AU5494299A

AU5494299A - Conveyor skirtboard sealing system

Info

Publication number: AU5494299A
Application number: AU54942/99A
Authority: AU
Inventors: Giangregorio Massarotto
Original assignee: PENTAGON HOLDINGS Pty Ltd
Current assignee: PENTAGON HOLDINGS Pty Ltd
Priority date: 1990-11-22
Filing date: 1999-10-15
Publication date: 2000-02-03
Also published as: AU2002300257B2

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE

SPECIFICATION

STANDARD

PATENT

Name of Applicant: Actual Inventor Address for service is: PENTAGON HOLDINGS PTY LTD GIANGREGORIO

MASSAROTTO

WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: "Conveyor Skirtboard Sealing System" Details of Associated Application No(s): 24799/97 The following statement is a full description of this invention, including the best method of performing it known to me:r -2- THIS INVENTION relates to skirt seals for belt conveyors.

Skirt seals are used with belt conveyor systems which carry particulate material such as coal, ores or the like. The skirt seals are used at locations where material is delivered onto the conveyor belt, typically by way of a loading chute or a transfer chute at which material from one belt is transferred onto another belt.

The purpose of the skirt seal is to prevent the conveyed material from leaking between the bottom of the chute and the conveyor belt.

It is usual for the skirt seal to have a sealing element in contact with the upper surface of the conveyor belt. The lower edge of the sealing element is prone to wear due to abrasion and so the sealing element is periodically required to be lowered and eventually replaced.

Conventional skirt seals typically comprise a sealing element in the form of a thick rubber sheet which is adjustably mounted in some fashion onto a skirtboard.

There are three common arrangements by which the sealing element can be mounted and they are distinguished by the orientation of the sealing element. In the first arrangement the sealing element is disposed vertically. In the second arrangement, the sealing element is perpendicular to the section of the belt with which it is in contact. In the third arrangement, the sealing element is disposed obliquely with respect to the belt. In each case, the bottom edge of the sealing 20 element is in contact with the belt. A common feature of these arrangements is that the resilient nature of the sealing elements is utilised to maintain sealing contact with the belt but does not really accommodate vertical displacement of the belt.

Due to the shortcomings of the above three arrangements and so to attempt to accommodate movement in the belt a still further arrangement has also been used. This further arrangement is such that the lower edge of the sealing o element tucks inwardly and to some extent along a top surface of the belt. This method provides mixed results and is dependent upon the troughing angle of the conveyor belt and other factors common to the three arrangements noted above.

The present invention seeks to provide a skirt seal which provides a useful alternative to the conventional arrangements described previously.

To this end, according to the present invention there is provided a skirt seal for a belt conveyor, comprising a resiliently flexible sealing element, support means for supporting the sealing element in sliding contact with an upper face of the belt, the sealing element having a pair of opposed side faces and being curved at an intermediate portion thereof so that a lower portion of the sealing element extends inwardly and is in overlapping contact at one of the side faces thereof with the belt to establish a seal therebetween, said one face having an upper section extending downwardly from the support means, a lower section in contact with the upper face of the belt, and an intermediate section corresponding to the intermediate portion between the upper and lower sections, the intermediate section being arcuate and being disposed generally centrally between the upper and lower sections.

Preferably, there is a point of intersection between a first imaginary line extending along and beyond the upper section and a second imaginary line extending along and beyond the lower section, the point of intersection being approximately 20 equidistant from a point at which the upper section contacts the support means and a point on a lower edge of said one face.

Preferably, the sealing element has an upper portion above the lower portion with the intermediate portion being between the upper and lower portions, and wherein said upper and lower portions are disposed at an oblique angle with respect to each other.

0 Preferably, the upper portion is oriented so that it extends downwardly and inwardly with respect to the belt.

Still preferably, the upper portion of the sealing element is disposed at an angle of about 500 with respect to the upper face of the belt.

In one arrangement, the support means may include a clamping device for releasably engaging the upper portion of the sealing element, the clamping device comprising first and second clamping elements each defining a clamping face, and coupling means for coupling the first and second clamping elements together with the flexible sealing element clamped between the clamping faces.

In another arrangement, the support means may include a clamping device for releasably engaging the upper portion of the sealing element, the clamping device comprising first and second clamping elements each defining a clamping face, a bridging member having a first end attached to one of the clamping elements and a second end adapted to bear against the other clamping element, and connecting means for releasably connecting a portion of the bridging member between the ends thereof to said other clamping element.

While the connecting means may be of any suitable form such as a bolt, it is preferably in the form of a cam locking mechanism. The cam locking mechanism may comprise a cam mounted onto one end of a link the other end of which is pivotally mounted onto said other clamping element. For preference, the cam is adapted to engage against the outer face of the bridging member opposed to the 0 20 clamping faces.

The outer face of the bridging member may be provided with a recess to accommodate the cam. The cam may have stop means to limit the extent of its rotation in the locking direction.

Preferably the bridging member is substantially rigid with some resilient flexibility.

The invention will be better understood by reference to the following description of one specific embodiment thereof as shown in the accompanying drawings in which: Fig. 1 is a fragmentary perspective view of a belt conveyor on which there are installed skirt seals according to the embodiment; Fig. 2 is a schematic end view of one of the skirt seals; Fig. 3 is a fragmentary perspective view of the skirt seal with the clamping device shown in a condition prior to clamping engagement of the sealing element; Fig. 4 is a view similar to Fig. 3 with the exception that the clamping device is shown clampingly engaging the sealing element; Fig. 5 is an exploded view of the skirt seal; and Fig. 6 is a further schematic end view of one of the skirt seals, showing dimensional details of the sealing element.

The embodiment shown in the drawings is directed to skirt seal 10 for a belt conveyor 11 having an endless belt 13 and a loading chute 15 for loading particulate material, such as ore, onto the load carrying face of the belt. The loading chute 15 incorporates skirtboards 17 of conventional form having a lower edge 19 positioned a small distance above the load carrying face of the belt.

ftOne of the skirt seals 10 according to the embodiment is associated with each skirtboard 17 for sealing the gap between the bottom edge 19 of the skirtboard and the load carrying face of the belt 13 to prevent leakage of material.

Each skirt seal 10 comprises a flexible sealing element 21 carried by support means 23 for contact with the travelling belt. The sealing element 21 is of generally rectangular form and has an inner face 25, an outer face 27 and a peripheral edge 29 extending between the inner and outer faces. It is formed of ,-resiliently flexible elastomeric material such as rubber and can be formed in 0 ft sections for convenience. Channels 28 are formed in the outer face 27 of the f° ftsealing element to provide passageways by which material which has been spilled or has leaked passed the sealing element can return to the region of the conveyor belt disposed between the skirt seals.

The support means 23 supports the sealing element 21 in such a way that the lower portion 21a thereof extends inwardly and is in overlapping contact at an outer side face 27 thereof with the upper face of the belt to provide a seal therebetween, as best seen in Fig. 2 of the drawings. The upper portion 21b of the sealing element extends downwardly and inwardly at an angle of about 500 with respect to the conveyor belt. This downward and inward extent of the upper portion 21b is provided for by a curved intermediate portion 21c provided between the lower and upper portions 21a and 21b respectively. The lower and upper portions 21a and 21b respectively are disposed at an oblique angle with respect to each other of about 130' Each of the aforementioned angles have a variation of plus or minus 2.50 before performance is adversely affected.

The support means 23 comprises a plurality of clamping devices 30 for clampingly engaging the upper end section of the flexible element. The clamping devices 30 are spaced apart at regular intervals along the length of the skirt seal.

Each clamping device comprises a first clamping element 31 and a second clamping element 32 each defining a clamping face 33.

The outer side face 27 of the sealing element 21 has a lower section 27a, an o• upper section 27b and an intermediate section 27c of integral construction. The upper section 27b extends downwardly from the support means 23, and more 20 particularly downwardly from the clamping face 33 of the second clamping element 32. The lower section 27a is in sliding contact with the upper face of the belt 13. The intermediate section 27c is arcuate, with the curvature thereof corresponding to the curvature of the intermediate portion 21c of the sealing element 21.

:too: 25 The arcuate intermediate section 27c is disposed generally centrally between the upper section 27b and the lower section 27a. More particularly, as shown in Fig.

6 of the drawings, a first imaginary line 22 extending along and beyond the upper section 27b intersects with a second imaginary line 24 extending along and beyond the lower section 27a at a point of intersection 26 which is approximately -0 -7equidistant from a point 29 at which the upper section 27b contacts the support means 23 and the bottom edge of the sealing element 21. In Fig. 6, the distance between the point of intersection 26 and the point 29 is identified as dimension and the distance between the point of intersection 26 and the bottom edge of the sealing element 21 is identified as dimension the two dimensions and being approximately equal.

The relationship between the intermediate section 27c and the lower and upper sections 27a and 27b respectively in that it is centrally located therebetween is important as it defines the position of the curved intermediate portion 21 c which is in itself important in terms of maintaining effective sealing contact between the sealing element 21 and the belt 13 and so ensuring proper operation of the skirt seal The first clamping elements 31 are defined a longitudinal member mounted on the skirtboard 17. The longitudinal member is of channel form, having an inner wall 37, an outer wall 39 and a web 41 extending between the inner and outer walls. The inner wall 37 is adapted to be bolted or otherwise secured to the skirtboard 17. The outer wall 39 defines one of the clamping faces 33. For convenience, the longitudinal member may be formed in sections.

0. Each second clamping element 32 comprises a member having a pair of side walls 43, 45 disposed angularly with respect to each other, the side wall 43 defining the other of the clamping faces 33.

a.

The clamping devices 30 each further comprises a coupling means 50 for coupling the first and second clamping elements together with the flexible sealing o .element clamped between the clamping faces thereof The coupling means comprises a bridging member 51 adapted to extend between the first and second clamping elements. The bridging member comprises a metal bar shaped to define a central portion 52 and a pair of wing portions 53 which diverge with respect to each other. One of the wing portions 53 is bonded to the second clamping element 32 and the free end of the first wing portion is adapted to bear on the web 41 of the other clamping element 31.

A connecting means 55 is provided for releasably connecting the central region 52 of the bridging member to the first clamping element 31. The connecting means 55 comprises a cam 57 mounted on one end of a link 59 the other end of which is pivotally connected to the first clamping element. The link 59 is of generally U-shape, comprising two arm portions 61 and a central portion 63 interconnecting the arm portions. The cam 57 is rotatably mounted onto a shaft which is in the form of a bolt and which is supported between the free ends of the arm portions 61 of the link. The arm portions 61 extend through slots 67 each of which is formed in the inner wall and web of the longitudinal member defining the first clamping member 31 at the junction

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S S o *oe oo*** *o therebetween. The central portion 61 of the link is disposed within the interior of the longitudinal member 35 defining the first clamping element 31. With this arrangement, the link 59 is pivotally connected to the first clamping element so that it can swing about the first clamping element to move the cam into contact with the central portion 51 of the bridging member (as shown in Fig. 4 of the drawings) and away from such position so that the cam is clear of the bridging member to allow the first and second clamping elements to be separated (as shown in Fig. 3 of the drawings).

The cam 57 comprises a cylindrical element mounted eccentrically on the shaft 65. The cylindrical element has a circumferential recess 71 intermediate its ends and an opening 75 for receiving a tool to rotate the cam.

The central portion 51 of the bridge is configured to define a recess 77 which functions as a cradle to receive the cam when the cam is in the engaging position, as best seen in Figs. 2 and 4 of the drawings.

The cam is provided with stops 79 for limiting the extent of rotation of the cam in the locking direction.

o• o• The clamping devices 30 enable the sealing element 21 of each skirt seal 10 to be easily installed, periodically adjusted and eventually replaced, as necessary.

For each clamping device 30 to clamp the sealing element in position, the sealing element is placed between the clamping faces of the clamping device and the link 59 is pivoted into a position at which the cam 57 contacts the recess 77 in the bridge portion. At this stage, the cam 57 is rotated about the shaft in the locking direction to positively engage against the bridging member and in so doing apply an inwardly directed force onto the outer side of the bridging member 51. This force urges the free end of the bridging 0*o member into pressing engagement with the web 41 of the first clamping element 31. The resilient nature of the bridging portion allows some deflection of the bridging portion to ensure positive engagement between the bridging portion and the cam. At this stage, the sealing element is tightly clamped between the clamping faces of the first and second clamping elements. When it is desired to adjust or replace the sealing element, it is simply necessary to rotate the cam in the unlocking direction so as to move it out of positive engagement with the bridging member so that it can be pivoted clear of the bridging member by way of the link 59. This allows the first and second clamping elements to be separated and so release the sealing element.

When the sealing element is in position, the lower portion 21a thereof is in sliding contact with the load carrying face of the conveyor belt. This contact is along the outer face 27 of the sealing element adjacent the lower edge thereof. Because of the contact between the sealing element and the belt along the outer face of the sealing element and the orientation of the sealing element such that it extends downwardly and inwardly with respect to the belt at an angle of about 500, the resilient nature of the sealing element maintains the sealing element in sealing :o contact with the belt while also allowing the sealing element to rise and fall to ~accommodate any vertical displacement which may occur in the belt. Despite *o any vertical displacement of the belt the arrangement of the sealing element is ":such that the angle between the upper portion thereof and the conveyor belt is maintained. In other words, the resilient nature of the sealing element is utilised to maintain sealing engagement with the belt while allowing vertical movement of the sealing element as necessary. This provides particular advantages over conventional arrangements for sealing elements where the resilient nature of the sealing elements while tending to maintain sealing engagement with the belt a also tends to resist rise and fall to accommodate vertical displacement in the belt.

The preferred angles defined between the upper and lower portion of the sealing element and between the upper portion of the sealing element and the upper face of the belt have been shown to produce a consistency in performance and efficiency.

It should be appreciated that the scope of the invention is not limited to the scope of the embodiment described.

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Claims

1. A skirt seal for a belt conveyor, comprising a resiliently flexible sealing element, support means for supporting the sealing element in sliding contact with an upper face of the belt, the sealing element having a pair of opposed side faces and being curved at an intermediate portion thereof so that a lower portion of the sealing element extends inwardly and is in overlapping contact at one of the side faces thereof with the belt to establish a seal therebetween, said one face having an upper section extending downwardly from the support means, a lower section in contact with the upper face of the belt, and an intermediate section corresponding to the intermediate portion between the upper and lower sections, the intermediate section being arcuate and being disposed generally centrally between the upper and lower sections.

2. A skirt seal according to claim 1 wherein there is a point of intersection between a first imaginary line extending along and beyond the upper section and a second imaginary line extending along and beyond the lower section, the point of intersection being approximately equidistant from a point at which the upper section contacts the support means and a point on a lower edge of said one face.

3. A skirt seal according to claim 1 or 2 wherein the sealing element has an upper portion above the lower portion with the intermediate portion being between the upper and lower portions, and wherein said upper and lower portions are disposed at an oblique angle of about 1300 with respect to each other. °ooo S

4. A skirt seal according to claim 3 wherein the upper portion is oriented so that 25 it extends downwardly and inwardly at an angle of about 500 with respect to the belt.

A skirt seal according to claim 3 or 4 wherein the support means includes a clamping device for releasably engaging the upper portion of the sealing element, the clamping device comprising first and second clamping elements each defining a clamping face, and coupling means for coupling the first and second clamping elements together with the flexible sealing element clamped between the clamping faces.

6. A skirt seal according to claim 3 or 4, the support means including a clamping device for releasably engaging the upper portion of the sealing element, the clamping device comprising first and second clamping elements each defining a clamping face, a bridging member having a first end attached to one of the clamping elements and a second end adapted to bear against the other clamping element, and connecting means for releasably connecting a portion of the bridging member between the ends thereof to said other clamping element.

7. A skirt seal according to claim 6 wherein the connecting means comprises a cam mounted onto one end of a link the other end of which is pivotally mounted onto said other clamping element. go o•

8. A skirt seal according to claim 7 wherein the cam is adapted to engage against the outer face of the bridging member opposed to the clamping faces.

9. A skirt seal according to claim 8 wherein the outer face of the bridging member is provided with a recess to accommodate the cam.

A skirt seal according to claim 9 wherein the cam is provided with stop means to limit the extent of its rotation in the locking direction.

:11.A skirt seal according to any one of claims 7 to 10 wherein said cam 25 comprises a generally cylindrical member eccentrically mounted in the link.

12. A skirt seal according to any one of claims 7 to 11 wherein the bridging member is substantially rigid yet has some resilient flexibility.

13. A skirt seal substantially as herein described with reference to the accompanying drawings. Dated this fifteenth day of October 1999. PENTAGON HOLDINGS PTY LTD Applicant Wray Associates Perth, Western Australia Patent Attorneys for Applicant S S 0S S *SSS *SS* S S. S 5555 *r S S 5555 S S. S S S S.