MXPA01008031A - Bristle sub-assemblies and method of making same - Google Patents

Abstract

A bristle sub-assembly (78) includes first and second base strings (68, 70) and a plurality of polymeric monofilaments (80) connected to and extending between the first and second base strings. The polymeric monofilaments form a first arched row when the first and second base strings are brought together. Several types and configurations of brushes are made using either arched bristles or combinations of arched and straight bristles.

Description

SUBMONTATIONS OF PIGS AND METHOD OF PREPARATION OF THE SAME BACKGROUND OF THE INVENTION The present invention is generally concerned with articles made of polymeric monofilaments and more particularly, with bristles on a ring, methods for the manufacture of sub-assemblies of sows on a ring and sub-assemblies of bristles and sub-assemblies of filament bristles attached to bodies, of brush. The co-pending application mentioned above describes a manufacturing technique in which a rope or base chain is fed axially along a mandrel while at the same time a monofilament is wrapped around the mandrel, to thereby produce a plurality of "wrappers" that are transported along the mandrel through the base cord. Then, the wrappers are attached to the base cord using an ultrasonic welder and subsequently cut to thereby form an article having two rows of monofilament segments attached to the base cord. This item, called a "string (or string) of bristles," can then be cut to lengths and used to make a variety of brushes or other products that require bristles. In one example, several rows of bristles are formed in a toothbrush by mounting the bristle cord segments in the head portion of a toothbrush REF: 131145. Normally, the proximal ends of the bristles are attached to the head of the brush and the distal ends extend freely upwards. Brushes with ring bristles have been used in the past. For example, U.S. Patent No. 4,211,217 issued to Gueret discloses a hair brush and massage in which the bristles are bent to form rings that are fixed in perforations formed in the head of the brush by fusing the ends together. As another example, U.S. Patent No. 4,406,032 issued to Diamant discloses a toothbrush that includes a filament wrapped around the head to form a plurality of circular rings. U.S. Patent No. 4,493,125 issued to Collis discloses a toothbrush having a combination of curved bristles and straight bristles. The curved bristles were formed by having opposite ends of straight filaments embedded in the brush head for the teeth in groups, to thereby form rings. Then the rings are cut axially to form two rows of curved bristles. Other examples where ring bristles are used in a toothbrush are shown in US Patent No. 4,030,845 issued to Deckert, US Patent No. 2,599,191 issued to Meunier and US Patent No. 4,438,541 issued to Jacob et al.

While these documents show various forms of ring bristles, there is a need for a ring bristle structure that is relatively easy to manufacture and effective in cost to produce.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide means for expanding the brush design beyond the possible range with current bristle insertion techniques. Another object of the present invention is to provide a sub-assembly of bristles for a brush, in which the individual filaments are fixed positionally with respect to each other before connection to a brush body. Still another object of the present invention is to provide a brush assembly method in which the bristle sub-assemblies can be permanently connected to the body of the brush or alternatively, detachably connected for subsequent replacement, thus avoiding the waste. uneconomic of otherwise functional brush bodies. Still another object of the invention is to provide a brush having a combination of arched bristles and straight bristles, whereby both types of bristles can be assembled without using conventional bristle insertion techniques. These and other objects are obtained by providing a sub-assembly of bristles that includes two substantially parallel base ropes and a plurality of polymer monofilaments connected transversely between the two base ropes. When the two base strings are juxtaposed with each other, these form a single row of arched monofilaments. The row of arched onofilaments can be sized to a desired length by cutting the two base ropes and then connecting them to a brush head in desired configurations. Other objects and features of the invention will be more apparent from the following detailed description when taken in conjunction with the illustrative embodiments in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a horizontal sectional view of an apparatus for manufacturing sub-assemblies of bristles according to a preferred embodiment of the present invention, taken in an ultrasonic welding step; Figure 2 is a horizontal sectional view of an apparatus for manufacturing sub-assemblies of bristles according to a preferred embodiment of the present invention, taken in a cutting step; Figure 3 is a plan view of a sub-assembly of bristles made with the apparatus of Figure 1, before bending of the monofilament segments into arcuate formations; Figure 4 is an end view of a row of arched monofilaments made from the sub-assembly of bristles of Figure 3; Fig. 5 is a horizontal sectional view of an apparatus for manufacturing sub-assemblies of bristles according to another preferred embodiment of the present invention, taken in a cutting step; Figure 6 is an end view of a bristle string sub-assembly made by the apparatus of Figure 5. Figure 7 is an end view of the bristle string sub-assembly of Figure 6, bent to form an arcuate section; Figure 8 is a plan view of a sub-assembly of bristles made according to another embodiment of the present invention. Figure 9 is an end view of the sub-assembly of bristles according to claim 8, after the formation of a pair of arcuate segments; Figure 10 is a perspective view of a toothbrush made with the arcuate bristles made in accordance with the present invention; Figure 11 is a partial, longitudinal, cross-sectional view of the front portion of the brush for the teeth of Figure 10; Figure 12 is an end view of a brush head according to another embodiment of the present invention and having a row of arched bristles and two flanking rows of straight bristles; and Figure 13 is an end view of a brush head according to another embodiment of the present invention and having a first row of arcuate bristles concentrically arranged with a second row of bristles in a ring. Fig. 14 is an end view of a brush head according to another embodiment of the present invention and having a row of arched bristles extending over three longitudinal rows of straight bristles.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, a substantially rectangular, hollow mandrel 10 has four beveled corners 12, 14, 16 and 18 that include flat surfaces that are at 45 ° angles to the flat surfaces contiguous of the mandrel 10. The base cords 20, 22, 26, 28, 30, 32, 34 and 36, which enter an axial end of the mandrel 10, pass downwards through the inside of the mandrel 10. The base cords are rotated at the opposite end and 'guided for movement in the opposite direction in pairs along the respective corners of the mandrel 10 as shown. A monofilament 38 is wrapped around the mandrel 10 as the base ropes are translated to thereby form a plurality of wraps that are in contact with the base ropes. The base ropes move the shells under ultrasonic connecting horns 40, 42, 44 and 46, each of which is juxtaposed to a respective corner of the mandrel 10. The horns are energized to thermally fuse the monofilament shells to the ropes base. After joining, the base ropes additionally transport the monofilament shells, now connected to the base ropes, to a cutting station. As seen in Figure 2, the cutting station includes a cutting blade 48, 50, 52 and 54 disposed at the respective corners to cut the monofilament wraps between each pair of base ropes to form four separate bristle sub-assemblies. While it is shown that each cutting blade that is rotatable about an axis illustrated in dashed lines in Figure 2, any wave energy or mechanical cutting device may be employed. With reference to Figure 3, one of the bristle subassemblies 56 is shown with two base ropes 22 and 26 arranged parallel to each other and the plurality of wraps attached to the base ropes at substantially right angles to form a plurality of monofilament segments 58 As seen in Figure 4, as the parallel base strings 22 and 26 are moved towards each other, the monofilament segments 58 are bent to form an arcuate row 60 of monofilament. An alternative method of cutting is to use the ultrasonic horn to cut through the wrapped filaments in conjunction with the formation of the bond between the wrapped monofilaments and the base cords. This is done by raising the surface of the mandrel located between each pair of corner base cords, to achieve an angular edge so that the face of the flat horn vibrates in front. As a result, joining and cutting occur substantially simultaneously. Other sub-assemblies of monofilament bristles can be made by varying the number of base ropes and by repositioning the cutting discs. For example, in Figure 5, the mandrel 62 has a substantially square cross-sectional shape, with base cords 64, 64, 68 and 70 disposed respectively in each of the four corners of the mandrel 62. A monofilament 72 is wrapped around the mandrel 62 and transported by the base cords as before to form a plurality of wraps. After passing under the ultrasonic binders (not shown) and thermally fused to the base cords, the monofilament wrappers are transported to a cutting station including two cutting blades 74 and 76. The cutting blades cut the monofilament wrappers on opposite sides of the mandrel 62 to form two almost identical bristle rope sub-assemblies 78, of which one is shown in Figure 6. The sub-assembly 78 includes a plurality of monofilament segments 80 which connect and extend between the two base cords 68 and 70 and two rows of monofilament segments 82 and 84. As seen in Figure 1, when the base ropes 68 and 70 are brought together in the direction of the directional arrows, the monofilament segments 80 form an arc. In another embodiment, seen in FIG. 8, the monofilament shells are cut to form a sub-assembly of bristle rope 86 in which the monofilament segments 88 are connected to the base ropes 90, 92 and 94. As seen in FIG. 9, when the two outer base ropes 90 and 94 are moved towards the intermediate base chord 92, as illustrated by the directional arrows, a pair of arched segments 96 and 98 are formed. The various bristle sub-mounts described above can be used in a variety of products, including brushes. Figure 10 shows a toothbrush 100 having a handle portion 102, a head portion 104 and a portion of bristles including straight rows 106, 108, 110, 112, 114 and 116 of monofilament bristles, which are arranged alternately between rows with turns 118, 120, 122, 124 and 126 of monofilament bristles. Straight bristles may be made according to the techniques described in copending application Serial No. 09/092092 entitled Method and Apparatus For Making Articles Having Bristles, which is incorporated herein by reference. Alternatively, straight bristles can be made by using the techniques described herein with respect to the embodiment of Figure 7, whereby straight bristles are made from straight segments 82 and 84. Sub-assemblies of straight bristles and Arched bristles are assembled with the head portion 104 by using the techniques described in co-pending application Serial No. 09/092094 entitled Monofilament Bristle Assemblies and Methods of Making Brushes Using Same, which is incorporated herein by reference. For example, and as seen in Figure 11, the head portion 104 is provided with transverse grooves that receive the individual base cords of straight rows 106 and 108 and the two base cords of arcuate rows 118 and 120. Alternatively, the straight rows 106 and 108 may share respective grooves with the corresponding base ropes of the arcuate row 118 to form a more compact brush head. In the placement of the base ropes in the grooves, chemical, thermal or mechanical means are used to seal the grooves and fix the base ropes in place. The shank sub-assemblies described herein can be used to construct brushes with a variety of patterns and combinations of bristles. Figure 12, which is a front end view of a toothbrush 128, has two rows 130 and 132 of straight monofilament bristles flanking a single row 134 of monofilament bristles with turns. The rows 130 and 132 extend to a height greater than the apex of the row 134 of arched monofilaments. All three. rows extend longitudinally from the upper surface of a head portion 136 of the toothbrush 128. Each of the rows 130 and 132 have a base cord mounted on the head portion 136, while the row 134 has two base cords mounted on the head portion, one corresponding to each leg of the arched monofilaments. Figure 13, also a front end view of a toothbrush 138, has two rows 140 and 142 of arched monofilament bristles that are arranged concentrically with respect to each other. The row 140 has a vertex greater than that of the row 142 and the legs of the row 140 are disposed outside the legs of the row 142. Both rows extend longitudinally from the upper surface of a head portion 144 of the toothbrush. teeth 138. Each of the rows 140 and 142 has two base cords mounted on the head portion 144. Figure 14, also a front end view of a tooth brush 146, has a row 148 of arched monofilament bristles which runs longitudinally along the head of the brush 150 and three rows 152, 154 and 156 of straight bristles which likewise run longitudinally along the head of the brush. The various embodiments described herein may employ virtually any combination of sub-assemblies of arched and straight bristles and may further include the sub-assemblies of ring bristles described in US Application Serial No. 09 / 092,092.

An advantage of the present invention is that the bristle sub-assemblies can be mixed and matched or matched to create a variety of combinations of desired curved and straight bristles. For brush applications for the teeth, the arched bristles have the additional advantage that there are no distant ends to be treated, as is the case for straight bristles. The monofilaments used for both of the sub-assemblies of straight and arched bristles are each a single filament, opposed to a "multifilament", such as yarn, twine, etc. Although the monofilament can be a co-extrusion of one or more polymers to form a coaxial structure. The monofilaments can be made from several different materials, including aliphatic polyamides, aromatic polyamides, polyesters, polyolefins, polystyrene, polyvinyl chloride (PVC), polyurethane, polyvinylidene chloride, fluoropolymer styrene and styrene copolymers. A polymeric material particularly suitable for brush applications for the teeth is nylon 6.12; Other nylons can be used, which include nylon 4, nylon 6, nylon 11, nylon 12, nylon 6/6, nylon 6,10, nylon 6,14, nylon 10,10 and nylon 12,12 and others nylon copolymers. An example of a preferred polyester is polybutylene terephthalate (PBT).

When the monofilaments are spliced as in Figure 3, the interconnection of monofilaments adjacent to each other in a flow zone can be relatively strong compared to the interconnection of the base chords to the flow zone which is substantially composed of monofilament material. This characteristic allows, in some applications, the elimination of the base strings of the monofilaments at any time after the thermal fusion. Alternatively, the adhesion between the monofilaments and the base cord can be at least as strong as the adhesion between the monofilaments. While Figure 3 shows the monofilaments in a single row, from flange to flange, the density can be varied such that the adjacent monofilaments do not touch each other. Also, the density can be such that a second or greater number of rows of monofilaments are stacked together. Where nylon monofilament of 0.203 mm (8 mils) is used, for example, a density of approximately 125 monofilaments per 2.54 cm (1 inch) of base cord can be obtained with a single row, flange to flange, of monofilaments. While methods of toothbrushes have been described, any of the wide variety of known brushes could be constructed using the arched bristles, combinations of arched bristles and with rings or combinations of arched and straight bristles according to the present invention. For some brush applications, the monofilaments may include abrasive particles or grit for particular brush applications. The abrasive monofilaments are commercially available under the name TYNEX® A by E.l. Du Pont De Nemours and Company of Wilmington, Delaware, USA. Preferably, the abrasive material comprises 0-50% by weight of the polymeric monofilaments. TYNEX® is a nylon monofilament 6.12 that contains particles of silicon carbide on aluminum oxide, which are distributed throughout the monofilament. When ultrasonic welding is used, at least the monofilament or the base cord, preferably both, are made of thermoplastic polymeric materials. These have been described before with reference to other modalities. The monofilaments used in any of the above embodiments may be coextrusions of one or more polymers. Also, to achieve the desired physical characteristics of the bristles used for applications such as cleaning and rubbing brushes, it has been found that the preferred monofilaments are those having a diameter between 0.0508 and 5.08 mm (2 and 200 mils) and preferably between 0.0508 and 0.508 mm (2 and 20 thousandths of an inch). In a particularly preferred embodiment for the toothbrush, the monofilaments are 0.102 - 0.254 mm (4-10 mils) in diameter. Monofilaments of different diameters, cross sections, materials, surface properties and / or colors can be combined in a bristle assembly or sub-assembly to achieve specific brushing characteristics and / or appearance. In the modalities using nylon for either the monofilament or the base cord, or both, a preferred nylon is sold under the name TYNEX® and is manufactured by E.l. Du Pont de Nemours and Company of Wilmington, Delaware USA. TYNEX® is polyhexamethylene dodecanamide, which is the technical name for nylon 6.12. This has a melting point of between 208 and 215 ° C and has a specific gravity of 1.05-1.07 and is commercially available in many shapes and diameters. Monofilaments and / or base ropes suitable for use in the present invention may have shapes other than circular cross sections and may be hollow or have gaps in their cross section. The embodiments described above show circular, cross-sectional shapes for the base cord and the monofilaments. Either or both of the base cord and the monofilaments could have oval, rectangular or other shapes. In any form, the preferred thicknesses for the base cord and the monofilaments are selected to provide a level of functionality to the individual brush applications. With respect to the base cord, the modalities described above show a single strand of monofilament material. However, the base cord could be a bunch of monofilaments having at least one of the monofilaments made of polymeric thermoplastic material. The polymeric monofilaments used for bristles in the various embodiments described hereinabove may have other additives. For example, polymeric monofilaments could include 0-50% by weight of particles having functional and / or aesthetic quality. An example would be particulate material that provides a color characteristic that would improve the visual appearance of the bristles. Other functional particles could also be included, such as antimicrobial additives in the polymeric monofilaments. Other particulate materials or coatings may be applied or included within the monofilament such as therapeutic agents or dyes, or other desirable additives. Also, the monofilaments can be treated on the surface to provide desired properties, such as altering the coefficient of friction.

The modalities described above require "connection (or union)" between the monofilaments and the base cord. In this context, "connection" means that the monofilaments are attached to the base cord by a frangible seal formed by melting, bonding with adhesive, bonding with solvents or similar means. The degree of frangibility can be controlled in such a way that, if desired, the base rope can be easily separated from the monofilaments after joining. The arched bristles described herein may be placed on any brush head in any configuration or pattern. For example, the arcuate bristles may run parallel or transverse to the longitudinal axis of the brush head, or transverse and longitudinal bristles may be used concurrently. The head itself may have a substantially flat surface from which the bristles extend upward, as shown in the illustrated embodiments. Alternatively, the brush head may have a surface with geometric figures, that is, a curve, in which case the bristles will tend to unfold outwards, in the case of a convex surface, or to unfold inwards in the case of a concave surface . Also, the two base strings of a sub-assembly of arched bristles can be mounted on the brush head in a non-parallel manner, such that the arcuate row of bristles adopts a desired profile in which the apex of the arch changes along of the length of the row. Although the invention has been described with reference to several particular embodiments, it will be understood by those skilled in the art that the invention is capable of a variety of alternative embodiments within the spirit and scope of the appended claims. It is noted that, in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers.

Claims (18)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: .1. A sub-assembly of bristles, characterized in that it comprises: (a) first and second base ropes, (b) a plurality of monofilaments extending between the first and second base ropes and (c) a flow zone forming frangible seals connecting the monofilaments to the first and second base cord, whereby the monofilaments form a first arcuate row between the first and second base chains.
2. 2. A bristle overlay according to claim 1, characterized in that at least one of the base ropes and the monofilaments are made of a nylon material.
3. 3. A bristle overlay according to claim 1, characterized in that the base cord is a bundle of monofilaments at least one of which is made of a nylon material.
4. 4. A sub-assembly of bristles according to claim 1, characterized in that the monofilaments are fused with heat to the base ropes.
5. 5. A sub-assembly of bristles according to claim 1, characterized in that the monofilaments are glued with solvents to the base ropes.
6. 6. A sub-assembly of bristles according to claim 1, characterized in that the monofilaments have variable diameters between 0.0508 and 5.08 mm (2 and 200 thousandths of an inch).
7. 7. A sub-assembly of bristles according to claim 1, characterized in that it further comprises a third base rope disposed between the first and second base ropes and connected to the monofilaments, whereby the monofilaments form the first arched row between the first and third ropes. base rope and form a second arched row between the second and third base ropes.
8. 8. A brush assembly, characterized in that it comprises: (a) a brush body having a head; and (b) connected to the head of the brush body, a first sub-assembly of bristles according to any of claims 1-7.
9. A brush assembly according to claim 8, characterized in that it also comprises at least a second sub-assembly of bristles connected to the head of the brush body, wherein the second sub-assembly of bristles comprises: (a) at least third and fourth ropes base; and (b) a plurality of polymeric monofilaments that are bonded and extend between the third and fourth base cords and form a second arcuate row extending upwardly from the brush body.
10. A brush assembly according to claim 8, characterized in that it also comprises at least one row of straight monofilament bristles, mounted with the head of the brush body, each row includes a plurality of monofilament bristles extending upwards from a base cord.
11. A sub-assembly of bristles, characterized in that it comprises: (a) first and second base cords, (b) a plurality of monofilaments extending between the first and second base cords and (c) adhesive forming frangible joints connecting the monofilaments to the first and second base ropes, whereby the monofilaments form a first arched row between the first and second base ropes.
12. 12. A sub-assembly of bristles according to claim 11, characterized in that at least one of the base ropes and the monofilaments are made of a nylon material.
13. 13. A sub-assembly of bristles according to claim 11, characterized in that the base cord is a bundle of monofilaments, at least one of which is made of a nylon material.
14. 14. A sub-assembly of bristles according to claim 11, characterized in that the monofilaments have varying diameters between 0.0508 and 5.08 mm (2 and 200 thousandths of an inch).
15. 15. A sub-assembly of bristles according to claim 11, further comprising a third base cord disposed between the first and second base ropes and connected to the monofilaments, whereby the monofilaments form the first arched row between the first and third ropes. base ropes and form a second arched row between the second and third base ropes.
16. 16. A brush assembly, characterized in that it comprises: (a) a brush body having a head; and (b) connected to the head of the brush body, a first sub-assembly of bristles according to any of claims 11-15. A brush assembly according to claim 16, characterized in that it also comprises at least a second sub-assembly of bristles connected to the brush body head, wherein the second sub-assembly of bristles comprises: (a) at least third and fourth ropes base; and (b) a plurality of polymeric monofilaments that are bonded and extend between the third and fourth base cords and form a second arcuate row extending upwardly from the brush body. A brush assembly according to claim 16, characterized in that it also comprises at least one row of straight monofilament bristles, mounted with the head of the brush body, each row having a plurality of monofilament bristles extending towards up, from a base rope.