The invention relates to a method of forming a barrel neck connector, particularly for use for or between spaced filter cloths in producing a filter fabric for a filter press.

BACKGROUND ART

Filter cloths for use in filter presses which comprise side-by-side plates defining filter chambers therebetween are known which comprise separate filter cloths joined together by a barrel neck so positioned as to be registrable with a feed aperture in the plate, the neck being positioned to extend through the feed aperture with the individual filter cloths lying against the respective faces of the press plate.

For operational reasons it is necessary that the barrel neck be impermeable to the filtrate.

It is known in the art to provide a barrel neck as a flanged jointing tube and to secure the flanges each to a respective cloth as by sewing or by utilising polypropylene attachment rings having ferromagnetic particles therein which, on being subjected to induction radiation, serve to melt the polypropylene material of the ring and cause the same to adhere to the flange and to the filter cloth. The jointing tube may be fabricated from a woven, or braided, textile material which is of inherently low permeability or is

rendered relatively impermeable as by coating or may comprise a moulded elastomeric structure.

The fabrication of barrel necks from woven textile material is an intricate and time-consuming operation, and requires a high degree of operator skill whilst, in the case of the moulded barrel neck, the heat generated by the induction radiation rigidises the materials of the tube and the filter cloth, and makes more difficult the fitting of the filter fabrics to the press plate.

The object of the present invention is to provide an improved method for producing barrel necked filter fabrics which avoids, at least in part, the disadvantages experienced in relation to known structures.

DISCLOSURE OF INVENTION According to the present invention there is provided a method of forming a barrel neck connector for filter cloths which includes the steps of: arranging a first flange having a hole extending therethrough at one end of a tube, arranging a second flange having a hole extending therethrough at the other end of the tube, the flanges being arranged such that said holes are aligned with a channel defined by the tube and connecting each flange to the tube by securing a flexible material to at least one of the flanges and the tube.

This method of manufacture offers a cost effective

manner for making small numbers of a particular barrel neck in which case the cost of providing tooling is prohibitive.

In a preferred embodiment of the invention at least one, and preferably all, of the tube, first flange and second flange comprise an elastomeric material such as rubber. This material is preferably reinforced with fabric.

The flexible material used to secure the flanges to the tube is preferably in the form of a tape or sleeve. This flexible material may be secured to the inside of the tube to produce a cylinder of outer diameter slightly less than the inner diameter of the tube. The cylinder of flexible material preferably extends beyond both ends of the tube and the ends of the cylinder may be turned over to be in contact with the flanges. Adhesive may be used to bond the flexible material to the flanges and tube.

BRIEF DESCRIPTION OF DRAWINGS

In order that the present invention may be more readily understood a specific embodiment thereof will now be described by way of example only with reference to the accompanying drawings in which:-

Fig. 1 is a part exploded view of one barrel neck connector in accordance with the invention; and

Fig. 2 is a vertical cross section through the barrel neck connector of Fig. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawings a barrel neck connector

10, particularly for use between spaced filter cloths in a filter press, comprises a hollow tube 11, a first flange 12, a second flange 13 and a flexible sleeve 14. The tube 11 is typically made from a 3-layer elastomer sheet, non-reinforced, though use of a reinforced sheet is possible. The flanges are preferably made from a 3-layers, fabric reinforced rubber sheet, containing two rubber types. The sleeve consists of a 2-layer rubber sheet, comprising two rubber types, with the thickness of the sheet tapering at the sleeve ends to facilitate the necessary deformation prior to bonding.

In order to manufacture the connector the sleeve 14 is bonded with adhesive to the inside of the tube

11. The cylindrical sleeve 14 extends from both ends of the tube 11. The flanges 12,13 have central apertures, which are aligned with the channel through the tube 11. Once the flanges 12,13 are arranged in this manner at the ends of the tube 11 the sleeve 14 is passed through the apertures in the flanges 12,13 and turned over to be in contact with the flanges 12,13. The sleeve 14 is bonded to the flanges 12,13 with adhesive, or by fusion bonding, or by sewing.

The particular material used to make the sleeve 11 and flanges 12,13 and the adhesive chosen to bond these elements together will depend on the nature of solvents or . other liquids on the slurry to be

filtered. Thus, Neoprene, Chloroprene rubbers or the thermoplastic variety, for example Santoprene can be deployed. The flanges 12,13 should, however, be pliable and elastic to allow a cloth plus a flange to pass through the middle feed hole of the usually polypropylene plate of the filter press.

A filter cloth is finally adhered to a flange 12,13 by means of an adhesive. Once again the adhesive is chosen to suit the filtration environment. Alternatively the filter cloth can be fixed to the flange by sewing or fusion if the rubber is of a themoplastic variety and this can be melted locally by means of a hot air blast or ultrasonic energy. A rubber intermixed with a polyolefin, for example Santoprene, serves this purpose.

It is to be understood that the above described embodiment has been described by way of illustration only. Many modifications and variations are possible.