US3180093A - Hydraulic props - Google Patents

Hydraulic props Download PDF

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Publication number
US3180093A
US3180093A US292274A US29227463A US3180093A US 3180093 A US3180093 A US 3180093A US 292274 A US292274 A US 292274A US 29227463 A US29227463 A US 29227463A US 3180093 A US3180093 A US 3180093A
Authority
US
United States
Prior art keywords
reservoir
pump
shaft
ram
release valve
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
US292274A
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English (en)
Inventor
Town Frank
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.)
WE&F Dobson Ltd
Original Assignee
Dobson Ltd W E & F
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 Dobson Ltd W E & F filed Critical Dobson Ltd W E & F
Application granted granted Critical
Publication of US3180093A publication Critical patent/US3180093A/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
    • E21D15/44—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

  • This invention relates to a hydraulic pit prop of the type having a crank-operated internal pump and releasevalve and, more particularly, where the crank mechanism has a pump handle which requires one arcuate movement for operating the pump and a second arcuate movement for operating the release valve.
  • An object of the invention is to provide the prop with improved air valve means whereby the prop is able to operate etciently for a long period.
  • FIG. l is a general sectional view of a hydraulic pit prop equipped with air valve means according to the invention.
  • FIG. 2 is a side sectional view in enlarged scale of an upper part of the prop showing the air valve means
  • FIG. 3 is a eros-sectional view through the air valve means with the valve parts in the position they adopt during pumping up of the prop;
  • FIG. 4 is a similar view to FIG. 2 showing a pump handle tted and the valve parts in the position they adopt during tluid valve release contraction of the prop;
  • FIG. is a view similar to FIG. 3 but with the valve parts in the position of FIG. 4.
  • the hydraulic prop shown is of the type referred to having an internal pump 1 and release valve 2 which are operable by a crank mechanism indicated generally 3.
  • the crank 3 includes a crank axle 4 which, at its outwardly-projecting end (see FlG. 2), is formed with a transverse hole 4a for insertion of a pump handle 5 (FIGS. 3-5).
  • the pump handle 5 goes through a predetermined arc of movement to operate the pump 1 and a second arc of movement to operate the release valve 2.
  • the prop comprises a lower pressure cylinder 6 and an upper, reservoir-forming, hollow ram 7.
  • the pump 1 is housed in the lower end of the ram 7 and has an associated check valve 8 through which fluid can be pumped from the ram 7 into the cylinder 6.
  • the pump piston 1a is connected by a rod 9 to a crank 1i) secured to the crank axle 4.
  • the release valve 2 is also housed in the lower end ot the ram 7 and is connected by a rod 11 to a projection 12 on the -rod 9 by means of a lost motion slot 11a.
  • the crank axle 4 is connected by a collar 13 to the crank 10. Further, the axle 4 has a central bore 14 forming at its inner end an air chamber 15 open to the interior of the ram ⁇ 7.
  • the bore 14 also has an intermediate reduced diameter bearing part 16 and an outer end further reduced diameter bearing part 17 open to the transverse hole 4a.
  • crank axle 4 is mounted in a bearing sleeve 18 which is secured by welding to the ram 7.
  • the intermediate reduced diameter bearing part 16 of the bore 14 provides a shoulder 16a against which sealing is effected by a sealing ring 26 on the plunger 23 behind the shoulder 23a.
  • the plunger -23 is also formed with an annular air passage 27 substantially in the same general transverse or radial plane as that of the transverse air communication passage 22 and the outer air outlet 19.
  • the pump handle 5 When the prop is in use, the pump handle 5 is fitted so that the plunger 23 is pressed in, as shown in FIG. 4. Thereupon, the sealing ring 26 becomes spaced from the shoulder 16a, and the annular air passage 27 provides communication between the transverse air communication passage 22 and the air chamber 15. However, at this stage, as illustrated in ysolid line in PIG. 3, the transverse air communication passage 22 does not register with the outer air outlet 19. Instead, as shown in FIG. 3, during the time that the pump handle 5 is operated in its ypredetermined -arc of movement to operate the pump 1, the
  • transverse air communication passage 22 is carried around with the crank axle 4 through an arc of movement during which it is out of registry with the outer air outlet 19. This pumping action causes a comparatively small displacement of the uid and consequently ysmall displacement of air takes place by passage of air between the plunger 23 and the crank axle bore 14.
  • the pump handle When it is required to contract the prop, the pump handle is moved through a second arc of movement during which it operates the release valve 2, and during this movement, as shown in FlG. 5, the handle 5 turns the crank axle 4 to a position in which the transverse air communication passage 22 registers with the outer air outlet 19. Therefore in this position of the parts, the comparatively large displacement of iluid is accompanied by similar large ⁇ displacement of air which is drawn into the prop.
  • the air drawn into the'prop ows through the crank axle bore l14, the annular air passage 27, the transverse air communication passage 22, and the lregistering outer air outlet 19.
  • the handle After contraction of the prop and it it is not required kfor immediate reuse, the handle is turned back to the initial pumping position where the transverse air com- 3 municationpassage 22 .is again moved out of registry with the outer air outlet 19, thereby preventing the possibility of foreign matter entering into the valve.
  • a hydraulic jack comprising a cylinder, a reservoirproviding ram mounted in said cylinder, a pump and release valve mounted in said ram, passage means coupling said pump and ram, and second passage means coupling said ram and said reservoir, said release valve being positioned in said second passage means, a bearing sleeve fixed to and extending throughthe wall of said reservoir', a crankshaft journaled in said sleeve and having a crank portion within said reservoir coupled to said pump and release valve, said crankshaft having a portion outside said reservoir adapted to receive a pump handle, said shaft having an axial bore in the shaft portion intermediate the outside and crank portions thereof and communicating with said reservoir, said intermediate sha-ft portion being adapted to pass air from lsaid reservoir to the outside thereof, a seat in said bore, a slidevalve in said axial bore adapted to be engaged and unseated by said handle when said handle is received in said shaft outside portion, said intermediate shaft portion being equipped with a transverse passage communicating with said bore outward

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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)
  • Valves And Accessory Devices For Braking Systems (AREA)
  • Details Of Reciprocating Pumps (AREA)
US292274A 1962-07-31 1963-07-02 Hydraulic props Expired - Lifetime US3180093A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB29288/62A GB1030574A (en) 1962-07-31 1962-07-31 Improvements in or relating to hydraulic props

Publications (1)

Publication Number Publication Date
US3180093A true US3180093A (en) 1965-04-27

Family

ID=10289161

Family Applications (1)

Application Number Title Priority Date Filing Date
US292274A Expired - Lifetime US3180093A (en) 1962-07-31 1963-07-02 Hydraulic props

Country Status (4)

Country Link
US (1) US3180093A (lv)
BE (1) BE634933A (lv)
GB (1) GB1030574A (lv)
NL (1) NL295875A (lv)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3302529A (en) * 1964-01-18 1967-02-07 Dobson Ltd W E & F Hydraulic mine roof supports

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US686183A (en) * 1899-05-22 1901-11-05 Jay W Watkins Fire-extinguisher.
US1212757A (en) * 1914-11-05 1917-01-16 Carl A Waldron Hydraulic jack.
US1344919A (en) * 1919-05-05 1920-06-29 Alexander W Marr Hydraulic jack
US3055626A (en) * 1960-04-09 1962-09-25 Mastabar Mining Equip Co Ltd Hydraulic supports

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US686183A (en) * 1899-05-22 1901-11-05 Jay W Watkins Fire-extinguisher.
US1212757A (en) * 1914-11-05 1917-01-16 Carl A Waldron Hydraulic jack.
US1344919A (en) * 1919-05-05 1920-06-29 Alexander W Marr Hydraulic jack
US3055626A (en) * 1960-04-09 1962-09-25 Mastabar Mining Equip Co Ltd Hydraulic supports

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3302529A (en) * 1964-01-18 1967-02-07 Dobson Ltd W E & F Hydraulic mine roof supports

Also Published As

Publication number Publication date
GB1030574A (en) 1966-05-25
BE634933A (lv)
NL295875A (lv)

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