Toothbrush

A toothbrush which has a brush handle, a head on one end of the handle and a resilient, preferably multicellular pad fixed on the brush head. The pad has a concavity of a relatively large area across the pad in the area halfway between the ends of the pad on the upper surface, to form two protrusions on the opposite sides of the concavity. Each protrusion has at least one upside projection thereon substantially of the form of a triangular prism with the lateral edges extending in the lateral direction of the pad. The concavity lies preferably lower than the bottom of the troughs defined by the adjacent upside projections and can have a ridge or a plurality of ridges across the pad on the concavity. The pad has preferably an additional projection on each of the protrusions, which extends in the longitudinal direction of the pad and is of a form of a polygonal prism with the lateral edges extending in the lateral direction of the pad.

BRIEF SUMMARY OF THE INVENTION 
This invention relates generally to a toothbrush. More particularly, the 
invention is directed to a novel toothbrush having a resilient pad of a 
characteristic configuration and structure, which is particularly suitable 
for massaging both the exterior and interior sides of the teeth and gums 
as well as for cleaning the teeth in an ordinary manner as with the case 
of a conventional toothbrush having bristles at the brush head. 
It is common knowledge that massaging the teeth and gums greatly assists to 
maintain and promote the health of the teeth. However, the conventional 
type toothbrush has been designed with the main purpose to scratch the 
teeth and gums with the pointed ends of the bristles to remove and clean 
away foreign elements on and from the teeth, so that structurally the 
conventional type toothbrush is not fit for massaging the teeth and gums. 
Even if used for massaging, it does not effect satisfactory massaging, and 
what is worse, there is a possibility that the gums are wounded by the 
pointed ends of the bristles. In addition, since it has been difficult to 
place bristles onto the brush head at a high speed in a continuous way, 
the production of the conventional toothbrush requires a large-sized, 
complicated device, causing an increase in cost for the production. 
With the foregoing and other considerations in view, the principal object 
of this invention is to provide a toothbrush having a configuration and 
structure designed so as to be especially fit for massaging both the 
interior side as well as the exterior side of the teeth and gums, and thus 
to provide a toothbrush which can effectively remove protein films 
sticking on the teeth which produce a harmful influence upon the health 
thereof, and also to remove nicotine which renders the teeth unclean. 
Another object of this invention is to provide a toothbrush which will not 
wound the gums. Still another object of this invention is to provide a 
toothbrush which will retain its integrity and keep its effective 
massaging function after many uses. An additional important object of this 
invention is to provide a toothbrush which can be produced not only at a 
significantly lower cost but also at a higher speed than the conventional 
bristle type toothbrush in a continuous process, and consequently, may be 
disposed of after a single use if desired.

DETAILED DESCRIPTION OF THE INVENTION 
The toothbrush of this invention comprises a brush handle and a brush pad 
fixed at the head of the handle, the pad being made of resilient and 
preferably multicellular materials. The pad has a concavity of a 
relatively large area on the upper surface across the pad in the area 
halfway between both the ends of the pads, to form two protrusions on the 
opposite sides of the concavity. Each protrusion has at least one upside 
projection thereon as viewed in the drawings. The projection has the form 
of a substantially triangular prism with the lateral edges thereof 
extending in the lateral direction of the pad. 
Referring now to the drawings, wherein like reference characters designate 
like or corresponding parts throughout, and in particular first to FIGS. 1 
to 3, there is shown one possible embodiment according to a toothbrush of 
this invention. The toothbrush comprises a brush handle 1 made of rigid, 
low cost materials such as wood, bamboo or plastic materials, a brush head 
2, which is a continuation of the brush handle, and a pad 3 fixed on the 
brush head. The pad 3 is made of resilient, and preferably multicellular 
materials such as rubber, foamed plastic materials or the like. Among 
these materials, foamed silicone rubber, which is now readily available in 
the market, can be most preferably used for the pad of the toothbrush of 
this invention from the aspects of its elastic and multicellular 
properties. 
The pad 3 has a concavity 8 of a relatively large area across the pad on 
the upper surface of the pad in the area halfway between the ends of the 
pad, to form two protrusions on opposite sides of concavity 8, a fore 
protrusion 9 and a rear protrusion 10. Each of the protrusions 9, 10 have 
at least one upside projection 4, 5 thereon substantially in the form of a 
triangular prism, and lateral edges 6, 7 parallel to the axial line of 
which extends across the pad, or in other words, along the lateral 
direction of the pad. 
The concavity 8 can be of various configurations, for instance, rectangular 
as shown in FIG. 1, inverse trapezoidal as shown in FIG. 5 or arch-wise, 
that is, downward convex as shown in FIG. 7, when viewed from frontside 
respectively. 
In general, each of the protrusions 9, 10 is preferably provided with two 
to four upside projections 4, 5. As explained later, one of the most 
important and characteristic functions or actions of the pad resides in 
that when pressed against and moved along the teeth and gums, the pad 3 
will be resiliently deformed or distorted downwardly toward the brush head 
to produce a strong resilient repulsion or restitution against the 
deformation in the pad, particularly in the upside projections 4, 5, 
which, in turn, massage the teeth and gums. Therefore, in the case each 
protrusion has two to four upside projections, each projection has 
relatively large mass and consequently strong restitution when distorted. 
On the other hand, in case each protrusion is provided with five or more 
upside projections, each projection has relatively small mass and 
consequently weaker restitution, which only results in an insufficient 
massaging. This is the reason each of the protrusions 9, 10 is provided 
with two to four upside projections 4, 5 in the preferred embodiments of 
this invention. However, it should be understood that the number of the 
upside projections on each protrusion 9, 10 is in particular dependent on 
the relative size and the shape of the pad and/or the projections 
themselves as well as the properties of the material used for the pad. 
When each protrusion is designed to have two or more upside projections 4, 
5, the concavity 8 is preferably so formed that the bottom plane or bottom 
13 lies closer to the brush head 2, that is, lower than the bottom of the 
troughs 12. Troughs 12 are defined by two tilting side faces 11, inwardly 
tilting side face 11a and outwardly tilting side face 11b, tilting 
opposite to each other and forming part of the two adjacent triangular 
prismatic upside projections 4, 5, so as to have the pair of protrusions 
9, 10 resiliently deform relatively independently of each other. Thus each 
tooth is massaged relatively independently by the upside projections 4, 5 
on each of the protrusions 9, 10. The troughs 12 are of U-, or V-, inverse 
trapezoidally shaped or of other suitable shapes. This construction of 
both the projections and the concavity 8 permits the pad 3 not only to 
contact closely with the teeth and gums when the pad is pressed against 
them, but also, as described later, to massage them sufficiently even the 
interior sides of the teeth and gums. 
According to this invention, the pad can have a groove or grooves 15 across 
the pad 3 on the back side 14 thereof directly under the protrusions as 
shown in FIG. 4 and/or at the central part of the back side 14. In the 
case where the bottom of the concavity 8 lies relatively low, the pad may 
not be provided with the grooves 15. On the other hand, in the case the 
concavity 8 is positioned relatively high, one or more grooves are 
preferably provided on the back side 14 of the pad so that the protrusions 
9, 10 can be readily deformed or distorted relatively independently of 
each other. The groove is not restricted in its configuration, and can be 
U-, V-shaped or otherwise. 
The above described pad 3 may be fixed directly to the flat brush head 2 by 
means of adhesives, but in a preferred embodiment the pad 3 is glued into 
the flute or recess 16 of a rectangular form on the brush head 2 to 
receive the bottom of the pad formed into a rectangular parallelepiped. 
The pad 3 as shown in FIGS. 5 and 6 can have another projection which 
projects in the longitudinal direction of the pad, and is in the form of a 
polygonal prism with the lateral edges thereof extending in the lateral 
direction of the pad. FIGS. 5 and 6 show an embodiment of this kind of the 
toothbrush of this invention, in which the lower parts of the fore and 
rear sides of the pad 3 are cut off along the lateral direction thereof 
the to form the fore projection 18 and the rear projection 19, both of 
which are triangular prismatically shaped and project in the longitudinal 
direction of the pad, so that the lateral edges 17 thereof extend in the 
lateral direction of the pad. The embodiment of the pad 3 as shown in 
FIGS. 5 and 6, is provided with a concavity 8a of an inverse trapezoid 
thereon in the middle of the pad; and the concavity 8a is an extension of 
the inwardly tilting faces 11a of the innermost upside projections 4a, 5a. 
FIG. 7 shows another embodiment of the toothbrush of this invention, 
wherein the pad 3 has the concavity 8b which is downward convex arch-wise 
preferably as a continuation of the inwardly tilting faces 11a of the 
innermost upside projections 4a, 5a. 
The concavity 8b, as shown in FIG. 8, can have a ridge 21 at the central 
part thereof or a plurality of ridges at intervals therealong. In both the 
cases, ridge 21 extends across the pad 3 as shown in FIG. 8 through FIG. 
10. It is essential that the ridge 21 is so formed that it protrudes 
upwards a little from the surface of the concavity 8b and runs across the 
pad 3. Accordingly the ridge can be either comparatively sharp at the top 
thereof as shown at 21c in FIG. 10 or be a gentle, curved tableland in 
shape as shown at 21 in FIG. 8. The ridge 21 or 21c permits the fore 
protrusion 9 and the rear protrusion 10 to be deformed independently of 
each other almost completely. Other important roles of the ridge will be 
described in detail in connection with the functions and effects of the 
toothbrush of this invention hereinafter. 
FIG. 11 shows another embodiment of the toothbrush of this invention, 
wherein the pad 3 has the fore projection 18d and the rear projection 19d 
in of the form of a tetragonal prism. The section of the projections along 
the longitudinal direction of the pad is preferably a trapezoid which is 
turned sideways as shown. In both the embodiments shown in FIGS. 5 through 
11, the fore and the rear projections 18, 19 and 18d, 19d are preferably 
continuations of the outermost upside projections 4, 5. Also, the pad 3 is 
preferably fixed on the brush head 2 so that the fore projection 18 
extends beyond the free end 20 of the brush head 2 for the reason 
described later. 
Furthermore, according to this invention, as shown in FIG. 12 pad 3 can be 
provided with a gutter or gutters 22 across the pad at the ends of 
concavity 8e together with or without the grooves 15. An embodiment of 
this sort of toothbrush is shown in FIG. 12, wherein two gutters 22 are 
provided and are located between the protrusion 4, 5 and the concavity 8, 
leaving the ridge 21e in the form of a tableland on the concavity. The 
gutters are preferably of a relatively large area to prevent the tension 
from concentrating on the gutters 22 when the pad is deformed or extended. 
Since the pad 3 of the toothbrush of this invention has such configuration 
and structure as above described, it can be easily produced by integrally 
stamping out the sheet materials from rubber, foamed plastics or the like. 
In particular, foamed silicone rubber is suitably used for the material, 
as described earlier, since the pad stamped out therefrom possesses a 
multicellular, rough surface both on the upper and back sides, giving rise 
to a greater friction between the pad and the teeth or gums, thus raising 
the massaging effects remarkably. 
Now, the functions and effects of the toothbrush of this invention will be 
described. When the toothbrush of this invention with the pad 3 of FIG. 2 
for example is pressed against the teeth 24 and gums, and the toothbrush 
is drawn in the direction of the arrow toward the grip of the brush handle 
as shown in FIG. 13, the protrusions, in particular, the upside 
projections 4, 5 will be resiliently distorted toward the free end 20 of 
the brush head. This action mainly causes the inwardly tilting faces 11a 
of the upside projections 4 on the fore protrusion 9 and the outwardly 
tilting faces 11b on the rear protrusion 10 to rub and massage strongly 
the teeth and gums due to the resilient restitution force of the upside 
projections 4, 5 and also causes the concavity 8 to contact closely with 
the curved row of the teeth 24 and the gums, and thereby to effect 
massage. Furthermore, when the lateral edges 6, 7 of the upside 
projections 4, 5 come to a hollow or space between the teeth, the edges 
intrude into the hollow to remove foreign elements therein. If the pad has 
other lateral edges 22' which are defined as the lines of intersection of 
the concavity and the innermost upside projections as shown in FIG. 11, 
the similar function will be achieved by those edges 22'. On the other 
hand, it will be easily understood that the outwardly tilting faces 11b on 
the fore protrusion 9 and the inwardly tilting faces 11a on the rear 
protrusion 10 will in turn rub and massage the teeth and gums when the 
toothbrush is pushed toward the free end of the brush head. Therefore, the 
toothbrush according to this invention not only can massage the teeth and 
gums, but also can clear away foreign elements between the teeth simply by 
moving the toothbrush laterally along the row of the teeth and the gums 
with the pad pressed against them. 
In the above described functions and effects of the toothbrush of this 
invention, it is particularly to be noted that the concavity 8 between the 
fore and the rear protrusions 9, 10 makes it possible for each protrusion 
to greatly deform or distort independently of each other, and thus to 
contact with and massage every tooth of the curved row of the teeth and 
the gums with strong restitution force. Furthermore, when the ridge 21 is 
provided on the concavity, the ridge enhances the durability of the pad 
remarkably as well as provides for the above-mentioned independency of 
each protrusion during deformation, since the ridge makes the relatively 
limited part of the pad surrounding the ridge sufficiently massive to 
receive the tension due to the deformation of the protrusions, especially 
due to the expansion of the pad when the pad is pressed against and moved 
along the teeth and gums. Or in other words, the ridge permits the tension 
to be released from the pad through the ridge. This function of the ridge 
is important since elastic materials in general are less durable when 
subject to repeated tension whereas elastic materials are more durable 
when subjected to repeated compression. According to this invention, 
therefore, even in the case where the pad is excessively deformed, the pad 
will never be damaged or cracked at the concavity. 
Furthermore, as shown in FIG. 14, the fore protrusion 9 can be easily put 
into and positioned behind the teeth 24 and the gums 25 since the pad is 
upwardly provided with the relatively large and deep concavity 8 across 
the pad in the middle of the upper surface. Therefore, when the toothbrush 
is drawn in the direction of the arrow toward the grip of the brush handle 
while pressing the upside projections 4 against the interior or back sides 
of the teeth 24 and gums 25 as shown in FIG. 14, the inwardly tilting side 
faces 11a of the upside projection 4 and the lateral edges 6 on the fore 
protrusion 9 as well as the concavity exert a strong repulsive force upon 
the back sides of the teeth and gums, massaging them. Also in FIG. 14, the 
independent deformation of each protrusion due to the presence of the 
concavity and the ridge thereon is clearly illustrated; that is, while the 
fore protrusion 9 is so deformed as to cover the free end of the brush 
head, the rear protrusion 10 still remains its original configuration with 
no crack at the concavity. The gutters also serve for the independent 
deformation of each protrusion. 
In the next place, in the case the fore and rear projections 18, 19 are 
provided on the fore protrusion 9 and the rear protrusion 10 respectively, 
the fixed area between the pad and the brush head is relatively reduced 
while the mass of the pad is relatively increased so that the fore 
protrusion 9 is allowed to be more greatly deformed to exert a greater 
repulsive force on the teeth and gums. More particularly, when the pad is 
mounted on the brush head so that the fore projection 18 extends beyond 
the free end of the brush head, the fore protrusion 9 will be able to be 
resiliently distorted downwardly to such a degree so as to cover the free 
end of the brush head, thus not only exerting by far a greater repulsive 
massaging force on the teeth and gums, but also preventing the mouth 
cavity from being wounded by the free end of the brush head due to an 
accident. 
The grooves 15 on the back side of the pad serve to adjust the degree of 
deformation of the pad and the resulting restitution power thereof or of 
the protrusions and the projections. When the pad is made of relatively 
soft materials such as foamed polyurethane, or sponge, it has enough 
pliability and elasticity without the grooves, but when the pad is made of 
relatively hard materials such as rubber and foamed silicone rubber, it 
may be provided with one or more grooves so as to increase the degree of 
deformation of the pad, thus improving the massaging function of the pad. 
The adjustment of the degree of deformation and pliability of the pad can 
be effected also by the number and shape of the grooves, and also by 
gutters. This makes it possible to produce the pad with any desired degree 
of deformation and pliability for all ages of users and both sexes. In 
particular, when the toothbrush of this invention is used, the gums are 
rubbed and massaged by the resilient and pliable surface of the pad, so 
that the gums will never be wounded. This is in marked contrast to the 
conventional toothbrush having the bristles thereon, the sharp ends of 
which tend to wound the gums. Therefore, the toothbrush of this invention 
is especially fit for use by pyorrheal patients as well as healthy people. 
When the pad is produced from the multicellular materials according to this 
invention, the pad has waterholding capacity, permitting a dentifrice to 
lather well as it is used, although the toothbrush of this invention can 
be comfortably used without dentifrice. Provision of the multicellular, 
rough surface with the projections 4, 5 and the concavity 8 gives rise to 
greater friction between the teeth and gums to improve the massaging 
effects. In this connection, foamed silicone rubber is comparatively hard 
and highly elastic, and since the back surface 14 as well as the upper 
surface comprising the projections and concavity can be made multicellular 
when the pad is stamped integrally out from the sheet, foamed silicone 
rubber sheet is preferably used for the material for the pad. The 
roughness, or multicellularity of the back side of the pad provides for an 
additional advantage in that the pad can be more readily fixedly mounted 
onto or into the brush head by means of adhesives since the adhesives soak 
into the pad to a degree. 
The toothbrush of this invention has further advantages over the 
conventional bristle type toothbrush as follows: the pad of the toothbrush 
of this invention can be produced at a lower cost since the pad can be 
simply produced by being integrally stamped out from the sheet materials 
such as rubber, foamed plastics or the like, it can be produced at a 
higher speed in a continuous process since the integrally-stamped out-pad 
can be simply fixed onto the brush head. Furthermore, since the toothbrush 
can be produced at a low cost, it can be disposed of after single use if 
desired, although the pad can withstand long use.