US2895454A - Props, especially for use in coal mines - Google Patents

Props, especially for use in coal mines Download PDF

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Publication number
US2895454A
US2895454A US590185A US59018556A US2895454A US 2895454 A US2895454 A US 2895454A US 590185 A US590185 A US 590185A US 59018556 A US59018556 A US 59018556A US 2895454 A US2895454 A US 2895454A
Authority
US
United States
Prior art keywords
prop
spring
pressure
relief valve
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
US590185A
Other languages
English (en)
Inventor
Tebb Bernard
Perry Clarence Herbert
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.)
Mastabar Mining Equipment Co Ltd
Original Assignee
Mastabar Mining Equipment Co 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 Mastabar Mining Equipment Co Ltd filed Critical Mastabar Mining Equipment Co Ltd
Application granted granted Critical
Publication of US2895454A publication Critical patent/US2895454A/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
    • 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
    • E21D15/22—Telescopic props with parts held together by positive means, with or without relative sliding movement when the prop is subject to excessive pressure with member, pin, cross- piece, or the like, ruptured, sheared through, or permanently deformed upon excessive pressure
    • 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
    • E21D15/28—Telescopic props with parts held relatively to each other by friction or gripping
    • E21D15/30—Telescopic props with parts held relatively to each other by friction or gripping by means expanded or contracted by pressure applied through the medium of a fluid or quasi- fluid, e.g. rubber
    • E21D15/306—Telescopic props with parts held relatively to each other by friction or gripping by means expanded or contracted by pressure applied through the medium of a fluid or quasi- fluid, e.g. rubber by means of a liquid
    • 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
    • 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

Definitions

  • the present invention provides a hydraulic prop having a rising characteristic as regards its load releasing behaviour.
  • Suoh rising characteristic implies that an initial release will take place on the attainment of a minimum predetermined loading and that the loading to cause subsequent releases will increase with load displacement until the value of theload becomes equal to the maximumload sustaining capacity of the prop.
  • Fig. 2 is an elevation of the adjustable release control shown in Fig. 1
  • An inlet connection (not shown) is provided to the space 50, thus with any suitable preloading of the prop in its initial or maximum height condition, liquid may be pumped into this space 50 of the cylinder.
  • hydraulic displacement of the adjuster is efiected by making the adjuster in the form of a floating piston 81 displaceable within the piston skirt or hollow cylindrical part of. the upper portion 11 of the prop.
  • This. floating piston -81 then forms the upper wall of a chamber 82 of variable volume constituted by the space within the lower .part of the upper portion of the prop, i.e. between the floating piston 81 and the upper surface of the inverted head of the prop piston 12.
  • a relief valve 83 is arranged to discharge liquid into the variable volume chamber 82 with the result that the floating piston 81 is moved upwardly relative to the piston head- '12.
  • the relief valve 83 is disposed within the piston headI 12.
  • the upper telescopic member is secured at its upper end: by way of a collar 16 to an upper extension 17 which at its upper end is fixed to the head 18 of the prop.
  • the upper end of the piston rod is fixed in. av clevis 26 which is urge-d upwardly relative to the large pump piston 22 by a coiled compression spring 27.
  • a connecting rod 28 is pivoted. at its lower end to the clevis by means of a pin 29, and its upper end. is pivotally connected to a crank 30 adapted to-berotated by application of a suitable hand tool to the squared outer end 31. of its shaft 32 whichisjournall'edvina socket 33 secured in the wall of tlreextension: 17.
  • Suitable oil sealing or pacldng rings are provided/on the pump-pistons 22 and 25-and on the 'pump' crankshaft 32.
  • The. upper end of the torsion spring is fixed to an arm 64 which is pivotally connected to a link 65 which. in
  • This bar 73 is adjustable in a vertical direction relative to the lower telescopic prop member 14 by means of a clamp 74 so as to enable the cam profile to cause outward displacement of the plunger to a required extent in a given relative position of the two telescopic members 11 and 14 of the prop.
  • a hydraulically extensible pit prop having first and second relatively displaceable portions, a relief valve on said first portion, spring means for urging said relief valve into its closed condition, a displaceable wall in said first portion defining therein a chamber of variable volume, said wall being displaced in accordance with the amount of liquid contained in said chamber and constituting a displaceable anchorage for said spring means, and conduit means for feeding hydraulic liquid discharged by said relief valve into said chamber to thereby vary the pressure exerted on the relief valve by said spring means responsive to the relative positions of said first and second portions.
  • hydraulically extensible pit prop having a continuously. varying rising characteristic as regards its load releasing behaviour, hydraulic load sustaining means, pressure relief means adapted on opening to relieve hydraulic pressure within said load sustaining means, and hydraulically displaced relief pressure adjusting means for varying the hydraulic pressure at which said relief means opens responsive to a function of the amount of hydraulic liquid discharged by said relief means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Geology (AREA)
  • Cleaning Of Streets, Tracks, Or Beaches (AREA)
  • Emergency Lowering Means (AREA)
  • Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)
  • Actuator (AREA)
  • Control Of Presses (AREA)
  • Safety Valves (AREA)
US590185A 1955-06-10 1956-06-08 Props, especially for use in coal mines Expired - Lifetime US2895454A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB16827/55A GB793803A (en) 1955-06-10 1955-06-10 Improvements in or relating to props, especially for use in coal mines

Publications (1)

Publication Number Publication Date
US2895454A true US2895454A (en) 1959-07-21

Family

ID=10084401

Family Applications (1)

Application Number Title Priority Date Filing Date
US590185A Expired - Lifetime US2895454A (en) 1955-06-10 1956-06-08 Props, especially for use in coal mines

Country Status (5)

Country Link
US (1) US2895454A (xx)
BE (2) BE548513A (xx)
DE (2) DE1063554B (xx)
FR (2) FR1151305A (xx)
GB (2) GB793803A (xx)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3112705A (en) * 1961-10-05 1963-12-03 Jane Wallen Two-speed hydraulic pumps
US3119309A (en) * 1957-07-30 1964-01-28 Mastabar Mining Equip Co Ltd Cylinder and piston ram assemblies
DE1166125B (de) * 1960-04-19 1964-03-26 Mastabar Mining Equipment Comp Hydraulischer Grubenstempel
US3394634A (en) * 1966-10-21 1968-07-30 George M. Pfundt Internal relief valve for hydrauli cally actuated pole pullers
US3476019A (en) * 1967-09-08 1969-11-04 Berg Mfg & Sales Co Air-assisted emergency spring brake assembly
CN111594235A (zh) * 2020-04-22 2020-08-28 山东科技大学 一种缓冲式矿用支护设备及支护方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL299412A (xx) * 1962-10-19
FR2976058B1 (fr) 2011-05-30 2013-07-05 Prestige Solaire Systeme motorise d'entrainement en rotation pour un systeme de support suiveur pour capteur solaire

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2618122A (en) * 1946-04-18 1952-11-18 Gratzmuller Jean Louis Telescopic hydraulic jack
US2621631A (en) * 1948-01-12 1952-12-16 Dowty Equipment Ltd Telescopic hydraulic mine roof support
US2638075A (en) * 1948-03-06 1953-05-12 Mavor & Coulson Ltd Pneumatically controlled hydraulic prop
US2699180A (en) * 1951-07-19 1955-01-11 Dowty Equipment Ltd Relief valve with self-aligning seat
US2713773A (en) * 1953-09-24 1955-07-26 Dowty Auto Units Ltd Hydraulic pit prop or jack

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB636568A (en) * 1953-07-20 1950-05-03 George Herbert Dowty Improvements in pit props and other telescopic struts
DE928945C (de) * 1951-06-09 1955-06-16 Eisenwerk Wanheim G M B H Verstellbarer hydraulischer Grubenstempel
DE950183C (de) * 1953-02-26 1956-10-04 August Bilstein G M B H Hydraulische Hubvorrichtung, insbesondere zum Setzen von Grubenstempeln

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2618122A (en) * 1946-04-18 1952-11-18 Gratzmuller Jean Louis Telescopic hydraulic jack
US2621631A (en) * 1948-01-12 1952-12-16 Dowty Equipment Ltd Telescopic hydraulic mine roof support
US2638075A (en) * 1948-03-06 1953-05-12 Mavor & Coulson Ltd Pneumatically controlled hydraulic prop
US2699180A (en) * 1951-07-19 1955-01-11 Dowty Equipment Ltd Relief valve with self-aligning seat
US2713773A (en) * 1953-09-24 1955-07-26 Dowty Auto Units Ltd Hydraulic pit prop or jack

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3119309A (en) * 1957-07-30 1964-01-28 Mastabar Mining Equip Co Ltd Cylinder and piston ram assemblies
DE1166125B (de) * 1960-04-19 1964-03-26 Mastabar Mining Equipment Comp Hydraulischer Grubenstempel
US3112705A (en) * 1961-10-05 1963-12-03 Jane Wallen Two-speed hydraulic pumps
US3394634A (en) * 1966-10-21 1968-07-30 George M. Pfundt Internal relief valve for hydrauli cally actuated pole pullers
US3476019A (en) * 1967-09-08 1969-11-04 Berg Mfg & Sales Co Air-assisted emergency spring brake assembly
CN111594235A (zh) * 2020-04-22 2020-08-28 山东科技大学 一种缓冲式矿用支护设备及支护方法
CN111594235B (zh) * 2020-04-22 2021-06-18 山东科技大学 一种缓冲式矿用支护设备及支护方法

Also Published As

Publication number Publication date
DE1063554B (de) 1959-08-20
DE1064907B (de) 1959-09-10
BE553227A (xx)
FR1162002A (fr) 1958-09-08
BE548513A (xx)
GB802803A (en) 1958-10-15
GB793803A (en) 1958-04-23
FR1151305A (fr) 1958-01-29

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