Abstract:
Devices, apparatus and systems for raising and lowering watercraft such as personal watercraft, jet skis, inflatables from transoms on boats, from bulkheads and from docks, and for raising and lowering other types of vessels. A single actuator such as a fluid operated cylinder and single piston can raise and lower a cradle that supports the personal watercraft. An crank bracket can be fixably attached to a crank shaft, and an arm which supports the cradle can be fixably attached to the crank shaft. The arm can be extendable to different lengths. The cradle can include a self-leveling carriage that uses rollers to roll on a curved surface of the cradle allowing the supported watercraft to remain in a substantially level position thereon. An adjustable swivel mount can also be used to lock the cradle to the arm in a fixed orientation.

Description:
This invention relates to watercrafts and in particular to devices, apparatus and systems for raising and lowering watercrafts such as jet skis, inflatables, rowboats, small personal watercrafts, and the like, as well as other types of vessels from swim platforms on the back of larger pleasure crafts, from docks, from bulkheads, and the like. 
   BACKGROUND AND PRIOR ART 
   Small craft lift devices for raising and lowering small craft type boats into and out of the water which can be mounted off larger boats have been used over the years. However, the known devices have limitations and problems that effect their applications in the real world. 
   Old versions of the small craft lift devices have used pulleys, and block and tackle arrangements with lines to raise and lower a fixed cradle or platform. However, the lines and pulleys and blocks and tackle required can easily become tangled, and difficult to operate. Also, these old type devices generally require hand operated cranks that are not desirable nor efficient or practical for the person operating these lift devices. Still furthermore, the fixed platforms and cradles used are also problematic since many include surfaces which may scratch, mar and damage the hulls and bottoms of the small type boats. See for example, U.S. Pat. No. 582,069 to Leslie and U.S. Pat. No. 2,185,083 to Horton. 
   Many current type small craft boat lifts require complex and expensive arrangements of plural hydraulic type cylinders to raise and lower a platform or fixed cradle. These lifts often locate the small crafts at a distance from the main boat. The fixed platforms and cradles used are also problematic since many include surfaces which may scratch, mar and damage the hulls and bottoms of the small type boats. See for example, U.S. Pat. No. 5,544,606 to Schmidt, Jr.; U.S. Pat. No. 6,003,463 to Giesler; U.S. Pat. No. 6,327,992 to Martin; U.S. Pat. No. 6,474,256 to Vogel; U.S. Pat. No. 6,782,842 to Alvord; and U.S. Pat. No. 6,786,170 to Trowbridge 
   Thus, the need exists for solutions to the above problems with the prior art. 
   SUMMARY OF THE INVENTION 
   A primary objective of the present invention is to provide a practical, efficient, simple and easy to operate lift device, apparatus and system for raising and lowering watercrafts such as jet skis, inflatables, rowboats, personal watercrafts, and the like, and other vessels from swim platforms on the back of larger pleasure crafts, and the like. 
   A secondary objective of the present invention is to provide a practical, efficient, simple and easy to operate lift device, apparatus and system for raising and lowering watercrafts such as jet skis, inflatables, rowboats, personal watercrafts, and the like, and other vessels from docks, and the like. 
   A third objective of the present invention is to provide a practical, efficient, simple and easy to operate lift device, apparatus and system for raising and lowering watercrafts such as jet skis, inflatables, rowboats, personal watercrafts, and the like, and other vessels from swim platforms off pleasure crafts, from bulkheads, and the like. 
   A fourth objective of the present invention is to provide a practical, efficient, simple and easy to operate lift device, apparatus and system for raising and lowering watercrafts such as jet skis, inflatables, rowboats, personal watercrafts, and the like, and other vessels that only needs one actuator having a single fluid cylinder and single fluid operated piston. 
   A fifth objective of the present invention is to provide a practical, efficient, simple and easy to operate lift device, apparatus and system for raising and lowering watercrafts such as jet skis, inflatables, rowboats, personal watercrafts, and the like, and other vessels that does not scratch, mar or damage the underside of the watercrafts being raised and lowered. 
   The sixth objective of the present invention is to provide a practical, efficient, simple and easy to operate lift device, apparatus and system for raising and lowering watercrafts from support structures such as boat transoms, bulkheads and docks, where the watercrafts are raised and lowered in close proximity to the support structures. 
   A lifting device for raising and lowering water crafts can include a frame attached to a support, a rotatable crank attached to the frame, a fluid operated actuator having one end attached to the frame and an another end attached to the crank member, an arm having a first end attached to the crank member and a second end, and a cradle supporting a watercraft which is attached to the second end of the arm, wherein the fluid actuator lowers and raises the cradle with the supported watercraft. 
   The rotatable crank can include a rotatable crank shaft with a crank blanket fixably attached to the rotatable crank shaft, the one end of the fluid operated actuator pivotably attached to the crank bracket and the first end of the arm fixably attached to the rotatable crank shaft. 
   The arm supporting the cradle can include a telescoping section that allows the arm to have a varying length. 
   The actuator can be a single hydraulic cylinder and single actuated piston for raising and lowering the arm and the attached cradle. 
   The cradle can have a concave curved surface on the cradle, and a self leveling carriage positioned on the concave curved surface of the cradle, the carriage allowing the watercraft to remain in a substantial level position while the arm and the attached cradle are being raised and lowered. 
   The cradle can have rollers between portions of the carriage and the cradle for allowing the carriage to roll relative to the cradle while the arm and the attached cradle are being raised and lowered. The rollers can include a first set of three rollers arranged in a triangular pattern on one side of the carriage, and a second set of three rollers arranged in a triangular pattern on another side of the carriage, the first and second sets of rollers allowing the carriage to roll relative to the cradle. 
   The carriage can also include upright supports pivotally attached to the carriage, the pivotal upright supports allowing the water craft to be firmly supported in a stable position to the carriage. 
   A swivel mount can be used for locking the cradle to the arm. The swivel mount can include a swivel plate having a fastener for holding the arm in a selected fixed orientation position relative to the cradle. The fastener can include a first fastener along one side of the arm, and a second fastener along another side of the arm, wherein the first and the second fasteners lock the cradle in the selected fixed orientation position relative to the cradle. 
   An extra securing latch can be used for holding the arm in the raised position, and the latch can use another fluid operated actuator for opening and closing the latch. 
   The lift can be attached to an angled surface such as a bottom transom, such as a swim platform on a large watercraft. The lift can also be attached underneath a horizontal surface such as a dock. The lift can also be mounted on wall type surfaces such as along a bulkhead. 
   In another version, the novel lift can attach underneath a swim platform on the back of a pleasure boat for raising and lowering a personal watercraft such as a jet ski, inflatable, and the like. The lift can have a lift arm with one end in a fixed perpendicular connection to one end of a crank arm. The second end of the lift arm is fixed to a cradle having a carriage supported thereon by a rollers. A perpendicular connection point between the crank arm and the lift arm can be pivotally connected to a mount that is attached underneath the swim platform. A single hydraulic cylinder has a piston that moves a second end of the crank arm from a first position to a second position. In the first position, the lift arm is raised, and in the second position, the lift arm is lowered and the cradle is in a lowered position. While the cradle moves from an up position to a lowered position, the supported personal watercraft being held by the carriage rolls off the cradle and into the water. 
   Further objects and advantages of this invention will be apparent from the following detailed description of the present preferred embodiments which are illustrated schematically in the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE FIGURES 
       FIG. 1  is a back perspective view of the lift in an up position 
       FIG. 2  is a back perspective view of the lift of  FIG. 1  in a down position. 
       FIG. 3  is a side view of the lift of the preceding figures in an up position attached to a transom (swim platform) on a larger boat. 
       FIG. 4  is a side view of the lift of  FIG. 3  in a down position. 
       FIG. 5  is a side view of the lift in an up position attached to a dock. 
       FIG. 6  is a side view of the lift of  FIG. 5  in a down position. 
       FIG. 7  is a front view of the lift of  FIG. 1  along arrow F. 
       FIG. 8  is a back view of the lift of  FIG. 1  along arrow B. 
       FIG. 9  is a top view of the lift of  FIG. 1  along arrow T. 
       FIG. 10  is a bottom view of the lift of  FIG. 1  along arrow U. 
       FIG. 11  is an enlarged view of the cradle and carriage of the lift. 
       FIGS. 12A ,  12 B,  12 C are enlarged views of the rail and swivel mounts pivoting to conform to different hull shapes of a cradle supported watercraft. 
       FIG. 13  is a side view of the arm with attached cradle detached from the lift frame. 
       FIG. 14  is a side partial cut-away view of the lift showing the fluid actuator holding the arm and cradle in a raised position. 
       FIG. 15  is another side partial cut-away view of the lift of  FIG. 14  with arm and cradle in lowered position. 
       FIG. 16  is an enlarged side partial cut-away view of the carriage with rollers supported by the cradle. 
       FIG. 17  is an enlarged side view of the cylinder operated latch holding the arm of the lift in a raised position. 
       FIG. 18  is another view of  FIG. 17  showing the latch in an open position and arm of the lift in a lowered position. 
       FIG. 19  is a schematic view of the controls for the single main fluid actuator for the lift arm and the fluid actuator for the latch of the preceding figures. 
       FIG. 20  is a side view of the lift in an up position attached to a side of a bulkhead. 
       FIG. 21  is an enlarged view of the swivel mount separated from swivel plate for use with the cradle and arm. 
       FIG. 22  is another view of  FIG. 21  showing detached fasteners used for holding the arm in a fixed orientation position to the cradle. 
       FIG. 23  is another view of  FIG. 22  showing the fasteners attached to the swivel plate and mount holding the arm in the fixed orientation position to the cradle. 
       FIG. 24  is a top view of the swivel plate, mount, cradle and arm of  FIG. 23 . 
       FIG. 25  is a side view of the swivel plate, mount, cradle, arm of  FIG. 24  along arrow X 1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its applications to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation. A list of components will now be listed.
       1  lift device     100  frame assembly     110  Left bearing plate     112  flat portion left plate     120  Right bearing plate     122  flat portion right plate     130  Nose Shield     140  L-Shaped Cross Beam     150  Crank Shaft     151  Bearings     159  Bearings     160  Oblong Shaped Crank Bracket for actuator     162  Enlarged end     168  Narrow end     169  Pivot point     170  Left Arm Crank Socket     175  U-shaped Gosset     180  Right Arm Crank Socket     185  U-shaped Gosset     200  Single main actuator with single cylinder and single piston     210  Piston     212  Pivot end     220  Cylinder     222  Rearwardly protruding end     230  Parallel plates     300  lift arm assembly     310  left lift arm     315  Removable Cotter Pin     320  left extension member     328  End of left member     330  right lift arm     335  Removable Cotter Pin     340  right extension member     348  End of right member     400  Cradle     410  First End Beam     420  Second End Beam     430  First concave curved side beam     440  Second Concave curved side beam     500  Carriage     510  Left Arc Curved bracket     515  Left Triangular group of three rollers     520  Right Arc Curved bracket     525  Right Triangular group of three rollers     530  First Cross brace     540  Second Cross brace     550  First Craft support rail     555  Upper protective surface of rail     560  Second Craft support rail     565  Upper protective surface of rail     570  Upright riser     572  Bottom end of riser     574  Mid cylinder portion of riser     575  Tightening nut     578  Upper protruding portion     579  Pivot pin     600  Latch assembly     610  support bracket     612  side protrusion portion     615  pivot connection     620  latch fluid actuated cylinder     630  piston     640  latch lever     650  latch spring     660  upper latch member     665  latch pivot pin     670  lower latch member hook     680  lift stopper     690  latch pin     700  Swivel Mount assembly     710  mount on side beam of cradle     720  Side plate on for mount     730  Outwardly protruding cradle pivot pin     740  lift arm pivot plate     745  center hole in pivot plate     750  pivot plate mounting bolts     800  Personal Watercraft     900  Large Watercraft     910  Boat Transom     930  Dock     940  Bulkhead     950  Wall     960  Adapter   

     FIG. 1  is a back perspective view of the lift  1  in an up position  FIG. 2  is a back perspective view of the lift  1  of  FIG. 1  in a down position.  FIG. 3  is a side view of the lift  1  of the preceding figures in an up position attached to a transom (swim platform)  910  on the back of a larger boat  900 .  FIG. 4  is a side view of the lift  1  of  FIG. 3  in a down position.  FIG. 5  is a side view of the lift  1  in an up position attached to a dock  930 .  FIG. 6  is a side view of the lift  1  of  FIG. 5  in a down position.  FIG. 7  is a front view of the lift  1  of  FIG. 1  along arrow F.  FIG. 8  is a back view of the lift  1  of  FIG. 1  along arrow B.  FIG. 9  is a top view of the lift  1  of  FIG. 1  along arrow T.  FIG. 10  is a bottom view of the lift  1  of  FIG. 1  along arrow U. 
   Referring to  FIGS. 1 ,  2  and  7 - 10 , the lift  1 , generally includes a frame assembly  100 , single main actuator  200  that raises and lowers lift arm assembly  300  that is in turn attached to a cradle  400  that has a rollable carriage  500  supported thereon. 
   Frame Assembly  100   
   Referring to  FIGS. 1 ,  2  and  7 - 10 , the lift  1  can include a frame assembly  100  having a generally rectangular configuration with a left bearing plate  110 , right bearing plate  120 , an L-shaped cross beam  140  connecting the bearing plates parallel to one another, and a protective nose shield  130  at a front end of the frame assembly  100 . A rotatable crank shaft  150  can be inserted into through-holes of the bearing plates  110 ,  120  at a rear end of the frame assembly  100 . 
   The ends of the crank shaft  150  are held in place to the bearing plates  110 ,  120  outer located left arm crank socket  170  and right arm crank socket  180 . Bearings  151 ,  159  between crank sockets  170 ,  180  and bearing plates  110 ,  120  assist in allowing crank shaft  150  to be able to rotate in place. 
   Along a mid-portion of the crank shaft  150  can be an oblong shaped crank bracket  160  having an enlarged end  162  that is fixably attached about the mid-portion of the crank shaft  150 . A downwardly protruding narrow end  168  of the crank bracket  160  can have a pivot point connection  169  that can be pivotally connected to one end  212  of the piston rod  210  of the main actuator  200 . 
   Single Main Actuator  200   
   Referring to  FIGS. 1 ,  2 , and  7 - 10 , the single main actuator  200  can be a single fluid cylinder and single piston that can be a hydraulic cylinder and piston. Alternatively, the single main actuator can be a pneumatic cylinder and piston. Main actuator  200  generally includes a piston  210  having a piston end  212  that is pivotally attached at a pivot point  169  to the narrow end  168  of crank bracket  160 . The piston  210  can be fluid actuated to move in an out of a single cylinder  220 . An other end of the cylinder  222  can be a rearwardly protruding portion  222  that is pivotally attached between parallel plates  230  that are fixably mounted under a mid-portion of L-shaped cross beam  140 . 
   Lift Arm Assembly  300   
   Referring to  FIGS. 1 ,  2 ,  7 - 10 , the lift  1  can include a lift arm assembly  300  can include a left lift arm  310  having an end  312  inserted in and fixably attached to a U-shaped gusset portion  175  of left arm crank socket  170 . A left extension member  320  can telescope relative to left lift arm  310  and be held to a selected extension length by a removable cotter type pin  315 . The outer end  328  of left extension member  320  can bend upward in and be attached by swivel mount assembly  700  to cradle  400 . 
   Additionally, the lift arm assembly  300  can include a right lift arm  330  having an end  332  inserted and fixably attached to a U-shaped gusset portion  185  of a right arm crank socket  180 . A right extension member  340  can telescope relative to right lift arm  330  and be held to a selected extension length by another removable cotter type pin  335 . 
     FIG. 13  is a side view of the left extension member  320  with attached cradle  400  detached from the frame assembly  100 , by removing the cotter type pin  315 . 
   Cradle  400   
   Referring to  FIGS. 1 ,  2 ,  7 - 10 , the lift  1  can include a cradle  400  that can have a generally rectangular configuration formed from two end beams  410 ,  420  that are connected to one another by concave curved side beams  430 ,  440 . A swivel mount  700  can fixably attach the cradle  400  at a fixed orientation relative the ends  328 ,  348  of the telescoping arm extension members  320 ,  340 . 
   Carriage  500   
   Referring to  FIGS. 1 ,  2 ,  7 - 10 , the lift  1  can include a carriage  500  that rolls on the concave curved side beams  430 ,  440  of cradle  400 . Carriage  500  can include matching left arc curved bracket  510 , and right arc-curved bracket  520 . Each of the brackets can include a triangular arrangement of three rollers  515 ,  525  mounted thereon. The rollers  515 ,  525  are arranged so that two can rest and ride on the upper surface of concave curved side beams  430 ,  440 , while single rollers can rest and abut against a lower surface of the concave curved side beams  430 ,  440 . Two parallel cross braces  530 ,  540  can connect the right and left arc-curved brackets to one another in a generally triangular arrangement. 
     FIG. 11  is an enlarged view of the cradle  400  and carriage  500  of the lift  1 .  FIGS. 12A ,  12 B,  12 C are enlarged views of the parallel watercraft support rails  550 ,  560  and swivel upright riser mounts  570  that pivot to conform to different hull shapes of a cradle supported watercraft  800 . 
   Referring to  FIGS. 1 ,  2 ,  7 - 12 C, the arc-curved brackets  510 ,  520  can each include upright risers  570  that protrude upward from the ends of these brackets  510 ,  520 . A total of approximately four identical upright risers  570  can be used, that each include a bottom end  572  that can be fastened by nuts and the like to the upwardly curved ends of the brackets  510 ,  520 . A bottom cylinder portion  574  can have a nut that threadably locks an extension rod portion  578  thereon, so that the rises can be extended or retracted in the direction shown by arrow E. The extension rod portion  578  can have a pivot pin portion  579  that pivotally attaches the risers to the inside of downwardly facing open channel of the horizontal railings  550 ,  560 . The upper surface of the horizontal rails  555 ,  565  can have pads that can be plastic, rubber, and the like, that can be used as a protective surface for the hull surface portions of the watercraft being carried thereon. 
     FIG. 16  is an enlarged side partial cut-away view of the arc-curved bracket  510  of the carriage  500  with triangular arrangement of three rollers  515  that is attached to and rolls relative to the concave curved side beam  440  of the cradle  400 . 
   Latch Assembly  600   
     FIG. 17  is an enlarged side view of the cylinder operated latch assembly  600  holding the arm  310 ,  320  of the lift  1  in a raised position.  FIG. 18  is another view of  FIG. 17  showing the latch assembly  600  in an open position and arm  310 ,  320  of the lift in a lowered position. 
   Referring to  FIGS. 1 ,  2 ,  13 ,  17 ,  18 , the lift  1  can include a latch assembly  600  that allows the lifting arms  310 / 320 ,  330 / 340  to be locked as desired in a raised position. The left arm components  310 / 320  and the right arm components  330 / 340  can each include a latch assembly  600 . 
   The latch assembly can include a support bracket  610  that downwardly protrudes from and is attached to flat plate portion  112  of bearing plate  110 . A side protrusion portion  612  can extend sideways from the support bracket  610  and have a pivot pin connection to a rear end of a small fluid actuator  620  such as a small hydraulic cylinder, pneumatic cylinder and the like. A retractable piston  630  can extend from the opposite end of the cylinder  620  and have an end that is attached to both a latch spring  650  and an upwardly protruding end of an upper latch member  660 , which has a lower end fixably attached to a lower latch member hook  670 . The opposite end of the latch spring  650  can be fixably attached to a connector  658  on the side of bracket  110 . The upper latch member and lower latch member hook  670  can be pivotally attached to the bracket  110  by a pivot pin connection  665 . 
   Normally, the piston  630  of cylinder  620  can be pulled outward in an extended position by the bias of latch spring  650 . As arm  310 ,  320  is being raised, a side protruding latch pin  690  on arm  310  can push against curved surface edge  672  of latch hook  670  so that the latch hook will result in hooking about the latch pin  690 . A stopper member attached to the side of bracket  110  can limit the travel height of the lifting arms  310 / 320 . 
   The operator can release the latch hook  670  by controlling cylinder  620  to retract piston  630 , which results in upper latch member  660  and lower latch hook pivoting about pivot pin  665 , which unhooks the latch hook  670  from about latch pin  690 , and will allow arm  310 ,  320  to be lowered. 
   Controls for Main Actuator and Small Latch Actuator 
     FIG. 19  is a schematic view of the controls  5  for the single main fluid actuator  200 / 210 / 220  for the lift arms  310 / 320 ,  330 ,  330  and the fluid actuator  620 / 640  for the latch assembly  600  of the preceding figures. A manual hand pump  10  can be connected to a power pack  20  such as a 12 volt/24 volt electro hydraulic power pack. Fluid actuation lines  30 ,  40 ,  50  can be used to actuate the pistons  210 ,  630  of the main actuator  200  and latch assembly cylinder  620 . Conventional hydraulic controls such as that shown in U.S. Pat. No. 6,474,256 to Vogel, and U.S. Pat. No. 6,327,992 to Martin, which are both incorporated by reference can be used to control the actuators of the subject invention. The motors used to run the actuator(s) can include but not be limited to 120 volt power supply, battery power supply, solar power, and the like. 
   Swivel Mount Assembly  700   
     FIG. 21  is an enlarged view of the swivel mount  710  separated from swivel plate  740  for use with the cradle  400  and lifting arm  320 .  FIG. 22  is another view of  FIG. 21  showing detached fasteners  750  such as bolts used for holding the arm  320  in a fixed orientation position to the cradle  400 .  FIG. 23  is another view of  FIG. 22  showing the fasteners  750  attached to the swivel plate  740  and side plate  720  on the mount  710  holding the arm  320  in the fixed orientation position to the cradle  400 .  FIG. 24  is a top view of the swivel plate  740 , side plate  720  on mount  710 , cradle  400  and arm  320  of  FIG. 23 .  FIG. 25  is a side view of  FIG. 24  along arrow X 1 . 
   Referring to  FIGS. 1 ,  2 ,  7 - 10  and  21 - 25 , the swivel mount assembly  700 , a mount  710  can be fixably attached to both concave curved side beams  440  (only one is shown for simplicity) of cradle  400 . A side plate  720  with flat exterior side can be fixed to the mount  710 . In the middle of the plate  720  can be an outwardly protruding cradle pivot pin  730 . Next the center hole  745  of the lift arm swivel plate  740  can be positioned over the cradle pivot pin  730 . 
   When first installing the lift  1 , the user can orient the upper curved ends  328  (only one is shown for simplicity) of the arms  320 ,  340  so that when the arms  310 / 320  and  330 / 340  of the lift are in a raised position on both sides of a horizontal exterior brace beam  390 , the user can position the outer ends of the beams against the outside of the swivel plate  740 . 
   The user can orient the cradle between the outer ends of the arms  310 / 320 ,  330 / 340  until the cradle is in a substantially level position while the arms  310 / 320 ,  330 / 340  are in the raised position. 
   Next, the swivel plate  740  can be twisted clockwise or counter-clockwise in the direction of arrow SWP so that the side holes  743 ,  747  are positioned directly adjacent to side edges on opposite sides of the upper end  328  of the arm  320 . 
   When the level orientation position of the cradle is reached, the user can drill through the existing side holes  743 ,  747  into plate  720  and then attach bolts through holes  743 ,  747 , where the heads of the bolts  750  effectively lock the orientation of the cradle relative to the lift arms  310 / 320 ,  330 / 340 . 
   Operation 
   A preferred application of the invention is using the novel lift with a larger vessel for raising and lowering smaller watercrafts therefrom.  FIG. 14  is a side partial cut-away view of the lift  1  showing the fluid actuator  200  holding the arm  310 / 320  and cradle  400  in a raised position.  FIG. 15  is another side partial cut-away view of the lift  1  of  FIG. 14  with arm  310 / 320  and cradle  400  in lowered position. 
   Referring to  FIGS. 1-4 ,  14  and  15  top flat plate portions  112 ,  122  of the bearing plates  110 ,  120  can be used to flush mount the frame assembly  100  by fasteners such as conventional bolts (not shown) underneath an angled bottom of a boat transom (swim platform  910 ) that is attached to a larger vessel  900 . In the raised position a small personal watercraft  800  such as but not limited to a jet ski or inflatable can be supported by the hull conforming pivotable rails  550 ,  560 , on the carriage  500  in a substantially level position. 
   To lower the carriage  500  and cradle  400 , a single piston  210  from main cylinder  220  can move from a retracted position to an extended position and move narrow end  168  of crank bracket  160  at pivot point  169 . The enlarged end  162  of the crank bracket being fixably attached to crank shaft  150  effectively rotates the crank shaft  150  in a clockwise direction. Since the bottom ends of arms  310 ,  330  are fixably attached to crank sockets  170 ,  180  which are in turn fixably attached to ends of the crank shaft  150 , the lift arms  310 / 320 ,  330 ,  340  move downward lowering cradle  400 . As the cradle  400  is lowered into the water, the carriage  500  can roll off the curved side beams  430 ,  440  of the carriage by gravity and effectively allow the watercraft  800  to slip easily and safely into the water. 
   Retracting the piston  210  into actuator cylinder  220  reverses the operation allowing the cradle  400  to rise upward. An optional stopper-bumper on the cradle  400  can prevent the carriage  500  from fully rolling off of the cradle. 
   Another application of the novel lift is attaching the frame assembly portion underneath a horizontal surface.  FIG. 5  is a side view of the lift  1  in an up position attached to a dock  930 .  FIG. 6  is a side view of the lift  1  of  FIG. 5  in a down position. The ends  320 / 340  of the arms can be bent to allow the cradle to support the watercraft  800  in substantially level positions. The operation is similar to that previously described. 
   Another application of the novel lift is attaching the frame to a wall by using an adapter such as a triangular adapter type bracket  960 .  FIG. 20  is a side view of the lift  1  of the preceding figures in an up position attached to a side wall  950  of a bulkhead  940 . The operation of the lift can also be similar to that previously described. 
   The components used to make the lift can include but are not limited to stainless steel, galvanized steel, plastics, composites, combinations thereof, and the like. 
   The main actuator for the raising and lowering the arm(s), and the latch actuator, can be a fluid actuator such as but not limited to hydraulic, pneumatic, seawater, city water pressure supplies, and the like. 
   The lift can lift personal watercrafts having weights of up to approximately 800 to approximately 1,500 pounds or more. Using different sized components such as the actuators and the arm(s) can be used to lift larger craft such as but not limited to actual pleasure boats, manned submersibles, unmanned submersibles, that can weigh up to several tons or more. 
   Although the invention has been described as having a separate crank bracket for the main actuator and separate crank sockets for the arms, the invention can use a single bracket that is connected to both the actuator and the arms and to the crank shaft. For example, an L-shaped bracket where the angled corner of the L is fixed to the shaft and the outer legs of the L are each attached to the actuator and to control the raising and lowering of one or more arm(s) can be used. The actuator can be used to rotate the shaft component which can then raise and lower the arm or arms. 
   While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.