Articulation joint

An articulation joint for pivotally connecting adjacent sections of a vehicle. The joint includes a first slewing ring and a second slewing ring. Each slewing ring has an outer member and an inner member with a bearing race located between the outer and inner members to provide relative rotation of the members. The outer member of each slewing ring is constructed for connection to one section of a vehicle and the inner member of each slewing ring is constructed for connection to the other section of the vehicle.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to an articulation joint for 
connecting two sections of a vehicle, and in particular to such a joint 
for use in a vehicle which must be able to negotiate short radius turns. 
The joint may also be used in conveyors. 
An important use of such an articulation joint is as a vertical pivot joint 
in an articulated shuttlecar for use in mining operations having a 
plurality of pivotally connected sections. 
2. Description of the Prior Art 
Articulation joints for use in conveyors, shuttlecars and other haulage 
vehicles are known in the art. Most equipment of this type includes 
horizontal pivot joints which permit the equipment to operate on 
undulating surfaces. In haulage vehicles with vertical pivot joints, the 
loading on the joints is generally low since the joint is normally between 
the cab portion of the vehicle and the load carrying portion of the 
vehicle. 
U.S. Pat. No. 4,160,619 discloses a vertical pivot joint which is located 
in the middle of a mine shuttlecar. The pivot joint in that patent has 
spaced upper and lower plates on one part of the shuttlecar which are 
pivotally connected to spaced upper and lower plates on the other part of 
the shuttlecar. The pivotal connection incorporates bearing races, which 
are spaced apart to accommodate a pair of steering rams between them. 
Because of the spacing, the joint cannot withstand high loads. Also, the 
arrangement of the plates in the joint disclosed in that patent requires 
that the joint be assembled from above and from below, which is a 
disadvantage. 
SUMMARY OF THE INVENTION 
The present invention is directed to an articulation joint for pivotally 
connecting two adjacent sections of a vehicle such as a shuttlecar. The 
joint includes upper and lower slewing rings, each of which includes an 
outer member and an inner member with a bearing race located between the 
two members. The inner and outer members of each ring are connected and 
each outer member is connected to one section of the vehicle and each 
inner member is connected to the other section of the vehicle. The upper 
and lower slewing rings are rigidly connected to each other with an inner 
spacer therebetween. The connection of the outer members of the slewing 
rings to one section of the vehicle and the connection of the inner 
members of the slewing rings to the other section of the vehicle permits 
the sections to rotate relative to each other about a vertical axis. 
One section of the vehicle includes a flat horizontal annular tongue with a 
plurality of circumferentially spaced apertures therein extending parallel 
to the central axis of the annulus. The outer members of each slewing ring 
are secured to opposite faces of the horizontal tongue by bolts passing 
through the apertures in the outer members and aligned apertures in the 
tongue. 
One section of the vehicle forms a male half of the articulation joint and 
the other section of the vehicle forms a female half of the articulation 
joint. The female half of the joint has two vertically spaced 
substantially parallel horizontally extending plates which receive the 
male half between them. The inner members of each slewing ring are 
connected to the plates of the section of the vehicle which forms the 
female half of the articulation joint. 
The inner members of the two slewing rings and the inner spacer ring 
located therebetween are connected to the two spaced substantially 
parallel horizontally extending plates by threaded connecting bolts. The 
bolts pass through a plurality of vertically aligned, circumferentially 
spaced apertures in the inner members of the rings and aligned openings in 
the inner spacer ring. 
A location ring is preferably provided to locate the inner member of the 
upper slewing ring below the lower surface of the upper one of the two 
spaced horizontally extending plates of the female half of the 
articulation joint. A lower annular spacer is provided between the upper 
surface of the lower one of the two spaced horizontally extending plates 
of the female half of the articulation joint and the inner member of the 
lower slewing ring. 
The upper one of the two spaced horizontally extending plates of the female 
half of the articulation joint is provided with a plurality of 
circumferentially spaced recesses in its upper surface. The recesses are 
sufficiently deep to receive the heads of the connecting bolts so that the 
heads do not project above the upper surface of the upper plate. The heads 
of studs for securing the location ring for the inner member of the upper 
slewing ring are also located in the recesses. 
The male half of the articulation joint is formed with two vertically 
spaced substantially parallel plates attached to a vertical annular member 
with an arcuate step in the upper plate. The arcuate step is centered on 
the pivot axis of the articulation joint and the upper plate of the female 
half of the articulation joint has a projecting portion with an arcuate 
edge which snugly fits within the arcuate step on the male half of the 
articulation joint. 
The two joint halves form a relatively movable section of a vehicle and an 
upper run of a conveyor is movable across the upper surfaces of the upper 
plates of the two halves. A return run of the conveyor passes below the 
articulation joint. 
The arrangement described above provides a substantially rigid articulation 
joint and has the advantage that it can be completely assembled from above 
since the bolts connecting the outer members of the slewing rings to the 
horizontal tongue can be positioned before the joint is completely 
assembled. After assembly, all of the connecting bolts can be inserted 
from the top of the assembled joint. This is an important safety factor. 
A complete understanding of the invention will be obtained from the 
following description when taken in connection with the accompanying 
drawings wherein like reference characters identify like parts throughout.

DESCRIPTION OF A PREFERRED EMBODIMENT 
FIGS. 1a-1c of the drawings show an articulated shuttlecar, which is the 
subject of our co-pending U.S. patent application Ser. No. 07/906,569 
filed contemporaneously herewith. The articulation shuttlecar has end 
sections 1 and 5 pivotally connected to a center section 3 by articulation 
joints 7 of the present invention. Each section 1, 3 and 5 has a pair of 
laterally spaced ground engaging wheels 9 and end sections 1 and 5 are 
divided into vertically movable portions by a horizontal pivot joint 11, 
the longitudinal axis of which corresponds with the rotation axis of 
wheels 9 for that section of the shuttlecar. Each wheel 9 is rotatably 
supported on the free end of a trailing arm 13 of a bell crank lever which 
is pivotally connected to the chassis of that section of the shuttlecar by 
a suspension system which is the subject of our co-pending U.S. patent 
application Ser. No. 07/906,758 filed contemporaneously herewith. The 
shuttlecar is steered by a steering mechanism indicated generally at 15 in 
FIG. 1c of the drawings. The steering mechanism is the subject of our 
co-pending U.S. patent application Ser. No. 07/906,869 filed 
contemporaneously herewith. Each pair of wheels 9 is driven by a motor 
through a transmission system shown generally at 17 in FIG. 1c of the 
drawings. The transmission system is the subject of our co-pending U.S. 
patent application Ser. No. 07/906,894 filed contemporaneously herewith. 
An endless chain conveyor 19 has an upper run passing over the upper 
surface of the shuttlecar from end to end. The construction of the 
conveyor is well-known to those skilled in the art and has a plurality of 
spaced transverse flight bars. The conveyor has a lower return run 23 
along the underside of the shuttlecar as shown in FIG. 2b of the drawings. 
The articulation joint is described hereinafter with reference to FIGS. 
2a-2c of the drawings. Referring specifically to FIG. 2b of the drawings, 
a deck 25 of shuttlecar section 1 is stepped down to provide an arcuate 
edge 27. A portion of deck 25 is formed by a plate 25a which extends away 
from edge 27. A vertical annular member 29 has its upper edge welded to 
the edge of plate 25a and its lower edge is welded to the edge of a bottom 
plate 31 which is substantially parallel to and spaced below plate 25a. An 
annular horizontal tongue 33 is welded to the inner surface of annular 
member 29 approximately midway between the upper and lower edges of member 
29. The tongue is provided with a plurality of spaced apertures 35 around 
its circumference. 
When articulation joint 7 is assembled as shown in FIG. 2c of the drawings, 
the outer annular member 41 of an upper slewing ring 37 is supported on 
the upper face of annular horizontal tongue 33 and the outer annular 
member 41 of a lower slewing ring 39 bears against the lower face of 
annular horizontal tongue 33. Inner annular member 43 of each slewing ring 
is supported for rotation within outer member 41 of the slewing ring by a 
plurality of ball bearings 45 circumferentially spaced around the outer 
periphery of the inner member. Outer annular member 41 of each slewing 
ring has a plurality of circumferentially spaced apertures therethrough 
corresponding in size and spacing to apertures 35 in annular horizontal 
tongue 33. Slewing rings 37 and 39 are held in assembled relationship with 
horizontal tongue 33 by bolts 47 passing through the apertures in the 
slewing rings and apertures 35 in tongue 33. Each bolt 47 is threaded into 
a nut 49 located below lower slewing ring 39. 
Inner member 43 of each slewing ring is connected to center section 3 of 
the shuttlecar, a part of which is shown in FIG. 2a of the drawings. The 
deck 51 of center section 3 has a bulbous nose portion 51a with an arcuate 
edge 51b as shown in FIG. 4 of the drawings. The edge 51b is configured to 
form a snug fit with arcuate edge 27 in deck 25 of section 1 as shown in 
FIG. 2c of the drawings. A strengthening ring 53 is welded to the 
underside of nose portion 51a of deck 51 and a plurality of 
circumferentially spaced holes 55 are formed in deck 51 aligned with 
apertures 61 in ring 53. A downwardly extending transverse plate 57 is 
welded to the lower surface of deck 51 spaced away from edge 51b and a 
horizontal bottom plate 59 spaced from and substantially parallel with 
deck 51 is welded to the lower edge of plate 57. A plurality of 
circumferentially spaced apertures 63 are arranged in a circle in 
horizontal bottom plate 59 and have the same spacing as apertures 61 in 
strengthening ring 53. Each aperture 63 is tapped to provide internal 
screw threads therein. 
The inner and outer circumferences of strengthening ring 53 correspond with 
the inner and outer circumferences of inner annular members 43 of slewing 
rings 37 and 39. Each inner annular member 43 is provided with a plurality 
of circumferentially spaced axially extending apertures 65, the size and 
spacing of which correspond with the size and spacing of apertures 61 in 
strengthening ring 53 to enable the inner members of the slewing rings to 
be connected to shuttlecar section 3 by elongated threaded bolts 67. As 
shown in FIG. 2c of the drawings, the upper face of slewing ring 37 is in 
contact with the lower face of strengthening ring 53 and the lower face of 
slewing ring 39 is supported on a lower annular spacer 69 provided with a 
plurality of circumferentially spaced apertures 71 aligned with apertures 
63 in horizontal bottom plate 59. Annular spacer 69 is supported on the 
upper surface of horizontal bottom plate 59. 
In order to stiffen the articulation joint thus formed, an annular inner 
spacer 73 having a plurality of circumferentially spaced apertures 75, the 
spacing and size of which correspond with the spacing and size of 
apertures 65 in inner members 43 of slewing rings 37 and 39, is located 
between the inner members 43 of the slewing rings. Inner spacer 73 is 
stepped on its upper and lower edges as shown at 77 and 79 in FIG. 2b of 
the drawings to locate inner members 43 of the slewing rings and the outer 
diameter of inner spacer 73 is such that the inner spacer forms a snug fit 
within annular horizontal tongue 33. Apertures 75 in inner spacer 73 are 
aligned with apertures 65 in annular members 43 of the slewing rings. 
Bolts 67 pass through apertures 65 in upper slewing ring 37, apertures 75 
in inner spacer 73, apertures 65 in lower slewing ring 39, and apertures 
71 in lower spacer 69. The lower end of each bolt 67 is threadedly engaged 
in a tapped aperture 63 in horizontal bottom plate 59. The heads of bolts 
67 are received in recesses 55 of deck 51 so that they do not project 
above the upper surface of the deck. 
Strengthening ring 53 has an internal annular stepped recess 81 on its 
lower face and a plurality of circumferentially spaced apertures 83 are 
provided in ring 53 adjacent annular stepped recess 81. The annular 
stepped recess is designed to accept a location ring 85 which is provided 
with a plurality of circumferentially spaced apertures 87, the location 
and spacing of which correspond with those of apertures 83. Apertures 87 
are internally tapped to provide a screw thread and location ring 85 is 
held in position within strengthening ring 53 by a plurality of thread 
studs 89 passing through apertures 83 in strengthening ring 53 and 
threadedly engaged with threaded apertures 87. As shown in FIG. 2c of the 
drawings, there are alternate positions for location ring 85. An upper 
position is shown at 85a and a lower position is shown at 85b. The 
thickness of location ring 85 is greater than the depth of internal 
annular recess 81 and the outer diameter of location ring 85 corresponds 
with the inner diameter of inner member 43 of upper slewing ring 37 so 
that when the articulation joint is assembled location ring 85 forms a 
snug fit within inner member 43 to accurately locate upper slewing ring 37 
in shuttlecar section 3. 
As shown in FIGS. 2b and 2c of the drawings, spaced plates 25a and 31 of 
shuttlecar section 1 together with annular vertical member 29 provide a 
male half of an articulation joint 7 whereas upper plate 51 forming nose 
portion 51a and horizontal bottom plate 59 form a female half of an 
articulation joint 7. When the articulation joint is assembled, the male 
half of the joint fits within the female half of the joint and the outer 
members of the two slewing rings are firmly connected to the male half. 
The inner members of the slewing rings are firmly connected to the female 
half by location ring 85, inner spacer 73 and lower spacer 69 associated 
with the female portion. A substantially rigid articulation joint 
incorporating the spaced slewing rings is thereby provided. 
One or more brackets are connected to the outer surface of a portion of 
vertical annular member 29 as shown in FIG. 2c of the drawings and a pair 
of steering chains 90 pass between the brackets and have an end connected 
to vertical annular member 29. The opposite end of each steering chain 90 
is connected to a steering plate which is moveable by extensible and 
retractable means secured to shuttlecar section 3 so that extension and 
retraction of the means cause the steering chains to apply a moment arm to 
vertical annular member 29 to cause articulation of the joint which steers 
the shuttlecar. 
As shown in FIGS. 2b and 2c of the drawings, bolts 47 connecting the outer 
members of slewing rings 37 and 39 to annular horizontal tongue 33 can be 
inserted from above, and likewise, bolts 67 for connecting the inner 
members of the slewing rings to shuttlecar section 3 can be inserted from 
the top of the joint. This means that the assembly and servicing of the 
joint can be undertaken from above, which is an important safety feature. 
While a specific embodiment of the invention has been described in detail 
herein, it will be appreciated by those skilled in the art that various 
modifications and alternatives to the embodiment could be developed in 
light of the overall teachings of the disclosure. Accordingly, the 
particular arrangement is illustrative only and is not limiting as to the 
scope of the invention which is to be given the full breadth of the 
appended claims and any and all equivalents thereof.