Cutting device for sheets with at least one rotating cutting knife and conveyer

A cutting device for sheets as well as booklets with at least one revolving blade and a conveyer device. The conveyer device with which the material to be cut is transported by the cutting knife of the cutting device, and has at least one endless conveyer element which presses onto the material. This is pressed against the material by a pressure device that is spring loaded and rests against it. This pressure device consists of individual pressure pieces, arranged in a row in the running direction of the conveyer element, each of which is spring loaded independently from the others and mobile in the direction of stress. By the independent spring responsive mobility of each individual pressure piece, the contour of the conveyer element adapts automatically to the possibly irregular contour of the material to be transported. A lateral guide device avoids shifting crosswise to the running direction under the influence of crosswise forces during the cutting process.

BACKGROUND OF THE INVENTION 
This invention concerns a cutting device for folded and unfolded sheets, as 
well as booklets, with at least one rotating cutting knife and one 
conveyer which transports the material to be cut at least during the 
cutting process. The device also has at least one endless conveyer element 
which presses onto the material along a part of its length, and at least 
along this section, lies under spring pressure, with its side that is 
removed from the material to be cut, against a pressure device that 
extends in the lengthwise direction of the conveyer. 
A cutting device of this type is already known, see German DE-OS No. 25 14 
836.1. The conveyer element disclosed in this patent consists of a 
drivable V-belt, the slack side of which, running in the transport 
direction above the material, is pressed by a spring and a pressure device 
against the top side of the material which is lying on a lower transport 
element which, in the pressure area, i.e. the section in which the 
pressure device presses the V-belt against the material, is supported from 
below. This lengthwise section extends from a spot located at a distance 
from the cutting spot of the cutting knife, corresponding to about the 
length of the material, to a spot behind the cutting spot which is at 
about the same distance. The pressure device has the shape of an elongated 
spring-charged plate, extending in the lengthwise direction of the V-belt, 
of which both short sides are rounded and of which the outer rim is worked 
along all its sides in such a manner that an endless roller chain can run 
around the plate. Along the lower lengthwise side of the spring-charged 
plate, the roller chain presses against the inside upper side of the lower 
side of the V-belt, so that the lower belt side is pressed, along the 
pressure section, with its outside lower side against the material to be 
transported. 
When cutting folded or unfolded sheets, as well as booklets, the quality of 
the cut depends on the material being perfectly clamped in the cutting 
area. The known cutting device is not fully satisfactory in this respect, 
because if there are variations in thickness in the piles, booklets or 
sheets, it is possible that individual sheets, booklets or piles will not 
be clamped firmly, as required for a clean cut. 
SUMMARY AND OBJECTS OF THE INVENTION 
An object of the invention is to create a cutting device in which a 
correspondingly secure clamping of the material is guaranteed. 
In a cutting device of the type mentioned earlier, this object can be 
solved by using individual pressure pieces, which are spring-charged in 
themselves, in place of a pressure device in the shape of a rigid plate or 
rail. The clamping thus adapts itself in the area of each pressure piece 
to the possibly varying thickness of the material in question, so that a 
perfect clamping effect is obtained in each case. The area-wide adaption 
of the clamping gap also provides for each additional advantage that the 
device according to the invention, contrary to the known devices of this 
type, is also suitable for the treatment of material in which the 
individual parts, sheets, booklets or piles, are not fed in at a distance 
from each other, but where the parts are arranged in a scale like manner, 
partly on top of each other, i.e., a so-called scaled feed 
(Schuppenstrom). By the independent spring-loaded mounting of the 
individual pressure pieces, the clamping gap adapts to the wave-like 
contour of the scaled feed, so that the perfect cut is guaranteed also in 
this case. The lateral guiding of the pressure pieces makes sure that the 
lateral forces that become effective during the cutting process do not 
lead to a lateral movement of the material to be cut, together with the 
pressure pieces. 
An especially secure clamping effect is obtained, particularly when working 
on scale-fed goods, in a preferred embodiment in which each pressure piece 
is mounted pivotably against the spring force, around an axis extending 
crosswise to the transport direction of the conveyer element in addition 
to its mobility in the charged direction, vertically to the movement of 
the transport element. 
The design in a preferred embodiment provides for two endless transport 
elements, each in the form of a roller chain, of which each presses onto 
the material from above and from below, with the aid of a pressure device, 
constructed according to the invention. It is thereby advantageous for 
cutting individual sheets or booklets, to support with springs only the 
pressure pieces which press from above onto the roller chain that presses 
onto the material, and to rigidly support the pressure pieces of the other 
roller chain. However, for cutting a scaled feed, the best clamping can 
only be obtained when the pressure pieces for the lower roller chain are 
also mounted with springs. 
When using a roller chain as a conveyer element, it is possible to design 
each of the pressing elements to a segment of the roller chain. 
In another embodiment the pressure force is transmitted to the material by 
a flexible endless band which lies on the outside of the endless conveyer 
element, whereby this band consists preferably of a material with high 
static friction, so that the material is held securely by the non-skid 
position of the band in the area of pressure. 
With the foregoing and other objects, advantages and features of the 
invention that will become hereinafter apparent, the nature of the 
invention may be clearly understood by reference to the following detailed 
description of the invention, the appended claims and to several views 
illustrated in the attached drawings.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
The cutting device has a frame which is not shown, on which are mounted an 
upper drivable revolving blade 14 with a rotation axis 12 firmly attached 
to the frame and a lower drivable revolving blade 13, whose rotation axis 
is designated by 10. The drive for the revolving blades 13 and 14 is not 
shown in the drawing. In order to feed booklets to the revolving blades 13 
and 14 there is a conveyer device which has two endless conveyer elements, 
a lower roller chain 16 and an upper roller chain 17 arranged above each 
other in such a manner that two adjoining links of the roller chains 16 
and 17 form a clamping gap 18 between themselves, in which booklets 15 can 
be fed clamped to the cutting area where the revolving blades 14 and 13 
work together as cutting edge and counter cutter for the cut. The booklets 
15 are transported to the feeding area 19 of the clamping gap 18 by means 
of a conveyer device 19. 
As can be seen from FIG. 1, the rotation axes 12 and 10 for the revolving 
blades 14 and 13 are somewhat offset from each other in the conveyer 
direction. This offsetting is especially advantageous for obtaining a 
clean cut. The amount of offsetting can be adjusted to the optimal value 
in each case by shifting the rotation axis 10 of the lower revolving balde 
13 in the conveyer direction. The device for shifting the rotation axis 10 
is not shown. 
The pressure device which presses the roller chains 16 and 17 against each 
other in the area of the clamping gap 18, in order to clamp the booklets 
15 which are in the clamping gap 18, is constructed identically for both 
roller chains 16 and 17 in the model according to FIG. 1, which is 
designed as the upper conveyer element and shown in FIG. 3 and 5. The 
corresponding details of the pressure device installed for the roller 
chain 16--as can be seen in FIG. 1--are designated there by the same 
number primed (e.g. 45--45') as those for the same parts in the pressure 
device explained in detail with FIGS. 3 to 5. 
The pressure device for the roller chain 17 has an elongated main support 
41 in the shape of an essentially rectangular plate which is fixed to the 
frame and mounted lengthwise above the transport belt for the booklets 15 
which extends essentially across the whole pressure area of the clamping 
gap 18. At the front and back end, relative to the transport direction of 
the booklets 15, the main support 41 has in each case a pair of laterally 
screwed on plate shaped cheeks 42 and 43, which form extensions to the 
back and front for the main support 41. Between each pair of cheeks 42 and 
43 there is a deflection roller 44 and 45, respectively, mounted in a 
rotatable manner, over which the roller chain 17 is led. The rollers 44 
and/or 45 are driven by a drive device (not shown) in the direction 
indicated in FIG. 1 by arrows 25 and 26. The upper section of the roller 
chain 17 is also led across chain wheels 46 and 47 which are located above 
and to the side of the deflection rollers 44 and 45. As can be seen 
especially from FIGS. 3 and 4, the chain wheel 46 is mounted between the 
upper ends of the cheeks 42 and is freely turnable on a plug 49. The other 
chain wheel 47, pertaining to the upper segment of the roller chain 17, is 
mounted above and to the side of the deflection roller 45, and is meant to 
be a chain adjuster. See FIG. 3B. It is rotatably mounted in a bearing 
block 50, which is arranged along a guide groove 51 on the main support 
41, and is adjustable in its lengthwise direction. There is an adjustment 
screw 52 for positioning, see FIG. 3B, which sits in a lengthwise threaded 
bore in the main support 41, and whose head is supported by the bearing 
block 50. To determine the desired position of the bearing block 50, there 
are clamping screws 53, which extend through borings in the bearing block 
50 as well as oval holes 54 in the main support 41. 
The lower section of the roller chain 17 does not sit directly on the main 
support 41, but is led across a row of pressure pieces 55, which--as can 
be seen especially from FIGS. 3B and 4--are arranged, movably against a 
spring force, at the smaller lower lengthwise edge 56 of the main support 
41 (see especially FIG. 4). The mobile bearing of the pressure pieces 55 
along the lengthwise edge 56 of the main support 41 is identical in each 
pressure piece 55 and has--as can be seen in FIG. 3B and 4--a central, 
lengthwise guide groove 57, open towards the top, which is cut into the 
pressure piece 55 and grips slidingly the lengthwise edge 56. In the walls 
58 and 59, which dilineate the guide groove 57 laterally, the pressure 
piece 55 has coordinated elongated holes 60 and 61, into which extends a 
rod 62 for the purpose of a slit-plug connection between the lengthwise 
edge 56 and the pressure piece 55. The rod 62 is pressed into the 
lengthwise edge 56 and engages the holes 60 and 61 with its ends which 
protrude from the plane of the lateral surfaces of the lengthwise edge 56. 
The expansion of the elongated holes 60 and 61 extends along the direction 
in which the roller chain 17 exerts the clamping force onto the booklets 
15, i.e. in this case, where the clamping gap 18 runs horizontally, the 
elongated holes extend in a vertical direction. Thereby the vertical 
length of the elongated holes 60 and 61 and the depth of the guide groove 
57 are of such dimension that the pressure piece 55 can be shifted in the 
direction of stress between a fully advanced position, as shown in FIG. 4 
and corresponding to the smallest dimension of the clamping gap 18, and a 
pushed back position corresponding to one of the largest dimensions of the 
clamping gap. 
On its side which is opposite the opening for the guide groove 57, each 
pressure piece 55 forms a guide 67 for the roller chain 17 which has guide 
plugs 68 and 69 which protrude laterally from the rollers. These plugs 68, 
69 engage into grooves 70 and 71 which extend into lateral guide rails 72 
and 73 along the transport direction of the roller chain 17. The guide 
rails 72 and 73 are connected, in the gaps between the pressure pieces 55, 
with screws 74 and separators 77 (FIG. 5) to the lengthwise edge 56 of the 
main support 41, in a fixed manner. The width of the grooves 70 and 71 in 
the direction of stress is chosen in such a manner that the plugs 68 and 
69 which extend into them, rest against one edge of the grooves 70, 71 in 
the full forward position shown in FIG. 4, and against the other edge in 
full backward position of the pressure pieces 55. 
It can be seen in FIGS. 3A and 4 that the brackets of the roller chain 17 
are enlarged towards the inside and outside so that the inside guide 
brackets 75 sit laterally against the outer surface of the pressure pieces 
55. The pressure elements 76 are formed, protruding towards the outside, 
through which the pressure force is transmitted onto the booklets in the 
pressure gap 18. The pressure elements are, as shown in FIG. 4, connected 
to the roller chain, transversely without play, through brackets, which in 
turn are led transversely without play, laterally by the pressure pieces 
55, through guide brackets 75. For this reason it is possible that the 
pressure elements 76 can absorb and pass on to the main support 41, 
without lateral shift, crosswise forces, as they are exerted during the 
cutting process by the cut material on the pressure elements 76. 
As shown in FIGS. 3A and 4, the pressure elements 76 in the model, each of 
which is coordinated with a chain link of the roller chain 17, do not 
press directly onto the booklet 15 to be clamped, but through an endless 
flexible band 79 which surrounds the pressure elements 76 along their 
outside surfaces. This band 79 consists of a synthetic material with high 
adhesive friction. As a rule, however, the band 79, which is held away 
from the pressure elements 76 by deflection rollers 80 in the area of the 
deflection of the coordinated roller chains 16 or 17, as shown in FIGS. 3A 
and 3B, is not needed. 
The independent, spring resilient arrangement of the pressure pieces 55 
creates, during operation, an outline of the pressure elements 76 which 
adapts to the thickness and outline of the sequence of booklets 15 which 
are fed in. This adaption is enhanced by the fact that the pressure pieces 
55 are mobile not only in the direction of stress, but are also pivotable 
around the axis of the plug 62 of the slit-plug connection when two 
pressure springs 64 are pressed together with variable force. The amount 
of pivoting is limited simultaneously by the width of the grooves 70, 71 
in the lateral guide rails 72 and 73. Those grooves 70, 71 also ensure 
that in a unstressed condition, i.e. when there is no booklet 15 in the 
clamping gap 18, the pressure pieces 55 are horizontal in the fully 
advanced position, even if the bias of the two pressure springs 64 in any 
of the pressure pieces 55 is not exactly identical. The rotating movement 
of the roller chain 17 is also not hampered to any extent when the 
protruding plugs 68 and 69 touch the limiting surfaces of the grooves 70, 
71 in the guide rails 72 and 73, as the guide rails 72 and 73 are 
constructed from a synthetic material with good gliding properties. 
In addition to the pressure pieces 55 which are installed along the lower 
bands of the roller chain 17, similarly constructed upper pressure pieces 
85 are planned which are installed in a spring resilient shiftable way and 
pivotably similar to the lower pressure pieces 55, and serve as devices to 
keep the roller chain 17 taut, as it is led with its upper belt over the 
upper pressure pieces 85. 
The model according to FIG. 2, designed for cutting individual booklets 
15", varies from the above described model only by the fact that the 
pressure elements 76" and the lower roller chain 16" supporting it, are 
not led and supported by pressure pieces like the pressure pieces 55 in 
the area of the clamping gap 18, but instead by a rigid guide rail 55". 
Similar to pressure pieces 55, this rail 55" secures the roller chain and 
its pressure elements against a lateral shift, i.e. also forms a lateral 
guide. This guide rail is attached to the frame in such a manner that the 
contact surface of the pressure elements 76", facing upward in the 
clamping gap 18, defines a plane surface which is touched by the lower 
revolving blade 13". 
Although only preferred embodiments are specifically illustrated and 
described herein, it will be appreciated that many modifications and 
variations of the present invention are possible in light of the above 
teachings and within the purview of the appended claims without departing 
from the spirit and intended scope of the invention.