Abstract: A Pendulum Valve having Independently and Rapidly Controllable Theta- and Z-axis Motion. The valve actuator used in the present invention provides the benefit of wide open unrestricted flow of a pendulum valve coupled with the high-resolution and wide dynamic range flow throttling of a ball or butterfly valve. The actuator mechanism will include motor drives and associated control system so that the drives are closely coupled to give highly controlled motion. The drive assembly introduces a concentric shaft arrangement that, when coupled with the highly controllable motor drives, exploits a cam-follower arrangement to make the relative rotation between the two concentric shafts result in highly controlled theta and z-axis motion. Finally, the plate to seal spacing afforded is greater than previously possible with prior valve actuator mechanisms, thereby substantially reducing flow turbulence through the valve as the valve plate eclipses the valve ports.

Abstract: A Pendulum Valve having Independently and Rapidly Controllable Theta- and Z-axis Motion. The valve actuator used in the present invention provides the benefit of wide open unrestricted flow of a pendulum valve coupled with the high-resolution and wide dynamic range flow throttling of a ball or butterfly valve. The actuator mechanism will include motor drives and associated control system so that the drives are closely coupled to give highly controlled motion. The drive assembly introduces a concentric shaft arrangement that, when coupled with the highly controllable motor drives, exploits a cam-follower arrangement to make the relative rotation between the two concentric shafts result in highly controlled theta and z-axis motion. Finally, the plate to seal spacing afforded is greater than previously possible with prior valve actuator mechanisms, thereby substantially reducing flow turbulence through the valve as the valve plate eclipses the valve ports.

Abstract: A liquid crystal composition comprises a host material capable of exhibiting a smectic C phase, and a chiral dopant material which imparts or enhances chirality in the host material. The composition exhibits &tgr;-Vmin curves. The chiral dopant material comprises at least first and second chiral centers. The chiral centers individually produce, in the liquid crystal composition, different and complementary temperature coefficients of spontaneous polarization within a predetermined temperature range. The chiral centers are present in the liquid crystal composition in relative amounts such that regions of the &tgr;-Vmin curves across the predetermined temperature range are substantially coincident.

Abstract: An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.

Abstract: A liquid crystal composition comprising (1) an achiral host mixture comprising (a) at least 20% by weight, based on the total weight of the host mixture, of a mixture of fluorinated phenylpyrimidine compounds capable of exhibiting an SmC phase, and (b) at least 10% by weight, based on the total weight of the host mixture, of at least one fluorinated terphenyl compound which enhances the phase sequence of said mixture, wherein the total amount of (a) and (b) is at least 50% by weight based on the total weight of the host mixture; and (2) at least one chiral dopant in an amount of not more than 10% by weight of the total weight of the composition.

Abstract: An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.

Abstract: An electoclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.

Abstract: The invention describes liquid crystal compounds of formula (I) which are suitable for use in liquid crystal devices including those devices which exploit the electroclinic effect, ##STR1## where X may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, hydrogen, alkyl or alkoxy; X.sub.2 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, hydrogen, alkyl or alkoxy; X.sub.3 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, alkyl, alkoxy or hydrogen; X.sub.4 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, alkyl, alkoxy or hydrogen; provided that at lease one of X or X.sub.2 is CF.sub.3, CF.sub.2 H, CFH.sub.2, CN, NO.sub.2 or halogen; A and B are independently phenyl, mono-fluorinated phenyl, di-fluorinated phenyl or cyclohexyl; Y may be single bond, COO, OOC, C.dbd.C; q may be 0 or 1; R.sub.1 may be an end group of formula (II) wherein Z may be a single bond, O, CO.sub.2, (CH.sub.2).sub.n or (CH.sub.2).sub.

Abstract: A tachometer includes a transducer for sensing pressure variations at the end of the exhaust pipe, or other easily-accessible point, due to explosions in an internal combustion engine. The transducer produces a corresponding electrical signal having a prominent selected frequency component which varies in frequency in direct proportion with engine speed. As the engine speed is increased and decreased, the electrical signal is passed through an amplifier with automatic gain control, and through a tracking filter to separate the prominent frequency component from other components. The separated component may be applied to a frequency-measuring device calibrated to display the revolutions per minute of the engine, or to a computer which computes and displays the result of an acceleration burst test.