Adjustable toothbrush

A toothbrush handle with a hollow area through which a rotatable shaft passes has a soft rubber member surrounding the shaft. A thumb-operated gear ring is secured to the rubber and the assembly is disposed in a chamber of the handle so that the ring is accessible through an opening in the outer shell of the handle. The inner chamber surface has teeth which engage the teeth on the ring and maintain it in place when the ring is pressed to displace the rubber and attached ring against the chamber teeth which prevents the shaft from being rotated when a desired angular positon of the handle and brush is achieved.

FIELD OF THE INVENTION 
This invention relates to toothbrushes with adjustable brush handles. 
BACKGROUND 
A significant factor in the increasing expense of health-care is the cost 
of diseases of the teeth and gums. Considerable advances have been made in 
dentifrices, mouthwashes, medications and treatment modes employed in the 
dentist's office. However, the primary instrument for daily home care of 
the teeth and gums is still the conventional toothbrush which typically 
has a non-rotatable handle and a fixed set of bristles at one end. 
The purpose of regular brushing is, of course, not only cosmetic, such as 
for removal of loose food debris, but also prophylatic, such as for 
removal of plaque, which is believed to be a source of caries, gingivitis 
and periodontitis (PD). 
However, a conventional toothbrush is so angled that is is very difficult 
to use it to remove plaque from the gingival margin (GM) and sub-gingival 
area (SGA). Moreover, as noted in U.S. Pat. No. 4,454,623, such 
conventional toothbrushes have narrow handles and it is, therefore, 
difficult to rotate them by hand since they often slip. That Patent notes 
that, in order to get the bristles into the gingival crevice, they must be 
rotated at a forty-five degree angle (known as the Bass method) which is 
difficult to accomplish using such conventional toothbrushes. 
SUMMARY 
The object of this invention is to provide a toothbrush which has a brush 
head which can be changed in its angular position by simple manual 
operation at the handle of the brush. Indeed, the angular position can 
facilitate toothbrushing by individuals who are manually partially 
handicapped. 
A further object of the invention is to provide a toothbrush with an 
adjustable brush head which can be adjusted to remove plaque from the SGA 
and GM. 
Another object of the invention is to provide a large handle toothbrush 
that can be held in one hand and wherein the angle of the brush head can 
be changed by a thumb operated mechanical system incorporated in the 
handle.

DETAILED DESCRIPTION 
The novel toothbrush of this invention is generally designated 10 in the 
drawings and includes a main body 11 which is shaped to the configuration 
of the palm and fingers of the hand and, as such, is much larger than 
conventional toothbrushes, but, being so, is more easily gripped to 
prevent twisting during use. The body may be made of any suitable 
material, preferably one of the harder injection moldable plastics. 
As shown in FIG. 1, a brush handle 12 having bristles 13 at its front end 
has a bayonet insert 14 at its rear end designed to fit securely within a 
suitably shaped slot 15 formed within the front end of a shaft 16 which 
shaft 16 is positioned within the interior of the body 11. If desired, the 
handle and shaft can be an integral unit, but the preferred mode for most 
uses is that shown which allows replacement of brushes when old brushes 
become worn out. 
As shown in FIG. 2, shaft 16 has a portion 16a surrounded by a rubber 
member 17 which is disposed within a chamber 23 in handle 11. Member 17 
could be of material other than rubber which is deformable. 
Rubber member 17 has a ring gear 18 secured to it and ring 18 has 
upstanding teeth 18a. 
As shown best in FIG. 4, a portion of gear ring 18 is accessible through an 
opening or cutout 20 of the handle 11 for manipulation by the user. 
(Preferably, the teeth 18a are relatively fine and are not raised above 
the surface of handle 11 so that the teeth 18a do not cause the user 
discomfort.) The rest of the ring 18 and material 17 (the "assembly") is 
disposed within chamber 23 located in the handle 11 below opening 20. The 
front part 16c and the rear part 16d of shaft 16 are supported for 
rotatable movement on either side of the chamber 23 by suitable bearing 
means within handle 11. 
In the position shown in FIGS. 2 and 4, ring 18, attached deformable member 
17 and shaft 16 (to which member 18 is secured) can freely rotate within 
chamber 23. In this position, therefore, the user can use his thumb to 
rotate ring 18 which causes shaft 16 to rotate. Since brush handle 12 is 
fitted into shaft 16, handle 12 and, therefore, brushes 13 are moved into 
any desired angular position for the proper cleaning of that section of 
the teeth and adjacent GM and SGA. 
When the proper angle is achieved, the user exerts pressure downwardly on 
ring 18 as denoted by P in FIG. 3. This pressure causes the deformable 
material 17 and attached ring 18 to move down into chamber 23 so that gear 
teeth 18a engage teeth 24 disposed at the bottom of the chamber, so that 
shaft 16 now cannot move. At this position (the "down" position), brushing 
can commence at the desired brush head angle. 
When a given area of the teeth and adjacent gums are thoroughly brushed, 
the user releases pressure (usually exerted by the thumb) on the ring 18 
to allow the assembly to disengage from the teeth 24 whereby the assembly 
moves up to the position of FIGS. 2 and 4, thereby allowing a new angular 
position to be set for a different part of the teeth and adjacent gum area 
by repeating the angle adjustment prodedure described. 
It may be desirable to form gear ring 18 as an integral part of the 
deformable member 17, as shown in FIG. 5 wherein ring 18' is integrally 
formed as a part of member 17'. 
It is within the scope of this invention to make modifications of the basic 
concept described above. 
Thus, it may be desirable to provide means for locking the assembly in the 
"down" position once a desired angular position of the handle and brush 
head are obtained, so that it is unnecesary for the user to exert constant 
downward thumb pressure on the gear ring. 
One embodiment for providing a locking means is shown in FIGS. 6 and 7 
wherein parts common to those of FIGS. 1-4 are indicated by primes. 
Thus, in FIG. 6 there is provided a locking member attached by a hinge 31 
to the lip of cutout 20'. The user rotates ring 18' to the desired 
position, and then pushes the assembly down into the chamber as described 
to engage teeth 24'. Then, the user moves member over the opening 20' so 
that member 30 locks under a catch 32 disposed on the lip of the other 
sides of chamber 20' to maintain the assembly in the down position, as 
shown in FIG. 7. 
Another embodiment for providing a locking system is shown in FIGS. 8 and 9 
wherein, again, parts common to FIGS. 1-4 are shown with a double prime. 
In FIG. 8 there is provided a slide lock 40 which is curved and fits 
within a slot 41 in the wall of handle 11". When the lock 40 is in the 
open position shown in FIG. 8, the ring 18 is accessible through opening 
20" for adjustment of the assembly. When the ring 18" is pushed down into 
the chamber 23" to engage the teeth of ring 18" with teeth 24", the lock 
40 is slided across the cutout 20" and into a slot 42 to hold the assembly 
down in the locked position, whereby the shaft 16" is maintained in the 
desired angular position. 
Another embodiment for providing a locking system is shown in FIGS. 10-12 
wherein parts common to FIGS. 1-4 are shown in triple prime. In this 
embodiment, the hold down member or slide lock 50 moves along the 
longitudinal axis of handle 11 within a slot 56 and is movable by thumb 
manipulation. FIG. 12 shows lock 50 move over ring 18'" to depress it into 
locking engagement with teeth 24'" at the bottom of the chamber. FIG. 12 
is a cross-section of FIG. 11 and shows the lock 50 over the ring. In this 
embodiment, lock 50 has teeth 51 which engage the teeth on ring 18'". (It 
is to be noted that the locking members of the other embodiments shown and 
described herein, such as members 30 and 40 can also be equipped with 
teeth 51 to engage the teeth on ring 18.) 
FIG. 12 illustrates how lock 50 is held in place by the lips 52, 53 of the 
groove or track 56 in which it slides.