Outboard motor

Abstract

An outboard drive unit for a watercraft to allow propulsion of the watercraft in mud and water. The drive unit has a reduction gear assembly mounted between a motor and a propeller assembly, thereby allowing an engine of given capacity to turn a propeller with increase pitch and surface plane area. A propeller shaft is oriented at an obtuse angle in relation to an input shaft extending from the motor to allow the watercraft to accelerate easier, especially in mud conditions, while protecting the propeller from impact with grass and under water obstructions.

1 . An outboard drive unit for a watercraft, comprising: 
 an upper unit housing a motor with a drive shaft;    a lower unit operationally connected to the upper unit, the lower unit comprising an input shaft, a propeller assembly, a means for adjusting position of the propeller assembly between a fully submersed position to a partial above-water position during navigation in shallow water or mud, thereby reducing drag forces acting on the watercraft, and a reduction gear assembly mounted between and operationally connected to said input shaft and said propeller assembly.    
   
   
       2 . The outboard drive unit of  claim 1 , wherein said gear assembly has a reduction ratio of 1.5:1.  
   
   
       3 . The outboard drive unit of  claim 1 , further comprising a means for attaching the outboard drive unit to a hull of the watercraft.  
   
   
       4 . The outboard drive unit of  claim 3 , wherein said attaching means comprises a support assembly comprising an attachment plate detachably secured on said outboard drive unit, a swivel bracket attached to the attachment plate, a clamping bracket carrying the swivel bracket in a pivotal relationship thereto and a steering shaft threadably engaged in said swivel bracket to allow tilting of the drive unit about a pivotal axis of a pivot pin mounted between the swivel bracket and the clamping bracket.  
   
   
       5 . The outboard drive unit of  claim 4 , wherein said propeller assembly comprises a propeller shaft, said propeller shaft being oriented at an obtuse angle in relation to said input shaft, said propeller assembly generating a thrust force extending below the pivotal axis of the drive unit when the propeller assembly is fully or partially submerged below a water line.  
   
   
       6 . The outboard drive unit of  claim 5 , wherein said propeller assembly further comprises a propeller blade mounted on the propeller shaft, a cavitation plate and a skeg mounted at a generally right angle to said cavitation plate, said propeller blade and said cavitation plate being normally submerged under the surface of mud or water when the watercraft is in a stationary position and at least partially above the mud or water surface when the watercraft moves on plane on mud or water surface.  
   
   
       7 . The outboard drive unit of  claim 6 , wherein said cavitation plate and said skeg are secured on a stuffing tube, and wherein the propeller shaft extends through said stuffing tube.  
   
   
       8 . (canceled)  
   
   
       9 . The outboard drive unit of  claim 4 , wherein a proximate end of the propeller shaft is operationally connected to the input shaft through the reduction gear assembly, thereby allowing a propeller with an increased pitch to receive torque from said motor and facilitate acceleration of the watercraft in mud.  
   
   
       10 . An outboard drive unit for a watercraft, comprising: 
 an upper unit housing a motor with a drive shaft;    a lower unit operationally connected to the upper unit, the lower unit comprising an input shaft, a propeller assembly and a reduction gear assembly mounted between and operationally connected to said input shaft and said propeller assembly, said reduction gear assembly having a reduction ratio of 1.5:1 to thereby facilitate a propeller unit having an increased pitch to be rotated by the motor, and a means for adjusting position of the propeller assembly between a fully submerged position to a partial above-water position during navigation in shallow water or mud, thereby reducing drag forces acting on the watercraft.    
   
   
       11 . The outboard drive unit of  claim 10 , further comprising a means for attaching the outboard drive unit to a hull of the watercraft, said attachment means comprising a support assembly comprising an attachment plate detachably secured on said outboard drive unit, a swivel bracket attached to the attachment plate, a clamping bracket carrying the swivel bracket in a pivotal relationship thereto and a steering shaft threadably engaged in said swivel bracket to allow tilting of the drive unit about a pivotal axis of a pivot pin mounted between the swivel bracket and the clamping bracket.  
   
   
       12 . The outboard drive unit of  claim 11 , wherein said propeller assembly comprises a propeller shaft, said propeller shaft being oriented at an obtuse angle in relation to said input shaft, said propeller assembly generating a thrust force extending below the pivotal axis of the drive unit when the propeller assembly is fully or partially submerged below a water line.  
   
   
       13 . The outboard drive unit of  claim 12 , wherein a proximate end of the propeller shaft is operationally connected to the input shaft through the reduction gear assembly, thereby allowing a propeller with an increased pitch to receive torque from said motor and facilitate acceleration of the watercraft in mud.  
   
   
       14 . The outboard drive unit of  claim 12 , wherein said propeller assembly further comprises a stuffing a tube receiving the propeller shaft therethrough, a propeller blade mounted on a distant end of the propeller shaft, a cavitation plate and a skeg mounted at a generally right angle to said cavitation plate and in a substantially parallel relationship to the propeller shaft, said cavitation plate and said skeg being secured on said stuffing tube.  
   
   
       15 . The outboard drive unit of  claim 14 , wherein said lower unit is tilted to allow the propeller blade and the cavitation plate to be normally submerged under the surface of mud or water when the watercraft is in a stationary position and at least partially above the mud or water surface when the watercraft moves on plane on mud or water surface.  
   
   
       16 . The outboard drive unit of  claim 14 , wherein said cavitation plate extends above said propeller blade.  
   
   
       17 . The outboard drive unit of  claim 10 , wherein the drive unit has a reduced steering radius to facilitate maneuverability of the watercraft.  
   
   
       18 . The outboard drive unit of  claim 17 , wherein the steering radius is less than 20 inches.  
   
   
       19 . An outboard drive unit for a watercraft, comprising: 
 an upper unit housing a pre-determined power motor with a drive shaft;    a lower unit operationally connected to the drive shaft of the upper unit, the lower unit comprising an input shaft, a propeller assembly and a reduction gear assembly mounted between and operationally connected to said input shaft and said propeller assembly, said reduction gear assembly having a reduction ratio of 1.5:1 to thereby facilitate a propeller unit having an increased pitch to be rotated by the motor of predetermined power, and wherein the propeller assembly is oriented at an obtuse angle in relation to input shaft, and a means for adjusting position of the propeller assembly between a fully submerged position to a partial above-water position during navigation in shallow water or mud, thereby reducing drag forces acting on the watercraft during navigation in adverse conditions.    
   
   
       20 . The outboard drive unit of  claim 19 , wherein a steering radius of the propeller assembly is less than 20 inches.  
   
   
       21 . The outboard drive unit of  claim 19 , further comprising a means for attaching the outboard drive unit to a hull of the watercraft, said attachment means comprising a support assembly comprising an attachment plate detachably secured on said outboard drive unit, a swivel bracket attached to the attachment plate, a clamping bracket carrying the swivel bracket in a pivotal relationship thereto and a steering shaft threadably engaged in said swivel bracket to allow tilting of the drive unit about a pivotal axis of a pivot pin mounted between the swivel bracket and the clamping bracket.  
   
   
       22 . The outboard drive unit of  claim 19 , wherein said propeller assembly comprises a propeller shaft, and wherein a proximate end of the propeller shaft is operationally connected to the input shaft through the reduction gear assembly, thereby allowing a propeller with an increased pitch to receive torque from said motor and facilitate acceleration of the watercraft in mud.  
   
   
       23 . The outboard drive unit of  claim 22 , wherein said propeller assembly further comprises a stuffing tube receiving the propeller shaft therethrough, a propeller blade mounted on a distant end of the propeller shaft, a cavitation plate and a skeg mounted at a generally right angle to said cavitation plate and extending in a substantially parallel relationship to the propeller shaft, said cavitation plate and said skeg being secured on said stuffing tube.  
   
   
       24 . (canceled)