Abstract: Apparatus for indicating incomplete and complete fastening of a screw includes a washer and a ring of a generally flat synthetic resin sheet. The washer includes a pair of washer portions of a generally flat, round shape and a joint portion interconnecting the washer portions to face them in opposite directions to enable the washer portions to receive a shank of a screw in the openings thereof. The lengthwise section of the joint portion forms generally a U shape. The ring is made of a generally round, deformable material and is inserted between the pair of washer portions thus facing each other. The deformable material is expanded radially outward, when compressed by the washer portions receiving the shank of the screw when fastened. Upon the compressive force reaching a predetermined value, the ring will be broken due to the pair of washer portions overlaying one another.

Abstract: In a flooring panel, plural blocks are held by a holding member of a flexible material so that one section is formed by at least one block with a space for laying a cable defined between adjacent sections. A cover member overlying these spaces is arranged to present a surface continuous with the upper surface of the blocks to form a flat, top surface of the flooring panel. The flooring panel is in the form of a rectangular modular flooring panel of at least one shape and size. A plurality of cable laying spaces in communication with one another are defined by laying a plurality of such modular flooring panels on a building floor as a function of the amount of cables to be laid. In such a manner, the operation of cable laying and construction of the flooring panels on the permanent building floor may be performed more efficiently while the interaction between the cables of different kinds is minimized.

Abstract: A screw member having a plurality of heads by providing one or more thin neck portions to be sheared at a predetermined torque, in which a collar having a skirt portion with its one part being cut away is fitted on the thin neck portion from the lateral side to expose the outer head part alone and to engage the cap member fitted from the side of the bearing surface of the inner head part of the screw member, and the cap member is inserted between the skirt of the collar and the inner head part to thereby prevent the collar from slipping out.

Abstract: A screw member having a plurality of heads by providing one or more thin neck portions between them to be sheared at a predetermined torque, wherein a cap member surrounding the outer periphery of an inner head part from the side of its bearing surface is engaged with the inner head part so as not to displace outwardly slipping out of it, and the inner peripheral surface of the cap member is made conformable to a shape of the outer peripheral surface of a socket of a screw driving tool to be fitted on the inner head part.