Straightlayer for manufacture of tobacco

Abstract: A straightlayer (8) for orientation of tobacco leaves (7) prior to a cutting operation is disclosed. The straightlayer (8) comprises a lower belt conveyor (6) having an output direction (R), a number of, in respect of the belt conveyor (6), vertically projecting, channel forming partitions (5) that extend in the output direction (R) of the belt conveyor (6) and have some distance from the belt conveyor (6), and a feeding apparatus (1) that supplies from above tobacco leaves (7) down onto the straightlayer (8). Further, the straightlayer (8) comprises a vibrating unit (2) that is lying above the partitions (5) and that is able to shake down into the channels (10) those tobacco leaves (7) that lay down onto the vibrating unit (2) and orient the leaf stems in the longitudinal direction of the belt conveyor (6).

Description: The present invention relates to a straightlayer for orientation of tobacco leaves prior to a cutting operation, which straightlayer comprises a lower belt conveyor having an output direction, a number of, in respect of the belt conveyor, vertically projecting, channel forming partitions that extend in the output direction of the belt conveyor and have some distance from the belt conveyor, and a feeding apparatus that supplies from above tobacco leaves down onto the straightlayer. The invention also relates to a method for straightlaying and orientation of tobacco leaves prior to a cutting operation, in which tobacco leaves are supplied from above and down onto a straightlayer as disclosed above. A straightlayer of the above indicated type is known from NO 140 126. Straightlaying and orientation of tobacco leaves prior to cutting thereof is an extremely important part of the manufacture of smoking tobacco. In order to avoid that the stem of the tobacco leaves are cut lengthwise, it is of importance that the stems are oriented as much as possible in parallel and in the feeding direction thereof so that the stem is transversally or crosswise cut. It is very undesirable that long stem cuts are present in the finished product. A straightlayer that is extensively in use today, consists of several channels adjacent each other in the output direction having a common lower belt that advances the tobacco leaves forward to a press apparatus. The press apparatus compresses the leaves together to a compact string of tobacco that subsequently enters a cutting machine. The existing apparatus is provided with a chain drive on top of each individual partition and is supposed to assist the tobacco leaves in place into the channels. The chain moves forwards, respectively rearwards, on every other partition so that the leaves that lay down transversally over two partitions are turned into place and drop down into the channels. Those leaves that remain hanging over a partition are pulled either forwards or rearwards, and the leaves are falling into place in the channels by a dragging action against the tobacco already lying in the channel. Those leaves that do not fall into place in the channels during transit, proceed to the end of the straightlayer and at which location they are cut in two pieces that fall down into each respective channel. This apparatus is extremely maintenance demanding in respect of mechanical wear and cleaning. Further, the tobacco is given a rough handling that results in a partial destruction of the complete tobacco leaves. By the now proposed straightlayer the orientation and straightlaying of the leaves are substantially improved in that the leaves are well straightened out, and in a larger extent than before the stem is transversally cut. This results in less stems in the finished product and the quality is improved. In addition a more gentle treatment and handling of the complete leaves occur. Less destruction of the tobacco leaf stock and better utilisation of the raw material is achieved. The need for cleaning and maintenance is substantially reduced with the new straightlayer. The mechanical maintenance, that amounts the largest cost, is dramatic reduced. In addition, the daily cleaning is nearly absent. These circumstances result in that substantial annual savings are achieved. This prior art apparatus has frequent operational interruptions as a consequence of problems with the knife and chain system and clogging of channels. These problems are now eliminated and lead to less interruptions of the production. A substantial better operational reliability than before is thus achieved. In addition do tests reveal that the present straightlayer has larger capacity than previous apparatus in respect of production speed in kg/hour. In sum this leads to that the efficiency of the apparatus is substantially improved. This is achieved with a straightlayer of the introductorily described kind, which is distinguished in that the straightlayer comprises a vibrating unit that is lying above the partitions and that is able to shake down into the channels those tobacco leaves that lay down onto the vibrating unit and orient the leaf stems in the longitudinal direction of the belt conveyor. Suitably does the vibrating unit include a frame that supports a number of longitudinally extending bars, each bar is lying above respective partition. Each bar is preferably formed of a U-configured sheet section that is lying with some clearance above its corresponding partition. Preferably do the upper edge of the partitions and the bars incline downwards in a direction opposite of the output direction. The vibrating unit comprises a motorised drive that preferably provides a tilting motion to the frame and the bars. A kick off means is preferably arranged in that end of the straightlayer, which is opposite to the output end of the straightlayer. According to the invention also a method of the introductorily mentioned kind is provided, which is distinguished in that a vibrating unit throws the leaves rearwards and downwards in opposite direction of the output direction, that the leaves that do not drop directly into the channels are pulled in the output direction and down into the channels by leaves already present in the channels, which causes pulling down of leaves from the bars and straightening of the leaf stems in the longitudinal direction thereof. Leaves that do not fall into place in the channels are forwarded again by means of a kick off means. Other and further objects, features and advantages will appear from the following description of one for the time being preferred embodiment of the invention, which is given for the purpose of description, without thereby being limiting, and given in context with the appended drawings where: Fig.1 shows in a perspective view the straightlayer according to the invention, and Fig.2 shows the straightlayer according to fig. 1 viewed from the side. Firstly we refer to fig.1. The apparatus comprises an upper belt conveyor 1 that supplies tobacco leaves 7 to a straightlayer 8 which is located underneath the belt conveyor 1. The belt conveyor 1 is oscillating back and forth across the entire width extension of the straightlayer 8 such the arrow P indicates. The flow of tobacco is aimed at being so uniform as possible when it is supplied to the straightlayer 8. The straightlayer 8 includes a lower belt conveyor 6 that brings the straightlaid and oriented tobacco leaves 7 out from the straightlayer 8 and further on to a press apparatus (not shown) and a cutting device (not shown) that cuts the compressed tobacco string to cut tobacco. A number of vertically disposed partitions 5 are arranged standing above the lower belt conveyor 6. The partitions 5 are mutually parallel and extend in the longitudinal direction of the belt conveyor 6. The partitions 5 are stationary and have a small clearance along the lower edge thereof to the lower belt conveyor 6. Intermediate the partitions 5 channels 10 are formed into which the tobacco leaves partly drop from the upper belt conveyor 1. Above the partitions 5 is a vibrating unit 2 located. The vibrating unit 2 includes a surrounding frame 9 that supports a number of bars 3. The bars 3 do also extend in the longitudinal direction of the belt conveyor 6 and each individual bar is lying above a respective partition 5. In the illustrated embodiment each bar 3 is formed of a U-formed sheet metal section in which the U-form is facing downwards and is lying with clearance and freedom of motion over the partition 5. The frame 9 is supported in a number of vibration springs 4 that are able to cushion the motion back and forth. The vibrating unit 2 is driven by a motor having an eccentric crank (not shown). Thus the frame 9 and the bars 3 are imparted a tilting movement as indicated by the arrow V. We now refer to fig.2. As it appears from the figure, the bars 3 are inclined downwards in a rearward direction in respect of the output direction R for the tobacco leaves 7. The reason for this inclination will more clearly appear by studying the following functional description of the complete apparatus. In one end of the straightlayer 8 is a kick off means 11 located, which throws the tobacco leaves 7 that still remain on the bars 3 forwards again in the output direction R. This happens continuously and all the leaves 7 find little by little its place in the channels 10. What is particular with the present invention, is the way the tobacco leaves 7 is brought in place into the channels 10. The prior art chain drive is substituted by the vibrating unit 2 that is lying above the channels 10. As mentioned, the tobacco leaves 7 are supplied the straightlayer 8 by means of the upper belt conveyor 1, which is transversally reciprocating above the straightlayer 8. The flow of tobacco leaves 7 that is supplied to the straightlayer 8 from above, is aimed at being as uniform as possible on the upper belt conveyor 1 so that the leaves 7 are evenly distributed over all the channels 10. The leaves 7 land partly directly into the channels 10 and partly on top of the bars 3. The width of the channels 10 is adapted to the width of the leaves 7 so that those leaves falling directly into the channels 10 are in large extent oriented and straightened out in the longitudinal direction thereof. It is to be noted that it is the orientation of the leaf stems in the longitudinal direction that is material, such that the stem in largest possible extent is transversally or crosswise cut. Those leaves 7 that remain lying on top of the bars 3 will be hanging down onto the tobacco leaves 7 that already are lying in the channels 10. Simultaneously are new leaves 7 continuously dropped from above and lay down onto the down hanging portions of the leaves 7. The friction between the leaves 7 causes that the down hanging leaves are braked in such extent that most of them gradually slide off the bars 3 and are straightened out when they are dragged with by the leaves 7 in the channels 10 in the output direction R at the same time as they are vibrated and shaked in the opposite direction. Some of the leaves 7 that remain lying on top of the bars 3 will also be pulled into the channels 10 by the leaves 7 that are dropped from above. The lower conveyor 6 brings the tobacco in the output direction R towards the press apparatus (not shown) which is located in the extension of the straightlayer 8. The press apparatus compresses the leaves broadwise into a compact string that passes on into a cutting machine (not shown). Due to the conveyor motion in the output direction R, the tobacco will lay down at a level in the channels 10 inclining downwards opposite of the output direction R. The partitions 5 and the bars 3 are thus correspondingly sloping or inclining so that the distance from the top of the layer of leaves 7 to the upper edge of the bars 3 is approximately equal in the entire longitudinal direction thereof. This is of significance in order that the dragging effect of the leaves is to be equal over the entire longitudinal extent of the straightlayer 8. The inclination of the bars 3 does also have significance for the speed that the leaves 7 on the bars 3 advance opposite of the output direction R during the vibrating action. A less share of the tobacco leaves 7 do not fall into place in the channels 10 before they reach the rear end of the straightlayer 8. These leaves are by means of a kick off means 11 thrown forwards again in the straightlayer 8 in the output direction R until they fall into place in the channels 10.

Claims: A straightlayer (8) for orientation of tobacco leaves (7) prior to a cutting operation, which straightlayer (8) comprises a lower belt conveyor (6) having an output direction (R), a number of, in respect of the belt conveyor (6), vertically projecting, channel forming partitions (5) that extend in the output direction (R) of the belt conveyor (6) and have some distance from the belt conveyor (6), and a feeding apparatus (1) that supplies from above tobacco leaves (7) down onto the straightlayer (8), characterised in that the straightlayer (8) comprises a vibrating unit (2) that is lying above the partitions (5) and that is able to shake down into the channels (10) those tobacco leaves (7) that lay down onto the vibrating unit (2) and orient the leaf stems in the longitudinal direction of the belt conveyor (6). A straightlayer according to claim 1, characterised in that the vibrating unit (2) comprises a frame (9) that supports a number of longitudinally extending bars (3), each bar (3) is lying above a respective partition (5). A straightlayer according to claim 1 or claim 2, characterised in that each bar (3) is formed of a U-formed sheet section that is lying with some clearance above its respective partition (5). A straightlayer according to any of the claims 1-3, characterised in that the upper edge of the partitions (5) and the bars (3) are sloping downwards in a direction opposite of the output direction (R). A straightlayer according to any of the claims 1-4, characterised in that the vibrating unit (2) comprises a motor drive that causes a tilting motion of the frame (9) and the bars (3). A straightlayer according to any of the claims 1-5, characterised in that the straightlayer includes a kick off means (11) located at that end of the straightlayer (8) which is opposite of the output end of the straightlayer (8). A method for straightlaying and orientation of tobacco leaves prior to a cutting operation, in which tobacco leaves are supplied from above and down onto a straightlayer according to any of the claims 1-6, characterised in that a vibrating unit shakes the leaves rearwards and downwards in opposite direction of the output direction, that leaves that do not drop directly into the channels are dragged in the output direction and down into the channels by leaves already present in the channels and by leaves falling from above, which causes pulling down of leaves from the bars and straightening and orientation of the leaf stem in the longitudinal direction thereof. A method according to claim 7, characterised in that leaves that do not fall into place in the channels are forwarded again by means of a kick off means.

Inventors: BERG MORTEN, BERG, MORTEN
Applicants: J L TIEDEMANNS TOBAKSFABRIK AS, J.L. TIEDEMANNS TOBAKSFABRIK AS
Application year: 2000
Main classification: A24B3
IPC codes: A24B3