Abstract: An employed rear mold is comprised of a plurality of mold pieces. The plurality of mold pieces include a first mold piece which forms a first partial internal surface of the internal surface of the rear mold along the entire circumference of the internal surface, and a second mold piece which is located axially forward of the first mold piece and forms a second partial internal surface of the internal surface of the rear mold along the entire circumference of the internal surface. Releasing the molded body includes starting to move the first mold piece rearward in relation to a rear molded portion, and, subsequently to starting to move the first mold piece, starting to move the second mold piece rearward in relation to the rear molded portion, thereby disassembling the rear mold into the plurality of mold pieces.

Abstract: A method for manufacturing an insulator for a spark plug includes a molding process of forming a cylindrical molded product having an axial hole that extends in a direction of an axial line, by means of injection molding using a mold that has a columnar cavity therein and a bar-shaped member disposed in the cavity and extending in the direction of the axial line. In this method, the molding process includes an injection step of injecting a material containing a ceramic. In the injection step, the material is injected into the cavity from a plurality of injection openings that are opened at an inner circumferential surface, of the mold, that forms the cavity. The plurality of injection openings include two or more injection openings located at different positions in the direction of the axial line, or two or more injection openings located at different positions in a circumferential direction.

Abstract: Disclosed is a spark plug having a ground electrode in which a weld zone is formed a tip and electrode base. The weld zone has: a back region exposed at an opposite surface of the electrode base; a joint region at which the tip is joined; and a connection region connects the joint region and the back region without being exposed at side surfaces of the electrode base. In a cross section of the ground electrode taken through the side surfaces of the electrode base along a plane passing through the centers of the top and bottom surfaces of the tip, a value of a width of the top surface of the tip being divided by a width of the facing surface of the electrode base is greater than 0.3, and a maximum width of the connection region is larger than a width of the back region.

Abstract: Disclosed is a spark plug having a ground electrode in which a weld zone is formed a tip and electrode base. The weld zone has: a back region exposed at an opposite surface of the electrode base; a joint region at which the tip is joined; and a connection region connects the joint region and the back region without being exposed at side surfaces of the electrode base. In a cross section of the ground electrode taken through the side surfaces of the electrode base along a plane passing through the centers of the top and bottom surfaces of the tip, a value of a width of the top surface of the tip being divided by a width of the facing surface of the electrode base is greater than 0.3, and a maximum width of the connection region is larger than a width of the back region.

Abstract: An employed rear mold is comprised of a plurality of mold pieces. The plurality of mold pieces include a first mold piece which forms a first partial internal surface of the internal surface of the rear mold along the entire circumference of the internal surface, and a second mold piece which is located axially forward of the first mold piece and forms a second partial internal surface of the internal surface of the rear mold along the entire circumference of the internal surface. Releasing the molded body includes starting to move the first mold piece rearward in relation to a rear molded portion, and, subsequently to starting to move the first mold piece, starting to move the second mold piece rearward in relation to the rear molded portion, thereby disassembling the rear mold into the plurality of mold pieces.

Abstract: A method for manufacturing an insulator for a spark plug includes a molding process of forming a cylindrical molded product having an axial hole that extends in a direction of an axial line, by means of injection molding using a mold that has a columnar cavity therein and a bar-shaped member disposed in the cavity and extending in the direction of the axial line. In this method, the molding process includes an injection step of injecting a material containing a ceramic. In the injection step, the material is injected into the cavity from a plurality of injection openings that are opened at an inner circumferential surface, of the mold, that forms the cavity. The plurality of injection openings include two or more injection openings located at different positions in the direction of the axial line, or two or more injection openings located at different positions in a circumferential direction.

Abstract: A drum unit (20) for forming a toner image includes a cylindrical-shaped metal tubular member (31), a flange member (40) attached to one end of the metal tubular member (31) and a ground plate (50) attached to the flange member (40) and having an outer peripheral edge formed with a connection claw (52) that is so bent by the inner peripheral surface of the metal tubular member (31) as to bite into the inner peripheral surface for establishment of electrical conduction between the metal tubular member (31) and the ground plate (50). The flange member (40) has an edge, and the bending of the connection claw is carried out about a support point (412) defined by the edge. A calculational bending angle (?) at which the connection claw (52) is bent about the support point (412) is set in the range of 10 to 45 degrees.

Abstract: An electrostatic latent image developing device equipped with a developing housing, a developing roller rotatably disposed between the two side walls of the developing housing, and a feeding roller rotatably disposed between the two side walls of the developing housing neighboring the developing roller. A first bearing member is mounted on one side wall and has two bearings for supporting the ends of the rotary shafts of the developing roller and the feeding roller. A second bearing member is mounted on the other side wall and has a bearing for supporting the opposite end of either the rotary shaft of the developing roller or the feeding roller. A third bearing member is mounted on the other side wall and has a bearing for bearing support of the opposite end of the rotary shaft of the developing roller or the feeding roller not supported in bearing fashion by the second bearing member.

Abstract: A charging device is provided which is suitable for use in a compact electrophotographic image forming apparatus. The charging device includes: a pair of support members spaced a predetermined distance; and a discharge wire stretched between the pair of support members with one end thereof being fixed to one of the support members and with a middle portion thereof being supported by the other support member. One end of a coil spring is connected to the other end of the discharge wire, and the other end of the coil spring is received by a hooking portion of an electrode. The electrode is fixed in the vicinity of one of the support members.

Abstract: An image-forming machine includes a photosensitive drum rotatably disposed; a charger for electrically charging the peripheral surface of the photosensitive drum to a predetermined polarity; a developer for developing an electrostatic latent image formed on the peripheral surface of the photosensitive drum into a toner image; a transfer device for transferring the toner image formed on the peripheral surface of the photosensitive drum onto a transfer paper; a fixing roller for heat-fixing the toner image transferred onto the transfer paper by the transfer device; and a cooling fan for blowing cooling air to the surrounding area of the fixing roller. A guide plate having a plurality of openings formed along its length, guides the transfer paper onto which the toner image has been transferred by the transfer device, to the fixing roller.

Abstract: An image forming machine including a single layer dispersion type photoconductor drum, a charging device for charging the surface of the photoconductor drum to a specific polarity, and a developing roller for conveying a developer to the surface of the photoconductor drum having a latent electrostatic image formed thereon. The photoconductor drum and the developing roller are adapted to contact each other at their surfaces and to be rotationally driven in reverse directions. The photoconductor drum has a diameter set at 10 to 20 mm, while the developing roller has a diameter set at 90 to 110% of the diameter of the photoconductor drum.

Abstract: A transferring device in which a transfer roller having a diameter which is not less than 60% of the diameter of an organic photosensitive drum with a diameter of 10 to 20 mm is arranged with a clearance provided between the transfer roller and the organic photosensitive drum. The transferring device avoids problems such as current leakage and reverse transfer of toner in the case of miniaturization of an image forming apparatus or contamination of the transfer roller, and easily sets a transfer current because an effective transfer current width is large.

Abstract: An image-forming machine including a photosensitive drum which is rotatably disposed and successively passes through a charging zone, a developing zone and a transfer zone; a charger for charging the peripheral surface of the photosensitive drum into a predetermined polarity; a developing device for developing an electrostatic latent image formed on the peripheral surface of the photosensitive drum into a toner image; a transfer means for transferring the toner image formed on the peripheral surface of the photosensitive drum onto a transfer paper; and a foreign matter-recovering means which is disposed between the transfer zone and the charging zone and comes into contact with the peripheral surface of the photosensitive drum, and removes foreign matter adhered onto the peripheral surface of the photosensitive drum, the foreign matter-recovering means having a foreign matter-recovering brush brought into contact with the peripheral surface of the photosensitive drum, an elastic holding member made of an elas

Abstract: A process unit including a photoconductor unit having a photoconductor drum, a developing unit having a developing roller disposed in a development housing, and a support shaft means for supporting the developing unit pivotably relative to the photoconductor unit. The developing roller is disposed such that its surface is pressed against the surface of the photoconductor drum in a developing zone. The photoconductor drum and the developing roller are rotationally driven such that their respective surfaces move from below to above in the developing zone.

Abstract: According to the present invention, in the image forming apparatus in which so-called "cleaningless" is realized, no problems such as traces of paper powder, gray or foggy stripes and the like occur in a formed image. The image forming apparatus is provided with a brush for scratching toner remaining on the surface of the photosensitive drum and recovering paper powder adhering on the surface thereof. When the length of the brush extending from the root thereof to the photosensitive drum is taken as a?mm!, the length of the toughening member, toughening the brush materials, projecting from the root of the brush materials is taken as c?mm!, and the length of the portion of the brush, cutting into the photosensitive drum, is taken as b?mm!, the relationship among a?mm!, b?mm! and c?mm! satisfies the conditions that 0.3.ltoreq.(c/(a+b)).ltoreq.0.95, 0.1 ?mm!.ltoreq.b.ltoreq.1.5 ?mm!, and (a+b)<2 ?mm!.

Abstract: An image-forming apparatus for forming image through the electric charging of a photosensitive material drum, exposure to light, developing and transfer, wherein a developing device also works to clean the toner remaining on the photosensitive material; an electric charge for effecting the electric charging has a scorotron charger located within .+-.45.degree. from a perpendicular downwardly drawn from the center of the photosensitive material drum, and has a hole on the side opposite to the opening for charging; and an electric field E.sub.1 between a wire and a grid in the scorotron charger is set to be stronger than an electric field E.sub.2 between the wire and a shield.

Abstract: An image forming apparatus including a photoreceptor, an electrically charging unit for evenly electrically charging the photoreceptor to a predetermined potential, a light exposure unit for exposing a surface portion of the evenly electrically charged photoreceptor to light so as to form an electrostatic latent image, a developing unit for causing toner to adhere to the photoreceptor surface portion exposed to light so as to develop the electrostatic latent image into a toner image, and a transferring unit to which a predetermined transferring voltage is applied for transferring the toner image to a sheet. Before the tip end of the toner image reaches the position opposite to the transferring unit but after the tip end of the sheet has reached the position opposite to the transferring unit, the application of the predetermined transferring voltage to the transferring unit is started.

Abstract: A process unit comprising a photoconductor unit and a developing unit supported pivotably via a support shaft. The photoconductor unit and the developing unit each have a pair of support side walls having support holes formed on the same axis. One pair of the support side walls define a pair of inner support side walls having an outside width smaller than the inside width of the other pair of the support side walls, while the other pair of the support side walls define a pair of outer support side walls. The pair of outer support side walls and the pair of inner support side walls are supported via the support shaft passing through the respective support holes. One end of the support shaft is supported by one of the outer support side walls via a bearing member detachably mounted in the support hole of the one of the outer support side walls.

Abstract: A process unit of an image forming machine, comprising a photoconductor unit including a photoconductor drum, and a developing unit for developing a latent electrostatic image formed on the photosensitive layer of the photoconductor drum to a toner image, the photoconductor unit and the developing unit being connected by a support shaft so as to be pivotable relative to each other; in which a pre-transfer guide plate for guiding a transfer sheet to be conveyed to a transfer zone is disposed on a photoconductor support means for supporting the photoconductor drum rotatably, and the rear surface of the pre-transfer guide plate is brought into contact with the support shaft or a development housing.