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Title:
APPARATUS AND METHOD FOR MONITORING THE LINEAR SPEED OF A CONVEYOR
Document Type and Number:
WIPO Patent Application WO/2018/054660
Kind Code:
A1
Abstract:
Embodiments of the present invention provide an apparatus and method for monitoring a conveyor moving manufactured objects. The apparatus includes a rotatably mounted first gear and a second gear and an endless flexible power transfer means having a plurality of outwardly extending elements for engaging with a conveyor. The flexible power transfer means is arranged around the first and second gears to, in use, be at least partly in parallel linear arrangement to the conveyor. In use, the outwardly extending elements transmit a linear speed of the conveyor to at least one of the first gear and the second gear, and a sensor means is provided for measuring a rotational speed of the one or both of the first gear and the second gear.

Inventors:
PALMER CRAIG (GB)
Application Number:
PCT/EP2017/071805
Publication Date:
March 29, 2018
Filing Date:
August 30, 2017
Export Citation:
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Assignee:
JAGUAR LAND ROVER LTD (GB)
International Classes:
B65G43/00; B65G23/14; G01P3/00
Foreign References:
FR2709830A11995-03-17
US4407162A1983-10-04
US4440023A1984-04-03
US5563392A1996-10-08
Attorney, Agent or Firm:
BHIMANI, Alan (GB)
Download PDF:
Claims:
CLAIMS

1 . An apparatus for monitoring a conveyor moving manufactured objects, the apparatus comprising:

a support member having a first axle and a first gear rotatably mounted on the first axle, a second axle and a second gear rotatably mounted on the second axle, an endless flexible power transfer means arranged around the first and second gears to be at least partly in parallel linear arrangement to the conveyor, the power transfer means supporting a plurality of outwardly extending elements thereon, for engaging with a conveyor to, in use, transmit a linear speed of the conveyor to the first gear and second gear via one or more of the plurality of outwardly extending elements engaged with the conveyor; and

a sensor means for determining a rotational speed of one or both of the first gear and the second gear and outputting a signal indicative thereof.

2. An apparatus according to claim 1 , wherein a control means is arranged to receive the signal from the sensor means for monitoring a speed of the one or both of the first gear and the second gear. 3. An apparatus according to claim 2, wherein the control means is configured to determine whether the determined rotational speed of the one of the first gear and the second gear is outside one or more acceptable limits and is configured to control the conveyor when the measured rotational speed of the one of first gear and the second gear is determined to be outside the one or more acceptable limits.

4. The apparatus of claim 3, wherein the one or more acceptable limits comprise one or both of an upper limit and a lower limit.

5. The apparatus of any preceding claim, wherein the endless flexible power transfer means is a chain.

6. An apparatus according to any preceding claim, comprising a gearbox between the one of the first gear and the second gear and a rotational shaft of the sensor means. 7. An apparatus according to any preceding claim, wherein the gearbox has a gear ratio of between 10:1 and 2:1 . An apparatus according to any preceding claim, wherein the gearbox has a gear ratio of 6:1 .

An apparatus according to any preceding claim, wherein each outwardly extending elements comprises a roller for, in use, contacting the conveyor.

The apparatus according to claim 9, wherein the roller is arranged at an outer end of each outwardly extending element.

An apparatus according to any preceding claim, wherein one or both of the first gear and the second gear is a toothed gear.

An apparatus according to claim 1 1 when dependent on claim 5, wherein the chain is formed of links configured to cooperate with teeth of the one or both of the first gear and the second gear.

An apparatus according to any preceding claim, wherein the sensor means is an optical or an electronic speed sensor.

An apparatus according to claim 6 or any claim dependent thereon, comprising an encoder wheel arranged to rotate with the rotational shaft of the sensor means, wherein the sensor means is arranged to determine rotation of the encoder wheel.

An apparatus according to any preceding claim, comprising a bracket for fixing the support member relative to the conveyor such that the one or more of the plurality of outwardly extending elements is engageable with the conveyer.

An apparatus according to claim 15, wherein the bracket is provided with a plurality of connectors for adjustably locating the support member relative to the conveyor.

An apparatus according to any preceding claim, further provided with tensioning means for tensioning the power transfer means.

An apparatus according to claim 17, wherein the tensioning means is a spring loaded tension wheel, arranged to exert an outward biasing force on the power transfer means between the first and second gears.

A method of monitoring a conveyor moving manufactured objects, comprising: engaging one or more elements of a plurality of outwardly extending elements supported by an endless flexible power transfer means with a conveyor, wherein the power transfer means is arranged around a first gear rotatably mounted on a first axle and a second gear rotatably mounted on a second axle to be at least partly in parallel linear arrangement to the conveyor, and wherein the power transfer means is arranged such that linear movement of the conveyor causes rotational movement of one or both of the first gear and the second gear;

determining a rotational speed of one or both of the first gear and the second gear; and

outputting a signal indicative of the rotational speed.

The method of claim 19, wherein the engaging one or more elements of the plurality of outwardly extending elements comprises engaging a roller supported by each of the one or more elements with the conveyor.

The method of claim 19 or 20, comprising determining whether the rotational speed of the one or both of the first gear and the second gear is outside of one or more acceptable limits.

The method of claim 21 , wherein the one or more acceptable limits comprise one or both of an upper limit and a lower limit.

The method of claim 21 or 22, comprising causing the conveyor to stop in dependence on the rotational speed being outside of the one or more acceptable limits.

A conveyor driven to cause articles engaged with the conveyor to progress along the conveyor comprising:

one or more monitoring apparatus according to any of claims 1 or 5 to 18 arranged in relation to the conveyor; and

a control means, configured to receive the signal indicative of the rotational speed of the one or both of the first gear and the second gear from the sensor means, and to monitor the rotational speed of the one or both of the first gear and the second gear.

25. A conveyor according to claim 24, wherein the control means is configured to determine whether the rotational speed of the one or both of the first gear and the second gear is outside one or more acceptable limits. 26. The conveyor of claim 25, wherein the one or more acceptable limits comprise one or both of an upper limit and a lower limit.

27. A conveyor according to claim 25 or 26, wherein the control means is configured to control the conveyor if the rotational speed of the one or both of the first gear and the second gear is determined to fall outside of the one of more acceptable limits.

28. A conveyor according to any one of claims 24 to 27, wherein the conveyer is formed from a conveyor chain. 29. A conveyor according to any of claims 24 to 28, wherein two, three, four or five monitoring apparatus according to any of claims 1 to 18 are arranged in a spaced apart manner, distributed around the conveyor.

30. The conveyor of any of claims 24 to 28 comprising a plurality of monitoring apparatus arranged at intervals along the conveyor.

Description:
APPARATUS AND METHOD FOR MONITORING THE LINEAR SPEED OF A CONVEYOR

TECHNICAL FIELD

The present disclosure relates to an apparatus and method for monitoring a conveyor and particularly, but not exclusively, for monitoring a localised linear speed of a conveyor of a production line. Aspects of the invention relate to an apparatus, to a method, and to a conveyor.

BACKGROUND

Conveyors provide means for streamlining and improving production of manufactured objects in a production line. Conveyors can improve productivity by increasing the speed of certain processes and improving efficiency of the production process in many industries. Often, conveyors are endless and monitoring the conveyor is important for personnel safety. Safety monitoring of conveyors in particular in a production line is often only performed for the purpose of protecting the conveyor or production line itself i.e. for preventing damage to parts of the conveyor or production line.

It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide an apparatus, a conveyor, and a method of monitoring a conveyor as claimed in the appended claims. According to an aspect of the invention, there is provided an apparatus for monitoring a conveyor, comprising a rotatably mounted first gear, and a plurality of outwardly extending elements for engaging with the conveyor to, in use, transmit a linear speed of the conveyor to the first gear, and a sensor means for measuring a rotational speed of the first gear. The conveyor may, in use, move manufactured objects. The manufactured objects may be suspended from the conveyor. The manufactured objects may be spaced at periodic intervals along the conveyor.

A benefit of the apparatus is that changes in the linear speed of the conveyor can be sensed more quickly compared with monitoring changes in the linear speed of the conveyor by monitoring a drive gear of the conveyor. The apparatus may be used to detect localized reduction in the speed of the conveyor, for example, if the conveyor becomes slack or loses tension. Furthermore, the apparatus can be used to sense changes in the linear speed of the conveyor at one or more specific locations along the conveyor.

According to a further aspect of the invention, there is provided an apparatus for monitoring a conveyor, comprising a support member having a first axle and a first gear rotatably mounted on the first axle, a second axle and a second gear rotatably mounted on the second axle, endless flexible power transfer means arranged around the first and second gears, the power transfer means supporting a plurality of outwardly extending elements thereon, for engaging with a conveyor to, in use, transmit a linear speed of the conveyor to the first gear and second gear via one or more of the plurality of outwardly extending elements engaged with the conveyor; and a sensor means for determining a rotational speed of one or both of the first gear and the second gear and outputting a signal indicative thereof. According to a further aspect of the invention, there is provided an apparatus for monitoring a conveyor which, in use, moves manufactured objects, the apparatus, comprising a support member having a first axle and a first gear rotatably mounted on the first axle, a second axle and a second gear rotatably mounted on the second axle, endless flexible power transfer means arranged around the first and second gears to be at least partly in parallel linear arrangement to the conveyor, the power transfer means supporting a plurality of outwardly extending elements thereon, for engaging with a conveyor to, in use, transmit a linear speed of the conveyor to the first gear and second gear via one or more of the plurality of outwardly extending elements engaged with the conveyor; and a sensor means for determining a rotational speed of one or both of the first gear and the second gear and outputting a signal indicative thereof. Advantageously linear movement of the conveyor causes corresponding linear movement of the part of the flexible power transfer means. The linear movement of the part of the flexible power transfer means causes rotation movement of one or both of the first gear and the second gear which is monitored by the sensor means. The manufactured objects may be suspended from the conveyor. The manufactured objects may be spaced at periodic intervals along the conveyor. The manufactured objects may be suspended from the conveyor by being supported in carrier mechanism suspended upon the conveyor. Advantageously, in use, when the carrier moves manufactured objects, a force exerted by the manufactured objects on the conveyor may prevent non-linear arrangement of the conveyor. Thus monitoring linear movement of the conveyor is beneficial.

In one example, a sensor means is a sensing device. A benefit of the apparatus is that it can identify changes to the linear speed of a conveyor.

Optionally, a control means is arranged to receive the signal from the sensor means for monitoring a speed of the one or both of the first gear and the second gear. A control means may be a controller.

A benefit of providing a control means is that it can be used to output a signal to the conveyor to control a drive speed of the conveyor.

Optionally, the controller is configured to determine whether the determined rotational speed of the one of the first gear and the second gear falls is outside one or more acceptable limits and is configured to control the conveyor when the measured rotational speed of the one of first gear and the second gear is determined to be outside one or more acceptable limits. The controller may be configured to determine if the measured rotational speed first gear and/or the second gear is above an upper limit. The controller may be configured to determine if the measured rotational speed first gear and/or the second gear is below a lower limit. A benefit of providing a set of one of more acceptable limits is that the controller can determine whether the conveyor is operating normally and safely, and provide early detection of any problems with the conveyor.

Optionally, the outwardly extending elements are further provided with at least one roller. The roller may be arranged at a tip or outer end of the element. The roller provides improved engagement with the conveyor. In particular, the element may be directed to an aperture within the conveyor, such as in a link of conveyor chain.

The outwardly extending elements may be outwardly extending elongate elements. The outwardly extending elements may be outwardly extending arms. Advantageously the outwardly extending elements being elongate elements or arms allows interaction with a conveyor spaced a distance apart from the apparatus.

Optionally, a gear box is provided between the one of the first gear and the second gear and a rotational shaft of the sensing means.

Optionally, the gear box has a gear ratio of between 1 :10 and 1 :2. Optionally, the gear box has a gear ratio of 1 :6.

The endless flexible power transfer means may be a chain. Advantageously the chain is resilient to wear.

One or both of the first gear and the second gear is a toothed gear. The chain may be formed of links configured to cooperate with teeth of the one or both of the first gear and the second gear. Advantageously the chain securely engages with the teeth.

Optionally, the apparatus is further provided with a tensioning element for tensioning the chain. The tensioning element may be a spring loaded tension wheel, arranged to exert an outward biasing force on the chain between the first and second gears. The linear movement of the part of the flexible power transfer means may also cause the rotation of the spring loaded tension wheel.

Optionally, the tensioning element for the power transfer means may be mounted to the conveyor monitoring apparatus between but independently of the position of the first gear and second gear of the flexible power transfer means. The tensioning element may move relative to the position of the first gear and the second gear, and independently therefrom, to exert an outwardly biasing force on the chain between the first and second gears.

Optionally, the sensor means is an optical or an electronic speed sensor. The sensor means may be a sensing device.

Optionally, a bracket for fixing the support member relative to the conveyor such that the one or more of the plurality of outwardly extending elements is engageable with the conveyer. The bracket is be provided with a plurality of connectors for adjustably locating the support member relative to the conveyor.

The bracket provides a means for locating the monitoring apparatus on or close to the conveyor so that one or more of the plurality of outwardly extending elements is located sufficiently close to the conveyor so that they engage with the conveyor. According to a further aspect of the invention, there is provided a method of monitoring a conveyor, comprising: engaging one or more elements of a plurality of outwardly extending elements, supported by an endless flexible power transfer means with a conveyor, wherein the power transfer means is arranged around a first gear rotatably mounted on the first axle, and a second axle and a second gear, rotatably mounted on a first axle, and a second gear rotatably mounted on a second axle, the and wherein the power transfer means is, such that linear movement of the conveyor causes rotational movement of one or both of the first gear and the second gear determining a rotational speed of one or both of the first gear and the second gear; and

outputting a signal indicative of the rotation speed.

According to a still further aspect of the invention, there is provided a method of monitoring a conveyor moving manufactured objects, comprising engaging one or more elements of a plurality of outwardly extending elements supported by an endless flexible power transfer means with a conveyor, wherein the power transfer means is arranged around a first gear rotatably mounted on a first axle and a second gear rotatably mounted on a second axle to be at least partly in parallel linear arrangement to the conveyor, and wherein the power transfer means is arranged such that linear movement of the conveyor causes rotational movement of one or both of the first gear and the second gear, determining a rotational speed of one or both of the first gear and the second gear, and outputting a signal indicative of the rotational speed. Advantageously linear movement of the conveyor causes corresponding linear movement of the part of the flexible power transfer means. The linear movement of the part of the flexible power transfer means causes rotation movement of one or both of the first gear and the second gear which is monitored by the sensor means. A benefit of the method is that the linear speed of the production line is monitored so that snags or lurches experienced by the production line are readily identified.

Optionally the method comprises engaging a roller supported by each of the one or more elements with the conveyor. Advantageously the roller may provide improved engagement with the conveyor.

According to a still further aspect of the invention, there is provided a conveyor driven to cause articles engaged with the conveyor to progress along the conveyor comprising:

one or more monitoring apparatus according to the first aspect are arranged with the conveyor; and a control means, configured to receive the signal indicative of the rotational speed of the one or both of the first gear and the second gear from the sensor means, and to monitor the rotational speed of the one or both of the first gear and the second gear. A benefit of the conveyor comprising one or more monitoring apparatus is that changes in the linear speed of the conveyor can be rapidly identified which can provide a means for early detection of faults on the conveyor.

Optionally, the control means is configured to determine whether the rotational speed of the one or both of the first gear and the second gear is outside one or more acceptable limit.

Optionally, the control means is configured to control the conveyor if the rotational speed of the one or both of the first gear and the second gear is determined to fall outside of the one of more acceptable limits.

Optionally, the conveyer is formed from a conveyor chain.

Optionally, two, three, four or five monitoring apparatus according to the first aspect are arranged in a spaced apart manner, distributed around the conveyor.

Optionally, a plurality of monitoring apparatus are arranged at intervals along the conveyor.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows an example of an apparatus for monitoring a conveyor; Figure 2 shows another view of the apparatus for monitoring a conveyor; and Figure 3 shows an example of a conveyor with a plurality of monitoring apparatus. DETAILED DESCRIPTION

Figures 1 and 2 illustrate a conveyor monitoring apparatus 100 according to an embodiment of the invention. The monitoring apparatus 100 includes a support member 120, a first axle 122 and a second axle 123 located on the support member 120. A first gear 124 is mounted on the first axle 122 such that the first gear 124 can rotate about the axle 122. A second gear 125 is rotatably mounted on the second axle 123. An endless flexible power transfer means 128 is arranged to cooperate with the first and second axles 122, 123. The endless flexible power transfer means 128 is arranged in one embodiment in the form of a loop around the first and second gears 124, 125. The endless flexible power transfer means 128 may be a chain 128 arranged around the first gear 124 and the second gear 125. However in other embodiments the endless flexible power transfer means may be a belt. The chain 128 supports a plurality of outwardly extending elements 126 thereon. The first and second gears 124, 125 are spaced apart on the support member 120. The chain 128 runs around opposing outer ends of each of the first and second gears 124, 125 and is suspended under tension there-between.

The outwardly extending elements 126 are configured so as to be able to engage with a conveyor 20. The outwardly extending elements 126 are further provided with rollers either fixed, or rotatably fixed to an end portion of the outwardly extending elements 126. The rollers improve engagement of the outwardly extending elements 126 with a conveyor 20 of a production line 10. A production line 10 for transporting goods and objects through a manufacturing site may comprise a beam 12 for suspending a conveyor 20, or alternatively, a base for supporting the conveyor. Production lines 10 often include at least one conveyor for carrying manufactured items or manufacturing related objects along a production line. In Figure 1 , a suspended conveyor 20 in the form of a conveyor chain is shown. The conveyor 20 is suspended from a beam 12 via a plurality of wheeled runners 30. The runners 30 are configured to allow smooth transition of the conveyor 20 along a rail of the beam 12. The rail may be formed by the beam being l-shaped. A drive gear (not shown) and driver such as a motor is used to drive the conveyor 20 around the production line 10. Figure 1 and 2 show the conveyor 20 as a conveyor chain 20. The conveyor chain is provided with a number of carrier mechanisms along the length of the conveyor 20, adapted to carry manufactured objects and move the objects forwards by the conveyor chain. Manufactured objects may be caused to move by the conveyor chain 20. In some embodiments each object is carried by a carrier mechanism or apparatus associated with the chain, such as suspended from the chain where a plurality of carrier mechanisms or apparatus are distributed along the length of the conveyor chain 20. The manufactured objects may be vehicles, for example.

The monitoring apparatus 100 also includes a sensor means such as a sensing device 130 for measuring the rotational speed of the first gear 124 and/or the second gear 125. When one or more of the outwardly extending elements 126 is in engagement with a portion of the conveyor 20, the outwardly extending elements 126 on the chain 128 cause the first gear 124 and/or the second gear 125 to rotate at a speed related to the linear speed of the conveyor 20. The diameter of the first gear 124 and/or the second gear 125 dictates the relationship between the linear speed of the conveyor and the rotational speed of the first gear 124 and/or the second gear 125. A smaller diameter first gear 124 and/or the second gear 125 will have a corresponding greater rotational speed as a function of the linear speed of the conveyor 20. A larger diameter first gear 124 and/or the second gear 125 has a corresponding smaller rotational speed as a function of the linear speed of the conveyor because linear speed = radius (of the first gear) x angular speed (i.e. rotational speed).

The sensing device 130 may be a speed sensor, and is configured to measure the rotational speed of the first gear 124 and/or the second gear 125 which is indicative of the linear speed of the conveyor 20. A rotary encoder can be used to convert the angular position or motion of the first axle 122 of the first gear 124 and/or the second axle 123 of the second gear 125 to an analogue or digital code. An encoder wheel includes visible markings that enable the sensing device 130 such as the speed sensor 130 to determine the rotary speed of the first gear 124 and/or the second gear 125. In one example, the speed sensor provides a pulse every predetermined period of time such as 1 .2 seconds although it will be appreciated that other time periods are envisaged. It will be appreciated that, the time period of the speed sensor 130 will depend on the overall size of the conveyor, the speed of the conveyor 20 and the gear ratio of the monitoring device 100.

Changes in the linear speed of the conveyor 20 may be identified more quickly by the sensing device 130 in the monitoring apparatus 100 compared with a sensing device used on a drive gear of a conveyor 20. The sensing device 130 is configured to, in use, output a signal indicative of the local linear speed of the conveyor 20.

A gearbox is provided between the first gear 124 and/or the second gear 125 and a rotational shaft of the sensing device 130, or speed sensor 130. The apparatus 100 can be used to identify changes in the linear speed of the conveyor 20 rapidly. In one example of the apparatus 100, a gearbox is provided having a gear ratio of between 10:1 and 2:1 . In another example of the apparatus 100, the gearbox provides a gear ratio of 6:1 . The gear ratio is selected so as to provide an acceptable response time of the monitoring apparatus and will depend on the overall size of the production line the apparatus is to be used with.

A control means such as a controller (not shown) is provided for monitoring a speed of the first gear 124 and/or the second gear 125 dependent on the sensing device 130 or speed sensor. The controller is adapted to monitor the output signal from the sensing device 130. The controller is arranged to determine if the measured rotational speed of the first gear 124 and/or the second gear 125 falls outside one or more acceptable limits. The controller may be further configured to control the conveyor 20 when the measured rotational speed of the first gear 124 and/or the second gear 125 is determined to fall outside one or more acceptable limits. For example, if the controller determines that the measured rotational speed of the first gear 124 and/or the second gear 125 falls outside of one or more acceptable limits, the controller may cause the conveyor 20 to come to an abrupt stop. The controller may output a signal dependent on the determination of the output signal from the sensing device 130 to cause the conveyor 20 to stop. Alternatively, the controller may output a signal to cause the conveyor 20 to reduce the linear speed of the conveyor 20 until the controller determines that the rotational speed of the first gear 124 and/or the second gear 125 falls within one or more acceptable limits, and then return the conveyor 20 to a normal operating speed. The controller can detect if the conveyer speed increases or decreases. In one example, the first gear 124 and/or the second gear 125 is a toothed gear.

The chain 128 may be a caterpillar like chain 128, similar to a bicycle chain, but having the plurality of outwardly extending elements 126 formed as part of the chain 128. The plurality of outwardly extending elements 126 are attached in a spaced apart manner, distributed along the chain 128. The spacing between the plurality of outwardly extending elements 126 is selected so as to provide that at least one of the outwardly extending elements 126 is engageable with the conveyor at any time. In particular, a spacing between elements 126 is determined to match a spacing between links of the conveyor chain 20 in some embodiments of the invention.

When the chain 128 is supported at least partly in parallel linear arrangement to the conveyor 20, the outwardly extending elements 126 from the chain 128 engage the conveyor 20 and cause corresponding linear movement of the chain 128 to the conveyor 20, thereby allowing the speed of the conveyor 20 to be reflected by the speed of the chain 128. A bracket 1 10 is provided for fixing the support member 120 in relation to the conveyor 20 so that the one or more of the plurality of outwardly extending elements 126 is engageable with the conveyor 20 of the production line. The bracket 1 10 is provided with a plurality of connectors 1 12, 1 14 for adjustably locating the support member 120 relative to the conveyor 20. The connectors 1 12, 1 14, may be connector holes adapted to receive fixings such as connector bolts. The connectors may 1 12, 1 14 provide a means for aligning the support member 120 so that the outwardly extending elements 126 easily engage with the conveyor 20.

One or more tensioning means may be provided to exert an outward biasing force on the chain 128 between the first and second gears 124, 125. In one embodiment, the chain 128 is maintained under tension with a tensioning element 127. In one example, the tensioning element 127 is mounted to the conveyor monitoring apparatus 100 between the first and second gears 124, 125 and is independent of the position of the first and second gears 124, 125. The tensioning element 127 may be a spring loaded tension wheel, arranged to push the chain away from the tension wheel, outwardly towards the conveyor. The tensioning element 127 moves relative to the position of the first gear and second gear 124, 125, and independently therefrom, to exert outwardly biasing force on the chain 128 between the first and second gears 124, 125. This facilitates engagement of the outwardly extending elements 126 with the conveyor 20.

The speed sensor 130 may be any type of sensing device 130 configured to measure the speed of the first gear 124 such as an optical or an electronic speed sensor. The speed sensor 130 may be arranged to measure rotation of one of the first and second axles 122, 123.

A method of monitoring a production line according to an embodiment of the invention includes the following steps. One or more elements of a plurality of outwardly extending elements 126 engaged in use with a conveyor of the production line by locating the plurality of outwardly extending elements sufficiently close to the conveyor to enable said engagement. The one or more elements of the plurality of outwardly extending elements 126 are engaged with the conveyor 20 by locating the monitoring apparatus 100 close to the conveyor 20 using the support bracket 1 10. Other means for locating the apparatus 100 close to the conveyor 20 are also envisaged such as mounting the monitoring apparatus 100 on a free standing frame, or providing a wall mounted monitoring apparatus.

Linear movement of the conveyor 20 causes rotational movement of the engaged outwardly extending elements located around the first gear 124 and/or the second gear 125 so that the linear movement of the conveyor 20 pushes the outwardly extending elements and rotates the first gear 124 and the second gear 125. The rotational speed of the first gear 124 and/or the second gear 125 is then determined. If the rotational speed of the first gear 124 and/or the second gear 125 falls outside of one or more acceptable limits, an indication that the conveyor is not running normally is output. By using the above described method, changes in speed of the conveyor can be quickly identified at one or more locations about the conveyor. Changes in speed can come about for a variety of reasons, including problems such as snagging of the conveyor which may also result in the lurch forward of the conveyor once the snag becomes unstuck. The sensor means 130 measures the rotational speed of the first gear 124 and/or the second gear 125 and a controller is used to determine if the rotational speed of the first gear 124 and/or the second gear 125 falls outside one or more acceptable limits.

A benefit of the method is that the conveyor 20 is monitored along the length of the production line 10 in a localised manner. Existing conveyor monitoring apparatus monitor the conveyor 20 by observing a drive gear of the production line 10 and monitoring changes in the drive gear. However, these apparatus fail to identify changes in speed of the conveyor 20 far from the drive wheel and the responsiveness of such monitoring equipment is relatively slow. The present invention, provides a method for a secondary independent means of monitoring localised changes to the speed on a conveyor which may be indicative of a problem with the conveyor. The method provides a safer working environment because the conveyor is more closely monitored.

In another embodiment, a conveyor driven to cause articles engaged with the conveyor 20 to progress along the conveyor 20, one or more monitoring apparatus 100 as described above arranged with the conveyor 20 and a control means, configured to receive the measured rotational speed of the first gear and/or the second gear from the speed sensor, and to monitor the measured speed of the first gear. A plurality of monitoring apparatus 100 may be located in a spaced apart manner, distributed around a conveyor 20 of a production line 10 to provide zonal monitoring of the conveyor or the production line as shown in Figure 3. This enables the conveyor 20 to operate more safely since the response time of identifying potential problems with the conveyor 20 of the production line is reduced. Furthermore, the zonal monitoring of the conveyor 20 provides a means for operatives to easily identify a zone S1 , S2, S3, and S4 in which a potential problem has occurred, since each zone S1 , S2, S3, and S4 is identifiable from the plurality of monitoring apparatus 100 arranged around the conveyor 20. Furthermore, zonal monitoring of the conveyor 20 enables the identification of snags or lurches on the conveyor 20 which may not be identifiable without zonal monitoring of the conveyor 20. In one example, each of the plurality of monitoring apparatus 100 are configured to output a unique signal profile such that changes in speed along the conveyor are easily identifiable from the unique signal of each monitoring apparatus. Two, three, four, five or more monitoring apparatus 100 may be arranged in a spaced apart manner, distributed around the conveyor 20. The number of monitoring apparatus 100 required to provide sufficient localised monitoring of the conveyor 20 will depend on the overall size of the production line 10. Each zone S1 , S2, S3, and S4 is provided with a monitoring apparatus 100.

The monitoring apparatus may also be used in other types of conveyors such as baggage conveyors.

It will be appreciated that embodiments of the present invention can be realised in the form of hardware, software or a combination of hardware and software. Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like a ROM, whether erasable or rewritable or not, or in the form of memory such as, for example, RAM, memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a CD, DVD, magnetic disk or magnetic tape. It will be appreciated that the storage devices and storage media are embodiments of machine-readable storage that are suitable for storing a program or programs that, when executed, implement embodiments of the present invention. Accordingly, embodiments provide a program comprising code for implementing a system or method as claimed in any preceding claim and a machine readable storage storing such a program. Still further, embodiments of the present invention may be conveyed electronically via any medium such as a communication signal carried over a wired or wireless connection and embodiments suitably encompass the same. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. The claims should not be construed to cover merely the foregoing embodiments, but also any embodiments which fall within the scope of the claims.