WO2009120099A1

WO2009120099A1 - Drain plug and assembly

Info

Publication number: WO2009120099A1
Application number: PCT/NZ2009/000045
Authority: WO
Inventors: Michael Adair Mcmaster
Original assignee: Michael Adair Mcmaster
Priority date: 2008-03-26
Filing date: 2009-03-26
Publication date: 2009-10-01

Abstract

A drain plug assembly for a water bourne vessel comprising: a plug housing (1) with a flow path (8) for coupling to the drain of a floatation chamber or volume, a drain plug (2) comprising a plugging member (40) and locking actuator (3), the plugging member (40) being adapted to be installed into the flow path (8) to substantially block the flow path, and the locking actuator (3) being operable to retain the plugging member (40) in the flow path (8) once installed, wherein the locking actuator (3) is not operable until the plugging member (40) is installed.

Description

DRAIN PLUG AND ASSEMBLY

FIELD OF THE INVENTION

The present invention relates to a drain plug and a drain plug assembly for a boat or other water bourne vessel. The drain plug assembly is adapted for use in a warning system that advises if the drain plug is properly installed.

BACKGROUND TO THE INVENTION

Drain plugs, commonly known in the art as bungs, have been provided in boat hulls for centuries Early boat bungs were simply a cork or plug inserted or hammered into a corresponding drilled hole (or dram) in the hull of the boat, typically at a low point of the boat's transom. The purpose of a bung and corresponding bung hole in the hull of a boat is to allow water that collects in the hull while the boat is at sea to drain from the hull.

Once the boat has been removed from the sea to dry land, the bung is removed from the bung hole and an₎ water remaining in the hull of the boat drains from the hull via the bung hole. When the boat is put back in the water, the bung should be inserted into the bung hole to prevent water entering the hull.

Modern boat bungs consist of an assembly comprising a bung (or plug), and a bung housing (or plug housing) in which the bung fits. The bung housing is fitted and sealed to the drain of the boat hull and provides an open conduit or flow path through the hull. The bung fits into the open conduit and closes and seals the conduit, preventing water ingress via the bung assembly into the hull while the boat is at sea. Modern bungs often use a screw thread interface between the bung and bung housing, and an elastomeπc sealing interface to create the seal. Such assemblies can be used in other floatation volumes/chambers too, such as in pontoons in water bourne vessels and the hulls of jetskis or other wateibourne vessels

A problem with prior art bung assemblies is the risk involved in a boat person putting a boat to sea with the bung absent from the bung housing. Such an error by a boat person may result in a catastrophe at sea, with the possible sinking and loss of the boat, and the potential for loss of lrves of the people on board In this specification where ieference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of pioviding a context for discussing the features of the invention Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art

SUMMARY OF THE INVENTION

It is an ob_ject of the present invention to provide a drain plug and/or drain plug assembly adapted to reduce the chances of inadvertently leaving the drain plug out or improperly fitting the drain plug, or which will at least provide the public with a useful choice

In one aspect the present invention may be said to consist in a drain plug assembly for a boat comprising a plug housing with a flow path for coupling to the drain of a boat, a drain plug comprising a plugging member and locking actuator, the plugging member being adapted to be installed into the flow path to substantially block the flow path, and the locking actuator being operable to retain the plugging member in the flow path once installed, wherein the locking actuator is not operable until the plugging member is installed

Preferably the plugging member has a thread and the flow path has an internal surface with a complementary thread, wherein the plugging member is installed into the flow path by rotating the plugging member within the flow path to an engaged position

Preferably the locking actuator is moveable relative to the plugging member and is operable by moving the actuator to engage with the plug housing

Preferably the plug housing comprises a recess and the locking actuator engages with the plug housing by seating within the recess

Preferably the recess is positioned so that the locking actuator cannot seat within the recess until the plugging member is rotated to the engaged position Preferably a first transducer that triggers when the locking actuator is operated.

Preferably a second transducer that triggers when the plugging member is installed in the flow path.

Preferably the first and/or second transducer are connectable to an alarm system.

Preferably the floatation chamber or volume is the hull of a boat or other water bourne vessel.

Preferably the floatation chamber is a pontoon in a water bourne vessel.

In another aspect the present invention may be said to consist in a drain plug assembly for a boat comprising: a plug housing with a flow path for coupling to the drain of a boat, a drain plug for installation into the plug housing to block the flow path, the drain plug comprising a plugging member and locking actuator, a detector that is tnggerable detect a state where the drain plug is installed, wherein the plugging member is adapted to be installed into the plug housing to substantially block the flow path, and the locking actuator is actuable to retain the plugging member in the plug housing, and wherein when actuated, the locking actuator triggers the detector.

Preferably, the detector can be coupled to a warning system such that when the detector is triggered by the actuator, the warning system indicates that the drain plug is blocking the flow path and when the detector is not triggered, the warning system indicates that the drain plug is not blocking the flow path.

Preferably, the plugging member has a thread and the flow path has an internal surface with a complementary thread, wherein the plugging member is installed into the plug housing by inserting the plugging member into the drain member and rotating the plugging member to an engaged position.

Preferably, the locking actuator comprises a latch pivotably coupled to the plugging member and the plug housing comprises a recess for the latch, the recess being aligned with the latch when the plugging member is in the engaged position, wherein the locking actuator can be actuated when the plugging member is in the engaged position by pivoting the latch to seat in the recess.

Preferably, the detector is disposed in the latch and/or recess such that by seating the latch in the recess the detector is triggered.

Preferably, the detector comprises a reed switch.

Preferably, the detector is triggered by installing the plugging member into the plug housing to substantially block the flow path.

Preferably, the locking actuator comprises a locking bar and the plug housing comprises a recess for the locking bar, the recess being aligned with the latch when the plugging member is in the engaged position wherein the locking actuator can be actuated when the plugging member is in the engaged position b) mo\ ing the locking bar to seat in the recess.

In another aspect the present invention may be said to consist in a drain plug for a plug housing installed in a boat drain, the drain plug being for insertion into the plug housing to block the flow path, the bung comprising: a plugging member, locking actuator, and at least part of a detector diat is tnggerable detect a state where the drain plug is blocking the flow path, wherein the plugging member is adapted to be installed into the plug housing to substantially block the flow path, and the locking actuator is actuable to retain the plugging member in the plug housing, and wherein when actuated, the locking actuator triggers the detector.

In another aspect the present invention may be said to consist in a drain plug assembly for a boat comprising: a first member adapted to be sealingly attached to a drain of a boat, the first member having a flow path therethrough and an actuable element, a second member insertable into the flow path of the first member to achieve a first engagement between the first and second members, the first engagement preventing a flow of water through the flow path, the second member having a tab, the tab being moveably attached to the second member, the tab being moveable to an installed position once the first engagement is achieved, the installed position pioviding a second engagement between the first member and the second member, the second engagement maintaining the first engagement between the first member and the second members, and the tab having an actuator, the actuator capable of actuating the actuable element when the tab is in the installed position, the actuable element adapted to provide a signal for controlling a warning system

In another aspect the present invention may be said to consist in a drain plug for a plug housing installed in a boat drain, the drain plug being for insertion into the plug housing to block the flow path, the plug comprising a plugging member and locking actuator, the pluggmg member being adapted to be installed into die flow path to substantially block the flow path, and the locking actuator being operable to retain the plugging member in the flow path once installed, wherein the locking actuator is not operable until the plugging member is installed.

Preferably the locking actuator comprises a latch pivotably attached to the plugging member that can be maneuvered to seat within the plug housing.

Preferably the locking actuator comprises a locking bar and actuator that can be maneuvered to seat within the plug housing.

The term "comprising" as used in this specification and claims means "consisting at least in part of. When interpreting each statement in this specification and claims that includes the term "comprising", features other than that or those prefaced by the term may also be present Related terms such as "comprise" and "comprises" are to be interpreted in the same mannei

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. The invention consists in the foregoing and also envisages constructions of which the following gives examples only.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention will be described by way of example only and with reference to the drawings, in which.

Figures Ia to Id show plan, side elevation and front elevation views of the drain plug assembly comprising a plug housing and a drain plug according to a preferred embodiment, and its installation in a boat,

Figure 2 shows an exploded perspective view of the drain plug assembly,

Figure 3 shows the drain plug in further detail comprising a plugging member and a latch,

Figures 4a and 4b show a cross section of a portion of the drain plug assembly with the latch in an open and actuated or lock position respectively, Figure 4c shows a cross section of a portion of the drain plug assembly with the latch in an lock position,

Figures 5a and 5b show elevation cross sectional views of the drain plug assembly with the latch in an actuated position,

Figures 6a to 6d show various views of the under side of the drain plug assembly indicating a position of a detector,

Figure 7 shows a schematic diagram of two drain plug assemblies connected to a warning system on a boat,

Figure 8 shows in further detail how a drain plug assembly is wired to a warning system on the boat, Figure 9 shows a warning system indicator unit for the dashboard of a boat,

Figure 10 shows an additional detector for the drain plug assembly,

Figure 11 shows an exploded perspective view of a drain plug assembly according to a second embodiment,

Figures 12a and 12b show a cross section elevation views of an assembled drain plug assembly according to the second embodiment,

Figure 13 shows a plan and elevation view of a drain plug assembly according to a third embodiment. Figure 14 shows forward and reverse angle perspective views of the drain plug assembly according to the third embodiment,

Figure 15 shows forward and reverse angle perspective views of a housing according to the third embodiment, Figure 16 shows top and bottom perspective views of a latch according to the third embodiment,

Figure 17 shows forward and reverse angle perspective views of a plug member according to the third embodiment,

Figure 18 shows a plan and elevation view of a drain plug assembly according to a fourth embodiment,

Figure 19 shows forward and reverse angle perspective views of the drain plug assembly according to the fourth embodiment,

Figure 20 shows forward and reverse angle perspective views of a housing according to the fourth embodiment, Figure 21 shows two perspective views of a plug member according to the fourth embodiment,

Figure 22 shows a perspective view of a latch according to the fourth embodiment,

Figure 23 shows a partial cross-sectional view of the latch of die fourth embodiment

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention as defined by the accompanying provisional claims.

The Figures show various embodiments of a drain plug assembly. The invention described could comprise the assembly itself, comprising a drain plug and a plug housing in assembled or unassembled form, either installed in a boat, or in an uninstalled state Alternatively, the invention could comprise the drain plug, adapted for installation into a drain plug housing. The assembly is for installation in a boat or other water bourne vessel, such as a _jetslα. The assembly can be inserted in the hull of any such vessel and/or in any floating chamber, such as a pontoon. The preferred embodiments are described with reference to a boat hull, but this is by way of example only. The assembly can be used in any suitable situation where plugging of a floatation volume (such as a hull or similar) is required.

In general terms, the drain plug or drain plug assembly generally comprises a two stage installation procedure. The first stage comprises installing at least a portion of the drain plug into the plug housing to substantially block water flow through the plug housing. Installation might comprising screwing, locking, latching or otherwise engaging the drain plug to retain it in place. This results in the primary engagement. The second stage comprises locking or latching the drain plug to using a lock actuator to further retain the drain plug in place in the plug housing. This results in the secondary engagement. Full installation takes place upon secondary engagement. Partial installation takes place on primary engagement, which will still usually provide sufficient sealing to prevent leakage. The secondary engagement provides an additional safety measure. Secondary engagement cannot take place until primary engagement has taken place.

The drain plug/plug assembly preferably comprises a detector for detecting when the drain plug is installed in the plug housing, thus blocking flow. In a preferred embodiment, the detector detects when secondary engagement takes place. It may also optionally detect when primary engagement occurs. The drain plug/plug assembly is adapted to be used with a warning system installed in a boat. The warning system indicates when the drain plug is installed or not installed, based on detection of secondary and optionally primary engagement.

Figures 1 a to 6d show a first embodiment of a drain plug assembly. It comprises a plug housing 1 that is mounted to the drain hole in the hull of a boat 85 (see Figure Id). A flow path, passage or channel (hereinafter: passage) 8 passes through the plug housing 1 (see Figure 2). Typically, the plug housing 1 will be mounted in a drain hole at a low position on the transom of a boat 85. The housing is fitted to the transom drain hole in a watertight manner, so that no water may pass around the housing 8, between the transom drain hole and the housing 1. The housing preferably has a flange 10, the flange providing a bearing face to bear against an outer surface of the transom. The housing 1 is preferably fixed to the transom by screws 5, each screw 5 fixing the housing to the transom via a corresponding screw hole 9 in the flange 10. The plug housing provides a flow passage 8 through the transom of the boat to allow water in the hull to drain from the hull via the flow passage 8, when the boat is removed from the water to dry land.

A drain plug or bung (hereinafterdrarn plug) 2 is comprises a plugging member 40 adapted to be installed into the flow passage 8. Preferably the flow passage 8 and corresponding plugging member 40 are cylindrical. Preferably the plugging member 40 has a male screw thread 6 (more visible in Figure 3), and the plug housing a corresponding female screw thread 7 on an internal surface of the flow passage 8. The plugging member can be installed into the plug housing in a threaded engagement to provide a primary engaged position, resulting in primary engagement. Preferably, the member is installed by inserting the plugging member into the flow passage 8, and screwing it in place via the thread using a single turn to position it in an engaged position. Once the plug 2 is screwed into place within the flow passage 8, the plug 2 seals the flow passage and substantially prevents or blocks the flow of water through the flow passage 8.

The seal between the drain plug and the plug housing is preferably made with an elastomeric o-ring 11 as seen in Figures 4a, 4b. The o-ring 11 is preferably located in an annular o-rmg channel 12 formed around the outer circumference of the plugging member 40 Once the plugging member is threaded into the housing, the o-ring is captured between the plug o-nng groove 12 and a seat 13 extending around the internal face of the flow passage 8. The o-ring is slightly compressed to provide a water-tight seal between the plug and the plug housing. The o-nng is preferably located on the water side of the plug thread 6

The plug pieferably has a flange 14. The flange 14 has a diameter larger than the diameter of the pugging member 40 that installs into the flow passage 8. A bearing surface 15 of the plug flange 14 bears against a corresponding bearing surface 16 of the plug housing 1 once the plugging member 40 is fully engaged with the plug housing 1. The screw threads 6, 7 are arranged so that the plugging member must be rotated a predetermined number of turns, beginning at a predetermined start position and finishing at a predetermined primary engagement position. Arranging the screw threads in this way ensures the drain plug has a particular orientation within the plug housing in the primary engaged position. Preferably the plug must be screwed one full revolution, or 360 degrees, from a fully disengaged position to a primary engaged position within the housing 1. However, the plug could be designed to required multiple revolutions.

The plug is fitted with a movable latch 3, in the form of a lever, handle or tab. In the preferred embodiment, the tab is hinged to the plug with a hinge pin 4. In the preferred embodiment, the latch has a pair of arms 17 extending from a substantially planar, substantially flat, latch body 18. A pin hole 19 is located in the distal end of each arm. A pin receiving portion or pivot 20 is provided on an external end of the plug 2, the pin receiving portion 20 having a pin hole 21. When the latch is assembled to the plug 2, the latch arms 17 extend either side of the plug pin receiving portion 20, and die latch arm pin holes 19 and plug pin receiving portion hole 21 align, so that a hinge pin 4 may be received through one arm pin hole 19, through the plug pin receiving portion pin hole 21, and through the second arm pin hole 19, attaching the latch to the plug in a hinged configuration. This configuration is one suitable embodiment for attaching the latch to the plug in a hinge fashion. However, any such hinged arrangement hinging the latch to the plug may be suitable. The actual hinge arrangement is not important to the present invention.

The latch 3 forms a lock actuator that can be actuated from an open position (see Figure 4a) to a lock position (see Figure 4b), by pivoting the latch on the hinge pin 4. The pivot 20 comprises a camming surface 28 that bears against a corresponding camming surface 27 on the inside pivot region of the latch arms 17. The camming surface 28 allows the latch to be moved from the open position to the lock position The lock position results in a secondary engagement position or secondary engagement.

In the preferred embodiment, the drain plug 2 is installed into the drain housing 1, by inserting the plugging member 40 into the flow passage 8 and screwing it one full revolution to the threaded engaged/installed position. The latch 3 is in the open position, pointing substantially vertically from the drain plug 2. In this open position, the latch body 18 is hinged out from the plug with the plane of the latch body 18 substantially parallel to the longitudinal axis of the plug 2. The latch, in the open position, may be used as a handle for a user to grip when threading the plugging member 40 into the plug housing. Once the plugging member 40 has been threaded into the housing 1 to the primary engaged position, the latch 3 is moved from the open position to the lock position to provide the secondary engagement. To accommodate the latch in the installed position, an external face of the housing has a cavity or recess in which the latch may be hinged into and seated. The cavity 23 is shaped to match the perimeter shape of the latch, and is slightly larger than the latch 3 so that when in the fully installed position, the latch 3 neatly fits within the cavity 23, the latch 3 being closely bounded on at least one side by a wall 24 of the cavity. The cavity wall 24 provides a bearing surface against an edge 25 of the latch. Once in the installed position, the bearing surface of the cavity wall 24 bears against the edge 25 of the latch to prevent the plug 2 from unthreading from the housing 1. For example, for a right hand thread, the plug 2 must be turned anti-clockwise to be removed from the housing 1. The cavity wall 24 bears against the leading edge of the latch when considering the thread direction required to remove die plug 2 from the housing 1. When in the installed position, the latch bearing against a wall of the cavity 23 accommodating the latch 3 provides the second engagement position (secondary engagement) between the plug 2 and the housing 1.

The first, or primary engagement makes the seal between the plugging member and plug housing. The primary engagement is protected by die secondary engagement. That is, the secondary engagement must be disengaged before the primary engagement may be disengaged. Further, the secondary engagement is not possible until primary engagement takes place. Installing the plug 2 by rotating it will align the latch 3 with the recess/cavity 23. The latch cannot be seated in the cavity (i.e. secondary engagement cannot occur) until the plug is properly installed (i.e. primary engagement) so that the latch is aligned with the cavity. The latch (locking actuator) is not operable (i.e. cannot effect secondary engagement) until primary engagement has occurred. This two stage engagement and disengagement provides a safety benefit that helps to prevent the drain plug from accidentally disengaging from the housing. First, secondary engagement cannot take place until primary engagement occurs. This means that once secondary engagement takes place, you can be sure that primary engagement (resulting in blocking of the flow path) has occurred. Also, as secondary engagement only takes place at a certain rotational position, this reduces the chances that over tightening of the plugging member will occur upon primary engagement The drain plug assembly may have an additional safety feature consisting of a lock that locks the latch in the installed position The lock may consist of a clip or cam type arrangement, the clip or cam providing a resistance that must be overcome to move the latch away from the installed position A preferred arrangement for the latch lock is best shown m Figure 3 A ramp and step 27 on an inside surface of one latch arm 17 is formed by a relatively shallow ramped surface 26 passing around the arm pin hole 19, the shallow ramp ending in a relatively steep transition The shallow ramp may pass entirely around die pin hole 19, the steep transition, or step, 27 joining the start and end of the shallow ramp Alternatively, the shallow ramp may pass around a portion of the hole, for example a quarter turn around the hole 19, with the top of the step 27 _joining an upper extent of the ramped surface, and the bottom of the step 27 joining to the inside surface of the latch arm 17, the inside surface being substantially normal to the hinge pin axis The ramp passing around the hole 19 for a quartei turn is preferred, as in the preferred embodiment the latch is moved 90 degrees from the open position to when the latch is in plane widi the longitudinal axis of the plug 2, the in plane position being a preferred gapping position when inserting or removing the plug from the housing 1

A corresponding ramp 28 and step 29 is provided at one end of the plug pin receiving portion 20 The ramp and step 28, 29 of the plug pin receiving portion 20 has preferably the same geometry as the tab arm ramp and step 26, 27, although the plug pin receiving portion ramp and step are reversed with respect to the axis of the hinge pin 4 For this preferred arrangement, the corresponding ramped surfaces 26 and 28 provide a cam arrangement This cam arrangement results in the latch handle moving along the direction of the pin axis when the latch 3 is hinged from the open position to the lock position (secondary engagement) and vice versa The extent of the movement along the pin axis is equal to the combined height of step 27 and step 29 There is sufficient clearance between the edge 25 of the latch 3 and the wall 24 of the housing cavity 23 to allow this axial movement

In the installed position, step 27 and step 29 bear against each other, providing a resistance to movement of the latch away from the installed position The plug assembly may include a spring element, such as a spring washer, to provide a bias maintaining the latch in the axial position along pin 4 relating to the latch installed position The spring washer may be located between the plug pin receiving portion 20 and the latch arm 17 ad_jacent to the latch arm 17 incorpoiating the cam surface 26 and step 27 Alternatively, the spring washer may be located between an external surface of the latch and the cavity wall 13 Alternatively, no spring biasing means may be used

The latch installed position is clearly shown in Figure 5a, where step 27 and step 29 are in bearing contact In order to move the latch away from the installed position, the spring bias must be overcome to move the latch along the pin axis to disengage steep step 27 and steep step 29

When in the installed position, the latch preferably lies substantially flat within the housing cavity 23 As well as being aesthetically pleasing, this also prevents edges of the latch being accidentally knocked by foreign objects which may knock the latch out of the lock position and put the plug at risk of becoming unplugged However, preferably the latch has a handle portion 22 that allows a user to exert the necessary pressure on the latch required to overcome the latch locking mechanism provided by step 27 and step 29, to move the latch away from the installed position prior to removing the plug 2 from the housing 1

The drain plug assembly described above provides a two stage engagement safety feature which helps to maintain the drain plug in the plug housing This two stage principle provides the user with added security that the drain plug will remain within housing 1 The user can be comfortable that there is a very low πsk that the plug may work free from the housing The second stage engagement between the plug and the housing, including the locking mechanism provided by steps 27 and 29, reduces this risk

In addition to the primary and secondary engagement, the drain plug assembly of the pieferied embodiment also comprises a detector The detector is triggered when secondary engagement takes place The detector, in the form of the reed switch, when connected to a warning system can be used to warn a user when a drain plug is or is not installed correctly

As noted, the detector is triggered when the drain plug is in the secondary engagement position, thus providing an indication when the drain plug is fully installed As secondary engagement can only occur once primary engagement is successfully, detecting secondary engagement provides a good indication that the plug is properly installed. Optionally, the same or another detector can be used to determine when primary engagement occurs, as an extra safety feature.

The detector arrangement of the preferred embodiment is shown in Figures 5b and 6a-6d. The detector comprises a reed switch embedded in the flange of the plug housing. The two electrical terminals of the reed switch are connected to terminals or contacts 61a, 61b in the outer surface of the flow passage 8 Preferably, the terminals take the form of contact plates that follow the circumference of the plug housing 1. The contacts of the reed switch 60 can be seen in Figure 6c. A magnetic element 62 is embedded in the edge of the latch 3. When the latch is pushed into the lock position and rests in the recess or cavity 23 then the magnetic element 62 comes into proximity of the reed switch 60 and actuates them to effect contact. This closes the detector switch circuit which can be used to indicate when secondary engagement has taken place.

A drain plug assembly with such a detector can be integrated into a warning system on a boat as shown in Figure 7. Figure 7 shows two drain plug assemblies in schematic form with detectors that are wired in series to a light, buzzer or other indicator 70 on a dashboard unit on a boat. When a drain plug is fully installed in the plug housing into the secondary engagement then the reed switch contact will be shut thus completing the circuit. When both drain plugs are properly installed in this manner a complete circuit is made with the indicator 70 on the dashboard unit and it will activate indicating that the drain plugs 2 are fully installed and it is safe to proceed with boating.

Clearly, it would be possible to have a single drain plug assembly connected to a warning system in this manner, or more than two drain plug assemblies. It will also be appreciated by those skilled in the art that the electronics of the indicator could be arranged such that it alerts or indicates when the plugs are not properly installed. This would provide a default to safety position. The indicator would only become deactivated when the drain plugs are properly installed. Such as drain plug assembly could also be connected to a motor cut out switch or similar to prevent use of the boat if the drain plugs are not correctly installed. Figure 8 shows in further detail how the reed switch might be connected up to a warning system. Wires 80a, 80b can be connected to the connect 61a, 61b that are coupled to the reed switch 60. The wires are then connected to an alarm system that is installed in an alarm housing 81. As mentioned previously, the alarm could be any suitable alarm such as an audible or visual alarm, or a cut out switch for a motor or similar.

The housing 81 comprises the audible/visual alarm itself 82 which is installed into a dashboard surface 83. There is a fascia on the dashboard 84 covering the alarm 82. Figure 9 shows the dashboard assembly in further detail. It comprises the housing 81 and internal electronics, which can be inserted into a cut out 90 in the dashboard 83. A fixing nut is provided over the cut out 91 to retain the alarm in place, and the dashboard cover or fascia 84 is placed over the top.

Figure 10 shows an alternative preferred embodiment that further comprises a second detector that is triggered when primary engagement takes place. Figure 10 shows a cross sectional view of the drain plug assembly when in the secondary engagement position The components and reference numerals comprise: 3 — Tab Handle, 62 — Magnet, 60 - Reed Switch; 11 - O-Ring; 80a/80b - Wiring Circuit (Reed Switch); 101a/101b - Wiring Circuit (primary circuit); 2 — Plug /Bung; 4 — Handle axle.

Here, magnetic element 62 in the latch 3 and the reed switch 60 in the housing can be seen. The primary engagement detector comprises contacts embedded into the main body of the drain plug housing 100a, 100b. When the plugging member 40 is screwed completely into the flow passage 8, the contacts will align and a bridge connection will occur to complete the circuit. This wiring 101a, 101b can be connected to the alarm unit 81, such as that described in relation to Figure 8. The primary detection circuit could be connected to a separate warning/alarm system so that a user can determine whether it is primary or secondary engagement that has occurred or not. Alternativel} , the primary engagement detection circuit could be wired in series with the secondary engagement circuit such that both must be completed in order to receive an indication of installation or otherwise.

The drain plug assembly could be sold as a single unit comprising the drain plug and the drain plug housing either assembled or unassembled. Alternatively or in addition, the individual components of the assembly could be sold separately. A drain plug assembly or components thereof could be sold as part of a completed boat, or sold for retrofitting.

It will be appreciated that the detection circuits, alarm system and/or particular implementation of the drain plug and housing could be altered by those skilled in the art while still falling within the scope of the present invention. The above preferred embodiment is shown by way of example only.

An alternative embodiment is shown in Figures 11 and 12 in exploded and cross section forms. The components and reference numerals comprise for Figure 11: 110 - Wheel fixing screw; 111 — Fixing screw hole; 112 — Secondary Locking Wheel; 113 — Secondary Locking Wheel thread; 114 — Plug Handle, 115 — Slot for assembling Locking Bar; 116 — Plug thread; 117 — Locking Bar thread; 119 — Main Body circuit contacts; 120 - Main Body Locking Bar location slots; 122 — Main Body thread; 123 — Ramp; 124 — Main Body. The components and reference numerals comprise for Figure 12: 110 — Fixing Screw; 111 — Fixing Screw hole; 112 — Secondar₎ Locking Wheel, 113 — Secondary Locking Wheel thread; 114 — Plug Handle, 115 — Slot for assembling Locking Bar; 116 — Plug thread; 117 — Locking Bar thread; 119 - Main Body Locking Bar location slots, 122 — Main Body thread; 124 - Main Body; 118 - Locking Bar, 11 - O-Ring

A main body plug housing 124 is provided with a flow passage 8 and a flange 10. The flow passage contains a main body thread 122 and contacts 119 for the secondary engagement detection circuit, similar to that described above. The plug housing 124 also comprises locking bar location slots 120 for receiving a locking bar for secondary engagement.

The drain plug 2 comprises a plugging member 40 with a thread 116. The drain plug 2 also comprises a plug handle 14 for twisting the plugging member 40 for threading it into the flow passage 8 into a primary engagement position. As with the preferred embodiment, a certain number of turns can be provided, such as one single turn, which results in the plug handle being substantially aligned with the location slots 120 upon primary engagement. A locking bar 118 with two wings and a central aperture with a locking bar thread 117 is also provided. The locking bar sits in the locking bar slot 115 in the plug handle 114. A secondary locking wheel 112 with a secondary locking wheel thread 113 can threadedly engage with the thread 117 of the locking bar 118. A wheel fixing screw 110 inserts through a fixing screw hole 111 in the secondary locking wheel 112 to retain the drain plug in an assembled state.

The drain plug is installed in the plug housing 124 in the following manner. First the plugging member 40 is inserted into the flow passageway 8 and the plug 2 is screwed into the primary engagement position by rotating the plug handle 114. At this point the drain plug 2 is in the primary engagement position. If there is a primary detection circuit, this will be triggered via suitable contacts as described for the preferred embodiment. Next, the drain plug is actuated with a locking actuator to provide the secondary engagement. This is done by twisting the secondary locking wheel 112 which by way of threads 113 and 117 will force the locking handle 118 downwards within the locking bar slot 115 through the centre of the plug 2. The secondary locking wheel 112 is continually rotated until the locking bar has travelled sufficiendy to seat in the locking bar location slots 120.

At this point secondary engagement has taken place and the drain plug will be securely locked into the plug housing effecting secondary engagement, the drain plug and primary engagement will still substantially block water flow through the passageway 8. However secondary engagement provides additional safety. Upon secondary engagement the contacts 119 will detect secondary engagement and provide a signal to a warning system to indicate that secondary engagement has taken place. This could be done via any suitable means, such as that described for the preferred embodiment. The locking bar cannot be put into position until primary engagement takes place, as only upon primary engagement do the locking bar location slots align with the locking bar. That is, operation of the locking actuator (locking bar and locking wheel) cannot take place until the plugging member is in place.

A third embodiment is shown in Figures 13 to 17. This embodiment operates in a similar manner to the first embodiment, but has some configuration differences. In this embodiment the plug assembly 130 comprises a housing and a drain plug 132 comprising a plug 134 and latch 132 (forming the locking actuator). The plug 134 further comprises plug retainer 135 that inserts through the flow path 8. The plug retainer 135 comprises two flexible extensions 136a, 136b with lateral extensions 137a, 137b at each distal end. The extensions are a sufficient length to allow the plug to be removed from the flow path 8. However, the lateral extensions 137a, 137b reduce the risk that the plug 132 will become fully detached from the housing 131, reducing the risk of losing the plug 132. Squeezing the flexible retainer extensions 136a, 136b allows for the plug 132 to be fully removed from the housing 131 if necessary. The plug 132 has a thread 170 that allows for the plug to be rotated into and screwed into a corresponding thread 150 in the internal surface of the flow path 8. The plug housing 131 has apertures 140, 141 for screws to attach the assembly to the transom of a boat 85, and a recess 151 for allowing secondary engagement as described previously.

A fourth similar embodiment as shown in Figures 18 to 23. The body of this embodiment is larger and has four holes e.g. 200 for allowing screws for attachment to the transom of a boat 85.

In the third and fourth embodiments, the locking actuator is latched in the secondary engagement position in a different manner to the first embodiment. Referring to Figures 16, 22 and 23, rather than having on the cam arrangement previously described, the latch 133 comprises a protrusion/cam 230 on the plug receiving portion that extends the length of that portion 20. The latch 3 comprises a corresponding protrusion 231 on the latch 133 that snap fits underneath the protrusion 230 once the latch 133 has been pushed into the recess 151 in the housing 131 into the secondary engagement position. To remove the latch upwards from the secondary engagement position requires additional force to manoeuvre the protrusions 230/231 past each other. This provides a means by which to retain the latch in the secondar) engagement position.

The third and fourth embodiments have a recess 152 for the reed switch (see Figures 15 and 20). A cap 153 (see Figures 14 and 19) is provided over the recess to hold the reed switch in place. This allows for more effective seal and easier assembly. The cap also has peg lugs (e.g. 155 in Figures 14 and 19), which engage with corresponding recesses (e.g. 154 on Figures 15 and 20) in the external wall of the flow path. This provides for additional strength and component integrity. In the third and fourth embodiments, the external part of the flow path has iear ribs, (e g 142 in Figures 14 and 19) This enables some of the flow path 8 material to be reduced The rear ribs hold the flow path in place in the aperture and the transom of the boat, however the cut away portion retains a flow path wall Removing some of the material by use of rear πbs reduces the πsk of distortions of the flow path during the manufacture process

The invention also allows the drain plug assembly to be installed on boats of all types, including fϊbreglass and aluminium hull boats, other water bourne vessels (such as jet skis, yachts and the like) and also in flotation volumes other than hulls

Claims

1. A drain plug assembly for a water bourne vessel comprising a plug housing with a flow path for coupling to the drain of a floatation chamber or volume, a drain plug comprising a plugging member and locking actuator, the plugging member being adapted to be installed into the flow path to substantially block the flow path, and the locking actuator being operable to retain the plugging member in the flow path once installed, wherein the locking actuator is not operable until the plugging member is installed.

2. A drain plug assembly according to claim 1 wherein the plugging member has a thread and the flow path has an internal surface with a complementary thread, wherein the plugging member is installed into the flow path by rotating the plugging member within the flow path to an engaged position.

3. A drain plug assembly accoiding to claim 2 wherein the locking actuator is moveable relative to the plugging member and is operable by moλing the actuator to engage with the plug housing

4. A drain plug assembly according to claim 3 wherein the plug housing comprises a recess and the locking actuator engages with the plug housing by seating within the recess.

5. A drain plug assembly according to claim 4 wherein the recess is positioned so that the locking actuator cannot seat within the recess until the plugging member is rotated to the engaged position.

6. A drain plug assembly according to claim 5 further comprising a first transducer that triggers when the locking actuator is operated.

7. A drain plug assembly according to claim 6 further comprising a second transducer that triggers when the plugging member is installed in the flow path.

8 A diain plug assembly according to claim 7 or 8 wherein the fust and/or second transducei are connectable to an alarm system

9 A drain plug assembly according to any preceding claim wherein the floatation chamber or volume is the hull of a boat or other water bourne vessel

10 A drain plug assembly according to any preceding claim wherein the floatation chamber is a pontoon in a water bourne vessel

11 A drain plug assembly for a boat comprising a plug housing with a flow path for coupling to the drain of a boat, a drain plug for installation into the plug housing to block the flow path, the drain plug comprising a plugging member and locking actuator, a detector that is triggerable to detect a state where the drain plug is installed, wherein the plugging member is adapted to be installed into the plug housing to substantially block the flow path, and the locking actuator is actuable to retain the plugging member in the plug housing, and wherein when actuated, the locking actuator triggers the detector

12 A drain plug assembly according to claim 11 wherein the detector can be coupled to a warning system such that when the detector is triggered by the actuator, the warning system indicates that the drain plug is blocking the flow path and when the detector is not triggered, the warning system indicates that the drain plug is not blocking the flow path

13 A drain plug assembly according to claiml wherein the plugging member has a thread and the flow path has an internal surface with a complementary thread, wherein the plugging member is installed into the plug housing by inserting the plugging member into the drain member and rotating the plugging member to an engaged position

14 A drain plug assembly according to claim 13 wherein the locking actuator comprises a latch pivotably coupled to the plugging member and the plug housing comprises a recess for the latch, the recess being aligned with the latch when the plugging member is in the engaged position, wherein the locking actuator can be actuated when the plugging member is in the engaged position by pivoting the latch to seat in the recess.

15. A drain plug assembly according to claim 14 wherein the detector is disposed in the latch and/or recess such that by seating the latch in the recess the detector is triggered

16. A drain plug assembly according to claim 15 wherein the detector comprises a reed switch.

17. A drain plug assembly according to one of claims 11 to 16 wherein the detector is triggered by installing the plugging member into the plug housing to substantially block the flow path

18. A drain plug assembly according to claim 13 wherein the locking actuator comprises a locking bar and the plug housing comprises a recess for the locking bar, the recess being aligned with the latch when the plugging member is in the engaged position wherein the locking actuatoi can be actuated when the plugging member is in the engaged position by moving the locking bar to seat in the recess.

19. A drain plug for a plug housing installed in a boat drain, the drain plug being for insertion into the plug housing to block the flow path, the plug comprising. a plugging member, locking actuator, and at least part of a detector that is tπggerable detect a state where the drain plug is blocking the flow path, wherein the plugging member is adapted to be installed into the plug housing to substantially block the flow path, and the locking actuator is actuable to retain the plugging member in the plug housing, and wherein when actuated, the locking actuator triggers the detector

20. A drain plug assembly for a boat comprising- a first member adapted to be sealingly attached to a drain of a boat, the first member having a flow path therethrough and an actuable element, a second member insertable into the flow path of the first member to achieve a first engagement between the first and second members, the first engagement preventing a flow of water through the flow path, the second member having a tab, the tab being moveably attached to the second member, the tab being moveable to an installed position once the first engagement is achieved, the installed position providing a second engagement between the first member and the second member, the second engagement maintaining the first engagement between the first member and the second members, and the tab having an actuator, the actuator capable of actuating the actuable element when the tab is in the installed position, the actuable element adapted to provide a signal for controlling a warning system.

21. A drain plug for a plug housing installed in a boat drain, the drain plug being for insertion into the plug housing to block the flow path, the plug comprising a plugging member and locking actuator, the plugging member being adapted to be installed into the flow path to substantially block the flow path, and the locking actuator being operable to retain the plugging member in the flow path once installed, wherein the locking actuator is not operable until the plugging member is installed.

22 A drain plug assembly according to claim 1 wherein the locking actuator comprises a latch pivotably attached to the plugging member that can be maneuvered to seat within the plug housing.

23 A drain plug assembly according to claim 1 wherein the locking actuator comprises a locking bar and actuator that can be maneuvered to seat within the plug housing