Riso Kagaku Corporation

Mitsubishi Kinzoku Kabushiki Kaisha

Hideo Negishi

Yasuhiro Takahashi

Katsuro Motoe

Takanori Hasegawa

Yoshiharu Ohinata

Nagon Takita

Sueji Takaya

Kaoru Goto

Yoshitaka Tanaka

Toshimitsu Sakai

Yoshihara Ohinata

In a stencil printer system, a stencil is made by the use of master material unrolled from a stencil material roll and is wound around a printing drum by clamping the leading end of the stencil on the printing drum and rotating the printing drum while the stencil is once slackened on the way to the printing drum. There is provided along the stencil conveyance path between the stencil material roll and the printing drum a tension blade which is pressed against the stencil to apply back tension to the stencil when the stencil is run by the printing drum and the tension blade is formed so that the stencil undergoes force which tends to displace outward the stencil from the central portion in the direction of width of the stencil.

Stencil printer system

A stencil printing machine has a printing drum having a cylindrical circumferential wall adapted to receive a perforated stencil sheet wrapped on an outer circumferential surface thereof and driven to rotate around a central axis thereof the circumferential wall having an opening portion with many through holes formed therein, a non-opening portion formed around the opening portion, and at least one recessed portion formed in at least one part of the opening portion adjacent to the non-opening portion in an axial direction of the circumferential wall; an ink supplying roller situated in the printing drum for supplying ink to an inner circumferential surface of the cylindrical circumferential wall of the printing drum; and a press roller situated adjacent to the printing drum and being urged against the outer circumferential surface of the cylindrical circumferential wall of the printing drum.

Stencil printing machine and stencil printing drum

A printing drum of a stencil printing machine is formed of a base member having two annular members spaced apart from each other and a transverse bar connecting the two annular members; a flexible multi-porous sheet having a filled portion at at least a part of a peripheral portion except a central portion thereof and being wrapped into a cylindrical shape around the outer peripheral surface of the base member, and around which a stencil sheet is wrapped; a spring member situated between one end of the flexible sheet and the base member to attach the flexible sheet resiliently on the base member; a stencil clamping device provided on the transverse bar for selectively clamping one end part of the stencil sheet; and an inner pressing device situated inside the flexible sheet for supplying ink outwardly. The inner pressing device pushes the flexible sheet radially outwardly when the base member and flexible sheet assembly rotates. Sliding areas are formed at portions of the annular members contacting the filling portion of the flexible multi-porous sheet. Thus, the flexible sheet can smoothly move on the annular members.

Stencil printing drum with friction reducing means

A stencil printing screen body includes an ink-previous printing area, an ink-impervious non-printing area provided around the printing area, and a pressure sensitive adhesive area formed on the surface where the stencil sheet of non-printing area is attached and having adhesion to the stencil sheet. The stencil printing body is wrapped in a cylindrical form on peripheral surfaces of annular members, and a squeeze member is provided in the screen body for supplying ink. The stencil sheet is applied onto the screen body without leaking ink.

Stencil printing drum

In a stencil printer having a printing drum 10 which has a circumferential wall portion for mounting a stencil sheet made of a flexible sheet member 20 and including a perforated portion 20c, an inking roller 12 provided inside of the printing drum for supplying ink to the printing drum from its inside with radially shifting out the perforated portion, and a back press roller 14 for supporting a print sheet against the printing drum by holding a leading end of the print sheet by a clamp 25, a means is provided for restricting the radial shifting out of the inking roller 12 when the inking roller is opposed by the clamp 25 to prevent ink leakage from the perforated portion 20c of the printing drum due to insufficient support of the print sheet by the back press roller 14 at the portion of the clamp 25. As an embodiment, an annular cam follower 23 mounted on the inking roller 12 is engaged by a cam 48 mounted on the back press roller.

Stencil printer having ink leakage preventing construction

Disclosed is a printing drum of a stencil printing machine, which includes a base member having two annular members disposed at a specific space on a common central axis and a transverse bar connecting the two annular members; a flexible multi-porous sheet wrapped into a cylindrical shape around the outer peripheral surface of the base member, and around which a stencil sheet is wrapped; a stencil clamping device provided on the transverse bar of the base member for selectively clamping one end part of the stencil sheet; an inner pressing device provided on the back side of the flexible multi-porous sheet for supplying ink outwardly from the inside of the flexible multi-porous sheet, and for radially outwardly deforming the flexible multi-porous sheet by pushing outwardly the inner peripheral surface of the flexible multi-porous sheet when the base member and flexible multi-porous sheet assembly rotates on the central axis stated above; and a frictional resistance reducing device for reducing a circumferential frictional resistance which is generated between the base member and the flexible multi-porous sheet.

Strap-like step portions each having a smaller external diameter than the external diameter of an ink supply roller are provided at opposite ends of the ink supply roller provided in a drum. Guide surfaces of ink dams urged by springs are brought into contact with the strap-like step portions respectively. Inclined surfaces of the ink dams are brought into contact with the strap-like step portions and side end surfaces of the strap-like step portions respectively. Ink leaked onto the strap-like step portions is led to the inclined surfaces in conjunction with the rotation of the ink supply roller and returned to the inner side of the ink supply roller. Ink is prevented from being leaked out of the ink supply range of the ink supply roller, so that a printing apparatus and sheets of printing paper are not stained with ink. The state of contact between the ink dams and the ink supply roller is kept stable. If the elastic force of the springs is changed, the state of contact can be changed.

Stencil printing drum structure

A stencil printing drum comprises: a rotary cylindrical drum including an ink non-passage region, an ink passage region surrounded by the ink non-passage region, and an axis around which the rotary cylindrical drum rotates; an ink supplying roller whose axis of rotation is in parallel with the axis of the rotary cylindrical drum, the ink supplying roller being brought into contact with the inner cylindrical surface of the rotary cylindrical drum to push a printing ink out of the rotary cylindrical drum through the ink passage region; and an ink non-passage strip formed along the border between the ink non-passage region and the ink passage region except the start end portion thereof as viewed in the direction of rotation of the rotary cylindrical drum, in such a manner that the ink non-passage strip protrudes radially inwardly of the rotary cylindrical drum.

Stencil printing drum which prevents ink leakage

A stencil printing machine comprises: a rotary cylindrical drum having an ink passage part; an ink supplying roller rotatable around an axis in parallel with the central axis of the rotary cylindrical drum, the ink supplying roller being brought into contact with the inner cylindrical surface of the rotary cylindrical drum; a pair of cylindrical protrusions on both ends of the ink supplying roller, the cylindrical protrusions being smaller in outside diameter than the ink supplying roller and coaxial with the ink supplying roller; an ink coating roller arranged in parallel with the ink supplying roller, the ink coating roller applying ink onto the surface of the ink supplying roller in accordance with the ink supplying roller turning, an ink pool forming between the ink coating roller and the ink supplying roller; and a pair of ink banks are provided at both ends of the ink pool, respectively, the ink banks having sloped surfaces in contact with the cylindrical surfaces of the cylindrical protrusions, the sloped surfaces for leading the ink into the ink pool when ink leaks onto the cylindrical protrusions.

Stencil printing drum having squeegee and doctor roller end ink banks

A printing drum for a rotary stencil printer having a sidewall in the form of a flexible perforated sheet. In order to allow for a bulging out deformation of the sidewall by an internal press roller to be easier and more uniform over the entire width of the printing, the flexible cylindrical body of the printing drum has its opposite side edge portions seated around the outer circumferential surfaces of a pair of annular portions (10a, 10b). The drum is constructed to have an inner circumferential length greater than the circumferential length of the outer circumferential surface of the annular portions by a predetermined amount which allows for a predetermined bulging out deformation of the flexible cylindrical body.

Printing drum of rotary stencil printer having a predetermined allowance

A rotary stencil printing machine is formed of a cylindrical member, a clamping device formed on the cylindrical member for clamping a leading edge portion of a stencil sheet, and a back-up device provided outside the cylindrical member. The back-up device grips a printing sheet together with the cylindrical member to transfer the same. The cylindrical member includes a cylindrical peripheral surface for mounting thereon the stencil sheet; a first ink-pervious area formed on the peripheral surface on which an image forming area of the stencil sheet is disposed; at least one second ink-pervious area formed on the peripheral surface on which a trailing edge portion of the stencil sheet is disposed; and at least two first ink-impervious areas formed on the peripheral surface. The second ink-pervious area has an elongated shape continuously extending parallel to a center axis of the cylindrical member, and the ink-impervious areas sandwiches the second ink-pervious area.

Rotary stencil printing machine

In order to make the bulging out deformation of the printing drum of a rotary stencil printer having a flexible cylindrical body by the internal press roller to be more easy and more uniform over the entire width of the printing, a flexible perforated sheet (20) forming the flexible cylindrical body of the printing drum is beforehand constructed to be a cylindrical body with its opposite annular edge portions being laid over a pair of annular portions (10a, 10b) connected with one another by a transverse bar portion (12), wherein the internal circumferential length of the cylindrical body made of the flexible perforated sheet is larger than the outer circumferential length of the annular portions by a determinate amount for allowing a part of the flexible cylindrical body to bulge radially outwardly, and the flexible cylindrical body is latched at a portion thereof laid one over the other with the transverse bar portion against relative circumferential movement while relatively movable in the radial direction within a determinate range against the transverse bar portion.

Printing drum of rotary stencil printer having flexible perforated

A sheet feeding device is provided for taking up and feeding a plurality of sheets one by one by a selectively driven sheet feeding roller from the stack thereof positioned on a sheet feeding base to a register roller and for transporting the sheet to an image developing and processing device at a predetermined timing by the register roller; the feeding device comprising a movable sheet guide member provided between the feeding roller and the register roller which is adapted to be displaced by the curving deformation of a sheet between the feeding roller and the register roller in the direction of the growing of the curving deformation. The feeding device may further comprise a detector for sensing the displacement of the sheet guide member to determine based upon the displacement that a predetermined curvature of a sheet has been reached, and a control for stopping the rotation of the feeding roller in response to the detection by the detector so as to prevent the sheet from deforming excessively.

Sheet feeding device for a image developing and processing machine

A rotary mimeographic printing apparatus comprises a rotary drum for mounting on a peripheral surface thereof a perforated stencil, a clamp pivotally supported on the rotary drum for clamping one end of the stencil in such a manner that the stencil may be wound around the peripheral surface of the rotary drum in response to rotation of the rotary drum, structure for removing the stencil from the rotary drum after printing is finished, and a stencil guide disposed above the rotary drum and engageable with the clamp so as to move following the pivotal movement of the clamp.

Mimeographic printing apparatus with a stencil guide

A drill bit comprises a body having a shank portion and an end face at its forward end. The drill bit body has at the forward end a cutting means having at least one cutting edge provided on the end face. The cutting edge is spaced from the axis of rotation of the body. The body has a rake surface which terminates in the cutting edge and extends along the axis of rotation.

Growing community of inventors

Tokyo, Japan

Hideo Negishi