Title:
Combined mine drill, timber jack, and mine post
United States Patent 2556357
Inventors:
Baldwin, John C.
Publication Date:
06/12/1951
Export Citation:
Click for automatic bibliography generation
Assignee:
Baldwin, John C.
Primary Class:
173/35
Other Classes:
173/36, 173/42, 173/145, 248/200.1, 248/354.4, 254/13
International Classes:
E21B15/00; E21D15/24; E21B15/00; E21D15/00
View Patent Images:
Download PDF 2556357        PDF help
US Patent References:
2532168Mine roof and timbering jack
1937547Screw thread device
1776439Adjustable shore
1524711Drill support
1514262Mine jack
1450709Column or support for rock drills
1189901N/A
0977734N/A
0965024N/A
0861373N/A
0689766N/A
0685011N/A
Foreign References:
FR372509A
GB190926630A
AU114575B