The idea for designing these arches was created thanks to cooperation with the mining industry and is a response to the requirements of a rectangular coal mine to obtain a large width of the excavation.
Square arches consist of elements made of V-25 section shape joined by “overlapping” SD25 or SDO25 clamps.
Square arches consist of elements made of V-29 section shape joined by “overlapping” SD29 or SDO29 clamps.
The grips are made of typical J25, J29, and J36 type section and are fixed by two bolts or by bolt and hook screw M24 or M20.
The pipe spreaders consist of the following elements:
The connector, which is the main spacing element, is manufactured in the size ø42.4 x 3.2 mm, whilst its length depends on the arch spacing. Both connector ends are appropriately bevelled and formed into oval shape to achieve better adherence to the holder. Assembly holes of ø22 mm make it possible to join the connector with V25 section. The holder is made of a flat bar of 8 x 40. The middle part of the holder tightly adheres to the arch section and the arms fit the connector. U bar and hook bolts are made of plain bar with M20 thread.
SP-220, SP-270, and SP-320 W-straps have a similar design. They differ only in terms of steel sheet thickness and section width. There are deformations for added strength and appropriately spaced holes along the straps (round or oval as requested). It is possible to connect two or more mats cross wisely or length wisely.
In terms of a range of application and production method the mats can be divided into the following types: