GB746779A - Improvements in hydraulic pit props - Google Patents
Improvements in hydraulic pit propsInfo
- Publication number
- GB746779A GB746779A GB2385653A GB2385653A GB746779A GB 746779 A GB746779 A GB 746779A GB 2385653 A GB2385653 A GB 2385653A GB 2385653 A GB2385653 A GB 2385653A GB 746779 A GB746779 A GB 746779A
- Authority
- GB
- United Kingdom
- Prior art keywords
- ram
- cylinder
- space
- pump
- annular chamber
- 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
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
- E21D15/14—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
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)
- Actuator (AREA)
- Details Of Reciprocating Pumps (AREA)
Abstract
746,779. Hydraulic pit props. DOWTY HYDRAULIC UNITS, Ltd., [formerly DOWTY AUTO UNITS Ltd.], BARNETT, L. L. S., and FRYE, C. M. Aug. 27, 1954 [Aug. 28, 1953], No. 23856/53. Class 20(2). [Also in Group XXVIII] In a hydraulic pit prop having a hollow cylindrical ram 11 which houses at its inner end a two stage pump (see Group XXVIII) for delivering fluid from a reservoir constituted by the ram 11 into the space 20 in a cylinder 12 into which the ram 11 slides, the pressure in the space 20 is releasable by an externally operable release valve 33 adjacent the outer end of the ram 11 and communicating with the space 20 through a conduit 34 extending down the ram 11 to a point adjacent the pump and through an annular chamber surrounding the larger diameter cylinder of the pump. When a sealing gland 16 is carried by the upper end of the cylinder as in Fig. 1, or when the sealing gland is carried on the ram 11 above the lower end of the conduit 34, the annular chamber is constituted by the annular clearance between the ram 11 which forms the larger diameter cylinder and the cylinder 12. When a sealing gland 38 is carried by the inner end of the ram 11, as in Fig. 3, the annular chamber is constituted by a space 40 between the ram 11 and a length of tubing 39 which forms the larger diameter cylinder of the pump. A modification according to Fig. 2 (not shown) differs from the arrangement of Fig. 1 in that the dispositions of the small piston and cylinder are reversed, the annular chamber being formed by the clearance between the ram 11 and cylinder 12.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2385653A GB746779A (en) | 1953-08-28 | 1953-08-28 | Improvements in hydraulic pit props |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2385653A GB746779A (en) | 1953-08-28 | 1953-08-28 | Improvements in hydraulic pit props |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB746779A true GB746779A (en) | 1956-03-21 |
Family
ID=10202426
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2385653A Expired GB746779A (en) | 1953-08-28 | 1953-08-28 | Improvements in hydraulic pit props |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB746779A (en) |
-
1953
- 1953-08-28 GB GB2385653A patent/GB746779A/en not_active Expired
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