Sealed drain for rotating case pumps

A sealed drain tool for a pump with a drain has a cylindrical tool housing. The housing has a mounting end for attaching the tool to the pump. The housing also has a free end and a bore extending longitudinally through the housing from the mounting end to the free end. The bore defines an inlet opening at the mounting end for communicating with the drain opening of the pump and has a free and opening at the free end. A plunger is slidably received within the bore. A stop element prevents the plunger from exiting the free end opening. A seal is provided between the plunger and bore adjacent the free end for preventing fluid from exiting the free end opening. A discharge opening in the tool housing permits fluid to pass from the drain of the pump through the inlet opening into the bore of the tool housing and to exit the tool housing through the discharge opening to a suitable container.

BACKGROUND OF THE INVENTION
 This invention relates generally to drains for pumps, and particularly to a
 sealed drain for removing toxic materials from a pump.
 Case pumps are known in the art and typically have a stationary outer
 housing or shell with an interior chamber and a rotary case therein.
 Typically, the rotary case has a drain hole and a plug received therein to
 prevent fluid from escaping. The outer stationary housing also has a drain
 opening. When the drain opening of the outer housing and the drain hole of
 the rotary case are aligned, the plug may be removed and the fluid drained
 from the pump cavity under force of gravity.
 In some instances, these types of pumps are used to move hazardous or toxic
 materials. These materials pose many risks and may cause problems if
 exposed to the atmosphere. Therefore, the conventional method of draining
 such a pump is not adequate in that one cannot simply pour the hazardous
 material from the pump through the drain hole and drain opening into a
 container.
 SUMMARY OF THE INVENTION
 It is one object of the present invention to provide a sealed drain tool
 which may be utilized to drain fluid from such a case pump. Another object
 of the present invention is to provide a drain tool which seals against
 the case pump so that the drained fluid does not leak from the case pump
 or from the drain tool. An additional object of the present invention is
 to provide a drain tool which is directly connectable to a hazardous or
 toxic fluid collection device so that the fluid drained via the drain tool
 does not escape to the atmosphere. To accomplish these and other objects
 of the invention, a novel sealed drain tool is disclosed.
 In an embodiment of the invention, a sealed drain tool for a pump having a
 drain opening is provided. The drain tool has a cylindrical tool housing
 having a mounting end which attaches the tool to the pump. The tool
 housing also has a free end and a bore extending longitudinally through
 the housing from the mounting end to the free end. The bore defines an
 inlet opening at the mounting end for communicating with the drain opening
 of the pump and a plunger opening at the free end of the housing. The tool
 also has a plunger slidably received within the bore. The tool also has a
 stop element which prevents the plunger from exiting the housing bore via
 the plunger opening at the free end. The tool also has a seal provided
 between the plunger and the bore at the free end for preventing escape of
 fluid from the drain tool. A discharge opening is provided on the tool
 housing which permits fluid to pass from the drain opening of the pump
 through the inlet opening and the bore of the tool and then to exit the
 tool housing through the discharge opening.
 In an embodiment of the invention, the drain tool also has an O-ring seal
 in the bore at the free end which forms the seal. In an embodiment, three
 O-rings are provided adjacent one another at the free end which form the
 seal between the bore and the plunger.
 In an embodiment of the invention, external threads are provided on the
 tool housing at the mounting end which are utilized for attaching the tool
 housing to the pump concentric with the drain opening.
 In an embodiment of the invention, an engaging end is provided on one end
 of the plunger which attaches to a drain plug for removing the plug from
 the drain opening of the pump.
 In an embodiment of the invention, a seal is provided on the mounting end
 of the tool housing to seal between the pump and the drain tool when
 attached to the pump. In an embodiment of the invention, the seal is in
 the form of a O-ring on the mounting end of the housing.
 In an embodiment of the invention, the plunger has an elongate circular
 cylindrical shaft machined from a material such as steel to a first
 diameter and an annular shoulder machine as a part of the shaft to a
 second diameter. The second diameter is larger than the first diameter of
 the shaft and therefore defines a portion of the stop element.
 In an embodiment of the invention, a method of draining a pump having a
 drain opening in a stationary housing and a drain outlet in a rotary case
 held within the housing is disclosed. The method first includes aligning
 the drain outlet of the rotary case with the drain opening of the housing.
 A drain tool is then attached to the pump at the drain opening. The tool
 has a cylindrical tool housing with a fluid discharge in the tool housing
 and a plunger received within a longitudinal bore of the tool housing. The
 housing of the tool is then sealed to the pump. A sealed collector is
 attached to the discharge for receiving the material drained from the
 pump. The plunger is then retreated away from the pump within the bore to
 permit the fluid to pass from the drain opening of the pump into the bore
 of the tool housing and then to exit the tool housing through the
 discharge into the collector.
 In an embodiment of the invention, the method further includes coupling an
 engaging end of the plunger to a drain plug held within the drain outlet
 of the rotary case and then removing the drain plug by manipulating the
 plunger. In an embodiment, the step of removing the drain plug is done
 partially simultaneously with the step of retreating the plunger.
 In an embodiment of the invention, the step of sealing also includes
 providing a seal on the mounting end of the tool housing and then
 threading the mounting end of the tool housing into the pump at the drain
 opening so that the seal is formed between the housing and the pump.
 In an embodiment of the invention, the step of attaching the collector
 includes attaching a vacuum scrubber to the discharge in order to collect
 fluid evacuated from the pump.
 In an embodiment of the invention, the step of aligning includes inserting
 an alignment device through an alignment opening in the stationary housing
 and into an additional alignment opening in the rotary case which serves
 to correspondingly align the drain outlet of the rotary case with the
 drain opening of the pump housing.
 These and other objects, features and advantages of the present invention
 are described herein, and will become apparent from the detailed
 description of the presently preferred embodiments and related drawing
 figures.

DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
 Referring now to the drawing figures, FIG. 1 illustrates a perspective view
 of a sealed drain tool 20 constructed in accordance with one embodiment of
 the present invention. FIG. 2 illustrates an exemplary view of a rotary
 case pump 22 for which the sealed drain tool 20 is useful. The components
 of the rotary case pump 22 are described generally herein in order to
 provide a proper understanding of the invention.
 The exemplary case pump 22 of FIG. 2 generally has a stationary housing 24
 and an end cover 26 together defining a pump cavity 28 therein. A rotary
 case 30 is housed within the pump cavity 28 of the stationary housing 24.
 The rotary case 30 is typically carried on a rotary shaft 32 which is
 driven to rotate the case 30 within the pump cavity 28 for pumping fluid.
 Such a rotary case pump 22 is sometimes used to pump fluids which include
 hazardous chemicals, toxic material or otherwise caustic substances which
 may cause severe harm to individuals, the environment or any objects with
 which the fluid contacts once it leaves the pump 22 and is exposed to
 atmosphere. It is occasionally necessary to drain such a case pump 22 and
 remove all of the fluid within the pump cavity 28. Typically, the rotary
 case also has an inner fluid chamber 34 which must also be drained of
 fluid.
 A conventional pump 22 of this type typically includes a drain outlet 36 in
 the rotary case 30 which is closed off by a removable drain plug 38
 received within the outlet. To drain the inner fluid chamber 34 of the
 rotary case 30, the drain plug 38 must be removed from the opening 36 in
 order that the fluid may exit the chamber. The casing 30 includes a second
 drain plug which is not shown in FIG. 1. However, if the fluid is of the
 hazardous type, it is extremely undesirable for the fluid to merely be
 poured into a container or awaiting vessel and exposed to atmosphere. The
 present invention is directed to a sealed drain tool 20 which is capable
 of removing the drain plug 38 and draining the hazardous fluid from the
 pump 22 without exposing the fluid to atmosphere or allowing the fluid to
 contact any objects near the pump. The present invention also includes an
 alignment device 40 which is used to align the appropriate openings for
 inserting the tool 20 and draining the fluid from the casing 30 and
 chamber 34.
 FIGS. 3-6 illustrate a tool housing 50 of the drain tool 20 in more detail.
 The housing 50 in one embodiment has an exterior cylindrical wall 52 shown
 in FIGS. 3 and 5 as an elongate circular cylinder. FIG. 4 illustrates the
 housing 50 in longitudinal cross section in order to show the interior
 construction of the housing 50. As it will be evident to those skilled in
 the art, the drain tool housing 50 may take on other forms and
 constructions other than the circular elongate cylinder as illustrated
 without departing from the scope of the invention.
 As shown in FIGS. 3, 5 and 6, the tool housing 50 has a free end including
 a hex head formation 54 for installing the drain tool 20 as is described
 below. The tool housing 50 has a mounting end with a smaller diameter
 cylindrical end portion 56 which is insertable into the pump assembly 22
 as is also described below. The mounting end has an externally threaded
 section 58 disposed between the smaller diameter end portion 56 and the
 cylindrical exterior surface 52 of the housing 50. The threaded section 58
 has a diameter smaller than the exterior surface 52 but larger than the
 end portion 56. This threaded section 58 is utilized to secure the drain
 tool assembly 20 in place on the pump 22 as is also described below.
 The end portion 56 has a generally planar end face 60 for abutting against
 a flat surface of the pump assembly 22 when installed. A groove 62 is
 formed in the planar face 60. An O-ring seal 64 is received within the
 groove 62 for providing a fluid tight seal between the pump assembly 22
 and the end portion 56 as described below.
 The tool housing 50 also includes a plunger longitudinal bore 65 extending
 longitudinally through the entire housing. The bore includes a first bore
 section 66 of a first diameter extending from the end portion 56. The
 plunger bore 65 also includes a second bore section 68 of a second
 diameter extending from the hex head end 54 and meeting the first bore
 section 66 within the tool housing 50. A shoulder or step 69 is defined by
 the change in diameter at the juncture between the first and second bore
 sections 66 and 68 of the bore. The first diameter of the first bore
 section 66 is larger than the second diameter of the second bore section
 68 for reasons described in more detail below. The first bore section 66
 defines an inlet opening 70 in the planar end face 60 of the end portion
 56. The second bore section 68 defines a free end opening 71 in the free
 end of the tool housing 50 defined by the hex head end 54.
 It is preferred that the plunger bore 65 is machined to a precise diameter
 and smooth surface finish in order for the invention to function most
 efficiently. Thus, it is preferred that the tool housing 50 is formed from
 a material such as steel, aluminum or some adequate alloy in order that it
 may be precisely machined to include all of the elements in the bore 65.
 The tool housing 50 also includes one or more discharge openings 72
 illustrated in FIGS. 3 and 5. In one embodiment illustrated in FIG. 5,
 three discharge openings 72 are provided in the tool housing 50 formed
 radially into the exterior surface 52 and extending into the first section
 66 of the bore 65. Each of the discharge openings 72 are spaced radially
 120.degree. apart relative to one another as illustrated in FIG. 5. As
 will be apparent to those skilled in the art, the number of discharge
 openings 72, the orientation and position relative to one another, and the
 orientation and position relative to the tool housing 50 may vary without
 departing from the scope of the present invention.
 Disposed at one end of the second bore section 68 are three O-rings 74
 received in annular grooves 76 formed within the bore 65. These O-rings 74
 are intended to provide a fluid tight seal around a portion of a plunger
 assembly as described below and yet permit the plunger to slide within the
 bore 65 and extend beyond the free end or the hex head end 54 of the tool
 housing 50. As will be evident to those in the art, the number and
 positioning of the O-rings 74 and the type of seal used may vary without
 departing from the scope of the invention.
 FIG. 7 illustrates a perspective view of a plunger assembly 80 constructed
 according to one embodiment of the invention. The plunger assembly 80
 includes an elongate shaft section 82, a free end having a hex head 84
 formed at one end of the shaft, and an engaging tool 86 removably carried
 on an adaptor end 88 of the shaft. The engaging tool 86 is illustrated in
 FIG. 8 and its function is described in more detail below.
 The plunger assembly 80 includes an annular shoulder section 90 adjacent
 the adaptor end 88. The diameter of the annular shoulder 90 precisely
 corresponds with the first diameter of the larger first section 66 of the
 bore 65. The diameter of the shaft section 82 of the plunger assembly 80
 precisely corresponds with the second diameter of the second section 68 of
 the bore 65. As illustrated in FIG. 2, the hex head end 84 of the plunger
 assembly 80 is inserted into the tool housing 50 through the inlet opening
 70. The length of the plunger assembly 80 is such that the hex head end 84
 protrudes from the free end opening 71 of the tool housing 50 as
 illustrated in FIG. 1 while the engaging tool 86 remains extended from the
 inlet opening 70. The diameter of the annular shoulder 90 is such that the
 shoulder will abut against the step 69 in the bore 65 preventing the
 plunger assembly 80 from traveling any further through the bore 65. Thus,
 the combination of the annular shoulder 90 and the step 69 within the bore
 65 together define one embodiment of a stop element which limits travel of
 the plunger assembly 80 within the bore 65.
 FIGS. 7 and 8 illustrate the engaging tool 86 constructed in accordance
 with one embodiment of the invention. The engaging tool 86 has an
 attachment end 92 for insertion over the adaptor end 88 of the plunger 80.
 The engaging tool 86 also includes a tool end 94 which is adapted to
 rotationally engage a portion of the drain plug 38 when the tool assembly
 20 is inserted. In the present embodiment, the tool end 94 is in the form
 of an Allen wrench configuration having a hexagonal cross section. The
 drain plug 38 will include a corresponding hex-shaped recess for receiving
 the tool end 94 therein, though the drain plug is not shown in detail in
 these drawings. As will be evident to those skilled in the art, the tool
 end 94 may take on other tool and fastener configurations and
 constructions such as, for example, a torx-head arrangement, a screwdriver
 head arrangement, or a nut and socket arrangement without departing from
 the scope of the present invention.
 Also as illustrated in FIGS. 7 and 8, the attachment end 92 may include a
 detent opening 96 for engaging a roll pin (not shown) carried on the
 adaptor end 88 of the plunger 80. Such a configuration permits the
 engagement tool 86 to snap into place over the adaptor end 88 with a roll
 pin urged outward into the detent opening 96.
 FIG. 9 illustrates one embodiment of the alignment device 40 originally
 shown in FIG. 2. The device 40 in the present embodiment includes a
 elongate shaft 100 having a hex head end 102 at one end and threads 104
 formed along a portion of the shaft at the opposite end. A reductor 106 is
 also illustrated in FIG. 9 for being received over the threaded end 104 of
 the alignment device 40. The reductor 106 includes internal female threads
 108 and a hex head portion 110 at one end. The threads 108 correspond to
 the threads 104 of the alignment device 40 in order that the reductor 106
 threadingly engages the device 40 and moves by relative rotation between
 the reductor and the device.
 As will be evident to those skilled in the art, the alignment device may
 take on many configurations and constructions but is intended to properly
 align the rotating case 30 to the stationary housing cover plate 26 so
 that the sealed drain tool 20 properly aligns with and engages the drain
 outlet 36 and drain plug 38.
 To utilize the sealed drain tool 20 of the invention, the rotating case 30
 must be properly aligned with the stationary housing cover plate 26. As
 illustrated in FIG. 2, the stationary housing 24 includes a drain opening
 120 which must be concentrically aligned with the drain outlet 36 of the
 case 30. The alignment device 40 performs this function. The cover plate
 26 of the stationary housing 24 includes an alignment opening 122 which
 has a hex configuration in cross section for receiving therein the hex
 section 110 of the reductor 106. The opening 122 also includes a step 124
 for preventing the reductor 106 from passing any deeper into the opening
 122. Thus, the reductor 106 is held within the opening 122 and prevented
 from rotating by the corresponding hex configuration of the opening 122
 and hex section 110 of the reductor.
 The shaft 100 is then inserted and threaded into the reductor 106 via the
 threaded end 104 until it engages the rotating case 30. The rotating case
 30 has a precisely placed threaded opening 126 into which the threaded end
 104 of the shaft 100 is received. By aligning the rotating case 30 in this
 manner, the drain opening 120 and drain outlet 36 between the cover plate
 26 and the rotating case 30 will align properly. The hex head end 102 of
 the device 40 is rotated until the device 40 fully engages the rotating
 case in order to securely hold the case in proper alignment.
 The assembled sealed drain tool 20 shown in FIG. 1 is then positioned over
 the opening 120 and inserted therein with the engaging tool 86 entering
 first. The tool end 94 is then inserted into and engages the corresponding
 opening in the drain plug 38. The housing 50 is then rotated using the hex
 head end 54 so that the threaded end 58 threads into the opening 120 which
 has corresponding threads. The housing 50 is threaded into the opening 120
 until the flat surface 60 and the O-ring 62 engages a corresponding flat
 surface a step 128 of the rotating case 30. The housing 50 is rotated
 further until the O-ring 64 is sufficiently compressed providing a fluid
 tight seal between the step 128 of the rotating case 30 and the tool 20.
 A suitable tool is then placed over the hex head end 84 of the plunger
 assembly 80 and rotated in order to draw the drain plug out of the drain
 outlet 36. Once the drain plug 38 releases from the drain outlet 36, the
 plunger 80 moves rearward toward the free end of the tool housing 50 until
 the shoulder 90 abuts the step 69 within the bore 65. Fluid passes from
 the drain outlet 36 to the drain opening 120 and into inlet opening 70 of
 the bore 65. The fluid exiting the chamber 34 of the pump 22 passes
 through the bore 65 and exits the openings 72 into a suitable collector
 which is attached to the drain tool 20 so that no fluid may escape. For
 example, one or more discharge fittings 130 may be attached to the one or
 more discharge openings 72 by corresponding threads 132 of the openings
 72. The discharge fitting 130 illustrated in FIG. 1 may be tightly
 connected to a suitable waste container for collecting the drained fluid.
 Some fluid may pass between the annular shoulder 90 and the first section
 66 of the bore 65 and between the diameter of the shaft section 82 of the
 plunger 80 and the second section 68. The fluid is prevented from exiting
 the free end opening 71 of the bore 65 by the multiple seal arrangement
 illustrated by O-rings 64.
 Once the pump assembly 22 is sufficiently drained of fluid, the plunger is
 forced forward again toward the housing 26. The drain plug 38 is threaded
 back into the drain outlet 36. In order to ensure that all of the excess
 fluid is drained from the sealed drain tool 20, a suitable vacuum
 discharge or vacuum scrubber 134 may be connected to the discharge fitting
 130 to completely evacuate the bore 65 prior to releasing the tool 20 from
 the cover plate 26 of the stationary housing 24.
 It should be understood that various changes and modifications to the
 presently preferred embodiments described herein will be apparent to those
 skilled in the art. Such changes and modifications may be made without
 departing from the spirit and scope of the present invention and without
 diminishing its attendant advantages. It is therefore intended that such
 changes and modifications be covered by the appended claims.