Process for making rotating brushes for automatic car washes

Abstract: A process for making rotating brush (21), in particular, the type used in automatic car washing facilities, and comprising a support (21s) which has inner face (6) and outer face (7), having attached to the outer face flexible cleaning elements (3n), wherein the process includes the following stages: a) preparation of mold (24) capable of making desired rotating brush (21); b) arrangement of said flexible cleaning elements (3n) with one end inserted into mold (24) and the other end projecting outwardly; c) injection into the mold (24) of components in the fluid state intermixed to form synthetic resin (8) which is able to polymerize; d) opening of mold (24) once polymerization is complete and extraction of brush (21) in which these flexible cleaning elements (3n) are attached to this support (21s) because they are embedded in the polymerized resin.

Description: This invention relates to the technological field of rotating brushes, of both flat and cylindrical shape, in particular, those used in automatic car washing facilities. These brushes comprise a support which is flat or cylindrical and which has an inner face and outer face; attached to the outer face are flexible cleaning elements, filiform or of a flat design, which -- set in motion by the rotation of the brush -- clean the vehicle or whatever flat washable surfaces with which they come into contact. These cleaning elements, because they are subjected to the action of centrifugal force and because of the friction exerted on the surfaces to be cleaned, need to be attached to their support in a firm and stable way, and currently there are a number of processes for accomplishing this attachment. When the cleaning elements are of the filiform type, they are gathered into bunches which are attached manually to the support via a long and sometimes costly sewing operation. When the cleaning elements are of the flat type, whether fringed or not, each must be attached -- either by sewing, riveting, soldering or a similar process -- to a suitably shaped intermediate support which is then connected to a cylindrical jacket designed so that it can be connected mechanically to a rotating part of the washing device. Since a single brush is composed of a few dozen radially attached flexible cleaning elements, the complex task of preparing a brush, with can be up to 3 or 4 meters long, is an especially long and expensive undertaking. Efforts have been made to avoid this long preparation time and concomitant high costs by using computer-aided automatic machines for preparing brushes by pressing, but these machines are suitable only for making a certain type of brush with specific dimensions and characteristics, so that in order to change the type of brush being produced, the machine must be re-fitted and the computer program must be reset so that the advantages of using this sort of procedure in terms of production time and costs are more or less cancelled out. The process of making a rotating brush according to the preamble of claim 1 is known from document US-A-3 643 282. Also a new process is known, (see injection molding Handbook - Rosato, 1995) with which it is possible to obtain plastic items by injection into a mold with the use of polymer synthetic resins having a number of fluid. The object of this invention is a process to make rotating brush of the type described above with one end of each cleaning element realized so as to result automatically blocked by the polymerized resin after their polymerization. In particular, the subject of this invention is a process to make a rotating brush as described in the preamble of appended claim 1, characterized by the features disclosed in its characterizing portion. One non-limiting and non-restrictive example of the process according to the invention will be illustrated in more detail in the description below, in which reference is made to the attached figure, which represents a transverse cross-section of a mold according to the invention, to make a rotating brush with a cylindrical support and flat radial cleaning elements. The attached figure shows the shape and arrangement of parts of mold 24 in a preferred embodiment of a rotating brush according to the invention, for producing rotating brush 21 with cylindrical support 21s and with radial cleaning elements 3n of the flat type. In this case, mold 24 comprises two coaxial cylinders 24i, 24e. On the radially outermost cylinder 24e there is a series of cavities 9 equidistant from one another, with a length and width essentially equal to the lenght and width of flexible cleaning elements 3n -- fringed or unfringed -- which are to be used. In the space between the two cylinders 24i, 24e there is cylindrical support 21s for the rotating brush. These cleaning elements 3n are inserted through cavities 9 so as to project into mold 24 to a desired depth and in such a way as to leave distance d between their end located inside mold 24 and the innermost cylinder 24i. Thus a ring of synthetic resin is formed with thickness d capable of withstanding the various mechanical stresses to which brush 21 is subjected. By injecting the fluid components of synthetic resin 8 into mold 24, in the manner known by experts in the field in this case also we can obtain, in a single operation, a cylindrical rotating brush 21 which is already ready to use and need only be pulled from the mold one the synthetic resin polymerizes. On the end of the flat cleaning elements 3n which are located in the space between the two coaxial cylinders 24i, 24e, there should be a plurality of holes 11 which pass through, thus providing synthetic resin 8 with a means of entering and passing through them, thus forming a series of mechanical bonds more stable than simple embedding. It is also possible, in a manner similar to that usable for filiform cleaning elements, to fold the flat cleaning elements in two, thus forming a loop along their entire length, and to insert this loop, on which there are through openings arranged on its apex or on its sides so that the synthetic resin, after having passed through it, fills up this loop, creating a new bond with a desired mechanical resistance to breakage. This case is not represented in the drawing. In the preferred embodiment of a rotating brush of the type described just above, coaxial cylinders 24i, 24e comprising the mold can be made of thermoplastic synthetic resin, for example polyethylene, so as to emerge out firmly embedded due to adherence of the synthetic resin 8 comprising the body of the brush, forming a whole with the latter, and thus being used as part of a "disposable" mold which functions as a layer on the outer and inner surface of the body of the brush, which advantageously can be sold and used as it is. Thus, the problem of maintaining and re-fitting the molds is solved and the disassembly stage requiring detachment of the molds from the brush and subsequent polymerization of the synthetic resin which comprises the body is eliminated. Moreover, in this way a rotating brush is obtained which has a compact layer resistant to mechanical or chemical stresses of various types, thereby eliminating the cost of depreciation of the molds, a cost which can become considerable when there is a need to produce a limited number of rotating brushes with a certain type of mold, as is frequently the case. For producing rotating brushes according to the invention, various types of polymer synthetic resin having a number of components which are initially in the fluid state can be used, as long as the entire area of the mold is filled thoroughly after polymerization. The inventor suggests, however, that polyurethane foam be used which, as is known, is composed of isocyanate and polyol and polymerizes with the addition of water. Any of various types of cleaning elements can be chosen, adapting to them the method of the process and the shape of the molds, including a filiform design, made from filaments composed of a synthetic material, including polythene, nylon and polypropylene, or a flat design, fringed or unfringed, made of a felt pad composed of polyethylene, polyethylene with vinyl acetate added, or of a plastic foam with closed cells such as for example polyurethane.

Claims: Process for making a rotating brush (21), particularly a brush adapted to be used in automatic car washing facilities, the process including the following stages: a) preparation of mold (24) capable of making desired rotating brush (21); b) arrangement of flexible cleaning elements (3n) with one end inserted into the mold and the other end projecting outwardly through suitable openings (9) made in the mold (24); c) injection into the mold (24) of components in the fluid state intermixed to form synthetic resin (8) which is able to polymerize; characterized in that said mold (24) has two coaxial cylinders (24i, 24e), the outermost of which (24e) has a plurality of apertures (9) which allow radial insertion of one end of one or more flexible cleaning elements (3n) in the space between these two coaxial cylinders, (24i, 24e) said ends of the flexible cleaning elements (3n) being shaped, hollowed out or folded so as to be embedded and secured in the polymerized synthetic resin (8) which fills the space between the coaxial cylinders (24i, 24e). Process according to claim 1, wherein said coaxial cylinders (24i, 24e) are made of a thermoplastic synthetic resin which is able to adhere to the aforementioned synthetic resin (8) after its polimerization, the coaxial cylinders (24i, 24e) providing a cover layer for inner and outer surface of said rotating brush (21). Process according to claim 2, wherein said coaxial cylinders (24i, 24e) are made of polyethilene. Process according to any of the preceding claims, wherein said flexible cleaning elements (3n) are filiform and made with filaments composed of a synthetic material from the group containing polythene, nylon and polypropylene. Process according to claim 1, 2, or 3, wherein said flexible cleaning elements (3n) are flat, fringed or unfringed, made of felt. Process according to claim 1, 2 or 3, wherein said flexible cleaning elements (3n) are flat, fringed or unfringed, made of closed-cell plastic foam. Process according to claim 1, 2, or 3, wherein said flexible cleaning elements (3n) are flat, fringed or unfringed and composed of polyethylene or polyethylene with vinyl acetate added (EVA). Process according to any of the preceding claims, wherein the components of the synthetic resin (8) in the fluid state are isocyanate, polyol and water and the polymerized synthetic resin is polyurethane.

Inventors: ZIGERLIG MAX, ZIGERLIG, MAX
Applicants: NOWITECK ESTABLISHMENT
Application year: 1996
Main classification: A46B3
IPC codes: B60S3, A46D3, A46D1, A46B3, B29C45