Abstract: A process for manufacturing a siamese-type clyinder block which is disclosed herein comprises a blank making step of providing a cylinder block blank in which a sleeve made of a cast iron is cast in each cylinder barrel of a siamese-type barrel made of an aluminum alloy and consisting of a plurality of cylinder barrels connected in series, and a mechanically working or machining step of forming the inner peripheral surface of each sleeve of the cylinder block blank into a true circle. The process is characterized in that the blank making step includes placing highly rigid sleeves each having a thickness set as large as 10% or more of the inner diameter thereof into a siamese-type cylinder barrel molding cavity in a mold and then pouring a molten metal of aluminum alloy under a pressure into the cavity to effect a casting. The sleeve is cast-in as it is at an ambient temperature or in a heated state.

Abstract: A siamese-type cylinder block blank which is composed so that upon the pouring a molten metal under a pressure, a sleeve of cast iron is cast in each cylinder barrel of a siamese-type cylinder barrel made of an aluminum alloy and consisting of a plurality of cylinder barrels connected in series. The cylinder block blank is characterized in that each sleeve cast presents a substantially oval configuration in section with the lengthwise axis parallel to the direction of cylinder barrels arranged, as a result of the reception of the solidification shrinkage force of each cylinder barrel.

Abstract: A method for manufacturing a siamese-type cylinder block, which comprises the steps of pouring under pressure a molten metal of aluminum alloy into a siamese-type cylinder barrel molding cavity with an expansion force applied to the sleeve placed in such cavity, and then removing the expansion force after the completion of solidification of the molten metal to cast a cylinder block blank, and subjecting the resulting blank to a working operation for forming the peripheral inner surface of the sleeve into a true circle.

Abstract: An image-generating device for an electrophotographic copying machine; is provided with a white-color reflection plate at a specific position on a component part supporting the light source that is used for illuminating the original document in order to prevent charge from being generated at the position where the separation belt comes into contact with the photoreceptor, while the device sufficiently cancels charge by effectively applying a tapered tip part of the white-color reflection plate without causing a black streak to be generated.

Abstract: A toner replenishing device is improved to prevent unexpected dropping of toner when attaching a toner storage cartridge to a toner receptacle of a developer and detaching it therefrom. The cartridge is easily attached to the developer and is hooked in place thereto when a sheet sealing an open end of the cartridge is removed. The cartridge easily is detached from the developer by the operation of a cam portion engaging with a hooking member as a result of displacement of the cartridge by a distance equal to the thickness of the sheet and a sheet tearing member which previously are removed from the cartridge.

Abstract: Toner collecting apparatus in which a toner collecting container for collecting toner remaining on the surface of a photosensitive drum in a copying machine or a facsimile machine is provided, at the lower side thereof, with a toner receiving port, a sponge roller for rotatingly feeding collected tone disposed adjacent the toner receiving port, and an optical detector for detecting that a predetermined amount or more toner has been collected in the toner collecting container. The optical detector, is disposed on the toner collecting container. At least those portions of the toner collecting container located opposite to the optical detector are made of a light-permeable material.

Abstract: A copying paper is deflected at least twice in the conveying process thereof from a paper feeding means to a photoreceptor which is disposed in the lower reaches of the conveying direction, whereby the positional state of the top edge of the copying paper is corrected at least twice. Since the extent of each deflection of the copying paper can be reduced, a habit of creasing, which has been a bad influence upon the transferring process, is not inflicted on the copying paper. The correction of the position of the top of the copying paper can be accurately carried out, whereby a clear image can be formed on the appointed position of the copying paper.

Abstract: A paper feeder equipped with copying paper cassettes comprises a cassette-receiving section within the housing of a copying apparatus for mounting thereon a plurality of copying paper cassettes containing sheets of copying paper having different sizes. Each of the paper cassettes includes a main body for holding paper sheets which has an opening formed at the forward end portion of its bottom wall and a bottom plate for placing paper sheets thereon which is mounted on the bottom wall of the main body of the cassette so that it can freely pivot about its rear end portion as a fulcrum. The housing of the coyping apparatus has provided therein a press-contacting mechanism adapted to act on the bottom plate of the cassette through the opening in the main cassette body.

Abstract: A cleaning device for use with transfer type electrostatic copying machines wherein a wiping assembly disposed upstream of a charging-purpose corona discharger along the direction of travel of a photoreceptor is brought into slide contact with the photoreceptor during exposure to intercept residual toner particles on the photoreceptor. The wiping assembly comprises upstream and downstream members adapted to be brought into slide contact with the photoreceptor, and a pressure setting assembly for applying individual preset pressures to the two members, the arrangement being such that some of the residual toner particles are intercepted by the upstream member and then the remainder are intercepted by the downstream member.

Abstract: A power transmitting device especially suitable for use in photocopying machines includes a driving shaft and a driven shaft. When locking members on the respective shafts are axially disengaged from each other, the driven shaft and the driving shaft are rotatively displaced with respect to each other by a predetermined angle so that the locking members may be freely and positively locked when the driving shaft and driven shaft are axially reengaged.

Abstract: A cleaning device in an electrostatic copying apparatus, for removing residual toner particles from the surface of a photosensitive member adapted to move through an endless conveying passage, includes a blade holding mechanism mounted pivotally around an axis extending substantially parallel to the surface of the photosensitive member and substantially perpendicular to the moving direction of the photosensitive member, and a cleaning blade mounted on the blade holding mechanism. The cleaning device further includes a first spring elastically biasing the blade holding mechanism to a non-operating position in which the cleaning blade is away from the surface of the photosensitive member and an operating mechanism selectively positioning the blade holding mechanism against the elastic biasing action of the first spring to an operating position in which the cleaning blade is pressed against the surface of the photosensitive member.

Abstract: A display apparatus comprising a display device for displaying a character and one or more special symbols to modify the character, by means of a dot matrix, and a control means for controlling the display device. The special symbols may be an underline sign, a bold face sign, etc. The control means effect alternate display at the same position on the display device, of a desired character and one or more special symbols to modify the desired character.

Abstract: A variable magnification electrostatic copying apparatus comprising a transparent plate on which to place a document to be copied, an optical system for projecting the image of the document onto an electrostatographic photosensitive member at any desired projecting ratio selected from a plurality of projecting ratios in an exposure zone located along the moving path of the photosensitive member, and a driving means for moving at least a part of the optical system and the transparent plate relative to each other. The optical system includes at least one position-variable optical element assembly adapted to be held at any of a plurality of positions corresponding to the aforesaid plurality of projecting ratios. The variable magnification electrostatic copying apparatus includes a unique improved means for varying the projecting ratio of the optical system by moving the position-variable optical element assembly.

Abstract: An electrostatic copying apparatus including a support frame having a front support wall and a rear support frame. The support frame is mounted on a housing slidably in the front and rear direction between an operating position within the housing and a pull-out position outside of the housing. A rotating drum and a developing device are mounted on the support frame. Each of the rear surface of the front support wall and the front surface of the rear support wall has a semicircular receiving portion with an open top, and each end of the rotating drum has a shaft bearing member with a circular peripheral surface. By inserting each bearing member into the associated receiving portion, the drum is rotatably mounted. The developing device has a front wall and a rear wall, with a projecting portion formed at the end of each. An abutting lower edge is defined on each projecting portion, and an abutting front edge is defined on each of the front wall and the rear wall, below the projecting portion.

Abstract: A copy paper counting method for a copying apparatus including the steps of: counting the copy paper by means of a first counter; terminating the feed of the copy paper when the counting value stored in the first counter becomes equal to the preset number of the copy paper; counting the discharged copy paper by means of a second counter; and detecting paper jamming, and supplying the counting value of the second counter to the counting value of the first counter. It is not necessary to preset the number of required copies again after a jammed paper is expelled. Since the copying operation is continuously restarted, the preset number of copies are precisely reproduced.

Abstract: An optical device in a variable magnification electrostatic copying apparatus includes a first reflecting mirror assembly mounted for reciprocal movement, a second reflecting mirror assembly mounted for reciprocal movement substantially parallel to the reciprocating direction of the first reflecting mirror assembly, and a speed-reduction interlocking mechanism for moving the second reflecting mirror assembly at a speed equal to one-half of the moving speed of the first reflecting mirror assembly, upon movement of the first reflecting mirror assembly. The optical device further includes a magnification setting mechanism for changing the relative position of the second reflecting mirror assembly with respect to the first reflecting mirror assembly according to a desired copying magnification.

Abstract: An electrostatic copying apparatus wherein a stationary original document image is projected onto a photosensitive member during movement of an optical device for exposing, and an electrostatic latent image formed on the photosensitive member is transferred onto a copy sheet and is fixed, comprising (a) a jam detecting means for immediately detecting a copy sheet being jammed on a transport path; and (b) a cleaning device for removing residual toner particles remaining on the photosensitive member by means of magnetic force and for storing the removed toner particles after transferring operation. According to this invention, an occurrence of jam is detected immediately, and thus a fault or an accident of the electrostatic copying apparatus due to jam is prevented from expanding.

Abstract: A latent electrostatic image developing device for developing a latent electrostatic image formed on an image-bearing member by applying a developer thereto. The developing device comprises a developer applicator means for holding the developer on its surface, carrying the developer to a developing zone and applying it to the latent electrostatic image in the developing zone and a bias voltage applying means for applying a bias voltage to the developer held on the surface of the developer applicator means. The developing device further includes a detector means for detecting the relative humidity of the environmental atmosphere and a control means for changing the magnitude of the applied bias voltage to a lower value when the detected relative humidity of the atmosphere exceeds a predetermined value.

Abstract: A fixing and heating device for an electrostatic copying apparatus includes a fixing roller which (a) remains stationary at least until a toner is softened, (b) is driven at a low speed to even the surface temperature of the fixing roller when the surface temperature is lower than a temperature suitable for fixing, and is equal to the temperature suitable for fixing except during a fixing operation, and (c) is driven at a speed suitable for fixing when the surface temperature is suitable for fixing during the fixing operation.