Abstract: A hand guard removably mountable on the barrel of a firearm such as a rifle. The hand guard is formed in two complementary mating housing components joined in a vertical plane which contains the longitudinal axis of the barrel. The housing components together define a convection chamber which envelops a substantial length of the barrel of the firearm. The joined housing components are generally of pear-shaped cross section having a broadened, flattened bottom member and a narrow, tall chimney member. Heat from the barrel of the firearm creates convection currents in the convection chamber as cooling air is drawn through inlet ports in the bottom member, around the barrel, and out through exhaust ports in sidewalls of the chimney member. A heat shield is carried by each of the housing components and is positioned between the barrel and the outer housing.

Abstract: The present invention is a shaftless butterfly valve that does not require a valve housing and may be mounted to a length of pipe by merely drilling a hole into the wall of the pipe. A stuffing box is attached to a pipe by a U-bolt or other conventional means. The stuffing box serves as a drill jig to center the hole that must be drilled in the pipe. A threaded rotatable stem is arranged to penetrate one side of a pipe perpendicularly to the axis thereof. In the interior of the pipe, the stem is threaded into a stem nut which travels along the length of the stem as the stem rotates. Its travel is limited by a stop pin which is located at the extremity of the stem in the interior of the pipe. An elliptical disc is attached to the stem nut by a hinge pin. The valve is closed and opened by rotating the stem nut along the threaded rotatable stem, which in turn forces the disc to pivot about the stem nut and also about the center of the pipe.

Abstract: A butterfly valve seal arrangement is described in which an annular rubber seat is inserted in the valve body, and a retaining ring is pressed against the seat and retained in position by a number of J-shaped clips which are inserted in a groove of the valve body at spaced intervals and engage another groove in the retaining ring.

Abstract: An eccentric plug valve having a resilient annular ring seating surface surrounding the inlet to the valve and a metal ring, matching the resilient annular ring, embedded in the sealing face of the eccentrically mounted valve plug.

Abstract: An eccentric plug valve having a resilient annular ring seating surface surrounding the inlet to the valve and a metal ring, matching the resilient annular ring, embedded in the sealing face of the eccentrically mounted valve plug.

Abstract: A gate member for a gate valve provides improved sealing by providing for proper orientation of the gate member as it approaches its closed position and then providing improved sealing action as the gate member is closed further. A lip on the gate member overlaps a ledge on the valve body at the opening where the gate member enters the valve chamber. The lip is covered by a seal of resilient material having a cross-sectional shape that cooperates with the valve body to orient the gate member and that controls the compression of the seal between the lip and ledge as the gate member closes further. The shape of the gate member also helps to orient it while it is closing. A spine and a ridged cap of resilient material on the leading edge of the gate member cooperate to prevent blow-by of pressurized fluid when the gate member is closed. Pads integral with the seal contact the corners of the opening initially to orient the gate member and then to fill the corners when the gate member is closed further.

Abstract: The work is scanned by acoustic energy from a focused-arc transducer and from an acoustic-lens transducer. An echo-ranging subassembly energizes the focused-arc transducer and processes the echo trains relfected from the lines or pencils in the work along which the acoustic energy is focused. A holographic echo-processing subassembly is connected to energize the acoustic-lens transducer and to process the echoes reflected from the work where the energy from the acoustic lens impinges. The echo-ranging subassembly and the holographic echo-processing subassembly are enabled alternately and the acoustic energy from the focused-arc transducer and from the acoustic-lens transducer impinge on, and is reflected by, each of a succession of elemental areas of the work. The outputs of the echo-ranging subassembly and of the holographic echo-processing subassembly are supplied to an elastic store which may include one or more shift registers.

Abstract: A digital circuit for detecting changes in the gray scale of scanned images is disclosed. Each line of video information produced by scanning the image is digitized. Each digital sample is compared to digital samples delayed a predetermined amount to generate a difference signal which is indicative of a change in the gray scale having a component perpendicular to the direction of scan. The digitized samples of the video signal are also stored in a memory having a capacity sufficient to store data representing a plurality of scan lines with a typical memory having a capacity for storing digital information representing eight scan lines. Selected digital samples from the stored data are compared to samples of the line being scanned to detect changes in the gray scale having a component parallel to the direction of scan.

Abstract: This invention is a system of automatically classifying defects both for sorting defective products (metallic surfaces, especially tube surfaces) as to the reworking operation required for correcting the defect, and for classifying the defect as to the preceding manufacturing operation which is the most probable cause of that defect and sending a signal to that operation to provide for adjustments to minimize future defects. The system uses a source of electromagnetic radiation (typically a laser beam which is scanned across the surface) and at least two sensors (adjusted such that the radiation is reflected from a defect-free surface principally received by one of the sensors but that there is a measured amount of radiation in the other sensor). An average signal of the principal sensor is developed as a function of scan position. Threshold circuitry detects when the ratio of sensor signal to average signal varies by a predetermined amount.

Abstract: A method and apparatus for lowering the contrast range between a welding arc and its surroundings for remote viewing of an arc welding process. A monochromatic light source (10) is used to illuminate the area surrounding the welding arc (18) and a narrow band interference filter (22) tuned to the wavelength of the monochromatic light (10), is placed in front of a viewing camera (24). The monochromatic light enhances the arc background while the filter (22) attenuates the arc illumination that reaches the camera for a more desirable contrast ratio so that the arc, weld puddle and surrounding area can be visible with a high degree of definition on the monitor.

Abstract: A standard television picture is transmitted over conventional phone lines by sampling and storing one picture element per TV line, and transmitting the information of the stored samples over the phone line as a reduced bandwidth television signal. At the receiver end the transmitted signal is placed into storage and extracted at standard TV rates and written as a TV line onto a rotating video disc. The process is repeated until the final picture to be displayed is assembled on a line-by-line basis on the disc.

Abstract: A reference signal reflecting distortion characteristics caused by surrounding interference conditions is applied to transmitted television video or quasi-video information to effectively cancel the distortion characteristics of the incoming transmitted video information. In the event the signal distortion results from randomly occurring interference such as "airplane flutter" the reference signal may be updated periodically such as during the vertical blanking of each and every incoming television frame. This regular and periodic updating of the reference signal will serve to compensate continuously for varying interference conditions as well as compensating for fixed interference patterns. In the event the interference causing signal distortion is the result of a fixed condition, it may not be necessary to update continuously the reference signal and thus a random or manually initiated update may be acceptable.