US2734732A

US2734732A - tracy

Info

Publication number: US2734732A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

Feb 14, 1956 B. F. TRACY ADJUSTABLE DIAMETER ROTARY CUTTING HEAD FOR MINING MACHINES 2 Sheets-Sheet 1 Filed NOV. 13, 1955 fleg 'am z'rz 1 172 04 INVENTOR ATTORNEYS.

Feb. 14, 1956 B. F. TRACY 4,

ADJUSTABLE DIAMETER ROTARY CUTTING HEAD FOR MINING MACHINES Flled Nov 13, 1953 2 Sheets-Sheet 2 M MMN WM RN v jazz am inliTnac y INVHN'I'OR ATTORNEYS.

United States PatentfO ADJUSTABLE DIAMETER ROTARY CUTTING HEAD FOR NHNING MACHINES Benjamin F. Tracy, Point Pleasant, W. Va., assignor to Goodman Manufacturing Company, Chicago, ,Ill., a corporation of Illinois Application November 13, 1953, Serial No. 391,789

8 Claims. (Cl. 262-7) This invention relates generally to boring type mining machines and particularly to an improved adjustable diameter boring head. I v

By the present invention, the boring head comprises a rotatable hub having a rod or pair of rods mounted transversely across it and having diametrically opposed cutter bit clusters at least on the extreme outer ends. The cutter bit means are eccentrically disposed, on long and short arms, so the cutter bits are non-tracking and, therefore, cut separate concentric kerfs.

An important object of the present invention is to provide a structure for adjustably varying the boring diameter of the head by shifting the rod means lengthwise of itself to change the eccentricity of the cutter bit means relative to the hub without changing the spacingbetween the cutter bits and without changing the length of the rod means itself. Thus, the machine may be adapted to mine seams of varying thickness.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claims, it being understood that changes may be made in the construction and arrangement of parts.with out departing from the spirit of the invention as claimed.

Referring to the drawings:

, Figure l is an elevational view illustrating mining machine heads constructed in accordance with the invention.

Fig. 2 is a view illustrating the operation of the breaker roller and breaker cone forming a part of the cutting head.

Fig. 3 is a sectional view illustrating the. operation of the breaking cone formed integral with the pilot anger of the head. a v

Fig. 4 is an elevational view ilustrating the cutting head as it appears in operation.

Fig. 5 is an end elevational view illustrating bits as supported by the tool holders.

Referring to the drawings in detail, as illustrated by Fig. 1 of the drawings, a supporting bar 5 is shown representing a supporting beam forming a part of a mining machine, not shown, the supporting bar providing a support for the

cutting heads

6 and 7. I

While two of these cutting heads are shown, forming a part of the mining machine, in the instant case, it is to be understood that it is within the scope of the invention to use a single cutting head in a mining machine, or as many cutting heads as required, without departing from the spirit .of. the invention.-- Since these cutting heads are identical in construction, a single cutting head will be described in detail. The cutting head comprises a block or hub 8 which is formed with spaced longitudinally disposed bores 9 in which the rods 10 slide, the rods being of lengths to extend substantial distances beyond the ends of the block or hub 8, as better shown by Fig. 1 of the drawings.

Secured on the outer ends of the rods 10 are cutter arm extensions 11 and 111. Extension 11 is a one-piece construction serving the triple functions of: bridging or connecting the rods; forming a stop to limit shifting of the rods in one direction; and providing support for tool holder 11a. Extension 111 serves the same three functions but comprises a two-part construction including a bridging section 50 anda tool-holdingsection 51 for tool holder 11b. Both tool holders 11a and 11b support bits 12 in the conventional manner, these bits being arranged in circular arcs to match the arcs of the kerfs cut thereby. Sections 51 are formed with lugs 9' that fit in notches 10' of sections 50, there being provided apertured lugs 12' and 13' on these two sections and through which bolts 14 extend, removably securing thecutter arm end portion 51. Due to this construction, it will be seen that the cutter arm portions 51 may be replaced by longer or shorter counterparts to increase or decrease the maximum diameter of the cut.

The section 50 serves as a spacer, placing the tool holder 11b radially outward with respect to holder 11a so that their cutter bits cut non-tracking

concentric kerfs

52 and 53 respectively in the mine face.

The block or hub 8 also supports the tool holder 14 in which the bits 15 are secured, the tool holder 14 being formed with its outer edge or the edge in which the bits 15 are mounted, in the arc of a circle, so that in operation the bits 15 will cut a circular kerf 54 concentric with

kerfs

52 and 53.

The reference character 16 indicates the pilot auger which is secured to the forward side of the block or hub 8. The pilot auger extends forwardly beyond the

bits

12 and 15, whereby the bits are centered and held against lateral movement while in operation.

At the inner end of the pilot auger is the breaking cone 17 which fits into the bore formed by the pilot auger 16, and contacts with the outer edges of the bore to we'dge the material being mined laterally from the bore into the clearance provided by the kerf 54. Secured to the cutter arm extension 11 at one end of the cutting head, is a breaking roller 18 which is arranged on the side of the cutter arm extension 11, the breaking roller 18 being disposed at an oblique angle with respect to the side of the cutter arm extension 11 on which it is mounted, so that it will track inthe kerf 53 and break the outer core 56 into the clearance provided by kerf 52.

A breaker cone'19 is mounted in a bracket 20 secured on one side edge of the block or hub 8, and is adapted to track within the kerf or cut 54 formed by the bits 15 and dislodge the core 57 into the clearance provided by kerf 53.

It will be understood that it is within the scope of the invention to use a breaker cone such as shown at 19, in lieu of the breaker rollers 18, or vice verse if desired.

Power is applied to the cutter head by means of the shaft 21 which forms a part of the mining machine, not shown, and is'operated in the usual manner.

It might be further stated that since the rods 10 are mounted for sliding movement within the bores of the block or hub 8, the diameters of the kerfs cut by the bits 12 may be varied to meet various requirements of use. In order to hold thecutter arm extensions in their adjusted positions, andprevent sliding movement of the rods 16 after the adjustment hasbeehmadegthe'wedge'block 22 is drivenbetween one e'nd or the block or hub 8, and the cutter arm extensions 11 associated therewith.

Extending from the edges of the cutter arm extensions 11 are the shovels or sweeps 23, which contact the dislodged material mined and convey the material to the conventional conveying system, not shown.

In operation it is obvious that the cutting head is advanced into the wall of material being mined, with the result that the pilot auger 16 will maintain the heads centered, while the

bits

12 and 15 cut circular kerfs, the material between the kerfs being spread laterally or broken away from the mass, where it may be readily conveyed to a place of deposit.

Just by way of a specific example of the utility of the present invention, assume that the machine is used in mining a seam of coal which varies between 5 /2 and 6 feet in thickness. When in 5 /2-ft. coal, the head would be adjusted as shown in the drawings, with block or wedge 22 being three inches thick. When the machine reaches an area where the coal is the full 6 feet high, the boring arms can be adjusted for the new height simply by removing the wedge and driving it between the hub and the stop 50.

In making the change from 5 /2 foot to 6 foot coal in accordance with the example above, the core 56 would be thickened to six inches and the core 57 would be thinned by a like amount. There is a practical limit to how much these cores can be thickened and have the miner perform satisfactorily; just where this limit is must be determined for each mine depending on the type of coal or other mineral being worked.

Having thus described the invention, what is claimed is:

1. In a mining machine, a rotary cutter head comprising a hub, a power shaft to which said hub is secured, said hub having bore means extending therethrough in a direction transverse to the rotational axis of the hub, supporting rods slidably mounted within said bores, forwardly projecting cutting tools mounted on both ends of said rods, means for adjusting said rods, and means for securing the rods in their adjusted positions varying the diameters of the cuts formed by said cutting tools.

2. In a mining machine, a rotary cutting head comprising a hub, a power shaft to which said cutting head is secured for rotating said cutting head, said hub having bore means extending therethrough in a direction transverse to the rotational axis of the hub, tool Supporting rods slidable through said bores, said rods being substantially longer than the lengths of said bores, forwardly projecting cutting tools secured to both ends of said rods, adjustable by adjusting the rods in the bores and securing the rods in adjusted position thereby regulating the cutting range of said cutting tools, means for securing the cutting tools in their positions of adjustment, and a power auger extending through the hub to guide said cutting tools to their work.

3. An adjustable diameter, multiple-kerf-cutting boring head comprising a rotatable hub having a cutter-bit-carrying shaft mounted transversely across it and having forwardly extending cutters at the extreme opposite outer ends thereof, said shaft being disposed to provide long and short arms for said cutters to place the latter in non-tracking relationship to cut concentric kerfs in a mine face, said shaft being shiftable lengthwise to vary the ratios between the long and short arms, and means for selectively locking said shaft in one of at least two shifted positions to vary the effective boring diameter of the head without changing the diametrical spacing between the cutters.

4. An adjustable diameter multiple-kerf-cutting boring head comprising a rotatable hub having rod means transversely mounted thereacross, having forwardly extending cutter bit means on opposite ends thereof, and being transversely shiftable along its own axis, said rod means being disposed to provide long and short arms for said cutter bit means to place the latter in non-tracking relationship to cut at least two concentric kerfs, stop means acting between said hub and each end of said rod means to limit 4 movement of the latter relative to the hub in both directions, and locking means acting between said rod means and hub and being selective to hold said hub in a position of engagement with either of said stop means for varying the effective boring diameter of the head without changing the diametrical spacing between the cutter bit means.

5. An adjustable diameter, multiple-kerf-cutting boring head comprising a rotatable hub having bore means extending therethrough in a direction transverse to the retational axis of the hub, rod means slidably engaged within said bore means and having forwardly extending cutter bit means on opposite ends thereof, said rod means being disposed with a long arm and a short arm thereby placing said cutter bit means in non-tracking relation to cut at least two annular kerfs concentric with said axis, stop means acting between said hub and each end of said rod means to limit movement of the latter relative to the hub in both directions, and locking means acting between said rod means and hub and being selective to hold said hub in a position of engagement with either of said stop means for varying the effective boring diameter of the head without changing the diametrical spacing between the cutter bit means.

6. An adjustable diameter, multiple-kerf-cutting boring head comprising a rotatable hub having bore means extending therethrough in a direction transverse to the rotational axis of the hub, rod means slidably engaged within said bore means and having forwardly extending cutter bit means on opposite ends thereof, stop means acting between said hub and each end of said rod means to limit movement of the latter relative to the hub in both directions, and locking means acting between said rod means and hub and being selective to hold said hub in a position of engagement with either of said stop means for varying the effective boring diameter of the head without changng the diametrical spacing between the cutter bit means.

7. An adjustable diameter, multiple-kerf-cutting boring head comprising a rotatable hub having a pilot bit extending forwardly therefrom, said hub having a pair of bores extending therethrough transversely straddling the rotational axis of the hub, a pair of rods slidably engaged within said bores, cutter bit means on opposite ends of said pair of rods, stop means carried at each end of each pair of rods, said stop means being spaced apart greater than the width of the hub and alternately engageable with the hub to vary the operating radii of said cutter bit means, and locking means acting between said hub and said rods for fixing the position of the cutter bit means at operating radii determined by said stop means.

8. The combination of claim 7 in which the locking means includes a wedge driven between the hub and at least one of said stop means.

References Cited in the file of this patent UNITED STATES PATENTS 241,483 Faught May 17, 1881 1,335,723 Campbell Apr. 6, 1920 1,603,621 McKinlay Oct. 19, 1926 2,325,294 Woytych July 27, 1943 2,670,190 Cartlidge Feb. 23, 1954 2,680,034 Robbins June 1, 1954 FOREIGN PATENTS 981,860 France Jan. 17, 1951