Manufacturing device for machine plate for printer

A printer-machine-plate manufacturing device for manufacturing a printer machine plate configured such that a rectangular sheet of a magnetic material having elasticity is formed into a cylindrical shape with opposite end portions of the sheet superposed on each other and joined together to form a joint portion whereby a cylindrical machine-plate body is formed;

• an end portion of the sheet located on the inner side of the joint portion is bent inward whereby an engagement portion is formed;
• and a formed area is provided at a predetermined portion of the outer circumferential surface of the machine-plate body excluding the joint portion,
• the manufacturing device comprising:
• an elongated cylinder section having:
• an outer circumferential portion extending along an axis for winding the sheet around;
• and a groove for removably receiving the engagement portion of the sheet;
• a magnetic attraction member formed of a magnetic material mounted on an inner side of the outer circumferential portion of the cylinder section;
• and
• a permanent magnet rotatably mounted in the magnetic attraction member, the permanent magnet having a knob for rotating the permanent magnet between a magnetization position for magnetizing the magnetic attraction member to magnetically hold the cylindrical machine-plate body to the elongated cylinder section and a demagnetization position for demagnetizing the magnetic attraction member to release the cylindrical machine-plate body from the elongated cylinder section, wherein the cylinder section has a cylindrical columnar portion with at least two opposing projections such that the at least two opposing projections is:
• a first opposing projection defining a first axial groove for receiving a plate-shaped electrode for spot welding the sheet;
• and a second opposing projection defining a third axial groove for receiving a diameter adjustment member and the diameter adjustment member includes a rectangular body with at least two radial holes having adjustment screws that threadably engage the radial holes to press against the second opposing projection and thereby selectively move the rectangular body radially inward and outward to selectively vary the outer circumference.

A device for manufacturing a printer machine plate comprising:

• a cylinder section having:
• a cylindrical columnar portion along a central axis;
• at least two opposing projections extending from the cylindrical columnar portion;
• at least one arcuate attraction member extending between the at least two opposing projections and defining an axial passage;
• and a pair of opposing semicylindrical halves surrounding and supported by the at least two opposing projections and at least one arcuate attraction member to form an outer circumference with the at least two projections;
• and
• at least one switching assembly including:
• a central shaft;
• a plurality of permanent magnets mounted on the central shaft so that magnetic poles are formed on opposite sides of a plane passing through the central shaft;
• a plurality of spacers mounted on the central shaft between each pair of permanent magnets;
• and a knob mounted on one end of the shaft,
• wherein the at least one switching assembly is mounted in the axial passage for selective rotational movement within the axial passage between:
• a magnetization position that magnetizes the one arcuate attraction member for magnetically holding the sheet to the cylinder section;
• and a demagnetization position that demagnetizes the one arcuate attraction member that releases the sheet from being held by the cylinder section, wherein the at least two opposing projections is:
• a first opposing projection defining a first axial groove for receiving a plate-shaped electrode for spot welding the sheet and the plate shaped electrode defines a second axial groove for receiving an inwardly bent engagement portion of the sheet;
• and a second opposing projection defining a third axial groove for receiving a diameter adjustment member and the diameter adjustment member includes a rectangular body with at least two radial holes having adjustment screws that threadably engage the radial holes to press against the second opposing projection and thereby selectively move the rectangular body radially inward and outward to selectively vary the outer circumference.

A printer-machine-plate manufacturing device for manufacturing a printer machine plate, the manufacturing comprising:

• a cylinder section having an outer circumferential portion, wherein on the inner side of the outer circumferential portion of the cylinder section, magnetic attraction members formed of a magnetic material are provided, and permanent magnets are provided in such a manner that their position can be switched, and wherein permanent-magnet switching means is provided in order to switch the position of the permanent magnets between a magnetization position for magnetizing the magnetic attraction member and a demagnetization position for demagnetizing the magnetic attraction member,
• wherein the outer circumferential portion has a groove into which an engagement portion of a sheet that is wound around the outer circumferential portion is removably insertable from its distal end, and said permanent magnet switching means comprises a support shaft extending in the frontrear direction of the cylinder section, and a knob fixed at a front end portion of the support shaft projecting frontward from the front end wall member of the cylinder section, the permanent magnets having the form of a short cylindrical column and being rotatably supported between grooves of the magnetic attraction members, said permanent magnets being concentrically fixed to the support shaft, wherein the cylinder section has a cylindrical columnar portion with at least two opposing projections such that the at least two opposing projections is:
• a first opposing projection defining a first axial groove for receiving a plate-shaped electrode for spot welding the sheet;
• and a second opposing projection defining a third axial groove for receiving a diameter adjustment member and the diameter adjustment member includes a rectangular body with at least two radial holes having adjustment screws that threadably engage the radial holes to press against the second opposing projection and thereby selectively move the rectangular body radially inward and outward to selectively vary the outer circumference.

A printer-machine-plate manufacturing device for manufacturing a printer machine plate comprising:

• a rectangular sheet of a magnetic material is formed into a cylindrical shape,
• a cylinder section having an outer circumferential portion around which the sheet is wound and which has a groove into which an engagement portion of the sheet is removably inserted from its distal end, wherein, on the inner side of the outer circumferential portion of the cylinder section, a magnetic attraction member formed of a magnetic material is provided, and permanent magnets are provided in such a manner that orientation of the permanent magnets can be changed, and wherein permanent-magnet switching means is provided in order to switch the orientation of the permanent magnets between a magnetization position for magnetizing the magnetic attraction member and a demagnetization position for demagnetizing the magnetic attraction member, and
• when the permanent magnets are in the demagnetization position, the magnetic poles of each permanent magnet are arranged in the radial direction of the cylinder section and when the permanent magnets are in the magnetization position, the magnetic poles of each permanent magnet are arranged in the circumferential direction of the cylinder section, wherein the cylinder section has a cylindrical columnar portion with at least two opposing projections such that the at least two opposing projections is:
• a first opposing projection defining a first axial groove for receiving a plate-shaped electrode for spot welding the sheet;
• and a second opposing projection defining a third axial groove for receiving a diameter adjustment member and the diameter adjustment member includes a rectangular body with at least two radial holes having adjustment screws that threadably engage the radial holes to press against the second opposing projection and thereby selectively move the rectangular body radially inward and outward to selectively vary the outer circumference.