GB2285381A - Dual rod cigarette manufacturing machine - Google Patents

Description

a DUAL ROD CIGARETTE MANUFACTURING MACHINE 2285381 The present invention

relates to a dual rod cigarette manufacturing machine.

US Patent n. 4,336.812 granted to the present Applicant relates to a dual rod cigarette manufacturing machine comprising a shredded tobacco feedbox, and a carding unit for withdrawing the shredded tobacco from the f eedbox and f eeding it to the inlet of a downf low conduit with an elongated rectangular section, the length of which, measured parallel to the longer axis of the section, is much greater than the width. The downflow conduit feeds the shredded tobacco to a hurling unit extending crosswise to the longitudinal axis of the conduit and parallel to the longer axis of the conduit section, and which provides for feeding a continuous stream of shredded tobacco, either directly or via the interposition of a conveyor belt, to the base of an upflow conduit divided in various ways into two upflow ducts presenting respective elongated rectangular outlets at the top. The two outlets are normally positioned offset in relation to each other and substantially parallel to the cross section of the downf low conduit, and are closed by respective suction belts parallel to each other and positioned side by side in the same traveling direction parallel to the longer side of the outlets.

In all known embodiments of machines of the above type, the length of each of the two outlets, measured in the traveling direction of the suction belts, is substantially equal to half the length of the cross section of the downflow conduit.

Such a design feature may present drawbacks in the sense that each outlet, measured parallel to the traveling direction of the respective suction belt, may not be long enough to permit the formation of a relatively uniform layer of shredded tobacco on the suction belt.

Though one obvious solution would be to increase the size of the two duct outlets in the traveling direction of the respective suction belts, this has never been attempted as yet f or economic and commercial reasons. Increasing the length of the outlets, in f act, would automatically result in a corresponding increase in the length of the machine, and hence in the bed and all the machine supporting members, thus impairing the market potential of the machine as a whole.

It is an object of the present invention to provide a dual rod cigarette manufacturing machine wherein the above drawbacks are eliminated with no increase in the length of the machine.

According to the present invention, there is provided a dual rod cigarette manufacturing machine comprising a conduit f or supplyi.-.g a stream of shredded tobacco; two upf low ducts presenting respective upper outlets and respective lower inlets; two suction belts, each closing a respective said outlet which is elongated in shape in the traveling direction of the respective belt; and a hurling unit interposed between the supply conduit and the inlets of the upflow ducts; characterized in that said inlets are aligned with each other along the hurling unit; and, over part of their length, said ducts are arranged at least partly side by side and superimposed in a direction crosswise to said traveling direction, and are flared towards the respective outlets.

The outlets of the above machine are preferably arranged parallel to each other and side by side over substantially the whole of their length measured in said traveling direction.

A number of non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a schematic, three-quarter top view in perspective, with parts removed for clarity, of a first preferred embodiment of the machine according to the present invention; Figure 2 shows a schematic side view, with parts removed for clarity, of the Figure 1 machine; Figure 3 shows a schematic side view, with parts removed for clarity, of a variation of the Figure 1 machine.

Number 1 in Figures 1 and 2 indicates a dual rod cigarette manufacturing machine comprising a conduit 2 for supplying a stream 3 of shredded tobacco. Conduit 2 presents a substantially vertical axis 4; and an elongated rectangular section, the longer axis 5 of which extends p(rpendicular to axis 4 and to the Figure 2 plane. Conduit 2 provides f or f eeding stream 3, in a downward direction 6 parallel to axis 4, to a chamber 7 connected to the bottom end of conduit 2 and housing a known powered hurling unit 8 extending along the full length of the section of conduit 2 measured along axis 5. Hurling unit 8 comprises a toothed roller 9 housed inside chamber 7 and rotating anticlockwise, in Figure 2, about an axis 10 parallel to axis 5; and a toothed hurling roller 11 housed inside chamber 7, substantially tangent to roller 9 along a generating line, and rotating clockwise, in Figure 2, about an axis 12 parallel to axis 10.

Hurling unit 8 provides in known manner for deviating stream 3 and forming a deviated stream 13 of a width equal to the length of rollers 9 and 11 and directed, crosswise to direction 6, towards the inlets 14 and 15 of two ducts 16 and 17. Ducts 16 and 17 comprise respective input portions 18 and 19 extending in a substantially horizontal direction crosswise to axes 10 and 12; respective substantially horizontal intermediate portions 20 and 21; and respective output portions 22 and 23 curving upwards and terminating with respective elongated rectangular outlets 24 and 25. Outlets 24 and 25 are positioned with their longer longitudinal axes substantially parallel to axes 10 and 12, and are closed by respective known suction belts 26 and 27 moving in a direction parallel to axes 10 and 12.

Inlets 14 and 15 of ducts 16 and 17 are aligned with each other in a direction parallel to axes 10 and 12, are substantially similar to each other, present a total length equal to that of hurling unit 8, and are separated by a partition wall 28 perpendicular to axes 10 and 12 and which divides deviated stream 13 into two substantially similar substreams 29 and 30.

Input portion 18 of duct 16 is defined at the bottom by a substantially horizontal wall 31 with a number of air inlets 32 for conveying the particles of substream 29, and at the top by a wall 33 sloping downwards from inlet 14; and portions 18, 20 and 22 of duct 16 are defined laterally by a first common outer lateral wall 34 aligned with one end of hurling unit 8 and substantially parallel to partition wall 28. Conversely, input portion 19 of duct 17 is defined at the top by a substantially horizontal wall 35, and at the bottom by a wall 36 sloping upwards from inlet 15 and presenting a number of air inlets 37 for conveying the particles of substream 30; and portions 19, 21 and 23 of duct 17 are defined laterally by a f irst common outer lateral wall 38 parallel to, and on the opposite side of hurling unit 8 in relation to, wall 34. Together with partition wall 28, input portions 18 and 19 extend as f ar as the line indicated by K in Figure 2, at which point the plane of bottom wall 36 of input portion 19 of duct 17 intersects the plane of top wall 33 of portion 18 of duct 16, and intermediate portion 21 of duct 17 is at a higher level than intermediate portion 20 of duct 16.

on the opposite side to wall 34, duct 16 is defined laterally by a second lateral wall 39 diverging in relation to wall 34 towards outlet 24, and the edge of outlet 24 facing wall 38 is substantially coplanar with wall 38. Similarly, on the opposite side to wall 38, duct 17 is defined laterally by a second lateral wall 40 diverging in relation to wall 38 towards outlet 25, and the edge of outlet 25 facing wall 34 is substantially coplanar with wall 34.

The above configuration enables intermediate portions 21 and 20 of ducts 17 and 16 to be arranged one over the other, and output portions 22 and 23 of ducts 16 and 17 to be positioned side by side with respective outlets 24 and 25 side by side and parallel to each other over substantially the whole of their length measured in the traveling direction of the suction belts.

Ducts 16 and 17 may thus be positioned, over part of their length, side by side in a direction parallel to axes 10 and 12, and, over part of their length, side by side in a direction crosswise t.:- axes 10 and 12, thus enabling, with absolutely no increase in the length of machine 1, a considerable increase in the size of ducts 16 and 17 in the traveling direction of respective belts 26 and 27, and hence a considerable improvement in the uniformity of both substreams 29, 30 and the tobacco layers (not shown) formed on belts 26 and 27. The above arrangement in fact provides for flaring ducts 16 and 17 towards outlets 24 and 25, the length of which may be increased - in the example shown, even doubled - as compared with that of respective inlets 14 and 15.

The Figure 3 variation relates to a machine 41 similar to machine 1 except that input portions 18 and 19 of ducts 16 and 17 extend from a common conduit 42 constituting the outlet of chamber 7 housing hurling unit S. Conduit 42 houses the output end of a conveyor 43 comprising a belt 44 looped about pulleys 45 (only one shown) and presenting an upper transportation branch 46 for receiving deviated stream 13 and feeding it to input portions 18 and 19 of ducts 16 and 17 to f orm substreams 29 and 30. In the case of machine 41, walls 33 and 35 also present respective air inlets 47 and 48 for conveying substreams 29 and 30.

Claims (8)

1) A dual rod cigarette manufacturing machine (1) comprising a conduit (2) for sur-plying a stream (3) of shredded tobacco; two upflow ducts (16, 17) presenting respective upper outlets (24, 25) and respective lower inlets (14, 15) two suction belts (26, 27), each closing a respective said outlet (24; 25) which is elongated in shape in the traveling direction of the respective belt (26; 27); and a hurling unit (8) interposed between the supply conduit (2) and the inlets (14, 15) of the upf low ducts (16, 17); characterized in that said inlets (14, 15) are aligned with each other along the hurling unit (8); and, over part of their length, said ducts (16, 17) are arranged at least partly side by side and superimposed in a direction crosswise to said traveling direction, and are flared towards the respective outlets (24, 25).

2) A machine as claimed in claim 1, characteriz--d in that, in said traveling direction, said inlets (14, 15) are shorter in length than the respective outlets (24, 25).

3) A machine as claimed in claim 1 or 2, characterized in that said outlets (24, 25) are arranged side by side and parallel to each other over substantially the whole of their length measured in said traveling direction.

4) A machine as claimed in any one of the foregoing Claims, characterized in that said two ducts (16r 17) comprise respective input portions (18, 19) arranged side by side and separated by a common central partition wall (28); the inpl--.t portions (18, 19) tapering towards said outlets (24, 25), and respectively presenting a first wall (33) and a second wall (36) opposite each other and located in respective planes sloping in relation to each other and intersecting at a given line (K).

5) A machine as claimed in Claim 4, characterized in that the part of each duct (16; 17) extending between said line (K) of intersection and the respective outlet (24; 25) is at least partially superimposed over the corresponding part of the other duct (17; 16).

6) A machine as claimed in any one of the foregoing Claims, characterized in that the hurling unit (8) is located immediately adjacent to said inlets (14, 15).

7) A machine as claimed in. any one of the foregoing Claims from 1 to 5, characterized in that a conveyor belt (43) is interposed between the hurling unit (8) and said inlets (14, 15).

8) A dual rod cigarette manufacturing machine, substantially as described and illustrated herein with reference to the accompanying drawings.