Brush head for an oral cleansing device

1. A brush head for an oral cleansing device, the brush head comprising:

a shaft including an interior surface defining an interior cavity; and

an adapter received within the shaft and configured to couple the brush head to a drive shaft of the oral cleansing device, wherein the adapter includes a cantilevered beam configured to engage the drive shaft of the oral cleansing device to transfer a rotational motion of the drive shaft to the brush head;

wherein the cantilevered beam includes a fixed end supported by the adapter, an opposite free end, and an intermediate portion between the fixed end and the free end;

wherein a gap is defined between the intermediate portion of the cantilevered beam and the interior surface of the shaft, the gap providing clearance for outward flexing of the cantilevered beam during insertion of the drive shaft into the adapter; and

wherein outward flexing of the cantilevered beam causes the free end of the cantilevered beam to contact the interior surface of the shaft before bending of the intermediate portion of the cantilevered beam.

2. The brush head of claim 1 ,

wherein contact of the drive shaft with the intermediate portion of the cantilevered beam causes the free end to engage the shaft.

3. The brush head of claim 1 , wherein the cantilevered beam comprises an inward curvature defined by the intermediate portion extending inward from the fixed end and the free end extending outward from the intermediate portion.

4. The brush head of claim 1 , wherein:

the fixed end of the cantilevered beam is positioned proximate a drive shaft opening of the shaft; and

the free end of the cantilevered beam is positioned distal the drive shaft opening.

5. The brush head of claim 1 , wherein a base of the adapter includes a flange, and the fixed end of the cantilevered beam is positioned proximate the flange.

6. The brush head of claim 1 , wherein the adapter further includes one or more alignment features to align the adapter within the shaft.

7. The brush head of claim 6 , wherein the one or more alignment features comprise an alignment rib defined by a pair of alignment notches defined in an exterior surface of the adapter.

8. The brush head of claim 1 , wherein the cantilevered beam extends lengthwise along a longitudinal direction of the shaft.

9. The brush head of claim 1 , wherein the cantilevered beam is configured such that after the free end of the cantilevered beam contacts the interior surface of the shaft, further insertion of the drive shaft into the adapter causes the intermediate portion of the cantilevered beam to bend outward, in turn causing the free end of the beam to slide in a longitudinal direction along the interior surface of the shaft.

10. The brush head of claim 1 , wherein

contact of the drive shaft with the intermediate portion of the cantilevered beam causes the cantilevered beam to flex outward towards the interior surface of the shaft.

11. The brush head of claim 1 , wherein the cantilevered beam is configured to apply a force to the drive shaft, the force concentrated midway between the fixed end and the free end.

12. The brush head of claim 1 , further comprising a sealing element positioned between the adapter and a drive shaft opening of the shaft.

13. The brush head of claim 1 , wherein:

the adapter and the drive shaft each include a respective flat; and

the cantilevered beam presses the flat of the drive shaft against the flat of the adapter such that motion of the drive shaft is transferred to the brush head.

14. The brush head of claim 13 , wherein the flat of the adapter extends to a leading edge of the adapter.

15. The brush head of claim 13 , wherein the adapter further includes a shoulder extending from the flat of the adapter to engage the drive shaft and define a fully inserted position of the brush head on the drive shaft.

16. The brush head of claim 1 , wherein the outward flexing of the cantilevered beam comprises the cantilevered beam bending substantially as a rigid body.

17. The brush head of claim 1 , wherein the adapter is sonically welded to the interior surface of the shaft.

18. The brush head of claim 1 , wherein the cantilevered beam includes an interior surface with a first segment that extends inward at a first angle and transitions into a second segment that extends inward at a second angle that is less than the first angle.

19. The brush head of claim 18 , wherein a length and the first angle of the first segment are configured such that the drive shaft contacts the second segment of the inner surface of the cantilevered beam substantially at the same time as the free end of the cantilevered beam contacts the interior surface of the shaft.

20. The brush head of claim 19 , wherein the interior surface of the cantilevered beam further includes a third segment that extends outward relative to the second segment such that an insertion force required to insert the drive shaft into the adapter is reduced as the drive shaft contacts the third segment.