Shock absorber

Claim 1

87,335 The claims defining the invention are as follows:- 1. A shock absorber piston construction comprising, a piston body having means cooperable with an associated piston rod for operative attachment thereto, said piston body being formed with first and second sets of axially extending, circumferentially spaced flow ports, said sets of flow ports being concentrically oriented, with said first set being spaced radially inwardly from said second set, a first annular axially extending valve seat on one end of said body adjacent said first set of flow ports, a first valve member engageable with said i first valve seat to block fluid flow through said first set of flow ports, second and third annular axially extending valve seats on the opposite end of said piston body and located radially inwardly and outwardly from said second set of flow ports, a second valve member in the form of a flat annular valve disc disposed adjacent said second and third valve seats and engageable therewith to block fluid flow through said second set of flow ports, an annular compression plate disposed on the axially opposite side of said valve disc from said piston body, 14 472889 87.335 means supporting and guiding said compression plate for axial movement relative to said piston body between a first position maintaining said second valve member adjacent said second and third valve seats but permitting a first magnitute of fluid flow through said second set of flow ports, and a second position wherein said second valve member is displaced predeterminately from said piston body to permit a second magnitude of fluid flow through said second set of flow ports, and at least one spring disc disposed on the axially opposite side of said compression plate from said valve disc yieldably resisting axial movement of said plate and said valve disc, 2. The invention as set forth in claim 1 wherein said means for guiding said compression plate comprises a guide member concentrically located adjacent said piston interiorly of said compression plate. 3. The invention as set forth in claim 1 which includes means defining a flow passage in said second valve member communicable with said first set of flow ports. 4. The invention as set forth in claim 3 wherein said flow passage is defined by a generally circumferen- tially extending slot in said second valve member, said slot being generally axially aligned with said first set of flow ports. 472889 87,335 The invention as set forth in claim 1 wherein said compression plate is formed with a plurality of radially extending circumferentially spaced notches on the side thereof confronting said second valve member and communicating with said first set of flow ports. 6. The invention as set forth in claim 1 which includes annular spacer means disposed adjacent said one spring disc for limiting axial displacement of said compression plate. 7. The invention as set forth in claim 1 wherein said piston body is formed with a central axially extending opening adapted to receive at least a portion of one end of said piston rod. 8. The invention as set forth in claim 7 whdi. includes a coil spring disposed in part within a recessed area of said piston body and adapted to resiliently urge said first valve member toward a position engaging said first valve seat. 9. The invention as set forth in claim 1 wherein said second valve member is fabricated of a spring-like material and has an outer peripheral portion normally engaging said second and third valve seats. The invention as set forth in claim 9 wherein the side of said compression plate confronting said second valve member is tapered, whereby to permit the outer peripheral portion of said second valve member to 472 889 87,335 move away from one of said second and third valve seats and thereby allow said first magnitude of fluid flow through said second set of flow ports. 11. A shock absorber piston substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. Dated this 16th day of February, 1976. MONROE AUTO EQUIPMENT COMPANY, By their Patent Attorneys, COLLISON CO. 17 47Z889 87,335 47 Z889 1.9