Technical Field

The invention relates to a conveyor belt cleaner assembly for use on a conveyor belt apparatus, and to a conveyor belt apparatus comprising the assembly.

Background

Conveyor belts are used in a wide variety of industries to transport solid material. In some cases liquid material may also be included with the solid material, which can make transport more challenging.

Conveyor belts generally have an endless loop formation, wherein an upper surface of the conveyor belt carries solid material to be transported, which loops back as a lower surface after passing around an end roller. In general the solid material carried by the upper surface is held in place due to gravity. Likewise, gravity causes the solid material to fall off the conveyor belt as it moves past an end roller. However in many industries it is not sufficient to rely on gravity to release all of the solid material from the conveyor belt, particularly where some liquid material is also present.

To address this, so-called conveyor belt cleaners are employed which act to scrape the lower surface of the conveyor belt to assist in the removal of solids that have not fallen off the conveyor belt due to gravity alone.

A common arrangement of conveyor belt scraper comprises a horizontal support bar wherein a scraper blade is mounted upon the horizontal support bar arranged to provide a scraping action on the surface of a conveyor belt.

It has been found however that material carried by conveyor belts may foul the scraper blade and there is a need to periodically remove any built-up undesirable material from the scraper blade. Various methods of doing this have been proposed.

However, improvements in this area would be desirable.

Detailed Description of the Invention

In a first aspect, the invention relates to a conveyor belt cleaner assembly, for scraping the surface of a conveyor belt, the assembly comprising a horizontal support bar mounted thereupon is a scraper blade, the blade comprising a conveyor belt contact surface, the assembly having (1 ) a first scraping orientation wherein the scraper blade is positioned to come into contact with the surface of the conveyor belt, and (2) a second cleaning orientation wherein the scraper blade is positioned away from the surface of the conveyor belt, wherein the assembly comprises a slideably mounted blade wiper, arranged to wipe the surface of the conveyor belt contact surface of the scraper blade when the assembly is in its second cleaning orientation.

In this way, the conveyor belt cleaner assembly comprises a self-cleaning arrangement, whereby the blade wiper wipes the scraper blade, physically removing any built-up undesirable material, which is then allowed to fall away due to gravity.

Typically, the scraper blade is rotatably mounted, such that it can move from the first scraping orientation to the second cleaning orientation by rotation of the conveyor belt contact surface towards and away from the surface of the conveyor belt respectively.

In a preferred arrangement the horizontal support bar has a first end and a second end, the horizontal support bar being mounted on a first end support mount and a second end support mount. This enable movement of the horizontal support bar to be controlled by its mounting on the end support mounts. Preferably the horizontal support bar is rotatably mounted on the first and second end supports, so as to move the assembly from the first scraping orientation to the second cleaning orientation by rotation of the horizontal support bar. Preferably the horizontal support bar is moveable towards and away from the surface of the conveyor belt to be scraped in use. This is usefully combined with the rotatably mounted feature, so that in moving from the first scraping orientation to the second cleaning orientation, the horizontal support bar can first be moved away from the surface of the conveyor belt before rotating to the second cleaning orientation. In practice the conveyor belt cleaner assembly will generally be positioned beneath the conveyor belt and so preferably the horizontal support bar is vertically moveable towards and away from the surface of the conveyor belt.

The blade wiper may take a variety of forms, however preferably the blade wiper has a retracted position and is arranged to adopt its retracted position when the assembly is in its first scraping orientation, and has an extended position, adoptable when the assembly is in its second cleaning orientation, such that wiping of the conveyor belt contact surface is carried out during movement from the retracted position to the extended position. Thus, the blade wiper can move from a retracted position to an extended position and carry out wiping of the scraper blade while doing so. Preferably the blade wiper is arranged to slide along the conveyor belt contact surface of the scraper blade, in order to carry out its wiping function, i.e. by physically brushing against the scraper blade. To facilitate the wiping, it is preferred that the scraper blade comprises a sliding surface and the blade wiper is arranged to slide along the sliding surface of the cleaner blade.

In a particularly preferred arrangement the blade wiper is arranged to move in a direction perpendicular to the conveyor belt contact surface of the scraper. In this way, since the undesired material build-up on the scraper blade has arrived from the conveyor belt, arranging to have the blade wiper move in this manner is particularly effective at removing undesired material from the scraper blade.

In a preferred embodiment, the conveyor belt cleaner assembly comprises a secondary wiper, positioned to wipe the blade wiper as it moves from its extended position to its retracted position. Such a secondary wiper can simply be a static component attached to the scraper blade, that acts to wipe the blade wiper. This provides an additional cleaning function and helps to ensure that the blade wiper remains in a cleaned state.

In a second aspect, the invention relates to a conveyor belt apparatus comprising a conveyor belt cleaning assembly as defined herein.

Preferably the conveyor belt apparatus comprising a plurality of conveyor belt cleaning assemblies as defined herein, wherein they are arranged such that at least one is in its first scraping orientation at any one time. In this way, the conveyor belt can be continually scraped without needing to be stopped in order to carry out cleaning of the conveyor belt cleaning assemblies.

Preferably the horizontal support bar of each conveyor belt cleaning assembly is positioned beneath a horizontal section of the conveyor belt. This position is particularly advantageous because any material that needs to be scraped will already have fallen off due to gravity before scraping occurs.

In a third aspect, the invention relates to a method of operating a conveyor belt apparatus as defined herein, the method comprising the steps of: operating the conveyor belt with the conveyor belt cleaner assembly in its first scraping orientation, moving the conveyor belt cleaner assembly to its second cleaning orientation, activating the blade wiper to wipe the surface of the conveyor belt contact surface of the scraper blade, and returning the conveyor belt cleaner assembly to its first scraping orientation.

In a preferred embodiment, the method is carried out automatically via a programmed controller.

The invention will now be illustrated, by way of example, and with reference to the following figures, in which: Figure 1 is a perspective view of a conveyor belt cleaner assembly according to the present invention in a first scraping orientation.

Figure 2 is perspective sectional view through the conveyor belt cleaner assembly shown in figure 1.

Figure 3 is a perspective view of the conveyor belt cleaner assembly shown in figure 1 in a second cleaning orientation.

Figure 4 is a close-up perspective view of the conveyor belt cleaner assembly shown in figure 3 showing the blade wiper in a retracted position.

Figure 5 is a close-up perspective view of the conveyor belt cleaner assembly shown in figure 3 showing the blade wiper in an extended position.

Figure 6 is a side sectional view through a conveyor belt apparatus comprising two conveyor belt cleaning assemblies positioned beneath.

Turning to the figures, figure 1 shows a conveyor belt cleaner assembly 10 comprising a horizontal support bar 12 mounted at either end on a first end support mount 14 and second end support mount 16. Mounted on the horizontal support bar is a scraper blade 18. The top ridge 20 of the scraper blade 18 provides the conveyor belt contact surface. Also mounted on the horizontal support bar 12 is a blade wiper 22.

Figure 2 shows more detail of the arrangement of the conveyor belt cleaner assembly 10. The scraper blade 18 is wedge-shaped with a triangular crosssection, providing exterior sloping surface 24 and sliding surface 26 and is mounted onto the horizontal support bar 12 via mount 28.

Also mounted on the horizontal support bar 12 is an L-shaped blade wiper 22, comprising a horizontal portion 30 and a vertical portion 32, terminating in a horizontal blade wiper surface 33. The blade wiper 22 is mounted onto the horizontal support bar 12 via a number of hydraulic pistons 34. The blade wiper 22 is in its retracted position.

Also provided is a secondary wiper 36 which runs along the length of the scraper blade 18 and also has a triangular cross-section, providing exterior sloping surface 38 and sliding surface 40, that meet at the secondary wiper top ridge 41, held in place by bracket 37.

Vertical portion 32 of the blade wiper 22 is in contact with the side wall of the horizontal support bar 12 and also sandwiched between the sliding surface 26 of the scraper blade 18 and the sliding surface 40 of the secondary wiper.

In use during cleaning, the lower return surface of a conveyor belt (not shown) passes above the conveyor belt cleaner assembly 10 such that the top ridge 20 of the scraper blade 18 scrapes the surface thereof, providing a cleaning function. Removed material leaves the surface of the conveyor belt and falls under gravity onto sloping surface 24, where it continues to descend away from the conveyor belt.

When it is desired to clean any built-up material from the scraper blade 18, the horizontal support bar 12 descends vertically by action of the end support mounts 14, 16 and rotates 90° until it is in its second cleaning orientation in the position shown in figure 3, and shown in detail in figure 4.

Once in this second cleaning orientation, hydraulic pistons 34 are actuated so as to cause a sliding movement of the blade wiper 22 in a direction perpendicular to the conveyor belt contact surface 20 of the scraper blade 18 as shown, until it reaches the position shown in figure 5, where it is in its extended position. In doing so the blade wiper 22 slides along the sliding surface 26 of the scraper blade 18 and the sliding surface 40 of the secondary wiper and slides along the conveyor belt contact surface 20 of the scraper blade 18. In doing so, any residues accumulated around the top ridge 20 of the scraper blade 18 are physically forced away from the scraper blade 18 by the blade wiper 22

In the next stage of the cleaning operation, hydraulic pistons 34 are actuated so as to cause a sliding movement of the blade wiper 22 in a direction perpendicular to the conveyor belt contact surface 20 of the scraper blade 18 as shown, until it reaches the position shown in figure 4, where it is in its retracted position. In doing so the blade wiper 22 slides along the sliding surface 26 of the scraper blade 18 and the sliding surface 40 of the secondary wiper and slides along the conveyor belt contact surface 20 of the scraper blade 18. In this case, any residues removed from the scraper blade 18 by the blade wiper 22 but which remain in place on the blade wiper 22, are removed by the action of the secondary wiper 36 and the scraper blade 18, as the blade wiper 22 retracts to its fully retracted position. Any remaining residues thus fall vertically downwards due to gravity.

The cleaning stage is now completed and the horizontal support bar 12 is now rotated 90° again, until it is in the position shown in figure 1 , and in its first scraping orientation once again.

Figure 6 shows a conveyor belt apparatus 100 comprising a conveyor belt 110 having a lower return surface 112. Positioned beneath the lower return surface 112 are a first conveyor belt cleaner assembly 10 and a second conveyor belt cleaner assembly 50.

The second conveyor belt cleaner assembly 50 is essentially identical to first conveyor belt cleaner assembly 10 and has a horizontal support bar 52 mounted at either end on a first end support mount (not shown) and second end support mount 56 mounted onto which is a scraper blade 58. The top ridge 60 of the scraper blade 58 provides the conveyor belt contact surface. Also mounted on the horizontal support bar 52 is a blade wiper 62. The scraper blade 58 is wedge- shaped with a triangular cross-section, providing exterior sloping surface 64 and sliding surface 66. Also mounted on the horizontal support bar 52 is an L-shaped blade wiper 62, terminating in a horizontal blade wiper surface 73. The blade wiper 62 is mounted onto the horizontal support bar 52 via a number of hydraulic pistons 74.

Also provided is a secondary wiper 36 which runs along the length of the scraper blade 18 and also has a triangular cross-section, providing exterior sloping surface 38 and sliding surface 40, that meet at the secondary wiper top ridge 41.

As shown in figure 6, the first conveyor belt cleaner assembly 10 is in its first scraping orientation, and conveyor belt contact surface 20 is in contact with lower return surface 112. The second conveyor belt cleaner assembly 50 is in its second cleaning orientation. In view of the fact that there are two conveyor belt cleaner assemblies 10, 50 each may carry out its cleaning cycle in its second cleaning orientation whilst the other remains in a first scraping orientation. In this manner, continuous scraping of the conveyor belt may be maintained whilst self-cleaning of the scrapers occurs without the need for stopping the conveyor belt 110.