Abstract: A net formed integrally of blended incompatible polymers, with parallel smooth longitudinal ribs interconnected by a plurality of split strands non-uniformly interspersed with a plurality of differently sized voids, by stretching a film with a generally longitudinal set of parallel primary grooves and a transverse or angled set, on the other surface, of parallel secondary grooves.

Abstract: A melt-embossed polymer film with primary parallel grooves on one surface and secondary parallel grooves on the other surface such that the combined tapes of the grooves is at least substantially equal to the film thickness, the two sets of grooves being located at an angle to each other of not less than 30.degree., is stretched at right angles to the direction of the primary grooves by a small amount to give a perforate product which can be formed into strips tearable longitudinally or transversely and thus useful as a vapor-permeable substrate for adhesive-coated tape.

Abstract: An extruded sheet or the like of cold-drawable polymer such as polypropylene is embossed as a molten sheet by a circumferentially multi-grooved roller and stretched in the direction of the embossed grooves to split into filaments along the grooves.

Abstract: A non-woven fabric is produced by stretching the film with on one surface a regular pattern of raised areas such as spaced hexagonal bosses and on the other surface a plurality of parallel grooves. Stretching is carried out in the groove direction. Preferably the polymer is a mixture of incompatible polymers so that on stretching a fibrous structure is formed. The film can be produced by melt-embossing. The stretched non-woven fabric may be coated with various adhesives to provide a tape useful in a medical context.

Abstract: A melt-embossed polymer film is provided on one surface with a set of parallel grooves and on the other surface with a second set of parallel grooves at an angle to the first, the combined tapes of the grooves being at least substantially equal to the thickness of the film. The ratio between the intersection area common to two ribs on different surfaces and the cross-sectional area of each rib is low, e.g. not greater than 2:1 to ensure transmission of orientation on subsequent stretching. The ribs between the grooves may be square, trapezoidal (provided that the included angle of the tapering sides is not greater than 45.degree.) or wider at its outer part than at its inner part. Ribs of these shapes, especially the last named, can be produced by using deformable, e.g. rubber, profiling means.

Abstract: A coupling assembly adapted for releasably connecting a sidecar to a motorcycle includes a first coupling member attached to the motorcycle and having a ball-shaped portion with a first lateral dimension adjacent to second portions with a second lateral dimension greater than the first lateral dimension. A second coupling member is attached to the sidecar and has a bell-shaped configuration. Retaining means for engaging the ball-shaped portion of the first coupling member includes a plurality of fingers resiliently expandable to the second lateral dimension to receive the ball-shaped portion and contractable to the first lateral dimension to substantially enclose the ball-shaped portion. Screw means extending through the second coupling member draws the retaining means into the second coupling member. In this position the second coupling member prevents the expansion of the fingers from the first lateral dimension to the second lateral dimension thereby coupling the sidecar to the motorcycle.

Abstract: Interconnected fibres banded by cross-sectional orientation and morphology differences, in an array which can be bundled up to separate the fibres at least partially. A thermoplastic sheet emboding areas of different degrees of fibrillation is cold drawn to initiate longitudinally extending cracks in the areas of lower resistance to fibrillation such that the cracks terminate at the areas of higher resistance to fibrillation. The sheet is then further drawn at a higher temperature to open the cracks and to cause the cracks to propagate through the areas of higher resistance to fibrillation. Both drawing steps are performed without lateral extension.