Delivery apparatus for sheet-fed printing press

A delivery apparatus for a sheet-fed printing press includes a holding member, a delivery chain, at least two sheet stacking units, an engaging member, and a switching unit. The switching unit selectively switches a sheet release position where the engaging member abuts against the holding member and a retreat position where the engaging member does not abut against the holding member. The switching unit includes an air cylinder having a movable actuating rod, a first lever, having two ends pivotally mounted on the actuating rod and the engaging member, respectively, for coupling the actuating member and the engaging member, and a second lever having one end swingably supported and the other end swingably and pivotally mounted on a coupling portion between the actuating rod and the first lever. The first and second levers are located substantially on a straight line when the engaging member is at the sheet release position.

BACKGROUND OF THE INVENTION 
The present invention relates to a multi-pile type delivery apparatus for a 
sheet-fed printing press, which alternately deliveries printed and 
conveyed paper sheets to a plurality of sheet stacking units lined up in a 
sheet convey direction. 
Generally, in a sheet-fed printing press, a paper sheet printed by a 
printing press is transferred from the grippers of a printing cylinder to 
the delivery grippers of delivery chains, and conveyed as the delivery 
chains travel. When the delivery grippers holding the paper sheet abuts 
against the sheet release cam at the convey end portion, the paper sheet 
is released from the delivery grippers, falls and is stacked on the pile 
of the delivery apparatus. Conventionally, a multi-pile type delivery 
apparatus is proposed in which a plurality of sheet stacking units, i.e., 
piles are lined up in the sheet convey direction. For this reason, when 
the number of paper sheets stacked on the pile reaches a predetermined 
number, the printing press need not be stopped to change the pile. In this 
case, a sheet release cam is provided above each sheet stacking unit. A 
cam switching means is provided in correspondence with each sheet release 
cam except for the most downstream cam to individually move the sheet 
release cam between a sheet release position where the sheet release cam 
abuts against the delivery grippers to cause the paper sheet to be 
released and a retreat position where the sheet release cam retreats not 
to abut against the delivery grippers. An adjusting unit for moving and 
adjusting the position of the sheet release cam is provided to each sheet 
release cam. The adjusting unit selects an optimum sheet release position 
and an optimal sheet release timing in accordance with the printing speed, 
the sheet size, the sheet thickness, or the sheet material, thereby 
preventing sheet misalignment or sheet jamming in the delivery unit. 
Sheet-fed printing presses having such a cam switching means or movement 
adjusting units for a sheet release cam are disclosed in Japanese Utility 
Model Laid-Open Nos. 63-161253 and 4-5452, and Japanese Patent Laid-Open 
No. 58-167348. However, the movement adjusting unit of the sheet release 
cam disclosed in Japanese Utility Model Laid-Open No. 63-161253 has a 
structure in which the swinging fulcrum of the sheet release cam is free 
to shift inside an elongated hole, one end of a lever swingably supported 
at the central portion is pivotally mounted on the sheet release cam, and 
the other end is coupled to a piston rod. When the piston rod is moved, 
the swinging fulcrum of the sheet release cam is shifted inside the 
elongated hole, and at the same time, the sheet release cam is pivoted 
about the swinging fulcrum. For this reason, the sheet release cam is 
nonlinearly moved to make it difficult to correctly adjust the position, 
and when a cam follower abuts against the cam, the lever directly applies 
a load on the piston rod. The cam switching means disclosed in Japanese 
Utility Model Laid-Open No. 4-5452 has a structure in which the cam is 
vertically escaped with respect to the traveling direction of the cam 
follower. For this reason, when the printing speed is increased, it 
becomes difficult to set the timing of cam switching. In the worst case, 
the cam strikes the cam follower from the side to damage the printing 
press. The cam switching means disclosed in Japanese Patent Laid-Open No. 
58-167348 has a structure in which one end and the other end of the lever 
swingably supported are simply coupled with the piston rod and the sheet 
release cam, respectively. For this reason, when the cam follower abuts 
against the cam, the lever directly applies the load on the piston rod. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a delivery apparatus 
for a sheet-fed printing press, which prevents the damage or the failure 
of a driving source for sheet conveyance. 
It is another object of the present invention to provide a delivery 
apparatus for a sheet-fed printing press, capable of easily adjusting a 
sheet release timing. 
In order to achieve the above objects, there is provided a delivery 
apparatus for a sheet-fed printing press, comprising a holding member for 
holding a printed paper sheet, conveying means for causing the holding 
member to travel to convey the held paper sheet, at least two sheet 
stacking units respectively arranged on upstream and downstream sides of a 
sheet convey direction of the conveying means, an engaging member, 
arranged above the sheet stacking unit on the upstream side, for releasing 
the held paper sheet by abutting against the traveling holding member, and 
switching means for selectively switching a sheet release position where 
the engaging member abuts against the holding member and a retreat 
position where the engaging member does not abut against the holding 
member, the switching means including driving means having a movable 
actuating rod, a first lever, having two ends pivotally mounted on the 
actuating rod and the engaging member, respectively, for coupling the 
actuating member and the engaging member, and a second lever having one 
end swingably supported and the other end swingably and pivotally mounted 
on a coupling portion between the actuating rod and the first lever, so 
that the first and second levers are located substantially on a straight 
line when the engaging member is at the sheet release position.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
An embodiment of the present invention will be described below with 
reference to the accompanying drawings. FIG. 1 shows a delivery apparatus 
for a printing press according to the present invention, FIGS. 2, 3, 4, 
and 5 show a sheet release mechanism in FIG. 1. Referring to FIG. 1, a 
delivery apparatus 2 comprises a pair of left and right delivery frames 3. 
A pair of left and right sprockets 4 are axially mounted on the rear ends 
of the upper end portions of the delivery frames 3, i.e., the terminal 
ends in the sheet convey direction, respectively. Sprockets (neither are 
shown) corresponding to the sprockets 4 are coaxially provided to a 
delivery cylinder (not shown) in contact with the last printing cylinder 
of the printing unit connected with the delivery apparatus. A pair of left 
and right delivery chains 5 respectively extend between the sprockets 
along upper and lower chain guides (neither are shown), and travel in a 
direction indicated by an arrow A in FIG. 1 by the sprockets rotated by a 
motor. 
Delivery gripper members 6 for gripping and conveying the paper sheets are 
supported between the left and right delivery chains 5 at predetermined 
intervals. Reference numerals 7 and 8 denote first and second piles 7 and 
8, respectively, which are lined up in the traveling direction of the 
delivery chains, i.e., in the sheet convey direction. Sheet release 
mechanisms 10 and 11 are disposed above the first and second piles 7 and 
8, respectively. A cam switching means 15 to be described later is 
provided to the sheet release mechanism 10 above the first pile 7. The cam 
switching means 15 selectively operates the sheet release mechanism 10 to 
cause the traveling delivery gripper member 6 to release a gripped paper 
sheet 9 to be fallen and stacked on the first pile 7, or cause the 
delivery gripper member 6 to pass while keeping the paper sheet 9 gripped. 
The sheet release mechanism 11 comprising a fixed cam is disposed above 
the second pile 8. The delivery gripper member 6 passing over the first 
pile 7 abuts against the fixed cam of the sheet release mechanism 11. When 
the paper sheet 9 is gripped by the delivery gripper member 6 passing over 
the first pile 7, the paper sheet 9 falls and is stacked on the second 
pile 8. First and second front gauges 12a and 12b are disposed near the 
upper rear end portions of the first and second piles 7 and 8, 
respectively. The leading end of the paper sheet 9 released from the 
delivery gripper member 6 abuts against the front gauge 12a or 12b, and 
fallen onto the first or second pile 7 or 8. Vertically movable sheet 
stacking plates (neither are shown) for stacking paper sheets 9 thereon 
are provided to the first and second piles 7 and 8, respectively. 
The sheet release mechanism 10 as a feature of the present invention will 
be described below in detail with reference to FIGS. 2 to 5. The sheet 
release mechanism 10 is schematically constituted by the cam switching 
means 15 and a cam moving means 16. The cam switching means will be 
described first. Reference numeral 20 denotes an elongated base plate 
vertically disposed with its longitudinal direction being arranged in 
parallel to the sheet convey direction. An air cylinder 23, a first lever 
27, a second lever 28, and a cam 30, all of which constitute the cam 
switching means 15, are mounted on the base plate 20. More specifically, 
the air cylinder 23 is arranged in parallel to the base plate 20, and has 
one end pivotally supported, by a pin 22, on a plate 21 fixed by screws at 
the distal end portion of the base plate 20, and a screw portion 24a is 
formed at a piston rod 24 projecting from the air cylinder 23. 
The bottom portion of a substantially U-shaped holder 25 is threadably 
engaged with the screw portion 24a and fixed by a nut 26 integrally with 
the piston rod 24. One end of the first lever 27 and one end of the second 
lever 28 are axially mounted between the arms of the holder 25 by a screw 
29 so as to overlap each other and are coupled to the piston rod 24 
through the holder 25. Reference numeral 30 denotes a sheet release cam 30 
having, on its lower surface, a cam surface 30a against which a cam 
follower 37 of the delivery gripper member 6 to be described later abuts. 
The sheet release cam 30 has its one end axially mounted on the base plate 
20 by a screw 31, and is free to swing about the screw 31. 
The other end of the first lever 27 is axially mounted on and coupled to 
the other end of the sheet release cam 30 by a screw 32. The other end of 
the second lever 28 is axially mounted on the base plate 20 by a screw 33, 
and the second lever 28 is supported to be swingable about the screw 33. 
When the air cylinder 23 is operated to retreat the piston rod 24, the 
second lever 28 is pivoted clockwise about the screw 33. Accordingly, the 
first lever 27 is moved obliquely upward to cause the sheet release cam 30 
to swing counterclockwise about the screw 31 and move to the retreat 
position indicated by a chain double-dashed line. On the other hand, when 
the piston rod 24 is moved forward, the second lever 28 is pivoted 
counterclockwise about the screw 33. Accordingly, the first lever 27 is 
moved obliquely downward to cause the sheet release cam 30 to pivot 
clockwise about the screw 31 and move to the sheet release position 
indicated by a solid line. When the sheet release cam 30 is at the sheet 
release position, the first and second levers 27 and 28 are located 
substantially on a straight line. Reference numeral 34 denotes a stopper 
threadably engaged with a block 34a fixed to the base plate 20, and has 
its distal end projecting from the block 34a in contact with the second 
lever 28. 
The arrangement of the delivery gripper member 6 fixed to the delivery 
chain 5 will be described. The delivery gripper member 6 is constituted by 
disposing a gripper pad 35 and a gripper 36 to oppose each other, and a 
biasing force in a close direction to press the distal end of the gripper 
36 against the gripper pad 35 is applied by a spring member (not shown). 
On the other land, the gripper 36 is separated from the gripper pad 35 
against the applied biasing force when the cam follower 37 abuts against 
the cam surface 30a of the sheet release cam 30. 
The arrangement of the cam moving means 16 will be described. As shown in 
FIGS. 4 and 5, a sliding member 38 is mounted on one side surface of the 
base plate 20 to be free to linearly slide. On the other hand, a guide 
member 39 engaged with the sliding member 38 is mounted, in parallel to 
the traveling direction of the delivery gripper member 6, on a fixed plate 
40 fixed on the frame 3. The base plate 20 is freely slid along the guide 
member 39 by the sliding member 38. As shown in FIG. 3, a pin 41 stands 
upright from one side surface of the base plate 20, and a screw portion 
41a is formed to extend through a head portion of the pin 41 in the 
sliding direction of the guide member 39. A pair of bearing plates 42a and 
42b are mounted on the fixed plate 40 to oppose each other. A screw rod 43 
is rotatably supported by the bearing plates 42a and 42b to be parallel to 
the guide member 39. A step-like distal end of the screw rod 43 is stopped 
at the bearing plates 42a and the other end is stopped at the bearing 
plate 42b by a nut 44, so that the horizontal movement of the screw rod 43 
is hindered. The screw rod 43 is threadably engaged with the screw portion 
41a of the pin 41. A bevel gear 45 is fixed to the other end as the 
projecting portion of the screw rod 43. 
A bearing sleeve 46 extends through the frame 3. A shaft 47 having a bevel 
gear 48 meshed with the bevel gear 45 at one end and a bevel gear 49 fixed 
at the other end is rotatably supported by the bearing sleeve 46. A bevel 
gear 52 fixed to a motor shaft 51 of a reversible motor 50 is meshed with 
the bevel gear 49. 
An operation of the present invention having the above arrangement will be 
described below. The paper sheet 9 printed by a printing press (not shown) 
is transferred from the gripper of a printing cylinder to the gripper 36 
and the gripper pad 35 of the delivery gripper member 6 of the delivery 
chains 5, and conveyed to the upper portion of the first pile 7 as the 
delivery chains 5 travel. If the paper sheets are stacked on the first 
pile 7, the air cylinder 23 of the sheet release mechanism 10 above the 
first pile 7 is operated to cause the piston rod 24 to move forward. The 
sheet release cam 30 is pivoted clockwise about the screw 31 and moved 
downward to the sheet release position indicated by the solid line in FIG. 
2. 
When the cam follower 37 of the delivery gripper member 6 traveling in the 
direction indicated by the arrow A abuts against the cam surface 30a of 
the cam 30, the gripper 36 is pivoted in the open direction to cause the 
gripper 36 to release the paper sheet 9 to be fallen onto the first pile 
7. At this time, when the cam follower 37 abuts against the cam surface 
30a, an upward external force is applied to the cam 30, so that the sheet 
release cam 30 receives a counterclockwise load to pivot about the screw 
31. However, since the first and second levers 27 and 28 are located 
substantially on a straight line, no force component is generated from the 
applied load in the moving direction of the piston rod 24. Therefore, no 
actual load is applied to the piston rod 24 to prevent damage to the air 
cylinder 23. 
On the other hand, if the paper sheets are stacked on the second pile 8, 
the air cylinder 23 of the sheet release mechanism 10 above the first pile 
7 is operated to retreat the piston rod 24. The sheet release cam 30 is 
pivoted counterclockwise about the screw 31 and moved upward to the 
retreat position indicated by the chain double-dashed line. The traveling 
cam follower 37 does not abut against the cam surface 30a of the cam 30, 
so that the paper sheet passes over the first pile 7 while being gripped 
by the gripper 36. When the cam follower 37 abuts against the fixed cam of 
the sheet release mechanism 11 above the second pile 8, the paper sheet 9 
is released from the gripper 36 and fallen onto the second pile 8. 
An adjusting operation of the opening/closing timing of the gripper 36 in 
the traveling direction of the delivery gripper member 6 will be described 
below. When the motor is rotated, the rotation of the motor 50 is 
transmitted from the motor shaft 51 to the shaft 47 through the bevel 
gears 52 and 49, and further to the screw rod 43 through the bevel gears 
48 and 45. When the screw rod 43 is rotated, the pin 41 threadably engaged 
with the screw rod 43 is moved in a direction indicated by an arrow B in 
FIG. 3. The base plate 20 integral with the pin 41 is slid in the 
direction indicated by the arrow B along the guide member 39 fitted in the 
sliding member 38. Accordingly, the cam 30 mounted on the base plate 20 is 
also moved in the direction indicated by the arrow B, i.e., in parallel to 
the traveling direction of the delivery gripper member 6, thereby 
adjusting the position of the cam 30, i.e., the opening/closing timing of 
the gripper 36. When the motor is reversely rotated, the base plate 20 is 
slid in a direction opposite to that of the arrow B, and the cam 30 is 
also moved in the same manner as described above. 
As described above, since the cam 30 is linearly moved in parallel to the 
traveling direction of the delivery gripper member 6, the moving amount of 
the cam 30 is equivalent to the adjusting amount of the opening/closing 
position of the gripper 36. Therefore, the adjusting amount can be easily 
grasped and correctly adjusted. In this case, if a stepping motor or the 
like is used as the motor 50 to electrically measure and control the pivot 
amount of the motor shaft, the moving amount of the cam 30 can be 
correctly and easily controlled. Since the air cylinder 23, the first and 
second levers 27 and 28, and the cam 30 are mounted on the moving base 
plate 20, the relative positions among these members are not changed when 
the base plate 20 is moved. The positional relationship between the 
swinging position of the cam 30 swung by the switching means 15 and the 
delivery gripper member 6 is always constant. For this reason, the sheet 
gripping/releasing operation of the delivery gripper member 6 becomes 
stable, and at the same time, an erroneous operation can be prevented. If 
a detection mechanism for detecting the printing speed, the sheet size, 
the sheet thickness, or the sheet material is provided to the cam moving 
means 16, the sheet release cam 30 can be automatically moved to an 
optimum position by using a signal from the detection mechanism. 
Although, in this embodiment, the present invention is applied to a 
delivery apparatus having two delivery piles, it may be used to a delivery 
apparatus laving three or more delivery piles. In addition, the cam 
switching means 15 may be operated by a pile switching signal generated 
when a predetermined number of paper sheets are stacked on one of delivery 
piles. Further, the cam switching means 15 may be operated by a signal 
from a known detection unit for detecting a defective paper sheet, thereby 
delivering the defective paper sheet onto a predetermined erroneous paper 
sheet delivery pile. 
As has been described above, in the delivery apparatus for a sheet-fed 
printing press according to the present invention, when the paper sheet is 
released from the delivery gripper member by the sheet release cam, the 
sheet release cam receives a load from the delivery gripper member. 
However, no force component is generated in the direction of the actuating 
rod of the drive source while only the first and second levers located 
substantially on a straight line are loaded. For this reason, the drive 
source for swinging the sheet release cam receives no load, thereby 
preventing the damage or failure of the drive source.