Patent Publication Number: US-2006000315-A1

Title: Handheld tool with barbed end for repacking encapsulated valve actuators

Description:
BACKGROUND OF THE INVENTION  
      In general, the present invention relates to tools employed for the removal of packing, e.g., ring packs, split-ring packing, V-ring packing, flexible spacers, and such, that is in place around a conventional cylindrical stem (typically made of metal/metal alloy) inside a valve actuator assembly. By way of example only, pneumatic valve actuators that have an encapsulated spring mechanism are used to convert air pressure into motion. Valve assemblies of the type containing a valve stem with which the tool of the invention may be used, include those manufactured and/or distributed by: Johnson Controls, Inc., Siemens Building Technologies, Inc., Honeywell Corporation, among others.  
      Typically, the removal of such flexible packing—which is made of an elastomeric material—is done when the packing no longer is performing its function to provide a hermetic seal around the stem to a sufficient degree within an encapsulated/encased type valve actuator assembly. It is not uncommon for this packing to breakdown one or more times over the useful lifetime of a valve assembly. Conventional practice is to replace the whole valve actuator assembly. This, however, is extremely costly as the valve assemblies are quite expensive. Valve assemblies of the type that utilize such packing around a stem, are found in a wide variety of complex pneumatic and/or hydraulic systems: HVAC (Heating Ventilation Air-Conditioning) systems found in buildings (commercial and residential), manufacturing equipment, jet airliners, vehicles that run on tracks (subway, light-rail trains, etc.), trucks and other large vehicles. As one can imagine, where hundreds of valve actuators are in-use, replacing packing utilizing the effective tool of the invention, rather than replacing expensive whole valve assemblies, can result in substantial decrease in overall system maintenance costs. Furthermore, waste associated with disposing of whole valve assemblies containing functionally operational components, but simply not functioning as a unit due to a leaky packing, can be by-and-large eliminated. The handheld tool of the invention permits an environmentally useful mechanism with opportunity for maintenance cost reduction: A winning combination.  
      There are a wide variety of valve actuator assembly configurations that incorporate packing installed around the stem (a smooth cylindrical rod used as a support around which components are built to produce the desired actuator movement) so as to provide a hermetic seal, preventing fluid leaks (whether air or a liquid). This packing is often referred to as ring packs, spacers, and so on, and is typically made of an elastomeric or other such flexible, pliable material that, under pressure, can provide a good seal. Conventional techniques used to remove and ‘repack’ the valve actuator assembly—such as the small, cylindrical ˜2½ inch long brittle plastic device depicted in the drawing labeled “FIG. 5: Bullet Installation Method” on p. 2 of Reference D (3 pgs.) fully incorporated herein by reference, and the sharp hooked-end pick-tool, made of metal, typically recommended by valve manufacturers to dig out the old packing—have several drawbacks. The small brittle plastic device, while it has a few ridges at a “Removal End” as labeled in FIG. 5 Reference D (p. 2), it is extremely difficult to remove packing from around a valve stem without damaging the small brittle device. The sharp metal hooked-end pick-tool provided with most valve repacking kits is very dangerous to use: The hooked-end is used to dig out the packing from around the valve stem and pull it off the stem. Doing so often damages the stem with scratches. Worse yet, is the painful injury often resulting to the technician while pulling back with the pick-tool. For reference, see the pages labeled Reference D which include drawings taken from a Valve Repacking Kit product brochure distributed by Johnson Controls, Inc. for use to repack Johnson&#39;s VT Series Valves, and a cross-sectional drawing of components of a valve assembly, labeled FIG. 4, taken from a brochure distributed by Siemens Building Technologies, Inc.  
      One can readily appreciate the many fundamental distinguishing features of the new packing removal tool and associated method for removing flexible packing in place around the stem of a valve assembly using a handheld tool according to the invention, from conventional devices/mechanisms used to remove and/or repack valve actuator assemblies having a stem about which the packing is placed.  
     SUMMARY OF THE INVENTION  
      It is a primary object of this invention to provide a handheld tool, and associated technique, for removing flexible packing in place around the stem of a valve assembly.  
      The tool has: (a) an inner-surface defining a hollow extending within the tool and sized to accept the stem at an end-port of the hollow and to permit a sliding of the hollow along the stem; (b) an integral handle having a grip surface around at least a portion of the hollow; and (c) at one end of the tool and located a distance, d N , from the handle, is an integral barbed-end comprising a plurality of barbs, each barb having a length of sharp edge. The length of sharp edge of a barb is preferably disposed between a tapered surface and a blade surface oriented generally orthogonal to the inner-surface of the hollow such that the blade surface will contact the flexible packing for the removing thereof. The tool is preferably elongated in shape. The integral handle may surround the hollow with the grip surface having a textured knurl. Upon the sliding of the hollow along the stem so that the lengths of sharp edge penetrate the flexible packing, a first and second of the blade surfaces contact the flexible packing.  
      As one will appreciate, in a further distinguishing characterization of the invention the tool can also have, located a second distance, d 2 , from the handle, an integral second barbed-end comprising a plurality of second barbs; each of these second barbs can, likewise, have a length of sharp edge.  
      In one aspect of the invention, each of the plurality of barbs of one of the barbed-ends is curve-tooth shaped and further comprises an outer curvilinear surface. In this case, along the distance from the handle to the one end, the tool preferably has a cylindrical outer surface, whereby the curve-tooth shaped barbs are arranged around the one end with their outer curvilinear surfaces flush with the cylindrical outer surface. The plurality of barbs are preferably arranged such that each of the tapered surfaces taper inwardly toward the inner-surface, and a base of each curve-tooth shaped barb is generally equidistant around the cylindrical outer surface of the one end from the base of adjacent curve-tooth shaped barbs. The blade surface of one of the plurality of barbs may be oriented generally facing the tapered surface of an adjacent of the plurality of barbs, with an angle between the blade surface of each of the plurality of barbs and an axis of the inner-surface being between 30 degrees and 60 degrees (with an angle of approx. 45 degrees being quite suitable). Preferably, the inner-surface is cylindrically shaped permitting the hollow to slidably-revolve around the stem upon application of a tangential-twisting force applied to the handle. Furthermore, each of the blade surfaces can be triangularly shaped having at least one curvilinear side.  
      In another aspect of the invention, the plurality of barbs of one of the barbed-ends are arranged such that each of the tapered surfaces is concentrically oriented along an axis of the inner-surface, the length of sharp edge of each barb being respectively concentrically oriented along the axis. In this case, each of the blade surfaces is generally ring-shaped and oriented radially orthogonal to the inner-surface. An angle between the blade surface of one of the plurality of barbs and the tapered surface of an adjacent of the plurality of barbs, is preferably between 30 degrees and 60 degrees (with an angle of approx. 45 degrees being quite suitable). Preferably, the inner-surface is cylindrically shaped permitting the hollow to slidably-revolve around the stem upon application of a tangential-twisting force applied to the handle.  
      In another characterization, the invention is a method for removing flexible packing in place around the stem of a valve assembly using a handheld tool. The method comprises the steps of: (a) inserting the stem into an end-port of a hollow extending within the tool and sliding an inner-surface defining the hollow, along the stem; (b) upon penetrating the flexible packing with at least a portion of a length of sharp edge of a first of a plurality of barbs of an integral barbed-end of the tool, applying a tangential-twisting force to an integral handle having a grip surface around at least a portion of the hollow, slidably-revolving the hollow around the stem, to further penetrate the flexible packing such that a blade surface of the first barb contacts the flexible packing; and (c) applying an axial force to the integral handle in a direction opposite to an initial force used during the step of inserting, and pulling the flexible packing in contact with the first barb in the opposite direction along the stem for the removing. Further distinguishable features of the method characterization include: (a) the step of applying the tangential-twisting force further results in penetrating the flexible packing with each of a respective length of sharp edge of a second, third, and fourth of the barbs, such that a respective blade surface of each of the second, third, and fourth barbs also contact the flexible packing; and (b) the step of pulling the flexible packing further comprises pulling flexible packing in contact with each of the respective blade surfaces.  
      In a first aspect of the method of the invention, each of the barbs is curve-tooth shaped and further comprises an outer curvilinear surface, the plurality of curve-tooth shaped barbs being arranged around the barbed-end such that the outer curvilinear surfaces are flush with a cylindrical outer surface of the barbed-end. In this case, the step of penetrating the flexible packing with each of a respective length of sharp edge of the barbs further comprises a generally simultaneous penetration of the respective blade surfaces into the flexible packing.  
      In a second aspect of the method of the invention, the step of applying the tangential-twisting force further results in penetrating the flexible packing with each of a respective length of sharp edge of a second, third, and fourth of the barbs. In this case, the plurality of barbs are arranged such that each of the tapered surfaces is concentrically oriented along an axis of the inner-surface, the length of sharp edge of each barb being respectively concentrically oriented along the axis; such that, the step of penetrating the flexible packing with each of a respective length of sharp edge of the barbs further comprises a sequential penetration of the respective blade surfaces into the flexible packing.  
      As one will readily appreciate in connection with the instant technical disclosure, the applicant has identified unique handheld tool structures, and associated techniques, targeted for removing flexible packing in place around the stem of a valve assembly using a handheld tool. The tools can be machined, cut, cast, molded, or otherwise fabricated of a material that has sufficient structural integrity to hold the lengths of sharp edge of the barbs. While, preferably, the tool is made of a metal, alloy, or a glass-filed nylon, a multitude of materials are contemplated for use according to the invention in connection with fabricating the tool—including alloys, metals, reinforced resins, and other rigid plastics (thermoplastic and thermosetting structures).  
      Certain of the several unique features, and further unique combinations of features, as supported and contemplated in the instant technical disclosure may provide a variety of advantages; among these include: (a) Design flexibility and versatility—basic structure is adaptable for use to remove packing from within valve-type assemblies of a variety of shapes and sizes; (b) reduction of waste associated with disposing of a whole valve-type assembly having degraded/defective packing, where components of the assembly are still functioning, which may result in maintenance/replacement cost savings, over time; and (c) installation is handy employing the new tool and technique—conventional packing removal devices currently used for removing packing from around the stems of encapsulated valve assemblies are often ineffective and/or dangerous to use. Other advantages of providing the new handheld tool structures and associated method of removing, will be appreciated by perusing the instant technical discussion, including the drawings, claims, and abstract, in light of drawbacks to existing devices that have been identified, or may be uncovered.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      For purposes of illustrating the innovative nature plus the flexibility of design and versatility of the preferred tool structures supported and disclosed hereby, the invention will be better appreciated by reviewing the accompanying drawings (in which like numerals, as included, designate like parts). The drawings have been included to communicate and demonstrate, in pictorial fashion, the unique features of the innovative structures of the invention by way of example, only, and are in no way intended to unduly limit the disclosure hereof.  
       FIGS. 1A-1C  depict tool structure of the invention  10  having, at one end, an integral barbed-end  14 .  FIG. 1A  is an isometric view of the tool  10 ,  FIG. 1B  a side plan view of barbed-end  14 , and  FIG. 1C  is a plan view taken along  1 C- 1 C of  FIG. 1B  of barb  17 .  
       FIGS. 2A-2B  depict an alternative tool  20 , of an elongated shape, having a barbed-end  24  and another barbed-end  22 .  FIG. 2A  is an isometric view of the tool  20 , and  FIG. 1B  an end plan view of barbed-end  24   
       FIG. 3  is another isometric view of tool  20  of the invention.  
       FIG. 4  is a sectional view of tool  10  taken at the centerline along the axis of the hollow labeled  13 .  
       FIG. 5A  is a sectional view of tool  20  taken at the centerline along the axis of the hollow labeled  23   b - 23   c.    
       FIG. 5B  is an enlargement of barbed-end  24  of tool  20 .  
       FIG. 5C  is an enlargement of barbed-end  22  of tool  20 .  
       FIGS. 6A-6B  depict conventional valve assemblies  61   a ,  62   a  with which barbed-ends  14 ,  22 , respectively, are operationally engaged to remove packing  65   a ,  65   b , respectively. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS DEPICTED IN DRAWINGS  
      In connection with discussing the unique features depicted in the figures, occasional reference will be made back-and-forth to other of the figures which detail core, as well as further unique and distinguishing features of the tool and associated method for removing flexible packing in place around the stem of a valve assembly using a handheld tool according to the invention—demonstrating the flexibility of design of the invention.  
      While, preferably, the tool is made of a metal, alloy, or a glass-filed nylon, a multitude of materials are contemplated for use according to the invention in connection with fabricating the tool—including alloys, metals, reinforced resins, and other rigid plastics (thermoplastic and thermosetting structures). By way of background, only, for general reference: Thermoplastics include those plastics having polymer chains more-easily broken with heat; vs. the polymer chains in thermosetting plastics typically do not separate completely with heat. The term “nylon” refers, generically, to polymer materials having long-chain polymeric amide molecules in which recurring amide groups are part of the main polymer chain. The term ‘alloy’ refers to any combination of elements typically having metallic properties. Resins are any of a class of solid or semisolid organic products of natural or synthetic origin with no definite melting point, generally of high molecular weight—typically composed of a polymer. In any case and as one can appreciate, many well known manufacturing techniques exist (such as extruding/extrusion, casting, pulling, many types of molding, machining, cutting, and so on) that may be suitable for use in fabricating the handheld tool of the invention, depending upon whether a metal or rigid plastic, such as a glass-filed nylon is selected.  
      In  FIGS. 1A-1C , barbed-end  14  of tool  10  has four barbs  15 - 18 , each having a length of sharp edge (not labeled) disposed between a respective tapered surface  15   t - 18   t  and a blade surface  15   f - 18   f . An integral handle  11 , here, surrounds the hollow with a grip surface having a textured knurl. Integral barbed-end  14  (labeled in  FIG. 1B , but not in  FIG. 1A ) is located a distance, d 1 , from handle  11 . Preferably, an inner-surface of the hollow (unlabeled in  FIGS. 1A-1C , but labeled at  13  in the cross-sectional of tool  10  in  FIG. 4 ) is cylindrically shaped permitting the hollow to slidably-revolve around the stem upon application of a tangential-twisting force applied to the handle  11  along direction  50 , for example. The inner-surface defining the hollow (see  FIG. 4  at  13 ) preferably extends within tool  10  at least along distance, d 1 , to the barbed-end and is sized to accept the stem (examples depicted in  FIGS. 6A-6B ) at an end-port of the hollow and to permit a sliding of the hollow along the stem. Reference D (3 pgs.) as mentioned above, provides further detail of the stem and packing features of conventional valve assemblies. In  FIG. 4 , one can see that hollow  13  extends the full length of tool  10 , permitting use over a stem (e.g.,  62   a ,  62   b ,  FIGS. 6A-6B ) of equal or longer length than the tool length. Turning also to  FIGS. 6A-6B , in the event the tool is shorter than the stem (e.g.,  62   a ,  62   b ), the stem will exit the hollow  13  upon moving the tool along the stem a sufficient distance to penetrate the flexible packing (e.g.,  65   a ,  65   b ) with at least a portion of a length of sharp edge of one or more barbs.  
      Each blade surface  15   f - 18   f  is oriented generally orthogonal to the inner-surface of the hollow.  FIG. 1C  is representative of blade surfaces  15   f - 18   f : It is a plan view taken along  1 C- 1 C of  FIG. 1B  of barb  17 . Blade surface  17   f , by way of example only, is triangularly shaped having at least one curvilinear side. By way of reference only, the term ‘blade’ typically refers to a flat sharp-edged cutting part of a tool used for lifting and moving material. Upon the sliding of the hollow along a stem of a valve assembly so that the lengths of sharp edge penetrate the flexible packing, one can appreciate that blade surfaces  15   f - 18   f  will contact the flexible packing. In this aspect of the invention (shown in  FIGS. 1A-1C  and  FIG. 4  as well as in  FIGS. 2A-2C ,  3 ,  5 A- 5 B at  24 ), each of the barbs  15 - 18  is curve-tooth shaped and has an outer curvilinear surface, such as that labeled for barb  17  at  17   c  ( FIG. 1A ) and that labeled for barb  16  at  16   c  ( FIG. 1B ). Along distance, d 1 , to barbed-end  14 , tool  10  has a cylindrical outer surface  19 . The curve-tooth shaped barbs are arranged around the end with respective outer curvilinear surfaces (e.g.,  16   c ,  17   c ) flush with cylindrical outer surface  19 . Likewise, as can be appreciated in  FIGS. 2A-2B  and  3 , along distance, d 1 , to barbed-end  24 , tool  20  has a cylindrical outer surface labeled  29   b . The curve-tooth shaped barbs  25 - 28  are arranged with respective outer curvilinear surfaces ( 25   c - 28   c ) flush with cylindrical outer surface  29   b.    
      As depicted in  FIGS. 1A-1C  at  14  as well as in  FIGS. 2A-2C ,  3 ,  5 A- 5 B at  24 , barbs  15 - 18 ,  25 - 28  are preferably arranged such that respective tapered surfaces  15   t - 18   t ,  25   t - 28   t  taper inwardly toward the hollow&#39;s inner-surface, and a base of each curve-tooth shaped barb is generally equidistant around the cylindrical outer surface, respectively  19 ,  29   b . A symmetrical configuration of barbs around the tool may be obtained whether more or fewer than four barbs—as shown by way of example only—are fabricated into a barbed-end  14 ,  24  of the one end from the base of adjacent curve-tooth shaped barbs. The blade surface  15   f - 18   f ,  25   f - 28   f  of each respective barb  15 - 18 ,  25 - 28  is oriented generally facing the tapered surface of an adjacent barb, with an angle between the blade surface (e.g., at  17   f ,  FIG. 1B ) of each barb and an axis of the inner-surface (labeled z,  FIG. 1B ) being between 30 degrees and 60 degrees (with an angle of approx. 45 degrees, as depicted here, being quite suitable).  
      Alternatively, as best seen in  FIGS. 3, 5A ,  5 C, and  6 B, the barbs of the barbed-end may be arranged in a ‘tiered style’ such that each of the tapered surfaces  35   t - 38   t  (with an alternative configuration in phantom angled slightly, such as the tapered surface at  45   t ) is concentrically oriented along an axis (for reference, see  FIGS. 3 and 5 C at z) of the inner-surface, the length of sharp edge (not labeled, for simplicity) of each barb being respectively concentrically oriented along the axis. Each of the blade surfaces  35   f - 38   f  is generally ring-shaped and oriented genearlly radially orthogonal to the inner-surface. As depicted, blade surfaces  35   f - 38   f  are generally flat/planar in the radial x-y plane (plus or minus a few degrees, as shown) identified in  FIG. 5B  along φ (Greek symbol phi). An angle between the ring-shaped blade surface  35   f  and the tapered surface  36   t  of an adjacent barb is labeled a (Greek symbol alpha), and is preferably between 30 degrees and 60 degrees (with an angle of approx. 45 degrees, as shown, being quite suitable). By way of example, blade surfaces of an alternative set of barbs of the  FIG. 5C  embodiment may be slightly offset as depicted in phantom at  45   f  (with an associated tapered surface  45   t  of the end-barb labeled for reference). Once again, as can be seen in  FIGS. 2A-2B ,  3 ,  5 A- 5 C the inner-surface of hollow  23   b - 23   c  is cylindrically shaped permitting the hollow to slidably-revolve around the stem upon application of a tangential-twisting force applied to handle  21 .  
      In a further distinguishing characterization of the invention, the tool  20  depicted in  FIGS. 2A-2C ,  3 ,  5 A- 5 C has two barbed-ends  22 ,  24 , each one located a distance, respectively d 2 , d 1 , from a knurled handle  21 . Referring also to  FIGS. 6A-6B , removing flexible packing (such as that at  65   a ,  65   b ) in place around a stem (e.g.,  62   a ,  62   b ) of a valve assembly (e.g.,  61   a ,  61   b ) can be done with any of the barbed-end configurations depicted (e.g.,  14 ,  22 ). The stem  62   a ,  62   b  is inserted into an end-port of the hollow extending within the tool—stated another way, the hollow of the tool is placed over the stem—and the stem is slid therealong until barbs  15 - 18 ,  25 - 28 ,  35 - 38  penetrate the flexible packing with at least a portion of a length of the sharp edge. Applying a tangential-twisting force (e.g., see directional arrow  50 ) to the handle  11 ,  21  slidably-revolves the hollow (e.g.,  13 ,  23   b - 23   c ) around the stem, permitting a further penetration into the flexible packing such that a blade surface  15   f - 18   f ,  25   f - 28   f ,  35   f - 38   f ,  45   f - 48   f  of one or more barbs of the end (e.g.,  14 ,  24 ,  22 ) contacts the flexible packing. Thereafter, applying an axial force to the handle (e.g.,  11 ,  21 ) in a direction opposite to an initial force used during the step of inserting, and pulling the flexible packing in contact with the barb surfaces in the opposite direction along the stem, the packing may be removed. For the most part, upon application of this opposite force, the flexible packing is pulled out against respective generally flat/planar blade surfaces  15   f - 18   f ,  25   f - 28   f ,  35   f - 38   f , and  45   f  (depending upon embodiment employed) as oriented, for removal from around the stem (e.g.,  62   a ,  62   b ).  
      As can be better appreciated in connection with  FIGS. 1A-1B ,  2 A- 2 B,  4 ,  5 A- 5 B and  6 A, barbed-end  14 ,  24  the application of tangential-twisting force (e.g., in the direction of arrow  50 ) to penetrate the flexible packing results in a generally simultaneous penetration of respective blade surfaces  15   f - 18   f ,  25   f - 28   f  into the flexible packing (e.g.,  65   a ,  FIG. 6A ). Applying a tangential-twisting force to barbed-ends  14 ,  24  as configured, causes tapered surfaces  15   t - 18   t ,  25   t - 28   t  to also contact (penetrate) the flexible packing.  
      As can be better appreciated in connection with  FIGS. 3, 5A ,  5 C, and  6 B, for the ‘tiered-style’ barbed-end labeled  22 , the application of a tangential-twisting force (either in direction  50 , or—due to the symmetry of barbs  35 - 39 —in a tangential-twisting directed opposite direction  50 ) results in penetrating the flexible packing (e.g., at  65   b ) of respective length(s) of sharp edge of the barbs in a sequential fashion, whereby the tapered surface  35   t  of the end-most barb  35  (though not specifically labeled as such) penetrates first, and thereafter penetration of the respective tapered surfaces ( 36   t - 38   t ) and blade surfaces ( 36   f - 38   f ) penetrate, sequentially into the flexible packing.  
      While certain representative embodiments and details have been shown for the purpose of illustrating the tool and method of the invention, those skilled in the art will readily appreciate that various modifications, whether specifically or expressly identified herein, may be made to any of the representative embodiments without departing from the novel core teachings or scope of this technical disclosure. Accordingly, such modifications are contemplated and intended to be included within the scope of the claims. Although the commonly employed preamble phrase “comprising the steps of” may be used herein in a method claim, applicants do not intend to invoke 35 U.S.C. §112 ¶6. Furthermore, in any claim that is filed herewith or hereafter, any means-plus-function clauses used, or later found to be present, are intended to cover at least all structure(s) described herein as performing the recited function and not only structural equivalents but also equivalent structures.