CA2017223A1 - Toothbrush with rotatable head - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A toothbrush includes a pivotal head having bristles mounted thereon with the head arranged so that it can be moved into any desired angular orientation relative to the handle portion of the toothbrush. Two embodiments are illustrated with one being adapted for direct manual manip-ulation of the head and the other including a remote thumbwheel disposed along the handle portion of the toothbrush for manipulating the angular orientation of the head relative to the handle. The bristles on the toothbrush are bonded together along a portion of their length to rigidify the bristles so that they can be made longer without sacrificing a proper balance between flexi-bility and rigidity.

Description

2~7223 ~ ~

TOOTHBRUSH WITH ROTATABLE HEAD

~ACKGROUND OF THE INVENTION ~ ;~

Field of the Invention The present invention relates generally to oral " ;
hygiene devices and more particularly to a new and improved toothbrush having an improved bristle arrangement and a;~
pivotal or rotatable head enabling its user to vary the angular relationship of the bristles on the head with the -~
handle.
DescriDtion of the Prior Art `
For many years oral hygiene has been recognized as -~
being of critical importance in maintaining desired quality ~ ~
of the teeth and gums. As a consequence, numerous types of ~ :
devices have been developed for cleaning the teeth. `~
Of course, the most commonly used device is the con-vertional toothbrush which is merely an elongated handle having a plurality of bristles at one end usually forming a right angle to the handle so that the brush can be inserted into the mouth to brush the accessible surfaces. As will be appreciated, however, the teeth have surfaces which are difficult to access. Some of such surfaces are the proximal surfaces and the surfaces along the gum line. The -~ ;
proximal surfaces are those that are between the teeth and become less accessible as the proximal surfaces approach a `~
contact area with another tooth. Similarly the surfaces of the teeth along the gum line become less accessible as the .

teeth approach the gum line. Conventional toothbru~hes have proven to be less than satisfactory in cleaning all of the surfaces. As a consequence, attempts have been made at modifying conventional toothbrushes so that they are better adapted to cleaning all surfaces rather than just those that are readily accessible.
For example, in an attempt to develop toothbrushes which are more effective than the conventional toothbrush, toothbrushes or other tooth cleaning devices have been formed with bristles that form an angle relative to the handle. These brushes, however, while being more suitable ~han the conventional toothbrush in getting into certain areas, are less satisfactory for getting into other areas.
Another example of a tooth cleaning device that was developed to be more efficient than a conventional toothbrush is found in U.S. Patent No. 4,712,266 issued to Yamaki which discloses a device wherein the angle of the bristles can be varied relative to the handle by appropri-ately bending a predesignated portion of the device. It would not appear that a device of this type would have a - very long life, however, as repeated bending would appear -,to have a deteriorating effect on the plastic from which the device is made. Another interesting device is shown in ;
the U.S. patent to Rosofsky No. 4,486,109 which shows an angled massaqing device on the end of a toothbrush. The angular portion of this toothbrush does not have a ~-'' " '' ' conventional array of bristles but rather an array of bristles which are arranged in a concave brushing surface to provide a massaging rather than cleaning function.
Another illustration of a tooth cleaning device having the bristles formed at an angle relative to the handle is found in the patent to Larson No. 4,150,457 which discloses the use of angular heads at opposite ends of an elongated ~-handle with each head having a plurality of bristles disposed at a predetermined angle relative to the handle with the bristles at one end forming an acute angle while the bristles at the opposite end form an obtuse angle. One obvious objection to a device of this type is that after ~ ~
using one end of the toothbrush it becomes dirty and must ; --be held in the user's hand while using the other end.
Other toothbrushes have provided curved handles in an i attempt to access difficult locations in the mouth with an;;~
example of such a toothbrush being disclosed in U.S. Patent ~ -~
No. 4,137,593 issued to Porper. Another similar device having an angular handle in an attempt to make the ~ -toothbrush more adaptable to hard-to-reach locations in the mouth is disclosed in the Hitzman Patent No. 4,724,570. ~ -Still another patented device which is of interest in - I
disclosing the recognition of the problem of accessing all locations in the mouth is disclosed in the patent to Cheng No. 4,712,267 which shows a convertible toothbrush having a handle of generally S-shaped configuration and with a set `~ 201~223 of bristles that are moveable along the handle to occupy selected locations thereby varying the angle of the bristles relative to the handle.
Unique arrangements of the bristles themselves have also been utilized to improve the cleaning capability and efficiency of a toothbrush. For example while most toothbrushes utilize a rectangular array of bristles, some more recent toothbrushes have utilized an array that is substantially conical in configuration as it is felt that this array will better penetrate the proximal surfaces of the teeth as well as the surfaces which are along the gum line. -Some prior art toothbrushes have also incorporated finer bristles, i.e. bristles having a smaller diameter than what is found in most conventional toothbrushes. It ~-i5 ~elt that the finer bristles are less abrasive to the teeth and gums and are more efficient in cleaning the small germs from which plaque is formed but the finer bristles ~ -have the drawback of being too flexible and therefore have -`
a short life and in some cases have been too flexible to effectively clean the teeth.
Other devices for oral hygiene that illustrate the extent to which the prior art has gone in providing means ~ -for keeping the teeth clean include professional devices of the type utilized by dentists or oral hygienists such as a dental instrument that can be forced into the spaces -20~7223 ~ -between the teeth and into the gingival crevices between the teeth and the gums to scrape deposits from the teeth.
Dentists and oral hygienists also use rotating rubber cups to apply abrasive compounds to the teeth in an attempt to obtain a very thorough cleaning of the teeth on a periodic basis.
The present invention has been developed to overcome the limitations of prior art devices by providing an oral - -~
hygiene device that satisfactorily cleans most surfaces of the teeth.
SUMMARY OF THE INVENTION
The toothbrush of the present invention incorporates a ~
pivotal or rotatable head so that a plurality of bristles ;
mounted in the head can be selectively moved into an infi- -nite number of angular orientations relative to the handle to enable the toothbrush to be used in cleaning most sur-faces within the mouth. In one embodiment of the inven-tion, the head in which the bristles are mounted is -~
manually pivotable by finger contact with the head. The bristles are mounted in a disk forming the head of the toothbrush so as to extend radially from a rounded bulbous end of the handle. The disk is frictionally receivqd in the end of the handle so that the head can be positively positioned in any desired angular orientation relative to the handle thereby disposing the bristles at desired orien-tations.

2~7223 In a second embodiment of the device, ~he head in which the bristles are mounted is rotatably mounted rela-tive to the handle and is connected by an endless belt to a control wheel disposed approximately midway along the length of the handle so that the angular relationship of the head with the handle can be controlled from a remote location by simple finger manipulation of the control wheel. of course, the angular relationship of the head relative to the handle also affects the angular orientation of the bristles relative to the handle so that the bristles can be easily and conveniently disposed in any desired orientation.
The invention further provides the use of relatively fine bristles which are reinforced along a portion of their leng~h to maintain a desired balance between rigidity and flexibility.

Other aspects, features and details of the present `~
invention can be more completely understood by reference to the following detailed description of the preferred 2~ embodiments, taken in conjunction with the drawings, and;~;~
from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
,. :,,..:
Fig. l is a perspective view of the toothbrush of the present invention.
Fig. 2 is an enlarged side elevation of the toothbrush shown in Fig. l.

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Fig, 3 is a front elevation of the toothbrush shown in Fig. 2.
Fig. 4 is an enlarged fragmentary side elevational view of the head portion of the toothbrush of the present invention.
Fig. 5 is a section taken along line 5-S of Fig. 4.
Fig. 6 is a section taken along line 6-6 of Fig. i4.
Fig. 7 is a perspective view of the head of the -toothbrush having the bristles therein and removed from the ~
handle portion. ~;
Fig. ~ is a fragmentary perspective view of one end of the handle of the toothbrush showing the slot in which the head is pivotally received. -~
Fig. 9 is a perspective view of a second embodiment of the toothbrush of the present invention.
Fig. 10 is an enlarged fragmentary side elevation of ^~
the toothbrush shown in Fig. 9.
Fig. 11 is an enlarged fragmentary section taken along line 11-11 of Fig. 10.
Fig. 12 is an enlarged section taken along line 12-12 of Fig. 10.
Fig. 13 is a section taken along line 13-13 of Fig. 11. ;~
Fig. 14 is a section taken along line 14-14 of Fig. 11.
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20~7223 Fig. 15 is a perspective view of the head of the toothbrush shown in Fig. 9.
Fig. 16 is a diagrammatic view of the toothbrush of the present invention in operative relationship with a set of teeth.
DESCRIPTION OF THE PREFERRED EM~ODIMENTS
Referring first to Fig. 1, a toothbrush 10 in accor- -dance with the present invention is illustrated as having an elongated handle 12 with a gripping portion 14 at one end and an enlarged bulbous portion 16 on the opposite end.
A pivotal head 18 is disposed in the bulbous portion of the handle and is positively positionable relative to the handle in a manner which will become clear hereinafter.
The enlarged bulbous portion 16 of the handle is inte- ~
I5 gral therewith and is generally spherical in configuration. ~ ~;
The bulbous portion has a transverse slot 20 formed therein ~; .
with the slot being defined by a pair of confronting concave surfaces 22, as best seen in Figs. 5 and 6. The - slot is adapted to pivotally receive the head 18. The ~ -handle 12 could be made of any suitable material but a `
plastic material having a slight amount of resiliency is desirable.
The pivotal head 18, as best seen in Fig. 7, comprises a generally disk-like body 24 having a cylindrical periph- --`
, ~. .. ..
eral surface 26 and diametrically opposed convex faces or ~ - `
surfaces 28 which are adapted to mate with the concave , ~

-surfaces 22 in the bulbous portion of the handle. The head has a radial extension 30 from the cylindrical surface 26 in which a plurality of bristles 32 sui~able for cleaning the teeth are permanently positioned in a manner to be described in more detail later. While these bristles could take different configurations, in the preferred configura- ~
tion, they form a generally conical brushing surface. ~ -The head 18 is also preferably made of a plastic mate-rial and is insertable into the slot 20 formed in the~ -bulbous portion of the handle. Since the material of which the handle is made is slightly resilient, the bulbous portion 16 will flex enough to allow the head 18 to be forced into the slot. Once the head is positioned in the slot, it is frictionally as well as mechanically retained therein. In addition, as the angular orientation of the head is changed relative to the handle, the bristles 32 can ;~ -be moved through an arc that is approximately 240 so that the bristles can form an infinite number of desirable angles relative to the handle. The frictional relationship of the head and the bulbous portion of the handle will inherently retain any desired angular relationship while the toothbr;ush is being used to clean the surfaces of the teeth. The generally spherical cQnfiguration of the ~-bulbous portion 16 of the handle in addition to providing a suitable receptacle for the pivotal head 18 provide~ a blunt surface which does not damage the gums or other surfaces in tho mouth when the toothbrush ls belnq used.

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~' ~7223 As is probably best shown in Fig. 4, the bristles are affixed to the radial extension 30 on the head 18 in a unique manner such that relatively fine bristles approxi~
mately .003 to .005 inches in diameter, in comparison to bristles used on most conventional toothbrushes of .007 inch diameter, can be utilized while retaining a desired balance between flexibility and rigidity of the bristles.
It has been found that the bristles 32 can be bonded together in an area 33 contiguous with their connection to ;~
lo the head 18 and for a short distance along their length to unify the bristles and increase the stiffness of the bristles so that relatively fine bristles can be used with-out being too flexible. As mentioned previously relatively fine bristles have the advantage of being less abrasive to the teeth and the gums and are better suited to clean the - ;
small germs from the surface of the teeth which form plaque. A disadvantage, however, is that they are too ~ `
flexible for efficient cleaning and have a shorter than desired lifespan when of an adequate length to separate the ~ ~-~ 20 tooth engaging surfaces of the bristles from the head of -~ the toothbrush. The head of the toothbrush, of course, is made of aireiatively hard material and if the bristles are not adequately long the relatively hard head will `~
undesirably rub against the teeth and gums. By reinforcing the bristles, however, with a bonding medium along a por~
tion of their length, adequate stiffness can be given to ~ ~

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2~7223 --the bristles while leavin~ them at an adequate length and without losing the desirable features of relatively fine bristles.
The bristles can be bonded together in the ar0a 33 in any suitable manner but the use of suitable chemicals and heat has been found to work satisfactorily. The bonding medium can also be used to adhere the bristles to the radial extension 30 by bonding the bristles directly to a flat face 35 on the end of the radial extension.
By way of example, bristles projecting away from the ~-radial extension a distance A, which might be 8 mm, can be used as longer bristles and bristles extending away a distance B, which might be 4 mm, as shorter bristles with the bristles being bonded together for a distance C, which might be 2 mm, from the radial extension. In other words, the bonding area would preferably extend along approxi-mately 20% to 40% of the length of the longest bristles.
With reference to Figs. 9-14, a second embodiment 34 of the toothbrush of the present invention is illustrated.
In this embodiment, an elongated handle 36 is provided with a gripping portion 38 at one end and a bulbous portion 40 at the oither end with the bulbous portion adapted to rotatably receive a head 42. The head is of generally hemispherical configuration having a hemispherical surface 44 and a flat surface 46 with a square segmented shaft 48 projecting perpendicularly away from the flat - 2~ ~ ~2~3 surface. A radial projection 50 from the hemispherical ~ ~-surface 44 permanently receives a plurality of bristles 52 for brushing the teeth. The bristles generally take the configuration of a cone, it being understood that any desirable configuration for the bristles would be accept~
able. The bristles are positioned on the head so as to always form an angle of approximately 60 with a plane , ~ ~;-.
including the longitudinal axis of the handle and with the plane being perpendicular to the square shaft 48.
The handle 36 is formed from a front segment 54 and a rear segment 56 with the segments being elonqated and ;~
having flat faces 58 and 60 respectively maintained in con~
fronting relationship in any suitable manner such as by adhesive. The abutted faces 58 and 60 lie in the aforenoted plane that forms a 60 angle with the bristles. ; ~;~
The segments 54 and 56 of the handle have notches 62 and 64 respectively formed therein at approximately their longitudinal centers so that when the segments are placed in confronting relationship a cavity 66 is defined in the handle. The rear segment 56 has a pair of channel-shaped -grooves 68 (Fig. 14) formed in the flat face 60 extending from the cavity 66 to the bulbous portion 40 of the handle.
~t the bulbous portion 40 of the handle, the rear segment has a generally cylindrical recess 70 opening through the flat face 60. The recess 70 includes two cylindrical por- ~ `
tions with the first portion 72 adjacent to the flat : ' :

-:` 201~223 face 60 of the rear segment 56 being of a larger diameter than a second slightly smaller diameter portion 74.
At the bulbous portion 40 of the handle, the front segment 5~ of the handle has a ~enerally cylindrical passage 78 therethrough with a counterbore 80 defining a relatively large diameter portion adjacent the flat face 58 and a peripheral shoulder 81. The opposite face 82 of the front segment 54 is flat at the bulbous end to confront the flat surface 46 of the head 42 and establish a rotational relationship between the flat portion 46 of the head and the face 82 of the handle. -An inner pulley 84 is disposed in the bulbous portion 40 of the handle and is best illustrated in Figs. 11 and 12. The pulley 84 is cylindrical in configu- ~ -lS ration and has a peripheral groove 86 formed in its outer surface. The pulley has an outer diameter of the same dimension as the diameter of the second portion 74 of the recess 70 in the rear segment 56 so that the pulley can be rotatably seated in the rear segment. The pulley is ~ -retained in position within the bulbous end of the toothbrush by the peripheral shoulder 81 when the front and rear segments are bonded together. The peripheral groove 86 is in alignment with the channel shaped grooves 68 in the rear segment for a purpose to be -expla1ned here~nafter.

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2 0 ~ 7 2 2 3 The pulley 84 has a square-shaped recess 88 formed axially therein that receives the square shaft 48 on the head of the toothbrush so that the head 42 and pulley will rotate in unison. The square recess 88 has a peripheral channel 90 (Figs. 11 and 12) extending therearound which ~ ~;
mates with a peripheral bead 92 (Fig. 15) formed around the ~-~
square shaft 48 so as to provide a snap-type means for ;~
releasably retaining the head in the pulley. The shaft ~8 is segmented into four parts which flex slightly relatively to each other so that the square shaft can be easily inserted into the recess 88. ;~
A thumbwheel 94 is rotatably disposed in the cavity 66 defined by the confronting notches 62 and 64 in the handle -~
segments at approximately their longitudinal center. The notches 62 and 64 include cylindrical bores 96 and 98 respectively adapted to receive shafts 100 projecting axially from opposite sides of the thumbwheel. The thumbwheel has a circular groove 102 formed in one side ~
thereof in alignment with the two grooves 68 formed in the ~ ~ -rear handle segment and a relatively large cylindrical portion 104 adjacent thereto which projects above the external surfaces of the handle. The enlarged port!ion lO~
has a serrated circumferential surface to establish a fric~
tional relationship with the thumb or another finger of a user's hand so that the wheel can be easily rotated. A -belt or an 0-ring 106 preferably made of a nylon material , ,,", - '~

connects the circular groove 102 in the thumbwheel with the peripheral groove 86 in the internal pulley with the belt extending through the pair of grooves 68 formed in the rear segment.
The belt 106 frictionally grips both the thumbwheel and the internal pulley 84 so that rotation of the thumbwheel affects rotation of the pulley thereby rotating the head 42 in a corresponding manner. Of course, as the head rotates, so do the bristles 52 so that the angular relationship of the bristles to the handle can be easily -~
changed from a remote location. The head can therefore be releasably retained in any selected angular orientation so that the bristles can be directed in one desired orienta-tion to brush certain surfaces in the mouth and moved to another orientation to brush other surfaces. This movement is probably best illustrated in Fig. 9 and the usefulnessof the various angular positions relat-ive to the teeth in Fig. 16.
Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example, and changes in detail or structure may be made without departing from the spirit of the invention, as defined in the appended claims.

Claims (15)

1. A toothbrush comprising in combination:
an elongated handle, and a pivotally-mounted head connected to said handle adjacent one end thereof, said head including a plurality of bristles protruding therefrom whereby rotation of said head relative to said handle changes the angular relationship of the bristles to the handle.

2. The toothbrush of claim 1 wherein one of said head and handle have a slot formed therein and the other of said head and handle is pivotally seated in said slot.

3. The toothbrush of claim 1 wherein said handle has two ends with a slot formed in one end thereof, and wherein said head is pivotally seated in said slot.

4. The toothbrush of claim 3 wherein said slot is defined by a pair of opposed concave surfaces and wherein said head is of generally disk-shaped configuration having a pair of convex surfaces adapted to mate with said concave surfaces whereby said head is pivotally retained in the slot in said handle.

5. The toothbrush of claim 1 further including retention means for retaining the head in one of an infi-nite number of selected angular orientations relative to the handle.

6. The toothbrush of claim 4 further including retention means for retaining the head in one of an infinite number of selected angular orientations relative to the handle.

7. The toothbrush of claim 6 wherein said retention means is a friction fit between said concave and convex surfaces.

8. The toothbrush of claim 1 further including con-trol means mounted on said handle and extending from a remote location on said handle to said head for controlling the relative angular relationship of the handle and head.

9. The toothbrush of claim 8 wherein said control means includes an endless belt extending between said remote location and said head.

10. The toothbrush of claim 9 wherein said control means further includes a rotational wheel mounted on said handle at said remote location and said head includes a surface for frictionally receiving said belt whereby said belt can be passed around said wheel and said surface to cause rotative movement of said head when the wheel is rotated.

11. The toothbrush of claim 10 wherein said head is generally hemispherical in configuration and has a shaft projecting away therefrom, said rotational wheel having means for frictionally receiving said belt, and said handle having means for receiving and retaining said head for unitary rotation with said belt whereby rotational movement of said wheel will cause said belt and said head to rotate in unison to vary the angular relationship of the handle with the head.

12. In a toothbrush having a handle and a head por-tion, the head portion having a plurality of bristles proj-ecting therefrom, the improvement comprising bonding means along a portion of the length of said bristles to unify and rigidify the bristles along said portion.

13. In the toothbrush of claim 12 wherein said bonding means is adjacent to said head.

14, In the toothbrush of claim 13 wherein said bonding means is contiguous with said head.

15. In the toothbrush of claim 14 wherein said bonding means extends along approximately 20% to 40% of the length of the longest bristles.