Compensating plunger for solenoid valve and method of making

Claim 2

A compensating plunger for a solenoid valve, said plunger having an axially elongated generally cylindrical body including a bore extending coaxially therethrough, said bore including a generally cylindrical main portion and one end portion having a diameter substantially smaller than the diameter of said main portion, said bore including an inwardly facing annular transitional portion between said main portion and said one end portion, an insert assembly slidably received in said bore and including a relatively thin-walled tubular shell and an elastomeric insert received in said shell, said shell having a generally cylindrical enlarged portion received in said main bore portion, a generally cylindrical reduced potion received in and having a diameter substantially equal to the diameter of said one end portion and an intermediate portion between said enlarged and reduced portions for engaging said transitional portion, said insert having a generally cylindrical first portion received in said reduced portion and defining a radially disposed seating surface exposed at said one end of said plunger when said intermediate portion is in engagement with said transitional portion, said first portion having a diameter before assembly with said shell substantially equal to the inside diameter of said reduced portion so that no substantial compressive stress is exerted upon said first portion by said reduced portion in the vicinity of said seating surface, said insert including a second generally cylindrical portion having a diameter before assembly greater than the inside diameter of said enlarged portion, said insert being retained in assembly with said shEll by radially inwardly directed compressive force exerted upon said second portion by said enlarged portion, a spring received in said bore for biasing said insert assembly toward said one end portion, and means for retaining said spring in said bore.

Claim 3

A compensating plunger as set forth in claim 1 wherein said transitional portion comprises a generally conical portion diverging from said one end portion to said main portion.

Claim 4

A compensating plunger as set forth in claim 1 wherein said means for retaining said spring comprises an elastomeric plug received in snap-fit engagement with said body in the other end of said bore, said plug having a generally radially disposed bearing surface exposed at said other end.

Claim 5

A compensating plunger as set forth in claim 1 wherein said means for retaining said spring comprises a retaining washer received in said bore in gripping engagement with the wall thereof.

Claim 6

A compensating plunger as set forth in claim 4 wherein said retaining washer is further characterized as a resilient washer having a plurality of generally radially outwardly extending legs in gripping engagement with the wall of said bore.

Claim 7

A compensating plunger as set forth in claim 5 wherein said washer is made from material harder than the material of said body, said legs incising the wall of said bore in gripping engagement therewith.

Claim 8

A compensating plunger as set forth in claim 1 including a bearing member between said spring and said insert assembly and engaging said shell, said spring engaging said bearing member for biasing said insert assembly toward said one end portion.

Claim 9

A compensating plunger as set forth in claim 7 wherein said second portion has a chamfered inner edge and said bearing member is received within said second portion and engages said chamfered inner edge.

Claim 10

A compensating plunger for a solenoid valve, said plunger having an axially elongated generally cylindrical body including a bore extending coaxially therethrough, said bore including a generally cylindrical main portion and one end portion having a diameter substantially smaller than the diameter of said main portion, said bore including an inwardly facing annular transitional portion between said main portion and said one end portion, said bore having an enlarged generally cylindrical portion opening through the other end of said plunger and partially defined by an axially outwardly facing annular bearing surface and a radially inwardly opening annular recess spaced axially inwardly from said outwardly facing bearing surface and partially defined by an axially inwardly facing annular shoulder, said plunger bore further including a conical portion converging from said enlarged bore portion toward said recess, an insert assembly slidably received in said bore and including a thin-walled tubular shell and an elastomeric insert, said shell having a generally cylindrical enlarged portion received in said main bore portion, a generally cylindrical reduced portion received in and having a diameter substantially equal to the diameter of said one end portion and an intermediate portion between said enlarged and reduced portions for engaging said transitional portion, said elastomeric insert received in said shell and defining a radially disposed seating surface exposed at said one end of said bore when said intermediate portion is in engagement with said transitional portion, a spring received in said bore for biasing said insert assembly toward said one end, and an elastomeric plug received in the other end of said bore, said plug having a generally cylindrical flange portion received in said enlarged bore portion and partially defined by a radially inwardly facing abutment surface engaging said bearing surface, said flange portion having a diameter substantially equal to said enlarged bore portion and defining a radially disposed outwardly facing seating surface, said plug further including a radially outwardly projecting annular portion received in said annular Recess and partially defined by an axially outwardly facing annular shoulder engaging said inwardly facing shoulder, said recess and said outwardly projecting portion of said plug comprising means for retaining said plug in said bore.

Claim 11

A compensating plunger for a solenoid valve, said plunger having an axially elongated generally cylindrical body including a bore extending coaxially therethrough, said bore including a generally cylindrical main portion and one end portion having a diameter substantially smaller than the diameter of said main portion, said bore including an inwardly facing annular transitional portion between said main portion and said one end portion, said bore having an enlarged generally cylindrical portion opening through the other end of said plunger and partially defined by an axially outwardly facing annular bearing surface and a radially inwardly opening annular recess spaced axially inwardly from said outwardly facing bearing surface and partially defined by an axially inwardly facing annular shoulder, said plunger bore further including a conical portion converging from said enlarged bore portion toward said recess, an insert assembly slidably received in said bore and including a thin-walled tubular shell and an elastomeric insert, said shell having a generally cylindrical enlarged portion received in said main bore portion, a generally cylindrical reduced portion received in and having a diameter substantially equal to the diameter of said one end portion and an intermediate portion between said enlarged and reduced portions for engaging said transitional portion, said elastomeric insert received in said shell and defining a radially disposed seating surface exposed at said one end of said bore when said intermediate portion is in engagement with said transitional portion, a spring received in said bore for biasing said insert assembly toward said one end, and an elastomeric plug received in the other end of said bore, said plug having a generally cylindrical flange portion received in said enlarged bore portion and partially defined by a radially inwardly facing abutment surface engaging said bearing surface, said flange portion having a diameter substantially equal to said enlarged bore portion and defining a radially disposed outwardly facing seating surface, said plug further including a radially outwardly projecting annular portion received in said annular Recess and partially defined by an axially outwardly facing annular shoulder engaging said inwardly facing shoulder, said recess and said outwardly projecting portion of said plug comprising means for retaining said plug in said bore.

Claim 12

A compensating plunger for a solenoid valve, said plunger having an axially elongated generally cylindrical body including a bore extending coaxially therethrough, said bore including a generally cylindrical main portion and one end portion having a diameter substantially smaller than the diameter of said main portion, said bore including an inwardly facing annular transitional portion between said main portion and said one end portion, said bore having an enlarged generally cylindrical portion opening through the other end of said plunger and partially defined by an axially outwardly facing annular bearing surface, an insert assembly slidably received in said bore and including a thin-walled tubular shell and an elastomeric insert, said shell having a generally cylindrical enlarged portion received in said main bore portion, a generally cylindrical reduced portion received in and having a diameter substantially equal to the diameter of said one end portion and an intermediate portion between said enlarged and reduced portions for engaging said transitional portion, said elastomeric insert received in said shell and defining a radially disposed seating surface exposed at said one end of said bore when said intermediate portion is in engagement with said transitional portion, a retaining washer received in said bore in gripping engagement with the wall of said bore, a spring received in said bore between said washer and said insert assembly for biasing said insert assembly toward said one end, said spring having one end thereof bearing against said insert assembly and the other end thereof bearing against said washer, an elastomeric plug received in the other end of said bore, said plug having a generally cylindrical flange portion received in said enlarged bore portion and partially defined by a radially inwardly facing abutment surface engaging said bearing surface, said flange portion having a diameter substantially equal to said enlarged bore portion and defining a radially disposed outwardly facing seating surface, and means for retaining said plug in said bore.

Claim 13

A compensating plunger for a solenoid valve, said plunger having an axially elongated generally cylindrical body including a bore extending coaxially therethrough, said bore including a generally cylindrical main portion and one end portion having a diameter substantially smaller than the diameter of said main portion, said bore including an inwardly facing annular transitional portion between said main portion and said one end portion, said bore having an enlarged generally cylindrical portion opening through the other end of said plunger and partially defined by an axially outwardly facing annular bearing surface, an insert assembly slidably received in said bore and including a thin-walled tubular shell and an elastomeric insert, said shell having a generally cylindrical enlarged portion received in said main bore portion, a generally cylindrical reduced portion received in and having a diameter substantially equal to the diameter of said one end portion and an intermediate portion between said enlarged and reduced portions for engaging said transitional portion, said elastomeric insert received in said shell and defining a radially disposed seating surface exposed at said one end of said bore when said intermediate portion is in engagement with said transitional portion, a retaining washer received in said bore in gripping engagement with the wall of said bore, a spring received in said bore between said washer and said insert assembly for biasing said insert assembly toward said one end, said spring having one end thereof bearing against said insert assembly and the other end thereof bearing against said washer, an elastomeric plug received in the other end of said bore, said plug having a generally cylindrical flange portion received in said enlarged bore portion and partially defined by a radially inwardly facing abutment surface engaging said bearing surface, said flange portion having a diameter substantially equal to said enlarged bore portion and defining a radially disposed outwardly facing seating surface, and means for retaining said plug in said bore.

Claim 14

A compensating plunger as set forth in claim 10 wherein said retaining washer is further characterized as a resilient washer having a plurality of generally radially outwardly extending legs engaging the wall of said bore.

Claim 15

A compensating plunger as set forth in claim 11 wherein said resilient washer is made from material harder than the material of said body, said legs incising the wall of said bore in gripping engagement therewith.