Abstract:
The disclosure relates to a plastic jacket having air spaces formed by spaced walls used to insulate hot and cold piping systems and the fittings for those systems. The jacket is made from multiple segments, which are joined together along their longitudinal joints. The segments are joined to each other by tongue and groove connections. One segment can be cut longitudinally and glued to another segment to make a larger segment to fit various diameters of pipe. In a further embodiment, the plastic jacket is modified to form the duct of a heating, ventilating and air conditioning system. The inner wall of the jacket forms the air duct. In both embodiments, at least some of the segments have hinge portions created by omitting the inner wall at the hinge portions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     In our U.S. Pat. No. 5,797,415, an insulating jacket was described for use with hot or cold fluid piping systems. The insulating jacket is of especial value on chilled water piping systems. The jacket is used on pipe sections and fittings, such as elbows, and includes thermoplastic sections, which snap together and resilient seals. In our U.S. Pat. No. 6,000,420, we described a similar insulating jacket for a hot or cold piping system having alternate embodiments for fastening and sealing the jacket around the piping system. These insulating jackets are designed to utilize one or more air gaps and to seal the fittings and pipe sections off from the surrounding ambient environment thereby providing an effective vapor barrier to prevent the migration of moisture to the cold surfaces of fittings and pipe sections and of the insulation. The disclosure of U.S. Pat. Nos. 5,797,415 and 6,000,420 to Nicholson et al for Insulating Jacket for Hot and Cold Piping Systems and Method of Use is hereby incorporated by reference into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     The insulated jacket designed for use with hot and cold fluid piping systems is thoroughly discussed in the previously cross-referenced patents. 
     The insulated jacket as used with the air duct system is designed to carry and insulate the air for heating, ventilating and air conditioning (HVAC) systems. Many of the present HVAC systems are formed from metal ducts, which are insulated by adding fiberglass insulation after the ducting system has been installed. 
     Since thermoplastics are the preferred materials of construction, a number of forming methods were described in our previous applications including injection molding and extrusion. However, the expense involved in fabricating the large numbers of molds and dies required to produce insulating jackets to cover all the pipe and fitting sizes from ¼ inch to 42 inches would be prohibitive. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an insulating jacket of thermoplastic having the insulating features described in our previous patents but incorporating a latching design which permits various size insulating jackets to be formed by latching together a number of segments fabricated using only one die or mold. 
     To this end, an insulating jacket assembly for a pipe section has been provided which includes a number of identical flexible thermoplastic segments that snap together end to end through the use of snap and lock/latch mechanisms located along their longitudinal lengths. 
     To extend the jackets capability to fit all pipe sizes, a single adjustable/modified segment is provided which may be adjusted in size to connect with the other identical segments thereby permitting the insulating jacket assembly to enclose more sizes of pipe. Split gaskets and tape are used to form a seal between the junctions of each assembly. 
     Alternatively, an insulating jacket assembly for a fitting in a piping system, has been provided which includes a number of identical flexible thermoplastic segments and a single adjustable segment, as described above, to enclose the fitting of a piping system, such as a Tee. The jacket assembly for the fitting is formed by cutting a jacket assembly for a straight pipe and re assembling the cut sections to form a jacket assembly for the fitting. The jacket sections are joined to each other by welding or gluing. These segments snap together through the use of snap and lock mechanisms, again as described above. Split gaskets and tape are used to form a seal between each end of the fitting jacket assembly and the adjacent pipe section insulating jacket assemblies described in this application. 
     It is a further object of the invention to provide a pre-insulated air duct for use in fabricating the ducting in heating, ventilating and air conditioning (HVAC) systems using the same technology that was applied to the piping system. 
     To that end, an insulating jacket assembly has been provided to form a pre-insulated circular or rectangular air duct which includes a number of identical flexible thermoplastic segments and may include single adjustable segment, as described above, to form the duct. In this application, the flexible and the adjustable thermoplastic segments not only provide the air gap insulation but also provide the carrier pipe that transports air in a heating, ventilating and air conditioning (HVAC) system. As in the piping system applications, the segments are snapped together through the use of snap and lock mechanisms. The flexible stand-offs of the insulating piping jacket are reduced in length (for circular ductwork) or eliminated (for square ductwork) to form the inner wall of the air duct. The pre-insulated duct has at least a singular air gap to provide the insulation. Split gaskets and tape are provided to form a seal between each end of the assemblies. The elbows and tees of the air duct system can be fabricated in the same manner described for the insulating piping jacket. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood when viewed with the following drawings, wherein: 
     FIG. 1 is an exploded perspective view showing all the various elements of the insulating jacket assembly consisting of three identical flex segments on a pipe. 
     FIG. 2 is an end view of FIG.  1 . 
     FIG. 3 is an end view of an individual flex segment. 
     FIG. 3A is an enlarged end view of the finger/spacer and part of the jacket wall 
     FIG. 4 is a partial end view of a pipe jacket assembly consisting of two flex segments of equal length and an adjustable segment installed on a pipe section. 
     FIG. 5 is an end view of an adjustable segment. 
     FIGS. 6A and 6B show end and side views of a short radius elbow covered with a jacket assembly consisting of three identical flex segments and an adjustable segment. 
     FIGS. 7A and 7B show end and side views of a long radius elbow covered with a jacket assembly consisting of three identical flex segments and an adjustable segment. 
     FIGS. 8A and 8B show end and side views of a tee covered with a jacket assembly consisting of three identical flex segments and an adjustable segment. 
     FIGS. 9A and 9B show end and side views of a flanged gate valve covered with a jacket assembly consisting of three identical flex segments and an adjustable segment. 
     FIG. 10 is an end view of an individual flex segment for use in a different application. This segment is modified to create both an inner wall, which acts as an air carrier duct of a HVAC system and a single air gap to provide the insulation for the circular air carrier duct. 
     FIG. 11 is an end view of the multiple flex segments snapped together to produce a circular air duct. 
     FIG. 12 is a perspective view of the multiple flex segments snapped together to form the circular duct section of FIG.  11 . 
     FIG. 13 is an end view of another design of an individual segment, which may be used to create both an inner wall to act as an air carrier pipe and a single air gap to provide the insulation for use on a square duct. 
     FIG. 13A is a partial end view of the segment of FIG. 13 modified to form the duct of FIG.  18 . 
     FIG. 14 is an end view of a 9-inch×9-inch square duct formed from two segments shown in FIG. 13 snapped together. 
     FIG. 15 is an end view of an 18-inch×18-inch square duct formed from four segments shown in FIG. 13 snapped together. 
     FIG. 16 is an end view of another design of individual segments snapped together to form 12-inch×12-inch duct. 
     FIG. 17 is a perspective view of two segments snapped together to form a 9-inch×9-inch square duct (reinforcement inside). 
     FIG. 18 is a perspective view of multiple segments snapped together to form a 9-inch×9-inch square duct (reinforcement outside). 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, the reference numerals denote like elements throughout the several views. FIG. 1 is an exploded view of an installed insulating jacket assembly  1  installed on a pipe  2 . At the junction of the pipe insulating jacket assembly  1  which can be connected to another pipe insulating jacket assembly  1  or fitting insulating jacket assembly is an insulating jacket joint  3  that consists of a split gasket  8  having a hole to receive the pipe  2  and sealing tape  10 . A slit 9 permits the gasket to be installed on the pipe  2 . The sealing tape  10  provides the seal at the junction of two insulating jacket assemblies. An appropriate tape would be 3M 4910 TM acrylic tape. Also shown are three identical extruded thermoplastic segments  4 , which snap together through the use of a latch, which consists of a flap  7  containing a tongue (shown later) that is inserted in a groove (shown later). The pipe jacket assembly  1  can be made of any thermoplastic but PVC is the preferred thermoplastic in approximately 0.050-inch wall thickness. Since the preferred method of making is to extrude the segments, the thickness will vary, preferably, between 0.040-0.050 inches. Clear or translucent PVC is used where monitoring of the system is desirable. Only a portion of the jacket needs to be clear or translucent. The clear or translucent portion preferably extends longitudinally but could extend circumferentially or at an angle to the centerline of the pipe  2 . Further, the clear or transparent section needs to be on only some of the insulating jacket assemblies  1  on a pipe  2 , especially if they are not isolated from each other by seals such as the gasket  8 . The assembly can be made up of two or more identical segments depending upon the diameter of pipe  2 . 
     FIG. 2 is an end view of FIG. 1 showing the three identical segments  4  which snap together through the use of a latch which consists of a flap  7  containing a tongue  18  that is inserted in groove  19 . This view shows the three segments enclosing the pipe  2  with the relative orientation of the outer  11  and the inner  12  jacket assembly walls that produce the insulating properties. This pipe jacket assembly is similar to the jacket assembly described in our U.S. Pat. No. 6,000,420 but differs from that assembly in that it incorporates flexible fingers  14  with an angled end portions  14   a  as stand-offs or spacers to hold the inner wall  12  of the jacket off of the pipe  2  instead of the more rigid stand-offs or spacers described in the first jacket assembly. The flexible fingers  14  provide the inner air gap  15  between the inner wall  12  and the pipe  2  and their flexibility permits the jacket segments  4  to enclose pipe having small variances in diameter. The spacers  16  between outer wall  11  and inner wall  12  form two sides of a triangle  17  without a bottom leg and produce the outer air gap  13 . The apex  17   a  of the triangle functions as a “live” hinge. The fingers  14  produce the inner gap  15  and provide a movable bottom leg for the triangle  17 . The triangle  17 , which has a movable bottom leg, formed by finger  14 , permits the outer wall  11  to flex as a “live” hinge. Of course, a different material of the proper flexibility could be co-extruded at  17   a  to form the hinge. As shown in FIG. 3A, the flexibility of the fingers  14  can be increased by reducing the thickness of the fingers  14  at root portion  14   b  and connecting portion  14   c . For example, the fingers  14  can have a thickness of 0.050 inches with the root portion  14   b  and the connecting portion  14   c  having thickness of 0.030 and 0.040 inches respectively. By making the root portion  14   b  thinner than the connecting portion  14   c , the finger  14  will close off the triangle  17  before reaching its final installed position. The end view also shows how the three flexible jacket segments  4  interlock together as tongue  18  on flap  7  fits in groove  19 . Seal  20  seals at the junctions between adjacent segments  4 . Seal  20  can be made of an elastomeric, flexible material or of strips of a flexible material such as ALCRYN TM, which can be co-extruded (shown in FIGS.  13  and  14 ). Tongue  18  in groove  19  and seal  20  seal the jacket along its longitudinal joints. However, if only one is used to form a seal or neither is used to form a seal, tape could be added later to form a seal along the longitudinal joint between one segment and the next segment. Where there are more than three segments forming the circumference, the latches  7  of some of the adjoining segments may be glued down, taped over or just preassembled to form “halves” or pieces which can be more easily handled in the field as shown in FIG.  6 A. 
     FIG. 3 shows an end view of an individual flex segment  4  in greater detail. The segment is extruded with a curvature. It shows more clearly the flap  7  with its tongue  18  with a barb  18   a  which fits into groove  19  with a lip  19   a  of a connecting identical flex segment and the seal  20 . The flexible fingers  14  with angled end portions  14   a ; root portions  14   b  and connecting portions  14   c  and spacers  16  are also shown in greater detail. The barb  18   a  and the lip  19   a  serve to releasably lock the longitudinally extending joint under the flap  7  together. The angled end portion  14   a  serves to contact the pipe  2  to space the jacket from the pipe thereby forming the inner air gap  15 . 
     FIG. 4 shows a partial end view of a pipe jacket assembly showing two of four. identical flex segments  4  and an adjustable segment  21 . This view shows how the jacket assembly can be enlarged to enclose a larger pipe section (or fitting section). The adjustable segment  21  is created by taking a flex segment  4  and cutting off a portion. The adjustable segment  21  and another flex segment  4  are then joined to form a larger segment  4 , 21  which than can be snapped to the other flex segments  4  to form the jacket assembly  1 . The joining of the cut end or ends  11   b ,  12   b  of the adjustable segment  21  to flex segment  4  can be done by using PVC glue, for example. The swab that applies the PVC glue can usually coat both walls  11   b ,  12   b  by running a swab carrying the glue between them. Walls  11   b ,  12   b  are then slid over the end  11   a ,  11   b  (FIG. 5) of the adjacent segment having the groove  19  and held in place until the glue cures. A flex segment  4  is cut down to the appropriate length to create the adjustable segment  21  prior to joining it to the flex segment  4 . 
     FIG. 5 shows an end view of an adjustable segment  21 . The right end  11   b ,  12   b  of a flex segment  4  is cut down in size to accommodate the circumference of the pipe (or fitting) that the pipe jacket assembly  1  is covering to form the adjustable segment  12 . Then, a portion of this end  11   b  or  12   b  is glued to the other end  11   a ,  12   a  of adjacent flex segment  4  to form the larger segment  4 ,  21  that allows the jacket to fit larger pipe diameters than that which would be possible by only using flex segments  4 . If desired, the adjustable segment can be extruded from a separate die with the spacing between the walls  11 ,  12  being increased by the thickness of the walls  11 ,  12 , such a 0.100 inches for 0.050-inch walls. 
     FIG.  6 A and FIG. 6B show the end view and the side view of the insulating jacket assembly used on a fitting, such as a short radius elbow  25 . The short radius elbow jacket  22  is formed by assembling segments  4 , and  21  if needed. The fitting jacket  22  is manufactured by cutting up pieces/sections of a pipe jacket section  1 . The assembled segments  4  of a length of the pipe insulating jacket assembly  1  has a cylinder of foam of the appropriate size inserted into the jacket assembly to expand the jacket assembly to its maximum circumference which will hold the assembly taut. Then, the jacket assembly  1  is cut along lines which will form sections  24  which will be joined along seams  23  to form the fitting, a short radius elbow. The cuts can be made using a fitting saw, which is a band saw on a movable, miter tabletop that is mounted on ball bearings. A cylinder of foam of the appropriate size is placed in the jacket assembly  1  to hold the assembled segments  4  in proper alignment during the cutting process. The cut sections  24  can be joined to each other by hot air welding or by gluing using adhesives. An acceptable glue is 3M JET MELT ADHESIVE 3792 LM TM. Flex segments  4 , and adjustable segment  21  where needed, are snapped together around the elbow  25  in a manner similar to their installation around a pipe. The four sections  24  make up each half of the jacket, as shown in the side view. The segments  4 ,  21  can be reassembled to form two halves. The halves can be formed by gluing down latch  7  onto wall end  11   a , taping over the latch  7  and wall end  11   a  or by merely placing tongue  18  in groove  19  thereby joining one segment  4  to the next segment  4 . 
     FIG.  7 A and FIG. 7B show the end view and side view of the flex system used for a long radius elbow  26 . Flex segments  4 , and adjustable segment  21  if needed, are snapped together around elbow  26  in a manner similar to their installation around the short radius elbow  25 . The latch  7  may be opened and closed at the top and bottom of the elbow. The six sections  24  make up each half of the jacket, as shown in the side view. 
     FIG.  8 A and FIG. 8B show the end view and side view of the insulated fitting jacket  22  used for a tee  27 . Flexible segments  4  and adjustable segment  21  are snapped together around the tee  27  in a manner similar to their installation around the elbows. The latches  7  may be opened and closed at the top and bottom of the tee. The three sections  24  make up each half of the jacket, as shown in the side view. 
     FIG.  9 A and FIG. 9B show the end view and side view of the flex system used on a flanged gate valve  29 . Flexible segments  4  and adjustable segment  21  are snapped together around the valve in a manner similar to their installation around the tee. Similar to the jacket assembly around the tee, the section  24  covering the bonnet having a protruding V-shaped cut may be glued at the seams  23  to the other section  24  having an inverted V-shaped cut. As with the body of the valve, the bonnet may be enclosed with multiple flex segments  4 . The latch  7  may be opened and closed at the top and bottom of the valve. Also, since the valve body flange  30  exceeds the diameter of the pipe  2 , the ends of the valve body jacket section must be sealed with split gaskets  8 , so that the air space between the valve body jacket and the pipe  2  are sealed from the surrounding environment. Tape  33  seals the junctions of the valve body jacket  22  and the gaskets  8 . The tape or a caulk may also be used at the junction of the gaskets  8  and the pipe  2 . Similarly, the top of the section  24  on the valve bonnet should also be sealed with a solid gasket  34  so that the air space between the valve bonnet jacket, which encloses the valve bonnet and handle, is sealed from the surrounding environment. Tape  33  seals the junction at the valve bonnet section  24  and the gasket  34 . Gasket  34  is similar to gasket  8  except it has no hole for the pipe or slit for mounting. 
     FIG. 10 shows the end view of a modified flex segment  36  being used in a different application. The segment  36  is modified to form a section of an insulated circular air duct  35 . The legs  37  are free to move relative to the wall  12 , close the triangles  17  and create a portion of the inner wall  12  of the air carrier duct  35  of the HVAC system. The legs  37 , like fingers  14 , seal off the triangular portion  17  of the air gap  13  to provide insulation. Multiple flex segments  36  may be latched together to form a section of pre-insulated, circular air duct  35 . The thickness of the wall segments  36  can be of the same order of magnitude as that of segments  4 . The segments  36  can also be extruded from PVC plastic. 
     FIG. 11 shows an end view of four joined segments  36  forming an insulated circular duct  35 . These segments  36  are latched together in a manner similar to those in FIG. 2, that is, by using tongue  18  having barb  18 A and groove  19  having lip  19 A. As in FIG. 4, an adjustable segment, like segment  21 , can be used with segments  36  where the segments  36  are not sufficient to create the duct size. The adjustable segment for the air duct would be created and joined as disclosed previously. 
     FIG. 12 shows a perspective view of four joined segments  36  forming an insulated circular duct section  35 . One duct section  35  can be assembled with other duct sections  35  by the use of gaskets and tape in the same method that is used in FIG.  1 . Only in this instance, the gasket would have a central hole that would match the size of the inner wall  12  of the duct  35 . Alternatively, the gasket can be omitted, and the duct sections  35  can be merely taped to each other to form a run of ducting. The duct sections can be supported by the conventional duct hangers or other support devices. 
     FIG. 13 shows an end view of another embodiment of the air duct flex segment  38  which can be used for square insulated HVAC ducting  35 . The segment  38  consists of reinforced sections  39  and center sections  40 . Segments  38  have a groove  19  in the side of the segment. Tongue  18  located at one end of the segment  38  is designed to fit inside groove  19  of another segment  38 . ALCRYN TM strips  20  can be used to provide a seal at the latch. 
     FIG. 13A shows an end view of the segment  38  of FIG. 13, which has been modified to form the duct of FIG.  18 . In this modification, tongue  18  is formed on the outer wall  11  which will become the inner wall in the configuration of FIG.  18 . The seal  20  formed by ALCRYN TM strips is moved from reinforced section  39  to wall  11 . The strips  20  will seal against the wall that contains groove  19 . 
     FIG. 14 shows an end view of two flex segments  38  joined together to form a 9×9-inch square insulated duct section  35 . The center  41  of each flex segment  38  located between the two reinforced portions  39  of these segments has a thickness of 0.050 inches and is flexible and therefore can bend on a 90° angle. FIG. 14 shows the two segments bent on 90° angles, joined, and latched at two corners by inserting tongues  18  in grooves  19 . The strips  20  also help provide seals at the latch. 
     FIG. 15 shows an end view of four segments  38  joined together to form an 18×18-inch square insulated duct section  35 . For this duct section, the individual segments  38  are not bent on 90° angles and are assembled in their straight configuration. The segments  38  are joined at each corner by inserting the tongue  18  of one segment into the groove  19  of the other. The strips  20  help provide a seal at the corners. 
     FIG. 16 shows the end view of a 12×12-inch square insulated duct section  35  which incorporates two flex segments  44  having a slightly different design from flex segment  38 . The center portions  40  of each segment are doubled in length. Each segment  44  is bent at 90° angles in the center  41  and joined and sealed at two corners by inserting tongues  18  in grooves  19  in a manner similar to that shown in the 9×9-inch insulated square duct section. The strips  20  help provide a seal at the corners. 
     FIG. 17 is a perspective view of the duct section  35  of FIG. 14 showing multiple flex segments snapped together to form a 9×9-inch insulated square duct section. The FIGS. 14,  15 ,  16  and  17  show the reinforced corners on the inside of the duct. However, the segment corners could be bent 90° in the opposite direction so that the reinforcement  39  at the corners of the duct  35  is on the outside and the flat surfaces on the inside as shown in FIG.  18 . 
     As an example of the relative dimensions of a segment for piping insulating jacket, the outer circumferential length from end of latch  7  to the end of seal  20  is 10⅝ inches, and the outer circumference from the tongue to the groove is 9⅞ inches. The outer air gap/space  13  is ⅜ inches thick and 2¼ inches on the outside by 1⅞ inches on the inside. The standoff is ⅜ inches on the triangle leg portion and ⅜ inches on the angled end portion. The longitudinal length of the segment is 3 feet. 
     Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof, which is assessed only by a fair interpretation of the following claims.