[0001] This invention relates to a toothbrush having means for reforming the hair edge.
[0002] By repetition of usage, the hair edge of a toothbrush is gradually bending outward.
[0003] Some parts of hair edge is likely to bend toward side directions. Another parts of
hair edge is likely to bend toward forward or rear directions.
[0004] If one cleans his teeth with a toothbrush whose hair edge has bent outward, the outward
bending hair edge rubs his gums. Sometimes the gums are hurt and blood oozes.
[0005] Therefore toothbrushes with outward bending hair edge tend to be abandoned.
[0006] The inventor has been trying to make an improved toothbrush having hair edge which
would be unlikely to band outward. If the hair was fabricated from the material with
higher rigidity, the hair edge would resist the force which acts to bend the hair
edge outward. However heightening the rigidity of hair is not an appropriate remedy
for prohibiting hair edge from bending outward, because the material of hair of toothbrush
is definitely determined. It is hopeless to prevent hair edge of toothbrush from bending
outward by changing the material of hair.
[0007] The Inventor thinks that reforming hair edge inward is the best way to prevent hair
edge from bending outward.
[0008] A convenient way of reforming hair edge may be to enclose the hair-planted part by
some case and push the hair edge inward by the side walls of case.
[0009] However such toothbrushes have never been manufactured.
[0010] Japanese Utility Model Laying Open No. 62-24726 ( laid open on Feb. 14,1987 ) has
disclosed a folding toothbrush having a case for enclosing the hair-planted part.
In the folded state the case encloses the hair planted part. But the hair edge separates
from the wall of case. Thus this toothbrush could enjoy no effect for reforming hair
edge despite having a case. The case only protects the hair-planted part from being
soiled.
[0011] Japanese Utility Model Laying Open No.62-42435 ( laid open on March 13,1987 ) has
disclosed a toothbrush having a case for enclosing only the hair planted part. The
brush case has two side walls which can open sideward. When one cleans his teeth with
the toothbrush, he opens the side walls of the case and extracts the toothbrush out
of the case. When he finishes cleaning, he places the hair-planted part into the case
and shuts the case. The role of the case is only to protect the hair-planted part
from being soiled. The case has not the role of reforming the hair edge.
[0012] One purpose of the invention is to provide a toothbrush in which hair edge is prevented
from bending outward.
[0013] Another purpose of the invention is to provide a toothbrush convenient for carrying
with.
[0014] To achieve the foregoing purposes the toothbrush of this invention comprises a front
stick with both ends having plvots on one end, a hair-planted part planted on another
end of the front stick, an upward opened rear stick with both ends having connection
holes on one end for connecting the pivots therein, and a case part shaped on another
end of the rear stick, the case part having slanting case side walls, a case bottom
wall, a case rear wall and a slanting case front wall, wherein the front stick is
rotatably connected to the rear stick by the pivots and the connection holes, the
front stick and rear stick can be folded or extended by rotating the sticks around
the pivots and connection holes , in the extended state the front stick and the rear
stick are aligned along a straight line, in the folded state the hair-planted part
of the front stick is enclosed by the case part of the rear stick, characterized in
that in the folded state, the hair edge of the hair-planted part is inward reformed
at least by the slanting case side walls and the slanting case front wall.
[0015] Preferably the rear stick includes an elastic piece formed on the end near the connection
holes, the elastic piece includes a claw, the front stick includes a projection on
the end near the pivots and in the extended state the claw of the rear stick grips
the projection of the front stick.
[0016] The upward opened rear stick preferably has side walls and a bottom wall, middle
part of the front stick has step sides and the middle part of the front stick is partially
held between the side walls of the rear stick in the folded state.
[0017] It is also preferred that the case rear wall is also slanting for reforming the rear
hair edge inward.
[0018] The invention will be more fully understood from the following description given
by way of example only with reference to the several figures of the accompanying drawings
in which
FIG. 1 is a partially sectioned front view of a unified asymmetric planetary gear
assembly as an embodiment of the invention
FIG.2 is a front view of the toothbrush in an extended state.
FIG.3 is a bottom view of the toothbrush in an extended state.
FIG.4 is a vertically-sectioned front view of the toothbrush in an extended state.
FIG.5 is a front view of the toothbrush in a folded state.
FIG.6 is a front view of the toothbrush in an intermediate state.
FIG.7 is an enlarged vertically sectioned front view of the toothbrush in a folded
state.
FIG.8 is an enlarged view of the case part sectioned in a plane vertical to the longitudinal
direction in a folded state.
[0019] The toothbrush of this invention is a folding toothbrush. A brushstick (1) consists
of a front stick (4) having a hair-planted part (2) and a rear stick (3) having a
case part (5).
[0020] The rear end of the front stick (4) is rotatably connected with the front end of
the rear stick (3).
[0021] The means for connecting both sticks is now explained. The front stick (4) has pivots
(6) formed on both sides at the rear end. The rear stick (3) is an elongate box-shaped
stick opened upward. The rear stick (3) has connection holes (7) perforated at the
front ends of side walls.
[0022] The pivots (6) on the rear ends of the front stick (4) have been inserted into the
connection holes (7) of the rear stick (3).
[0023] The front stick (4) can rotate in relation to the rear stick (3) around the pivot
(6) and the connection holes (7).
[0024] The brushstick (1) can be extended along a straight line by aligning the front stick
(4) with the rear stick (3) as shown in FIG.1 to FIG.3. This state is called extended
state.
[0025] Otherwise the brushstick (1) can be folded by putting the front stick (4) in the
rear stick (3) as shown in FIG.5 and FIG.7. This state is called folded state.
[0026] One cleans his teeth by the toothbrush in an extended state. To stabilize the extended
state, a notch (10) is vertically cut at the rear end of the front stick (4) and a
projection (11) with a slanting wall is formed, following the notch (10).
[0027] Two longitudinal slits (13) are cut at the front end ( rear the connection holes
(7) ) of the rear stick (3). The middle portion sectioned between two slits (13) becomes
an elastic piece (8) cantilevered by a bottom wall (20) of the rear stick (3).
[0028] A claw (9) is shaped at the free end of the inner surface of the elastic piece (8).
[0029] In the extended state the claw (9) of the rear stick (3) grips the projection (11)
of the front stick (3). By the grip of the claw (9) to the projection (11) the front
stick (4) and the rear stick (3) align along a straight line. The claw (9) and the
projection (11) stabilize the extended state of the brushsticks.
[0030] The rear end of the rear stick (3) is a case part (5) which is slightly lower than
other part of the rear stick (3). A plurality of ventilating holes (12) are perforated
on a bottom wall (23) of the case part (5). The ventilating holes (12) allow air to
ventilate in the case part (5) for drying wet hair-planted part (2).
[0031] Preferably the rear stick (3) and the front stick (4) are made from plastics e.g.
polyacetal, polypropylene, polyvinylchloride, polyethylene, polystyrene and so on.
Both sticks (3) and (4) can be made from same material.
[0032] But it is more preferable to make the rear stick with more elastic material than
the material of the front stick for heightening the elasticity of the elastic piece
(8) of the rear stick (3).
[0033] The rear stick (3) has a room for receiving most portion of the front stick (4).
Thus the rear stick (3) is an elongate, upward-opened, box-shaped stick. Upper verges
of the opened rear stick (3) consist of straight verges (15), curved verges (16) and
straight case verges (17) in turn from the end near the pivots (6). The straight case
verges (17) are lower than the straight verges (15) near the pivots (6). The curved
verges (16) smoothly connect the straight verges (15) with the straight case verges
(17).
[0034] Both sticks (3) and (4) can be tinted in same color. But it is more preferable to
tint the front stick (4) and the rear stick (3) in different colors. For example,
the front stick (4) is white, and the rear stick (3) is tinted in some colors other
than white, e.g. in green, blue or red. The bright contrast of colors heightens the
aesthetic value of the toothbrush.
[0035] The rear stick (3) includes right and left side walls (21) vertical to the direction
of pivots (6) and a bottom wall (20) in parallel with the pivots (6). Owing to the
side walls (21) and the bottom wall (20), vertically-sectioned view of the rear stick
(3) looks like "U". The U-shaped rear stick (3) can receive most part of the front
stick (4).
[0036] The gap between side walls (21) is narrower in the middle but wider near the front
and rear ends.
[0037] The rear ends of the side walls (21) are smoothly continue to the case side walls
(22).
[0038] The bottom wall (20) is a flat plane which is succeeded by a case bottom wall (23)
via a case rear wall (24). The case bottom wall (23) is lower than the bottom wall
(20) of the rear stick (3).
[0039] The case side walls (22) include slanting planes which bend inward near the bottom.
[0040] Similarly the case front wall (25) and the case rear wall (24) include slanting planes
which bend inward near the bottom. The slanting planes of the case walls (22), (24)
and (25) are important for this invention, because the slanting planes play essential
role for reforming hair edge.
[0041] The front stick (4) includes a cavity (14) on the upper surface near the pivots (6).
The existence of cavity (14) spares plastic material and lightens the toothbrush.
The cavity (14) is dispensable.
[0042] The front stick (4) includes a hair-planted part (2) on its front end i.e. the end
far away from the pivots (6). The hair-planted part (2) has a wide surface. But the
middle part following the hair-planted part (2) of the front stick (4) is narrow in
width. Behind the hair-planted part (2), step sides (18) are formed at a level lower
than half of thickness of the stick (4). The step sides (18) are horizontal from the
rear end to the middle of the stick. But the step side (18) is upward succeeded by
curved step (19) in the vicinity of the hair-planted part (2).
[0043] The bottom surface (28) of the front stick (4) is slightly tapered in the neighborhood
of the pivots (6). Namely the thickness of the stick (4) is biggest at the end neighboring
the notch (10) and decreases with the distance from the notch (10).
[0044] The tapered bottom surface (28) is ended at a vertical terminal surface (26) just
before the notch (10).
[0045] The operation for closing the sticks will now be explained. As shown in FIG.6, the
front stick (4) is inserted into the upper opening of the rear stick (3) by rotating
the sticks (3) and (4) relatively. In the folded state, middle part (29) of the front
stick (4) is held between the side walls (21) of the rear stick (3). The step sides
(18) of the front stick (4) touch the straight verge (15) of the rear stick (3). The
curved steps (19) of the front stick (4) touch the curved verges (16) of the rear
stick (3).
[0046] The hair-planted part (2) is received in the case part (5) of the rear stick (3).
The state of the hair-planted part (2) in the case part (5) is important.
[0047] As shown in FIG.7, the hair edge is inwardly reformed in the longitudinal direction
by the case part (5). The hair edge of the front end is backwardly pushed by the slanting
case front wall (25). The hair edge of the rear end is forwardly pushed by the slanting
case rear wall (24). By the slanting case walls the hair edge is inwardly reformed
in the folded state.
[0048] To assure the effect of reformation, some conditions are required regarding the slant
walls and the length of the hair-planted part (3). "A" denotes the longitudinal distance
between the case front wall (25) and the case rear wall (24) at a higher level. "C"
denotes the longitudinal distance between the case front wall (25) and the case rear
wall (24) at the bottom. "E" denotes the length of the hair-planted part (2). A, C
and E must satisfy the inequality
A > E > C (1)
[0049] Furthermore another requirement shall be satisfied. "x" denotes the distance between
the center of the case part (5) and the center of the connection hole (7). "y" denotes
the center of the hair-planted part (2) and the pivot (6). "x" must nearly be equal,
namely
x ≅ y (2)
[0050] More strictly speaking , x, y, A, C and E must satisfy the inequalities,
| x - y | ≦ | A - E | (5)
and
| x - y | ≦ | E - C | (6)
[0051] FIG.8 shows an enlarged vertically sectioned view of the hair-planted part and the
case part. In this sectional view the hair edge is pushed inwardly by the slanting
surfaces of the case side walls (22).
[0052] Thus the case side walls (22) prevent the hair edge from bending outwardly. The hair
edge is reformed also in the vertical direction.
[0053] "B" denotes the inner width of the case part (5) at a higher level. "D" denotes the
inner width of the case part (5) at the bottom. "F" denotes the width of the hair-planted
part (2). To assure the effect of vertical reformation, B, D and F must satisfy the
inequality
B > F > D
[0054] The reformation of hair edge continues as long as the toothbrush is in the folded
state. Usually the toothbrush is left in the folded state. Thus even if inward bending
of hair edge is slight, the reformation effect is sufficient.
[0055] The toothbrush in the folded state is very short. The length is nearly half of the
ordinary toothbrush. Thus the folded toothbrush is convenient to carry with. The folded
state is secured by the friction force which the side walls (21) of the rear stick
(3) applies on the middle part (29) of the front stick (4).
[0056] The operation of opening is reverse to that of closing. The sticks (3) and (4) can
be opened by plucking the front stick (4) out of the rear stick (3) and rotating the
sticks relatively. The sticks extend around the pivots (6) and connection holes (7)
as a fan.
[0057] When the rotation angle held between the front stick (4) and the rear stick (3) attains
nearly 135 degrees, the claw (9) of the rear stick (3) touches the arc surface of
the projection (11). The elastic piece (8) is being extruded, while the claw (9) is
climbing the arc surface.
[0058] When the rotation angle increases to near 180 degrees, the claw (9) overruns the
projection (11). The claw (9) grips the forehead of the projection (11). At last the
sticks are fully extended. The sticks are aligned along a straight line. The end wall
(26) of the front stick (4) touches the end (27) of the rear stick (3). Therefore
further relative rotation is forbidden. The extended state is secured by the grip
of the claw (9) on the projection (11).
[0059] One of advantages of the invention is to prolong the lifetime of toothbrush. The
case part prevents the hair edge from bending outward in the folded state. The hair
edge is reformed automatically.
[0060] Another advantages of the invention is to provide a toothbrush which is unlikely
to hurt gums, because the hair edge is not bent outward. The toothbrush is excellent
from the standpoint of oral hygiene.
[0061] Other advantage of the invention is to provide a toothbrush convenient for carrying
with, because it can be folded to about half length of an ordinary toothbrush.
[0062] Besides, the toothbrush is also excellent from an aesthetic standpoint of view, if
the front stick is white and the rear stick is tinted in colors other than white -
blue, green or red.
(1) A toothbrush comprising a front stick with both ends having pivots on one end,
a hair-planted part planted on another end of the front stick, an upward opened rear
stick with both ends having connection holes on one end for connecting the pivots
therein, and a case part shaped on another end of the rear stick, the case part having
slanting case side walls, a case bottom wall, a case rear wall and a slanting case
front wall, wherein the front stick is rotatably connected to the rear stick by the
pivots and the connection holes, the front stick and rear stick can be folded or extended
by rotating the sticks around the plvots and connection holes, in the extended state
the front stick and the rear stick are aligned along a straight line, in the folded
state the hair-planted part of the front stick is enclosed by the case part of the
rear stick, characterized in that in the folded state, the hair edge of the hair-planted
part is inwardly reformed at least by the slanting case side walls and the slanting
case front wall.
(2) A toothbrush as claimed in claim (1), wherein the rear stick includes an elastic
piece formed on the end near the connection holes, the elastic piece includes a claw,
the front stick includes a projection on the end near the pivots and in the extended
state the claw of the rear stick grip the projection of the front stick.
(3) A toothbrush as claimed in claim (2), wherein the upward opened rear stick has
side walls and a bottom wall, middle part of the front stick has step sides and the
middle part of the front stick is partially held between the side walls of the rear
stick in the folded state.
(4) A toothbrush as claimed in claim (3), wherein the case rear wall is also slanting
for reforming the rear hair edge inwardly.
(5) A toothbrush as claimed in claim (4), wherein the width B of the upper case part,
the width D of the lower case part and the width F of the hair-planted part satisfy
the inequality
B > F > D
(6) A toothbrush as claimed in claim (5), wherein the longitudinal length A of the
upper case part, the longitudinal length C of the lower case part and the longitudinal
length E of the hair-planted part satisfy the inequality
A > E > C
(7) A toothbrush as claimed in claim (6), wherein the case bottom wall has ventilating
holes.
(8) A toothbrush as claimed in claim (7), wherein the front stick includes a cavity
formed on an upper half surface near the pivot.
(9) A toothbrush as claimed in claim (8), wherein the front stick is white and the
rear stick is colored with a color except white.
(10) A toothbrush as claimed in claim (9), wherein the rear stick includes straight
verges originating near the pivot, curved verges continuing downward from the straight
verges and straight case verges continuing from the curved verges.