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Publication numberUS3499685 A
Publication typeGrant
Publication dateMar 10, 1970
Filing dateAug 8, 1968
Priority dateAug 8, 1968
Also published asDE1940577A1, DE1966173A1
Publication numberUS 3499685 A, US 3499685A, US-A-3499685, US3499685 A, US3499685A
InventorsKniff Thomas J
Original AssigneeKennametal Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Pick-type mining bit with support block having rotatable seat
US 3499685 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

T; J. KNIFF March 10, 1970- PICK-TYPE MINING BIT WITH SUPPORT BLOCK HAVING ROTATABLE SEAT Filed Aug. 8, 1968 TOE . V ow N Q @Q om 1 ll NN Ev \g W: m vw\ Q 2% v Ww Q N QE Q9 T 1| Q ow N TN Q0 .vm

INVENTOR. THOMRS J. KNlFF United States Patent 3,499,685 PICK-TYPE MINING BIT WITH SUPPORT BLOCK HAVING ROTATABLE SEAT Thomas J. Kniff, Bedford, Pa., assignor to Kennametal Inc., Latrobe, Pa. Filed Aug. 8, 1968, Ser. No. 751,094

Int. Cl. F21c 13/02 US. Cl. 299-86 9 Claims ABSTRACT OF THE DISCLOSURE A pick type mining bit with a cylindrical shank has a support block with a bore and a hard insert detachably and rotatably mounted in the bore. The insert has a bore for rotatably receiving the shank of the bit.

The bit has a cylindrical working end projecting from the support block which tapers in at the tip and has a hard insert mounted in the tip.

This invention relates to mining tools, particularly to pick type bits for use with mining machines and to a support arrangement therefor.

Pick type mining bits are, of course, well known and, in general, take the form of an elongated body round in cross section and symmetrical about a central axis with a cylindrical supporting shank at one end and with the other end generally tapering inwardly to a point in which is mounted a cemented carbide wear resistant element. Such hits, it has been found, by a proper support thereof, will rotate on their axis when properly supported. The rotation is preferably caused by the engagement of the bit with the work and has the advantage of distributing the wear about the periphery of the bit or by the life of the bit is substantially lengthened while, furthermore, the point end of the bit remains sharp.

The portion of the bit immediate rearwardly of the point is usually conical and as the bit is used and rotates in use, the body of the bit adjacent the hard cemented carbide insert wears away so that the carbide insert remains exposed. A bit of this nature has the disadvantage that as the point end of the bit wears away in use, the area of the body surrounding the carbide insert increases and this places a greater work load on the machine driving the bit and can also interfere with maintaining the proper exposure of the carbide insert.

In connection with the rotation of the bit in the holder, the bit and holder comprise cooperating inclined or conical shoulder areas, and these shoulder areas are subjected to substantial loads as the bit is used. Because of the loads involved, the shoulders sometimes wear relatively rapidly. With the bit itself, relatively rapid wear of the shoulder is not particularly important because, at worst, it will not wear away nearly as rapidly as the working point end thereof. The support for the bit, however, is in the form of a block which is usually welded in place on the drive machine and rapid wear of the shoulder on the block is a serious problem because the block is normally expected to remain in good condition for the life of several bits.

With the foregoing in mind, it is a primary object of the present invention to provide a pick type mining bit and a support block therefor which overcomes the disadvantages referred to above.

Another object of this invention is the provision of a pick type mining bit having improved operating characteristics.

Still another object of this invention is the provision of a supporting arrangement for a rotatable pick type mining bit in which the wear of the supporting arrangement is maintained at a minimum.

3,499,685 Patented Mar. 10, 1970 "ice The foregoing objects, as well as still other objects and advantages of the present invention, will become more apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:

FIGURE 1 is an exploded side elevational view showing a bit arrangement and support therefor according to the present invention, and

FIGURE 2 is a view partly in section looking at the bit and supporting arrangement from the side and showing the bit assembled with the supporting arrangement.

Referring to the drawings somewhat more in detail, in FIGURES 1 and 2 it will be seen that the arrangement comprises a support block 10,v which may be a forging, and which is adapted for being secured to a support member as by welding. It will be noted that the block 10 comprises a curved lower portion 12 which adapts the block for welding to the surface of a drum or the like, but it will be understood that the block could be shaped for mounting on a chain length or any other suitable supporting and driving device.

Block 10 has a shoulder bore 14 extending therethrough with a larger forward portion 14a and a smaller rearward portion 1421 which are interconnected by a forwardly facing inclined seat region 16. Seated in bore 14 is a hardened metal sleeve 18 comprising a larger forward portion 18a which rotatably fits in bore portion 14a, and a smaller diameter rearward portion 18b which rotatably fits in bore portion 14b. Portion 18b extends out the back of the block and has a groove 20 therein in which snap rings 22 are mounted.

Joining portions 18a and 18b is an inclined region 24 which fits against inclined region 16 of bore 14. The arrangement is such that sleeve 18 is held in block 10 with a slight degree only of freedom of axial movement therein so that the sleeve is relatively freely rotatable in the block.

Sleeve 18 has a central bore 30 which at the forward end has a flared out seat 32. Spaced rearwardly from seat 32 in bore 30 in an annular recess or undercut or groove 34.

The arrangement described above is the support for the bit to be described and is characterized in the sleeve 18 which reduces the wear on the block and which is itself readily replaceable when excessive wear thereof occurs.

Referring now to the bit, thiswill be seen to comprise a rearward cylindrical shank 40 having at its one end a flared out seat region 32 adapted for engagement with seat region 32 at the forward end of bore 30. Following seat region 42, the bit body has an annular groove 44 therein which is for the purpose of receiving a tool for removing the bit from the support when it is to be changed. Forwardly of groove 44 the bit body tapers inwardly rapidly as shown at 46 and then has a substantially cylindrical region 48 which may be of about the same diameter as shank 40. Near the forward end of the bit, there is a frusto-conical portion 50. An axial bore 52 is provided extending inwardly into the frusto-conical end of the bit and seated in bore 52 and preferably retained therein by brazing is a tip element 54 of a hard material, preferably cemented tungsten carbide. Tip element 54 has a pointed end 56 which is a substantial continuation of the inclined wall of frusto-conical portion 50.

Shank portion 40 has an annular groove 60 formed therein in which is seated a split spring band 62 having dimples or protuberances 64 therein distributed about the periphery therefo. The groove 60 and the protuberances 64 are so located along the shank 40 that when the bit is pressed into bore 30 into its FIGURE 2 position, the said protuberances 64 will snap into annular groove 34 in bore 30 so as to retain the bit in assembled relation with sleeve 18. The resilient keeper arrange ment is illustrated in the copending Engle, et al., application Ser. No. 479,094 filed Aug. 12, 1965, and assigned to the same assignee as the present application. The keeper in the form of a spring band 62 will yield inwardly in groove 60 so as to permit the bit to be pushed into bore 30 and will then snap outwardly when the bit is completely seated in the bore. The keeper firmly retains the bit in sleeve 18 and permits a slight amount of axial movement of the bit in bore 30 so that the bit is not locked against seat region 32 and is freely rotatable in bore 30.

Inasmuch as the bit can rotate in bore 30 and sleeve 18 can rotate in block 10, there will always be rotation of the bit whether this occurs between the bit and sleeve 18 and block or at both places. The possibility of the bit binding and failing to rotate thus becomes remote. Furthermore, the wear on the block is substantially reduced over the wear that takes place on the block which directly supports the bit and in which a bit rotates. It will be appreciated that the bit can be replaced as often as necessary while block 10 will have greatly increased wearing characteristics and will not have to be replaced nearly as often as heretofore has been the case. Rather, the principal wear areas will be on the bit, and sleeve 18 will normally outwear many bits and can itself easily be replaced.

The particular configuration of the bit illustrated herein is of importance because the point end of the bit as it wears and rotates in use will be worn off substantially at the angle of the inclined outer surface of frustoconical portion 50. It will be seen that the bit can wear down until the carbide tip is used up before the diameter of the body material surrounding the tip element commences to increase. The driving machine for the bit will thus not be subjected to increased load as the bit wears and the important characteristic of a pick type bit of removing material by a sort of exploding action is not interfered with and the quality of the material removed by the bit with respect to the content of lines and the particle size, does not change as the bit wears down in use.

What is claimed is:

1. In combination; a none rotatable support block having a bore, a sleeve of hard wear resistant material rotatably mounted in said bore, first means retaining said sleeve in said bore while permitting rotation of the sleeve in the bore, a pick type bit having a cylindrical shank at one end and tapering in at the other end to a point, said shank being receivable in one end of said sleeve and being rotatable therein, second means detachably retaining said shank in said sleeve while permitting rotation of the shank in the sleeve whereby rotation of said bit can occur during working either with or without rotation of said sleeve, and said sleeve and support block having interengaging shoulders thereon for sustaining axial thrusts imposed on said sleeve by said bit during working operations, the said shoulder on said sleeve facing away from the said one end of the sleeve.

2. The combination according to claim 1 wherein said bore in said support block has a larger end part nearest the bit and a smaller end part remote from the bit, and the said shoulder on the block is at the juncture of said parts of said bore, and said sleeve has a larger end part nearest the bit and a smaller end part remote from the bit, rotatably fitting the larger and smaller end parts respectively of said bore, the shoulder on the sleeve being formed at the juncture of the respective end parts thereof.

3. The combination according to claim 2 in which said shoulders taper outwardly toward the bit end of said sleeve.

4. The combination according to claim 3 in which the smaller end part of said sleeve projects beyond said block and said first means is mounted on the projecting portion of said smaller end part of the sleeve outside said block.

5. The combination according to claim 3 in which said bit comprises a flared seat at the juncture of the shank of the bit with the other end of the bit, said sleeve having a flared region engaged by said seat.

6. The combination according to claim 4 in which said sleeve has an integral groove past which said shank extends when the bit is mounted in the sleeve, and keeper means engaging the shank and groove and releasably retaining the shank in the sleeve.

7. The combination according to claim 6 in which said keeper means is resilent so that the bit can be pried out of the sleeve and forced into the sleeve.

8. The combination according to claim 7 in which said shank has an annular recess and said keeper means is mounted in the recess and is captive on said shank.

9. The combination according to claim 8 in which said keeper means is in the form of a spring band.

References Cited UNITED STATES PATENTS 1,582,332 4/1926 Brutus 354 X 1,820,511 8/1931 Van Patten 175354 3,397,012 8/1968 Krekeler 299-86 ERNEST R. PURSER, Primary Examiner Us. 01. XIR. .99

Patent Citations
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US1582332 *Dec 8, 1923Apr 27, 1926William V SeifertRoller-bits drilling tool
US1820511 *Aug 15, 1927Aug 25, 1931Patten Burton VanEarth boring drill
US3397012 *Dec 19, 1966Aug 13, 1968Cincinnati Mine Machinery CoCutter bits and means for mounting them
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3614164 *Aug 1, 1969Oct 19, 1971Carmet Co TheMine tool adapter
US3833265 *Nov 6, 1972Sep 3, 1974Elders GRotatable sleeve for self-sharpening bit
US3841707 *Mar 19, 1973Oct 15, 1974Kennametal IncCutter chain with staggered rotary bits
US3957307 *Sep 18, 1974May 18, 1976Olind VardaRough cutter mining tool
US4026605 *Jan 6, 1976May 31, 1977Fansteel Inc.Mining tool
US4201421 *Sep 20, 1978May 6, 1980Besten Leroy E DenMining machine bit and mounting thereof
US4335921 *Mar 12, 1979Jun 22, 1982Cmi CorporationCutting head for a paved roadway resurfacing apparatus
US4337980 *Apr 8, 1980Jul 6, 1982The Cincinnati Mine Machinery CompanyWedge arrangements and related means for mounting means, base members, and bits, and combinations thereof, for mining, road working, or earth moving machinery
US4627665 *Apr 4, 1985Dec 9, 1986Ss Indus.Cold-headed and roll-formed pick type cutter body with carbide insert
US4678238 *Mar 17, 1986Jul 7, 1987Fansteel Inc.Coolant sleeve for mining tools
US4736533 *Jun 26, 1986Apr 12, 1988May Charles RInteriorly located, rotating, self sharpening replaceable digging tooth apparatus and method
US4784517 *Sep 13, 1985Nov 15, 1988Sandvik AktiebolagMethod and device for working of road surfaces
US5370448 *May 17, 1993Dec 6, 1994Cincinnati Mine Machinery CompanyWedging arrangement for attaching a bit holder to the base member of a mining road working, or earth moving machine
US5498069 *Nov 9, 1994Mar 12, 1996Voest-Alpine Bergtechnik Gesellschaft M.B.HBit holder with a detachably fixed bit bushing
US5690393 *May 1, 1996Nov 25, 1997Kennametal Inc.Cutting tool retention system
US6712431 *Dec 6, 1999Mar 30, 2004Genesis Mining Technologies (Pty) LimitedCutting arrangement
US7234782Feb 18, 2005Jun 26, 2007Sandvik Intellectual Property AbTool holder block and sleeve retained therein by interference fit
US7270379Sep 22, 2006Sep 18, 2007Sandvik Intellectual Property AbTool holder block and sleeve retained therein by interference fit
US20140152074 *May 3, 2012Jun 5, 2014Sandvik Mining And Construction G.M.B.H.Arrangment for fixing a cutter
DE2348446A1 *Sep 26, 1973Apr 4, 1974Carmet CoGeraet mit einem abnehmbaren werkzeug
DE2915510A1 *Apr 17, 1979Dec 20, 1979Voest Alpine AgMeisselanordnung fuer ein schraemwerkzeug
DE3441949C1 *Nov 16, 1984Apr 24, 1986Paurat FDevice for holding the picks and for controlling the spray-medium feed in a cutting head for a heading machine
DE3441950C1 *Nov 16, 1984Apr 24, 1986Paurat GmbhDevice for holding the picks and for controlling the spray-medium feed in a cutting head for a heading machine
U.S. Classification299/104
International ClassificationE21C35/00, E21C35/197
Cooperative ClassificationE21C35/197
European ClassificationE21C35/197