Guide for a sheet aligning station of a package producing machine

A guide for a sheet aligning station for lateral positioning of a sheet includes a supporting surface mounted on a belt to support the trailing edge of a sheet and a roller extending slightly beyond the supporting surface to contact the sheet edge and reduce friction between the guide and the sheet during crosswise shifting of the sheet, for example by a lateral guiding ruler.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to an aligning station such as in a 
package producing machine and, more particularly, to an assembly for 
positioning sheet like workpieces using guides. 
2. Description of the Related Art 
During the production of packages from, for instance, corrugated board, 
sheets of corrugated board are taken from a pile and carried individually 
into subsequent processing stations for cutting and/or shaping, for 
example. 
Transportation of the various successive sheets from the pile to the 
processing station is achieved by pushing the sheet by means of two 
movable guides which act as stops for the rear, or trailing, edge of the 
sheets, these rear guides being fitted onto an endless toothed belt. 
However, due to the difficulty of centering sheet pile along a lengthwise 
central axis of the machine, the sheets, while moving from the pile to the 
processing station, travel through a so-called aligning or lateral guiding 
station. The aligning station performs a crosswise positioning, in other 
words perpendicular to the direction of travel, of the various successive 
sheets so that the sheets are in a desired position relative to the tools 
of the subsequent processing station. To achieve this perpendicular 
positioning, the aligning station includes a reference or guiding ruler on 
one lateral side along which the corresponding side edge of the moving 
sheet is to be guided. The guiding ruler includes a guiding surface 
parallel to the motion of the sheet, in other words parallel to the 
lengthwise axis of the machine, and can be positioned crosswise. The 
crosswise shift of the sheet, until it touches the guiding ruler is 
generally obtained by means of so-called oblique rollers which are in 
contact with the upper side of the sheet and running either freely or are 
power driven with a peripheral rotary speed which includes a crosswise 
motion component. 
Up to now, every rear guide that contacts the sheet edge has a smooth 
contact surface perpendicular to the direction of sheet motion. Experience 
has shown that when the guide driven by the belt is in contact with the 
cardboard, friction occurs at the contact points, which results in the 
following drawbacks: 
A slight crosswise shift of the belt occurs during lateral shifting of the 
sheet so that one lateral edge of the belt rubs rather strongly against a 
corresponding lateral guiding device, resulting in friction which quickly 
wears out the belt and necessitating its change, particularly at high belt 
running speeds of, for example, 300 m per minute. 
Sheet displacement occurs due to the fact that the crosswise shifting of 
the sheet may be of a distance of up to 15 mm, so that the combined action 
of the friction forces acting on the rear guide and on the oblique rollers 
results in a type of swivel action which obviously would be harmful to 
subsequent operations since it obstructs proper lateral guidance 
SUMMARY OF THE INVENTION 
The present invention provides a guiding station involving none of the 
aforementioned drawbacks and, in particular, provides rear guides which 
insure a proper lengthwise guiding or positioning of the sheet without 
simultaneous interference by forces encountered during lateral guiding of 
the sheet. 
This and other objects and advantages of the invention are attained by a 
guiding station including a guide mounted on an endless belt, the guide 
having a supporting surface positioned to contact a trailing edge of a 
sheet to push and position the sheet along the lengthwise axis of the 
processing machine, means for moving the sheet perpendicularly to the 
machine axis to provide lengthwise alignment, a ruler or similar sideways 
aligning guide, and at least one roller having a rotary axis lying 
essentially perpendicular to the sheet, the roller being mounted so that a 
small portion of the roller extends before the supporting surface so as to 
act as a guide for the trailing edge of the sheet. 
The objects and advantages are also achieved by a rear guide for an 
aligning station in a package producing machine having a surface to 
contact a trailing edge of a sheet to push and position the sheet along 
the lengthwise axis of a processing machine and a roller having a small 
periphery portion extending before the supporting surface to act as a stop 
for the trailing edge of the sheet. 
Further characteristics and advantages of the invention will become 
apparent from a description of an example of an apparatus according to the 
invention, with reference being made to the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A guide-type aligning station, such as for use in a package producing 
machine includes, according to the state of the art, at least two belts 10 
lying parallel to one another, each of which is a closed loop. The belt 
10, which is preferrably a toothed belt, carries at regular intervals 
guides T, only one of which is shown in FIG. 1. Each of the guides T has a 
surface 20 destined to act as a support for the rear, or trailing, edge of 
a sheet F. The belt 10 is driven in a way known in the art and 
synchronisly with other movements of the machine so that the rear guide T 
is able to achieve positioning of the sheet F moving in a direction B of 
the machine axis. 
Every rear guide T includes two parallelepipedic blocks 12 and 14 of 
identical shape. The block 12 and 14 are arranged crosswise at regular 
intervals on the belt 10. Both blocks 12 and 14 are formed of polyurethane 
and are vulcanized onto a surface of the belt 10 opposite to and along a 
tooth 24 of the toothed belt 10. Every block 12 and 14 is provided with a 
bore 16 extending parallel to the belt 10 and into which a metal bushing 
30 is inserted. The metal bushing 30 is of a length which is slightly less 
than that of the corresponding bore 16. 
The guide T also includes a first metal square 50 of which a first leg 52 
is provided with a supporting surface 20 which is in contact with the 
front, or leading, side of each block 12 and 14. The first square 50 also 
includes a second leg 54 which is in contact with an upper side of the 
blocks 12 and 14. The guide T also includes a second metal square 40 
having a first leg 42 which is in contact with the belt 10 and a second 
leg 44 in contact with the side of the two blocks 12 and 14 which lies 
opposite the supporting surface 20. The height of the second leg 44 is 
slightly less than the height of either of the blocks 12 and 14. The two 
squares 40 and 50 extend over the entire width of the belt 10 and are 
provided with holes 46 which are threaded at 56 so as to provide the 
possibility of clamping the two squares 40 and 50 onto the two blocks 12 
and 14 with the assistance of two screws 60 which pass through the holes 
46 and into the bushings 16. The screw ends are engaged in the threads 56. 
Attention is drawn to the fact that the leg 42 of the second square 40 
extends over a relatively large surface of the belt to counteract the 
forces originating from the tilting of the guide caused by the action of 
the sheet F on the supporting surface 20. 
The upper leg 54 of the first square is provided in its center area with an 
orifice or aperture 58 perpendicular to the belt 10. An axle 72 of a free 
roller 70 is riveted in the orifice. The dimensions and arrangements of 
the two blocks 12 and 14 and of the two squares 40 and 50 permit the 
roller 70 to occupy a space between the belt 10 and the upper leg 54 of 
the second square 50 and between the two blocks 12 and 14. The leg 52 of 
the second square 50 is provided with an aperture 57 through which extends 
a slight peripheral portion of the roller 70. Preferably, the outer 
periphery of the roller 70 extends approximately 1 mm beyond the 
supporting surface 20. 
As can be seen in FIGS. 1 and 2, the roller 70 eliminates, or at least 
greatly reduces, frictional forces between the guide T and the sheet F 
during crosswise shifting of the sheet F in a direction perpendicular to 
the processing direction B. Moreover and surprisingly, even if the 
supporting surface 20 is not perfectly perpendicular to the trailing edge 
of the sheet F, as indicated by the dashed line F' in FIG. 1, the roller 
70 will still exert its full force on the trailing edge of the sheet with 
full efficiency. 
On the other hand, experience has revealed that even if the roller 70, on 
account of its slight penetration into the trailing edge of the sheet F 
due to the relatively smaller supporting surface, still brings about an 
uncertainty or an inaccuracy in the guiding and positioning of the sheet 
in line with the machine axis, the inaccuracy will still be compensated to 
a considerable extent by the ease and safety which the roller 70 
contributes to the crosswise shifting of the sheet for lateral alignment. 
Of course, numerous modifications may be added to the invention as 
described above without going beyond the limits of the invention. For 
example, screws or rivets may be used for fastening the two blocks 12 and 
14 onto the belt 10. Endless chains may be used instead of the belt 10, 
etc. 
Thus, there is disclosed a guide-type sheet aligning station for a package 
producing machine which includes an aligning guide fitted onto a belt to 
support the trailing edge of a sheet during lateral adjustment of the 
sheet position. A supporting surface which abuts the trailing edge of the 
sheet includes a roller which slightly precedes the supporting surface to 
reduce friction between the guide and the sheet during the lateral 
adjustment of the sheet position, for example by a lateral guiding ruler. 
Although other modifications and changes may be suggested by those skilled 
in the art, it is the intention of the inventor to embody within the 
patent warranted hereon all changes and modifications as reasonably and 
properly come within the scope of his contribution to the art.