AU736955B2

AU736955B2 - A sub-level caving hydraulic support with a low-positioned door for passing caved coal

Info

Publication number: AU736955B2
Application number: AU27673/00A
Authority: AU
Inventors: Fanzeng Meng; Xiurui Qiao; Bin Xie
Original assignee: Yankuang Group Corp Ltd
Current assignee: Yankuang Group Corp Ltd
Priority date: 1999-11-10
Filing date: 2000-04-11
Publication date: 2001-08-09
Anticipated expiration: 2020-04-11
Also published as: CN1296116A; CN1087807C; AU2767300A

Description

Our Ref:7465497 P/00/011 Regulation 3:2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT .0.0 .:O*o .0.0 0*00 0 0.

0.0.

0 00000 IP Australia vi Documents received on: ca B 1 1 APR 2100 8&tch No: I r Applicant(s): Address for Service: Yankuang (iroup Corporation No. 40 Fushan Road Zoucheng City Shandong 273500 People's Republic of China DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 Invention Title: A sub-level caving hydraulic support with a low-positioned door for passing caved coal The following statement is a full description of this invention, including the best method of performing it known to me:- 5020 A SUB-LEVEL CAVING HYDRAULIC SUPPORT WITH A LOW- POSITIONED DOOR FOR PASSING CAVED COAL The present invention relates to a sub-level caving hydraulic support with a low-positioned door for passing caved coal, which is especially suitable for mining a coal seam over 5m with a good capability of a top coal, i.e. for the working face at which the immediate roof is caved immediately following the face advance.

To keep an enough space for caving coal at a rear portion of a support, two types of structures are generally selected and used for the sub-level caving hydraulic supports with a low-positioned door for passing caved coal.

The sub-level caving hydraulic support with a low-positioned door for *.."passing caved coal and a reverse four bar linkage occupies too much passage space, and is difficultly to be operated so that it can not satisfy requirements Sof high-efficiency and high-output at a coal face. When the sub-level caving hydraulic support is equipped a normal four bar linkage with the Y-shape front bar, the front bar is loaded up unreasonably and its strength is lowered because only one hinge point is provided between the front bar and the base of the support. Because of the lower connection strength between the base and the front bar, the stability and the forsional strength of the support are 1 P:\WPDOCSXDYS\spccic\7465497spe.doc-19 June 2001 -2lower so that the failure rate thereof is higher. Therefore, the lower reliability of the support restricts to increase the output of the face and hinders the normal operation.

According to one aspect of the present invention there is provided a sub-level caving hydraulic support including a base and a canopy each having a forward end portion and a rearward end portion, forward and rearward pairs of hydraulic legs operatively interconnecting the base and the canopy, said forward legs being laterally spaced apart from one another and disposed towards the forward end portions of said base and canopy and said rearward legs being laterally spaced apart and disposed towards the rearward end portions of the base and canopy; a debris shield pivotally connected to the rearward end portion of the canopy, a tail canopy pivotally connected to the debris shield a retractable plate operatively connected to the tail canopy for movement relative thereto between an extended position and a retracted position, a drive cylinder for causing said movement of said retractable plate, front and rear bar link means pivotally connected to the rearward end portion of the base and the debris shield, said front bar link means including two bars each disposed behind a respective one of said rearwards legs.

S: Preferably, the base has a bottom surface and the rear bar means is a single bar pivotally mounted to the base at a pivot point, the height from the pivot point to the bottom surface of the support is in a range of 750mm to 950mm.

R Preferably, the upper surface of the canopy makes an angle of a 300 400 with the debris shield at working positions. The height B for passing caved coal from the tail P:\WPDOCS\DYSspecic\7465497spc.doc-19 Jun 2001 -3canopy to the bottom surface of the base is 1000mm to 1200mm.

As compared with the prior art, remarkable advantages of the present invention are as follows: As compared with the hydraulic supports with the reverse forbear linkage, a proper position and sufficient space for passing workers are provided by the present support since the front bars are positioned behind the rear legs. This facilitates operation of miners. As compared with the sub-level caving hydraulic support with a low-positioned door for passing caved coal and the normal lemniscate linkage in which the front lemniscate bars are shaped in Y-shape, two bars can be used as the front bars according to the design of the present invention so as to greatly improve load conditions of the support and to enhance strength and reliability of the support.

To keep an enough space for passing caved coal at the rear portion of the support, the height A from the pivot point of the rear lemniscate bar (a single rear bar) on the base to the bottom surface of the base is preferably selected within a range of 750mm to S: 950mm. In the operation positions, a inclination angle a between the upper surface of the canopy and the debris shield should be 300 400. The height B for passing caved coal from the tail canopy to the bottom surface of the base is about 1000mm to 1200mm.

Because of the selections to the above parameters and the structure according to the P RAN present invention, an enough space for passing caved coal are kept in the support and the capacities against the deflection load as well as the horizontal force are increased. The P.\WPDOCS\DYS\.spcie\7465497spc.doc-19 Jm 2001 -4stability, strength and reliability of the support are, therefore, greatly enhanced. All the advantages maintain a long operating time and provide a possibility to be continuously operated so that it is possible to obtain a high output with high efficiency and to decrease the maintenance cost as well as the production cost.

The description of attached figures of a preferred embodiment of the present invention are as follows: FIG 1. is a schematic drawing showing the whole structure of the present invention; FIG. 2 is a vertical view showing A-A section in FIG. 1.

•The present invention will be explained as accompanying the figures in details.

oo *o with a forepole. The base 2 and the canopy 3 are connected together by legs 1 at its two end respectively. The rear end of the canopy 3 is pivoted to a debris shield 4. The debris shield 4 is pivoted to a tail canopy 6 equipped with a retractable plate 5. Tail canopy cylinder 9 for actuating a canopy 6 is connected with the debris shield 4 and the tail canopy 6. The retractable plate is moved by the tail canopy cylinder 9 as well as a cylinder 10, which is disposed in the tail canopy, to break big pieces and to adjust the opening of **"the coal door for passing caved coal. The front and rear bars are positioned between the rear portion of the base 2 and the debris shield 4. The front bar 7 is arranged behind the rear legs of the support. According to this structure, the front bar 7 can be designed as double-bars (as shown is Fig.2) so as to improve the load condition of the support and to enhance the strength and reliability of the support.

In order to form an enough space for passing caved coal and to facilitate o the operation and the maintenance at the rear portion of the support, the rear bar can be designed as a single bar 8. The cross-section of the bar 8 is larger than that of the front bar 7 to meet the requirement of the strength of the support. The height A from the pivot point of the rear bar 8 on the base 2 to the bottom surface of the support is in a range of 750mm to 950mm at the working positions (the height of the support is from 2.8m to 3.2m generally), the inclination angle a between the upper surface of the canopy 3 and the caving shield 4 is preferably in a range of 300 to 40 and the height B for passing caved coal from the tail canopy 6 to the bottom surface of the support ranges from 1000mm to 1200mm.

ZFS6200/18/35 Type Sub-level Caving Hydraulic Support with A lowpositioned door for passing caved coal made on the basis of aforesaid design concept, in which height A from the pivot point of the rear bar on the base to bottom surface of the support is 800mm; the height of the support is 3m, a 34.6 ,B 1155mm.The test for the specimen of the support carried out by the national test and check center has proved that the rear space of the support is larger; whole structure of the support is reasonable; the anti deflection load capability of the support is stronger; the support has passed the test of operating life of 30000 operation cycles (the national standard of operating life is 7000 operation cycles). The support has been tested "underground at Xinglongzhuang Coal MIine, Yanzhou Mining (Group) Company. The coal seam at the testing coal face averages 8.2m. On the basis of the requirement about ventilation at the coal face, operators passage, roof control, reasonable ratio of mined coal to caved coal, as well as the requirement of high efficiency and high output, 3m height of sheerer mining is selected. The ratio of mined coal to caved coal is 1:1.75.When a sub-level 6 caving mining system is used to mine super thick seam, the support can be used to achieve slicing mining and caving, which ratio of caved coal to caving coal must be controlled in the range of 1:1.2.

An industrial underground test of the support of the present invention has been carried out from April to June, 1999.The test coal face advanced 634.75m,producing coal of 1066104 ton over 3 months by June 30 t h 1999.Output was 400368 ton in June, 1999. Maximum coal output per day was 20169 ton; average production efficiency achieved 177.981 ton/man at coalface; no damage of the support occurred, so the support has been ratified because the high reliability of the support satisfies the requirement of the user. We believe that the support of the present invention can be used for reference in designing sub-level caving hydraulic support in the future.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

1. A sub-level caving hydraulic support including a base and a canopy each having a forward end portion and a rearward end portion, forward and rearward pairs of hydraulic legs operatively interconnecting the base and the canopy, said forward legs being laterally spaced apart from one another and disposed towards the forward end portions of said base and canopy and said rearward legs being laterally spaced apart and disposed towards the rearward end portions of the base and canopy; a debris shield pivotally connected to the rearward end portion of the canopy, a tail canopy pivotally connected to the debris shield a retractable plate operatively connected to the tail canopy for movement relative thereto between an extended position and a retracted position, a drive cylinder for causing said movement of said retractable plate, front and rear bar link means pivotally connected to the rearward end portion of the base and the debris shield, said front bar link means including two bars each disposed behind a respective one of said rearwards legs.

S2. A sub-level caving hydraulic support as defined in claim 1 wherein said base has a bottom surface and rear bar means is a single bar pivotally mounted to the base at a pivot o point, the height from the pivot point to the bottom surface of the support is in a range of 2 0750mm to 950mm.

3. A sub-level caving hydraulic support according to claim 1 or claim 2, wherein the inclination of the canopy has an upper surface which is inclined to the debris shield at an :angle from 300 to 400; the height for passing caved coal from the rear end of the tail canopy .to the bottom surface of the support is from 1000mm to 1200mm. 25

4. A sub-level caving hydraulic support substantially as hereinbefore described with reference to the accompanying drawings. Dated this 19 th day of June, 2001 YANKUANG GROUP CORPORATION RA By Its Patent Attorneys DAVIES COLLISON CAVE