Patent ID: 7389658

Claim:
Apparatus for cleaning a material, said material being a fabric or other sheet-like porous material, said apparatus comprising a manually driven pump for pumping a cleaning substance through a local area of said material, the pump comprising a first reservoir with an opening for communication with a local area of a first side of said material, said reservoir having a first volume in a deactivated state of said pump, said first reservoir being constructed with a variable volume for pumping of said cleaning substance through said local area of said material upon manual activation of said pump, wherein said pump comprises an elastic member with a force acting on the first reservoir to attain said first volume in said first reservoir, wherein said first reservoir has a boundary in a first reservoir-chamber, said boundary comprising a cylindrical or substantially cylindrical inner wall of said first reservoir-chamber and a piston closely fitting to said inner wall, where a displacement of said piston varies the volume of said first reservoir, wherein said piston is equipped with a resilient sealing for fitting closely to said inner wall, said sealing comprising a an inert, low friction sealing ring having a smooth outer side abutting said inner wall and an alternating thickness variation in its longitudinal direction for easing the elastic change of length of said inert, low friction sealing ring.