GB901168A - Improvements in hydraulic props or struts - Google Patents
Improvements in hydraulic props or strutsInfo
- Publication number
- GB901168A GB901168A GB618959A GB618959A GB901168A GB 901168 A GB901168 A GB 901168A GB 618959 A GB618959 A GB 618959A GB 618959 A GB618959 A GB 618959A GB 901168 A GB901168 A GB 901168A
- Authority
- GB
- United Kingdom
- Prior art keywords
- valve
- rod
- push
- chamber
- feb
- 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
Links
- 239000007788 liquid Substances 0.000 abstract 2
- 238000005065 mining Methods 0.000 abstract 1
- 230000004048 modification Effects 0.000 abstract 1
- 238000012986 modification Methods 0.000 abstract 1
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
Landscapes
- 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)
- Fluid-Pressure Circuits (AREA)
- Actuator (AREA)
Abstract
901,168. Hydraulic pit props. DOWTY MINING EQUIPMENT Ltd. Feb. 15, 1960 [Feb. 23, 1959; May 22, 1959], Nos. 6189/59 and 17551/59. Class 20 (2). [Also in Group XXIX] An hydraulic pit prop, Fig. 1, comprising a piston-and-cylinder unit 13, 10 defining a pressure chamber 28 therebetween is provided with an excess pressure relief-valve 34, 37, 38 adapted to be opened by a push-rod 46 which is adjustably mounted in the roof-supporting cap 23 and is axially displaced when the prop is over-loaded to vent the chamber 28 to atmosphere through passages 52, 53, 25, 26, 27. In a modification, Fig. 2, the piston 65 is elevated by liquid fed from a chamber 72 to a chamber 73 through a conduit 86 and a valve 89, the liquid being pressurized by air introduced through a valve-controlled nozzle 78, 81, 83. The valve 89 acts as an excess pressure relief valve in the manner described above when a spring-loaded push-rod 92 carried by the cap 66 is axially displaced. The valve 89 also acts as a pressure release mechanism to which end the push-rod may be manually displaced by a cam-actuated plunger 103, 104 bearing on balls 99, 95 in contact with said push-rod and an adjustable ball 98.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL248713D NL248713A (en) | 1959-02-23 | ||
GB618959A GB901168A (en) | 1959-02-23 | 1959-02-23 | Improvements in hydraulic props or struts |
US8796A US3000358A (en) | 1959-02-23 | 1960-02-15 | Hydraulic props or struts |
DED32700A DE1145122B (en) | 1959-02-23 | 1960-02-20 | Hydraulic pit ram |
FR819351A FR1249070A (en) | 1959-02-23 | 1960-02-23 | Improvements to hydraulic props for mines |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB618959A GB901168A (en) | 1959-02-23 | 1959-02-23 | Improvements in hydraulic props or struts |
Publications (1)
Publication Number | Publication Date |
---|---|
GB901168A true GB901168A (en) | 1962-07-18 |
Family
ID=9810046
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB618959A Expired GB901168A (en) | 1959-02-23 | 1959-02-23 | Improvements in hydraulic props or struts |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB901168A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3220686A (en) * | 1962-10-19 | 1965-11-30 | Guardian Mining Props Ltd | Telescopic pit prop |
-
1959
- 1959-02-23 GB GB618959A patent/GB901168A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3220686A (en) * | 1962-10-19 | 1965-11-30 | Guardian Mining Props Ltd | Telescopic pit prop |
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