US2521089A - Mining machine cutter bit - Google Patents

Description

Sept. 5, 1950 o. PHIPPS 2,521,089,

MINING MACHINE CUTTER BIT Filed Sept. 21, 1946 //v YEN Tax? OPV/LLE' PH/PPJ Patented Sept. 5, 1950 UNITED STATES PATENT OFFICE MINING MACHINE crrrraa nvr Orville Phipps, Adams Connty, near Denver, Colo. Application September 21, 194e, Serial No. 698,554

3 Claims.

This invention relates to teeth or bits for removable and replaceable association with and to function as the cutting elements of powerdriven endless chains constituting the scarf -forming agencies of conventional mining machines, and has as an object to provide an improved construction and association of elements constituting such a tooth or bit.

A further object of the invention is to provide an improved bit adapted for removable, replaceable, and reversible operative association with and as a cutting element of the successive lugs'in a chain-type, mining machine cutter assembly.

A further object of the invention is to provide an improved operating head conformation in a mining machine bit, whereby certain disadvantages of hitherto-known'bits are obviated to enhance the practical utility of otherwise conventional cutter assemblies.

A further object of the invention is to provide an improved cooperative relationship of special alloy insert with the head of a mining machine chain bit or tooth, whereby the operative security and durability of the assembly is enhanced and manufacture of the unit is conveniently simplified.

A further object of the invention is to provide an improved multiple-insert construction for mining machine cutter assembly bits, whereby the efilciency and operative dependability of such bits is extended.

A further object of the invention is to provide an improved cutter bit conformation and construction adapted for practical development in bits of varying sizes and specific mounting characteristics; which is simple, inexpensive, and practical of manufacture; which is efficiently long-lived in use; and which is susceptible of simple and convenient repetitious rehabilitation throughout a long period of actual operative utility.

With the foregoing and other objects in view, my invention consists in the construction, arrangement, and combination of elements hereinafter set forth, pointed out in my claims and illustrated by the accompanying drawing, in which- Figure 1 is a side elevation, partially in section, of adjacent units of a conventional cutter assembly chain in operative association with alternative forms of the instant invention. Figure 2 is a section similar to the right-hand showing of Figure 1 illustrating a reversed position of the associated bit. Figures 3 and 4 are side elevations, on an enlarged scale, of the bits shown in Figure 1 separate and apart from their operative mountings. Figure 5 is a forward or leading edge elevation of the construction shown in Figure 4. Figure 6 is a trailing edge elevation of the construction according to Figure 4. Figure 7 is a face elevation of the special alloy insert employed to complete the improved bit unit as shown.

Certain types of mining machines extensively in use are characterized by a cutter assembly wherein an endless chain equipped with outwardly projecting teeth or bits is power driven for travel about and between fixedly-related axes for the development of a continuous scarf or out within and through the material to be mined; the specific tooth or bit arrangement of a given cutter assembly varying in particular instances in accordance with the nature of the material to be intersected and the open width of the desired scarf. In the operation of machines of the type noted, the leading edges or margins of the bits or teeth accomplish the actual cutting as they are moved along and in pressure engagement against the face to be intersected and are hence subject to rapid wear and deformation, particularly when the material operated upon is highly-refractory in character, for which reason it has become general practice to mount the bits or teeth for convenient removal and replacement. Further, the exposure of the bit or tooth leading margins to rapid wear has inspired the use of highly wear resistant special alloy inserts in fixed relation with andto function as the bit or tooth leading edges, but the hitherto-known insert-type removable and replaceable cutter assembly bits have presented certain shortcomings in respect of their convenience of removal and replacement, the permanance and security of their insert mountings, and the operative dependability in the event of leading edge damage, and the improvements of the instant invention are hence directed to the overcoming and obviating of such deficiencies.

In the drawing, a fragment of a conventional cutter chain is shown as comprising chain links ll, of any operatively suitable specific construction, hingedly connecting between a succession of like bit-mounting blocks ll thereby uniformly spaced apart along the entire length of and for travel with the chain assembly. The blocks II are formed and mounted to project outwardly beyond the associated chain links l0 when the chain assembly is operatively disposed, and each of said blocks is formed with a cross-sectionally angular bore or socket I! which opens through aeeaoee and centrally of the block outer end in perpendicular relation with the chain link axes and preferably extends entirely through the block, a bolt I3, or comparable clamping element, threadedly engaging through an outwardly-projectin side portion of block it in alinement with the path of chain travel for adjustable extension of its inner end within the bore or socket I2. The construction and cooperative association of the elements III, II, I2 and I3, as shown and described, is but representative of conventional chain assemblies commonly in use and in and of itself forms no part of the instant invention, and is illustrated solely to exemplify an operative mounting for the novel and improved bit.

The cutting elements or bits carried by the chain assembly, whatever be their particular form and construction, are each formed, with a straight, cross-sectionally angular shank I4 of a size and shape to be received within and freely reciprocate longitudinally of the block bore or socket I2 and of a length such as will extend from the block outer end inwardly of the bore or socket I2 well beyond the bolt I3 inner end and hence in position for engagement of one of its margins by said bolt in a manner to effectively clamp the shank to and within its mounting bore or socket. The improved bit of the present invention includes the shank I4 for bitmounting cooperation with the block II and associated bolt I3 in the manner above described and a head portion I5 on and integral with one end of said shank, the shank I4 and head portion I5 of each bit being formed from tractable, conveniently-workable metal, such as steel, in any usual or convenient manner adapted to shape and work the bit unit to the form and element relationship hereinafter defined; the tractability desirable in the material forming the elements I4 and I5 being an order of malleability and ductility accommodating working and forging of the metal at moderate temperatures.

Giving effect to the principles of the invention, the improved bit shankand head portion are preferably of equal thickness defined by the parallel side surfaces, and the head portion I5 has a width in alinement with the path of chain travel considerably exceeding the like dimension of the shank I4, the relatively greater width of said head portion being evidenced as projections at each side of and beyond the associated shank. At its operatively rearward or trailing margin, the head portion I5 terminates in a plane parallel with and offset from the corresponding shank margin, but the junction between the rearward extension of the head portion and said shank is defined by a plane perpendicular to the shank and head portion rear margins at a point determined by the desired shank penetration within the bore or socket I2, said latter plane cooperating with the shank rear margin to form a right-angular shoulder I6 engageable against the socket-adjacent block II outer end to limit penetration of the shank Il inwardly of its bore or socket, to thereby position the head portion I5 outer margin in a desired predetermined extension outwardly beyond its mounting block, and to function as a buttress for the secure bracing and support of the head portion I5 in its resistance to forces encountered during operation and to hold the bit unit securely in its clamped relation within the block bow or socket with a minimum of pressure or strain on-the bolt I3 end therewith enures 1 and 2, the shoulder to effectively accomplishes its purposes as above set forth regardless of the head portion i5 directional disposition relative to the associated bolts I3, it being wholly immaterial whether said bolt intersects the leading or trailing side, in the direction of chain assembly travel, of its associated block I I. Similarly, forward margins of the head portion I5 and shank I4 are parallel and relatively offset, a plane perpendicular to said forward margins in parallel, offset relation with the plane definitive of the shoulder I6 cooperating with the shank forward margin to define a shoulder ll laterally traversing and directed forwardly from the unit forward margin in position to overhang and be spaced outwardly from its socket-adjacent mounting block end when the shoulder 86 is engaged against the block, such spacing of the shoulder I'I outwardly from and in overhanging relation with the block end providing a notch or recess adapted to accommodate the end of a lever, or equivalent tool, therein advantageously employable to initiate extraction of the bit shank I4 from its seated, and perhaps wedged, engagement within the bore or socket I2. Additionally, formation of the shoulder H in association with the head portion I5 forward margin has operative advantage in the direction and interruption of the flow of cuttings from the working margin of the bit and toward the adjacent end of the bore or socket I2. In certain former constructions of analogous bits, the head forward margin inclines from its working or cutting edge to merge with the shank forward margin near the block I I outer surface and without the overhang provided by the shoulder I1, which former constructions have disadvantage in that cuttings flow from the bit working edge along said inclined head forward margin to wedge within the outward end of the bore or socket I2 and to compact in the angle between the head forward margin and the adjacent block end with loss of cutting efficiency and with increase in the difficulty of bit removal and replacement. With the arrangement of forward margin surface characteristic of the improved bit, there is no smoothly-unbroken, continuous surface connecting the bit cutting edge with the outer end of the block socket, and hence cuttings impelled to move along the head portion forward margin of the improved bit have no opportunity to enter and pack within the socket nor to build up in the angle between the bit forward margin and the block end, the notch underlying the shoulder I! of the mounted bit providing for lateral-outflow relief of cuttings which might otherwise compact forwardly of the bit.

The tractable material from which the shank I 4 and head portion I5 of the bit unit are composed does not long withstand the abrasive effects developed during cutting operations and hence, no matter how tempered or' treated, is not suited to accomplish the desired cutting operations. However, certain of the non-ferrous alloys, particularly one compounded from tungsten, titanium, tantalum, nickel, and cobalt, are known to be exceedingly hard, tough, strongly resistant to abrasion, susceptible of being welded, and amenable to grinding and are hence eminently suited to function as, or to arm, the cutting edges of bits and like tools subject to extreme abrasion. Since the alloy material is diflicult and costly to work otherwise then by grinding, it is expedient to form the alloy material into flat wafers or blocks insertable in, securable to, and related to funcgaged. As'is clear from a comparison of Fig-. ion as the cutting edges (lithe v d One such insert block or wafer being illustrated by Figure 7 and designated by the numeral l8. The special alloy insert or inserts completing the bit of the instant invention are relatively thin, homogeneous blocks having coplanar front and rear surfaces and side margins conforming to, or conformable by means of grinding with, the transverse outline of the bit head portion outer or working margin. Such inserts have been heretofore employed in fixed association with mining machine cutter bits, but an important novelty of the improved bit resides in the particular arrangement utilized for mounting and permanently associating one or more such inserts in operative relation with the bit head P rtion l5. As is clearly shown in the drawing, a rectangular slot having a width sufficient to freely accommodate the thickness of an insert block I8 is formed transversely of and entirely across the outer leading corner of the head portion l5 at a slight inward inclination with and toward the shank M, an in such manner as to open outwardly and forwardly through the head portion leading outer corner, to intersect the forward or leading margin of said head portion, and to extend inwardly of the head portion beyond the line of intersection with said forward margin a considerable distance to form a wedge-like lip l9 as an outwardlydirected termination of the head portion forward margin. With the transverse slot intersecting the head portion outer leading corner in the relationship shown and set forth, the base of an insert block I8 is fitted within the slot inner portion between the lip I9 and the opposed head portion body with the rear surface of the block closing against the inclined longer or rearward face of the slot, and the said block is securely Welded or brazed to the head portion and lip surfaces and margins with which it is in contact to permanently fix the block to the bit head portion with a slight positive rake or bit angle and with the major portion of its forward face exposed in the direction of cutting travel, the base of said block being anchored behind the lip iii to enhance the security of such mounting and to brace the block against tendency to tilt or rock in a manner which might disrupt the mounting bond. The particular welding or brazing technique employed to secure the block 18 in mounted association with its bit head portion may vary throughout the full range of acceptable practice, the modified socket type of insert block mounting facilitating use of a technique wherein thin sheets or laminations of suitable fusible metals may be interposed between the adjacent block and head portion surfaces and heat-bonded into connection of said surfaces. The forward face of the mounted block I8 is laterally traversed by the outer margin of the lip IS, the line of junction therebetween being closed by the welding or brazing operation, so that cuttings moving along the exposed portion of the inclined block outer face are deflected to travel along the head portion forward margin and past the shoulder 11 in a manner which minimizes, if not wholly obviates, any tendency of said cuttings to enter the block socket I2 or to pack between the block outer end and bit forward margin.

As is usual practice, the outer or working end of the head portion I5 is transversely rounded or otherwise contoured for effective cutting action and is arcuately rearwardly inclined so that its leading, block-armed corner is advanced outwardly of the block ll well beyond its trailing outer corner, thus insuring clearance of the head portion within the scarf being developed, and the side margins of the mounted insert block [8 are ground to merge smoothly with the adjacent head portion surfacesv and to provide sharply angular forward corners or margins bounding the exposed face of the block and directed forwardly in the line of chain assembly travel against the material to be cut.

As is exemplified in Figures 1 an 3, a second transverse slot, similar to and paralleling the slot intersecting the head portion outer leading corner, may be formed in and to open through the outer margin of said head portion for the reception and fixed accommodation of a second special alloy block I 8', substantially identical with the blockl8, welded or brazed within its slot adjacent and rearwardly of the head portion I5 from the block I8. Exposed side and end margins of the second insert block iii are ground into smooth conformity with the adjacent head portion surfaces so that said second insert block is positioned and disposed as a cutfl'ng "element auxiliary to the block l8 and is thus made available to take up the cutting functions of the block It in the event of such damage to the latter as results in exposure of the block l8 cutting edges to contact with the material being worked, thereby reducing the frequency and minimizing the necessity for removal and replacement of damaged bit units.

As should be obvious from the foregoing, the improved bit is characterized by a useful life exceeding that of bits heretofore in use, since the seating of the forward insert block inner end within a slot or notch adds to the security of block mounting to forestall separation of the block from its operating association withtfie bit head portion, the provision of the auxiliary block l8 operates to continue the cutting function of the bit after damage to or loss of the block l8, and dressing of the head portion contours by means of simple grinding results in rehabilitation of the insert block cutting margins after margindeforming wear. Further, provision of the shoulders l6 and I1, and the non-coplanar relation of the head portion forward margin with the insert block forward face, as developed in the improved bit, serve to enhance the efficiency of the tool in actual use and to speed the interchange or adjustment of the bits, all as hereinabove elaborated and fully set forth.

Since many changes, variations, and modifications in the form, construction, and interrelation of the elements shown and described may be had without departing from the spirit of my invention, I wish to be understood as being limited solely by the scope of the appended claims, rather than by any details of the illustrative showing and foregoing description.

I claim as my invention:

1. A mining machine cutter bit comprising integrally-related head and shank portions of tractable metal, a head portion forward margin substantially perpendicular to the path of bit travel, a slot transversely of and obliquely intersecting the head portion outer leading corner to open outwardly therefrom in intersecting relation with said head portion forward margin, an insert block of hard, abrasive-resistant, alloy material fixed in and to fill said slot with its exposed forward surface angularly cooperating with the adjacent head portion forward margin and, its edges smoothly conforming with the adjacent head portion surfaces, 9, second slot rearwardly adjacent and paralleling said first slot to open through the head portion free end, a second insert block of alloy material fixed in and to fill said second slot with its edges smoothly conforming with the adjacent head portion surfaces, a right-angular shoulder determinative of bitmounting shank penetration defining the head and shank portion junction on the bit trailing side, and a similar shoulder paralleling and offset toward the head portion free end from the plane of said first shoulder terminating the head portion forward margin inwardly of the bit.

2. In a mining machine cutter bit having integrally-associated head and shank portions, a slot laterally traversing and opening obliquely outwardly and forwardly through the head portion outer leading corner, a head portion forward margin substantially perpendicular to the path of bit travel angularly intersecting and i'oreshortening the slot forward wall, a hard, abrasive, resistant, alloy insert block fixed in and to fill said slot with its outer, forward face portion exposed beyond and in angular relation with said head portion forward margin, a second slot rearwardly paralleling and adjacent said first slot in intersecting relation with the head portion free end, a second alloy insert block fixed within and to fill said second slot, and bitmounting means effective to space the head portion forward margin inner termination outwardly from an adjacent mount surface.

3. In a mining machine cutter bit, a head portion, a hard, abrasive-resistant, alloy insert block fixedly slot-seated to laterally traverse and extend obliquely of the head portion outer leading corner, and a second alloy insert block fixedly slotseated transversely of the head portion outer end in rearwardly-adjacent parallelism with said first block.

ORVILLE PHIPPS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,908,161 Meutsch May 9, 1933 2,330,081 Phipps Sept. 21, 1943 FOREIGN PATENTS Number Country Date 705,133 France Mar. 3, 1931 OTHER REFERENCES Mining Congress Journal, Jan. 1946, page 6.

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