Shaft guard

Abstract

A shaft guard for a watercraft is disclosed. The shaft guard is located inside a jet propulsion unit and at least partially surrounds the drive shaft. The drive shaft and the engine shaft are not substantially parallel. The shaft guard is attached to the housing of the jet propulsion unit at one end and may be attached to the drive shaft at the other end allowing for free rotation of the drive shaft.

What is claimed is:  
     
         1 . A watercraft comprising: 
 a hull;    an engine mounted within the hull;    an engine output shaft operatively connected to the engine;    a jet propulsion unit associated with the hull, wherein the jet propulsion unit comprises 
 a housing defining a water passage;  
 a drive shaft with a first end and a second end, wherein the drive shaft first end is rotationally coupled with the engine output shaft and the second end extends into the water passage;  
 an impeller operatively attached to the drive shaft second end and disposed within the water passage; and  
   a shaft guard with a first end and a second end, the shaft guard at least partially surrounding the drive shaft second end, the shaft guard first end mounted to the housing, the shaft guard permitting free rotation of the drive shaft therein.    
     
     
         2 . The watercraft according to  claim 1 , wherein the engine output shaft and drive shaft are substantially parallel.  
     
     
         3 . The watercraft according to  claim 1 , wherein the engine output shaft and drive shaft are not substantially parallel.  
     
     
         4 . The watercraft according to  claim 1 , wherein the shaft guard fully surrounds the drive shaft second end.  
     
     
         5 . The watercraft according to  claim 4 , wherein the shaft guard is a tube.  
     
     
         6 . The watercraft according to  claim 5 , wherein the shaft guard is circular in cross-section.  
     
     
         7 . The watercraft according to  claim 5 , wherein the shaft guard is streamlined in cross-section.  
     
     
         8 . The watercraft according to  claim 6 , wherein the shaft guard is made from stainless steel.  
     
     
         9 . The watercraft according to  claim 1 , wherein the first end of the shaft guard comprises at least one eyelet affixed thereto, adapted to receive a fastener therethrough.  
     
     
         10 . The watercraft according to  claim 1 , wherein the at least one eyelet comprises two eyelets that are welded to the first end of the shaft guard.  
     
     
         11 . The watercraft according to  claim 1 , further comprising: 
 a through-hull fitting mounted to the housing;    a collar attached to the first end of the shaft guard; and    at least two keys affixed to the collar in registry with the through-hull fitting,    wherein the keys maintain the collar and shaft guard in positional relationship with the through-hull fitting.    
     
     
         12 . The watercraft of  claim 11 , further comprising: 
 a C-clamp attached to the drive shaft;    a carbon seal positioned around the drive shaft adjacent to the C-clamp;    a compression spring disposed between the carbon seal and the collar,    wherein the compression spring biases the shaft guard away from the carbon seal.    
     
     
         13 . The watercraft according to  claim 1 , further comprising: 
 a through-hull fitting mounted to the housing, the through-hull fitting defining at least two openings therein; and    at least two bent steel spring forms connected to the first end of the shaft guard,    wherein the bent steel spring forms register with the openings in the through-hull fitting to maintain the shaft guard in positional relationship with the through-hull fitting.    
     
     
         14 . A watercraft comprising: 
 a hull;    an engine mounted within the hull;    an engine output shaft operatively connected to the engine;    a jet propulsion unit associated with the hull, wherein the jet propulsion unit comprises 
 a housing defining a water passage;  
 a drive shaft with a first end and a second end, wherein the drive shaft first end is rotationally coupled with the engine output shaft and the second end extends into the water passage;  
 an impeller operatively attached to the drive shaft second end and disposed within the water passage; and  
   a shaft guard with a first end and a second end, the shaft guard at least partially surrounding the drive shaft second end, the shaft guard second end comprising a support member that slidingly engages one of the impeller or the drive shaft second end, allowing for free rotation of the drive shaft.    
     
     
         15 . The watercraft according to  claim 14 , wherein the support member is a bushing.  
     
     
         16 . The watercraft according to  claim 15 , wherein the bushing is made of bronze.  
     
     
         17 . The watercraft according to  claim 14 , wherein the engine output shaft and drive shaft are substantially parallel.  
     
     
         18 . The watercraft according to  claim 14 , wherein the engine output shaft and drive shaft are not substantially parallel.  
     
     
         19 . The watercraft according to  claim 14 , wherein the shaft guard fully surrounds the drive shaft second end.  
     
     
         20 . The watercraft according to  claim 19 , wherein the shaft guard is a tube.  
     
     
         21 . The watercraft according to  claim 20 , wherein the shaft guard is circular in cross-section.  
     
     
         22 . The watercraft according to  claim 20 , wherein the shaft guard is streamlined in cross-section.  
     
     
         23 . The watercraft according to  claim 22 , wherein the shaft guard is made from stainless steel.  
     
     
         24 . A watercraft comprising: 
 a hull;    an engine mounted within the hull;    an engine output shaft operatively connected to the engine;    a jet propulsion unit associated with the hull, wherein the jet propulsion unit comprises 
 a housing defining a water passage;  
 a drive shaft with a first end and a second end, wherein the drive shaft first end is rotationally coupled with the engine output shaft and the second end extends into the water passage;  
 an impeller operatively attached to the drive shaft second end and disposed within the water passage; and  
   a shaft guard with a first end and a second end, the shaft guard at least partially surrounding the drive shaft second end, the shaft guard first end mounted to the housing, the shaft guard second end comprising a support member that slidingly engages one of the impeller or the drive shaft second end, wherein the shaft guard allows free rotation of the drive shaft therein.    
     
     
         25 . The watercraft according to  claim 24 , wherein the support member is a bushing.  
     
     
         26 . The watercraft according to  claim 25 , wherein the bushing is made of bronze.  
     
     
         27 . The watercraft according to  claim 24 , wherein the engine output shaft and drive shaft are substantially parallel.  
     
     
         28 . The watercraft according to  claim 24 , wherein the engine output shaft and drive shaft are not substantially parallel.  
     
     
         29 . The watercraft according to  claim 24 , wherein the shaft guard fully surrounds the drive shaft second end.  
     
     
         30 . The watercraft according to  claim 29 , wherein the shaft guard is a tube.  
     
     
         31 . The watercraft according to  claim 30 , wherein the shaft guard is circular in cross-section.  
     
     
         32 . The watercraft according to  claim 30 , wherein the shaft guard is streamlined in cross-section.  
     
     
         33 . The watercraft according to  claim 31 , wherein the shaft guard is made from stainless steel.  
     
     
         34 . The watercraft according to  claim 24 , wherein the first end of the shaft guard comprises at least one eyelet, adapted to receive a fastener therethrough, permitting attachment of the shaft guard to the housing.  
     
     
         35 . The watercraft according to  claim 34 , wherein the at least one eyelet comprises two eyelets that are welded to the first end of the shaft guard.  
     
     
         36 . The watercraft according to  claim 24 , further comprising: 
 a through-hull fitting mounted to the housing;    a collar attached to the first end of the first end of the shaft guard; and    at least two keys affixed to the collar in registry with the through-hull fitting,    wherein the keys maintain the collar and shaft guard in positional relationship with the through-hull fitting.    
     
     
         37 . The watercraft according to  claim 24 , further comprising: 
 a through-hull fitting mounted to the housing, the through-hull fitting defining at least two openings therein; and    at least two bent steel spring forms connected to the first end of the shaft guard,    wherein the bent steel spring forms register with the openings in the through-hull fitting to maintain the shaft guard in positional relationship with the through-hull fitting.    
     
     
         38 . A shaft guard comprising: 
 a first end having at least one tab affixed thereto, the tab having a hole adapted to receive a fastener therethrough for mounting to the housing of a jet pump assembly;    a second end, adapted to at least partially surround a drive shaft of a jet pump assembly; and    a support member, disposed within the second end and adapted to slidingly engage one of an impeller or drive shaft of a jet pump assembly,    wherein the shaft guard allows free rotation of the drive shaft therein.    
     
     
         39 . A shaft guard comprising: 
 a hollow tube with a first end;    a collar affixed to the first end; and    at least two keys affixed to the collar, wherein the keys are adapted to register with a through-hull fitting,    wherein the keys maintain the collar and hollow tube in positional relationship with the through-hull fitting.    
     
     
         40 . A shaft guard comprising: 
 a hollow tube with a first end;    at least two bent steel spring forms connected to the first end;    wherein the bent steel spring forms are adapted to register with one of either the holes and notches in a through-hull fitting to maintain the hollow tube in positional relationship with the through-hull fitting.