Method of making a brush and brush obtained in this way

Abstract

Described is an industrial brush (1) comprising a brush body (2) obtained by the solidification of a metal in which the metal wires are locked in a rigid fashion for a first portion (3) thereby having a rigid body. The second portion of metal wires (4) is, on the other hand, free to perform brushing when the brush body (2) is rotated about a relative axis (5). The brush body (2) incorporates the metal wires with a structural coupling (with zero tolerance) which keeps unaltered the relative characteristics over time, with heat variations and at high speeds of rotation. It is also possible to construct the elements of traditional brushes with the same metal and a process is described for constructing new geometrical shapes for producing brushes with synthetic and natural wires with the traditional systems. Also described is a process for making a brush (1) comprising the steps of feeding in a mold (8) a metal in the molten state (melting temperature less than 2000 C.), in such a way that the first portion of the metal wires (3) is immersed in the metal which, when solidifying, forms a brush body with a rigid structure with a high mechanical strength such as to render perfectly stable the operation of the brush at high speeds and at high temperatures. During solidification of the molten metal there is also a heat treatment on the metal wires which improves their mechanical characteristics. Flanges, outer cups and inner cups with innovative embodiments can also be made with the same molding process, improving the characteristics of the traditional brushes.

Claims

1. A method for making a brush or brush element (1) comprising a first portion of wires (3) embedded in a brush body (2) made of metal and a second portion of free metal wires (4), comprising at least the following steps: preparing a plurality of metal wires positioned in such a way as to form at least one bundle having a predetermined width such as to occupy a predetermined space; the wires having a first portion (3), in use embedded in the brush body (2), and the second portion of free metal wires (4), in use not embedded; preparing a portion of the metal wires inside a cavity of a mould having a predetermined geometrical shape; feeding a molten metal inside the cavity of the mould until the cavity is filled; cooling the molten metal to allow the solidification with the first portion (3) of metal wires inside, so as to form a single brush body (2) from which the second portion of free metal wires (4) protrudes, designed to perform the brushing operation, and further comprising a step for tempering the metal wires made from carried out by the molten metal fed into the mould (8) in the first portion (3) of the wires and by the mould (8) itself or by auxiliary components in the second portion (4).

2. The method according to claim 1, further comprising, between the preparing step and the feeding step, a step for locking the metal wires inside the cavity, transversely to a direction of extension of the metal wires themselves, by at least one necking (30) having a width less than the predetermined width of the bundle in such a way as to compress the bundle causing a separation of the metal wires into the first portion (3), in use embedded, and into the second portion (4), in use not embedded; the necking (30) keeping being in contact the wires so as to perform a tempering of the wires.

3. The method according to claim 1, wherein metal wires extend with a radial direction starting from a central annular body (16) for forming a circular brush; the mould (8) having at least one half-part (8a) equipped with an annular protrusion (30a), concentric with the annular body (16) and extending transversely to the wires for compressing them so as to form the necking (30) and delimit the radial extension of the brush body (2).

4. The method according to claim 3, wherein the mould comprises (8) two half-parts (8a) each equipped with a relative annular protrusion (30a) opposite the annular protrusion of the other half-part (8a) for forming the necking (30).

5. The method according to claim 1, wherein the mould (8) comprises a hollow central portion (32) and a plurality of radial ducts (34) extending from the central portion (32); the step of preparing a portion of the metal wires inside a cavity of a mould having a predetermined geometrical shape being performed by locating the first portion (3) of the wires in the central position (32) and the second portion (4) in the ducts.

6. The method according to claim 5, wherein the wires are twisted bundles (33) and the step of preparing a portion of the metal wires inside a cavity of a mould having a predetermined geometrical shape comprises locating each twisted bundle (33) with a radial and angular orientation spaced from the adjacent twisted bundle (33).

7. The method according to claim 5, wherein the mould (8) is defined by two superposable half-moulds (8a), each equipped with a central cavity (32a) and a plurality of radial grooves (34a) extending from the central cavity (32a); each groove (34a) being superposable with a corresponding groove (34a) of the other half-mould (8a) for making the duct (34) during the casting.

8. The method according to claim 1, wherein the step of locking the metal wires inside the cavity comprises the following steps: positioning a disc-shaped body (10) substantially concentric with an axis of rotation of the brush; positioning metal wires on the perimeter of the disc-shaped body (10); positioning an external annular body (9), in such a way as to define a circular crown for housing the metal wires (3) interposed between the disc-shaped body (10) and the annular body (9) so as to form the necking (30).

9. The method according to claim 8, wherein the locking step also comprises the following sub-steps: preparing a metal bushing (31) made from a different material from the molten metal and from the metal wires and having a diameter less than a diameter occupied by the second portion (4), in use not embedded, of the metal wires; inserting the second portion (4) of the metal wires in the bushing (31) for further reducing the radial extension of the metal wires.

10. The method according to claim 9, wherein the bushing (31) has an axial extension greater than or equal to the second portion (4) of the metal wires in such a way as to remain in contact with it during the feeding step so as to perform a complete tempering of the metal wires.

11. The method according to claim 9, further comprising a step of removing the bushing (31) following the cooling step.

12. The method according to claim 1, further comprising a step for defining first constraint means (6, 13) on the brush body (2) designed to allow reversible connection with second constraint means complementary to them, defined by an operational support or modular brush.

13. The method according to claim 12, wherein the step for defining the first constraint means (6, 13) comprises a step for making a threaded cavity inside the brush body (2).

14. The method according to claim 12, wherein the step for defining the first constraint means (6, 13) is performed at the same time as the step for feeding molten metal into the cavity of the mould (8).

15. The method according to claim 1, wherein the molten metal comprises aluminium or aluminium alloys and that the set of wires (3) is made of metal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of this invention are more apparent from the non-limiting description which follows of a preferred, non-limiting embodiment of an industrial brush as illustrated in the accompanying drawings, in which:

(2) FIG. 1 shows a cross-section of a cup-shaped brush according to this invention with a ring of crimped metal wires embedded in the brush body 2;

(3) FIG. 2 shows a cross-section of a cup-shaped brush according to this invention with twisted bundles ring embedded in the brush body 2;

(4) FIG. 3 shows a cross-section of a cup-shaped brush according to this invention with twisted bundles ring and with metal elements to have a precise positioning of the brush inside the cavity of the mould for injection moulding or by casting embedded in the brush body 2;

(5) FIG. 4 shows a brush unit for machining processes according to a further embodiment;

(6) FIG. 5 shows a schematic side view of a step of the production method in question for making a different type of brush, that is, a circular-type brush with shank;

(7) FIG. 6 shows a view of the circular brush produced using aluminium flanges produced by injection moulding or by casting;

(8) FIGS. 7 and 8 show a mould and a twisted bundles brush made using the mould according to this invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

(9) With reference to the accompanying drawings, the numeral 1 denotes an industrial brush according to this invention.

(10) The brush 1 comprises a brush body 2 and a plurality of metal wires.

(11) The wires have a first portion 3 embedded in the metal brush body 2 and a second portion 4 designed to perform brushing when the brush 1 (that is, the brush body 2) is rotated about its relative longitudinal axis 5.

(12) Originally, the brush body 2 is formed by a molten metal in which the first portion of the metal wires 3 is fed; the binding metal incorporates the first portion of the wires 3 to make it rigidly integral with the brush body 2.

(13) The above-mentioned brush 1 is made with a method having a step of preparing a plurality of metal wires positioned in such a way as to form at least one bundle having a predetermined width such as to occupy a predetermined space.

(14) The metal wires are positioned inside a cavity of a mould having a predetermined geometrical shape, in which a molten metal is subsequently fed until filling the mould.

(15) Lastly, the molten metal is cooled to allow the solidification with the first portion 3 of metal wires inside, so as to form a single brush body 2 from which the second portion 4, in use not embedded, of the metal wires protrudes, designed to perform the brushing operation.

(16) Thus, the metal brush body 2 originally comprises a rigid block encapsulating the wires or the ring with the wires, obtained by solidifying a molten metal in a mould 8 (for example, by casting or injection moulding).

(17) It should be noted that the method comprises a tempering of the metal wires, made by the molten metal fed into the mould 8 on the first portion 3 of the wires and by the mould 8 (or by auxiliary components) on the second portion 4.

(18) More specifically, the method comprises, between the preparing step and the feeding step, a step for locking the metal wires inside the cavity transversely to a direction of extension of the metal wires by at least one necking 30 having a width less than the predetermined width of the bundle in such a way as to compress the bundle causing a separation of the metal wires into the first portion 3 and into the second portion 4 (that is, delimiting also the brush body 2).

(19) It should be noted that the necking 30 is maintained keeping in contact with the wires so as to perform a tempering of the wires.

(20) In the circular brushes (FIG. 3), the metal wires extend in a radial direction starting from a central annular body 16.

(21) In this embodiment, the mould 8 has at least one half-part 8a equipped with an annular protrusion 30a, concentric with the annular body 16 and extending transversely to the wires for compressing them so as to form the necking 30 and delimit the radial extension of the brush body 2.

(22) Preferably, the mould comprises 8 two half-parts 8a each equipped with a relative annular protrusion 30a opposite the annular protrusion of the other half-part 8a for forming the necking 30.

(23) On the other hand, to make a circular brush with twisted bundles (FIGS. 7 and 8), in which each bundle is angularly spaced from the adjacent one, the mould 8 comprises a central hollow portion 32, wherein a first portion 33a of the twisted bundles, in use embedded in the brush body 2, is positioned.

(24) Starting from the central hollow portion 32, the mould comprises a plurality of radial ducts 34 housing the second portion 33b, in use not embedded, of the twisted bundles, which keep in contact the respective second portion 33b for performing the tempering and the perfect centring of the ring with respect to the axis of rotation.

(25) Preferably, also in this case the mould 8 is defined by two superposable half-moulds 8a, each equipped with a central cavity 32a and a plurality of radial grooves 34a extending from the central cavity 32a.

(26) Each groove 34a superposes a corresponding groove 34a of the other half-mould 8a to make the ducts 34 during the casting.

(27) Thus, the twisted bundles brush obtained in this way comprises a brush body 2 formed by a disc 35 equipped along a relative periphery with a plurality of angularly spaced openings 36 in which the wires (that is, the first portion of the bundles) are housed.

(28) In the cup shaped brushes (FIG. 1), on the other hand, the step of locking the the metal wires comprises the following steps: positioning a disc-shaped body 10 substantially concentric with an axis of rotation of the brush; positioning metal wires on the perimeter of the disc-shaped body 10; positioning an external annular body 9, in such a way as to define a circular crown for housing the metal wires interposed between the disc-shaped body 10 and the annular body 9 so as to form the necking 30.

(29) Moreover, preferably, the locking step also comprises a sub-step of preparing a metal bushing 31 made from a different material from the molten metal and from the metal wires and having a diameter less than a diameter occupied by the second portion 4, in use not embedded, of the metal wires.

(30) Also, there is a further sub-step of inserting the second portion 4 of the metal wires in the bushing 31 for further reducing the radial extension of the metal wires (in particular of the second portion 4).

(31) Therefore, the bushing 31 in turn forms a further portion of the necking 30. It should be noted that, after the cooling, there is a step for removing the bushing 31 to complete the making of the brush 1.

(32) With regard to the materials, preferably the binding metal consists in a metal in the liquid phase with a melting temperature of less than 2000 C. and then solidified around the first portion of the wires 3 to incorporate them in the brush body 2.

(33) Preferably, the metal brush body 2 is made of aluminium or an aluminium alloy (melting temperature approximately 800 C.).

(34) Preferably, the brush body 2 made of molten metal forms a recess 6 inside.

(35) The purpose of the recess 6 is to facilitate a connection of the brush 1 to a spindle, that is, to a rotary shaft for rotating the brush during the brushing. However, it should be noted that the presence of the recess 6 is not essential, as the brush 1 could be connected to means for rotating the brush using jaws or other connecting means.

(36) However, the presence of the recess is advantageous as it facilitates the coupling of the brush 1 to the spindle; in addition, there are no tolerances in the centring of the brush when this is fixed to the spindle.

(37) For this reason, in the embodiment shown in FIG. 1 the brush 1 comprises a particularly reduced number of components, that is, it comprises only a ring with metal wires 3 embedded in the brush body 2 formed by the solidified metal.

(38) For this reason, the brush 1 is free of reduction device, as well as flange and cups which are replaced by the solidified metal which considerably improves the mechanical characteristics compared with the current standard.

(39) In light of this, the recess 6 also forms internally a thread to allow screwing of the brush body 2 to the spindle.

(40) FIG. 2 shows a brush 1 equipped with the recess 6 and the flange with twisted bundles 7.

(41) According to another embodiment of this invention (shown in FIG. 3), the brush also comprises a brush body made of molten metal with a geometrical shape suitable for the circular brush with embedded inside a ring with crimped metal wires and with a central hole 6.

(42) According to another embodiment of this invention (shown in FIG. 4), the circular brush is obtained from a ring with twisted bundles embedded in the metal brush body 2 with a central hole 6.

(43) This facilitates, advantageously, the screwing of the circular brush 1 to a spindle; if necessary, the metal die can be threaded directly thereby avoiding the presence of the reduction device.

(44) The cup-shaped brush shown in FIG. 5 comprises metallic elements (outer ring 9 and inner cup 10) for the perfect centring of the brush inside the cavity of the mould 8 and an inner flange 10 for holding the metal wires or bundles (as in this case it is not possible to use the ring nut with metal wires for the crimped wire or the drilled holes for the twisted bundles).

(45) The metallic ring 9 with the inner flange 10 are used to have a precise centring of the metal wires with respect to the axis of rotation and to keep them stationary during the moulding step (by casting or injection).

(46) In FIG. 6 the brush tool 1 comprises basically a first portion comprising a brush body 2 which will be formed by the free space inside the mould 8 and a first portion of wires 3 positioned inside the mould.

(47) The method comprises the following steps: preparing a portion of the above-mentioned set of metal wires 3 inside a cavity of the mould 8 having a suitable geometrical shape feeding a metal in a molten form inside the above-mentioned cavity of the mould 8 until filling the cavity through the hole 11. solidifying the molten metal with a portion of the set of metal wires 3 locked inside to form a brush unit 1 (see FIGS. 7 and 8).

(48) Looking at the method in more detail, the above-mentioned step of preparing the portion of wires 3 can be, for example, a manual positioning introduced in the special cavity of the mould 8.

(49) The cavity of the mould 8 is then closed with a second mobile part 8A of the mould.

(50) The above-mentioned step of feeding the liquid material occurs, preferably, but without restricting the scope of the invention, through the holes 11 of the mould 8.

(51) Purely by way of an example, the above-mentioned feeding step can be achieved by injecting molten metal (preferably aluminium or an aluminium alloy) inside the mould 8, or (see FIG. 6) by casting the molten metal inside the mould 8 with passage of the liquid through the area 11 engaged by the set of wires 3.

(52) Obviously the feeding methods can be of various kinds depending on the shape of the cavity of the mould 8 and on the final shape of the brush body 2.

(53) FIG. 5 shows, by way of an example, a mould 8 for circular brushes 1 with supporting shank 12 to confirm the universal nature of the production method.

(54) FIG. 6 shows a circular brush with synthetic or natural wires with flanges 16 and 17 made of aluminium, produced with moulding by casting or injection, wherein they are pressure fitted relative to each other and with special configurations.

(55) In the figure they are shown for example with a toothing 18 in their inner part (to lock the wires).

(56) In both cases described above, the brush 1 can be obtained in different combinations (with metal or synthetic wires); the liquid material can comprise a metal alloy (aluminium-based) and the set of wires 3 must be made of metal or if the elements are moulded in aluminium the wires 3 can be made from metallic or synthetic or natural material.

(57) In general, the brush 1 for mechanical processes therefore comprises the metal brush body 2 which constitutes the means of joining with the above-mentioned set of metal wires 3 to form a single compact rigid body.

(58) Basically, it may be said that the brush body 2 forms, in a first solution, the actual brush body and also the means of retraining the set of wires 3 to the brush body 2, whilst the free part of the wires 4 is used to perform the brushing.

(59) At a structural level, the above-mentioned first restraining means 6 can comprise a thread made inside the brush body 2.

(60) Alternatively, the brush body 2 can form an intermediate element of association (compaction in a single body) of the above-mentioned set of wires 3 and where the brush body 2 is equipped with the above-mentioned restraining means 13 (see FIGS. 7 and 8).

(61) This intermediate brush element 1 is equipped, on the relative outer surface, of the above-mentioned restraining means 13 matchingly shaped to be associated, in a removable fashion (that is to say, reversibly), with the second restraining means presented by a relative brush body operating inside at least one relative cavity (not illustrated) for removably housing the brush element 1.

(62) As may be seen in FIG. 7, the first removable restraining means 13 comprises a relative thread made, respectively, inside the above-mentioned cavity made on the brush body and on the surface of the brush element 1.

(63) If the threads are made on the brush element 1, the shape of the brush body 2 can be substantially cylindrical.

(64) Alternatively, the brush element 1 can have a substantially frusto-conical shape (see FIG. 8) of the brush body 2 and the application of the brush body can be by interference using the precision characteristics of the brush element 1.

(65) By way of a non-limiting example, a brush is made with the brush element 1 (see FIGS. 7 and 8) and wherein there is a plurality of sets of wires 4 to form the above-mentioned second portion of the wires which perform the brushing.

(66) The second portion of wires 4 is therefore formed by a corresponding plurality of brush elements 1 joined in a single body using the above-mentioned first removable restraining means 13 to a single brush body equipped with a corresponding plurality of cavities equipped with relative second restraining means.

(67) In practice, a modular brush is formed.

(68) The method just described and the brush element obtained achieve the pre-set aims thanks to the simple and fast steps designed to obtain an extremely compact final product, with high technical characteristics and reduced cost.

(69) The homogeneous casting of the molten metal and the set of metal wires with the brush body 2 achieves a modular brush with high mechanical strength with consequent improvement of the operational speeds and the necessary safety thanks to the mechanical locking axis of the various brush elements 1.

(70) Another solution concerns the making of the elements (flanges, cups or the like) with the same process, which can be used in place of those currently used for the brushes.

(71) The method allows a repeatability of the construction standard of the brush in a fast and precise fashion with considerable reductions in the costs and with materials which define characteristics of safety and lightness of the brush element and of the brush which cannot be achieved by traditional brushes.

(72) By exploiting the characteristics of the metals (such as for example aluminium and its alloys) and using brass wires, brushes are obtained which are fully explosion-proof and non-magnetic if elements made with non-magnetic metals are also used for holding the brass wires.