GB901168A - Improvements in hydraulic props or struts - Google Patents

Improvements in hydraulic props or struts

Info

Publication number
GB901168A
GB901168A GB618959A GB618959A GB901168A GB 901168 A GB901168 A GB 901168A GB 618959 A GB618959 A GB 618959A GB 618959 A GB618959 A GB 618959A GB 901168 A GB901168 A GB 901168A
Authority
GB
United Kingdom
Prior art keywords
valve
rod
push
chamber
feb
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
Application number
GB618959A
Inventor
Michael John Marlow
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.)
Dowty Mining Equipment Ltd
Original Assignee
Dowty Mining Equipment Ltd
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
Priority to NL248713D priority Critical patent/NL248713A/xx
Application filed by Dowty Mining Equipment Ltd filed Critical Dowty Mining Equipment Ltd
Priority to GB618959A priority patent/GB901168A/en
Priority to US8796A priority patent/US3000358A/en
Priority to DED32700A priority patent/DE1145122B/en
Priority to FR819351A priority patent/FR1249070A/en
Publication of GB901168A publication Critical patent/GB901168A/en
Expired legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D15/00Props; Chocks, e.g. made of flexible containers filled with backfilling material
    • E21D15/14Telescopic props
    • E21D15/44Hydraulic, pneumatic, or hydraulic-pneumatic props

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Actuator (AREA)

Abstract

901,168. Hydraulic pit props. DOWTY MINING EQUIPMENT Ltd. Feb. 15, 1960 [Feb. 23, 1959; May 22, 1959], Nos. 6189/59 and 17551/59. Class 20 (2). [Also in Group XXIX] An hydraulic pit prop, Fig. 1, comprising a piston-and-cylinder unit 13, 10 defining a pressure chamber 28 therebetween is provided with an excess pressure relief-valve 34, 37, 38 adapted to be opened by a push-rod 46 which is adjustably mounted in the roof-supporting cap 23 and is axially displaced when the prop is over-loaded to vent the chamber 28 to atmosphere through passages 52, 53, 25, 26, 27. In a modification, Fig. 2, the piston 65 is elevated by liquid fed from a chamber 72 to a chamber 73 through a conduit 86 and a valve 89, the liquid being pressurized by air introduced through a valve-controlled nozzle 78, 81, 83. The valve 89 acts as an excess pressure relief valve in the manner described above when a spring-loaded push-rod 92 carried by the cap 66 is axially displaced. The valve 89 also acts as a pressure release mechanism to which end the push-rod may be manually displaced by a cam-actuated plunger 103, 104 bearing on balls 99, 95 in contact with said push-rod and an adjustable ball 98.
GB618959A 1959-02-23 1959-02-23 Improvements in hydraulic props or struts Expired GB901168A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL248713D NL248713A (en) 1959-02-23
GB618959A GB901168A (en) 1959-02-23 1959-02-23 Improvements in hydraulic props or struts
US8796A US3000358A (en) 1959-02-23 1960-02-15 Hydraulic props or struts
DED32700A DE1145122B (en) 1959-02-23 1960-02-20 Hydraulic pit ram
FR819351A FR1249070A (en) 1959-02-23 1960-02-23 Improvements to hydraulic props for mines

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB618959A GB901168A (en) 1959-02-23 1959-02-23 Improvements in hydraulic props or struts

Publications (1)

Publication Number Publication Date
GB901168A true GB901168A (en) 1962-07-18

Family

ID=9810046

Family Applications (1)

Application Number Title Priority Date Filing Date
GB618959A Expired GB901168A (en) 1959-02-23 1959-02-23 Improvements in hydraulic props or struts

Country Status (1)

Country Link
GB (1) GB901168A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3220686A (en) * 1962-10-19 1965-11-30 Guardian Mining Props Ltd Telescopic pit prop

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3220686A (en) * 1962-10-19 1965-11-30 Guardian Mining Props Ltd Telescopic pit prop

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