Note: Descriptions are shown in the official language in which they were submitted.
i451~
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The handle and brush of the prior art devices are generally
a rigid unit; therefore, use of the unit is similar to holding
a pencil of a comparable length and projecting it into the back
of the mouth, while trying to fit the point into a gap under a
05 bridge or between adjacent teeth. This kind of rigidity may
require an extension of the cheek or the use of two hands.
Once the gap is found, the brushing must occur without a
loss of gap orientation unless one is willing to go through the
process of finding the gap again. Also, if one brushes too
vigorously and loses the gap while doing so, he may jab himself
in the gum or tooth and also bend the wire stem brush. Thus,
interdental cleaning may be difficult to perform, especially
where visual contact is not easy to achieve.
Accordinglyl an ob~ect of the invention is to pr~vide new
and novel interdental brushes and, more particularly, to
provide small and portable units which may be carried in pocket
or purse.
~ nother object oE the invention is to provide an
interdental brush which may be guided into a brushing position
responsive to the user's sense of touch. Yet another object is
to provide such a brush which may be guided into position by a
slight change in the attitude of the tip of a finger. Here, an
object is to provide a brush with a handle which may be flexed
at the tip end, especially so that it may be used more easily
in the back of the mouth and other hard to reach places in the
mouth. In this connection, an object is to provide a brush
which is bendable to a proper angle during use and which can be
s~raightened when not in use.
~'?
3--
A further object is to provide a brush where very small
movements at the tip of the finger may be used to brush in the
interdental spaces, thereby reducing the possibility of jabbing
the gum responsive to a loss of brush-to-tooth contact.
05 ~n keeping with an aspect of the invention, these and other
objects are accomplished by providing an interdental brush
having a handle with a selected amount of flexibility in a neck
region at a junction between the handle and brush, while being
substantially rigid in the handle. The dimensions of the brush
and handle are such that a small amount of finger pressure upon
the neck region causes the tip of the brush to deflect, bend or
flex to a convenient brushing angle. After use, the neck may
be straightened from the deflected position. The brush may be
repeatedly bent and straightened for repeated use.
Furthermore, it may be bent at different angles to afford
access to different areas of the mouth. Thus, during brushing,
one side of the iltterdental space may be brushed by slightly
increasing the deflection responsive to an added finger
pressure and the other side of the space may be brushed
responsive to decreasing the deflection by reduced finger
pressure. If need be, the brush may be rolled between the
fingers to enable the finger tip to help straighten or to
change the angle of the tip. Thus, the brushing itself may be
accomplished by slight movements of the finger tip and thumb.
A preferred embodiment of the invention is shown in the
attached drawing in which:
45~
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Fig. 1 is a side elevation of the inventive brush and
cap, as it might be viewed by the user;
Fig. 2 is a side elevation, partly in cross section,
showing the inventive brush and cap;
05 Figs. 3 - 6 are end views taken along lines 3~3 to
6-6, respectively, of Fig. 2;
Fig. 7 is an assembled showing of the cap and brush,
as they appear while the brush is being carried in packet or
purse, for example:
E'ig. 8 shows the brush in operation, illustrating how
the brush is deflected responsive to finger pressure;
Fig. 9 shows an alternative embodiment of the
invention shown in Figs. 1-7;
Fig. 10 is a side elevation of an embodiment of the
invention, with the top partially broken away to show internal
grooves within the cap, with the cap closed over the handle;
Fig. 11 is a side elevation also showing the
embodiment of figure 10 wlth the cap on the bottom of the
handle extending the length thereof; and
Fig. 12 is a cross sectional view of the cap of figure
1 also showing an enlar~ed portion showing internal
longitudinal ribs.
The brush of Figs. 1 and 8 include a handle 20 and a cap
22. The cap 22 is a cylindrical member, having one end 23
closed. The other end 24 is open and slips over the brush
handle 20 with friction fit (as best seen in Fig. 7).
Optionally, one or more vents 21 may be provided in the cap to
facilitate drying of the brush after use. A reduction in
5~
internal diameter, such as annular stop 25, limits the distance
which the cap 22 may be slipped over the end oE handle 20 and,
therefore, protects the brush 26 from the cap being jammed
downwardly internal ribs 29 (Fig. 12~ run longitudinally within
05 the cap 22 to provide added friction for holding the cap in
place on the handle 20. The added holding forces occur because
it is impossible to mold plastic with a completely circular
interior to close enough tolerances to always fit snuggly.
With the longitudinal ribs, the cover will stretch slightly
between the ribs on undersized tolerances and yet the
unstret~hed cap still holds on oversized tolerances. This
holding force is especially important if it is necessary to
cover the brush after use and while it is still wet, when there
could be a tendency for the cap to slip off the handle.
In the embodiment of Fig. 2 the internal diameter o the
cap is uniform throughout the distance from the step 24 to the
closed end 23 to give a smooth internal wall. It is desirable
for the outside of the handle 20 and cap 22 to be serrated with
longitudinal ribs so that they may be better manipulated by a
person with wet hands. These ribs add friction, in the mold
between the cap 22 and walls of the cavity in which it was
formed.
Therefore, when the male member of the mold parts is
opened, it often slipped out of the cap 22 with the smooth
internal wall, thus leaving the cap ~2 trapped inside the
female member of the mold. This required a knock-out pin which
would leave unslightly marks on the cap. To avoid this problem
the male mold part is given a plurality of circumferential
,. ..
~45~
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grooves to ~orm a number of ribs 25a, inside the cap 22. When
the male part of the mold is open, these rlbs and grooves are
engaged to provide enough holding forces to overcome the
friction between the cap 22 and the female mold part.
05 Thereafter the cap 22 may be knocked off the male part since
the depth of the grooves (or the height of the ribs 25a) is
very shallow. To help with the knock-off without causing a
blemish on the cap~ a smooth surfaced ~lange 24a is provided
for on the bottom of the cap. This flange also provides a
controlled amount of resistance to a flaring of the open end
(i.e. it acts somewhat as a rubberband would act to hold the
cap 22 in place).
Handle 20 has a twisted wire brush 26 of any suitable
design projecting longitudinally therefrom. The opposite end
27 of handle 20 is solid. When the cap 22 is in place on the
handle 20, the brush 26 is kept clean and sanitary. When the
cap 22 is placed on the opposite end of the handle 20, the
handle is made longer. The internal ribs 29 help secure the
cap 22 on the opposite end of the handle 20 so that, together,
they provide a more secured tool which may be gripped with
greater ease within the hand and braced against the palm at the
fleshy fold 34 between the thumb and the index finger~ The
stop 25 limits the distance that the end of the handle 20
extends into the cap 22.
The handle 20 is a solid member which is approximately a
quarter-inch in diameter, for a distance A, which may be about
one-inch. Beginning at shoulder 28, the diameter of a tip end
30 gradually reduces over a distance, which may be about
;4~5~
--7--
one-quarter inch, to an outer tip 31, which is also
approximately one-quarter inch in length and an eighth-inch in
diameter. The wire stem 32 is exposed over a distance between
the top of tip end 31 and the bottom of brush 26 which is about
05 one-sixteenth of one-inch.
The wire stem 32 of brush 26 extends through and is
embedded in the tip end and handle of the molded part. This
wire stem continues for a substantial distance into the full
diameter section of handle 20, as shown, for example in Fig.
2. Preferably, the brush stem 32 is molded into the plastic of
the handle at the time when the handle is made. To aid in
preventing the brush from being pulled out of the handle, the
end of the wire may be bent or crimped, as shown at 36 in
Fig. 9.
Longitudinal ribs 38 are provided in the handle 20 and the
cap 22. These ribs enhance the esthetic appearance of the
product and give the handle and cap a better feel to the user.
The ribs also aid in removal of the cap from the handle,
particularly after the brush has been used.
In order to achieve a desired flexing characteristic, the
handle 20 is preferably made from a mixture of a thermoplastic
elastomer, polymer material and a polypropylene of a general
purpose homopolymer grade. More particularly, in one
embodiment which was constructed and found satisfactory, the
handle was made of approximately 80 ~'C-Flex" and 20%
"Polypropylene #5820".
rrhe "C-Flex~' material is manufactured by Concept Polymer
Technologies, Inc. of 12707 U.S. 19 South~ Clearwater, Florida
, . . .
5~;~
--8--
33546. In its technical data sheets, the manufacturer reports
that "C-Flex" has the following properties:
MECHANICAL ASTM C-FLEX C-FLEX C-FLEX
PROPERTIES METHOD 42-3500 42-35i0 42-3515
05 Durometer Hardness D-2240 50A 65A 70A
Tensile Str. Break
PSI @23~C D-412 1650 1780 1900
Tensile Modulus
PSI at 100~ D-412 175 330 340
PSI at 300% D-412 310 540 650
Tensile - Set
% (5)
after Break D-412 55 100 43
Elongatlon %
at Break @23~C D-412 850 800 790
Compression Set
at 70C D-395 72 66 70
Tear Strength -
Method-Die C lbs/in D-624 130 183 220
Specific Gravity + .02 D-792 .90 .90 .90
Water Absorption (5) at
73F
1 week at 50% RH D~570 .14 .27 .30
1 week at 100% RH D-570 .42 .26 .17
THERMAL
P ERTIES
Brittle Temperature D-746 -100F -100F -100F
Melt Index-Cond. E D-1238 .25 1.9 1.8
ELECTRICAL
PROPERTIES
Dielectric Strength
(Volts/Mil) 450 740 800
Volume Resistivity
(1016 ohm-cmj 1.2 3.0 0.8
Surface Resistivity
(1015 ohm) 3.6 3.6 2.6
Dielectric Constant
(lo2Hz~ 2.33 2~27 2.27
(103Hz) 2.33 2~27 2.27
(106HZ) 2.31 2.27 2.15
Dissi~ation Factor
(103Hz) 0.0004 0.0002 0.0002
(10 Hz) 0.0006 0.0002 0.0002
(106Hz) 0.0022 0.0008 0.0008
45~.~
g
Polypropylene #5820 (]2 melt) is manufactured by the Shell
Chemical Company, having an address at 1415 West 22 Street, Oak
Brook, Illinis 60521. The manufacturer of this product
describes its physical properties as follows:
05 TRADITIONAL SI ASTM
PROPERTY UNITS UNITS TEST
Melt Flow 12g/10 min 12g/10 min D 1238
Density at 23~C 0 903 g/cc 0.903 g/cc D 1505
Tensile yield
s~rength, at
2.0 in/min 5100 psi 35 MPa D 6382
Yield elongation
at 2.0 in/min 10% 10% D 6382
1~ Secant modulus~
at 0.2 in/min 200,000 psi 1375 MPa D 6382
Flexural modulus,
at 0.05 in/min,
2 in span 220,000 psi 1500 MPa D 790A2
Notched Izod
impact strength,
at 73F/23C 0.5 ft-lb/in 27 J/~ D 2562
at 0F/-18C 0.4 ft-lb/in 20 J/m D 2562
Hardness, Rockwell R95 R95 D 785
Heat deflection
temp at 66 psi/
455 kPa 220F 104C D 648
Vicat softening
temp 305F 152C D 1525
1 Condition L, 230C, 2160g
2 ASTM Type 1 specimen, 1/8" thick (injection molded)
Shell further describes this product as being a high flow,
general purpose material suitable for injection molding of
intricate parts where long flow paths are involved. An
antistat component reduces electrical charges during processing
and subsequent storage, thereby reducing dust pickup. The
- ]~o -
manufacturer claims that the product has an excellent flex
life, good chemical and solvent resistance, high
strength-to-weight ratio, and exceptional stress cracking
resistance.
05 8Oth of these materials meet exacting Federal standards for
bio-medical use and for making direct contact with food.
To further control the amount of flexing which may occur in
the neck region 30, 31, the diameter of wire stem 32 may be
either increased or decreased somewhat and the diameter and
length of the neck region 30, 31 may be modified. It is
thought that those who manufacture the inventive brush will
determine the best diameters and lengths for themselves and for
their own particular needs. In general, the wire stem of a
conventional interdental brush may be increased in diameter in
the approximate range of 10-50%.
The method of using the inventive brush is shown in
Fig. 8. The length of handle 20 is such that, when the tip end
30 is held between the thumb and index finger, the opposite end
of the handle is captured and stabilized along the length of
the finger. Or, if the cap is in place on the end of the
brush, its end might be captured in or near the palm of the
hand, as in the fleshy fold 34, which is between the thumb and
index finger. By pressing the index finger against the tip end
30 while holding the handle 20 by the thumb, it is possible to
deflect~ bend, or flex, the brush to point, more or less, in
i4~
llne with the finger tip. If the user wishes to point the
brush in another direction, the handle may be rolled between
the thumb and index finger or a small amount of thumb pressure
may be applied to the brush to straighten it or bend it to the
05 other position. Thus, the flexed angle of the brush may be
varied, at the will of the user.
It is relatively easy to point one's finger at an object
since the sense of touch tends to assist the pointer. This
ma~es the invention easy to use. On the other hand, it is more
difficult to point an instrument with a relatively long handle
since the instrument may be held at almost any angle and since
the user cannot always take advantage of the sense of touch to
tell the user where the tip end of the long handled brush is
located. Moreover, none of the existing long-handled or other
interdental brushes have f~exible tip ends similar to the
inventive brush so their tip ends cannot be deflected as in the
inventive brush. While the tip end is held and deflected, as
seen in Fig. 8, use of the instrument is much more like
pointing a finger since the method of bending inherently tends
to align the brush with the finger. This is an important
advantage over the prior interdental brushes.
Another factor is that, when the brush is held in the hand
as seen in Fig. 8, it is much easier to place the brush in the
space between the teeth in the back of the mouth as compared to
attempting to position it when the brush is straight, as seen
-12-
in Fig. l, because the natural curvature of the hand in this
position is most appropriate to reaching into that back of the
mouth space. An advantage is that the portion of the wire
brush encased in plastic is more resistant to breaking from
05 repeated or excessive bending than would be the case if the
wire were exposed.
The claims are to be construed to cover all equivalent
structures which fall within the scope and of the invention.
