A transported-object stacking apparatus includes first fluid discharge unit and second fluid discharge unit. The first fluid discharge unit is disposed on one side of a transported object and is adapted to discharge working fluid in order to press the transported object against transporting unit. The second fluid discharge unit is disposed downstream from the first fluid discharge unit with respect to the direction of transport of the transported object and on the other side of the transported object, and is adapted to discharge working fluid toward a rear half portion of the transported object in order to separate the transported object from the transporting unit. When working fluid is discharged from the first fluid discharge unit, an object transported by the transporting unit is pressed against the transporting unit. Subsequently, when working fluid is discharged from the second fluid discharge unit toward a rear half portion of the transported object, the transported object is separated from the transporting unit.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to a transported-object stacking apparatus.
 2. Description of the Related Art
 Conventionally, in a transported-object stacking apparatus for stacking
 sheetlike transported objects one by one, a high-speed conveyor running at
 high speed and a low-speed conveyor running at low speed are arranged
 adjacent to each other, while a speed-reducing section is provided at the
 entrance of the low-speed conveyor. Objects transported on the high-speed
 conveyor are reduced in speed during transfer to the low-speed conveyor
 and are stacked on the low-speed conveyor.
 However, in the conventional transported-object stacking apparatus, the
 front end of an object transported at high speed by the high-speed
 conveyor may collide with a rear portion of the preceding object
 transported at low speed by the low-speed conveyor, potentially resulting
 in jamming of transported objects.
 Since the angle of a transported object entering the speed-reducing
 section, i.e., the angle of entry, is difficult to adjust, the preceding
 transported object may be hit hard by the front end of the following
 transported object. As a result, the surface of the preceding transported
 object may be damaged, rendering the object defective. Particularly, when
 a transported object is lightweight, the transported object enters the
 speed-reducing section at a relatively high speed. As a result, the
 posture of the transported object becomes very unstable during entry into
 the speed-reducing section.
 To avoid such a postural instability, an object may be transported while
 being held between the high-speed conveyor and a guide belt running at a
 speed identical to that of the high-speed conveyor. However, this causes
 variations in, for example, positioning or timing curing transfer of a
 transported object from the high-speed conveyor to the low-speed conveyor.
 To avoid such variations, the traveling speed of the high-speed conveyor
 may be decreased, or the span between transported objects may be
 increased. In such a case, however, the throughput of the
 transported-object stacking apparatus is impaired accordingly.
 SUMMARY OF THE INVENTION
 An object of the present invention is to solve the above-mentioned problems
 in the conventional transported-object stacking apparatus and to provide a
 transported-object stacking apparatus capable of preventing both jamming
 of transported objects and rendering an object defective without
 impairment of throughput.
 To achieve the above object, a transported-object stacking apparatus
 according to the present invention comprises first fluid discharge means
 and second fluid discharge means. The first fluid discharge means is
 disposed on one side of a transported object and is adapted to discharge
 working fluid in order to press the transported object against
 transporting means. The second fluid discharge means is disposed
 downstream from the first fluid discharge means with respect, to the
 direction of transport of the transported object and on the other side of
 the transported object, and is adapted to discharge working fluid toward a
 rear half portion of the transported object in order to separate the
 transported object from the transporting means.
 In this case, when working fluid is discharged from the first fluid
 discharge means, an object transported by the transporting means is
 pressed against the transporting means. Subsequently, when working fluid
 is discharged from the second fluid discharge means toward a rear half
 portion of the transported object, the transported object is separated
 from the transporting means.
 Accordingly, the transported object can assume a very stable posture and
 thus can be constantly stacked in a magazine at a predetermined position.
 Since the transported object to be stacked is inclined, two consecutive
 transported objects can be free from such a collision that the preceding
 transported object is hit hard by the front end of the following
 transported object, thereby preventing jamming of transported objects.
 Another transported-object stacking apparatus according to the present
 invention comprises first transporting means, second transporting means,
 fluid discharge means, and fluid inversion means. The first transporting
 means is adapted to transport a transported object and travels on one side
 of the transported object. The second transporting means is adapted to
 transport the transported object and travels on the other side of the
 transported object. The fluid discharge means is disposed on one side of
 the transported object and is adapted to discharge working fluid. The
 fluid inversion means is disposed on the other side of the transported
 object, and has an entrance port for introducing thereinto working fluid
 discharged from the fluid discharge means and a discharge port for
 discharging therefrom working fluid introduced through the entrance port.
 The discharge port is located downstream of the entrance port with respect
 to the direction of transport of the transported object.
 In this case, when working fluid is discharged from the fluid discharge
 means on one side of the transported object, the object transported by the
 first and second transporting means is pressed against the second
 transporting means. Subsequently, when the rear end of the transported
 object passes through a gap between the second transporting means and the
 fluid discharge means, working fluid discharged from the fluid discharge
 means enters the fluid inversion means through the entrance port and is
 discharged through the discharge port on the downstream side with respect
 to the direction of transport of the transported object to thereby press a
 rear end portion of the transported object downward.
 Accordingly, the object is transported while being held between the first
 and second transporting means. Subsequently, the object is transported
 while being pressed against the second transporting means by means of
 working fluid. Then, the transported object is forcibly released from the
 second transporting means by means of working fluid discharged from the
 discharge port. Accordingly, the transported object can assume a very
 stable posture in a stacking region and thus can be constantly stacked in
 a magazine at a predetermined position.
 Since the transported object to be stacked is inclined to thereby establish
 a wide gap between the second transporting means and the rear end of the
 transported object, two consecutive transported objects can be free from
 such a collision that the preceding transported object is hit hard by the
 front end of the following transported object, thereby preventing jamming
 of transported objects.
 Still another transported-object stacking apparatus further comprises
 positioning means for positioning the fluid inversion means in the
 direction of transport of the transported object.
 Since the fluid inversion means and the fluid discharge means can be
 positioned in the direction of transport of objects, the angle of entry of
 a transported object into the stacking region can be easily adjusted.
 Accordingly, two consecutive transported objects can be free from such a
 collision that the preceding transported object is hit hard by the front
 end of the following transported object. As a result, the surface of the
 preceding transported object cannot be damaged, so that rendering an
 object defective can be prevented. Particularly, when the surface of
 transported object bears printing, there can be reliably prevented an
 impairment in printed image quality which would otherwise result from
 damage to the printed surface.
 Further, since transported objects can be stably stacked, there is no need
 for reducing the traveling speed of the first and second transporting
 means or increasing the interval between transported objects. Thus, the
 throughput of the transported-object stacking apparatus is not impaired.

DESCRIPTION OF PREFERRED EMBODIMENT
 An embodiment of the present invention will next to described in detail
 with reference to the drawings.
 In the drawings, reference numeral 11 denotes a sheetlike object, such as a
 blank, to be transported along a transport passage TR. Reference numeral
 12 denotes a first conveyor which travels under the transport passage TR
 so as to transport the object 11 while facing one side of the transported
 object 11. The first conveyor 12 includes a plurality of transport rollers
 14 and an endless belt 13 extending along the transport rollers 14.
 Reference numeral 16 denotes a second conveyor which travels above the
 transport passage TR so as to transport the object 11 while facing the
 other side of the transported object 11. The second conveyor 16 includes a
 plurality of transport rollers 17 and an endless belt 18 extending along
 the transport rollers 17. The first conveyor 12 serves as first
 transporting means, and the second conveyor 16 serves as second
 transporting means. Being disposed for supporting the transported object
 11, the belt 13 has a width wider than that of the transported object 11.
 Being disposed for guiding the transported object 11, the belt 18 has a
 width narrower than that of the transported object 11.
 According to the present embodiment, the first and second conveyors 12 and
 16 travel at the same speed. However, the first and second conveyors 12
 and 16 may travel at different speeds.
 A stacking section P1 is located ahead (left-hand side in FIG. 1) of the
 first conveyor 12 and under the second conveyor 16 and is adapted to stack
 in an unillustrated magazine the objects 11 transported by the first and
 second conveyors 12 and 16. A stacking apparatus 21 is disposed in the
 stacking section P1. The stacking apparatus 21 includes a housing 22, a
 pair of nozzles 23, and a pair of inversion manifolds 24. The nozzles 23
 are supported by the housing 22 and are adapted to discharge compressed
 air serving as working fluid and supplied from an unillustrated air
 source, thus serving as first fluid discharge means. The invention
 manifolds 24 are supported by the housing 22 and are adapted to invert
 compressed air introduced from the corresponding nozzles 23 so as to
 discharge compressed air against the transported object 11.
 The housing 22 includes a pair of side walls 22a and 22b, a connection
 member 22c, and brackets 22d and 22e. The side walls 22a and 22b are
 disposed such that a predetermined space greater than the width of the
 transported object 11 is left therebetween. The connection member 22c is
 adapted to connect the side walls 22a and 22b together. The inversion
 manifolds 24 are attached to the connection member 22c via the bracket
 22d. The nozzles 23 are attached to the connection member 22c via the
 bracket 22e. The inversion manifold 24 substantially assumes a shape of a
 inverse letter U and has an entrance port 25 and a discharge port 26
 formed at opposite ends thereof. The entrance port 25 is directed downward
 so as to face the tip of the corresponding nozzle 23 in order to introduce
 compressed air discharged from the nozzle 23 into the inversion manifold
 24. The discharge port 26 is directed downward so as to discharge
 compressed air introduced through the entrance port 25 toward a rear end
 portion of the transported object 11, thus serving as second fluid
 discharge means. The discharge port 26 is located downstream of the
 entrance port 25 with respect to the direction of transport of the object
 11. Distance K between the entrance port 25 and the discharge port 26
 along the direction of transport of the object 11 is determined according
 to the length of the transported object 11.
 Thus, compressed air discharged from the nozzle 23 enters the inversion
 manifold 24 through the entrance port 25 and is inverted within the
 inversion manifold 24. Then, the compressed air is discharged through the
 discharge port 26 toward the transported object 11.
 When the object 11 transported by the first and second conveyors 12 and 16
 reaches the stacking section P1, compressed air discharged from the
 nozzles 23 causes the transported object 11, from the front end toward the
 rear end, to come into contact with the belt 18. Being pressed against the
 belt 18, the object 11 is transported by means of inertia thereof and the
 belt 18, during which the transported object 11 intercepts air flow
 between the nozzles 23 and the inversion manifolds 24.
 Subsequently, when the rear end of the transported object 11 passes through
 the gaps between the nozzles 23 and the inversion manifolds 24, compressed
 air discharged from the nozzles 23 enters the invention manifolds 24
 through the entrance ports 25. Thus-introduced compressed air is inverted
 within the inversion manifold 24 and is then discharged through the
 discharge ports 26 toward a rear half portion of the transported object
 11, thereby pressing the transported object 11, for example, at point m
 (FIG. 1) located near the rear end (right end in FIG. 1) of the object 11.
 The distance between the point m and the rear end of the transported
 object 11 is determined on the basis of distance K mentioned above.
 However, the position of point m is set so as to be located between the
 center and the rear end of the transported object 11.
 Accordingly, the transported object 11 is separated from the second
 conveyor 16 while assuming an inclined posture and is stacked in the
 aforementioned magazine. A guide roller 28 is disposed ahead of the
 stacking apparatus 21 in order to align front ends of the transported
 objects 11 being stacked. The guide roller 28 is rotated at a
 predetermined speed in the direction of the arrow of FIG. 1.
 As described above, in the stacking section P1, the transported object 11
 is inclined, so that a wide space is established between the belt 18 and
 the rear end of the transported object 11. Thus, the two consecutive
 transported objects 11 are free from such a collision that the front end
 of the following transported object 11 collides with the rear portion of
 the preceding transported object 11, thereby preventing jamming of the
 transported objects 11.
 A shaft 31 is disposed in the vicinity of the front end of the housing 22
 and rotatably supports the transport roller 17. The shaft 31 is supported
 by an unillustrated frame via a vertical support member 32 and a
 horizontal support member 33. An elongated hole 32a is formed in the
 vertical support member 32. An elongated hole 33a is formed in the
 horizontal support member 33 in such a manner as to cross the elongated
 hole 32a. A pin 34 is disposed in such a manner as to extend through the
 elongated holes 32a and 33a. By positioning the pin 34 as desired along
 the elongated holes 32a and 33a and fastening the pin 34 by means of the
 fastening handle 35, the housing 22 can be vertically and horizontally
 positioned. The elongated holes 32a and 33a, the pin 34, and the fastening
 handle 35 cooperatively serve as positioning means.
 As inclined support member 37 extends obliquely upward from the shaft 31.
 An arc-shaped elongated hole 38 is formed in the side wall 22b at an upper
 predetermined position. The shaft 31 is the center of the arc into which
 the elongated hole 38 is shaped. A pin 39 is disposed at such a manner as
 to extend through the elongated hole 38. By positioning the pin 39 as
 desired along the elongated hole 38 and fastening the pin 39 by means of
 the fastening handle 40, the housing 22 can be inclined at a predetermined
 angle. The elongated hole 38, the pin 39, and the fastening handle 40
 cooperatively serve as positioning means.
 Further, an elongated hole 42 is formed in the side wall 22b at a lower
 predetermined position. A pin 43 is disposed in such a manner as to extend
 through the elongated hole 42. By positioning the pin 43 as desired along
 the elongated hole 42 and fastening the pin 43 by means of the fastening
 handle 45, the inversion manifolds 24 and the nozzles 23 can be
 horizontally positioned with respect to the housing 22. The elongated hole
 42, the pin 43, and the fastening handle 45 cooperatively serve as
 positioning means.
 As described above, the housing 22 can be vertically and horizontally
 positioned and can be inclined at a predetermined angle, and the invention
 manifolds 24 and the nozzles 23 can be horizontally positioned with
 respect to the housing 22. Thus, the angle of entry of the transported
 object 11 into the stacking section P1 can be easily adjusted. Therefore,
 the two consecutive transported objects 11 can be free from such a
 collision that the preceding transported object 11 is hit hard by the
 front end of the following transported object 11. As a result, the surface
 of the preceding transported object 11 cannot be damaged, so that
 rendering the object 11 defective can be prevented. Particularly, when the
 surface of the transported object 11 bears printing, there can be reliably
 prevented an impairment in printed image quality which would otherwise
 result from damage to the printed surface.
 Further, since the transported objects 11 can be stably stacked in the
 aforementioned magazine, there is no need for reducing the traveling speed
 of the first and second conveyors 12 and 16 or increasing the interval
 between the transported objects 11. Thus, the throughput of the
 transported-object stacking apparatus is not impaired.
 For example, when the transported object 11 is a sheet having a length of
 about 300 mm, a width of about 300 mm, a thickness of about 0.5 to 2 mm,
 and a weight of about 40 g, the transported object 11 enters the stacking
 section P1 at a relatively high speed of about 3 to 5 m/s. However, the
 transported object 11 can assume a very stable posture in the stacking
 section P1 and thus can be constantly stacked in the aforementioned
 magazine at a predetermined position, for the following reason. The object
 11 is transported while being held between the first and second conveyors
 12 and 16. Subsequently, the object 11 is transported while being pressed
 against the belt 18 by means of compressed air. Then, the transported
 object 11 is forcibly released from the belt 18 by means of compressed air
 discharged from the discharge port 26.
 The present invention is not limited to the above-described embodiment.
 Numerous modifications and variations of the present invention are
 possible in light of the spirit of the present invention, and they are not
 excluded from the scope of the present invention.