Abstract: Method and apparatus for determining the length of a tubular member such as a pipe are disclosed. A burst of acoustical pulses are emitted from a sending unit and are received by a reference acoustical transducer and by a slave acoustic transducer. The slave transducer emits a return pulse which is used to compute the duration of the sound propagation interval between the ends of the pipe. A phase angle compensation factor is computed by measuring the phase shift of the signal received by the reference transducer with respect to the signal emitted by the master transducer.

Abstract: A method for teaching word recognition in a course of reading instruction in which a student is taught to identify letters of the alphabet, to identify letters as being vowels or consonants and to recognize that combinations of letters and vowels form syllables. The method is based upon the student's recognition of the following voewl (V) and consonant (C) syllable patterns: V; CV; VC; CVC; CVV; and CVCE. A set of cards is provided with each card within the set bearing a syllable having a vowel or a combination of one or more consonants with one or more vowels arranged according to one or more of the syllable patterns. The student is instructed to select the card from the set which corresponds in sound with the first syllable of a selected word until the assembled cards define a selected word.

Abstract: A closure member for a pressure vessel having a ring assembly that has a radially expansible outside diameter and an inside diameter defining a central area, with the central area of the diameter greater than one-half the outside diameter, and with the ring assembly selectively engaging the pressure vessel between a locked position and an unlocked position.

Abstract: Cyclonic separator apparatus for extracting entrained lint particles from an effluent air stream prior to discharge into the atmosphere. A rotary filter is combined with a cyclonic separator of the type having a vertical settling chamber for separating relatively dense fiber product from airborne lint entrained in a product stream. The separator apparatus includes a housing forming an air stream inlet, a lint discharge outlet and a clean air outlet. A rotatable screen is interposed between the air stream inlet and the clean air outlet whereby the entrained lint is accumulated on the screen as the effluent air stream flows through the screen for discharge into the atmosphere. The accumulated lint deposit is presented to the lint discharge outlet as the screen turns. A first fan blower is coupled to the separator for inducing an upwardly moving inner vortex for entraining the airborne lint, and coupled to the filter inlet for discharging the entrained lint onto the rotatable screen.