Combination end cover seal arrangement

Claim 2

In a power cylinder having an annular cylinder side wall and an end wall and a power transfer rod reciprocably extending through said end wall, a seal assembly comprising: a diaphragm seal having a center opening defined by an annular axially extending inner lip having a frusto-conical inner surface in free form, a radially extending disc body operatively engaging said end wall, and an outer peripheral seal lip extending axially from the disc body in the same axial direction as said lip and terminating in an annular rolled edge contacting said cylinder side wall in sealing relation; and an annular seal expander having inner and outer peripheral flanges and a disc body joining said flanges, said inner flange being frusto-conical and positioned in radially outward spaced juxtaposed relation to said seal inner lip, said outer flange extending axially to provide radially outward acting support force holding said seal rolled edge in sealing engagement with said cylinder side wall, said outer flange terminating in a radially outward extending section in axially spaced relation with said seal rolled edge; said cylinder side wall having a shoulder thereon adjacent to and of a smaller diameter than said expander outer flange radially outward extending section and normally axially spaced therefrom on the side thereof opposite said seal rolled edge and providing a limit stop against movement of said seal expander in one direction.

Claim 3

A hydraulic power cylinder end wall seal arrangement for a power cylinder having a cylinder side wall, a piston reciprocably mounted therein, a piston force output rod, a cover forming an end wall secured to one end of said cylinder side wall and having said output rod reciprocably Extending therethrough, and a piston return spring acting on said piston and operatively against said end wall, said seal arrangement comprising: a recess in the inner face of said end wall surrounding said rod and having received therein a first annular seal having an inner frusto-conical lip sealing and wiping said output rod, and outer frusto-conical lip sealing against the recess side wall, and circumferentially spaced lip segments extending axially out of said recess radially intermediate said inner and outer lips; a groove in the inner face of said end wall communicating with said recess and providing a fluid drain path for hydraulic fluid wiped from said output rod by said first annular seal; a seal support plate covering the inner face of said end wall and said recess and said groove and engaging said intermediate cylindrical lip segments to retain said first annular seal in said recess; a diaphragm-like second annular seal having an inner frusto-conical lip sealing said output rod, an outer cylindrical lip terminating in an outwardly rolled edge sealing said cylinder side wall and a disc section joining said lips; and an annular seal expander having an inner frusto-conical flange fitting over said second annular seal inner frusto-conical lip in juxtaposed but spaced relation, an outer flange extending axially to provide radial support for said seal outwardly rolled edge and then extending radially outward toward said cylinder side wall, and a body section joining said flanges and in surface engagement with said second annular seal disc section and providing a spring seat for said piston return spring, the force exerted by said piston return spring being transmitted to said cylinder end wall through said seal expander and said second annular seal and said seal support plate.

Claim 4

A hydraulic power cylinder end wall seal arrangement for a power cylinder having a cylinder side wall, a piston reciprocably mounted therein, a piston force output rod, a cover forming an end wall secured to one end of said cylinder side wall and having said output rod reciprocably Extending therethrough, and a piston return spring acting on said piston and operatively against said end wall, said seal arrangement comprising: a recess in the inner face of said end wall surrounding said rod and having received therein a first annular seal having an inner frusto-conical lip sealing and wiping said output rod, and outer frusto-conical lip sealing against the recess side wall, and circumferentially spaced lip segments extending axially out of said recess radially intermediate said inner and outer lips; a groove in the inner face of said end wall communicating with said recess and providing a fluid drain path for hydraulic fluid wiped from said output rod by said first annular seal; a seal support plate covering the inner face of said end wall and said recess and said groove and engaging said intermediate cylindrical lip segments to retain said first annular seal in said recess; a diaphragm-like second annular seal having an inner frusto-conical lip sealing said output rod, an outer cylindrical lip terminating in an outwardly rolled edge sealing said cylinder side wall and a disc section joining said lips; and an annular seal expander having an inner frusto-conical flange fitting over said second annular seal inner frusto-conical lip in juxtaposed but spaced relation, an outer flange extending axially to provide radial support for said seal outwardly rolled edge and then extending radially outward toward said cylinder side wall, and a body section joining said flanges and in surface engagement with said second annular seal disc section and providing a spring seat for said piston return spring, the force exerted by said piston return spring being transmitted to said cylinder end wall through said seal expander and said second annular seal and said seal support plate.