VTS Props

The Salzgitter Hydraulic Props, now produced by VTS and marketed in North America by American Commercial Incorporated, offer safety on the face. They can be easily maintained and operated, and, according to the requirements and depending on the prop type, readily extended with slip-on extension pieces.

The VTS Props are set by hydraulic pressure pump and fed into the setting gun via a setting line installed in the face. The setting gun will be put on the filling valve of the prop, mechanically secured with a one-hand locking mechanism, and operated by one hand.

The pressure flows through the setting gun and filling valve into the interior of the prop and causes the internal prop and the piston to telescope. After having been set against the support (articulated bar) the prop is braced with the setting force existing in the setting line, thus immediately supporting the roof.

Due to the rock pressure the prop can now be loaded till the set pressure on the operating valve will have been reached. If the nominal pressure is reached, the operating valve will open and some hydraulic fluid will be sprayed off till a pressure spring will close the operating valve again. This process repeats itself every time the nominal pressure is reached. Thus, the prop remains always protected from overload by the rock pressure.
Large lifting heights permit a large range of convergences.

Due to the possible extensions according to the prop types, the prop length can be readily adapted underground to the changes of the face heights. The prop can be withdrawn with a releasing key that - extended by means of a rope or a chain - actuates the releasing valve from a safe place of the miner and lets the hydraulic fluid escape from the cylinder. An installed return spring rapidly retracts the internal prop. Herewith, the prop is ready for use again for a new setting operation.

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