GB742118A - Improvements in hydraulic pit props - Google Patents

Improvements in hydraulic pit props

Info

Publication number
GB742118A
GB742118A GB210853A GB210853A GB742118A GB 742118 A GB742118 A GB 742118A GB 210853 A GB210853 A GB 210853A GB 210853 A GB210853 A GB 210853A GB 742118 A GB742118 A GB 742118A
Authority
GB
United Kingdom
Prior art keywords
cylinder
hydraulic
dowty
units
ram
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
GB210853A
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.)
COLIN MICHAEL FRYE
Dowty Hydraulic Units Ltd
Original Assignee
COLIN MICHAEL FRYE
Dowty Hydraulic Units 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
Application filed by COLIN MICHAEL FRYE, Dowty Hydraulic Units Ltd filed Critical COLIN MICHAEL FRYE
Priority to GB210853A priority Critical patent/GB742118A/en
Priority to FR1102978D priority patent/FR1102978A/en
Publication of GB742118A publication Critical patent/GB742118A/en
Expired legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH 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

Abstract

742,118. Hydraulic pitprops. DOWTY HYDRAULIC UNITS, Ltd., [formerly DOWTY AUTO UNITS, Ltd.], DOWTY, G. H., and FRYE, C. M. Dec. 23, 1953 [Jan. 24, 1953], No. 2108/53. Class 20(2). In an hydraulic pit prop the ram 11 which forms also the reservoir 12 is of smaller outside diameter than the inside diameter of the cylinder 13 thus leaving a gap 22 between them so that the ram slides freely even when the cylinder is dented, in bearing bushes 23, 24 and a sealing gland 25 in the cylinder and carries a protective tubular casing 36 of such length that it extends over the upper part of the cylinder at all times. The operating fluid is pumped into the working space by a hand pump 16. The combined relief and release valve 29 is discribed in Specification 636,568.
GB210853A 1953-01-24 1953-01-24 Improvements in hydraulic pit props Expired GB742118A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB210853A GB742118A (en) 1953-01-24 1953-01-24 Improvements in hydraulic pit props
FR1102978D FR1102978A (en) 1953-01-24 1954-01-22 Improvements to hydraulic props for mines

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB210853A GB742118A (en) 1953-01-24 1953-01-24 Improvements in hydraulic pit props

Publications (1)

Publication Number Publication Date
GB742118A true GB742118A (en) 1955-12-21

Family

ID=9733763

Family Applications (1)

Application Number Title Priority Date Filing Date
GB210853A Expired GB742118A (en) 1953-01-24 1953-01-24 Improvements in hydraulic pit props

Country Status (2)

Country Link
FR (1) FR1102978A (en)
GB (1) GB742118A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1188536B (en) * 1958-06-30 1965-03-11 Dowty Mining Equipment Ltd Hydraulic pit ram
US3220686A (en) * 1962-10-19 1965-11-30 Guardian Mining Props Ltd Telescopic pit prop

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1206830B (en) * 1962-08-27 1965-12-16 Bochumer Eisen Heintzmann Hydraulic pit ram

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1188536B (en) * 1958-06-30 1965-03-11 Dowty Mining Equipment Ltd Hydraulic pit ram
US3220686A (en) * 1962-10-19 1965-11-30 Guardian Mining Props Ltd Telescopic pit prop

Also Published As

Publication number Publication date
FR1102978A (en) 1955-10-27

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