US3503302A - Mine roof supports - Google Patents

Mine roof supports Download PDF

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Publication number
US3503302A
US3503302A US637569A US3503302DA US3503302A US 3503302 A US3503302 A US 3503302A US 637569 A US637569 A US 637569A US 3503302D A US3503302D A US 3503302DA US 3503302 A US3503302 A US 3503302A
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US
United States
Prior art keywords
ram
chamber
roof
hydraulic
piston
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US637569A
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English (en)
Inventor
Hermann-Josef Schulze-Heiming
Herbert Schulze-Heiming
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HERBERT SCHULZE HEIMING
HERMANN JOSEF SCHULZE HEIMING
Original Assignee
HERBERT SCHULZE HEIMING
HERMANN JOSEF SCHULZE HEIMING
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HERBERT SCHULZE HEIMING, HERMANN JOSEF SCHULZE HEIMING filed Critical HERBERT SCHULZE HEIMING
Application granted granted Critical
Publication of US3503302A publication Critical patent/US3503302A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D23/00—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor
    • E21D23/006—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor provided with essential hydraulic devices

Definitions

  • the present invention relates to the operation of mine roof support arrangements and more particularly to the depressurisation of hydraulic rams of self-advancing longwall support units, each such unit comprising a roof-engaging beam and at least one hydraulic ram.
  • one aim of the present invention is to provide for the avoidance of such jerks or dynamic stresses in the roof, so that damage to the roof is prevented: that is to say, a roof which is sufficiently sound not to collapse spontaneously when one or more of the rams of the self-advancing units are depressurized slowly should not be damaged by a rapid depressurisation so that collapse occurs, or is likely to occur if for one reason or another there is a delay in advancing and repressurisation.
  • the present invention consists in a self-advancing roof support unit comprising a beam, at least one hydraulic ram for holding the beam against the mine roof, a pump for pressurizing the ram, means for releasing hydraulic fluid from the ram, and means for controlling the releases of the fluid.
  • the means for releasing hydraulic fiuid from the ram and the means for controlling the release of the fluid include a piston in a chamber, means for moving the piston, and means for setting the stroke of the piston.
  • the stroke setting means can be in the form of an abutment or alternatively, in a preferred embodiment of the invention, the means are in the form of a scale.
  • the arrangement comprises a valve placed at the opposite end of a chamber whose other end is defined by the piston, and means which provide for lost motion and cause the valve to be opened when the piston has moved to allow a certain amount of hydraulic fluid to escape from the ram into the chamber.
  • FIG. 1 is a section through a preferred embodiment of the invention, an associated pump and self-advancing mine roof support unit being shown diagrammatically.
  • FIG. 2 is a surface view of the right-hand end of the control arrangement shown in FIG. 1.
  • the arrangement for releasing hydraulic liquid from a hydraulic ram comprises a housing 1 with an end portion 2, an O-ring 3 being placed between them to effect a sealing joint.
  • a valve element 4 which prevents hydraulic fluid under pressure from escaping over a seating 5 from a chamber 20 inside the housing 1.
  • the chamber is connected by a union 6 with a ram R of a selfadvancing mine roof support unit SU.
  • This ram R can be extended, that is to say pressurized, by a pump P.
  • the pressure inside the ram R equals the pressure inside the chamber 20.
  • a spindle 7 with an O-ring between it and the valve elements 4.
  • the spindle carries a cap 10 which is attached by means of a screw 11.
  • the spindle can move in direction of its axis but carries a part of a rectangular cross-section 12 which prevents the spindle rotating.
  • the right-hand end of the spindle carries a screw thread 13 with a setting nut 14 with a scale 15 so as to indicate. the position of the spindle.
  • the piston 7' carries an O-ring 8 and defines the right-hand end of chamber 20 while the valve element 4 defines the left-hand end.
  • the last-named spring presses the valve element 4 against its seating 5 on the portion 2.
  • the chamber 20 holds fluid under pressure at the same pressure as in the ram and the valve element 4 is pressed against the portion 2 so that no hydraulic liquid can escape from the chamber 20.
  • the setting nut 14 is turned so as to move the piston 7' to the right, the amount of movement being controlled by reading the scale 15 at an index mark 21. Consequently the chamber 20 is increased in size so that hydraulic liquid flows from the ram R. T o depressurize the ram R completely the nut 14 is turned until the cap 10 pulls the valve element 4 away from its seat so that hydraulic liquid rapidly escapes from the ram R. When the nut 14 is turned in the opposite direction the valve element 4 is closed again by the spring 18.
  • the operation is so carried out that depressurisation of the ram occurs within a period of not less than about 5 seconds and not more than about 15 seconds.
  • a self-advancing mine roof support unit having at least one hydraulic ram for holding a beam against a roof support and a pump for pressurizing the ram
  • the improvement which comprises a device for controlling the release of hydraulic pressure fluid from the ram, said device having an expansible hydraulic fluid containing chamber communicating with said ram, means for releasing fluid from said chamber, and controllable means for en larging the volume of said chamber, thereby to accommodate a greater volume of pressure fluid from said ram to lower the pressure thereof
  • said controllable means comprising a manually operated member for effecting an alteration in the size of said chamber, said manually operated member comprising a shiftable spindle, a piston on said spindle, a setting nut on said spindle for predetermining the position of said piston, and a scale associated with said nut for determining the position of said piston.
  • said fluid releasing means comprises a valve, and means including a lost motion connection between said spindle and said valve for opening the latter upon predetermined adjustment of said setting nut.

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  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Transmission Devices (AREA)
  • Prostheses (AREA)
US637569A 1966-05-14 1967-05-10 Mine roof supports Expired - Lifetime US3503302A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEK0059250 1966-05-14

Publications (1)

Publication Number Publication Date
US3503302A true US3503302A (en) 1970-03-31

Family

ID=7229060

Family Applications (1)

Application Number Title Priority Date Filing Date
US637569A Expired - Lifetime US3503302A (en) 1966-05-14 1967-05-10 Mine roof supports

Country Status (3)

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US (1) US3503302A (enrdf_load_html_response)
BE (1) BE697578A (enrdf_load_html_response)
GB (1) GB1179597A (enrdf_load_html_response)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4838516A (en) * 1986-06-10 1989-06-13 The Jacobs Manufacturing Company Compression release retarder with valve motion modifier
AU633706B2 (en) * 1986-06-10 1993-02-04 Jacobs Manufacturing Company, The Compression release retarder with valve motion modifier

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US901712A (en) * 1907-06-13 1908-10-20 Jeannot W Kenevel Valve-controlling means.
US974189A (en) * 1907-12-23 1910-11-01 Frank Ritter Valve mechanism for dental or other similar chairs.
US2585389A (en) * 1950-03-11 1952-02-12 Gen Motors Corp Hydraulic control
US2657028A (en) * 1949-06-15 1953-10-27 Joy Mfg Co Walking jack
US2748799A (en) * 1952-11-15 1956-06-05 Standard Oil Co Simultaneously-operated liquid and gas vent valves
US2783773A (en) * 1953-11-30 1957-03-05 Rasch Albert Replacement for faucet valves
US2825240A (en) * 1954-10-14 1958-03-04 Radiart Corp Hydraulic antenna rotator
GB982978A (en) * 1960-08-10 1965-02-10 Dowty Mining Equipment Ltd Roof supports suitable for use in mines
US3216201A (en) * 1959-10-12 1965-11-09 Coal Industry Patents Ltd Mine roof supports

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US901712A (en) * 1907-06-13 1908-10-20 Jeannot W Kenevel Valve-controlling means.
US974189A (en) * 1907-12-23 1910-11-01 Frank Ritter Valve mechanism for dental or other similar chairs.
US2657028A (en) * 1949-06-15 1953-10-27 Joy Mfg Co Walking jack
US2585389A (en) * 1950-03-11 1952-02-12 Gen Motors Corp Hydraulic control
US2748799A (en) * 1952-11-15 1956-06-05 Standard Oil Co Simultaneously-operated liquid and gas vent valves
US2783773A (en) * 1953-11-30 1957-03-05 Rasch Albert Replacement for faucet valves
US2825240A (en) * 1954-10-14 1958-03-04 Radiart Corp Hydraulic antenna rotator
US3216201A (en) * 1959-10-12 1965-11-09 Coal Industry Patents Ltd Mine roof supports
GB982978A (en) * 1960-08-10 1965-02-10 Dowty Mining Equipment Ltd Roof supports suitable for use in mines

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4838516A (en) * 1986-06-10 1989-06-13 The Jacobs Manufacturing Company Compression release retarder with valve motion modifier
AU633706B2 (en) * 1986-06-10 1993-02-04 Jacobs Manufacturing Company, The Compression release retarder with valve motion modifier

Also Published As

Publication number Publication date
GB1179597A (en) 1970-01-28
BE697578A (enrdf_load_html_response) 1967-10-02

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