The support structure 202 may be made from any suitably strong material, for example aluminum, steel or plastic. The end 205 is fixedly coupled to a first upright support 202 a of the support structure 202 by adhesives, mechanical coupling via fasteners, or any other secure means of attachment. Equation 3, above, clearly shows the non-linear nature of the torque versus θ relationship. The torque applied to the piezo flexure 12 deforms the piezo flexure 12 to an angle whereat the piezo flexure 12 is stable at two locations as shown in FIG.
A biasing element is operably associated with the free end of the beam and the support structure to exert a compressive force on the beam. The biasing element 208 and the beam 204 are secured to the support structure 202 such that the biasing element 208 can exert a compressive force on the beam 204 with an over-center compressive biasing force. The beam is secured at one of its ends to the support structure. The biasing element 208 is also supported fixedly or on a hinge from the support structure 202. The beam 204 includes at least one piezoelectric layer 210 which is secured to a surface of a substrate 212. Even more preferably, a second piezoelectric layer 214 is secured to an opposing surface of the substrate 212. Thus, in one form, the beam 204 is formed by substrate 212 with piezoelectric layers 210 and 214 disposed on opposite surfaces of the substrate 212. The substrate 212 itself may be formed from any suitable flexible material, such as plastic, aluminum, steel, titanium, or even composite materials.
Dolor Espalda Media
4 and 5, each end 138B, 139B of the flexure components 138 and 139 include an opening 140A, 140B which receives an end 142, 143 of the biasing element 114. In practice, any suitable means for attaching the ends 142, 143 of biasing element 114 can be employed. Still further, a mass under gravity could be employed to exert the compressive force on the piezoelectric beam 204, 304 or 404. Still further, a force developed by flowing air or water could be used to provide the compressive force on the beam 204, 304 or 404. Virtually any form of force that can be controlled such that it applies a compressive force to the piezoelectric beam 204, 304, 404 could be implemented.
11 and 12 represent only a small plurality of potential configurations to provide the compressive force on the piezoelectric beam 204, 304 or 404. For example, instead of using coil or at leaf springs, a pressure vessel, a pressurized diaphragm, a rubber bumper, a hydraulic piston, or a centripetal force produced by a rotating mass could be employed to provide the compressive force.
- En cuclillas
- Montagu, A.: El sentido del tacto, Aguilar
- Presión arterial baja
- Cuando lleve tiempo sentado, levántese y estire, camine, y cambie de posición con frecuencia
The increased frequency band is a significant advantage in systems requiring variable frequency drive motors. The limitation of needing to “tune” the system around the resonant frequency of the cantilever beam imposes a significant limitation in terms of efficient operation of the system shown in FIG. The selection of the tip mass, to essentially tune the system to operate efficiently at the resonant beam frequency, means that the system will not be efficient in harvesting energy at other frequencies above and below the resonant frequency of the cantilever beam. When properly matched, the apparatus 10 is highly efficient. Como solucionar el dolor de espalda . The compressive force generated by the biasing elements 114, 116 is sufficient to maintain the flexure assembly 102 in a deflected (i.e., bowed) orientation at one of two stable positions 144 or 146. Longitudinal line 148 represents the plane the flexure assembly 102 would reside in without the compressive force from the biasing elements 114, 116. When in either of positions 144 or 146, the flexure assembly 102 is highly responsive to low frequency vibration energy and is easily deflected to the other stable position by such energy.