Abstract:
A high strength safety tether adapted to restrain motor flipping in the event of an underwater strike between the motor and an underwater object. In one embodiment the tether is sized to generally surround the exhaust housing of the motor. The free ends of the tether are adapted to be bolted to the transom of the boat. In another embodiment a second leash is attached to a first leash so that the first leash surrounds the steering arm assembly and the second leash surrounds the exhaust housing of the motor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of co-pending U.S. patent application Ser. No. 14/977,920, filed Dec. 22, 2015, which is hereby incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to marine engines and more particularly to devices for the prevention of accidental flipping of outboard motors. 
       BACKGROUND OF THE INVENTION 
       [0003]    Small boats, such as bass boats and the like, can be provided with fairly large outboard motors and can reach speeds of up to 100 miles per hour. These speeds are often obtained during bass fishing contests when the bass boats race to reach a preferred fishing location. Other recreational boats can similarly be equipped with outboard motors which allow them to obtain speeds in the 60 to 70 mile per hour range. At such high speed there is a danger of contact with objects just below the surface of the water such as a submerged log or other impediment often found in rivers and lakes. 
         [0004]    Outboard motors are pivotally mounted on the transom of the boat for rotation of the drive mechanism, particularly the propeller, above the surface of the water or above the ground for towing, launching and recovering the boat. At high speed should the drive mechanism contact a submerged object, such as a log, the impact will cause the motor to violently rotate or flip and if the impact is severe enough the motor will be torn from the transom may actually be flipped into the boat. Since the motor will be running when this occurs the occupant of the boat can be fatally or seriously injured by the propeller. A listing of motor flip accidents compiled in July 2014 lists 63 motor flip accidents and reports 9 fatalities. Even if there is no injury to occupants of the boat the damage to the boat and motor is expensive and in some cases the motor does not flip into the boat but is thrown into the water resulting in the loss of an expensive motor. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention relates to a high strength safety tether adapted to restrain motor flipping in the event of an underwater strike between the motor and an underwater object. In one embodiment the tether is sized to generally surround the exhaust housing of the motor. The free ends of the tether are adapted to be bolted to the transom of the boat. In another embodiment a second leash is attached to a first leash so that the first leash surrounds the steering arm assembly and the second leash surrounds the exhaust housing of the motor. 
         [0006]    The tether may comprise a chain, cable or preferably multifilament high strength polymer fiber. In the preferred embodiment the tether is designed to prevent the motor flipping of a 750 pound outboard motor striking a submerged object at 70 miles per hour. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0007]      FIG. 1  is a side view partially broken away illustrating the leash tether around an outboard motor mounted on a marine vessel; 
           [0008]      FIG. 2  illustrates the two leash embodiment of the tether of the invention; 
           [0009]      FIG. 3  illustrates the motor tethered by the two leash tether of  FIGS. 2 ; and 
           [0010]      FIG. 4  is a cross sectional view of the leash tether of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0011]    Referring to  FIG. 1  a marine vessel  10 , for example a bass boat, has a large multi-cylinder outboard motor  12  comprising a power head  13 , the exhaust housing  14 , the steering arm assembly  26  and drive section  15  including the propeller. The motor  12  is conventionally secured on the transom  16  of the vessel  10  by being directly bolted or by a suitable bracket that is bolted to the transom. The drive mechanism  15  extends slightly below the keel of the vessel  10 . As is conventional, motor  12  can be tilted up either manually or electronically for travelling through shallow water where there may be propeller damaging debris. It is this pivoting action that can result in a motor flip when the drive section  15  of the motor  12  strikes a submerged object at high speed. Such a high speed strike causes the motor  12  to pivot violently tearing it off the transom  16  and flipping it into the passenger and/or driver&#39;s compartment of the vessel  10 . Since the motor  12  will still be running, the passengers are subject to serious injury or even death. Even if the motor  12  is not flipped into the vessel  10  it can separate from the vessel and be lost in the water. 
         [0012]    In accordance with the invention as shown in  FIG. 1  a high strength leash tether  20  surrounds the exhaust housing  14  to prevent the flipping of the motor  12 . Each free end  22  of the leash  20  is formed around a metal spool  24  ( FIG. 2 ) for receiving a bolt for bolting the free end to the transom  16  of the vessel  10 . 
         [0013]    Referring to  FIG. 4  a preferred embodiment of the high strength leash tether  20  comprises a ½ to ¾ inch rope core  24  of multifilament yarn spun from liquid crystal polyester distributed under the trademark Vectran™ by Kuraray. Co. LTD. As illustrated, the core  24  is a 7/16 double braided rope that is capable of a tensile strength of 18,000 pounds. The core  24  is provided with a polymer coating  26  that is most conveniently applied by a heat shrinkable polyolefin tube such as SUMITUBE B2™ distributed by Heatsink.com of Ogdon, Utah. The outer coating over the core provides some rigidity for the leash so that it retains its position around the exhaust housing  14  of the motor  12  and helps to maintain the integrity of the monofilament core  24 . In the event of a high impact strike the leash tether prevents the motor  12  from pivoting and avoids a motor flip accident. 
         [0014]      FIG. 2  and  FIG. 3 , in which like parts are referenced by like numbers, illustrate another embodiment of the tether of the invention. A secondary leash tether  30  is looped at its free ends  33  to define rings  34 . The primary leash tether  20  is passed through the rings  34  so that the ends  33  of the secondary leash tether  30  are slidingly attached to the primary leash tether. In this embodiment the primary leash tether  20  passes around the steering arm assembly  26  which is separate from the exhaust housing  14 . The secondary leash tether  30  passes around the exhaust housing  14 . The primary leash tether  20  is bolted to the transom  16  of the vessel  10  as described in connection with  FIG. 1 . The secondary leash tether  22  is constructed of the same materials as the primary leash tether  20  and is the same diameter so that both leash tethers are of extremely high strength. 
         [0015]    While the invention has been described in connection with the preferred embodiment it will be understood that the leashes  20  and  30  may comprise any high strength material such as high strength turbostratic carbon fiber, para-aramid synthetic fiber, high strength steel chain and the like. 
         [0016]    From the foregoing it will be seen that the present invention provides convenient, readily installed and economical device that can prevent accidental motor flipping due the high speed strikes of the drive section of an outboard motor with a submerged object. With the powerful outboard motors available the danger of such accidents is ever present since submerged objects such as logs and other submerged debris are often present in rivers and lakes. 
         [0017]    One feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors including a power head, an exhaust housing, a steering arm assembly and a drive section to prevent violent motor flipping when the drive section strikes a submerged object, the safety device comprising a high strength leash tether disposed about the exhaust housing, the leash tether including free ends that are secured to a marine vessel at the transom thereof. 
         [0018]    Another feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors, wherein the free ends of the leash tether are formed about metal spools and the spools are secured to the transom by bolts whereby the leash tether is secured to the marine vessel. 
         [0019]    Yet another feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors, wherein the leash tether comprises a high strength material selected from the group consisting of high strength turbostratic carbon fiber, para-aramid synthetic fiber yarn, liquid crystal polyester yarn, high strength steel chain and combinations thereof. 
         [0020]    Still another feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors, wherein the high strength leash comprises multifilament yarn spun from liquid crystal polyester. 
         [0021]    A further feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors, wherein the leash tether comprises a core consisting of multifilament yarn spun from liquid crystal polyester and a polymeric outer coat. 
         [0022]    Another feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors, wherein the polymeric outer coat is a polyolefin. 
         [0023]    Yet another feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors including a power head, an exhaust housing, a steering arm assembly and a drive section to prevent violent motor flipping when the drive section strikes a submerged object, the safety device comprising a primary leash tether defining free ends that are formed about metal spools, the spools being securely attached to a marine vessel at the transom thereof thereby to secure the primary leash tether to the marine vessel, a secondary leash tether having rings formed on the free ends thereof, the primary leash tether extending through the rings thereby to attach the secondary leash tether to the primary leash tether. 
         [0024]    Still another feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors, wherein the primary leash tether extends around the steering arm assembly of the outboard motor and the secondary leash tether extends around the exhaust housing of the outboard motor. 
         [0025]    A further feature or aspect of an illustrative example is believed at the time of the filing of this patent application to possibly reside broadly in a safety device for outboard motors, wherein the primary and secondary leash tethers comprise a rope core consisting of multifilament yarn spun from liquid crystal polyester and a polymeric outer coat.