Abstract: A constant-force spring of the liquid-gas type comprising a piston slidable n a cylinder and an elastomeric bladder enclosed in the cylinder. The bladder is filled with a gas, preferably nitrogen. The rest of the cylinder is filled with a compressible liquid having a low bulk modulus. A liquid that can be used is dimethyl silicone which has a bulk modulus of only 150,000 psi. The low bulk modulus gives a low spring constant which is necessary if a constant force characteristic is to be achieved.

Abstract: A self-positioning shock and vibration isolating suspension system is disclosed which incorporates one or more pneumatic mounts for supporting a load on a base. Each pneumatic mount comprises a hollow elastomer body with a diaphragm at each end, means for connecting one diaphragm to a base and the other to the load, means for pressurizing the elastomer body with a fluid so that the diaphragms and the fluid acting thereon form a pneumatic spring having a spring stiffness less than that of the hollow body, and means for varying the fluid pressure within the elastomer body in accordance with changes in the magnitude of the load.

Abstract: The dash-pot connected to the balance beam of a portable balance is sealed about the piston rod of the dash-pot by a rubber ring mounted in the cover of the dash-pot and resiliently deformed when an abutment leg projecting from the balance housing is lifted from a supporting surface. The dash-pot arrangement is held thereafter automatically in the locked position, thereby also immobilizing the balance beam, by a spring-loaded detent until the detent is manually released.