Monday, January 14, 2008
Sunday, January 13, 2008
Facilitator's Question
Our facilitator, Mr Johnny Tan has given us something to ponder on and we are here to share with you the answer we came up with.
Under what circumstance/s does the truck become a preferred choice instead of conveyor system (as shown in your Blog). Explain.
ANSWER:
Here are some situations where trucks are preferred:
1. Small scale operation with low throughput and similar products
When a company is operating in a small scale especially when the products are not of high throughput, trucks are the preferred choice. Relatively, when the materials handled are similar and are of smaller quantity, or when movements or shipments are performed batch by batch, trucks are used more often than the conveyors.
Using trucks in this situation is more beneficial to the company because the volume of the products transported may not be able to justify the cost of operating the conveyor system. In addition, the investment cost required in using conveyors is quite significant. Thus, small scale operation and handling of low throughput products may not be able to justify the investment cost as well.
2. Numerous pick-up and drop-off points
Several operations require various pick-up points or drop-off points that differ from time to time. For this situation, trucks are the preferred choice because conveyors require a specifically defined pick-up bay and drop-off section.
3. Varying route of movement
For production flows that are not constant with direction that changes occasionally from one point to another because several products are being produced simultaneously, moving equipments such as trucks would be preferable.
Conveyors would not be able suit this situation because just like the pick-up and drop-off points, the route taken by the conveyor system should also be specific and defined. Once the direction of the goods’ movement is set, the route is precise throughout the operations. Hence, the movement of the goods is not flexible with the use of conveyors and trucks are chosen instead.
4. Space constraints
Some warehouse and distribution centers may not have the luxury of space. With the use of conveyors, the space dedicated for the system will not be accessible anymore. The space used will be specifically for the conveyors only and even when the system is idle, the conveyors could not be removed from its location to accommodate any other operations or movements.
Thus, if the warehouse operator wishes to eliminate this idle space when conveyors are not used and to increase the flexibility in the floor space, trucks are preferred. When not used, trucks can be parked elsewhere so as not to have them hindering the use of relevant space; and even when they are being operated, they are not kept stationary on specific locations so the space can be further utilized for other operations or movement.
OUR TEAM,
QUESTION:
Under what circumstance/s does the truck become a preferred choice instead of conveyor system (as shown in your Blog). Explain.
ANSWER:
Here are some situations where trucks are preferred:
1. Small scale operation with low throughput and similar products
When a company is operating in a small scale especially when the products are not of high throughput, trucks are the preferred choice. Relatively, when the materials handled are similar and are of smaller quantity, or when movements or shipments are performed batch by batch, trucks are used more often than the conveyors.
Using trucks in this situation is more beneficial to the company because the volume of the products transported may not be able to justify the cost of operating the conveyor system. In addition, the investment cost required in using conveyors is quite significant. Thus, small scale operation and handling of low throughput products may not be able to justify the investment cost as well.
2. Numerous pick-up and drop-off points
Several operations require various pick-up points or drop-off points that differ from time to time. For this situation, trucks are the preferred choice because conveyors require a specifically defined pick-up bay and drop-off section.
3. Varying route of movement
For production flows that are not constant with direction that changes occasionally from one point to another because several products are being produced simultaneously, moving equipments such as trucks would be preferable.
Conveyors would not be able suit this situation because just like the pick-up and drop-off points, the route taken by the conveyor system should also be specific and defined. Once the direction of the goods’ movement is set, the route is precise throughout the operations. Hence, the movement of the goods is not flexible with the use of conveyors and trucks are chosen instead.
4. Space constraints
Some warehouse and distribution centers may not have the luxury of space. With the use of conveyors, the space dedicated for the system will not be accessible anymore. The space used will be specifically for the conveyors only and even when the system is idle, the conveyors could not be removed from its location to accommodate any other operations or movements.
Thus, if the warehouse operator wishes to eliminate this idle space when conveyors are not used and to increase the flexibility in the floor space, trucks are preferred. When not used, trucks can be parked elsewhere so as not to have them hindering the use of relevant space; and even when they are being operated, they are not kept stationary on specific locations so the space can be further utilized for other operations or movement.
OUR TEAM,
Ann, Shireen and Izz
NEWS: roadmap to efficiency
Conveyors provide roadmap to efficiency: your packaging line depends on a smooth highway system of conveyors—while avoiding bumps in the road - Techno
If you were to take an overhead photo of a packaging line, the conveying system would look a lot like a highway or, in some cases, a roller coaster.
Referred to as "intelligent bridges between islands of automation," conveyors are key components to a smooth running packaging line. The idea, obviously, is to get packaging elements from point A to point Z in the quickest and most efficient way possible.
Selecting the optimum conveyor system is dependent on your packaging operation. Flat-top chain is the most commonly used style of conveyor in packaging operations and is available in several generic styles including channel frame, sanitary and open frame conveyors.
But sophisticated conveyor systems are expanding beyond the generic and improvements are being made while using established conveying technologies (see our list of conveyor manufacturers at the end of this article).
Some technological improvements in conveyors include:
* Convenient and ergonomic solutions.
* Easy belt reversal for inclined conveyors to increase productivity.
* Screw style conveyors to protect products while cutting costs.
* Improvements in bucket conveyor system for handling and packaging bulk materials and powders.
Food & Drug Packaging, July, 2002 by Christopher Barry
Izz
Saturday, January 12, 2008
NEWS: maintenance-free conveyors?
New Lube-for-Life Bearings make conveyors maintenance free.
(Equipment Update)
(Equipment Update)
1 December 2007
Frozen Food Digest
ISSN: 0889-5902; Volume 23; Issue 2
Copyright 2007 Gale Group Inc. All rights reserved.
QC Industries has replaced their standard bearings with Lube-for-Life Bearings featuring a permanently applied Micro-Poly Lubricant specially designed to meet the unique needs of their conveyors.
With this change, QC Industries' conveyors are now maintenance-free.
This new greaseless design eliminates the need to periodically lubricate the bearings and the possibility of grease escaping the bearings and contacting product on the surface of the conveyor. In addition, the bearings are sealed to prevent contamination from debris, significantly extending their life. These features result in long-term cost savings through reduced conveyor maintenance.
The Micro-Poly Lubricant is comprised of polymers and oils. The oils retained by this porous structure continually lubricate the bearing surfaces--even those in hard-to-reach places--through capillary action. The precision roller bearings provide an increased surface area which offers greater load capacities and longer bearing life.
All QC Industries, Lube-for-Life Bearings are approved by the USDA and FDA for H-1 food processing applications, where there may be incidental contact between food and the bearing. They contain corrosion inhibitors, anti-oxidants and an EP (extreme pressure) additive.
For more information contact Chris Thompson, Marketing Coordinator, at 513-388-4820; or Chris Round, Marketing Manager at 513-388-4840.
E-mail: sales@qcindustries.com
Web site: www.qcindustries.com [http://www.qcindustries.com]
COPYRIGHT 2007 Frozen Food Digest, Inc.
© 2008 Factiva, Inc. All rights reserved.
credits: factiva
available at: http://ezproxy.tp.edu.sg:2056/aa/default.aspx?napc=S&fcpil=en&_XFORMSTATE=AC57MTp7Mjp7MTA6MCw4OjAsOTpbezQ6IiBOZXcgTHViZS1mb3ItTGlmZSBCZWFyaW5ncyBtYWtlIGNvbnZleW9yeAEAI2ludGVuYW5jZSBmcmVlLihFcXVpcG1lbnQgVXBkYXRlKSAgICIsNTo2Miw3OiJmcmZkIiw5XA0AHDA6IkZSRkQwMDAwMjAwNzEyMjllM2MxMDAwMWMiLDI6ezA6IkFydGljbGUiLDGgEwFOZXdzKUwADyJkaXN0ZG9jOmFyY2hpdmUvQbwAAkRvYzo63QQvO5ABCCIyMzUxIn1dLDI6IB4xAX1wCAYxOjAsMTc6MSxgKnEBMmECNnAACzM6Miw1OjIsMTU6MCw3ZAKcAwgyOjAsMTk6MH19fREAAI0BAAA%3d
SUMMARY: The improvements in the design of the conveyors will help reduce the costs of maintenance of the system. Thus, it is now more cost-effective to use conveyors as the warehouse's material handling equipment.
-ann-
Examples of Improvements in Conveyor components
Primary or Pre-Cleaners
Belt cleaners are an essential part of any conveyor system. Belt cleaners help remove product carry back and prevent it from falling off at various points along the return side of the belt causing various housekeeping and maintenance problems. Carry back can lead to:
Excessive buildup and wear on belt idlers and pulleys
Conveyor belt misalignment due to the artificial crown created by the carry back
Accumulation of material falling off idlers and structure to the ground or on buildings, vehicles or even people
Negative and unsafe work environment
E-Z Skalper belt cleaner
The E-Z Skalper conveyor belt pre-cleaner provides effective carryback removal in the toughest environments. The patented blade is designed for removing high volumes of material and for quick and easy maintenance. Excellent Performance – of our patented E-Z Skalper Blade design is available in a 1-piece blade or segmented blades that can be changed for the optimum in blade coverage across the belt’s material carry path for better cleaning efficiency.
Advanced Composites – using ASGCO’s experience with urethane composites, provides belt cleaner blades that can handle the toughest environments; Aggregate, Cement, Coal, Gypsum, Potash, Pulp and Paper and Coal industries.
E-Z Torque Tensioner (lifetime warranty) – made of stainless steel allows the blades to self adjust and is the most robust and accurate belt cleaner tensioner in the industry.
Easily Maintained - and tensioned from one side of the conveyor.
Belt cleaners are an essential part of any conveyor system. Belt cleaners help remove product carry back and prevent it from falling off at various points along the return side of the belt causing various housekeeping and maintenance problems. Carry back can lead to:
Excessive buildup and wear on belt idlers and pulleys
Conveyor belt misalignment due to the artificial crown created by the carry back
Accumulation of material falling off idlers and structure to the ground or on buildings, vehicles or even people
Negative and unsafe work environment
E-Z Skalper belt cleaner
The E-Z Skalper conveyor belt pre-cleaner provides effective carryback removal in the toughest environments. The patented blade is designed for removing high volumes of material and for quick and easy maintenance. Excellent Performance – of our patented E-Z Skalper Blade design is available in a 1-piece blade or segmented blades that can be changed for the optimum in blade coverage across the belt’s material carry path for better cleaning efficiency.
Advanced Composites – using ASGCO’s experience with urethane composites, provides belt cleaner blades that can handle the toughest environments; Aggregate, Cement, Coal, Gypsum, Potash, Pulp and Paper and Coal industries.
E-Z Torque Tensioner (lifetime warranty) – made of stainless steel allows the blades to self adjust and is the most robust and accurate belt cleaner tensioner in the industry.
Easily Maintained - and tensioned from one side of the conveyor.
Skalper MDX Belt Cleaner
The ASGCO Skalper MDX pre-cleaner is designed for high speed and tonage conveyor systems in above and underground mining. The heavy-duty urethane blade mounts against the head pulley for efficient cleaning, and our unique torque cam action lever adjusts itself to remove high volumes of carryback while minimizing blade wear and wear from mechanical fasteners.
Heavy Duty 14" High Urethane Blade – designed to with stand the most abusive mine use conditions.
6" Blade Segments – easily removed for quick blade change.
Delivers Continuous, Effective Cleaning Force
Easily Maintained - and tensioned from one side of the conveyor.
Available at: http://www.asgco.com/e_z_skalper.shtml and http://www.asgco.com/Skalper_MDX.shtml
Izz
Thursday, January 10, 2008
Improved Conveyor Design
The main idea that keeps material handling competitive is optimization. The design of the conveyor system should be cost-effective while remaining technically sound.
The current version of the conveyor design program has evolved from 2 earlier versions.
FIRST program: the design primarily delas with peoducing only the belt tensions at the head end, the motor power required and the belt safety factors based on the head end tensions. this program assumed the conveyor profile to be a straight line between the head and tail pulleys; and that all the materials to be carried is loaded at the tail.
An approximate tail tensions is calculated so that the necessary tension to limit sag on the carry side is checked at the point of least tension instead of at the head. Another addition was that once a suitable motor has been selected from a library within the program, the maximum starting tension, counterweight tension and belt safety factors are recalculated.
FUTURE ENHANCEMENTS:
The current version of the conveyor design program has evolved from 2 earlier versions.
FIRST program: the design primarily delas with peoducing only the belt tensions at the head end, the motor power required and the belt safety factors based on the head end tensions. this program assumed the conveyor profile to be a straight line between the head and tail pulleys; and that all the materials to be carried is loaded at the tail.
SECOND program: this version was written so that the program is more use friendly. the conveyor designer now has the opportunity to move between the 4 pages of data and the main menu of the program options at the push of specifil Special Function Keys on the keyboard. This has greatly improved the time taken during the optimization phase, where quick changes of data are required between successive calculations.
An approximate tail tensions is calculated so that the necessary tension to limit sag on the carry side is checked at the point of least tension instead of at the head. Another addition was that once a suitable motor has been selected from a library within the program, the maximum starting tension, counterweight tension and belt safety factors are recalculated.
THIRD program: the most current conveyor program was a complete rewrite of the previous versions. the new program was written so the conveyor can be cut into many sections and each section is analyzed in turn. this means that conveyors of almost any configuration can be analyzed and that the designer can now have data regarding belt tensions and safety factors at any point along the conveyor.
FUTURE ENHANCEMENTS:
Conv 3 has proved to be the most useful and profitable tool. the following additions will be made to the program:
- print out of required take-up weight
- automatic input of belt weight and belt thickness from a library of commonly used belts.
- automatic belt selection, with the facility to override the selection when belt standardization over a number of conveyors is desired.
- computer generated sketch of conveyor outline, basically as a quick check to verify the input data.
- calculation of the belt stretch and take-up travel
- design of conveyors with two or more drive units located at different points
- automatic input of idler rotating wiehgts from a library of typical idlers
- idler selection
- linking our "SHAFT" program t calculate pulley shaft sizes
- pulley bearing selection
- holdback torque and holdback unit selection
- torque arm position and force
- calculation of power to CEMA formulae
- calculation of power to Pipe Conveyors
- horizontal and vertical curve analysis for Pipe Conveyors
In conclusion, the conveyor design by computer is proving to be a very cost effective exercise and even achieves a high degree of optimization. Also, the degree of confidence is possible and there is little chance left for any human error affecting the results.
taken from: Conveyor Belt Technology, 1987 (Reinhard H. Wohlbier)
-ann-
Improvements..
Title: Improvements relating to conveyors
This invention is concerned with improvements relating to conveyors, and in particular to corner units for conveyors.
Where it is necessary for a conveyor to change direction (e.g. on a bend) a corner unit is provided to transfer the conveying action from one straight run to another.
A conventional conveyor corner unit comprises a frame on which a plurality of frusto-conical rollers are mounted, with a conveyor belt entrained around the rollers. Tension is applied to the belt by separative movement of the rollers, and to restrain the belt against movement in a direction inwardly of the corner, restraining means is utilised.
A conventional construction of restraining means comprises a plurality of roller assemblies secured around the outer edge of the belt, each roller assembly comprising one roller member disposed above and one roller member disposed below the belt. In the operation of the conveyor corner unit, tension applied to the belt by the frusto-conical rollers pulls the roller assemblies against a split trackway, to restrain the belt against movement in a direction inwardly of the corner unit.
Because corner units are more complicated in their construction than straight conveyor units, they are more prone to failure, and in need of more frequent maintenance, the most common form of maintenance requiring removal of the belt from the frusto-conical rollers. In many circumstances the time over which a conveyor is out of commission for repair or maintenance can cause great difficulties, e.g. in use as part of an automated production line, or as part of a baggage handling system at an airport, and it is one of the various objects of this invention to provide a conveyor corner unit having a construction which lends itself to speedy repair.
According to this invention there is provided a conveyor corner unit of the kind having a conveyor belt entrained around frusto-conical rollers, the belt
being restrained against movement in a direction inwardly of the corner by roller members secured to an outer region of the belt acting against a trackway disposed inwardly of said outer region, wherein the trackway comprises separable parts to enable the conveyor belt and the roller members thereof to be moved inwardly between said separable parts.
Preferably the trackway parts are separable generally in a plane extending at right angles of operation to the plane of operation of the conveyor. Thus if the belt operates in a generally horizontal plane, preferably said parts are separable generally vertically. In this manner when the conveyor corner unit is in need of repair, by effecting such separation of the trackway parts, the conveyor belt may be moved inwardly of the corner unit from the rollers thereof, and repair, maintenance or replacement effected relatively quickly.
Preferably the belt is so constrained against movement in both directions of its reach - i.e. upper and lower reaches of a conveyor operating in the horizontal plane, and preferably two trackways are provided for engagement with the roller means of the belt.
Preferably both trackways comprise separable parts, and preferably means is provided, such as an over centre device, to facilitate such separation.
Preferably separation is effected simultaneously, and conveniently one part of one of said trackways is mounted for movement with one part of the other trackway. Preferably the other part of each trackway is fixedly secured to a frame of the conveyor corner unit.
There will now be given a detailed description, to be read with reference to the accompanying drawings, of a conveyor corner unit which is the preferred embodiment of this invention, having been selected for the purposes of illustrating the invention by way of example.
In the accompanying drawings:
FIGURE 1 is a schematic plan view of a conveyor of which the preferred embodiments form a part; and
FIGURE 2 is a sectional view taken on the line 2-2 of Figure 1.
The conveyor corner unit 6 which is the preferred embodiment of the invention is used as part of a conveyor 4 (Figure 1), the corner unit transferring the movement from direction A, effected by linear conveyor 7 to direction B, effected by linear conveyor 8, around a bend which may be of any appropriate angle, typically being between 45° and 90°.
The corner unit 6 comprises a plurality of frusto-conical rollers 10 mounted for rotation between inner and outer curved walls 12, 14 respectively, means (not shown) being provided to urge one or both the outermost frusto- conical rollers in a separative direction, to maintain a tension on the conveyor belt 16.
In conventional manner means is provided to restrain the conveyor belt 16 against movement in a direction inwardly of the corner unit (i.e. in the direction of the arrow C), such means being afforded by a plurality of roller assemblies 18 disposed around the outer edge region of the belt 16. Each roller assembly 18 comprises a pair of roller members 20 mounted for movement around a common axis extending at right angles to the plane of the belt, tension in the belt pulling the roller members against upper and lower trackways 22, 24.
Each trackway comprises upper and lower parts designated a and b_ respectively, against which the upper and lower roller members of each pair engage. For convenience of maintenance each track comprises a frame member 25 into which a bearing member 26, which conveniently comprises a low friction material such a nylon or PTFE, is releasably mounted.
Each lower part 22b. 24b_ of the trackways is se, . red to a bracket 27 fixed to the outer wall 14 of the conveyor corner unit, whilst each upper part 22a. 24a, of the trackway is secured by a bracket 30 mounted on a slide plate 32 mounted for sliding movement on the inner side of the outer wall 14. Locking means 40 is provided to secure the trackway parts 22a. 24a. in their desired positions, the locking means 40 comprising a pair of lugs 42 extending outwa ly from the wall 14, and through which a bolt 44 extends, a lug 46 secured to the slide plate 32 being slidably received on an upper portion of said bolt 44, a
locking nut 48 being provided to secure the lug 46 in a position adjacent to the lug 42, and hence the parts 22a. 24a. of the trackways in a desired position in relation to the parts 22b. 24b.
On the occurrence of a need to change the belt of the conveyor, the nut 48 may be slackened, and the slide plate 32 lifted relative to the wall 14, the lug 46 moved upwardly on the bolt 44, causing the trackway parts 22a. 24a. to separate from the trackway parts 22b 24b, Shown generally in dotted lines in Figure 2. Such separation allows the roller assemblies 18 to pass between the said trackway parts, allowing the conveyor belt to be drawn on both upper and lower reaches from the frame in the direction C inwardly of the corner unit. Necessary repair or maintenance which may typically be replacement of one of the roller assemblies, or replacement of the bearing strip 26, or effecting repair to the belt itself, may then be carried out relatively easily, prior to the remounting of the conveyor belt on the frusto-conical rollers 10, and return of the trackway parts to their Figure 2 positions. Finally, the end most roller 10 may be moved outwardly to tension the belt, prior to recommencement of use of the conveyor system.
If desired the locking means 40 illustrated in Figure 2 may be replaced by an over centre mechanism, whereby desired separative movement between the trackway parts may be obtained relatively quickly, conveniently a plurality (such as two or three) such over centre devices being spaced around the periphery of the outer wall 14.
Additionally whilst in the preferred embodiment the invention has been described in relation to obtaining separative movement of the trackway parts of both reaches in the same direction (viz, the upper parts of each trackway are moved vertically upwardly in separation of the lower trackway parts) if desired the upper trackway part of the upper reach, and the lower trackway part of the lower reach may be moved away from the axis of the frusto-conical roller, or the lower part of the upper reach and the upper part of the lower reach may be moved towards the axis of the frusto-conical roller, similarly obtaining separation of the
trackway parts as may accommodate inward movement of the roller assemblies 20.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
Available at: http://www.wipo.int/pctdb/en/wo.jsp?IA=WO1995%2F11182&WO=1995%2F11182&DISPLAY=DESC
Izz
This invention is concerned with improvements relating to conveyors, and in particular to corner units for conveyors.
Where it is necessary for a conveyor to change direction (e.g. on a bend) a corner unit is provided to transfer the conveying action from one straight run to another.
A conventional conveyor corner unit comprises a frame on which a plurality of frusto-conical rollers are mounted, with a conveyor belt entrained around the rollers. Tension is applied to the belt by separative movement of the rollers, and to restrain the belt against movement in a direction inwardly of the corner, restraining means is utilised.
A conventional construction of restraining means comprises a plurality of roller assemblies secured around the outer edge of the belt, each roller assembly comprising one roller member disposed above and one roller member disposed below the belt. In the operation of the conveyor corner unit, tension applied to the belt by the frusto-conical rollers pulls the roller assemblies against a split trackway, to restrain the belt against movement in a direction inwardly of the corner unit.
Because corner units are more complicated in their construction than straight conveyor units, they are more prone to failure, and in need of more frequent maintenance, the most common form of maintenance requiring removal of the belt from the frusto-conical rollers. In many circumstances the time over which a conveyor is out of commission for repair or maintenance can cause great difficulties, e.g. in use as part of an automated production line, or as part of a baggage handling system at an airport, and it is one of the various objects of this invention to provide a conveyor corner unit having a construction which lends itself to speedy repair.
According to this invention there is provided a conveyor corner unit of the kind having a conveyor belt entrained around frusto-conical rollers, the belt
being restrained against movement in a direction inwardly of the corner by roller members secured to an outer region of the belt acting against a trackway disposed inwardly of said outer region, wherein the trackway comprises separable parts to enable the conveyor belt and the roller members thereof to be moved inwardly between said separable parts.
Preferably the trackway parts are separable generally in a plane extending at right angles of operation to the plane of operation of the conveyor. Thus if the belt operates in a generally horizontal plane, preferably said parts are separable generally vertically. In this manner when the conveyor corner unit is in need of repair, by effecting such separation of the trackway parts, the conveyor belt may be moved inwardly of the corner unit from the rollers thereof, and repair, maintenance or replacement effected relatively quickly.
Preferably the belt is so constrained against movement in both directions of its reach - i.e. upper and lower reaches of a conveyor operating in the horizontal plane, and preferably two trackways are provided for engagement with the roller means of the belt.
Preferably both trackways comprise separable parts, and preferably means is provided, such as an over centre device, to facilitate such separation.
Preferably separation is effected simultaneously, and conveniently one part of one of said trackways is mounted for movement with one part of the other trackway. Preferably the other part of each trackway is fixedly secured to a frame of the conveyor corner unit.
There will now be given a detailed description, to be read with reference to the accompanying drawings, of a conveyor corner unit which is the preferred embodiment of this invention, having been selected for the purposes of illustrating the invention by way of example.
In the accompanying drawings:
FIGURE 1 is a schematic plan view of a conveyor of which the preferred embodiments form a part; and
FIGURE 2 is a sectional view taken on the line 2-2 of Figure 1.
The conveyor corner unit 6 which is the preferred embodiment of the invention is used as part of a conveyor 4 (Figure 1), the corner unit transferring the movement from direction A, effected by linear conveyor 7 to direction B, effected by linear conveyor 8, around a bend which may be of any appropriate angle, typically being between 45° and 90°.
The corner unit 6 comprises a plurality of frusto-conical rollers 10 mounted for rotation between inner and outer curved walls 12, 14 respectively, means (not shown) being provided to urge one or both the outermost frusto- conical rollers in a separative direction, to maintain a tension on the conveyor belt 16.
In conventional manner means is provided to restrain the conveyor belt 16 against movement in a direction inwardly of the corner unit (i.e. in the direction of the arrow C), such means being afforded by a plurality of roller assemblies 18 disposed around the outer edge region of the belt 16. Each roller assembly 18 comprises a pair of roller members 20 mounted for movement around a common axis extending at right angles to the plane of the belt, tension in the belt pulling the roller members against upper and lower trackways 22, 24.
Each trackway comprises upper and lower parts designated a and b_ respectively, against which the upper and lower roller members of each pair engage. For convenience of maintenance each track comprises a frame member 25 into which a bearing member 26, which conveniently comprises a low friction material such a nylon or PTFE, is releasably mounted.
Each lower part 22b. 24b_ of the trackways is se, . red to a bracket 27 fixed to the outer wall 14 of the conveyor corner unit, whilst each upper part 22a. 24a, of the trackway is secured by a bracket 30 mounted on a slide plate 32 mounted for sliding movement on the inner side of the outer wall 14. Locking means 40 is provided to secure the trackway parts 22a. 24a. in their desired positions, the locking means 40 comprising a pair of lugs 42 extending outwa ly from the wall 14, and through which a bolt 44 extends, a lug 46 secured to the slide plate 32 being slidably received on an upper portion of said bolt 44, a
locking nut 48 being provided to secure the lug 46 in a position adjacent to the lug 42, and hence the parts 22a. 24a. of the trackways in a desired position in relation to the parts 22b. 24b.
On the occurrence of a need to change the belt of the conveyor, the nut 48 may be slackened, and the slide plate 32 lifted relative to the wall 14, the lug 46 moved upwardly on the bolt 44, causing the trackway parts 22a. 24a. to separate from the trackway parts 22b 24b, Shown generally in dotted lines in Figure 2. Such separation allows the roller assemblies 18 to pass between the said trackway parts, allowing the conveyor belt to be drawn on both upper and lower reaches from the frame in the direction C inwardly of the corner unit. Necessary repair or maintenance which may typically be replacement of one of the roller assemblies, or replacement of the bearing strip 26, or effecting repair to the belt itself, may then be carried out relatively easily, prior to the remounting of the conveyor belt on the frusto-conical rollers 10, and return of the trackway parts to their Figure 2 positions. Finally, the end most roller 10 may be moved outwardly to tension the belt, prior to recommencement of use of the conveyor system.
If desired the locking means 40 illustrated in Figure 2 may be replaced by an over centre mechanism, whereby desired separative movement between the trackway parts may be obtained relatively quickly, conveniently a plurality (such as two or three) such over centre devices being spaced around the periphery of the outer wall 14.
Additionally whilst in the preferred embodiment the invention has been described in relation to obtaining separative movement of the trackway parts of both reaches in the same direction (viz, the upper parts of each trackway are moved vertically upwardly in separation of the lower trackway parts) if desired the upper trackway part of the upper reach, and the lower trackway part of the lower reach may be moved away from the axis of the frusto-conical roller, or the lower part of the upper reach and the upper part of the lower reach may be moved towards the axis of the frusto-conical roller, similarly obtaining separation of the
trackway parts as may accommodate inward movement of the roller assemblies 20.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
Available at: http://www.wipo.int/pctdb/en/wo.jsp?IA=WO1995%2F11182&WO=1995%2F11182&DISPLAY=DESC
Izz
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