Abstract:
An outrigger assembly for the support and stabilization of a mobile work machine, such as a vehicle-mounted telescopic belt conveyor, while the machine is operating. The outrigger assembly includes a vertical outrigger leg assembly. The vertical outrigger leg assembly is attached to the end of a horizontally extending member and includes multiple telescopically extendable sections that extend until a support pad is in contact with the work surface, then raise the mobile work machine off of the ground into a stabilized position. The multiple leg sections allow for increased vertical lifting distance, thus improving stability on uneven work surfaces, and allow the outrigger assembly to be used on larger machines.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to an outrigger assembly for stabilizing a mobile work machine. More specifically, the present invention is an outrigger assembly for stabilizing a self-propelled, vehicle-mounted conveyor system used to place concrete or other materials in a desired location where the vertical movement of the outrigger leg is actuated by utilizing multiple cylinders to direct the multiple telescoping leg sections.  
         [0002]     Vehicle-mounted, extendable material placement systems have been in use for some time and are the subject of numerous prior patents. In such vehicles, a telescopic or sectional-unfolding boom extends from a rotating turret attached to the vehicle. The substantial amount of weight extending from the vehicle chassis necessitates the use of outriggers to stabilize the vehicle and prevent the vehicle from tilting or overturning. Extendable material placement systems are most typically utilized during the construction of new buildings. This often requires placement and operation of the vehicle on rough and uneven ground. The use of outriggers increases the footprint of the extendable material placement system thereby making it more stable. For the outrigger legs to properly serve their function, the outrigger legs must have sufficient clearance to fully extend out over the uneven ground.  
         [0003]     Vehicle-mounted, extendable concrete conveyor systems, such as shown in U.S. Pat. No. 4,624,357 has been in use for some time. In such vehicles, a discharge conveyor assembly includes a telescoping boom having its base pivotally mounted to the torque tube of the vehicle chassis. The substantial amount of weight extending from the vehicle chassis necessitates the use of outriggers to stabilize the vehicle and prevent the vehicle from tilting or overturning.  
         [0004]     The most common type of outrigger system includes a plurality of telescoping legs that can each be extended from a stationary housing fixed to the vehicle. An example of this type of outrigger is shown in U.S. Pat. No. 4,949,808. This common outrigger assembly employs multiple horizontal telescoping members. Because both the discharge conveyor assembly and the infeed conveyor assembly are rotatable about a turnable assembly mounted to the vehicle chassis, multiple sections must be used to cover the necessary distance in order to create an outrigger footprint that will achieve the desired stability. In this common type of outrigger design, both the horizontal and vertical travel over the outrigger leg is achieved by a single hydraulic cylinder.  
         [0005]     A vehicle-mounted conveyor system presents unique problems in the design of the outrigger assembly. The outrigger assembly must be mounted to the vehicle in a way such that the conveyor assemblies can rotate about the vehicle without contacting the outrigger assemblies. However, due to the length of the extendable boom contained on the discharge conveyor, a significant amount of weight positioned away from the center of gravity of the vehicle must be supported by the vehicle chassis. Therefore, in addition to being designed to avoid contact with the conveyor assemblies, the outrigger assemblies must extend a sufficient distance from the vehicle chassis in order to provide the required stability for the vehicle. The combination of these two requirements dictates that the height the outriggers at their furthest point from the chassis will be limited. Because of this height limit, a single-stage vertical leg will be very limited in its capability to elevate the entire machine into a stable condition. Additionally, uneven terrain on the job site prevents a stable set up unless the vertical legs were of a telescoping design of multiple cylinders used to drive the multiple leg sections.  
         [0006]     It is an object of the present invention to provide an outrigger assembly for use with a vehicle-mounted conveyor system to provide the required stability of the vehicle while preventing possible contact between the main discharge conveyor assembly and the individual outrigger. Further, it is an object of the invention to provide a vertical outrigger leg for use on rough, unmade, or uneven ground by extending the frame of the machine laterally and lifting the machine vertically. It is another object of the present invention to provide a plurality of outrigger assemblies in which each outrigger assembly is contained within the overall vehicle width when in its completely retracted position. Additionally, it is an object of the present invention to provide an outrigger assembly that includes a multi-section, vertically telescoping assembly to increase the vertical distance the outrigger leg assembly can travel in order to make solid contact with the ground to establish the desired stability.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention is an outrigger assembly for use with a mobile work machine, such as a vehicle-mounted telescopic belt conveyor, to stabilize the machine when the machine is operating. The work machine includes a plurality of the individual outrigger assembly to provide multiple points of stabilization for the vehicle when the extendable conveyor is in use.  
         [0008]     Each outrigger assembly for stabilizing a mobile work machine includes an outer support housing having an open interior, a hydraulic cylinder movable within the outer support housing and having an open interior, and a leg member telescopically positioned within the hydraulic cylinder. The hydraulic cylinder is operatively positioned within the outer support housing and moves between a retracted position within the outer support housing and an extended position. The leg member also moves from a retracted position in which the leg member is contained within the hydraulic cylinder to an extended position. The outer support housing, the hydraulic cylinder, and the leg member are all centered along a common vertical axis and the hydraulic cylinder and leg member move along this vertical axis.  
         [0009]     The hydraulic cylinder and the leg member of the outrigger assembly are each movable by hydraulic pressure supplied through a first hydraulic inlet for movement from the retracted to the extended position and a second hydraulic inlet for movement from the extended to the retracted position. The hydraulic fluid is able to pass from the hydraulic cylinder to the leg member by a hydraulic passage formed in the wall of the hydraulic cylinder.  
         [0010]     The outrigger assembly additionally includes a stationary support housing that is mounted to the concrete placing machine, an inner housing that is telescopically positioned within the stationary support housing, and a drive cylinder, that is operably positioned between the support housing and the inner housing. The drive cylinder is operable to move the inner housing between a retracted position in which the inner housing is positioned within the support housing and an extended position in which the inner housing extends from the stationary support housing. The outrigger assembly is vertically oriented and connected to the extendable end of the inner housing. The drive cylinder, hydraulic cylinder, and leg member are all independently operable such that the hydraulic cylinder and leg cylinder, or both, can be extended while the inner housing is in either the retracted position or the extended position.  
         [0011]     The outrigger assembly of the invention includes a vertically oriented outrigger leg housing having an open interior, a vertically oriented hydraulic cylinder having an open interior and being operably positioned within the support housing, a vertically oriented leg member that is telescopically positioned within the hydraulic cylinder, and an inner housing that is extendably movable relative to the mobile work machine. The outrigger leg housing is aligned along the same vertical axis as the hydraulic cylinder and the leg member and is connected to the distal end of the inner housing.  
         [0012]     In a preferred embodiment of the invention, the inner housing extends from the mobile work machine until the proper extended width is achieved. Both the hydraulic cylinder and the leg member may be extended vertically by use of hydraulic pressure to a ground-engaging position with the support pad mounted at the lower end of the leg member contacting the ground. Further extension of the hydraulic cylinder and the leg member results in the lifting of the vehicle body off the ground to further stabilize the machine during operation. An advantage of the outrigger assembly of the present invention is that it affords greater stabilization for the mobile work machine because of the expanded outrigger leg horizontal reach positions, and increased vertical lift whereby the mobile work machine may be stabilized more effectively in a greater range of ground types and slopes.  
         [0013]     The preferred embodiment of the invention also calls for the implementation of a plurality of outrigger legs attached to the mobile work machine.  
         [0014]     Various other features, objects, and advantages of the invention will be made apparent from the following description taken together with the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     The drawings illustrate the best mode presently contemplated of carrying out the invention.  
         [0016]     In the drawings:  
         [0017]      FIG. 1  is a side elevation view of a self-propelled vehicle including a vehicle-mounted conveyor system and a plurality of outrigger assemblies constructed in accordance with the present invention;  
         [0018]      FIG. 2  is a top plan view of the vehicle illustrated with the outrigger assemblies of the present invention in their fully extended, ground-engaging position;  
         [0019]      FIG. 3  is a rear view of the vehicle with the rear outrigger assemblies in their fully retracted position;  
         [0020]      FIG. 4  is a rear view similar to  FIG. 3  illustrating the outrigger assemblies in their fully extended position;  
         [0021]      FIG. 5  is a section view showing an outrigger assembly of the present invention in its fully retracted position;  
         [0022]      FIG. 6  is a section view of an outrigger leg assembly of the present invention in which the leg member is extended and the hydraulic cylinder is in the retracted position;  
         [0023]      FIG. 7  is a cut away view of an outrigger leg assembly of the present invention in the fully extended, ground-engaging position with both the leg member extended and the hydraulic cylinder extended. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     A mobile work machine, such as a self-propelled vehicle  20  including a vehicle-mounted conveyor system  22  for transporting an aggregate material such as concrete is best shown in  FIGS. 1 and 2 . The vehicle  20  includes a conventional cab  24  and a torque tube  26 . The vehicle  20  is of a size such that it does not exceed the legal dimensional limits for over the highway travel.  
         [0025]     The conveyor system  22  includes an in-feed conveyor assembly  28  that receives the supply of aggregate material, such as concrete, from a supply source  30  and transports the material upward along a moving in-feed conveyor belt. The in-feed conveyor assembly  28  is rotatable about the vehicle  20  such that the in-feed conveyor assembly  28  can receive the supply of material at various locations around the vehicle  20 .  
         [0026]     The conveyor system  22  includes a main turret  32  that is rotatably mounted to the torque tube  26  of the vehicle  20 . A discharge conveyor assembly  34  is pivotally mounted to the main turret  32  about a horizontal pivot axis and also rotates along with the main turret  32 . Specifically, the discharge conveyor assembly  34  includes a telescoping boom  36  having its base end mounted in a cantilever manner to the main turret  32 . The discharge end  38  of the discharge conveyor assembly  34  is extendable away from the main turret  32  to control placement of the conveyed aggregate from the discharge end  38 .  
         [0027]     As can be seen in  FIG. 2 , the vehicle  20  includes a pair of front outrigger assemblies  40   a  and  40   b,  and a pair of rear outrigger assemblies  42   a  and  42   b.  Each of the outrigger assemblies extends from the torque tube  26  in a direction transverse to the longitudinal axis of the vehicle  20 . The outrigger assemblies are operable to elevate the vehicle  20  above the ground and stabilize the vehicle to allow the discharge conveyor assembly  34  to be extended in the manner shown in  FIG. 1 . In general, each of the outrigger assemblies  40   a,    40   b,    42   a  and  42   b  includes identical operating components and function in an identical manner such that the single description of the outrigger assembly below is applicable to each of the outrigger assemblies. The four individual outrigger assemblies shown in  FIGS. 1 and 2  provide the required stabilization for the vehicle  20  during operation of the telescoping boom  36 .  
         [0028]      FIG. 3  illustrates the rear outrigger assembly  42   b  in its fully retracted position. The outrigger assembly  42   b  includes a stationary support housing  44  that is securely mounted to the vehicle chassis and is positioned behind the rear wheels  47  of the vehicle  20 .  
         [0029]     The rear outrigger assembly  42   b  is shown in  FIG. 4  in its fully extended, ground-engaging position. When in the fully extended position, the movable inner housing  46  extends from the stationary support housing  44 . An outrigger leg assembly  48  is securely attached to the outermost end of the inner housing  46 . The outrigger leg assembly  48  includes an outrigger leg housing  54 , a hydraulic cylinder  52 , and a leg member  50 , all of which are vertically aligned along a common central axis  118 . The leg member  50  is telescopically movable into and out of the hydraulic cylinder  52  which, in turn, is telescopically movable into and out of the outrigger leg housing  54 . A support pad  56  is mounted to the leg member  50 . The support pad  56  contacts the ground  60  when the outrigger assembly  42   b  is in its fully extended, ground-engaging position. In addition to the rear outrigger assembly  42   b,    FIG. 4  also illustrates the rear outrigger assembly  42   a  in its fully extended position. The combination of the pair of fully extended rear outrigger assembles  42   a  and  42   b  elevate the rear wheels  47  of the vehicle  20  above the ground  60 , as can be clearly seen in  FIG. 4 .  
         [0030]      FIGS. 5, 6  and  7  illustrate the detailed construction of the rear outrigger assembly  42   b,  although the following description is equally applicable to each of the outrigger assemblies. As previously discussed, the outrigger assembly  42   b  includes the stationary support housing  44  securely connected to the chassis of the vehicle  20 . The support housing  44  is formed from a generally rectangular outer shell  45  constructed from a metallic material, such as steel. In the preferred embodiment of the invention, the support housing  44  has an overall length of approximately 98 inches, which is approximately equal to the width of the vehicle chassis.  
         [0031]     As can be seen in  FIG. 5 , the outer shell  45  of the support housing  44  defines a generally open interior  64  that extends between a closed back end  66  and open-front end  68 . The front end  68  of the support housing  44  includes a reinforcing ridge  70  extending upward from the outer shell  45 . The reinforcing ridge  70  contacts a corresponding reinforcing ridge  72  formed on an outer shell  74  that defines the inner housing  46 .  
         [0032]     As can be seen in the combined views of  FIGS. 2 and 5 , the inner housing  46  is also generally rectangular and defines an open interior  76  extending between an open back-end  78  and an open-front end  80 . As can be understood in  FIGS. 2, 3  and  4 , the inner housing  46  is extendable into and out of the open interior  64  defined by the support housing  44 . Specifically, the inner housing  46  is movable between a retracted position in which nearly the entire inner housing  46  is contained within the support housing  44 , and an extended position in which a substantial portion of the inner housing  46  extends from the support housing  44 , as shown in  FIG. 4 .  
         [0033]     In the preferred embodiment of the invention, the means for moving the inner housing  46  into and out of the support housing  44  is a first drive cylinder  82 . The first drive cylinder  82  is a fluid-actuated cylinder having a cylinder body  84  and an extendable cylinder rod  86 . The cylinder body  84  is contained in the open interior  76  defined by the outer shell  74  of the inner housing  46  and extends between a first end  88  and a second end  89 . The second end  89  of the cylinder body  84  is securely connected by a pivot pin  91  to the inner surface  90  of a support plate  93  at the closed back end  66  of the stationary support housing  44 . Specifically, the pivot pin  91  passes through a mounting block  92  to secure the second end  89  of the cylinder body  84  to the inner surface  90 . In this manner, the cylinder body  84  is securely attached to the stationary support housing  44 .  
         [0034]     The first end  88  of cylinder rod  86  is securely attached to saddle  94  by a mounting pin  96 . The saddle  94  is securely attached to the inner surface  95  of the mounting beam  49 , which is secured to the inner wall of the inner housing  46 . When the first drive cylinder  82  is actuated, the cylinder rod  86  is forced out of the cylinder body  84 , causing the inner housing  46  secured to the first end  88  of the cylinder body  84  to move outward. The inner housing  46  continues to move outward relative to the stationary support housing  44  until the cylinder rod  86  is completely extended. When the cylinder rod  86  is fully extended, the inner housing  46  is in its completely extended position.  
         [0035]     In the preferred embodiment of the invention, the first drive cylinder  82  is a two-directional fluid-actuated cylinder such that the first drive cylinder  82  can be operated in a reverse direction to retract the cylinder rod  86  into the cylinder body  84  and move the inner housing  46  from the fully extended position to the retracted position.  
         [0036]     In the preferred embodiment of the invention, the first drive cylinder  82  is positioned inside the outer shell  74  of the inner housing  46 . Thus, when the inner housing  46  is in its extended position, the first drive cylinder  82  is concealed within the inner housing  46 , as can be seen in  FIG. 4 .  
         [0037]     The outrigger leg assembly  48  is perpendicularly connected to the mounting beam  49 , which is securely attached to the inner surface of the inner housing  46 . The outrigger leg assembly  48  is vertically oriented and is shown in its completely retracted position in  FIG. 5  and in its extended position in  FIG. 7 . The outrigger leg assembly  48 , and specifically the hydraulic cylinder  52  and leg member  50 , is vertically movable along the common vertical axis  118  from the retracted position ( FIG. 5 ) to the extended ground-engaging position ( FIG. 7 ) in which the support pad  56  contacts the ground  60 . The support pad  56  is connected to a first end  50   a  of leg member  50 . The second end  50   b  of the leg member  50  is movably positioned within hydraulic cylinder  52 .  
         [0038]     As shown in  FIG. 7 , the hydraulic cylinder  52  has a first end  52   a  and a second end  52   b  and is movably positioned within outrigger leg housing  54 . The hydraulic cylinder  52  is further comprised of an outer wall  52   c  having a hydraulic passage  102  disposed within the outer wall  52   c  and an open interior  98  surrounded by the outer wall  52   c.    
         [0039]     The outrigger leg housing  54  generally includes a bottom end  54   a,  a top end  54   b,  and an outer wall  54   c.  The outer wall  54   c  defines an open interior  100 . The outer wall  54   c  includes a first hydraulic inlet  58  and second hydraulic inlet  60  connected to the outrigger leg housing  54  at top end  54   b  and bottom end  54   a  respectively. A first hydraulic channel  59  passes through outer wall  54   c  connecting the first hydraulic inlet  58  to the open interior  100  and a second hydraulic channel  61  connects second hydraulic inlet  60  to a first hydraulic cavity  104 . As shown in  FIG. 6 , the first hydraulic cavity  104  is defined as the space between the second end  52   b  of the hydraulic cylinder and the bottom end of the outrigger leg housing  54   a.    
         [0040]     In the preferred embodiment of the invention, the means for moving the leg assembly  48  from its retracted position depicted in  FIG. 5  to its extended position depicted in  FIG. 7  is hydraulic pressure. Starting in the retracted position depicted in  FIG. 5 , hydraulic fluid is pumped through first hydraulic inlet  58  and first hydraulic channel  59  of leg assembly  48  into the open interior  100 . As the pressure within the open interior  100  increases, the pressure is displaced against the second or top ends of the leg member  50   b  and the hydraulic cylinder  52   b.  A first cylinder seal member  108  and a second cylinder seal member  112  allow the hydraulic pressure in the open interior  100  to force the hydraulic cylinder  52  to telescope out of the outrigger leg housing  54  and the leg member  50  to telescope out of the hydraulic cylinder  52 .  
         [0041]     As shown in  FIG. 6 , the leg member  50  continues to extend until the first end  52   a  of the hydraulic cylinder  52  comes in contact with the second end  50   b  of the leg member  50 . As shown in  FIG. 7 , the hydraulic cylinder  52  also continues to extend until the second end  52   b  of the hydraulic cylinder comes in contact with the bottom end  54   a  of the outrigger leg housing  54  and the outrigger leg assembly is in its fully extended position. The hydraulic pressure is maintained in the open interior  100  while the outrigger leg  48  is extended by the first cylinder seal  108  located between the outer surface of the second end  52   b  of the hydraulic cylinder and the inner surface of the outrigger leg housing outer wall  54   c.  A cylinder seal  112  is positioned between the outer surface of the leg member second end  50   b  and the inner surface of the hydraulic cylinder outer wall  52   c.    
         [0042]     In the preferred embodiment of the invention, the leg assembly  48  also moves from its fully extended position depicted in  FIG. 7  to its retracted position depicted in  FIG. 5  by means of hydraulic pressure. To effect such movement, hydraulic fluid is pumped into the second hydraulic inlet  60  and through the outrigger leg housing outer wall  54   c  by means of the second hydraulic channel  61 . The supply of hydraulic fluid is received in the first hydraulic cavity  104 , as shown in  FIG. 7 . As the hydraulic pressure within the first hydraulic cavity  104  increases, the pressure is exerted on the hydraulic cylinder second end  52   b,  forcing the hydraulic cylinder  52  to retract into the open interior  100  of the outrigger leg housing  54 . As the hydraulic cylinder  52  retracts into outrigger leg housing  54 , the first hydraulic cavity  104  increases in volume. Hydraulic pressure is maintained in the first hydraulic cavity  104  due to the first cylinder seal  108  and a second cylinder seal  110 . The second cylinder seal  110  is between the interior surface of the outrigger leg housing bottom  54   a  and the outer surface of the hydraulic cylinder outer wall  52   c.  As the hydraulic cylinder  52  is retracted, hydraulic fluid is allowed to flow out of the open interior  100  through the cavity  59  and the inlet  58 .  
         [0043]     When the hydraulic cylinder  52  sufficiently retracts into the open interior  100  of the outrigger leg housing  54 , the inflow end  116  of hydraulic passage  102  connects to the first hydraulic cavity  104  and allows hydraulic fluid to flow from the first hydraulic cavity  104  to a second hydraulic cavity  106  located between the bottom surface of the leg member second end  50   b  and the top surface of the hydraulic cylinder first end, as shown in  FIG. 6 . As the hydraulic pressure within the second hydraulic cavity  106  increases, the leg member  50  is retracted into the open interior  98  of the hydraulic cylinder  52 . As the hydraulic pressure within the first hydraulic cavity  104  and the second hydraulic cavity  106  continues to increase, the hydraulic cylinder  52  and the leg member  50  are further retracted into the open interiors  100  and  98 . As discussed, the hydraulic fluid that had been residing in the open interiors  100  and  98  is forced back through the first hydraulic channel  59  and the first hydraulic inlet  58 .  
         [0044]     Although the first drive cylinder  82 , the outrigger leg housing  54  and the hydraulic cylinder  52  are shown and described as being fluid-driven cylinders, it is contemplated by the inventors that each of these cylinders could be replaced by an equivalent means for driving the inner housing  46 , the hydraulic cylinder  52 , and the like member  50  between their extended and retracted positions. For example, it is contemplated by the inventors that a rotating screw drive mechanism, air cylinder, or other equivalent structure could replace the fluid-driven cylinders shown.  
         [0045]     In the preferred embodiment of the invention the outrigger assemblies  40   a,    40   b,    42   a,  and  42   b  operate as discussed above utilizing a single source of hydraulic pressure. This results in optimal operation of the outrigger assembly during use upon ground of a varying elevation. When the outrigger assemblies  40   a,    40   b,    42   a,  and  42   b  begin to extend from their fully retracted position, hydraulic pressure will be supplied to each assembly evenly and the leg members  50  and hydraulic cylinders  52  will extend evenly. However, once a support pad  56  of one of the outrigger leg assemblies  40   a,    40   b,    42   a,  and  42   b  contacts the ground, it will require less pressure to extend the other outrigger leg assemblies. The outrigger leg assembly in contact with the ground will stop extending while the other outrigger leg assemblies continue to extend until all of the support pads are in contact with the ground. The pressure required to extend each of the outrigger leg assemblies will then be even and the mobile work machine  20  will rise and be supported in a level fashion despite the uneven extension of each of the outrigger leg assemblies. This maintains the mobile work machine&#39;s center of gravity between the outrigger leg assemblies, thus ensuring the stability of the mobile work machine  20  in its raised position, despite the ground underneath each outrigger leg assembly being of a different elevation.  
         [0046]     Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regard as the invention.  
         [0047]     While the invention has been described with reference to a preferred embodiment, those skilled in the art will appreciate that certain substitutions, alterations and omissions may be made without departing from the spirit thereof. Accordingly, the foregoing description is meant to be exemplary only and should not be deemed limitative on the scope of the invention set forth with the following claims.