Abstract:
The present invention provides a synchronizing assembly for locking to a dual throttle control assembly having a first control lever and a second control lever, for selectively choosing between independent and simultaneous manipulation of the first and second control levers. The synchronizing assembly has a first housing for releasably connecting to the first control lever, a second housing for releasably connecting to the second control lever and a synchronizing device moveable from a first position to a second position wherein when in the first position the synchronizing device is not connected to the second housing and when in the second position a portion of the synchronizing device is connected to the second housing so that movement of one of the first housing or the second housing moves the other.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 61/447,397 filed on Feb. 28, 2011 and titled “Device to Synchronize Dual Throttle Levers for Watercraft” which is incorporated herein in its entirety by reference and made a part hereof. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to an assembly for mounting to dual lever controls such as on a power boat for synchronizing the movement of the lever controls. 
     2. Background Art 
     Dual throttle lever assemblies have been used within the industry for controlling watercraft that is equipped with two individual engines such as jet propulsion systems that are independently controllable. Each of the dual throttle assembly levers controls adjusts engine speed and revolutions per minute. Typically, the right lever is used to control the starboard engine, and the left one is for controlling the portside engine. 
     Prior art dual throttle lever assemblies for some watercraft with jet propulsion are typically operated by pushing each of the throttle levers forward or backward individually to control each of the two engines to maneuver the boat. The farther the lever is moved from a neutral position the greater the speed of the engine up to a maximum displacement of the lever. In another typical use it is desired to shift both levers forward or backward simultaneously in a dynamic motion with the intention to keep both engines at similar RPM-levels. In other words, when one lever is being motioned forward or backward, the other one moves with it. 
     These and other aspects and attributes of the present invention will be discussed with reference to the following drawings and accompanying specification. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The present invention provides a synchronizing assembly for locking to a dual throttle control assembly having a first control lever and a second control lever, the synchronizing assembly for selectively choosing between independent and simultaneous manipulation of the first and second control levers. The synchronizing assembly has a first housing for releasably connecting to the first control lever, a second housing for releasably connecting to the second control lever and a synchronizing device moveable from a first position to a second position wherein when in the first position the synchronizing device is not connected to the second housing and when in the second position a portion of the synchronizing device is connected to the second housing so that movement of one of the first housing or the second housing moves the other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic view of a dual throttle control of a power boat; 
         FIG. 2  is a 3D CAD-model side view of the dual throttle synchronizing assembly with a synchronizing pin in an disengaged condition; 
         FIG. 3  is a 3D CAD-model side view of the of the dual throttle synchronizing assembly with the synchronizing pin engaged; 
         FIG. 4  is a 3D CAD-model bottom view of the of the dual throttle synchronizing assembly with the synchronizing pin in an engaged condition; 
         FIG. 5  is a 3D CAD-model side view of a second embodiment of the dual throttle synchronizing assembly of the invention displaying individual components in an unassembled condition; 
         FIG. 6  is a 3D CAD-model of a side elevation view in vertical cross section of the second embodiment of the of the dual throttle synchronizing assembly with the synchronizing pin in an engaged condition; 
         FIG. 7  is a 3D CAD-model of a bottom view of the left housing assembly of the second embodiment of the dual throttle synchronizing assembly in an unassembled condition; 
         FIGS. 8  and  FIG. 9  are 3D CAD-models of a side and isometric view respectively of different embodiments of the synchronizing pin; 
         FIG. 10  is a 3D CAD-model of a perspective view of the second embodiment of the dual throttle control with the synchronizing pin in an engaged condition; and 
         FIG. 11  is a side-elevation view of the first embodiment of the dual throttle synchronizing assembly mounted to the dual throttle lever control assembly and in an engaged condition. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention is susceptible of embodiment in many different forms, there is shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
     I will explain my invention with reference to jet boats from the Yamaha Motor Corporation. However, it should be understood this invention can be used for other boat types (jet boats, stern drive boats, etc.) that use two throttle levers. Jet boats that are commercially available from Yamaha Motor Corp. typically have two engines and two throttle levers. Each lever controls one engine individually. This makes it very difficult for the driver to keep both engines synchronized at all speed ranges. The existing and preinstalled lever assembly on Yamaha boats (but also other boat manufactures) does not provide for any means to synchronize both levers and “lock” them so they act as one. This would allow the driver to keep both engines at the same or nearly the same RPM&#39;s, which can be desired in many driving situations. 
       FIG. 1  shows a dual throttle lever assembly  10  mounted in a cockpit  12  of a powerboat  14 . Typically, the dual throttle lever assembly  10  is mounted in close proximity to a steering mechanism such as the steering wheel  16  so that a person operating the power boat can control the speed and direction of the boat simultaneously. The dual throttle lever assembly  10  has a first arm  18  and a second arm  19  that independently control the flow of fuel to separate engines and are generally “L” shaped having a first leg  20  and a second leg  22 . In a preferred form of the invention, the first arm and second arm, when each arm is in a neutral position, or equally displaced from the neutral position, extend toward the other along the same axis and are generally collinear with a gap  24  separating distal ends  26  of each of the arms. The farther the first and second arms are displaced from a neutral position the higher the flow rate of fuel to their respective engines and the higher the revolutions of the engine and, when in gear, the higher the speed of the boat. 
       FIG. 2  shows a first preferred form of a dual throttle synchronizing assembly  30  for mounting to the dual throttle lever control assembly  10 . The synchronizing assembly  30  has two housings  32  and  34  each of which define a generally “L” shaped chamber  36  for receiving arms  18  and  19  respectively. The housings  32  and  34  can be formed as a unitary part or from multiple parts that are, for example, fastened together about the control levers using fasteners, or snap-fit about the control levers or a combination of the two, or any other suitable means known to those of skill in the art. In a preferred form of the invention, the synchronizing assembly  30  is removably attached to the control levers as is shown in  FIG. 11 . 
     The first housing  32  has a synchronizing pin  38  mounted within the chamber  36  to allow for reciprocating translational movement between a first position where the housings  32  and  34 , and their corresponding arms  18  and  19 , can be independently operated ( FIG. 2 ), to a second position where the housings and levers are coupled together for dual or simultaneous control ( FIGS. 3 and 11 ). 
     In a preferred form of the invention, the synchronizing pin  38  will have a grasping flange  40 , a bolt  42  and a wall  44  connecting the two (See  FIGS. 8 and 9 ). The bolt  42  is mounted in a first slot  50  of the first housing  32  and the grasping flange  40  extends outward from the first housing where it can be manipulated by an operator of the boat. A second slot  52  is positioned in the second housing  34  and is dimensioned to receive a portion of the bolt  42  as shown in  FIG. 6  when the synchronizing pin is in the second or locked position. Each of the slots  50 ,  52  have a bottom wall surface  54 , an upper wall surface  55  and a groove  56  through the wall  54 . The vertical distance between the bottom and top wall surfaces  54 ,  55  is slightly greater than the thickness of the bolt  42  to allow for smooth sliding of the synchronizing pin  38 . The groove  56  provides a guide that engages a portion of the wall  44  of the synchronizing pin  38 . The groove  56  terminates in an end wall  58  that engages the synchronizing pin  38  to prevent it from sliding out from the first housing  32 . 
     In a preferred form of the invention, a steel spring and steel ball assembly  60  is positioned in a bore provided on the bolt  42  ( FIG. 6 ). The ball  60  is biased upward by the spring to engage the top wall surface  55  of the first slot. Detents  68  are provided in the top wall surface  55  at two horizontally spaced locations. The detents are shown to have a generally triangular shape, but other shapes such as round, oval or polygonal; could be used without departing from the scope of the present invention. When the synchronizing pin  38  is in a fully retracted, disengaged condition, the ball  60  is positioned within the first detent and provides resistance from further inadvertent movement of the synchronizing pin that may otherwise occur from, for example, movement of the boat or vibration of the engine, and until acted upon by the operator. Similarly, when in a fully extended, engaged condition, the ball locks into the second detent and provides resistance against further inadvertent movement of the synchronizing pin until acted on by the operator. 
       FIGS. 2-4  show housings  32  and  34  that are formed from a first portion  70  that defines the “L” shaped chamber and a bottom wall  72  that is removably attached to the first portion  70 . The bottom wall  72   a  of housing  32  differs from bottom wall  72   b  as bottom wall  72   a  provides the groove  56 . To mount the housing  32  to the left arm  18 , the first portion  70  is placed over the arm, the synchronizing pin is positioned in the groove  56  and the bottom wall  72  is attached to the first portion  70  by any suitable means such as snap fitting or by threaded fasteners or the like ( FIG. 11 ). 
       FIGS. 5-7  show a second embodiment where the first and second housings  32 ,  34  are each formed from mirror-image half assemblies. The two half-assemblies have a main body portion  80  and an end cap portion  82  that are snap fit together. The first half and second half-assemblies are positioned on opposite sides of the control lever to capture the lever and connected together by snap fitting or by threaded fasteners to releasably connect the assembly to the control lever. Of course, when assembling the first housing  32  one must insert the synchronizing pin into position prior to connecting the first half assembly to the second half assembly. Snap features  84  and  86  and alignment fins  88  and  90  are provided in a preferred form of the invention to ensure proper engagement of the parts. It is also contemplated replacing this four piece assembly with an assembly having from two parts to more than four parts. 
       FIGS. 8 and 9  show preferred forms A,B,C,D of the synchronizing pin. Different pin designs are preferred to allow for a well achieved ergonomic feel to the end user of this invention. Other shapes and design are possible to provide best performance of this invention. 
       FIGS. 10 and 11  show a bore  85  which is positioned through a wall of each of the housings  32  and  34  which accommodates a threaded fastener for threaded engagement to a threaded hole on each of the lever arms  18  and  19  (not shown). 
     The parts of this invention are generally formed from polymeric materials using techniques such as injection molding. Suitable polymeric materials include polyolefins, polyamides, polyesters, PVC, polycarbonates, ABS, AAS and the like. Suitable polyolefins include homopolymers, copolymers, terpolymers from alpha-olefins having from two to eight carbon atoms. Suitable copolymers include ethylene and propylene with monomers selected from these alpha-olefins, excluding of course those having the same number of carbon atoms. 
     From the foregoing, it will be observed that numerous variations and modifications may be affected without departing from the spirit and scope of this invention. It is to be understood that no limitation with respect to the specific device illustrated herein is intended or should be inferred.