GB2477207A

GB2477207A - Supporting a rack bar haulage system to a conveyor.

Info

Publication number: GB2477207A
Application number: GB1100997A
Authority: GB
Inventors: Nigel Hill; Gordon Edmund Powell
Original assignee: Joy MM Delaware Inc
Current assignee: Joy MM Delaware Inc
Priority date: 2010-01-22
Filing date: 2011-01-21
Publication date: 2011-07-27
Also published as: GB201100997D0; US20110181095A1; PL393706A1; RU2011102054A; AU2011200256A1; CN102152791A

Abstract

A rack bar haulage system comprising part of the drive system for moving a mining machine along a conveyor wherein the rack bar 107 is mounted on a bracket (clog) 10 and fixed by a pin 111 inserted through a first opening in a sidewall 116 of the bracket and being received in an opening in the other sidewall 116 which has a portion 138 which is smaller than the diameter of the pin such that it forms a pocket so that the pin can not pass through the sidewall opening. The pin may be secured by a plate 120.

Description

A RACK BAR HAULAGE SYSTEM WITH AN IMPROVED RACKEAR TO LINE PAN

CONNECTION

BACKGROUND

This disclosure relates to rack bar haulage systems and the means by which the rack bars are secured and retained to armor face conveyors, in particular. though not necessarily exclusively, for underground longwall mining0 Longwall conveyors normally operate with a powered coal cutting machine, a shearer that is mounted onto the face conveyor. The shearer hauls itself along the face conveyor in both directions by means of a haulage system. A rack bar haulage systems comprise a series of rack bars pinned to support brackets, called clogs, welded to the individual armor face conveyor elements, the line pan0 The shearer engages with the racks via a shoe that permits free movement in the direction of shearer travel only0 The shoe also houses a drive sprocket that engages the rack teeth to provide the required haulage load to cut the mined material. The shearer drive gear wheel meshes with uniformly spaced horizontal teeth extending between two spaced apart cheek plates to form the rack bar.

All rack systems must withstand shearer haulage forces in various directions and their retention methods must cope with the tendency of the shearer shoe to bulldoze material in front of it as it passes along the conveyor.

In conventional longwall mining, as illustrated in Figures 1 2 taken from US Lanfermann et al Patent 4,155,600, a drum cutter mining machine 1 is traversed along a face conveyor 2 by means of a driving wheel 3 secured to a long'wall shearer 4. The driving wheel 3 meshes with a gearwheel or drive sprocket S that is rotatably supported on the machine frame 6 forming part of the drum cuttermining machine6 The teeth of the drive sprocket mesh with rack gear teeth of a rack bar or device 7 As illustrated in Figure 2, the face conveyor 2 is made up of a plurality of conveyor pan sections or line pans 9 joined together enthto-.-end by connecting elements 8 By means of these connecting elements, the conveyor pan sections are maintained movable with respect to each other so that the conveyor pan sections are adaptable to characteristics of the mine floor0 The individual conveyor pan sections are connected together by the connecting elements 8 to provide not only limited mobility with respect to each other in the horizcntal direction of the conveyor 2, but also to provide vertical or horizontal angling of one conveyor pan section with respect to another when set on the mine floor0 The rack device 7 that is mounted onto the face conveyor 2 undergoes the same horizontal motions as the conveyor pan sections6 When the face conveyor is shifted, the rack device also undergoes the same vertical angular motions which the conveyor pan sections undergo particularly when it is desired to work undulating portions of a mine seam6 The rack device 7 includes a plurality of elongated rack bars consisting of movable rack bars 7a and immovable rack bars 7b, Holders or clogs 10 that are directly or indirectly connected to the face conveyor 2 support all the rack bars0 Connecting bolts 11 are used to join the individual rack bars to the clogs 10 The movable and immovable rack bars 7a and 7b, respectively, of the rack device 7 are provided at both ends of each segment with a noseshaped extension 12 which projects downwardly0 This extension includes a bore for accommodating a connecting bolt 11 forming a pivot shaft0 As shown in Figure 1, the movable rack bars 7a bridge a joint A between the conveyor pan sections0 The movable rack bars 7a are mounted onto the same two holders 10 which are used to mount one end of adjacent inmtovable rack bars 7b0 These immovable rack bars are each entirely disposed to extend along a single conveyor pan section0 Thus, two rack clogs 10 are secured at. spacethapart locations to a conveyor pan sectionc Each immovable rack bar 7b is secured by connecting bolts or pins 11 at its opposite ends to the two rack holders which additionally support the adjacent ends of movable rack bars.

Each of the clogs 10 is provided with a slot 13 located on oneha1f of the holders that is nearest the joint between the conveyor pan sections The slots 13 in the clogs 10 extend in a direction corresponding to the longitudinal orientation of the face conveyor0 The connecting pins 11 extend through the slots and provide the associated movable rack bar Ia with adequate mobility with respect to the face conveyor0 The immovable rack bars 7b are fixed with respect to the face conveyor 2 by the connecting bolts 11 which retain these rack bars by extending through bores 13 formed in the remaining half of the holders Each bore 13 corresponds to the diameter of the pin 1l Thus, it is common to have two rack bars 7 per line pan 9 One rack bar 7b is fixed in the center of the line pan 9, and the second rack bar 7a spans the joint between adjacent line pans 9 Relative articulation between line pans during the mining process can cause the interpan gap to vary consi.derably and this could cause problems as the shearer drive sprocket S moves from the fixed rack bar lb to the interpan rack bar 7a, if the inter-pan rack bar is firmly pinned to either adjacent pan0 The common solution is for the interpan rack bar pins 11 to be retained in slots 13 in the clogs 10 rather than holes.

In this manner, the error in tooth pitch between adjacent rack bars is halved and is kinder to the shearer sprocket 5, but causes added difficulty with pin retention, as the pin 11 must be allowed to move along the slot 13 More particularly7 as shown in Figures 3, 4 and 5, the longwall line pans 9 include a goat side fabrication or shield plate 14. The shield plate 14 is located adjacent the rack bar haulage systen In order to secure the rack bar 7 to the clog 10, the pin 11 is inserted into the clog 10 through an opening in the shield plate l4 The clog 10 has a width corresponding to the width of the noseshaped extension 12, and the clog 10 defines a cavity for engaging and providing support for the rack bar 7 by receiving the noseshaped extension 12, the cavity being defined by two spaced apart bracket sidewalls 16, and end walls 17 connecting the sidewalls 16 The clog 10 also has openings 18 through the sidewalls 1$, the pin ii being insertable through one sidewall opening 18 and being received in the other sidewall opening 18 The pin has a head 19 that is larger than the opening through the sidewall of the clog 10, so the pin 11 cannot pass through the clog 10 In order to retain the pin 11 within the clog 10, a retainer plate 20 is dropped into the area between the head of the pin 11 and the shield plate 14 The retainer plate 20 prevents the pin 11 from coming out of the clog 10.

Thus, as shown in Figure 3 5, the conventional rack bars 7are retained in the clogs 10 by the headed pins 11 that can only be assembled through the opening 15 in the goat side shield plate l4 The headed pins 11 are themselves retained by the retainer plates 20 that locate in lugs 21 welded to the goat side shield plate l4. The retainer plates 20 are kept in place by gravity alone, but can be made more secure with another fastener, such as a bolt or a spring pine The primary role of the clog 10 is to provide fixing points on the line pans 7 for the semiflexible rack bar system along which the shearer hauls itself in order to cut material from the seam. The nature of the system is that rack bars 7 are easily replaced if damaged, but the clogs 10 cannot be repaired in a hazardous environment, as the required cutting and welding is prohibited. Hence there is a need for a strong, reliable, simple rack -clog retention assembly.

SUMMARY

It is an object of this disclosure to provide such a strong, reliable, simple rack clog retention assembly.

This disclosure provides a rack bar system utilizes a forged or cast clog with integral lugs that accept a retainer plate. The plain rack bar pins cannot pass fully through the clog and are held in place by a plate retainer, The retainer is simply secured by a spring pin, or is held in place by gravity.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure1 is a side elevation view of a prior art rack device for propelled movement by a drumtype cutter machine along a mine face.

Figure 2 is an enlarged view of the rack device shown in Figure 1 while supported by a face conveyor in its normal position Figure 3 is an exploded perspective view of one of the line pans shown in figure 1.

Figure 4 is a partial perspective view of the connection of one of the rack bars to a clog attached to a line pan.

Figure 5 is a cross-sectional vertical view through the rack bar attachment to the clog shown in Figure 4.

Figure 6 is a partial perspective view of an improved mechanism for attaching a rack bar to a clog.

S

Figure 7 is a perspective view of the clog and pin assembi.y shown in figure 66 Figure 8 is a bottom perspective view of the back side of the clog and pin assembly shown in figure 79 Figure 9 is a side view of the clog and pin assembly shown in figure 88 Figure 10 is a crosssectional view of the clog and pin assembly shown in figure 9, taken along the line 10 10 in figure 98 Before one embodiment of the disclosure is explained in detail, it is to be understood that the disclosure is not limited in its application to the details of the construction and the arrangements of components set forth in the following description or illustrated in the drawings2 The disclosure is capable of other embodiments and of being practiced or being carried out in various ways6 Also it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting8 use of inc]uding and comprising and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items8 Use of consisting of and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof8 Further, it is to be understood that such terms as forwar&, arearwardn, "lefty', "fright", upwar& and downward', etc8, are words of convenience and are not to be construed as limiting terms8

DESCRIPTION OF THE PREFERRED EMBODIMENT

This description takes as its starting point the typical longwall conveyor fitted with rack haulage, as described above, where a strong clog pin plate retention assembly is contained h entirely within the clog. Changing the clog position on the line pan does not require any consequent change to the line pan.

More particularly, as illustrated in Figures 6 -10, this disclosure provides a rack bar haulage system 100 forming part of a drive system for moving the mining machine along the conveyor, said rack bar haulage system 100 including a plurality of rack bars 107, each having spaced apart gear teeth 124 extending between cheek sections 128 at opposite sides of the rack bar 107, and a downwardly extending nose extension 112.

The rack bar haulage system 100 also includes a clog 110 that has a width corresponding to the width of the nose-shaped extension 112, and the clog 110 defines a cavity 132 for engaging and providing support for the rack bar 107 by receiving the nose-shaped extension 112, the cavity 132 being defined by two spaced apart bracket sidewalls 116, and end walls 117 connecting the sidewalls 116. The clog 110 also has openings 118 and 138 through the sidewalls 116. A pin ill is insertable through the sidewall opening 118 and the pin 111 is received in the other sidewall opening 138, the other sidewall opening 138 being smaller than the end 136 of the pin ill. The other sidewall opening 138 forms a pocket that receives the end 136 of the pin 111 that does not permit the pin 111 to pass through the other sidewall opening 138.

The clog 110 also includes means for receiving a retainer plate 120 for retaining the pin 111 within the first sidewall opening 118 * The means for retaining the plate 120 ccuprises spaced apart lugs 121 attached to the one side of one of the sidewalls 116, the lugs 121 including opposed slots 140 that receive the ends of the retainer plate 120. The lugs 121 also include a retaining spring pin 144 or similar for retaining the plates 120 within the lugs 121.

In sntary, the disclosed rack bar system 100 utilizes a forged or cast clog 110 with integral lugs 121 that accept a retainer plate 120. The plain rack bar pins 111 cannot pass fully through the clog 110 and are held in place by a plate retainer 120 * The retainer is simply secured by a spring pin 144, or can be merely held in place by gravity.

The retainer plate is a simple, strong device to retain clog pins in one direction only. Note that the tent plate only defines its general shape -it is not necessarily made from rolled plate and can be cast or forged.

The pin is plain on the prime proposal and requires no head for retention purposes. This is cost-effective.

various other features of this disclosure are set forth in the following claims.

tent ron is tii too ten to a ii. paer:s and documents which mre flied concurrent i y with or previous to th speoxtioation in connect ion with this appi icati on and S which are open to Pub inspection with this soeoi fica tion and the contents ot all such papers and documents are inoornorated herein by r:eterenoe All or t.he features disclosed n this smecirication inciudinc any aooomoanyinq claims abstract and drawinqs) and/or; all of the steps of any method or: process so disclosed, may be combined in any contbinat:ion.

except combinations where at least some of such features and/or: s tens are mu tuali yaxclusive Ic Each teatur:e di sciosed in this spec]. ficatlon may he r:eplaced i' alternative features servinq-thee ame.

0 C' ---

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. \\ C' - _\ teatur:e disc]. osed is one example only of a cener:io series Ot equivalent or similar: features The invention is not. res:trioted to the details of the foreqoin embdlment ( s) The nvention extends to any nnve one or: any novel, combination ci' the featur:es disclosed in this speoi floation mci udino any ac:oompantinq c:laims, abstract and drawinqs) r or to any novel one.. or: any novel combinati.on of the steos of any u metnoc or: proc ass so di soroseo

Claims

CLAIMS1. A rack bar haulage system forming part of a drive system for moving the mining machine along a conveyor, said rack bar haulage system including a plurality of rack bars, each having spaced apart gear teeth extending between cheek sections at opposite aides of the rack bar, and a downward extension, a clog having a width corresponding to the width of the downward extension, and the clog defining a cavity for engaging and providing support for the rack bar by receiving the downward extension, the cavity being defined by two spaced apart bracket sidewalls, and end walls connecting the sidewalls, openings through the sidewalls, a pin being insertable through one sidewall opening and being received in the other sidewall opening, the other sidewall opening being smaller than the end of the pin, and the other sidewall opening forming a pocket that receives the end of the pin, the other sidewall opening not permitting the pin to pass through the other sidewall opening.
2. A rack bar haulage system in accordance with Claim 1 wherein the lugs include a pin for retaining the plates within the lugs.

3 A rack bar haulage system forming part of a drive system for moving the mining machine along a conveyor, said rack bar haulage system including a plurality of rack bars, each having spaced apart gear teeth extending between cheek sections at opposite sides of the rack bar, and a downward extension, a clog having a width corresponding to the width of the downward extension, and the clog def..ifling a cavity for engaging and providing support for the rack bar by receiving the downward extension, the cavity being defined by two spaced apart bracket sidewalls, and end walls connecting the sidewalls, openings through the sidewalls, a pin being insertable through one sidewall opening and being received in the other sidewall opening, the other sidewall opening being smaller than the end of the pin, and the other sidewall opening forming a pocket**ha receives the end of the pin, the other sidewall opening not peritti.ng*he pin to pass through the other sidewall opening, the clog further including means for receiving a plate for retaining the pin within the first sidewall opening, the means for retaining the plate comprising spaced apart lugs attached to one side of the one sidewall, the lugs including opposed slots that receive the ends of the plate 4 A rack bar haulage system in accordance with Claim 3 wherein the lugs include a pin for retaining the plates within the lugs S A rack bar haulage system constructed and arranged substantially as herein described, with reference to fiqures 6' to 10 of the accompanying drawings,