Shuttle car

A mine-haulage vehicle is provided which consists of a first elongated body section providing a pair of steering wheels and coupled in articulating relation to an intermediate body section which is coupled in articulating relation to a third elongated body section providing a second pair of steering wheels. A first pair of driven wheels is provided by the intermediate body section with a common axis of rotation at or proximate to the first point of articulation. A second pair of driven wheels is provided by the third elongated body section with a common axis of rotation at or proximate to the second point of articulation.

BACKGROUND OF THE INVENTION 
This invention relates to improved material haulage vehicles and, more 
particularly, to low-height mine-haulage vehicles of the type commonly 
known as "shuttle cars" used for hauling loose materials in underground 
trackless mines. 
Shuttle cars have to carry heavy loads through low height, closely confined 
mine passageways with rough, uneven floors. Cars commonly used have a 
loading end with a pair of undriven steering wheels and a pair of driven 
wheels coupled in articulating relation to a discharge end also providing 
a pair of undriven steering wheels. The undriven steering wheels of the 
discharge end are coupled by a steering mechanism to the steering wheels 
of the loading end such that turning the steering wheels of the discharge 
end will result in an equal and opposite rotation of the steering wheels 
of the loading end. 
Specific cars in common use are known as 18-SC shuttle cars manufactured 
and sold by Joy Manufacturing Company of Pittsburgh, Pennsylvania. 
The structure of such cars is identified with U.S. Pat. Nos. 2,426,960; 
2,590,300; 2,654,547; 2,777,526; 2,962,176; 2,472,048; 2,593,643; 
2,654,548; 2,777,530; 2,970,664; 2,543,519; 2,654,382; 2,598,104, 
2,913,964; 3,008,592; 2,589,235; 2,654,383; and 2,858,897 and U.S. Pat. 
No. Re. 24,178, each incorporated herein by reference. 
While adaptive to many mining situations, where the mine surface is wet and 
uneven, the cars have experienced serious haulage problems. At times, the 
problem has become so acute that the cars could not be used, and the only 
coal produced was by using a scoop. 
A need, therefore, exists for a car providing better traction on wet, 
uneven surfaces to alleviate the problems presently encountered with six 
wheel cars, providing a pair of driven wheels and two pair of undriven 
steering wheels. 
SUMMARY OF THE INVENTION 
According to the present invention, there is provided a shuttle car with 
two points of articulation and having driven wheel pairs coincident with 
or otherwise selectively located relative to such points of articulation. 
In particular, the mine-haulage vehicle of this invention provides a body 
member comprising a first elongated body section providing at the first 
end thereof, a first pair of steering wheels and connected at an end 
opposite the first end thereof in articulating relation to a second 
intermediate body section to form a first point of articulation. The 
second intermediate body section is connected at a second end opposed to 
the first end thereof in articulating relation to the first end of a third 
elongated body section to form a second point of articulation. The second 
point of articulation is spaced from the first point of articulation, and 
the third elongated body section provides a second end opposed to the 
first end thereof a second pair of steering wheels. The body member 
includes compartments and conveying means for loading, carrying, and 
discharging mined materials. A first pair of driven wheels providing a 
common axis of rotation is coupled to the second intermediate body section 
at or proximate to the first point of articulation, and a second pair of 
driven wheels providing a common axis of rotation is coupled to the third 
elongated body section at or proximate to the second point of 
articulation. Preferably, the first pair of driven wheels having a common 
axis of rotation, is coupled to the second intermediate body section at or 
between the first and second points of articulation. A second pair of 
driven wheels is coupled to the third elongated body section at or between 
the second point of articulation and the second pair of steering wheels. 
There is provided means to drive the first and second pair of driven 
wheels. 
It is presently preferred that the points of articulation be transverse and 
the axis of rotation of the driven wheels be at or adjacent and upwards 
from the respective first and second points of articulation.

DETAILED DESCRIPTION 
FIGS. 1 and 2 illustrate an 18-SC shuttle car modified in accordance with 
the invention. With reference thereto, the body member 10 consists of a 
first elongated body section 12, commonly known as the discharge end of 
the shuttle car, an intermediate body section 14 coupled to the first body 
section in articulating relation and providing a pair of driven wheels 18 
and 20, and the third elongated body section 16, commonly known in the art 
as the loading end of a shuttle car, coupled to the intermediate body 
section 14 in articulating relation and providing a second pair of driven 
wheels 22 and 24. The first elongated body section 12 may be of 
conventional manufacture consisting of an operator's cabin 26, a portion 
of roller supported endless conveyor belt 28, conveyor drive shaft 30, 
conveyor drive motor 32, cable reel 34, hydraulic steering jack 36, 
hydraulic pump motor 38, a pair of steering wheels 40 and 42, which may be 
driven or undriven, coupled by arms 44 and 46 to steering yoke 48 
operating about pivot point 50. Arm 52 extends from yoke 48 and is 
connected by a ball and socket joint 54 to steering member 56, coupled to 
the steering linkage 58 added to the 18-SC shuttle car by means of the 
intermediate body section 14, as detailed below. Extending from the side 
walls 60 and 62 are semicircular members 64 and 66 which fit inside 
intermediate body section 14 and mate with apertures in intermediate body 
section 14 which are connected to hinge tube 68 to provide a first point 
of transverse articulation 70 ahead and downward of adjacent driven wheels 
18 and 20, which are rigidly mounted to the side walls 72 and 74 of the 
intermediate body section 14 through axle mounts 76 and 78. A suitable 
hinge tube which incorporates part of the total steering linkage is 
described in U.S. Pat. No. 2,962,176, identified above and incorporated 
herein by reference. 
Added intermediate body member 14 includes surfaces for travel of an 
endless conveyor belt 28, the driven wheels 18 and 20, and a steering 
linkage 58 to cause by rotation of steering wheels 40 and 42 in one 
direction, an equal and opposite rotation of steering wheels 80 and 82. 
Steering linkage 58 consists of a ball and socket joint 88 connected to 
bar 56, and is in turn connected by link means 84, providing pivot 86 and 
by ball and socket joint 90 to member 92, which is in turn connected by 
ball and socket joint 94 through linkage 96 having pivot point 98 to bar 
100 by ball and socket joint 102. Bar 100 provides ball and socket joint 
104 for coupling to arm 106 of yoke 108, having pivot point 110, which is 
in turn coupled by arms 88 and 90 to steering wheels 80 and 82. The 
intermediate section 14 is coupled to the third elongated body section 18 
in the same manner as the first elongated section is coupled to the 
intermediate section, providing a second point of articulation 112, 
employing sections 64' and 66', extending from the intermediate body 
section 14 into third elongated body section 16 and hinge tube 114 
extending transverse of body member 10. 
While any means of driving driven wheels 18, 20, 22, and 24 may be 
employed, there is, as illustrated, presently employed two-speed drive 
motors 116 and 118 mounted outside of the side walls 120 and 122 of the 
cargo storage section 124. A chain and sprocket drive 126 extend from 
motor 116 to corresponding sprocket on axle 128 of driven wheel 22 and by 
chain and sprocket drive 130 to axle 132. Corresponding chain and sprocket 
drives 134 and 138 couple motor 118 to driven wheels 24 and 20. A more 
detailed illustration of useful drive systems is shown in U.S. Pat. No. 
2,962,176, with a system for driving two wheel pairs being shown in U.S. 
Pat. No. 3,185,324, incorporated herein by reference, with particular 
reference being made to FIG. 16 and the related description. Braking is 
accomplished by friction brakes 142 and 144 on either side of the cars. 
Controllers 146 and 148 are coupled to the traction motors to provide 
energy thereto and control the speed of operation. 
While the points of articulation, or hinge points, may vary in location for 
an 18-SC shuttle car, it is preferred that they be, as shown, adjacent to 
and below the line of the common axis of couplings 128 and 136, and 132 
and 140 of the driven wheels 22, 24, 18 and 20 to the shuttle car. 
Alternate systems of articulation are described in U.S. Pat. No. 3,827,720; 
3,880,303 and 3,908,441, each incorporated herein by reference. Another 
preferred location for the points of articulation is coincident with the 
axis of rotation of the driven wheels. Although requiring to be attached 
to their respective intermediate and third elongated body sections, the 
driven wheels may also be ahead of the points of articulation. 
The 18-SC shuttle car modified in accordance with this invention, provides 
two pairs of driven wheels with a point of articulation, or hinge point, 
between the two pairs of driven wheels and another point of articulation, 
or hinge point, between a pair of driven wheels and a pair of steering 
wheels. All wheels may, as described by U.S. Pat. No. 3,302,739, 
incorporated herein by reference, be driven. The axle assemblies may, as 
shown, be secured to the sidewalls of the body sections or extend 
transverse of the body sections, as described in U.S. Pat. No. 3,403,797, 
incorporated herein by reference. 
With respect to the Joy 18-SC cars, cars with existing unaltered discharge 
ends and unaltered loading ends may be adapted for use in accordance with 
the invention by the addition of a 36-inch intermediate body section with 
steering linkage 58, driven wheels 18 and 20, chain and sprocket drives 
130 and 138, and hinge tube 114. 
FIG. 3 illustrates schematically the increased flexibility of the 18-SC 
shuttle car, modified in accordance with this invention, over a variety of 
terrains. The axis of steering wheels 40 and 80 of body sections 12 and 16 
are illustrated as coupled to the points of articulation 70 of body 
section 14 and point of articulation 112 of body section 16. The axis of 
driven wheels 18 and 22 are respectively 132 and 128. The broken lines are 
taken normal to the points of articulation 70 and 112 relative to the 
intermediate and rear sections 14 and 16 to illustrate how they shift with 
changes in terrain. 
As compared to the unmodified cars, the shuttle cars of the invention 
retrofitted with a 36-inch intermediate section providing an extra pair of 
driven wheels and an extra point of articulation conform more readily to 
undulations in the roadway and provide traction under wet conditions where 
the unadapted cars would be unable to operate. 
Without changing the pair of 25 hp, two-speed, constant torque motors 
provided with the car as manufactured, the additional section provides a 
24-cubic foot increase, enabling the coal carrying capacity to be 
increased by one ton and, because of more equal distribution of weight on 
all traction wheels, traction jacks and accumulators previously employed 
to shift weight when traction was lost have been eliminated from the 
hydraulic system. 
The principles of the instant invention may be employed in the design of 
new shuttle cars as well as providing a retrofit intermediate section for 
modification of existing cars to enable the cars to travel where other 
six-wheel shuttle cars having a pair of traction wheels and a single point 
of articulation cannot, in practice, venture.