The principle of post stall use

For the use of standard of crossbeam type goods shelves of many users, after retaining bar design seems to be dispensable. Then after blocking rod of what is the use?
Similar goods should drop after the gear rod has the advantages of: 1) can effectively prevent the tray 2) can make goods shelves looks very neat blocking rod design principles are: 1) after retaining bar overhang dimensions and tray overhang dimensions correspond to 2) after retaining rod position determined: it is used to block the push plate, and not on the tray 3) after retaining rod material is not too big, not too small, the stop lever principle and circuit of fuse and material over the General Assembly will forklift impact force most of the transfer to the shelf, shelf impact safety, if the material is too small, and not to the stop bar.
After the retaining structure: different companies use different design from the principle is consistent, but the details are different. Is generally a torque tube + after the retaining member of the bar.