GB2319170A - Power-driven toothbrush - Google Patents

Abstract

The removable head 100 of a driven toothbrush has brush heads 210, 220 rotated via gears 170, 180, 190, by shaft 140, 165 which connects at one end 142 to the motor handle. The shaft has telescoping, rotation-transmitting parts 144, 160 which are biased by spring 150 to allow the shaft to retract upon connection of the head to the handle.

Description

POWER-DRIVEN TOOTHBRUSHES This invention relates to a brush head for a toothbrush and to a toothbrush. More particularly, this invention relates to a power-driven brush head and a power-driven toothbrush having an improved teeth cleaning capability.

This application is divided from applicants prior UK patent application published under No. 22O224.

Knawn power-driven toothbrushes have the disadvantage. t.hat they are complicated in construction and do not effectively clean the teeth and gums.

An object of this invention is to overcome the above disadvantages or difficulties or at least to provide the public with a useful choice.

Accordingly, this invention comprises a brush head for a power-driven toothbrush comprising at least two rotatable brush members having a plurality of bristle tufts, and gear nEcanC3 for connection to a drive meane for driving the brush members in rotation including a rotatable shaft which comprises first and second shaft parts engaged with each other in the rotational direction, the first shaft part being movable relative to h the second in in the direction.

The firgl haft part ie preferably slidably receivable within a recess in the second shaft part.

The brush head preferably includes resilient means to urge the first shaft part out of the recess in the second shaft part.

In a further aspect the invention comprises a power-driven toothbrush comprising a brush hes fined above, and a handle containing drive means connected to the gear means.

Preferred embodiments ot the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1: is a side view of a brush head oL a preferred embodiment of a toothbrush of the invention with the cover cutaway.

Figure 2: is an underncath view of a brush head of a preferred embodiment of a toothbrush of the invention showing the positions of bristle tufts in ghost lines.

Figure 3: is a cross-section through line A-A of figure 1.

Figutc 4: is a cross-section. through line B-B of figure 1.

Figure 5: ia a side view of a preferred embodiment of a power-driven toothbrush of the invention.

Pigure 6: is a top view of a preferred embodiment of a power-driven toothbrush of the invention.

Rçfo.rring tn figures 1 and 2, a preferred embodiment of the brush head of the invention is indicated generally at loo.

The brush head has a casing 120 which is preferably formed in two halves for ease ot assembly. Within the casing is formed a socket 130 for receiving a drive means enclosed with the toothbrush body shown in figures 4 and 5.

Received by the drive means is a drive shaft 140 with a first eìd 142 which cooperates with the drive means so that the drive means may transmit torque to the drive shaft. To facilitate efficient torque transmission, the end 142 of the drive shaft 140 is of cruciform shape and is received by a similar shaped rcccoo in the drive means.

The drive shaft transmits torque to a drive gear 170 having a gear shaft 165. The gear shaft 165 comprises a drive shaft receiving rconee n, which receives a second end 144 of the drive shaft (see figure 4). Again to facilitate efficient torque transmission, the second end 165 of the drive Y1s 140 is o of cruciform shape and the recess 160 is of a similar, cooperating shape.

In order to avoid damage to the drive shaft 140 during insortion into a recese in the drive means, a spring 150 is provided. The spring 150 allows the drive shaft 140 limited axial movement and this prevents the drive shaft from snapping, if incorrectly inserted in the drive means.

The drive gear 170 has a plurality of annularly spaced teeth, preferably bevelled, which mesh with similarly shaped and spaced teeth on a tirst crown gear lt3u.

The teeth on the first crown gear 180 in turn mesh with similarly shaped and spaced teeth on a second crown gear 190. The two crown gears loo, 190 are rotatably mounted on guide pins 240 in the casing 120 Thus, torque produced by a drive means may be transmitted via drive shaft 140, gear shaft 165 and drive gear 170 to crown gears 180 and 190, thus rotating the gears 180, 190.

Crown gears 180, 190 each form part of a base to which a plurality of bristle tufts 230 are secured to form brush members 210 220. The hristle. tufts extend through suitable apertures in the casing 120 (see figure 3).

Rotation of the gears 180, 1so therefore causes members 210, 220 to rotate. The arrangement of gears depicted in figure 1 results in contra-rotation of the two brush members. This contra-rotation provides for efficient brushing of the teeth and guma.

The bristles tufts 230 are preferably arranged in such a way that the brush members 210, 220 have a circular base and, prcferibly, are cylindrical in shape.

In order to facilitate cleaning of the teeth and gums, especially those at the back ot the mouth, the brush head 100 is tapered at one end 250. The brush member 220 positioned at the tapered end 250 of the head 100 is smaller in diameter than brush member 210, again to tacilitate cleaning, especially towards Llic back of the mouth. The bristle tufts 230 of brush member 220 are preferably longer than those of member 210. The brush head loo also preferably comprises a slim neck 260 to, among other thirtys, reduce the bulk of material entering the mouth, and for aesthetic purposes.

Referring now to figures 5 and 6, in use the brush head 100 i3 connected to a handle 270 by any conventional means, and the drive-means in the handle is received by socket 130.

The handle suitably has a tapered portion 280 and on/off switch or switches 290. T handle may contain batteries to power the drive means, or the drive means in the handle may be connected by way of a lead extending through the handle, to a mains power supply, or both.

All the components in the toothbrush are suitably made of plastics or similar materials, apart from the spring which is preferably formed of metal.

The above describes a preferred embodiment of the invention, variations and modifications in which may be made without departing from the scope of the invention as deind in the accompanying claims.

There may be a plurality of brush members. Three brush members could be arranged in a triangular pattern, one smaller brush member being situated in the tapered end of the toothbrush.

The cauiiry may be of any suitable shape.

The brush members may be conical or any other suitable shape.

The handle may be of any suitable configuration and may include indentations in the shape of a hand. There may be a plurality of switches provided, one of which may provide for reversing the direction of rotation of the brush members.

The gear means dcacribed ic a simple and effective way of transferring torque from a drive means to the brush members. However, other conventional gear means may be employed as will be clear to one skilled in the art to which the invention relates. The end of the Ariv haft need not be of cruciform shape but may be of any shape which, when received by a similar shaped recesses, can transfer torque.

Claims (13)

1. A brush heat for a power-drivel Luu61brusll comprising at least two rotatable brush members having a plurality of bristle tufts, and gear means for connection to a drive means for driving the brush members in rotation including a rotatable chaft which comprises first and second shaft parts engaged with each other in 1the rotational direction, the first shaft part being movable relative to the second in the axial direction.

2. A brush head according to claim 1 wherein the first shaft part is slidably receivable within a recess in the second shaft part.

3. A brush head according to claim 2 including resilient means to urge the first sbaft part out of the recess in the second shaft part.

4. A brush head as claimed in any of claims 1 to 3, wherein Lhe brush members can be continuously rotated by the drive means.

5. A brush head as claimed in any one of claims 1 to 4, wherein the bruch head is tapered at one nc3.

6. A brush head as claimed in claim S wherein the brush member or members at the tapered end of the brush head is or are of reduced base width relative Lu the other member or members.

7. A brush head as claimed in any one of claims 1 to 6 wherein the brush members have a circular base.

8. A brush head as claimed in any of claims 1 to 7, wherein the brush members are of cylindrical shape.

9. A brush head as claimed in any one of claims 1 to 8, wherein the gear means further comprises a driving gear which meshes with a first-cr'wn gear associated with a first brash member which gear in turn meshes with a second crown gear associated with a second brush member.

10. A brush head as claimed in claim 6 wherein the brush member or members of reduced base width have longer bristles relative to the bristles of the other member or members.

11. A power-driven toothbrush comprising a brush head as claimed in any one of claims 1 to 10, and a handle containing a drive mcwnc connected to the gear mean.

12. A brush head substantially as herein described with reference to any one of the accompanying drawings.

13. A power-driven tooth brush substantially as herein described with reference to Figure 5 or 6 of the accompanying drawings.