| 摘要 |
<p>921,958. Ventilators. CONNOR ENGINEERING CORPORATION. June 17, 1959 [July 9, 1958], No. 20860/59. Class 137. [Also in Group XXIX] A pneumatic damper or ventilator comprises a housing 1, hollow distensible vanes formed by metal plates 11, 12, a flexible casing 10 in each vane which is inflated in order to distend the vane, simultaneous inflation of the several casings 10 causing the vanes to reduce or close the spaces between them, and means for supplying air to the casings. The vanes, which may be of aluminium, are fitted at their ends in notches 9 of struts 8 extending between upper and lower walls of the housing. The casings 10, which may be of rubber, neoprene, synthetic plastics or treated or coated fabric, have a neck at one end coupled to a nipple projecting from an air supply pipe 20.</p> |
