CA1081720A - Wedge arrangement for removably affixing a work tool or work tool holder to a base member on mining machinery and the like - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A wedge arrangement is disclosed for removably affixing a work tool or work tool holder to a base member on mining, road working or earth moving machinery, and the like, and being particularly useful in the mining, road planing and earth digging areas. The arrangement is such that the removable member may be readily replaced and wear and tear on the base member greatly reduced to the extent that such base member will not be destroyed or otherwise rendered useless, such base member may be a part which is permanently secured to the basic machine or it may in fact be the machine itself or some integral part thereof. The base member is preferably provided with a slot of a size sufficient to receive both the removable member and a wedge element; such member and element may be placed within the slot from above thereof, lateral entry of the removable member and wedge element into the slot often being unnecessary. Means are provided to move the wedge element so as to effect a frictional engagement between the removable member and the base member to effect an interference fit in which there is no relative motion between these members and thus virtually no wear. (It is possible to reverse this arrangement and provide the removable member with the slot and the base member with a suitable male element which, along with the wedge element, will be received in the slot.) The removable member may be provided with a bit, road planing device or digging tooth, which working elements may in turn be removably affixed to and/or within the removable part.

Description

This application is a division o:E application 257,100, filed July 11, 1976.
This invention has particular use in the mining, road planing and earth digging fields. More specifically, the invention relates to means for affixing removable members such as cutter bit lugs to a base member such as the driven element of a mining machine or the like. It has particular application to cutter bit lugs and base members whereby the lugs may be easily and quickly installed or removed and replaced, all without damage to the driven element or base member. In like manner the invention may be utilized for remorably securing the working element of a road working machine to the driven element thereof or for removably securing the digging tooth to the driven e~ement of an earth digging or dipping machine.
The prior art has disclosed the provision of means for quickly and easily removing and replacing worn bits from the lugs provided to carry them.
United States of America Patent No. 2,965,365 discloses quite satisfactory arrangements for accomplis~ing this. Means for retaining a rotatable bit within a lug of a mining machine in such manner that the bit may be readily replaced are shown in United States of America Patent No. 3,397,012. Other such means are disclosed ln United States of America Patent No. 3,114,537.
In Uni~ted States Patent No. 3,622,206 similar means are shown for enabling - quick and easy removal of a non-rotatable bit from a bit carrying lug.
~; ~ In addition to various arrangements for permitting the ready removal of worn bits, some~of which are alluded to above, the prior art recognized the importance of also proyiding arrangements by means of which the bit carrying lug itself could be easily and readily removed from the base :~
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member on which it was mounted. United States Patent No. 33338~634, for example, discloses a pin arrangement by means of which a bit carrying lug or block may be removed from the base member or driven element of a mining machine and the like. This particular arrangement, however, placed a great deal of strain on the pin used to connect the block to the base member.
United States Patent No. Re. 28,310 descri'bed a pin-on-block arrangement for removab'ly securing a block to the driven element of a mining machine or the like in which pins were used to effect the connectiong the arrangement being such, however, that most of the stress resulting from the cutting forces arising during the mining or digging functions were taken off the pin. This latter arrangement, while quite satisfactory in many respects, required a certain amount of room for manipulation of the pins in securing the removable blocks to the base members; it was not possible to place such blocks in flush side-by-side relationship on a driven member. ~ -There are other patents which disclose various ways of not orly removably affixing bits, teeth and the like to suitable lugs or ~ ~blooks provided therefor, but also for removably affixing the lugs or blocks ; ~ to the driven elements of a mining or digging machine and the like. Some of th~se, for example, were applicable to l'plumb-bob" bits. These prior known arrangements~ while generally satisfactory~yin many respects, dld requ~ire a relati~ely large amoun~ of spaoe to accommodate the various means for affi~ing the removable lug or block to the driven element of the working maohine whate~er~it was.
Aooording to parent application 257,100~ there is provided a wedging;iarrangement for removably affixing a work tool holder to a base

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member in mining, road working and earth moving machinery, said arrangement comprising:
one of said base member and said work tool holder having a slot therein, the other of said base member and said work tool holder being received in said slot, a wedge element in said slot; and holding means to hold said wedge elemen~ in said slot in wedging engage-ment with both of said work tool holder and said base member.
According to one aspect of the present invention, there is provided a base member of the type to removably receive a work tool holder of a mining~ road working or earth moving machine by means of a wedging arrangement, said base member comprising: a block having top and bottom walls~ front and back walls, and a pair of side walls, said block having a slot therein extending from said top wall towards and spaced from said bottom wall and adapted to receive a portion of a s~id work tool holder and a portion at least of said wedging arrangement, a portion of said slot being undercut so as to extend beneath said top wall.
According to another aspect of the present invention there is provided a base member of the type to removably receive a work tool holder of a mining, road working or earth moving machine by means of a wedging arrangement, said base member comprising: a cylindrical drum, and a plurality of parallel dove tailed groo~esin the outer surface of said drum, said gr~o~sbeing adapted to receive a portion of said work tool holder and a portlon at least of said wedging ar~angement Aocording to a further aspeot of the present imention there is _3_ , .

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provided a base member of the type to removably receive a work tool holder of a mining, road working or earth moving machine by means of a wedging arrangement~ said base member comprising: a cylindrical drum; and a plurality of blocks affixed to said drum, each said block having top and bottom walls, front and back walls~ and a pair of side walls, said ~ -block having a slot therein extending from said top wall towards and spaced from said bottom wall and adapted to receive a portion of a said work tool and a portion at least of said wedging arrangement, a portion of said slot being undercut so as to extend beneath said top wall.
According to a still further aspect of the present invention there is provided a base member of the type to removably receive a work tool holder of a mining, road working or earth moving machine by means of a wedging arange-ment, said base member comprising: a block having top and bottom walls~ front and back walls, and a pair of side walls; and a male eleme~t extending from said top wall and adapted to be received within an aperture provided in a said work tool holder, said male element having an undercut portion to receive a portion at least of said wedging arrangement.
In the accompanying drawings, which illustrate exemplary embodiments of the present invention:
Figure 1 is a perspective view illustrating a removable member secured within a dove-tailed slot of a base member by means of a wedge element and bolt, the particular removable member there depicted being a lug designed to accommodate a knook-in, pry-out mining bit and the like.
Figure 2~is a side elevation, partly in section, of the arrange-ment depicted in Figure 1.

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Figure 3 is an exploded view illustrating how the removable member, wedge element and bolt may be placed within the dove-tailed slot provided in the base member3 Figure 4 is a perspective view similar to Figure 1 but showing the parts as they would preferably be arranged if the direction of machine movement is reversed, the chief difference being the use of two bolts instead of one in this case.
Figure S is a perspective view of the drum of a mining or road planing machine and the like in which the dove-tailed slot to receive the cooperating removable member and wedge element is provided directly therein as distinguished from the slot being provided in a base member or o~her integral part of the machine.
Figure 6 is a perspecti~e view generally similar to that of Figure 4 but showing the arrangement as including side walls closing what would otherwise be the open ends of the dove-tailed slot, a cross sectiong for example~ through the center of this Figure along that axis thereof which is in the direction of movement indicated~ would be the same as a similar cross section through Figure 4.
Flgure 7 is a semidiagrammatio perspective view showing a plurality of base membePs' such as depicted in Figure 6 permanently affixed to the drum of a road planing or mining machine and the like.
Figure 8 is an exploded perspective view, with certain parts ommitted, showing a removable member and base member provided;with a keyway and slot for preventing lateral movement between such members.
Figure 9 is a fragmentary side elevation of a portion of the : .

base member of Figure 8.
Figure 10 is a side elevation, partly in section, similar to Figure 2 but showing the use of a wedge element having two tapered surfaces rather than one.
Figure 11 is a side elevation~ partly in section, depicting an arrangement generally similar to that of]Figure 4 but disclosing a key connection between the removable member and the base member at the rear thereof along the path of travel indicated.
Figure 12 is a side elevation, partly in section, showing the general arrangement of parts depicted in Figure 4 but with one of the dove-tailed portions of the slot omitted.
~igure 13 is a side elevation, partly in section, generally similar to that of Pigure 1 but showing the removable member as designed to accommodate a specific~ non-rotatable bit.
Figure 14 is a side elevation of an arrangement generally ~ .
similar to that of Pigure 4 but disolosing a different kind of removable member and a di$ferent relationship between such member and the base member to the rear thereof along the indicated pakh of travel of these members.
~igure 15 is a side elevation of an arrangement generally like that of Figure 1 but deplcRing the use of a specifically different removable member.
Figure 16 is a side elevation illustrating an arrangement .
generally similar ~o that depicted in Figure 14 but showing a different ~; relationship between the removable member and the base member at the ~ ~ ' ~:~ ' . .

rear of the dove-tailed slot as considered in the direction of movement indicated.
Figure 17 is a side elevation illustrating an arrangement like that shown in Figure l but depicting a ~ifferent s~yle of removable member.
Figure 18 is a side elevation of an arrangement wherein a mining machine bit and the like is directly secured within the dove-tailed s ot of the base member, such bit responding to the removable member disclosed in the ~igures previousl~ described.
Figure l~ is a front elevation of the arrangement sho~l in Figure 18, a variation being illustrated in dotted lines.
Figure 20 is a side elevation illustrating an arrangement wherein the removable member is provided with a dove-tailed slot designed to accommodate both a male element provided on the base member and a wedge element. ~ `
Figure 21 is a side elevation illustrating an arrangement in which a different type of wedge is employed and in which the bolt is not in direct contact with the wedge.
Figure 22 is a side elevation of a further arrangement showing a specifically different utilization of the bolt and wedge element.
Figure 23 is a side elevation depicting what in effect is the reverse of the arrangement shown in Figure 22.
Figure 24 is a side elevation of an arrangement employing an adiustable shim in place of the wedge element.
Figure 25 is an exploded perspective view of the adjustable shim shown in Flgu~e 24.

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Figure 26 is a side elevation of an arrangement generally sI~ilar to that depicted in Figure 24 but disclosing a variation wherein a portion of the wedge-shim means is built into the removable member itself.
Figure 27 is a side elevation showing an arrangement wherein the ~-bolts are eliminated and the wedge element is of a knock-in variety.
Figure 28 is a side elevation of a modification of the arrangement depicted in Figure 27 wherein the wedge element is further held in locking position by means of the bit carried by the removable member.
Figure 29 is a fragmentary side elevation disclosing an arrangement whereby a p~urality of removable members may be secured to a machine element by providing the machine element with dove-tailed slots to receive nut-like members and shims to cooperate with wedge elements and bolts.
Figure 30 is a fragmentary side elevation generally similar to that of Figure 29 but showing an arrangement in which the shims are omitted.
Figure 31 is a side elevation depicting an embodiment of the invention as applied to a mining chain wherein the base member comprises a chain block.

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Fîgure 3?. is a side elevation of an arrangement wherein the wedge .
~` 20 element is provided with a non-threaded hole to receive a bolt which is threaded into the removable member.
Flgure 33 is a side elevation of an arrangement wherein the wedge element is provided w*h an integral threaded stud which passes through a non-threaded opening in the removable member, the parts being held together b~ a nut on said threaded stud.

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Figure 34 is a perspective view of a modification of the arrangement of Figure 4 and shows the cutting tool and cutting direction oriented at 90 to that of Figure 4.
Referring first to Figures 1, 2 and 3, the arrangement there depicted is that of a base member Por a mining machine, the removable member comprising a bit carrying lug or block such as that generally shown in United States Patent No. 2~965,365.
In Figures 1 through 3 the base member 50 is provided with a dove-tailed slot 51 adapted to accommodate a removable member 52 and a wedge element 53. A bolt 54 has a threaded engagement with the member 53.
As shown in Figure 3 the wedge element 53 may be placed in the dove-tailed slot 51 from above (it is not necessary to insert any of these elements into the slot 51 from the sides thereof) and the removable member 52 may then be placed within this slot, also from above. It will be understood that when the member 52 is completely down in the slot 51, and the portion 52a is in contact with the portion 50a~ there will be a slight space between the removable member portion 52b and the wedge element portion 53b. When~ however, the bolt 54 is passed through the shouldered orifice 55 into threaded engagement with the wedge ele~ent 53 and tightened~ the wedge element is thereby moved from the floor of the slot 51 to the position indicated in ~igure Z. In this manner the member 52 is wedged into position within the slot 51 of the base member 50. There is good frictional engagement between the members 50 and 53 and between the members ~50 and 52 in the re~ion 50a, 52a? Considering the line of movement imparted to the~assembly by the~driven elemént of the mining machine (not shown) .: ~ .

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of which base member 50 is an integral part or to which base member 50 is affixed ¦i.e.~ the cutting direction) as indicated by arrows A in Figures 1 and 2, there is thus good frictional engagement among these parts both fore and aft.
As the members a~e moved in the direction of arrow A the forces resulting from rontact of the bit 52c (Figure 2~ carried by lug 52 with the material being acted upon will tend to rock the member 52 in a counter clock-wise direction, thus further insuring good engagement within the slot 51. In this arrangement, therefore, one bolt 54 is sufficient.
Respecting Figures 1 through 3, the orifice 56 in lug 52 is intended to receive the shank of a cutter bit 52c of the type sh~n in Uni~:ed ~tates Patent No. 2,965,365, the orifice 57 will receive an appropriate bit retainer 52d of the type shown in the same Patent, and the orifice 58, communicating with shank receiving perforation 56, may :
serve as a bleed hole for mine fines, foreign materials and the like.
To remove lug 52 from dove tail slot 51 it is only necessary to remove bolt 54. With bolt 54 removed, it is only necessary to reverse the steps described wlth respect to Figure 3. If, under particularly adverse mining conditions, the bolt 54 should become frozen in lug 52 or wedge element 53 through the action of corrosive mine waters, fines and foreign materials, it will be apparent from Figure 2 that a portion 54a of the bolt is exposed and can be cut~ burned or broken with an appropriate drift. In this manner lug 52 and wedge element 53 may be remoYed and base member 50 and its transverse slot 51 remaini undamaged.
It will be evident that similar emergency measures may be taken with a t~

majority of the other embodiments of the invention, to be described hereinafter.
Figure 4 illustrates a base member having a transverse slot substantially identical to that illustrated in Figures 1 through 3 and like parts have been giren like index numerals. In Figure 4, a removable lug 59 is shown. For purposes of an exemplary illustration lug 59 is adapted to receive the same type of cutter bit as lug 52 of Figures 1 through 3 and to this end has a shank receiving perforation 60, a transverse retaining means perforation 61 and a bleed hole 62.
Again~ the direction of motion imparted to the assembly by the driven element (not shown) of the mining machine or the like (i.e., the cutting direction) is illustrated by arrow A~ The embodiments of Figure 4 differs from that of Figures 1 through 3 primarily in that the wedge element 63, equivalent to wedge -element 53 of Figures 1 through 3, is ~
located at the forward end of lug 59. -Lug element 59 may be mounted in dove tail slot 51 of base member 50 in substantially the same manner described with respect to lug 52. Wedge element 63 is first located in slot 51 and then lug 59 may be rocked into position. In this embodiment a pair of bolts 64, equivalent 20 to bolt 54 of Figures 1 through 3, pass through perforations 65 and 66 in lug 59 and into engageLent with threaded perforations 67 and 68 in wedge member 63. ~hen bolts 64 are tightened, the wedge element 63, lug 59 and .
dove tailed slot 51 will cooperate in much the same manner described with respect to the embodi~ent of Figures 1 through 3 to firmly maintain lug~
59 in slot 51 and to permit substantially no relative movement therebetween.

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Since the wedge element 63 is at the forward end of lug 59 in the embodiment of Figure 4, the resultant cutting forces during the mining action will tend to rock lug 59 rearwardly placing bolts 64 in tension. For this reason, it is preferred to use two bolts in this embodiment.
Figure 5 is a perspective view of a cutting drum 69 of a mining machine or the like. The cutting drum is provided with a plurality of longitudinally extending dove tail slots 70 about its periphery. Slots 70 are equivalent to the slot 51 of Figures l through 3 or the slot 51 of Figure 4. It will be immediately eviden~ that the lug-wedge-bolt assembly of Figures l through 3, or the lug-wedge-bolt assembly of Figure 4, could be utilized directly in the slots 70. While these lug-wedge-bolt assemblies could be slid into slots 70 from the s~de~ this is not necessary as described with respect to Figure 3. Since the assemblies may be placed in the slots from above, it will be apparent that the assemblies may be located in any appropriate pattern about the cutting drum The assemblies may be individually affixed to the drum, or removed from the drum for replacement~ both rapidly and efficiently. When the pattern of bit carry1ng lugs requires it, lug-wedge-bolt assemblies may be located in side-by-side abutting relationship within the same slot 70.
In F1gure 6 a lug-yedge-bolt assembly identical to that of Figure 4 is shown and like parts have been give like index num~ral-s.
The difference between the embodiment of ~igure ~ and that of Figure 4 lies in~base member;71. Base member 71 has a central depressi~n 72 :
~equiva1ent in config~ration to slot 51 of base member 50 of Figure 4. In this instanoei, howe~er, the slot does not pass through the sides of base --?

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member 71. Since the lug 59 and wedge 63 may be located in place from above the depression 72, it is not necessary that the depression 72 extend through the sides of base member 71.
Figure S described above is an example of an instance where the driven element of the mining machine or the like, itself, constitutes the base member for a plurality of bit holding lug-wedge-bolt assemblies. In contrast, Figure 7 is a semi-diagramatic representation of a cutting drum 73 of a mining machine or the like wherein a plurality of base members 71 (Figure 6) are affixed to the drum 73 in an appropriate cutting pattern about its periphery. Base members 71 may be attached to cutting drums 73 in any appropriate manner, as by welding or the like. The bottom surfaces of base members 71 may be configured as shown in Figure 15 of United States Letters Patent ~e 28,310 so that they may be readily attached to a cutting drum of any appropriate diameter. It will be understood that the lug-wedge-bolt assemblies of Figures 1 th~rough 3 or Figures 4 and 6 can be located in base members 71 as described above.
~igure 8 is an explo~ed view of a structure substantially identical to that of Figure 4 with like parts having been given like index numerals. In Figure 8 the wedge 63 and bolts 64 have been omitted for purposes of clarity. The embodiment of Figure 8 differs from that of Figure 4 only in that a notch 74 is provided in the rearward most end of lug 59 and a corresponding pin 75 is provided in a perforation 76 in base member 50, the perforation 76 intersecting the dove tailed slot 51, as is most clearly seen in the fragmentary side elevational view of F1gure 9.
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Pin 75 in base member SO constitutes a key and notch 74 in the rearward end of lug 59aans~itu~es a key-way. These elements cooperate to perform two functions. First of all, when the lug 59 is secured in dove tailed slot 51, the pin 75 and notch 74 will prevent forcea~le lateral shifting of the lug-wedge-bolt assembly in slot 51. More particularly, however, the pin 75 and notch 74 constitute means for preceisely locating the lug-wedge-bolt assembly within slot 51. Thus, for example, if such pins were located in an appropriate pattern in the slots 7O of the cutting drum 69 of Figure 5, lug-wedge-bolt assemblies could be precisely located on the drum in a predetermined pattern much the same way as on cutting drum 73 of Figure 7 wherein the base members 71 predetermine a pattern for the bit carrying lug-wedge-bolt assemblies.
Figure 10 illustrates an embodiment similar to that of Figures 1 through 3 and like parts have been given like index numerals. Th embodiment of Figure lO differs from that of Figures 1 through 3 in that the surface 52e of lug 52 (equivalent to the surface 52b of ~igure 3) and the cooperating surface 53c of wedge 53 (equivalent to surface 53b of Figure 3) are themselves tapered, but to a lesser extent than th0 cooperating tapered surfaces of the wedge 53 and dove tail slot 51. This enables 2a : the remo~val of lug 52 upon remova~l of bolts 54 even if fines and ~foreign material do not permit wedge member 53 to shift fully downwardly within dove~tailed slot 5~1.
The struature of Figure 11 is similar to that of Figure 4 and again l1ke parts have been given like index num~ ss; The embodiment ~of Figure 11 differs from that of Figure 4 in that the rearward dove tail ' :

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of slot 51 has been eliminated and replaced by a rectangular undercut 77.
In similar fashion the rearward extending foot of lug 59 has been replaced by a relieved lug or extension 78. The lug extension 78 and rectangular undercut 77 cooperate to key lug 59 to base member 50.
Figure 12 is again substantially similar to Figure 4 and like parts have been giv~ like index numerals. In this embodiment, the difference lies in the fact that the rearward dove tail or undercut in slot 51 and the rearward foot of lug 59 have been eliminated completely. While the embodiments of Figures 11 and 12 are not preferred, they will perform adequately in those assemblies wherein the wedge element is located at the forward end of the lug.
Thus far all of the embodiments described have been illustrated, for purposes of an exemplary showing~ as having removable lugs of the type adapted to receive cutter bits such as are shown in the above mentioned UnIted States Letters Patent 2,965,365. However, other embodiments may haYe removable lugs of any appropriate type to recciYe any appropriate type of cutter bit. To this end, F1gure 13 illustrates an assembly substantially the same as that illustrated in Figures 1 through 3 and operating in the same manner but utilizing a differentt style bit. For this reason, like parts have been given like index numerals~
In Figure 13 the lug 52 is provided with a shank receiving perforation 79 adapted to receive a cutter bit 80 of the type described in United States~Letters Patent 3,622,206. The cutter bit 80 is provided with a hard cutting tip 81 at one end and a downwardl~and reaI~a~rdl~ sloping abutment surface 82 at the other. The lug 52 has a transverse perforation :

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83 intersecting the shank receiving perforation 79 and through which a pin 84 extends providing a rearwardly and downwardly sloping abutment sur-face 84a adapted to cooperate with the abu~ment sur~ace 82 of cutter bit 80. The abutment surfaces 84a and 82 cooperate to urge the cutter bit to its fully seated position and to keep the cutter bit from rotating within the shank receiving perforation 79 during the cutting action. Again, the cutting direction is indicated by arrow A.
The shank receiving perforation 79 may have an annular notch 85 formed therein to receive a pair of split metal rings 86 and 87 serving as retaining means for the cutter bit 80, as is described in the last mentioned United 5tates Letters Pa~*ent.
In all other ~espects, the lug-wedge-bolt assembly of Figure 13 cooperates with the base member ~0 and slot 51 therein in an identical manner to that described with respect to Figures 1 and 3 and may be located and remo~ed from slot 51 as taught above~
Figures 14 through 16 illustrate embodiments having lugs and cutter bits of the type taught in United States Letters Patent 3,397,012.
Turning first to Figure 14, a base member 88 equivalent to base member 50 of Figure 4 is provided with a transverse dove tailed slot 89 equivalent to slot 51 of ~igure 4. A removable lug 90 is illustrated having a forward extension 91 p-~ovided with a pair of perforations~ one of which is shown at 92 to accommodate a pair of bolts, one of which is shown at 93. The bolts are adapted to threadly engage a wedge member 94. It will be apparent that bolts 93 and wedge member 94 are equivalent to bolts 64 and wedge member 63 of ~igure 4. The lug 90 has a shank recei~ing perforation 95 .: :

, .. , . . ~ , a rearwardly extending foot 96 adapted to engage the rearward dove tail undercut of slot 89, and a rearward anvil 97 overlying the upper surface of base member 88 and presenting a rearward abutment surface 98.
The cutter bit 99 has a cylindrical shank portion terminating at its forward end in a hard cutting tip 100 and at its rearward end in an abutment surface 101 adapted to cooperate with abutment surface 98 of the anvil portion 97 of lug 90. Near its rearward end the shank of cutter bit 99 has an annular notch 102 adapted to receive a split metal retaining ring 103. Cutter bit 99 is rotatable in shank receiving perforation 95.
The placement and removal of the lug 90 and wedge member 94 in slot 89 are identical to those described with respect to Figure 4 and the various elements cooperate in an identical manner.
Figure 15 illustrates a base member identical to that of Figure 14 and like parts have been given like index numerals. The lug 104 of Figure 15 is adapted to receive the same type of cutter bit as is shown at 99 in Fîgure 14. To this end the lug 104 is provided with a shank receiving perforation 105 equiralent to shank receiving perforation 95 of Figure 14 and an anvil portion 106 proriding a rearward abutment surface 107 equivalent to abutment surface 98 of Figure 14.
In this embodiment the anvil 106 is provided with a perforation 108 to re~ceive a bolt 109 adapted to threadly engage a wedge member 110 equivalent to wedge member 53 of Figures 1 through 3. It will be evident that the embodiment of Figure 15 is simply a modification of the embodiment of Figures 1 through 3 to accommodate a rOtating piCk-type bit. The lug 104 and vedge llO cooperate with slot 89 in base 88 in precisely the same , ': .
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manner described wi.th respect to lug 52 and wedgeS3i.n Figures 1 through 3.
Figure 16 is a modification of the embodiment of Figure 14 and like parts have been given like index numerals. The embodiment of Figure 16 i-~r differs from that of Figure 14 only in that the rearward portion 88a of base member 88 is extended upwardly and the anvil portion 97a of lug 90 no longer overlies the top surface of base member 88.
Figure 17 is similar to Figure 15 but illustrates a lug adapted to carry a typical plumb-bob bit of the type taught in United States Letters Patent 3,519,309. The base member, wedge and bolts are identical to those illustrated in Figure 15 and have been given the same index numerals. The lug 111 has a rearward extension 112 provided with a perfo~a~ion~ 113 to accommodate bolt 109. A shank receiving perforation is illustrated at 114 to receive the plumb-bob bit 115. Bit : 115 comprises a cylindrical shank 116 so sized as to be freely rotatable within shank receivi.ng perforation 114. At its forward end, sh~nk 116 terminates.~ a conical shoulder 117 adapted to cooperate with the flared forward end 118 of shank reeeiving perforation 114 to serve as a gauge-determining abutment. The forward end of bit 115 comprises a nose 119 te~inating in a hard cutting tip 120. Retaining means (not shown) are normally provided to maintain the shank 116 of cutter bit 115 within shank receiving per~oration 114. The assembly comprisi~g the lug 111, bolt 109 and wedge 110 cooperate with base member ~8 and its transverse slot 89 in precisely the same manner taught with respect to Figures 1 through 3 and 15 The various embodiments of Figures 13 through 17 illustrate that the proportions ancl configurations of the base members and lugs may vary, ' ` ~ : ~ ` ' ~ ` ! ' .
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but the wedging principle is applicable to all of these embod:~nents.
Figures 18 and 19 illustrate an instance wherein a lug for removably mounting a cutter bit has been eliminated. In essence, the lug and cutter bit comprise an integral one-piece structure. For purposese of an exemplary showing, a base is illustrated at 121 having a transverse dove tailed slot 122. Ba~e member 121 may be substantially identical to that described with respect to Figure 4. It will be understood that it can be a separate member to be welded to the driven element of a mining or digging machine~ or it may constitute an integral part of the machine, such as the cutting drum illustrated in Figure 5.
The cutter bit of Figures 18 and 19 is generally indicated at 123 and comprises a wide base portion 124 equivalent to a lug. This wide base portion has a rearwardly extending foot 124a adapted to cooperate with the rearward undercut of dove tail slot 122 and a vertical forward surface 124b adapted to cooperate with a wedge element 125. Wedge element 125 is substantially identical to t-hose wedge elements illustrated previous b~ as for example in Figures 1 through 4.
The upper p~tion 126 of cutter bit 123 is narrow and carries at ltS: uppennost forward portion a hard cutting tip 127.
~ 20 ~ ~ A forward extension 128 is provided having a perforation 129 ;~ therein to receive bolt 130 threadly engaged in perforation 131 of wedge , element~l25~ ~
Arrow A indicates the cutting direction and it will be evident that~this is an in~tance wherein the wedge element 125 is located at the front o~ cutter bit 123. Therefore, the assembly of cutter bit 123~ wedge ~:

element 125 and bolt 130 cooperates with base member 121 and its dove tailed slot 122 in the same manner described with respect to the structure of Figure 4 To this end, wedge element 125 and cutter bit 123 may be located in the slot 122. When wedge element 125 is engaged by bolt 130 and the bolt is tightened, the cutter bit-wedge-bolt assembly will be firmly held in dove tail slot 122 of base member 121 with substantially no relative movement of the assembly within the slot. When cutter bits of the type sho~n at 123 in Figures 18 and 19 are applied to the driven element of a mining machine, it will be understood by one skilled in the art that they will 10 be located on the driven element in an appropriate cutting pattern, as is conventional in the art.
The same sort of structure may serve as a digger Or dipper tooth for trenching or digging machines. It will be understood by one skilled in the art that the digger teeth of trenching or digging machines are generally located in side-by-s~de relationship and there is no bit pattern as in a mining machine application wherein groups of bits follow each other, each group cutting the kerf left by the group of bits ahead of it.
It is desirable, therefore, in a digger or dipper tooth application, to have a wide tooth. An exemplary wide configuration is illustrated in broken -20 lines at 132 in Figure 19. When the upper portion of the digging tool is wide as shown at 132 it will be preferable to widen the forward extension 128 and provide two bolts 130 in threaded engagement with wedge 125.
It will further be evident that either in its cutter bit or digger tdoth oonfiguration, the structure of Figures 18 and 19 may be modified to provide wedge 125 r~ar~ardly of the cutter bit or dipper tooth, ~ .

after the manner described with respect to Figures 1 through 3.
In all of the embodiments thus far described, the base member (whether a separate member affixed to the driven element of the mining or digging machine or whether constituting an integral part thereof) has been described as being provided with a transverse dove tailed slot. Figure 20 illustrates a reverse situation wherein the base member may be provided with an upstanding, undercut male member to be received within a transverse slot in the removable and replaceable bit-holding lug. To this end, a base member is illustrated at 133 as constituting either a separate structure to 10 be affixed to the driven element of the mining or digging machine or as an integral part thereof. Base member 133 has an upstanding male element 134 ;
with undercut side surfaces 135 and 136.
A removable and replaceable lug 137 is provided with a transverse slot 138. For purposes of an exemplary showing the cutting direction is again illustrated by arrow A. The forward edge 138a of slot 138 is dove tailed so as to cooperate with surface 135 of male elemen* 134. The rearward edge 138b of slot 138 is vertical in configurationa and spaced from surface 136 of male element 134 by a distance sufficient to accommodate wedge element 139.
Wedge element 139 is substantially the same as wedge element 53 of Figure 1 and is provided with a threaded perforation 140 adapted to receive bolt 141 passing through per~oration 142 in lug 137. The lug 137 may have any appropriate configuration to receive any appropriate digger tooth or cutter bit.~ For purposes of an exemplary showing it is illustrated as having a shank receiving perforation 143~ a transverse perforation 144 :: :
,' ` ' ' ' ~ ' ! , : . ' , , ~, . . . . . . . . . . .

8~72~

for a resilient retaining means~ and a blced hole 145, these are equivalent to shank receiving perforation 56, resilient retaining means perforation 57 and bleed hole 58 of Figures 1 and 2. Therefore~ the lug illustrated as adapted to accommodate a cutter bit of the type shown in Figure 2.
It will be evident from Figure 20 that wedge~èlemeht 139 may first be locat~dd in place and the lug 137 may be placed thereover.
Bolt 141 is inserted in lug hole 142 and engaged in the threaded perforation 140 of wedge element 139. As the bolt 141 is tightened, wedge 139 will firmly engage surface 136 of male element 134 of base 133 and surface 138b of lug slot 138~ Si~ilar~ly~ male element surface 135 will firmly engage lug surface 138a and the lug will be locked in place on base member 133.
The embodiment of Figure 20 is an instance wherein the w~dge element is located rearwardly of the digger tooth or cutting tool, and therefore is analogous to the embodiment of Figures 1 through 3. If the cutting direction were re~rersed in Figure 20 and appropriate modifications were made in lug 137 to mount and r~tain the cutting tool or digging tooth, no other change need be made in the structure although it might be preferable to provide two bolts 141 rather than one.
Figures 21 through 28 illustrate other ways in which the wedging action may be accomplished. Again, the cutting direction is in-dicated by arrow A.
Turning flrst to Figure 21 a base member 146 is shown having a dove tail transverse slot 147. A replacable lug is generally indicated at 148. While the lug may be o~ any appropriate type, for purposes of an exemplarr showing it ia illustrated as a lug of the general character .

: ; .
:: .

taught in the above mentioned United States Letters Patent 3,397,012 adapted to receive a cutter bit similar to cutter bit 99 of Figure 14. To this end the lug is shown as having a shank receiving perforation 149, and an anvil portion 150 providing a rearward abutment surface 151. At its rearward end, the lug is provided with a foot 152 adapted to cooperate with the rearward surface of slot 147. At the forward end, lug 148 has an extension 153 provided with a threaded perforation lS4 to receive a bolt 155. Extension 153 has a forward surface 156 sloping forwardly and down wardly. Finally, the embodiment of Figure 21 includes a shim 157.
In the mounting of lug 148 in the slot 147 of base member 146 *he lug is first located in place. The distance between the forward surface 156,of the lug and the adjacent dove tailed surface of slot 147 is such that shim 157 may be placed therebetween. As bolt 155 is tigh~ened, its bottom end will abut the bottom of the base member slot 147 causing the forward end of lug 148 to shift upwardly. Surface 156 on the lug will -shift into substantial parallelism with the forward surface of base mem~er slot 147, flrmly engaging shim 157 therebetween. In this manner~
lug 148 will be locked in place with no relative movement between the parts -The resultant cuttlng forces will tend o~ly to reinforce the engagement ... ..
of lug 148 in slot 147. The dotted line at the left of Figure 21 shows how both the foot 152a and slot 147a may be rounded to produce a socket-type engagement between the lug 148 and base member 146.
~ ` ~ Figure 22 illustrates another wedging arrangement. The base ; ~member 1n Figure 22 is identical to that of Figure 21 and l;ke parts have been give~ like index numerals, Lug 148a of Figure 22 is similar to lug ::: : :

'.', ,'".',:'','''..'''"~.':''.'''' .', '' ' ' ' ' ' ' .';, " ' '' ~L~8~l72~;11 148 of Figure 21 and again like parts have been given like index numerals.
In this instance, lug 148a is provided with a forward extension 158. A
wedge element 159 is provided above extension 158 and has a threaded perforation 160 adapted to receive bolt 161. Initially, lug 148a may be placed in slot 147 in the position showrl. Wedge member 159, in this instance, must be inserted from the side of the base member 146. Bolt 161 is threadedly engaged in perforation 160 in wedge 159 and as bolt 161 is tightened its bottom end will abut lug extension 158 and further tightening will cause wedge 159 to shift upwardly. The wedge will engage the vertical ~0 front surface 162 of lug 148a and the adjacent forward surface of slot 147 with a wedging action firmly locking lug 148a in base member 146.
The embodiment of Figure 23 is similar to that of Figure 22 with the exception that the wedge element is located rearwardly of the lug. To this end~ the base member, bolt and wedge means are identical and have been given like index numerals. Lug 148b is quite similar to lug 148a and like portions have beon given like index numerals. In this -~
instance, however~ the lug is provided with a forward foot 163 similar to the rearward foot 152 of Figure 22. A rearward extension 164 similar to forward extens1on 158 of Figure 22 is located at the rear of lug 148b.
To lock lug 148b in the slot 147 of base 146 the lug is first located in the slot in the position shown and thereafter the w~dge is slid in from the side of the base to the position shown. Initial tightening of bolt 161 will cause t to abut extens1on 164. Further tightening of the bolt will result in an upward movement of wedge 159 which will engage between the rertical rear surface 165 of the lug and the adjacent rear surface of slot 147, ~:.

'7ZV

locking lug 148b in place.
Figure 24 illustrates a base substantially identical to the base of Figures 21 through 23 and again like parts have been given like index numerals. A lug generally indicated at 148c is shown as being substantially like lug 148 of Figure 121 and like parts have been given like index numerals. Lug 148c differs from that of Figure 21 only in that the forward extension 153 does not have a threaded perforati~n 154.
In the embodiment of Figure 24 a wedging action to maintain lug 148c within the slot 147 of base 146 is accomplished through the use of a composite wedge structure. Reference is also made to Figure 25, constituting an exploded view of the elements making up the composite wedge structure. The composite wedge comprises a bolt 166 and first and second wedge elements 167 and 168~ respectively. The first wedge element is of inverted L,shaped configuratio~ and has a forward surface 169 adapted to abut the forward surface of base member slot 147. The rearward surface 170 of wedge member 167 slopes downwardly and toward surface 169. The second wedge element 168 has a rear surface 171 adapted to abut forward surfaoe 156 of lug 148c. The forward surface 172 ~a~getelQhe~t~l~&
slopes downwardly and away from its rearward surface 171 and is adapted 20 ~ to lie in abutting relationship with the rearward surface 170 of the ~- first wedge ele~ent 167. A perforation generally indicated at 173 is provided for bolt 166. As is most clearly seen in Figure 24~ the perforation extends through the upper portion of the first wedge member.
Thereafter, one half of;the perforation is located in the first wedge member -, :
;~ as at 173a~and the second half o~ the perforati~n is located in the second :
~, , -2~, ' ', '' ' , . .

l'7~

wedge, member as at 173b. The portion 173a of the perforation and that part thereof which extends through the upper portion of the first wedge member is unthreaded. On the other hand, that portion 173b of the bolt perforation located in the second wedge element 168 is threaded, as can be seen from Figure 25.
In assembly, lug 148c is first located in base member slot 147.
Thereafter, bolt 166 is passed through that portion of perforation 173 in the upper part of the first wedge element 167. The second wedge element is thereafter mated with the first wedge element and the composite wedge structure is located in the space between the forward surface 156 of lug 148c and the forward surface of base member slot 147, as shown in Figure 24. The axis of bolt 166 lies in that plane defined by surface 170 of the first wedge element and abuting surface 172 of the second uedge element.
A turning of bolt 166 ~ill, by virtue of its threaded engagement with the second~wedge element 168, cause the second wedge element to shift upwardly along the ~urface 170 of the first wedge element. This~ in turn, increases the effective width of the composite wedge assembly firmly locking lug ~-~::
148c within base member slot 147.
A~modification of the structure of Figure 24 is illustrated ln Figure~6. The base member is identical to that of Figure 24 and like parts have been given like numerals. The lug 143d is similar to that of Figure 24 and again like parts have been given like index numerals.
In essence, in the embodiment of Figure 26 the second wedge element (168 in ~igures 24 and 25) has been incorpo~ated as an integral .
~ part of lug 148d. To this end~ the forward extension 153a of lug 148d has been enlarged ~orwardly and terminates in a surface 156d equivalent to the surface 172 of second edge wedge element 168 (Figure 25). The surface 156d carries a threaded depression 174 equivalent to the threaded depression 173b of the second wedge element (Figure 25). A wedge~ element 175 is provided somewhat similar to the first wedge element 167 of Figure 25.
Wedge element 175 is ~edge-sharped rather than I-shaped and has a longitudinal unthreaded depression 176 forming the other half of the perforation,~to !~, receive bolt 166.
In use, lug 148d is located in the position shown within base member slot 147 and bolt 166 with wedge 175 lying there agai~st is turned into engagement with the threaded depression 156d. As the bolt 166 is further-tightened, wedge 175 shifts downwardly with bolt 166~firmly locking lug 148d within base member slot 147.
Figure 27 illustrates a bas~ member 177 having a dove tailed slot 178 therein as described above. A lug is generally indicated at 179~and lS of the type described in the above mention:edU~nited States Letters Paten~ 3,397~012~ intended to receive a rotatable pick-typ0 bit;such as bit 99 of Figure 14. To this end, lug 179 is il~ustrated as having a shank receiving perforation 180~ an anvil portion 181 providing an~abutment surface 182. The forward end of lug 179 is provided with a foot 183 adapted to cooperate with the forward surface of dove tail slot 178.
The rearward end of the 1ug terminates in a downwardly and rearwardly sloping surface 184 spaced from and non-parallel to the rearward surface of dove tail notch I78. A simple wedge member 185 is provided. To lock lug ~: :
~ 179 within base member ~slot 178 it is only necessary to first locate lug :: ~ ~~~~ .:

'iJ2~

l79 within the base member slot and thereafter to firmly insert wedge 185 between the rearward surface of slot 178 and the rearward surface 184 of the lug by a series of blows from an a,ppropriate tool. Lateral blows with an appropriate tool applied to wedge 18~ will release the wedge for removal and replacement of lug 179.
Figure 28 illustrates a modification of the embodiment of Figure 27. The base member is identical to that of Figure 27 and like parts have been given like index ~umerals. Lug 179a is similar to that of Figure 27 and is adapted to carry a pick-type cutter bit 186 of the type shown at 99 in Figure 14, with a hard cutting tip 187 at its forward end and a gauge-determining abutment surface 188 at its rearward end.
The bit 186 is freely rotatable in the shank receiving perforation 189 of lug 179a.
The lug has a forward foot 190 adapted to cooperate with the forward undercut of dove tailed slot 178. The lug differs from that of F1gure 27 large b in that it bears no an~il portion and no abutment surface to cooperate with abutment surface 188 of cutter bit 186. Instead, the lug 179a has a rearward extension 191 providing a downwardly and rearuardly ~sloping surface 192 spaced from the rearward surface of base member slot 178. ~In this embodiment, the lug 179a is first located in the base member slot 178 from the side thereof~ Thereafter, a wedge element 193 :~ : : . .
is located between the lug surface 192 and the rearward surface of dove tall slot 178, also from the side thereof. Wedge 193 may be driven into wedging ~ngagement with the~adjacent surface of the base member slot and ~surface~192 of lug 179a by an appropriate tool extending through shank 28~

~ , l'7~

receiving perforation 189 of the lug. In thislmanner wedge 193 will firmly maintain lug 179a in place within base member slot 178.
The forwardmost surface 194 of wedge 193 serves in this embodiment as an abutment surface adapted to coopera~e with the gauge-determining abutment surface 188 of cutter bit 186. As the assembly is driven in the cutting direction indicated by arrow A, the resul~ant forces on cutter bit 186 will be substantially axially thereof. The abutment of cutter bit surface 188 and surface 194 of wedge 193 will therefore tend to maintain~nd reinforce the wedging action of wedge 193. To remove lug 179a, it is o~ly necessary to apply lateral blows with an appropriate tool to wedge member 193 to remove it from the assembly. Upon removal of ~he wedge, lug 179a may be taken out of base member slot 178.
Figure 29 illustrates another application of the wedging concept. In F1gure 29, for purposes of an exemplary showing, a cutting drum is fragmentarily illustrated at 195. The cutting drum is provided with a plurality of longitudinal dove tailed slots about its periphery, one of which is shown at 196~ To this extent, the cutting drum is similar to drum 69 of Figure 5. In this instance, howevery cutting or~digging tooi carrying lugs are intended to be located on the periphery of the drum between the longitudinal slots therein by wedge elements located~within the ~lots. To this end, a pair of tool carrying lugs are fragmentarily indicated at 197 and 198. The ends of these lugs .
provide surfaces tapering downwardly and outwardly as is indicated at ;~

197a~and 198a, respeotively. The bottom surfaces of the lugs, 197b and 198b , :: :
::: :~ ~

7~

respectively~ are appropriately shaped to rest upon the driven element 195.
A first wedge element 199 is located within slot 196 and is so sized as to be insertable from the top thereof. Wedge element 199 is provided with a threaded perforation 200. A second wedge element 201 is provided, having anl~unthreaded perforation 202 adapted to receive a bolt 203. Wedge element 201 is so sized as to engage surfaces 197a and 198a of lugs 197 and 198.
To assemble the embodiment of Figure 29, wedge element 199 is first located in the slot 196 of driven element 195. A shim member 204 is thereafter located between wedge element 199 and an adjacent side of slot 196. Lugs 197 and 198 are thereafter appropriately located on driven element 95 and wedge element 201 is then located between them.
Bolt 203 is caused to pass throu~h perforation 202 of wedge element 201 and into threaded engagement with perforation 200 of wedge element 199.
As illustrated in Figure 29 the ~ssembly is shown in its untightened condition. It will be evident from the Figure however, that as bolt 203 ;
is further I~ightened~ wedge element 199 will be drawn upwardly in slo$
196 while wedge element 201 will be drawn downwardly toward wedge element 199. I$ is to be assumed that similar wedge and bolt assemblies wi~L

be located at the other ends ~ lugs 197 and 198 and in this way the lugs will be firm~Ly a~fixed to driven element 195. While, for purposes of an exemplary illustration driren element 195 has been described as being a cutting drum, it wiLL be understood by one skilled in the art that the driven element can be of any appropriate type and configurati~n, the bottom surfaces of lugs~ 197 and 198 being appropriately shaped to rest : ~ . , -: . . . . : , . . . . . ~ ,. . .. . . .. .. ;

'7~

thereupon.
Figure 30 illustrates a modification of Figure 29. Figure ~0 illustrates a driven element 205 of a mining machine or the like, again shown in the form of a cutting drum substantially identical to cutting drum 195 of Figure 29. The cutting drum is again provided with a plurality of longitudinally extending slots 206 and 207. Tool-carrying lugs are located between slots 206 and 207 as at 208~ 209 and 210. Lugs 208 through 210 have their bottom surfaces configured to rest upon the periphery of cutting drum 205 and p~esent opposed, downwardly and outwardly sloping end surfaces 208b, 209a, 209b and 210a~ respectively.
First wedge elements 211 and 212 are located in slots 206 and 207, respectively. Second wedge elements are located between lugs 208 through 210 as at 213 and 214. The pairs of cooperating wedge elements 213-21~ and 214-212 are provided with bolts 21S and 216, respectively.
The primary difference between the embodiment of Flgure 30 and that of Figure 29 lies in the fact that wedge elements 211 and 212 are so sized to be just nicely received in their respective slots 206 and 207.
While this eliminates the requirement for a shim of the type shown at 204 in Fig~re 29g it requires that wedge elements 211 and 212 be inserted in their respective slbts from the sides thereof, rather than from the top thereof. In all other respects, the wedge-bolt assemblies of Figure 30 ~ .
when tightened, lock lugs 208 through 210 in place in substantially the same manner described with respect to Figure 290 It will immediately be apparent that inbboth embodiments of Figures 29 and 30 a loosening of the .~ .
D-:: .
': ~

: ,., ,',: ' ' , , ,' , ' , ' , . . " ' " . ' :

7~

wedge-bolt assemblies will enable ready removal and replacement of the tool carrying lugs. While not show~ n the drawings, it will be understood that each of lugs 197 and 198 of Figure 29 and lugs 208, 209 and 210 of Figure 30 may be appropriately configured and provided with a shank receiving perforation for any suitable cutter bit such as those heretofore described.
Figure 31 is generally similar to FiguEe 4 but shows the wedging arrangement as applied to a base member which is in fact the chain block 250 of a mining machine chain. Lug 59 is located in slot 51 provided in the chain block 250 and so also is the wedge element 63. One or more bolts 64 will effect the desired wedging action among the lug 59 element 63 and chain block 250.
A modi~ied wedging arrangement is illustrated in Figure 32.
The base member 350 is provided with a dove-tailed slot 351 to receive a ~ -removable member or work tool holder 352 and a wedge element 353. The element 353 is provided with a non-threaded, shouldered bore 353a to reoeive a;headed bolt having a threaded stem 354 which passes freely through the element 353 but into threaded engagement with the work tool holder 352 as indicated a-t 352~. These parts 352, 353 and 354 may be loosely assembled and~,placed within the dove-tailed slot 351 from an open end thereof whereafter a suitable tool placed in the socket 354b of the ; bol~ 354 will effect the wedging arrangement depicted.
Another embodiment is depicted in Figure 33 wherein the wedge element 453 has an integral threaded stud 454 which passes through a non-: - :
threaded bore 452a in the work tool holder 452. The loosely assembled work tool~holder 452 and wedge element 453, 454 are placed in the slot :: ~ .
-~ -32-7~

451 of the base member 450 laterally from an open end thereof. A nut 452b is then placed on the end of the threaded stud 454 extending beyond the upper surface of the member 452 and tightened to effect the wedging arrangement depicted.
Figure 34 depicts an arrangement much like that of Figures 1 and 4 but wherein the cutting tool and cutting direction are moved through as indicated by the arrow A This Figure 34 emphasize~ the fact that the wedging arrangement is effective to hold the removable member (work tool holder 559) in the slot 551 of the base member 550; by reason only of the element 563 and bolts 564. Thus in this arrangement the bolts 564 effect good frictional engagement of the removable member 559 (the bit carrying block or lug and the like~ with the base member both sideways (starboarcl and port, as distinguished from fore and aft as earlier .: -described) along the line of travel of the driven element of which the base member is a part.
Modifications may be made in the invention without departing from the spirit of it Varlous numbers of bolts, for example, may be employed to effect the wedging arrangement and action depicted; the invention is not to be considered as limited to the use of either the one or two bolts illustrated. Furthermore it is possible to place a `
pluralit~ of work tools in each work tool holder rather than just the one indicated. Similarly some arrangement may utiliæe a plurality of ~ork : : :
tool holders arrangecl side by sicle in a common dove tail groove provided in a suitable base member3 the cutting drum 69 of Figure 5 could, for .
~ ~ exa~ple be so used. ~-~

:: ~ : -. . , . , . ., :.. .,, . : ~,- ., .. ;: , . . , , . , . . .:

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. ! ` ' ' '. ' ., ~ ' ~ .. , ' ' , , ! , '. " ~ .

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Claims (13)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A base member of the type to removably receive a work tool holder of a mining, road working or earth moving machine by means of a wedging arrange-ment, said base member comprising: a block having top and bottom walls and a pair of side walls, said block having a slot therein extending from said top wall towards and spaced from said bottom wall and adapted to receive a portion of a said work tool holder and a portion at least of said wedging arrangement, a portion of said slot being undercut so as to extend beneath said top wall.

2. The base member of claim 1 in which said slot extends from side wall to side wall.

3. The base member of claim 1 in which said slot is located between and spaced from said side walls.

4. The base member of claim 1 including an alignment means located in said slot and adapted to abut said portion of said work tool holder which is received in said slot.

5. The base member of claim 1 in which an undercut portion of said slot is rectangular in cross section.

6. The base member of claim 1 in which the portion of said slot which is opposite said undercut portion is vertical.

7. The base member of claim 1 in which the portion of said slot which is opposite said undercut portion is also undercut so as to extend beneath said top wall.

8. The base member of claim 1 in which the said top wall extending above the undercut slot portion extends above that portion of said top wall which is removed from the undercut slot portion.

9. The base member of claim 1 wherein said block comprises a cylindrical drum, and said slot comprises a dovetailed groove in the outer surface of said drum.

10. A base member of the type to removably receive a work tool holder of a mining, road working or earth moving machine by means of a wedging arrange-ment, said base member comprising: a cylindrical drum; and a plurality of blocks affixed to said drum, each said block having top and bottom walls, front and back walls, and a pair of side walls, said block having a slot therein extending from said top wall towards and spaced from said bottom wall and adapt-ed to receive a portion of a said work tool and a portion at least of said wedging arrangement, a portion of said slot being undercut so as to extend beneath said top wall.

11. The base member of claim 10 in which said slot is located between and spaced from said front and back walls and between and spaced from said side walls.

12. A base member of the type to removably receive a work tool holder of a mining, road working or earth moving machine by means of a wedging arrange-ment, said base member comprising; a block having top and bottom walls, front and back walls, and a pair of side walls; and a male element extending from said top wall and adapted to be received within an aperture provided in a said work tool holder, said male element having an undercut portion to receive a portion at least of said wedging arrangement.

13. A base member of the type to removably receive a work tool holder of a mining, road working or earth moving machine by means of a wedging arrangement, said base member comprising: a block having top and bottom walls, and a pair of side walls; and a first formation on the block that is at least partially undercut and adapted to engage and retain a second forma-tion on said work tool holder and a portion at least of said wedging arrange-ment.