Hydraulic positioner with integral continuously adjustable stroke limiter

Claim 2

A hydraulic positioner of the type having a cylinder defining hydraulic chamber means, a piston in said chamber means, a piston rod connected to said piston and extending through a closed end of said chamber means, and valve means actuatable for releasing said piston for movement in said chamber means, said cylinder extending continuously from said closed end to define a tubular extension terminating in a stop end, a threaded inner sleeve axially on said rod, a stop ring threaded on said inner sleeve and engageable by said stop end upon compression of said rod into said cylinder; and an outer sleeve rotatable for axially displacing said stop ring along said inner sleeve to a continuously selectable stroke limiting position, a spring between said cylinder and said inner sleeve for returning said rod to an extended position relative to said cylinder; said spring being partly contained in said extension and partly in said inner sleeve.

Claim 3

The positioner of claim 1 wherein an outer end of said inner sleeve is fixed to said rod and said spring bears against said outer end.

Claim 4

The positioner of claim 1 wherein said inner sleeve has an outer end supported on said rod and said outer sleeve is axially fixed to said inner sleeve.

Claim 5

The positioner of claim 3 wherein said outer sleeve has an inner end slidably supported on said extension.

Claim 6

The positioner of claim 4 wherein said inner end of said outer sleeve receives said stop end of said extension.

Claim 7

The positioner of claim 1 wherein said outer sleeve and said extension are in telescoping relationship.

Claim 8

The positioner of claim 1 wherein said extension is an integral continuation of said cylinder.

Claim 9

A hydraulic positioner of the type having a cylinder, a hydraulic chamber in said cylinder, a piston in said chamber, a piston rod connected to said piston and extending axially from said cylinder, valve means actuatable for releasing said piston for movement in said chamber, movable stop means for stopping compression of said rod into said cylinder, an outer sleeve rotatable for axially displacing said stop means to a continuously selectable stroke limiting position, a spring between said cylinder and inner sleeve for returning said rod to an extended position relative to said cylinder, said outer sleeve and an cylinder being in telescoping relationship to form an enclosure containing said spring with said spring at least partly contained in said inner sleeve, one end of said cylinder being radially contained between said inner sleeve and said outer sleeve.

Claim 10

A hydraulic positioner of the type having a cylinder, a hydraulic chamber in said cylinder, a piston in said chamber, a piston rod connected to said piston and extending axially from said cylinder, valve means actuatable for releasing said piston for movement in said chamber, movable stop means for stopping compression of said rod into said cylinder, an outer sleeve rotatable for axially displacing said stop means to a continuously selectable stroke limiting position, a spring between said cylinder and inner sleeve for returning said rod to an extended position relative to said cylinder, said outer sleeve and an cylinder being in telescoping relationship to form an enclosure containing said spring with said spring at least partly contained in said inner sleeve, one end of said cylinder being radially contained between said inner sleeve and said outer sleeve.

Claim 11

The positioner of claim 8 wherein said movable stop means comprise a inner sleeve on said rod and a stop ring threaded onto said inner sleeve and circumferentially engaged to said outer sleeve.

Claim 12

A hydraulic positioner of the type having a cylinder, a hydraulic chamber in said cylinder, a piston in said chamber, a piston rod connected to said piston and extending axially from said cylinder, valve means actuatable for releasing said piston for movement in said chamber, an inner sleeve on said rod and a stop ring threaded onto said inner sleeve and circumferentially engaged to said outer sleeve, an outer sleeve rotatable for axially displacing said stop means to a continuously selectable stroke limiting position, a spring between said cylinder and said inner sleeve for returning said rod to an extended position relative to said cylinder, said outer sleeve and said cylinder being in telescoping relationship to form an enclosure containing said spring, said spring being partly contained in said inner sleeve, one end of said cylinder being radially contained between said inner sleeve and said outer sleeve.

Claim 13

A hydraulic positioner of the type having a cylinder, a hydraulic chamber in said cylinder, a piston in said chamber, a piston rod connected to said piston and extending axially from said cylinder, valve means actuatable for releasing said piston for movement in said chamber, an inner sleeve on said rod and a stop ring threaded onto said inner sleeve and circumferentially engaged to said outer sleeve, an outer sleeve rotatable for axially displacing said stop means to a continuously selectable stroke limiting position, a spring between said cylinder and said inner sleeve for returning said rod to an extended position relative to said cylinder, said outer sleeve and said cylinder being in telescoping relationship to form an enclosure containing said spring, said spring being partly contained in said inner sleeve, one end of said cylinder being radially contained between said inner sleeve and said outer sleeve.

Claim 14

A hydraulic positioner comprising a cylinder, a piston chamber in said cylinder closed at one end by an axially displaceable gland, a piston axially reciprocable in said first chamber, a rod axially connected to said piston and slidable through said gland, said rod moveable with said piston between an extended and a compressed condition, hydraulic fluid in said piston chamber, valve means in said piston actuatable for allowing flow of said fluid across said piston, said valve means being normally closed for locking said piston and said rod against movement in said cylinder, first spring means urging said rod to said extended condition, said first spring means cooperating with second spring means for jointly urging said gland against said fluid to compensate for changes in fluid volume in said chamber, a threaded inner sleeve axially on said rod, a stop ring threaded on said inner sleeve and engageable by an end of said cylinder upon compression of said rod into said cylinder; and an outer sleeve rotatable for axially displacing said stop ring along said inner sleeve to a continuously selectable stroke limiting position.

Claim 15

A hydraulic positioner comprising a cylinder, a piston chamber in said cylinder closed at one end by an axially displaceable gland, a piston axially reciprocable in said first chamber, a rod axially connected to said piston and slidable through said gland, said rod moveable with said piston between an extended and a compressed condition, hydraulic fluid in said piston chamber, valve means in said piston actuatable for allowing flow of said fluid across said piston, said valve means being normally closed for locking said piston and said rod against movement in said cylinder, first spring means urging said rod to said extended condition, said first spring means cooperating with second spring means for jointly urging said gland against said fluid to compensate for changes in fluid volume in said chamber, a threaded inner sleeve axially on said rod, a stop ring threaded on said inner sleeve and engageable by an end of said cylinder upon compression of said rod into said cylinder; and an outer sleeve rotatable for axially displacing said stop ring along said inner sleeve to a continuously selectable stroke limiting position.

Claim 16

A hydraulic positioner comprising a cylinder, a piston chamber in said cylinder closed at one end by an axially displaceable gland, a piston axially reciprocable in said first chamber, a rod axially connected to said piston and slidable through said gland, said rod moveable with said piston between an extended and a compressed condition, hydraulic fluid in said piston chamber, valve means in said piston actuatable for allowing flow of said fluid across said piston, said valve means being normally closed for locking said piston and said rod against movement in said cylinder, first spring means urging said rod to said extended condition, second spring means compressed between said cylinder and said gland, movable stop means for stopping compression of said rod into said cylinder, an outer sleeve rotatable for axially displacing said stop means to a continuously selectable stroke limiting position, said outer sleeve and said cylinder being in telescoping relationship to form an enclosure containing said first spring means.

Claim 17

A hydraulic positioner comprising a cylinder, a piston chamber in said cylinder closed at one end by an axially displaceable gland, a piston axially reciprocable in said first chamber, a rod axially connected to said piston and slidable through said gland, said rod moveable with said piston between an extended and a compressed condition, hydraulic fluid in said piston chamber, valve means in said piston actuatable for allowing flow of said fluid across said piston, said valve means being normally closed for locking said piston and said rod against movement in said cylinder, first spring means urging said rod to said extended condition, second spring means compressed between said cylinder and said gland, movable stop means for stopping compression of said rod into said cylinder, an outer sleeve rotatable for axially displacing said stop means to a continuously selectable stroke limiting position, said outer sleeve and said cylinder being in telescoping relationship to form an enclosure containing said first spring means.

Claim 18

The positioner of claim 12 wherein said movable stop means comprise an inner sleeve on said rod and a stop ring threaded onto said inner sleeve and circumferentially engaged to said outer sleeve.

Claim 19

The positioner of claim 13 wherein said spring is partly contained in said inner sleeve.

Claim 20

The positioner of claim 13 wherein said cylinder has one end radially contained between said inner sleeve and said outer sleeve.

Claim 21

A hydraulic positioner of the type having a continuous cylinder, a closure axially fixed at an intermediate point in said cylinder and partitioning said cylinder into a positioner portion and a tubular extension, said extension terminating at a stop end; said positioner portion including hydraulic chamber means, a piston in said chamber means, a piston rod connected to said piston and extending through said closure and said extension portion, and valve means actuatable for releasing said piston for movement in said chamber means; movable stop means for stopping compression of said rod into said cylinder upon contact of said stop means with said stop end of said extension, a sleeve axially rotatable on said rod for axially displacing said stop means to a continuously selectable stroke limiting position, a spring partially contained in said extension between said closure and said stop end and bearing against said inner sleeve for returning said rod to an extended position relative to said cylinder.

Claim 22

A hydraulic positioner of the type having a continuous cylinder, a closure axially fixed at an intermediate point in said cylinder and partitioning said cylinder into a positioner portion and a tubular extension, said extension terminating at a stop end; said positioner portion including hydraulic chamber means, a piston in said chamber means, a piston rod connected to said piston and extending through said closure and said extension portion, and valve means actuatable for releasing said piston for movement in said chamber means; movable stop means for stopping compression of said rod into said cylinder upon contact of said stop means with said stop end of said extension, a sleeve axially rotatable on said rod for axially displacing said stop means to a continuously selectable stroke limiting position, a spring partially contained in said extension between said closure and said stop end and bearing against said inner sleeve for returning said rod to an extended position relative to said cylinder.

Claim 23

The positioner of claim 16 wherein said sleeve is in telescoping relationship with said extension such that said spring is fully enclosed by said extension and said sleeve in all positions of said rod.