Articulation joint

Abstract: An articulation joint for pivotally connecting together two portions of a mining machine such as an articulated shuttlecar is described, the joint comprising first and second slewing rings (37,39) each made up of outer members (41) and inner members (43) with a bearing ring (45) located between the two members, the outer members (41) being connectable to one portion (1) of the mining machine and the inner members (43) being connectable to the other portion (5) of the mining machine, and wherein the two slewing rings are rigidly connected to each other. Suitable spacing members and location rings are provided between the portions of the mining machine and the slewing rings. This construction provides a very strong and rigid articulation joint.

Description: The present invention relates to an articulation joint, and in particular to such a joint for use in mining machinery. While it is envisaged the joint would be very useful in conveyors, especially portable ones, it has been designed for use in an articulated haulage vehicle. The joint has been particularly designed for use as a vertical pivot joint in an articulated shuttlecar for use in mining operations. Joints for use in conveyors, haulage vehicles and even articulated shuttlecars are known. Articulated shuttlecars are also known. Most of these have a horizontal pivot to allow them to negotiate uneven mine floors. Most haulage vehicles have vertical pivot joints, and the loadings on the pivot joint are not very high, since these joints are normally between a cab portion and a load carrying portion of the vehicle. However, in US-A-4160619, a vertical pivot joint in the middle of a shuttlecar is disclosed, which is comprised of spaced upper and lower plates on one portion of the shuttlecar pivotally connected to upper and lower plates on the other portion, the pivotal connections incorporating bearing races, and the two races being spaced apart to accommodate a pair of steering rams between them. Because of the spacing, the joint is not sufficiently stiff for use in a commercially acceptable shuttlecar. Also, because of the arrangement of the plates in the joint, it is necessary for the joint to be assembled partly from above and partly from below, and this is a disadvantage. The articulation joint of the present invention does not suffer from these disadvantages. According to the present invention, we provide an articularion joint for pivotally connecting together two portions of a mining machine, the joint comprising first and second slewing rings, each comprising an outer member and an inner member with a bearing race located between the two members, the outer members being connectable to one portion of the mining machine and the inner member being connectable to the other portion of the mining machine, and wherein the two slewing rings are rigidly connected to each other. Preferably, the outer members are connected to one portion of the mining machine and the inner members are connected to the other portion of the machine, so that, in use, the one portion can pivot relative to the other portion about a vertical axis. Preferably, the one portion comprises a flat annular clevis with a plurality of circumferentially spaced apertures extending parallel to the central axis of the annulus therein, the respective outer members of each slewing ring being secured to opposite faces of the clevis by a plurality of bolts passing through apertures in the members and the apertures in the clevis. Preferably, the said one portion comprises a male half of the joint. Preferably, the other portion of the mining machine comprises a female half of the joint and is formed of two vertically spaced, horizontally extending plates between which the male part extends, the inner members of each slewing ring being connected, respectively, to the inner faces of the respective plates. Preferably, the two inner members are spaced apart by an inner spacer ring, and the two inner members, the inner spacer ring and the two horizontal, vertically spaced plates are connected together by a plurality of threaded studs passing through respective ones of a plurality of vertically aligned apertures arranged in a circle and circumferentially spaced from each other. Preferably also, an upper location ring is provided to locate one of the inner members beneath the upper one of the two horizontal, vertically spaced plates, and a lower spacer is provided between the inner face of the lower one of the two horizontally spaced plates and the lower one of said inner members. Preferably, a lower location ring is provided which initially is located within the male half of the joint, but when the male and female halves of the joint are assembled, it seats within the inner spacer ring, and extends into a lower part of the joint. Preferably, the lower location ring therefore has a lower portion of reduced internal diameter, which locates tightly within the lower space and the lower one of said two horizontally spaced plates of the female half of the joint, with a step defining the reduced diameter resting on said lower spacer. The lower location ring thus relieves the threaded studs of excessive loads. Preferably, the upper one of said spaced plates is provided with a plurality of circumferentially spaced recesses in its upper face, in the base of which the apertures for said threaded studs are provided, the recesses being sufficiently deep to receive the heads of the bolts so that they do not project above the main surface of said upper plate. Studs for securing the location ring are also preferably located in said recess. The above construction provides an absolutely rigid articulation joint, and has the further advantage that it can be assembled from above, since the bolts connecting the outer members of the slewing rings to the clevis can be put in position before the joint is assembled, and after assembly all the studs can be inserted from the top of the assembled joint. This is an important safety factor. Preferably, the clevis is welded within an annular plate, to which one or more brackets is welded and to which a steering means may be connected to cause the one portion of the machine to pivot relative to the other about the articulation joint. Preferably, the male half of the joint is formed of two vertically spaced plates held apart by said annular plate, there being an arcuate step in the upper one of said plates, the arcuate step being centred on the pivot axis of the joint, and the upper plate of the female half of the joint has a projecting portion with an arcuate edge which fits with a snug fit within the arcuate step. Preferably, the two joint halves form part of two relatively movable portions of a mine shuttlecar, and an upper run of a conveyor chain is movable across the upper plates of the two halves, and a return run of the chain passes beneath the joint and on top of bottom plates forming part of each joint half. A preferred embodiment of articulation joint according to the invention is now described by way of example with reference to the accompanying drawings, in which:- FIGURE 1a is a partly schematic plan view of an articulated shuttlecar incorporating two of the joints; FIGURE 1b is a partly schematic side elevation, partly in section, of the shuttlecar; FIGURE 1c is a scrap plan view showing one of the joints articulated; FIGURE 2a is a section through a female half of the joint, to a larger scale; FIGURE 2b is an exploded section through a male half of the joint; FIGURE 2c is a section through the assembled joint; FIGURE 3 is a plan view of one of the slewing rings shown in figure 2b, and FIGURE 4 is a plan view of the joint to a larger scale. Referring to the drawings, Figures 1a - 1c show an articulated shuttlecar which is the subject of our copending Patent Application EP-A-0552027 claiming priority from U.K. Application No.9200678.2 being filed contemporaneously herewith. The shuttlecar has two end portions 1 and 5, separated by a central portion 3, adjacent portions 1 and 3, and 3 and 5, being pivotally connected about vertical pivots by an articulation joint 7 of the present invention. Each portion 1, 3 and 5 has a pair of ground engaging wheels 9 and the central portion is divided into two relatively movable parts by a horizontal pivot joint 11, the longitudinal axis of which corresponds with the rotational axis of the respective wheels 9 for that shuttlecar portion. Each of the wheels 9 is supported on a trailing arm 13 connected to the chassis of the portion by a suspension system, the subject of a further co-pending Patent Application. The shuttlecar is steered by a steering mechanism indicated generally at 15 in Figure 1c. Drive to each pair of wheels 9 is through a transmission system shown generally at 17. An endless chain type conveyor 19 is arranged in use to sweep across the upper face of the shuttlecar, the conveyor being of largely known construction with a plurality of spaced transverse flight bars 21. The conveyor has a return run 23 running along the underside of the shuttlecar as shown at 23 in Figure 1b. The articulation joint between the shuttlecar portions 1 and 3 will now be described with reference to Figures 2a-2c (the other joint being identical). Referring to Figure 2b, a deck 25 of the shuttlecar portion 1 is stepped down at 27, the step being arcuate as shown in Figure 4. Below the step 27 the deck 25 is formed by a plate 25a which terminates in an annular plate 29 welded at its top edge to the plate 25a and at its bottom edge to a further plate 31. An annular clevis 33 is welded to a central portion of the plate 29, this clevis being provided with a plurality of circumferentially spaced apertures 35. An upper slewing ring shown generally at 37 is supported on the upper face of the clevis 33 and a lower slewing ring 39 bears against the lower face of the clevis 33, each slewing ring having an outer annular member 41 and an inner annular member 43, the inner member 43 being supported for rotation within the outer member 41 by a plurality of ballbearings 45. The outer member 41 has a plurality of circumferentially spaced apertures therein corresponding in size and spacing to the apertures 35 in the clevis 33 and the two slewing rings 37 and 39 are held in assembled relationship with the clevis 33 by a plurality of bolts 47, the ends of which are threaded to accept nuts 49. The inner members of each slewing ring are designed to be connected to the portion 3 of the shuttlecar, part of which is shown in Figure 2a. The deck 51 has a bulbous arcuate nose portion 51a, a peripheral edge 51b of which is arranged to mate with and form a snug fit within the arcuate step 27 in the deck 25 of the shuttlecar portion 1 as shown in Figure 2c. Welded to the underside of the nose portion of the deck 51 is a strengthening ring 53 thus allowing a plurality of circumferentially spaced recesses 55 to be formed in the deck. On the side of the ring 53 remote from the edge 51b a transverse plate 57 is welded to the underside of the deck 51, and a bottom plate 59 is welded to the bottom edge of the plate 57. A plurality of circumferentially spaced apertures 61 are arranged in the form of a circle in the strengthening ring 53 and a further circle of circumferentially spaced apertures 63, the spacing and location of which correspond with those of the apertures 61, are formed in the bottom plate 59. Each of the apertures 63 is tapped to provide an internal screw thread. The inner and outer circumferences of the strengthening ring 53 correspond with those of the inner member 43 of each slewing ring 37, 39, and each of the said inner members 43 is provided with a circle of circumferentially spaced axially extending apertures 65 therein, the size, location and spacing of which apertures 65 correspond with those of apertures 61, thus enabling the inner members of each slewing ring to be connected to the shuttlecar portion 3 with a plurality of threaded studs 67. As can be seen from Figure 2c, the top face of the slewing ring 37 is connected to the underface of the strengthening ring 53 and the bottom face of the slewing ring 39 is supported by means of a lower annular spacer 69 provided with a circule of apertures 71 therein on the upper face of the bottom plate 59. In order to stiffen up the joint thus formed, an annular inner spacer 73, also provided with a circle of apertures 75 therein, the spacing and size of which match those of the aperture 65, is also located between the inner member 43 of the slewing ring 37 and the inner member of the slewing ring 39, the inner spacer 75 being stepped on its top and bottom faces as shown at 77 and 79 so as to locate on the respective inner members 43 and the outer diameter of the annular inner spacer 73 being such that the ring forms a snug fit within the clevis 33. Furthermore, also to assist in stiffening the joint, a lower location ring 48 is provided within the joint. The ring 48 has an overall external diameter such that it forms a close fit within the inner spacer 73. The ring 48 really forms part of the male half of the joint (see Figure 2b) for assembly purposes. The ring 48 has a lower portion 50 of reduced external diameter corresponding to the internal diameters of the lower spacer 69 and an aperture 60 in the bottom plate 59. When the male and female joint halves have been assembled, as shown in Figure 2c, it will be noted that the reduced diameter portion of the lower location ring sits tightly within the aperture 60 and lower space 69, and thus, any major forces which would otherwise have been borne by other studs 67, are now borne by the lower location ring, which also sits tightly within the inner space 73. The studs 67 pass through the apertures 65 in the slewing ring 37, the apertures 75 in the inner spacer 73, the apertures 65 in the lower slewing ring 39, and the apertures 71 in the lower spacer 69 and are then threadedly engaged in the tapped apertures 63 in the bottom plate 59 with the heads of the studs 67 being received in the recesses 55 of deck 51 so that they do not project above the surface of the deck. The strengthening ring 53 incorporates an internal annular recess 81 on its under face and a plurality of circumferentially spaced apertures 83 are also provided in the ring 53 in the area of the annular recess 81, the apertures 83 extending in a circle. The recess 81 is designed to accept a location ring 85 which itself is provided with a plurality of circumferentially spaced apertures 87 therein, the location and spacing of which correspond with those of the apertures 83. The apertures 87 are internally tapped so as to provided a screw thread and the location ring 85 is held in position within the strengthening ring 53 by a plurality of threaded studs 89 passing through the apertures 81 and screwthreadedly engaging with the threaded apertures 87. There are two alternative positions for the location ring 85, an upper position being shown at 85a in Figure 2c and a lower position being shown at 85b in Figure 2c. As can be seen from Figure 2c, the thickness of the location ring 85 is greater than the depth of the recess 81 and the outer diameter of the ring 85 corresponds with the inner diameter of the inner member 43 of the slewing ring 37 so that when the articulation joint is assembled, the ring 85 will form a snug fit within the inner member 43 thus accurately locating the slewing ring 37 in the shuttlecar portion 3. The lower ends of the studs 89 can be used to hold the lower location ring 48 in position, as shown in Figure 2c. Alternatively, ring 85 when in its lower position 85b can be used for this purpose. As can be seen from Figures 2b and 2c, the plates 25a and 31 of the shuttlecar portion 1 together with the annular plate 29 provide a male portion of the articulation joint whereas the plate forming the nose portion 51a and the bottom plate 59 form a female portion of the articulation joint. When the articulation joint is assembled, the male portion of the joint fits within the female portion and the outer members of the two slewing rings are firmly connected to the male portion, whereas the inner members of the two slewing rings are firmly connected to the female portion. By virtue of the location ring, inner spacers and lower spacers associated with the female joint portion and the clevis associated with the male portion of the joint. an absolutely rigid articulation joint is provided in which two spaced apart slewing rings are incorporated. One or more brackets (not shown) is connected to the annular plate 29 to each of which brackets a steering chain 87 is connected. The opposite end of each chain 87 is connected to extendible and retractable means secured to the shuttlecar portion 3, the arrangement being such that extension and retraction of these means cause the chain to apply a moment arm to the plate 29, thus causing articulation of the joint. This allows the articulated shuttlecar to be steered. As can be seen from Figures 2b and 2c, the bolts 47 connecting the outer members of the slewing rings to the clevis 33 can be inserted from above, and likewise, the two sets of studs 67 for assembling the inner members of the slewing rings on the shuttlecar portion 3 can be inserted from the top of the articulation joint. This means that assembly and servicing of the joint can all be undertaken from above, which is an important safety feature. It will of course be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

Claims: An articulation joint for pivotally connecting together two portions (1, 3, 5) of a mining machine, the joint comprising first and second slewing rings (37, 39), each comprising an outer member (41) and an inner member (43) with a bearing race (45) located between the two members, the outer members being connectable to one portion of the mining machine and the inner member being connectable to the other portion of the mining machine, and wherein the two slewing rings are rigidly connected to each other. A mining machine having a first portion and a second portion pivotally connected to the first portion by an articulation joint as claimed in claim 1, and wherein the outer members are connected to the first portion of the mining machine and the inner members are connected to the second portion of the machine, so that the one portion can pivot relative to the other portion about a vertical axis. A mining machine as claimed in claim 2 wherein the two pivotally connected portions are part of a shuttlecar, and a upper run of a conveyor chain (19) is movable across the top of the two portions, and a return run (23) of the chain passes beneath the joint. The invention as claimed in claim 1, 2 or 3 wherein the one portion comprises a flat annular clevis (33) with a plurality of circumferentially spaced apertures (35) extending parallel to the central axis of the annulus therein, the respective outer members of each slewing ring being secured to opposite faces of the clevis by a plurality of bolts (47) passing through apertures in the members and the apertures in the clevis. The invention as claimed in claim 4 wherein the clevis (33) is welded within an annular plate, to which one or more brackets is welded and to which a steering means is connected to cause the one portion of the machine to pivot relative to the other about the articulation joint. The invention as claimed in any one of claims 1-5 wherein said one portion comprises a male half of the joint, and the second portion of the mining machine comprises a female half of the joint. The invention as claimed in claim 5 wherein the female half of the joint is formed of two vertically spaced, horizontally extending plates (25a, 31) between which the male part extends, the inner members of each slewing ring being connected, respectively, to the inner faces of the respective plates. The invention as claimed in claim 7 wherein the two inner members are spaced apart by an inner spacer ring, and the two inner members, the inner spacer ring (73) and the two horizontal, vertically spaced plates are connected together by a plurality of threaded studs passing through respective ones of a plurality of vertically aligned apertures arranged in a circle and circumferentially spaced from each other. The invention as claimed in claim 7 or 8 wherein a location ring (85) is provided and locates one of the inner members beneath the upper one of the two horizontally spaced plates, and a lower spacer is provided between the inner face of the lower one of the two horizontal, vertically spaced plates and the lower one of said inner members. The invention as claimed in claim 8 or 9 wherein a lower location ring is provided which seats within the inner spacer ring, and extends into a lower part of the joint. The invention as claimed in claim 10 when dependent on claim 9 wherein the lower location ring has a lower portion of reduced external diameter which locates tightly with the lower spacer and the lower one of said two horizontally spaced plates of the female half of the joint, with a step defining the reduced diameter resting on said lower spacer. The invention as claimed in claim 8 or claim 9 when dependent on claim 8 wherein the upper one of said spaced plates is provided with a plurality of circumferentially spaced recesses in its upper face, in the bases of which the apertures for said threaded studs are provided, the recesses being sufficiently deep to receive the heads of the bolts so that they do not project above the main surface of said upper plate. The invention as claimed in claim 12 wherein studs for securing the location ring are also located in said recess. The invention as claimed in any one of claims 6-13 when dependent on claim 5 wherein the male half of the joint is formed of two vertically spaced plates held apart by said annular plate, there being an arcuate step in the upper one of said plates, the arcuate step being centred on the pivot axis of the joint, and the upper plate of the female half of the joint having a projecting portion with an arcuate edge which fits with a snug fit within the arcuate step.

Inventors: ETHERINGTON MICHAEL, LONG MICHAEL ROBERT, ETHERINGTON, MICHAEL, LONG, MICHAEL ROBERT
Applicants: DOSCO OVERSEAS ENG LTD, DOSCO OVERSEAS ENGINEERING LIMITED
Application year: 1993
Main classification: B62D53
IPC codes: B60D5, B62D53, B62D47