1. An air permeable cushioning structure comprising:
a first elastic layer having plural first plastic threads irregularly wound therein, wherein a wound connection portion of any two first plastic threads is melted together, and a disconnection portion of any two first plastic threads has a first pore formed thereon;
a second elastic layer having plural second plastic threads irregularly wound therein, wherein a wound connection portion of any two second plastic threads is melted together, and a disconnection portion of any two second plastic threads has a second pore formed thereon;
a third elastic layer having plural third plastic threads irregularly wound therein, wherein a wound connection portion of any two third plastic threads is melted together, and a disconnection portion of any two third plastic threads has a third pore formed thereon.
2. The air permeable cushioning structure as claimed in claim 1, wherein a density of the first elastic layer is 30 to 80 kgand a thickness of the first elastic layer is 5 to 100 mm.
3. The air permeable cushioning structure as claimed in claim 1, wherein a density of the second elastic layer is 30 to 100 kgm3, and a thickness of the second elastic layer is 30 to 200 mm.
4. The air permeable cushioning structure as claimed in claim 1, wherein a density of the third elastic layer is 40 to 100 kgm3, and a thickness of the third elastic layer is 30 to 200 mm.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An electro-mechanical actuation system comprising;
a first motor and a second motor, wherein the first and second motor are controlled such that when said first motor is operating said second motor is not operating;
a linear actuation component connected to said first motor via a gear system and connected to said second motor via said gear system;
a brake associated with the second motor and connected to the gear system via a brake gear; and
wherein said brake is operable to dissipate a torque spike in excess of a corresponding maximum static torque rating when said brake is in an engaged position and said first motor is operating.
2. The electro-mechanical actuation system of claim 1, wherein said brake comprises:
a brake plate having a friction material thereon;
a clapper plate engaged with said brake plate when said brake is engaged and disengaged from said brake plate when said brake is disengaged;
at least one spring operable to maintain said clapper plate engaged against said brake plate via a spring force; and
an electromagnet, wherein the electromagnet is controlled to overcome said spring force when said electromagnet is activated, thereby disengaging said clapper plate from said brake plate.
3. The electro-mechanical actuation system of claim 2, wherein said brake is engaged in a non-energized state and disengaged in an energized state.
4. The electro-mechanical actuation system of claim 1, wherein the linear actuation component comprises an internal stop, and wherein said linear actuation component is configured such that continued actuation of the linear actuation component is prevented upon contact with said internal stop.
5. The electro-mechanical actuation system of claim 4, wherein said torque spike is caused by contact between said linear actuation component and said internal stop.
6. The electro-mechanical actuation system of claim 1, wherein said gear system is a gear train.
7. The electro-mechanical actuation system of claim 6, wherein said gear train includes a differential.
8. The electro-mechanical actuation system of claim 6, wherein said gear train includes a planetary gear and a sun gear.
9. The electro-mechanical actuation system of claim 1, wherein when said brake is in an engaged position, the brake is configured to slip when said torque spike is in excess of said corresponding maximum static torque rating, thereby dissipating said torque spike.
10. A method for dissipating torque spikes in an electro-mechanical actuation system comprising the steps of:
operating a first motor;
maintaining a second motor in a non-operating state, the second motor having a corresponding brake;
maintaining said brake in an engaged position;
dissipating a torque spike in excess of a maximum static torque rating of the first motor in said brake while said first motor is operating.
11. The method of claim 10, wherein maintaining said brake in said engaged position comprises maintaining said brake in a non-energized state.
12. The method of claim 11, further comprising transmitting said torque spike from said first motor to said brake through a gearing system.
13. The method of claim 10, wherein the step of dissipating a torque spike in said brake comprises allowing said brake to slip in response to the torque spike, thereby dissipating said torque spike.
14. The method of claim 10, wherein said torque spike is a torque spike resulting from a linear actuation component of the electro-mechanical actuation system contacting an internal stop.