GB2447704A

GB2447704A - Rod rotation device

Info

Publication number: GB2447704A
Application number: GB0705630A
Authority: GB
Inventors: Keith Jarman
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 2007-03-23
Filing date: 2007-03-23
Publication date: 2008-09-24
Also published as: GB0705630D0

Abstract

A rod rotation device 6 is disclosed. The rod is collected by a collection portion 26 of a sampling probe 2. The device has a receiving portion 10 having a vacuum port 22 at one end thereof for biasing a rod held therein. The receiving portion 10 is pneumatically rotatable through 90{ so that rods can be rotated from a horizontal orientation to a vertical orientation and vice versa. The device is suitable for use in handling and reorienting cigarettes or cigarette filters, especially for quality sampling. The vacuum biasing of the rod away from an aperture ensures that the receiving portion 10 is not jammed and prevented from rotating.

Description

1 2447704

ROD ROTATION DEVICE

This invention relates to the field of rod rotation devices, used during the manufacture and testing of rods such as cigarettes and cigarette filters.

Modern manufacturing techniques for cigarettes, cigarette filters, and other rod-shaped smoking articles can produce up to 20,000 rods per minute. These rods are generally transported away from manufacturing machinery in a mass flow, travelling in a direction perpendicular to the longitudinal axes of the rods. It is important that the manufactured rods meet an acceptable quality standard, and in order to test this, individual rods are often selected for testing from the mass flow.

Testing apparatus may be arranged to check the quality of many different aspects of the sampled rods; for example, the draw resistance, density, moisture content, weight, filter paper quality, and so on. The testing apparatus may even provide information on corrective actions, should a sample rod have characteristics outside of a tolerance band around a target specification. In advanced systems there may be an automated method of feedback should a fault be detected with a rod, or an undesired trend be detected in a sample of rods. These testing systems offer great advantages to cigarette and filter manufacturers as errors may be corrected at the point of manufacture rather than after later inspection; this provides a clear opportunity for cost savings and improved product quality.

Generally, a sampling probe is used to select a single rod from the mass flow for testing. Known sampling probes include those described in US 5,209,127 and EP 1,286,602. In EP 1,286,602, a system is described in which a rod drops out of the mass flow and into an elongate passage in a sampling probe. The probe comprises a shuttle for moving the collected rod axially along a passage in the probe. In this way, an individual rod may be selected and transported away from a mass flow for testing.

In practice test stations tend to be large and sophisticated pieces of apparatus that are positioned close to a cigarette manufactunng machine, and away from a sampling probe in a mass flow. Sampled cigarettes or filters can be extracted from the horizontal mass flow and then transported to a test station. In the case of filters this is usually along pneumatic piping, although this is used less commonly for cigarettes. Generally, any pneumatic piping leading away from a sampling probe needs to be in a vertical plane initially in order to avoid hazards that are associated with horizontal pipe work at factory floor level. The mass flow of rods is generally in the horizontal plane, and so a rod rotation device is necessary to rotate rods until their longitudinal axes are vertically oriented. An example of a known rod rotation device is described in US 4,363,235. In this document, rods are pushed horizontally into a diametral hole in a disc. The disc then rotates, with the rod inside, by 90 so that the rod's longitudinal axis becomes vertically oriented.

A problem in the prior art is that rod rotation devices are susceptible to jamming.

Cigarettes and cigarette filters are light and may easily bounce or become stuck when introduced to a rod rotation device. If rotation is attempted with improperly positioned rods then rod rotation devices may jam.

It is an object of the present invention to provide a rod rotation device with improved reliability.

According to an aspect of the present invention there is provided a rod rotation device for rotating a rod so that the orientation of its longitudinal axis is altered, the device comprising: an elongate receiving portion for a rod, the receiving portion having a longitudinal axis, and the receiving portion being rotatable about an axis that is not coincident with its longitudinal axis, and wherein the receiving portion comprises an aperture at one end thereof for receiving a rod, and biasing means arranged to bias the rod away from the aperture.

In this way, the biasing means may hold rods away from the aperture such that they are less likely to jam the device by protruding from the aperture during rotation of the receiving portion. Thus, the reliability of rod rotation devices may be improved.

Often rods may be delivered to the receiving portion, via the aperture, by a pneumatic line. Since the receiving portion is rotatable there may be a gap to allow relative rotation between the receiving portion and a pneumatic line. By biasing received rods away from this gap, rods may be less likely to jam the device.

The biasing means may be pneumatic, being operable with pressurised air. In particular the pneumatic biasing means may be vacuum biasing means such as a vacuum port, for example situated in an end wall of the receiving portion opposite the aperture. A suction force may be applied through the vacuum port for biasing rods towards the end wall of the receiving portion. In this way, rods may be held firmly in registration with the end wall of the receiving portion before any rotation of the receiving portion is attempted.

Preferably there is a filter for preventing blockage of the pneumatic biasing means. Thus, any loose materials may be filtered through a particle trap to avoid blockages in pneumatic piping. This may optimise the continuity of operation by reducing the amount of maintenance that is required. The filter may be most advantageously situated within the vacuum biasing means so as to filter out any material that is sucked in.

The rod rotation device may comprise a pneumatic controller for controlling a supply of pressurised air within the device. The controller may be implemented in software or hardware to control the pneumatic operations of various components within the device. For example the controller may control the supply of pressurised air to the pneumatic biasing means. Thus, the pneumatic biasing means may be switched on before a rod is present in the receiving portion, and may be switched off once a rod is securely positioned in the receiving portion.

In another example, where rods are delivered to the receiving portion by a first pneumatic line, the controller may also control the supply of pressurised air to the first pneumatic line. Pressurised air may be supplied before a rod arrives in the receiving means, but switched off when it is desired to rotate the receiving portion.

The controller may receive several inputs, and one may advantageously be from a sensor for measuring the position of a rod in the device. For example, sensor response may be indicative of when a rod has been successfully received by the receiving portion. A sensor located towards the end of the first pneumatic line or close to the aperture of the receiving portion may be able to indicate whether and when a rod has been received by the receiving portion. Once the rod has been successfully received by the receiving portion the receiving portion may be arranged to rotate; there may be a pre-determined delay before the rotation of the receiving portion begins, implemented in software or hardware.

There may be a plurality of sensors for tracking the passage of a rod through the device, and most preferably the, or each, sensor is an optical sensor.

The rod rotation device may comprise a rotation mechanism for rotating the receiving portion, and preferably the rotation mechanism is driven pneumatically.

Preferably the rotation mechanism is arranged to rotate the receiving portion about an axis that is substantially perpendicular to the longitudinal axis of the receiving portion. Also, by rotating the receiving portion through 900, a rod contained therein may be conveniently oriented for transportation, along its longitudinal axis, to testing equipment.

Due to space constraints on factory floors it may be advantageous to rotate a rod so that its longitudinal axis is aligned vertically. Thus, it is preferable for the receiving portion to be rotated so that the orientation of its longitudinal axis is changed from being substantially horizontal to being substantially vertical. This may enable vertical transportation of a rod to a test station. An advantage of the vertical transportation of rods is that pipe work is directed away from factory workers and machinery, making the apparatus less hazardous.

The rotation mechanism of the rod rotation device may be arranged for control by the pneumatic controller. The rod rotation device may comprise means for expelling a rod from the receiving portion. Preferably a rod is pneumatically expelled from the receiving portion once the receiving portion has rotated from a horizontal inclination to a vertical inclination; the precise control of this operation may be performed by the pneumatic controller. One option for expelling a rod would be to make use of the pneumatic biasing means at the end of the receiving portion. By reversing the direction of pressurised air through the pneumatic biasing means it may be possible to expel a rod out of the aperture in the receiving portion.

Preferably the receiving portion has a longer axial extent than a rod received therein. However, it would also be possible for the receiving portion to accommodate only a portion of a rod.

The rod rotation device may be most suitable for use with cigarette filters, other rod-shaped smoking articles and cigarettes. The rod rotation device is preferably used as part of a rod delivery system in a smoking article manufacture and testing line.

Thus, according to another aspect of the present invention there is provided a rod delivery system comprising: a rod rotation device as previously defined; and a first pneumatic line for delivering rods to the receiving portion.

A pneumatic line may be a convenient method for transporting individual rods to the rod rotation device, whereby the rods travel along the direction of their longitudinal axes. While a pneumatic line may provide an efficient delivery method it further enhances the likelihood of jamming, in the absence of the present invention. Rods that are delivered pneumatically and at high speed are more likely to bounce in the rod rotation device when they arrive; this may cause rods to be incorrectly positioned for rotation by the receiving portion. By biasing a rod away from the aperture of the receiving portion, the bouncing effect of the rod in the receiving portion may be reduced or eliminated.

Rods may be pushed towards the receiving portion by pressurised air in the first pneumatic line, and rods may also be sucked into the receiving portion by the pneumatic biasing means. This combined effect may allow a reduction in the air pressure applied to the first pneumatic line, allowing for finer control in rod transportation. In turn this may reduce the stresses experienced by a rod as it passes through the device which is advantageous as it helps to maintain rods in their original condition for testing.

An alternative to a pneumatic line may be a mechanical shunt for delivering a rod to the receiving portion along its longitudinal axis.

Rods may be pneumatically expellable from the receiving portion into a second pneumatic line. Expelled rods may be transported along the second pneumatic line to testing equipment, and the second pneumatic line may be arranged for control by the pneumatic controller.

For example, the receiving portion may be rotatable between first and second positions, and the first pneumatic line may be arranged for alignment with the receiving portion, when the receiving portion is in a first position, and the second pneumatic line may be arranged for alignment with the receiving portion in a second position. Preferably the receiving portion must rotate by 900 from the first position to the second position.

The rod delivery system may further comprise a sampling probe for receiving a rod from a mass flow of rods; the sampled rod may be delivered from the sampling probe to the receiving portion. Thus, the apparatus may be used to select individual rods from a mass flow and to deliver them for testing via the rotation device. The characteristics of a sampled rod may be indicative of the characteristics of all of the rods in the mass flow. Thus, if an error is detected in a sampled rod then this error may be corrected for all rods.

According to another aspect of the present invention there is provided a method of operating a rod rotation device, wherein a rod is rotated so that the orientation of its longitudinal axis is altered, the method comprising the steps of: receiving a rod in an elongate receiving portion via an aperture at an end of the receiving portion; rotating the receiving portion about an axis that is not coincident with its longitudinal axis; and biasing the rod received by the receiving portion away from the aperture in the receiving portion.

Any of the apparatus features may be combined with any of the method features and vice-versa.

Preferred features of the present invention will now be described, purely by way of example, with references to the accompanying drawings, in which: Figure 1 is a front view of a rod rotation device in an embodiment of the present invention with the external cover removed so that the internal components are visible; Figure 2 is a top view of the rod rotation device of Figure 1; Figure 3 is a left end view of the rod rotation device of Figure 1; and Figure 4 is a right end view of the rod rotation device of Figure 1.

Referring to Figures 1 -4, a sampling probe 2 is arranged to collect rods and feed them to a rod rotation device 6 via a pneumatic line 4. The sampling probe 2 has a collection portion 26 with semicircular cross section so that a rod in a mass flow may drop, under gravity, into the probe. The direction of the mass flow of rods is perpendicular to the longitudinal axis of the sampling probe 2; the direction is shown with an arrow 30 in Figure 2. The sampling probe 2 comprises an actuator 8 that controls the operation of a gate in the collection portion 26. Rods are transported along the pneumatic line 4 from the sampling probe 2 to the rod rotation device 6, and the supply of pressurised air to the pneumatic line 4 is via an air inlet point 5.

The rod rotation device 6 comprises a receiving portion 10 that is rotatable about an axis 12 between a first position and a second position. The receiving portion 10 has a longitudinal axis that is aligned with the longitudinal axis of the sampling probe 2 when the receiving portion 10 is in its first position. In its second position, the longitudinal axis of the receiving portion 10 is aligned with an expulsion port 14. In the first position the longitudinal axis of the receiving portion 10 is horizontal, and in the second position the longitudinal axis of the receiving portion is vertical. The receiving portion 10 is arranged to be driven from the first position towards the second position and vice-versa, by a pneumatic actuator of a rotation mechanism (not shown); air supply to the rotation mechanism is provided via an air inlet point 32.

The receiving portion 10 has an open end 11, adjacent the pneumatic line 4 when the receiving portion 10 is in its first position, and the receiving portion 10 has a closed end 13 that comprises a vacuum port 22. A vacuum is applied through the vacuum port 22 so that a rod received by the receiving portion 10 is biased towards the vacuum port 22 at the closed end 13 of the receiving portion 10.

Specifically, a rod is biased away from the pneumatic line 4 to ensure that the rod is entirely received by the receiving portion; thus the rod does not block the rotation of the receiving portion 10 from its first position to its second position. In the absence of the vacuum port 22, rods would enter the receiving portion 10 at high speed via the pneumatic line 4 and bounce within the receiving portion 10.

Rods could then come to rest so that they straddle the gap 24 between the receiving portion 10 and the pneumatic line 4. Rods positioned over this gap 24 would tend to block the rotation of the receiving portion 10 from the first position to the second position.

Many of the operations of the turning device 6 are pneumatic and these may be powered by a single supply of pressurised air to the rod rotation device 6, via an air inlet port 16. The air inlet port 16 feeds into a pneumatic manifold 18 which is used for the distribution of the air supply within the rod rotation device 6, and the external actuator 8. The pneumatic manifold 18 may be electronically controlled by software or hardware. Alternatively, or in addition, the pneumatic manifold 18 may be controlled by mechanical switches.

The vacuum port 22, together with the other pneumatic components of the turning device, is arranged for connection (not shown) with the pneumatic manifold 18.

In this way the strength of the vacuum applied through the vacuum port 22 can be controlled. The pneumatic manifold 18 is also arranged to switch the supply of pressurised air to the vacuum port 22 on or off, as required.

In order to prevent the piping between the vacuum port 22 and the pneumatic manifold 18 becoming blocked, a filter 30 is provided in connection with the vacuum port 22. The filter 30 is arranged to collect loose materials and to prevent such material from blocking pneumatic piping. The filter 30 may be removable for cleaning.

An optical sensor 31 is provided at the end of the pneumatic line 4 for tracking the position of rods in the apparatus. The optical sensor 31 is able to detect when a rod has passed by, and therefore when a rod has been captured by the receiving portion 10. The optical sensor 31 may be connected to control circuitry (not shown) and may be able to indicate when it is safe to rotate the receiving portion from the first position to the second position. Use of the vacuum port 22 ensures that rods do not bounce in the receiving portion 10 so that they are detected by optical sensors for a second time. This is advantageous because a second detection of the same rod could be misinterpreted as a first detection of a new rod being conveyed towards the receiving portion 10. Such misinterpretations could lead to the incorrect operation of the rod rotation device 6.

In operation, a rod from a mass flow of rods is received by the collection portion 26 of the sampling probe 2. The rod is then pneumatically transferred through the pneumatic line 4 to the turning device 6 by the pneumatic actuator 8. The rod is received in the receiving portion 10 and is held in place, at the closed end 13, by pneumatic forces acting through the vacuum port 22. Signals from optical sensors in the turning device 6 may be used as indicators that a rod is being held correctly in the receiving portion 10.

Once a rod is correctly held by the receiving portion 10, control logic is arranged to shut off the pressunsed air supply to the pneumatic line 4 and the vacuum port 22, via the pneumatic manifold 18. The control logic also turns on a pressurised air supply to the mechanism (not shown) for rotating the receiving portion 10 from its first position to its second position, about the pivot axis 12. Thus, the receiving portion 10 is turned through 900, by pneumatic actuation, so that its main axis becomes oriented vertically. A switch 20 is provided on the receiving portion 10, and the switch 20 is arranged to be engaged by a vertical protrusion 28 inside the rod rotation device 6 when the receiving portion 10 arrives in its second position. The mechanical depression of the switch 20 is an indication that the receiving portion 10 has arrived at its second position. The depression of the switch 20 is used by control logic to switch off the pressurised air supply to the rotation mechanism and to switch on a pressurised air supply for expelling the rod through the expulsion port 14. Of course, it would be possible to reverse the direction of pressurised air through the vacuum port 22, and to use this for expelling a rod out of the receiving portion 10.

The expulsion port 14 is arranged for connection with another pneumatic line (not shown) which leads to testing equipment.

Claims

Claims I. A rod rotation device for rotating a rod so that the

orientation of its longitudinal axis is altered, the device comprising: an elongate receiving portion for a rod, the receiving portion having a longitudinal axis, and the receiving portion being rotatable about an axis that is not coincident with its longitudinal axis, and wherein the receiving portion comprises an aperture at one end thereof for receiving a rod, and biasing means arranged to bias the rod away from the aperture.
2. A rod rotation device according to claim 1 wherein the biasing means are pneumatic biasing means.
3. A rod rotation device according to claim 2 further comprising a filter for preventing blockage of the pneumatic biasing means.
4. A rod rotation device according to claim 2 or claim 3 wherein the pneumatic biasing means are vacuum biasing means.
5. A rod rotation device according to any of the preceding claims further comprising a pneumatic controller for controlling a supply of pressurised air in the device.
6. A rod rotation device according to any of the preceding claims further comprising a sensor for measuring the position of a rod in the device.
7. A rod rotation device according to any of the preceding claims further comprising a rotation mechanism for rotating the receiving portion.
8. A rod rotation device according to any of the preceding claims further comprising means for expelling a rod from the receiving portion.
9. A rod delivery system comprising: a rod rotation device according to any of the preceding claims; and a first pneumatic line for delivering rods to the receiving portion.
10. A rod delivery system according to claim 9 wherein the biasing means in the rod rotation device are arranged to bias a rod away from the first pneumatic line.
11. A rod delivery system according to claim 9 or claim 10 further comprising a second pneumatic line for receiving rods from the receiving portion.
12. A rod delivery system according to any of claims 9 to 11 further comprising a sampling probe for receiving a rod, and wherein the sampled rod is delivered from the sampling probe to the receiving portion.
13. A method of operating a rod rotation device, wherein a rod is rotated so that the orientation of its longitudinal axis is altered, the method comprising the steps of: receiving a rod in an elongate receiving portion via an aperture at an end of the receiving portion; rotating the receiving portion about an axis that is not coincident with its longitudinal axis; and biasing the rod received by the receiving portion away from the aperture in the receiving portion.
14. A rod rotation device substantially as described herein with reference to and/or as illustrated in the accompanying drawings.
15. A method substantially as described herein with reference to and as illustrated in the accompanying drawings.