US 3010708 A
Description (OCR text may contain errors)
Nov. 28, 1961 J. HLINSKY EI'AL 3,010,708
ROTARY MINING HEAD AND CORE BREAKER THEREFOR Filed April 11, 1960 INVENTORS Emil J. Hh'nsky BY 'chard C. Lundquist United States 3,019,708 ROTARY MINlNG HEAD AND CURE BREAKER THEPEFGR Emil J. Hlinsky, La Grange Park, and Richard C. Londquist, Palos Heights, 111., assignors to Goodman Manufacturing Company, Chicago, 111., a corporation of Illinois Filed Apr. 11, 1960, Ser. No. 21,548 3 Claims. (Cl. 2629) This invention relates to improvements in rotary boring heads for continuous mining machines, for boring out a complete working face in coal, rock and the like, and more particularly relates to an improved core breaker arrangement for breaking the cores between the the annular kerfs cut by the rotary cutters of the boring head.
A principal object of the invention is to provide improved core breaker means for rotary boring types of continuous mining machines operating on the principle of rolling the cores from the mine face with an intermittent rolling wedging action periodically exerting increasing wedging pressures to break the cores from the mine face.
Another object of the present invention is to improve upon the rotary boring heads for use in continuously mining coal and the like by breaking down the cores between the annular kerfs cut by the rotatable cutter arms of the boring head, by utilizing freely rotating core breakers engageable with the kerf wall and by so constructing and arranging the core breakers that they will periodically exert a core breaking action on the cores bet-ween two adjacent kerfs.
A further object of the invention is to provide an improved form of boring head for continuous mining machines and the like in which rotatable core breaker discs operate on the kerf walls left by the rotary cutters of the boring head, and periodically come into wedging engagement with the kerf walls with increasing pressure until the core is wedged down.
A further object of the invention is to provide an improved form of boring head for rotary boring types of continuous mining machines, in Which the efiiciency of boring is increased and the thrust and torque required for boring is reduced by breaking the core by engaging the other kerf walls on the inner side of the cores between two adjacent kerfs with periodic wedging forces at random, increasing in force to break the core down.
These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to accompanying drawings wherein:
FIGURE 1 is a front end wew of a rotary boring head constructed in accordance with the principles of the present invention;
FIGURE 2 is an enlarged fragmentary View in side elevation of the boring head shown in FIGURE 1, showing the boring head in the operation of making a boring cut in a mine face; and
FIGURE 3 is a top plan view of one of the core breaker discs.
In the embodiment of the invention illustrated in the drawing, 10 generally designates a boring head having a plurality of radially extending arms 11. Any number and spacing of boring arms may be provided. As herein shown, two arms are provided, which extend diametrically in opposite directions from a central hub (not shown), rotatably driven by suitable reduction geming carried in a gear casing for the mining machine (not shown).
The boring head, as shown in FIGURE 1, has a cen- Patented Nov. 2-8, 1951 tral pilot cutter 12 in the form of a segment of acircle and having cutter bits 13 projecting therefrom for cutting out a core or plug from the working face.
Each boring arm 11 is provided with a series of radially spaced, forwardly projecting cutter supports 15, 16 and 17, each being arcuate in end view and conforming to the circumferential path of travel of the associated cutter support and having cutter bits 19 projecting from their forward ends, and inclined at various angles with respect to each other, to cut clearance for said cutter supports and cut a series of concentric kerfs in a working face of a seam of material to be mined. In FIG- URE 2 of the drawings we have shown the cutter supports 15 and 16 cutting concentric kerfs 21 and 22 in a working face of the seam of material being mined.
Mounted in trailing relation with respect to the cutter supports 15 and '16 are rotary breaker discs or rollers 25 and 25 respectively, mounted on the boring arms 11 for rotation about generally radial axes intersecting the axis of rotation of the boring head in advance of the forward face thereof and canted backwardly toward the boring head. The core breaker discs or rollers 23 and 25 are so positioned as to enter the kerfs 21 and 22 in trailing relation with respect to the cutter supports 15 and 16 and come into engagement with outer walls 26 and 27 of the respective kerfs 21 and 22 as the boring head is advanced into the working face, to periodically exert 'wedging and breaking forces on cores 28 and 29 between the annular kerfs 21 and 22 and the annular kerf 22 and the annular kerf (not shown) cut by the cutter bits 19 on the outer cutter support 17, which increase in force as the boring head rotates until the core is broken down.
The core breaker discs 23 and 25 are of a similar construction and are mounted on the boring arms 11 in a similar manner. The construction and mounting of the core breaker disc 23, therefore, need only be described in detail herein and the same part numbers will be applied to the mountings for each core breaker disc.
As shown in FIGURES 1 and 2, two radially spaced support arms 39 project forwardly from each boring arm 11 in trailing relation with respect to the respective cutter supports 15 and 16 and are inclined outwardly with respect to the axis of rotation of the boring head as they extend outwardly from the boring arm. The support arms 39 cant the axes of rotation of the core breaker discs 23 and 25 inwardly toward the boring arm 11, and generally tilt the core breaker discs 23 and 25 outwardly or upwardly, to enter the respective kerfs 21 and 22 at outwardly or upwardly inclined angles, depending upon the position of rotation of the boring head, and engage the kerf wall along lines of action perpendicular to the axis of rotation of the respective breaker discs as indicated by reference character A in FIGURE 2.
Each support arm 30 has a relatively flat upper face 31 recessed between parallel spaced outwardly projecting retainer walls 32, extending outwardly of the support arm 30 and face 31 thereof. The flat outer face 31 of the support arm 30 terminates in an inner shoulder 33. A bearing support member 35 has a lower or inner block-like portion 36 fitting between the retainer walls 32 and abutting the shoulder 33 and retained to the support arm 30 as by machine screws 37.
The block-like portion 36 has a stepped boss 39 projecting outwardly therefrom at generally right angles to the face 31 of the support arm 30, and forming a bearing support for mounting the rotary core breaking disc 23 for rotation about an axis eccentric of its center and inclined back ardly toward the boring arm 11, from the lower to upper end of said rotary core breaker disc. The stepped boss 39 has a thrust bearing 40 mounted on the enlarged diameter portion thereof, and an oppositely facing thrust bearing 41 mounted on the small diameter portion thereof. The oppositely facing thrust bearings 40 and 41 form supports for the rotary core breaker disc 23 on the boss 39 retaining said core breaker disc from axial movement, and rotatably mounting said core breaker disc on the boss 39 for rotation about an axis eccentric of the center of said core breaker disc. An annular dust retainer 43 is mounted on the enlarged diameter portion of the boss 39 and abuts an upwardly facing shouldered portion 44 thereof and is recessed within the rotary core breaker disc 23, to seal the bearing 49 from dust.
A bearing cap 45 is partially recessed within the upper end portion of the boss 39 and extends over the inner race of the thrust bearing 41, to form a retainer therefor. The cap 45 is secured to the boss 39, as by machine screws 46.
The rotary core breaker disc 26 has a pair of opposed frusto-conical side faces 47 and 49, forming a generally circular wedged shaped periphery. The lower face 47 affords ready access for the rotary core breaker disc into the kerf. The upper face 49 is longer than the lower face 47 and provides a wedging surface engaging the outer wall of the core to effect rotation of the core breaker disc as the boring head is rotatably driven by engagement with the kerf wall, to intermittently bring the face 49 into wedging engagement with the kerf wall, to wedge down the core between two kerfs.
The upper end of the core breaker disc 23 is closed by an end cap 50 having a depending annular flanged portion 51 encircling the bearing 41 and spaced outwardly therefrom and recessed within the core breaker disc 23 and secured thereto as by machine screws 53. The end cap 59 has a frusto-conical surface 54 forming a continuation of the frusto-conical wedging surface 49.
The frusto-conical wedging surface 49 has a plurality of generally radially extending hard metal wearing strips 55 spaced throughout the wedging surface thereof. The wearing strips 55 extend outwardly of the face of the core breaker disc a slight distance and may be made from a carbide or other hard metal, harder than the face of the core breaker disc to resist wear on said core breaker disc and to increase the frictional contact between said core breaker disc and the kerf wall. The hardened wearing strips 55 besides lengthening the life of the core breaker disc efiect a more positive rotation of the core breaker disc by engagement with the kerf wall as the boring arm is rotatably driven and advanced into the mine face. The rotating eccentric wedging surface 49 will thus intermittently come into wedging engagement with the kerf wall and wedge off the core between two adjacent annular kerfs with a wedging force, which increases as the core breaker disc is rotated from the solid line position shown in FIGURE 2 to the dotted line position shown in this figure.
In operation of the mining machine, as the boring arms are rotatably driven and advanced into the mine face by bodily feeding movement of the machine, the cutter supports 15, 16 and 17 and the cutter bits 19 carried thereby will cut a series of concentric annular kerfs in the mine face. As the machine is further advanced, the core breaker discs 23 and 25 will enter the respective kerfs 21 and 22 and come intoengagement with the outer walls 26 and 27 thereof along lines of action perpendicular to the axes of rotation of the respective breaker discs. The frictional resistance between the core breaker discs and the outer kerf walls will effect rotation of said discs about their eccentric axes and initially ream or wear off the edge of the kerf wall, effected by movement of the wedging peripheries of the core breaker discs toward and from the kerf wall. As the machine is advanced further, the contact between the core breaker discs 23 and 25 and the kerf walls will be sufficient to exert intermittent wedging actions on the kerf walls, increasing as the discs rotate from the solid line position shown in FIGURE 2. to the dotted line position shown in this figure. This will effect a building up of the wedging forces perpendicular to the axes of rotation of the breaker discs, as the core breaker discs rotate and move further into the kerf, with the resultant breaking of the cores from the face with outward forcing actions. The core breaker discs then will have little or no contact with the kerf Walls until they again advance a sufficient distance to ream off the leading edges of the kerf walls and then wedge down the cores with increasing force effected by the eccentric mounting of the core breaker discs.
Thus the cores between the annular kerfs cut by the radially spaced cutter supports and cutter bits carried thereby, are intermittently attacked with increasing force throughout rotational movement of the boring head and the wedging actions of the core breaker discs may be at random relation with respect to each other, intermittently breaking down and forcing the-cores outwardly generally perpendicular to the lines of action of the breaker discs on the cores, and in such a manner that the core breaker discs individually exert core breaking forces on the kerf walls at random, with a resultant reduction in power from that required to break off the cores by attacking the cores head on or simultaneously brealc'ng the cores with positive'wedging actions solely by advance of the boring head into the mine wall as the boring head is rotatably driven about and within the mine face.
While we have herein shown and described one form in which our invention may be embodied, it will be understood that various changes and modifications in the invention may be attained without departing from the spirit and scope of the novel concepts of the invention, as defined by the claims appended hereto.
We claim as our invention:
1. In a rotary core breaker adapted for continuous mining machines of the boring type having a rotatable boring arm having radially spaced annular cutters projecting forwardly therefrom for cutting a series of concentric annular kerfs in a mine face, at least one freely rotatable core breaker disc mounted on said arm in trailing relation with an inner of said annular cutters, said core breaker disc having a fiusto-conical wedging face engageable with an outer wall of a kerf cut by said annular cutter, and means for mounting said core breaker disc on said arm including a bracket projecting from said arm, bearing support means projecting radially outwardly from said bracket, and bearing means journalling said core breaker disc on said bearing support means eccentric of the center of said core breaker disc.
2. A rotary core breaker in accordance with claim 1, wherein the bearing support means is inclined inwardly toward said arm as it extends outwardly from said bracket, to pitch said core breaker disc at an outwardly inclined angle with respect to the wall of the kerf cut by the associated annular cutter, as said core breaker disc advances into the kerf.
3. A core breaker in accordance with claim 2, where in the wedging face of said core breaker disc has a series of spaced hardened wearing strips extending generally radially therealong and projecting outwardly from said wedging face.
References Cited in the file of this patent UNITED STATES PATENTS 1,603,621 McKinley Oct. 19, 1926 2,754,099 Tracy July 10, 1956 2,768,820 Russell Oct. 30, 1956 2,823,025 Biedess Feb. 11, 1958