GB2066784A - Folding machine - Google Patents

Abstract

A rotating folding cylinder (1) carries an odd number of equidistantly spaced pairs (I-III) of folding blades (8, 10), which are actuated by formations (47, 50) on two rotating cams (7, 9). Trailing blades (8) are actuated by cam (7) when a cam formation and a set of blades coincide at product entraining station (A) and leading blades (10) are actuated by cam (9) at a product discharge station (B) or (C). The cams rotate in the same direction as the cylinder, at a speed ratio of 3:2 where there are three sets of blades and two sets of actuating formations and at other speed ratios for other arrangements. <IMAGE>

Description

SPECIFICATION Folding machine The present invention relates to a folding machine, and has particular reference to the controlling of the folding blades of a folding blade cylinder of such a machine.

In the folding of products it is often necessary after the provision of a first transverse fold formed in known manner by the co-operation of a folding blade cylinder, to provide the products with a second longitudinal fold, also termed a third fold. Since the operating speed of the device for the third fold is limited, two such folds are often needed in order to feed a printing machine at such a rate as to permit the printing machine to operate at an optimum output capability.

In a folding blade cylinder with an even number of folding blade pairs, it is known to discharge the products at a discharge station and to subsequently direct them via a controlled switch to two belt conveyors each connected to, for example, a device for providing the third fold. A disadvantage in this case is that usually the lower belt conveyor cannot extend sufficiently closely to the switch for the products to be accurately guided in the transfer region between the folding blade cylinder and belt conveyor. In addition, access in this region is restricted, which is a drawback especially during stoppages.

Independently of this, problems also arise in the controlling of the folding blades of high-speed rotary printing machines. The cam rollers running on stationary cams, and also the oscillating levers connecting the rollers to the folding blades, are subjected to high dynamic loadings as a consequence of the high relative speed between cam rollers and cam discs. Irregular running of the cam rollers, considerable noise output and high wear of associated gear mechanisms are the consequence.

In order to reduce the relative speed between the cam disc and cam roller, the diameter of the cam disc can be decreased as described in DE-PS 633 756 and DE-PS 2 316 227. However, this measure requires additional transfer elements, such as plungers, as compared with the conventional arrangement of an oscillating lever journalled at one end in the folding blade cylinder and carrying the cam roller at the other end. With the proposed solution to reduce the relative speed between cam disc and roller there is inevitably associated a rise in the inertia of the gear mechanism and a greater number of articulation points and guides for the transfer element, which, due to increased wear and imprevise transmission of movement, mitigates against an increase in output of the folding machine.

There is accordingly a need for a folding machine which is operationally reliable even at high machine speeds in providing a division of the products stream after the folding blade cylinder, and which has a reduced dynamic loading and therefore wear of the means for controlling the folding blades.

According to the present invention there is provided a folding machine comprising a rotatable cylinder provided around its circumference with an odd number of equidistantly spaced pairs of pivotable folding blades, the blades of each pair being arranged to respectively lead and trail in a given direction of rotation of the cylinder, a first rotatable cam for actuating the trailing blade of each of the blade pairs at and only at an article entraining station, a second rotatable cam for actuating the leading blade of each of the blade pairs at and only at an article discharge station selectably provided at two locations angularly spaced about the cylinder, and drive means to rotate the cams and cylinder in the same rotational direction but at different speeds in a ratio of the speed of the cams to the speed of the cylinder of 2:3 or 4::3 in the case of three blade pairs, 4:5 or 6:5 in the case of five blade pairs, and 6:7 or 8:7 in the case of seven blade pairs, each of the cams having two or four blade actuating zones in the case of three blade pairs, four or six such zones in the case of five blade pairs and six or eight such zones in the case of seven blade pairs, the actuating zones of the first cam being equidistantly spaced apart, and one or each alternate one of the actuating zones of the second cam being selectably angularly spaced in or counter to the rotational direction depending on whether the cams are rotated slower or faster than the cylinder and by an angle determined by the angular spacing of the discharge station locations divided by the number of actuating zones of the second cam, from a respective notional position for spacing of the zones of the second cam in the manner of the zones of the first cam.

This arrangement makes possible, in a folding blade cylinder with an odd number of blade pairs, a product discharge at two positions which can be established as desired within the scope of the spatial relationships within the folding machine. As a result, a reliable division of the product flow is possible.

For onward conveying of the two streams of discharged products there can be provided two belt conveyors associated in an optimum manner with a switch, so that the guiding of the products in this region is improved. Due to the higher functional reliability, the output of the folding machine can be increased and access to the switches can be improved. The two streams of products can each be fed to the belt conveyors to a device for the third fold operating at reduced speed.

As a further advantage with continuously rotating cams, the relative speed between the cams and, for example, cam rollers running thereon may be reduced. Favourable conditions are thus obtained for an increased output as a consequence of reduction in dynamic loading of the cams and associated components controlling the folding blades. Thus any gear mechanisms used to drive the cams may be subjected to considerably less wear. Moreover, noise produced by cam rollers may be reduced. Thus, with reference to the aforementioned transmission ratios between the cams and cylinder, the speed of associated cam rollers in the case of three blade pairs is 1/2 or 1/4, in the case of five blade pairs 1/4 or 1/6, and in the case of seven blade pairs 1/6 or 1/8, of the speed of a cam roller running on a stationary cam.

The folding machine may advantageously be used when different printed products are to be separately discharged after the second fold (first transverse fold), possibly for receiving a third fold.

For varying the positions of the product discharge rotation it is favourable if the cam for actuating the leading blades comprises two cam elements axially displaced from each other, one of the cam elements being provided with a respective recess for said one or each alternate one of the actuating zones, the recess extending over a larger angle than actually needed for the zone, and the other cam element having a respective projection serving for variable lateral coverage of the or each recess. The two cam elements are also adjustable and each have a cam track on which a respective cam roller runs, the cam rollers being disposed alongside one another on an axle fixed to an arm for actuating a respective leading blade.

By appropriate rotational displacement of the two cam elements relative to each other, the angular position of said one or each alternate one of the actuating zones can be arbitrarily varied from a position coinciding with the respective notional position to a position spaced from the notional position by a maximum amount determined by the angular extent of the associated recess. When in fact the position of said one or each alternate one of the actuating zones coincides with the respective notional position, the discharge station has a single location.The variation in the number of positions for the discharge station within the folding machine affords considerable advantages for inexpensive production conversion in a folding machine embodying the invention, for example instead of 2 x 3rd fold, direct discharge after the 2nd fold, or for subsequent conversion of a conventional folding machine where the production conditions have changed, due to the optimum adaptability to the available space conditions.

Preferably, for drive of the cams, cylinder, and an associated folding knife cylinder, a drive input gear engages a first gear wheel coupled by way of a shaft with a first cylindrical body of the folding knife cylinder which carries sheet guide elements. The first gear also drives the cams by way of a plurality of intermediate wheels, two of which are disposed one at each end of the folding blade cylinder and are connected together by a shaft. A second gear, which is of the same size as the first gear but has oblique teeth of opposite inclination, is coupled through a gear with the folding blade cylinder and through a hollow shaft with a second cylindrical body, carrying folding knives, of the folding knife cylinder, the hollow shaft housing the first-mentioned shaft.Both the first and second gears engage an axially displaceable double gear, the two sets of teeth of which each have a tooth inclination adapted to that of the teeth of the respective one of the first and second gears.

This form of drive offers the advantage that a folding adjustment, i.e. the rotation of the second cylindrical body with the folding knives and of the folding blade cylinder, relative to the first cylindrical body with the sheet guide elements, is possible without adjustment of the cams.

Embodiments of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which: Fig. 1 is schematic longitudinal sectional view of a folding blade cylinder, and associated cams and cam drive, of a folding machine according to a first embodiment of the invention, Fig. 2 is a schematic longitudinal sectional view of a folding knife cylinder and its drive connection to the folding blade cylinder, of the folding machine of Fig. 1, Fig. 3 is a schematic end view of the folding blade cylinder of the folding machine of Fig. 1, the cylinder having three folding blade pairs set at 1200 from each other and the facility of a product discharge at two different positions.

Fig. 4 is a view, similar to Fig. 1, of a folding machine according to a second embodiment of the invention, with a facility for a variable product discharge, Fig. 5 is a view similar to Fig. 3 but of the folding blade cylinder of the machine of Fig. 4, and Fig. 6 is a view, similar to Fig. 5 but showing the product discharge arranged at only one position.

Referring now to the drawings, there is shown in Fig. 1 part of a folding machine comprising a folding blade cylinder 1 mounted on a shaft 2 which is rotatably mounted in two side walls 3 and 4 of the machine. The cylinder is provided around its circumference with three equidistantly spaced pairs I, II and Ill (Fig. 3) of pivotable sheet folding blades 8 and 10, wherein the blades 10 are arranged to lead, and the blades 8 to trail, in the direction of rotation of the cylinder as indicated by the arrow in Fig. 3.

Rotatably mounted on the shaft 2 adjacent the ends of the cylinder 1 are two gear wheels 5 and 6.

The gear wheel 5 mounted on the right side is firmly bolted to a cam disc 7 for controlling the trailing blades 8, which are actuated exclusively at a product entraining station A (Fig. 3). The gear wheel 6 disposed on the left side is bolted to a cam disc 9 for controlling the leading blades 10, which are actuated exclusively at a product discharge station arranged at two angularly spaced positions B and C.

The cam discs 7 and 9 have cam tracks 14 and 1 5, respectively, which are formed by grooves 1 6 and 17 in which cam rollers 20 and 21, respectively, are engaged, the rollers 20 and 21 being mounted on arms 1 8 and 1 9 rigidly connected to the blades 8 and 10, respectively. In Fig. 1, in the interests of clarity, the arms 18 and 1 9 are illustrated in a rotated position so that the rollers 20 and 21 are shown out of engagement with the grooves 1 6 and 1 7.

The gear wheels 5 and 6 engage intermediate gear wheels 11 and 12, respectively, which are mounted on a common shaft 1 3 extending through and journalled in the walls 3 and 4. The gear wheel 11 is connected, via two intermediate wheels 22 and 23 (Fig. 1), with a gear wheel 28 (Fig. 2) fixed on a shaft 24, which extends from the side wall 3 to the side wall 4 and which carries a cylindrical body 26 of a a folding knife cylinder 27, the body 26 carrying sheet guide elements 25. The gear wheel 28 is driven by a gear wheel 29 of a drive for the folding machine.

Rotatably mounted on the shaft 24 is a hollow shaft 30, which is journalled in the side wall 3 and which carries a cylindrical body 32 of the cylinder 31, the body 36 carrying folding knives 31. Mounted on one end of the shaft 30 is a gear wheel 33 of the same size as the gear wheel 28 but having inclined teeth of opposite slope (Fig. 2). The two coaxially arranged gear wheels 28 and 33 mesh with corresponding sets of teeth 34 and 35, respectively, of a double gear 36 (Fig. 2). The gear 36 is mounted on a shaft 37 journalled in the side wall 3 and can be axially displaced via an entraining device 38 by means of a threaded bolt 41 provided at one end with a handwheel 40 and guided in a hood 39 bolted to the side wall 3.The sets of teeth 34 and 35 each have a tooth inclination to suit that of the respective one of the gear wheels 28 and 33. Arranged between the hood 39 and handwheel 40 is a threaded lock ring 43, which is equipeed with a hand lever 42 and serves to prevent undesired rotation of the bolt 41. The gear wheel 33 also engages a gear wheel 44 fixed on the shaft 2 for driving the cylinder 1.

As previously mentioned and as shown in Fig. 3, the cylinder 1 has three blade pairs I, II and Ill displaced at 1200 from one another. The cam discs 7 and 9 rotate in a speed ratio of 3:2 to the cylinder.

For this purpose, the gear wheels which provide the drive connection between the cylinder 1 and the cam discs have the appropriate size relationships.

The cam track 14 has two actuating zones 47 disposed at uniform intervals, i.e. spaced apart by 1800 and each having a rise 45 and a fall 46. In an analogous manner, the cam track 1 5 has two actuating zones 50 and 50', each having a rise 48 and a fall 49. However, the actuating zone 50' is rotationally offset, as compared with the layout of cam 14, by an angle a in opposition to the rotational direction of the disc 9. In general it is true that the actuating zone 50', or each such zone when the cam disc 9 has more than two such zones, is offset by the angle a in opposition to the rotational direction of the cam disc where the cam discs rotate more rapidly than the cylinder 1, as in the case of the present embodiment, but in the same rotational direction as the cam discs where the cam discs rotate more slowly than the cylinder.

The cam discs 7 and 9 are set so that in each case the product take-over from the folding knife cylinder 27 takes place at the station A with simultaneous transverse folding of the product through co operation of the folding knife 31 with the blades 8 and 10 of the cylinder 1 , whereby, however, only the previously opened trailing blade 8 is actuated, i.e. closed, so as to engage the product, while the respective leading blade 10 remains closed during this procedure. On the other hand, for the purpose of product discharge at the positions B and C, only the leading blade 10 is alternately opened at the two positions, while the blades 8 remain closed.In the first case, a cam roller 20 for actuating a blade 8 is situated in the lower part of an actuation zone 47 of the cam track 14 and a cam roller 21 for actuating a leading blade 10 is situated in an upper part 55 of the cam track 1 5. In the second case, where the relationships are reversed, the cam roller 20 is situated in an upper part 56 of the cam track 1 4 and the cam roller 21 in the lower part of the actuation zone 50 or 50' of the cam track 1 5. The two positions B and C for the product discharge from the cylinder 1 are rotationally offset from each other by the angle p, whereby if b is the number of actuating zones of the cam track 1 5, the mathematic relationship between the angles a and p is as follows:: P b In the present embodiment, therefore, a=-.

2 In fig. 3 it is shown how, at the station A a product is transferred, with simultaneous transverse folding, from the folding knife cylinder 27 to the folding blade pair I of the folding blade cylinder 1, while at the position B a folded product is discharged from the blade pair II to a belt conveyor 51. The blade pair Ill has already discharged a folded product at the position C to a belt conveyor 52. The folding blade pairs I, II and III thus alternately discharge their products at the position B or C.

In collected production, all the products are discharged either at the position B or at the position C, depending upon which sections of the folding knife cylinder 27 functioning as collecting cylinder are doubly loaded.

For the product discharge, the upper belt conveyor 51 has a controlled guide tongue 53 and the lower belt conveyor 52 an uncontrolled guide tongue 54. The belt conveyors are each coupled to, for example, a third folding device (not shown).

The drive illustrated in Figs. 1 and 2 for the folding blade cylinder 1 and folding knife cylinder 27 offers the advantage that a fold adjustment, which is carried out with means not described in more detail, can take place independently of the drive for the cam discs 7 and 9. For this purpose, after the lock ring 43 has been loosened, the gear 36 is axially displaced by the hand wheel 40.As a consequence of the previously described slope relationships, indicated symbolically by a circle each in Figs. 1 and 2, of the inclined sets of teeth of the gear wheels 28 and 33 and the gear 36, the position of the gear wheel 28 including the cylindrical body 26 and the drive connected to the gear wheel 28 for the cam discs 7 and 9, remains unchanged through the intermediate gear wheels 23, 22, 11 and 12, whereas the gear wheel 33, including the cylindrical body 32, and also the gear wheel 44 for the drive of the cylinder 1 are rotationally offset by the corresponding amount.

As a departure from the arrangement shown in Figs. 1 and 2, the cam discs 7 and 9 can be driven directly from the folding machine drive via spur gear or bevel gear steps.

In Figs. 4 to 6 there is shown an embodiment which makes possible a variation in the two positions B and C for product discharge including causing the discharge to be at only one of these positions (Fig. 6). For this purpose, the cam disc for actuating the leading blades 10 consists of two mutually axially displaced cam elements 57 and 58 (Fig. 4), the cam element 57 having a cam track 59 which is provided with a valley 61 larger by the angle a max than the desired size of an associated actuating zone 60. The came element 58 has a cam track 62 provided on a projection serving for variable lateral coverage of this valley 61 to provide an uncovered area of the desired size of the zone 60. The cam element 58 is capable of being fixed to the cam element 57 in a desired rotational setting relative thereto by screw connections (Fig. 4).On each of the two cam tracks 59 and 62 there runs a cam roller 63 or 64, the rollers being mounted alongside each other on an axle fixed to the arm 19 for actuating a leading blade 10.

After release of the screw connections, the two cam elements 57 and 58 can be relatively rotated so as to correspondingly vary the position of the actuation zone 60 so that it is offset by a desired angle a within the range a max (Fig. 5). As a result, the mutual association between the two positions B and C for product discharge, i.e. the angle P, is changed in accordance with the previously mentioned equation.

The two positions B and C for the product discharge station can, of course, also be varied together while maintaining a constant angle p. For this purpose, the cam elements 57 and 58 must be rotated together relative to the gear wheel 6. The same applies in a corresponding sense to the cam disc 9.

A setting of the two cam elements 57 and 58 in which cr=O is shown in Fig. 6. In this case, product discharge takes place only at the position B. This application occurs when the products, after the first transverse fold, are to be fed jointly to a further processing station or jointly directly discharged.

The relationships illustrated in Fig. 1 to 6 can be utilised in a folding blade cylinder equipped with a different odd number of blade pairs.

The table below gives a summary for common applications of the machine:

Number of Speed ratio of Angle of the Folding blade actuation zones cam disc: folding rotational staggering pairs per cam blade cylinder of the actuation zones 2 3:2 2 3 B 4 5:4 4 5 8 5:6 P 8 7:8 8

Claims (13)

1. A folding machine comprising a rotatable cylinder provided around its circumference with an odd number of equidistantly spaced pairs of pivotable folding blades, the blades of each pair being arranged to respectively lead and trail in a given direction of rotation of the cylinder, a first rotatable cam for actuating the trailing blade of each of the blade pairs at and only at an article entraining station, a second rotatable cam for actuating the leading blade of each of the blade pairs at and only at an article discharge station selectably provided at two locations angularly spaced about the cylinder, and drive means to rotate the cams and cylinder in the same rotational direction but at different speeds in a ratio of the speed of the cams to the speed of the cylinder of 2:3 of 4:3 in the case of three blade pairs, 4:5 or 6:5 in the case of five blade pairs, and 6:7 or 8::7 in the case of seven blade pairs, each of the cams having two or four blade actuating zones in the case of three blade pairs, four or six such zones in the case of five blade pairs and six or eight such zones in the case of seven blade pairs, the actuating zones of the first cam being equidistantly spaced apart, and one or each alternate one of the actuating zones of the second cam being selectably angularly spaced, in or counter to the rotational direction depending on whether the cams are rotated slower or faster than the cylinder and by an angle determined by the angular spacing of the discharge station locations divided by the number of actuating zones of the second cam, from a repsective notional position for spacing of the zones of the second cam in the manner of the zones of the first cam.

2. A machine as claimed in claim 1, wherein each of the actuating zones in each cam comprises a respective fall and rise in a cam track.

3. A machine as claimed in either claim 1 or claim 2. wherein the second cam comprises a first and second cam element each defining a respective part of said one or each alternate one of the actuating zones of the second cam, the cam elements being angularly adjustable relative to each other to vary said angular spacing of the or each said zone from its respective notional position.

4. A machine as claimed in claim 3, wherein the actuating zones of the second cam are in the form of valleys, the first cam element being provided with a respective recess for the valley of said one or each alternate one of the actuating zones, the recess extending over a larger angle than the valley, and the second cam element being provided with a respective projection so overlapping part of the or each such recess that the associated valley is defined by the remaining part of the recess, the cam elements being angularly adjustable to vary the part of the or each recess overlapped by the respective projection.

5. A machine as claimed in either claim 3 or claim 4, wherein each of the trailing blades is connected to and controlled through two coaxial rollers each running on a cam track of a respective one of the two cam elements of the second cam.

6. A machine as claimed in any one of the preceding claims, comprising a folding knife cylinder with first and second cylindrical bodies which are provided with respectively, sheet guide elements and folding knife elements and which are connected to be driven by the drive means.

7. A machine as claimed in claim 6, wherein the drive means comprises a first helical gear drivingly coupled to the cams and to said first cylindrical body, a second helical gear drivingly coupled to said second cylindrical body and to the cylinder with the folding blades, the helical gears being of the same diameter and being constructed and arranged so that the teeth of one of the gears are inclined in the opposite direction to the teeth of the other gear, and an axially displaceable coupling gear provided with two sets of teeth each meshed with and having a tooth inclination corresponding to that of the teeth of a respective one of the helical gears.

8. A machine as claimed in claim 7, wherein the second helical gear is coupled to the second cylindrical body by way of a hollow drive shaft and the first helical gear is coupled to the first cylindrical body by way of a drive shaft extending in the hollow drive shaft.

9. A machine as claimed in either claim 7 or claim 8, wherein the first helical gear is coupled to the cams by way of at least two intermediate gears, which are arranged one adjacent each end of the cylinder with the folding blades and which are connected together by a shaft.

10. A machine as claimed in any one of claims 7 to 9, wherein the second helical gear is coupled to the cylinder with the folding blades by way of an intermediate gear.

11. A machine as claimed in any one of claims 7 to 10, further comprising a drive input gear engaging the first helical gear of the drive means.

12. A folding machine substantially as hereinbefore described with reference to Figs. 1 to 3 of the accompanying drawings.

13. A folding machine substantially as hereinbefore described with reference to Figs. 4 to 6 of the accompanying drawings.