GB525845A - Improvements in or relating to pit props and the like - Google Patents

Improvements in or relating to pit props and the like

Info

Publication number
GB525845A
GB525845A GB677839A GB677839A GB525845A GB 525845 A GB525845 A GB 525845A GB 677839 A GB677839 A GB 677839A GB 677839 A GB677839 A GB 677839A GB 525845 A GB525845 A GB 525845A
Authority
GB
United Kingdom
Prior art keywords
bar
sprag
shaped
screw
section
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
GB677839A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to GB677839A priority Critical patent/GB525845A/en
Publication of GB525845A publication Critical patent/GB525845A/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
    • E21D15/60—Devices for withdrawing props or chocks
    • 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
    • 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
    • E21D15/16—Telescopic props with parts held together by positive means, with or without relative sliding movement when the prop is subject to excessive pressure
    • E21D15/20—Telescopic props with parts held together by positive means, with or without relative sliding movement when the prop is subject to excessive pressure with pawl, pin, cross-piece, or the like engaging with ratchet teeth, notches, holes, or the like, spaced apart at intervals
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D17/00—Caps for supporting mine roofs
    • E21D17/02—Cantilever extension or similar protecting devices
    • E21D17/08—Cap joints for obtaining a coal-face free of pit-props

Abstract

525,845. Mine supports. SYLVESTER, W. March 2, 1939, Nos. 6778 and 3777140. [Class 20 (ii)] A sprag or stay for use with a mine prop for supporting a bent-bar adjacent to a working face comprises a bar with a screw extension part, one part being shaped at its end to allow of rotation while the other part is shaped to resist rotation while in engagement with its abutment. The prop may be provided with a post having a number of teeth or abutments as described in Specification 518,084 but, according to the present form, the post is provided with teeth 26 against which abuts the chisel-shaped end of a screw 15 which is adapted to screw in and out of a fitting at one end of a channel-shaped bar, the other end of which is provided with a pointed fitting, allowing the bar to rotate for adjustment. The pointed end of the sprag engages the end of a bent-bar 25. The sprag may be formed in telescopic sections 1, 2 adapted to be screwed together for rough adjustment by pins 7 engaging registering apertures in the sections, the pins having projections 9 adapted to pass through slots in washers 5 welded to one section and by rotation to engage beneath the washers. One end of the section 2 is provided with a pin 11 for engaging the end of the bent-bar. The end screw 15 may be carried in a head fitted on the end of the main section, this head having an inclined plate 13 to abut against an inclined plate on the end of the section so that the head can be quickly released when a retaining lever 17 is tripped as described in Specifications 514,185, and 514,197. The lever is held in operative position by a sliding spring clip 21 on the flange of the main section of the sprag.
GB677839A 1939-03-02 1939-03-02 Improvements in or relating to pit props and the like Expired GB525845A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB677839A GB525845A (en) 1939-03-02 1939-03-02 Improvements in or relating to pit props and the like

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB677839A GB525845A (en) 1939-03-02 1939-03-02 Improvements in or relating to pit props and the like

Publications (1)

Publication Number Publication Date
GB525845A true GB525845A (en) 1940-09-05

Family

ID=9820562

Family Applications (1)

Application Number Title Priority Date Filing Date
GB677839A Expired GB525845A (en) 1939-03-02 1939-03-02 Improvements in or relating to pit props and the like

Country Status (1)

Country Link
GB (1) GB525845A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102226404A (en) * 2011-06-07 2011-10-26 中国矿业大学 Method for retracting surplus hydraulic supports of fully mechanized mining face
US10247001B2 (en) * 2016-01-29 2019-04-02 China University Of Mining And Technology Anti-spalling blocking bar for large cross-section coal gallery excavation work surface and supporting method
CN114970016A (en) * 2022-05-13 2022-08-30 安徽省城建设计研究总院股份有限公司 Pi-shaped support inclined strut displacement calculation method, Pi-shaped support design method and support method

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102226404A (en) * 2011-06-07 2011-10-26 中国矿业大学 Method for retracting surplus hydraulic supports of fully mechanized mining face
US10247001B2 (en) * 2016-01-29 2019-04-02 China University Of Mining And Technology Anti-spalling blocking bar for large cross-section coal gallery excavation work surface and supporting method
CN114970016A (en) * 2022-05-13 2022-08-30 安徽省城建设计研究总院股份有限公司 Pi-shaped support inclined strut displacement calculation method, Pi-shaped support design method and support method

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