Patent GB-1054823-A (GB)
IPC: B29C48/13
Abstract: 1,054,823. Flexible hoses. HOOVER Ltd. March 19, 1964 [March 26, 1963], No. 11715/64. Heading F2P. A method of making a multi-ply, flexible hose from a single-ply corrugated hose cornprising a thin elastomeric thermoplastic tube 11 surrounding and bonded to a helical reinforcing coil 12 whereof at least the surface comprises an elastomeric thermoplastic material, includes stretching the hose to flatten out the corrugations, knitting a sleeve 19 of shrinkable fabric over the stretched hose, heating the hose and sleeve to cause the sleeve to shrink into tight contact with the single-ply hose, extruding a second tube 20 of a thin elastomeric thermoplastic material over the sleeve, and applying suction between the tubes as the second tube is extruded to cause the walls of the tubes to be drawn together through the interstices of the knitted sleeve and to be bonded together with the sleeve trapped between them. The coil may be a metal wire sheathed with a thermoplastic material. As shown. the apparatus for making a single-ply hose includes a power driven reel from which wire 14 passes through an extruder to apply a sheath 15 thereon, and a spring coil winder from which coils of indefinite length issue axially without rotation, or short lengths of coil may be wound and secured in end to end relation. The coil passes to a conveyer belt 24, Figs. 1A and 1B (not shown), against which the coil is held by a roller 25, into a capstan 26 comprising two sets 27, 28 of conveyer belts, and is then advanced successively through pinch rolls 29, a heating chamber 30, a vacuum chamber 31, an extruder 32, water rings 33, 34, a water spray 42 and a conveyer belt 35. The belts 27 are driven at a greater speed than the belts 28 so that the turns 13 of the coil 12 are brought into contact with each other, the pinch rolls 29 being driven at the same speed as the belts 28 and at a speed to push the coil through the extruder which offers resistance to movement of the coil and to keep the latter partially compressed axially. Hot air is blown into the chamber 30 to warm the sheath 15 to a bonding condition and the chamber 31 communicates with the extruder to draw the walls of the tube 11 inwardly. The hose passes through the cooling rings 33, 34 which spray water on to the hose to render the tube 11 non-tacky, and then to the conveyer 35 whereon cold water is sprinkled on to the hose to set the hose to the final form thereof. The finished hose is coiled on to a power-driven reel 45, a switch arrangement co-ordinating the coiling speed with that of the hose as the latter leaves the apparatus. Further apparatus for applying the knitted sleeve 19 and outer tube 20, the reel 45 being omitted, includes a reel 49, Figs. 3A and 3B, not shown, guide rolls 50, pinch rolls 51, a knitter 52, drive rolls 53 . . . 56, a guide roll 57, a heating chamber 58 a vacuum chamber 59, an extruder 60, water ring 61, capstan 62, a compression tube 63, pinch rolls 67, a conveyer 64, an air ring 65 and a reel 66. A retarding force is applied to the hose 10 by the rolls 51 so that the hose is stretched for the application of the sleeve 19, the heating chamber 58 softening the surface of the tube 11 and shrinking the sleeve so that the latter cuts into the surface of the tube. The vacuum chamber 59 communicates with the interior of the extruder 60 to produce a suction between the tubos 11 and 20 and to thereby draw the two tubes into bonding contact through the interstices of the sleeve. The completed hose is drawn by endless belt conveyers 75, 76 through the cold water sprinkler ring 61 and passes, with the tension in the coil 12 released, to a combined compression and setting tube 63, inclined upwardly and flooded with water and to the ring 65 which plies jets of air about the hose to remove and evaporate any water remaining on the hose before transfer to the reel 66. The latter may be replaced by a cutting device.