Patent GB-770352-A (GB)
Title: Improvements relating to the manufacture of rubber strip
Filed: 1954-12-22
Abstract: 770,352. Moulding rubber sealing-strip. GENERAL MOTORS CORPORATION. Dec. 22, 1954 [Jan. 18, 1954; Jan. 18, 1954; Jan. 18, 1954; Jan. 18, 1954], No. 37014/54. Class 87(2). [Also in Group X] Apparatus for continuously moulding rubber sealing-strip containing a wire having spaced projections, comprises a mould element and an endless band forming a mould-closing element, one of these elements being an endless rubber band having a longitudinal slit for receiving the continuously-fed wire as the latter is fed into the mould. Figs. 1 and 2 show apparatus for making weatherstrip 65 from foamed rubber or the like, comprising a series of lower mould sections 30, a continuous band 22 which forms an upper mould section, a device 62, 60 for feeding foamed latex into the mould cavity formed between the parts 30, 22, and a heating chamber 64 for setting or gelling the latex. The weatherstrip is reinforced by an embedded wire 52, Figs. 10 and 11, (Fig. 10, being an elevation and Fig. 11 a plan) which is fed into the mould cavity as shown in Fig. 1, being correctly positioned by tongues 56 thereon entering a slit 51 in band 22. This slit is closed to grip the tongues 56 during moulding, but is opened, by flexing of band 22, on completion of moulding to release the tongues. The lower mould sections are made of metal and are secured to a flexible band 40, made of natural or synthetic rubber, which passes around driven wheels 32, 34. The band 22 also is preferably formed of rubber and passes around driven rollers 42, 44. In modifications (1), Figs. 3-7 (not shown), the articulated lower mould sections 30 are replaced by long straight sections which run on rollers, one after another, below the band 22, and a doctor blade levels the latex in the mould. (2), Figs. 8 and 9, the mould cavity is formed by two endless belts 20, 22 having the tongue-and-slot interengaging formation shown in Fig. 9. The edges of belt 22 are temporarily spread apart at the input end by convex roller 54, to allow the entry of reinforcement 50 and belt 20. The belts are then pressed tightly together by rollers 72, 74 and are again spread apart at the delivery end by roller 541 to disengage the belts and allow emergence of the moulded strip 80. The belt 20 may be replaced by the articulated metallic mould sections 30 of Fig. 1. Fig. 12 shows another design for use in the Figs. 8 and 9 arrangement, the lower mould sections 20A (made of metal or rubber) having dovetail projections 32A (or other projections, Figs. 13 and 14 (not shown)). (3), Figs. 15, 16 and 19, the mould cavity is formed wholly in the lower band 10, the upper band 80 being in the nature of a clamp which fits around projections 84, 86 on the lower band. The edges of the lower band are spread apart at the input end by a rib 31 on a roller 30 and similarly spread apart at the delivery end ; the upper band is similarly spread as by roller 68. The wire reinforcement 20 is fed in along a stationary shoot 43. The latex feed nozzle 42 extends horizontally into the mould cavity. (4), Figs. 21 and 24, upper and lower bands 22, 20 define the mould cavity and side bands 30, 32 clamp the upper and lower bands together.