GB2043426A - Tobacco cutting apparatus - Google Patents

Abstract

Tobacco cutting apparatus comprises a carrier (1) which has contour knives (4) attached thereto. A tobacco leaf is laid on the knives and an element is reciprocated over the knives to force the leaf into contact with the cutting edges. In the present apparatus, the element comprises one or more bodies (27) each comprising at least part of a right circular cylinder. The bodies are preferably completely cylindrical rollers and are preferably reciprocated up and down by an electric motor (17) provided with eccentrics (19) on its output shaft (18), so that the leaf is urged more firmly into contact with the knives. The rollers may both oscillate together or they may oscillate output of phase with each other. <IMAGE>

Description

SPECIFICATION Tobacco cutting apparatus This invention relates to apparatus for cutting wrappers or binders from tobacco leaf, and particularly to such apparatus comprising a carrier having one or more contour knives across which the tobacco leaf is spread, and a holder which is movable parallel to the carrier and is provided with at least one element which rolls over the cutting edges of the contour knives.

In the tobacco industry it is known to spread tobacco leaf manually across the contour knives, the tobacco leaf being retained by suction applied via the carrier. Two freely rotatable conical rollers are passed across the cutting bed and the pressure exerted between the conical rollers on the cutting edges causes them to cut the tobacco leaf. The contour knives usually have the shape of the desired wrapper or binder so that by picking up the tobacco leaf from inside the contour knives the desired wrapper or binder can be conducted away.

In the technique described above, the cutting bed usually has one or, at the most, two contour knives so that cutting of the tobacco leaf can be performed without much difficulty, provided that there is always someone to supervise the operation of the apparatus.

Apparatus according to the invention is characterised in that the element is in the form of at least part of a cylinder.

This element shape provides more effective cutting of the tobacco leaf.

In an embodiment of the invention, a sheath of the element which rolls over the cutting edges comprises two layers, the outer layer being harder than the underlying layer.

Hence, although the outer layer is relatively hard and therefore wear-resistant, the sheath of the element is overall quite flexible, which improves the cutting effect of the contour knives.

The element preferably comprises two mutually parallel, cylindrical rollers, so that a comparatively cheap but effective construction is obtained.

Preferably the element can vibrate in a direction at right angles to the direction of movement.

In an embodiment the two rollers are jour nalled in the same bearing seat, which is slidable along a guide extending in a direction at right angles to the direction of movement of the holder. Hence, the two rollers will perform similar vibratory movements.

In order to obtain a desired vibration frequency, the holder is provided with an electric motor, and an eccentric mechanism arranged on the output shaft of the motor is directly coupled to the bearing seat.

In order to remove the remnants of tobacco leaf which are not suitable for use, a suction nozzle communicating with a vacuum source is disposed at the side of the element.

A suction nozzle may be arranged at each side of the element, and a change-over flap provided to connect the suction nozzles alternately to reduce the consumption of air by the device.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of cutting apparatus according to the invention, Figures 2 and 3 are front side views, respectively, of part of the apparatus, Figure 4 is a perspective view of a cylindrical element of the apparatus, Figures 5a, 5b and 5c are a longitudinal sectional view and end elevations, respectively, of an eccentric mechanism for producing a vibratory movement of the cylindrical element, Figure 6 is a side view of an alternative form of the Fig. 3 apparatus.

Referring to Fig. 1, a flat carrier 1, in which or on which contour knives 2 are arranged, is fastened to a substructure 3 of any suitable kind. The cutting edges 4 of the contour knives 2 are all coplanar. Parallel to the plane through the cutting edges 4, a holder 5 is moved along a straight guide comprising two parallel bars 6' and 6" which are held at both ends in a frame 7 which is secured by posts 8 to the substructure 3.

The holder 5 is reciprocated by a toothed belt 9 fastened to the rear thereof (not shown in Fig. 1), the belt 9 being passed, at the rear, about a reversing roller journalled in the framework 7 and, at the front, around a wheel 1 2 arranged on the shaft of an electric motor 11. The electric motor 11 is reversible so that the holder 5 can be moved to and fro along the guide bars 6' and 6" above the carrier 1.

Figs. 2 to 5 show in detail the holder with cylindrical roller elements.

The holder 5 basically comprises a bridge portion 1 3 extending between the guide bars 6' and 6" and rigidly secured to bearing bushes 1 6 which slide along the bars. On the bridge portion 1 3 is mounted an electric motor 1 7 having an output shaft 1 8 protruding at each end. Each end of the shaft 1 8 is provided with an eccentric sleeve 19, which is shown in detail in Fig. 5. The sleeves 19 are fastened to the shaft 1 8 by keys in keyways 20 formed in the sleeves 1 9. The sleeves are journalled in bearings 21 (Fig. 2) in a bearing housing 22 which is rigidly secured to the bridge portion 1 3.

At its end remote from the electric motor, each bearing sleeve is provided with an eccentric stud 23, the centre line of which is eccentrically located with respect to the centre line of a blind bore in the sleeve 19 by a distance e. The stud 23 carries a bearing 24 arranged in a bracket 25, which, in turn, is connected to a vertical leaf spring 26 (see also Fig. 3).

At the bottom of the bridge portion 1 3 are suspended two cylindrical rollers 27 which are parallel to one another, for which purpose stub shafts projecting one on each side are arranged in bearing seats 28. Each bearing seat 28 is furthermore connected through a coupling piece 29 with the leaf spring 26.

At the sides of the stub shafts of the rollers 27 the respective bearing seat 28 is rigidly secured through screws 30 to two vertical pins 31, each of which is slidable up and down in a vertical lower guide 32 and an upper guide 33. Each lower guide 32 is directly connected to the bridge portion 13, whereas each upper guide 33 is connected with the bearing housing 22 by arms 34. The stub shafts of the rollers 27 are freely rotatable in the bearing seat 28 by means of bearings 35.

Each bearing sleeve 1 6 is provided with a downwardly extending arm 36 having at its lower end a bearing sleeve 37 in which is journalled a stub shaft 38 of a wheel 39. The wheel 39 is guided in a guide rail 40 which is rigidly secured to the carrier 1.

On each side of the rollers 27 is disposed a suction nozzle 41 at the lower end of a duct 42 which gradually narrows upwards to a common outlet conduit 43 communicating with a vacuum source (not shown). The two ducts 42 are interconnected by a manifold 44 in which a flap 45 can pivot to and fro about a shaft 46 so that it closes the passage to either one or the other of the ducts 42. The flap 45 is actuated by a lever 47 (Fig. 2) which is secured to a shaft portion 46 projecting out of the manifold 44. The lever 47 cooperates with end stops 48 rigidly secured to the framework 7 (see Fig. 1).

Fig. 4 shows a roller 27 in a perspective view, parts being broken away. The roller 27 comprises a sheath composed of two layers i.e. an outer layer 1 5 of comparatively hard material, for example hard polyurethane, and beneath the layer 1 5 a softer layer 51, for example also of polyurethane having a lower degree of hardness. The interior of the roller may be filled with any foam substance 52.

The apparatus operates as follows. A tobacco leaf is first spread across the contour knives 2 on the carrier 1, and the electric motor 11 is energised. The motor causes the toothed belt 9 to move in a manner such that its lower run moves towards the rear of the machine as shown in Fig. 1. The lower run of the toothed belt 9 is secured to the hindmost bearing sleeve 1 6 and therefore carries along the bridge portion 1 3 with the holder 5 secured thereto. In the meantime the electric motor 1 7 has started, so that the shafts 1 8 and the eccentric sleeves 1 9 rotate.Hence, each stud 23 performs a rotary movement around the centre line of the respective bearing sleeve 1 9. The stud 23 moves the respective bearing 24 in the bearing sleeve 25 in a vibratory movement mainly in an upward and downward direction, the movement being transferred through the spring 26 to the bearing seat 28. Owing to the guides formed by the pins 31 and the sleeves 32 and 33, the bearing seats 28 will perform upward and downward vibrations so that the rollers 27 will perform a vibratory movement at right angles to the direction of movement determined by the toothed belt 9.

As soon as the sheaths of the rollers 27 touch the cutting edges 4 of the contour knives 2, the tobacco leaves will be cut through by the cutting edges 4, so that a useful tobacco portion inside the region enclosed by the cutting edges 4 is obtained, whilst the waste tobacco portions located outside the cutting edges 4 are conducted away through the suction nozzles 41 and channels 42 to the conduit 43. The flap 45 is positioned such that it is always the hindmost suction nozzle, viewed in the direction of movement, which is operative.

Due to the rigid connection between the bearing sleeves 1 6 and the guide 40 of the carrier 1, the lowest position of the sheath of the roller 27 relative to the cutting edge 4 of the contour knife 2 is fixed, so that the tobacco is accurately cut.

Fig. 6 shows a second embodiment of the apparatus which mainly corresponds with the embodiment described above. The same reference numerals are used to designate the same parts. In this second embodiment a bearing seat 53 is constructed differently. The bearing seat 53 is pivoted to the holder 5 at a point 54 between the bearings 35 of the rollers 27.

A pivotal joint 55 is coaxial with one of the rollers 27 on the bearing seat 53 and is associated with a connecting rod 56, the other end of which is journalled on the eccentric stud 23, which is driven by the electric motor 17.

In this embodiment, when the electric motor 1 7 is energized, the eccentric mechanism 23 will cause the connecting rod 56 to move up and down so that the bearing seat 53 will perform a rocking movement about the pivot point 54. Since the pivot point 54 is accurately located midway between the bearings 35 of the rollers, the rollers will perform identical vibrations but in relatively opposite phases. This embodiment has the advantage that the cutting frequency is doubled as compared with that of the preceding embodiment, whilst at the same time the machine runs more quietly.

The invention is not limited to the embodiments described above. It may, for example, suffice to use a single roller 27, which may have a much larger diameter so that only part of the sheath need be constructed as shown in Fig. 4. As an alternative, the roller may be omitted and only one element of the partcircular segment shape may be used, provided that the surface of the sheath is such that the whole cutting edge 4 of each of the contour knives 2 is touched.

Claims (11)

1. Apparatus for cutting wrappers or binders for cigars from tobacco leaf, comprising a carrier having at least one contour knife over which the tobacco leaf is to be spread; a holder movable parallel to the carrier and having at least one element to roll along the or each cutting edge to force the leaf against the or each cutting edge, the or each element being in the form of at least part of a cylinder.

2. Apparatus as claimed in Claim 1, including means to oscillate the or each element in a direction at right angles to the direction of movement of the holder.

3. Apparatus as claimed in Claim 1 or Claim 2, wherein the or each element has a sheath comprising an inner layer and an outer layer over the inner layer, the outer layer being of harder material than the inner layer.

4. Apparatus as claimed in any preceding claim, wherein two of said elements are provided, each being a cylindrical roller.

5. Apparatus as claimed in Claim 4, including a bearing seat supporting the two rollers, the bearing seat being slidable in a guide of the holder extending at right angles to the direction of movement.

6. Apparatus as claimed in Claim 4, including a bearing seat supporting the two rollers, the bearing seat being pivotally connected with the holder at a point located between the bearings.

7. Apparatus as claimed in Claim 5 or Claim 6, including an electric motor; and an eccentric mechanism arranged on the output shaft of the motor and coupled to the bearing seat to cause reciprocation of the or each element.

8. Apparatus as claimed in any preceding claim, including a straight guide fastened to the carrier at each side of the contour knives, along which guides the holder of the rolling element is guided.

9. Apparatus as claimed in any preceding claim, including a suction nozzle disposed at the side of the element and communicating with a vacuum source.

1 0. Apparatus as claimed in Claim 9, including a suction nozzle at each side of the element, the nozzles being alternately connectable to the vacuum source by means of a change-over valve.

11. Apparatus as claimed in Claim 1 and substantially as hereinbefore described with reference to Figs. 1 to 5 of the accompanying drawings.

1 2. Apparatus as claimed in Claim 1 and substantially as hereinbefore described with reference to Figs. 1 to 6 of the accompanying drawings.