US2474464A - Pit prop and the like - Google Patents

Pit prop and the like Download PDF

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Publication number
US2474464A
US2474464A US21023A US2102348A US2474464A US 2474464 A US2474464 A US 2474464A US 21023 A US21023 A US 21023A US 2102348 A US2102348 A US 2102348A US 2474464 A US2474464 A US 2474464A
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United States
Prior art keywords
prop
cylinder
valve
load
liquid
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Expired - Lifetime
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US21023A
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English (en)
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Cable Richard George
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Individual
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Individual
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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
    • E21D15/46—Telescopic props with load-measuring devices; with alarm devices
    • E21D15/465—Telescopic props with load-measuring devices; with alarm devices with essential hydraulic or pneumatic details
    • 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
    • E21D15/005—Props; Chocks, e.g. made of flexible containers filled with backfilling material characterised by the material
    • 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
    • E21D15/50—Component parts or details of props
    • E21D15/51—Component parts or details of props specially adapted to hydraulic, pneumatic, or hydraulic-pneumatic props, e.g. arrangements of relief valves
    • E21D15/512—Arrangement of valves

Definitions

  • This invention relates to props and more especially to pit-props.
  • Ah object of the invention is to provide a prop which can easily be assembled in position e. g. in a mine, in such manner that the prop makes adequate contact with the supporting surface and the superimposed load.
  • a prop comprises two relatively movable portions and means for admitting liquid under pressure to move said relatively movable portions apart and thus adjust the overall height of the prop.
  • Known pit-props are rigid members of fixed length and consequently, upon relative movement of the floor and roof in a mine towards one another, the props either break or bend.
  • the floor and roof surfaces are good firm surfaces such relative movement of the floor and roof may be permitted to some extent. But such movement may often be of such an extent as would cause the known timber or metal props to break or to bend, to such degree that their load supporting capacities are seriously impaired.
  • a further object of the invention is to provide an improved prop which will still possess adequate supporting capacity even after a substantial movement of the surfaces on which it bears has occurred.
  • the invention accordingly provides a prop which is collapsable when the load thereon exceeds a predetermined value while maintaining its load carrying capacity substantially unimpaired during variation of the height of the strut under such load.
  • the invention further provides a prop which comprises means for permitting some of the liquid to escape from the cylinder when the load on the prop exceeds a predetermined value and thereby enable the Height of the prop to be decreased under the influence of the load.
  • the invention further consists in a prop which comprises a portion adapted to rest on a load supporting surface, a further portion adapted to bear against a superimposed load, a cylinder connected with one of said portions, a piston connected with the other of said portions, a nonreturn inlet valve for admitting liquid under pressure to the cylinder whereby the two first-mentioned portions may be forced against the supporting surface and the load respectively and valve means for permitting liquid to escape from the cylinder when the load on the prop exceeds a predetermined value and thereby cause the height 55 2 of the prop to be adjusted in dependence on the load on the prop.
  • Fig. 2 is a part sectional elevation on the line A-A of Fig. 1.
  • Fig. 3 is an elevation on a smaller scale of the pit-prop shown in Figs. 1 and 2.
  • Fig. 4 is a fragmentary section on a larger scale of a part of Fig. 1 showing the inlet valve and Fig. 5 is a, fragmentary section on a larger scale of a part of Fig. 2 showing the bleeder or escape valve.
  • the pit-prop comprises a column I of which the upper portion is formed by a cylinder 2, and upper block 3 which is in screw-threaded engagement with the cylinder 2.
  • the lower portion of the column I is formed by a piston 4 into the lower end of which is screwed a foot 5.
  • the under surface of the foot 5 is dished as shown.
  • a collar 6 and fixed to this collar by bolts 6a is a further collar 1.
  • a packing ring of suitable material for example, leather, which makes a tight fit on the piston 4 while permitting relative movement between the cylinder and piston to take place.
  • the inner surface of the cylinder 2 and the outer surface of the piston 4 are stepped at 8 so that upward movement of the cylinder relative to the piston is limited.
  • the head 9 of the piston is formed by a block I'D which is screwed to the piston barrel and to this head 9 a cup leather II is clamped by bolts l2 and a washer is.
  • the upper block 3 comprises a chamber l 4 which is open to the interior of the cylinder 2.
  • a non-return inlet valve 16 (see particularly Fig. 4) is provided to admit liquid to the cylinder and to prevent es cape of the liquid therefrom via this valve.
  • the valve 16 comprises a valve member I! which is urged by a spring I 8 against a seating l 9 formed in a valve body 29, in the direction to close the valve.
  • is provided to receive a pipe-fitting for connection with a source of liquid under pressure.
  • the outer surface of the block 3 is recessed to receive the valve l6 which is secured-to the block by studs 22. Seals 23 and 24, suitably leather washers, are
  • a bleeder valve is arranged in the block 3.
  • the bleeder valve 25 (see particularly Fig. 5) comprises a valve body plug 26 which is provided with a bore in which the stem of a valve member 28 is movable.
  • the head of the valve member 28 is located in a valve chamber 29 in the valve body 30 and is urged by a spring 31 towards a valve seating 32 in the valve body, 30.
  • the valve body plug 26 is also provided with a number of ducts 33 of small bore to permit of escape of liquid from the cylinder via the valve chamber 29 when the pressure in the cylinder 2 exceeds the predetermined value and the head of the valve member 28 is forced from the seating 32 against the action of the spring 3i.
  • the wall of the valve chamber 29 abuts against a seal 34 suitably a leather washer, which is interposed between the inner surface of a recess formed in the block 3 to receive the valve 25 and the outer wall of the valve chamber 29.
  • a further seal 35 e. g. a, leather washer, is provided between a further surface in the'r'ecess in the block 3 and the valve body 30.
  • the valve 25 is secured to the block 3 by studs 36. Adjustment of the pressure at which the bleeder valve 25 permits liquid to escape from the cylinder 2 is effected by screwing or unscrewing the valve body plug 26 in the valve body 30 so as to vary the compression of the spring 3
  • the upper part of the block 3 is recessed to form a socket in which is mounted a ball member 3'1.
  • Fixed to the ball member 37 by studs 38 is a short joist 39.
  • the block 3 is formed with upstanding ears or flanges 40 between which the ball member 31 is located and held by a pin 4
  • the arrangement is such that the ball member 3'! is movable on the surface of the socket in the block 3 so that the joist 33 may accommodate itself to the slope of a mine roof.
  • the joist 39 forms part of the head of the prop but it will be understood that the joist itself may be absent if it is so desired.
  • the foot 5 may also be pivotally mounted to the piston 4 if desired while the under-surface of the foot, and also the upper surface of the head, may be serrated or otherwise roughened.
  • the adjustment of the bleeder valve 25 may be so effected that liquid is permitted to escape from the cylinder before the head or foot of the prop is forced into the roof or floor so as to break up the surface adjacent the supporting surfaces of the prop or at least the tendency of the prop to efiect such damage of the roof or floor may be reduced by suitable adjustment of the setting of the bleeder valve.
  • liquid escaping through the bleeder valve may be caused to flow to a suitable receptacle.
  • the .piston may be attached to the head of the prop and the cylinder to the foot.
  • the prop provided by the invention may be removed when desired, the supply of liquid to the prop first having been interrupted and the bleeder valve opened to release the pressure in the cylinder; The prop may then be collapsed and removed for use at a different site. The prop is consequently recoverable for further use to a degree greater than was hitherto possible.
  • the prop may be made of any suitable material, e. g. an aluminium alloy.
  • the bearing surfaces of the piston and cylinder may be given a hard bearing surface by a hard chrome coating formed on these surfaces.
  • the joist 39 may be connected rigidly to the block 4.
  • a prop which comprises a portion adapted to rest on a load supporting surface, a further portion adapted to bear against a superimposed load, a cylinder connected with one of said portions, a piston connected with the other of said portions, a non-return inlet valve for admitting liquid under pressure to the cylinder whereby the two first-mentioned portions may be, forced against the supporting surface and the loads respectively and valve means for permitting liquid to escape from the cylinder when. the load on the prop exceeds a predetermined value and thereby cause the height of the prop to be adjusted in dependence on the load on the prop.
  • a prop which comprises a cylinder connected with one end of the prop, a piston connected with the other end of the prop, valve means for admitting liquid under pressure to the cylinder whereby the overall length of the prop may be adjusted and valve means adapted to ⁇ permit liquid to escape from the cylinder when the pressure on the prop exceeds a, predetermined value, the arrangement being such that liquid which has escaped from the cylinder is visible on the exterior of the prop.
  • a prop which comprises a portion adapted to rest on a load supporting surface, a portion pivotally mounted at the top of the prop and adapted to bear against a'surface opposite to the load supporting surface, a cylinder connected with one of said portions, a piston connected with the other of said portions, a non-return inlet valve for admitting liquid under pressure to the cylinder whereby the two first mentioned portions may be forced respectively against the said load supporting surface and the said opposite surface and valve means for permitting liquid to escape from the cylinder when the load on the prop exceeds a predetermined value and thereby cause the height of the prop to be adjusted in dependence on the load on the prop.
  • a prop having opposite end portions, a member pivotally attached by a ball and socket joint to and extending beyond one of said end portions, a cylinder connected with one or said end portions, a piston connected with the other of said end portions, a non-return valve for admitting liquid under pressure to the c linder whereby the two end portions may be forced apart to'extend the prop against opposite surfaces and valve means for permitting liquid to escape from the cylinder when the load on the REFERENCES CITED prop exceeds a predetermined value and thereby
  • the following references are of record in the cause the height or the prop to be adjusted in file of this patent: dependence on the load on the prop. 5
  • a prop as claimed in claim 1 which com- UNITED STATES PATENTS prises manually operable means adapted to ac- Number Name Date tuate the valve means for permitting liquid to 752,201 hri nsen Feb- 19 4 escape from the cylinder. 1,418,336 Stage June 6, 1922 RICHARD GEORGE CABLE. 10 1,744,673 Pomeror Jan. 21, 1

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  • 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)
  • Actuator (AREA)
  • Safety Valves (AREA)
US21023A 1947-04-24 1948-04-14 Pit prop and the like Expired - Lifetime US2474464A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB10974/47A GB641894A (en) 1947-04-24 1947-04-24 Improvements in or relating to pit-props

Publications (1)

Publication Number Publication Date
US2474464A true US2474464A (en) 1949-06-28

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ID=9977734

Family Applications (1)

Application Number Title Priority Date Filing Date
US21023A Expired - Lifetime US2474464A (en) 1947-04-24 1948-04-14 Pit prop and the like

Country Status (4)

Country Link
US (1) US2474464A (cs)
BE (1) BE482083A (cs)
FR (1) FR965222A (cs)
GB (1) GB641894A (cs)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2695764A (en) * 1949-10-01 1954-11-30 Grebe Konrad Mine prop
US2721051A (en) * 1949-04-07 1955-10-18 Lobbe Armin Hydraulic pit props
US2816728A (en) * 1949-04-07 1957-12-17 Lobbe Armin Dieter Hydraulic pit props
US2830563A (en) * 1954-03-26 1958-04-15 Burton B Burckhalter Automatic jack leg
DE1047737B (de) * 1957-08-13 1958-12-31 Gutehoffnungshuette Sterkrade Hydraulischer Grubenstempel und aehnliche Stuetzvorrichtung
DE1068200B (cs) * 1959-11-05
US2973178A (en) * 1956-10-29 1961-02-28 Schwarz Hermann Kg Two-part metallic mine prop
DE1127841B (de) * 1955-08-13 1962-04-19 Kronprinz Ag Hydraulischer Grubenstempel
DE1131625B (de) * 1955-08-13 1962-06-20 Kronprinz Ag Hydraulischer Grubenstempel
US3463559A (en) * 1967-02-20 1969-08-26 Int Harvester Co Hydraulic track adjuster for tractor
US4142449A (en) * 1976-02-03 1979-03-06 Thyssen Industrie Ag Hydraulic mine prop
US20060024138A1 (en) * 2004-08-02 2006-02-02 Rudolf Barmann Prop head bearing
US20140050538A1 (en) * 2012-08-17 2014-02-20 Mine Support Products (Pty) Ltd Prop
CN103670459A (zh) * 2013-11-30 2014-03-26 河北工业大学 一种矿用液压支柱压力实时监测仪

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US752201A (en) * 1904-02-16 Fluid-pressure jack
US1418336A (en) * 1919-01-13 1922-06-06 Harold I Stage Pneumatic drill column
US1744673A (en) * 1927-06-10 1930-01-21 Timothy C Pomeroy Hydraulic jack

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US752201A (en) * 1904-02-16 Fluid-pressure jack
US1418336A (en) * 1919-01-13 1922-06-06 Harold I Stage Pneumatic drill column
US1744673A (en) * 1927-06-10 1930-01-21 Timothy C Pomeroy Hydraulic jack

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1068200B (cs) * 1959-11-05
US2721051A (en) * 1949-04-07 1955-10-18 Lobbe Armin Hydraulic pit props
US2816728A (en) * 1949-04-07 1957-12-17 Lobbe Armin Dieter Hydraulic pit props
US2695764A (en) * 1949-10-01 1954-11-30 Grebe Konrad Mine prop
US2830563A (en) * 1954-03-26 1958-04-15 Burton B Burckhalter Automatic jack leg
DE1131625B (de) * 1955-08-13 1962-06-20 Kronprinz Ag Hydraulischer Grubenstempel
DE1127841B (de) * 1955-08-13 1962-04-19 Kronprinz Ag Hydraulischer Grubenstempel
US2973178A (en) * 1956-10-29 1961-02-28 Schwarz Hermann Kg Two-part metallic mine prop
DE1047737B (de) * 1957-08-13 1958-12-31 Gutehoffnungshuette Sterkrade Hydraulischer Grubenstempel und aehnliche Stuetzvorrichtung
US3463559A (en) * 1967-02-20 1969-08-26 Int Harvester Co Hydraulic track adjuster for tractor
US4142449A (en) * 1976-02-03 1979-03-06 Thyssen Industrie Ag Hydraulic mine prop
US20060024138A1 (en) * 2004-08-02 2006-02-02 Rudolf Barmann Prop head bearing
US7201541B2 (en) * 2004-08-02 2007-04-10 Dbt Gmbh Prop head bearing
US20140050538A1 (en) * 2012-08-17 2014-02-20 Mine Support Products (Pty) Ltd Prop
EP2698500A3 (en) * 2012-08-17 2017-06-21 Mine Support Products (pty) Ltd Prop
CN103670459A (zh) * 2013-11-30 2014-03-26 河北工业大学 一种矿用液压支柱压力实时监测仪
CN103670459B (zh) * 2013-11-30 2015-08-05 河北工业大学 一种矿用液压支柱压力实时监测仪

Also Published As

Publication number Publication date
GB641894A (en) 1950-08-23
BE482083A (cs)
FR965222A (cs) 1950-09-06

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