Abstract:
A dynamic system for making use of an exercise bicycle supported on front and rear struts, the system permitting the bicycle to sway side to side when ridden vigorously, the system including a first and a second housing for resting on a support surface, a platform retained by each housing, the platform of the first housing serving to receive thereon the bicycle front strut and the platform of the second housing serving to receive thereon the bicycle rear strut, each platform being pivotal end to end and at least one deflectable resilient member engaging each platform and functioning to normally retain the exercise bicycle uprightly.

Description:
REFERENCE TO PENDING APPLICATIONS 
     This application is not based upon any pending domestic or international patent applications. 
     FIELD OF THE INVENTION 
     This invention relates to dynamic bases for supporting the front and rear struts of an exercise bicycle that permit the exercise bicycle to sway from side to side when ridden vigorously to thereby replicate the feel of a regular bicycle when vigorously ridden on the open road. 
     BACKGROUND OF THE INVENTION 
     Stationary exercise bicycles have been available for many years and offer a good alternative to bicycling outdoors. The standard stationary bicycle is arranged to support a bicycle in an upright position and typically includes front and rear end struts. The struts are configured to engage a support surface such as a floor, deck or concrete surface. Most stationary bicycles include a wheel, which may be in front of or behind the rider, that spins as the rider pedals. Further, most bicycles have facilities for varying the intensity of resistance applied to the wheel so that the amount of energy required to pedal the bicycle can be varied. 
     Most riders of a bicycle outdoors experience varying terrain including uphill and downhill situations. For this reason nearly all bicycle riders tend to stand with their weight supported on the pedals at least part of the time. Cyclists rise out of the saddle for several reasons including to stretch their legs, relieve discomfort of the buttocks, to change the emphasis on muscles and, most importantly, to provide power for acceleration or for hill climbing. When a cyclists stands on their feet, he or she can shift the body weight from one side to the other to apply greater force to rotation of the pedals. 
     It is estimated by some that professional bicycle riders may ride out of the saddle in the standing position, as much as 30 to 40% of the time over the course of a race. While most recreational bicyclists do not ride out of the saddle this much, nevertheless nearly all bicycle riders spend at least part of the time in the standing position. When in the standing position, a bicyclists tends to sway the bicycle back and forth as he or she pedals so that as force is applied by one leg to push the pedal downwardly the leg is extending substantially straight with the biker&#39;s weight over the straight leg and as the biker&#39;s weight is shifted as force is applied by the other leg. By swaying the bicycle back and forth less stress is placed on the bikers skeletal components and the muscles operate more effectively and efficiently. Most exercise or stationary bicycles in use today do not provide for replicating the swaying action that is encountered in riding a bicycle in the normal way. This lack of a swaying action that is characteristic of the typical stationary bicycle imposes additional stress on the legs of the user and does not afford opportunity for varying the combination of muscles employed while riding a bicycle in the normal way. 
     For these reasons, the invention herein provides a dynamic system for a stationary bicycle that permits the bicycle to sway from side to side when ridden vigorously by a rider while at the same time supporting the bicycle in the usual upright position when ridden less vigorously. 
     For background information relating to exercise type of bicycles, reference may be had to the following previously issued United States patents. 
     
       
         
               
               
               
             
           
               
                   
               
               
                 U.S. Pat. No. 
                 Inventor 
                 Title 
               
               
                   
               
             
             
               
                 US 2004/0053751 
                 Pizolato 
                 Bicycle Trainer Allowing Lateral Rocking 
               
               
                   
                   
                 Motion 
               
               
                 3,762,703 
                 Gibbs 
                 Exercising Apparatus 
               
               
                 4,925,183 
                 Kim 
                 Indoor-Rollbike Apparatus 
               
               
                 4,958,832 
                 Kim 
                 Stationary Exercising Bicycle Apparatus 
               
               
                 5,492,516 
                 Trotter 
                 Exercise Apparatus For Use With Bicycles 
               
               
                 5,662,559 
                 Vasquez 
                 Bicycle Side-Suspension System 
               
               
                 5,685,806 
                 Yu 
                 Magnetic Damping Device Of An 
               
               
                   
                   
                 Exercise Apparatus 
               
               
                 6,056,672 
                 Carbonell 
                 Training Apparatus For Cyclist and For 
               
               
                   
                 Tendero 
                 Physical Exercise 
               
               
                 6,126,577 
                 Chang 
                 Exercise Stationary Bicycle 
               
               
                 6,322,480 
                 Lim et al. 
                 Indoor Bicycles For Physical Exercise 
               
               
                   
               
             
          
         
       
     
     BRIEF SUMMARY OF THE INVENTION 
     The invention herein relates to improvements in stationary exercise bicycles. While there are a large number of exercise bicycles in existence today, they universally are built to include front and rear support struts that rest on a support surface, such as the floor of a building, or a garage or patio surface. Thus the standard exercise bicycle remains rigidly upward regardless of how vigorously it is ridden by the user. This invention provides an inexpensive and easy to use way of improving the exercise experience of a typical user. 
     The dynamic system of this invention is adapted for use with an exercise bicycle having front and rear support struts. The system permits the bicycle to sway side to side when ridden vigorously. 
     The dynamic system of this invention consists of a first and second housing for resting on the support surface. A platform is retained by each housing. The platform of the first housing serves to receive thereon an exercise bicycle front strut and the platform of the second housing serves to receive thereon the exercise bicycle rear strut. Each platform is pivotal end to end. 
     At least one deflectable resilient member engages each platform and functions to normally retain the exercise bicycle uprightly. However, each platform tilts in response to action applied by a rider to the bicycle as the bicycle is ridden vigorously. 
     In this way, the rider experiences the normal attitude of a bicycle when ridden vigorously as well as when ridden leisurely. 
     A better understanding of the invention will be obtained from the following detailed description of the preferred embodiments and the claims taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention will now be described in further detail. Other features, aspects, and advantages of the present invention will become better understood with regard to the following detailed description, appended claims, and accompanying drawings (which are not to scale) where: 
         FIG. 1  is a front elevational view of a biker on a touring bicycle on the open road, his right leg extended. 
         FIG. 2  is a front elevational view of a biker on a touring bicycle on the open road, his left leg extended. 
         FIG. 3  is a perspective view illustrating a typical exercise bicycle secured atop a pair of dynamic bases of the current invention. 
         FIG. 4  is a top plan view of a first embodiment of the current invention. 
         FIG. 5  is a sectional elevational view taken along cutting plane  5 - 5  of  FIG. 4 . 
         FIG. 6  is a sectional elevational view showing a different position from  FIG. 5 . 
         FIG. 7  is a sectional elevational view showing yet another different position from  FIG. 5 . 
         FIG. 8  is a top plan view of a second embodiment of the current invention. 
         FIG. 9  is a sectional elevational view taken along cutting plane  9 - 9  of  FIG. 8 . 
         FIG. 10  is a sectional elevational view showing a different position from  FIG. 9 . 
         FIG. 11  is a sectional elevational view showing yet another different position from  FIG. 9 . 
         FIG. 12  is a sectional elevational view of a third embodiment of the current invention. 
         FIG. 13  is a sectional elevational view showing a different position from  FIG. 12 . 
         FIG. 14  is a sectional elevational view showing yet another different position from  FIG. 12 . 
         FIG. 15  is a sectional elevational view of a fourth embodiment of the current invention. 
         FIG. 16  is a sectional elevational view showing a different position from  FIG. 15 . 
         FIG. 17  is a sectional elevational view showing yet another different position from  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     It is to be understood that the invention that is now to be described is not limited in its application to the details of the construction and arrangement of the parts illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or carried out in a variety of ways. The phraseology and terminology employed herein are for purposes of description and not limitation. 
     Elements shown by the drawings are identified by the following numbers: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                  10 
                 Biker riding a bicycle 
               
               
                   
                  12R 
                 Right leg 
               
               
                   
                  12L 
                 Left leg 
               
               
                   
                  14 
                 Downward force 
               
               
                   
                  16R 
                 Right pedal 
               
               
                   
                  16L 
                 Left pedal 
               
               
                   
                  17 
                 Bicycle tire 
               
               
                   
                  18 
                 Bicycle 
               
               
                   
                  19 
                 Road 
               
               
                   
                  20 
                 Biker 
               
               
                   
                  22 
                 Vertical centerline 
               
               
                   
                  24 
                 Biker&#39;s ankle 
               
               
                   
                  26 
                 Biker&#39;s knee 
               
               
                   
                  28 
                 Biker&#39;s quadricep muscle 
               
               
                   
                  30 
                 Biker&#39;s hip joint 
               
               
                   
                  38 
                 Exercise bicycle 
               
               
                   
                  40 
                 Components 
               
               
                   
                  42 
                 Straps 
               
               
                   
                  44 
                 Platform 
               
               
                   
                  46 
                 Assemblies 
               
               
                   
                  48 
                 Front bicycle cross member 
               
               
                   
                  50 
                 Rear bicycle cross member 
               
               
                   
                  52A 
                 Collar 
               
               
                   
                  52B 
                 Collar 
               
               
                   
                  54 
                 Underneath side 
               
               
                   
                  56 
                 Tension spring 
               
               
                   
                  56A 
                 Spring coils 
               
               
                   
                  56B 
                 Spring center portion 
               
               
                   
                  56C 
                 Spring arms 
               
               
                   
                  58 
                 Tension spring 
               
               
                   
                  58A 
                 Spring coil 
               
               
                   
                  58B 
                 Spring center portion 
               
               
                   
                  58C 
                 Spring arms 
               
               
                   
                  60 
                 Tubular rod 
               
               
                   
                  62 
                 Housing 
               
               
                   
                  64A 
                 Bearing pad 
               
               
                   
                  64B 
                 Bearing pad 
               
               
                   
                  66 
                 Radiused groove 
               
               
                   
                  68R 
                 Resilient member 
               
               
                   
                  68L 
                 Resilient member 
               
               
                   
                  70A 
                 Post 
               
               
                   
                  70B 
                 Post 
               
               
                   
                  72A 
                 Extendable coiled spring 
               
               
                   
                  72B 
                 Extendable coiled spring 
               
               
                   
                  74A 
                 Compressed coiled spring 
               
               
                   
                  74B 
                 Compressed coiled spring 
               
               
                   
                  76A 
                 External spring guide 
               
               
                   
                  76B 
                 External spring guide 
               
               
                   
                  78A 
                 Internal spring guide 
               
               
                   
                  78B 
                 Internal spring guide 
               
               
                   
                  80 
                 Large diameter coiled spring 
               
               
                   
                  82 
                 Cylindrical disc 
               
               
                   
                  84 
                 Housing bottom 
               
               
                   
                  88 
                 Base 
               
               
                   
                  90A 
                 Conical volute spring 
               
               
                   
                  90B 
                 Conical volute spring 
               
               
                   
                  92A 
                 Pin 
               
               
                   
                  92B 
                 Pin 
               
               
                   
                  93A 
                 Cup 
               
               
                   
                  93B 
                 Cup 
               
               
                   
                  94 
                 Strap clip 
               
               
                   
                  96A 
                 Housing sidewalls 
               
               
                   
                  96B 
                 Housing sidewalls 
               
               
                   
                  98A 
                 Housing end wall 
               
               
                   
                  98B 
                 Housing end wall 
               
               
                   
                 100 
                 Pins 
               
               
                   
                 102 
                 openings 
               
               
                   
                 104 
                 Pillow block 
               
               
                   
                 106A 
                 First bellows 
               
               
                   
                 106B 
                 Second bellows 
               
               
                   
                 108A 
                 First tube 
               
               
                   
                 108B 
                 Second tube 
               
               
                   
                 110 
                 Valve 
               
               
                   
                   
               
             
          
         
       
     
       FIGS. 1 and 2  are each front elevational views of a biker  20  on a bicycle  18  as ridden on the open road, illustrating the swaying motion common to this endeavor, particularly during times when biker  20  is “standing up” on pedals  16 L and  16 R for increased exertion.  FIG. 1  shows the biker&#39;s right leg  12 R extended, applying downward force  14  to pedal  16 R. The lean of bicycle  18  is typically about 6° to the left of biker  20 . This allows the right leg  12 R to push downward in a vertical plane, the edge of which is indicated by a vertical centerline  22 . Note that the pedal  16 R and the biker&#39;s ankle  24 , knee  26 , quadricep muscle  28 , hamstring muscle set (not visible) and hip joint  30  are within this vertical plane, thus providing optimum leverage during the downward push of right leg  12 R. During straight-ahead travel the center of gravity of the system  10  (that is, the biker  20  plus bicycle  18 ) lies generally directly above the contact point between the bicycle tire  17  and the road  19 . An exception to this, of course, would be when biker  20  was negotiating a turn. 
       FIG. 2 , conversely, illustrates the geometry when the biker&#39;s left leg  12 L is extended, applying downward force  14  on pedal  16 L. The above description of  FIG. 1  may be applied to  FIG. 2  in a mirror-opposite fashion. 
       FIGS. 1 and 2  show, as background information, how a bicycle typically sways side to side when ridden vigorously by a biker. The invention herein, to now be described, provides a system, method and apparatus by which a typical stationary exercise bicycle can readily and inexpensively be adapted to replicate the normal feel of a bicycle when ridden vigorously. 
       FIG. 3  is a perspective view illustrating an embodiment of the invention whereby an existing stationary exercise bicycle  38  is secured atop two identical components  40  which, working in concert, allow stationary bicycle  38  to oscillate left and right with the body motion of a rider, not shown, thereby emulating the swaying experienced with a touring bicycle on the open road as illustrated in  FIGS. 1 and 2 . Straps  42  are shown as a method of securement of stationary bicycle cross-members  48  and  50 , but any well-known securing device, such as clamps or brackets, would suffice. Stops, not shown, can be provided to prevent bicycle  38  from sliding on the individual platforms  44 . A simple exercise bicycle  38  is illustrated, but it may be one of any degree of technology or design. 
     The invention herein is in components  40 , a pair of which can be used to quickly adapt a typical stationary exercise bicycle so that a user thereof experiences the natural oscillations of a normal bicycle being ridden vigorously on the open road. 
       FIGS. 4 ,  5 ,  6  and  7  depict a first embodiment of the current invention wherein the left-to-right oscillating motion is accomplished by means of two identical assemblies  46 , one under the lower front cross-member  48  and one under the lower rear cross member  50  of bicycle  38  as seen in  FIG. 3 . 
     Each of the two assemblies  46  of this embodiment comprises a rectangular platform  44  having two integral axially-aligned collars  52 A and  52 B affixed to the underneath side  54 . Two identical tension springs  56  and  58 , best seen in  FIG. 4 , are nested in opposing orientation and placed so that spring coils  56 A and  58 A align with the inside diameters of tubular collars  52 A and  52 B. Tubular rod  60  is inserted through collar  52 A, spring coils  56 A and  58 A, and collar  52 B, thereby securing springs  56  and  58  in place. Means (not shown) to secure rod  60  within collars  52 A and  52 B can include cotter pins, retaining rings, or simply a press fit, considering that rod  60  need not rotate. 
     Once springs  56  and  58  are held in place by rod  60  secured in collars  52 A and  52 B, the platform  44  of each assembly  46  is attached to a cross-member  48  or  50  of exercise bicycle  38  by means of straps  42  (best seen in  FIG. 3  but not seen in  FIGS. 4 ,  5 ,  6  and  7 ), or any well-known method such as brackets or clamps. Tension spring  56  includes spring coils  56 A, a spring center portion  56 B and spring arms  56 C. In like manner, tension spring  58  includes spring coils  58 A, a spring center portion  58 B and spring arms  58 C. 
     The assembly  46  is contained in a housing  62 . Tubular collars  52 A and  52 B rest in bearing pads  64 A and  64 B respectively (best seen in  FIG. 4 ), each of which has a radiused groove  66  in its top surface. The radius of groove  66  is half the outside diameter of tubular collars  52 A and  52 B, providing an arcuate mating surface. The material of bearing pads  64 A and  64 B may be a plastic having a low coefficient of friction, such as Teflon® or nylon, or one of the many self-lubricating molybdenum-impregnated fiberglasses or plastics. Bearing pads  64 A and  64 B are attached to the floor of housing  62  in any well-know manner, such as bonding or bolting. 
     The weight of exercise bicycle  38  is sufficient to flex the tension springs  56 A and  56 B and allow collars  52 A and  52 B to contact bearing pads  64 A and  64 B respectively. Identical resilient members  68 R and  68 L are also flexed by the weight of exercise bicycle  38  and provide further stability and additional recuperative forces outboard of springs  56  and  58 . 
       FIG. 4  is a top plan view of an assembly  46  of this embodiment. Platform  44  is indicated with phantom lines to better illustrate the mechanism below. 
       FIG. 5  is a front elevational cross section view taken along cutting plane  5 - 5  of  FIG. 4 . By way of orientation, a rider would be facing the viewer.  FIG. 5  illustrates the “at rest” or neutral position, or the position midway through the side-to-side oscillating motion. An existing exercise bicycle  38  is partially indicated by phantom lines. Tension spring  56  has a spring center portion  56 B bearing against the underneath side of platform  44  and spring arms  56 C bearing against the floor of housing  62 . Tension spring  58  is nested in opposing orientation from spring  56  and has a spring center  58 B bearing against the underneath side of platform  44  and arms  58 C bearing against the floor of housing  62 . Thusly arranged, identical tension springs  56  and  58  provide equal and opposite forces to platform  44  and therefore to the exercise bicycle  38 . Likewise, identical resilient members  68 R and  68 L, partially compressed, offer equal and opposite forces to the system. The resulting “at rest” position is one in which exercise bicycle  38  is vertical with respect to the horizontal. 
       FIG. 6  depicts the assembly of  FIG. 5  in a position caused by the downward thrust of the rider&#39;s right foot, that is, swaying to the right as would a touring or racing bike on the open road. Spring  56  is torqued tighter and spring  58  is relaxed somewhat, but still under some torque. Resilient member  68 R is further compressed and resilient member  68 L is relaxed somewhat, but still slightly compressed. The above described condition of spring  56  and resilient member  68 L is important for the smooth and quiet operation of the exercise bicycle while in vigorous use. 
       FIG. 7  depicts the alternate, or mirror-opposite position of that position shown in  FIG. 6 . Spring  58  is torqued tighter and resilient member  68 L is further compressed as a result of the downward thrust of a rider&#39;s left foot. Spring  56  is relaxed somewhat but still under some torque, and resilient member  68 R is relaxed somewhat but still slightly compressed. 
     As a seated rider pedals the exercise bicycle  38  the motion of platform  44  would be slight and gentle, not reaching the maximum positions shown in  FIGS. 6 and 7 . When the rider stands on the pedals and exercised more vigorously the oscillating motion would increase to approximately the positions shown in  FIGS. 6 and 7 . In both instances, seated and pedaling easy or standing and pedaling vigorously, the resulting motion would emulate that motion of a touring or racing bike on the open road, thereby providing a more natural and efficient regimen or training session. 
     An alternate embodiment of the invention is illustrated in  FIGS. 8 through 11 , each of which shows a housing  62  that supports a tiltable platform  44  that receives thereon an exercise bicycle  38  as described with reference to  FIGS. 3 through 7 . However, the new embodiment illustrates different spring arrangements. In  FIGS. 8 through 11  opposed posts  70 A and  70 B are secured to housing  62  beyond either end of the tiltable platform  44 . Affixed to upper ends of post  70 A is an extendable coiled spring  72 A while suspended from an upper end of post  70 B is an extendable coiled spring  72 B. The lower end of each of the coiled springs  72 A and  72 B is attached to an outer end portion of tiltable platform  44 . Platform  44  pivots about a tubular rod  60  that is rotatably supported by a bearing pad  64 A having a semi-circular recess therein. Springs  72 A and  72 B function to keep platform  44  normally in a horizontal position or, that is, in a position horizontal to the surface on which housing  62  is positioned.  FIGS. 8 and 9  show platform  44  in a normal or usual position in which it is horizontal and each of the springs  70 A and  70 B are subjected to the same tension.  FIG. 10  shows the situation in which bicycle  38  is being pedaled vigorously so that the rider moves the bicycle to the left, shifting the center of his body to the right, and thereby stretching extendable coiled spring  72 A, while reducing the extension of the opposed coiled spring  72 B.  FIG. 11  shows the opposite in which the rider of the bicycle  38  as shifted the bicycle to the right. 
     In addition, as with  FIGS. 4 through 7 , left and right resilient members  68 R and  68 L are employed to provide further resiliency of the tiltable position of platform  44 . 
     It is to be understood, as stated with reference to  FIGS. 4 through 7 , that it is not imperative that both means of establishing resiliency be employed. That is, in some embodiments of the invention the use of the resilient member  68 R and  68 L may not be required and the entire resilient positioning of tiltable platform  44  is controlled by springs  72 A and  72 B or, on the contrary, springs  72 A and  72 B may be eliminated and only the resilient members  68 R and  68 L are employed to maintain platform  44  normally in a horizontal position but to permit it to pivot in response to the shifting weight of the rider of exercise bicycle  38 . 
       FIGS. 12 ,  13  and  14  show an alternate embodiment of the invention. In this embodiment housing  62 , platform  44 , tubular rod  60  and a bearing pad  64 A are employed as in the embodiment of  FIGS. 10 and 11 . However, in  FIGS. 12 ,  13  and  14  the resilient force that is provided to maintain platform  44  essentially horizontal is different. In this embodiment, compressed coiled spring  74 A and  74 B are utilized. Compressed coiled spring  74 A and  74 B are positioned within housing  62  and engage the underneath side  54  of platform  44 . 
     External spring guides  76 A and  76 B are secured to the underneath side  54  of platform  44 . Spring guides  76 A and  76 B are short length tubular members of internal diameters greater than the external diameters of springs  74 A and  74 B and fit about the springs to ensure that they are retained in position. Short length internal spring guides  78 A and  78 B are secured to the interior surface of the bottom of housing  62 . These internal spring guides are in the form of short upstanding posts which may typically be cylindrical and of external diameter less than the internal diameter of springs  74 A and  74 B. Springs  74 A and  74 B remain under compressive tension at all times. That is, in  FIG. 13  which shows the platform  44  tilted to the right and therefore compressed external spring  74 A extended, nevertheless spring  74 A is still under slight compression. The compressive force exerted by springs  74 A and  74 B serve to balance each other and keep the platform  44  in a substantially horizontal pattern, as seen in  FIG. 12 , except when a rider leans exercise bicycle  38  to his left or right. 
       FIGS. 15 through 17  show another alternate embodiment which provides a different compressive arrangement for maintaining platform  44  normally in an essentially horizontal position except when a rider moves bicycle  38  to left or right in the process of vigorously riding. This embodiment employs a large diameter coiled spring  80  positioned centrally within housing  62  to engage the underneath side  54  of platform  44 . A cylindrical disc  82  is secured to the internal surface of the bottom portion of housing  62 . The cylindrical disc  82  is of external diameter less than the internal diameter of large diameter coiled spring  80  and serves to keep the large diameter coiled spring centrally positioned within housing  62  and central of platform  44 . 
     Platform  44  pivots on a tubular rod  60  as described with the previous embodiments. The tubular rod  60  rests in a bearing pad which is not seen in  FIGS. 15 through 17  but is similar and provides the same function as the bearing pad  64 A in  FIGS. 12 through 14 . The bearing pad can be made integral with cylindrical disc  82  or can be a separate element in which the cylindrical disc  82  has recesses to accommodate the bearing pad. 
     Resilient members  68 R and  68 L are positioned within the housing  62  and below platform  44  and function to assist in providing resilient forces to normally maintain platform  44  horizontally as described with reference to  FIGS. 4 through 9 . Essentially, the resilient member  68 R and  68 L take place of the coiled compressive springs  74 A and  74 B in the embodiment of  FIGS. 12 through 14 . 
       FIGS. 18 and 19  show another alternate embodiment of the invention. Whereas the previous embodiments have shown a housing that contains the dynamic system for an exercise bicycle, in  FIGS. 18 and 19  only a housing bottom  84  is shown, that is, in these figures the sidewall to the housing are not illustrated. While sidewalls are not indispensable nevertheless the use of a housing with sidewalls is preferred to prevent objects from lodging under platform  44  or to prevent a bystander&#39;s hands or toes getting under the oscillating platform. 
     As with the previous embodiments, in  FIGS. 18 and 19  platform  44  oscillates with respect to a tubular rod  60 . In this embodiment, tubular rod  60  is positioned on a larger base  88  which rests on the housing bottom  84 , the base  88  having a radiused groove  66  therein. 
     As compared with the embodiments of  FIGS. 12 through 14 , in  FIGS. 18 and 19  resiliency is applied to platform  44  by conical volute type springs  90 A and  90 B that have a range in motion somewhat greater than the constant diameter of the springs shown in the embodiment of  FIGS. 12 through 14 . 
     The largest diameter or lower ends of springs  90 A and  90 B are received in shallow cups  93 A and  93 B, the cups being affixed to base  84 . The upper or smaller diameter ends of conical volute springs  90 A and  90 B are received by pins  92 A and  92 B that are secured to the bottom of platform  44 . 
     In a manner similar to the embodiments of  FIGS. 5 and 9 , in addition to springs that provides resiliency in the embodiment of  FIGS. 18 and 19 , resilient members  68 R and  68 L are employed. These resilient members are flexed or compressed as platform  44  tilts when a bicycle  38  supported on the platform is ridden vigorously. 
     Exercise bicycle  38  includes, as shown in dotted outline, a cross member  48  that forms a part of the strut which supports either the front end or rear end of the exercise bicycle. This cross member  48  is secured to platform  44  by means of straps  42  as seen in  FIGS. 3 ,  18  and  19  and other figures. The straps are retained in position by means of strap clip  94  secured to the bottom surface of platform  44 . 
       FIG. 18  shows the relationship of components when bicycle  38  is not being used or when being used and the rider is riding at a relaxed pace while  FIG. 19  shows the bicycle as it is moved side to side when the rider is vigorously pedaling the bicycle.  FIG. 19  shows the exercise bicycle  38  pivoted in one direction causing pivotation in the opposite direction being similar except that springs  90 B and resilient members  68 L are compressed. 
       FIGS. 20 through 24  show an additional alternate embodiment. Housing  62  is illustrated in more detail to show, in addition to a housing bottom  84  as previously referenced, housing sidewalls  96 A and  96 B and end walls  98 A and  98 B. Bearing pad  64 A is of greater depth than in any other view and has radiused groove  66  therein. Tubular rod  60  is shown as a solid member that is provided with a flat surface secured to the bottom surface of platform  44 . 
     Positioned within housing  62  are resilient members  68 R and  68 L. In this embodiment the resilient members are each formed of a stack of resilient pieces such as made of plastic foam or the like and in which the resiliency of each portion of the stack is different and showing higher density portions being on the bottom of the stack and lower density portions on the top of the stack. Pins  100  on the top of bearing pad  64 A extend through openings  102  in platform  44 , the pins serving to maintain platform  44  in position but allowing it to pivot on bearing block  64 A. 
       FIG. 21  shows the components of  FIG. 20  assembled and ready to receive the forward or rearward strut of an exercise bicycle thereon.  FIGS. 22 ,  23  and  24  illustrate the operation of the embodiment of  FIGS. 20 and 21 . In  FIGS. 22 through 24  the sidewalls and end walls of housing  62  are not shown. Only housing bottom  84  is shown.  FIG. 22  shows the relationship of components without any weight applied to platform  44 , such as the condition if a front or rearward strut portion of a bicycle was not in place. 
       FIG. 23  shows the exercise bicycle  38  in place and held to platform  44  by means of straps  42 . Sufficient weight is on platform  44  to cause the tubular rod  60  to rest in radiused groove  66  and the resilient members  68 R and  68 L are slightly compressed. 
       FIG. 24  shows the relationship of components when a biker is riding the exercise bicycle  38  vigorously and shows the bicycle tilted to one side. 
     Referring to  FIGS. 25 and 26  an additional embodiment of the invention is illustrated in which platform  44 , as retained within housing  62 , is pivoted about tubular rod  60  that is received within a pillow block  104  that is secured to the bottom of platform  44 . Tubular rod  60  is supported at either end such as by attachment to opposing housing sidewalls of which only housing sidewall  96 A is shown. In this manner, platform  44  can tilt back and forth about tubular rod  60 . A stationary exercise bicycle  38  is mounted on platform  44  as with the other embodiments previously illustrated and described. 
     Positioned between the underneath bottom surface of platform  44  and the top surface of housing bottom  84  is a first bellows  106 A and a second bellows  106 B. The interior of bellows  106 A and  106 B are connected to each other through a first flexible tube  108 A and a second flexible tube  108 B. Tubes  108 A and  108 B are joined end-to-end by a manually controllable valve  110 . Valve  110  is located convenient to the rider of the bicycle  38  so that the rider may adjust the resistance to fluid flow between bellows  106 A and  106 B. By tightening valve  110 , the fluid flow in the bellows is restricted and therefore resistance to tilting of platform  44  is increased. When valve  110  is open to a greater degree fluid flows more readily between bellows  106 A and  106 B meaning that platform  44  can more easily tilt from side to side. When valve  110  is turned towards the closed position the resistance to pivotation of platform  44  will serve to accommodate a heavier rider or, for reduce the degree of tilt that a rider experiences as the bicycle sways during vigorous riding activity. By opening the valve and therefore increasing fluid flow between bellows  106 A and  106 B the rider decreases the resistance which serves to accommodate a smaller rider. If the valve  110  is fully closed then fluid flow between the bellows stops and the pivotation of platform  44  is effectively eliminated. Thus the rider can lock the attitude of bicycle  38  in place when mounting or dismounting by closing valve  110 . 
     While not shown, the bellows system of  FIGS. 25 and 26  may additionally employ the use of springs and/or resistance members such as shown in  FIGS. 4 through 24  to bias platform  44  to the horizontal position, while bellows  106 A and  106 B serve to control the resistance encountered in pivoting platform  44  from side to side, that is, the resistance a biker experienced to the swaying action of the bicycle  38  when ridden vigorously. 
     Bellows  106 A and  106 B are shown of the pleated type but other types such as a bladder-type may be employed. Further, instead of bellows, cylinders with pistons therein can take the place of the bellows and provide for moving fluid from one to the other to control the resistance to swaying of the bicycle. 
     Fluid used in bellows  106 A and  106 B can be either gas or liquid. Due to the compressibility of gas the use of liquid will provide for specific control of pivotation of platform  44 . However, the use of gas as a fluid medium has the advantage of providing cushioning action as the bicycle resting on platform  44  is swayed during vigorous exercise. 
     While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but is to be limited only by the scope of the attached claims, including the full range of equivalency to which each element thereof is entitled.