Dragline hoe, method and apparatus

A method of excavating overburden from a mineral or coal deposit seam using a low wall winch component, a high wall winch component and a hoe, the hoe including an upper body frame and a downwardly extending scraper blade pivotally attached to the rear end of the body frame, and the hoe being attached to the low wall winch component by one or more draglines and to the high wall winch component by a tail line, the method including the step of creating a pre-strip zone and spoil bank over the mineral or coal deposit seam by:

• (i) moving the hoe by tensioning of the dragline or lines by the low wall winch component through overburden created by preliminary drilling and blasting to move an upper layer of the overburden away from the mineral or coal deposit seams in one or more traverses to create a pre-strip zone wherein the layer of overburden is scraped into the hoe, transported thereby and subsequently dumped onto a spoil bank;
• (ii) moving the hoe at the end of each traverse by untensioning of the dragline or lines by the low wall winch component and tensioning of the tail line by the high wall winch component;
• and
• (iii) excavating remaining overburden over the mineral or coal deposit by secondary excavating means located on or adjacent the pre-strip zone;
• and wherein step (i) includes floatingly supporting the upper body frame of the hoe at a generally horizontally disposed bottom surface thereof on a load of scraped overburden being transported by the hoe and using plural spike-like elements extending downwardly from the bottom surface to retain the load of scraped overburden under the hoe, thereby to minimize working of the load of scraped overburden during transport.

A method of excavating a multi-seam mineral or coal deposit wherein a first mineral or coal deposit seam is uncovered by secondary excavating means which removes the overburden from the seam and dumps the overburden on an adjacent spoil bank whereafter the seam is mined, the adjacent spoil bank is removed and a support bridge for the secondary excavating means is created using a low wall winch component, a high wall winch component and a hoe, the hoe including an upper body frame and a downwardly extending scraper blade pivotally attached to the rear end of the body frame, and the hoe being attached to the low wall winch component by one or more draglines and to the high wall winch component by a tail line, the overburden being moved and the bridge created by the steps of:

• (i) moving the hoe by tensioning of the dragline or lines by the low wall winch component through overburden to move the overburden away from a second lower mineral or coal seam in one or more traverses wherein the overburden is scraped into the hoe, transported thereby and formed into a bridge;
• (ii) moving the hoe at the end of each traverse to a return position by untensioning of the dragline or lines and tensioning of the tail line by the high wall winch component;
• and
• (iii) thereafter excavating the second mineral or coal deposit seam by secondary excavating means supported by the bridge;
• and wherein step (i) includes floatingly supporting the upper body frame of the hoe at a generally horizontally disposed bottom surface thereof on a load of scraped overburden being transported by the hoe and using plural spike-like elements extending downwardly from the bottom surface to retain the load of scraped overburden under the hoe, thereby to minimize working of the load of scraped overburden during transport.

Apparatus for excavating overburden comprising:

• (i) a low wall winch component including a housing, a boom extending outwardly of said housing and supporting one or more draglines, winch means rotatably carrying said one or more draglines, drive means for actuating said winch means, and traversing means supporting said housing;
• (ii) a high wall winch component including a housing, a boom extending outwardly of said housing and supporting a tail line, winch means rotatably carrying said tail line, drive means for actuating said winch means, and traversing means supporting said housing;
• and
• (iii) an excavating hoe attached to said one or more draglines and to said tail line for traversing said hoe, said hoe including an upper body frame and a scraper blade pivotally attached to the rear end of said body frame, said blade being pivoted to a material scraping position when said hoe is traversed in a forward direction by said dragline or draglines for scraping material and advancing a load of scraped material forwardly of said scraping blade, said blade being reversely pivoted to a forwardly extending return position when said hoe is traversed by said tail line, and said body frame having generally horizontally disposed bottom surface means for floating said body on the load of scraped material advanced by said scraper blade and plural spike means extending downwardly from said bottom surface means for retaining scraped material under said hoe, whereby working of the load of scraped material is minimized.