AS ISO 24410:2021 – Earth-moving machinery -Coupling of attachments to skid steer loaders.
engagement system
mechanical system of the quick coupler (3.2) which engages with the attachment mounting frame (3.3) and retains the attachment (3.1) in its workmg position
[SOURCE: ISO 13031:2016. 3.2. modified — The term attachment Is replaced by attachment mounting frame,I
wedge-type engagement system
engagement system (3.4) of at least two interconnecting parts which engage with one another in a wedge action whereby the combination of the wedge angle and the friction coefficient counteract the tendency of the working forces (3.5) to cause disengagement
[SOURCE: ISO 13031:2016. 3.2.4. modified — The Note Ito entry is not included hcre.J
working forces
forces created by the working operations of the skid steer loader and attachments (3.1) that act upon the quick coupler (3.2) during intended use and reasonably foreseeable misuse
[SOURCE: ISO 13031:2016. 3.3.1. modified — The term earth-moving machine is replaced by skid steer loader.]
4 General requirements
The quick coupler system shall he designed in accordance with Clause S and the following, using the attachment mounting frame dimensions given In Clause 6 as guidance.
a) The dimensions of the quick coupler should be such that the interface of the vertical face of the quick coupler and the attachment mounting frame does not result In surface-to-surface contact when engaged and locked together. This connection shall result in contact in each of the three zones of interface contact surface between the quick coupler and the attachment mounting frame during all operating modes of the loader and attachment. The design of the quick coupler may allow a gap between the quick coupler and the attachment mounting frame. See Figure 1.
b) See Figure 5. The quick coupler shall not protrude
— above surface A,
— forward of surface B, or
— below surface C.
NOTE Some attachments could require added support structure to the attachment mounting frame between surfaces A and B.
c) The linkage of the quick coupler to the loader lift arms should provide a minimum of 5 rollback beyond vertical of the quick coupler towards the loader with the lift arms in their lowest position. The amount of rollback may be less for quick couplers used on smaller skid steer loaders, compact tool carriers and other compact equipment.
5 Safety requirements
A skid steer loader quick coupler shall comply with the requirements of ISO 13031:2016, 4.1. for a wedge-type engagement system.
NOTE A skid steer quick coupler Is a combrn.tlon of two different wedge-type engagement systems. See Annex A For further information on how these different wedge-type engagement systems apply to the skid steer quick coupler system.
The wedges/pins of the quick coupler shall engage the attachment mounting frame at the wedge/pin contact surfaces (see Figure 1) when the attachment is properly connected.
The locking system shall prevent retraction of the wedges/pins from attachment mounting frameduring operation of the loader with the attachment when the working forces are pulling the attachmentmounting frame in a direction away from the quick coupler (e.g.forcing a bucket against the groundpushing upward on the bottom of the bucket, loader traveling rearward with a scarifier attachment).see Figure A.2.
6Attachment mounting frame dimensions
The dimensions for the attachment mounting frame shall be as shown in Figures 2 to 5.The attachmentshall only have components outside the described space.
Some attachments can require added support structure to the attachment mounting frame betweensurfaces A and B in Figure 5. See Figure 2 b) and 3 b) for dimensions of area that centre supportstructure may be allowed.
A.1Application of working forces
Skid steer loaders can be equipped with many different attachments with some being operated whilethe loader is moving forward or moving rearward or both, or while stationary.The direction of theworking forces changes depending on the direction the loader is traveling and the operation of theattachment.The direction of the working forces applied to the quick coupler during these different usescan either cause the attachment to wedge/tighten into the quick coupler or cause the attachment to tryto pull away from the quick coupler.
For this reason, when the working forces are pushing the attachment mounting frame toward thequick coupler (e.g. lifting a bucket with load, loader traveling forward with a blade attachment), theworking forces do not exert any upward force on the wedges/pins of the skid steer loader quick coupler.See Figure A.1.