GB2137579A

GB2137579A - Improvements in scraper units for scraper-chain conveyors

Info

Publication number: GB2137579A
Application number: GB08408211A
Authority: GB
Inventors: Dieter Grundken; Manfred Redder; Franz Roling; Harmut Schewinski; Gunther-Dietmar Schoop
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1983-04-06
Filing date: 1984-03-30
Publication date: 1984-10-10
Also published as: DE3312323A1; BE899337A; GB8408211D0; FR2543925A1

Abstract

A scraper unit for a scraper-chain conveyor or assembly has a scraper 4 clamped to horizontal links of a chain or a pair of chains with a locking member 5 therebeneath. The locking member 5 is fixed to the scraper with the aid of nuts and bolts 6, 15 and the bolts 6 engage in aligned bores 8, 11 in depending webs of the scraper 4 and end portions of the locking member 5. The bolts 15 extend in the general direction of the chains. Either the bores 8, 11 or abutting faces 10, 16 of the webs and the end portions are inclined to ensure that the links are subjected to a positive clamping force as the nuts and bolts 6, 15 are tightened. <IMAGE>

Description

SPECIFICATION Improvements in scraper units for scraper-chain conveyors The present invention relates in general to scraperchain conveyors as used in mineral mining and more particularly to scraper-chain assemblies and scraper units for use therein.

Various types of scraper-chain assembly are known. The so-called "in-board" assembly has one or more chains disposed at the central region of a series of conveyor pans and scraper units are detachably fixed to the chain or chains at intervals along the chain or chains. The units extend transversely of the chain or chains and entrain material such as mineral ore which is transferred along the pans as the scraper-chain assembly is driven.

German patent specification 1506979 describes a known construction in which each scraper unit is composed of a scraper proper and a clamping strap which lies beneath the scraper. The scraper and strap trap a horizontal link of a single chain therebetween. The strap is fixed to the scraper with the aid of nuts and bolts. German patent specification 2031874which has a counterpart US 3653492, describes a double-chain arrangement wherein the scraper has a recessed central region which receives the horizontal links of the chains trapped with a locking member engaging therebeneath. Depending lugs on the underside of th is central region project into the chain links and both the scraper and the locking member have recesses which engage with the links.The locking member is fixed to upstanding web plates of the scraper with the aid of nuts and bolts and the bolts extend generally parallel to the chains and to the floor of the conveyor.

In the known constructions the chain links are trapped in compartments formed partly by the scraper and partly by the locking member with a certain clearance on a shape-locked principle. The links tend to move in the compartments and after a period of use wear occurs and in time the assembly can be disabled.

A general object of the invention is to provide a improved form of connection between a chain or chains and a scraper unit.

A scraper unit for a scraper-chain assembly constructed in accordance with the invention is composed of a scraper and a locking member secured thereto with the aid of nuts and bolts extending generally transversely to the scraper and the locking member so as to trap at least one link of a chain therebetween in generally known manner. In contrast to the known constructions however, the link is coupled to the scraper on a force-locking principle rather than a shape-locked principle. As the nuts and bolts used to fix the locking member to the scraper are tightened an upwardly-directed component of force urges the link against the scraper. The link is thus subjected to a positive force by the locking member which urges the link against the scraper.As is known, a recessed central region of the scraper has recesses which receive the chain link and lateral web plates with bores aligned with bores in end portions of the locking member and receiving the shanks of the bolts. In one embodiment of the invention the bores are inclined to provide the upwardly-directed force component. The web plates and the end portions of the locking member then may have abutting planar faces which are perpendicular to the floor of the conveyor. In another embodiment of the invention these abutting faces are inclined while the bores are more or less parallel to the floor of the conveyor.

In contrast to the prior art, the locking member is urged against the scraper by the pre-stressed force in the bolts and this ensures the links are less apt to wear free. It is possible to have the bores in the webs or in the end portions inclined.

The shanks of the bolts can engage in the one or both bores with ample clearance or with only slight clearance. A preferred arrangement has clearance in relation to the bores in the webs above the shanks and clearance in relation to the bores in the end portions below the shanks.

The invention may be understood more readily and various other aspects and features of the invention may become apparent, from consideration of the following description.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings wherein: Figure 1 is a plan view of a scraper unit forming part of a scraper chain assembly and constructed in accordance with the invention; Figure 2 is a sectional end view of the scraper unit of Figure 1, the view being taken along the line A-B of Figure 1 and on a somewhat larger scale to that adopted in Figure 1; Figure 3 is a view corresponding to Figure 2 but depicting an alternative embodiment of the invention; Figure 4 is an elevation of the scraper of the unit shown in Figure 1; Figure 5 is an elevation of the complementary locking member used with the unit of Figure 1, the view being taken on a somewhat larger scale to that adopted in Figure 4; and Figure 6 is a plan view of the locking member shown in Figure 5.

Referring to Figure 1, and as is known, a scraper chain assembly for use in a scraper chain conveyor is composed of a pair of oval link chains 2,2' to which spaced-apart scraper units 3 are coupled. Only one such unit 3 is depicted in the drawing. During use, the assembly is propelled in the direction of arrow X in Figure 1 along the pans of a scraper chain conveyor of which the floor thereof is designated 17 in Figure 2. The units 3 thereby transfer mineral ore, such as coal, along the floor 17.

Each scraper unit is composed of a scraper 4 shown separately in Figure 4 and a detachable locking member shown in Figures 5 and 6. The locking member is fixed to the associated scraper 4 with the aid of nuts and bolts 6, 15 extending generally parallel to the chains 2, 2'. The locking member 5 and the associated scraper 4 are shaped to trap horizontal links of the chains 2,2' therebetween. More particularly, horizontal links 7,7' of the chains 2, 2' engage in recesses at the underside of a recessed central region 18 of the scraper 4 and in recesses 22 formed at the upperside of a recessed central region 21 of the locking member 5.

The end regions 20 of the locking member 5 has recesses 12 which accommodate the heads 13 of the bolts 6 while the bores 8 in the webs 19 of the scraper 4 adjoin further recesses 14 into which are engaged the nuts 15 screwed onto the bolts 6.

Between the associated pairs of recesses 24 in the central region 18 of the scraper 4 there are downwardly projecting lugs 26 which are received directly in the links 7,7' as shown in Figure 4. At the sides of the central region 18 of the scraper 4 there are upstanding webs 19 provided which bores 8 for receiving the shanks of the bolts 15. The locking member 5 has corresponding end portions 20 laterally offset from the central region 21 as shown in Figure 6. These end portions 20 locate with the webs 19 of the scraper4 and have bores 11 which align with the bores 8 and thus also receive the shanks of the bolts 15. The webs 19 and the end portions 20 have abutting planar faces 10, 16 (Figures 2 and 3).

As shown in Figure 2 the bores 11,8 are inclined and the faces 12, 10 are substantially perpendicular to the floor 17. The angle a between the engaging faces 10, 16 of the scraper 4 and the locking member 5 and the common axis of the bores 8, 11 is greater than 90 . In the alternative construction depicted in Figure 3, the engaging faces 10, 16 are inclined in relation to the floor 17 while the common axis of the bores 8, 11 is substantially parallel to the floor 17 to provide the same angle a.

In both embodiments, the arrangement is such that when the nuts and bolts 15, 6 are tightened to bring the surfaces 16,10 into close abutment an upward component of force is exerted on the member 5 to urge the horizontal links 7,7' against the recesses 24 of the scraper 4 on the force-locked principle.

In both constructions it is preferred to have clearance between the shanks of the bolts 6 and the bores 8 above the shanks and between the shanks of the bolts 6 and the bores 11 below the shanks as shown in Figures 2 and 3.

Claims

1. A scraper unit for a scraper chain conveyor which is composed of a scraper and a locking member detachably secured to the scraper with nuts and bolts extending generally transversally to the scraper and the locking member in a manner to trap at least one horizontal chain linktherebetween; wherein the link is located on a force-locked prin ciple.

2. A scraper unit for a scraper chain conveyor which is composed of a scraper and a locking member detachably secured to the scraper with nuts and bolts extending generally transversally to the scraper and the locking member in a manner to trap at least one horizontal chain linktherebetween; wherein the link is subjected to a positive force by the locking member which urges the link against the scraper.

3. A scraper unit according to claim 1, wherein the link is subjected to a positive force by the locking member which urges the link against the scraper.

4. A scraper unit according to any one of claims 1 to 3, wherein the scraper and the locking member have central regions with recesses for locating the link, the scraper has webs adjacent the central region and the locking member has corresponding end portions, and wherein the webs and end portions having alignable bores for receiving the shanks of the bolts and inter-engaging planar faces.

5. A scraper unit according to claim 4, wherein the alignable bores are each inclined to the horizontal.

6. A scraper unit according to claim 4, wherein the planar faces are each inclined to the horizontal.

7. A scraper according to claim 5 or 6, wherein the angle between the common axis of the alignable bores and the planar faces is greater than 90 .

8. A scraper unit according to claim 4, wherein the bores in the webs are inclined to the horizontal.

9. A scraper unit according to claim 4, wherein the bores in the end portions are inclined to the horizontal.

10. A scraper unit according to any one of claims 4 to 9, wherein the shanks of the bolts are received in the bores with ample clearance.

11. A scraper unit according to any one of claims 4 to 10, wherein the shanks of the bolts are received in the bores in the webs with ample clearance and the shanks of the bolts are received in the bores in the end portions of the locking member with only a slight clearance.

12. A scraper unit according to any one of claims 4to 10, wherein the shanks of the bolts are received in the bores of the webs with clearance above the shanks and remote from the locking member and the shanks of the bolts are received in the bores of the end portions of the locking member with clearance below the shanks.

13. A scraper unit according to any one of the preceding claims wherein a pair of chain links are trapped between the scraper and the locking member.

14. A scraper unit substantially as described with reference to and as illustrated in any one of Figures 1,2, 4,5and6or Figures 1,3,4,Sand6ofthe accompanying drawings.

15. Ascraper-chain assembly orconveyorem- ploying scraper units in accordance with any one of the preceding claims.