FR2506418A1 - Composite moulded weights for counterbalancing machinery etc. - made from pieces of scrap mild steel etc. encapsulated in polyester resin - Google Patents

Abstract

Corrosion resistant weight, e.g. for use as balance/ballast in rotary machinery such as washing machines, are made from pieces of scrap metal encapsulated in a resin with suitable moisture and chemical resistance to protect the metal. Pref. the metal pieces are of mild steel or other corrodible material, as waste turnings or pieces less than 2 cm across, suitably cleaned and degreased, and the binder resin is a polyester which will harden rapidly but having a low peak exotherm. The wts. may be cast to shape with inserts to accept anchorage bolts, support pads etc. More dense, hence compact and less friable than wts. made of concrete, can be shaped to follow small radii.

Description

SOLID BALLAST INSENSITIVE TO CORROSION,
ITS MANUFACTURING PROCESS,
AND WASHING MACHINE PROVIDED WITH SUCH A BALLAST.

 The present invention relates to a massive ballast insensitive to corrosion, its manufacturing process, and a washing machine provided with such a ballast.

 The weights usually come in various forms depending on their uses, which range from powder form to massive forms. These weights are made up of also various materials which go from sand to metals through materials such as concrete. The weights which are part of the invention are massive weights having a fixed configuration, specific to each of their applications, and which can be securely fixed by means of known fixing systems such as bolts, rivets, glues, etc.

 A device such as a washing machine is usually able to ballast. These weights are often heavy pieces having a configuration allowing them to closely fit the surface of the tank at the contact points and thus obtain a solid fixing.

 In a large number of known devices, weights used are constituted by cast iron parts.

 The cast iron weights can have any configuration suitable for allowing them to be firmly fixed in these devices, but they are sensitive to humidity and corrosive agents. Furthermore, a casting of cast iron or a casting of a metal in general requires an installation for melting the metal and an installation for casting this molten metal. These installations are often expensive and the melting of the metal usually results in significant energy consumption.

 To obtain a better cost price, certain known devices are mounted with concrete weights. However, concrete weights have many disadvantages. The density of concrete (around 2.2) is about three times lower than that of cast iron (around 7.5). As a result, for an equivalent weight of ballast, a concrete ballast is much larger than a metallic ballast. Their large volume makes them unusable in certain applications.

 In the manufacture of concrete weights, it takes on average seven or eight hours for the molded weights to have sufficient strength to allow their handling or assembly for use.

 According to their constitution, concrete weights do not usually have a very smooth exterior surface. This surface has numerous roughness or small bosses which are mechanically more or less resistant to the tightening of the fixing. As a result, after a certain operating time of the device in which these weights are mounted, vibrations and shocks gradually destroy these small bosses and, the fixing of these concrete weights becomes more and more loose. Improper attachment of the weights can lead to mechanical imbalances and create serious disturbances in the operation of the device.

 The aim of the present invention, with the aim of avoiding these drawbacks, is to easily produce an economic massive ballast, insensitive to corrosion, having a density greater than or equal to 5, a configuration specific to its application, a selected degree of hardness and a surface united exterior favoring a solid and durable fixing.

 The subject of the invention is also a method of manufacturing this ballast and an apparatus or machine, such as a washing machine, provided with this ballast.

 According to the invention, a massive ballast, insensitive to corrosion having a configuration allowing it to marry the surface to which it is applied and to be securely fixed thereto, is con located by a solid part formed of metallic debris completely embedded in a curable binder.

To better understand the invention, an embodiment is described below, illustrated by the attached drawings, in which:
FIG. 1 represents a schematic view of the weights produced according to the invention, mounted on the lateral sides of a tub suspended from a washing machine, with horizontal drum, and
FIG. 2 represents a schematic view of an installation for mass production of ballasts of FIG. 1 according to the method of the invention.

 The weights, object of the invention, can have any configuration chosen. In their application to a washing machine 1, illustrated in Figure 1, the weights 2 each have a general shape of a rectangular parallelepiped, provided on one of its longitudinal edges with spaced recesses 3 and 4 and through its body has several fixing holes 5. The weights 2 are fixed to the sides of the suspended tank 6 of the machine 1. The recesses 3 and 4 are intended either to constitute free spaces separating the suspended tank 6 and its weights 2, organs with fixed stations, measurement, control or command systems, not shown, of the washing machine 1 or to house certain organs of these systems, fixed on the suspended tank 6.

 The washing machine 1 shown further comprises in the tub 6, a rotary laundry drum not shown, an access door 7 opening towards the top, and a control panel 8.

 According to the invention, the weights 2 are constituted by solid parts formed from metallic debris completely embedded in a curable binder, the shaping of which takes place at ambient temperature. This binder is a binder of the type insensitive to humidity and / or to corrosive agents in the environments in which these weights stay.

These corrosive agents can be chemicals, detergents, bleach, the ambient atmosphere, etc.

This binder gives manufactured weights good characteristics
mechanical allowing a durable conservation of configuration and a solid fixing.

 This binder preferably gives the manufactured weights a uniform external surface and a selected degree of hardness. The attenuation of the noise or the damping of shocks possibly occurring between these weights 2 and neighboring members of the machine 1, is all the greater the lower the degree of hardness chosen for these weights.

 In the embodiment illustrated in FIG. 1, the weights 2 consist of parts formed from metallic debris susceptible to corrosion such as falling steel sheets, embedded in a hardenable binder based on polymerizable polyester resin giving preferably a rapid setting and a low exothermic peak.

 The metal debris or sheet metal scraps used are chosen from those which have an average size making it possible to easily obtain both a predetermined configuration for the manufactured weights and good compaction of these scraps giving these weights a density equal to or greater than 5 These metallic debris or falling sheet metal preferably have a dimension of less than two centimeters.

 In the example illustrated, the debris with which the weights 2 are formed are formed with rounds of tale resulting from the cutting of the notches of the stator and rotor sheets of the electrical machines.

 The small size of these rounds of tale makes it possible to easily carry out complicated configurations of weights with rounding with small radii and to obtain, by great ease of compaction, a density greater than 5.

 In a first alternative embodiment, the binder used is provided with fillers chosen from chemically compatible materials and which contribute to reinforcing one or more selected physical or mechanical characteristics of the manufactured weights.

 In a second alternative embodiment, the binder used is provided with a dye which strengthens the aesthetics of the manufactured weights.

 According to the invention, a method of producing by weighting the weights described in the preceding paragraphs comprises at least the following operations: -making an opening mold whose internal shape represents the configuration of the weights to be manufactured, -covering the interior of this mold of a non-stick coating vis-à-vis the binder used in the construction of the ballast to be manufactured, subject the mold to continuous vibration and simultaneously fill it with a predetermined quantity of selected metal debris, previously degreased, washed and dried, -maintain the continuous vibration of the mold provided with metallic debris and simultaneously introduce into this mold, a selected hardenable binder, -remove the vibration of the mold and allow it to harden in the latter for a predetermined time, the ballast in manufacture, and -extract from this mold, a hardened solid ballast.

 A continuous vibration imposed on the mold during its filling with metallic debris and with binder makes it possible to achieve good compaction of these metallic debris in the mass of the binder, and to obtain according to the above process a ballast insensitive to humidity and to corrosive agents, having a predetermined density, a configuration and a hardness previously chosen.

 In the example illustrated, the curable mixture used consists of a mixture of a polyester resin and a selected catalyst or polymerization agent.

 In an exemplary implementation of the above method, for a series production of corrosion-resistant ballast described, a set of several opening molds 9 are mounted on mold carriers 10 rolling on rails 11 schematically illustrated in the Figure 2. These molds 9 and mold carriers 10 form an endless chain or a carousel 12 and move along different stations preparing the molds and proceeding to molding in series. The molds 9 # are successively cleaned at the cleaning station 13 , coated with non-stick product at the coating station 14, closed at the closing station 15, then subjected to continuous vibration on a vibrating table 16, during their filling by a supply station 17 with degreased sheet metal scraps, washed , dried and weighed in the specialized stations 18, 19, 20, 21 and during their filling, by a supply station 22, in a polymerizable mixture freshly prepared in a mixing station 23 by incorporation of a polymerization agent in a polyester resin, then guided through a zone, called polymerization zone 24, for a period required for this polymerization, finally opened and subjected to demolding, by an opening and extraction station 25, of weights molded, hardened which are evacuated by a conveyor belt 26. The empty molds 9 directed towards the start repeat another molding cycle by subjecting themselves again to cleaning at station 13 and so on.

 The stations 13 to 25 fulfilling the various functions which are stations of known technical design are not described in detail. These stations can have another arrangement than that schematically illustrated in FIG. 2. These stations can for example be brought close to each other or arranged above the carousel 12.

 The manufacturing time of the weights 2 according to the manufacturing method described above is greatly reduced compared to that of the cast iron or concrete weights. In addition, metallic debris, sensitive to corrosion such as sheet metal rounds recovered from the cutting of stator and rotor sheet notches of electric machines, not only have a reduced or insignificant price and a high density of the order of 6 to 7.8 but also a dimension favorable to the formation of ballasts with a density greater than 5 and having complicated configurations or rounding with small radii. The cost price of the weights produced according to the invention is therefore considerably reduced. These weights help to give the machine 1 in which they are mounted, a particularly low cost price.

The weights 2 according to the invention can thus be manufactured with a selected degree of hardness adjusted to each of their applications while being compatible with their solidity of structure, shape and
fixation.

 Thanks to a well chosen degree of hardness, an appreciable reduction in noise and a substantial damping of mechanical shocks which could possibly occur between these weights and the organs of the machine 1 located in their vicinity are obtained.

 An advantageous combination between a binder based on polymerizable polyester resin and metallic debris vulnerable to corrosion makes it possible not only to obtain weights insensitive to corrosion but also economical weights with a complicated configuration and with predetermined hardness.

Claims (12)

 1. Massive ballast insensitive to corrosion having a configuration allowing it to marry the surface to which it is applied and to be firmly fixed thereto, characterized in that it is constituted by a solid part, formed from completely embedded metallic debris in a curable binder.  2. Ballast according to claim 1, characterized in that it comprises in its constitution, metal debris formed of metal debris vulnerable to corrosion and a binder of the type resistant to humidity and to chemical and atmospheric corrosive agents and giving ballast fabricates a smooth exterior surface.  3. Ballast according to one of claims 1 and 2, characterized in that it comprises in its constitution, metallic debris used formed of sheet metal falls and a curable binder, at selected degree of hardness, based on polymerizable polyester resin .  4. Ballast according to claim 3, characterized in that it comprises in its constitution, a binder giving a rapid setting and a low exothermic peak.  5. Ballast according to one of claims 1 to 4 characterized in that it comprises in its constitution, metallic debris having a dimension less than two centimeters.  6. Ballast according to one of claims 1 to 5, characterized in that it comprises in its constitution, metallic debris formed of steel sheet circles.  7. Ballast according to one of claims 1 to 6, characterized in that it comprises in its composition, a binder provided with charges chosen from chemically compatible materials helping to reinforce one or more of the physical or mechanical characteristics previously chosen.  8. Ballast according to one of claims I to 7, characterized in that it comprises in its constitution, a binder provided with a dye reinforcing its aesthetic characteristic.  9. A method of manufacturing ballast by molding of any one of claims 1 to 8, characterized in that it comprises at least the following operations: - making an opening mold whose internal shape represents the configuration of the ballast to be manufactured, -cover the inside of this mold with a non-stick coating vis-à-vis the binder used in the constitution of the ballast to be manufactured, -submit the mold to a continuous vibration and simultaneously fill it with a predetermined quantity of selected metallic debris , previously degreased, washed and dried, -maintain the continuous vibration of the mold provided with its quantity of metallic debris and simultaneously introduce into this mold, a selected hardenable binder, -remove the vibration of the mold and allow the ballast to harden in manufacture , and - extract from this mold, a hardened solid ballast.  10. Method according to claim 9, characterized in that it comprises a preparation of the curable binder by forming a mixture of a polyester resin and a polymerization agent, immediately preceding the operation of introducing this binder into the mold previously provided with metallic debris and subjected to a continuous vibration.  11. Method according to any one of claims 9 and id, characterized in that it consists, in a series production in: -mounting a set of several opening molds (9) on rolling mold holders (10) on rails (11) to form an endless chain (12) - run these molds successively first in front of the cleaning stations (13), coating of non-stick product (14), closing these molds ( 15), then on a vibrating table (16) during their filling with scrap metal and curable binder respectively by supply stations in scrap metal (17) and supplying binder (22), scrap metal being previously weighed, degreased, washed, dried in specialized stations (18, 19, 20, 21) and the curable binder being a polymerizable mixture freshly prepared in a mixing station (23) by incorporating a polymerization agent into a polyester resin, then in a polymerization zone (24) and finally before t an opening and extraction station (25) which unmoulds the formed, hardened weights, and - direct the unmolded weights on an evacuation conveyor belt (26), the empty molds being returned to the start to make a new cycle .  12. Washing machine characterized in that it comprises on the sides of its suspended tank (6) ballasts (2) of any one of claims 1 to 8.