2.0 BACKGROUND ART A pipe freezer works by removing heat quickly enough from the liquid within a section of pipe that an ice plug forms in that section of pipe, thus effectively preventing the flow of liquid through that section of pipe. This ice plug acts as a temporary valve. When the ice plug is properly maintained (kept frozen), repairs can be performed on the pipe in the vicinity of the ice plug without the need to drain the piping system.

2.1 Two Primary Methods of Freezing Pipes 1. Expendable refrigerants sprayed directly onto the pipe and vented to the atmosphere.

2. Compression cycle refrigeration, which circulates the same refrigerant in a closed loop as a refrigerator does.

1. Expendable refrigerants: These are the traditional refrigerants for freezing the contents (in a small section of pipe 5.08 cm-25.4 cm (2 in-10 in) in length) within plumbing piping or other fluid carrying conduits with a liquid that will freeze within the temperature range of the refrigerant being used.

The three more commonly used expendable refrigerants are listed below with their refrigerant number and boiling point at sea level (14.7PSIA).

1. Liquid Carbon Dioxide: R744,-109 F (-78 C) 2. Liquid Nitrogen: R728,-320 F (-196 C) 3. Liquid Helium: R707,-425 F (-269 C) On pipes up to three 7.62 cm (three inches) of inner diameter the refrigerant of choice is carbon dioxide. There are five or more kits using carbon dioxide currently on the market in the US. Liquid nitrogen and liquid helium are not as available, are only packaged in large containers, and require additional safety training. There are companies that specialize in pipe freezing of pipes up to 152.4 cm (60 in) inside diameter. On pipes this large, liquid nitrogen or liquid helium would be used depending upon the application.

The current expendable refrigerant pipe freezing kits (for pipes up to 7.62 cm (3 in) ID) employ bags or collars that wrap around the pipe. The collars are hinged on one side and have a locking screw. The bags are wrapped around the pipe and tied on each end. Each type of kit has a spray head, which sprays the refrigerant over the pipe. A high-pressure hose delivers the liquid refrigerant to the spray heads from the tank.

As the liquid refrigerant is sprayed over the pipe within the bag or collar, dry ice is being formed due to the containment of the refrigerant (i. e., the refrigerant is not allowed to fully evaporate into the atmosphere). When enough dry ice is formed, the refrigerant valve on the tank is closed stopping the flow of refrigerant in to the bag or collar. To conserve refrigerant, heat is now removed from the pipe through the dry ice. The ability of the dry ice to remove heat from the pipe is much less than that of the denser liquid refrigerant. Throughout the process, the liquid refrigerant is turned on and off to conserve

refrigerant, while depending on the dry ice, which was formed, to remove heat from the pipe.

Draw backs of free flow systems over Applicant's Multi-Cavity Adapter/Cartridge Evaporator 1. Requires longer freeze times.

2. Consumes more refrigerant 3. Cannot control vented gas location 4. Cost of equipment.

5. Danger of hose failure due to cold bending.

DESCRIPTION OF RELATED ART INCLUDING INFORMATION DISCLOSED UNDER 37 CFR 1.97 AND 37 CFR 1.98.

The present inventor invented United States Patent 4,309,875 issued to Radichio Jan, 12,1982 for a Pipe Freezer or the Like, in which a self contained freezing device forms a plug of ice within a pipe section. A refrigeration unit supplies refrigerant to a cradle-like freezer unit within which the section of pipe to be frozen is held in spaced relation to the inner face of the freezer. The space between the underside of the pipe and the inner face of the freezer is filled with water, for example, by spraying. As the water in contact with the cradle-like freezer unit freezes, it covers the outer surface of the pipe section with an ice jacket. Alternatively, a bag of freezable gel may be substituted for the water spray and placed over the inside face of the freezer; and then the pipe section is placed within the fold of the bag. In the case of either alternative, the refrigerant is maintained inside the freezer, and out of contact with the pipe.

My United States Patent 5,548,965 to Chen and Radichio issued on Aug. 27,1996 for a Multi-cavity Evaporator which has an outer surface and an inner chamber. The outer surface has at least two pipe receiving surfaces and a pair of ends. The evaporator has a

bore extending from one of the ends to the inner chamber. A tube extends into the bore sealing the chamber, such that a refrigerant flows into the inner chamber through an inner tube and out of the inner chamber through the outer tube. Each of the pipe receiving surfaces has a distinct surface adapted for receiving different size pipes.

Patent EP 0 145 114 B1 issued to H. Ronald discloses a pipe freezing device having collar and saddle arrangements.

Patent 5,836,167 issued to S. D. Clouston et al discloses a method and apparatus for freezing a large pipe. The apparatus utilizes a hinge/latch combination to encircle and secure a section of a large pipe.

Patent 5,680,770 issued to R. M. Hall et al discloses an apparatus for freezing liquid in a fluid conducting pipe. This apparatus comprises a freeze jacket having two halves for releasably surrounding a section of pipe.

Patent WO 89/01110 issued to Laiho et al discloses a heat transfer device comprising preformed grooves for different pipe sizes and shapes.

3.0 DISCLOSURE OF INVENTION 3.1 Opening The present invention uses a multi-cavity adapter having from two to eight cavities to fit standard plumbing pipes in copper, steel and plastic, metric and US standard. The refrigeration evaporator fits into a cylindrical bore in the core of the radial multi-cavity array. The cavities are arrayed around the circumference of the bore. The extrusion that forms the array is of aluminum or the like.

The coolant lines are elbowed at 90 degrees to the evaporator's longitudinal axis to facilitate attachment to pipes in small or tight spaces and from the side of the pipes. The central bore

in the adapter body has a diameter slightly larger than the diameter of the evaporator which allows the evaporator to swivel freely in the adapter body thus minimizing wear and tear on the refrigeration lines to the evaporator when the evaporator is inserted into the central bore of an adapter body of the multi cavity adapter. Any of the cavities on the adapter body can be lined up with the pipe. When a single adapter is being used, the adapter is positioned on the pipe and secured with a strap having hook and loop fastening material. Then the cartridge evaporator is plugged into the adapter.

More preferably two units, a unit on either side of the pipe, are strapped in place to fully surround the pipe. Most preferably a special set of adjustable retainer mechanisms is used to tightly secure the adapters to the section of pipe to be frozen.

3.2 Contents The above features are objects of this invention. Yet further objects are as follows: An object of the instant invention is to provide a pipe freezer that is and sturdy, light weight, and easy to use.

A further object is to provide a pipe freezer that is economical in cost to manufacture A still further object is to provide a pipe freezer which easily accommodates pipes of different outside diameters.

Still another object is to provide an evaporator specially adapted to be used in applicant's pipe freezer.

A further object is to provide a retainer mechanism for Applicant's pipe freezer which enables it to be quickly fastened

and tightened on pipes of various outside diameters.

Yet another object is to provide pipe freezing systems for both the use of expendable and nonexpendable refrigerants.

Still another object is to provide a pipe freezing system which can be used with pipes which have restricted access.

These and other objects, features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings and will be otherwise apparent to those skilled in the art.

For the purpose of illustration of this invention, several preferred embodiments are shown in the accompanying drawings.

It is to be understood that this is for the purpose of example only and that the invention is not limited thereto.

4.0 BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a perspective view of a pipe freezing system utilizing my multi cavity adapter and using nonexpendable refrigerants; Fig. 2 is a perspective view of one of the adapter bodies of the multi cavity adapter; Fig. 3 is an enlarged perspective view of Figure 1 with most of the protective hose and the refrigeration system removed; Fig. 4 is a bottom view of the Fig. 3; Fig. 5A is a side perspective view of an adapter body with the cartridge evaporator removed; Fig. 5B is an exploded view of Fig. 5A, and also shows a turned over evaporator cap to show its details; Fig. 6 shows an elevation in section of a pipe with frozen plug; Fig. 7 is a diagrammatic plan view of the refrigeration unit of Fig. 1; Fig. 8 is an illustration of the fact that the secondary adapter

body is substantially a mirror image of the primary adapter body ; Fig. 9 shows the adjustment settings of the special retainer mechanism required to interconnect the adapter bodies around any of the four standard pipe sizes that the adapter bodies can accommodate ; Fig. 10 is an exploded view of the special retainer mechanisms ; Fig. 11 shows a single adapter strapped to a pipe ; Fig. 12 which shows two adapters strapped to a pipe; Fig. 13A shows a perspective view of a pipe freezing system having one evaporator utilizing expendable refrigerants which utilizes my multi cavity adapter ; Fig. 13B shows a perspective view of a pipe freezing system having two evaporators utilizing expendable refrigerants which utilizes my multi cavity adapter ; Fig. 14 is an enlarged perspective view of Figure 13 with most of the protective hose and the tank removed; Fig. 15 is a diagrammatic plan view of the invention in use when using an expendable refrigerant ; Fig. 16 is a diagrammatic plan view of the invention in use when using an nonexpendable refrigerant; Fig. 17 is a perspective view of the tight space of Fig. 16 showing the invention mounted upon the section of pipe to be frozen ; Fig. 18 is a perspective view of the tight space of Fig. 16 showing the invention mounted upon the section of pipe to be frozen; Fig. 19 is a perspective view of Fig. 18; 5.0 BEST MODE FOR CARRYING OUT THE INVENTION 5.1 Detailed Description of the Elements Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, Figure 1 illustrates a perspective view of a pipe

freezing system (utilizing non-expendable refrigerants) utilizing my multi-cavity adapter. (Figure 13, described later, illustrates a perspective view of a pipe freezing system utilizing expendable refrigerants which utilizes my multi cavity adapter.) The multi-cavity adapter, generally designated as 20 in fig. 1, is designed for the removal of heat from liquid filled pipes, such as 22, to bring the liquid contents 24, as in Figure 6, below the liquid's freezing point, and to cause an ice blockage 26, as in fig. 6, within pipe 22. With ice plug 26 in place, pipe 22 may now be cut open as at 28, to make plumbing repairs without the need of a valve.

As best seen in Figures 2 and 3, the multi-cavity adapter for a pipe freezer, generally shown by reference numeral 20, consists of an elongated piece of thermally conductive material 30 which has a first end face 32, a second end face 34, and a bore 36 passing through the piece of thermally conductive material 30. This elongated piece of thermally conductive material 30 will be referred to as an adapter body. The bore 36 serves as a cartridge evaporator receiving port for the reception of a cartridge evaporator 38 therein. Figure 5A shows a cartridge evaporator 38 removed from the cartridge evaporator receiver port 36 of an adapter body 30. Figure 5B is an exploded view of Figure 5A, and also shows a evaporator cap 136 upside down to reveal its structure. The bore 36 extends from the first end face 32 to the second end face 34 of the adapter body 30.

Preferably, the bore 30 is a central bore 30. The outer surface 40 of the adapter body 30 has a plurality of concave pipe receiving surfaces 42-48. Preferably, each concave pipe- receiving surface 42-48 has an arc of approximately 180 degrees.

Each concave pipe receiving surface 42-48 has a specific distinct radius of curvature which is different than the radii of curvature of the other pipe receiving surfaces 42-48. Thus, pipes 22 with different outside diameters can be quickly and easily accommodated. (Please see Figure 9.) The intersection of each pipe receiving surface 42-48 and the outer surface 40

defines a first corner edge 50,54,58,62 and a second corner edge 52,56,60,64 of each of the pipe receiving surfaces 42- 48. The intersection of each corner edge 50-64 with the first end face 32 defines a corner point of the first end face. The intersection of each corner edge with the second end face 34 defines a corner point of the second end face 34.

Applicant's preferred embodiment of a multi cavity adapter 20 has an adapter body 30 with at least four pipe receiving surfaces 42-48 so that various sized pipes can be accommodated.

As shown in Figures 2 and 9, the four pipe receiving surfaces 42-48 of the adapter body can accommodate pipes with outside diameters of 1.651 cm, 2.921 cm, 2.286 cm, and 4.191 cm (0.65, 1.15,0.90, and 1.65 inches) respectively. The adapter body 30 of the multi cavity adapter 20 is thus designed to fit standard plumbing pipes in copper, steel and plastic, in both metric and US standard sizes. Occasionally, however, one will be required to freeze a pipe with a diameter which is different from that of the four pipe receiving surfaces 42-48. For this purpose applicant's invention also includes a bushing adapter 70 (also called a reducer bushing, or sleeve) for accommodating pipes with other outside diameters. As shown in Figures 11-12, the outer surface 72 of the bushing adapter 70 is convex and complimentary to one of the concave pipe receiving surfaces 42- 48 of the adapter body 30. The inner surface 74 of the bushing adapter 70 is concave and has a specific distinct radius different from the pipe receiving surfaces 42-48 of the adapter body 30 and is adapted to receive a pipe.

Preferably, as shown in Figure 3, Applicant's invention includes a second elongated piece of thermally conductive material 78 which will be referred to as the secondary adapter body 78, and, in this case, the first elongated piece of thermally conductive material 30 will be referred to as the primary adapter body. The secondary adapter body 78 is substantially a mirror image of the primary adapter body 30. (It

should be noted, as shown in Figure 8, that if one places two of the primary adapter bodies 30,31 in a row 80 from left to right, and the second one 31 in the row 80 is rotated about the central axis of its central bore 36 by 180 degrees (as shown in row 82) and then turned upside down (as in row 84), it is a mirror image of the first one 30 in the row.) Applicant's invention contemplates two ways of fastening the multi cavity adapters 20 to the section of pipe 22 to be frozen. In Applicant's preferred embodiment as shown in Figure 3, both the primary 30 and secondary 78 adapter bodies have locking channels 86 which are substantially parallel to the axes of the central bores 36 of the adapter bodies and extend from the first end face 32 to the second end face 34 of each of the adapter bodies 30,78. As shown in Figure 1 there are four locking channels 86 in each adapter body. Each locking channel 86 has a channel opening 88 in the first end face 32 and a second channel opening 89 in the second end face 34. Preferably, the circular edges of the channel openings 88,89 of these locking channels 86 are approximately 0.25 cm (0.1 inches) from an edge of the adapter first end face 32 and situated between the corner points of the first end face 32 at a position where there will be no interference between the pipe section 22 to be frozen and the retainer mechanisms 90,92 when the retainer mechanisms 90,92 are inserted in those channels 86. Most preferably as shown in Figure 9, the channel openings 88 of these locking channels 86 are situated such that the number of adjustment settings of the special retainer mechanism required to interconnect the adapter bodies around any of the four standard pipe sizes that the adapter bodies can accommodate are minimized.

Special adjustable fastening mechanisms such as the retainer mechanisms 90,92 as shown in Figure 3 (and in greater detail in Figure 10 which is an exploded view of these) are used

to fasten the primary 30 and secondary 78 adapter bodies to the section of pipe 22 to be frozen. The first retainer mechanism 90 has a first prong 94 and a second prong 96. These prongs 94,96 are threaded at their ends 98. The first prong 94 is adapted to be received into a channel opening 88 of the primary adapter body 30, and the second prong 96 is adapted to be received into a channel opening 88 of the secondary adapter body 78, so that when the primary 30 and secondary 78 adapter bodies are aligned such that a pipe receiving surface 42-48 of the primary adapter body 30 is facing a pipe receiving surface 42-48 of the secondary adapter body which has the same radius of curvature as the primary adapter body 30, the primary 30 and secondary 78 adapter bodies can be hingedly fastened together by the first retainer mechanism 90, such that the primary 30 and secondary 78 adapter bodies can be draped around the section of pipe 22 which is to be frozen. The first retainer mechanism 90 includes two nuts 100,100 for threading onto the ends 98,98 of the threaded prongs 94,96 for securing the first retainer mechanism 90 in the locking channels 86,86.

The second retainer mechanism 92 is essentially similar to the first retainer mechanism 90. It has a first prong 94 and a second prong 96, and the prongs are threaded at their ends. The first prong 94 is adapted to be received into a locking channel 86 of the primary adapter body 30, and the second prong 96 is adapted to be received into a locking channel 86 of the secondary adapter body 78, so that the primary 30 and secondary 78 adapter bodies can be fastened together, such that the primary 30 and secondary 78 adapter bodies can tightly encompass and secure the section of pipe 22 which is to be frozen.

In Applicant's preferred embodiment, special retainer mechanisms 90,92 as shown in Figure 3, are used to fasten the multi-cavity adapters 20 to the section of pipe 22 to be frozen.

Each retainer mechanism 90,92 consists of a first and second

locking pin 102,104, a straight pin 116, which interconnects them, and a spring 118 under tension mounted on the straight pin 116 between the two locking pins 102,104 to hold the locking pins 102,104 apart from one another. As best seen in Figures 3 and 10, the first retainer mechanism generally shown by reference number 90 in Figure 10 consists of a first locking pin 102 whose first end 106 has a golf club-like head 108 which has a nonthreaded hole 110. The golf club-like head 108 is offset from the central axis of the locking pin 102 so that when the retainer mechanisms 90,92 are inserted into the adapter bodies to be joined, the offsets will ensure that the straight pins 116,116 of the retainer mechanisms 90,92 will not come in contact with the section of pipe 22 to be frozen. These golf club-like heads 108,110 are referred to as offset golf club- like heads. The second end 120 of the first locking pin 102 is threaded. The second locking pin 104, likewise, has a golf club- like head 110 which has a threaded hole 114. The diameter of this threaded hole 114 is smaller than the diameter of the nonthreaded hole 112 in the golf club-like head 108 of the first locking pin 102. The second end 120 of the second locking pin 104 is threaded. These two locking pins 102,104 are connected via a straight pin 116. The straight pin 116 has a first end with an Allen head 122 with a diameter larger than the diameter of the nonthreaded hole 112 in the golf club-like head 108 of the first locking pin 102. The straight pin is threaded except for the Allen head end 122. The straight pin 116 is adapted to be inserted into the nonthreaded hole 112 of the offset golf club like head 108 of the first locking pin 102. It is then pushed through that hole 112 until it engages the threaded hole 114 of the offset golf club like head 110 of the second locking pin 104, and then is screwed into the threaded hole 114 of the second locking pin 104. A pair of nuts 110,110 are screwed onto the second ends 120,120 of each locking pin to secure the first retainer mechanism 90 in the locking channels 86,86. The Allen head end 122 of the straight pin 116 is then turned to draw

together the golf club-like heads 108,110 of the locking pins 102,104 and thus tighten and secure the adapter bodies 30,78 on the section of pipe 22 to be frozen.

Preferably, a spring 118 under tension is mounted on the straight pin 116 of each retainer mechanism 90,92. This spring 118 serves to push apart and hold the first and second locking pins 102,104 in substantially parallel alignment to one another, which enables one to simultaneously insert the locking pins 102,104 into corresponding locking channels 86,86 of the primary 30 and secondary 78 adapter bodies.

The second retainer mechanism 92 consists of a first locking pin 102 whose first end 106 has a golf club-like head 108 which has a nonthreaded hole 110. Again, the golf club-like head 108 is offset from the central axis of the locking pin 102 so that when the retainer mechanisms 90,92 are inserted into the adapter bodies to be joined, the offsets will ensure that the straight pins 116,116 of the retainer mechanisms 90,92 will not come in contact with the section of pipe 22 to be frozen. As mentioned above in the description of the first retainer mechanism, these golf club-like heads 108,110 are referred to as offset golf club-like heads. The second end 120 of the first locking pin 102 is threaded. The second locking pin 104, likewise, has a golf club-like head 110 which has a threaded hole 114. The diameter of this threaded hole 114 is smaller than the diameter of the nonthreaded hole 112 in the golf club-like head 108 of the first locking pin 102. The second end 120 of the second locking pin 104 is threaded. These two locking pins 102,104 are connected via a straight pin 116. The straight pin 116 has a first end with an Allen head 122 with a diameter larger than the diameter of the nonthreaded hole 112 in the golf club-like head 108 of the first locking pin 102. The straight pin is threaded except for the Allen head end 122. The straight pin 116 is adapted to be inserted into the nonthreaded

hole 112 of the offset golf club like head 108 of the first locking pin 102. It is then pushed through that hole 112 until it engages the threaded hole 114 of the offset golf club like head 110 of the second locking pin 104, and then is screwed into the threaded hole 114 of the second locking pin 104.

In use, the locking pins 102,104 of the second retainer mechanism 92 are not fully inserted into the locking channels 86,86. Therefore, when the Allen head 122 of the straight pin 116 is tightened, thus pulling the upper parts of the locking pins 102,104 together, the lower tips 120,120 of the locking pins 102,104 spread apart and contact the inner walls of the locking channels 86,86. Thus the locking pins 102,104 bind in the locking channels 86,86, thus securing the locking pins 102, 104 in the locking channels 86,86, and a second set of nuts is not needed to hold the locking pins 102,104 of the second retainer mechanism in the locking channels 86,86. In other words, by tightening the Allen head 122 of the straight pin 116 interconnecting the two locking pins 102,104, we can make the distance between the two locking pins 102,104 less than the distance between the channel openings 88,88 of the adapter bodies 30,78 we are fastening together around the section of pipe 22 to be frozen, and thus the locking pins 102,104 will bind as you push them into their set of channel openings 88,88.

The approximate distances between channel openings of the adapter bodies to be joined by the retainer mechanisms 90,92 in Applicant's preferred embodiment are shown in Figure 9.

Applicant has found that if both retainer mechanisms 90,92 are inserted in the same ends of the adapter bodies 30,78, when the Allen heads of the straight pins 116,116 are turned to tighten the locking pins 102,104, the adapter bodies 30,78 are pulled together at that end and tend to spread apart at the other end. The result is that there is not a good overall contact of the adapter bodies 30,78 on the section of pipe 22

to be frozen. Therefore, preferably, if the first retainer mechanism 90 is inserted in channel openings 88,88 of the first end faces 32,32 of the primary 30 and secondary 78 adapters, the second retainer mechanism 92 should be inserted in channel openings 89,89 of the second end faces 34,34 of the primary 30 and secondary 78 adapters. When this is done, the two adapter bodies 30,78 can be tightly secured to the section of pipe 22 to be frozen.

An alternate adjustable fastening mechanism for fastening a multi cavity adapter 20 to the section of pipe 22 to be frozen is a flexible strap with hook and loop fastener material such as shown in Figure 11 which shows a single adapter 20 strapped to a pipe 22 and Figure 12 which shows two adapters 20,20 strapped to a pipe. In use, pipe 22 is wet. Then two adaptors 20 and 20 are strapped by hook and loop (such as Velcro@) strap 124 around pipe 22. Thus the two adaptors 20,20 clamp to both sides of pipe 22.

As shown in Figures 1,3, and 4, a close fitting cartridge type evaporator 38 is inserted in the central bore 36 of each adapter body 30,78. This type of cartridge evaporator provides a way for using a refrigerant to freeze a pipe 22 for those types of pipe freezers which use Applicant's multi cavity adapter 20 to encompass the section of pipe 22 to be frozen.

As best seen in Figures 5A and 5B (which is an exploded view of Fig. 5A), the cartridge evaporator 38 has an inner chamber 126 and a bore 128 which extends from the first end surface 130 of the cartridge evaporator to the inner chamber 126. A metering tube 132 extends into the bore 128 and protrudes into the inner chamber 126 of the evaporator 38 for moving a refrigerant into the inner chamber 126 of the evaporator 38 at a predetermined rate. The metering tube 132 of Applicant's invention is a capillary tube having an outside diameter of

1.778 mm (0.07 inches) and an inside diameter of 0.5588 mm (0.022 inches). A return tube 134 extends out of the bore 128 for moving evaporated refrigerant out of the inner chamber 126 of the evaporator. In use, refrigerant flows into the inner chamber 126 through the metering tube 132 and evaporated refrigerant flows out of the inner chamber 126 through the return tube 134. Preferably, as shown in Figures 5A and 5 B, the metering tube 132 passes through and is surrounded by the return tube 134, thus providing protection for the metering tube 132.

Preferably, the first end 138 of the cartridge evaporator 38 has a cap 136 which is fixedly fitted over the first end 138 of the cartridge evaporator 38. The cap 136 has a side wall 140 which extends along the outer surface 39 of the evaporator 38 for at least a portion of the length of the outer surface 39.

The cap 136 has a first end 144 which is closed, and a second end 146 which has a face 150 with a sufficiently large bore 148 in it for the second end 146 of the cap 136 to fit over the first end 138 of the evaporator 38. The face 150 of the second end 146 of the cap 38 has an outside diameter which is greater than the diameter of the central bore 36 of the adapter 38 serving as the cartridge evaporator receiving port 36. Thus, when the second end 152 of the evaporator 38 having this cap 136 is inserted into the central bore 36 at one end of the adapter body 30,78 and pushed along the bore 36, the face of the cap 136 eventually comes to rest against the end face (32 or 34) of that adapter 30,78.

As shown in Figures 1 and 13, in which a nonexpendable refrigerant is being used, Applicant's invention contemplates a complete pipe freezing system 154 for freezing the contents of a section of pipe 22. As shown in Figure 7 which shows the interior details of the refrigeration unit, this pipe freezing system 154 consists of a refrigeration unit 156 having a compressor 158 for compressing the refrigerant from a low

pressure to a high pressure, a pair of condensers 160,160 downstream of the compressor 158 for condensing the refrigerant from a high temperature gas to a lower temperature liquid, Applicant's multi-cavity adapter 20, fastened to the section of pipe 22 which is to be frozen, and a cartridge type evaporator 38 inserted into a cartridge receiving port 36 of the multi- cavity adapter 20. Metering tubes 132,132 extend between the condensers 160,160 of the refrigeration unit 156 and the evaporators 38,38 for moving the refrigerant to the evaporators 38,38. Return tubes 134,134 extend between the evaporators 38, 38 and the compressor 158 of the refrigeration unit 156 for moving refrigerant from the evaporators 38,38 to the compressor 158.

Refrigerant enters each evaporator 38 through a metering device such as capillary tube 132, or a thermostatic expansion valve (not shown), or an automatic expansion valve (not shown), or a fixed orifice (not shown). The pressure within the evaporator chamber 126 is much lower than the liquid entering.

As shown in Figure 16, as the liquid enters the chamber 126, it expands 170 into a saturated vapor, reducing its pressure and temperature. Because higher temperature travels to cooler temperature, this evaporation results in the removal of heat from evaporators 38,38. Then superheated refrigerant returns via return suction tube 134 to the compressor 158 (fig. 7).

As in Figures 3 and 5, when the evaporators 38,38 are positioned within the central evaporator receiving ports 36,36 of the adapter bodies 30,78 of the multi cavity adapter 20, the heat will flow from the adapter bodies 30,78, and when the adapter 20 is cradling a pipe 22, heat is removed from the pipe 22. For best thermal transfer, water, or any heat transfer media, may be sprayed between pipe 22 and the adapter bodies 30, 78, and in the evaporator receiving ports 36,36 of the adapter bodies 30,78 before placing the evaporators 38,38 therein.

As shown by Figure 13A, in the special case where an expendable refrigerant is being supplied by a tank of refrigerant, a complete pipe freezing system 200 will consist of Applicant's multi-cavity adapter 20 fastened to the section of pipe 22 which is to be frozen, and a cartridge evaporator 38 is inserted into a cartridge receiving port 36 of one of the adapter bodies 30,78. A metering input tube 132 extends between the tank 202 and the evaporator 38 for receiving refrigerant at its first end 204 from the tank 202 and for moving the refrigerant out of its second end 206 (see Figure 5B) to the evaporator 38 at a predetermined rate. Preferably, the metering input tube 132 extends into the evaporator 38, a distance which is three quarters of the length of the evaporator 38. (Please see Figures 5B and 15.) Evaporated refrigerant is expelled to the atmosphere through the return tube 208 which, for expendable refrigerants, is actually a discharge vent. Preferably, this discharge vent 208 extends to a safe discharge area 210. (A typical flow rate would be 0.675 kg (1.5 pounds) in 5 minutes for a 3.81 cm (1.5 inch) ID copper pipe with an ambient temperature of 70 F. The time to freeze the section of pipe 22 under these circumstances would be about 13 minutes.) The tank 202, of course, should be sufficiently charged with refrigerant to freeze the contents of the section of pipe 22. Since the metering tube 132 is somewhat fragile, Applicant's invention utilizes a protective hose or tube 212 (which will be referred to as the original protective tube) to encircle the metering input tube 132 for at least a portion of the length of the metering input tube 132.

Most preferably, as shown by Fig 13B, in the above pipe freezing system using expendable refrigerants, a cartridge evaporator 38 is inserted into the cartridge receiving ports 36, 36 of each of the adapter bodies 30,78 of the multi-cavity adapter 20. (Please see Figures 5A and 5B.) For this configuration, as shown in Figures 13B-15, a metering input tube

132 extends outward from the tank 202 for receiving refrigerant at its first end 204 from the tank 202 and for moving the refrigerant out of its second end 206 (Fig. 15) at a predetermined rate. Preferably this metering input tube 132 is a capillary tube. An input tee 214 is situated between the second end of this metering input tube 132 and the two evaporators 38, 38. This input tee 214 has an input port 216 and two output ports 218,218. This tee 214 receives refrigerant from the second end 206 of the metering input tube 132 through the tee's input port 216 and supplies refrigerant out of each of the tee's two output ports 218,218. An additional metering input tube 220,220 is situated between each of the two output ports 218, 218 of the tee 214 and each of the two evaporators 38,38. These additional metering input tubes 220,220 receive refrigerant from each of the two output ports 218,218 of the input tee 214 at their reception ends 222,222 and supply this refrigerant out of their supply ends 224,224 to each of the two evaporators 38, 38. Preferably, these additional metering input tubes 220,220 are capillary tubes as well. An additional protective tube (220 with 226) extends from each evaporator 38,38. An additional protective tube (220 with 226) encircles each of the two additional metering input tubes 220 for at least a portion of the length of each additional metering input tube 220. Discharge vents 208,208 extend from the bore 128,128 of each evaporator 38,38 so that evaporated refrigerant can flow from the inner chamber 126 of each evaporator 38,38 and be expelled to a safe environment 210,210. Preferably, as shown in Figures 13A-15, each of the evaporators 38,38 is equipped with a supply/discharge tee 228,228. These supply/discharge tees 228, 228 are mounted on the evaporators 38,38 such that the central axes of their straight through legs 230,230 are collinear with the central axes of the respective evaporators 38,38. The supply ends 232,232 of these supply/discharge tees 228,228 are mounted directly in the central bores 128,128 in the evaporator caps 136,136. The reception ends 234,234 of each

supply/discharge tee 228,228 are blocked off 236 (except for a hole through which one of the additional metering tubes 230,230 passes). The bull end 238,238 of each supply/discharge tee 228, 228 has an opening 240 to the atmosphere. With this configuration, the supply ends 224,224 of each of the additional metering input tubes 220,220 enter the reception ends 234,234 of the straight through legs 230,230 of the supply/discharge tees 228,228, pass through the straight through legs 230,230, and exit the supply ends 232,232 of the straight through legs 230,230 of the supply/discharge tees 228,228 on their way into the cartridge evaporators 38,38. (Preferably, as noted above, these additional metering input tubes 220,220 extend into each evaporator 38,38 a distance which is three quarters of the length of each cartridge evaporator 38,38.) In this preferred configuration, the return 242 from the cartridge evaporators 38, 38 is directly into the supply ends 232,232 of the supply/discharge tees 228,228. Since the reception ends are blocked off 234,234 (except for the additional metering tubes 132,132 which pass through those blockages 236,236), expendable refrigerant passing into the supply ends 232,232 of these supply/discharge tees 228,228 is shunted out the bull ends 238,238 (which function as a discharge vent) of the supply/discharge tees 228,228, and thus is discharged into the atmosphere.

As shown in Figure 15, refrigerant enters the evaporators 38,38 through a metering device such as capillary tube 220, or a thermostatic expansion valve (not shown), or an automatic expansion valve (not shown), or a fixed orifice (not shown). The pressure within the evaporator chamber 126 is much lower than the liquid entering. As the liquid enters the chamber 126, it expands 246 into a saturated vapor, reducing its pressure and temperature. Because higher temperature travels to cooler temperature, this evaporation 246 results in the removal of heat from evaporator 38,38. Then the used refrigerant is shunted out

the bull ends 238,238 of the supply/discharge tees 228,228, and thus is discharged into the atmosphere. (Fig. 15).

As in Figures 3 and 4, when the evaporators 38,38 are positioned within the central evaporator receiving ports 36,36 of the adapter bodies 30,78 of multi cavity adapter 20, the heat will flow from the adapter bodies 30,78, and when the adapter bodies 30,78 of the multi cavity adapter 20 are cradling a pipe 22, heat is removed from the pipe 22. For best thermal transfer, water, or any heat transfer media, may be sprayed on the pipe section 22 to be frozen and the selected pipe receiving surfaces of the adapter bodies 30,78, and also in the evaporator receiving ports 36,36 of the adapter bodies 30,78 before placing the cartridge evaporators 38,38 therein.

It is preferred that the inside diameter of the capillary tubes used for the various metering tubes would compliment the evaporator by optimizing the freeze time versus refrigerant use.

By properly metering the refrigerant through a fixed orifice, refrigerant usage can be minimized.

Fig. 17 shows a space in which the invention may be used.

Limited access space 174 is available around pipe 22. Water is sprayed onto pipe 22 for good thermal contact. As in Figures 18 and 19, the pipe receiving surfaces 42-48 of each adapter body 30,78 that best fit the pipe 22 to be frozen are selected, and the adapter bodies 30,78 are oriented so that they encompass the pipe 22 to be frozen with the selected pipe receiving surfaces of the adapter bodies 30,78 contacting the pipe 22.

The water which was sprayed on the pipe section 22 and the selected pipe receiving surfaces acts as a thermal transfer medium.

As shown in Figures 18 and 19, the right angle elbow 176 in additional protective hose 226,226 which surrounds the

additional metering input tubes 220,220 allows the unit to fit into the tight space without bending the additional protective hose 226,226, thereby reducing wear-and-tear on the protective hose 226,226 and the additional metering input tubes 220,220 which are encircled by that protective hose 226,226.

Below is an overview of the steps for freezing the contents of a pipe using a pipe freezing system which has a refrigeration system having a compressor, a condenser, a cartridge evaporator, and a multi-cavity adapter having a single adapter body which has a plurality of concave pipe receiving surfaces on its adapter body: (a) based on the diameter of the section of pipe to be frozen, select the proper concave pipe receiving surface of the adapter body.

(b) align and secure the adapter to the pipe such that the proper concave surface engages the pipe.

(c) insert a cartridge evaporator in the evaporator receiving port of the adapter body of the multi cavity adapter.

(d) circulate a refrigerant through the refrigeration system thereby reducing the temperature of the evaporator and the adapter within which it is inserted. As a result, the temperature of the pipe is reduced which causes the contents of the pipe to freeze.

Following is a more detailed view of the steps of Applicant's preferred method for mounting a single multi-cavity adapter on the section of pipe to be frozen and installing a cartridge evaporator into the evaporator cartridge receiving bore of the multi-cavity adapter: (a) wet the outer surface of the section of pipe to be frozen.

(b) select the pipe receiving surface of the adapter which has a diameter equal to the outside diameter of the pipe to be frozen.

(c) wet the pipe-receiving surface.

(d) hold the elongated cylindrically shaped piece of thermally

conductive material against the pipe to be frozen such that the pipe rests in the pipe receiving surface.

(e) strap the adapter to the pipe with an adjustable strap, and tighten the adjustable strap.

(f) wet the evaporator receiving surface of the bore of the adapter.

(g) insert a cartridge evaporator into the cartridge receiving bore of the adapter.

Following is an overview of the steps for freezing the contents of a pipe using a pipe freezing system which has a refrigeration system having a compressor, a condenser, two cartridge evaporators, and two multi-cavity adapters, the adapter bodies of each of which have a plurality of concave pipe receiving surfaces on their adapter body: (a) based on the diameter of the section of pipe to be frozen, select the proper concave pipe receiving surfaces of the adapter bodies.

(b) align and secure each adapter to the pipe such that the proper concave surface of each adapter engages the pipe and the concave pipe receiving surface of each adapter is aligned with and facing the concave pipe receiving surface of the other adapter.

(c) insert a cartridge evaporator in the evaporator receiving port of the adapter body of the multi cavity adapter.

(d) circulate a refrigerant through the refrigeration system thereby reducing the temperature of the evaporator and the adapter within which it is inserted. As a result, the temperature of the pipe is reduced which causes the contents of the pipe to freeze.

Following is a more detailed view of the steps of Applicant's preferred method for mounting two multi-cavity adapters on the section of pipe to be frozen and installing the cartridge evaporators into each multi-cavity adapter:

(a) position the primary and secondary adapter bodies such that the pipe receiving surface of the first adapter body which has a diameter equal to the outside diameter of the pipe to be frozen is facing and aligned with the pipe receiving surface of the second adapter having that same.

(b) orient the first retainer mechanism with respect to a first side of the section of pipe to be frozen such that the central axes of the pin bodies of the first retainer mechanism are substantially parallel to the central axis of the section of pipe to be frozen.

(c) turn the offset golf club-like heads of the first retainer mechanism such that the offset golf club-like heads are oriented away from the section of pipe.

(d) simultaneously insert the second ends of the first and second locking pins of the first retainer mechanism into corresponding locking channels of the primary and secondary adapter bodies, thus forming a hinge. Now the primary and secondary adapter bodies are swivelable with respect to each other.

(e) secure the ends of the first and second locking pins of the first retainer mechanism with nuts.

(f) swivel the primary and secondary adapter bodies outward with respect to each other.

(g) wet the outer surface of the section of pipe to be frozen.

(h) wet those pipe-receiving surfaces of the multi-cavity adapter which are to receive the section of pipe to be frozen.

(i) drape the hinged primary and secondary adapter bodies around the pipe to be frozen.

(j) swivel the primary and secondary adapter bodies toward each other.

(k) orient the second retainer mechanism with respect to the side opposite the first side of the section of pipe to be frozen such that the central axes of the pin bodies of the second retainer mechanism are substantially parallel to the

central axis of the section of pipe to be frozen.

(1) turn the offset golf club-like heads of the second retainer mechanism such that the offset golf club-like heads are oriented away from the section of pipe to be frozen.

(m) simultaneously insert the second ends of the first and second locking pins of a second retainer mechanism into corresponding locking channels of the primary and secondary adapter bodies, thus securing the section of pipe to be frozen.

(n) wet the evaporator receiving surface of the bore of the adapter.

(o) insert cartridge evaporators into the evaporator receiving ports of each of the adapter bodies.

5.3 Advantages of the Invention The previously described multi cavity adapter has many advantages, including: (a) Rather than have many individual adapters (Eight for a four cavity adapter), only two are required.

(b) The evaporator can swivel within the adapter body of a multi cavity adapter reducing stress on the protective hose and the input metering tube contained therein.

(c) Angle adapters are not required, because the evaporator is angled at 90 degrees from the hoses.

(d) The adapters can be exchanged for different sizes to go from metric to US standard sizes.

(e) If any pipe receiving surface is damaged, the adapter body can be replaced without entering the sealed system.

(f) The evaporator is protected by the adapter body of the Multi-Cavity Adapter.

The chance of refrigerant leakage is reduced, because the number of welded areas are reduced, and, when ported within the

adapter, evaporator damage due to rough handling is less likely, because the evaporator is sheltered by the adapter body of the multi cavity adapter.

5.5 LIST OF REFERENCE NUMBERS 20 multi cavity adapter 22 liquid filled pipe 24 liquid contents of pipe 26 ice blockage in pipe 28 cut in pipe 30 elongated piece of thermally conductive material (primary adapter body) 31 second primary adapter in row in Figure 7 32 first end face of adapter body 34 second end face of adapter body 36 bore for reception of a cartridge evaporator 38 cartridge evaporator 39 outer surface of cartridge evaporator 40 outer surface of adapter body 42 pipe receiving surface #1 (for pipes with an outside diameter of 1.651 cm (0.65 in)) 44 pipe receiving surface #2 (for pipes with an outside diameter of 2.286 cm (0.90 in))

46 pipe receiving surface #3 (for pipes with an outside diameter of 2.921 cm (1.15 in)) 48 pipe receiving surface #4 (for pipes with an outside diameter of 4.191 cm (1.65 in)) 50 first corner edge of pipe receiving surface #1 52 second corner edge of pipe receiving surface #1 54 first corner edge of pipe receiving surface #2 56 second corner edge of pipe receiving surface #2 58 first corner edge of pipe receiving surface #3 60 second corner edge of pipe receiving surface #3 62 first corner edge of pipe receiving surface #4 64 second corner edge of pipe receiving surface #4 66 a corner point of the first end face 68 a corner point of the second end face 70 bushing adapter 72 outer surface of bushing adapter 74 inner surface of bushing adapter 78 second elongated piece of thermally conductive material (secondary adapter body)

80 row of two primary adapters 30,31 82 row after primary adapter 31 is rotated by 180 degrees 84 row after primary adapter 31 is turned upside down 86 locking channel 88 channel opening in first end face 89 channel opening in second end face 90 first retainer mechanism 92 second retainer mechanism 94 first prong 96 second prong 98 end of prong 100 nut 102 first locking pin 104 second locking pin 106 first end of retainer mechanism 108 golf club-like head with a nonthreaded hole 110 golf club-like head with a threaded hole

112 nonthreaded hole 114 threaded hole 116 straight pin 118 spring under tension 120 threaded second end of locking pin 122 first end of straight pin with an Allen head 124 strap with hook and loop material at the ends thereof 126 inner chamber of cartridge evaporator 128 bore of cartridge evaporator 130 first end surface of cartridge evaporator 132 metering input tube 134 return tube 136 evaporator cap 138 first end of cartridge evaporator 140 side wall of evaporator cap 142 an evaporator cap turned upside down to show details 144 first end of evaporator cap 146 second end of evaporator cap

148 bore in second end of evaporator cap 150 face of second end of evaporator cap 152 second end of evaporator 154 complete pipe freezing system using nonexpendable refrigerants 156 refrigeration unit 158 compressor 160 condenser 162 discharge vent 164 first end of metering input tube 166 second end of metering input tube 168 return from the cartridge evaporator 170 expansion of liquid entering the evaporator chamber 172 supply end of metering input tube 174 limited access space 176 right angle elbow in return tube surrounding metering input tube 200 pipe freezing system utilizing expendable refrigerants 202 tank containing expendable refrigerant

204 first end of metering input tube 206 second end of metering input tube 208 discharge tube or vent 210 safe discharge area 212 protective hose or tube 214 input tee 216 input port of tee 218 output port of tee 220 additional metering input tube 222 reception end of additional metering input tube 224 supply end of additional metering input tube 226 additional protective tube 228 supply/discharge tee 230 straight through leg of supply/discharge tee 232 supply end of straight through leg of supply/discharge tee 234 reception end of supply/discharge tee 236 blocked off portion of supply/discharge tee

238 bull end of supply/discharge tee 240 opening in bull end of supply/discharge tee 242 return from the cartridge evaporator 246 expansion of liquid entering the evaporator chamber

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of devices and methods differing from those types described above.

5.6 Alternatives and the Closing Thus the reader will see that my multi cavity adapter supplies a long felt need for a simple, economical, easy to use means for freezing a plug of ice in a section of pipe. If one should aver that my multi cavity adapter is obvious, then one is hard put to explain why users of pipe freezers continue to use pipe freezing methods without the advantages of Applicant's invention.

Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible which will be apparent to those who are skilled in the art. While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein, but by the appended claims and their legal equivalents.