Abstract: A magnetic rotary locking mechanism for locking a plate or sheet-like member by placing it in tension which may be adapted to provide a self-tensioning locking device for securing a printing plate to a printing cylinder in a rotary printing press. The base and rotatable bar each have formed therein a plurality of magnetic strips which generate a plurality of magnetic fields so that the bar magnetic fields are attracted to the base magnetic fields at a first angular position of the bar with respect to the base and are repelled by the base magnetic fields at a second angular position of the bar with respect to the base.

Abstract: A magnetic rotary locking mechanism for locking a plate or sheet-like member by placing it in tension which may be adapted to provide a self-tensioning locking device for securing a printing plate to a printing cylinder in a rotary printing press. The base and rotatable bar each have formed therein a plurality of magnetic strips which generate a plurality of magnetic fields so that the bar magnetic fields are attracted to the base magnetic fields at a first angular position of the bar with respect to the base and are repelled by the base magnetic fields at a second angular position of the bar with respect to the base.

Abstract: Gutter cleaning apparatus is disclosed comprising a housing having a first and second opening therein for delivering fluid under pressure into a rain gutter mounted on a building. The openings are diametrically opposed and the flow of fluid through the openings is controlled by a valve that alternately opens one opening and closes the other. The valve is controlled by increasing and decreasing the fluid pressure in the housing. When fluid pressure is at a pre-determined lower level, the valve is in a neutral position between the two openings. A stream deflector plate extends from the bottom of the valve and depending on which direction the deflector plate is positioned, increasing the pressure in the housing will cause the valve to move into one of the openings. Once the valve is positioned in one of the openings the direction of the stream deflector plate is changed since it is mounted on the valve in a manner so as to engage the housing when the valve is closing one of the openings.

Abstract: Oil tank cleaning appartus is disclosed comprising a rotary cutter rotatably mounted on a shaft and operatively connected to impellers to turn the cutter. A conduit is operatively connected to the cutter for leading a fluid away from the cutter. The cutter extends into edges that are pitched in a manner to propel the cutter and conduit when the cutter is rotated. When the cutter and conduit are immersed in an oil tank, oil drawn through the conduit will impinge against the impellers to turn the cutter and thereby provide the torque necessary to cause the cutter to move through sludge in the bottom of the oil tank, the sludge also being taken up through the conduit along with the oil.The conduit may comprise a flexible conduit having a pair of opposed wires secured along the length thereof, the wires lying in a common plane to prevent the flexing of the conduit in a direction in which the plane extends.