Abstract:
A motorless exercise treadmill has a flywheel of 7 to 10 inches radius, weighing 40 to 60 pounds. The flywheel provides a fluid motion for the belt when the brake system is engaged and smooth transition through increasing or decreasing speeds. Inclination of the treadmill is fixed at 9 to 20 degrees, which accommodates the large size of the flywheel. Handle and other attachments of different designs are provided so the user can exercise in various positions with various resistance levels for developing specific leg, core, arm and other muscles, not normally achievable on a treadmill.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the full benefit of U.S. Provisional Application 61/782,998 filed Mar. 14, 2013 and U.S. Provisional Application 61/858,854 filed Jul. 26, 2013, both of which are hereby incorporated herein by reference in their entireties. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to exercise treadmills. In particular, it relates to motorless treadmills—that is, treadmills powered by the user. Handle and other attachments of different designs are provided so the user can exercise in various positions with various resistance levels for developing specific leg, core, arm and other muscles. A large flywheel of a particular design is arranged to provide a fluid motion for the belt when the brake system is engaged and smooth transition through increasing or decreasing speeds. Inclination of the treadmill is fixed. 
       BACKGROUND OF THE INVENTION 
       [0003]    Generally, treadmills are powered by a motor and are used mainly for aerobic (cardiac) exercise such as walking and running, but provide little or no possibility of simultaneous specific or varied muscle strengthening regimes with resistance training. Some elliptical machines are designed to strengthen leg muscles, but must be further equipped if they are to exercise the arms, upper body and other muscles. Equipping an exercise machine of any kind with a motor adds significant cost, operating expense, liability, and limited mobility. The art is in need of an affordable highly versatile exercise machine. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is a manually powered inclined treadmill with various levels of resistance. The conventional motor is replaced with a large heavy weighted flywheel, obviating the expense and maintenance necessitated by a motor. The motor is replaced with a 40-60 pound flywheel having a large diameter and other attributes explained below, which captures the energy of the belt motion. The flywheel keeps the belt in motion, and maintains a fluid motion through transitions of resistance and speed. A brake effect may be applied to the flywheel at the discretion of the user. The brake system when applied creates resistance on the flywheel, enabling the user to enhance a strength profile. The resistance to the flywheel is applied incrementally, affording the user with a wide range of resistance levels. In order to generate the desired moment of inertia, the large diameter flywheel must contain a high percentage of its mass, or weight, toward its outer edge. Since the user must use muscle power entirely to move the inclined belt and the treadmill can have various levels of resistance applied, he or she simulates actual incline climbing more effectively than when the belt is powered by a motor, burning more calories and effecting greater muscle stimulation. 
         [0005]    The motorless, inclined treadmill is designed to be a crossover between (that is, to incorporate the benefits of) an inclined treadmill and an elliptical. It offers the cardio benefits of a treadmill motion with the muscle stimulation of elliptical, while enabling variable resistance levels and facilitating arm, shoulder and upper body muscle development as well as providing significant leg muscle challenges. It is equipped with multiple vertical and horizontal hand stations so the user can position himself or herself into various postures simulating an elliptical motion, a football sled, or other regimes not readily available with other types of exercise machines. 
         [0006]    Solidly attached to the frame of my treadmill is an elongated socket adapted to receive elongated stems or shafts for a variety of handles and pressure surfaces which may be used at different heights and with a wide variety of speed and resistance. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view showing an exerciser on the treadmill using an arm rest attachment. 
           [0008]      FIG. 2  illustrates an exercise position on the treadmill different from that of  FIG. 1 , employing a different front attachment. 
           [0009]      FIG. 3  shows the treadmill equipped for using the shoulders to push. 
           [0010]      FIG. 4  shows a front attachment that facilitates a forward leaning position, enabling a longer stride. 
           [0011]      FIG. 5  shows the braking device. 
           [0012]      FIG. 6  is a graph showing speed change of the perimeter weighted treadmill over a single stride at different speeds and at various inclinations. 
           [0013]      FIG. 7  is a graph showing force required to maintain a constant speed at various inclinations. 
           [0014]      FIGS. 8   a  to  8   f  illustrate the treadmill with separated attachments. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Referring now to  FIG. 1 , the treadmill is seen to have a continuous treadmill belt  1  forming a treadmill exercise surface  2  and supported by front roller  3  and back roller  4 , which are mounted in frame  5 . Exercise surface  2  of treadmill belt  1  rides on a support surface (not shown) as is known in the art. Frame  5  rests on feet  14 . Attachment support socket  6  is fixed to the front of frame  5 . Attachment socket  6  is hollow and may be cylindrical or define a square or other cross section in order to receive snugly the stem  7  of an accessory positioner  8 . Accessory positioner  8  has a particular shape and configuration, in this case including an arm rest portion  15 , but other, interchangeable, accessory positioners may have different shapes and configuration as will be explained below. Attachment socket  6  is provided with holes  9  so that pins  10  can pass through them and through complementary holes  11  on stem  7  and similar stems for other accessory positioners. As depicted in  FIG. 1 , user  16  is resting her arms on arm rest portion  15  of accessory positioner  8  and grasps handles  17 . She is thus able to exert significant forward thrust on the treadmill exercise surface  2 . Front roller  3  is turned by the treadmill belt  1  and, since flywheel  12  is fixed to front roller  3 , the flywheel  12  will rotate in a clockwise direction, as depicted. The significant moment of inertia of the perimeter weighted flywheel soon assures a smooth continuous movement of the treadmill belt  1 . User  16  is able to regulate the application of resistance to flywheel  12  by manipulating resistance control  13  at any time. 
         [0016]    Flywheel  12  is a perimeter weighted flywheel fixed to rotate with front roller  3 , the flywheel  12  having a radius of 7 to 10 inches and a mass of 40 to 60 pounds; in this case, it has a radius of 8inches and a mass of 55 pounds. 
         [0017]    For a flat disc of any thickness and even weight distribution, there is a constant relationship between the peripheral weight and the total weight. In Table 1, the relationship is laid out: 
         [0018]    Table 1—percent of weight in the periphery of a disc flywheel of evenly distributed weight, measured at various distances from the center, where r is the radius: 
         [0019]    Outside 0.6r: 64% 
         [0020]    Outside 0.7r: 51% 
         [0021]    Outside 0.8r: 36% 
         [0022]    Outside 0.9r: 19% 
         [0023]    These percentages are true for a flywheel having evenly distributed weight of any radius, but my invention calls for a radius of 7 to 10 inches. This means, for example, that a plain, evenly distributed mass flywheel of my minimum radius  7  will have 51% of its weight in the area outside 4.9 inches radius (0.7r). At my maximum radius of 10 inches (as with a 7 inch disc), all of the above percentages apply. My criteria also call for a mass of 40 to 60 pounds for the flywheel as a whole. Thus a 55 pound, 8 inch flywheel will have 0.36×55, or 19.8, pounds in the area defined by the outside (near the edge) 1.6 inches of radius; of course it will satisfy all the other percentages of Table 1 also. A flywheel of less than 7 inches radius will not have any mass at all that far from its rotation center. 
         [0024]    Persons skilled in the art will recognize that flywheels need not be plain, evenly distributed discs. For example, they may be hollowed out in the center or thin in various patterns, or may be completely open in certain areas to define spokes or spoke-like members. Such types of construction which may tend to reduce the amount of weight near the center of the flywheel relative to that near the perimeter are useful in my invention, so long as the total weight and radius criteria are met. The flywheel should not be of a shape or construction which distributes weight with an uneven bias toward the center of the flywheel; it must be at least evenly distributed or perimeter weighted. By “perimeter weighted” is meant that the average of the centers of gravity for all radii is located farther toward the perimeter than 0.5r, where r is the radius—that is, the flywheel may have an uneven bias of weight toward the periphery. 
         [0025]    Persons skilled in the art will also recognize that the rollers or spindles on which the belt turns also have a modest flywheel effect. As discussed above, flywheel  12  is attached or fixed directly onto front roller  3  so they turn together. Although the roller  3  has a modest flywheel effect, my criteria for the flywheel do not consider it, nor do they consider that the center of the flywheel may be open—that is, completely absent—so the end of front roller  3  can be inserted into it as shown. Thus, a flywheel meeting my criteria of 40 to 60 pounds and having a radius of 7 to 10 inches will include such a flywheel. 
         [0026]    The flywheel  12  may be in the form and placement illustrated or may be split into two perimeter weighted flywheel parts, one on each end of front roller  3 , each having a radius of 7 to 10 inches and each having half of a total of 40 to 60 pounds. I consider this arrangement a single flywheel. In either case—whether the flywheel  12  is on one end of the roller or two, as shown or split, with one part on each end of front roller  3 , its large diameter is accommodated by the overall inclination of the treadmill. As indicated by the difference in length between front legs  18  and rear legs  19 , frame  5  and treadmill surface  2  are maintained at an angle from 9 to 20 degrees. In the case of  FIG. 1 , the angle is 12 degrees, as an angle of 11 to 13 degrees is preferred. Side rails  20  are an optional safety feature. 
         [0027]    In  FIG. 2 , unlike the stance of the user in  FIG. 1 , the exerciser assumes a more upright position but grasps handles  21  of attachment  22  which has been inserted into support socket  6 , secured by pins  10 . Resistance control  13  of  FIG. 1  has been replaced by knob  30  for varying resistance on flywheel  12 , as will be further explained with reference to 
         [0028]      FIG. 5 . Otherwise the treadmill is identical to the one depicted in  FIG. 1 , comprising frame  5 , treadmill belt  1 , and flywheel  12 . Front legs  18  and rear legs  19  are of different lengths in order to provide a slope of 11 degrees for the treadmill surface  2 . 
         [0029]    In  FIG. 3 , the basic treadmill is also similar to that of  FIGS. 1 and 2 , comprising frame  5 , treadmill belt  1 , and flywheel  12 . In this case, however, front legs  18  and rear legs  19  are of different lengths in order to provide a slope of 13 degrees for the treadmill surface  2 . But also, attachment support  25  holds a crosspiece  26  to which are attached two reinforced pads  27  adapted for contact with the user&#39;s shoulders. Handles  28  in this case extend downwardly and outwardly so the user can exert part of his strength on them if desired. Insert  29  snugly receives attachment support  25  at its upper end. Handles  28  are welded or otherwise firmly attached to insert  29 , which fits into attachment socket  6  in a manner similar to the way stem  7  fits into attachment socket  6  in  FIG. 1 . With an appropriate resistance adjustment applied through brake bracket  13 , the resultant “uphill” exertion simulates a football exercise device. It should be noted that, since the treadmill does not require electricity, it may be placed on an athletic field or anywhere remote from an electrical outlet. 
         [0030]    The user in  FIG. 4  has chosen to employ insert  29  and its handles  28  without using attachment support  25  or the reinforced pads  27  of  FIG. 3 . She assumes a more forward leaning posture than the user in  FIG. 3 , pushing only on the handles  28 , and is able to take longer strides than the user in  FIG. 3 , who has chosen to exert the most force on reinforced pads  27 . The treadmill of  FIG. 4  is otherwise similar to the treadmills of  FIGS. 1 ,  2 , and  3 , comprising treadmill belt  1 , frame  5 , and flywheel  12 . The fixed inclination of the treadmill in  FIG. 4  is 12 degrees. 
         [0031]    Since it is an object of the invention to eliminate the expense of a motor, it is important to understand the effect of the fixed, rather steep, inclination of the treadmill. Not having a motor, there is no way to change the inclination of the treadmill using external power. Of course, one can simply prop up the front of the treadmill by placing a temporary platform under front legs  18  if additional slope is desired. The invention does not require a variable slope, but if for some reason one would want to incorporate a motor to vary the slope, it could be accommodated without changing the basic relationship between the size of the flywheel and the slope of the treadmill. 
         [0032]    As indicated elsewhere herein, the flywheel should have an outside diameter of 14 to 20 inches, and therefore the front of the treadmill must be high enough for it to turn freely. As also indicated elsewhere, its mass should be within a range of 40 to 60 pounds. Some of the effects of the heavy large-diameter, perimeter weighted, flywheel are shown in the graphs in  FIGS. 6 and 7 . They are based on an arbitrarily selected value of 24.5 kg (54.2 pounds) for the flywheel assumed to be concentrated entirely in the form of a torus. Where the radius of the torus from its center to the middle of the ring on the other side is 0.2285 meter (9 inches) and the radius within the torus body, or tube, is assumed to be zero, applying the formula I=½mr 2  where r is the radius of the torus (taken from its center to the center of the cross section of the torus tube, which is assumed to have a radius of zero), and m is the mass of the torus, yields a mass moment of inertia I=0.64. This number is used to develop the information in the following paragraphs. 
         [0033]    The exponential effect of the deliberately chosen long radius of the flywheel results in an aggressive inertia. The inertia created by the large perimeter weighted flywheel allows the tread belt to move smoothly under heavy resistance by the braking system. If such inertia is not created then the user would experience a stop and start action of the tread belt while under resistance by the braking system. 
         [0034]    In a sense, all treadmills have fly wheels, motorized and non motorized. Even where there is no device called a flywheel, the rollers or spindles on which the belt turns store a certain amount of energy as they are turned. It is a natural function of moving the tread belt. But the previous designs of the flywheels have been much smaller and weights are typically in the range of 10 to 18 pounds in wheels of smaller dimensions. My design is much different. The size and weight differs but the function is the key. My flywheel is designed to distribute a significant weight at longer distances from the center and generally more than half way to the edge, a technique which may be called “perimeter weighting.” The perimeter weighting, size of the OD (outside diameter) and heavy weight all contribute to the principle of aggressive inertia which I employ. The aggressive inertia drives the tread belt in a way similar to a motorized driven unit. No other treadmill employs my principle of aggressive inertia and perimeter weighting. 
         [0035]    In  FIG. 5 , the mechanism of the brake is shown. Brake base  40  is mounted on pivot  41  and is integral to plate  42  through which an elongate screw  43  passes. Brake pad  44  lines the concave surface of brake base  40 . Brake base  40  and brake pad  44  are positioned in relation to pivot  41  and plate  42  so that the end of brake pad  44  nearest pivot  41  touches or almost touches the perimeter surface of flywheel  12 . The shaft  45  of elongate screw  43  passes through bracket  13  and terminates in knob  30  when the brake is not actuated. Bracket  13  and pivot  41  are fastened securely to frame  5  (not shown) in any suitable manner. Flywheel  12  is fixed to front roller  3  as indicted in  FIG. 1 . To apply resistance to the flywheel  12 , the user turns knob  30  clockwise to elevate plate  42 , which causes brake base  40  to urge brake pad  44  into increasing contact with flywheel  12 . Elongate screw  43  is made so that ten complete clockwise rotations of knob  30  will fully apply brake pad  44  to flywheel  12 . The amount of resistance generated is generally directly related to the turns of the knob  30 . Resistance is reduced by turning the knob  30  counterclockwise. Brake pad  44  may be made of any suitable material offering some resilience and able to tolerate the friction generated. 
         [0036]    The effect of the aggressive inertia is graphically illustrated in  FIG. 6 .  FIG. 6  shows the percentage of speed change for a single stride at two different speeds (a typical walking speed and a typical running speed), over a wide range of slope. One important thing to note here is what happens when the deck is inclined at a slope steeper than 8.5 degrees, as in the present invention. Basically, gravity is now assisting the user to the point where the flywheel urges the belt to speed up. However, the calculations of the graph are based only on the flywheel and a hypothetical user. There is also present an inherent “drag” from the contact of the belt on the rollers, the contact of the user&#39;s feet on the belt (and the support surface under it), and the belt tension both with and without the effect of the user&#39;s weight. The user can easily achieve an equilibrium between the motion of the belt and the force of his or her own stride, which can still vary over a wide range of speed with or without application of the brake. The user can, of course, hold onto the handles  17 ,  28  or others, and/or can grasp side rails  20 , while modifying his or her stride if desired or deemed necessary; the user may also simply step on the stationary sides of frame  5  next to the belt at any time. 
         [0037]    The data for  FIG. 6  were calculated using an average body weight of 175 pounds and speeds of 3 miles per hour walking and 8 miles per hour running. Note that the inclination angle affects the percent change of speed more dramatically at a walking speed than it does at a running speed. This may seem counterintuitive, but the running speed value is higher to begin with. The user will find that, with or without the appropriate application of the braking mechanism, the belt motion will nevertheless be both challenging and smooth. At a fixed slope of 12 degrees, for example, the flywheel and braking mechanism are designed to provide a full range of resistance and speeds. 
         [0038]      FIG. 7  shows graphically the additional force required to maintain a constant speed over the course of one stride, once the treadmill has achieved the desired speed. Positive values indicate additional force needed from the user; negative values indicate that additional belt resistance is needed, Note that deck angles higher than 8.5 degrees again show the need for additional resistance. Steady resistance is easily provided by the brake system. Again, the calculations do not include factors of friction from the belt or other sources. 
         [0039]    The versatility of the invention is illustrated in  FIGS. 8   a  to  8   f.  The basic treadmill comprising frame  5 , treadmill belt  1 , and flywheel  12  is seen without attachments in  FIG. 8   a.  Attachment socket  6  is empty, ready for one of the attachments, but it is not necessary for a user to install one. Lift handles  50  and rollers  51  are provided so the treadmill can readily be moved.  FIG. 8   a  shows knob  30  for controlling resistance by means of elongated screw  43  as shown in  FIG. 5 , but it may be replaced by levered resistance control  13  ( FIG. 8   b ) as shown in  FIG. 1 . Each of the attachments shown in  FIGS. 8   c,    8   d,  and  8   e  has a stem  7  sized for secure insertion into attachment socket  6  and adjustable for height using pins  10 .  FIG. 8   d  shows a sled pad attachment.  FIG. 8   e  is a forearm attachment having an arm rest portion  15 . The shoulder harness attachment of  FIG. 8   c  in this case has an intermediate collar  60  for handles  28 . The steer&#39;s horn attachment of  FIG. 8   f  has an elongated socket  61  able to receive and fasten onto a shaft (not shown) extending from attachment socket  6 . Other types of attachments may be designed and easily attached to the treadmill. 
         [0040]    This unit is eco-friendly, requires no external power and is made of recycled steel. The incline is fixed at an optimal position for cardio and muscle development. It has a wide range of resistance, features a raised textured belt surface, and includes various front hand stations (attachments) that are adjustable to suit the user, particularly as to height. 
         [0041]    Thus it is seen that my invention includes a motorless treadmill comprising (a) a frame, (b) a high front roller and a low rear roller held by the frame, (c) a continuous treadmill belt in contact with the front and rear rollers, the treadmill belt having an outer surface and an inner surface, the inner surface in contact with the rollers, the rollers and the treadmill belt defining an exercise surface inclined at a fixed angle of 9 to 20 degrees from the low rear roller to the high front roller, (d) a flywheel fixed to the front roller, the flywheel having a radius of 7 to 10 inches and a perimeter weighted mass of 40 to 60 pounds. 
         [0042]    My invention also includes a motorless treadmill comprising (a) a treadmill frame including a front end and a rear end, the frame including a treadmill belt, a front roller on the front end, and a rear roller on the rear end, the front and rear rollers for enabling the treadmill belt to turn, the treadmill frame including at least one front support member fixedly elevating the front roller at an angle of 9 to 20 degrees from the rear roller, (b) an elongate socket fixed to the front end of the frame, the socket being adapted to receive and fix a shaft of one or more interchangeable handles for grasping by a user to assume a variety of positions and apply a variety of muscles by a user, and (c) a perimeter weighted flywheel fixed to the front roller, the perimeter weighted flywheel having a mass of 40 to 60 pounds. 
         [0043]    And, in another aspect, my invention includes a motorless treadmill having a fixed inclination of 9 to 20 degrees comprising (a) a frame including a socket for receiving an accessory shaft, and (b) a plurality of accessory shafts adapted to fit securely in said socket and having handles deployed in various orientations.