Abstract: A flat type resinoid grinding wheel, which comprises abrasive grains and phenol resin bond, contains inorganic substance particles in the abrasive grains. The particles are almost the same as the abrasive grains in size but are lower than the abrasive grains in hardness value. Furthermore, the porosity of the grinding wheel is limited to 15% or less.

Abstract: A stapler including a staple extruding member, a staple magazine and a base plate, which are pivotally held together by means of a pin. Underneath the staple magazine is fitted a sliding member of a specified thickness and shape so as to cover only one side of the staple ejection slot at the front of the staple magazine. The sliding member is mounted on the magazine so as to move from a position underneath the staple ejection slot to a position away from the staple ejection slot and closer to the pin. The staple magazine is adapted to receive a staple holding block, which block carried staples upon its upper surface. The staple holding block is provided with a hollow which extends longitudinally of the block and is open to the upper and lower surfaces of the block by means of a split groove. Inside this hollow is fitted a columnar spring bearing portion of a magazine follower. A detachable spacer may be fitted to the staple ejection slot at the end of the magazine.

Abstract: A process for producing a highly porous and extremely hard resinoid rotating disk grindstone that withstands rapid rotation comprising the steps of forming uncalcined unit grindstones by inserting 1-3 glass mesh cloths into a layer of polishing powder every 2-10 mm in the grindstone; press molding this reinforced composition; and these unit grindstones being laminated and united by calcination. The grindstone obtained using this process is highly porous compared to ordinary composite grindstones. Its bulk specific gravity is 2.2 or below and the degree of bonding indicates great hardness (0.25 or below). Also, its grinding capacity proved to be about 2-3 times that of grindstones formed using the same materials, and about 1.3-1.8 times that of commercial high-performance products.

Abstract: A laminated rotary grinder including a parallity of thin grinding stone discs laminated together in an axial direction wherein the thickness of each of the discs is in the range of one to ten mm, the width of each space between each of the laminated discs is substantially within the range of 0.05 to 4 mm and the thickness of each of the discs is always greater than the space between discs.

Abstract: Connected temporary fastening nails including vertically oriented connecting parts formed by making cuts at fixed intervals along the length of a continuous elastic part which is substantially square in cross-section and which has a hollow space in the interior of the continuous elastic part and a plurality of small diameter nails each provided through adjacent connecting parts at fixed intervals along the length of the continuous elastic part.

Abstract: This invention relates to a novel structure for securely joining ceiling boards, wainscots and other similar types of paneling and boarding to supports or base members such as joists or furring strips. This joining structure finds application in securing ceiling boards (such as gypsum boards or slag wool boards) having relatively low mechanical strength to joists. Employment of the novel and unique joining devices permits easy construction and assembly at high working efficiency. Since the boards are joined together securely by the devices fitted into slots formed at the edges of the boards and are not suspended from the ceiling but are tightly attached to the joists, an elegant and monolithic finish as well as increased structural strength is provided.