| 摘要 |
832,302. Non-metallic tubes. SHELLY, R. S. Feb. 17, 1958 [Feb. 25, 1957], No. 5101/58. Class 99(2). A multiple-tube structure of paperboard material comprises a rigid, inner tube 10 and a rigid, outer tube 11 concentric with but having greater cross-sectional area than the tube 10, the tubes having mutually different configurations such that they intersect and are contiguous along areas extending longitudinally therewith. A rigid-set adhesive coating covers substantially the entire wall surface of at least one of those tube walls which have mutually contiguous areas, and rigily bonds the tubes together at and along the contiguous areas. As shown, a single sheet 17 of material is passed under a series of circular blades 19 which form in one face of the sheet spaced and parallel, longitudinal, V-shaped grooves 18 which constitute fold lines 12 about which the sheet is folded to form the tube 11, the lateral edges of the sheet meeting in abutting relationship along a junction line 13. A coating of glue is applied by a roller 20 to the undersurface of the sheet and an outer lamination 16 of kraft paper wide enough to provide an overlap 16a is secured to the sheet. Prior to folding, the grooved and laminated sheet has applied to the grooved face thereof a rigid-setting adhesive, the adhesive applying roller being provided with circumferential grooves corresponding in placement and spacing with the grooves 18 whereby a greater quantity of adhesive is applied over and along the grooves than along the panel sections of the sheet. When the sheet is folded about the tube 10, the adhesive within the grooves 18 is caused to exude at the corners of the tube 11 and result in columns 25 of adhesive to reinforce the corners 11b of the tube 11 ; also, the adhesive exudes laterally of the tangential areas 15 to provide structural reinforcements 26. |
