Machine for making paper booklets

Abstract

 In a machine for making paper booklets from a multiplicity of paper strips on bobbins that are converged into a continuously advancing strand a reciprocating cutting station (25) defined by leading and trailing plates (27, 28) performs the operations of firstly clamping the strand while the station (25) moves with the strand and secondly of cutting off booklet lengths of paper by means of a knife (156). Cut booklets are ejected into a discharge chute (32) by ejection means (200) including an ejector bar (211) terminating a thrust plate (214). According to the invention the ejection means (200) is separated from the cutting station (25) and is fixedly located opposite to the chute (32). Connection between the cutting station (25) and the ejection means (200) is established by a common rotating hexagonal shaft (76) which is operably connected to clamping and cutting mechanisms of the station (25) and which carries a pair of cams (207, 208) that actuate the ejector (211) through a parallelogram linkage. By this means the motion of the ejector (211) can be gradual rather than abrupt, the machine is easier to set up, and the ejector thrust plate (214) can span substantially the full width of chute (32) so that the likelihood of cut booklets becoming misplaced is reduced.

Description

[0001] This invention relates to a machine for making paper booklets which is particularly, though not exclusively, intended for making booklets of interleaved cigarette paper.

[0002] It is known from Patent Specification No. GB-A-­688144 (Korber) to make booklets of folded and ziz-zag interleaved cigarette papers by withdrawing paper strip from a plurality of supply rolls or bobbins, folding and interleaving the strips by passage through a succession of combs to form a folded and interleaved strand, and cutting the strand to form booklets. But the machine employed by Korber had a stationary cutting knife which was impractical for high speed operation and did not make a clean transverse cut through the strand which is required to move continuously. U.K. Patent No. 2165080 (Kastner) describes a similar machine in which the paper is cut by a movable or "flying" cutting station. Such a device is known in the context of severing tobacco rod from, e.g. US Patent No. 3686989 (Drehr).

[0003] Our Patent Specification No. EP-A-0165747 describes and claims apparatus as aforesaid in which a rotatory movement of the cutting station drive is brought onto the moving "platform" of the cutting station and used to operate the cutting knife. Thus rotation of a driven member in the cutting station could be transmitted to the knife by means of a cam and follower, by means of gearing or by means of a chain or belt. The knife was driven positively from the same drive that reciprocated the cutting station, and a desirable guillotine-like or slicing cutting action was achieved. An ejector was also mounted on the cutting station as also was a clamping device, and bringing of rotatory movement to the cutting station enabled these additional functions to be independently coupled to the rotating shaft to perform differently timed operations along independent paths. Cut booklets were fed to a discharge chute having an inlet spring providing a ratchet-like function so that cut booklets once in the chute did not return.

[0004] Although the apparatus described in Specification No. EP-A-0165757 operates as described, it has a number of features that render extended continuous periods of operation difficult to achieve. Cut booklets could incompletely engage into the discharge chute so that operation has to be stopped until the misplaced booklet or booklets were cleared. The eject operation had to be carried out in a small part of the machine cycle, requiring a rapid movement of the ejector that was difficult to achieve and demanded great accuracy in setting up.

[0005] The present invention also achieves an extended continuous operation. This is achieved by separating the ejector from the cutting station and relocating it to a fixed position opposite to the discharge chute and by coupling the ejector to the cutting station so that both operate in correct timed relationship in each machine cycle.

[0006] The invention therefore provides a machine for forming booklets of paper, comprising a plurality of sources of paper strip, forming means for converging paper strips from the several sources into a single strand, means for advancing the strand in a first direction, a cutting station for reciprocably moving along the strand whereby a booklet length of the strand enters the cutting station while the cutting station moves counter to the strand in a second direction opposite to the first direction, an ejector means for ejecting booklets from said cutting station into a fixed outlet passage said ejector means also being fixed and receiving booklets from the cutting station when the cutting station is towards the end of its travel in the first direction, and means defining a coupling between the cutting station and the ejector means so that the ejector means operates in a predetermined timed manner in each reciprocation of the cutting station.

[0007] The outlet passage will normally have ratchet spring means at its entrance acting on the booklets entering the passage to prevent them returning to the ejector, and the ejector has thrust plate means extending substantially the full width of the outlet passage. Very advantageously the ejector means is operated by a first coupling means on a rotating shaft providing a forward and reverse movement and by a second coupling means on the rotating shaft providing a rise and fall movement so that the ejector means advances in the direction of the outlet passage, rises above the path of the strand and then returns. With this arrangement the thrust plate can occupy substantially the full width of the discharge chute, not leaving the upstream end unsupported and prone to deflect as it passes the ratchet spring means which is a major cause of booklet misengagement. The reason why the thrust plate can be made full width is that on the return stroke it rises above the incoming booklet strand.

[0008] The machine preferably includes a wall leading to the outlet passage, first and second links pivoted to the wall for rotation in a plane generally parallel to the outlet passage, a third link connecting the first and second links to form a parallelogram linkage, the first link being relatively short and nearer the outlet passage a first cam on the rotating shaft being coupled to the first link by means including a follower at the end of the first link to effect the forward and reverse movement, the second link being relatively long and having pivoted thereto a fourth link carrying a thrust plate at its tip, a second cam on the rotating shaft being coupled to the second link by means including a follower partway along the second link to effect the rise and fall movement. Advantageously the thrust plate is bifurcated to define a pair of vertically spaced tines facing the cutting station, and the cutting station has a paper guide that passes between the tines as the cutting station completes its travel in the first direction, said paper guide defining a linear path for paper strand past the cutting station.

[0009] A rotating shaft of non-circular cross-section advantageously extends through said cutting station parallel to the first direction and is operably connected to the cutting station, a knife means responsive to rotation of the rotating shaft is disposed in the cutting station for cutting a booklet from the strand which the cutting station moves alongside the strand in a first direction, and knife coupling means translates rotational movement of the rotating shaft into rotational slicing movement of said knife means across the strand in a plane substantially perpendicular to the first direction, the path of the knife means and the path of the ejector being mutually independent. A strand clamping member may be disposed on the cutting station and disengaging cam means disposed on the tubular sleeve disengages the clamping member when the cutting station is moving in the second direction. The cutting station is preferably coupled to its reciprocating drive via a constant velocity cam arrangement.

[0010] The converging means preferably comprises a primary folding comb adjacent the rolls that folds the strips, a spreader comb that facilitates the first stage of interleaving, a secondary folding comb that substantially defines the interfolded shape of the strips, and a final forming comb that determines the height of the interleaved strand.

[0011] An embodiment of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is an end view of a folding and interleaving machine according to EP-A-0165757;

Figure 2 is a view of the bobbin holder and interfolding part of the machine of Figure 1;

Figure 3 is a plan of a drive and cutting unit forming part of the modified machine of the invention;

Figure 4 is a view of a drive unit for pull-through rollers that is in turn driven from the drive unit of Figure 3;

Figures 5a-5d are fragmentary perspective views of the drive and cutting unit of Figure 3. In Figure 5a which is an end view of the machine, the ejection unit is completing its stroke into the discharge chute, in Figure 5b which is an oblique view from the discharge chute side of the machine, the ejection unit is in its return stroke, in Figure 5c which is again an end view of the machine the ejection unit is making a return stroke and a fresh booklet is entering the cutting station, and in Figure 5d which is an oblique view from a side of the machine opposite to the discharge chute cutting of a booklet has taken place and the ejection unit is beginning its forward stroke;

Figure 6 is a view on the leading or upstream outer face of the cutting unit of Figure 3 showing a clamping mechanism;

Figures 7 and 8 are respectively a partly sectional plan view and a view on the leading inner face of the cutting unit of Figure 3 showing the knife mechanism;

Figures 9 and 10 are fragmentary side and end views showing the ejector mechanism of the unit of Figure 3;

In Figures 1 and 2 of the drawings, there is shown a machine for folding and interleaving fifty sheets of cigarette paper into a so-called booklet, each booklet being separated from adjacent booklets by a strip of cardboard or the like separating material. There are therefore fifty paper strips and a single cardboard strip that have to be fed into the machine from the same number of bobbins. In Figures 1 and 2, these bobbins 10, 11 are arranged in two arcuate rows one above the other and in such a manner that the bobbins 10 in the upper row are in staggered relation to the bobbins 11 in the lower row. The arcs of the bobbins 10, 11 are struck from a centre coinciding with the point of convergence of the eventual interleaved paper strip as they enter a drive and cutting unit generally indicated by the reference numeral 12. The paper leaving bobbins 10, 11 is deflected into a generally horizontal path by upper and lower sets of guide rollers 13, 14 and passes to a first former 15 that is arcuate in plan with its centre coinciding with that of the bobbin arc which folds the several strips. The strips pass from the former 15 to a spreading comb 16 that is also arcuate in plan, the purpose of the spreading comb being to spread out and align the folded strips in order to facilitate the first step of interleaving. The paper passes from comb 16 to a second former 17 which substantially defines the interfolded shape of the sheets and thence to a final former 18 that serves to bring the interleaving to its final stage and to determine the height of the interleaved booklets. From the former 18 the interleaved strips converge at the inlet to a pair of parallel guides 19, 20 (Figure 3) defining a channel along which the resulting interleaved strand is conveyed and at which the leaves are compressed to form a flat strand for cutting into booklets.

[0012] Interleaved booklet strand from the guide channel passes between a pair of knurled drive or pull-through rollers 21, 22 both of which are driven through gearing (described below) at a proper surface speed. The roller 22 is reciprocable transversely and is spring loaded into engagement with the advancing strand. The purpose of this arrangement is to maintain a proper pressure on the strand and to compensate for any variation in paper thickness. The spring loading enables even a single leaf of paper to be pinched and pulled through, thus simplifying thread up of the complete machine. In machines where the drive or pull-through rollers have fixed centres, these are not effective until all the leaves are present between the rollers. It is important that positive drive on the booklet strand should be maintained and that no slippage between the strand and the rollers 21, 22 should occur, otherwise there will be an irregularity in the length of the cut booklets. The booklet strand leaving the rollers 21, 22 passes through a further pair of parallel guides 23, 24 which maintain the strand in its compressed state and stop the advancing strand from buckling.

[0013] The strand then enters a cutting unit 25 through an aperture 26 in a leading plate 27 (see Figure 8) which is closed off by means of a high calibre steel fixed die 30. The unit 25 has a trailing plate 28 that is mounted in closely spaced parallel relationship to the plate 27. A knife 156 (Figures 5a-5d, 7 and 8) located between the plates 27, 28 has its cutting surface against the inner face of the die 30 and is mounted for slicing movement across the aperture 26 to sever booklets from the advancing booklet strand. The term "slicing movement" means that the knife 156 has components of motion both across the strand and through the thickness of the strand. The cutting unit 25 is mounted on linear bearings and is reciprocated by means of a constant velocity cam and follower arrangement so as to move downstream of the paper strand at the same speed as the paper strand advances and to return upstream. The upstream face of the leading plate 27 has a cam operated paper clamping mechanism. Thus the strand enters the aperture 26 while the unit 25 is moving upstream of the strand with the clamping mechanism in a disengaged position and with the blade 157 of knife 156 clear of the aperture 26. The travel of the cutting unit 25 is, of course, half the length of a cut booklet. After the cutting unit return is complete, the clamping mechanism closes to hold the booklet strand against the die 30 and during the forward stroke the blade 157 of knife 156 is rotated so as to make a slicing movement across the aperture 26 in appropriately timed relationship to sever a booklet length from the strand.

[0014] Downstream of the plate 28 there is provided a separate fixed pusher mechanism 31 operated by cams to remove the cut booklet at the downstream extremity of the travel of the unit 25. Cut booklets are supported on table 35 (Figure 5) that is mounted on and travels with the unit 25. The cut booklets are removed by the pusher mechanism 31 (Figure 1) in a plane normal to the line of advance of the booklet strand onto a discharge chute 32 bounded by upstanding guides 33, 34 to hold the cut booklets in position thereon. The inlet ends 36 of guides 33, 34 are provided with springs 37 that engage the ends of the last cut booklet as the cutting unit 225 returns so that the advance of the booklet strand into the cutting unit at the next stroke is not impeded by unwanted return of the last cut booklet or part thereof from the conveyor and control of the last cut booklet is not lost.

[0015] A general arrangement of the drive unit is shown in Figures 3 and 4. Power from a drive belt of an electric motor is transmitted via pulley wheel 50 to drive input shaft 51 that carries a worm 52 and a hand wheel 53, the shaft 51 being supported from rotation in bearings 54. The worm 52 meshes with worm wheel 55 of a transverse shaft 56. The shaft 56 carries a helical gear 57 and a sprocket wheel 58. A chain 59 connects the sprocket wheel 58 with a further sprocket wheel 60 of a second transverse shaft 61 that drives a constant velocity cam 62 and the pull-­through rollers 21, 22. The cam 62 is generally heart-­shaped and provides a uniform motion to a follower assembly including a pair of follower rollers 63 that engage opposite sides of cam 62 and are carried in a link 64 that is pivotally connected at 64ʹ (Figure 6) to the leading plate 27 of the cutting unit 25. The shaft 61 also carries a helical gear 65 that drives a vertical shaft 66 by means of a helical gear 67. At the upper end of shaft 66 is a straight spur gear 68 (Fig. 4) which in turn drives the two pull-through rollers 21, 22 by a series of interlocking gears.

[0016] As seen in Figures 5 to 8, the plates 27 and 28 carry sleeves 70 that each run on a bearing rod 72 defining linear bearings for reciprocation of the cutting unit 25.

[0017] Referring again to Figure 3, the helical gear 57 on the transverse shaft 56 drives a helical drive gear 75 of a shaft 76 of hexagonal section that is supported in a fixed transverse plate 78 and in end plate 79. The shaft 76 passes through apertures in the plates 27, 28 and carries a sleeve 81 of hexagonal core profile and cylindrical external profile which is supported in ball bearings in plates 27, 28. The sleeve 81 carries on the outer face of the plate 27 a cam 82 (Figure 6) for operating the clamping mechanism that has a raised lobe 83 that occupies about 180° of rotation. The clamping mechanism comprises a clamping bar 90 on the outer face of the leading plate 27 and guided for movement towards and away from the aperture 26 by means of straps 91, 91a. A tension spring 92 between a pin 93a on the strap 91a nearer the aperture 26 and a pin 93 on the bar 90 urges the clamping bar 90 towards clamping engagement with the interfolded strand of paper entering the aperture 26, and the bar 90 is lifted from clamping engagement therewith by a link 94 pivoted to the plate 27 and to the bar 90 at pivots 95, 96 and having a follower roller 97 engaged with the cam 82 so that the bar 90 is lifted from engagement with the advancing interfolded strand while the follower roller 97 is on the raised sector 83. As will be apparent from the earlier description, this is timed to be when the cutting unit 25 is in the return half of its travel.

[0018] Figures 7 and 8 show the cutting function. A knife support 150 rotates in recess 151 in the inner face of leading plate 27 and is supported for rotation between the plates 27, 28 by stub shafts 152, 153 that are supported in rolling contact bearings 154, 155. The support 150 rotatably carries a knife 156 having a generally crescent-­shaped cutting blade 157 that traverses the aperture 26 once per rotation of the support. The blade 157 not only compresses the paper strip during cutting but also moves across it, thereby giving a highly effective slicing action with low force required. The knife 156 is held to the support 150 by means of a clamping disc 158 which is held in place by a nut 159. The support 150 is rotated by means of a drive gear 160 that is rotated by driven gear 161 which is rotated by the hexagonal shaft 76. The timing of the knife traverse of the aperture 26 is such that the unit 25 is advancing with the interfolded paper strip clamped in position relative thereto. Furthermore the blade 157 may be arranged to traverse a sharpening stone at each revolution so that it is maintained sharp in service and only has to be replaced at infrequent intervals. The cut booklets of paper are supported by the table 35 and are controlled by T-shaped guide bar 38 on a bracket that is bolted to the trailing plate 28 of station 25 downstream of the aperture 26 a short distance above the table 35. The guide bar 38 prevents paper from entering the space between plates 27, 28 and ensures that it takes a straight path towards the downstream end of the table 35.

[0019] Referring to Figures 3, 9 and 10, a feature of the invention is that the fixed pusher mechanism or ejection station 31 is fixed opposite to the discharge chute 32 rather than being carried by the station 25 as in the apparatus described in Specification No. EP-A-0165747. A pair of links 201, 202 are pivoted at 203, 204 to the inner face of end plate 79 and are connected by tie bar 205 to form a parallel linkage. The shaft 76 has a second sleeve 206 carrying first and second cams 207 and 208. The link 201 which is close to discharge chute 32 is relatively short and has at its top end a follower roller 209 for the cam 207. The link 202 is connected adjacent its upper end to a tension spring 210 by which the links 201, 202 are biased away from the chute 32 so that follower 209 is maintained in contact with the surface of the cam 207. Ejector bar 211 is pivoted at 212 to the upper end of link 202, passes through a slotted plastics guide 213 and has at its tip a thrust plate 214 which is divided at the end which faces aperture 26 into upper and lower furcations 214a, 214b. The bar 211 is biased downwardly by tension spring 215 to maintain a follower roller 216 in contact with the surface of the roller 208. Accordingly as shaft 76 rotates there are two independent components of motion, firstly in a generally back and forward direction via cam 207 and follower 209 and secondly in a rise and fall direction via cam 208 and follower 216 (see Figures 5a-5d).

[0020] The ability to lift the plate 214 permits the entire cut booklet to be supported by the ejector. In the apparatus described in Specification No. EP-A-0165747 the ejector was carried on the outer face of the plate 28 and was movable only in translation. Even though the ejection station operated within only a small angle of rotation of the shaft 76, by the time that the ejector begins to return, an appreciable length of new booklet material has entered the cutting station 25. The state of the cutting station and eject station is apparent from Figure 5a where the thrust plate 214 has entered the discharge chute 32 and fresh booklet strand is emerging between plate 27 and die 30 To avoid the thrust plate 214 fouling this new material on the return stroke it was made only about 70% of the width of a cut booklet. The unsupported upstream end of the cut booklet could not always be correctly engaged behind an inlet spring at the entrance to chute 32 but might return and foul incoming paper, causing a jam and consequent machine downtime. Such downtime is avoided by the independent movements provided via cams 207, 208. Forward movement of the thrust plate 214 occurs along a substantially straight path aligned with the chute 32, so that the guide bar 38 passes between furcations 214a, 214b of the plate 214 (Figures 5c, 5d) which thrusts the cut booklet from the table 35 into the chute 32 so that both its ends are retained behind springs 37 (Figure 5a). Before the return stroke has proceeded appreciably the thrust plate 214 is lifted by cam 208 and follower 216 clear of the bar 38 and of the path of new booklet strand entering the cutting station 25 (Figure 5b), and the thrust plate 214 does not fall significantly until it has passed behind bar 38. Consequently thrust plate 214 follows a looped path clear of incoming booklets. Such a complex motion would be difficult to provide if the ejector station 200 were on the cutting station 25 because the dwell of the station 25 at the downstream end of its travel in register with chute 25 is very brief. By contrast the operative sectors of cams 207, 208 are very broad, typically 90° in extent and have gently sloping flanks so that timing is easier having regard to the response time of the links 201, 202, 205, 211 and springs 210, 215 and operating forces and wear are reduced.

Claims

1. A machine for forming booklets of paper, comprising a plurality of sources (10, 11) of paper strip, forming means (15, 17, 18) for converging paper strips from the several sources into a single strand, means for advancing the strand in a first direction (21, 22), a cutting station means (25) for reciprocably moving along the strand so that a booklet length of the strand enters the cutting station means (25) while the cutting station means (25) moves counter to the strand in a second direction opposite to the first direction, an ejector means (31) for ejecting booklets from said cutting station means (25) into a fixed outlet passage (32) characterised by said ejector means (31) also being fixed and receiving booklets from the cutting station means (25) when the cutting station means (25) is towards the end of its travel in the first direction, and by means (76, 201-210, 215, 216) defining a coupling between the cutting station means (25) and the ejector means so that the ejector means (31) operates in a predetermined timed manner at each reciprocation of the cutting station means (25).

2. A machine according to Claim 1, wherein the outlet passage (32) has ratchet spring means (37) for preventing the booklets from returning to the ejector means (31) at its entrance (36) acting on the booklets entering the passage (32), wherein the ejector means (31) includes thrust plate means (214) spanning substantially the full width of the outlet passage (32) and wherein the ejector means (31) is operated by a means for guiding the thrust plate means (214) to travel from a first position along the direction of the outlet passage (32), above the path of the strand and back to the first position.

3. A machine according to Claim 1 or 2, wherein the ejector means (31) is operated by a first coupling means (207, 209) on a rotating shaft (76) providing a forward and reverse movement and by a second coupling means (208, 216) on the rotating shaft (76) providing a rise and fall movement so that an ejector member (211) advances in the direction of the outlet passage (32), rises above the path of the strand and then returns.

4. A machine according to Claim 3, wherein the machine includes a wall (79) leading to the outlet passage (32), and the ejector means (31) includes first and second links (210, 202) pivoted to the wall (79) for rotation in a plane generally parallel to the outlet passage (32), a third link (205) connecting the first and second links (201, 202) to form a parallelogram linkage, the first link (201) being relatively short and nearer the outlet passage (32) a first cam (207) on the rotating shaft (76) being coupled to the first link (201) by means including a follower (209) at the end of the first link (201) to effect the forward and reverse movement, the second link (202) being relatively long and having pivoted thereto a fourth link (211) defining the ejector member and carrying a thrust plate (214) at its tip, a second cam (208) on the rotating shaft (76) being coupled to the fourth link (211) by means including a follower (216) partway along the fourth link (211) to effect the rise and fall movement.

5. A machine according to Claim 4, wherein the thrust plate (214) is bifurcated to define a pair of vertically spaced tines (214a, 214b) facing the cutting station means (25), and the cutting station means (25) has a paper guide (38) that passes between the tines (214a, 214b) as the cutting station means (25) completes its travel in the first direction, said paper guide (38) defining a linear path for paper strand past the cutting station means (25).

6. A machine according to any preceding claim, wherein the stroke of the ejector means (211) occupies about half the period of reciprocation of the cutting station means (25).

7. A machine according to any of Claims 3 to 6, wherein the a rotating shaft (76) is of non-circular cross-section and extends through said cutting station means (25) parallel to the first direction, a knife means (156, 157) responsive to rotation of the rotating shaft (76) is disposed in the cutting station means (25) for cutting a booklet from the strand while the cutting station means (25) moves alongside the strand in a first direction, knife couplng means (81, 160, 161) translating rotational movement of the rotating shaft (76) into rotational slicing movement of said knife means (156, 157) across the strand in a plane substantially perpendicular to the first direction, a path of the knife means (156, 157) and the path of the ejector menber (211) being mutually independent.

8. A machine according to Claim 7, wherein firstly the knife means (156) has a generally crescent-shaped blade (157), wherein secondly the rotating shaft (76) is hexagonal in cross-section and tubular sleeve means (81) on the rotating shaft (76) operably couples the cutting station means (25) to the rotating shaft (76), and/or thirdly wherein a strand clamping member (90) is disposed on the cutting station means (25) and disengaging cam means (82) disposed on the tubular sleeve (81) disengages the clamping member (90) from the strand when the cutting station is (25) is moving in the second direction and/or fourthly the converging means comprises means (15-18) for folding and interleaving the paper strips in a zig-zag configuration.

9. A machine according to Claims 7 or 8, wherein the rotating shaft (76) extends through the cutting station means (25) to the ejector means (31).

10. A machine according to any of Claims 1 to 9, further comprising a driven shaft (61) oriented normal to the first direction and having a constant velocity cam (62) and a follower (63) mounted thereon, the cutting station means (25) being connected by means of a pivoted link (64, 64ʹ) to the follower (63) of the constant velocity cam (62).

Drawing