AU632667B2

AU632667B2 - Braking apparatus

Info

Publication number: AU632667B2
Application number: AU72070/91A
Authority: AU
Inventors: Michael John Nicholas Manning; Edwin George Pink
Original assignee: EDA Co Ltd
Current assignee: Anglo Operations Pty Ltd
Priority date: 1990-03-01
Filing date: 1991-03-01
Publication date: 1993-01-07
Anticipated expiration: 2011-03-01
Also published as: FR2659072A1; BR9100835A; CA2037231C; DE4106595C2; GB9004643D0; GB2241488B; GB2241488A; FR2659072B1; GB9104245D0; CA2037231A1; DE4106595A1; ZA911490B; ZW1991A1; AU7207091A

Description

AUSTRALIA

PATENTS ACT 1952 ArVADwVP%7 Form COMPLETE SPECIFICATION FOR OFFICE USE Short Title: Int. CI: Application Number: Lodged; Complete Specification Lodged: Accepted: Lapsed: Published: Prioity: Related Art: 0940 9 0 0 0 4 TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: A612HARAP,-S CO4MPAPJ-4 L-1(AVT Actual Inventor: Edwin George Pink 3 Blackwood, Coalville, Leicestershire LE6 3RG

ENGLAND

I)

44 so0 Michael John Nicholas Manning 2 Healy Close, Rugby, Warwickshire CV21 1 NE

ENGLAND

Griffith Hack Co.

Patent Trade Marks Attorneys 256 Adelaide Terrace PEFT-H W.A. 6000 Address for Service: Compiete Specification for the Invention entitled: BRAKING APPARATUS The following is a full description of this invei 4 ion, including the best method of performing it known to me:- -1 -L, 0000 00 0 0 0000 0 C 0000 0 0 0 00 0 0 00 o0 00 0 0 0000 0 00 00 0 o a o f0 00 0 0 00 r B 0 o o "BRAKING APPARATUS" 'HIS invention relates to a braking apparatus to be used in a shaft conveyance system.

It has already been proposed in PCT/GB90 90/00335 to provide a mine shaft conveyance system in which linear motors are used to transport men, ore and materials to and from the surface in a mine shaft. This contrasts with the conventional mine shaft conveyance system in which mine conveyances, such as personnel cages and ore and material skips are suspended at the cads of ropes which are paid out and wound in by surface, or in some cases, underground, winding apparatus.

A first aspect of the present invention provides a braking apparatus for a shaft conveyance system in which a conveyance driven up and down an upright track in the shaft, the braking apparatus comprising a brake associated with the conveyance which is operable to engage a counter-member in the shaft to hold the conveyance at a chosen elevation on the track, a load cell for sensing the vertical load on the brake when it is engaged with the counter-member and means operable in response to the load cell to disengage the brake from the counter-member when the load cell senses a prtdetermined load on the brake.

The shaft is typically a mine shaft.

The conveyance system may be of the linear motor type disclosed in PCT/GB90/00335. Accordingly, a second aspect of the invention provides a braking apparatus for a shaft conveyance system in which a conveyance carried by a reaction Lr-- klo JI "LI II -3- :rember is driven up and down the shaft, by electromagnetic forces, relative to a 'Jlning support member extending vertically in the shaft, the braking apparatus wmprising a brake on the conveyance or reaction member which is operable to ;ngage a counter-member extending vertically in the shaft to hold the conveyance arul reaction member at a chosen elevation in the shaft, a load cell for sensing the 'ertical load on the brake when it is engaged with the counter-member and means operable in response to the load cell to disengage the brake when the load cell 'enses a predetermined vertical load on the brake.

In the interests of safety, the brake is preferably of the spring-applied, hydraulically released type. In a preferred brake construction, the brake includes a caliper S. 'carrying brake pads which are adapted to engage the counter-member between I° em under spring force and wherein the means for disengaging the brake from the o ccmounter-member includes hydraulic actuators operable to separate the brake pads o00 against the spring force.

h'lere may be a housing accommodating the caliper and a mounting plate for milouinting the brake on the conveyance, the load cell being arranged between the o,o0 housing and the mounting plate and being sensitive to tension or compression 00 o ;applied to it.

0 o o 'lhe invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which F'igure 1 shows a diagrammatic horizontal cross-section through a mine shaft; Figure 2 shows an exploded view of a braking apparatus of the invention; and L -I II a, 'I Figure 3 shows a side view of the assembled braking apparatus.

In Figure 1, the numeral 10 designates a vertical, circular cross-section mine shaft. Fixed in the shaft is steelwork which includes structural members 12 and 14. The members 14, which are located at vertically spaced intervals in the shaft, have T-section brake reaction rails 16 fixed to them as illustrated, the members 16 extending in the shaft from the top to the bottom thereof.

Figure 1 also shows two mine conveyances 18, such as ore, personnel or equipment conveyances which are driven vertically up and down the shaft as required by electromagnetic forces generated by linear motors indicated generally with the numeral 00o." 10 20. Each linear motor is constituted by a vertically extending winding support member 00 °and a reaction member, typically incorporating permanent magnets, as described in the specification of PCT/GB 90/00335, the disclosure of which is incorporated herein by o* °reference. The conveyances 18 are carried by the reaction members of the linear SO motors. In each case, the reaction member interacts electromagnetically with the winding support member, which carries appropriate electrical windings, to drive the shaft 0 a conveyance 18 up or down the mine shaft in accordance with known electromagnetic principles.

Caliper brakes 22 are mounted on the conveyances 18, although it is also within the .scope of the invention for the brakes to be mounted directly on the reaction members.

S 20 Referring to Figures 2 and 3, each caliper brake has a mounting plate 24 which is secured to the underside of the conveyance and a pair of hydraulic brake actuators 26 which act on a caliper carrying brake pads 28 of friction material.

The brakes 22 are mounted on the conveyances 18 in such positions that the webs of the counter-members 16 are located between the brake pads 28. The brakes are of the spring-applied, hydraulically released type. Thus the normal operation of the springs in the actuators is to apply the brakes, i.e. to force the brake pads 28 together to clamp the webs 30 between them. When the brakes are to be released, hydraulic fluid is suppled to release cylinders in the actuators which pull the brake

I

pads apart and off the webs Between the mounting plate 24 and the caliper housing 32 of each brake 22 is a series of load cells 34 which may be of a conventional type designed to sense vertical loads tending to force the plate 24 towards the housing 32 or tending to force the plate and housing apart.

When a conveyance 18 is travelling vertically in the shaft 10 under electromagnetic forces and it is desired to brake the conveyance at a desired elevation, an electromagnetic control is used to decelerate the conveyance to zero speed and then hold the conveyance in a "hover" mode at the desired elevation. Hydraulic feed to the actuators is terminated and the springs apply the brakes to clamp the conveyance relative to the counter-members 16. The electrical supply to the winding support members of the linear motors can now be terminated and the conveyance remains in a stationary position, held only by the mechanical braking forces.

If it is now desired to cause the conveyance to rise or descend, the electrical supply o" o to the winding support members is re-established. It will be appreciated that it will take a short time for the linear motors to build up sufficient thrust to support the 0 00 weight of the conveyance and its contents, and in the case of upward movement, to lift it. It would clearly be extremely dangerous for the brakes to be released too o o early, since this could have the result that the conveyance falls down the shaft under gravity.

Assuming that the conveyance is to be lifted up the shaft by the linear motors, the load cells 34 will come under tension as the linear motors build up thrust. It is only when a predetermined thrust has been attained that the load cells relay a signal to a hydraulic control circuit (not shown) which operates, in response to that signal, I I- 11 g -6to feed hydraulic fluid to the actuators to pull the brake pads 28 apart.

Normally the load cells will not permit the brakes to be released until at least about of the thrust required to take the dead weight of the conveyance and its contents is attained. This will permit the conveyance to drop a small distance before the full thrust is attained to take the weight of the conveyance and contents, whereafter further thrust which is generated will serve to lift the conveyance and contents.

If it is intended that the conveyance will descend in the shaft from its braked S o position, the load cells will again sense when sufficient thrust has been built up to °take at least the major part of the dead weight of the conveyance and contents, and only then will a signal be transmitted to the hydraulic control circuit to cause the o °o o brakes to be released.

0 Qi3 o 0 0 0 0 a o 0 G00 0 oo a o."

Claims

1. A braking apparatus for a shaft conveyance system in which a conveyance is driven up and down an upright track in the shaft, the braking apparatus comprising a brake associated with the conveyance which is operable to engage a counter- member in the shaft to hold the conveyance at a chosen elevation on the track, a load cell for sensing the vertical load on the brake when it is engaged with the counter-member and means operable in response to the load cell to disengage the brake from the counter-member when the load cell senses a predetermined load on the brake. 4444 4i 4 a g 4444 r4 4 4 4E# :4,41 444 44 4 4 4 41 A braking apparatus for a shaft conveyance system in which a conveyance carried by a reaction member is driven up and down the shaft, by electromagnetic forces, relative to a winding support member extending vertically in the shaft, the braking 4 apparatus comprising a brake on the conveyance or reaction member which is operable to engage a counter-member extending vertically in the shaft to hold the S conveyance and reaction member at a chosen elevation in the shaft, a load cell for sensing the vertical load on the brake when it is engaged with the counter-member 4 and means operable in response to the load cell to disengage the brake when the 4 S load cell senses a predetermined vertical load on the brake.

3. A braking apparatus according to claim 1 or claim 2 wherein the brake is of the spring-applied type. -rc- r_ 1 4. A braking apparatus according to claim 3 wherein the brake is of the spring-applied, hydraulically released type. A braking apparatus according to claim 4 wherein the brake includes a caliper carrying brake pads which are adapted to engage the counter-member between them under spring force and wherein the means for disengaging the brake from the counter-member includes hydraulic actuators operable to separate the brake pads against the spring force.

6. A braking apparatus according to claim 5 wherein the brake includes a housing accommodating the caliper and a mounting plate for mounting the brake on the conveyance and wherein the load cell is arranged between the housing and the mounting plate and is sensitive to tension or compression applied to it. 4 7. A braking apparatus according to claim 6 and including a plurality of load cells between the housing and the mounting plate.

8. A braking apparatus according to any one of the preceding claims wherein the predetermined load is approximately 90% of the upward thrust required to support the dead weight of the conveyance. I rr L ~I -9-

9. A braking apparatus according to any one of the preceding claims when used in a mine shaft conveyance system. A braking apparatus substantially as herein described with re' ce to Figures 2 and 3 of the accompanying drawings. Dated this 29th day of October 1992. o 0 o j 0 0$0 EDA COMPANY LIMITED By Its Patent Attorneys: 0 0 o 0) 0 S" 10 GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. S o 0 00 0 0 o 0 S04 00 0