A toothbrush employing a force indicator which visually and tactually signals the user that a predetermined brushing force has been exceeded. The force indicator is comprised of a resilient twin beam structure located between the toothbrush handle and the toothbrush head which includes a scrubbing or polishing medium, typically bristles. The twin beam structure is itself comprised of a back side beam and a face side beam. During normal use, the back side beam is subjected to compressive stress whereas the face side beam is subjected to tensile stress. The at rest configuration of the back side beam permits it to behave as an upwardly convex arch upon initial application of compressive force resulting from a user gripping the handle and bringing the bristles or other cleansing or scrubbing medium in contact with the teeth and gums. When a predetermined force is exceeded, the back side beam resiliently buckles and inverts to a downwardly convex arch configuration. In a preferred embodiment, the back side and face side beams are nonparallel with a convergent taper from the brush handle in the direction of the brush head. The disclosed twin beam structures resist deflection up to a predetermined force which is determined primarily by their material properties and their precise geometric configuration. Attempting to exceed the predetermined force which the toothbrush is capable of transmitting by applying additional manual force to the brush handle results in resilient buckling of the back side beam in the twin beam structure, followed by substantial deflection of the brush head relative to the brush handle without a corresponding increase in the force applied to the teeth and gum tissue via the bristles on the brush head.
A toothbrush comprising, generally in a sole piece, an elongated handle (10); one head (20) carrying, on the front side, a set of bristles (40); and a flexible neck (30) joining the handle (10) and the head (20) and comprising a pair of front (31) and rear (32) spaced longitudinal beams (33) and having their opposite extreme ends respectively united to the head (20) and the handle (10) through localized bending regions (34) which allow the beams to operate as parallelogram articulation arms when the head (20) is displaced in transversal direction in relation to the handle (10) and in a plane containing the longitudinal axis of the handle (10) and being parallel to the longitudinal axes of the bristles (40), from an inoperative rest position to operative positions. The brush is provided with a shock absorbing means (50), acting against the neck (30) and preferably by means of an elastic element fitted to the aperture (33) between the beams, in such a manner as to be elastically deformed when the head (20) is displaced from its inoperative position to any of its operative positions.
A toothbrush, comprising a body having a head portion, a neck portion connected to the head portion, and a handle portion connected to the neck portion, and further comprising a plurality of bristles attached to the head portion. The body comprises a thermoplastic elastomer that is sufficiently strong to be used in the normal, intended manner for dental hygiene purposes and is sufficiently flexible to resist being fashioned into and used as a weapon. In a preferred embodiment, the body comprises approximately 50% Kraton.TM. DRP6031 thermoplastic rubber and approximately 50% polypropylene.
A bent wire serves to form a loop for assembly receiving a brush head of a toothbrush, the bent wire also forming a pair of shanks which are received in a handle holding the shanks together to close the loop and return the brush head assembly therein. At least one of the shanks has formations indexable in the handle. Between the end portions of the shanks and the loop, coil springs are formed in the wire to allow mobility of the brush head in all directions perpendicular to the longitudinal axis thereof.
The pressure sensing system includes a hinged member that is fixedly attached to a brushhead body. An arm member is attached at one end to said hinged member and pivots about a hinge portion of the hinged invention. The pivoting arm member and the brushhead member nestle within the toothbrush body. The brushhead member includes a striking element portion that extends away from a rear surface of the brushhead. Mounted on the toothbrush body beneath the brushhead member is a collapsible, recoverable dome member, which provides an alarm indication by collapsing when excessive pressure is applied by the user on the brushhead against the teeth.
A bent wire serves to form a loop for assembly receiving a brush head of a toothbrush, the bent wire also forming a pair of shanks which are received in a handle holding the shanks together to close the loop and return the brush head assembly therein. At least one of the shanks has formations indexable in the handle. Between the end portions of the shanks and the loop, coil springs are formed in the wire to allow mobility of the brush head in all directions perpendicular to the longitudinal axis thereof.
