Article Handling Apparatus

Abstract

This invention is mainly concerned with a sensor for controlling one of two conveyors extending horizontally in opposite directions from a junction which may, for example, be a T junction into which cigarettes are delivered in an upward stream. The sensor consists of two sensor members which rest on the cigarettes at the junction and which both control a single speed-regulating mechanism controlling the speed of one of the conveyors. Each sensor member is particularly sensitive to a drop in the level of the cigarettes above the end of one of the conveyors, and the arrangement is preferably such that the position of the speed-regulating mechanism is determined by whichever sensor member is lower.

Description

This invention is concerned with conveyor systems, for conveying rodlike articles, particularly cigarettes and other similarly light articles (including for example cigarette filter rods), in stack formation on conveyors in relation to which the articles lie transversely. In particular this invention is concerned with a sensor for controlling the stack flow at a junction of two or more stacks to or from which the articles are carries by separate conveyors, though a sensor according to this invention may be used in other circumstances in which a signal is required in relation to the height of the stack of articles beneath the sensor, for example while loading cigarettes into a tray.

A conveyor system according to this invention includes two substantially horizontal conveyors extending in opposite directions from a junction zone above which is arranged a sensor mechanism comprising two sensor members which are arranged to rest on the articles in positions lying respectively approximately above the ends of the two conveyors, and including a conveyor speed-regulating mechanism which controls the speed of one of the conveyors and is coupled to each sensor member by a lost-motion device so that the speed-regulating mechanism can be moved in one predetermined direction as a result of movement of either one of the sensor members while the other sensor member remains stationary.

In a preferred arrangement the predetermined direction in which either sensor member can move the speed-regulating mechanism corresponds to downward movement of either of the sensor members. In other words, the speed-regulating mechanism always takes up a position determined by whichever sensor member is in a lower position. The converse is however in principle possible.

Furthermore, a preferred arrangement is one in which the two sensor members are pivoted about spaced axes parallel to the articles, and in which the sensor members extend towards one another and cross one another as viewed in a direction parallel to the articles.

The parts of the plates resting on the articles are preferably shaped so as to have a convex underneath surface as viewed in the direction of the articles.

Examples of arrangements according to this invention are shown in the accompanying drawings. In these drawings:

FIG. 1 is a side view of one arrangement;

FIG. 2 is a plan view; and

FIG. 3 is a side view of a different arrangement.

The sensor shown in the accompanying drawings consists of two sensor plates 10 and 11 which have downwardly convex portions 12 and 13 resting on a horizontal stack of cigarettes carried by two band conveyors 14 and 15. The "Junction Zone" lies below the plates 10 and 11. A single row of cigarettes is fed upwards into the junction zone by two bands 17 and 18 which return over small idler pulleys 19 and 20. The conveyors 14 and 15 pass round further pulleys 21 and 22, and the horizontal surface on which the complete horizontal stack rests is completed by two small bridge pieces 23 and 24.

It will be seen that the convex parts 12 and 12 of the plates 10 and 11 lie on opposite sides of a vertical plane passing through the single row of cigarettes 16, this plane being the vertical centerline of the T junction. Moreover, the plates 10 and 11 and the conveyors 14 and 15 form a symmetrical arrangement so that the function of the conveyors 14 and 15 can be interchanged.

The plates 10 and 11 are secured respectively to spindles 25 and 26 by which they are pivotably mounted. As shown in FIG. 2, the two plates are slightly staggered laterally and each has two slots leaving three legs 27, the arrangement being such that the legs of each plate can pass through the slots in the other plate. In other words, the plates intermesh with one another.

Outside the cigarette flow channel, the spindles 25 and 26 carry respectively two arms 28 and 29 which are connected by links 30 and 31 to the arms 32 and 33 of a bellcrank secured to a spindle 34 of a rotary speed-regulating mechanism 35 which controls the direction of rotation and the speed of a motor driving the conveyor 15. Each link 30 or 31 passes through a hole in the cooperating arm 32 or 33 and has end nuts so that it can transmit a pull from the arm 28 or 29 to the arm 32 or 33, as the case may be, but not a push. In other words, there is a lost-motion connection between each arm 28 or 29 and the arm 32 or 33 of the bellcrank. As a result of this lost-motion connection, the bellcrank position is determined by whichever of the plates 12 or 13 is the lower position. The bellcrank is biased in an anticlockwise direction, for example by the weight of the arm 32.

FIG. 1 shows the plates 12 and 13 in their lowest positions, while the highest possible positions are shown in chain dotted lines, the limit of upward movement being determined by stops 36 and 37. It is important to note that the volume (in terms of the number of cigarettes) lying between the uppermost and lowermost positions of the sensor plates is substantial, i.e. the same order as the average volume of the junction zone. This is significant as it means that the sensor also serves as a useful reservoir to allow for short term variations in the rates of feed to and from the junction zone.

Plates 38 and 39 cooperate with the ends of the pivoted plates 12 and 13 to prevent the escape of cigarettes, and are appropriately slotted to intermesh with the sensor plates. As shown in FIG. 1, the plate 38 at its lower end 38A extends horizontally for a short distance so as to serve as a top wall confining the upper surface of the stack of cigarettes for a short distance from the junction. The plate 39, on the other hand, merely curves upwards slightly to a point close to a band 50 which serves as a top wall confining the upper surface of the stack in the other direction from the junction.

In one possible example, the conveyor band 14 continuously carries to the left a stack of cigarettes delivered by the bands 17 and 18, while the conveyor 15 serves as part of a reservoir which receives cigarettes (i.e. with the conveyor 15 moving to the right) when the upward supply of cigarettes 16 exceeds the rate of withdrawal of cigarettes by the conveyor 14; on the other hand, when the rate of withdrawal of cigarettes by the conveyor 14 exceeds the rate of supply to the junction by the bands 17 and 18, the conveyor 15 moves to the left so as to deliver cigarettes from the reservoir. Further details of this arrangement are described in British Pat. application Nos. 54034/68 and 4195/69. The sensor in this case may control the speed and direction of movement of the conveyor 15, while another sensor (which may be similar to the sensor shown in the drawings) may control the speed of the conveyor 14; for example, the far end of the conveyor 14 which is not shown may be at a further junction with an upward deliver similar to that shown in FIG. 1.

An important advantage of a double plate sensor according to this invention is that each plate can be made particularly sensitive to a drop in the level of cigarettes caused by an excessive delivery away from the junction by a conveyor beneath it or nearer to it. Considering for example a mode of operation in which, for the moment, the conveyor 15 is stationary while the conveyor 14 is rotating at a speed which exactly carries away the amount of cigarettes fed upwards by the bands 17 and 18; if then the speed of the conveyor 14 where to increase slightly, or if the rate of upward delivery of cigarettes by the bands 17 and 18 were suddenly to decrease according to our observation this change would be most quickly manifested by a drop in the level of cigarettes at the end of the conveyor 14, that is to say adjacent to the stationary bridge piece 23 as a result a hollow would form in the upper surface of the stack of cigarettes, and the convex part 12 of the pivoted plate 11 is so shaped (as nearly as possible) that it will sink snugly into the hollow, thus rotating the spindle 34 of the speed-regulating mechanism 35 in a clockwise direction which causes the conveyor 15 to start moving to the left at a speed such as to meet the deficiency in the cigarette supply to the conveyor 14. If the double plate sensor were replaced by a single central sensor (i.e. lying directly above the bands 17 and 18), the response would be slower as the level of cigarettes would take longer to fall away beneath such a centrally positioned sensor (and in a very extreme case might even fail to drop at all); in other words, the arrangement shown in the present application has a greater sensitivity.

In a different situation the conveyors 14 and 15 may, for example, both be moving away from the junction, and if then the rate of upward feed by the bands 17 and 18 were suddenly to decrease or stop (for example as a result of the cigarette-making machine stopping) there would be an immediate tendency for two hollows to appear in the upper surface of the stack above the ends of the conveyors 14 and 15 (i.e. beneath the convex parts 12 and 13 of the pivoted plates), so that both pivoted plates would drop and accordingly reduce the speed of the conveyor 15 or stop the conveyor 15 or even, in an extreme case, reverse the movement of the conveyor 15, the extreme case being where the supply of cigarettes 16 ceases so that the reservoir conveyor 15 must deliver the necessary cigarettes to the conveyor 14. In such a case, if the conveyor 15 was initially moving at a greater speed than the conveyor 14 then the level of cigarettes would tend to fall away more rapidly beneath the convex part 13 of the plate 10, so that the presence of a sensor plate immediately above the end of the conveyor 15 would in this case again give a greater sensitivity than would be possible with a single centrally positioned sensor.

The mechanism 35 in the example shown is a proprietary motor speed-regulating mechanism which preferably provides for stepless speed control. It and the spindles 25 and 26 and the stops 36 and 37 are mounted on a sidewall 51, as shown particularly in FIG. 2.

In the example shown in FIG. 3 of the drawings there are two horizontally extending endless band input conveyors 101 and 102, each of which supports a moving stack of cigarettes. The return run of the upper band 101 is prevented from interfering with the top of the stack of cigarettes moving in the opposite direction on the lower band 102 by means of a guard plate 103. The bands 101 and 102 are carried at their downstream ends on rollers 104 and 105 respectively. The cigarettes are delivered from the apparatus in two separate streams on output conveyors 106 and 107, a guard plate 108 being provided to protect the return run of the conveyor 106 from interfering with the cigarettes moving out on the conveyor 107. The upstreams ends of conveyors 106 and 107 are carried on rollers 109 and 110 respectively.

Between the input conveyor 102 and the output conveyor 107, and above a junction zone 131 there is disposed a flow-breaking device comprising an endless band 111 carried on a small idler roller 112 and a larger drive roller 113. The band 111 is provided with some slack so that it can move along a curved path between the rollers 112 and 113, and a pressure roller 114 is provided to press it against the roller 113. A curved guide plate could be provided to support the upper curved run of the band 111 as it moves from the idler roller 112 to the drive roller 113. The roller 113 is driven by a chain 115 extending around a gear carried on its shaft and extending also around gears carried on the shafts of drive rollers 104 and 105 for the conveyors 101 and 102. Each of the connections between the chain 115 and the rollers 104 and 105 is through a one-way sprag clutch (not shown) so that the roller 113 is driven by the faster one of the rollers 104 or 105. The speed ratios are chosen so that the band 111 travels at a speed such as to provide the best flow of cigarettes through the apparatus, and this speed may in fact be somewhat greater than the faster of the conveyors 101 or 102. The gaps between the flow-breading band 111 and the input conveyor 102 and between the output conveyor 107 are closed by bridges 116 and 117 respectively.

The upper part of the apparatus is closed off by a top wall member 118 which extends above the upper conveyors 101 and 106 and is formed with an aperture 119 between the conveyors to accommodate a sensor mechanism. This sensor mechanism comprises two sensor plates 102 and 121 pivoted at 122 and 123 respectively and having convex parts 120A and 121A which extend through the aperture 119 and rest on the cigarettes in the junction zone. At their extremities remote from the pivots 122 and 123, the plates 120, 121 are formed with upward extensions 124, 125 which are hooked so as to be able to engage the upper surface of a feeler arm 126 which is carried on a disc 127 for pivotal movement about a center 128, and which is urged upwards by a spring 129, downward movement of the feeler arm being limited by a stop 130. The mechanism is arranged so that the feeler arm 126 moves upwards under the influence of the spring 129 when the cigarette flow raises both of the plates 122 and 123, but it does not move if only one of the plates is raised.

Each of the conveyors 101 and 102 delivers cigarettes from a separate reservoir (not shown) which is supplied by one or more cigarette-making machines. These reservoirs may each be basically as described in British Pat. No. 995,663.

Each of the output conveyors 106 and 107 carries a continuously moving stack of cigarettes to a packing machine or to a number of packing machines. The speed of each conveyor is adjusted according to the demands of the packing machines so as to keep the channels through which the cigarettes are conveyed filled with cigarettes, thereby helping to maintain an orderly flow.

The movement of the feeler arm 126 is used to control the speeds of the conveyors 101 and 102 to reduce the feed when there is a buildup of cigarettes. Thus, as long as the plates 120 and 121 hold the arm 126 in its horizontal position, the level of cigarettes in the apparatus is either normal or a little below normal. In either event the supply of cigarettes requires to be maintained and the control signal is therefore continued until an excess buildup of cigarettes occurs; the excess buildup causes both the plates 120, 121 to be raised, releasing the feed arm 126 to move upwards under the action of spring 129 and causing a control signal for the conveyors 101 and 102 to reduce the feed rate until the excess accumulation has been eliminated and the normal level has been restored, whereupon feeler arm 126 returns to its horizontal position and the supply feed continues. If required, the sensor and the control means for the conveyors 101 and 102 can be arranged so that the feed rate of conveyors 101 and 102 is increased as the feeler arm 126 drops below the normal position.

The control means for the conveyors 101 and 102 is arranged so that, at any given instant, their speeds are in a fixed ratio to one another. This ratio is adjusted, however, so as to balance the feed of the cigarettes from their associated reservoirs to ensure as far as possible that during normal running each reservoir contains approximately the same number of cigarettes. This can be done by arranging for the speed of each band to be proportional to the volume of cigarettes contained in the associated reservoir from which it is taking cigarettes. A convenient way of doing this is by means of a control device which measures the reservoir length. Such a device might be a drum arranged to take in and pay out a wire or line extending between a fixed and a movable part of the reservoir, the speed ratios of the conveyors 101 and 102 being controlled according to the displacement of the drum, possibly by direct gearing.

Cigarettes travel along the pairs of conveyors 101, 102 and 105, 106 in closely packed stacks in each of which the cigarettes are arranged in parallel alignment end to end across the conveyors and with no movement relative to one another in the stack. However in order that there can be exchange of cigarettes between the flows, it is desirable to "fluidise" the flows between the input and output conveyors. This is done by means of the band 111 which accelerates the cigarettes coming in on the conveyor band 102 and causes them to start rolling relative to one another, the effect of which is to cause the stack to roll this batch of the stack and to cause the flow of cigarettes to be fluidized over a considerable area which corresponds very roughly with the shaded area. The band 111 also imparts an upward component of movement to the cigarettes to enable them, if required, to move from the lower input conveyor 102 to the upper output conveyor 106.

In this way the apparatus enables the proportion of cigarettes flowing on the conveyors 106 and 107 to be varied independently of the proportions of cigarettes being fed in on the conveyors 101 and 102. The apparatus also increases the flexibility of the system of machinery which comprises the packing machine 103 supplied from the conveyors 106 and 107, the reservoirs feeding the conveyors 101 and 102, and the cigarette-making machines feeding the reservoirs. Thus if for example the cigarette-making machine or machines supplying the upper conveyor 101 were out of action for a prolonged period of time such that the store of cigarettes in the associated reservoir becomes excessively depleted, then the supply of cigarettes to the packing machine along the conveyor 106 could be made up from the cigarettes from the input conveyor 102. Otherwise prolonged failure of the cigarette-making machine supplying the conveyor 101 would eventually bring to a standstill the operation of the packing machine supplied by the conveyor 106. In this way the two cigarette reservoirs are effectively combined and can be considered as one reservoir of double the capacity of the individual reservoirs.

Claims

I claim:

1. A conveyor system for conveying cigarettes and other rodlike articles in stack formation in relation to which the articles lie transversely, including two substantially horizontal conveyors extending in opposite directions from a junction zone above which is arranged a sensor mechanism comprising two sensor members which are arranged to rest on the articles in positions lying respectively approximately above the ends of the two conveyors, and including a conveyor speed-regulating mechanism which controls the speed of one of the conveyors and is coupled to each sensor member by a lost-motion device so that the speed-regulating mechanism can be moved in one predetermined direction as a result of movement of either one of the sensor members while the other sensor member remains stationary.

2. A conveyor system according to claim 1 in which the predetermined direction in which either sensor member can move the speed-regulating mechanism corresponds to downward movement of either of the sensor members.

3. A conveyor system according to claim 1 in which the two conveyors and the two sensor members form a substantially symmetrical arrangement about a vertical plane passing through the center of the junction zone.

4. A conveyor system according to claim 1 in which the two sensor members are pivoted about spaced axes parallel to the articles, and in which the sensor members extend towards one another and cross one another as viewed in a direction parallel to the articles.

5. A conveyor system according to claim 4 in which the sensor members are slotted and intermesh with one another.

6. A conveyor system according to claim 5 in which the ends of the sensor members remote from the pivots also intermesh with stationary members to prevent any articles from escaping.

7. A conveyor system according to claim in which the parts of the sensor members which bear on the articles in the junction zone are convex, as viewed in the direction of the articles.

8. A conveyor system according to claim 2, in which the speed-regulating mechanism has a rotary movement, and in which the lost-motion devices connecting the sensor members to the speed-regulating mechanism consist of lever means connected to the speed-regulating mechanism and pulling means connected respectively to the two sensor members, each pulling means being arranged to transmit only a pulling force to the lever means of the speed-regulating mechanism, and not a push force.

9. A sensor mechanism comprising two pivoted sensor members, substantially in accordance with claim 4.