A recumbent stepper includes a frame, a pair of lever arms, pedals, pulleys, flexible members, springs and adjustable resistance devices The pair of lever arms are pivotally attached to the frame and are movable from a retracted position to an extended position. Pedals are attached to each lever arm. The pair of pulleys are rotatably attached to the frame. The pair of flexible members are attached between the lever arms and pulleys and are wound around the pulley when the lever arm is in the retracted position and deploys as the lever arm moves to the extended position. Springs are operably attached to each pulley such that each lever arm is biased to the retracted position. Adjustable resistance devices are operably connected to each pulleys whereby increasing the resistance on the pulley increases the force required to move the lever from the retracted position toward the extended position.

FIELD OF THE INVENTION

This invention relates to steppers and in particular recumbent steppers wherein the each leg works independently.

BACKGROUND OF THE INVENTION

The exercise category of steppers includes both upright and recumbent devices designed for both exercise and rehabilitation of certain conditions. Recumbent steppers are a relatively recent addition to the category, originally designed to provide a full body work-out for those recovering from cardiac episodes. Aside from providing cardiovascular exercise, the major advantage of recumbent steppers is their ability to accommodate a joint range of motion (from extension to flexion) of less than 110°, a figure that devices based on circular pedal require.

U.S. Pat. No. 5,356,356 issued Oct. 18, 1994 to Hildebrandt et al. discloses a recumbent exercising device that works both the upper and lower extremities and includes an integrated, adjustable seat. In the Hildebrandt device, the action of the arm levers are coupled together and the action of the foot pedals are coupled together and the upper and lower halves are contralaterally synchronized to simulate a natural “walking” motion. Resistance is generated magnetically, providing constant, smooth, and adjustable effort.

While the action of the lever arms (both upper and lower) and contralateral synchronization provides a familiar and natural motion, the dependence of the lever arms restricts range of motion in the elbow joint and knee joint, respectively, if the range of motion is not identical side-to-side. In other words, each joint is not allowed to work to its respective abilities because the joint with the least range of motion dictates how long the stroke length will be because the motion is dependent.

U.S. Pat. No. 6,790,162 issued September 2004 to Ellis et al. discloses a similar recumbent exercising device, working both the upper and lower extremities and also including an integrated, adjustable seat, but the two foot pedals and two arm levers employ a one-way clutch so that the action of each respective movement is independent and not coupled together as found in the U.S. Pat. No. 5,356,356. In addition in the Ellis device the upper half and lower half are not synchronized in any way. A stop structure is employed to limit movement in both fore/aft directions and resistance is provided by way of eddy current brake. However magnetically (or eddy current) generated resistance is speed dependent, so the resisting force is only constant at a constant operator rate. This device allows each joint to work to its respective abilities due to the use of a one-way clutch and resulting independent movement, but the resisting force is common to both sides. This has the effect of the weakest leg and/or arm dictating the amount of resistance and not allowing the stronger arm and/or leg to work to its muscular ability.

In this single resistance generator arrangement, the resisting force works against all operator inputs. Therefore if more than one limb is moving against the resistance at the same time, the resistance felt by each limb will be less than if fewer (down to one) limbs are moving. This results in a varying resistance felt by the limbs as input movements overlap.

All of these devices transform the linear movement of the operator, into a circular motion about a fixed shaft, by means of a rigid mechanical connection to the shaft. This means the point of operator input, be it a foot pad or handle, travels in an arc centered on the fixed shaft. The result is that the input force of the operator is divided into a radial component and tangential component, relative to this shaft. Only the tangential component of the input force acting through the length of the input lever, creates torque to overcome the resisting torque and cause movement of the shaft and hence lever. Therefore, the current art requires a varying input force to move any input lever against a resisting force. The operator may not notice this variation, but for rehabilitation purposes, this is not a desirable condition and can cause injury to the recovering limb.

Accordingly it would be advantageous to provide a recumbent stepper that has a generally constant resistance force. It would be advantageous to provide a recumbent stepper wherein each pedal is operated independently such that the stroke length may be different for each leg and the resistance may be different for each leg. Further it would be advantageous to provide a recumbent stepper that can easily be used with different chairs including wheel chairs.

SUMMARY OF THE INVENTION

The present invention relates to a recumbent stepper having a frame, a pair of lever arms, pedals, pulleys, flexible members, springs and adjustable resistance devices The pair of lever arms are pivotally attached to the frame and are movable from a retracted position to an extended position. Pedals are attached to each lever arm. The pair of pulleys are rotatably attached to the frame. The pair of flexible members are attached between the lever arms and pulleys and are wound around the pulley when the lever arm is in the retracted position and deploys as the lever arm moves to the extended position. Springs are operably attached to each pulley such that each lever arm is biased to the retracted position. Adjustable resistance devices are operably connected to each pulleys whereby increasing the resistance on the pulley increases the force required to move the lever arm from the retracted position toward the extended position.

In another aspect of the invention there is provided a recumbent stepper having a frame, a pair of lever arms and a pair of pedals. The frame has a hole therethrough and a generally elongate rod adapted to be removably positioned in the hole and extending outwardly on the either side of the frame, whereby the elongate rod is adapted to engage the front legs of a four legged chair. The pair of lever arm systems each have a lever arm pivotally attached to the frame whereby each lever arm is movable from a retracted position to an extended position The pair of pedals are pivotally attached proximate to the distal end of the respective lever arm.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIG. 1the recumbent stepper10of the present invention includes a frame12and a pair of left and right tangent lever system14,16.

In one embodiment the frame12is releasably attachable to a chair18as shown inFIG. 1. In another embodiment the frame12is releasably attachable to a wheel chair20as shown inFIG. 16. Alternatively as shown inFIGS. 14 and 15a chair22may form part of the device24. It will be appreciated by those skilled in the art that the recumbent stepper10may be attached to a wide variety of chairs and that the chairs shown herein are by way of example only.

As best seen inFIG. 6, the frame12includes a pair of left and right shaft frame members26,28. The left and right tangent lever systems14,16(shown inFIGS. 1 to 4) are pivotally attached to lever shaft30which are attached to left and right shaft frame members26,28. Right and left pivot shaft frame members26,28are attached together with the shaft30and a foot plate32. Foot plate32is designed to support the weight of the device10. Bridge member34connects the pivot shaft frame members26,28to the rear portion of the frame36. The rear portion of the frame36includes a right and left arm38,40and a leg42extends downwardly therefrom. A cross member44is attached to leg42and right and left casters46,48are attached thereto. Arms38,40each have a chair rod bore50formed therein adapted to receive chair rod52(shown inFIG. 4). Outer bushing bores54are formed in the arms38,40.

The chair rod52is preferably a removable rod which passes through the bores50in the arms38,40of frame12. The chair rod52is positionable behind the front legs of a chair18on which the operator sits.

As can be seen inFIGS. 4,5and7, each tangent lever systems14,16has a lever arm56pivotally attached to shaft30. A pedal58is attached to each lever arm56proximate to the distal end thereof. A pedal nut60may be used to attach each pedal58to each lever arm56. Alternatively pedal58may be attached to the lever arm56without a nut60. A bushing62is positioned on the shaft30and is pressed into lever arm56. The lever arm56moves between a retracted and extended position.

Each pulley64is rotatably attached to frame12. Each flexible member63is attached between the respective pulley64and respective pedal58. Preferably the flexible member63is a non elastic strap. Pulley64has a flat strap groove around the circumference, a strap anchor hole in strap groove, a clutch hub hole in center and a spring pocket on one side thereof. Each pulley64has a spring66attached thereto to bias the pulley and therethrough the lever arm into the retracted position. Preferably spring66is a flat stainless steel spiral spring wound within the pulley pocket with inner end attached to clutch hub and the outer end attached to frame12. A stud67protrudes from the arm40of frame12and it engages a loop on the outer end of the spiral spring66. Pulley64is rotatably attached to frame12through resistance shaft72.

A right and left clutch68is operably connected between the frame12and the respective pulley such that the pulley freewheels when the lever moves from the extended position to the retracted position. Preferably the clutch68is a roller clutch. Preferably clutch68is a mechanical component (preferred type supplied by Torrington) that is pressed into a clutch hub70and slipped onto a resistance shaft72such that left roller clutch free wheels in clockwise direction and right roller clutch free wheels in the counter clock wise direction. Clutch hub70is a metal hub with finished bore into which roller clutch68is pressed and is inserted into bore in pulley64. The shaft72is a metal shaft with finish surface to accept roller clutch68and is supported by outer bushing74and center bushing76and accepts disc hub78. An outer bushing80is positioned in finished bore for resistance shaft72to slip into, attached to a hole in arm38of frame12. A center bushing76is a metal hub with finished bore through which resistance shaft72is attached and to which friction disc74is attached such that it rotates around resistance shaft72axial center.

A friction disc84, as seen inFIGS. 7 to 9, is a flat round metal disc that is attached to the disc hub78. Friction disc84has a plurality of evenly spaced holes86proximate to the perimeter of the disc and the holes86define a circle that is just smaller than the outside diameter of the disc. An optical switch88is mounted on the frame12such that a light beam from optical switch88passes through holes86as the disc84turns. Optical switch88is a device which uses an electric current to project a small focused beam of infrared light across a gap to a receiver, which produces an electrical signal if the beam is being received. The optical switch is operably connected to a control system or chip attached to a display92if present.

A resistance caliper94is attached to the frame12and straddles the friction disc84. Caliper94holds a station friction pad96and a moveable friction pad98in place. Stationary friction pad96is mounted on a metal backing plate and is attached in a fixed position to the resistance caliper94such that the friction surface is parrallel to the friction disc84surface. The pad area of the stationary friction pad96is projected normal to its exposed surface (parrallel to the resistance shaft axis of rotation) this projected area contacts the friction disc84. Moveable friction pad98is a friction material which is mounted on a metal backing plate and is attached in a moveable position to the resistance caliper94such that the friction surface is parallel to the friction disc84surface such that if the pad area is projected normal to its exposed surface (parrallel to the resistance shaft axis of rotation) this projected area would all contact the friction disc84. A caliper support bolt100(shown inFIG. 9) passes horizontally through the frame member12and supports the calipers94vertically but does not restrict the calipers movement horizontally. A cable102operably connects the calipers94to a force lever104and in turn to a knob106(shown onFIG. 5) which is adjustable by the operator. Cable102is a steel cable connecting the caliper actuation lever105to the force levers104to transfer the movement of the force levers104to the caliper levers105. Cable102is provided with a cable sheath108which is a flexible sheath that is not compressible axially and which the cable102passes through and moves freely within. The force lever104is a lever actuated by the threaded shank of the force adjustment knob106. The force lever104pivots on the lever pivot shaft110and pulls the cable102. The lever pivot shaft110is a shaft on which the force levers104pivot and connected to the frame12. Knob106is a hand actuated knob, preferably with an ergonomic rubber grip. Knob106is operably connected to a knob plate112attached to the frame12. Knob106is connected such that it faces the operator. Knob106is connected to a threaded shank that turns in a mating threaded hole in the knob plate112so that the end of the shank advanced against the force lever104. Calipers94are moveable responsive to the caliper actuation lever106that is actuated by a cable102such that the space between the friction pads96,98is reduced when the lever is actuated against its spring return.

The stepper includes a device for determining an accurate work measurement. Specifically it includes a strain gauge120that is operably connected to the pulley64for determining the load on the pulley. Strain gauge transducer120is a commercially available component that converts the tensile load applied along the center line of the pulley64to a proportional electric voltage. Strain gauge transducer120is attached between the frame12by way of an anchor bolt122and calipers94with male rod end124and female rod end126.

It will be appreciated by those skilled in the art that a basic version of the device may also be produced which does not include a strain gauge120as shown inFIG. 9wherein a connector121is used to connect male rod end124and female rod end126. This version would like be used in association with the basic version of the device shown inFIG. 3, specifically the version without the display panel.

A cover128, as shown inFIGS. 4 and 5, houses the frame12and a portion of the right and left lever tangent lever systems14,16as can be seen inFIGS. 1 to 4. The recumbent stepper10may have a digital display130. The digital display130may be connected to a computer132either wirelessly or with a wire or by way of thumb drive134so that the data from the digital display may be stored and progress may be tracked.

The left and right tangent lever system14,16may also each include a return stopper135whereby the retracted position may be varied. Specifically the return stopper includes a return stop bar136having a plurality of holes therein137adapted to receive a return stop pin138. The return stop bar136is attached to the lever arm56and the position is adjusted by the position of the return stop pin138. A stopper139extends outwardly from the return stop bar136such that it hits the frame12thereby stopping the movement of the lever arm56and defining a retracted position. Preferably stopper139is a leaf spring so that when the operator moves the lever arm into the retracted position it is a “soft” stop.

It will be appreciated by those skilled in the art that there are a number of ways of providing resistance to the pulley64of the recumbent stepper10. For example an internal brake drum140is shown inFIGS. 10 and 11and an external brake drum156is shown inFIGS. 12 and 13.

Internal brake drum140includes a drum142attached to the resistance shaft72. Upper144and lower146internal shoe are moveable into contact with the drum142. A cam or internal shoe lever148is pivotally connected to arm40of frame12. A return spring150is a tension spring that connects the upper internal shoe144to the lower internal shoe146and pulls the shoes away from the drum142when the cam or lever148is released.

External brake156includes a drum158attached to the resistance shaft72. Upper160and lower162external shoe are moveable into contact with the drum158. A cam or external shoe cable164is operably connected to arm40of frame12. A sheath165protects the cam shoe cable164. A return spring166is a compression spring that connects the upper external shoe160to the lower external shoe162and pushes the shoes away from the drum158when the cam or lever164is released.

One of the advantages of the embodiment of recumbent stepper10shown inFIGS. 1 to 5is that it can be easily moved and it can easily be used with a wide variety chairs that have two front legs. However, in an alternate embodiment a chair22may form part of the device as shown inFIGS. 14 and 15.

Chair22has a seat170and a back172which is a component of the chair22for the operator that is integrated with the rest of the recumbent stepper24. The seat170and back172provide optimum positioning and support. The chair22can be transport while attached to the recumbent stepper device24. The recumbent stepper24is essentially the same as the recumbent stepper10described above except that the chair22is attached to the chair rod174. The front legs176of the chair22are attached to the chair rod174and chair rod is pivotally attached to the frame12whereby the chair can be pivoted from the in use position shown inFIG. 14to the transport position shown inFIG. 15. Preferably the chair has arm rests178that are pivotally attached to the back172at the sides thereof. A central support180attaches the seat170to the frame and is moveable from the in use position to the transport position.

As shown inFIG. 16the recumbent stepper10can also be easily used with a wheel chair20.

There are a number of advantages that are realized by the embodiments herein. For example the recumbent stepper of the present invention is portable. Further in at least one embodiment it can be used in association with a standard chair. It includes an attachment means that allows the recumbent stepper to be easily attached to standard chair.

The recumbent stepper10is designed to be portable and preferably is of a size and weight that a person who is able to walk will be able to move. The fore aft weight distribution of the device is biased away from the front, where the transport handhold (not shown) is located. PLEASE CONFIRM. Two wheels46,48under the rear of the device provide stability. These wheels46,48rotate about a common horizontal axis that is perpendicular to the main fore aft axis of the stepper10and primary direction of transport movement. These wheels46,48can also swivel about a vertical axis to provide maneuverability during transport. The stepper10is sized to fit through standard doorways.

The stepper10is used from a sitting position as provided by a standard chair of a variety of common designs that have four legs, a horizontal seat with height of approximately 17 inches and a back angle of between 0 and 15 degrees from vertical. This would include wheelchairs20as discussed above.

The stepper10easily connects to a chair18by means of a single rod52that is positioned behind the front legs of the chair18. This rod52is free to be removed from the mating sleeve in the device from either side and then be inserted back through the device after the device has been located such that the chair rod52is behind the chair's front legs. This rod52resists movement of the stepper10away from the chair due to the foreward force that the operator exerts on the stepper10during use. No other connection activity is required.

The operator (patient) can be seated in the chair18before the stepper10is positioned for attachment and use. The stepper10is easily maneuverable due to the little effort required to move it and dual caster wheels46,48at the chair end. The attachment to the chair via the simple horizontal transverse rod52is extremely simple and fast.

As discussed above the left and right lever systems14,16are independent of each other. Thus someone could exercise only one leg or they could have different range of motion for each leg and still use the stepper10. As well, they could have different resistance on each leg.

The range of stroke of the lever arm56and pedal58of the stepper10accommodates adult users of any height. The entire range pedal travel available begins with the pedal retracted to the bodywork just in front of the operator's seat and in one embodiment extends forward 26 inches. Referring toFIGS. 17 and 18the fully retracted position is shown at A and the fully extended position is shown at B and the distance between A and B is 26 inches. The maximum leg stroke for the an operator 6 foot 4 inches is 14 inches, therefore, the entire spectrum of operator starting and ending points is contained within the range of pedal58travel, making adjustment based on operator height unnecessary.

The end of the return stroke or the retracted position may be set by use of return stop bar136as described above. Therefore, the minimum knee angle can be set independently for each leg by an adjustable stop on each lever. Referring toFIG. 17the stepper10is shown with a 6 foot 4 inch operator200and referring toFIG. 18the stepper10is shown with a 5 foot 2 inch operator202. As can be seen the starting or retracted position204is quite different for tall operator200than the retracted position206for small operator202. Similarly the extended position208for tall operator200is quite different than the extended position210for short operator202. Further, the starting, and ending point of the leg stroke is completely independent for each leg. As discussed above, the left and right legs operate mechanisms that are completely separate, to the extent that a one-legged operator can use the device. The return stroke stop136is spring loaded to provide a soft stop for the operator.

The resistance force to movement of the pedal58by the operator can be set independently for the needs of each leg. The movement of each leg drives a separate pulley64. This pulley64drives a shaft72on which a brake or friction disc84is rigidly mounted. A brake caliper94is mounted over each brake or friction disc84and is anchored to the device's chassis. The cable102that activates the lever106, which moves each of the caliper's friction pads against the rotating disc, is actuated by a lever which is moved by the rotation of the left or right force adjustment knob106.

The resistance setting is independent of the adjustment of the caliper94or wear of the brake pads96,98. The caliper94and the linkage that anchors it to the chassis incorporate spherical rod ends. These allow the caliper94to float transversely (parallel to the pulley shaft) to accommodate for brake pad wear and adjustment differences, without affecting the calipers parallelism alignment to the disc.

The resistance force is constant throughout the length of the leg stroke due to the constant tangential transfer of the operator's force to the resistance mechanism pulley64. The operator force acts along a flexible tension member63in the form of a flat strap. This strap63is wrapped on a pulley so that the force to move the pulley is generally tangential at all points in the pedal travel. Therefore, the constant resistance of the mechanical brake is resisted by a constant force vector along the strap63.

The resistance force is generally constant regardless of the operator's rate of stroke due to the mechanical brake used to provide the resistance force.

Mechanical brakes use friction to create resisting force. This is governed by the equation Force=Area×normal force×coefficient of friction for the contacting materials. Speed does not enter into this relationship, except at higher speeds, which are unlikely to be encountered in this design.

The calculation of work and power is based on force measurements taken over each inch or less of foot movement. The accuracy of the measurement is independent of stroke rate. This is achieved by using a photo eye signal or optical switch88to trigger reading the force measurement from the strain gauge transducer120. This photo eye straddles the brake or friction disc84which has a series of holes86near the edge of the disc and evenly spaced around its perimeter. As the disc turns due to the input from the operator, the light beam can pass through and signal the switch as each hole passes by the beam. The disc does not turn during the return stroke and therefore no force measurements are taken when the operator is not contributing any work. The calculation of work and power is computed and displayed independently for each leg. There is a separate photo eye switch or optical switch88and strain gauge transducer120for each leg and the data is stored separately. All force, distance and time data is stored by leg for the duration of the therapy session. This is stored on a memory chip mounted on the device. The memory chip is attached to display panel130. All force, distance and time data for the therapy session can be transmitted wirelessly to a computer132or to a thumb drive134for further analysis, comparison and storage.

As with all resistance mechanisms, the resisting force is created by converting the operator work into heat. This is done by the caliper pads sliding along the moving brake disc which is all located under the bodywork. The pulleys are equipped with slots, shaped to move air outward transversely as the pulley turns due the operator's foot retracting to the beginning of the stroke. Cooler fresh air is drawn up through the opening in the bottom of the bodywork, through the turning pulley to be exhausted through a hole in the bodywork covering the outer surface of the pulley. This air movement will transfer heat from the mechanical brake assemblies from under the bodywork.

Embodiments of present invention utilize generally all of the operator's linear input force, throughout the entire length of the stroke, to turn a fixed shaft that is providing a constant resisting torque. This is accomplished firstly by having the operator input lever rotate freely about a shaft. Secondly, a flexible tension member, in the form of a non elastic strap, transfers the operator's linear input force to the resisting force mechanism. The strap is wound on to a pulley that is rigidly affixed to the resisting shaft in the operator input direction. The strap pulls on the pulley tangentially at all points throughout the entire stroke range. Therefore, all of the operator force acts tangentially to the radius of the pulley, which is the resisting force lever.

Generally speaking, the systems described herein are directed to recumbent steppers. As required, embodiments of the present invention are disclosed herein. However, the disclosed embodiments are merely exemplary, and it should be understood that the invention may be embodied in many various and alternative forms. The Figures are not to scale and some features may be exaggerated or minimized to show details of particular elements while related elements may have been eliminated to prevent obscuring novel aspects. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. For purposes of teaching and not limitation, the illustrated embodiments are directed to recumbent steppers.

As used herein, the terms “comprises” and “comprising” are to construed as being inclusive and opened rather than exclusive. Specifically, when used in this specification including the claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or components are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.