Abstract: A first washer is disposed on an upper surface of a member to be tightened and its projecting portion is inserted into a clearance formed between a trunk of a bolt and a piercing hole of the member to be tightened. A second washer is disposed on an upper surface of the first washer and its claw portion is met with engaging teeth of the first washer. A head portion of the bolt is fitted into a fitting portion of the second washer. The first washer and the second washer are allowed to relatively rotate in a direction of tightening the bolt which is achieved by the claw portion sliding along sloped wall surfaces of the engaging teeth and are prevented from relative rotation in a direction of loosening the bolt which is achieved by the claw portion engaging with substantially vertical wall surfaces of the engaging teeth.

Abstract: Means for preventing the common rotation of one of a bolt and a nut in the case where the other of said bolt and said nut is rotated by means of a tool, such as spanner, to screw up a plurality of members by the use of the bolt and the nut is provided.

Abstract: The present invention is directed to a method and an apparatus for formation of images by particles on a photosensitive plate. Particles employed are translucent, whereby a charge holding the particles to the photosensitive plate may be efficiently removed from selected particles by image-wise light from an original document, etc., so ensuring production of well-defined images. For production of color images, there is employed a panchromatized plate and particles which are transparent to different types of light and have associated therewith dye material permitting production of clearly defined color images, it being made possible to obtain a color copy of an original document in a process requiring only one exposure stage and only one development stage.

Abstract: Disclosed is a light transmission particle containing a colorless sublimable dye, an acyl leucophenoxazine compound suitable for use in the formation of a color image. This particle can produce a clear color image having little fogging and having an excellent resolving power.

Abstract: Disclosed is a light transmitting particle containing a sublimable color-former that is a pyridine derivative suitable for use in the formation of a color image. This particle can produce a clear color image having little fogging and having an excellent resolving power.

Abstract: Disclosed is a light transmission particle containing a colorless sublimable dye that is a spirobenzopyrane indole compound suitable for use in the formation of a color image. This particle can produce a clear color image having little fogging and having an excellent resolving power.

Abstract: Image forming particles for use in electrostatic image formation, which particles have a light transmitting property, said particles comprising an electrically conductive material and subliming substance. The electrically conductive particles exhibit superior translucency which enables a charge preliminarily imparted to a photoconductive support member to be readily erased upon exposure to light image from an original, with consequent reduction of electrostatic attraction between the particles and the support member to minimum for presenting clear and definite images without fogging.

Abstract: An electrophotographic process of forming a dye image comprising the steps of:(1) charging a photosensitive element formed on an electroconductive support by electrical charging, said photosensitive element consisting essentially of photoconductive particles and sublimable dyes, (2) exposing the charged photosensitive element to a light image, (3) developing the photosensitive element with acidic toners, (4) heating the photosensitive element to sublime the sublimable dyes, and (5) transferring the dye images to a dye-image accepting substrate with the aid of solvents.An electrophotographic material comprising an electroconductive support and a photosensitive element (i.e., photoconductive layer) formed thereon, said photosensitive element consisting essentially of photoconductive powders and sublimable dyes.

Abstract: The present invention relates to an electrophotographic color process comprising the steps of: (a) charging an electrophotographic light-sensitive material by corona discharge, said material having at least two kinds of color-producing photoconductive particles disposed at random on an electroconductive support, said color-producing photoconductive particles consisting essentially of a photoconductive particle, a sensitizer and a leuco dye, (b) exposing said charged material to light, (c) developing said material by toner containing acid substance, and producing color in the leuco dye by the interaction of the leuco dye with the acid substance, and forming a color image by carrying out once the procedure of charging, exposing and developing.