Abstract:
The invention relates to a variable-height platform, which is fitted to a watercraft and has an additional travel and/or a longitudinally movable mounting plate, by means of positive control means such that obstructions by technical means in the pivoting area can be fully bypassed without long pivoting arms and special linear-movement cylinders, and a reasonable immersion depth of the platform is ensured in all cases and, in the event of failure of the linear-movement cylinder, the platform can always be moved to the position A by means of an energy store or accumulator.

Description:
[0001]    This application claims priority of PCT application PCT/CH2008/000314 having a priority date of Jul. 12, 2007, the disclosure of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention is based on an adjustable drop down and coercion controlled moving platform for picking up tender and persons on watercraft. 
       BACKGROUND OF THE INVENTION 
       [0003]    Drop down platforms for swimmers, divers and for tender vessels are known, as described in patents DE 196 02 331, U.S. Pat. No. 6,327,992, U.S. Pat. No. 5,690,045, enabling persons or material to be lowered comfortably into the water or to be taken on board. 
         [0004]    Surface piercing drives, which have a relatively long propeller shaft placed just under the waterline behind the transom of the watercraft, is for e.g. a drop down swimplatform only possible with an electric or hydraulically activated horizontal sliding of the platform, which then can be lowered behind the propeller 
       SUMMARY OF THE INVENTION 
       [0005]    The invention involves a drop down platform mounted at the transom of a watercraft for reason to pick up persons or a tender or to be lowered into the water, to generate an additional lift by means of mechanical means so that the lifting stroke is finally larger as that would be possible with a given cylinder or given swiveling arm kinematics as well as to have a controlled radius to bypass technical mean attached at the transom of a watercraft or to keep the drop down movement of the platform closer to the watercraft transom, to keep e.g. the gap between the watercraft and platform small. 
         [0006]    Drop down tender and swimplatforms have a limited market, if these devices are produced in series with the most possible structurally identical parts as the transoms of the craft differ in a high extent in height and draught. In addition the hulky technical means on watercraft&#39;s transoms make it impossible to have a comfortable utilization of such lowering devices e.g. by protruding rudder blades, jet nozzles, transom drives, trim tabs and therefore additionally limit the assembly and utilization of such drop down platforms. 
         [0007]    Long pivoting arms to avoid the hulky technical means would affect to a large extent the side stability of the pivoting arms and therefore would have to be dimensioned accordingly and would therefore increase the weight at the transom with the result that the transom would have to be reinforced as well. 
         [0008]    The invention solves the stroke limitation due to stroke limited cylinders, or narrow space in the transom area or because of the protruded technical means or because of the limited pivot arms length due to safety reasons, by means of mechanical add-on stroke means, generating an additional lift and thereby can be mounted onto a large number of craft enabling a larger amount of persons to be able to get in or out of the water as well as allowing tender boats to be easily loaded or unloaded. In case of a technical failure of a hydraulic cylinder, by means of stored energy e.g. by a gas spring, it can be ensured that the platform may always be returned to its initial position. 
         [0009]    Quintessence of the invention is that by means of a drop down swimplatform to generate an additional lift as well with limited cylinder dimensions or limited pivoting arm dimensions or stroke hindrances by means of mechanical forced adjustment mean, an accordingly stroke radius is generated so as to go around hindrances in a simple and safe way and in every event to attain elegantly an additional drop down stroke and in an emergency by means of stored energy the platform may be returned to its home position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Various exemplary aspects of the invention will be described with reference to the drawings, wherein: 
           [0011]    It shows 
           [0012]      FIG. 1  A schematic side view of a drop down platform with a set of cantilever pivot arms and cylinder attached to a console, as well as a steering rod between the console and the platform, as well as a shifting mean. 
           [0013]      FIG. 2  A schematic side view of a drop down platform with a set of cantilever pivot arms and cylinder attached to a console, as well with a gear wheel and transmission between platform chassis and platform having beneath a rack and pinion mean as well as a shifting mean 
           [0014]      FIG. 3  A schematic side view of a drop down platform with a set of cantilever pivot arms and cylinder attached to a console and attached to the platform a guidenut and a cranked pivoting arm with a guide pin as well as a shifting mean 
           [0015]      FIG. 4  A schematic side view of a drop down platform with a set of cantilever pivot arms and cylinder attached to a console a control arm, connected to the pivoting arm and to the platform as well as a shifting mean 
           [0016]      FIG. 5  A schematic side view of a drop down platform with a set of cantilever pivot arms and cylinder attached to a console as well as cranked pivoting arm attached to the platform, which is hinged to the platform chassis and to the panel as well as an additional cantilever between the panel and the platform chassis 
           [0017]      FIG. 6  A schematic side view of a drop down platform with a set of cantilever pivot arms and cylinder attached to a console as well as cranked pivoting arm attached to the platform which is hinged to an intercarrier which is mounted to the panel as well an additional cantilever between the intercarrier and the platform chassis. 
           [0018]      FIG. 7  A schematic side view of a drop down platform with a set of cantilever pivot arms attached to a console and cylinder, as well a steering bar between the console and the platform, a shifting mean and two lifting storage mean variances. 
       
    
    
       [0019]    Only essential elements of the invention are schematically shown to facilitate immediate understanding. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]      FIG. 1  Shows a schematic side view of a drop down platform  1  consisting of panel  2  and the platform chassis  3 , which is situated on transom  4  of a watercraft. The console  5  is attached to the transom  4 , onto which a pivoting arm  6  is hinged, consisting of a cantilever pivoting arms  6   a , 6   b , by which platform  1  is supported and lift guided. Between the platform chassis  3  and the panel  2  is a shifting mean  10  attached, which guides and holds panel  2  with a minimum of friction. By means of cylinder  7 , which is on the one hand attached to transom  4  and on the other hand to the pivoting arms  6   a , 6   b  by which the lift H 1  is set and fixed. The appropriate arm lengths, respectively the pivot points on the cantilever pivoting arms  6  yields the radius on platform  1 . In case technical means  8  are attached at the lower part of transom  4 , for e.g. stern drive, rudder, trim tabs, jets etc., it may happen therefore that the panel  2  as a result of the given radius cannot be pivoted around the technical means  8 . 
         [0021]    For this reason the invention makes provision that the panel  2 , with a simple mean, shown here by the steering bar  9 , can be lengthwise coercion shifted to avoid a hindrance. The steering bar  9  is on the one hand fixed to the console  5  and on the other hand to the panel  2  through the preferred but not mandatory different length of the steering bar  9  in accordance to the pivoting arms  6   a , 6   b  and or on another pivot point Dp hinged as the pivoting arms  6   a , 6   b  and or on another upper pivot point Dp positioned compared to the pivoting arms  6   a , 6   b , panel  2  will be shifted by the shifting mean  10  while activating the lift over the platform chassis  3  accordingly and at the same time shifted mechanically, e.g. from position A via the reference position P to position B. Thereby panel  2  can be elegantly and absolutely mechanically pivoted around the technical means  8 , which are situated between or next to the cantilever pivoting arms  6 . The total distance T 1  of panel  2  away from transom  4  comprises deflection radius L of the cantilever arms  6  and the lengthwise shifting distance from A to B. 
         [0022]      FIG. 2  Shows a schematic view of a drop down platform  1  with a cantilever arm  6  attached to a console  5 , identical to  FIG. 1  with the difference that the lengthwise shifting of panel  2  takes place by means of a gear  11 , which is firmly attached to one of the pivoting arms  6   a  or  6   b , depicted here with pivoting arm  6   a . Due to the pivoting, activated by cylinder  7 , the gear  11  undergoes a process of unwinding on the gear racks  12  attached under panel  2 , which has a gear evolvent which meshes properly into gear  11 . Thus panel  2  shifts under the coercion by means of shifting mean  10  placed between this and platform chassis  3 , which can be a gliding or rotating bearing. Because of the anyway limited lift H 1  of the drop down platform  1 , not very large meshing distances can be achieved with such gear  11 , therefore no large shifting distances can be effectuated with such panel  2 . Therefore between gear  11  and gear rack  12  a gear reduction gear  13  is placed and fixed onto platform chassis  3 , which transforms the limited pivoting angle and meshing distance on gear  11  into a higher speed and thereby generating additional meshing distance. This reduction gear  13  can be a planetary gear which builds very short and allows a realistic gear reduction and thereby the panel  2 , additionally to the deflection radius of pivoting arms  6   a,b  from for e.g. shifting mechanically from position A to position B and allows therefore a total shifting length of panel  2  away from transom  4  according T 2 . 
         [0023]      FIG. 3  Shows a schematic view of a drop down platform  1  with a cantilever arm  6  attached to a console  5 , whereby a pivoting arm, here shown by pivoting arm  6   a , a bended arm, which means showing a cranked pivoting element  6   c  and attached and hinged to the platform chassis  3 . The pivoting arm  6   b  connects via the pivot point Dp the console  5  and the platform chassis  3  and is set in motion and held also in position by cylinder  7 . By generating a pivoting motion on the cantilver arm  6  which generates a lift H 1  allowing the pivoting element  6   c  to pivot arcwise on the platform chassis. At the end of positioned a guide pin  14 , which slots into the guide nut  15  which is attached on panel  2  and according to the arc movement of pivoting element  6   c  creating the deflection radius and offsets the height difference in the guide nut  15  and shifts mechanically the panel  2  parallel and linear to the platform chassis  3  onto the shifting mean  10 . The total shifting distance of the panel  2  away from transom  4  is in this case T 3 . 
         [0024]      FIG. 4  Shows a schematic view of a drop down platform  1  with a cantilever arms  6  attached to a console  5  on which a control lever  16  is attached and which fixed to panel  2 . By pivoting the cantilever arms  6 , activated by cylinder  7 , generates a lift H 1 , on which the control lever  16  generates a compensating function between pivoting arm  6   a  and the shiftable panel  2 , whereby in this case during lifting operation H 1  a nonlinear shifting away from transom  4  of the platform  1  is desired but that the platform  1  stays as close as possible to transom  4  so that the gap between transom  4  and the platform  1  is kept as small as possible while lowering or lifting the platform  1 . By adequately placing the control lever  16  to the cantilever arms  6 , a possible larger or smaller linear shifting distance of the panel  2  is generated and may cause a positive shifting i.e. away from transom  4 , or a negative shifting i.e. toward the transom  4 . Shown is a minimal positive shifting T 4 . 
         [0025]      FIG. 5  Shows a schematic view of a drop down platform  1  with a cantilever arms  6  attached to console  5 , whereby the pivoting arm  6   b  generates an angle with a cranked pivoting element  6   d  and is fixed and hinged to the platform chassis  3 . The pivoting arm  6   b  is hinged to console  5  and keeps platform chassis  3  in position by means of cylinder  7 . By pivoting the cantilever  6 , a lift H 1  is generated, which sets the pivoting element  6   c  arcwise into motion on platform chassis  3 . This effect is used, in that at the end of the pivoting element  6   d  the panel  2  is attached and hinged onto it and parallel to it, operates an additional pivoting lever  17 , hinged and fixed onto platform chassis  3  and panel  2 , so that when pivoting the cantilever arms  6  besides the lift H 1 , the pivoting element  6   d , allows at the same time the panel  2  to pivot away from the transom  4  in a arclike manner, shown by way the arc arrow S. The total distance T 5  of panel  2  away from transom  4  comprises of a deflection radius L of the cantilever arms  6  and arclike shaped and lengthwise shifting S of the panel  2 . The advantage of this construction is that no shifting parts have to be exposed to sea water and therefore pivoting elements can be sealed much easier with O-rings. 
         [0026]      FIG. 6  Shows a schematic view of a drop down platform  1  with a cantilever arms  6  attached to console  5 . One of the pivoting arms, shown here as pivoting arm  6   a , has a cranked pivoting element  6   e  and is attached and hinged to platform chassis  3 , as well as being connected to cylinder panel  18 , in addition to which an pivoting lever  17   a  is attached and hinged to platform chassis  3  so as to ensure that the platform  1  remains horizontal when pivoting the pivoting arms  6   a , 6   b . By pivoting arm  6   a  of the attached cylinder  7 , the platform  1  will generate a lift H, resulting in that the cantilever arms  6  creating a lift H 1 , when pivoting the pivoting arm  6   a  with pivoting element  6   e  a pivoting movement on the pivoting element  6   e  is generated, which according to the length of pivoting element  6   e  creates an additional lift and thereby platform  1  reaches a total lift H 2 . 
         [0027]    In this manner it is possible to reach an additional coercion controlled lift with a given cylinder length or pivoting arm length, whereby an such additional stroke may be achieved by introducing a gear combination or steering bar implementation. 
         [0028]      FIG. 7  A schematic side view of a drop down platform  1  consisting of a panel  2  and a platform chassis  3  carried by a set of cantilever pivot arms attached and hinged to a console  5  and all of it attached to the transom  4  of a watercraft. The steering bar  9  triggers while pivoting the platform  1  by the cylinder  7  the shifting stroke from A to B between the panel  2  and the platform chassis  3 . In an energy storage  19  e.g. a gas spring, the gas will be compressed and stored. In case of a hydraulic or electric failure, the gas in the energy storage  19  can expand again and lifts by crossing the panel  2  over the platform chassis  3  the platform  1  up to the upper limit, which means to position A. This function may be used for the other horizontal shifting means as well.
       Another way to store energy is to do it directly at the cylinder  7 , by means in case the cylinder rod is pushed out for lifting lift H 1 , the fluid, most of the time oil, the oil in the counterchamber will not flow into the tank  22 , but into an accumulator  20 . The accumulator  20  is set in such a way, that it can at least lift the weight of the platform  1  to the position A and the power is higher than the weight of the platform  1 . The accumulator  20  can be used in a stand by position by means of a valve  21  locking the exit of the accumulator  20 , thus the fluid is transported as usual into the tank  22  and only in case of emergency, the valve  21  will be opened, at the same time the line to the tank  22  is blocked to have the requested pressure and oil volume in the cylinder  7  to lift the platform  1 .         
         [0030]    Of course the invention is not only applicable on shown and described examples 
       DRAWING LIST 
       [0000]    
       
           1  Platform 
           2  Panel 
           3  Platform chassis 
           4  Transom 
           5  Console 
           6  Cantilever arms 
           6   a , 6   b  Pivoting arm 
           6   c , 6   d , 6   d , 6   e  Pivoting element 
           7  Cylinder 
           8  Technical mean 
           9  Steering bar 
           10  shifting mean 
           11  Gear 
           12  Gear rack 
           13  Reduction gear 
           14  Guide pin 
           15  Guide nut 
           16  Control lever 
           17  Pivoting lever 
           18  Cylinder panel 
           19  Energy storage 
           20  Accumulator 
           21  Valve 
           22  Tank 
         H 1 , 2  Lift 
         Dp Pivot point 
         S Arc 
         T  1 - 5  Total horizontal shifting