24,859 research outputs found

    Apparatus of small size can be extended into long, rigid boom

    Get PDF
    Three metal sheets, having prenotched edges, are interlocked as they are unrolled from three feed rollers which form a triangle. The apparatus is relatively small, and the sheets can be erected into a rigid triangular boom of considerable length

    Analysis of the forming characteristics for Cu/Al bimetal tubes produced by the spinning process

    Get PDF
    Tube spinning technology represents a process with high forming precision and good flexibility and is increasingly being used in the manufacture of bimetal composite tubular structures. In the present study, a forming analysis of clad tube and base tube in spinning process was conducted through numerical simulations and experiments. There was an equivalent stress transition on the interface since the stress transmission was retarded from clad tube to base tube. The yield strength became a main consideration during a design bimetal composite tube. Meanwhile, the strain distributions in axial direction, tangential direction, and radial direction were also investigated to determine the deformation characteristics of each component. As the press amount increased, the strain of clad tube changed more than base tube. As the feed rate increased, the strain decreased in axial direction and tangential direction but almost unchanged in radial direction. Simultaneously, a method for controlling the wall thickness of the clad tube and the base tube is proposed. These results to guide the design of bimetal tube composite spinning process have the certain meanings

    Determination of the main parameters of apparatus for densification of veneer

    Get PDF
    Considered the principal device for sealing veneer with two drive rollers, each with a diameter of 150 mm. Defined the required compression force and feed force veneer veneer with his seal. The simplified scheme of heating of sheet of an interline interval is offered during its consolidation by two steams of rollers. The numerical estimations which have shown possibility of achievement of temperature of plastic deformation of an interline interval approximately on 57% of its thickness from outer sides of sheet are executed.,Considered the principal device for sealing veneer with two drive rollers, each with a diameter of 150 mm. Defined the required compression force and feed force veneer veneer with his seal. The simplified scheme of heating of sheet of an interline interval is offered during its consolidation by two steams of rollers. The numerical estimations which have shown possibility of achievement of temperature of plastic deformation of an interline interval approximately on 57% of its thickness from outer sides of sheet are executed

    AFES Circular 135

    Get PDF

    Development of a beam builder for automatic fabrication of large composite space structures

    Get PDF
    The composite material beam builder which will produce triangular beams from pre-consolidated graphite/glass/thermoplastic composite material through automated mechanical processes is presented, side member storage, feed and positioning, ultrasonic welding, and beam cutoff are formed. Each process lends itself to modular subsystem development. Initial development is concentrated on the key processes for roll forming and ultrasonic welding composite thermoplastic materials. The construction and test of an experimental roll forming machine and ultrasonic welding process control techniques are described

    Tension is servo controlled in film advance system

    Get PDF
    Servocontrol device feeds film into a roller system. Two linear potentiometers connected to spring loaded tension rollers furnish servo input signal. Can be used in any continuous material transport system

    Integration and Conventional Systems at STAR

    Full text link
    At the beginning of the design and construction of the STAR Detector, the collaboration assigned a team of physicists and engineers the responsibility of coordinating the construction of the detector. This group managed the general space assignments for each sub-system and coordinated the assembly and planning for the detector. Furthermore, as this group was the only STAR group with the responsibility of looking at the system as a whole, the collaboration assigned it several tasks that spanned the different sub-detectors. These items included grounding, rack layout, cable distribution, electrical, power and water, and safety systems. This paper describes these systems and their performance.Comment: 17 pages, 6 figures, Contribution to a NIM Volume Dedicated to the Detectors and the Accelerator at RHI

    Tethered satellite control mechanism

    Get PDF
    The tethered satellite control mechanisms consist of four major subsystems. The reel drive mechanism stores the tether. It is motor driven and includes a level wind to uniformly feed the tether to the reel. The lower boom mechanism serves two primary functions: (1) it measures tether length and velocity as the tether runs through the mechanism, and (2) it reads the tether tension at the reel. It also provides change the direction for the tether from the reel to the upper boom mechanism. The deployment boom positions the upper boom mechanism with satellite out of the cargo bay. The deployment function places the 500-kg satellite 20 m away from the Space Shuttle (producing a small natural gravity gradient force), impacts an initial velocity to the satellite for deployment, and allows for satellite docking at a safe distance from the body of the Space Shuttle. The upper boom mechanism (UBM) services three functions: (1) it provides tether control to the satellite as the satellite swings in and out of plane; (2) it reads tether tension in the low range during the early deployment and final retrieval parts of the mission; and (3) it produces additional tether tension at the reel when tether tension to the satellite is in the low range

    Innovative solution for reducing the run-down time of the chipper disc using a brake clamp device

    Get PDF
    Wood-chippers are widely used machines in the forestry, urban and agricultural sectors. The use of these machines implies various risks for workers, primarily the risk of contact with moving and cutting parts. These machine parts have a high moment of inertia that can lead to entrainment with the cutting components. This risk is particularly high in the case of manually fed chippers. Following cases of injury with wood-chippers and the improvement of the technical standard (Comit\ue9Europ\ue9en de Normalisation-European Norm) EN 13525: 2005 + A2: 2009, this technical note presents the prototype of an innovative system to reduce risks related to the involved moving parts, based on the \u201cbrake caliper\u201d system and electromagnetic clutch for the declutching of the power take-off (PTO). The prototype has demonstrated its potential for reducing the run-down time of the chipper disc (95%) and for reducing the worker\u2019s risk of entanglement and entrainment in the machine\u2019s feed mouth
    corecore