GB2143792A - Scraper or cleaning conveyor belts - Google Patents

Abstract

For removing unwanted material from a conveyor belt, normally, a fixed scraper bar is provided in contact with the belt, but has the problem of requiring constant monitoring and frequent adjustment to compensate for uneven wear across its length, and the added disadvantage of suffering damage when contacted by e.g. belt fastening clips, as they pass across the scraper. The object of the invention is to avoid these disadvantages, and is met by a construction comprising a carrier member 2, a number of individual scraper blades 6 located in side-by-side relationship on the carrier member, each scraper blade being mounted on the carrier such that it can move relative to the carrier and there being spring means to urge each individual scraper blade, outwardly of the carrier. <IMAGE>

Description

SPECIFICATION Scraper This invention relates to scrapers, and is particularly concerned with scrapers for removing unwanted material from, e.g., a conveyor belt.

When material such as coal is carried by a conveyor, it is inevitable that a proportion of its fines content adheres to the conveyor. Thus as the conveyor passes around a head-end drum for the discharge of the coal from the conveyor, that fines content adhering to the conveyor is carried around the head-end drum. The weight of such adhering fines adds noticeably to the weight of the conveyor belt thereby causing increased running costs, and along substantially the full length of the return run, the adhering fines can fall indiscriminately to the floor from where it must be removed periodically, again adding noticeably to running costs.

It is therefore known to provide at the head-end of such a conveyor means for scraping adhering fines from the belt. Such scraper means normally take the form of a scraper bar suitably attached between side plates at the head-end and held in contact with the belt surface. With fixed scraper bars, the inevitable wear that takes place at its edge necessitates frequent monitoring and adjustment of its position to maintain it in contact with the belt, and by being fixed there is the added problem of damage to the edge of the scraper on each occasion that it is hit by the clips of belt fasteners.In an attempt to avoid frequent adjustment and in an attempt to mitigate damage caused by belt fastening clips, it has already been proposed to spring load a scraper bar into contact with the belt, so that wear at the edge of the scraper is compensated for automatically and the bar can move away from the belt when contacted by such items as belt fastener clips.

It is the object of the present invention to provide an improved construction of scraper.

According to the present invention, a scraper comprises a carrier member, a number of individual scraper blades located in side-by-side relationship on the carrier member, each scraper blade being mounted on the carrier such that it can move relative to the carrier and there being spring means to urge each individual scraper blade and the carrier, outwardly of the carrier.

Preferably beyond the endmost scraper blade at each end of the carrier a spacer block is provided to maintain the scraper blades in their side-by-side relationship, which spacer blocks additionally prevent any side loading on the scraper blades which could otherwise restrict movement of the scraper blades when required.

In order to mount the carrier in close proximity to a conveyor belt, it is preferred to provide mounting plates at each end which can be secured in simple manner to, e.g., the side plates at the head-end, each mounting plate being provided with flange means to which the carrier is attached.

Thus each flange may be provided with a slot through which passes a connecting bolt and whereby any width deviation can be compensated for.

Each scraper blade may be formed from a suitable wear resistant material, e.g. plastics or metal, and preferably each blade is provided with means to engage co-operating means on the carrier to locate the scraper blade in position.

The spring means to urge each scraper blade outwardly of the carrier may be a compression coil spring or leaf spring placed between each blade and the carrier. Alternatively, and when the scraper blade is of plastics material, its inherent resilience can be utilised by so forming the end of each blade towards the carrier to produce an integral spring.

The carrier may be a simple pressed metal construction of generally U-shaped cross-section, or may be formed by two plate members suitably secured in parallel spaced relationship by one or a number of base members. By its very nature, the fines material scraped from a conveyor, is such that it can pass between the scraper blades and the carrier walls, and it is therefore highly desirable that fines can escape from within the carrier.

Thus, when the carrier is of U-section pressed metal, holes can be provided in the base, or the base slotted to leave lands to support the scraper blades, and when of plates secured together, they can be secured by relatively narrow bridging members at the points where the scraper blades are to be supported.

With the carrier in the form of a channel, each scraper blade may have a lengthwise through slot to align with bolt holes in the channel sidewalls, with a bolt passing through the bolt holes and the co-operating slot. Alternatively, each scraper blade may have ribs or grooves to co-operate with corresponding grooves or ribs on the channel sidewalls.

Each scraper blade may also be provided with a tail to pass through a corresponding hole in the bottom of the channel, and when a compression coil spring is provided, the coil spring may surround the tail, for correct location of the spring.

Equally, the bottom of the channel may be provided with an upstanding stem or boss for each scraper blade, to engage in a corresponding hole in a respective scraper blade, and again when a coil spring is provided it can surround the stem for correct location.

In an alternative construction, the carrier is a bar like member, on which are provided a number of spaced upstanding support members, and when each scraper has a lower section that is hollow and adapted to fit over a support member. Thus, spring means, e.g. a coil spring, can be fitted between the inner end of the hollow portion of each scraper and the outer end of the support member, and the spring, when a coil spring, may be located in a bore in the support member or on a spigot on the support member.

It is desirable to provide a means of adjusting each scraper, so that all scrapers can be brought into contact with the belt and put the spring means in compression. Within the construction last referred to, this can readily be brought about by forming each support member on the bar-like carrier as a threaded sleeve in which is screwed a threaded bolt, a compression coil spring lying within the sleeve and between the bolt and the scraper blade. Thus, adjustment of the bolt can lift the scraper blade into contact with a conveyor belt, with further adjustment of the bolt suitably compressing the spring.

With, then, the scraper mounted at the head-end of a conveyor in contact with the belt, each individual scraper blade is spring loaded against the belt.

Any wear on an individual scraper blade is automatically compensated for and (when provided) the tail projecting from the channel can serve as a wear indicator, and as each individual scraper blade is contacted by, e.g., a belt fastener clip it can move against the action of its spring to prevent unnecessary damage. In addition by having a number of individual scraper blades any change in belt contour across its width is also compensated for thereby increasing noticebly the efficiency of the scraper of the invention in comparison with known scraper assemblies.

Two embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of a scraper in accordance with one embodiment of the invention; Figure 2 is an underneath plan of the scraper of Figure 1; and Figure 3 is a sectional side elevation through a scraper blade and its support means of a second embodiment of the invention.

In Figure 1 a scraper 1 has a carrier 2 in the form of a simple pressed metal construction of generally U-shaped cross-section. To each end of the carrier, mounting plates 3 are provided, each having a flange 4 for securing the plates 3 to the carrier 2.

The bolt means (not shown) for securing the flange 4 to the carrier also serves to secure a scraper block 5 within the channel-like carrier at the outer ends thereof.

Located across the carrier, and within the channel, are a number of scraper blades 6 of a suitable tough, resilient, plastics material, each scraper blade having a tail 7 to pass through an appropriate hole in the base of the channel-like carrier. For further location of each scraper blade, its body is provided with a lengthwise slot 8 to co-operate with a bolt 9 extending across the arms of the channel-like carrier. Between the bottom end of each scraper blade and the bottom of the carrier, a coil spring 10 is provided, the coil spring being located in its position by surrounding the tail 7.

Thus, with the scraper assembled and secured by the plates 3 at, e.g., the head end of a conveyor belt, and with the scraping edges of the scraper blades in contact with the conveyor belt, the scraper of the invention removes efficiently any fines adhering to the belt. Any wear of the scraper blades during use is compensated for by the springs, with the further advantage that any obstruction on the belt such as the inevitable belt fastener clips are accommodated for by the spring allowing the scraper blade to move away from the belt and hence allow such obstruction to pass across the scraper without damaging the scraper blade.

By its very nature, fines material scraped from the belt can pass into and lodge in the channel-like carrier. Thus, as is shown in Figure 2, the bottom of the channel-like carrier is provided with slots 11 between the positions occupied by springs 10 and whereby fines entering into the carrier can fall through the base of the carrier.

In the alternative embodiment shown in Figure 3, the carrier takes the form of a bar-like member 12.

At spaced locations along the length of the carrier holes are provided , and on the carrier are mounted a corresponding number of locating blocks 13 in the form of a threaded sleeve positions to be co-axial with a corresponding hole.

Mounted on each locating block is a scraper blade 14, each scraper blade having a downwardly extending hollow stem 15 to engage over the locting block 13. A bolt 16 is screwed into the locating block and has an end section 17 of reduced section. A coil spring 18 is located around the end section 17 within the locting block, and extends into a corresponding locating hole 19 in the scraper blade.

Thus with the carrier located at the head end of a conveyor e.g. by means generally similar to those displayed in Figure 1, the scraper of Figure 3 functions in similar manner to that of Figure 1 but has the added advantage of enabling individual adjustment of each scraper blade to ensure that all scraper blades contact correctly the face of the conveyor belt and with each compression spring put under a suitable degree of compression. This is brought about quite simply by adjusting the bolt to raise or lower the scraper blade on the locating block.

Claims (21)

1. A scraper comprising a carrier member, a number of individual scraper blades located in side-by-side relationship on the carrier member, each scraper blade being mounted on the carrier such that it can move relative to the carrier and there being spring means to urge each individual scraper blade and the carrier, outwardly of the carrier.

2. A scraper as in Claim 1, wherein beyond the endmost scraper blade at each end of the carrier a spacer block is provided to maintain the scraper blades in their side-by-side relationship.

3. A scraper as in Claim 1 or Claim 2, wherein to mount the carrier in close proximity to a conveyor belt, mounting plates are provided at each end.

4. A scraper as in Claim 3, wherein each mounting plate is provided with flange means to which the carrier is attached.

5. A scraper as in Claim 4, wherein each flange is provided with a slot through which passes a connecting bolt and whereby any width deviation can be compensated for.

6. A scraper as in any of Claims 1 to 5, wherein each scraper blade is formed from a suitable wear resistant material.

7. A scraper as in any of Claims 1 to 6, wherein each blade is provided with means to engage cooperating means on the carrier to locate the scraper blade in position.

8. A scraper as in any of Claims 1 to 7, wherein the spring means to urge each scraper blade outwardly of the carrier is a separate spring (compression coil or leaf spring) placed between each blade and the carrier.

9. A scraper as in any of Claims 1 to 7, wherein the scraper blade is formed from a resilient plastics material and its inherent resilience utilised by so forming the end of each blade towards the carrier to produce an integral spring.

10. A scraper as in any of Claims 1 to 9, wherein the carrier is a pressed metal construction of generally U-shaped cross-section.

11. A scraper as in any of Claims 1 to 9, wherein the carrier is formed by two plate members secured in parallel spaced relationship by one or a number of base members.

12. A scraper as in Claim 10 or Claim 11, wherein the base of the carrier has a number of holes, slots, or gaps to permit the exit therethrough of fines entering the carrier.

13. A scraper as in any of Claims 10 to 12, wherein each scraper blade is located within the carrier and has a lengthwise through slot to align with bolt holes in the channel side walls, with a bolt passing through the bolt holes and aligned slot.

14. A scraper as in Claims 10 to 12, wherein each scraper blade is located within the carrier, and has ribs or grooves to co-operate with corresponding grooves or ribs on the channel side walls.

15. A scraper as in any of Claims 10 to 14, wherein each scraper blade has a tail to pass through a corresponding hole in the bottom of the channel.

16. A scraper as in any of Claims 1 to 9, wherein the carrier is a bar-like member, on which are provided a number of spaced upstanding support members, and when each scraper has a lower section that is hollow and adapted to fit over a support member.

17. A scraper as in Claim 16, wherein spring means are fitted between the inner end of the hollow portion of each scraper and the outer end of the support member.

18. A scraper as in any of Claims 1 to 17, wherein each scraper blade is adjustably mounted on the carrier.

19. A scraper as in any of Claims 16 to 18, wherein each support member on the bar-like carrier is a threaded sleeve in which is screwed a threaded bolt, a compression coil spring lying within the sleeve and between the bolt and the scraper blade.

20. A scraper substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

21. A scraper substatially as hereinbefore described with reference to Figure 3 of the accompanying draings.