Drain plug assembly and system incorporating the same

Abstract

An assembly for draining fluid from a sump having a receiver. A plug is adapted for threaded engagement with the receiver, has a transverse outlet arranged for communication with the sump, and is rotatable between: sealed, where flow is inhibited across the outlet; and drain, where fluid from the sump flows across the outlet. A head is rotatably attached to the plug. A limiter between the head and plug operates in: lock, where the head and plug rotate concurrently in a first direction to move the plug from sealed to drain; slip, where the head rotates in a second direction independent of the plug in response to torque acting on the head exceeding a threshold; and limit, where the head and plug rotate concurrently in the second direction in response to torque acting on the head being less than the threshold to move the plug towards sealed.

What is claimed is: 
     
         1 . A drain plug assembly for use in draining fluid out of a receiver operatively attached to a sump, said drain plug assembly comprising:
 a plug adapted for threaded engagement with the receiver and having a transverse outlet arranged for fluid communication with the sump, said plug being rotatable about an axis between a sealed position where fluid in the sump is inhibited from flowing across said outlet, and a drain position where fluid in the sump is permitted to flow across said outlet transverse to said axis;   a head coupled to said plug and arranged for rotation in opposing first and second rotational directions in response to rotational torque applied to said head; and   a torque limiter interposed between said head and said plug, said torque limiter being operable between:
 a lock configuration where said head and said plug rotate concurrently in said first rotational direction to move said plug toward said drain position in response to rotational torque applied to said head in said first rotational direction, 
 a limit configuration where said head and said plug rotate concurrently in said second rotational direction to move said plug toward said sealed position in response to rotational torque applied to said head in said second rotational direction being less than a predetermined torque threshold, and 
 a slip configuration where said head rotates independent of said plug in said second rotational direction to interrupt rotation of said plug in response to rotational torque applied to said head in said second rotational direction being greater than said predetermined torque threshold. 
   
     
     
         2 . The drain plug assembly as set forth in  claim 1 , wherein said plug further comprises a shank extending along said axis to a shank end; and
 wherein said outlet is formed in said shank arranged axially between said shank end and said head.   
     
     
         3 . The drain plug assembly as set forth in  claim 2 , wherein said outlet is formed in said shank transverse to said axis to direct fluid flowing across said outlet away from said axis when said plug is in said drain position. 
     
     
         4 . The drain plug assembly as set forth in  claim 2 , wherein said plug further comprises:
 an inlet formed in said shank adjacent to said shank end; and   a channel formed in said shank extending in fluid communication between said inlet and said outlet to permit fluid in the sump to flow across said inlet, along said channel, and across said outlet when said plug is in said drain position.   
     
     
         5 . The drain plug assembly as set forth in  claim 1 , wherein said plug further comprises a coupler arranged to support said head for rotation about said axis and shaped to inhibit axial movement of said head with respect to said plug. 
     
     
         6 . The drain plug assembly as set forth in  claim 1 , wherein said torque limiter includes a torque receiving element operatively attached to said plug, and a torque delivery element operatively attached to said head and disposed in engagement with said torque receiving element such that said head and said plug rotate concurrently in response to rotational torque applied to said head in either of said first and second rotational directions being less than said predetermined torque threshold. 
     
     
         7 . The drain plug assembly as set forth in  claim 6 , wherein one of said torque receiving element and said torque delivery element comprises a plurality of splines arranged radially about said axis, and the other of said torque receiving element and said torque delivery element comprises a plurality of resilient cogs arranged radially about said axis;
 wherein said plurality of resilient cogs engage said plurality of splines to facilitate concurrent rotation of said head and said plug when said torque limiter operates in one of said lock configuration and said limit configuration; and   wherein said plurality of resilient cogs are shaped so as to deflect to interrupt concurrent rotation of said head and said plug when said torque limiter operates in said slip configuration.   
     
     
         8 . The drain plug assembly as set forth in  claim 6 , wherein said torque delivery element comprises at least one resilient cog extending radially away from said axis and defining a brace surface; and
 wherein said torque receiving element comprises at least one spline defining a flat surface arranged to abut said brace surface of said at least one resilient cog to facilitate concurrent rotation of said plug and said head in said first rotational direction when said torque limiter operates in said lock configuration.   
     
     
         9 . The drain plug assembly as set forth in  claim 8 , wherein said at least one resilient cog of said torque delivery element further comprises a cam surface; and
 wherein said at least one spline of said torque receiving element further comprises a ramp surface arranged to abut said cam surface of said at least one resilient cog to facilitate concurrent rotation of said plug and said head in said second rotational direction when said torque limiter operates in said limit configuration.   
     
     
         10 . The drain plug assembly as set forth in  claim 9 , wherein said at least one resilient cog of said torque delivery element is shaped to deflect away from said at least one spline to bring said cam surface of said at least one resilient cog out of abutment with said ramp surface of said at least one spline when said torque limiter operates in said slip configuration. 
     
     
         11 . A system for use in draining fluid from a sump, said system comprising:
 a receiver adapted for attachment to the sump, said receiver extending along an axis between opposing first and second ends and comprising a bore extending between said first end and said second end, a drain port arranged between said first end and said second end and disposed in fluid communication with said bore, a first seal surface arranged between said first end and said drain port, and a second seal surface arranged between said drain port and said second end; and   a drain plug assembly for draining fluid from the sump, said drain plug assembly comprising:
 a seal arranged for engagement with said first and second seal surfaces of said receiver; 
 a plug supporting said seal, disposed in threaded engagement with said receiver, and having an outlet arranged for fluid communication with the sump, said plug being rotatable about said axis between a sealed position where said seal engages said first seal surface of said receiver to inhibit fluid in the sump from flowing across said outlet, and a drain position where said seal engages said second seal surface of said receiver to allow fluid in the sump to flow across said outlet and out of said drain port of said receiver; 
 a head coupled to said plug and arranged for rotation in opposing first and second rotational directions in response to rotational torque applied to said head; and 
 a torque limiter interposed between said head and said plug configured to translate applied rotational torque from said head to said plug to move said plug between said sealed position and said drain position, and further configured to interrupt rotation of said plug in response to rotational torque applied to said head exceeding a predetermined torque threshold. 
   
     
     
         12 . The system as set forth in  claim 11 , wherein said plug of said drain plug assembly further comprises a mount supporting said seal, and a shank extending along said axis to a shank end; and
 wherein said outlet is formed in said shank arranged axially between said shank end and said head to permit fluid in the sump to flow across said outlet and out of said drain port of said receiver when said plug is in said drain position.   
     
     
         13 . The system as set forth in  claim 12 , wherein said drain port of said receiver and said outlet of said plug are each formed transverse to said axis to direct fluid flowing across said outlet away from said axis and out of said drain port of said receiver when said plug is in said drain position. 
     
     
         14 . The system as set forth in  claim 12 , wherein said plug of said drain plug assembly further comprises:
 an inlet formed in said shank adjacent to said shank end; and   a channel formed in said shank extending in fluid communication between said inlet and said outlet to permit fluid in the sump to flow across said inlet, along said channel, across said outlet, and out of said drain port of said receiver when said plug is in said drain position.   
     
     
         15 . The system as set forth in  claim 11 , wherein said torque limiter of said drain plug assembly includes a torque receiving element operatively attached to said plug, and a torque delivery element operatively attached to said head and disposed in engagement with said torque receiving element such that said head and said plug rotate concurrently in response to rotational torque applied to said head in either of said first and second rotational directions being less than said predetermined torque threshold. 
     
     
         16 . The system as set forth in  claim 15 , wherein one of said torque receiving element and said torque delivery element comprises a plurality of splines arranged radially about said axis, and the other of said torque receiving element and said torque delivery element comprises a plurality of resilient cogs arranged radially about said axis;
 wherein said plurality of resilient cogs engage said plurality of splines to facilitate concurrent rotation of said head and said plug when rotational torque applied to said head is less than said predetermined torque threshold; and   wherein said plurality of resilient cogs are shaped so as to deflect to interrupt concurrent rotation of said head and said plug when rotational torque applied to said head is greater than said predetermined torque threshold.   
     
     
         17 . The system as set forth in  claim 11 , wherein said bore of said receiver further comprises:
 a first cylindrical region disposed adjacent to said first end of said receiver, at least partially defining said first seal surface, and having a first inner diameter; and   a second cylindrical region disposed adjacent to said second end of said receiver, at least partially defining said second seal surface, and having a second inner diameter larger than said first inner diameter.   
     
     
         18 . The system as set forth in  claim 17 , wherein said seal of said drain plug assembly has an outer seal diameter larger than said first inner diameter of said bore of said receiver such that said seal is compressed between said plug and said first seal surface of said receiver when said plug is in said sealed position to prevent fluid from flowing out of the sump. 
     
     
         19 . The system as set forth in  claim 17 , wherein said seal of said drain plug assembly has an outer seal diameter larger than said second inner diameter of said bore of said receiver such that said seal is at least partially compressed between said plug and said second seal surface of said receiver when said plug is in said drain position to prevent fluid in the sump from flowing out of said second end of said receiver as fluid from the sump flows across said outlet of said plug and out of said drain port of said receiver. 
     
     
         20 . The system as set forth in  claim 17 , wherein said bore of said receiver further comprises a tapered region extending between said first cylindrical region and said second cylindrical region to promote compression of said seal between said plug and said first cylindrical region of said receiver as said plug moves toward said sealed position. 
     
     
         21 . The system as set forth in  claim 17 , wherein said drain port of said receiver is formed at least partially in said second cylindrical region of said receiver. 
     
     
         22 . The system as set forth in  claim 21 , wherein said drain port of said receiver is disposed in spaced relation with said first cylindrical region of said receiver. 
     
     
         23 . The system as set forth in  claim 11 , wherein said torque limiter of said drain plug assembly is operable between:
 a lock configuration where said head and said plug rotate concurrently in said first rotational direction to move said plug toward said drain position in response to rotational torque applied to said head in said first rotational direction,   a limit configuration where said head and said plug rotate concurrently in said second rotational direction to move said plug toward said sealed position in response to rotational torque applied to said head in said second rotational direction being less than said predetermined torque threshold, and   a slip configuration where said head rotates independent of said plug in said second rotational direction to interrupt rotation of said plug in response to rotational torque applied to said head in said second rotational direction being greater than said predetermined torque threshold.