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Publication numberUS3690728 A
Publication typeGrant
Publication dateSep 12, 1972
Filing dateSep 8, 1970
Priority dateSep 8, 1970
Publication numberUS 3690728 A, US 3690728A, US-A-3690728, US3690728 A, US3690728A
InventorsKrekeler Claude B
Original AssigneeCincinnati Mine Machinery Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Resilient retaining means for joining work tools and work tool holders
US 3690728 A
Abstract
Resilient retaining means for securing work tools either rotatable or non-rotatable, in appropriate work tools holders or mounting means. The work tools and holders are intended primarily for use on mining, excavating and earth working machines and the like. The work tools comprise elongated elements having a shank portion with a working tip at one end and a gauge-determining abutment surface at at least the other end. The holders or mounting means comprise bodies having a shank receiving perforation and means in association with the bottom of the perforation having an abutment surface adapted to cooperate with the abutment surface on the work tool. Either the work tool or the holder, and in a few cases, both, is provided with a recess to receive a resilient retaining means, usually, in the present invention, a special form of spring clip, to frictionally retain the work tool in the holder against longitudinal movement. In some cases the spring clip will be captive in the holder and will frictionally engage the work tool shank portion in such manner that the work tool will be non-rotatable in the shank receiving portion of the holder. In other cases the spring clip will also be captive in the holder and will also frictionally engage the shank but both the shank and retainer will rotate together with respect to the perforation. And in still other cases the spring clip will be captive on the shank, in a particular manner, and will frictionally engage the lug, the work tool usually being rotatable within the clip and perforation. Some of the clips may be arranged to either permit or prevent rotation of the work tool in the perforation. Various configurations and characteristics will be given these clips, such as special shapes, surfaces and twists.
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United States Patent Krekeler I54] RESILIENT RETAINING MEANS FOR JOINING WORK TOOLS AND WORK TOOL HOLDERS [72] Inventor: Claude B. Krekeler, Cincinnati,

Ohio

[73] Assignee: The Cincinnati Mine Machinery Co.,

Cincinnati, Ohio [22] Filed: Sept. 8, 1970 211 Appl. No.: 70,340

Related US. Application Data [63] Continuation-in-part of Ser. No. 842,791, June 30, 1969, Pat. No. 3,622,206, which is a continuation-in-part of Ser. No. 753,398, Aug. 19, 1968, abandoned.

Primary Examiner-Ernest R. Purser I Attorney-Melville, Strasser, Foster & Hoffma [451 Sept. 12, 1972 ABSTRACT Resilient retaining means for securing work tools either rotatable or non-rotatable, in appropriate work tools holders or mounting means. The work tools and holders are intended primarily for use on mining, excavating and earth working machines and the like. The work tools comprise elongated elements having a shank portion with a working tip at one end and a gauge-determining abutment surface at at least the other end. The holders or mounting means comprise bodies having a shank receiving perforation and means in association with the bottom of the perforation having an abutment surface adapted to cooperate with the abutment surface on the work tool. Either the work tool or the holder, and in a few cases, both, is provided with a recess to receive a resilient retaining means, usually, in the present invention, a special form of spring clip, to frictionally retain the work tool in the holder against longitudinal movement. In some cases the spring clip will be captive in the holder and will frictionally engage the work tool shank portion in such manner that the work tool will be non-rotatable in the shank receiving portion of the holder. In other cases the spring clip will also be captive in the holder and will also frictionally engage the shank but both the shank and retainer will rotate together with respect to the perforation. And in still other cases the spring clip will be captive on the shank, in a particular manner, and will frictionally engage the lug, the work tool usually being rotatable within the clip and perforation. Some of the clips may be arranged to either permit or prevent rotation of the work tool in the perforation.

V arious configurations and characteristics will be given these clips, such as special shapes, surfaces and twists.

29 Claims, 32 Drawing Figures Patented Sept. 12, 1972 3,690,728

3 Sheets-Sheet 1 540, FIG. II 98b 98c FIG. IO

FIG. I

FIG. 17

1 FIG. 1% FIG. 195 $011,441 M9 A] TORNEYS Patanted Sept. 12, 1912 3,690,728

:5 Sheets-Sheet 2 Wm. a, @7-

FIG.5

FIG. 6 F167 F168 FIG 9B FIG, 90

INVENTORS FIG. 25 CLAUDE 5. KREKELER BY k% j(7 (1210 6%21/111 ATTORNEYS Patented Sept. 12,1912 3,690,728

3 Sheets-Sheet 5 lNVENTOR/S CLAUDE B. KkEKELER ATTORNEYS RESILIEN'I RETAINING MEANS FOR JOINING WORK TOOLS AND WORK TOOL HOLDERS CROSS REFERENCE TO RELATED INVENTION This is a continuation-in-part of the copending application of the same inventor, Ser. No. 842,791 filed June 30, 1969 and entitled CUTTER BITS AND MEANS FOR MOUNTING THEM now US. Pat. No. 3,622,206, said application Ser. No. 842,791 is a continuation-in-part of the application of the same inventor, Serial No. 753,398 filed Aug. 19, 1968 and entitled CU'II'ER BITS AND MEANS FOR MOUNTING THEM, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to mining, excavating and earth working machinery and the like, particularly to improved means for mounting work tools, such as cutter bits or digger teeth, in holders which are fixed to the machinery for presenting the bits or teeth in proper working position so that they may be driven against the face of the material to be mined, excavated or worked.

2. Description of the Prior Art In the present specification most of the embodiments of the present invention will be described as applied to work tools and holders therefor as applied to mining machines, excavating apparatus and earth working machines and the like, including trenching machines, wheel type and chain type. It will be apparent to those skilled in the art, however, that uses other than holding various mining bits and trenching teeth in place may be made of the invention.

Cutter bits and holders to which the present invention may be applied are shown in US. Pat. Nos. 2,613,069; 2,950,096; 2,965,365; 3,057,609; 3,093,365; 3,114,537; 3,397,012 and 3,397,013. In some instances the cutter bit or work tool is rotatable within the holder, in others it is not. (The terms cutter bit and work tool are intended to encompass digger teeth, trenching teeth and the like; the terms work holder and mounting means are intended to encompass the various structures, such as lugs, socket members, bit holders and teeth holders, which receive the work tools to make them operable by and with the particular machinery involved.) Most of these work tool, work holder arrangements are of the knock-in, pry-out type as will be seen from an examination of the patents referred to herein. The foregoing patents show various resilient retaining means for releasably maintaining the work tool within the work holders. As the shank receiving perforation, however, becomes worn during use and the work tool shank is more loosely accomodated therein, the shank holding capabilities of such retaining means are diminished.

Although no search of the prior patent art has been conducted with respect to the improved resilient retaining means for joining work tools and holders according to the present invention, it is believed that the patents above noted are representative of the general state of the art. FIGS. 6 and 7 of Pat. No. 3,397,012 along with Pat. Nos. 3,498,677; 3,499,685 and 3,519,309 may be the closest prior patent art.

. 2 SUMMARy OF THE INVENTION The present invention relates particularly to improved resilient retaining means for securing the shanks of work tools, such as mine cutter bits, earth digging teeth and trenching teeth, in their respective holders. For the most part, as indicated, these retaining means are resilient and will maintain the work tool shanks in their respective shank receiving perforations by friction; these retaining means will function efficiently in spite of wear on the shank receiving perforation or even on the shank. Thus, as indicated, certain, at least, of the retaining means of the present invention are capable of functioning with full efficiency despite wear of the shank receiving perforation. Despite long use and wear of the work tool and work tool holder assembly, the work tool will be tightly and adequately retained in its respective shank receiving perforation.

The foregoing results constitute the objects of this invention; indeed, as will be amplified in the description to follow, such results and objects are achieved by the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1s a side elevational view of a work tool and work tool holder assembly illustrating one type of resilient retaining means vention. 1

FIG. 2 is a cross sectional view of a lug similar to that which is a part of the assembly of FIG. 1 but without any work tool or retaining means being depicted.

FIG. 3 is a perspective view of one form of retaining means according to the present invention.

FIGS. 4 and S are perspective views of coiled retaining means.

FIGS. 6 and 7 are perspective views illustrating retaining means which are well suited'for work tool's having non-circular shanks such as are depicted in FIG. 27.

FIG. 8 is a perspective view of a retaining means for work tools having shanks of rectangular cross section.

FIGS. 9A, 9B and 9C are plan views of other retaining means for work tools having shanks of rectangular cross section.

FIG. 10 is a plan view of a modified form of the retaining means depicted in FIG. 3.

FIGS. 11, 12 and 13 are perspective views of the retaining means shown in FIG. 10 showing its characteristics and certain modifications in greater detail.

FIGS. 14 and 15 are perspective views of modified forms of the coiled retaining means depicted in FIGS. 4 and 5. 1

FIGS. 16 and 17 are perspective views of modified forms of the retaining means shown in FIGS. 6 and 7.

FIG. 18 is a perspective view of a modified form of the retaining means depicted in FIG. 8.

FIGS. 19A, 19B and 19C are plan views of modified forms of the retaining means shown in FIGS. 9A, 9B and 9C.

FIG. 20 is a perspective view, with parts broken away, of a work tool shank having one of the retaining means of this invention held captive thereon.

FIG. 21 is a sectional view, with parts broken away, through the shank and retaining means of FIG. 20, a portion of the perforated work tool holder also being shown.

according to the present inp FIG. 22 is a side elevational view of a lug like that depicted in FIG. 2 and illustrating arrangements by which a retaining means may be gotten out of the lug when desired.

FIG. 23 is an exploded view, with parts in section. showing a work tool and work tool holder arrangement wherein the retaining means which clamps on the work tool shank is held captive in the holder, both the shank and retaining means being rotatable together with respect to the holder. 7

FIG. 24 is an exploded view, with parts in section, of a modification of the work tool shank and retaining means of the general type depicted in FIG. 23.

FIG. 25 is a side elevational view of a work tool and work tool holder assembly illustrating the use of more than one resilient retaining means of the present invention.

FIG. 26 is a cross sectional view of a work tool holder similar to that shown in FIG. 25, and illustrates another form of resilient retaining means.

FIG. 27 is a side elevational view, partly in cross section, illustrating a retaining means according to this invention as applied to a modified work tool work tool holder FIG. 28 is a side elevational view, partly in cross section, illustating a retaining means according to this invention as applied to yet another work tool work tool holder assembly.

DESCRIPTION OF THE PREFERRED ENIBODIMENTS FIGS. 3 through 9C and 25 through 28 of the instant continuation-impart application are exact reproductions, except for reference numerals, of FIGS. 41, 33, 34, 47, 48, 45, 44A, 44B, 44C, 1, 6, 43 and 46 respectively of the parent application Ser. No. 842,791. These figures, therefore, and the embodiments of the invention they illustrate, will be described first.

In some of the description to follow, reference will be made to structures such as cutter bits and lugs; these are usually associated with the mining industry. It is to be remembered, however, as pointed out in some of the foregoing material, that the present invention has much wider application than that. Cutter bits are but a portion of the items to which the present invention may be applied, other items bearing such designations as digger teeth and trenching teeth; the term work tool used herein is intended to cover all of these items and others similar thereto, although in some instances the items will be referred to specifically. Similarly, designations such as lugs, mounting means, socket members, bit holders, teeth holders and the like are considered as being closely related and included within the terms work tool holder and holder. Again, some specific references may be made to these various items from time to time. All such terms as just described herein, however, are not to constitute a limitation on the instant invention except insofar as they are specifically set forth in the subjoined claims.

FIG. 25 illustrates a cutter bit (work tool) lug (work tool holder) assembly of the present invention. The cutter bit is generally indicated at 50 and the lug is generally indicated at 51. The lug comprises a body 52.

The lugs of the present invention may be installed upon cutter chains, cutter wheels, rotary cutter bars or cutter arms of mining machinery (usually by welding them to the driven element which carry them) and they may be oriented at different angularities to the driven elements so that the cutting points of the various bits will form a cut of sufficient width to permit the passage of the driven element and its appurtenances.

The body 52 has a shank receiving perforation 53. The axis of the shank receiving perforation 53 is inclined toward the cutting direction (indicated by arrow A). As used herein, the term cutting direction refers to the direction in which the cutter-bit lug assembly is moved by the driven element to which they are mounted, irrespective of any movement of the entire mining machine itself.

The angularity of the shank receiving perforation axis to the cutting direction does not constitute a limitation on the present invention. This angularity may be or less. An angularity of less than 90 is generally preferred so that the component of force tending to shove the cutter bit into the shank receiving'perforation is greater and so that the resultant cutting stresses on the bit will be more nearly in line with the bit axis.

The bit 50 comprises an elongated shank 54, in this instance preferably of circular cross section. The upper end of the shank terminates in a clearance surface 55 lying at an angle to the shank axis and is relieved on opposite sides as at 56 so as to form a cutting tip 57 presenting a cutting surface substantially parallel to the axis of the shank 54. The lower end of the shank 54 terminates in an abutment surface 58 lying at an angle to the shank axis.

The lug body 52 has a transverse hole 59 extending through the body and intersecting the shank receiving perforation 53. A pin 60 is located in the hole 59 and may be replacably held or permanently affixed therein as by welding or the like. The pin 60 may have a length equal to or less than the length of the hole 59. The pin 60 is relieved to form an abutment surface 61 adapted to cooperate with the abutment surface 58 on the cutter bit. The abutment surface 61 may exist only on that portion of the pin lying within the shank receiving perforation. On the other hand, the surface 61 may extend the full length of the pin. The latter arrangement has two advantages. First of all, it provides lateral bleed holes for fines and other foreign material which might I tend to accumulate in the shank receiving perforation. It is for this same reason that the shank receiving perforation 53 preferably extends through the lug body 52 forming an opening both at the top and bottom thereof. Secondly, if the surface 61 extends throughout the length of the pin 60, this would enable the insertion of a drift through the open portion of hole 59 should difficulty be encountered in removing the cutter bit, or if the exposed part of the cutter bit were to be broken away, leaving a portion of the bit inside the shank receiving perforation.

FIG. 25 illustrates one form of a novel retaining means for maintaining the shank 54 in the shank receiving perforation 53 in accordance with the present invention. In this instance, the inside surface of the perforation 53 has an annular notch or groove 62 formed therein. The notch 62 is adapted to receive one or more resilient, C-shaped elements of metal or the like. For purposes of an exemplary showing, two C-shaped metal elements 63 and 64 are illustrated. The elements 63 and 64 are substantially identical. They have an outside diameter greater than the diameter of the shank receiving perforation but slightly less than the diameter of the annular notch 62. The rings 63 and 64 have an inside diameter slightly less than the diameter of the cutter bit shank 54. In use, the C-shaped elements are contracted (which can be accomplished by virtue of the fact that the ends of each element are spaced from each other) and are shoved into the shank receiving perforation 53 until they reach the annular notch or groove 62. When the notch 62 is reached, the C-shaped elements are captively held in the annular notch or groove 62.

The cutter bit 50 may be mounted in the lug 51 by inserting it into the shank receiving perforation. Since the diameter of the cutter bit shank 54 is greater than the inside diameter of the elements 63 and 64, the bit must be forced therethrough. A blow by a suitable tool will be sufficient to cause the bit 50 to assume its proper seated position against the abutment surface 61, as shown in FIG. 25. The elements 63 and 64 frictionally engage the shank 54 and prevent removal thereof by centrifugal force or other forces operating to remove the bit. During normal cutting conditions, there will be a large component of force tending to urge the bit towards its seated position.

Removal of the cutter bit 50 may be accomplished merely by engaging the exposed portion of the bit by a suitable tool and pulling upwardly thereon.

FIG. 26 illustrates a lug in every way identical to that shown in FIG. 25, and like parts have been given like index numerals. The figure illustrates, however, the use of another form of resilient retainer according to the present invention. In this instance, a resilient ring 65 of rubber or the like is provided. The ring has an outside diameter greater than that of the shank receiving perforation 53, but less than that of the annular notch 62. As in the case of the elements 63 and 64 of FIG. 25, the inside diameter of the ring 65 is less than the diameter of the cutter bit shank 54. Insertion and removal of a cutter bit in the lug of FIG. 26 can be accomplished in the same manner described with respect to FIG. 25. The resilient ring 65 will maintain the cutter bit in place in substantially the same manner as described with respect to elements 63 and 64.

With respect to the retainers just described, it is important to note that their retaining action is not affected by wear of the shank receiving perforation 53. They frictionally engage the cutter bit shank and operate primarily on the upper and lower faces of the annular notch or groove 62. These retaining means are not as constantly worked as are prior art resilient retainers so that hysteresis in the case of rubber or the like and fatiguing in the case of metal or the like are greatly reduced.

The resilient C-shaped elements 63 and 64 may have any suitable cross sectional configuration. This is illustrated, for example, in FIG. 3. Here the resilient C- shaped element 63a is shown as having a rectangular cross sectional configuration. Further, the elements 63 and 64, or 63a, may be provided with serrations on that portion thereof which engages the cutter bit shank. Such serrations are illustrated at 63b in FIG. 3.

In the assembly shown in FIG. 25, it will be understood that although the shank 54 and the shank receiving perforation 53 are circular in cross section, the angularity and interaction of the shank abutment surface 58 and the lug abutment surface 61 will prevent any rotation of the bit about its axis. The same interaction and angularity will also tend to cause the bit 50 to be self-aligning during insertion into the shank receiving perforation 53.

In FIG. 25 the cutter bit shank 54 and shank receiving perforation 53 are (for purposes of clarity) illustrated by separate dashed lines. These dashed lines are not intended to be indicative of clearance dimensions. It will be understood by one skilled in the art that the respective diameters of the shank 54 and perforation 53 will be so sized as to permit a sliding fit of the shank within the perforation. Prolonged use of the assembly will cause wear of the parts, particularly the perforation 53, and the clearance dimensions will be changed thereby.

Most of the embodiments of the present invention are, however, adapted to both reduce and counteract such wear. The combination of two factors, the interaction of abutment surfaces 58 and 61 and the frictional engagement of the retaining means 63-64 on the bit shank while not being fixedly held in the lug, yield two important results. First of all, when the assembly is moved in the cutting direction (arrow A of FIG. 25) the material being cut will exert a force on the cutter bit, one component of which is directed rearwardly (in a direction opposite that of arrow A) and another component of which is directed downwardly. The nature of the retaining means and the cooperation of abutment surfaces 58 and 61 not only permit but also encourage a full line or surface-to-surface contact between adjacent rear surfaces of the perforation 53 and shank 54. Thus all along the surface to which the lead line of index numeral 53 is directed there will be contact between the shank and the surface of the shank receiving perforation. It has been found in actual field use that this greatly reduces wear of the parts, particularly wear of the shank receiving perforation 53.

As wear does occur, the two above mentioned factors together with the two above mentioned components of force cooperate to ensure that the cutter bit remains fully seated with the above noted line or surfaceto-surface contact. Meanwhile, the retaining means of the present invention maintain their full effectiveness.

These two results or features (i.e. full line or surfaceto-surface contact and proper seating and retention in spite of wear) have rendered the useful life of cutter chains, cutter wheels, cutter arms and the like, no longer so dependent on the wear of the shank receiving perforations. Thus, service life is greatly increased.

FIGS. 4 and 5 illustrate additional embodiments of resilient means according to this invention and suitable for the cutter bits described. In FIG. 4, there is illustrated a retaining means 66 comprising a single piece of coiled, resilient wire having about 1 V4 convolutions. The retainer 67 in FIG. 5 is similar to that of FIG. 4, but has about 2 convolutions. 'I'he resilient retaining means 66 and 67 are adapted to be used in much the same way as the C-shaped elements 63 and 64 in FIG. 25. The retainers 66 and 67 will have an outside diameter greater than the diameter of the shank receiving perforation 53 of the lug, but less than the diameter of the notch or groove 62. Either of the retainers 66 and 67 may be spirally or transversely compressed and inserted into the shank receiving perforation 53, and will snap into place when they reach the notch or groove 62.

The retainers 66 and 67 have an inside diameter less than the diameter of the cutter bit shank. In this way, when the cutter bit shank is inserted into the shank receiving perforation in the lug, it will be frictionally engaged by the resilient retainer 66 or 67.

Retainers 66 and 67 function in an identical manner. It has been discovered that, by utilizing a series of loops, the holding power of a resilient retainer can be appreciably multiplied. Thus, the resilient retainers 66 and 67 can be expected to have a greater holding power than the C-shaped elements 63 and 64. Similarly, the holding power of retainer 67 should be greater than that of retainer 66. It will be understood by one skilled in the art that retainers 66 and 67 may have any desired cross sectional configuration and may be provided with serrations, all as is shown in FIG. 3 with respect to the retainer 63a, 63b.

FIG. 27 illustrates the application of the principles of the present invention to cutter bit lug assemblies of a type having a shank and a shank receiving perforation of non-circular cross section.

The cutter bit or other work tool as hereinbefore explained, generally indicated at 68 has a head portion 69, a shank portion 70 and a hard cutting tip 71. The head may be provided with one or more surfaces 72 which may be engaged by an appropriate pry-out tool. The shank 70 is illustrated as being rectangular in cross section. The bottom end of this shank 70, in this instance, is provided with an abutment surface 73 sloping downwardly and rearwardly.

The lug or work tool holder 74 has a shank receiving perforation 75 of rectangular cross section. In this instance the lug is provided with a transverse hole 76 having a rod-like element 77 therein. This rod-like element is, in every way, similar to the pin 60 in FIG. 25. The rod 77 has an abutment surface 78 cooperating with the bit abutment surface 73. (With this particular arrangement it is no longer necessary to provide a gaugedetermining abutment surface in association with the bit head 69.)

The shank receiving perforation 75 is provided with an annular notch 79. This notch may be circular in configuration to receive resilient retaining means of the general type shown in FIGS. 25, 4, and 3 or the resilient band type shown in FIG. 26. Alternatively, the notch may be rectangular, conforming generally to the cross section configuration of the shank receiving perforation. When this is the case, use may be made of a resilient band-type retainer, or one or more of the retainers next to be described.

A resilient retaining means is shown at 80 in FIG. 27. The retaining means 80 may comprise one or more open ring-like structures of the type shown at 81a, 81b or 810 in FIGS. 9A, 9B and 9C respectively or the retainer 82 of FIG. 8.

In FIG. 8, the retainer 82 is similar to that shown in FIG. 9A but is provided with more than one convolution, in the manner of those retainers shown in FIGS. 4 and 5.

All of the retainers of FIGS. 9A, 9B and 9C may be compressed and inserted in the notch 79 (FIG. 27), or they may be introduced through a slot extending from the notch 79 through any of the sides of the lug. Such a slot is indicated in dotted lines at 83 in FIG. 27. Once the bit shank is in place the retainer cannot exit through the slot. By the same token, the slot may be provided with shoulders at its entrance to the notch 79 so that the retainer means will be substantially captively held in the notch 79. The retainer means could be so sized and configured as to have a snap fit in the notch 79, once it had passed thereinto from the slot 83.

All of the last mentioned retainers will frictionally engage the bit shank at two or more points. When desired, the bottom end of the bit shank may be provided with appropriate relief to aid its insertion into the retaining means.

In the embodiment of FIG. 27, the resilient retainer 80 again is captively held in the notch 79 and frictionally engages the shank 70. As illustrated, the cutter bit 68 will be adequately and firmly retained and a full surface-to-surface engagement will be maintained between the rear shank surface a and the rear shank receiving perforation surface a.

The retaining means of FIGS. 9 and 8 could have any cross sectional configuration and could be provided with serrations and/or granules in the manner shown with respect to the retainers of FIGS. 3, l2 and 13.

FIG. 28 illustrates the application of the principles of the present invention to cutter bit (work tool) lug (work tool holder) assemblies of the type taught in US. Pat. No. 3,093,365. In this instance, the bit 84 is of the double-ended trapezoidal type, having cut surfaces 85 and 86 each terminating respectively in cutting tips 87 and 88. While the invention is not so limited, such bits generally have substantially diamond shaped cross section and the bit 84 is so illustrated. When the cutting tip 87 is being used, the surface 86 will serve as an abutment surface. Similarly, when the cutting tip 88 is being used, the surface 85 will serve as an abutment surface.

The lug body 89 has a shank receiving perforation 90 extending therethrough. It is preferable that the shank receiving perforation 90 extend all the way through the body 89 so as to prevent the accumulation of fines and other foreign material within the shank receiving perforation and to permit the use of a drift to remove the bit, where possible.

The cross sectional configuration of the shank receiving perforation 90 will depend, in large part, on the cross sectional configuration of the bit. In this instance, the perforation 90 is illustrated as having a substantially diamond shaped cross section. It will be understood by one skilled in the art, however, that the bit 84 and the shank receiving perforation 90 could have circular or other cross sectional configuration, as desired.

The lug 89 is provided with a transverse hole 91 having a rod-like member 92 permanently or removably affixed therein. As in the case of the rod-like element in FIG. 25, the element 92 may have a length equal to or less than the hole 91. The element 92 has an abutment surface 93 thereon, adapted to cooperate with the surface 86 or the surface 85, depending upon the orientation of the bit 84. Again, the surface 93 may extend throughout the length of the rod-like element 92 or be present only on that portion of the rod-like element which extends into the shank receiving perforation 90.

The shank receiving perforation 90 is provided with an armular notch 94 to receive retaining means, indicated at 95. The retaining means may be of the general type shown in FIGS. 25, 4, or 3, or it may be a resilient band of the type shown in FIG. 26.

In FIG. 6, a retaining means similar to that shown in FIG. 25 is illustrated at 96. This retaining means difiers from that of FIG. 25 only in its diamond shaped configuration. FIG. '7 illustrates a retaining means 97 similar to that of FIG. 6 but having more than one convolution in the manner of those retaining means shown in FIGS. 4 and 5. Again it will be understood by one skilled in the-art that the retaining means of FIGS. 6 and 7 may have any desired cross sectional configuration and may be provided with serrations and/or granules in the manner described with respect to the retainers of FIG. 3, I2 and 13.

The retaining means of FIG. 6 will act in substantially the same manner described with respect to the embodiments of FIGS. 9A, 9B, 9C and 8. It may also be inserted into the notch 94 in any of the ways taught with respect to the retainers 81a, 81b, 81c and 82. The retaining means of FIG. 7 may be inserted via a lateral slot of the type described at 83 in FIG. 27.

It will be noted that with the above described types of retaining means and with the orientation of the abutment surface 93 and surfaces 85 and 86, when the bit is moved in the cutting direction (arrow A) the components of force acting thereon will tend to maintain the bit in fully seated position with full surface-to-surface contact between the bit surface 84a and the shank receiving perforation surface 98a.

It will be immediately evident to one skilled in the art that the bit-lug assembly of FIG. 28 is far simpler than previous assemblies incorporating such bits. The lug need no longer be a multi-piece member having latch or other means for retaining the bit.

Departing now somewhat from the disclosures originally contained in copending parent application Ser. No. 842,791, as described in connection with FIGS. 25 through 28 and FIGS. 3 through 9C, above, the showing of FIGS. 1, 2 and 10 through 24 will now be considered. Wherever conveniently possible, like numerals will be used to designate like parts.

FIG. 1 is much like FIG. 25 with respect to the lug body 52a, the perforation 53a and the bit shank 54a. Similarly, a hole 59a is provided in the lug to receive the pin titla which has the abutment surface 61a thereon. A notch or groove 62a is provided in the wall defining the shank receiving perforation 53a. The G shaped resilient retaining ring 98, although generally similar to the elements 63 and 64 of FIG. 25, is specifically different.

Referring now to FIGS. It) and 11, the resilient retaining means 98 is shown in greater detail. The retainer 98 is illustrated as forming a part of a helix. Note that the central portion 98a is on a slant with respect to the horizontal, the end 98b being above this portion and the end 980 extending below this portion. When the retainer 98 is forced into the groove 62a of lug 52a of FIG. I, for example, the end 98b will bear against the upper wall defining the groove 62a while the end 980 will bear against the lower wall. This constitutes an improvement over the arrangement of FIG. 25, and those like it, in that longitudinal or axial jiggling of the retaining means and/or bit shank is eliminated. Arrangements like that shown in FIG. 25 must of practical necessity permit a certain amount of play; as just indicated, this play may be eliminated by modifying the retaining element to impart to it the configuration shown in FIGS. 1, 10 and 11. Another way of picturing this, is to consider the retainer 98 as having been bent or twisted in order to spread the ends 98b and 980 away from one another a distance somewhat more than the width of the groove into which the member 98 will be forced. This will produce the result illustrated in FIG. 1.

FIGS. 12 and 13 illustrate further refinements. In FIG. 12 the interior or bit shank grippingsurface of the resilient retaining member 98 is shown as provided with serrations 98d like those discussed in connection with 63b of FIG. 3. In FIG. 13 improved gripping action for the retainer 98 is obtained by affixing granular material to the inner side thereof as indicated at 98e.

FIGS. 14 through 19C illustrate other forms of improved resilient retaining elements. The elements of these figures correspond generally to those shown in FIGS. 4 through 9C respectively. In each instance, however, the retainers of FIGS. 14 through 19C are, in effect, spread out so that each is initially, when at rest, wider than the groove into which it will eventually be forced thereby to obtain the improved gripping action just described in connection with FIGS. 1 and 10 through 1.3. I

Thus, it will be observed that the resilient retaining means 99 of FIG. 14 generally correspond to the means 66 of FIG. 4, the resilient retaining means 100 of FIG. 15 generally corresponds to the retainer 67 of FIG. 5, the resilient retaining means 101 of FIG. 16 generally corresponds to the retainer 96 of FIG. 6, the resilient retaining means 102 of FIG. 17 generally corresponds to the retainer 97 of FIG. 7, the resilient retaining means 103 of FIG. 18 generally corresponds to the retainer 82 of FIG. 8 and the resilient retaining means 104a, 104b and 104c generally correspond to the retainers 81a, 81b and 810 of FIGS. 9A, 9B and 9C. In all of these FIGS. 14 through 19C, the free ends of the respective resilient retaining means are, in effect, bent away from one another. In those arrangements involving more than one convolution, adjacent convolutions are separated a slight bit one from the other. As indicated above, the purpose for me modifications just described is to obtain the action described in connection with FIGS. 1 and 10 through 13.

Further refinements are illustrated in FIGS. 2 and 22. FIG. 2 is like FIG. 26 but without any retainer being shown in the notch or groove 62. FIG. 22 is like FIG. 2 except that it is not in section. The resilient retaining elements of FIGS. 10 through 19C, due to the fact that they are initially wider than the width of the groove into which they will be forced, tend to fit very tightly within their respective grooves, a fact which often makes them difficult to remove when that is desired. This problem may be overcome in a couple of ways, both of which are illustrated in FIG. 22, although in practice only one or the other would ordinarily be utilized. The preferred manner of facilitating the removal of a retaining means from, for example, the groove 62 of FIG. 22 is to provide a hole 105 in the lug 52 extending at least to the groove 62; it may be desirable to extend this hole 105 completely through the lug. A suitable punch or pin may be inserted through this hole 105 to contact the retainer and force it out of the groove 62. Similarly, as also indicated in FIG. 22, a groove in the wall of the lug defining the perforation 53 could extend to the groove 62 so that a suitable instrument could be moved through such groove 106 to come behind the retainer and pry it from the groove 62.

A modification in the invention and utilization thereof is illustrated in FIGS. 20 and 21. The shank of any work tool embraced within the scope of this invention as explained earlier herein is shown at 107. In this instance the shank itself is provided with an annular groove 108. A resilient retaining member 109 is captively held within this groove 108. The groove 108 defines a neck 110 as a part of the shank 107. The resilient retainer 109 may be like any of those shown in FIGS. 1 and through 19C, particularly like those of FIGS. 10 through 15. The exterior of the retainer 109 may be serrated as discussed, for example, in connection with the inner surface 98b of FIG. 12 or it may be provided with granular material as indicated at 98e with respect to the interior surface of the member shown in FIG. 13; in FIG. this arrangement is generally indicated at 109a. As will be seen from an examination of FIG. 21, the retainer 109 is specifically like that shown in FIG. 10; this is for purposes of illustration only.

In its relaxed condition the exterior diameter of the resilient retainer 109 is greater than the diameter of the perforation 111 provided in the lug 112 and into which the shank 107 will be forced. To facilitate insertion, the entrance end of the perforation 111 should be countersunk. The interior diameter of the resilient retaining member 109 is such that when the shank 107 and retainer 109 are received in the perforation 111, whereby to compress the retainer 109, such retainer 109 will still be spaced from the neck portion 110 of the shank 107. This relationship, plus the fact that one end portion of the retainer 109 bears against the upper wall defining the groove 108 while the other end portion of the retainer 109 bears against the lower wall defining the groove 108, insures that the shank and retainer will be prevented from longitudinal jiggling within the perforation 111 of the lug 112.

Further modifications of the invention are shown in FIGS. 23 and 24. In FIG. 23 a work tool shank is indicated at 113 and a work tool holder is indicated at 114. The holder 114 is provided with a shank receiving perforation 115 and an abutment 116. An annular notch or groove 117 is provided in the holder 114. A resilient retainer 118 is captively held within the groove 117. The interior surface of this retainer 118 may be serrated or provided with granular material as discussed in connection with others of the various figures and as is generally indicated at 118a. In its relaxed condition, the interior diameter of the retainer 118 is smaller than the outside diameter of the shank 113. As illustrated in FIG. 23, the retainer 118 is generally like that shown at 63b in FIG. 3.

The arrangement of FIG. 23 emphasizes the fact that the resilient retaining means of the present invention may be utilized with work tools and work tool holders wherein the tool is either rotatable or non-rotatable within its holder. Thus, although many of the figures and illustrations previously discussed herein show cooperating abutment surfaces on the work tool shank and work tool holder, or in association with the work tool holder, whereby rotation is prevented, this is not a limitation on the improved resilient retaining'means according to the present invention.

In FIG. 24 additional holding power is obtained by providing the retainer 119 with a protuberance or head 120 adapted to engage within a shallow groove 121 on the work tool shank 113.

In the arrangements of FIGS. 1 through 19C and 22 the resilient retainer is held captive within a groove provided in the lug; this retainer frictionally engages the shank and the work tool is non-rotatable with respect to the work tool holder. In the arrangement of FIGS. 20 and 21 the resilient retainer is captive within a groove provided on the shank of the work tool, the retainer being formed on a helix and the like, such retainer frictionally engaging the work tool holder; by this arrangement the work tool is rotatable with respect to the retainer and work tool holder. In the arrangement of FIGS. 23 and 24 the resilient retainer is held captive within a groove provided in the lug, such retainer frictionally engaging the shank of a work tool; in this instance the work tool and retainer, together, are rotatable within the shank receiving perforation of the work tool holder.

Modifications may be made in this invention without departing from the scope and spirit thereof. As pointed out in the above mentioned U.S. Pat. No. 3,622,206, for example, any of the work tools contemplated may be provided with a shallow depression to receive the various retaining means taught herein. Such a depression would increase the retaining ability of the retaining means, but should be shallow so as not to constitute a I significant stress raiser. The depression should be so configured as not to present a shoulder interfering with the pry-out feature of the work tools. Such depression may lie on one side only of the work tool shank, or more than one depression may be provided located at various positions about the shank. Similarly, the depression may be a continuous annular one extending fully about the shank. This is illustrated at 222 in dotted lines in FIG. 50 of the said parent application. In using the term depression it is to be understood that what is meant is a configuration which will help to increase the holding power of the retaining means with respect to the shank, but not to a degree to preclude the pry-out feature. A modification of such an arrangement is shown in FIG. 24 of the instant application.

Although this invention has been described with respect to certain particular structures and arrangements, this has been for purposes of illustration only, and the invention is not to be limited to such specific structures and arrangements except insofar as they are positively set forth in the subjoined claims.

Modifications may be made in the invention without departing from the spirit of it.

Having thus described the invention, what is claimed as new and what is desired to be protected by Letters Patent is:

1. A non-rotatable cutter bit and mounting means therefor for a mining machine and the like, said cutter bit comprising an elongated shank, at least one end of said shank terminating in a bit abutment surface lying at an angle to the axis of said shank, atleast the other end of said shank having a cutting tip, said mounting means comprising a lug having a body with a shank receiving perforation, a lug abutment in association with said perforation and comprising at least one lug abutment surface lying at an angle to the axis of said perforation, said cutter bit shank located within said shank receiving perforation, said bit abutment surface and said lug abutment surface lying parallel to each other and in abutting relationship, and means for retaining said cutter bit in said shank receiving perforation, said cutter bit shank and said shank receiving perforation being of non-circular cross section, said shank receiving perforation having a groove therein, said retaining means comprising at least one member of non-circular configuration substantially surrounding said shank and having outside dimensions larger than the cross sectional dimensions of said perforation and smaller than the dimensions of said groove, said retaining means having inside dimensions smaller than the cross sectional dimensions of said cutter bit shank, said retaining means adapted to be within said groove and frictionally engage said shank at at least two points.

2. The structure claimed in claim 1 wherein said retaining means comprises at least one non-circular, substantially C-shaped element having spaced ends.

3. The structure clm'med in claim 1 wherein said retaining means comprises a single piece of coiled resilient wire having at least one complete non-circular convolution.

4. The combination of a cutter bit and a mounting means therefor, for use in mining, excavating and earth working machines and the like, said cutter bit having a shank of non-circular cross section and said mounting means having a perforation to just nicely receive said shank, said mounting means having a recess therein adjacent said perforation, and non-circular resilient retaining means located in said recess and adapted to substantially surround and receive said shank, the inner dimension of said resilient retaining means being normally smaller than the outer dimension of said shank and the outer dimension of said resilient retaining means being greater than the outer dimension of said shank, whereby said resilient retaining means frictionally engages said shank at at least two points and remains engaged in said recess when said shank is received in said perforation.

5. A retaining means for maintaining a work tool shank of non-circular cross section within a work tool holder perforation of non-circular cross section which comprises a resilient member formed into a non-circular configuration to substantially surround said shank and adapted to be received within at least one groove located in at least one of said work too] and said work tool holder, the outside dimension of said resilient member being greater than the outside dimension of said shank and also greater than the inside dimension of said perforation, and the inside dimension of said resilient member is less than the outside dimension of said shank, whereby, regardless of whether the groove is on the shank or within the wall defining the perforation, said resilient member will frictionally engage said work tool with said work tool holder.

6. The retaining means of claim 5 in which said groove is in the wall defining said perforation and said resilient member comprises at least one non-circular, substantially C-shaped element having an outside dimension slightly less than the outside dimension of the said groove.

7. The retaining means of claim 6 in which said C- shaped element is provided with a roughened surface on that portion which engages said shank.

8. The retaining means of claim 5 in which said groove is in the wall defining the said perforation and said resilient member comprises a single piece of coiled wire and the like having at least one non-circular convolution with an outside dimension slightly less than th outside dimension of said groove.

9. The retaining means of claim 8 in which saidsingle piece of coiled wire and the like has at least two noncircular convolutions.

10. The retaining means of claim 5 in which said groove is in the wall defining said perforation, said perforation being non-circular in cross section, and said resilient member comprises an open ended, non-circular, ring-like structure having an outside dimension slightly less than the outside dimension of said groove.

11. The retaining means of claim 10 in which said resilient member comprises a closed non-circular ringlike structure having more than one convolution.

12. The retaining means of claim 5 in which said resilient member forms a part of a non-circular helix, one end of said resilient member being in a different horizontal plane than is the other end, whereby one end of said resilient member will bear against one edge of said groove and the other end of said resilient member will bear against the opposite edge of said groove.

13. The retaining means of claim 12 in which said resilient member is provided with a roughened surface on that part thereof which engages said shank.

14. The retaining means of claim 5 in which said groove is in said shank, said resilient member forming a part of a helix, one end of said resilient member being in a different horizontal plane than is the other end, whereby one end of said resilient member will bear against one edge of said groove and the other end of said resilient member will bear against the opposite edge of said groove.

15. The retaining means of claim 5 in which said resilient member is arranged to be received in a said groove provided in said work tool holder, the said inside dimension of said resilient member having a rough surface to frictionally engage a said work tool.

16 The retaining means of claim 5 in which said resilient member is arranged to be received in a said groove provided in said work too]. holder, the said inside dimension of said resilient member having a protrusion adapted to be received in a groove provid on said work tool.

17. The structure claimed in claim 5 wherein said shank and said perforation have a rectangular cross section, said retaining means having a cooperating substantially rectangular configuration.

18. The structure claimed in claim 5 wherein said shank and said shank receiving perforation have a diamond-shaped cross section, said retaining means having a cooperating substantially diamond-shaped configuration.

19. In mining, excavating and earthworking machines and the like having a work tool with a shank of non-circular cross section and a work tool holder having a perforation to just nicely receive said shank, improved means for holding said shank within said perforation in said work tool holder, said improved means comprising a groove in said work tool holder adjacent to and communicating with said perforation, and a resilient retaining means within said groove, said retaining means being formed into a non-circular configuration to substantially surround said shank, said retaining means having outside dimension larger than the cross sectional dimensions of said perforation and smaller than the dimensions of said groove, said retaining means having inside dimensions smaller than the cross sectional dimensions of said shank, whereby when said shank is received in said perforation said shank is frictionally engaged by said retaining means at at least two points and thereby retained in said perforation.

20. The structure claimed in claim 19 wherein said retaining means comprises a non-circular, substantially C-shaped element.

21. The structure claimed in claim 19 wherein said retaining means comprises a single piece of coiled wire or the like having at least one non-circular convolution with an outside dimension less than the dimension of like structure having more than one convolution, at least one of said convolutions having an outside dimension less than the dimension of said groove.

24. The structure claimed in claim 19 wherein said retaining means comprises a part of a non-circular helix, one end of said resilient member being in a different horizontal plane than is the other end, whereby one end of said resilient member will bear against one edge of said groove and the other end of said resilient member will bear against the opposite edge of said groove.

25. The structure claimed in claim 19 wherein said retaining means is provided with a roughened surface on that part thereof which'engages said shank.

26. The structure claimed in claim 19 wherein said shank and said perforation have a rectangular cross section, said retaining means having a cooperating substantially rectangular configuration.

27. The structure claimed in claim 19 wherein said shank and said shank receiving perforation have a diamond-shaped cross section, said retaining means having a cooperating substantially diamond-shaped configuration.

28. The structure claimed in claim 19 wherein said shank has a shallow depression at least at one of said points of engagement.

29. The structure claimed in claim 19 including a slot in said work tool holder extending perpendicular to the axis of said perforation and intersecting said groove whereby said retaining means may be positioned in said groove through said slot.

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Classifications
U.S. Classification299/109, 37/459
International ClassificationE21C35/19, E21C35/197, E21C35/00
Cooperative ClassificationE21C35/19, E21C35/197
European ClassificationE21C35/19, E21C35/197