Patent Publication Number: US-9415252-B2

Title: Rotor with variable hydrodynamic resistance for a stationary water bicycle and related bicycle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
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     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
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     INCORPORATION-BY- REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC OR AS A TEXT FILE VIA THE OFFICE ELECTRONIC FILING SYSTEM (EFS-WEB) 
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     STRATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINT INVENTOR 
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     BACKGROUND OF THE INVENTION 
     1) Field of the Invention 
     The present invention refers to a rotor with variable hydrodynamic resistance for a stationary water bicycle and to a related bicycle. 
     2) Description of Related Art 
     Stationary water bicycles, called stationary “hydrobikes”, are known to be used for carrying out fitness activities, rehabilitation, developing and toning of muscles in the legs and in the waist, athletic training and weight loss activities. 
     Stationary water bicycles comprise a frame and a pair of pedals to which means are generally connected for increasing the peddling resistance and thus the intensity of the physical activity. 
     A different type of hydrobike comprises a bladed rotor, fixedly connected centrally to the frame and connected to the pedals. The intensity can be set by manually adjusting the opening of the blades and the related resistance according to a plurality of preset positions. 
     U.S. Pat. No. 5,690,588 shows, for example, a device of this type in which the flat blades can be manually oriented according to a preset number of angular positions with respect to the axle of the rotor. A button loaded by a helical spring ensures that the preset angular position is held until it is pressed to carry out a new adjustment. 
     BRIEF SUMMARY OF THE INVENTION 
     The purpose of the present invention is that of making a rotor with variable hydrodynamic resistance for a stationary water bicycle and a relative bicycle that solve the drawbacks described. 
     Another purpose of the present invention is that of making a rotor with variable hydrodynamic resistance for a stationary water bicycle and a related bicycle in which the hydrodynamic resistance can vary while carrying out the exercise according to controlled parameters. 
     Another purpose of the present invention is that of making a rotor with variable hydrodynamic resistance for a stationary water bicycle and a related bicycle which is particularly simple and functional, with low costs. 
     These purposes according to the present invention are achieved by making a rotor with variable hydrodynamic resistance for a stationary water bicycle comprising a central body ( 12 ) provided on its perimeter with a plurality of blades ( 13 ), characterized in that said blades ( 13 ) are of the a marine type, comprising an inlet edge)( 13 ′), an outlet edge ( 13 ″)and a convex helical surface, said rotor being provided on opposite outer faces with axles ( 14 ) for pedals ( 15 ) , wherein each blade ( 13 ), at said outlet edge ( 13 ″), is connected to said rotor ( 10 ) with elastic fixing means ( 20 ) adapted to allow the automatic orientation of the blade ( 13 ) as a function of the rotation speed imparted to the rotor ( 10 ) through the pedals ( 15 ), wherein said central body ( 12 ) houses means for adjusting the maximum possible opening ( 30 ) of the blades comprising a mechanical end stop element ( 31 ) movable for Modifying the maximum possible opening of each blade ( 13 ), said means for adjusting the maximum possible opening ( 30 ) being able to be actuated by control means ( 40 ) connected at one end to said means for adjusting the maximum possible opening ( 30 ). 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The characteristics and the advantages of a rotor with variable hydrodynamic resistance for a stationary water bicycle and of a related bicycle according to the present invention shall become clearer from the following description, given as an example and not for limiting purposes, with reference to the attached schematic drawings, in which: 
         FIGS. 1 and 2  are perspective views of opposite sides of a rotor for a stationary water bicycle; 
         FIG. 3  is an exploded perspective view of a blade and of the elastic fixing means according to a first embodiment; 
         FIG. 4  is a partial exploded view of the rotor of  FIG. 1 , which shows the means for adjusting the maximum possible opening of the blades according to a first embodiment; 
         FIG. 5  is an exploded view of an example embodiment of the control means of the maximum possible opening of the blades, coupled with the means for adjusting the maximum possible opening of the blades of  FIG. 4 ; 
         FIGS. 6A, 6B and 6C  show, by means of a single blade, three different possible positions of the maximum possible opening of the blades; 
         FIG. 7  is a perspective view of a stationary water bicycle carrying the rotor with variable hydrodynamic resistance according to the invention; 
         FIGS. 8 and 9  show enlarged details, in an exploded view, of two different embodiments of centralized adjustment means of the load of the springs for a rotor according to the invention; 
         FIGS. 10 and 11  respectively show the rotor according to the invention equipped with the centralized adjustment means of the load of the springs of  FIGS. 8 and 9 ; 
         FIG. 12  shows an enlarged detail, in an exploded view, of a second embodiment of the means for adjusting the maximum possible opening of the blades, shown in the rotor of  FIG. 11 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the figures, a rotor is shown with variable hydrodynamic resistance for a stationary water bicycle, wholly indicated with reference numeral  10  and a related stationary water bicycle, indicated with reference numeral  100 . 
     According to the invention, the hydrodynamic resistance can vary progressively based upon the rotation speed imparted to the rotor due to the peddling, between a fixed minimum resistance value and a maximum resistance value that can be predetermined before starting or while doing exercise and not necessarily reached during it. 
     The rotor  10 , that constitutes a rotating mass, comprises a central body  12  on the perimeter of which a plurality of blades  13  are applied equally spaced apart from one another. The central body  12 , from which axles  14  of the pedals  15  extend outside on opposite faces, houses means for adjusting the maximum possible opening of the blades  13  ( FIGS. 1 and 2 ). 
     In the non limiting example shown, the rotor  10  can be hexagonal, round or circular, as shown, as well as having any other shape, and it is provided with six blades  13 . According to the invention, the number of blades can also be different and, in any case, at least two. 
     Each blade  13  is of the marine type, in other words it has a helical shape with an inlet edge  13 ′ and an outlet edge  13 ″ and a convex surface. 
     Each blade  13  is connected to the rotor through elastic fixing means  20 , which allow it to be automatically oriented, as a function of the rotation speed and thrust imparted to the rotor  10  by the legs of the person peddling, so as to increase or decrease the screwing pitch in the fluid in which it is dipped, and thus the resistance to force. 
     This makes it possible to vary, during the programmed operation, continuously and automatically, the smaller or greater opening of the blades  13  and thus the hydrodynamic resistance, based upon the greater or lower speed set for peddling. 
     The stiffness factor of the elastic fixing means  20  determines the ratio between the peddling speed and the opening of the blade. 
     On the extension of the outlet edge  13 ″ of the propeller there is a rotation pin  21  constrained to the blade  13  and coupled with the central body  12  of the rotor  10  through elastic means  22  which in part oppose its rotation ( FIG. 3 ). 
     According to what has been shown in  FIG. 1 , in which the rotor  10  must rotate in a clockwise direction as schematized with the arrow R to introduce the inlet edge  13 ′ of the blades  13  first into the water. As the rotation speed increases, the blades  13  progressively widen as indicated by the arrows F. 
       FIG. 2  shows the same rotor  10  of  FIG. 1  from the opposite side. 
     The rotation pin  21  of the blades  13  placed on the extension of the outlet edge  13 ″ of the blades ensures, thanks to their helical shape, the conveying of the fluid, and in this specific case water, which creates a current that starts at the centre of the propeller and radiates towards the outer perimeter determining a water current that licks legs and waist. Advantageously, while peddling, a toning massage of the muscles is obtained without jeopardizing the stability of the bicycle. 
     Indeed, if the rotation pin  21  of the blades  13  were placed on the extension of the inlet edge  13 ′ of the water, the hydrodynamic resistance of the rotor  10  would be nullified and consequently there wouldn&#39;t be any water movement. 
     The elastic means, in the examples, consist of a strip spring  22 , the tension of which can be adjusted manually so as to increase or decrease the force opposing the rotation of the blades  13  and thus reaching of a resistance position which is more or less high. By “strip springs” we mean any type of spiral spring with any height, comprising both a metallic band and a wire, equivalent to one another and which can be interchanged with one another for the purposes of the invention. 
     According to a first preferred embodiment shown, the rotation pin  21  is inserted and is free to rotate in a removable support  23 , which can be connected to the central body  12  of the rotor  10 , and in an adjuster bushing  24  of the strip spring  22 . The strip spring  22  comprises a first end engaged with the pin  21  and a second end engaged with the bushing  24 , in which it is contained. 
     A worm screw  25  is engaged with the outer surface of the adjuster bushing  24  of the strip spring  22 . 
     The adjustment of the load of the spring  22  can be carried out by adjusting the worm screw  25  from outside the rotor  10 , with a special wrench that is not shown, said screw then being locked through a locking screw  26  singularly for each blade when the rotor is not moving. 
     According to further embodiments of the rotor according to the invention, shown in  FIGS. 8-12 , centralized adjustment means  50  of the load of the springs  22  are foreseen, which make it possible to vary the load of all the springs simultaneously and also while the rotor is moving. 
     The centralized adjustment means  50  of the load of the springs  22  comprise an outer dome  51  fixed to one of the two support plates  16 , which support the rotor  10  on opposite sides, and equipped with helical grooves  52 , in which drive screws  53  are engaged extending out from the outer surface of a thrust ring  54  that is set in rotation by control means  60  and guided in translation by the helical grooves  52 . 
     The thrust ring  54  is coupled in abutment with an annular slider  55 , on the circumference of which a plurality of connection elements with a bushing  24  are fixedly connected, in an equal number to the bushings  24  themselves. 
     In the first embodiment of  FIG. 8 , the connection elements are made up of a plurality of threaded adjuster pins  56  fixedly connected, for example with screws, to a flat annular surface of the annular slider  55 , oriented towards the body of the rotor  12 , and each engaged with the outer surface of the bushing  24  of the elastic fixing means  20  of the blades  13 . 
     The annular slider  55  comprises, on the inner surface of the hole, at least one key  58  for engaging in at least one matching seat  17  of the central body of the rotor  12  that guides the axial sliding of the annular slider  55  with respect to the central body  12  of the rotor  10 , as shown in the exploded view of  FIG. 10 . 
     The connection between the thrust ring  54 , which stays still during operation, unless it is set in rotation by the control means  60 , and the annular slider  55 , which rotates as a unit with the central body of the rotor  12 , unless it is also moved in translation by the control means  60 , is obtained with a ball crown  37  and with a relative ring  38  that identifies a seat for the balls  37  which is held in position by a clip ring. 
     Thanks to this, the system can operate even when the rotor  10  is moving, in other words, carrying out the adjustment while continuing to peddle. 
     The control means  60  of the centralized adjustment means  50  of the load of the springs  22  comprise, according to the preferred embodiment of the invention, a manoeuvring lever  61  applied to the frame  11  of the stationary water bicycle  100 , in a position which is practical for the user. The manoeuvring lever  61  can be pivoted in a box, not shown, and can be rotated continuously or in a preset number of positions. 
     Therefore, by rotating the thrust ring  54  with respect to the outer dome  51 , fixed to one of the support plates  16 , an axial movement of said thrust ring  54 , of the annular slider  55  and of all that is connected to it, is obtained. 
     All the threaded adjuster pins  56  are simultaneously brought into engagement with the relative adjuster bushings  24 , varying the angular position to determine a variation of the load of the springs  22 . 
     In the second embodiment of  FIG. 9 , the connection elements are, on the other hand, made up of a plurality of adjuster levers hinged on the outer shell of an annular slider  55 ′, for each engaging with a bushing  24  of the elastic fixing means  20  of the blades  13 . 
     The enlarged detail of  FIG. 9  shows the adjuster lever  57  pivoted outside an adjuster bushing  24 ′ that houses a strip spring  22  made up of a wire. 
     The axial translation of the annular slider  55 ′ on the central body  12  of the rotor  10  shown in the exploded view of  FIG. 11 , is controlled in a completely analogous way as that described for the first embodiment through the keys  58 . 
     Moreover, in all the described embodiments, at the end of the rotation pin  21  that extends with respect to the bushing  24  an abutment cross beam  27  is applied. 
     The purpose of the spring  22  is that of holding the cross beam  27 —in its rest position—in contact with an initial position adjuster screw  28 , which is screwed and locked onto the central body  12  of the rotor  10  in a direction perpendicular to the rotation axis of the pin  21 , and can be accessed from outside of it ( FIG. 1 ). The initial position of minimum opening of each blade  13  is thus determined. 
     The adjustment of the initial position adjuster screw  28  and of the load of the spring  22  are preset by the manufacturer, so therefore the user should not have to intervene, other than through personnel specialized in equipment maintenance. 
     Through the adjustment of the strip springs  22  it is possible to automatically program even a fast pace peddling with a minimum or preset opening of the blades so as to control the effort in overcoming the resistance of the water without necessarily making it conditional upon the complete opening of the blades. 
     The field of rotation of the blades  13 , which in the example shown is of about 60°, is determined by the means for adjusting the maximum possible opening  30 , shown in  FIG. 4 , that set an end stop which can be modified by the user, even during operation. 
     During operation, the blades  13  are progressively arranged in positions, based upon the speed of the peddling, ranging between a fixed initial position of “minimum possible opening” and a position of “maximum possible opening” which can be controlled manually before or during operation. 
     It is thus possible that during operation, at the peak of resistance encountered, the blades  13  do not reach the end stop of maximum possible opening. 
     It is thus necessary to make a distinction between the “position of maximum possible opening”, that represents the one which can be achieved in theory and defined by the adjustment means  30 , and the “position of maximum resistance”, which represents the actual position reached by the blade during operation due to the elastic fixing means  20 . 
     According to the preferred embodiment shown, the field of rotation of the blades  13  is determined by the distance between the initial position adjuster screw  28  and a movable end stop flange  31 , that constitutes a mechanical end stop element to limit the rotation of the cross beam  27  and therefore of the blade  13  itself. 
     The movable end stop flange  31  comprises a plurality of abutment pins  32 , one for each blade  13 , the ends of which are situated opposite with respect to the respective initial position adjuster screws  28 . This configuration makes it possible to simultaneously adjust the same end stop for all the blades of the rotor. 
       FIGS. 6A, 6B and 6C  show, as an example on a single blade, three different positions of the movable end stop flange  31 . They are respectively, a first position in which the blades  13  are fixed, in other words, the position of maximum possible opening coincides with the minimum opening position and corresponds to an angle of incidence in the water of about 30°; an example intermediate position; as well as a final position in which the blades  13  are left free to reach a position of maximum possible opening equal to an angle of incidence in the water of 90°. 
     According to the invention, any number of intermediate positions between the minimum and maximum opening of the blades  13  can be foreseen, just as different angles of the blades  13  in the minimum and maximum opening positions can also be foreseen. 
     The movable end stop flange  31  is able to translate towards and away from the initial position adjuster screw  28  by means of a cam mechanism, which according to a first embodiment, shown in  FIG. 4 , comprises an oscillating and translating slider  33  axially coupled to the flange  31 , at one end, and at a bushing  34  on which it can rotate and slide, at the opposite end, as shown in  FIG. 4 . 
     The bushing  34  is indeed provided with a helical groove  35 , in which a drive screw  36  is engaged that is locked on the slider  33  by a lock nut. 
     The connection between the flange  31 , which rotates during operation, and the oscillating slider  33 , which stays still, unless it is controlled to roto-translate for the adjustment, is obtained with two ball crowns  37  and with a relative ring  38  that identifies a seat for the balls  37  which is held in position by a clip ring. 
     Thanks to this, the system can also work with the rotor  10  moving, in other words, carrying out the adjustment while continuing to peddle. 
     The rotor  10  also comprises control means of the maximum possible opening  40 , which can be set at the user&#39;s or instructor&#39;s discretion depending on the programmed exercise, for example light training, toning with variable intensity, rehabilitation with maximum intensity, or other. 
     The control means of the maximum possible opening  40  comprise, according to the preferred embodiment of the invention, a manoeuvring lever  41  applied on a frame  11  of the stationary water bicycle  100 . 
     In practice this system gives the user the opportunity to vary the greater or smaller automatic opening of the blades in a continuous or differentiated manner as a function of the programmed workout. 
     In the example shown in  FIG. 5 , the manoeuvring lever  41  is pivoted in a box  42 , and can be rotated by about 90° continuously or in a preset number of positions. 
     Indeed, if the adjustment of the manoeuvring lever  41 , which corresponds to a variation of the end stop of the blades  13 , occurs continuously, it is possible to set any end stop value. Otherwise, if it occurs according to preset positions, even very close to one another, the end stop of the blades will move by discrete values. 
     The manoeuvring lever  41  is connected to a ball joint  43  of the oscillating slider  33  for example by means of rigid or flexible connection elements  44 . 
     The connection elements  44  can be rigid tie rods and levers, suitably fixedly connected to the frame  11  of the bicycle  100 , as well as other known systems, like for example, flexible wires contained by sheaths, as schematically shown in  FIG. 7 . 
     The control box  42  is mounted on the frame  11  of the bicycle  100  in a position such that it is as easy as possible to reach and manoeuvre. 
     For the different positions of the control lever  41  there are just as many corresponding angular positions of the oscillating slider  33  and axial sliding positions of the movable flange  31  and thus just as many levels of maximum opening of the blades. 
     According to a further embodiment of the means for adjusting the maximum possible opening  30  of the blades, shown in the enlarged detail of  FIG. 12  and in the exploded views of  FIGS. 10 and 11 , the movable end stop flange  31 , which carries an abutment pin  32  for each blade  13 , is able to translate towards and away from the initial position adjuster screw  28  by means of a cam mechanism that comprises a translating slider  33 ′ coupled through a key  134  with a fixed bushing  34 ′ with respect to one of the support plates  16 , as well as an oscillating flange  39  directly set in rotation by the control means  40 , which determines the axial movement of the translating slider  33 ′. 
     The oscillating flange  39  is indeed provided with a helical groove  35 ′, in which a drive screw  36  is engaged locked on the translating slider  33 ′. 
     Even according to this embodiment, the connection between the flange  31  and the translating slider  33 ′ is obtained with at least one ball crown  37  and a relative ring  38 , held in position by a clip ring. Thanks to this, the system can also operate while the rotor  10  is moving, in other words, carrying out the adjustment while continuing to peddle. 
     The control means of the maximum possible opening  40 , comprise the manoeuvring lever  41 , which can be rotated continuously or in a preset number of positions, rigid or flexible connection elements  44 , corresponding to those described above and ending with a cylindrical pin  45 , arranged with the axis parallel to the axle of the rotor  10  connected to the oscillating flange  39  to set it in rotation. 
     In this last embodiment, the separation of the oscillating movements and of the axial translation in two distinct elements, in other words, the oscillating flange  39  and the translating slider  33 ′, simplifies the mechanical coupling between parts. In particular, it is possible to replace the ball joint  43 , which transmits the rotary motion to the oscillating slider  33  of  FIGS. 4 and 10  and the axial motion follows, with the simple cylindrical pin  45 , axially fixed and coupled with a hole  139  of the oscillating flange  39 , the relative rotation between the cylindrical pin  45  and the hole  139  being free. 
       FIG. 7  shows, as an example, the stationary water bicycle  100 , according to the invention, comprising the frame  11  on which the rotor  10  is applied, and to which the peddles  15  are connected. 
     The rotor  10 , only schematically shown in  FIG. 7  in a dashed and dotted line, is positioned on the frame  11  in a central position with the inlet edge  13 ′ of the blades  13  frontally directed. The rotor  10  is possibly protected by an open casing, but it is preferably supported simply by two support plates  16 , constrained to the frame  11 , the function of which is also that of giving the structure stability. 
     The control means of the maximum possible opening  40  of the blades, connected to the adjustment means  30 , are fixedly connected to the frame  11  so that the control lever  41  is in a position which is easy for the user to reach. 
     In a completely analogous manner, also the control means  60  of the centralized adjustment means of the load of the springs  50  are applied onto the frame  11  in a practical position for the action of a user. 
     The control means  40  and  60  can also undergo simultaneous activation since the relative adjustment means  30 ,  50  are arranged concentric and do not obstruct each other. 
     The rotor with variable hydrodynamic resistance for a stationary water bicycle and the related stationary water bicycle object of the present invention have the advantage of not foreseeing any manual adjustment of the opening of the blades which is automatic and can vary as a function of the peddling. 
     Advantageously, in the field of the same programmed activity both of water fitness and rehabilitation, or other, the blades never have the same opening since they are always moving (partial opening, gradual opening, total opening, etc. . . . ). The greater opening or closure thereof will depend upon the greater or lesser power imparted by the peddling of the end user. 
     A further advantage consists in the fact that the adjustment can be carried out without interrupting the peddling. 
     A further advantage of the centralized control of the load of all the spiral springs consists of the simplicity and rapidity of the adjustment, as well as of the reduction of possible calibration mistakes between one spring and the other. 
     The control means of the centralized adjustment means of the load of the springs can also advantageously be adjusted with the rotor in movement even simultaneously with the control means of the adjustment of the maximum adjustment opening of the blades. 
     Moreover, the rotor with variable hydrodynamic resistance for a stationary water bicycle, according to the invention, advantageously creates a water current that licks the surface of the legs amplifying the therapeutic benefits. 
     The rotor with variable hydrodynamic resistance for a stationary water bicycle and the relative bicycle thus conceived may undergo numerous modifications and variants, all covered by the invention; moreover, all the details can be replaced by technically equivalent elements. In practice the materials used, as well as the sizes, can be any according to the technical requirements.