GB2072078A

GB2072078A - Machine for cutting book blocks

Info

Publication number: GB2072078A
Application number: GB8108359A
Authority: GB
Original assignee: Grapha Holding AG
Current assignee: Grapha Holding AG
Priority date: 1980-03-21
Filing date: 1981-03-17
Publication date: 1981-09-30
Also published as: JPS571698A; JPS6026680B2; GB2072078B; DE3104492A1; DE3104492C2; CH645294A5

Abstract

A machine for cutting book blocks includes a support member (1) to which a book block (2) is conveyed for cutting by knives (3,4). In the region of the support member (1), the conveying surface of the conveying means (6) is co-planar with the plane (5) of the support member so that the lower surface of a book block (2) in the cutting position engages with both the support member (1) and the conveying means (6). A retaining device (40 to 46) is located above the support member (1) and includes a plurality of rollers (42) which can be moved into engagement with the upper surface of a book block (2) on the support member (1). The retaining device (40 to 46) is arranged to be held with the roller (42) in engagement with the book block at least during initial forward movement of the conveying means (6) to transport the cut book block (2) away from the cutting station on the support member (1). <IMAGE>

Description

SPECIFICATION Machine for cutting book blocks This invention relates to machines for cutting book blocks.

It is know to provide such machines which include knives for head and tail cutting of a book block located on a support member situated between the cutting planes, a conveying line extending over and beyond said support member for conveying the book blocks, and a conveying surface arranged, in the region of the support member, to be co-planar with said member and which operates in the direction of the conveying line in such a manner that a book block lying on the support member also contacts the conveying surface.

Such a cutting machine is described in, for example, Swiss patent 340 479. This known machine is particularly suitable forthree-sided cutting ortrimming of thin book blocks and brochures. The light weight and low inertia of thin brochures allow rapid braking and re-acceleration of the brochures when passing them through the cutting station of the cutting machine, while the conveyor belts, which continue to run during the cutting operation under the stationary brochures, do not cause any striping prejudicial to the book block. When cutting thick book blocks, however, the travelling conveyor belts form stripes on the stationary book block during a cutting operation and also during initial movement of the cut book block, said stripes making the book block unattractive in appearance and unsuitable for further processing.

It would be advantageous to provide a cutting machine of the kind specified initially in which, after cutting, the book block can be removed quickly from the cutting machine without striping and so as to leave it free for the next working cycle.

According to the present invention there is provided a machine for cutting book blocks, the machine comprising a path of conveyance along which a book block is transported, a support memberforthe book block over which said path of conveyance extends, conveying means for transporting the book block along said path of conveyance, said means including a first conveying surface movable in step by step manner which, in the region of the support member, is co-planar with the supporting surface of said member whereby a book block on the support member also contacts the first conveying surface, cutting means for trimming a book block positioned on the support member, and a retaining device movable between an operative position adjacent the support member and on inoperative position remote from said support member, the retaining device including a plurality of rollers the shafts of which extend parallel with and transversely of the said first conveying surface whereby said rollers, in the operative position of the device, engage with the upper surface of a book block on the support member, the machine further comprising means which, at least during initial forward movement in each step of the first conveying surface, hold the retaining device in its operative position with the rollers in engagement with the book block.

Preferably the means holding the retaining device comprises a press unit displaceable between an inoperative position remote from the support member and an operative position adjacent the support member and in which, during trimming of the book block, said unit presses the book block towards the support member, the retaining device being mounted on the press unit, a spring reacting between the press unit and the retaining device urging said device towards the first conveying surface whereby said device is movable relative to the press unittowards and away from said first conveying surface.

Conveniently the retaining device is pivotal relative to the press unit about an axis extending parallel with the roller shafts.

In a preferred machine, abutment members are movable into and out of the path of conveyance, one from each side of said path, adjacent the downstream end of the support member, considered in the direction of movement of the conveying means, to locate a book block on the support member.

The path of conveyance may include, upstream of the support member, a further conveying surface movable towards the first conveying surface, a pushing-in device of said further conveying surface acting towards the first conveying surface.

Preferably, the pushing-in device is mounted to be displaceable in the direction of the path of conveyance between a foremost position adjacent the first conveying surface and a rearmost position remote from said first conveying surface, and between an uppermost position above the further conveying surface and a lowermost position below said further conveying surface, the machine comprising control means for lifting the pushing-in device into said uppermost position in displacement of said device from the rearmost position to the foremost position, and for lowering the pushing-in device into said lowermost position on displacement of said device from the foremost position to the rearmost position.

Such a machine may further comprise a transfer device pivotal into and out of a position flush between the first and further conveying surfaces whereby said surfaces form continuations one of the other, and control elements which, at least on initial displacement of the pushing-in device from its rearmost position to its foremost position, hold the transfer device in a position flush between the first and further conveying surfaces.

By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig. 1 is a diagrammatic side view of part of a cutting machine according to the invention; Fig. 2 is a view in the direction of the arrow II in Fig.

1, with some parts omitted, and Fig. 3 shows movement curves for the main parts of the cutting machine of Fig. 1.

Reference numeral 1 designates a support member for a book block 2 to be cut in a singlestation cutting machine. Two side knives 3 spaced from one another are provided to carry out head and tail cutting of the top and bottom edges of the book block, only one of said knives being shown in the drawings. Cutting of the front edge of a book block is effected by a knife 4which can be swung outwardly relative to the support member 1. The construction, drive and methods of operation of the knives 3 and 4 are described in detail in Swiss patent application 8122177.

A support plane 5 formed by the support member 1 is at the same time a conveying plane in which two endless intermittently-driven conveyor belts 6, the horizontal runs of which are co-planar with the support plane 5, operate as conveying elements in the direction of the illustrated arrow. The sides of the support member 1 comprise the co-operating surfaces for the knives 3 and 4.

Two abutments 7 and 8, one to each side of the support member, are movable symmetrically over the support member 1 into the conveying line of the book block 2 to limit and define, in co-operation with a pushing-in device 9, the position of the book block 2 on the support plane 5. A press unit 10 presses the book block 2 during a cutting operation -- i.e. during the descent of the knives 3 and 4 against the support member 1 - and holds the book block 2 securely on the support member 1.

The support member 1 is formed of three parallel, spaced-apart solid bodies 11 the ends of which are connected to one another, the flat upper surfaces of said bodies 11 forming the support plane 5. The two outer solid bodies 11 and the end connection therebetween form counterknives 11' for the knives 3 and 4.

Mounted between the two outer solid bodies 11 are two shafts 12 and 13 which each carry two guide rollers 14 and 15 rotatable with said shafts. The endless conveyor belts 6 are each guided about the associated guide rollers 14 and 15 aligned in the conveying direction.

Also mounted on the shaft 13 is a freewheeling pinion 17 which meshes with a toothed segment 18.

Said segment 18 is pivotably mounted on a pin 19 and has integrally formed therewith a bellcrank lever 20 the free end of which carries a cam roller 21. The toothed segment 18 is drawn into its end position shown in Fig. 1 by means of a preloaded helical tension spring 22. As a result the cam roller 21 remains in physical contact with a cam disc 23 mounted on a shaft 24 to be rotatable with said shaft in the direction of the illustrated arrow. When the shaft 24 rotates, the toothed segment 18 rocks to and fro as shown by the curve 25 in Fig. 3.On pivoting movement of the segment 18 from the left-hand position into the right-hand end position as viewed in Fig. 1, the freewheeling pinion 17 also turns but without a driving connection with the shaft 13, whereas, on pivoting movement in the opposite direction, the shaft 13 is rotated in accompaniment with the pinion 17 and the conveyor belts 6 are thus driven intermittently. Referring to curve 25, the conveyor belts 6 move in the direction of the illustrated arrow in the region of the rising curve sections and are stationary in the region of the falling curve sections.

The press unit 10 operating towards the support plane 5 comprises a ram 27 which is mounted to be movable up and down in a vertical sliding bearing 26 and which carries at its lower end a two-part pressure plate 28 the front portion of which has been omitted from the drawings. The ram 27 is acted upon vertically by a spring force 29 pressing downwards towards the support plane 5. The lifting and lowering of the ram 27 is effected by means of a two-arm lever 30 one end of which acts on a pivot pin 31, the lever being mounted on a stationary pivot 32. One end of a connecting rod 33 is pivotally attached to the free end of the lever 30, the other end of said rod 33 being pivotally connected at 34 to one arm of a bellcrank lever 35.The bellcrank lever 35 is pivotable about a stationary pivot 36, the other arm of said lever carrying a cam roller 37 which runs on a cam disc 38 also mounted on the shaft 24 to be rotatable with said shaft. As the movement curve 39 (Fig. 3) of the pressure plate 28 shows, the pressure plate 28 is lifted and lowered again during an advancing stroke of the conveyor belts 6 so that it assumes its lower end position when the conveyor belts 6 are stationary.

A stationary shaft 40 is arranged between the two pressure plate portions 28, on which shaft are pivotably mounted two parallel roller supports 41. A plurality of shafts 43 carrying the pressure rollers 42 extend between the supports 41. The two roller supports 41 are connected to one another by a strap 44 positioned opposite a strap 45 secured between the two parts of the pressure plate 28. Between the straps 44 and 45 is situated a preloaded helical spring 46 which presses the roller supports 41 downwardly relative to thepressure plate 28 and against the action of which the roller supports 41 can be pivoted upwardly about the shaft 40. The portions 40 to 46 form a retaining device 40 to 46 the movement curve of which is designated with the reference numeral 39' in Fig. 3.This curve shows that, at the beginning of lifting up of the pressure plate 28, the retaining device 40 to 46 remains in its lower end position until the helical spring 46 is completely relaxed. Only thereafter is the retaining device lifted together with the pressure plate 28 into the upper end position. When the pressure plate 28 descends, the retaining device 40 to 46 leads relatively thereto and reaches the lower end position before the pressure plate 28 i.e. it engages with the book block before the pressure plate 28. Thus, at the beginning of an advancing stroke of the conveying belts 6, the retaining device 40 to 46 presses against the book block 2, so that the latter can be accelerated with the conveyor belts 6 without slip, and thus without striping.

The abutments 7 and 8 each consist of a side abutment 47 and a back abutment 48. The side abutments 47 press against the head and tail edges respectively of the book block 2, whereas the back abutments 48, in co-operation with the pushing-in device 9, align the book block back at right angles to the conveying direction. The side abutments 47 are each provided with a slot 49 extending in the convey ing direction and in which the associated back abutment48 is mounted to be longitudinally displaceable therein and fixable by means of a screw 50 in accordance with the book block format.

Each of the abutments 7 and 8 is secured, by means of an arm 51, on a shaft 52 pivotally mounted in a bearing element 53, the shaft 52 being secured to a lever 54. The end of the lever 54 carries a cam roller 55 which is guided in a horizontal U-rail 56. The two levers 54 are situated symmetrically with respect to the longitudinal centre line of the machine, so that there is a correspondingly symmetrical pivoting movement of the abutments 7 and 8 when the U-rail 56 is moved vertically up and down.

This up and down movement of the U-rail 56 is achieved by securing the rail 56 to a parallelogram linkage 57 which is movable vertically about stationary pivot shafts 58 and 59. The parallelogram linkage 57 is acted upon by a connecting rod 60 which is in driving connection, by means of a pivot pin 61, with one arm of a bellcrank lever 62 pivotable about a pin 63. The other arm of the bellcrank lever 62 carries a cam roller 65 which is urged by the tensile force of a spring 64 against a cam disc 66 mounted on the shaft 24 to be rotatable with said shaft.

The cam disc 66 is so arranged that, as shown by curve 67 (Fig. 3), the parallelogram linkage 57 takes up its upper end position at the beginning of an advancing stroke of the conveyor belts 6 (curve 15), in which position the abutments 7 and 8 are swung out upwardly and laterally. Only immediately before the end of the advancing movement of the conveyor belts 6 are the abutments 7 and 8 swung downwardly and inwardly again into the conveying line of the book blocks 2.

The bearing elements 53 are mounted to be displaceable along a cylindrical guide bar 16 and are adapted to be fixed in any position to which they have been displaced by means of screws. As a result, the abutments 7 and 8 can be adjusted to the height of the book block format being dealt with. If the spacing of the abutments 7 and 8 from one anothervar- ies, the rollers 55 remain in the U-rail 56 and the vertical movement of said rail swings the abutments 7 and 8 irrespective of their spacing, which spacing is determined by the book format. As a result the book block 2 can be centred precisely at its head and tail during the application of the pressure plate 28.

The pushing-in device 9 comprises a plurality of conveyor belts 68 which operate in the direction of the illustrated arrow and which transport the arriving book blocks towards the support plane 5. For rapid pushing of a book block 2 on to the support plane 5, there is provided a pushing-in element 69 provided with rollers 70 mounted in a rail 71 whereby the element 69 is pivotable to and fro, the forward end position being adjacent the support plane 5 and the rear end position being distant therefrom. The rail 71 is pivotable up and down about a horizontal pivot 72.

The movement of the rail 71 is effected by a cam disc 73 on which bears a lever 75 pivotable about a stationary pivot 74, one end of said lever carrying a cam roller 77 which bears against the disc 73 under the action of a spring 76. The movement of the lever 75 is transmitted to the rail 71 by a connecting rod 78, the movement of which is shown in Fig. 3 by the curve 79. This shows that the rail 71, at the beginning of an advancing stroke of the conveyor belts 6, takes up its lower end position and is moved upwards approximately in the middle of the advancing stroke, so that it has reached its upper end position at the end of the advancing stroke of the conveyor belts 6.

Control in the movement of the pushing-in element 69 is effected by a lever 80 one end of which is pivotable about a pivot 81, the other end of said lever 80 being connected by a link 82 to the pushing-in element 69. A spring 83 draws a cam roller 84 mounted on lever 80 against a cam disc 85 mounted together with the cam disc 73 on a shaft 86 to be rotatable with said shaft. The movement of the pushing-in element 69 is represented in Fig. 3 by the curve 87. Approximately in the middle of the advancing movement of the conveyor belts 6, the pushingin element 69 is displaced from its rear end position remote from the support plane 5 forwardly towards the support plane 5, and reaches its front end position at the end of the advancing stroke of the conveyor belts 6, whereupon it is moved back before the start of the new advancing stroke of the conveyor belts 6.A comparison of the curves 79 and 87 shows thatthe rail 71 reaches its upper end position before the pushing-in element 69 has reached its front end position. On the other hand the pushing-in element 69 reaches its rear end position before the rail 71 has reached its lower end position.

In order to bridge the gap between the end of the conveyor belts 68 on the one hand and the support plane 5 on the other hand, a transfer device 88 is provided. This comprises a bridging flap 89 pivotally mounted on a shaft 90. Atwo-arm lever 91 pivots the bridging flap 89 by means of a connecting rod 92, the movement being controlled by a further cam disc 93 mounted on the shaft 86, the lever 91 carrying a cam roller 95 which contacts said further cam disc under the influence of a spring 94. The lever 91 itself is pivotable about a stationary pivot 96.

The curve 97 in Fig. 3 shows the movement of the bridging flap 89. This flap is in the horizontal position shown in Fig. 1 during movement of the pushing-in element 69 from its rear end position towards its front end position, and is pivoted downwardly before the conclusion of this advancing movement, more particularly when the bottom of the book block 2 to be pushed-in abuts the support plane 5.

The rotational positions of the cycle control shafts 24 and 86 are plotted as abscissae in Fig. 3, in degrees of angle. The curve 98 shows the movement rhythm of the front knife 4, while the curve 99 shows that of the side knives 3. In the initial part of the graphs (0 to 80 ) a book block 2 on the support plane 5 engages the abutments 7 and 8, the front knife 4 (curve 98) takes up its upper end position again (after the front cut has been made), while the side knives 3 conclude the side cuts. The bridging flap 89 is swung downwards (curve 97). The pushing-in element 9 (curve 87) is situated in the rear end position, while the rail 71 (curve 79) is pivoted away downwardly.

The abutments 7 and 8 (curve 67) are swung away laterally and upwardly. The conveyor belts 6 are stationary, whilst the toothed segment 18 is swung back into the left-hand end position (curve 25). The pressure plate 28 (curve 39) bears with pressure on the book block 2, the retaining device 40 to 46 also pressing on said block but with less force.

As soon as the side cut using the side knives 3 is ended (80 to 240 ) the pressure plate 28 is lifted and the advancing stroke of the conveyor belts 6 begins (curves 25 and 39). In the first phase (80 to 1300) of the lifting of the pressure plate 28 the pressure rol lers 42 continue to press on the book block 2 (curve 39'), so that the said block bears with considerable friction on the conveyor belts 6 and is accelerated with these without any slipping. The conveyor belts 6 transfer the cut book block to the following con veyor 100 whereby it is transported to a de-stacking apparatus. The pressure rollers 42 produce a uniform pressure on the book block 2, so that it is in uniform physical contact with the conveyor belts 6.

As the curve 39' shows, by adjustment of the pivotins travel of the roller supports 41 it is possible to define the length of time during which the rollers 42 press the book block 2 against the conveyor belts 6 afterthe lifting-awayofthe pressure plate 28 and the advance of the conveyor belts 6 has started. The slip-free frictional contact between book block 2 and conveyor belts 6 makes it possible to drive the conveyor belts 6 out of the condition of rest with high acceleration, and to remove the book block 2 with similar acceleration from the cutting station. The slip-free frictional connection between the book block 2 and the conveyor belts 6 obviates the formation of stripes on the undermost sheet of paper and also ensures rapid removal of the book block from the cutting station.

After about 260 , the advancing movement of the conveyor belts 6 is ended, and the next book block 2 is centred by the pushing-in element 69 against the abutments 7 and 8 (curve 67) which have been swung into its path of displacement At this instant the front knife (curve 98) has already descended so far that it begins the actual cutting operation, whilst the side knives 3 have almost reached their upper reversal point.

The co-operation of the pushing-in element 9 with the abutments 7 and 8, more particularly in conjunction with the transfer device 88, ensures rapid feeding of the arriving book blocks to the cutting station, whereas the retaining device 40 to 46, in conjunction with the intermittently driven conveyor belts 6, effect a rapid removal of the cut book blocks 2.

Claims

1. A machine for cutting book blocks, the machine comprising a path of conveyance along which a book block is transported, a support member for the book block over which said path of conveyance extends, conveying means for transporting the book block along said path of conveyance, said means including a first conveying surface movable in step by step manner which, in the region of the support member, is co-planar with the supporting surface of said member whereby a book block on the support member also contacts the first conveying surface, cutting means for trimming a book block positioned on the support member, and a retaining device movable between an operative position adjacent the support member and an inoperative position remote from said support member, the retaining device including a plurality of rollers the shafts of which extend parallel with and transversely of said first conveying surface whereby said rollers, in the operative position of the device, engage with the upper surface of a book block on the support member, the machine further comprising means which, at least during initial forward movement in each step of the first conveying surface, hold the retaining device in its operative position with the rol lers in engagement with the book block.

2. A machine as claimed in claim 1 in which the- means holding the retaining device comprises a press unit displaceable between an inoperative position remote from the support member and an oper3- tive position adjacent the support member and in which during trimming of the book block, said unit presses the book block towards the support member, the retaining device being mounted on the press unit, a spring reacting between the press unit and the retaining device urging said device towards the first conveying surface whereby said device is movable relative to the press unit towards and away from said first conveying surface.

3. A machine as claimed in claim 2 in which the retaining device is pivotal relative to the press unit about an axis extending parallel with the roller shafts.

4. A machine as claimed in any one of claims 1 to 3 in which the first conveying surface in the region of the support member is formed by one or more conveyor belts acting in the direction of the path of conveyance.

5. A machine as claimed in any one of claims 1 to 4 in which abutment members are movable into and out of the path of conveyance one from each side of said path adjacent the downstream end of the support member, considered in the direction of movement of the conveying means, to locate a book block on the support member.

6. A machine as claimed in claim 5 in which each abutment member is mounted to be movable along and securableto a bar extending transversely of the path of conveyance and parallel to the first conveying surface.

7. A machine as claimed in claim 6 in which each abutment member is mounted on an associated bearing element slidable along said bar, the bearing elements each carrying a stub shaft extending parallel with the path of conveyance, a two-armed lever being pivotally mounted on each stub shaft, the two levers being located symmetrically one to each side of the path of conveyance, one arm of each lever carrying a back abutment of an associated one of the abutment members, a control mechanism acting on the other arms of the two levers.

8. A machine as claimed in claim 7 in which the other arm of each lever carries a cam member mounted to be displaceabte in a guide rail extending transversely of the path of conveyance and parallel to the first conveying surface, said guide rail being movable up and down relative to and perpendicular to the first conveying surface.

9. A machine as claimed in claim 7 or claim 8 in which each abutment member includes a side abutment on which the associated back abutment is mounted to be displaceable relative to the side abutment in a direction parallel to the path of conveyance.

10. A machine as claimed in any one of claims 1 to 9 in which the path of conveyance includes, upstream of the support member, a further conveying surface movable towards the first conveying surface, a pushing-in device of said further conveying surface acting towards the first conveying surface.

11. A machine as claimed in claim 10 in which the pushing-in device is mounted to be displaceable in the direction of the path of conveyance between a foremost position adjacent the first conveying surface and a rearmost position remote from said first conveying surface, and between an uppermost position above the further conveying surface and a lowermost position below said further conveying surface, the machine comprising control means for lifting the pushing-in device into said uppermost position on displacement of said device from the rearmost position to the foremost position, and for lowering the pushing-in device into said lowermost position on displacement of said device from the foremost position to the rearmost position.

12. A machine as claimed in claim 11 comprising a transfer device pivotal into and out of a position flush between the first and further conveying surfaces whereby said surfaces from continuations one of the other, and control elements which, at least on initial displacement of the pushing-in device from its rearmost position to its foremost position, hold the transfer device in a position flush between the first and further conveying surfaces.

13. A machine for cutting book blocks substantially as described with reference to and as illustrated by the accompanying drawings.