| abstract |
An apparatus adapted to be inflated and deflated in response to selective communication with a source of pressurized fluid includes a bladder having a semi-rigid shell body portion and a relatively thin membrane portion defining an inflatable chamber. The elongate semi-rigid shell body preferably includes a contoured, concave inner surface terminating at a peripheral side edge. At least one passage extends through the shell body defining an opening in the inner surface of the shell body. The flexible membrane is continuously bonded to the shell body adjacent the peripheral side edge to define the enclosed inflatable chamber in communication with the passage. The membrane has a reduced waist portion defining a membrane tension zone adjacent the opening of the passage into the chamber to reduce the probability of occluding the entrance while deflating the chamber. |