| 摘要 |
<p>A force sensor device establishes a balance of forces on an axially-displaceable sensor member (70) which is at least partly of magnetic material. For a horizontal sensor member (70) the balance is between a constant magnetic bias force (F4) and an opposed counteracting magnetic force (F1) generated by an energised coil (L1) whose energisation is controlled in a feedback loop (88) dependent on the sensed axial positions of the sensor member (70). For a vertical sensor member the balance is between gravity (weight) and the counteracting magnetic force (Fig. 2). The feedback loop (88) is preferably of the second-order kind (fig. 7). The generation of magnetic force is by having an end (75) of a magnetic portion (72) of the sensor member terminate within a coil (L1) to generate a solenoid-like attractive force thereon. A magnetic-position sensing device detects the position-sensitive coupling of two coils (L2:L3) by a magnetic portion (74) of the sensor member (70) which extends entirely through one coil (L2) and terminates within the other. A force (T) to be measured is applied axially to the sensor member (70) acting to disturb the force balance. The force sensor device has application to measuring tension in a running thread (Fig. 4).</p> |
