parts being arranged in a longitudinally overlapping side by side relationship on opposite sides of a plane parallel to the longitudinal axis and to the bristle direction, the overlapping parts being able to rotate relative to each other through a restricted angle about an axis generally perpendicular to the longitudinal axis, the two parts being linked by a torsion element between them. 2. A toothbrush according to claim 1 characterised in that the hinge is located between the handle and the neck. 3. A toothbrush according to claim 1 characterised in that the hinge is located between the neck and the head. 4. A toothbrush according to any one of claims 1, 2 or 3 characterised in that the toothbrush has a single first hinge part extending from the head end of the toothbrush toward the handle end, and a single second part extending from the handle end toward the head end, the two hinge parts being respectively on either side of a plane which includes the longitudinal axis. 5. A toothbrush according to any one of claims 1, 2 or 3 characterised in that the toothbrush has at least two respectively first or second hinge parts extending either from the head end of the toothbrush toward the handle end, or from the handle end of the toothbrush toward the head end, and respectively either a respectively second or first hinge part extending from the handle end toward the head end, the said first or second hinge part extending between the respective second or first hinge parts. 6. A toothbrush according to any one of the preceding claims, characterised by an axle defining the axis passing through a bearing hole, or fitting into a bearing socket, through or in at least the first or second hinge part, and the said relative rotation through a restricted angle is about this axis. 7. A toothbrush according to any one of the preceding claims characterised in that the torsion element comprises an elastomeric material, bonded to one or both of the said hinge parts, and located between them. 8. A toothbrush according to claim 7 characterised in that the elastomeric material is in the form of a layer sandwiched laterally between the said overlapping parts. 9. A toothbrush according to claim 7 characterised in that the elastomeric material is in the form of an axle or torsion bar between the first and second hinge parts. 10. A toothbrush according to claim 1 characterised by a separate head end and handle end which are connected only by the torsion element. 11. A toothbrush according to any one of claims 1 to 10 characterised in that the torsion element comprises a thin integral link between the said parts such that the relative rotation of the said parts as described above about the axis applies a twisting force to the link. 12. A toothbrush according to claim 11 characterised in that the torsion element comprises a spiral or helical structure linking the head end and handle end, and the said relative rotation between the first and second hinge parts winds the spiral or helix up, and thereby creates a torsion force in the opposite twist direction. 13. A toothbrush according to claim 11 characterised in that the integral link is made so thin that it can flex completely freely or even snap or shear when the toothbrush is used. 14. A toothbrush according to any one of the preceding claims characterised by a construction in which the head end and handle end are provided with respective torsion parts, at least one of which is resilient, and such that when the head end and handle end rotate relative to each other the respective torsion parts bear upon each other as a result of the relative movement of one torsion part circumferentially relative to another, and the resilience generates a torsional force. 15. A toothbrush according to claim 14 characterised in that one or more of the said torsion parts comprises a first part extending radially from the axis of relative rotation of the head end and handle end, and the other part comprises a second part located upon the arc followed by the first part during the relative rotation, such that the first and second parts bear upon each other during the relative rotation. 16. A toothbrush according to claim 14 characterised in that two of respectively the first and second torsion parts are located upon the arc followed by the first or second torsion part during the relative rotation, such that the first and second parts bear upon each other during the relative rotation. 17. A toothbrush according to any one of the preceding claims characterised by co-operating end-stop means to encourage or cause the said parts to rotate relative to each other through a restricted angle. 18. A toothbrush according to claim 17 characterised in that the end stop means comprise structures which abut against each other at the limits of the restricted angle to thereby prevent further relative rotation. 19. A toothbrush according to any one of the preceding claims characterised by a separate head end and handle end having respective connecting parts which co-operate together to retain the head end and handle end together. 20. A toothbrush according to claim 19 characterised in that the connecting parts co-operate by a snap fit co-operation where one or both of the connecting parts are resilient and the action of bringing the connection parts together forces a ramp surface on one part over and beyond a ramp surface on the other part, so that to disconnect the connecting parts again requires resilience to be overcome.