Power sensing eddy current resistance unit for an exercise device

• US 7,585,258 B2
• Filed: 10/31/2007
• Issued: 09/08/2009
• Est. Priority Date: 03/23/2005
• Status: Expired due to Fees

• Current Assignee: Saris Cycling Group Incorporated
• Original Assignee: Saris Cycling Group Incorporated
• Inventors: Watson, Edward M., Kolda, Clint D., Wendt, David L.
• Primary Examiner(s): Thanh; Loan H
• Assistant Examiner(s): GINSBERG, OREN ISAAC
• Application Number:
  US11/930,916
• Publication Number:
  US 20080103030A1
• Time in Patent Office: 678 Days
• Field of Search: 482/51, 482/57, 482/63, 482/1, 482 4- 7, 482/61, 482/65, 482/903, 733/790.7, 738/49, 737/79, 738/621.93, 73862331-862336, 188/159, 188161-164
• US Class Current: 482/63
• CPC Class Codes: A63B 2024/0078 Exercise efforts programmed as a function of time
• CPC Class Codes: A63B 2069/164 supports for the rear of the bicycle, e.g. for the rear forks
• CPC Class Codes: A63B 2069/166 supports for the central frame of the bicycle, e.g. for the crank axle housing, seat tube or horizontal tube
• CPC Class Codes: A63B 2069/168 Force transfer through the rim of the wheel
• CPC Class Codes: A63B 21/0051 using eddy currents induced in moved elements, e.g. by permanent magnets
• CPC Class Codes: A63B 21/015 including rotating or oscillating elements rubbing against fixed elements
• CPC Class Codes: A63B 21/225 with flywheels
• CPC Class Codes: A63B 22/0605 performing a circular movement, e.g. ergometers
• CPC Class Codes: A63B 2220/34 Angular speed
• CPC Class Codes: A63B 2220/54 Torque
• CPC Class Codes: A63B 2225/50 Wireless data transmission, e.g. by radio transmitters or telemetry
• CPC Class Codes: A63B 24/00 Electric or electronic controls for exercising apparatus of preceding groups; Controlling or monitoring of exercises, sportive games, training or athletic performances
• CPC Class Codes: A63B 69/16 for cycling , i.e. arrangements on or for real bicycles
• CPC Class Codes: Y10S 482/903 Utilizing electromagnetic force resistance

Abstract

An exercise system includes a user input arrangement; a rotatable member that rotates in response to an input force applied by a user on the user input arrangement; a power sensing arrangement that senses power applied to the rotatable member due to the input force applied by the user; and a variable resistance arrangement interconnected with the power sensing arrangement and with the user input arrangement. The resistance arrangement applies resistance to rotation of the rotatable member, and is variable in response to the power sensing arrangement to vary the resistance applied to the rotatable member. The variable resistance arrangement may be a brake that interacts with the rotatable member to resist rotation of the rotatable member, and to thereby resist the input force applied by the user. The variable resistance arrangement includes a controller for controlling the brake in response to the power sensing arrangement.

Claims

1. A power sensing resistance arrangement for an exercise device that includes an input area for applying user input power, comprising:

a rotatable member that rotates in response to the application of the user input power to the input area, wherein the input area comprises a pedal arrangement, wherein the rotatable member rotates about an axis of rotation in response to the application of user input power to the pedal arrangement;

a conductive member associated with the rotatable member, wherein the conductive member is formed of an electrically conductive material and rotates in response to rotation of the rotatable member; and

a magnet assembly which cooperates with the conductive member to establish eddy currents to resist rotation of the rotatable member, wherein the magnet assembly includes a magnet carrier having one or more magnets located adjacent the conductive member at a location radially offset from the axis of rotation;

a nonrotatable beam having a supported inner end and an unsupported outer end, wherein the inner end of the beam is fixed and wherein the magnet carrier is secured to the beam at a location axially outwardly of the supported inner end of the beam; and

one or more strain sensing members interconnected with the beam between the magnet carrier and the supported inner end of the beam, wherein the beam, the magnet carrier and the one or more strain sensing members are configured and arranged such that the magnet carrier is spaced outwardly from the one or more strain sensing members in an axial direction parallel to the axis of rotation, and wherein the beam, the magnet carrier and the one or more strain sensing members are spaced radially outwardly from the axis of rotation, and wherein the one or more strain sensing members are configured and arranged to sense strain experienced by the beam when the rotatable member is rotated to establish eddy current resistance by the interaction between the magnets of the magnet carrier and the conductive member, wherein the strain in the beam corresponds to the user input power.

2. The resistance arrangement of claim 1, wherein the rotatable member comprises a wheel of an exercise cycle, wherein the input area comprises a pedal arrangement associated with the exercise cycle.

3. The resistance arrangement of claim 1, wherein the magnet assembly comprises a mounting member secured to the inner end of the beam, wherein the mounting member is configured to support the inner end of the beam, and wherein the one or more strain sensing members comprise one or more strain gauges secured to the beam outwardly of the mounting member.

4. The resistance arrangement of claim 3, wherein the beam includes an area of reduced thickness to increase the tendency of the outer end of the beam to bend upon application of eddy current resistance.

5. The resistance arrangement of claim 3, further comprising means for causing relative movement between the magnet carrier and the conductive member for varying the magnitude of the eddy current forces caused by rotation of the conductive member relative to the magnet carrier.

6. The resistance arrangement of claim 5, wherein the means for causing relative movement between the magnet carrier and the conductive member comprises a linear actuator interconnected with the mounting member, wherein the linear actuator is operable to axially move the beam, and thereby the magnet carrier, toward and away from the conductive member.

7. The resistance arrangement of claim 6 wherein the linear actuator comprises a linear motor having an output member interconnected with the mounting member.

8. The resistance arrangement of claim 7 wherein the mounting member comprises a bracket that includes a tab, wherein the output member is secured to the tab.

9. The resistance arrangement of claim 8, wherein the linear motor is operated by electronic components carried by a circuit board to selectively move the magnet carrier relative to the conductive member.

10. A method of controlling a resistance arrangement of an exercise system that includes an input area for applying user input power, wherein the exercise system includes a rotatable member that rotates in response to a user-applied input force at the input area, comprising the steps of:

rotating the rotatable member about an axis of rotation in response to application of the user-applied input force to the input area, wherein the input area comprises a pedal arrangement, wherein rotation of the rotatable member in response to the application of input power to the pedal arrangement causes rotation of a conductive member; and

resisting the rotation of the rotatable member through the use of eddy currents established by interaction of the conductive member and a magnet arrangement, wherein the magnet arrangement includes a magnet carrier having one or more magnets located adjacent the conductive member at a location radially offset from the axis of rotation;

a nonrotatable beam having a supported inner end and an unsupported outer end, wherein the inner end of the beam is fixed and wherein the magnet carrier is secured to the beam at a location axially outwardly of the unsupported inner end of the beam, wherein the beam, the magnet carrier and the one or more strain sensing members are configured and arranged such that the magnet carrier is spaced outwardly from the one or more strain sensing members in an axial direction parallel to the axis of rotation, and wherein the beam, the magnet carrier and the one or more strain sensing members are spaced radially outwardly from the axis of rotation; and

sensing strain in the beam using one or more strain sensing members when the rotatable member is rotated to establish eddy current resistance by the interaction between the magnets of the magnet carrier and the conductive member, wherein the beam, the magnet carrier and the one or more strain sensing members are configured and arranged such that the magnet carrier is spaced outwardly from the one or more strain sensing members in an axial direction parallel to the axis of rotation, and wherein the strain in the beam corresponds to the user input power.

11. The method of controlling a resistance arrangement as set forth in claim 10, further comprising the step of sensing a speed of rotation of the rotatable member, and calculating the user input power based on the sensed strain in the beam in combination with the speed of rotation of the rotatable member.

12. The method of controlling a resistance arrangement of claim 10, further comprising the step of adjusting the position of the magnet carrier relative to the conductive member in order to adjust the resistance of the resistance arrangement.

13. An exercise system, comprising:

a user input area that includes a pedal arrangement;

a rotatable member that rotates about an axis of rotation in response to an input force applied by a user on the pedal arrangement;

a conductive member that rotates in response to rotation of the rotatable member; and

a resistance unit comprising a magnetic member positioned adjacent the conductive member at a location spaced radially outwardly of the axis of rotation, for providing eddy current resistance to rotation of the rotatable member in response to rotation of the conductive member;

means for causing relative movement between the magnetic member and the conductive member for varying the eddy current resistance; and

torque sensing means associated with the magnetic member, including a nonrotatable cantilever member defining an unsupported outer end with which the magnetic member is interconnected, and strain sensing means for sensing strain in the cantilever member, wherein the strain sensing means comprises one or more strain sensors interconnected with the cantilever member at a location radially outwardly of the axis of rotation and axially inwardly of the magnetic member.

14. The exercise system of claim 13, wherein the cantilever member comprises a beam having an outer end and a supported inner end, wherein the magnetic member is interconnected with the outer end of the beam and wherein the strain sensing means is secured to the beam inwardly of the outer end of the beam and outwardly of the inner end of the beam.

15. The exercise system of claim 14, wherein the means for causing relative movement between the magnetic member and the conductive member comprises an actuator interconnected with the inner end of the beam.

16. A power sensing resistance arrangement for an exercise device that includes an input area for applying user input power, comprising:

a rotatable member that rotates in response to the application of the user input power, wherein the rotatable member rotates about an axis of rotation;

a conductive member associated with the rotatable member, wherein the conductive member is formed of an electrically conductive material and rotates in response to rotation of the rotatable member; and

a magnet assembly which cooperates with the conductive member to establish eddy currents to resist rotation of the rotatable member, wherein the magnet assembly includes a magnet carrier having one or more magnets located adjacent the conductive member at a location radially offset from the axis of rotation;

a nonrotatable beam having a supported inner end and an unsupported outer end, wherein the inner end of the beam is fixed and wherein the magnet carrier is secured to the beam at a location axially outwardly of the supported inner end of the beam;

one or more strain sensing members interconnected with the beam between the magnet carrier and the supported inner end of the beam;

a mounting member secured to the inner end of the beam, wherein the mounting member is configured to support the inner end of the beam, and wherein the one or more strain sensing members comprise one or more strain gauges secured to the beam outwardly of the mounting member; and

means for causing relative movement between the magnet carrier and the conductive member for varying the magnitude of the eddy current forces caused by rotation of the conductive member relative to the magnet carrier, wherein the means for causing relative movement between the magnet carrier and the conductive member comprises a linear actuator interconnected with the mounting member, and wherein the linear actuator is operable to axially move the beam, and thereby the magnet carrier, toward and away from the conductive member, and wherein the beam, the magnet carrier and the one or more strain sensing members are configured and arranged such that the magnet carrier is spaced outwardly from the one or more strain sensing members in an axial direction parallel to the axis of rotation, and wherein the beam, the magnet carrier and the one or more strain sensing members are spaced radially outwardly from the axis of rotation, and wherein the one or more strain sensing members are configured and arranged to sense strain experienced by the beam when the rotatable member is rotated to establish eddy current resistance by the interaction between the magnets of the magnet carrier and the conductive member, wherein the strain in the beam corresponds to the user input power.

17. The resistance arrangement of claim 16 wherein the linear actuator comprises a linear motor having an output member interconnected with the mounting member.

18. The resistance arrangement of claim 17 wherein the mounting member comprises a bracket that includes a tab, wherein the output member is secured to the tab.

19. The resistance arrangement of claim 18, wherein the linear motor is operated by electronic components carried by a circuit board to selectively move the magnet carrier relative to the conductive member.