Abstract: A molded foam article with an integral skin is produced by blow-molding a parison in a cavity of a metal mold to form a hollow member, filling the hollow member with pre-expanded thermoplastic resin besides before cooling and solidification of the hollow member, and heating the pre-expanded beads to cause the beads to expand further and fuse together. A filler for the pre-expanded thermoplastic resin beads is provided with a cutter for making a hole in the hollow member before introducing the resin beads into the hollow member.

Abstract: A process for producing expanded plastic with a skin and a molding apparatus therefor, the process including blowing a parison being held in a closed blow mold to obtain a hollow article, filling the hollow article with thermoplastic preexpanded resin beads before the hollow article is cooled to solidify, heating and fusing said beads, and cooling the expanded plastic. A hollow article and an expanded body are completely fused together, and improved productivity is obtained.

Abstract: A photoconductive toner of the present invention contains a resin binder, zinc oxide, and a dye for sensitization of the zinc oxide, the sensitizer dye being represented by the following formula (1): ##STR1## wherein, X.sup.1 to X.sup.8 represent hydrogen or methoxy groups with a proviso that at least one of X.sup.1 to X.sup.8 represents a methoxy group, R.sup.1 and R.sup.2 are independently alkyl groups or derivatives thereof, and n is an integer. A photoconductive toner of the present invention satisfies requirements for both sensitivity and coloration, and, moreover, possesses high photosensitivity in the laser wavelength region as compared with conventional toners.

Abstract: A hydraulic cylinder unit which comprises a cylinder, a piston slidably inserted in the cylinder in a fluid-tight manner, and a piston rod connected to the piston at one end thereof and projected outwardly from the cylinder and which is operated to extend the piston rod by a fluid supplied under pressure into one chamber in the cylinder and to retract the piston rod by a mechanical force applied to the piston or piston rod (single-acting type) or by a fluid supplied under pressure into the other chamber in the cylinder (double-acting type) is used for lifting, transporting or displacing a material in various industries. In the use of such hydraulic cylinder unit, load in the axial direction of the unit is applied to the cylinder unit by a load or material carried on operated by the cylinder unit or the piston rod thereof and detection of such load is often required. This load is detected by a strain gauge mounted in the piston rod.

Abstract: A safety-guard for a crane having a boom, comprising stress-detecting means which is provided to lifting hydraulic cylinder unit for the boom so as to detect a stress applied to the cylinder unit in the direction along the axis of said unit and to give out a signal, one or more functional potentiometers which correspond to respective spans of the boom and give out safety-limit stress-reduced signals at the concerned span of the boom respectively with the movement of movable contacts that are moved in response to the vertical revolution of the boom, and a safety device which receives said signals coming from the stress-detecting means and one of the functional potentiometers corresponding to the concerned span of the boom and indicates the concerned ratio of operation of the crane or gives a warning on falling-down and/or breaking-down of the crane. Thus, operator can catch operation state of the crane with ease for a safe operation of the crane.