[0001] The invention relates to a toothbrush with a deflecting part which has a deflection
profile and is positioned between brush head and stem, serving to deflect the brush
head when a certain contact pressure is reached.
[0002] German Offenlegungsschrift 3,706,345 discloses a similar toothbrush for manual or
mechanical operation. With this toothbrush the brush head can be deflected on the
brush stem when a certain contact pressure is reached, in such a way that an optimum
contact pressure can be maintained when brushing the teeth. The deflecting part is
designed similar to a leaf spring, and can be cambered or angular and have a central
longitudinal slit so that, when too high a contact pressure is exceeded, the brush
head can move from its previously extended position into a deflected position with
respect to the longitudinal axis of the stem. This gives a signal to the user; further
brushing of the teeth would also at least be made more difficult, if not impossible.
The deflection can occur more or less progressively or, beyond a click point, very
fast.
[0003] Due to the narrowing of the deflecting part similar to a leaf spring, the toothbrush
appears to be disproportioned, and due to the spring being exposed there is a risk
of injuries to the mouth because of the edges, and of pinching if a longitudinal slit
is present, when the toothbrush is used.
[0004] The object of the invention is to specify a toothbrush with a deflecting part having
a deflection profile, which toothbrush has an attractively shaped appearance without
the deflecting being obstructed, and is free from edges presenting a risk of injuries
and free from slits.
[0005] This object is achieved by a toothbrush having the features of Claim 1 or Claim 2.
[0006] Advantageous embodiments of the invention can be taken from the subclaims.
[0007] The invention is explained in more detail below with the aid of exemplary embodiments
with reference to drawings, in which:
Figure 1 shows a plan view of a toothbrush,
Figure 2 shows a side view of the toothbrush,
Figure 3 shows a deflecting part on an enlarged scale,
Figure 4 shows a design variant of a deflecting part on an enlarged scale.
[0008] A toothbrush consists of a brush head 1 with the bristles 2 and a transition part
3, a deflecting part 4 and a stem 5. The deflecting part 4 connects the transition
part 3 to the stem 5, serving as handle. The deflecting part 4 can have a metallic
leaf spring 6 or a link 7 of any type of material, including plastics. Preferably,
the link 7 and the leaf spring 6 are entirely enclosed by a jacket 8 made of an elastomer,
covering all sharp edges of the leaf spring 6 or of the link 7. The jacket 8 made
of elastomer is designed so that it forms a positive connection of the free end of
the transition part 3 of the brush head 1 with the connecting end of the stem 5 and
nevertheless enables the leaf spring 6 or the link 7 to be deflected. The jacket 8
can also serve the optical design of the toothbrush and, for example, have a concave
or convex camber and can have different colours compared with the other parts of the
toothbrush.
[0009] If a metallic leaf spring 6 is used, this is preferably firmly anchored in the transition
part 3 or in the stem 5, for example by means of the injection moulding procedure.
In this case, the jacket 8 can either have been applied previously or it can be applied
subsequently,when the transition part has already been firmly connected by means of
the leaf spring 6 to the stem 5.
[0010] In the case of the deflecting part 4 having a link 7, the brush head 1 can be made
without bristles 2, the transition part 3, the deflecting part 4 and the stem 5 can
be manufactured of one material in one manufacturing step, for example by injection
moulding. The link 7 can also be manufactured in one piece with either the transition
part 3 or the stem 5 and can then be plugged into a correspondingly designed indentation
9 (Figure 4) of the respective complementary part. Preferably a snap-on connection
10 is provided which ensures a firm connection of the link 7 in the transition part
3 and/or stem 5. The leaf spring 6 or the link 7 are arranged and designed in such
a way that the brush head 1 can only be deflected in the direction indicated by an
arrow in Figure 2.
[0011] In the case of the link not being connected in one piece with the brush head 1 and
the stem 5, it can be pushed onto the link 7 in the form of an annular element prior
to assembly.
[0012] Otherwise, the jacket 8 can be applied as one piece around the leaf spring 6 or the
link 7 by means of injection moulding. In the case of the jacket 8 consisting of
a material which does not form a firm connection with the material of the transition
part 3 or of the stem 5, or is difficult to bond, a mechanical anchoring of the jacket
8 (see Figure 3) can also be provided, in which case indentations or undercuts 11
can be provided in the deflecting part 4 and/or at the end of the stem 5. The jacket
8 would then have a slit (not represented) for pushing it on sideways, which can be
bonded, if required.
[0013] The metallic leaf spring 6 preferably consists of electrogalvanized or chromium-plated
steel, or of a rust-proof metal or metal alloy, preferably a copper beryllium alloy.
[0014] The elastomer of the jacket 8 preferably consists of natural or synthetic rubber,
such as styrene-butadiene rubber, butyl rubber, ethylene rubber, propylene rubber,
silicone rubber or an ethylene vinyl acetate copolymer or plasticized PVC, in which
case a Shore hardness of A 40 to 80 is preferably to be provided.
1. Toothbrush with a deflecting part (4) which has a deflection profile and is positioned
between brush head (1) and stem (5), serving to deflect the brush head (1) when a
certain contact pressure is reached, characterized in that in the case of a deflecting
part (4) with a metallic leaf spring (6), the latter consists of electrogalvanized
or chromium-plated steel, a rust-proof metal or a metal alloy and in that the leaf
spring (6) is covered at least on its front and back by an elastomer.
2. Toothbrush with a deflecting part (4) which has a deflection profile and is positioned
between brush head (1) and stem (5), serving to deflect the brush head (1) when a
certain contact pressure is reached, characterized in that the deflecting part (4)
is a link (7) similar to a leaf spring, which connects the brush head (1) to the stem
(5) and is covered at least on the front and back by an elastomer.
3. Toothbrush according to Claim 2, characterized in that the stem (5), the brush
head (1) and the link (7) are manufactured in one piece.
4. Toothbrush according to Claim 2, characterized in that the link (7) is mechanically
connected to the brush head (1) and/or the stem (5).
5. Toothbrush according to one of Claims 1 to 4, characterized in that the elastomer
ensure a smooth transition from the deflecting part (4) to the stem (5) and/or brush
head (1).
6. Toothbrush according to one of Claims 1 to 5, characterized in that the elastomer
is applied by means of injection moulding.
7. Toothbrush according to one of Claims 1 to 5, characterized in that the elastomer
is mechanically anchored to the stem (5) and/or brush head (1).
8. Toothbrush according to one of Claims 1 to 7, characterized in that the elastomer
is a natural or synthetic rubber, such as styrene-butadiene rubber, butyl rubber,
ethylene rubber, propylene rubber, silicone rubber, or an ethylene vinyl acetate copolymer
or plasticized PVC.
9. Toothbrush according to Claim 8, characterized in that the elastomer has a Shore
hardness of A 40 to 80.