MXPA96002769A - Cable drag with side access voltage block, in volad - Google Patents

Abstract

A cable dredger comprising a main housing, a bucket-winch mechanism mounted on the housing, a dredge-bucket mechanism mounted on the main housing, a movement mechanism for moving the main housing on the ground, a boom which it has an upper end, a hoist and a winch cable that has one end connected to the winch bucket mechanism that extends over the pulley and that has an opposite end, a dredge cable that extends between the bucket and the bucket mechanism -draga, a tipping block including a structure having a main portion connected to the opposite end of the winch cable and a cantilevered shaft extending from the main portion and a tipping block pulley mounted on the shaft for rotation around an axis of the pulley, and a tipping cable that extends over the pulley of the tipping block and that has one end connected to the dr wire aga and an opposite end connected to the bucket, in such a way that the overturning cable can be removed from the pulley in the direction separating it from the main portion of the structure.

Description

CABLE DRAGON WITH SIDE ACCESS VOLTAGE BLOCK. IN VOLADIZO BACKGROUND OF THE INVENTION The invention relates to cable dredges. A cable dredger typically includes a movable main housing on the ground and a boom which extends up and out of the main housing. The upper end of the pen has on it a pulley mounted for rotation about a horizontal axis. A dredge cable extends from a bucket dredger mechanism to a bucket to cause horizontal movement of the bucket in relation to the boom. A winch cable extends from a dredger bucket mechanism to a bucket to cause vertical movement of the bucket. In particular, a tipping block is connected to the end of the winch cable and a tipping cable extends over the tipping block pulley and has one end connected to the dredger cable and an opposite end connected to the bucket.

Most of the current tumbling blocks are of a rigid structure design. The tipping cable (typically a wire cable) can not be easily removed. First a bushing should be removed from the end of the cable and then slide the bushing out of the tipping block or remove an upper bolt, spacer or spacers and the guide wire to gain access to the cable. Since the bucket funtion is greatly affected by the length of the dump cable, many mines are willing to use "pre-encasquillados" cables. These cables come from the factory adjusted to a specific length and without removable ferrules attached at the ends. This avoids the maintenance of the equipment either accidentally or intentionally changing the length of the overturning cable and affecting the operation of the bucket and / or the structural load. In rig configurations using a double dump cable, uneven loading occurs, if the cables are not of equal length. Currently there are two solutions in the market for this. One design uses a top cover that rotates once a bolt / screw is removed. Sometimes, a top separator must also be removed. The lid is attached to the rigging above them and is extremely difficult to handle as the rig weighs many hundreds of pounds even in the smallest of the buckets. Another design also allows lateral access, but needs tools (hammer and punch) to remove a bolt to allow a heavy door to turn down out of the way. This design also requires that the structure be wound around the lower part of the overturning block, so that a conventional small bolt and bearings can be used. This bolt and bearing design is virtually the same as rigid frame designs during use by many manufacturers and virtually does not provide stability to the halves of the structure. It also creates an excessively heavy structure with design that is almost twice as heavy as the rigid structure design.

BRIEF DESCRIPTION OF THE INVENTION The invention provides a new tumbling block design that allows easy access for pre-jammed cables (although unscaled wires can still be used), does not require tools to change the cable and suffers only from a light weight gain. This is done by placing the pulley and the bearings on a cantilevered shaft that projects from an individual structure. This removes the other side of the structure as an obstruction to get the cable in and out of the flip block. The design consists of an individual structure, which is provided for joining to the upper part of the rig. An end cap keeps the assembly together and also provides adjustment and protection for the bearings and seals. The pulley can be made of steel or nylon material. The structure contains an integral protector for the protection of one side of the perimeter of the pulley. The other side uses a protector that is screwed on and rotates with the pulley or the pulley support (used only with a nylon pulley). The nylon pulley is held in place by the guard to prevent it from moving relative to its support.

This allows easy replacement of the nylon pulley. (Most applications require that the pulley be pressed on the support structure). The pulley or the pulley support is mounted on the bearings, which rotate around the cantilevered shaft. An alternative protector design is one which is integral with the end cap and does not rotate with the pulley. The cable is prevented from leaving the pulley by the rollers which rotate distributed in the way to allow the removal or replacement of the cable. The rollers are held in place during operation by a bolt or bolt lever which is movable by hand. The pulley is machined specifically for each cable diameter that is going to be used (different cable sizes for different bucket sizes) and together with the rollers, they usually prevent the cable from being tightened by the tipping block. Each roller preferably has a projection designed therein such that with each specific cable size, the clamping action of the cable between the pulley and the roller, which could occur with a straight roller, is eetantially avoided. No design requires tools such as spacers or heavy doors as previously mentioned. The design also allows the inclusion of an automatic lubricant injector in the shaft cavity. Other features and advantages of the invention will become apparent to those skilled in the art by reviewing the following detailed description, claims and drawings.

DETAILED DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view of a cable dredger exemplifying the invention. Figure 2 is an enlarged elevational view of the bucket and a tumbling block. Figure 3 shows a perspective view of one side of the turning block. Figure 4 is a perspective view of the other side of the turning block. Figure 5 is an elevation view of the side of the turn block shown in Figure 3. Figure 6 is a view taken along line 6-6 in Figure 5. Figure 7 is a view taken at along line 7-7 in Figure 5. Figure ß is an enlarged portion of Figure 6, with the pulley and structure partially shown. Figure 9 is a perspective, exploded view of the components shown in Figure & . Figure 10 is a view similar to Figure & of an alternative bearing arrangement. Figure 11 is a perspective view, in deepiece of the components shown in Figure 10.

Figure 12 is a perspective view of one side of the turn block showing an alternative roll arrangement. Figure 13 is a perspective view of the other side of the turn block showing the alternative roll arrangement. Before an embodiment of the invention is explained in detail, it should be understood that the invention is not limited in its application to the details of the construction and diepoeicionee of the components set forth in the following description or illustrated in the drawings. The invention is capable of other modalities and of being practiced or carried out in various ways. Also, if it is understood that the phraseology and terminology used herein, are for the purpose of description and should not be considered as limiting.

DESCRIFCION OF THE FREFERIDA MODALITY A movable rope dredge 10 exemplifying the invention is illustrated in the drawings. The cable dredge 10 comprises (see Figure 1) a main housing 12. The winch mechanism 20 of the bucket and a dredger bucket mechanism 22 are mounted in the main housing 12. A pen 24 ee extends upwards and outwards from the main housing 12. The upper end of the pen 24 has on it a pulley 26 which is rotatable about a horizontal axis. A winch 2ft cable extends from the bucket winch mechanism 20 on the pulley 26 to a bucket 29 to cause vertical movement of the bucket 29 relative to the boom 24. The way in which the cable 2 &; of winch is connected to bucket 29 is described in the following. A dredge cable 31 extends from the dredger bucket mechanism 22 to the bucket 29 to cause horizontal movement of the bucket 29. The jib 24 is supported relative to the main housing 12 by the conventional mast 32 and an A-structure 32a. The support lines 33 are connected between the upper ends of the mast 32 and the structure-A 32a and the boom 24 to support the boom 24. When the cable dredge 10 is dredging, the main housing 12 is supported by a pair of mechanisms 34 mobiles (one shown) move the main housing 12 on the ground between the dredging operations. The main housing 12 includes the operator's cabin 35. The cable dredger 10 as described so far is conventional. As seen better in Figure 2, the end of the cable 2 & of the winch is connected to the upper rig 5 &, which in turn is connected to a pair of tumbling blocks 40 (only one is shown). It should be understood that a single tumbling block can be used. The tumbling block 40 is substantially identical and only one will be described in & detail. The tumbling block 40 includes a pulley 44 (see Figures 3, 4 and 6), which can be either a steel pulley or a nylon pulley on a pulley support, as is more fully explained in the following. A turning cable 46 (see Figures 1, 2 and 7) extends over the pulley 44 and has one end connected to the dredge cable 31 and an opposite end connected to the bucket 29. The turning block 40 is illustrated in greater detail in Figures 3 - 9. The tumbling block 40 includes a structure 52 having a main portion 56 connected to the rope 26 of the winch by the upper rig 56 (see Figure 2). The upper end of the main portion 56 of the structure has on it a roller 60 (see Figures 3, 4 and 6) and the upper rig 56 includes (see Figure 2) a clamp 64 connected to the roller 60 in such a way that the main portion 56 of the structure can pivot freely in relation to the upper rig 56 around the roller 60. The structure 52 also includes (see Figure 6) a cantilevered axis 66 extending from the main portion 56 of the structure ( to the left of Figure 6). The shaft 66 has a cylindrical outer surface 72 (see Figure 6) and has through it (see Figure 6) an internal duct 76. The structure 52 also includes an integral pulley protector 60 for protecting one side (the right side in Figure 6) of the pulley 44 of the overturning block, which is mounted on the shaft 66 for relative rotation about the axis 64 of the concentric pulley with the outer surface 72 of the shaft. The pulley 44 is supported relative to the shaft 66 by a bearing assembly 66 (see Figures 6 and 6) which is described in detail in the following: The bearing assembly 66 is lubricated through one or more accessories 92 for grease or for a lubricant injector basket 94 (both shown in Figure 6) accessible through internal conduit 76. Two pulley constructions ee illustrated in Figure 6. As shown in the following, shaft 66, The pulley 44 is of one piece and is made of steel or emptied as a solid piece of nylon As shown in the foregoing, the shaft 66, the annular nylon shaft 96 is mounted on an annular pulley support 100, which it is supported on the shaft 66 by the bearing assembly 66. The pulley support 100 can be made of steel, aluminum, or any of many lightweight materials, since it is not an item of the deegaete type. it has a rim 102 extending radially (see Figure 6). The tumbling block 40 also includes an end cap 104, secured to the outer end of the shaft 66 by a suitable means such as the screws 106. The end cap 104 holds the pulley 44 and the bearing assembly 66 on the shaft 66 and also provides adjustment and protection for the bearing assembly 66, as described in the following. A pulley protector 112 is secured to the outside either of the pulley 44 or the pulley support 100 by a suitable means, such as the screws 116. When used with the nylon 96 pulley, the pulley guard 112 holds the pulley 96 nylon in its place relative to pulley support 100. Specifically, the pulley protector 112 presses the nylon pulley 96 axially against the flange 102 on the support 100 of the pulley. The pulley protector 112 rotates with the pulley 44 and protects the outside of the pulley 44 (the left side in Figure 6). Alternatively, the pulley protector 112 may be integral with the end cap 104, in which case the sheave protector 44 will not rotate with the pulley 44. The overturning block 40 also includes (see Figures 3-5 and 7) retaining mounts 120 and 124 to substantially prevent the tumbler cable 46 from coming out of the pulley 44. The retainer mounts 120 and 124 are substantially identical and only the assembly 124 will be described in detail. The retainer assembly 124 includes (see Figure 7) a roller 126 mounted on a roller support 132 for rotation about a roller shaft 136, which moves with the roller support 132. The roller support 132 includes a generally rectangular block portion 140 and a shaft portion 144 extending from the block portion 140. The roller 126 is rotatably mounted on the shaft portion 144 and is held in place by a screw 146 and a washer 152. The block portion 140 has through it first and second or right and left openings 156 and 160, respectively. amente. A pin 161 extends through the lugs 162 (see Figures 3-5) in the main portion 56 of the structure and through the right opening 156, such that the roller support 132 can pivot in relation to the structure 52 around a support shaft 164 (see Figures 5 and 7) which is transverse to the axis 64 of the pulley. The roller support 132 is pivotable relative to the structure 52, between a retention position (shown in solid lines in Figure 7) and a released position (shown in hidden lines in Figure 7). When the roller holder 132 is in the detent position, the roller shaft 136 is parallel to the axis 64 of the pulley and the roller 126 extends over the pulley 44 to retain the overturning cable 46 on the pulley 44. The end outer of the roller 126 has on it (see Figure 7) a projection 166 to substantially prevent the overturning cable 46 from becoming squeezed between the roller 126 and the pulley 44. When the roller support 132 is in the release position , the roller 126 allows removal of the overturning cable 46 from the pulley 44. Means are provided to releasably secure the roller support 132 in the detent position. Although several suitable means may be employed, in the illustrated construction, the lugs 162 of the structure have therein openings (not shown) which are aligned with the left opening 160 in the roll holder 132, when the roller holder 132 is in its retention position and a bolt 176 (see Figures 3, 5 and 7) is removably inserted into the openings in the lugs 162 and the openings 160 to releasably secure the roller support 132 in its retention feature. The overturning cable 46 can be easily removed from the turning block 40, by simply moving the rollers 126 to their release positions and removing the cable 46 from the pulley 44 in the direction away from the main portion 56 of the structure. The bolts 176 can be removed manually. No tools are required. This is much easier and less time consuming than with the arrangements known in the foregoing. It should be understood that other roller arrangements may be used to prevent the cable 46 from coming out of the pulley 44. For example, as shown in Figures 12 and 13 and as described in the following, the rollers may pivot about an axis which extends radially from the pulley 44 and other means can be used to releasably secure the rollers. Now the bearing assembly 66 will be described in detail. The shaft 66 can be considered an inner member having an axis 64, an axial surface extending axially and a radially extending surface 160 (see Figure 6) perpendicular to the outer surface 72. The pulley 44 can be considered a rotating outer member about the shaft 64 relative to the inner member or shaft 66. The outer member or pulley 44 has an axially extending inner surface 164, which includes a first inner flange or shoulder 166 that it faces inward or towards the surface 160 (on the right in Figure 6) and a second outer rim or flange 192 that faces outwardly or away from the surface 160 (on the left in Figure 6). The bearing assembly 66 includes (see Figure 6) the inner and outer bearings 196 and 200 axially, in respective form, which are preferably tapered roller bearings. Each of the pads 196 and 200 includes an inner race 204 that abuts the outer surface 72 of the axle, an outer race 206 that abuts the inner surface 164 of the sheave and a plurality of racers. of rollers 212 between the inner and outer race rings. The running ring 204 inside the bearing 200, has a radially extending bearing surface 214. This construction is conventional and will not be described in greater detail. The inner bearing 196 is captured between the inner shoulder 166 of the pulley and the surface 160 of the shaft. A separator 216 is preferably located between the inner bearing 196 and the surface 160 of the shaft and a seal 220 surrounds the separator 216 between the pulley 44 and the surface 160 of the shaft. The outer bearing 200 is captured between a mounting 224 of the bearing and the outer flange 192 of the pulley.

The mount 124 of the bearing includes a first radially outer ring or ring 226 which engages the surface 214 of the outer mounting 200, such that the outer bearing 200 is captured between the ring 226 and the outer flange 192. The ring 226 also has a tapered, annular surface 232 which faces radially inwardly and which tapers radially away from the shaft 66 and axially separating from the outer bearing 200 (to the left in Figure 6). The bearing holder assembly 224 also includes a second radially inner ring or fastener 236 having an extending surface interior 240 that engages the surface 72 of the shaft. The ring 236 is divided such that it has a variable diameter, whereby the ring 236 can conform to the outer surface 72 of the shaft. The inner ring 236 also has a complementary tapered surface 244 with and in engagement with the tapered surface 232 of the outer ring 226. In this way, the tapered surface 244 of the inner ring 236 faces radially outwards and tapers radially away from the shaft 66 and axially separates from the outer bearing 200. The inner ring 236 also has a radially extending end surface 246, facing away from the outer bearing 200 (to the left in Figure 6). As shown in Figure 6, the ring 236 preferably, generally L-shaped in cross section with the projection 252 extending radially outwardly bringing the outer ring 226. An annular spring 256 engages the end surface 246 of the inner ring 236. Although the preferred spring 256 is a polyurethane spring washer, it should be understood that other suitable springs, such as a conical disk or a wavy type washer, may be employed. The end cap 104 engages the spring 256, such that the reeve 256 is compressed between the end cap 104 and the inner ring 236 and exerts a force on the inner ring 236, whereby the inner ring 236 is tightened between the outer ring 226 and the outer surface 72 of the shaft, due to the engagement of the tapered surfaces 232 and 244. This effectively keeps rings 226 and 236 in position. The angle of the taper is calculated in such a way that the frictional forces between the surface 72 of the shaft and the inner ring 236 are greater than the axial separation force of the bearings. The spring 256 provides a predetermined preload on the bearings. It is not necessary to tighten the screws 106 at a particular torque. If the end cap 104 is fully seated, the bearings fit properly. This makes it much easier than the known arrangements to properly pre-charge the coents. A seal 260 surrounds the outer ring 226 between the end cap 104 and the flange 44. As shown in Figure 6, the end cap 104 is intimately adjacent to the outer end of the outer ring 226 (i.e., the left end of the ring 226). ring 226 in Figure 6) to limit movement axially outwardly of outer ring 226 (left in Figure 6). In other words, the end cap 104 keeps the bearing assembly 66 completely separate, in the event that the ring 226 and 236 slides or breaks. A reciprocating bearing mount 300 is illustrated in Figures 10 and 11. Except as described in the following, the bearing holder assembly 300 is identical to the bearing holder assembly 224 and the common elements have been given the same numbers reference. The bearing holder assembly 300 includes a means for axially retaining the rings 226 and 236. Although several suitable means may be employed, in the illustrated construction, such means include a plurality of screws 304 that engage the rings 226 and 236 by retention. More particularlyEach screw 304 extends through an opening 30-6 in the projection 252 of the inner ring and is threaded in the outer ring 226. The openings 306 in the inner ring 236 are large enough to allow some radial movement of the screws 304 relative to the inner ring 236. The spring 256 has therein notches or cut-outs 312, each of which received the head of a respective screw 304, such that the heads of the screw do not interfere with the spring 256. The screws 304 are used to retain the rings 226 and 236 instead and keep them from sliding relative to the shaft 66. This arrangement will allow a preload or space in the assembly as desired. Because the screws 304 will pull the outer ring 226 rearwardly on the inner ring 236, the preload induced by the spring 256 will be reduced. If the reduction in preload is less than the initial preload, a preload results. If the reduction in the preload is greater than the initial preload, a space results. It is to be understood that this fastener assembly 300 may also be used with ball, cylindrical or tapered roller bearings to provide a desired space. A tumbling block 400 having an alternative roll arrangement is illustrated in Figures 12 and 13. Except as described in the following, the tumbling block 400 is identical to the tumbling block shown in Figure 1-9 and to the elements commons have been given the same reference numbers. In place of the retaining mounts 120 and 124, the tipping block 400 has retaining mounts 420 and 424. The retainer mounts 420 and 424 are substantially identical and only the assembly 424 will be described in detail. The retainer assembly 424 includes a roller 126 mounted on a roller holder 432. The roller support 432 is mounted on the main portion 56 of the structure, such that the roller support 432 can pivot (see arrows in Figures 12 and 13) relative to the structure 52 about an axis, which it is transverse to and extends radially from the axis of the pulley. The roller support 432 is pivotable relative to the structure 52 between a detent position (see assembly 420 in Figure 12) and a release position (see assembly 424 in Figure 12). When the roller holder 432 is in the detent position, the roller axis is parallel to the axis of the pulley and the roller 126 extends over the pulley 44 to retain the turning wire 46 on the pulley 44. When the support 432 of roller is in the released position, the roller 126 allows removal of the overturning cable 46 from the pulley 44. Means are provided for securing 1 unbeatable between the roller support 432 in the detent position. In the illustrated construction, the roller support has a slot 450 therein and the main portion 56 of the structure has therein (see Figure 13) a notch 454, which is aligned with the slot 450 when the roll holder 432 it is in its retention position. An L-shaped lever 456 is mounted on the roller holder 432 for pivotal movement between a securing position (not shown) and a release position (see assembly 424 in Figure 12). When the lever 456 is in its secure position, the lever 456 is housed in the slot 450 and extends into the slot 454 to releasably secure the roller holder 432 in its detent position. The lever 456 can be moved manually between its securing and releasing positions. Several features of the invention are set forth in the following claims.

Claims (6)

1. NOVELTY OF THE INVENTION CLAIMS 1. A cable dredger characterized in that it comprises: a main housing, a winch-bucket mechanism mounted on the housing, a dredge-bucket mechanism mounted on the main housing, an ovulation mechanism for moving the main housing on the ground, a boom which is supported on the main housing and which has an upper end, a bucket, a winch cable having one end connected to the bucket-cabreetante mechanism that extends over the pulley and having an opposite end, a dredge cable which extends between the bucket and the bucket dredge shaft, a tipping block including a structure having a main portion connected to the opposite end of the winch cable and a cantilevered shaft extending from the main portion and a pulley of the tipping block mounted on the shaft for rotation about a pulley shaft, and a tipping cable extending over the tipping block pulley and having one end connected to the dredger cable and an opposite end connected to the bucket, such that the tipping cable can be removed from the pulley in the direction away from the main portion of the structure.
2. 2. The cable dredger according to claim 1, characterized in that the tipping block also includes a retaining assembly, which includes a retaining member mounted on the structure for relative movement with the structure between a retention position, in wherein the retaining member extends over the tumbler block pulley to hold the overturning cable on the tipping block pulley and a released position in which the retaining member allows removal of the tipping cable from the pulley of the tipping block. dump block.
3. 3. The cable dredger according to claim 2, characterized in that the retaining member is a roller. The cable dredger according to claim 3, characterized in that the retaining assembly also includes a roller support mounted on the main portion of the structure for pivotal movement about a support axis transverse to the pulley shaft and in As the roller is mounted on the roller support for rotation about a roller axis, the roller support is movable relative to the structure between a retention position in which the roller axis is parallel to the axis of the roller. pulley and the roller extends over the tipping block pulley to retain the tipping cable on the tipping block pulley and a release position in which the roller allows removal of the tipping cable from the tipping block pulley . 5. The cable dredger according to claim 4, characterized in that the retaining assembly also includes means for releasably securing the roller support in the retention position. 6. The cable dredger according to claim 5, characterized in that the roller support has through it first and second spaced openings, in which the main portion of the structure has in it a third opening, which is aligned with the second opening, when the roller holder is in the retention position, in which the roller holder is pivotally mounted on the main portion of the structure by a first pin extending through the first opening and along of the support shaft and wherein the means for releasably securing the roller support includes a second bolt insertable into the second and third openings, when the roller holder is in the detent position. 7. The cable dredger according to claim 3, characterized in that the roller has a positive influence on it to prevent the turning cable from becoming pressed between the roller and the pulley. 6. The cable dredge according to claim 1, characterized in that the overturning block also includes a pulley support mounted on the shaft for rotation about the axis of the pulley, the pulley support has a radially extending flange, on which the pulley is mounted on the support of pulley and in which the overturning block also includes a pulley guard, which is fixed to the pulley support and which presses the pulley against the flange to hold the pulley on the pulley support. 9. A cable dredger characterized in that it comprises: a main housing, a winch-cannister mechanism mounted on the housing, a dredge-bucket mechanism mounted on the main housing, a movement mechanism for moving the main housing on the ground, a boom which is supported on the main housing and which has an upper end, a bucket, a winch cable having one end connected to the bucket-winch mechanism which extends over the pulley and which has an opposite end, a dredge cable extending between the bucket and the bucket dredge mechanism, a tipping block including a structure having a main portion connected to the opposite end of the winch cable and a cantilevered shaft extending from the main portion and a tipping block pulley mounted on the shaft for rotation about a pulley shaft, a valtering cable extending The pulley of the tipping block and having one end connected to the dredge cable and an opposite end connected to the bucket, and a retaining assembly including a roller mounted on the structure for relative movement with the structure, between a position of retention in which the roller extends over the tipping block pulley to retain the tipping cable on the tipping block pulley and a releasing position in which roller allows removal of the tipping cable from the block of the tipping block. I turn The cable dredger according to claim 9, characterized in that the retaining assembly also includes means for releasably securing the roller support in the retention position. The cable dredger according to claim 10, characterized in that the roller support has through it first and second spaced openings, in which the main portion of the structure has in it a third opening, which is aligned with the second opening, when the roller holder is in the retention position, in which the roller holder is pivotally mounted on the main portion of the structure by a first pin extending through the first opening and along of the support shaft and wherein the means for releasably securing the roller support includes a second bolt insertable in the second and third openings, when the roller holder is in the detent position. 12. The cable dredger according to claim 9, characterized in that the roller has on it an eeliente to avoid etantancially that the overturning cable becomes squeezed between the roller and the pulley. The cable dredger according to claim 6, characterized in that the tipping block also includes a pulley support mounted on the shaft for rotation about the axis of the pulley, the pulley support has a flange extending radially, in which the pulley is mounted on the pulley support and in which the overturning block also includes a pulley guard, which is fixed to the pulley support and which presses the pulley against the flange to maintain the pulley on the pulley support. 14. A cable dredger characterized in that it comprises: a main housing, a winch-bucket mechanism mounted on the housing, a dredge-bucket mechanism mounted on the main housing, a movement mechanism for moving the main housing on the ground, a boom which is supported on the main housing and which has an upper end, a bucket, a winch cable having one end connected to the bucket-winch mechanism that is stretched over the pulley and having one end opposite, a dredger cable extending between the bucket and the bucket dredge mechanism, a tipping blade including a structure having a main portion connected to the opposite end of the winch cable and a cantilevered shaft extending from the main portion and a tipping block pulley mounted on the shaft for rotation about a pulley shaft, the tipping block pulley on one side facing the main portion of the structure and an opposite side, a end cap that secures the pulley on the shaft and a fixed pulley guard relative to one of the pulley and the end cap to protect the opposite side of the tipping block pulley, a cable of vol It extends over the pulley of the tipping block and has one end connected to the dredge cable and an opposite end connected to the bucket, and a retaining assembly that includes a roller support mounted on the portion of the main structure for the pivotal movement about a support axis, transvereal to the axis of the pulley and a roller mounted on the roller support for rotation about a roller axis, the roller support is movable in relation to the structure between a holding position in which the roller axis is parallel to the axis of the pulley and the roller extends over the roller block pulley to hold the overturning cable on the roller block pulley and a release position, in which the roller allows removal of the tipping cable from the tipping block pulley. 15. The cable dredger according to claim 14, characterized in that the retaining assembly also includes a means for releasably securing the support of the roller in the retention position. 16. The cable dredger according to claim 15, characterized in that the roller support has through it first and second spaced openings, in which the main portion of the structure has in it a third opening, which is aligned with the second opening, when the roller holder is in the retention position, in which the roller holder is pivotally mounted on the main portion of the structure by a first pin extending through the first opening and along of the support shaft and wherein the means for releasably securing the roller support includes a second bolt insertable into the second and third openings, when the roller holder is in the detent position. 17. The dredge dredge according to claim 14, characterized in that the roller has a projection on it to substantially prevent the tipping cable from becoming squeezed between the roller and the pulley. 16. The cable dredger according to claim 14, characterized in that the tipping block also includes a pulley support mounted on the shaft for rotation about the axis of the pulley, the pulley support has a ridge that extends radially, in which the pulley is mounted on the pulley support and in which the pulley guard is fixed to the pulley support and presses the pulley against the flange to hold the pulley on the pulley support. 19. A cable dredger characterized in that it comprises: a main housing, a winch-bucket mechanism mounted on the housing, a dredge-bucket mechanism mounted on the main housing, a movement mechanism for moving the main housing on the ground, a a boom which is supported on the main housing and which has an upper end, a bucket, a winch cable having one end connected to the bucket-winch mechanism that is disposed on the pulley and having an opposite end, a dredge cable extending between the bucket and the bucket dredge mechanism, a tipping block including a structure having a main portion connected to the opposite end of the winch cable and a cantilevered shaft which extends from the main portion and which has a pulley shaft, an axially extending outer surface and a radially outwardly extending shaft surface, a tumbling block pulley which is mounted on the shaft for rotation about the shaft of the pulley and which has an inner surface extending axially, a roller bearing, tapered between the inner and outer surfaces, the bearing has a radially extending bearing surface and a bearing holder assembly, which includes a ring outer which engages the bearing surface, such that the bearing is captured between the surface of the radially extending shaft and the ring ex terior, the outer ring has a first tapered surface facing radially inwardly, a split inner ring having a second tapered surface, which faces radially outwardly and which engages the first tapered surface, the ring The split also has an axially extending ring surface, which engages the outer surface of the shaft, and a radially extending ring surface, each of the first and second tapered surfaces, tapers radially away from the shaft and axially separates from the shaft. bearing, an annular spring that engages the surface of the ring and a cap which is fixed to the shaft and which engages the spring, such that the spring is compressed between the cap and the ring surface and forces the tapered surfaces against the other, and a tipping cable that extends over the pulley of the tipping block and that has one end connected to the dredge cable and one end opu sto connected to the bucket. 20. The cable dredger in accordance with the rei indication 19, characterized in that the pulley has a first flange that faces the surface of the radially extending axis and a second frontal flange, separating from the first flange, in which the apparatus further comprises a second tapered roller bearing, captured between the first flange and a radially extending shaft surface and wherein said first bearing is captured between the outer ring and the second flange. 21. The cable dredger according to claim 19, characterized in that the spring is made of polyurethane. 22. The cable dredger according to claim 19, characterized in that the fastener assembly also includes a means for axially holding the rings. 23. The cable dredger according to claim 22, characterized in that the means includes a plurality of threaded fasteners for clamping the rings. 24. The cable dredger according to claim 19, characterized in that the end cap extends intimately adjacent to the outer ring, to limit axially outward movement of the outer ring relative to the inner member.