Bellows

About: Bellows is a research topic. Over the lifetime, 15312 publications have been published within this topic receiving 73914 citations.

Fluid type accumulator spring with emergency back-up spring

Abstract: Accumulator or fluid spring or gas spring for use in supporting vehicles, e.g. railway cars, in combination with a back-up emergency spring: the accumulator includes a compressed gas filled bellows holding two plates apart; the back-up spring is a solid spring body that is prestressed; upon failure of pressure in the bellows, one of the plates presses against the already prestressed back-up spring and further stresses it, and the backup spring takes over the support function.

Artificial erection device

Abstract: A semi-rigid annular ring having individual expandable chambers on the internal wall that are distended separately by fluid pressure. A multi-port flexible conduit connected to the ring having individual ports for each chamber. Fluid pressure is supplied through the conduit manually by a bulb or electrically by a pump through a circular valve plate allowing the chambers to expand and contract in linear sequence. When a penis is placed into the ring and fluid pressure is applied, blood is forced to the end of the organ through the successive expansion and contraction of the bellows in wave fashion mechanically creating an erect condition of the organ.

Apparatus for positioning a workpiece in a localized vacuum processing system

Abstract: Apparatus for positioning a semiconductor wafer with respect to a localized vacuum envelope so as to maintain a prescribed gap between the tip of the vacuum envelope and the wafer includes an x-y table, a stage assembly movable along the z-axis for holding the wafer and a z-axis actuator assembly. The z-axis actuator assembly includes a plurality of fluid-containing bellows coupled between the x-y table and the stage assembly and a hydraulic controller operated by a linear stepper motor for varying the fluid volume in each of the bellows in response to an actuator control signal so as to move the stage assembly along the z-axis. The z-axis actuator assembly can further include a flexible disk positioned in the plane of x-y movement and coupled between the x-y table and the stage assembly for preventing lateral and rotational movement of the stage assembly relative to the x-y table. The positioning apparatus is suitable for use in an electron beam lithography system.

Accelerated heart valve testing apparatus and methods

Abstract: Apparatus and methods for durability (fatigue) testing of prosthetic heart valves or other check valves. The apparatus is circular in plan and includes a test fixture in which the valves are circularly arranged, located with communicating passages, such passages communicating with bellows closed at one end. The bellows are carried by a swash plate journalled to a motor by a coupling providing an adjustable tilt axis. The tilt axis determines the amplitude of the motion or flow of the fluid, as the bellows alternately expand and contract. A central bypass chamber includes orifices which are selectively varied in effective cross section to control an amount of the test fluid which bypasses the test samples, thereby determining fluid pressure differential across the sample valves. Fluid in the apparatus can be heated by an electric heater to temperatures similar to human blood, a temperature probe monitoring the temperature for its control. A pressure tap monitors the fluid pressure for shutting down the apparatus if abnormal pressures or leaks are developed. Several prosthetic heart valves, e.g., two, four, six, eight, etc., are held by the fixture at the same time for life testing at relatively high cyclic rates.