| 摘要 |
<p>Canvas cover comprises an antivandalism lattice sandwiched between a nonelastic outer membrane and an elastic inner membrane, the membranes being glued or heat-sealed together. The lattice comprises elongated metal elements arranged longitudinally and transversely with welds at their crossing points to form square or rectangular meshes, especially with sides of 2-20 cm. An independent claim is also included for producing a canvas cover as above by placing the outer membrane under tension, placing the lattice on the inside surface of the outer membrane, optionally together with a complementary lattice for connection to an alarm system, placing the inner membrane over the lattice, and gluing or heat sealing the membranes together.</p> |
