Patent Abstract:
A self-retracting step assembly is attached to a swimming platform provided on the rear of the hull of a boat. The self-retracting step assembly includes a ladder comprising a series of telescoping tubes which enable its extension and retraction. The step assembly including the ladder assembly are attached to the swimming platform in a position in which the ladder is capable of extending into the water wherein the watercraft or boat floats. The telescoping ladder assembly can be extended and placed from a normally horizontal position into an inclined position wherein at least the last step of the ladder reaches the water. The energy for extending the ladder is supplied by a human user. The step assembly includes a motor or mechanical means for storing the energy used for extending the ladder. The ladder assembly is locked into the extended and inclined position by an improved mechanism that is located within the assembly attached to the swimming platform. Retraction of the ladder assembly is triggered by a change in the angle of the ladder relative to the water, said change being triggered by force of the water relative to the ladder when the watercraft or boat moves. The energy utilized for the retraction is preferably the stored energy of the extension, or it can be supplied by a motor.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     The present application claims the priority of U.S. provisional application Ser. No. 60/489,823, filed on Jul. 23, 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention is directed to a step assembly which is mounted to a swimming platform in the rear of a watercraft or boat, such as a pleasure boat, and which can be extended and locked when the watercraft or boat is essentially motionless to allow persons to descend into the water or ascend into the watercraft or boat, and which retracts when the watercraft or boat is in forward motion in the water.  
         [0004]     2. Brief Description of the Prior Art  
         [0005]     Boats and ships are well known in the art. Many boats, primarily motor and sailboats used for pleasure include a swimming platform mounted to the rear of the hull. The swimming platform usually has a horizontal surface unto which a person can step prior to entering the water that floats the boat. Generally speaking, it is difficult for most persons to enter the water directly from the swimming platform and even more difficult, often virtually impossible, for the average person to ascend to the swimming platform from the water. For this reason the prior art provided ladders which can be lowered from the swimming platform into the water and which render it easier for a person to enter into and exit from the water. For several reasons it is usually considered undesirable to leave such ladders in the water when the boat is in motion, therefore the ladder is usually retracted before, or soon after, the boat begins moving. The prior art ladders utilized for this purpose, generally speaking, require extension and retraction by entirely manual operation. This involves manually folding the ladder downward when the ladder is placed into the water and the reverse manual operation when the ladder is retracted.  
         [0006]     U.S. Pat. No. 5,427,049 describes a self-retracting ladder assembly to be utilized in connection with personal watercraft. This ladder assembly is mounted underneath the riding platform of the personal watercraft and its surfaces are exposed to the thrust of the water generated by the jet pump. The ladder assembly of U.S. Pat. No. 5,427,049 functions reasonably well when used on personal watercraft powered by a jet pump.  
         [0007]     Other step or ladder assemblies used on boats are described in U.S. Pat. Nos. 5,152,244, 5,458,080 and 5,927,433. In spite of the availability of these prior art step or ladder assemblies an improvement of the prior art is needed for boats where the rear of the hull includes a swimming platform. The self-retracting step assembly of the present invention provides such improvement.  
       OBJECTS AND SUMMARY OF THE INVENTION  
       [0008]     It is an object of the present invention to provide a self-retracting step assembly mounted to the swimming platform of a boat which can be used to facilitate getting into the water from the boat and climbing aboard the boat from the water.  
         [0009]     It is another object of the present invention to provide a step assembly which meets the following objective and which includes an improved mechanism to lock a ladder into an extended and inclined position wherein at least a last step of the ladder is in the water.  
         [0010]     It is still another object of the present invention to provide a step assembly which meets the foregoing objectives and wherein retraction of the ladder is automatically triggered by forward movement of the boat in the water.  
         [0011]     The foregoing and other objects and advantages are attained in accordance with the present invention by a self-retracting step assembly which is attached to a swimming platform provided on the rear of the hull of a boat. The self-retracting step assembly includes a ladder comprising a series of telescoping tubes which enable its extension and retraction. The step assembly including the ladder assembly are attached to the swimming platform in a position in which the ladder is capable of extending into the water wherein the watercraft or boat floats. The telescoping ladder assembly can be extended and placed from a normally horizontal position into an inclined position wherein at least the last step of the ladder reaches the water. The energy for extending the ladder is supplied by a human user or by a motor. The step assembly includes the motor or mechanical means for storing the energy used for extending the ladder. The ladder assembly is locked into the extended and inclined position by an improved mechanism that is located within the assembly attached to the swimming platform. Retraction of the ladder assembly is triggered by a change in the angle of the ladder relative to the water, said change being triggered by force of the water relative to the ladder when the watercraft or boat moves. The energy utilized for the retraction is preferably the stored energy of the extension, or it can be supplied by a motor.  
         [0012]     The features of the present invention can be best understood together with further objects and advantages by reference to the following description, taken in connection with the accompanying drawings, wherein like numerals indicate like parts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view showing the self-retracting step assembly mounted to the swimming platform of a boat.  
         [0014]      FIG. 2  is a cross-sectional view taken on lines  2 , 2  of  FIG. 1  showing a ladder assembly in a retracted position.  
         [0015]      FIG. 3  is a plan view taken on lines  3 , 3  of  FIG. 2  showing the ladder assembly in the retracted position.  
         [0016]      FIG. 4  is a plan view similar to the one taken on lines  3 , 3  of  FIG. 2  showing the ladder assembly in an extended and inclined position.  
         [0017]      FIG. 5  is a plan view taken on line  5 , 5  of  FIG. 2 .  
         [0018]      FIG. 6  is a plan view taken on lines  6 , 6  of  FIG. 4  showing the ladder assembly in the extended and inclined position.  
         [0019]      FIG. 7  is a view, partly in cross section, taken on lines  7 , 7  of  FIG. 2 , showing the ladder assembly in the retracted position.  
         [0020]      FIG. 8  is a view, partly in cross section, taken on lines  8 , 8  of  FIG. 7 .  
         [0021]      FIG. 9  is a view, partly in cross section, taken on lines  9 , 9  of  FIG. 7  showing the ladder assembly in the retracted position.  
         [0022]      FIG. 10  is a view, partly in cross section, similar to the one taken on line  9 , 9  of  FIG. 7  and showing the ladder assembly in the extended position.  
         [0023]      FIG. 11  is a view, partly in cross section, similar to the one taken on line  8 , 8  of  FIG. 7  and showing the ladder assembly in the extended and inclined position.  
         [0024]      FIG. 12  is a view, partly in cross section, similar to the one taken on line  8 , 8  of  FIG. 7  and showing the ladder assembly moving up from the extended and inclined position.  
         [0025]      FIG. 13  is a view, partly in cross section, similar to the one taken on line  8 , 8  of  FIG. 7  and showing the ladder assembly moving still further up from the extended and inclined position.  
         [0026]      FIG. 14  is a view, partly in cross-section showing the cable spool of the first preferred embodiment in detail.  
         [0027]      FIG. 15  is a cross-sectional view taken on lines  15 , 15  of  FIG. 14 .  
         [0028]      FIG. 16  is a cross-sectional view taken on lines  16 , 16  of  FIG. 7 .  
         [0029]      FIG. 17  is a view, partly in cross section, similar to the view of  FIG. 7  and showing another preferred embodiment of the invention.  
         [0030]      FIG. 18  is a view, partly in cross section, taken on lines  18 , 18  of  FIG. 17 .  
         [0031]      FIG. 19  is a schematic view of the locking mechanism of still another preferred embodiment.  
         [0032]      FIGS. 20 and 21  are schematic views showing yet another preferred embodiment wherein a tension spring provides force to move the ladder assembly into a horizontal position.  
         [0033]      FIG. 22  is a view, partly in cross section, showing a further embodiment of the invention that includes a motor for retracting the ladder assembly.  
         [0034]      FIG. 23  is a schematic view of a still further embodiment showing an extension spring utilized for retracting the ladder assembly.  
         [0035]      FIG. 24  is a schematic view of a still further embodiment wherein a cable clamp is utilized for locking the ladder assembly into the extended and inclined position.  
         [0036]      FIG. 25  is a schematic view showing the same embodiment as  FIG. 23  with the ladder assembly extended.  
         [0037]      FIG. 26  is a schematic view of still another further embodiment showing compression springs utilized for retracting the ladder assembly.  
         [0038]      FIG. 27  is a schematic view showing hydraulically operated cylinders for retracting the ladder assembly.  
         [0039]      FIG. 28  is a schematic bottom plan view of yet another embodiment of the present invention wherein springs are utilized instead of cables and pulley for retracting the ladder assembly of the present invention.  
         [0040]      FIG. 29  is a view taken on lines  29 , 29  of  FIG. 28  when the ladder assembly is in extended and inclined position.  
         [0041]      FIG. 30  is a view showing the locking mechanism to keep extended the ladder assembly of the embodiment of  FIG. 29 .  
         [0042]      FIG. 31  is a view showing the release of the locking mechanism of the embodiment of  FIG. 29 .  
         [0043]      FIG. 32  is a schematic view indicating the release of the locking mechanism by movement of the boat in the water.  
         [0044]      FIG. 33  is a schematic view showing the self-retracting step assembly mounted above the swimming platform of a boat.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0045]     The following specification taken in conjunction with the drawings sets forth the preferred embodiments of the present invention. The embodiments of the invention disclosed herein are the best modes contemplated by the inventors for carrying out their invention in a commercial environment, although it should be understood that various modifications can be accomplished within the parameters of the present invention.  
         [0046]     Referring now to the drawing figures the novel self-retracting step assembly of the present invention is disclosed. The novel step assembly of the present invention is mounted to the swimming platform  50  of boats  52 . It is well known in the art that many boats, primarily the boats used for pleasure, include such swimming platforms  50  onto which a person may step when he or she desires to enter the water  51 . The novel step assembly of the present invention is designed to be attached to the underside of the swimming platform  50 . Nevertheless, in modern boats wherein the hull includes a swimming platform  50  that has no horizontally disposed bottom surface the novel step assembly of the invention can be attached to the upper surface of the swimming platform  50 . This is shown in  FIG. 33  of the attached drawings.  
         [0047]      FIGS. 1 through 16  disclose the first preferred embodiment of the novel step assembly of the present invention in detail. The step assembly includes a base plate  54  that is attached to cross-members  56  of the swimming platform  50  by a bolts and nuts assembly  58 . The step assembly also includes a cover  60  which is preferably made of fiberglass or plastic material. The cover  60  can be attached to side plates  62  of the step assembly by bolts and nuts, but in the preferred embodiment the bolt  64  that attaches the cover  60  to the side plates  62  includes a boss  66  into which the bolt  64  is fitted.  
         [0048]     The working mechanism of the self-retracting step assembly of the invention is contained in part within the box-like structure that is formed by the base plate  54 , side plates  62  and cover  60 . The working mechanism includes a ladder assembly that includes a pair of plurality of telescoping tubular members  68 . Because of their telescoping nature the telescoping members  68  can be extended and retracted. Each pair of the telescoping members  68  is disposed substantially parallel with the respective side plates  62  of the step assembly so that when the telescoping members  68  are extended they form a U-shaped structure. Cross bars or rungs  70  are attached between the telescoping members  68  and a substantially flat, substantially rectangular member  72  is mounted to each cross bar or rung  70 . The substantially flat rectangular members  72  serve as steps when a person (not shown) utilizes the ladder assembly for entering or coming out of the water  51  and into the boat  52 . In the herein described first preferred embodiment the tubular telescoping members  68  and the rungs  70  are made of steel and the rungs  70  are welded to the telescoping members  68 . The rectangular members  72  which serve as steps are preferably made of fiberglass or plastic material and are attached to the rungs  70  by screws or bolts (not shown). In the preferred embodiments of the invention each pair of the telescoping members  68  has three tubes of successively smaller diameter, three rungs  70  interconnect the telescoping members  68  and one step  72  is mounted to each rung  70 .  
         [0049]     The first or largest of the tubular members  68  on each side of the step assembly is attached to a pivot block  74  shown in several of the drawing figures and perhaps best shown in  FIGS. 8, 11 ,  12 , and  13 . Each pivot block  74  is attached to the respective side plate  62  of the step assembly on a hinge that is formed by a bolt  76 . The portion of the pivot block  74  that faces the interior of the step assembly is formed in a shape that cooperates with the mechanism or means that locks the ladder assembly in an extended and inclined position when the boat  52  is motionless in the water. The parts and operation of this mechanism or means are described below with primary reference to  FIG. 7 .  
         [0050]     Referring now primarily to  FIG. 7 a  cross member or cross plate  78  is mounted between the side plates  62 . The cross plate  78  serves as a brace to reinforce the substantially box shaped structure formed by the base plate  54  and side plates  62 . A reel or spool  80  is mounted in the space between the base plate  54  and the reinforcing cross plate or brace  78 . The spool  80  and its mounting to the base plate  54  are best shown in  FIGS. 8 and 11 . Proceeding in the description from the top of  FIG. 8  downward, first a round spacer  82 , preferably made of plastic materials is attached to the base plate  54 . One function of the round spacer  82  is to keep the spool  80  from wobbling. A boss  84  is attached, preferably by welding to the underside of the base plate  54  and the rotational axle  86  of the spool  80  is embedded in the boss  86 . The rotational axle  86  is in fact a shoulder bolt. A torsional spring  88  is disposed within a hollow space provided in the spool  80  and a flange  90  encloses the interior of the spool  80 . Below the flange  90  is the cross brace  78 , a washer  92  and a nut  94  that is placed on the shoulder bolt  86  whereby the spool  80  is solidly held and is nevertheless capable to rotate within the above described assembly.  
         [0051]     The circumference of the spool  80  includes a groove  96  in which a cable  98  rides. From the spool  80  the cable  98  is led through two pulleys  100  and a tensioner pulley  101  into the interior of each of the pair of telescoping tubular members  68 . Each end of the cable  98  is attached to the respective end of the last telescoping member  68  that has the smallest diameter among the three telescoping members  68 . A pulley  102  is attached to a flange  104  provided in each of the first telescoping members  68 , namely the ones that have the largest diameter. Thus, the cable  98  is wrapped around the spool  80  and rides in its groove  96  and also rides over the two pulleys  100 , the tensioner pulley  101  and the pulleys  102  attached to the flanges  104 . Placement of the cable  98  within the interior of the tubular members  68  and attachment of the ends of the cable  98  to the last of the tubular members  68  is best shown in  FIG. 9 . The flanges  104  also serve to prevent the first of the tubular members  68  from being pulled out of the assembly, as is shown in  FIG. 10 . Each of the remaining tubular members  68  have a flange or flared end in their interior to prevent the members  68  from being pulled out from each other.  
         [0052]     Detailed construction of the pulleys  100  of the herein described preferred embodiment is disclosed by  FIG. 16 . Each pulley  100  is mounted within a boss  106  welded to the base plate  54  on an axle formed by a bolt  108  and includes a retainer  110  which prevents the cable  98  from falling out of the groove of the respective pulley  100 . The herein described pulleys  100  and  101  are not self-adjusting to compensate for stretching of the cable  98 . Nevertheless the pulley  101  in the middle among the three in the herein described preferred embodiment can be adjusted to compensate for stretching of the cable  98  that may occur after prolonged use. As it is shown in  FIG. 7 , this tensioner pulley  101  is mounted on a plate  112  that includes a slot  114 . When adjustment is needed the plate  112  is moved further on its mounting, as permitted by the slot  114 . A tensioner pulley  116  that is spring loaded and therefore self-adjusts for stretching of the cable  98  is shown in  FIG. 17  in connection with an alternative embodiment.  
         [0053]     It should be already apparent from the foregoing description and inspection of the drawing figures that a user (not shown) can manually extend the three tubular members  68  of the ladder assembly by pulling the last member with a force that overcomes the force of the torsional spring  88  within the spool  80 . By virtue of the cable  98  being disposed in the groove  96  of the cable  98  the spool  80  rotates while the tubular members  68  are pulled out. In this process the torsion spring  88  is wound and, as a result, stores the energy expanded by the user (not shown) who extends the tubular members  68 . After the tubular members  68  have been pulled out in a horizontal or substantially horizontal direction the extended ladder assembly is rotated, still by the force of the human user (not shown), about the hinges or axles formed by the bolt  76 , into an inclined position. In the inclined position at portion of the ladder assembly is in the water  51 . In this inclined position of the ladder assembly a person (not shown) can utilize the ladder assembly to enter into or exit from the water  51 .  
         [0054]     In the prior art extendible and self-retracting ladder and step assembly of U.S. Pat. No. 5,427,049 there are camming surfaces which more or less correspond to the position of the pivot blocks  74  of this invention, and these camming surfaces tend to lock the extended ladder of that disclosure in an inclined position, until motion of the watercraft or boat tilts the ladder upward and the ladder is retracted by the force of a spring. The step assembly of this invention comprises a significantly improved locking mechanism which is best shown for the first preferred embodiment in  FIGS. 8 and 11 - 15 . Thus, the underside of the spool  80  includes a ramped recess that serves as locking channel  118 . Two bosses  120  are mounted to the underside of the cross plate or brace  78  and a plate  122  carrying a bolt  124  is mounted on an axle  125  which is held by the two bosses  120 . The bolt  124  serves as a spool locking pin. The two bosses  120  and the axle  125  held by them is also shown in  FIG. 7 . By virtue of being mounted on the axle  125  the plate  122  is capable of some pivoting movement. A rod  126  is attached to the plate  122  in a position which is transverse to the longitudinal axis of extension of the three tubular members  68 . The rod  126  is biased, that is being pulled towards the base plate  54  of the assembly by a tension spring  128  that is mounted both to the base plate  54  and to the rod  126 .  
         [0055]     For operation of the locking mechanism the rear ends of the two pivot blocks  74  interface with the rod  126 . In the retracted position of the tubular members  68  shown in  FIG. 8  the rear ends of the pivot blocks push the plate  122  downward against the biasing force of the tension spring  128 . In this position of the tubular members  68  the spool locking pin or bolt  124  carried on the plate  122  is not in the locking channel  118  of the spool  80 , nor is the locking channel  118  in a position facing the spool locking pin  124 .  
         [0056]     When the tubular members  68  are fully, or substantially fully, extended then, due to the rotation of the spool  80 , the recess forming the locking channel  118  in the underside of the spool  80  occupies a position facing the spool locking pin  124 . The ramp and stop shape of the locking channel  118  (shown in  FIG. 15 ) allows for multiple rotation of the spool  80  before the pin  124  is locked in the channel  118 . When the extended tubular members  68  are rotated downward to occupy an inclined position then the rear ends of the pivot blocks  74  disengage the rod  126  of the plate  122  and the biasing force of the tension spring  128  pulls the spool locking pin  124  into the locking channel  118 . This is shown in  FIG. 11 . In this inclined position of the tubular members  68 , the tubular members  68  are locked into the extended and inclined position. This is the position in which the ladder assembly is used by persons wishing to go into the water  51  or ascend to the swimming platform  50  of the boat  52 .  
         [0057]     It should be apparent to those skilled in the art in light of the foregoing description and the drawing figures that rotation of the extended tubular members  68  about the axles  76  reverses the above described process, as is shown in  FIGS. 12 and 13 . During this reverse process the rear ends of the pivot blocks  74  come into contact with the rod  126  and push the plate  122  downward and thereby pull the spool locking pin  108  out of the spool locking channel  118 . Torsion springs  130  mounted within the pivot blocks  74  on the axles  76  engage the cross brace  78  and the interior of the blocks  74 . These provide a force tending to place the tubular members  68  into the upward position wherein they are retracted by the cable  98  which is wound up on the spool  80  under the force of the torsional spring  88  inside the spool  80 .  
         [0058]     Upward rotation of the extended and inclined telescoping members  68  can be initiated by human force. More importantly in accordance with the present invention it is automatically initiated when the boat  52  moves forward relative to the water  51 . This is because the portions of the ladder assembly in the water  51  act as a hydrofoil and result in a force that rotates upward the extended tubular members  68 .  
         [0059]     Whereas the foregoing description in connection with  FIGS. 1 through 16  discloses the presently preferred embodiment, and particularly the presently preferred locking mechanism of the invention, other locking mechanisms still utilizing the cable and spool arrangement can be incorporated in the present invention. For example,  FIGS. 17 and 18  disclose another embodiment where the spool  80  has a recess  132  on its circumference and a spring-loaded arm  134  may engage the recess  132  and lock the inclined tubular members  68  into extended and inclined position.  FIG. 18  is a schematic representation of a bell crank  136  connected with a cable  138  to the spring-loaded arm  134 . When the rear end of the block  74  (shown only schematically in  FIG. 18 ) is in contact with the bell crank  136  then the spring-loaded arm  134  is not in the recess  132  nor is the recess  132  in position to accept the spring-loaded arm  134 .  FIG. 17  shows this embodiment in the position where the spring-loaded arm  134  is about to engage or about to disengage the recess  132 . However, when the rear end of the block  74  no longer pushes against the bell crank  136  then the spring loaded arm  134  engages the recess  132  and locks the ladder assembly.  
         [0060]      FIG. 19  schematically discloses still another embodiment for the locking mechanism, wherein a recess  138  is provided in one of the tubular members  68  and ball  140  is pushed under bias of a spring  142  into the recess  138 . The bias of the spring  142  is overcome by the pull of a cable  144  which is activated, for example, through a bell crank (not shown for this embodiment) interacting with the rear end of the block  74  when the tubular members  68  are not in the extended and inclined position.  
         [0061]      FIGS. 20 and 21  schematically disclose still another embodiment wherein instead of the torsion springs  130  of the first preferred embodiment tension springs  146  are used to assist motion of the extended tubular members  68  from the inclined into the upright position.  
         [0062]      FIG. 22  schematically discloses still another embodiment which includes the cable and spool assembly is for retracting the tubular members  68  and where any one of the previously described locking mechanism may be used optionally to lock the tubular members  68  into extended and inclined position. However, the retraction of the tubular members  68  is accomplished with an electric or hydraulic motor  148  which is connected to the spool  80  trough gears  150 . One or more swithches  152 , only one of which is shown, may control the operation of the motor  148  in accordance with the position of the pivot blocks  74 .  
         [0063]     The schematic views of  FIGS. 23, 24  and  25  disclose still another embodiment of the present invention where tensions springs  154  store the energy provided by a human user (not shown) when the user extends the tubular members  68 . This embodiment retains the cable  98  but has no spool. Locking of the tubular members  68  into extended and reclined position is accomplished by one or more cable locks  156  (shown schematically in  FIG. 24 ) which, as in the first preferred embodiment, are controlled by the position of the pivot blocks  74 .  
         [0064]     The schematic view of  FIG. 26  discloses yet another embodiment. This embodiment is analogous to the embodiment shown by  FIGS. 23, 24  and  25  except that instead of the tension springs  154  compression springs  156  are used to store the energy of the human user (not shown) when the user extends the tubular members  68 . The compression springs  156  retract the tubular members  68  when they are no longer in the extended and inclined position. This embodiment also utilizes the pivot blocks  74  and may utilize cable locks  156 , or the locking mechanism described in connection with  FIG. 19  to lock the extended tubular members  68  into the inclined position.  
         [0065]     The schematic view of  FIG. 27  discloses still another alternative embodiment that retains the cable  98  which interconnects the extended tubular members  68  with the retracting mechanism. In this embodiment the power to retract is provided by one or more hydraulically operated cylinders  158 . Switches (not shown) provided in appropriate locations in the assembly may control the operation of the hydraulic cylinders, or the cylinders can be operated manually.  
         [0066]     FIGS.  28  discloses still another embodiment of the present invention. In this embodiment there is no cable and no spool. A tension spring  160  stores the energy which is utilized by the human user (not shown) to extend the ladder assembly. The tension spring  160  also pulls the ladder assembly back into retracted position as described below. This embodiment, similarly to the previously described embodiments, also has three telescoping tubular members. There is a rod  162  in the tube  164  of the smallest diameter and the rod  162  ends in a camming surface  166 . A dog  168  is attached on an axle  170  to the smallest tube  164  and the dog  168  cooperates with the camming surface  166  of the rod  162 . The tension spring  160  is attached to the dog  168  and as a result the tension spring  160  exerts a pulling force on the smallest tube  164 .  
         [0067]     The remaining two tubes  172  and  174  include apertures or holes  176  in their interior surfaces and pins  178  which also include a camming surface  180 . The pins  178  can enter into the respective holes  176  and in cooperation with the dog  168  keep the ladder assembly in a retracted and inclined position.  FIG. 29  shows the pivot blocks  74  which, similarly to the previously described embodiments, make it possible to bend the extended ladder assembly into the inclioned position where the last step  72  (schematically shown) is mounted on an axle  182  to allow some pivoting motion.  
         [0068]     It should be readily apparent from the foregoing description and inspection of the drawing figures that when forward motion of the boat  52  creates a tilting force on the step  72  that acts as a hydrofoil, then cam  166  is pushed inward, moves the dog  168  out of the hole  176  and the tension spring  160  retracts the tube  164  of the smallest diameter. The inwardly moving dog  168  then engages the camming surfaces  180  of the respective pins  178  of the two tubes  172  and  174  and removes the pins  178  from the respective holes  176  in the tubes  172  and  174  whereby the entire ladder assembly is retracted.  
         [0069]     Still further variations of constructing a step assembly in accordance with the present invention may become readily apparent to those skilled in the art in accordance with the present disclosure. Therefore the scope of the present invention should be determined solely from the following claims, as such claims are interpreted in light of the disclosure and the relevant law and prior art.

Technology Classification (CPC): 4