Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
161 words
A piston comprising a piston body of a material selected from the group of aluminium and aluminium alloys, a plurality of piston ring grooves formed in the piston body and having substantially uniform depth around the piston, two side surfaces included in each piston ring groove, an annular reinforcing ring received within one of said piston ring grooves and having a substantially uniform radial width equal to the radial depth of the piston ring groove, a first surface included on the reinforcing ring and forming one side surface only of the piston ring groove, a second surface included on the reinforcing ring and forming an interface with one piston ring groove side surface, and means on the piston ring groove surface and means on the reinforcing ring surface defining a mechanical interlock therebetween at said interface including material of said piston penetrating recesses in said ring whereby the reinforcing ring is retained in the piston ring groove by a mechanical bond.
Claim 2
Dependent Claim
161 words
A piston comprising a piston body of a material selected from the group of aluminium and aluminium alloys, a plurality of piston ring grooves formed in the piston body and having substantially uniform depth around the piston, two side surfaces included in each piston ring groove, an annular reinforcing ring received within one of said piston ring grooves and having a substantially uniform radial width equal to the radial depth of the piston ring groove, a first surface included on the reinforcing ring and forming one side surface only of the piston ring groove, a second surface included on the reinforcing ring and forming an interface with one piston ring groove side surface, and means on the piston ring groove surface and means on the reinforcing ring surface defining a mechanical interlock therebetween at said interface including material of said piston penetrating recesses in said ring whereby the reinforcing ring is retained in the piston ring groove by a mechanical bond.
Claim 3
Dependent Claim
46 words
A piston according to claim 1, wherein the reinforcing element is of a porous material and the means on the reinforcing ring surface comprise pores in the surface of the reinforcing element and the means on the groove surface comprise piston material penetrating into said pores.
Claim 4
Dependent Claim
35 words
A piston according to claim 2, wherein the reinforcing element is of a sintered material to provide said pores and the material of the piston penetrates into said pores to interlock with the sintered material.
Claim 5
Dependent Claim
22 words
A piston according to claim 1, wherein the means on the reinforcing ring surface includes a channel formed in the reinforcing ring.
Claim 6
Dependent Claim
36 words
A piston according to claim 4, wherein the means on the groove surface comprises a ridge projecting into said channel, said ridge being inclined towards the axis of the piston in a direction towards the groove.
Claim 7
Dependent Claim
20 words
A piston according to claim 4, wherein said channel is formed with a neck portion, and is of key-hole shape.