Sheet hole punching apparatus and sheet hole punching method

Abstract

A cylindrical punch member equipped at the leading end thereof with a hole-punching blade is movably supported on a base frame in a hole-punching direction. A drive means is equipped that applies thrusting force to the punch member; a cam follower member disposed between the base frame and punch member engages a cam means disposed at either the base frame or punch member. An oblique cam surface inclined at a predetermined angle with regard to a hole-punching direction is equipped in cam means to give rotational drive force around an axis of rotation to the punch member that is moved in the hole-punching direction by the drive means. This configuration causes each of a plurality of cylindrical punch members to rotate around their axes of rotation when moved in a hole-punching direction by drive means thereby punching a hole in a sheet with a reduced shear force; the centrifugal force of that punch member rotation causing paper cutting debris to be scattered evenly under the punch member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an overall configuration of one embodiment of the hole-punching device according to the present invention.

FIGS. 2( a) and 2(b) are views of the essential portions of the device shown in FIG. 1; FIG. 2(a) is a sectional view; FIG. 2(b) is an example variation.

FIGS. 3( a) and 3(b) are views of cam means of the apparatus of FIG. 1; FIG. 3(a) is a perspective view; FIG. 3(b) is a circular cam expanded in plan view.

FIG. 4 is an explanatory diagram shown operation of the hole-punching device shown in FIG. 1.

FIG. 5 is an explanatory drawing of operating states when punching holes with the device shown in FIG. 1.

FIGS. 6( a) and 6(b) show a configuration of a drive mechanism position sensor apparatus shown in FIG. 1; FIG. 6(a) is a plan view; FIG. 6(b) is a sectional view.

FIGS. 7( a) to 7(e) are explanatory diagrams showing operations of the position sensor shown in FIGS. 6(a) and 6(b).

FIGS. 8( a) and 8(b) show shapes of hole-punching blades; FIG. 8(a) shows an obliquely cropped blade; FIG. 8(b) shows a V-shape blade.

FIGS. 9( a) and 9(b) are explanatory diagrams of the overall configuration of a second embodiment of a hole-punching device that is different from the device shown in FIG. 1; FIG. 9(a) shows a drive mechanism; FIG. 9(b) is a configuration of a drive cam.

FIGS. 10( a) to 10(c) are explanatory diagrams of a drive rotation cam structure of the device shown in FIG. 9 (second embodiment) FIG. 10(a) is a front view of the drive cam; 10(b) is a sectional view of the essential portion; 10(c) is an explanatory view of the position detection of the home position.

FIG. 11 is an explanatory diagram of the overall configuration of a third embodiment of the hole-punching device that is different from the device shown in FIG. 9.

FIG. 12 is a flowchart showing the control of the hole-punching device according to the present invention.

FIG. 13 is a sectional view showing a mechanical brake on the hole-punching devices shown in FIGS. 1, 9 and 11.

FIGS. 14( a) is a plan view of the device shown in FIG. 13; FIG. 14(b) is an expanded view of the essential portion thereof.

FIG. 15 is an explanatory view of the configuration of drive control of the first embodiment in the hole-punching devices shown in FIGS. 1, 9 and 11.

FIG. 16 is an explanatory view of the configuration of drive control of the second embodiment in the hole-punching devices shown in FIGS. 1, 9 and 11.

FIG. 17 is an explanatory view of the configuration of drive control of the third embodiment in the hole-punching devices shown in FIGS. 1, 9 and 11.

FIG. 18 is an explanatory view of the configuration of drive control of the fourth embodiment in the hole-punching devices shown in FIGS. 1, 9 and 11.

FIG. 19 is an explanatory view of the configuration of drive control of the fifth embodiment in the hole-punching devices shown in FIGS. 1, 9 and 11.

FIG. 20 is an explanatory drawing of a finisher device in an image forming apparatus according to the present invention.

Claims

1. A sheet hole-punching device comprising: a punch member the leading end thereof having a hole-punching blade;a base frame that movably supports the punch member in a hole-punching direction;a drive motor that drives the punch member;transmission means that transmit driving force of the drive motor as direct linear movement in the hole-punching direction or rotational movement around an axis of rotation to the punch member are disposed between the drive motor and punch members; andcam means, disposed between the base frame and punch member, for converting movement transmitted from the transmission means into linear motion or rotating motion, and for moving the punch member in the hole-punching direction while rotating the punch member around an axis of rotation.

2. The sheet hole-punching device according to claim 1, wherein the cam means is composed of a circular cam having an oblique cam surface inclined to a predetermined angle with regard to the hole-punching direction of the punch member; the circular cam is disposed at either the punch member or the base frame, and a follower pin member is disposed to engage that oblique cam surface; andthe punch member is moved in the hole-punching direction while being rotating around the axis of rotation by being guided by the follower pin along the oblique cam surface.

3. The sheet hole-punching device according to claim 1, wherein the transmission means has a gear rack that moves between a first and a second home position by rotation of the drive motor, at a predetermined stroke; the oblique cam surface and a passive gear that mates with the gear rack are disposed on the punch member;the follower pin member that engages the oblique cam surface is disposed on the base frame; andthe punch member is moved in the hole-punching direction while being rotating around the axis of rotation by the passive gear.

4. The sheet hole-punching device according to claim 3, wherein the gear rack applies a rotating force of one direction to the passive gear when the punch member is advancing, and of an opposite direction when the punch member is retreating; and the punch member punches a hole in a leading sheet in the advancing direction by the gear rack, and in a subsequent sheet in a retreating direction by the gear rack.

5. The sheet hole-punching device according to claim 1, wherein the transmission means has a sliding cam member that shuttles between a first and a second home position by rotation of the drive motor, at a predetermined stroke; a cam groove that moves the punch member up and down of the thrusting direction is equipped on the sliding cam member; anda passive pin member that engages the cam groove is disposed on the punch member.

6. The sheet hole-punching device according to claim 6, wherein the transmission means is composed of a rotating shaft connected a drive motor, and eccentric cam disposed on the rotating shaft; the punch member is configured to be moved in up and down directions of the hole-punching direction by the eccentric cam member;the cam means is composed of an oblique cam surface disposed at either the punch member or the base frame, and a follower pin member disposed at the other;the punch member is moved in the hole-punching direction by the eccentric cam while being rotating around the axis of rotation guided by the follower pin engaging the oblique cam surface.

7. The sheet hole-punching device according to claim 6, wherein the oblique cam surface of the cam means applies rotating force to the punch member in one direction when the punch member advances in the hole-punching direction, and an opposite direction when retreating therefrom, when applying rotating force to the punch member to rotate around an axis of rotation.

8. A sheet hole-punching device comprising: a punch member that moves from a top dead center to a bottom dead center to punch holes in sheets;a drive motor that drives the punch member;transmission means that convert and transmit rotating motion of the drive motor to the punch member as reciprocating motion, the transmission means having a sliding member that shuttles between a first and a second home position with a predetermined stroke, the sliding member being configured to move the punch member from the top dead center to the bottom dead center, then returning the punch member to the top dead center in the process to move between the first and the second home positions;drive control means that control the drive motor; andbrake means that increase movement load at the first and the second home positions are disposed on the sliding member.

9. The sheet hole-punching device according to claim 8, wherein the brake means is composed of a concave groove formed in the sliding member; a shoe member that engages the concave groove; and a spring member that urges the shoe member toward the concave groove.

10. A sheet hole-punching device comprising: a punch member that moves from a top dead center to a bottom dead center to punch holes in sheets;a drive motor that drives the punch member;transmission means that convert and transmit rotating motion of the drive motor to the punch member as reciprocating motion; anddrive control means that control the drive motor, having an electric brake means that brakes the rotation of the drive motor and hole-punching action detection means that detects the hole-punching action speed of the punch member or the amount of movement of the punch member per a predetermined amount of time, the drive control means being configured to vary the operational timing of the electric brake means according to detection results from the hole-punching action detection means when stopping the punch member after the hole-punching operation.

11. The sheet hole-punching device according to claim 10, wherein the hole-punching action detection means either (a) detects the operation of the drive motor; (b) detects the operation of the transmission means; or (c) detects the operation of the punch member.

12. A sheet hole-punching device comprising: a punch member that shuttles between a top dead center and a bottom dead center;a drive motor that drives the punch member;transmission means that convert and transmit rotating motion of the drive motor to the punch member as reciprocating motion; anddrive control means that control the drive motor, having brake means that brakes the drive motor rotation; andthe control means controls a stopping position of the punch member by varying the operational timing of the brake means according to a thickness and/or material of the sheet to be punched with holes.

13. The sheet hole-punching device according to claim 12, wherein the transmission means has a sliding member that shuttles between a first and a second home position with a predetermined stroke; the sliding member is configured to execute the hole punching operation by moving the punch member from the top dead center to the bottom dead center, then returning the punch member to the top dead center in the process to move between the first and the second home positions; andthe drive control means is configured to vary the operational timing of the brake means according to the thickness and/or material of the sheet to be punched with holes when stopping the sliding member at the first or the second home position.

14. A sheet hole-punching device comprising: a punch member that shuttles between a top dead center and a bottom dead center;a drive motor that drives the punch member;transmission means that convert and transmit rotating motion of the drive motor to the punch member as reciprocating motion; anddrive control means that control the drive motor being composed of a DC motor, the control means controlling movement of the punch member to stop at a predetermined home position by changing the duty ratio according to a thickness and/or material of the sheet to be punched with holes, the drive control means being configured to change the duty ratio of the pulse power supplied to the DC motor.

15. A hole-punching method including one or a plurality of punch members that shuttle between a top dead center and a bottom dead center, the hole punching method punching one or a plurality of holes with the punch members at one or a plurality of locations of a sheet set on a die plate; comprising the steps of: feeding and setting one or a plurality of sheets on the die plate at a predetermined position;punching holes with a punching operation in the sheet set on the die plate, by moving moves a punch member from a top dead center to a bottom dead center;recovering the punch member by moving from the bottom dead center to the top dead center after the hole-punching step; andconveying out from the die plate the sheet punched with holes at the hole-punching step;wherein the punch member rotates in a forward and a reverse direction around an axis of rotation; and the punch member penetrates the sheet while rotating around the axis of rotation when being moved from the top dead center to the bottom dead center, and when the punch member is being moved from the bottom dead center to the top dead center, the direction of rotation around the axis of rotation is opposite to the direction when the punch member is being moved from the top dead center to the bottom dead center in the hole-punching step.

16. The sheet hole-punching device according to claim 15, wherein the control means moves the punch member to the bottom dead center while the punch member is being rotated around an axis of rotation; and moving the punch member to top dead center while it is being rotated in a reverse direction around the axis of rotation.

17. The sheet hole-punching method according to claim 15, wherein the control means moves the punch member to the bottom dead center while the punch member is being rotated around an axis of rotation; wherein in the hole-punching step, the punch member is moved from the top dead center to the bottom dead center while being rotated around the axis of rotation, the rotation being reversed for a first sheet and a second, subsequent sheet set on the die plate.