ZIGZAG FOLDING APPARATUS FOR A FORM PRINTING MACHINE

Abstract: A zigzag folding apparatus for a form printing machine has folding arms (1) for folding paper form blanks in a zigzag along their respective transversely perforated lines through swing movements thereofeffected by crank shafts (4), and a plurality of rotary spirals (21) for arranging the paper blanks folded by the folding arms in a pile through guiding along the fold lines of the same. Particularly, the crank shafts (4) are connected via a rotating transmission mechanism of gearing to a servo motor (7) for folding drive which is controlled with control signals. Additionally, the apparatus has means for transverse and longitudinal positioning of said rotary spirals (21) in accordance with the width and length of the paper blank, comprising motors (27,29) which are controlled with control signals.

Description: The present invention relates to a zigzag folding apparatus for a form printing machine for printing and processing business forms. The form printing machine consists of a paper supply section, a printing section, a processing section including a punching device and a transverse perforating device, and the zigzag folding apparatus. In a known form printing machine, each of the paper supply section, printing section, processing section, and zigzag folding apparatus is driven by a drive means having a single motor. To control the drive of the zigzag folding apparatus, the speed-change gears are employed which require some operations of shifting, etc. Additionally, on the zigzag folding apparatus, paper form blanks are folded in a zigzag along the transversely perforated lines arranged therein by means of the rightward and leftward swing movements of folding arms and then arranged in a pile upon being folded up by rotary spiral members which is required to adjust for positioning in accordance with a change in folding length and width of the forms. However, in the prior art this adjustment has been made non-automatically without the use of an NC control, which is disadvantageous in producting various sizes of the forms. EP-A-0190749 discloses zigzag folding apparatus which provides for adjustment of its folding arms by non-automatic alteration of the amplitude of oscillation thereof. EPA 0228758 discloses adjustment of rotary spiral members by manual operation of a handle to provide lengthwise adjustment and movement of pinion gears for widthwise adjustment. This latter operation requires the loosening of set screws and hand displacement of the gears and associated sleeves along supporting bars. It is therefore an object of the present invention to provide a zigzag folding apparatus in which the aforesaid problem is eliminated. The other objects and advantages of the invention will be apparent from the following description. According to this invention there is provided a zigzag folding apparatus as set out in claim 1. This arrangement will also facilitate to shift the operation for fabricating products which may vary in length and width and therefore, minimize a time of set-up operation and energy consumption thus to provide high efficiency of production. BRIEF DESCRIPTION OF THE DRAWINGS Fig.1 is a perspective view illustrating a main section of one preferred embodiment of the present invention. Fig.2 is a front view of a folding arm section of the same. Fig.3 is a cross-sectional view illustrating a mechanism for adjusting a swing angle on the folding arm and an angle on the paper infeed rolls. Fig.4 is a perspective view illustrating a mechanism for determining a folding top-to-bottom length and a lateral width of the paper form blank. Fig.5 is a cross-sectional view of the mechanism in Fig.4. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT One preferred embodiment of the present invention will be described in conjunction with the accompanying drawings. As shown in Figs.1 and 2, the numeral 1 is a folding arm which moves rightwards and leftwards (in the top-to-bottom lengthwise direction) in a swing motion about a swing-center axle 2 disposed in the upper end thereof. The folding arm 1 has at lower end a pair of paper infeed rolls 3 mounted rotatably thereto so that a swing angle on the rolls can be changed. The numeral 4 is a link member connected at one end with the folding arm 1. The link 4 is connected at the other end thereof with an eccentrically movable cam 6 thus to cause the swing motion of the folding arm 1. The cam 6 is mounted to a rotary disk 5 so as to be eccentrically movable about a rotating center of the rotary disk 5. Accordingly, the link 4 performs crank actions with the movements of the rotary disk 5 and cam 6 thus to cause the swing movements of the folding arms 1 which is effected in a determined length of stroke and in accordance with an amount of eccentricity on the cam 6. The rotary disk 5 is driven by a servo motor 7 for folding drive. In the drive arrangement, as shown in Fig.3, the rotating power from the folding drive servo motor 7 is transmitted via gear members 8 and 10 to a rack shaft 9 on which the rotaty disk 5 is securely mounted. The eccentricity adjusting mechanism of the cam 6 is shown in Fig.3 having a rack 12 disposed on the back face of the cam 6 and a pinion 11 which is rotatably mounted on an axle in the rotary disk 5 thus to mesh with the rack 12, so that the cam 6 can be moved eccentrically by means of the pinion 11 through the axial displacement of the rack shaft 9. In the mechanism for the axial movement of the rack shaft 9, an operative place 15 is mounted on the rear end of the rack shaft 9 in relatively rotatable relationship while a guide pin 20 is secured to a fixed member so as to permit the axial movement of the rack shaft 9 and restrict the rotating movement of the same. Additionally, the operative plate 15 is threaded on a screw 14 arranged rotatably in bearing engagement with the fixed member so that the rack shaft 9 can move in the axial direction together with the operative plate 15 as the screw 14 rotates in the forward and reverse directions. The screw 14 is driven for the forward and reverse rotating movements by a motor 13 operating with a control signal. Accordingly, a determined length of swing stroke on the swing arm 1 can be automatically adjusted by the drive of the motor 13. The swing angle adjusting mechanism of the paper infeed rolls 3 will be described below. As shown in Fig.2, gears 15a and 16 for rotating the paper infeed rolls 3 and a lever 18 provided with a gear 17 meshing with the gear 16 are mounted to the swing arm 1. The lever 18 is connected with the end of a link 19, the link 19 having at the other end the same arrangement as the aforesaid combination of the rotary disk 5 connected with the end of the aforesaid link 4, the cam 6, and the eccentricity adjusting mechanism of the cam 6. While the link 19 moves in crank motions as being synchronized with the link 4, the eccentric movement of the cam 6 is transmitted via the lever 18 and the gears 17, 16, 15a thus to adjust automatically the paper infeed rolls 3 to have a desired swing angle. The paper infeed rolls 3 may be replaced with guide plates. The numeral 21 is a rotary spiral member, a plurality of which are disposed for the operation in which paper form blanks folded primarily in a zigzag by the swing arms 1 along the transversely perforated lines arranged therein are arranged in a pile upon being folded up. The rotary spirals 21 are also arranged in a mechanism in which the automatic control thereof can be made as corresponding to the folding top-to-bottom length and lateral width of a paper form. This mechanism will be described in conjunction with Figs.1, 4, and 5. In the mechanism, block members 23 are slidably mounted on a pair of guide shafts 22 extending in the rightward and leftward directions or folding top-to-bottom lengthwise directions, and between two of the blocks 23, a drive shaft 24, a lead screw shaft 28, and a spine shaft 30 in parallel relationship are arranged rotatably in bearing engagement with the blocks 23. The drive shaft 24 has at both ends pinions 25 secured thereto, each of which meshes with a rack 26 mounted to a fixed member. Each of the blocks 23 can travel on the guide shaft 22 as the drive shaft 24 rotates together with the pinion 25 an the rack 26. The lead screw shaft 28 has a support block 45 mounted with a nut threaded thereon. A pipe 40 extending perpendicularly is attached downwardly to the support block 45 and the rotary spiral 21 is mounted to the lower end of a rotating shaft 41 extending through the pipe 40. The rotating shaft 41 extending through the pipe 40 has at upper end a helical gear which is meshed with another helical gear mounted in spline engagement with the spline shaft 30, as not shown, so that the rotary spiral 21 can rotate as the spline shaft 30 rotates. The drive power for rotating the spline shaft 30 is transmitted along a rotating axis 31 from the aforesaid folding drive servo motor 7 via a transmitting mechanism 31 (See Fig.1). The drive shaft 24 is driven by a motor 27 for determining the folding top-to-bottom length while the lead screw shaft 28 is driven by a motor 29 for determining the lateral width. Both the motors 27 and 29 for respective length and width determining can be controlled with the use of control signals for their respective forward and reverse rotating movements. Accordingly, through operating the folding top-to-bottom length determining motor 27; the rotary spirals 21 can be located automatically in position relative to the folding top-to-bottom length as the blocks 23 move in the rightward and leftward (folding top-to-bottom lengthwise) directions, and at the same time, through operating the width determining motor 29, the rotary spirals 21 can be moved automatically for the widthwise positioning as the support blocks 45, in one side or both sides, move in the axial directions of the lead screw shaft 28 or widthwise directions on the lead screw shafts 28 driven.

Claims: A zigzag folding apparatus for a form printing machine for folding paper blanks along transverse lines comprising fold arms (1) rotatably mounted about a transverse axis so as to swing about that axis, having guide means (3) attached so as to guide the paper form blanks to be folded and a plurality of paper packing rotating spirals (21) which cooperate with the edges of the paper form blanks so as to pack them tightly, the rotating spirals (21) being driven by rotary spiral drive means (24, 28), and a servo motor (7) is connected to a crank arm (4) so as to cause pivotal oscillation of the fold arms (1) characterised in that said oscillation is adjustable by means of adjustment means (13) and at least one motor (27, 29) is provided for altering either or both of the transverse and longitudinal distance between the rotating spirals (21), said motors being controlled by control signals. Apparatus as claimed in claim 1 wherein the adjustment means is provided by a second motor (13) which adjusts the amplitude of swing of the fold arms (1) by altering the eccentricity of the crank arm (4) on a crank wheel (5). Apparatus as claimed in claims 1 or 2 wherein the adjustment means further comprises a rack shaft (9) on which the crank wheel (5) is mounted, the rack shaft meshing with a gear wheel (11) which is operably connected to a cam (6) eccentrically movable about a rotating centre of the crank wheel (5) and connected to the crank arm (4), the rack shaft (9) being connected by a rotary driven member (14) to the second motor (13). Apparatus as claimed in any preceding claim wherein guide adjusting means (19) are provided to adjust the swing angle of the guide means (3) relative to the fold arms (1). Apparatus as claimed in claim 4 wherein the guide adjusting means (19) includes a lever (18) mounted on the fold arms (1) and connected via a link (19) to a respective cam (6) located in a respective crank wheel (5).

Inventors: HANYU, AKINOBU, KUROKAWA, TSUKASA
Applicants: FUJI KIKAI KOGYO CO., LTD.
Application year: 1987
Main classification: B65H45
IPC codes: B65H45