AS 3785.3 pdf download – Underground mining—Shaft equipment Part 3: Drum winding gripper systems
An authority having statutory powers to review mine hoisting installations in the State orTerritory within the Commonwealth of Australia.
3.8 Working load limit
The maximum static load permitted to be carried by the conveyance suspension equipment.4MATERIALS
The materials selected for the manufacture of the gripper system components shall haveappropriate impact properties at the lowest expected temperatures of the operatingenvironment.Consideration should also be given to environmental conditions existing inthe shaft.
NOTE: For the specifications of the timber guides, see AS 3785.6.5 DESIGN
5.1 Design criteria
The gripper system shall be designed to—
(a)remain in the disengaged position under normal hoisting conditions and emergency
(b)effectively grip the guides and support the conveyance following an abnormal
hoisting event that causes the hoist rope to slacken; and
(c)automatically disengage when tension is restored to the hoist rope.5.2 Loads
The gripper system shall fulfil the design criteria for the following extremes of loading:(a)Dead load.
(b)Working load limit.
(c)Dynamic loads due to action of grippers.5.3Guide tolerances
The gripper system shall be designed to operate within the wear limits appropriate for thetimber guides.
NOTE: For the specification of the timber guides see AS 37126.96.36.199Stability
The gripper systems shall be positioned to ensure stability of the conveyance during itsoperation.
5.5 Energy-absorbing device
Energy absorption devices may be required to be provided within the gripper system toensure that impact loads fall within the design criteria for the extremes of loading (seeClause 5.2).
A method shall be provided for releasing the conveyance from a gripper system followingits operation.
Each new type of gripper system shall be subjected to the type test specified in Clause 6.2,and each component of every gripper system shall be subjected to the component testspecified in Clause 6.3.
The type test is intended to ensure that each type of gripper system will act in conjunctionwith the timber guides to stop and safely support the conveyance in response to a loss ofhoist rope tension.
A gripper system shall be type tested by free-fall testing using timber guides of thespecified material and with the minimum cross-section dimensions, and drop weights equalin mass to—
(a)dead load; and(b)working load limit.
For each of the above drop weights, the gripper system shall be attached to the drop weightin the same manner as it would be attached to the conveyance. The assembly shall then besuspended within timber guides using the same attachment point as would be used tosuspend the conveyance.
A suitable quick-release mechanism of adequate capacity shall be incorporated above thegripper/drop weight assembly being tested. This release mechanism shall be released and,for each drop weight, the distance through which it falls as the gripper system engages theguides and stops the drop weight shall be recorded.
6.3 Component test
The component test is intended to ensure that each component of every gripper system isfree from defects that could significantly affect its mechanical properties and performance.6.3.2 Procedure
Each component of every gripper system shall be subjected to non-destructive testprocedures and other tests as appropriate.
The following certificates shall be provided with each gripper system:(a)A type test certificate for the gripper system.
(b)Component certificates for each component of the gripper system.
Each certificate shall bear the name and address of the manufacturer, the date of test and thename, qualification， and status of the signatory of the testing organization. A copy of eachcertificate shall be retained by the manufacturer and the supplier.