Exercise Apparatus for Simulating Stair Climbing

The invention relates to the field of stair climbing apparatus and in particular to a stair climbing apparatus where the rate of stair climbing is controlled by an alternator.

Stair climbing has become recognized as a particularly effective type of aerobic exercise and as a result, exercise machines facilitating this type of exercise are becoming increasingly popular for both home and health club use.

There have been a variety of approaches taken in designing stair climbing apparatus including the simulation of an actual stair case as illustrated in U.S. Pat. Nos. 3,497,215 and 4,687,195. Another popular approach has been to simulate he action of stair climbing by using a pair of reciprocating pedals. Examples of this approach are disclosed in U.S. Pat. Nos.: Des. 263,490, 3,316,819, 3,529,474, 3,628,791, 3,979,302, 4,496,147, 4,600,187, 4,676,501, and 4,720,093.

In U.S. Pat. No. 4,708,388, a stair climbing apparatus is disclosed where two pedals operate independently of each other and they are connected to an alternator through a speed increasing transmission that, in turn, is connected to the pedals by a pair of chains running over a pair of one way drive sprockets. A microprocessor is used to control the alternator so that a variety of exercise programs can be implemented. However, because the pedals operate independently, the range of step motion is not measured and it is not, therefore, possible to provide the user with all the desired information, i.e., step range and effort range, regarding his exercise equipment.

Along with substantial forces exerted on the two pedals and the drive chains by users as they step up and down on the pedals, there are also sudden reversals in the pedal motion and the direction of movement of the drive chain. Thus, it has been found, results in significant wear of the drive chain as its movement is reversed from one direction to another. In addition, the drive chain, itself, encounters much friction and resistance from its interaction with other components of the stair climbing apparatus such as the sprockets over which the chain is run. This abrasion caused by the other machine parts, reduces both the life of the chain and the smoothness of the simulated motion of stair climbing to the user.

Since both the expense of changing chains and the down time of the stair climbing apparatus can be a significant cost to the owner of the stair climbing apparatus, it is desirable to increase the life of the drive chain. It is also desirable to provide the user with information regarding his exercise equipment.

It is therefore an objection of the invention to provide a reciprocating type stair climbing exercise apparatus having two pedals connected directly together where the reciprocating rate of the pedals is governed by a microprocessor controlled alternator.

It is an additional object of the invention to provide a stair climbing exercise apparatus having two foot pedals connected together by a drive chain and where an alternator is connected to the drive chain, either by a transmission or directly. Also included is a pair of one way clutches connected between the chain and the transmission such that the alternator only provides a resistance force when the pedals are operated by a user in a stair climbing direction. User comfort is enhanced by providing cross-connected cushioning or damping springs or bumpers which have the effect of limiting some portion, usually the lower portion, of the downward travel of each pedal in a resilient manner.

It is a further object of the invention to provide a stair climbing exercise apparatus having a pair of pedals that includes means for determining the relative location of each pedal during a stair climbing exercise Additionally included is a means for determining the step range of a user during a climbing exercise along with a display for displaying to the user information relating to his step range. Also displayed is a measure of the user's effort as compared to a user selected effort level.

It is a further object of this invention to provide a reciprocating type stair climbing exercise apparatus having two pedals directly connected to each other incorporating a lubricating device.

It is an additional object of this invention to provide a reciprocating type stair climbing exercise apparatus incorporating a lubricating device having two pedals connected directly together by a drive chain where the reciprocating rate of the pedals is governed by a microprocessor controlled alternator.

It is a further object of this invention to provide a stair climbing apparatus incorporating a lubricating device having two pedals directly connected together by a drive chain. Resistance to the drive chain is provided by an alternator which is either directly connected to the drive chain or is connected through a transmission to the drive chain. Furthermore, a pair of one way clutches are connected between the chain and the transmission such that the alternator only provides a resistance force when the pedals are operated by the user in a stair climbing direction. User comfort is enhanced by providing resilient cross-connected cushioning which partially limits a portion of the travel of each pedal.

It is a further object of the invention to provide a stair climbing apparatus incorporating a lubricating device having a pair of pedals and a means for determining the relative motion of each pedal during a stair climbing exercise. Further included is a means for determining the step height of a user during a climbing exercise along with a display showing the user information relating to his step height. The user's effort compared to his selected effort level can also be displayed

The present invention, together with further objects and advantages, will best be understood with the detailed description read in conjunction with the accompanying drawings.

FIG. 1 is a perspective view of a stair climbing exercise apparatus constructed in accordance with the invention;

FIG. 2 is a partially sectioned away perspective view of the apparatus of FIG. 1;

FIG. 3 is a partially sectioned side view of the apparatus of FIG. 1;

FIG. 4 is a partial detail view of the damping spring and stop shown in FIG. 3;

FIG. 5 is a partial detail view of a method of linking together two portions of the drive chain shown in FIGS. 2 and 3;

FIG. 6 is a detail view of the position sensor shown in FIGS. 2 and 3;

FIG. 7 is a front view of the control and display panel of the apparatus of FIG. 1;

FIG. 8 is a functional block diagram of the control circuit for the apparatus of FIG. 1;

FIG. 9 is a partially sectioned away perspective view of a second embodiment of a stair climbing exercise apparatus constructed in accordance with the invention;

FIG. 10 is a partially sectioned view of the apparatus of FIG. 9;

FIG. 11 is a perspective view of a stair climbing exercise apparatus constructed in accordance with the third embodiment of the present invention;

FIG. 12 is a partially sectioned side view of the apparatus of FIG. 11;

FIG. 13 is a partially sectioned front view of the apparatus of FIG. 11; and

FIG. 14 is a functional block diagram of the control circuit of the apparatus of FIG. 11.

FIG. 15 is a perspective view of the lubricating device of the present invention.

FIG. 1 provides a perspective view of a pedal type stair climbing exercise apparatus 10. A pair of foot pads 12 and 14 are attached to a pair of pedal members 16 and 18 respectively which move up and down in a reciprocating motion in order to provide a user who is standing on the pads 12 and 14 with a simulated stair climbing exercise program. Balancing support is provided to the user by a pair of handrails 20 and 22 that are secured to a U-shaped frame support base member 24 that provides support in addition to the inherent user stability resulting from connecting the pedal members 16 and 18. Also attached to the base member 24 is a housing 26 through which a pair of vertical support members 28 and 30 extend that serve to provide support for a control and display panel 32 and the handrails 20 and 22.

Illustrated in FIGS. 2 and 3 is a first embodiment of the mechanism contained within the housing 26 for operating the apparatus 10. As shown in these figures, the pedal members 16 and 18 are secured by a pair of bearings 34 and 36 to a rod 38 that in turn is attached to the vertical support members 28 and 30. The bearings 34 and 36 permit the pedal members 16 and 18 to angularly rotate in a vertical plane as indicated by arrows 40 and 42 in FIG. 2 through a pair of vertically aligned slots 44 and 46 in the housing 26. Since the rotation of the pedal members 16 and 18 and hence the foot pads 12 and 14 is limited to a relatively small angle, the horizontal displacement of the foot pads 12 and 14 will be relatively small so that the physical activity of stair climbing can be accurately simulated on the apparatus 10.

In this embodiment of the invention as shown in FIGS. 2 and 3, the pedal members 16 and 18 are cross connected by a linked chain 48 such that the pedal members are constrained to move in opposite directions. As a result when pedal member 16 is moving in an upward direction, pedal member 18 will be moving in a downward direction and vice versa. One end of the chain 48 is connected by a coupling 50 to the pedal member 16 and engages a first toothed sprocket 52 which leads it down to a toothed pulley 54 mounted for rotation on a frame base cross member 56. The chain 48 continues its run underneath the pedal members 16 and 18 parallel to the base member 56 to a second toothed pulley 58 rotatably secured to the base member 56. The second toothed pulley 58 serves to direct the chain 48 up to a second toothed sprocket 60 that in turn directs the chain 48 down to the pedal member 18 which is connected to the chain 48 by a coupling 62.

In order to regulate the rate at which the pedal members can be moved and thus control the rate of stair climbing, a variable source of resistance force in the form of an alternator 64 is provided. The alternator 64 is secured to a frame cross member 66 that can also be used, if desired, to attach the rod 38 to the vertical members 28 and 30. Rotational resistance is applied from the shaft of the alternator (not shown) to the chain 48 by a speed decreasing transmission which includes: a first drive belt 68 connected to a first pulley 70 coupled to a shaft 72; a second drive pulley 74 also coupled to the shaft 72; and a second drive belt 76 connecting the second drive pulley 74 to a third drive pulley 78 which is coupled to a shaft 80. Drive belts 68 and 76 are preferably micro-v belts to promote quiet operation of the apparatus 10 but drive chains or other types of power transmitting devices can be used as well. The shaft 72 is rotatably secured at one end to a frame support member 82 by a bearing 84 and at the other end by a bearing (not shown) to a second frame support member 85. Both frame members 82 and 85 are attached to the lower cross member 56 and attached respectively to the vertical supports 28 and 30. Similarly, shaft 80 is rotatably secured at either end to the frame members 82 and 84 by bearing assemblies 86 and 88. A pair of one way clutch assemblies 90 and 92 are used to connect the toothed sprockets 52 and 60 to the shaft 80. The function of the one way clutches 90 and 92 is to ensure that the shaft 80 and hence the alternator 64 only rotate in one direction even though the sprockets 52 and 60 will be rotating in both directions due to the reciprocating motion of the pedal members 16 and 18 transmitted to the chain sprockets 52 and 60 by the chain 48.

Another important feature of the invention is the provision as illustrated in FIGS. 3 and 4 for the cross damping of the pedal members. In order to prevent the pedal members 16 and 18 from striking the floor indicated at 94 or portions of the machine's 10 frame with undesirably high impact loads on the users legs and feet, it is considered desirable to limit the lower portion of the stroke of each pedal member 16 and 18 to prevent such impacts and further it is considered desirable to gradually reduce or dampen the velocity of the pedal members 16 and 18 as they approach the lower limit of their strokes. One approach to solving this problem involves placing springs or other resilient members under the pedal members to cushion the bottom portion of the users step motion. However, this approach has the disadvantage of producing a hitch effect in the operation of the mechanism shown in FIGS. 2 and 3. This effect occurs because the springs will cause the pedal member 16 or 18 to accelerate more quickly than the user can accelerate the opposite pedal resulting in slack in the chain 48. In the invention cross-damping is used to provide the cushioning effect while eliminating the above discussed hitch effect. As shown in FIGS. 3 and 4 a resilient member 96 such as a helical spring is attached to the upper side of each pedal member, shown for example on the pedal member 16 in FIGS. 3 and 4, by a bracket 98. A pair of stops such as the one shown at 100 in FIGS. 3 and 4 are attached to the frame support members 82 and 84. When each pedal member approaches the upper limit of its stroke the top portion of the spring, which as indicated in FIG. 4 includes a compliant elastomeric element 102, contacts one of the stops such as 100 and begins to compress thus providing the cushioning effect. But because the two pedal members are connected by the chain 48, the provision of the upper limit on the stroke of one pedal member such as 16 will effectively limit the downward portion of the stroke of the other pedal member 18. In this manner a damped lower limit can be provided for each pedal member 16 and 18 while maintaining smooth operation of the apparatus 10. It should be noted that as an alternative to the arrangement shown in FIG. 4, the spring 96 can be secured to the stop 100 and positioned so as to contact the top of the pedal member 16 at the upper limit of the stroke.

An additional feature of the invention is the use of a linked drive chain 48 to connect the one way clutches 90 and 92 to the pedal members 16 and 18 where the chain 48 is caused to run underneath the pedal members 16 and 18 as illustrated in FIGS. 2 and 3. This is facilitated by using a toothed composed of three separate sections. The first portion 104 of chain 48 is made up of links orientated to engage toothed sprocket 52, the second portion 106 is made up of links orientated to engage the toothed pulleys 54 and 58 which have a plane of rotation displaced ninety degrees from the toothed sprockets 52 and 60, and the third portion 108 is made up of links orientated to engage the chain sprocket 60. This ability to change the orientation of the links in the chain 48 is provided by the use of a pair of connecting links 110 and 112. Details of the connecting link 110 are shown in FIG. 5 where a pin 114 connects the chain portion 104 to the connecting link 110 and a pin 116 connects the connecting link 110 to chain portion 108.

A positive indication of the relative motion of each of the pedal members 16 and 18 is achieved by using a position sensor 118 as illustrated in FIGS. 2 and 6. In the embodiment shown, the position sensor 118 is a conventional electro-optical device that uses a light detector to sense when toothed portions indicated generally at 120 of a disk 122 pass a light source. The disk 122 as shown in FIG. 6 can be directly connected to a sprocket indicated at 124 which is engaged with the chain 48. As suggested by FIG. 2, the sprocket 124 can be separately attached to the frame 56 or alternatively one of the pulleys 54 or 58 can be used. In this manner, a signal which provides a positive determination of the location, motion or position of the pedal members 16 and 18 can be generated.

In FIG. 7 is illustrated the preferred embodiment of the control display unit 32. The unit 32 includes a digital display of the desired rate of exercise at 126 displayed in floors per minute; a digital display at 128 of the actual rate of exercise in floors per minute; a digital display at 130 of the exercise time in minutes; and a digital display at 132 of Work performed in calories. In one embodiment of the invention the display 132 automatically switches on a periodic basis between total calories expended during the exercise program and the current rate of calorie expenditure. Also provided in the unit is an alpha-numeric display which can be used to display messages to the user including instructions on how to use the apparatus 10. A program profile display 136 including present position indication 138 is included in the unit 32 and is preferably composed of a matrix of light emitting diodes (LEDs) on which a preset exercise program such as a hill profile illustrated at 140 can be displayed. Another display is shown at 142 which can be implemented as a column of LEDs where the individual LEDs are lit in sequence to indicate to the user the percent effort that he is expending. In this case the percent effort is the percent of the actual rate of exercise as compared to the desired rate. User information with respect to the height of the steps he is simulating on the pedal members 16 and 18 is provided on another LED display 144. Here the actual displacement of the pedal members 16 and 18 as for example measured by the position sen or 118, is compared to a predetermined or user selected height or range and a percent indication is graphically displayed on the column of LEDs 144.

The control unit 32 also includes an input keyboard indicated generally at 146. The keyboard 146 can be used by the user to select various exercise programs such as the hill profile 140 or to input information into the apparatus 10 including the users weight and desired step rate. Updates of all displays is performed by a computer (not indicated in the drawings). In the preferred embodiment, the periodic update of all graphic and alpha numeric displays associated with display unit 32 is performed by a second computer 156B, using data supplied by a computer 156A through serial link 160. In addition, keyboard input is monitored by the computer 156B and the inputted data is passed to computer 156A through serial link 160.

Operation of an embodiment of the invention will be described in connection with the block diagram of FIG. 8. Illustrated in schematic form are the basic mechanical elements shown in FIGS. 2 and 3 as described above. In normal operation the alternator 64 will apply a resistance force to the downward motion of the pedal member 16 through the mechanical elements 64, 68, 78, 76, 70, and 48. This resistance force is generated by the alternator 64 in response to a current applied to its field over a line 148. The field current is obtained from a power supply 150 and transmitted via a line 151 to a control amplifier 152. The power supply 150 also provides power to the various electronic elements shown in FIG. 8 as indicated by arrow 153. Current output of the alternator 64 which represents the energy being expended by the user is dissipated in a load resistor 154.

Operation of the alternator 64 is controlled by a computer 156 or in the preferred embodiment by a computer 156A. Included with the computer 156A is a non-volatile random access memory 356 for storing machine usage data. The computer 156A controls the field current on line 148 and therefore the rotational resistance force generated by the alternator 64 by applying a control signal such as pulse width modulated signal over a line 166 to the amplifier 152. In normal operation, the computer 156A regulates the maximum step rate of the user by causing the alternator 64 to generate the maximum resistance force when the step rate approaches a predetermined rate. In an embodiment of the present invention, the computer 156A obtains pedal member position information from the position sensor 118 over a line 168 and by differentiating this information, it can calculate the users step rate. This information can also be used to compute the distance traveled by the user in terms of floors for display 126. Alternatively, a signal from the alternator's RPM sensor (not indicated in the drawings), transmitted over a line 169 to the computer 156A, can be used to determine the user's step rate and the total distance traveled. By using the rate information on line 169 as a feedback signal, the computer 156A can in essence limit the step rate by increasing the resistance force produced by the alternator 64 to the point where the user finds it very difficult to drive the pedal members 16 and 18 down faster than the predetermined rate. As an alternative, the step rate derived from position sensor 118 can also be used as the feedback signal to the computer 156A.

Also by using the position information received from the computer 156A, the second computer 156B can via line 170 generate the data to drive the various displays that were discussed in connection with FIG. 7 although computer 156A can perform these functions. For example, the computer 156A can, by simply recording the distance between the upper and the lower point of a pedal member stroke, calculate the step height for that particular stroke. This data is passed to the second computer 156B for display on the display 144 as the actual step height as a percent of a predetermined step range. Alternatively, the alternator's RPM signal on line 169 can be analyzed by the computer 156A to measure the length preferably in time of all periods of acceleration. This data, along with the average alternator RPM and the resistance force currently applied to the alternator, will yield the step height data for the display 144. The predetermined step range along with other information can be supplied from the keyboard 146, monitored by the second computer 156B, and then sent over a serial communication link 160 to the computer 156A. By the same token, the display of the rate of exercise 128 can be produced by the second computer 156B based on the information received from the alternator's RPM sensor, which is monitored by the computer 156A and then transmitted to the second computer 156B.

Position information from the sensor 118 can be used to help limit the length of strokes of the pedal members 16 and 18. For example, as one of the pedal members 16 or 18 approaches a predetermined lower limit, the computer 156A responds to the position signal on line 168 by increasing the field current of the alternator 64. The resulting increased resistance on the lower pedal member 16 or 18 will decelerate it as it approaches its lower limit thus substantially reducing the physical requirements as well as wear on the stops such as 96.

Illustrated in FIGS. 9 and 10 is a second embodiment of the invention in which the elements which directly correspond to the elements in FIGS. 2 and 3 bear the same reference numbers. The pedal members 16 and 18 are cross connected by the linked chain 48 such that the pedal members are constrained to move in opposite directions. One end of chain 48 is connected by an arcuate sprocket coupling 50' to the pedal member 16, and the other end of the chain 48 is connected by an arcuate sprocket coupling 62' to the pedal member 18. Couplings 50' and 62' are mounted to a side surface of pedal members 16 and 18, rather than to the upper surface of pedal members 16 and 18, as in the first embodiment. Couplings 50' and 62' are arcuate portions of sprockets, which engage a portion of the respective ends of chain 48.

The frame support members 82' and 85' are positioned vertically, with their lower ends attached to the base frame cross members 56. At their upper ends frame members 82' and 85' are attached to a pair of horizontal frame members 200 and 202, respectively. Members 200 and 202 are attached to a horizontal frame cross member 204 which extends between the vertical frame members 28' and 30'. An additional horizontal cross member 206, such as an angle iron, is also secured between the vertical support members 28' and 30'. The shaft 72 is rotatably supported on the bearing 84' on frame member 82' and by another bearing (not shown) on frame member 85'.

The alternator 64 is mounted on a bracket 208 which extends between and is mounted to the frame cross members 204 and 206. Rotational resistance is applied from the shaft (not shown) of the alternator 64 to the chain 48 by a speed decreasing transmission, as discussed above in connection with the first embodiment.

A pair of resilient members 210 as illustrated in FIGS. 9 and 10 are secured to the stops 100 by bolts or pins 211 and positioned so as to contact the upper surface of the pedal members 16 and 18 at the upper limit of their stroke. These resilient members 210 in combination with the stops 100 provide the same cross damping function as the spring 96 which was described in connection with the first embodiment of the invention shown in FIGS. 3 and 4. A second pair of resilient members 212 are secured by bolts or pins 214 to a pair of supports 216 so as to contact the lower surface of the pedal members 16 and 18 at the lower limit of their stroke. The supports 216 are secured to the frame base cross member 56 by any conventional means, such as by welding or brazing. Resilient members 210 and 212 have a generally elliptically shaped configuration, preferably having a diameter in the range of about 0.5 to 1.0 inches. The resilient members 210 and 212 can be made from any suitable material, including polystyrene, polycarbonate, polyurethane, polyester, or mixtures thereof, and are preferably made of polyphenylene oxide. TECSPAC.RTM. bumpers, made by Eldyn, a division of Autoquip Corporation of Guthrie, Okla., and made of an Eldyn proprietary material including polyurethane and DuPont HYTREL.RTM. (polyester elastomers) have been especially useful as resilient members 210 and 212, although any other suitable material may be used. In their preferred embodiment, the resilient members 210 and 212 have a free uncompressed height in the range of 1.50 to 3.0 inches and the hardness of the material is preferably in the range of shore 30A to shore 8A; the resilient members have a compressed height in the range of 0.5 to 2.0 inches. Since the elliptical members 210 and 212 have significantly greater wear characteristics, their use is preferred over the spring 96 shown in FIG. 4. Secured to the top of each of the bolts or pins 214 is a rubber bumper 218 which provides a positive stop for the pedal members 16 and 18 and serves to reduce wear on the resilient members 212.

FIG. 11 provides a perspective view of a third embodiment of the invention in which the elements that directly correspond to the elements of the first and second embodiments bear the same reference numbers. As with the previously described embodiments, stair climbing exercise apparatus 10' has a pair of foot pads 12 and 14 which are attached to a pair of pedal members 16 and 18, respectively, and which move up and down in a reciprocating motion in order to provide a user who is standing on the pads 12 and 14 with a simulated stair climbing exercise program. Balancing support is provided to the user by a pair of handrails 20 and 22 that are secured to a generally V-shaped frame support base member 24". A housing 26 is also attached to the base member 24" through which the pair of vertical support members 300 and 301 extend. As shown in FIG. 13, the two vertical support members 306 and 308 each are attached to a support frame having a pair of upper portions 302, 303 respectively, which are bent inwardly from a vertical position and attached to a horizontal cross bar 304 extending from one upper portion 300 to another upper portion 302 thereby attaching the too vertical support bars 28" and 30", that together with the horizontal cross bar 304 serves to provide support for the control and display panel 32, the control and panel support bars 306, 308 upon which the control and display panel 32 is set, and the handrails 20 and 22.

As shown in FIG. 12, the pedal members 16 and 18 are secured by a pair of bearings 34" (the second bearing is not indicated in the drawings but is similar to bearing 37") to a rod 38" that in turn is attached to the vertical support members 300 and 301 which are not shown in FIG. 12. The bearings 34" (the second bearing is not indicated in the drawings but is similar to bearing 34") permit the pedal members 16 and 18 to angularly rotate in a vertical plane as indicated by arrow 40" in FIG. 12 through a pair of vertically aligned slots 44 and 46 in the housing 26. Since the rotation of the pedal members 16 and 18 and hence the foot pads 12 and 14 is limited to a relatively small angle, the horizontal displacement of the foot pads 12 and 14 will be relatively small so that the physical activity of stair climbing can be accurately simulated on the apparatus 10'.

In this embodiment of the invention as illustrated in FIGS. 12 and 13, the pedal members 16 and 18 are cross connected by a linked drive chain 48" such that the pedal members are constrained to move in opposite directions. As a result, when pedal member 16 is moving in an upward direction, pedal member 18 will be moving in a downward direction and vice versa. Preferably, one end of the drive chain 48" is connected by a coupling 310 to a shroud 312 (shown in a partially sectioned form in FIG., 12) which is attached to a frame support member 82" which corresponds to member 82' in FIG. 10. However, the drive chain 48" can alternatively be directly coupled to the frame instead of the shroud 312. The drive chain 48" is engaged with both a rotatable toothed sprocket 314 on the pedal member 18 and the toothed sprocket 52 mounted on a shaft 80 continuing to the first toothed pulley 54 which is mounted for rotation on the frame base member 24". The chain 48" continues its run underneath the pedal members 16 and 18 parallel to the base member 24" to a second pulley 58 rotatably secured to the base member 24". This pulley 58 serves to direct the chain 48" up to second chain sprocket 60 on shaft 80 that, in turn, directs the chain 48" down over a sprocket (not indicated in the drawings but similar to the rotatable toothed sprocket 314) on the pedal member 16 to a coupling (not indicated in the drawings but similar to coupling 310) on another shroud (not indicated in the drawings but similar to shroud 312) attached to frame support member 85", to which the other end of chain 48" is connected by a coupling.

In order to regulate the rate at which the pedal members 16, 18 can be moved and thus control the rate of stair climbing, a variable source of resistance force in the form of the alternator 64 is provided. The alternator 64 is secured to an upper frame cross member 316 connected to the vertical support bar 316 and the frame support member 85". Rotational resistance is applied from the shaft of the alternator 64 to the chain 48" by a transmission which includes: a first drive belt 68 connected to a first pulley (not indicated in the drawings) coupled to a second shaft (not shown); a second drive pulley (not indicated in the drawings) also coupled to the second shaft (not indicated in the drawings); and a second drive belt (not indicated in the drawings) also coupled to the second shaft (not indicated in the drawings) and a second drive belt (not indicated in the drawings) which is coupled to a shaft 80. The first and second drive belts are preferably micro-v belts which promote quiet operation of the apparatus 10" but drive chains, cables, belts, such as cog belts, or other types of power transmitting devices can be used equally as well. The second shaft (not indicated in the drawings) is rotatably secured at one end to the frame support member 82" by a bearing and at the other end by a bearing (not indicated in the drawings) to a second frame support member 85". Both frame members 82" and 85" are attached to the lower cross member 56" and to the vertical supports 28" and 30" respectively. Similarly, shaft 80 is rotatably secured at either end to the frame members 82" and 85" by bearing assemblies (not indicated in the drawings). A pair of one way clutch assemblies 90 and 92 are used to connect the toothed sprockets 52 and 60 to the shaft 80. The function of the one way clutches 90 and 92 is to ensure that the shaft 80 and hence the alternator 64 only rotate in one direction even though the chain sprockets 52 and 60 will be rotating in both directions due to the reciprocating motion of the pedal members 16 and 18 transmitted to the sprockets 52 and 60 by the chain 48".

In addition, the linked drive chain 48" used to connect the one way clutches 90 and 92 to the pedal members 16 and 18 runs underneath the pedal members 16 and 18 as illustrated in FIGS. 12 and 13. This is facilitated by using a chain composed of three separate sections The first portion 318 of the drive chain 48" is made up of links orientated to engage the rotatable toothed sprocket 314 and chain sprocket 52; the second portion 320 is made up of links orientated to engage the toothed pulleys 54 and 58 which have plane of rotation displaced ninety degrees from the sprockets 52 and 60, and third portion 322 is made up of links orientated to engage the toothed sprocket 60 on the clutch 92 and the rotatable toothed sprocket on pedal member 16. This ability to change the orientation of the links in chain 48" is provided by the use of a pair of connecting links 110 and 112. Details of the connecting link 110 are shown in FIG. 5.

Another important feature of this third embodiment of the invention is the provision as illustrated in FIG. 12 for cross damping of the pedal members. To prevent the pedal members 16 and 18 from striking the floor portions of the stair climbing apparatus 10" with undesirably high impact loads on the users legs and feet, it is considered desirable to limit the lower portion of the stroke of each pedal member 16 and 18 to prevent such impacts. Further, it is desirable to gradually reduce or dampen the velocity of the pedal members 16 and 18 as they approach both the lower and upper limits of their strokes.

To prevent pedal members from reaching the upper limits of their strokes, a pair of resilient members 210 as illustrated in FIG. 12 are utilized. The resilient members 210 are secured to the upper cross frame members 316, 324 by bolts or pins or any other suitable means so as to contact the upper surface of the pedal members 16 and 18 at the upper limit of their stroke. A second pair of resilient members 212 are secured by bolts, pins or any other suitable means to a pair of supports 326 so as to contact the lower surface of the pedal members 16 and 18 at the lower limit of the pedal stroke. The supports 326 are secured to the frame base cross member 56 by any conventional means, such as by welding or brazing. Although the spring means disclosed above in connection with the first and second embodiments can be utilized, it is preferred to utilize the resilient members having a generally elliptically shaped configuration as disclosed in FIGS. 12 and 13.

Another important feature of this invention illustrated with respect to the third embodiment, but applicable to all embodiments of the present invention, is a lubricating arrangement which reduces wear on the drive chain 48". A variety of lubricants are contemplated by this invention to lubricate the drive chain 48". For example, non-detergent, synthetic oil with additives can be utilized. However, the preferred embodiment utilizes a 30 weight non-detergent motor oil.

To dispense the fluid onto the chain 48", a positive displacement pumping system is utilized. In the preferred embodiment, two pumps 326 are utilized for simplicity only one pump is illustrated in FIGS. 12, 13 and 15, but it is understood that there are two pumps having the same general configuration and relative location in the apparatus. The pumps 326 are preferably single feed injector pumps made by Oil-Rite Corporation, Catalog No. B-2833 and are powered by an electric motor 328. The pumps 326, together with the motor 328, are secured by a support bracket 329 to vertical support bars 306 and 308. Each pump 326 separately applies the lubricating fluid onto the drive chain 48" on each side of the apparatus thereby permitting a single uniform and equal amount of lubricating fluid to be applied to the chain 48" on each side of the apparatus. It is also understood that a single pump can be utilized to pump fluid, however, because a single pump cannot be as finely adjusted to provide equal amounts of lubricating fluid to the drive chain 48" on each side of the apparatus as two pumps, two separate pumps 326 are used in the preferred embodiment. Both of the pumps 326 are in fluid communication with a reservoir 330. Any number of methods can be used to connect the reservoir 330 to the two pumps 326 such as plastic tubing. However, it has been found that it is preferable to use an elbow coupling 332 to fluidly connect the pumps 326 to the reservoir 330. The reservoir 330, itself, has a top gasket 334 and a check valve 336 which permits the egress of air bubbles out of the reservoir 330, and at the same time prevents contaminants from entering the reservoir. Optionally, the reservoir 330 can be provided with a spring loaded piston to pressurize the lubricating fluid thereby aiding the flow of the oil out of the reservoir. Of course, as one skilled in the art would recognize, other dispensing means such as gravity feed systems controlled by solenoid valve systems can be used in lieu of the pumps.

As shown in FIGS. 12 and 13, the two pumps 326 pump the lubricating fluid to elements capable of applying oil onto the drive chain 48". For applying oil onto the drive chain 48", a wide variety of methods can be used such as brush, roller, drip and spray. In the preferred embodiment, a pair of brushes 338 having bristles preferably composed of nylon are used to apply the lubricating fluid onto the drive chain 48".

The brushes 338 are supported by a pair of metal sleeves 340. The sleeves 340 are secured to the shroud 312 by a bracket 346 and are each connected to tubing 344. The tubing 344 is connected to the pumps 326, thereby providing a method to supply the brushes 338 with lubricating fluid. The brushes 338 are located so as to brush the upper-most portions of the chain 48" to apply lubricant to the chain 48" as it runs over the various sprockets. The brushes 338 are secured in such a manner that they just lightly touch the chain 48" so as to be effective in applying lubricant to the chain 48". In addition, the brushes 338 are also located in a manner sufficient to keep the chain 48" from slipping off the toothed sprockets 52 and 60. The brushes 338 do not press down on the drive chain 48" in order to permit the drive chain 48" to transverse the toothed sprockets 52 and 60, but at the same time, the brushes 338 are located just above the drive chain 48" to prevent the drive chain 48" from slipping off the sprockets 52 and 60.

In addition to using brushes 338, other structure is provided to keep the drive chain 48" from slipping during the operation of the apparatus. A splash cover 346 is provided for each sprocket 52 and 60 for the purpose of preventing the lubricant from being sprayed on other parts of the mechanism which results from the rotation of the chain 48" over the sprocket 52. The splash cover 346 has an aperture 348 for receiving the brush 338 and sleeve 340. Together with the brushes 338, the splash covers 346 also prevent the slippage of the drive chain 48" from either sprocket 52 and 60.

An additional pair of splash covers 350 is utilized to prevent the spraying of lubricant from the drive chain 48" as it rotates over the sprocket 314 on each pedal member 16, 18. Similarly, each pulley 54, 58 is positioned just above a drip tray 352 to allow free movement of the drive chain 48", but close enough to the drip tray 352 to collect the lubricant from the drive chain 48". In addition to its use for collecting lubricant, the tray 352 is positioned close enough to the drive chain 48" to prevent slippage of the drive chain 48" from each pulley 54, 58. The drip tray 352 is secured to a bottom portion of the apparatus 10".

Operation of the third embodiment of the present invention will be described in connection with the block diagram of FIG. 14. Illustrated in schematic form are the basic mechanical elements shown in FIGS. 12 and 13 as described above. In normal operation, the alternator 64 will apply a resistance force to the downward motion of the pedal member 16 through a speed increasing transmission. This resistance force is generated by the alternator 64 in response to a current applied to its field over a line 148. The field current is obtained from a power supply 150 and transmitted via a line 151 to a control amplifier 152. The power supply 150 also provides power to the other various electronic elements. Current output of the alternator 64 may be dissipated in a load resistor 154 when the user exceeds a predetermined maximum step rate. The user's energy is absorbed by the mechanical components of the apparatus 10" except when the user exceeds the maximums step rate.

The alternator 64 and the lubricating means 328 are controlled by computer 156A. In the preferred embodiment, step rate information is transmitted over a line 169 from a tachometer or a rpm sensor in the alternator 64 to the computer 156A. The user's step rate can then be translated into any one of several measurements. For example, the computer 156A can, by simply recording the user's step rate, calculate the step range for that particular stroke or compute the distance traveled by the user in terms of floors. The information generated from alternator enables the computer 156 to operate through an input/output unit 158 via the lines indicated at 160 and 182.

In order to control the alternator 64, the computer 156A contains a read only memory for storing both the preset exercise programs and the control instructions and a random access memory for storing user exercise data. In normal operation, a signal from the alternator's rpm sensor is transmitted over the line 169 to the computer 156A. After utilizing the instructions from its read-only memory and the data from its random access memory, the computer 156A controls the alternator 64, by applying a control signal such as a pulse width modulated signal over a line 166 to the amplifier 152. In this way, computer 156A governs the field current on line 148 and thus the rotational resistance force generated by the alternator 64.

By using the step rate information transmitted on line 169 as a feedback signal, the computer 156A also regulates the maximum step rate of the user by causing the alternator 64 to generate the maximum resistance force when the step rate approaches a predetermined rate. In essence, the computer 156A can limit the step rate by increasing the resistance force produced by the alternator 64 to the point where the user finds it very difficult to drive the pedal members 16 and 18 down faster than the predetermined rate. Thus the alternator 64 is set up to supply a resistance force when the user begins to exceed the predetermined rate, such as when the user begins to exceed the predetermined rate by 20%. Step rate information from the alternator can also be used to help limit the length of strokes of the pedal members 16 and 18. For example, as one of the pedal members 16 or 18 approaches a predetermined lower limit, the computer 156A responds to the position signal on line 168 by increasing the field current of the alternator 64. The resulting increased resistance on the lower pedal member 16 or 18 will decelerate it as it approaches its lower limit thus substantially reducing the user's physical exertions as well as wear on the stops such as 96.

In addition, the step rate information can be translated into a variety of data and transmitted to computer 156B for display on the control and display means 144 to the user. By using the information supplied by computer 156A, the computer 156 can via line 170 generate the various displays that were discussed in connection with FIG. 7 such as the number of floors per minute, the actual step range as a percent of a predetermined step range, the rate of exercise and the amount of calories burned by the user. Moreover, the predetermined step range along with other information can be supplied from the keyboard 146 over a line 172 to computer 156B. This data can then be transmitted over serial link 160 to computer 156A.

The measurements taken from the alternator 64 also help the microcompressor 156A to regulate the dispensing of the lubricating fluid onto the drive chain 48". The computer 156A controls the operation of the electric motor 328 for each pump via the lines indicated at 354. Included with the microprocessor 156A is a non-volatile memory 356 for storing machine usage and lubrication schedule data. The processor 156A controls the electric motor 328 which actuates the pumps 326.

In normal operation, the computer 156A actuates the electric motor 328 of the pumps 326 when a predetermined number of floors are traversed by the pedals 16, 18. The floors climbed may be calculated by algorithms incorporating the acceleration or deceleration of each pedal 16, 18. The acceleration and deceleration of each pedal 16, 18 is stored and added to the previous corresponding value for each step 16, 18. These values are then stored until the necessary number of floors to activate the dispenser are reached. The dispensing system can be activated by the computer 156A as desired by the user. Most preferably, the dispensing system is actuated every 1,000 floors. If a gravity system is utilized in lieu of a mechanized dispenser, the dispensing system is also activated about every 1000 floors although this number can be altered depending upon user preference. In addition, the computer 156A can also be programmed to increase the amount of lubricant pumped after a predetermined number of floors have been traversed. For example, lubricant can be pumped at a constant rate every 1,000 floors and after the number of floors reaches 1,000,000 floors, the amount of lubricant pumped can be adjusted. Optionally, the computer 156A can be programmed to activate the dispensing means after the apparatus 10" has been used for a predetermined time period or any other desirable variable as one skilled in the art would recognize.

Upon activation, the motor 328 runs for a time frame sufficient to pump enough lubricating fluid to adequately grease the drive chain 48". Varying amounts of fluid can be used depending upon a number of factors such as chain length, amount of use of the apparatus 10" and the time intervals between lubrication. Preferably, 0.040 ml. of lubricating fluid are dispensed onto the drive chain 48 for every 1,000 floors although other amounts depending on usage and preference can be utilized.