GB726384A - Improvements in pit props and other telescopic struts - Google Patents

Improvements in pit props and other telescopic struts

Info

Publication number
GB726384A
GB726384A GB2011253A GB2011253A GB726384A GB 726384 A GB726384 A GB 726384A GB 2011253 A GB2011253 A GB 2011253A GB 2011253 A GB2011253 A GB 2011253A GB 726384 A GB726384 A GB 726384A
Authority
GB
United Kingdom
Prior art keywords
space
fluid
reservoir
prop
pressure
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
GB2011253A
Inventor
George Herbert Dowty
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 Equipment Ltd
Original Assignee
Dowty 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 BE486663D priority Critical patent/BE486663A/xx
Priority to GB92548A priority patent/GB636568A/en
Priority to US58949A priority patent/US2621631A/en
Priority to NL143867A priority patent/NL76043C/xx
Priority to DEP25763A priority patent/DE808225C/en
Priority to FR978701D priority patent/FR978701A/en
Application filed by Dowty Equipment Ltd filed Critical Dowty Equipment Ltd
Priority to GB2011253A priority patent/GB726384A/en
Priority to FR69104D priority patent/FR69104E/en
Publication of GB726384A publication Critical patent/GB726384A/en
Expired legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D15/00—Props; Chocks, e.g. made of flexible containers filled with backfilling material
    • E21D15/60—Devices for withdrawing props or chocks
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D15/00—Props; Chocks, e.g. made of flexible containers filled with backfilling material
    • E21D15/14—Telescopic props
    • E21D15/44—Hydraulic, pneumatic, or hydraulic-pneumatic props
    • E21D15/45—Hydraulic, pneumatic, or hydraulic-pneumatic props having closed fluid system, e.g. with built-in pumps or accumulators

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)
  • Reciprocating Pumps (AREA)
  • Supply Devices, Intensifiers, Converters, And Telemotors (AREA)

Abstract

726,384. Reciprocating pumps. DOWTY EQUIPMENT, Ltd. July 20, 1953, No. 20112/53. Addition to 636,568, [Group X]. Class 102 (1). [Also in Groups X and XXX] In a fluid pressure telescopic strut, such as a pit prop (see Group X), the pressure fluid is delivered from a reservoir, formed within the ram 1, into the cylinder space 10, by means of a two-stage pump 9 which comprises outer and inner cylinders 11, 12 communicating with the reservoir through ports 20, 21, and having outer and inner reciprocating pistons 13, 14 each of which, during the initial extension of the prop, displaces fluid into the space 10 through non-return valves in the closure disc 8. Once the prop meets resistance to extension, pressure in the space 10 will increase and the outer piston 13 will no longer discharge into the space 10, but will return fluid into the reservoir through a blow-off valve 22 in a return passage 23. The pump is manually driven by means of a crankshaft 15, crank 16 and connecting rod 17.
GB2011253A 1948-01-12 1953-07-20 Improvements in pit props and other telescopic struts Expired GB726384A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
BE486663D BE486663A (en) 1948-01-12
GB92548A GB636568A (en) 1953-07-20 1948-01-12 Improvements in pit props and other telescopic struts
US58949A US2621631A (en) 1948-01-12 1948-11-08 Telescopic hydraulic mine roof support
NL143867A NL76043C (en) 1948-01-12 1948-12-15
DEP25763A DE808225C (en) 1948-01-12 1948-12-20 Pit stamp
FR978701D FR978701A (en) 1948-01-12 1949-04-05 forestay or prop
GB2011253A GB726384A (en) 1953-07-20 1953-07-20 Improvements in pit props and other telescopic struts
FR69104D FR69104E (en) 1948-01-12 1954-07-20 forestay or prop

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2011253A GB726384A (en) 1953-07-20 1953-07-20 Improvements in pit props and other telescopic struts

Publications (1)

Publication Number Publication Date
GB726384A true GB726384A (en) 1955-03-16

Family

ID=10140587

Family Applications (2)

Application Number Title Priority Date Filing Date
GB92548A Expired GB636568A (en) 1948-01-12 1948-01-12 Improvements in pit props and other telescopic struts
GB2011253A Expired GB726384A (en) 1948-01-12 1953-07-20 Improvements in pit props and other telescopic struts

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB92548A Expired GB636568A (en) 1948-01-12 1948-01-12 Improvements in pit props and other telescopic struts

Country Status (1)

Country Link
GB (2) GB636568A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1063554B (en) * 1955-06-10 1959-08-20 Mastabar Mining Equipment Comp Hydraulic pit ram
DE1171382B (en) * 1960-02-23 1964-06-04 H Joe Rheinbay Dipl Ing Hydraulic pit ram
DE1206830B (en) * 1962-08-27 1965-12-16 Bochumer Eisen Heintzmann Hydraulic pit ram

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL152226B (en) * 1949-04-07 Glaverbel METHOD AND APPARATUS FOR MANUFACTURING FLAT GLASS, IN ADDITION TO FLAT GLASS MANUFACTURED USING THIS METHOD.
BE526791A (en) * 1953-02-25
US2830563A (en) * 1954-03-26 1958-04-15 Burton B Burckhalter Automatic jack leg
CN112727481B (en) * 2021-02-05 2022-11-29 中铁工程装备集团有限公司 Excavation cabin direct discharge slurry shield machine and excavation cabin direct discharge slurry method

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1063554B (en) * 1955-06-10 1959-08-20 Mastabar Mining Equipment Comp Hydraulic pit ram
DE1171382B (en) * 1960-02-23 1964-06-04 H Joe Rheinbay Dipl Ing Hydraulic pit ram
DE1206830B (en) * 1962-08-27 1965-12-16 Bochumer Eisen Heintzmann Hydraulic pit ram

Also Published As

Publication number Publication date
GB636568A (en) 1950-05-03

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