Door frame (mining)

from Wikipedia, the free encyclopedia
Example of a German door frame
Polish door frame

A door frame extension is a form of construction in mining , it is a special version of the rectangular extension . This rectangular extension has the name door frame from its shape, which is very similar to the door frame of a house door. It can consist of different finishing materials .

Basics

The door frame is used to store two or three areas in a row . There are four different types of door frames: half door frames, whole door frames, double door frames, and grafted door frames. With the half door frame, the stamps of the door frames are placed at certain distances from one another and provided with caps . Since half the door frame is created with only one punch, the punch is set up on the section joint that has the poorer strength. The other end of the cap is baked into the opposite joint. In the area of ​​the hanging wall, so-called rind posts are driven in over the caps and in the area of ​​the recumbent behind the door frames. On the whole door frame, a cross piece (cap) is supported by two stamps, the door frames are at short intervals. If two whole door frames are placed very close together, they are called double door frames. Double door frames are placed in sections and lugs if both joints are not very stable. The grafted or shoed door frame is used for soft lying surfaces. For this purpose, stage holes are chiselled into the sole in preparation . The stamps are then placed in the stage holes and wedged with pegs. In addition, grafted door frames are installed in very high cleats. You will then be provided with an additional strut. There are also door frames that are anchored in the hanging wall for support . This type of door frame construction is called a combined anchor-door frame construction. Door frames are made of wood or steel and combinations of these two materials. So that door frames are secured against lateral displacement, they must be provided with bolts. The minimum expansion resistance of the door frame expansion can be determined by calculation; the calculation bases are given in the door frame guidelines.

Door frames made of wood

There are different types of construction for the production of wooden door frames : the German door frame , the Polish or Silesian door frame and the Swedish door frame .

Manufacture of the door frames

chartered stamp

Depending on the local conditions, the wood for the door frames is sawn to size either above ground or below ground. The wood is prepared for days when the rock at the installation site is so soft that it can be easily removed. The door frames are pre-sawn to a uniform size and the corners are prepared accordingly for installation. The disadvantage here is that the room is often very irregular. If the rock is solid, the wood is cut on site. This has the advantage that the timbers can be individually adjusted and the stamps and caps of all door frames are in alignment and also close exactly at the connection points. The spaces between the individual door frames are secured with a delay . If the sole of the route is particularly flexible, the stamps are placed on a so-called base sole . These base blocks can be used for all types of door frames. Base soles are made from long trunks that are laid lengthways along the side of the joint. So that the long pieces of wood do not shift, short round pieces of wood are installed transversely between the long pieces of wood. The stamps are then placed on the long pieces of wood. So that the stamps sit firmly enough on the base sole, holes are cut into the wood of the base sole at the points where a stamp is to be placed. There is also the option of using only short pieces of wood that sit crosswise as the base sole. These short pieces of wood are placed in small holes in the stage for security. This base plate creates a closed door frame. In many cases, it is sufficient to use half-timber instead of the round timber to create the base sole. The miner can create these half-timber himself by sawing or splitting a round timber lengthways. Whether short or long pieces of wood are used depends on the distance between the individual door frames. Long pieces of wood are used for small distances and short pieces of wood are used for the base sole for larger distances.

German door frame

German door frame

The German door frame, the caps with the punches verblattet . A distinction is made whether ridge printing or side printing predominates. Due to the different design of the leaf, the door frame is designed so that it can better absorb either the ridge or side pressure. For fixed slopes ends the cap is directly below the ridge fitted in friable slope ends a of slab between the rock and the cap is placed. An additional central punch is used for high heights. The German door frame was mainly used in ore mining.

Polish door frame

In the case of the Polish door frame, the stamp is provided with a recess (notch) at the upper end, the cap is not processed and placed in the group. As a result, the Polish door frame can only absorb ridge pressure and no lateral forces. In order to give the stamps better stability against the effects of lateral pressure, a wooden post, a so-called head spreader, is hammered in close under the cap. Thanks to the head brace, the Polish door frame can also absorb a small amount of lateral forces. The advantage of the Polish door frame is the simple construction, which can also be made by inexperienced carpenters. The main area of ​​application of the Polish doorframe was coal mining.

Swedish door frame

With the Swedish door frame, the stamp and cap are mitred . Since the cuts cannot be drawn on the round pieces of wood, the cutting directions are measured by plumbing with a square. Then the cutting direction is marked by inserting several Tscherper knives and then the miter cut is made. The Swedish door frame can take ridge and side pressure to a certain extent, but is not as stable as the German door frame. It was mainly used in the Swedish ore mining industry.

Steel door frames

Steel door frame

Different profile steels can be used in the creation . The easiest way to make a steel door frame is to use used railroad tracks . Due to the profile of the railroad tracks, a connection between the stamp and the cap is difficult. One possibility of connection is the use of angle brackets. For this purpose, the rail head and the rail foot must be processed accordingly. Another option is to use U-irons or double T-beams. Door frames made of steel can be used in mining routes if they are sufficiently flexible due to the construction of the door frame. Slightly curved channel profile pieces or stamps made from GI profiles are used as stamps for flexible steel door frames. The flexibility is achieved through the connection using specially shaped cut angles or cut shoes.

Mixed door frames

Mixed door frames are made of wooden stamps and iron caps. The iron caps often consist of used railroad tracks. Iron washers are placed between the cross-cut rail and the die head so that the pressure of the cross-cut rail is evenly distributed over the stamps with this design. These washers are bent over on the inside of the punch. If lateral pressure acts on the stamp, the stamp lies against this bent iron part. To support the stamp, additional strong iron bolts are attached in the area of ​​the stamp foot , which prevent the stamp from being pushed over. Wooden stamps and steel rails cannot be laminated together, which is why special steel fasteners are required. The connections between the wooden stamp and the steel cap in the case of mixed door frames are usually simple constructions made of angle iron or bent flat iron. Since the middle of the 20th century, web profiles have been used instead of the discarded railway tracks. Wood-steel cap shoes are used as a connection between the wooden stamp and the steel cap. In order to achieve a certain flexibility in the mixed door frame, the stamps on the base are sharpened.

literature

  • Mining Lexicon . In: Hans Grothe, Hermann Franke (Ed.): Lueger Lexikon der Technik . 4th completely revised and expanded edition. tape 4 mining. Deutsche Verlags-Anstalt, Stuttgart 1962, p. 576 .

Individual evidence

  1. ^ A b c Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition, Verlag Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7 .
  2. ^ Franz Rziha: Textbook of the entire art of tunneling. First volume, published by Ernst & Korn, Berlin 1867.
  3. ↑ a b c d Explanatory dictionary of the technical terms and foreign words that occur in the mining industry, in metallurgy and in salt works, and technical art expressions that occur in salt works. Falkenberg'schen Buchhandlung publishing house, Burgsteinfurt 1869.
  4. ^ A b Carl Friedrich Richter: Latest mountain and hut lexicon. Second volume, Kleefeldsche Buchhandlung, Leipzig 1805.
  5. ^ A b Carl von Scheuchenstuel: IDIOTICON of the Austrian mountain and hut language. kk court bookseller Wilhelm Braumüller, Vienna 1856.
  6. ^ A b Heinrich Veith: German mountain dictionary with evidence. Published by Wilhelm Gottlieb Korn, Breslau 1871.
  7. ^ Johann Christoph Stößel (Ed.): Mining dictionary. Chemnitz 1778.
  8. ^ A b c d e Carl Hellmut Fritzsche: Textbook of mining science. Second volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1962
  9. ↑ Door frame guidelines of the Arnsberg district government from July 20, 2001 [1] (accessed on November 16, 2011).
  10. ↑ a b Horst Roschlau, Wolfram Heinze, SDAG Wismut (Hrsg.): Knowledge storage mining technology. 1st edition. German publishing house for basic industry, Leipzig 1974, pp. 78-88.
  11. ↑ a b c d e Gustav Köhler: Textbook of mining science. 2nd edition, published by Wilhelm Engelmann, Leipzig 1887.
  12. ↑ a b c J. Niederist: Fundamentals of mining science. kk court book and art dealer FA Credner, Prague 1863.
  13. ↑ William Jicinsky, mountain and Hüttenmännischer club Mähr Ostrau (ed.): Catechism of the pit preservation for mine and mine Steiger supervisory bodies. Commissioned by Prokisch's Buchhandlung, Mähr-Ostrau 1876.
  14. ↑ a b c Emil Stens: About yielding pit support. In: Glückauf, Berg- und Hüttenmännische magazine. Association for Mining Interests in the Upper Mining District Dortmund (Ed.), No. 17, Volume 47, April 29, 1911, pp. 649–660.
  15. ↑ Pit expansion (2) on zeno.org (accessed on November 16, 2011)
  16. ^ Association for mining interests in the Oberbergamtsiertel Dortmund (ed.): The development of the Lower Rhine-Westphalian hard coal mining in the second half of the 19th century. Julius Springer's publishing bookstore, Berlin 1902.

Web links