Patent Publication Number: US-10315892-B2

Title: Portable davit

Description:
BACKGROUND 
     A davit is generally used to raise and lower a load at a projected distance away from a mounting location. One common use of davits is raising a load from water, swinging the load over a boat&#39;s hull, and then lowering the load to the deck. Performing these steps in reverse order to place an object in the water is also common. Davits are generally permanently mounted to a mounting surface and are often heavy and difficult to transport. However, in certain instances a user may transport the davit from one mounting location to another to utilize the function of the davit in multiple locations, e.g., from a boat to a truck. Therefore, a need exists for improved portability of davits to allow for transportation between areas and installation in multiple mounting locations. Embodiments of the present disclosure are directed to fulfilling these and other needs. 
     SUMMARY 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. In accordance with one embodiment of the present disclosure, a portable davit for raising, lowering, and transporting a load is provided. The portable davit generally includes at least one mount for mounting the portable davit to a mounting location, an elongate mast rotatably couplable to the mount, the mast extending from the mount, a jib hingedly couplable to an upper section of the mast, wherein the jib is positionable at a desired lifting angle, a pulley system mountable on the mast and the jib, wherein the pulley system includes a line removably couplable to the load, and a collar joint disposed between the mast and the at least one mount, the collar joint configured to allow rotation of the mast relative to the mount and to lock the mast in fixed position relative to the mount. 
     In accordance with another embodiment of the present disclosure, a portable davit for raising, lowering, and transporting a load is provided. The portable davit generally includes at least one mount for mounting the portable davit to a mounting location, an elongate mast rotatably coupled to the mount, a jib hingedly coupled to an upper end of the mast, an actuator connected to the mast and the jib, wherein the actuator is operable to adjust a lifting angle between the mast and the jib, and a pulley system for raising and lowering the load. The pulley system generally includes a line removably couplable to the load, a sheave mountable on the mast, the sheave operable to pass out and reel in the line, wherein the sheave is drivingly connected to a motor, and a lifting pulley mountable on the jib, the lifting pulley guiding the line between the sheave and the load. 
     In accordance with any of the embodiments described herein, the pulley system may include a sheave mountable on the mast, the sheave operable to pay out and reel in the line. 
     In accordance with any of the embodiments described herein, the sheave may be drivingly connected to a motor. 
     In accordance with any of the embodiments described herein, the motor may be electric powered. 
     In accordance with any of the embodiments described herein, the portable davit may include a controller electrically connected to the motor for controlling the level of torque applied by the motor to the sheave. 
     In accordance with any of the embodiments described herein, the pulley system may include a lifting pulley mountable on the jib, the lifting pulley may guide the line between the sheave and the load. 
     In accordance with any of the embodiments described herein, the lifting pulley may include a guard coupled to the pulley system, wherein the guard may be configured to interface the line. 
     In accordance with any of the embodiments described herein, the portable davit may include a handle coupled to the collar joint, wherein the handle may be configured to rotate the mast relative to the mount. 
     In accordance with any of the embodiments described herein, the mast may be at least partially hollow in construction. 
     In accordance with any of the embodiments described herein, the mast may be manufactured from a material selected from the group consisting of aluminum, titanium, carbon fiber, steel, iron, polyvinyl chloride, acrylonitrile butadiene styrene, and fiberglass. 
     In accordance with any of the embodiments described herein, the jib may be at least partially hollow in construction. 
     In accordance with any of the embodiments described herein, the jib may be manufactured from a material selected from the group consisting of aluminum, titanium, carbon fiber, steel, iron, polyvinyl chloride, acrylonitrile butadiene styrene, and fiberglass. 
     In accordance with any of the embodiments described herein, the portable davit may include an actuator extending between the mast and the jib, wherein the actuator may be operable to adjust the lifting angle between the mast and the jib, wherein the actuator may be coupled to the mast and the jib with pinned joints. In accordance with any of the embodiments described herein, the actuator may be operated by one of the following systems: hydraulic, electrical, or manual. 
     In accordance with any of the embodiments described herein, the lifting angle may be adjustable between about 50 degrees and 150 degrees. 
     In accordance with any of the embodiments described herein, the collar joint may include discrete rotational locking positions with the mast such that the rotatable coupling of the mast may be selectively stopped. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a portable davit formed in accordance with one embodiment of the present disclosure, showing the portable davit coupled to a mounting location; 
         FIG. 2  is an elevational view of the portable davit of  FIG. 1  with the jib in a fully lifted position; 
         FIG. 3  is an elevational view of the portable davit of  FIG. 1  with the jib in a fully lowered position; 
         FIG. 4  is a close-up elevational view of the lifting assembly of the portable davit of  FIG. 1 ; 
         FIG. 5  is a side view of the portable davit of  FIG. 1 ; 
         FIG. 6  is a close-up side view of the intermediate mount of the portable davit of  FIG. 1 ; 
         FIG. 7  is a close-up side view of the sheave assembly of the portable davit of  FIG. 1 , showing the sheave pulley and the guide pulley in cross section; and 
         FIG. 8  is a top view of the intermediate mount of the portable davit of  FIG. 1 , showing the rotational positioning of the portable davit. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings, where like numerals reference like elements, are intended as a description of various embodiments of the present invention and are not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Similarly, any steps described herein may be interchangeable with other steps, or combinations of steps, in order to achieve the same or substantially similar result. 
     In the following description, specific details are set forth to provide a thorough understanding of exemplary embodiments of the present invention. It will be apparent to one skilled in the art, however, that the invention may be practiced without embodying all of the specific details. In some instances, well-known process steps have not been described in detail in order not to unnecessarily obscure various aspects of the present disclosure. Further, it will be appreciated that embodiments of the present invention may employ any combination of features described herein. 
     The present application may include references to directions, such as “forward,” “rearward,” “front,” “back,” “upward,” “downward,” “right hand,” “left hand,” “lateral,” “medial,” “in,” “out,” “extended,” “advanced,” “retracted,” “proximal,” “distal,” “central,” etc. These references, and other similar references in the present application, are only to assist in helping describe and understand the particular embodiment and are not intended to limit the present invention to these directions or locations. 
     The present application may also reference quantities and numbers. Unless specifically stated, such quantities and numbers are not to be considered restrictive, but exemplary of the possible quantities or numbers associated with the present application. Also in this regard, the present application may use the term “plurality” to reference a quantity or number. In this regard, the term “plurality” is meant to be any number that is more than one, for example, two, three, four, five, etc. 
     Embodiments of the present disclosure are generally directed to davits for raising, lowering, and transporting loads. In general, davits described herein are portable and are capable of attaching to various mounting locations. Portable davits of the present disclosure are suitably installed in locations where permanent davits are not economically viable, physically feasible, or where permanent mounting of a davit is not desired (e.g., in the bed of a pickup truck, on board a boat, etc.). Portable davits in accordance with the present invention are capable of being disassembled into smaller sections such that the davit may be transported or stored when not in use. 
     A first embodiment of a portable davit  100  in accordance with the present invention is shown in  FIGS. 1-3 . The portable davit  100  includes a base mount  102  and an intermediate mount  104  for mounting the portable davit  100  to a mounting location. The base mount  102  and the intermediate mount  104  are couplable to a mast  106  for supporting the portable davit  100  when generally carrying a load L. As shown in the illustrated embodiment, the intermediate mount  104  is located at a point along the mast  106  such that the mast  106  is laterally supported in position. However, in other embodiments, the intermediate mount  104  is adjustable to any location along the length of the mast  106  to adapt to different installation heights. In some embodiments, a single mount is sufficient to support the portable davit. In other embodiments, the base mount  102  and multiple intermediate mounts  104  are used to support the portable davit. 
     The coupling of mast  106  in the base mount  102  and the intermediate mount  104  is rotatable such that the mast  106  rotates around a longitudinal axis. In some embodiments, the rotation of the mast  106  is facilitated by low-friction devices within each mounting location. Examples of low-friction devices are a bearing  150  (see  FIG. 8 ), a low-friction bushing  166  (see  FIG. 5 ), a lubricant (not shown), or a combination of low-friction devices. The low-friction bushing  166  is constructed from any suitable material, such as nylon, graphite, polytetrafluoroethylene, silicone, paraaramid synthetic fiber, and other plastics, resins, and polymers. In this regard, any low-friction device is suitably used in the mounts to facilitate rotation of the mast  106 . 
     As shown most clearly in  FIG. 8 , the intermediate mount  104  includes a collar joint  110  to allow rotation of the mast  106 . A handle  112  is coupled to the collar joint  110  to provide leverage while rotating the mast  106 . The collar joint  110  includes a plurality of circumferential bores  114 . Each bore  114  in the collar joint  110  includes a corresponding bore (not shown) in the underlying intermediate mount  104 . When a bore  114  in the collar joint  110  is aligned with a bore in the intermediate mount  104 , a pin  116  (see also,  FIG. 6 ) is inserted through the bores to lock the rotation of the mast  106  at discrete locations. In the illustrated embodiment, three discrete locking positions are included, depicted as handle positions A, B, and C, which place the jib  108  in locations X, Y, and Z, respectively. The locations X, Y, and Z are labeled as stowed, inboard, and outboard, respectively, to show one possible configuration of the handle  112  with respect to the jib  108 . In other embodiments, any number of discrete locking positions is suitably used, including infinitely variable locking schemes. Likewise, the handle  112  is positionable at any orientation with respect to the jib  108 . 
     Referring to  FIG. 2 , the portable davit  100  also includes a jib  108  hingedly coupled to the mast  106  through a coupling  118 . The jib  108  is configured to rotate about the coupling  118  such that the jib  108  is positionable at a lifting angle  120 . The lifting angle  120  is the included angle between the mast  106  and the jib  108 . In some embodiments, the lifting angle  120  is adjusted such that the load L is lifted over certain obstacles, for example, the side of a truck bed, or the side of a boat hull. In the illustrated embodiment, the lifting angle  120  is adjustable between about 80 degrees (see  FIG. 3 ) and about 125 degrees (see  FIG. 2 ). In other embodiments, the lifting angle is adjustable between about 50 degrees and 150 degrees. 
     In some embodiments, the mast  106  and the jib  108  are at least partially hollow in construction to reduce the weight of the components. In this regard, the mast  106  and the jib  108  are manufactured from a variety of materials, for example, aluminum, titanium, carbon fiber, graphite, steel, stainless steel, iron, polyvinyl chloride, acrylonitrile butadiene styrene, and fiberglass, or any combination thereof. 
     The lifting angle  120  is adjustable using an actuator  122  coupled to the mast  106  at a mast tab  124 , and coupled to the jib  108  at a jib tab  126 . In some embodiments, the coupling at the mast tab  124  and the jib tab  126  are pinned joints. In other embodiments, other coupling methods are suitably used. In the illustrated embodiment, the actuator  122  is extended and retracted with electric power. In other embodiments, the actuator  122  is extended and retracted with hydraulic power, or by manual input. In some of the manual input embodiments, the actuator  122  includes a torque-multiplying device. The actuator  122  is suitably extended (see  FIG. 2 ) and retracted (see  FIG. 3 ) to adjust the lifting angle  120 . Although the actuator  122  is illustrated in all the FIGURES as fully extended or fully retracted, the actuator  122  is adjustable to any intermediate location. 
     The portable davit  100  includes a line  128 , removably couplable to the load L, to raise, lower, and transport the load L. The line  128  is paid out and reeled in with a sheave assembly  130 . In the illustrated embodiment of  FIG. 2 , the sheave assembly  130  is mountable on the mast  106  at a first sheave mount  132  and a second sheave mount  134 . However, in other embodiments, a single mount, or more than two mounts are used to mount the sheave assembly  130  to the mast  106 . 
     The sheave assembly  130  generally includes a sheave pulley  136  configured to grip the line  128  to pay out and reel in the line  128  during raising and lowering maneuvers. As shown in  FIGS. 5 and 7 , in one embodiment, the sheave pulley  136  comprises two halves: (1) a first sheave pulley component  144 ; and (2) a second sheave pulley component  146 . Each pulley component is machined with a radial taper  148 , as shown most clearly in  FIG. 7 . When the first and second sheave pulley components  144  and  146  are combined, the included shape of the sheave pulley  136  grips the line  128 . In other embodiments, the sheave pulley  136  is manufactured as a single component. Likewise, in other embodiments, the sheave pulley  136  is manufactured by greater than two components. 
     Referring to  FIGS. 5 and 7 , in the illustrated embodiment, the sheave pulley  136  of the sheave assembly  130  is drivingly connected to an electric motor  138 . In some embodiments, a gear motor assembly (not shown) is attached to the output shaft of the electric motor  138  to alter the speed and torque transferred to the sheave assembly  130 . In this instance, the sheave assembly  130  is drivingly connected to a gear motor output shaft and is indirectly driven by the output shaft of the electric motor  138 . The electric motor  138  enables rotation of the sheave pulley  136  to pay out or reel in the line  128 . In this regard, the electric motor  138  is able to turn the sheave pulley  136  in both a clockwise and a counterclockwise direction. 
     In some embodiments, the sheave assembly  130  includes a controller (not shown) to control the electric motor  138 . As non-limiting examples, the controller is configured to adjust the power, torque, speed, direction, and position of the electric motor  138 . In another embodiment, the electric motor  138  is replaced with a manual crank (not shown). The manual crank may include a torque-multiplying device, such as planetary gears, to ease the effort required for rotation of the sheave pulley  136 . In other embodiments, the sheave pulley  136  is rotated by any suitable device. 
     In the illustrated embodiment shown in  FIG. 2 , the sheave assembly  130  further includes a first guide pulley  140  and a second guide pulley  142 . The guide pulleys  140  and  142  provide alignment for the line  128 , and increase the wrap of the line  128  on the sheave pulley  136  to increase grip during operation. In another embodiment, a single guide pulley is used in the sheave assembly  130 . In other embodiments, any number of guide pulleys is used to align the line  128  and increase the contact of the line  128  with the sheave pulley  136 . 
     As shown in  FIGS. 2 and 4 , the load L is raised and lowered through a lifting assembly  152 . The lifting assembly  152  is supported with a lifting bracket  154  mountable to the distal end of the jib  108  (opposite the coupling  118 ). The lifting assembly  152  includes a lifting pulley  156 . A pulley carrying bracket  158  and a link  160  connect the lifting pulley  156  to the jib  108 . The lifting pulley  156  guides the line  128  from the sheave assembly  130  to the load L. In this regard, the lifting pulley  156  provides a location for load transfer at the end of the jib  108 . In the illustrated embodiment, a guide loop  162  is connected to the distal end of the pulley carrying bracket  158  (opposite the link  160 ), to prevent the line  128  from disengaging the lifting pulley  156 . The guide loop  162  is configured such that the line  128  passes through the guide loop  162  before removably coupling to the load L. 
     In some embodiments of the present disclosure, various joints and mounts utilize devices to allow quick disassembly of the portable davit  100 . For example, a type of fastener removable without tools, such as a quick-release pin, is used. Pin  116  is depicted as a quick-release pin in  FIG. 6 . A quick-release pin is used at locations where quick disassembly is desired, for example, the coupling  118 , the mast tab  124 , the jib tab  126 , the first sheave mount  132  (see sheave pin  164  in  FIG. 7 ), and the second sheave mount  134 . Likewise, in one embodiment, the link  160  is a quick-release link, such as a carabineer. 
     The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. However, aspects of the present disclosure, which are intended to be protected, are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. It will be appreciated that variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the present disclosure, as claimed.