An in-line valve for a fluid line preferably in the environment of a hydrant, comprising a casing to which is mounted an attachment device and in which is disposed a rotatable stem. The attachment device and stem both have dividing walls in which are formed corresponding fluid ports through which fluid flows when the ports are aligned.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The invention is directed to a valve for controlling the flow of fluid;
 and, more particularly, the invention is directed to an in-line valve
 having a simplified valve stack construction.
 2. Related Art
 Contemporary in-line valves comprise a fitting with a valve seat seal,
 which is mounted in a fluid or water supply line. Typically, a portion of
 the supply line is removed and the fitting replaces the removed portion.
 The fitting is usually threaded on or welded to the supply line.
 The valve seat includes a rotatable shaft extending from the interior to
 the exterior of the fitting. The exterior end of the shaft mounts a handle
 or similar structure for grasping and rotating the shaft. The interior end
 of the shaft is mounted to a disk or washer. As the handle is rotated, the
 valve seat is moved into or out of compressive contact with a seal to
 close or open the valve depending on the direction of handle rotation.
 One disadvantage of the valve seat seal is that it requires multiple turns
 of the shaft to fully open or fully close the valve seat. It can also take
 a substantial amount of force to rotate the shaft and to compress the
 valve seat a sufficient amount to obtain an adequate seal. As the valve
 seat wears, especially from over-tightening, greater compressive force is
 usually needed to obtain a complete seal. The multiple rotations of the
 handle and the excessive force needed to rotate the handle and seal the
 valve is considered an inconvenience by many users.
 An alternative to the valve seat seal is a disk stack, which generally
 takes the form of a fixed disk and a rotating disk, each having
 corresponding openings that are aligned in one rotational position to
 permit water flow and un-aligned in another rotational position o prevent
 water flow. Examples of such in-line valves are show in U.S. Pat. Nos.
 3,426,797, issued Oct. 20, 1965 and 5,088,689, issued Feb. 18, 1992.
 The disk stacks are advantageous in that the control of water flow running
 through the disks is dependent on the rotational position of the disks,
 instead of the axial compressive force of the seat seal valve. The
 ceraminc disks are are disadvantageous in that they are difficult to
 manufacture and are subject to breakage.
 SUMMARY OF THE INVENTION
 The invention relates to an in-line valve alone or in the environment of a
 hydrant for controlling fluid flow through a supply line. The in-line
 valve comprises an outer casing that defines a casing passageway having a
 longitudinal axis. An attachment device is mounted to the outer casing for
 connecting the outer casing to a supply line. The attachment device
 defines an attachment passageway, and has a dividing wall spanning the
 attachment passageway with a fluid port extending through the dividing
 wall. The valve further includes a valve stem defining a valve stem
 passageway and has a dividing wall spanning the valve stem passageway with
 a fluid port extending therethrough. The valve stem passageway is in fluid
 communication with the casing passageway. The attachment device dividing
 wall cooperates with the valve stem wall to control fluid flow from the
 supply line through said valve by the movement of the valve stem wall
 relative to the dividing wall between an open position and a closed
 position where the at least one fluid port of the valve stem wall and the
 at least one port of the dividing wall are fluidly connected and fluidly
 disconnected, respectively.
 Preferably, the valve stem wall comprises a plate mounted to the valve
 stem, with the valve stem fluid port extending through the plate. A seal
 can surround one of the dividing wall fluid ports and the valve stem fluid
 port to seal the dividing wall relative to the plate.
 The valve can further include a handle connected to the valve stem with a
 portion of the handle extends externally of the casing for use in rotating
 the valve stem relative to the attachment device. The externally extending
 handle portion extends from the casing in a direction that is radial to
 the casing longitudinal axis. The externally extending handle portion can
 extend from the casing in a direction that is axial to the casing
 longitudinal axis. A control knob can be mounted to the handle.
 Preferably, the attachment device comprises an attachment portion and a
 removable casing portion, with the dividing wall spanning the removable
 casing portion.
 The valve stem comprises a body that is received within the removable
 casing portion, and the plate is mounted to the body. The body can include
 a handle coupler, which connects to one end of the handle, which can mount
 a control knob
 In another aspect of the invention, the in-line valve comprises an outer
 casing defining a casing passageway engageable with the supply line and an
 operating handle opening formed in and extending through a sidewall of
 said outer casing. An attachment device is receivable within and
 engageable with said outer casing for connecting said outer casing to the
 supply line. The attachment device includes an attachment passageway
 therethrough for fluid to flow through said valve. The attachment device
 further includes a dividing wall spanning said attachment passageway and
 having at least one fluid flow port formed therein. The in-line valve also
 includes a valve stem defining a valve stem passage, and which is mounted
 for selective rotation about a central axis. A plate spans an opening of
 said valve stem passage and has at least one fluid port formed therein.
 The plate being mounted onto said valve stem so as to be axially aligned
 along said central axis and abutting said dividing wall, wherein the
 selective rotation of the valve stem between an open position and a closed
 position about said central axis controls fluid flow through said valve by
 aligning and mis-aligining the fluid ports of said dividing wall and said
 plate. A handle extends from the valve stem through the handle opening to
 enable a user to rotate the valve stem.

DETAILED DESCRIPTION
 FIG. 1 illustrates a first embodiment in-line valve 10. The in-line valve
 10 comprises an outer casing 12, which defines a passageway 14 extending
 through the outer casing 12. The outer casing 12 comprises a large
 diameter portion 16 and a small diameter portion 18, having external
 threads 20. At the junction of the large diameter portion 16 and the small
 diameter portion 18, there is an annular shoulder 22 extending into the
 internal passageway 14. An operating handle slot 24 extends through the
 wall of the large diameter portion 16.
 The in-line valve 10 further comprises an attachment device 26, which
 defines an internal passageway 28. The attachment device 26 comprises a
 first portion 30, having internal threads 32 and a reduced diameter
 portion 34. The outer diameter of the reduced diameter portion 34 is sized
 to be received within the large diameter portion 16 of the outer casing
 12. The junction of the first portion 30 and the reduced diameter portion
 34 define an annular shoulder 36, which abuts the upstream end of the
 large diameter portion 16 when the attachment device 26 is mounted to the
 outer casing 12.
 A dividing wall 44 extends across the passageway 28 and forms an annular
 shoulder 38, which has an annular bearing surface 40 and a seal seat 42.
 The dividing wall 44 includes a pair of diametrically opposed fluid ports
 46, 48. A seal stud 50 extends from the downstream face of the dividing
 wall 44. An o-ring 51 circumscribes the seal stud 50.
 The first embodiment in-line valve 10 further comprises a rotating stem 56
 having a generally cylindrical body 58, defining an internal passageway 60
 through which fluid can flow. Annular grooves 62 and 64 are provided in
 the exterior surface of the cylindrical body 58 and receive o-ring seals
 63, 65. The upstream end of the cylindrical body 58 has a reduced diameter
 portion 66 having a slightly inwardly tapered cross section. The junction
 of the reduced diameter portion 66 with the rest of the cylindrical body
 58 defines an annular stop 68. A threaded opening 70 extends through the
 side of the cylindrical body 58 of the rotating stem 56 and is located
 between the annular grooves 62 and 64.
 The rotating stem 56 further comprises a plate 74, which extends across the
 upstream end of the cylindrical body 58. The plate 74 and the dividing
 wall 44 combine to form a valve device. The plate 74 has a pair of
 diametrically opposed ports 76 and 78, which when aligned with the holes
 46 and 48 in the dividing wall 44, permit fluid to flow through the
 in-line valve 10. The plate 74 is crimped onto the reduced diameter
 portion 66 of the cylindrical body 58 to mount the plate to the
 cylindrical body.
 The plate 74 is preferably made from metal, such as stainless steel or
 brass. The late 74 can also be made for non-metals, including plastics and
 ceramics.
 The first embodiment in-line valve 10 also includes an operating handle 86
 comprising a rotating stud 88 with externally threaded ends 90 and 92. The
 rotating stud 88 defines an internal passage 89, extending completely
 through the rotating stud 88. The operating handle 86 further comprises a
 bleeder cap 94 having internal threads 96. A bleeder seal 98 is disposed
 within the interior of the bleeder cap 94 at the end of the internal
 threads 96. A bleeder vent opening 99 extends through the sidewall of the
 bleeder cap 94.
 The in-line valve 10 includes a ferrule cap 80 defining an internal
 passageway 81, an upstream portion of which has internal threads 82. A
 ferrule 83 spans the ferrule cap 80 and the small diameter portion 18 of
 the outer casing 12 to secure the ferrule cap 80 to the outer casing 12.
 To assemble the first embodiment in-line valve 10, the plate 74 is first
 mounted, preferably by crimping or bonding, onto the cylindrical body 58
 of the rotating stem. 0-rings 63 and 65 are then placed in annular grooves
 62 and 64, respectively. Similarly, o-ring 43 is placed in seal seat 42
 and o-ring 59 is disposed around the seal embossment 50. Once the o-ring
 seals are in place, the assembled rotating stem 56 is inserted into the
 opened end of the reduced diameter portion 34 of the attachment device 26
 until the plate 74 contacts and compresses the o-rings 43 and 51. The
 insertion of the rotating stem 56 is limited by the plate 74 abutting the
 annular bearing surface 40.
 After the rotating stem 56 is inserted into the attachment device 26, the
 outer casing 12 is mounted onto the attachment device 26 by inserting the
 reduced diameter portion 34 of the attachment device 26 into the open end
 of the large diameter portion 16 of the outer casing 12. Prior to
 insertion of the assembled rotating stem 56 and the attachment device 26,
 a bearing 54 is inserted into the open end of the large diameter portion
 16 of the outer casing 12 and provides a bearing surface for the
 downstream end of the cylindrical body 58. The assembled rotating stem 56
 and attachment device 26 are inserted into the outer casing until the
 downstream end of the outer casing 12 abuts the annular shoulder 36 of the
 attachment device 26. In this position, the downstream end of the
 cylindrical body 58 contacts and bears against the bearing 54.
 After the rotating stem 56, attachment device 26, and outer casing 12 are
 assembled, the operating handle 86 is inserted through the operating
 handle slot 24 and the lower external threaded portion 90 of the rotating
 stud 88 is threaded into the internally threaded opening 70 of the
 cylindrical body 58 to mount the operating handle 86 to the rotating stem
 56. The ferrule cap 80 is threadably mounted onto the small diameter
 portion 18 of the outer casing and the ferrule 84 secures the ferrule cap
 80 to the outer casing.
 In operation, water is permitted to flow through the aligned passageways
 81, 14, 60, and 28 when the rotating stem 56 is oriented in such a way
 that the ports 76 and 78 of the plate 74 align with the ports 46 and 48 in
 the dividing wall of the attachment device 26. Flow is prevented through
 the aligned passageways when the plate ports 76 and 78 are not aligned
 with the dividing wall ports 46 and 48. The alignment or non-alignment of
 the corresponding dividing wall ports and plate ports is achieved by
 rotating the operating handle 86 through approximately a 90.degree. arc or
 throw. The short rotational throw permits a user of the first embodiment
 in-line valve 10 a quick way to control the flow of fluid through the
 first embodiment in-line valve 10. Furthermore, if for any reason the
 fluid downstream of the plate 74 should need to be bled out of the fluid
 line, the user only need to unscrew the bleeder cap 94 until the bleeder
 seal 98 opens the upper end of the internal passage 89 to permit fluid
 (air or water) to flow through the internal passageway 89 of the rotating
 stud 88 and through the bleeder vent opening 99.
 The first embodiment shows rotating the operating handle 76 through a short
 throw arc of approximately 90.degree. to obtain complete opening or
 closing of the valve. Other short throw distances are within the scope of
 the invention, for example, 180.degree.. The throw distance is dependent
 upon the orientation of the ports in the dividing wall and the rotating
 plates 74. The orientation of these openings can be selected as desired
 depending on the particular design conditions, such as flow rate and
 operating handle throw angle.
 The advantage of the invention is that the water flowing through the
 in-line valve 10 can be turned on or turned off by merely rotating the
 operating handle through the relatively short throw angle. This is in
 contrast to previous in-line valves that used a rotatable handle in
 connection with a washer seat seal, which require multiple rotations of
 the handle to completely turn off or turn on the flow of water.
 FIG. 2 illustrates a second embodiment in-line valve 110, which is
 substantially identical to the first embodiment 10. Therefore, like
 numerals will be used to identify like parts between the second embodiment
 in-line valve 110 and the first embodiment inline valve 10. New elements
 associated with the second embodiment in-line valve 110 will be identified
 with numerals in the 100 series.
 The main difference between the second embodiment in-line valve 110 and the
 first embodiment in-line valve 10 is that the plate 74 of the first
 embodiment in-line valve 10 is replaced by an end wall 112, which is
 integrally formed with the rotating stem 56. The end wall 112 has two
 ports 114 and 116. Preferably, the cylindrical body 58 and the end wall
 112 are all formed from brass and the ports 114 and 116 are drilled into
 the end wall 112. Other metals and non-metals can also be used to form the
 body. For example, the body can be made from plastic.
 The operation of the second embodiment in-line valve 110 is substantially
 the same as the operation of the first embodiment in-line valve 10. The
 flow of water though the in-line valve 110 is controlled by rotating the
 operating handle 86 through an arc of approximately 90.degree. or throw,
 which moves the ports 114 and 116 into or out of alignment with the ports
 46 and 48 of the dividing wall 37. When the ports 114 and 116 of the end
 wall are aligned with the ports 46 and 48 of the dividing wall, fluid is
 permitted to flow through the in-line valve. A reduced flow of fluid
 through the in-line valve can occur when the ports 114 and 116 are
 partially aligned with the ports 46 and 48. However, when the ports 114
 and 116 do not overlap the ports 46 and 48, the flow of fluid through the
 in-line valve 110 is shut off.
 FIG. 3 illustrates a third embodiment inline valve 210, which is
 substantially identical to the first embodiment in-line valve 10.
 Therefore, like numbers will be used to identify like parts. New elements
 associated with the third embodiment in-line valve 210 will use numerals
 in the 200 series.
 The main difference between the third embodiment in-line valve 210 and the
 first embodiment in-line valve 10 is that the third embodiment in-line
 valve 210 is a right angle configuration instead of a linear
 configuration. To achieve the right angle configuration, the third
 embodiment in-line valve 210 incorporates an outer casing 212 that is
 different than the outer casing 12 of the first embodiment in-line valve
 10. The outer casing 212 defines an internal passage 214 beginning at the
 upstream end of the outer casing and exiting out the downstream sidewall
 of the outer casing 212. A partial annular stop 216 and an annular
 shoulder 218 extend into the passageway 214 of the outer casing and
 perform that same function as the similar elements in the first
 embodiment. The casing 212 has a handle slot 216. A downstream outlet
 opening 220 is formed in the sidewall of the outer casing 212 near the
 downstream end of the outer casing 212.
 The third embodiment in-line valve 210 further includes a right angle
 extension 222 having a reduced diameter portion 224 on the upstream end
 and an externally threaded portion 226 on the downstream end. The terminal
 end of the reduced diameter portion 224 forms an annular stop 228. The
 right angle extension 222 is mounted to the outer casing 212 by inserting
 the reduced diameter portion 224 into the outlet opening 220 until the
 perimeter of the outlet opening contacts the annular stop 228.
 The third embodiment in-line valve 210 further comprises a ferrule cap 230
 defining an internal passageway 232. The upstream end of the internal
 passageway 232 contains internal threads 234, which are threaded onto the
 external threads 226 of the right angle extension 222 to mount the ferrule
 cap 230. A ferrule 236 is provided within the internal passageway 232 to
 further secure the ferrule cap 230 to the right angle extension 222.
 The operation of the third embodiment in-line valve 210 is identical to the
 operation of the first embodiment in-line valve 10, except that the water
 exits at a right angle from the outer casing 212 instead of passing
 linearly through the outer casing.
 FIGS. 4-6 illustrate a fourth embodiment inline valve 310 in the
 environment of a hydrant 302 comprising a spout 304 and a control knob 306
 for controlling the operation of the valve 310.
 The inline valve 310 comprises an outer casing 312 that couples to the
 spout 304 of the hydrant 302 and defines a passageway 314 extending
 through the casing and fluidly connected to spout 304, whereby fluid
 passing through the casing can exit the hydrant 302 through the spout 304.
 The casing and the spout can be formed of a single piece instead of the
 illustrated two-piece structure.
 An attachment device 326 is positioned within and secured to the end of the
 casing 312 opposite the spout 304 and is coupled to a handle 324 by a stem
 356 having a passageway 360. The attachment device 326 defines a
 passageway 328 that is fluidly connected to the passageway 314 of the
 casing through the stem 356.
 Preferably, the attachment device is bonded to the casing, but can be
 attached by other suitable methods, including welding and press-fit.
 Another alternative connection could include internal threads on the
 casing and external thread on the attachment device permitting the
 threading of the attachment device to the casing.
 The attachment device 326 comprises a collar 330 forming an annular seat
 332 against which the end of the casing 312 abuts when the attachment
 device 326 is slideably inserted into the casing. The annular seat 332
 limits the insertion depth of the attachment device 326. External threads
 334 are provided on the exterior of the attachment device on the external
 end of the casing and permit the mounting of the attachment device to a
 suitable water supply (not shown). Another set of external threads 336 are
 provided on the end of the attachment device located within the casing
 312.
 A dividing wall 337 extends across the passageway 328 defined by the
 interior of the attachment device 326. The dividing wall 337 includes
 ports 346, 348. The ports 346, 348 include inlet portions 346a, 348a and
 cup seal portions 346b and 348b. The cup seal portions 346b, 348b are of
 larger diameter than the inlet portions 346a, 346b, defining a spring seat
 350, 351, respectively. The dividing wall 337 effectively defines one
 portion of a valve stack.
 The stem 356 connecting the attachment device 326 to handle 324 comprises a
 body 358, which is slideably received within the passageway 328 of the
 attachment device 326 and defines an internal passageway 360. A handle
 coupler 362 is connected to the body 358 by a pair of axially extending
 and radially spaced supports 364. The handle coupler 362 defines a recess
 366 that is sized to receive an end of the handle 324, which is bonded to
 the handle coupler.
 Referring to FIG. 6 specifically and FIGS. 4 and 5 generally, a plate 374
 having diametrically opposed openings or ports 376, 378 is mounted onto
 the end of the body 358 by inserting the tabs or keys 380 into the
 corresponding key slots 382 on the sides of the body 358. The plate 374 is
 preferably made of a suitable material, such as metal, and effectively
 forms the other portion of a valve stack. Examples of suitable metals
 include stainless steel and brass. Suitable non-metals can also be used.
 A tapered coil spring 352 is disposed within each of the cup seal portions
 346b, 348b such that one end of the tapered spring abuts the spring seat
 350, 351, respectively. A cup seal 354 is positioned within the cup seal
 portion 346b, 348b and over the corresponding coil spring 352. The coil
 spring 352 inherently biases the cup seal 354 away from the dividing wall
 337. The cup seals 354 are fixed relative to the casing 312 by their
 location in the cup seal portion 346b, 348b of the ports 346, 348
 extending through the dividing wall 337.
 The plate 374 is rotatable along with the stem 356 so that openings 376,
 378 of the plate 374 can be brought into and out of axial alignment with
 the ports 346, 348 and the cup seals 354 to permit water flow through the
 valve. The coil spring 352 biases the cup seals against the plate 374 a
 sufficient amount so that when the stem 356 is rotated to mis-align the
 plate ports 376, 378 with the dividing wall ports 346, 348, the cup seals
 354 do not permit fluid to leak from the ports 346, 348 across the surface
 of the plate 374 to the plate openings 376, 378.
 The cup seals 354 and corresponding coil springs 352 could be replaced by
 sing 0-rings positioned within the port 346, which would require a
 reduction in the thickness of the dividing wall 337. A groove for
 receiving the 0-ring could also be provided in the downstream side of the
 dividing wall 337.
 The assembly of the fourth embodiment valve will be briefly described. It
 should be noted that the sequence of the assembly can easily vary with
 regard to the described sequence. The description of the assembly is
 provided to enhance the understanding of the invention and is not meant to
 be limiting as to a particular method of assembly.
 The attachment device 326 and stem 356 are initially preassembled. The
 attachment device 326 is prepared for assembly by inserting the coil
 springs 352 and cup seals 354 into the cup seal portion 346b, 348b of the
 dividing wall ports 346, 348. The plate 374 is affixed to the end of the
 stem body 348 by pressing the keys 380 into the key slots 382 on the body
 358. A bearing 384 (FIG. 4) is positioned about the exterior of the body
 358 where it will abut against the interior of the attachment device when
 the stem 356 is assembled to the attachment device 326.
 Once the attachment device 326 and stem 356 are prepared for assembly, the
 body 358 is inserted into the interior of the attachment device 326 until
 the plate 374 is adjacent the dividing wall 337, where the cup seals 354
 form a watertight seal against the plate 374. The body 358 is inserted
 into the attachment device 326 in a manner so that a rotational stop 386,
 extending from the interior wall of the attachment device 326, is axially
 aligned with a guide slot 388 on the body 358. Preferably, the body 358
 has a square-like cross section that permits the axial insertion of the
 body 358 over the rotational stop 386, but the body 358 contacts the stop
 386 upon rotation of the body 358. A retainer 390 having an o-ring 392 is
 threadably mounted onto the end of the attachment device 326 after the
 stem 356 is inserted into the attachment device 326. The retainer 390
 axially fixes the position of the body 358 relative to the attachment
 device. The securing of the retainer 390 to the attachment device 326
 effectively draws the body 358 to the dividing wall 337, which, in
 combination with the coil springs 352 applies a predetermined compressive
 force between the plate 374 and the cup seals 354. This predetermined
 compressive force effectively sets the sealing pressure between the plate
 374 and the cup seals 354.
 The shape of the body 358 along with the rotational stop 386 of the
 attachment device 326 aid in aligning the dividing wall ports 346, 348
 with the plate openings 374, 376. Specifically, it is preferred that the
 valve have a 90 degree operational range from water shut off to full water
 on. In achieving this operational range, the ports 346, 348 of the
 dividing wall 337 are oriented diametrically or 180 degrees apart.
 Similarly, the plate openings 376, 378 are also diametrically opposed or
 180 degrees apart. The plate openings 376, 378 are oriented with respect
 to the body 358 so that when the body 358 is aligned with the rotational
 stop 386 of the attachment device 326, the dividing wall ports 346, 348
 and plate openings 376, 378 will automatically be properly aligned upon
 the completion of the insertion.
 Other operational ranges are achievable by varying the angular spacing
 between the ports in the dividing wall and plate. For example, a 180
 degree operational range can be accomplished by provided the dividing wall
 and plate with one opening each and arranging the dividing wall and plate
 such that the ports are 180 degrees apart. If multiple ports, say two, are
 used in each of the dividing wall and plate, the ports on the dividing
 wall and plate need only be positioned on the dividing wall or plate at
 different radial distances from the dividing wall or plate center.
 Once the stem 356 is assembled to the attachment device 326, the attachment
 device is inserted into the casing 312 until the casing abuts the annular
 seat 332 of the attachment device. The spout 304 of the hydrant 302 is
 then inserted over the opposite end of the casing 312 until the spout
 seats on the casing. The handle 324 is inserted through the open end of
 the spout 304 and received in the recess 366 of the handle coupler 362. It
 should be noted that the handle 324 could be inserted into the recess 366
 prior to the mounting of the spout 304 to casing 312.
 A traditional spout end cap 394 is slideably received over the handle by
 threading the end cap into the open end of the spout 304. The end cap 394
 includes o-rings 395 and 396, that seal the end cap relative to the handle
 324 and the spout 304. A bearing washer 397 is preferably positioned
 between the end cap 394 and the collar 325.
 To complete the assembly, the control knob 306 is then mounted to the
 handle 324 by threading a bolt 398 through the control knob 306 into the
 tapped opening of the handle 324.
 In operation, water is prohibited from flowing through the aligned
 passageways 328, 360, and 314 of the attachment device 326, stem 356, and
 spout 304 when the dividing wall ports 346, 348 are not aligned with the
 plate openings 376, 378. The dividing wall ports 346, 348 and plate
 openings 376, 378 are brought into and out of alignment by rotating the
 control knob 306, which effectively rotates the stem 356. The rotation of
 the control knob 306 is limited by the interference between the rotational
 stop 386 of the attachment device 326 and the guide slot 388 of the body
 358.
 FIGS. 7 and 8 illustrate a fifth embodiment in-line valve 400, which is
 substantially similar to in-line valve 300. Therefore, like parts will be
 identified by like numerals between the fourth and fifth embodiments.
 The main difference between the fourth embodiment 300 and the fifth
 embodiment 400 is that the attachment device 426 of the fifth embodiment
 is divided into two pieces, instead of one, and comprises an attachment
 portion 440 and a removable case 442. The attachment portion 440 comprises
 a collar 330, annular seat 332, external threads 334, and defines
 passageway 328 in a similar manner as the attachment device of the fourth
 embodiment. The removable case portion 442 comprises the dividing wall 337
 and the ports 346, 348 of the fourth embodiment. The division of the
 attachment device into an attachment portion 440 and a removable case
 portion 442 enables the entire filter structure of the stem 356, plate
 374, and cup seals 354 to be removed for maintenance purposes through the
 end of the spout 304 without disconnecting the hydrant from the water
 supply.
 The attachment portion 440 includes a key slot 444 that aids in aligning
 the removable case portion 442 with the attachment portion 440. The
 removable case portion 442 comprises a reduced diameter neck 446 in which
 is formed an annular groove 448 that receives an o-ring 450. A pair of
 axially extending keys 452 extend from the neck 446 and are spaced so that
 they are received within the key slots 444 in the attachment portion 440.
 The assembly of the fifth embodiment is identical to the assembly of the
 fourth embodiment except that the removable case portion 442 must be
 assembled into the attachment portion 440 to form the attachment device
 426. The removable case portion 442 is aligned with the attachment portion
 440 so that the keys 452 align with the key slots 444 and the neck 446 is
 then inserted into the interior of the attachment portion 440. When
 inserted, the o-ring 450 forms a fluid tight seal against the interior of
 the attachment portion 440.
 While particular embodiments of the invention have been shown, it will be
 understood, of course, that the invention is not limited thereto since
 modifications may be made by those skilled in the art, particularly in
 light of the foregoing teachings. Reasonable variation and modification
 are possible within the scope of the foregoing disclosure of the invention
 without departing from the spirit of the invention.
 While the invention has been specifically described in connection with
 certain specific embodiments thereof, it is to be understood that this is
 by way of illustration and not of limitation, and the scope of the
 appended claims should be construed as broadly as the prior art will
 permit.