A stator winding apparatus includes devices for adjustment of the pivot of the needle and of the stroke of the needle. The apparatus includes a winding shaft assembly which includes a drive shaft, a second shaft which reciprocates linearly in response to rotation of the drive shaft, and a third shaft in which said second shaft is coaxially received. A crank shaft is coupled by an adjustable coupling to the drive shaft and the second shaft to adjust the stroke of the second shaft. Reciprocation of the second shaft causes the needle to pivot radially inwardly and outwardly.
A liquid crystal display device includes a liquid crystal display cell having a layer of a twisted-nematic liquid crystal material with a positive dielectric anisotropy constant and constructed such that a plurality of voltage potentials applied to the liquid crystal cell may firstly induce a Freedricksz transition of the liquid crystal material and then select either one of first and second metastable states caused by relaxation of the liquid crystal material succeeding the Freedricksz transition. A first voltage potential is adjusted higher than a threshold voltage necessary to cause changes from an initial state to the metastable states, a second voltage potential to select one of the metastable states is adjusted in comparison with a voltage potential necessary to switch between the metastable states, and a third voltage potential is applied as a modulation voltage during or succeeding the application of the second voltage potential. By applying at least one of these voltage potentials, the modulation of the metastable states can be carried out, thereby causing arbitrary changes in transmittance of the liquid crystal cells and achieving a multilevel gray scale in the liquid crystal display device.
An apparatus and method for driving a winding head of a stator winding machine. The winding head is the end of a winding shaft which reciprocates and oscillates. The reciprocation of the winding shaft (5) is driven by rocking drive means (13) connected to motor means (10) and comprises means for balancing comprising at least two counter rotating counterweights (26, 31) which rotate about a driving shaft (12) in planes parallel to the axis of the wire winding shaft (5). The rocking drive means comprise a bar (22), orthogonal to the wire winding shaft (5) and to the driving shaft (12), which has a component of motion parallel to the wire winding shaft (5). The reciprocation stroke (8) and the balancing of the apparatus can be carried out with an easy operation from the outside (39) by means of a tooling, manual or automatic.
Depending on the diameter of the wire wound into coils on a stator core, it is desirable to adjust the distance that the wire exit nozzle of a stator needle tip is spaced from the longitudinal axis of the winding head. An adjustable winding head comprising a needle head and one or more needle tips pivotally mounted on the needle head. Pivotal movement of the needle tips relative to the needle head changes the distance that the wire exit nozzles thereof are spaced from the longitudinal axis of the needle head. Adjustment is carried out preferably while the winding spindle is stationary, requires only simple tools, and does not require removal of the needle tips from the needle head.
