Patent EA-004288-B1 (EA)
Title: Electric toothbrush with a replaceable head section
Inventor: KRAMER HANS
IPC: A46B5/00
Filed: 2001-04-24
Abstract: 1. A toothbrush comprising: a handle containing an electric drive motor and having an engagement socket for a head section; a replaceable head section being an elongate structure having a driveable toothbrush head at one end and having a plug part which is engageable with the socket at its opposite end; the plug part having an end surface which when the plug part is engaged with the socket faces generally in the direction of the handle, and the socket having an end surface which faces generally in the direction of the head; wherein: the end surface of the plug part is resiliently deformable in the handle-head direction under the influence of pressure applied longitudinally to the end surface; one of either the end surface of the plug part or the end surface of the socket has a convexity thereon projecting along the head-handle direction, and the other has a concavity therein which receives the projection when the plug part is engaged with the socket. 2. A toothbrush according to claim 1 wherein the convexity is on the end surface of the plug part, and the concavity is located in the end surface of the socket. 3. A toothbrush according to claim 1 wherein the concavity is located in the end surface of the plug part, and the convexity is located on the end surface of the socket. 4. A toothbrush according to any one of claims 1 to 3 wherein the concavity in the end surface respectively of the socket or the plug part of the head conforms substantially to the shape and side of the convexity on the end surface respectively of the head section or the socket. 5. A toothbrush according to any one of claims 1 to 4 wherein the plug part and the socket are provided with connective elements for contribution of solid but in-cut connection of the plug part with the socket. 6. A replaceable head section for a toothbrush as claimed in any one of the preceding claims, the head section being an elongate structure having a driveable toothbrush head at one end and having a plug part which is engageable with the socket at its opposite end and wherein the plug part is in the form of a hollow, tubular body defined by a body wall and having an end surface which faces in the direction of the handle when the head section is engaged with a toothbrush handle. 7. A replaceable head section according to claim 6 wherein the end surface of the plug part of the head section is made resiliently deformable by means of an aperture adjacent to the end surface and passing completely through the body wall, and which is bounded by a resiliently flexible bridge part partly or wholly bridging the aperture on the side of the aperture adjacent to the end surface, a surface of the bridge part being an end surface of the plug part of the head section. 8. A replaceable head section according to claim 7 wherein the aperture is in the form of a slot having its length direction in the circumferential direction of the plug part. 9. A replaceable head section according to claims 7 or 8 wherein the convexity is on the end surface of the bridge part. 10. A replaceable head section according to claims 7 or 8 wherein the concavity is on the end surface of the bridge part. 11. A replaceable head section according to claim 10, wherein there is a ramp surface on the end surface of the plug part adjacent to the concavity. 12. A replaceable head section according to claim 11, wherein the ramp surface comprises part of the bridge part circumferentially adjacent to the concavity. 13. A replaceable head section according to claim 11 or 12 wherein the ramp surface comprises part of a concave region of the end surface of the plug part. 14. A replaceable head section for a toothbrush according to any one of claims 6 to 13 wherein the plug part of the head section which is engageable with the socket is in the form of a hollow, tubular body having an end surface which faces in the direction of the handle and is defined by a body wall, an aperture is located adjacent to the end surface and passes completely through the body wall and is bounded by a resiliently flexible bridge part bridging the aperture on the side of the aperture adjacent to the end surface, a surface of the bridge part is an end surface of the plug part of the head section, the concavity is in the end surface of the bridge part and part of the bridge part comprises a ramp surface at a sloping alignment relative to the longitudinal direction of the head part. 15. A replaceable head section according to any one of the claims 9 to 14 wherein the plug part of the head section is provided with bayonet connection engagement features to facilitate a locking but releasable engagement of the plug part with corresponding bayonet connection features in a socket. 16. A toothbrush handle containing an electric drive motor and having an engagement socket suitable for a head section as claimed in any one of claims 6 to 15, wherein convexity and concavity are on the end surface, made with the possibility of connection with corresponding convexity or concavity on the end surface of the plug of the head part of toothbrush, inserted into the socket. 17. A toothbrush according to claim 3 wherein: the plug part of the head section which is engageable with the socket is in the form of a hollow, tubular body having an end surface which faces in the direction of the handle and is defined by a body wall, an aperture is located adjacent to the end surface and passes completely through the body wall and is bounded by a resiliently flexible bridge part bridging the aperture on the side of the aperture adjacent to the end surface, a surface of the bridge part is an end surface of the plug part of the head section, the concavity is in the end surface of the bridge part and part of the bridge part comprises a ramp surface at a sloping alignment relative to the longitudinal direction of the head part, the ramp surface comprises part of a concave region of the end surface of the plug part, and when the plug part is inserted into the socket the convexity on the end surface of the socket fits into a gap between the end surface of the plug part and the end part of the socket bounded by the concave region, relative rotation of the plug part and the socket causes the ramp surface to ride over the convexity, and further relative rotation then causes the concavity to receive the convexity.