U.S. patent application number 10/236116 was filed with the patent office on 2003-03-06 for methods of manufacturing toothbrushes.
Invention is credited to DePuydt, Joseph, Firatli, Ahmet Cem, McConnell, Mark, Stein, Bernd, Vankov, Michael.
Application Number | 20030041402 10/236116 |
Document ID | / |
Family ID | 7697915 |
Filed Date | 2003-03-06 |
United States Patent
Application |
20030041402 |
Kind Code |
A1 |
Stein, Bernd ; et
al. |
March 6, 2003 |
Methods of manufacturing toothbrushes
Abstract
A method is provided for manufacturing a function element
carrier with function elements, for example, individual tufts made
up of bristles and/or massage elements, interproximal cleaning
elements, or other elements designed to be fastened to a toothbrush
and also perform special functions. The function elements are
equipped at their ends intended for anchoring in a toothbrush with
an anchor, retainer or axle element. The method includes: (a)
inserting several function elements in corresponding recesses of an
injection mold, said injection mold being connected via grid or bar
shaped channels formed in a die to recesses in the areas of the
anchoring ends of the function elements; (b) filling the grid or
bar shaped channels with liquefied plastic material and injecting
said material at the anchoring ends of the function elements or
embedding them therein; and (c) allowing the plastic material to
cool and removing a function element carrier made up of a grid or
bar shaped plastic frame and the function elements. Function
element carriers and toothbrushes are also provided.
Inventors: |
Stein, Bernd; (Schmitten,
DE) ; McConnell, Mark; (Oola, IE) ; DePuydt,
Joseph; (Quincy, MA) ; Vankov, Michael;
(Schmitten, DE) ; Firatli, Ahmet Cem; (Wiesbaden,
DE) |
Correspondence
Address: |
FISH & RICHARDSON PC
225 FRANKLIN ST
BOSTON
MA
02110
US
|
Family ID: |
7697915 |
Appl. No.: |
10/236116 |
Filed: |
September 6, 2002 |
Current U.S.
Class: |
15/167.1 ;
15/110; 15/188; 15/193; 15/27; 300/21; 601/141 |
Current CPC
Class: |
A46D 3/005 20130101;
B29C 45/14385 20130101 |
Class at
Publication: |
15/167.1 ;
300/21; 15/27; 15/110; 15/188; 15/193; 601/141 |
International
Class: |
A46B 003/04; A46D
003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 6, 2001 |
DE |
101 43 673.4 |
Claims
What is claimed is:
1. A method of manufacturing a function element carrier including
function elements, said function elements being equipped at their
ends intended for anchoring in a toothbrush with an anchor,
retainer or axle element, said method comprising the following
steps: inserting several function elements in corresponding
recesses of an injection mold, said injection mold being connected
via grid or bar shaped channels formed in a die to recesses in the
areas of the anchoring ends of the function elements; filling the
grid or bar shaped channels with liquefied plastic material and
injecting said material at the anchoring ends of the function
elements or embedding them therein; and allowing the plastic
material to cool and removing a function element carrier comprising
a grid or bar shaped plastic frame and the function elements.
2. The method according to claim 1, comprising, in a next step,
transferring the function element carrier to a further processing
station in which the function elements are severed from the plastic
frame, and subsequently the anchoring ends of the function elements
are secured in a brush holder.
3. The method according to claim 1 or 2, wherein the grid or rod
shaped plastic frame includes grid bars and grid points between
which tapers are formed.
4. The method according to claim 1, wherein additional assembly
aids or function faces are injection molded on the function
elements.
5. The method according to claim 4, wherein said assembly aids or
function faces are configured as anchors or motion axles.
6. The method according to claim 1, wherein the function elements
and the plastic frame are fabricated from dissimilar plastic
materials.
7. The method according to claim 1, wherein the function elements
are equipped with undercuts for securing to the plastic frame.
8. The method according to claim 1, comprising in a next step
transferring the function element carrier to a further processing
station in which said carrier is embedded in a brush holder by
injection molding plastic material around the carrier, such that
subsequently only the anchoring ends of the function elements are
enclosed by the brush holder.
9. The method according to claim 8, wherein the grid or rod shaped
plastic frame is made up of grid bars forming grid points at the
intersections, between which tapers are formed, and wherein the
plastic frame is deformed before being embedded in the molding
material of the bristle holder so that the function elements assume
their desired position in the brush holder following embedding.
10. The method according to claim 1 or 8, wherein various function
elements of elastomer plastic are provided on the plastic
frame.
11. The method according to claim 1 wherein the function elements
include elements selected from the group consisting of tufts of
bristles, massage elements, and interproximal elements.
12. A function element carrier comprising a plurality of function
elements equipped at their ends intended for fastening in a
toothbrush with an anchor, retainer or axle element, each function
element being fastened to a grid or rod shaped plastic frame
through its anchor, retainer or axle element.
13. A function element carrier according to claim 12 wherein the
function elements include elements selected from the group
consisting of tufts of bristles, massage elements, and
interproximal elements.
14. A function element carrier according to claim 12, wherein the
grid or rod shaped plastic frame is comprised of connected grid
bars forming grid points at the transitions to the anchoring ends,
with tapers being provided therebetween.
15. A function element carrier according to claim 12, wherein
additional assembly aids or function faces are arranged on the
function elements.
16. A function element carrier according to claim 15, wherein said
assembly aids or function faces are configured as anchors or motion
axles.
17. A function element carrier according to claim 12, wherein the
function elements and the plastic frame are made of dissimilar
plastic materials.
18. A function element carrier according to claim 12, wherein the
function elements are provided with undercuts at their anchoring
ends for fastening to the plastic frame.
19. A toothbrush with function elements that are each equipped at
their ends intended for anchoring in a brush holder of a toothbrush
with an anchor, retainer or axle element, wherein the individual
function elements are connected, through their anchor, retainer or
axle elements to a grid or rod shaped plastic frame which is
secured in the brush holder such that tooth cleaning ends of the
function elements protrude from the brush holder.
20. A toothbrush comprising function elements that are each
equipped at their ends intended for anchoring in a brush holder of
a toothbrush with an anchor, retainer or axle element, wherein said
anchor, retainer or axle elements include breaking, parting or
cutting faces.
21. The toothbrush according to claim 19 or 20, wherein at least
some of the function elements are made from an elastomer plastic
material.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of German application
serial number 101 43 673.4 filed Sep. 6, 2001.
TECHNICAL FIELD
[0002] This invention relates to methods for manufacturing
toothbrushes.
BACKGROUND
[0003] Methods for manufacturing plastic toothbrushes are already
known from the art. For example, DE-OS 3403341 describes a joining
method by which the bristle receiving side of a bristle carrier
and, where applicable, the fixing ends of the bristles are
transformed into a soft plastic state by melting and then joined by
pressing together. In this method it suffices to melt the bristle
carrier only locally in those places where individual bristle tufts
are to be fixed. When the ends of the bristles in a tuft are
melted, the thermoplastic material flows together and forms an
enlargement that simultaneously acts as the basis for joining the
bristles themselves together. Depending on the pair of materials
used for the bristles and the bristle carrier the result is a
welded connection in which coalescence of two materials takes
place, or a joined connection in which the bristles have their
enlarged ends enclosed by the soft plastic material of the bristle
carrier, being thus held captive.
[0004] From DE-OS 2812746 it is known to feed a continuous bristle
strand to a device, to cut the required length of bristle tuft off
the strand, and to simultaneously heat the receiving side of the
bristle carrier and the bristle ends and then bring them together
and fix them in this joined position until a firm connection is
established after sufficient cooling. With this method the feeding,
cutting, melting, joining and cooling operations are all performed
on a single work station.
[0005] Further, DE 19932377-A1 describes a method for manufacturing
brushes with a plastic bristle carrier and an attached set of
bristles consisting of individual plastic bristles or plastic
bristles arranged in tufts. In this method the ends of the bristles
or tufts at the fixing end are melted to form an enlargement.
Enlargements of adjacent bristles of tufts are joined together by
the remolding and displacement of the plastic mass, the joints
being subsequently embedded in the plastic material of the bristle
carrier. The method uses a molding tool to transform adjacent
enlargements into a defined supporting structure and connecting
bars, following which a short length of the supporting structure
and protruding bristles is embedded in the plastic material of the
bristle carrier.
[0006] The method for manufacturing brushes disclosed in DE
19542393 A1 works along similar lines. In this method tufts of
bristles are held in an array corresponding to their position in
the field of bristles, after which their fixing ends are melted in
this position and, as a result of this melting, joined together to
form a bristle tuft unit. In this method the part connecting the
fixing ends is also produced from the melt while melting the fixing
ends.
[0007] EP 0326634 A1 discloses a method for manufacturing bristle
products, comprising the steps of passing tufts of individual
bristles or bristle strands through channels and sleeves extending
the channels, and inserting them in a mold for the bristle carrier.
The bristle tufts are then melted by the action of heat at their
ends proximate the mold in order to form an enlargement, and the
enlargement created at the ends of the bristles during melting is
moved into sealing engagement with the mouth of the sleeve
projecting into the mold. The bristles and the sleeve are held in
position while the mold is filled, e.g., by injection molding. This
method is also referred to as the in-mold process.
[0008] WO 99/11156 discloses a method for manufacturing fields of
bristles. Here, too, the bristles in the area of the undercut are
heated so that the plastic of the bristles produces a melt or
plastic mass that fills the undercut either filly or partly, the
subsequently solidifying plastic mass producing the
positive-engagement connection between the bristles or bristle
tufts and the undercuts, and hence the holding plate. It is thus
possible for the undercuts to be formed either before or at the
same time as the ends of the plastic bristles are melted.
[0009] Further, DE 19937481 A1 proposes a two-component injection
molding method for manufacturing a brush comprised of a bristle
carrier having at least two essentially parallel layers of
dissimilar plastics, which methods includes fastening the bristles
to at least one of the layers. The layer of the bristle carrier
facing away from the bristles has openings that are closed on the
peripheral side and filled with the plastic of the other layer. The
result is a positive-engagement connection between the two
dissimilar plastic layers.
[0010] One disadvantage of the previously mentioned publications is
that after the function elements are produced it often requires an
unacceptable effort to isolate and approximately align them for
further processing before they are subsequently fixed in the
correct position in a bristle carrier.
SUMMARY
[0011] In preferred implementations, the present invention provides
an improved and simplified method for manufacturing function
elements for use in toothbrushes, which enables the function
elements to be manufactured with greater ease and economy. This
method is intended in particular to enable the low-cost
manufacturing and integration of function elements in toothbrush
production. The invention also features function elements
manufactured by the previously mentioned method that can be handled
more efficiently during their further processing. Additionally, the
invention features toothbrushes that are equipped in a simple and
economical manner with easy-to-use function elements.
[0012] Preferred methods of the invention also enable the simple
and economical manufacturing of toothbrushes with function
elements. Function elements according to the inventions are
understood to include tufts of bristles of various filaments and
other elements that perform a special function on a toothbrush, for
example massage elements and interproximal cleaning elements.
[0013] In one aspect, the invention features a method for
manufacturing a function element carrier with function elements,
for example, individual tufts made up of bristles and/or massage
elements, interproximal cleaning elements, or other elements
designed to be fastened to a toothbrush and also perform special
functions. The function elements are equipped at their ends
intended for anchoring in a toothbrush with an anchor, retainer or
axle element. The method includes: (a) inserting several function
elements in corresponding recesses of an injection mold, said
injection mold being connected via grid or bar shaped channels
formed in a die to recesses in the areas of the anchoring ends of
the function elements; (b) filling the grid or bar shaped channels
with liquefied plastic material and injecting said material at the
anchoring ends of the function elements or embedding them therein;
and (c) allowing the plastic material to cool and removing a
function element carrier made up of a grid or bar shaped plastic
frame and the function elements.
[0014] Preferred methods also enable various function elements to
be attached to a function element carrier in a predetermined
orientation that allows for simple integration and secure anchoring
in a brush head or a toothbrush hand piece. For example, several
tufts may be inserted in an injection mold or part of an injection
mold. The injection mold is also referred to as "mold bar". All the
elements are interconnected by channels called "hot runners," in
order to convey the liquid thermoplastic material to the respective
destinations. The function elements themselves can be arranged
preferably on the grid bars, i.e., on the longitudinal and cross
bars of the plastic frame.
[0015] The grid type array of channels can be made to correspond in
its dimensions and spacings to the positions occupied at a later
stage by the function elements in a brush product. This is not
necessary, however. Rather, the array can be based on machine
parameters dictated, for example, by the particular automatic
assembly unit or the like. In the following description the points
of intersection of the channels will be designated as grid
points.
[0016] With the method of the invention, a plurality of tufts may
be equipped in a single operation in one tool with anchorage
devices while at the same time a plastic frame is provided, thus
producing an easy-to-handle function element carrier comprising
aligned and sorted function elements, with which a plurality of
function elements can be inserted in a tool and have plasticized
material injection molded around them in a single operation, so
that a completely finished toothbrush head is obtained. With this
method of the invention it is possible to substantially shorten the
cycle time for manufacturing a toothbrush head.
[0017] The method may also include, in a next step, transferring
the function element carrier to a further processing station in
which the function elements are severed from the plastic frame, and
subsequently the anchoring ends of the function elements are
secured in a brush holder. The grid or bar shaped plastic frames
may be separated from the function elements either before or after
inserting the function elements in a tool so that only the function
elements remain in the toothbrush head. In this process, plastic
material can be injection molded around the individual function
elements so that they then form a finished toothbrush head, or
alternatively, the individual function elements can be inserted in
openings provided in a toothbrush head manufactured in a prior
injection molding operation where they engage behind undercuts,
being thus either rotatably or pivotally or non-rotatably fastened
in the brush holder. Alternatively, they can also be fastened in
the brush holder by special anchorage devices such as wires,
adhesives, wedges, or also by caulking, etc. It is also possible,
however, to heat both parts to a temperature causing them to fuse
intimately together.
[0018] The grid or rod shaped plastic frame may include grid bars
and grid points between which tapers are formed. Tapers can be
formed during the manufacturing process at the ends of the
anchorage, retainer or axle elements of the function elements and
can then be used during further processing as, for example,
breaking, cutting or parting points for easy disconnection of the
function elements from the plastic frame. Separating the function
elements can also be performed by receiving them all in openings of
a progressive die and severing the tapers in a single operation.
The separated plastic frame can then be removed from the
progressive die, and the function elements can be inserted in a
brush holder, or be immediately embedded in molding material in the
progressive die to form a brush head or a complete toothbrush.
[0019] The present invention enables function elements of brush
products to be simultaneously manufactured with integrated handling
aids for subsequent further processing, in addition to providing
the possibility of molding special assembly aids or function faces,
e.g., anchors, motion axles or the like, on these function
elements. This process enables the most diverse material
combinations to be used including, for example, tufts of bristles
made of extruded nylon filaments combined with embedded anchors or
axles made of an elastomer plastic material, massage elements made
of soft material, etc.
[0020] The function elements may be equipped with undercuts for
securing to the plastic frame. The undercuts may be formed, in the
case where bristle tufts are involved, for example, by melting the
rear tuft element. In the case of massage elements or the like,
which are manufactured either from a thermoplastic material or an
elastomer plastic material or even a combination of several
dissimilar materials, such undercuts can be provided in advance by
suitable design measures so that in this process step they only
need to be prepared, as by heating, for further processing. Using
liquid plastic mass, an anchor, retainer or axle element can then
be injection molded on these undercuts.
[0021] The method may also include, in a next step, transferring
the function element carrier to a further processing station in
which the carrier is embedded in a brush holder by injection
molding plastic material around it, so that subsequently only the
anchoring ends of the function elements are enclosed by the brush
holder. This allows the function elements to be integrated in the
brush holder in a particularly easy manner. In this process the
grid shaped plastic frame can also be configured like a skewed
parallelogram or adopt any other desired structure to which the
function elements are fastened. The function element carrier is
manufactured in a prior operation in accordance with the desired
array and position of the function elements on the brush holder so
that the function elements already occupy this final geometrical
position on the toothbrush.
[0022] The grid or rod shaped plastic frame may be made up of grid
bars forming grid points at the intersections, between which tapers
are formed, and the plastic frame may be deformed before being
embedded in the molding material of the bristle holder so that the
function elements assume their desired position in the brush holder
following embedding. In this case, the function elements in the
plastic frame, after being manufactured and shortly before being
integrated in a toothbrush, are relocated in the plastic frame
within certain limits by relative displacement of the longitudinal
bars, so that the function elements are arranged as they should be
later on in the brush head. The advantage of this method is that it
does not entail maneuvering individual function elements but a
function element carrier on which all the function elements
required for a brush head are already arranged. By relative
displacement of the longitudinal bars it is possible to position
the function elements closer together than would generally be
possible by maneuvering individual function elements, because the
use of picker devices to hold and guide said function elements
would require certain spacings in between. In this embodiment of
the invention the function element carriers would generally be
integrally molded in the brush head.
[0023] Various function elements of elastomer plastic may be
provided on the plastic frame. If desired, the most diverse
function elements made of dissimilar or like materials can be
arranged on one function element carrier. For example, provision
can be made for tufts of bristles comprising various filaments,
massage elements, or other elements performing various special
functions. All these function elements can subsequently be inserted
in a brush body in a single operation.
[0024] In another aspect, the invention features a function element
carrier including a plurality of function elements equipped at
their ends intended for fastening in a toothbrush with an anchor,
retainer or axle element, each function element being fastened to a
grid or rod shaped plastic frame through its anchor, retainer or
axle element.
[0025] Because, in this aspect, the function elements are fastened
by their ends intended for anchoring in a brush head to a grid or
bar shaped plastic frame, the resulting unit is easy to handle
during its further processing. As a result, it is possible to
insert a complete set of function elements in a tool and to join it
to a brush holder, e.g., by embedding it in a molding material, or
by mechanically inserting the unit in a prefabricated brush holder.
This eliminates an elaborate separation of function elements,
which, after their production, are held in a magazine where their
bristles tend to interlock. Moreover, the function elements can
already adopt the position they are required to occupy later on on
the brush holder. Integrated handling aids can be used for further
processing, as well as special assembly aids or function faces
(anchors, motion axles, etc.) that can be injection molded to these
function elements. With these function elements it is also possible
to use the most diverse material combinations.
[0026] The grid or rod shaped plastic frame may be comprised of
connected grid bars forming grid points at the transitions to the
anchoring ends, with tapers being provided therebetween. These
tapers may enable better separation of the function elements from
the plastic frame, i.e., making it easier to break, cut or remove
in some other way the individual function elements from the plastic
frame.
[0027] Additional assembly aids or function faces may be arranged
on the function elements, e.g., by molding the assembly aids or
function faces on the individual function elements. Such assembly
aids or function faces may include, for example, anchors, motion
axles or other elements that enable the function elements to be
fastened or supported in the subsequently used brush holder.
[0028] It is possible to manufacture the function elements and the
plastic frame from dissimilar plastic materials. This makes sense
in particular if, for example, the plastic frame not required in a
toothbrush is discarded or re-used, enabling it to be made of an
inferior or other grade of plastic.
[0029] The function elements may be provided with undercuts at
their anchoring ends for fastening to the plastic frame. These
undercuts, if they are pivotally mounted in the brush holder,
enable simple insertion in the provided recesses so that, like a
snap-fastener, they can be inserted once, after which they can no
longer be removed from the brush holder and yet are pivotal in one
or several directions as required.
[0030] In another aspect, the invention features a toothbrush with
function elements that are each equipped at their ends intended for
anchoring in a brush holder of a toothbrush with an anchor,
retainer or axle element, wherein the individual function elements
are connected, through their anchor, retainer or axle elements to a
grid or rod shaped plastic frame which is secured in the brush
holder such that tooth cleaning ends of the function elements
protrude from the brush holder.
[0031] Thus, the toothbrush may be comprised of a plastic frame
with several function elements that are inserted together with the
plastic frame in the brush holder, wherein however only those
sections intended to treat the teeth or the oral cavity protrude
from the toothbrush head. A toothbrush of this type affords economy
of manufacture and permits a random array of the individual
function elements, possibly consisting of various types, on the
brush holder.
[0032] In a further aspect, the invention features a toothbrush
including function elements that are each equipped at their ends
intended for anchoring in a brush holder of a toothbrush with an
anchor, retainer or axle element, wherein said anchor, retainer or
axle elements include breaking, parting or cutting faces.
[0033] The toothbrush may have function elements that were
previously severed from their plastic frame and integrated as
individual elements in the brush holder, i.e., they are embedded in
plastic molding material in such a way as to produce a brush holder
of the predetermined shape, or they are fixedly seated in
individual recesses provided for this purpose in a prefabricated
brush holder. The breaking, parting or cutting faces may be fully
enclosed by the plastic material if the anchor, retainer or axle
elements are embedded. If they are pivotally inset in recesses, the
breaking, parting or cutting faces can serve as lateral stop
faces.
[0034] At least some of the function elements may be made from an
elastomer plastic material. The toothbrush of the invention may
include various types of function element performing different
types of cleaning function such as plaque removal, gum massage,
whitening of the teeth, or other advantageous tooth cleaning
functions.
[0035] Further embodiments and advantages of the present invention
will be described in the following with reference to the
accompanying drawings. In the drawings,
DESCRIPTION OF DRAWINGS
[0036] FIG. 1 is a perspective view of a function element carrier
of the invention, comprising function elements manufactured in
accordance with a method of the present invention;
[0037] FIG. 2 is a top plan view of the function element carrier of
FIG. 1 after the two outer longitudinal bars have been displaced
relative to the inner longitudinal bar;
[0038] FIG. 3 is a perspective view of a further function element
carrier of the invention, showing function elements and, on the
outer periphery, upwardly extending rods which are intended to
protect the individual function elements from damage or external
wear during transportation;
[0039] FIG. 4 is a perspective view of a brush holder embodiment
showing function elements manufactured in accordance with the
method of the invention; and
[0040] FIG. 5 is a perspective view of another brush holder
embodiment showing function elements manufactured in accordance
with the method of the invention.
DETAILED DESCRIPTION
[0041] FIG. 1 is a perspective view of a function element carrier 1
according to the invention, which was manufactured by the method of
the invention. The function element carrier 1 includes a grid or
bar shaped plastic frame 2 made preferably from a thermoplastic
material.
[0042] As used herein, the term "thermoplastic material" refers to
any plastic that can be melted by heating. Thermoplastic materials
include polystyrenes and polystyrene copolymers, copolymers of
polyvinyl chloride and polyvinyl chloride acetate, polyfluorides
and copolymers thereof, polyamides, polyimides, polyester,
polypropylene, and polyurethanes.
[0043] According to FIGS. 1 to 3 the plastic frame 2 is made up of
grid bars comprising, in the embodiment shown, three longitudinal
bars 3 which are interconnected at grid points 7 by cross bars 4.
The cross bars 4 are distinctly shorter than the longitudinal bars
3, forming rectangles in FIGS. 1 and 3, and parallelograms in FIG.
2. Depending on the geometric setup they can, however, be longer,
curved or of some other shape. It is only important that they be
interconnected with each other and with the function elements.
[0044] According to FIGS. 1 to 3 the cross bars 4 have tapers 18 in
advance of the grid points 7, thus creating a narrow transition to
the longitudinal bars 3. On the one hand this creates movable grid
points 7 so that, by displacing the middle longitudinal bar 3
relative to one or several outer longitudinal bars 3 as shown in
FIG. 2, the function elements 5 can be arranged in more or less
arrow shape in the plastic frame 2. On the other hand the tapers 18
enable the individual function elements 5 to be severed more
easily.
[0045] In the embodiments shown in FIGS. 1 to 3, the cross bars 4
can form, on their anchoring sides 22, anchor, retainer or axle
elements 13 for the upwardly extending tufts 16. The anchor,
retainer or axle elements 13 extend almost to the longitudinal bars
3; for injection molding reasons they can also be shorter, however,
so that sections of cross bars (not shown) adjoin the tapers 18 and
merge into the longitudinal bars 3. The tufts 16 are comprised of a
plurality of close lying individual bristles 15 and, in combination
with the anchor, retainer or axle elements 13, form a function
element 5 as shown in FIGS. 1 to 3.
[0046] Considering that the function element carrier 1 of FIGS. 1
to 3 is a schematic representation designed to serve as an example,
the number of grid fields 14 formed by the longitudinal and cross
bars 3, 4 was restricted. It will be appreciated, however, that any
number is possible for the purposes of the invention. Individual
grid fields 14 can have different dimensions and shapes.
[0047] According to FIGS. 1 to 3 the bristles or filaments 15 are
preferably made of nylon and are anchored in the cross bars 4. The
one-piece function element carrier 1 shown in FIGS. 1 and 2 can be
mounted in its illustrated form on a brush holder 8 and be
connected to it, or it can be brought in a preparatory step into
the required shape as shown in FIG. 2, for example, whereupon
plasticized material is injection molded at and around it wholly or
in part, thus creating a complete toothbrush head with or without a
hand piece. This step involves displacing essentially the two outer
longitudinal bars 3 relative to the inner longitudinal bar 3.
Consequently, the cross bars 4 articulated to the locations of the
grid points 7 are equally displaced, and the function elements 5
can thus be arranged in wedge shape in cleaning direction. In this
process the grid fields 14 change their shape to parallelograms.
With this method it is possible in particular to produce complex
bristle arrays or arrangements of brushes with massage elements
made of elastomer plastic material or pure massage elements made
solely of elastomer plastic material in a parallel process to the
brush holder, and to join them together when both process lines are
merged.
[0048] FIG. 3 shows a function element carrier 6 that essentially
corresponds to the function element carrier 1 of FIG. 1 but differs
in that supports are molded to the outer corners of the outer
longitudinal bars 3 in the form of vertically upwardly extending
rods that protrude upwardly beyond the tooth-cleaning ends 21 of
the tufts 16. These rods 20 protect the bristles 15 from damage and
soiling during transportation and handling of the function element
carrier 1. The rods 20 are removed from the plastic frame 2 before
the function element carrier 6 is inserted. If, on the other hand,
only the individual function elements 5 are inserted in a brush
holder 8, 11, the complete plastic frame 2 with the rods 2 are
first removed from the function elements 5.
[0049] An embodiment of a brush holder 8 with various function
elements 9, 10 is shown in FIG. 4. In this embodiment the brush
holder 8 carries in its forward section a function element 9 with
conically pointed studs 19, which is constructed as a spherical
massage element. The massage element 9 is made of an elastomer
plastic material, being to a certain extent shielded from the tip
of the brush holder 8 by a tuft 16 with an essentially U-shaped
cross section acting as a further function element 10. Further
large tufts 16 or other massage elements are also provided as
additional function elements 10.
[0050] A grid shaped plastic frame (not visible in FIG. 4 because
it is enclosed by the brush holder 8) acts as a function element
carrier for the massage element 9 and for the function elements 10
configured as tufts 16. The function element carrier is adapted so
that the function elements 9, 10 adopt their position shown in FIG.
4. Then the lower sections (not visible because they are enclosed
by the brush holder 8) of the function elements are fastened
together with the plastic frame to the brush holder 8, or are
connected therewith as by partially embedding them in or injecting
molding material at them.
[0051] A further embodiment of a brush holder with function
elements 12 for special functions is shown in FIG. 5. In this
embodiment the brush holder 11 carries paddlewheel shaped function
elements 12 intended to perform cleaning and massage functions in a
person's oral cavity (not shown). The paddlewheel shaped function
elements 12 are rotatably mounted on a common axle 23.
[0052] Here, too, the function elements 12 are initially connected
to a grid or bar shaped plastic frame (not visible in FIG. 5
because it is enclosed by the brush holder). The process involves
in particular supporting the rotary axle 23 of the paddle shaped
function elements on the plastic frame. The plastic frame itself is
then transferred to a work station where it is fastened to the
brush holder 11 by welding or adhesive bonding, by embedding the
grid bars in injection molding material, or some by other
method.
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