Abstract: A fluid pump (10) has a compression member (12) having a variably-sized compression surface (13b) movable against fluid pressure in a chamber (22). The effective surface area of the compression member (12) decreases in size together with a corresponding cross-sectional area of the chamber (22) from a maximal area at a beginning of the compression stroke to a minimal area at the end of the compression stroke. Using a variably-sized surface area to compress a fluid volume allows obtaining a rapid gain of fluid pressure even for applications in which the compression member (12) is actuated at relatively low frequencies and under the action of relatively small forces.

Abstract: A fluid pump (10) has a compression member (12) having a variably-sized compression surface (13b) movable against fluid pressure in a chamber (22). The effective surface area of the compression member (12) decreases in size together with a corresponding cross-sectional area of the chamber (22) from a maximal area at a beginning of the compression stroke to a minimal area at the end of the compression stroke. Using a variably-sized surface area to compress a fluid volume allows obtaining a rapid gain of fluid pressure even for applications in which the compression member (12) is actuated at relatively low frequencies and under the action of relatively small forces.

Abstract: A pack boot comprises an outer rubber shell and a multi-ply felt bootie removably fitted inside the outer rubber shell. The multi-ply felt bootie has inner and outer felt layers superposed one over the other. An ankle pad is inserted between the inner and outer felt layers of the multi-ply felt bootie and bonded thereto to provide additional ankle support while preserving the insulation properties of the multi-ply felt bootie.