Backpack based system for human electricity generation and use when off the electric grid

• US 7,851,932 B2
• Filed: 03/31/2008
• Issued: 12/14/2010
• Est. Priority Date: 03/29/2007
• Status: Active Grant

• Current Assignee: Lighting Packs LLC
• Original Assignee: Lighting Packs LLC
• Inventors: Rome, Lawrence Craig, Hofmann, Heath Fred, Wang, Guanghui
• Primary Examiner(s): Patel; T C
• Assistant Examiner(s): Cuevas; Pedro J
• Application Number:
  US12/059,440
• Publication Number:
  US 20090015022A1
• Time in Patent Office: 988 Days
• Field of Search: 290/1.A, 290/1.R, 290/10, 735/141.8, 224/576, 224/633, 224/634, 224/641, 224/929, 224/930, 224/604, 224/627, 224/630, 224/631, 307125-131, 307/150, 323/222, 323/282, 363/21.12, 361/235, 320/114, 320/166, 703/24, 703/28
• US Class Current: 290/10
• CPC Class Codes: A45F 2003/003 combined with other objects; specially adapted for carrying specific objects
• CPC Class Codes: A45F 3/06 specially adapted for military purposes
• CPC Class Codes: A45F 3/08 Carrying-frames; Frames combined with sacks
• CPC Class Codes: F03G 5/00 Devices for producing mechanical power from muscle energy driving cycles B62M
• CPC Class Codes: H02J 7/32 for charging batteries from a charging set comprising a non-electric prime mover rotating at constant speed
• CPC Class Codes: H02K 7/1853 driven by intermittent forces
• CPC Class Codes: Y10S 224/929 Article carrier for electrical device
• CPC Class Codes: Y10S 224/93 Attached to animate bearer

Abstract

An electricity-generating backpack that is substantially lighter in weight, has the multiple springs replaced with one large spring whose spring constant can be adjusted in the field in seconds, and replaces a DC generator with a brushless AC generator that permits approximately 70% generator efficiency and the generation of up to 20 W of electrical power by converting mechanical energy to electrical power. A device is provided that always removes some electricity, but not too much, as necessary to extract large levels of the electricity while controlling damping by providing electrical damping circuits including a DC-DC converter designed to emulate a desired load at its input terminals. Additional electricity generating E-MOD devices may be used for generating additional power by hooking an E-Mod device to a generator and to the backpack belt at the wearer'"'"'s hip and includes a wand that fits against the wearer'"'"'s femur so as to move through a range of motion as the patient walks. The system also provides multiple possibilities of electricity generation when not walking including a light-weight bicycle ergometer which can be mounted to the backpack frame and generate very high power levels (100 W). The electricity generated and stored by the backpack may be used to charge batteries and to power a number of devices that may be carried by the backpack, such as a Sterling Cooler System that is powered by the backpack'"'"'s stored power to provide cooling power for cooling items carried by the backpack.

Claims

1. An electricity generating backpack, comprising:

shoulder straps;

means for accepting a load to be carried by said backpack;

a suspension system having a first portion connected directly or indirectly to said shoulder straps and a second portion connected to said load accepting means, said suspension system incorporating a compliant mechanism that permits said second portion of said suspension system and said load accepting means to be displaced relative to said first portion of said suspension system as a result of a gait of a wearer of the backpack or the application of force to the first or second portions of the suspension system;

a generator that converts a mechanical displacement of said first portion of said suspension system with respect to said second portion of said suspension system into electrical energy;

an energy storage device; and

a load emulating circuit that emulates a desired load to said generator and manages the storage of electrical energy in said energy storage device and/or the discharge of generated electrical energy to minimize overdamping and underdamping of said load by said suspension system.

2. An electricity generating backpack as in claim 1, wherein said compliant mechanism comprises a spring with an adjustable spring constant that can be matched to a frequency of up/down movement of said first and second portions of said suspension system with respect to each other as a result of the gait of the wearer of the backpack or the application of force to the first or second portions of the suspension system.

3. An electricity generating backpack as in claim 2, further comprising a spring tension adjuster for adjusting said spring constant at a position on an outside surface of said backpack.

4. An electricity generating backpack as in claim 1, wherein said compliant mechanism comprises at least one bungee cord with an adjustable spring constant that is matched to a frequency of up/down movement of said first and second portions of said suspension system with respect to each other as a result of the gait of the wearer of the backpack or the application of force to the first or second portions of the suspension system.

5. An electricity generating backpack as in claim 4, wherein said at least one bungee cord comprises a first bungee cord and a second bungee cord against which the first bungee cord can be pulled to control the spring constant of the suspension system independent of the weight carried by the backpack.

6. An electricity generating backpack as in claim 4, further comprising a cam that adjusts the length of the bungee cord, and hence the tension on the bungee cord, said cam being located at a position on an outside surface of said backpack.

8. An electricity generating backpack as in claim 4, further comprising pulleys within said suspension system about which said bungee cord is threaded to increase the length of the bungee cord and hence to increase the compliance of the bungee cord.

9. An electricity generating backpack as in claim 8, wherein said at least one bungee cord may be rerouted through said pulleys to change said suspension system from an electricity generating suspension system into an ergonomic suspension system.

10. An electricity generating backpack as in claim 1, further comprising a rack and pinion gear mechanism disposed such that said mechanical displacement of said first portion of said suspension system with respect to said second portion of said suspension system causes said pinion gear to rotate along said rack and to provide a displacement of a gear of said generator.

11. An electricity generating backpack as in claim 10, wherein said generator and said rack and pinion gear mechanism are located between said load accepting means and said suspension system so as to be substantially removed from environmental elements.

12. An electricity generating backpack as in claim 11, wherein at least said rack and pinion gear mechanism, suspension system, generator, energy storage device, and load emulating circuit are disposed within a protective casing that keeps out dust, dirt and/or water.

13. An electricity generating backpack as in claim 1, wherein said generator comprises a brushless AC motor.

14. An electricity generating backpack as in claim 10 wherein said generator comprises a single stage spur gear that is driven by said pinion gear.

15. An electricity generating backpack as in claim 14, wherein said generator is disposed in a space within dimensions of said means for accepting a load so that the generator or said spur gear may project into said space in a direction substantially perpendicular to a wearer'"'"'s body when the backpack is being worn.

16. An electricity generating backpack as in claim 1, wherein said energy storage device comprises capacitors.

17. An electricity generating backpack as in claim 16, further comprising a DC/DC converter connected to said capacitors for providing a DC output voltage to an electronic device.

18. An electricity generating backpack as in claim 1, wherein said energy storage device comprises a battery charger circuit and rechargeable batteries.

19. An electricity generating backpack as in claim 1, wherein said load emulating circuit comprises a full-bridge diode rectifier circuit having output terminals connected to input terminals of a DC/DC converter that emulates said desired load at input terminals of the generator.

20. An electricity generating backpack as in claim 19, wherein said load emulating circuit further comprises a removable resistive load that is inserted across said output terminals of said rectifier circuit when said energy storage device is full and no load is being powered by said generated electrical energy.

21. An electricity generating backpack as in claim 19, wherein said DC/DC converter comprises a flyback or buck/boost converter operating in a discontinuous current conduction mode.

22. An electricity generating backpack as in claim 21, further comprising a controller circuit that regulates an output voltage of said DC/DC converter and constrains a duty cycle of said DC/DC converter to a maximum value.

23. An electricity generating backpack as in claim 19, further comprising a single-ended primary inductor converter having an input inductor that regulates input current thereto, said single-ended primary inductor converter including means for setting said input current to be a function of input voltage thereto so as to emulate the desired load at input terminals of said single-ended primary inductor converter.

24. An electricity generating backpack as in claim 1, further comprising a bicycle ergometer connected to said generator, said bicycle ergometer including pedals that when pedaled by foot or cranked by hand by a user mechanically cranks said generator to cause said generator to create electrical energy.

25. An electricity generating backpack as in claim 24, further comprising a harness connected to said backpack for restraining the user with respect to the backpack while pedaling the pedals of the bicycle ergometer.

26. An electricity generating backpack as claim 24, wherein the bicycle ergometer includes a second generator and electrical power generated by said second generator is routed to the energy storing device.

27. An electricity generating backpack as in claim 1, further comprising a harness and foot pads configured so that force exerted on the footpads by the feet while the backpack is restrained with respect to the user by the harness causes the relative displacement between the first and second portions of the suspension system resulting in electricity generation.

28. An electricity generating backpack as in claim 1, further comprising an electricity generating module that is adapted to clip to a waist belt of the wearer of the backpack, said electricity generating module comprising:

a second generator having gears that, when cranked, causes a mechanical displacement that is converted into electrical energy; and

a wand that is connected to said second generator and adapted to attach to the outside of the wearer'"'"'s leg and to move with the wearer'"'"'s leg to thereby crank said gears.

29. An electricity generating backpack as in claim 28, wherein said wand comprises at least one hinge that facilitates the conformity of said wand to the contours of the wearer'"'"'s leg.

30. An electricity generating backpack as in claim 1, further comprising an electricity generating module that is adapted to attach at the knee of the wearer of the backpack, said electricity generating module comprising:

a second generator having gears that, when cranked, causes a mechanical displacement that is converted into electrical energy; and

wands that are connected to said second generator and adapted to attach to the outside of the wearer'"'"'s leg and to move with the wearer'"'"'s leg to thereby crank said gears.

31. An electricity generating backpack as in claim 1, wherein said load comprises a cooling system powered by said generated electrical energy.

32. An electricity generating backpack as in claim 31, wherein the cooling system comprises a Stirling Engine cooler.

33. An electricity generating backpack as in claim 1, wherein said generator is removably mounted to facilitate removal.

34. An electricity generating backpack as in claim 1, wherein said means for accepting a load to be carried by said backpack is mounted on and supported by said second portion of said suspension system, whereby said second portion of said suspension system together with said first portion of said suspension system define an internal frame for said backpack.

35. An electricity generating backpack as in claim 1, further comprising a locking mechanism for locking said first portion of said suspension system with respect to said second portion of said suspension system to prevent movement therebetween.

7. An electricity-generating backpack as in 6, wherein the at least one bungee cord is routed though at least one square tube at the outside surface of said backpack such that said cam projects into said square tube and clamps said bungee cord against an inside surface of said square tube.