US3871048A

US3871048A - Brush

Info

Publication number: US3871048A
Application number: US388917A
Authority: US
Inventors: Monty Leigh
Original assignee: LENG ARMAC Ltd
Current assignee: LENG ARMAC Ltd
Priority date: 1972-08-18
Filing date: 1973-08-16
Publication date: 1975-03-18
Anticipated expiration: 1992-03-18
Also published as: FR2208622A1; NL7311288A; FR2208622B3; GB1435084A; IT997286B; DE2341278A1

Abstract

A brush is formed by a bundle of straight parallel extruded plastic filaments which project from one end portion of an extruded plastic sheath, the portion of the bundle within the sheath completely surrounding a wedge. The sheath is attached to a handle, and the filament bundle is suitably of generally rectangular cross-section, to produce a flat brush. The brush is made by continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable. Continuously extruded around the core and filament bundle is a sheath of plastic material. The rope is sectioned into predetermined lengths, and part of the sheath is stripped from each length to expose the filaments. The filament ends are anchored to the sheath and to one another, and the core is severed adjacent the mouth of the sheath, which is attached to the handle. The handle may instead be formed by shaping the end of the sheath remote from the filaments. The core is formed with locally weakened portions extending transversely of the length of the extruded rope, to facilitate severing of the core.

Description

United States Patent 1191 Leigh 1451 Mar. 18, 1975 BRUSH [75] Inventor: Monty Leigh, Boreham Wood,

England [73] Assignee: Leng-Armac Limited, Boreham Wood, Hertfordshire, England [22] Filed: Aug. 16, 1973 [21] Appl. No.: 388,917

[30] Foreign Application Priority Data Aug. 18, 1972 United Kingdom 38757/7; Oct. 13, 1972 United Kingdom 47412/72 June 1 1, 1973 United Kingdom 27645773 [52] US. Cl 15/159 A, 15/193, 15/204,

15/DlG. 4, 161/175, 264/174, 264/147, 300/21 [51] int. Cl A46b 3/06, A46b 9/00, A46d H08 [58] Field of Search 15/159, 159 A, 191, 192, 15/193, 194, 204, DIG. 4; 300/21; 264/174,

[56] References Cited UNITED STATES PATENTS 1,103,515 7/1914 Husch l5/l59RX 1,616,858 2/1927 Jacob 15/204 2,581,561 l/l952 Shaw 15/159 A 3,266,624 8/1966 Shaw et a1 4. 15/159 R 6/1974 Weiss 300/21 FOREIGN PATENTS OR APPLICATIONS 931,517 7/1963 United Kingdom 15/193 Primary Examiner-Peter Feldman Attorney, Agent, or FirmWaters, Roditi, Schwartz & Nissen [57] ABSTRACT A brush is formed by a bundle of straight parallel extruded plastic filaments which project from one end portion of an extruded plastic sheath, the portion of the bundle within the sheath completely surrounding a wedge. The sheath is attached to a handle, and the filament bundle is suitably of generally rectangular cross-section, to produce a flat brush. The brush is made by continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable. Continuously extruded around the core and filament bundle is a sheath of plastic material. The rope is sectioned into predetermined lengths, and part of the sheath is stripped from each length to expose the filaments. The filament ends are anchored to the sheath and to one another, and the core is severed' adjacent the mouth of the sheath, which is attached to the handle. The handle may instead be formed by shaping the end of the sheath remote from the filaments. The core is formed with locally weakened portions extending transversely of the length of the extruded rope, to facilitate severing of the core.

18 Claims, 9 Drawing Figures BRUSH The present invention concerns an improved brush.

Conventionally brushes have been manufactured by fastening the bristles into a metal ferrule attached to a wooden or plastic brush handle.

It has already been proposed to use filaments of a plastic material instead of natural bristles, but brushes produced in this way still use a metal ferrule for holding the filaments and attaching them to the handle.

In many applications, however, it is highly advantageous to have available a brush with no metal parts.

In the prior art a rope has been produced in the form of parallel filaments of plastic material surrounded by a plastic sheath. It has been proposed to cut such rope into lengths from which the sheath is stripped away at one end to expose the filaments, the filaments and sheath being fused or bonded together and a further bond to the wall of the sheath at the opposite end. The resulting assembly forms a brush, and the brushes thus formed are suitable for a variety of applications.

Such brushes are of limited usefulness, however, in the larger sizes commonly in use. In conventional brush manufacture larger brushes have a hollow construction, in that a block of material (referred to in the art as a plug or wedge, although not necessarily wedge-shaped) is driven into the centre ofthe group of bristles within the ferrule.

The present invention is intended to provide an improved method of manufacturing brushes by means of a continuous extrusion process and with which larger sized brushes can be produced without the attendent disadvantages of unwedged construction.

In one aspect the invention provides a brush head formed by a bundle of straight parallel extruded plastic filaments which project from one portion of an extruded plastic sheath, the portion of the bundle within the sheath surrounding a wedge.

The invention also includes a brush comprising a brush head as defined in the preceding paragraph, the sheath being attached to a brush handle.

The filament bundle is suitably of generally rectangular cross-section, to produce a flat brush or brush head.

In a further aspect the invention provides a method of making a brush head, comprising the steps of: continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable; continuously extruding around the core and filament bundle a sheath of plastic material; sectioning the rope into predetermined lengths; stripping away part of the sheath from each length to expose the filaments; anchoring the filament ends to the sheath and to one another; and severing the core adjacent the mouth of the sheath.

The filament bundle is suitably of generally rectangular cross-section to provide a flat brush head.

The core is preferably formed with locally weakened portions extending transversely of the length of the rope.

The unstripped portion of the sheath on each length may be displaced away from the exposed filaments to leave an open-ended hollow space within the sheath, before the filament ends inside the sheath are bonded together and to the sheath. A brush handle may then be inserted into the open end of the sheath and the sheath fastened to the handle.

The invention also includes a method as defined in the preceding paragraph but three, in which longitudinally-extending ribs are formed by the extrusion process on the inside surface of the sheath and/or the outside surface of the core, the ribs extending into the filament bundle to locate the filaments.

It has been found that little difficulty is experienced in extruding an annular bundle of filaments, but when the filament bundle has the general shape of a hollow rectangle, to produce a flat brush, there is some tendency for the filaments in the bundle to migrate around its cross-section.

This produces an uneven distribution ofthe filaments in the finished brush.

The provision of the longitudinally-extending ribs of any suitable cross-section is intended for locating the filaments of the bundle.

The invention will now be described in more detail, by way of example only and with reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a cross-section through a continuously extruded rope used in the manufacture of a brush;

FIG. 2 is a side view of a length cut from the rope;

FIG. 3 shows the rope section after stripping away a portion of the sheath;

FIG. 4 shows the next step in the manufacture of the brush;

FIG. 5 shows a side elevation of the finished brush;

FIG. 6 is a side view of a core of the rope forming a wedge in the finished brush;

FIG. 7 is a cross-section through a continuously extruded rope used in the manufacture of a brush;

FIG. 8 is a cross-section through an alternative form of rope; and

FIG. 9 schematically shows one method of weakening'the core of the rope at regular intervals.

Referring to FIG. I, a continuously extruded rope consists of straight parallel plastic filaments l in the form of a bundle of generally rectangular cross-section around a core 2 also of generally rectangular crosssection. A plastic sheath 3 is extruded over the filament bundle l.

The core 2 has the form shown in side elevation in FIG. 6, and is continuously advanced at the speed of extrusion of the filaments 1 and sheath 3.

The extruded rope is sectioned into predetermined lengths, one of which is shown in side elevation in FIG. 2. The sheath 3 is then stripped away from part of each section to expose the filaments l, as shown in FIG. 3. The filaments will tend to splay lightly as shown in the Figure.

The remaining portion of the sheath 3 is then bodily displaced on the filaments l, away from their exposed ends. An open-ended hollow space 4 is thus formed within the sheath 3, as shown in dashed outline in FIG. 4. The core 2 is shown in chain-dotted outline in FIG. 4.

The filament ends inside the sheath 3 are then bonded together and to the sheath, suitably by fusing.

The core 2 is then severed adjacent the mouth of the sheath from which the filaments 1 project, to form a wedge 5 shown in dashed outline in FIG. 5.

To facilitate severing the core to form the wedge, the core has the form shown in FIG. 6. The core has locally weakened portions extending transversely of the length of the extruded rope, in the form of portions 6 of reduced cross-section at regular intervals along the length of the core. The core is suitably of a brittle foamed or otherwise easily severed material, and the appropriate choice of material may make the reduced cross-section portions unnecessary.

The material for the core is preferably chosen so that the broken-off portions can be re-used to make further core lengths, rather than being discarded and thus wasted.

. The method as so far described results in the production of a finished brush head.-

The final stage in the construction of the brush is to I insert a brush handle 7 into the open end of the sheath 3, as shown in FIG. 5, and to attach the sheath to the handle. This may be done in a conventional manner, by means of staples or pins for example or merely glued.

Referring to FIG. 7, a continuously extruded rope consists of straight parallel plastic filaments 1 in the form of a bundle of generally rectangular cross-section around a core 2 also of generally rectangular crosssection. A plastic sheath 3 is extruded over the filament bundle l, and has longitudinally-extending ribs 14 formed by the extrusion process on its inside surface. The ribs 14 extend into the filament bundle to locate the filaments thereof, to compensate for any tendency the filaments may have to migrate around the bundle cross-section on leaving the extrusion head. The ribs 14 may be of other cross-sections so as to provide a toothed appearance for example.

- The alternative form of rope shown in FIG. 8 also has straight parallel plastics filaments l in the form of a bundle of generally rectangular cross-section around a core 2 also of generally rectangular cross-section with a plastic sheath 3-extruded over the filament bundle l, but in this case longitudinally-extending ribs are formed on the outside surface of the core 2, by the extrusion process. The ribs 15 have the same function as the ribs 14 shown in H6. 7.

It will be appreciated that ribs may be provided on the inside surface of the sheath and on the outside surface of the core, but this will not generally be necessary, and ribs on one element or the other will usually suffice. I

The ribs are readily produced by appropriately shaping the outlet orifice of the extrusion die.-

The core 2 must'be easily sectionable, so that unwanted portions of it in the finished brushes can be broken off.

One way of achieving this, as already mentioned, is by means of reducing the core cross-section at periodic intervals.

This can be done by extruding the core through a wide outlet aperture, the extrudate being cut to provide lengths of core which are fed into the extrusion apparatus for the filament bundles and sheath. This method is not practicable, however, when the core is formed with longitudinally extending ribs.

FIG. 9 shows one method of achieving a similar periodic weakening of the core when it is provided with longitudinal ribs. The core 2 with ribs 15 leaves the extrusion head 16 and passes between

rollers

17 and 18 each of which carries radially-extending knives 19.

The

rollers

17 and 18 rotate in synchronism at such a rate that the peripheral speed of the tips of theblades 19 is substantially equal to the speed of advance of the core 2.

The synchronism of the

rollers

17 and 18 is such that blades come to-gether two-by-two, as clearly shown in FIG. 9, so as to cut through the major part of the core cross-section. Successive cuts in the core are made by successive pairs of blades, which progressively come into contact with the core as the rollers rotate. With the core advancing from left to right as seen in the Figure the upper roller 17 rotates anti-clockwise and the lower roller 18 clockwise.

It will be appreciated that FIG. 9 is diagrammatic, and that the shape of the blades 19 may need to be triangular or of some other suitable form to facilitate carrying out the process.

With certain plastic materials it may be possible to form an integral handle consisting of an appropriately would be stripped away to expose the filaments and the core broken off to form a wedge in the manner just described. The other end of the rope length would then be formed into a handle, perhaps by some form of induction heating and pressing operation.

The filaments used for the brush bristles may be of polypropylene, polyester or other suitable plastic material, as may the sheath. The core may be of a plastics material, but must be chosen so that it can be easily severed to produce the wedge.

With this method of construction, it is possible to produce a brush having no metal parts whatsoever. While it has been stated that the filament assembly may be stapled or pinned to the brush handle, it will be appreciated that other fixing methods may be used to avoid the use of metal staples or pins.

By appropriate choice of the plastic materials used in the brush construction, the following advantages may be realised:

The brush will not be affected by most of the commonly used solvents, and appropriate plastic materials will be inert to acids at ordinary temperatures.

The brush will not be effectedby alkalis, bleaching agents,'oils or greases, and will be suitable-for use with a wide variety of polishes, glues, inks, adhesives, paints,

varnishes, lacquers, paints, derusting agents, oven cleaners, penetrating oils, acids and so on.

It has been found that immersion of such a brush in boiling water for one hour has no effect other than a slight splay.

I claim: g

l. A brush head formed by an extruded plastic sheath, a bundle of straight parallel extruded plastic filaments which project from one end portion of said extruded plastics sheath, and a wedge, the portion of the bundle within the sheath completely surrounding said wedge. I v

2. A brush head as set forth in claim 1, in which said filament bundle is of generally rectangular flat, oval or round cross-section.

3. A brush head as set forth in claim 2, in which the inside surface of said sheath is formed with longitudinally extending ribs that extend into said filament bundle to locate said filaments.

4. A brush head as set forth in claim 1, in which'the outside surface of said core is formed with longitudinally extending ribs that extend into said filament bundle to locate said filaments.

5. A brush head as set forth in claim 1, in which the inside surface of said sheath and the outside surface of said core are formed with longitudinally extending ribs that extend into said filament bundle to locate said filaments.

6. A method of making a brush head, comprising the steps of: continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable; continuously extruding around said core and said filament bundle a sheath of plastic material; sectioning said rope into predetermined lengths; stripping away part of said sheath from each length to expose said filaments; anchoring the ends of said filaments to said sheath and to one another; and severing said core adjacent the mouth of said sheath.

7. A method as set forth in claim 6, in which said filament bundle is of generally rectangular cross-section to provide a flat brush head.

8. A method as set forth in claim 7, in which said core is of generally rectangular cross-section.

9. A method as set forth in claim 6, in which said core is formed with locally weakened portions extending transversely of the length of said rope.

10. A method as set forth in claim 6, in which the unstripped portion of said sheath on each length is displaced away from the exposed filaments to leave an open ended hollow space within the sheath, before the ends of said filaments inside said sheath are bonded together and to said sheath.

11. A method as set forth in claim 6, in which longitudinal!y-extending ribs are formed by the extrusion process on the inside surface of said sheath, the ribs extending into the filament bundle to locate the filaments.

12. A method as set forth in claim 6, in which longitudinally-extending ribs are formed by the extrusion process on the outside surface of said core, the ribs extending into the filament bundle to locate the filaments.

13. A method as set forth in claim 6, in which longitudinally-extending ribs are formed by the extrusion process on the inside surface of said sheath and the outside surface of said core, the ribs extending into the filament bundle to locate the filaments.

14. A method of making a brush. by:

continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable;

continuously extruding around said core and said filament bundle a sheath of plastic material; section- 6 ing said rope into predetermined lengths; stripping away part of said sheath from each length to expose said filaments;

anchoring the ends of said filaments to said sheath and to one another; severing said core adjacent the mouth of said sheath; and attaching a brush handle to said sheath.

15. A method of making a brush, by:

continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable; continuously extruding around said core and said filament bundle a sheath of plastic material; sectioning said rope into predetermined lengths; stripping away part of said sheath from each length to expose said filaments;

anchoring the ends of said filaments to said sheath and to one another; severing said core adjacent the mouth of said sheath;

inserting a brush handle into the open end of said sheath;

and attaching said sheath to said handle.

16. A method of making a brush, by:

continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable; continuously extruding around said core and said filament bundle a sheath of plastic material;

sectioning said rope into predetermined lengths;

stripping away part of said sheath from each length to expose said filaments; anchoring the ends of said filaments to said sheath and to one another; severing said core adjacent the mouth of said sheath; and deforming the end of said brush-head remote from said protruding filaments to produce an integral brush handle.

17. A brush, comprising a brush head formed by an extruded plastic sheath, a bundle of straight parallel extruded plastic filaments which project from one end portion of said extruded plastics sheath, and a wedge, the portion of the bundle within the sheath surrounding said wedge, attached to a handle.

18. A brush as set forth in claim 17, in which said sheath is hollow at the end opposite the protruding filaments and said handle is inserted into the hollow end of said sheath and said sheath fastened to said handle.

* l =l= l

Claims

1. A brush head formed by an extruded plastic sheath, a bundle of straight parallel extruded plastic filaments which project from one end portion of said extruded plastics sheath, and a wedge, the portion of the bundle within the sheath completely surrounding said wedge.

4. A brush head as set forth in claim 1, in which the outside surface of said core is formed with longitudinally extending ribs that extend into said filament bundle to locate said filaments.

11. A method as set forth in claim 6, in which longitudinally-extending ribs are formed by the extrusion process on the inside surface of said sheath, the ribs extending into the filament bundle to locate the filaments.

14. A method of making a brush, by: continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable; continuously extruding around said core and said filament bundle a sheath of plastic material; sectioning said rope into predetermined lengths; stripping away part of said sheath from each length to expose said filaments; anchoring the ends of said filaments to said sheath and to one another; severing said core adjacent the mouth of said sheath; and attaching a brush handle to said sheath.

15. A method of making a brush, by: continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable; continuously extruding around said core and said filament bundle a sheath of plastic material; sectioning said rope into predetermined lengths; stripping away part of said sheath from each length to expose said filaments; anchoring the ends of said filaments to said sheath and to one another; severing said core adjacent the mouth of said sheath; inserting a brush handle into the open end of said sheath; and attaching said sheath to said handle.

16. A method of making a brush, by: continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable; continuously extruding around said core and said filament bundle a sheath of plastic material; sectioning said rope into predetermined lengths; stripping away part of said sheath from each length to expose said filaments; anchoring the ends of said filaments to said sheath and to one another; severing said core adjacent the mouth of said sheath; and deforming the end of said brush-head remote from said protruding filaments to produce an integral brush handle.