GB735411A - Improvements in or relating to devices for removing pit props - Google Patents
Improvements in or relating to devices for removing pit propsInfo
- Publication number
- GB735411A GB735411A GB2624253A GB2624253A GB735411A GB 735411 A GB735411 A GB 735411A GB 2624253 A GB2624253 A GB 2624253A GB 2624253 A GB2624253 A GB 2624253A GB 735411 A GB735411 A GB 735411A
- Authority
- GB
- United Kingdom
- Prior art keywords
- reservoir
- lever
- space
- sept
- stowed position
- 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
- 238000004873 anchoring Methods 0.000 abstract 1
- 239000012530 fluid Substances 0.000 abstract 1
- 238000005086 pumping 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
- E21D15/60—Devices for withdrawing props or chocks
- E21D15/603—Devices for withdrawing props or chocks by means of hydraulic devices
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)
- Road Paving Machines (AREA)
Abstract
735,411. Hydraulic jacks. AUTOMOTIVE PRODUCTS CO., Ltd. Sept. 23, 1954 [Sept. 23, 1953], No. 26242/53. Class 78 (3). In a hydraulic jack for pulling out pit props the working chamber is put into communication with the reservoir by movement of the pump actuating handle beyond its normal working stroke. Pressure fluid is transmitted from a reservoir 25 via a conduit 28 to the working space 29 by a double-acting differential type pump having a stepped piston 22, 24 which is reciprocated in a cylinder 18 by a hand lever 19. During normal pumping an annular space 31, conmunicating with reservoir 25 through a duct 32, is covered by the piston portion 24, but when the lever 19 is moved to the stowed position shown, the space 31 is uncovered and the chamber 29 is exhausted. A spring catch 35 retains the lever in the stowed position where it forms a carrying handle. An overload valve 33 is provided. The jack has a chain connector 16 and an anchoring lug 15.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2624253A GB735411A (en) | 1953-09-23 | 1953-09-23 | Improvements in or relating to devices for removing pit props |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2624253A GB735411A (en) | 1953-09-23 | 1953-09-23 | Improvements in or relating to devices for removing pit props |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB735411A true GB735411A (en) | 1955-08-17 |
Family
ID=10240563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2624253A Expired GB735411A (en) | 1953-09-23 | 1953-09-23 | Improvements in or relating to devices for removing pit props |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB735411A (en) |
-
1953
- 1953-09-23 GB GB2624253A patent/GB735411A/en not_active Expired
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