US 5,290,010 A · Multiple thrust range live loade packing system for stems, shafts, etc.

Abstract

A multiple thrust range, live loaded packing system for stems and shafts extending into a packing chamber containing a packing ring, and a packing gland engaging the ring and having an outer end portion projecting outwardly of the chamber includes a first thrust member engaging an outer end portion of the gland and a second thrust member spaced from and facing the first thrust member. A spring is mounted between the thrust members for normally biasing the thrust members apart and a spacer is mounted between the thrust members around the spring for establishing a minimum spacing distance between the thrust members. One or more tension members extend between the thrust members to secure the thrust members against the spacer for exerting a selected live load on the packing gland via the spacer, the spring and the first thrust member. At least one of the thrust members has a plurality of opposite stop surfaces selectively engageable with the spacer to provide different thrust range values of live loading depending on which stop surface is engaged with the spacer.

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Drawings

Claims18

Dependent claims

A multiple thrust range, live loaded packing system for stems and shafts extending into a packing chamber containing a packing ring, and a packing gland engaging said ring and having an outer end portion projecting outwardly of said chamber, comprising:

a first thrust member engaging said outer end portion of said gland;
a second thrust member spaced from and facing said first thrust member;
spring means between said thrust members for normally biasing said thrust members apart;
spacer means between said thrust members around said spring means for establishing a minimum spacing distance between said thrust members;
tension means extending between said thrust members for securing said second thrust member in a selected position relative to said chamber for exerting a selected live load on said packing gland via said spacer means, said spring means and said first thrust means;
and
at least one of said first and second thrust members having opposite stop surfaces selectively engageable with said spacer means to provide different thrust range values of live loading depending on which stop surface is engaged with said spacer means.

4 more elements

A multiple thrust range rated, live loaded packing system for a valve of the type including a stem extending into a packing chamber having an annular shoulder at an inner end around said stem and an outwardly opening opposite end for receiving a packing gland exerting thrust toward said shoulder against a packing ring mounted in said chamber, said valve including a body defining packing chamber supporting said gland movable toward and away from said body, the improvement comprising:

a gland loading assembly between said body and a first thrust member for exerting a live load on said packing ring through said packing gland;
said loading assembly including said first and a second of said thrust members in spaced apart relation and an elongated tension member having a first end portion secured to said body and a second end portion in engagement with said second said thrust members;
resilient spring means mounted between said thrust members for biasing the same away from each other;
spacer means engaging a selected stop surface of at least one of said thrust members for setting up a predetermined spacing therebetween;
and
said spacer means having first and second stop surfaces for selectively engaging a stop surface on said one of said thrust members to provide different spacing intervals between said spaced apart thrust members dependent on which of said first and second stop surfaces is engaging said selected stop surface of said one thrust member.

3 more elements

Dependencies are inferred from the claim text.

Description4,250 words

Summary792 words

#1. Field of the Invention

#The present invention is directed towards a new and improved multiple thrust range, live loaded packing system for a valve stem and for a valve employing such system so that at least two ranges of thrust values may be provided to exert a live load on a packing ring around the valve stem. The packing system also provides a means to determine if the preferred or prescribed thrust values are being applied.

#2. Background of the Prior Art

Brief description of the drawings7 figures

#For a better understanding of the present invention, reference should be had to the following detailed description taken in conjunction with the drawings, in which:

#FIG. 1 is a longitudinal cross-sectional view of one embodiment of a new and improved multiple thrust range rated live loaded packing system constructed in accordance with the features of the present invention;

#FIG. 2 is a longitudinal cross-sectional view of the packing system of FIG. 1, illustrated in another operating condition having a different live loading thrust range;

Detailed description3,242 words

#Referring now to the drawings and FIGS. 1-4, therein is illustrated one embodiment of a new and improved valve 210 constructed in accordance with the features of the present invention and including a valve body 212 having a cylindrical bore 214 adapted to contain an elongated stem 216 having a threaded segment 218 adjacent an upper end and rotatable within the bore when turned. The bore 214 is formed with an upper end portion comprising a packing chamber 220 for containing one or a plurality of packing rings 224 in a stacked array. The packing rings 224 are formed of suitable packing material that is compatible with the fluid being handled in the valve 210.

#The elongated stem 216 is rotatable and is longitudinally or axially displaceable in the bore 214 in the packing chamber 220. Live loaded end thrust against an outer one of the respective packing rings 224 is provided in accordance with the present invention by means of a new and improved multiple load range, packing assembly, generally indicated by the reference numeral 226. The packing assembly 226 exerts a selected range of thrust force against a hollow packing gland 230 mounted on the stem 216 and coaxially aligned on a centerline or axis 235.

#The cylindrical packing gland 230 has a lower end portion extending downwardly into the packing chamber 220 with an annular lower end face bearing against an uppermost packing ring 224 to urge the ring and stack of rings downwardly towards a fixed annular shoulder (not shown) at the lower end of the chamber. The packing gland 230 projects upwardly through a stepped, frustoconical central bore 232 of a washer-like thrust plate 234 having a pair of radially outwardly extending opposite, annular, relatively flat, stop faces 233 and 235.

Facts

Application

08/026,532Filed 4 Mar 1993 · continuation in part

Priority

12 Jun 1992

Granted

1 Mar 1994

Term ended

12 Jun 2012

Estimated · how

Pre-1995 term; greater of 17 years from grant or 20 years from filing when eligible. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification4 codes

F16J 15/186
With continuous adjustment of the compression of the packing: using springs
F16K 41/02
Spindle sealings: with stuffing-box ; Sealing rings
F16J
Pistons
F16K
Valves

Multiple thrust range live loade packing system for stems, shafts, etc.

Life of this patent

Multiple thrust range live loade packing system for stems, shafts, etc.

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims18

Description4,250 words

Drawings

Classification4 codes

Life of this patent

Description4,250 words