GB1576166A

GB1576166A - Undercarriage for adverse terrain vehicle

Info

Publication number: GB1576166A
Application number: GB5243077A
Authority: GB
Original assignee: Standard Manufacturing Co; Standard Manufacturing Co Inc
Current assignee: Standard Manufacturing Co; Standard Manufacturing Co Inc
Priority date: 1977-09-22
Filing date: 1977-12-16
Publication date: 1980-10-01
Also published as: BE864767A; CA1091267A; JPS5451129A; DE2820723A1; AU512377B2; FR2403898B1; FR2403898A1; AU3070977A

Description

(54) UNDERCARRIAGE FOR ADVERSE TERRAIN VEHICLE (71) We, STANDARD MANUFAC TURING COMPANY, INC., a Corporation organised under the laws of the State of Texas, of 4012 West Illinois, Dallas, Dallas County, Texas, U.S.A. do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates generally to undercarriages for adverse terrain vehicles, and more particularly to a detachable undercarriage having either three or four tired wheels which may be utilized to support and propel virtually any type of mechanism.

Traditionally, adverse terrain vehicles have been track type vehicles. For example track type bulldozers, loaders, cranes, and similar devices have been known for decades. In some instances track type mechanisms of this type have utilized undercarriages to support and propel the mechanism. Such an undercarriage may comprise a frame for attachment to the mechanism, structure mounted on the frame for guiding a track around a predetermined course, and a drive motor for actuating the track around the course and thereby propelling the mechanism supported by the undercarriage.

More recently, adverse terrain vehicles utilizing tired wheels have been developed.

For example, see U.S. Patent Number 3,799,362 granted to Applicants herein on March 26, 1974. However, there has not heretofore been provided an undercarriage whereby a tired type vehicular supporting and propelling apparatus adapted for adverse terrain usage could be adapted to virtually any type of mechanism. It has also been found to be desirable to provide a tired type adverse terrain undercarriage having greater load carrying capacity than has been available heretofore.

The present invention comprises a detachable undercarriage for adverse terrain vehicles which overcomes the foregoing and other problems long since associated with the prior In accordance with the present invention, there is provided an undercarriage assembly for supporting and propelling a mechanism, comprising an elongate hollow load-bearing frame adapted for connection to the mechanism; at least three axle members each having a wheel receiving member at one end thereof; at least three wheel members each mounted on and secured to the wheel receiving end of one of the axle members; means rotatably supporting the axle members at longitudinally spaced points along the frame with each of the axle members extending through the frame and being rotatably supported in opposite sides of the frame; the middle wheel member or members extending below a plane lying tangent to the bottoms of the endmost wheel members to facilitate, when fixed to the mechanism and in use, skid steering of the mechanism; transmission means including sprockets and chains positioned within the frame and drivingly interconnecting at least two of the axle members; and drive means including a motor mounted on the frame and operably connected to the transmission means for actuation thereof whereby the drive means and the transmission means cause concurrent rotation of the interconnected axle members.

Either three of four nonaligned axle members carrying wheels of equal diameters can be utilized. In the case of three axle members the center axle member and in the case of four axle members the center two axle members rotate about axes situtated below a plane extending through the axes of rotation of the endmost two axle members. This facilitates the skid steering of the mechanism supported and propelled by the undercarriage, while simultaneously making wheels carried by all of the axle members available for ground contact under adverse terrain condi tions. If desired, structure may be provided for bringing all of the axle members into alignment in order to provide increased stability.

Either three or four aligned axle members carrying wheels of unequal diameters can be utilized. The center axle in the case of three axle members and the center pair of axles in the case of four axle members carry wheels relatively larger than those carried by the endmost axle members. The same result is accomplished, namely the facilitation of skid steering of the mechanism supported and propelled by the undercarriage with the concurrent availability for ground contact under adverse terrain conditions of all the wheels.

In accordance with still other aspects of the invention, the frame is a hollow load-bearing structure comprised of structural members around its entire periphery and throughout its entire length. This facilitates attachment of a mechanism to the undercarriage at any point along the entire length and around the entire periphery of the frame. The positioning of the hydraulic or electric motor relative to the frame can be varied in order to vary the spacing between the axle members. The motor is preferably drivingly connected to one of the axle members by means of a first drive sprocket connected to the output of the motor, a second drive sprocket connected to one of the axle members, and a drive chain interconnecting the two drive sprockets.

A more complete understanding of the invention may be had by referring to the following Detailed Description when taken in conjunction with the accompanying drawings, wherein: Figure 1 is a side view of an undercarriage for an adverse terrain vehicle incorporating a first embodiment of the invention; Figure 2 is a top view of the undercarriage shown in Figure 1 in which certain parts have been broken away more clearly to illustrate certain features of the invention; Figure 3a is an enlarged horizontal sectional view of the rear portion of the undercarriage of Figure 1; Figure 3b is an enlarged horizontal sectional view of the front portion of the uncercarriage of Figure 1, and comprising a continuation of Figure 3a; Figure 4 is a side view of a first modification of the undercarriage of Figure 1; Figure 5 is a side view of a second modification of the undercarriage of Figure 1; Figure 6 is a side view of the speed shifter assembly mounted on the hydraulic motor of the undercarriage of Figure 1; Figure 7 is a side view of the undercarriage for an adverse terrain vehicle incorporating a second embodiment of the invention; Figure 8 is a top view of the undercarriage shown in Figure 7; Figure 9 is a diagrammatic illustration of a portion of a hydrostatic drive control apparatus useful in conjunction with the present invention; Figure 10 is a detail of a wheel height adjustment assembly which may be used in conjunction with the invention; Figure 11 is an illustration of the application of the invention to a front-end loader; Figure 12 is an illustration of the application of the invention to a front-end loader with a backhoe; Figure 13 is an illustration of the application of the invention to a mobile drilling rig; Figure 14 is an illustration of the application of the invention to a backhoe; Figure 15 is a side view of a third modification of the undercarriage of Figure 1; Figure 16 is a top view of the undercarriage shown in Figure 15 in which certain parts have been broken away to illustrate more clearly certain features of the inven tion Figure 17 is a side view of an undercarriage for an adverse terrain vehicle incorporating a third embodiment of the invention; Figure 18 is a side view of an undercarriage for an adverse terrain vehicle incorporating a fourth embodiment of the invention; Figure 19 is an enlarged horizontal sectional view of the carriage of Figure 1 having an alternative drive system; Figure 20 is an illustration of the application of the invention to a power loader; Figure 21 is an illustration of the application of the invention to a power loader of heavier duty than that of Figure 19; Figure 22 is an illustration of the application of the invention to a power loader having a knuckle boom crane; and Figures 23 and 24 are illustrations of the application of the invention to a rotary drilling rig vehicle.

Referring now to the Drawings, and particularly to Figures 1 and 2 thereof, there is shown a detachable undercarriage for an adverse terrain vehicle 10 incorporating the invention. Normally, of course, a pair of parallel undercarriages 10 are employed to support the adverse terrain vehicle. The under carriage 10 consists of an elongate hollow load-bearing frame 12. Frame 12 is formed entirely of a material such as steel characterized by high strength and rigidity to permit attachment of undercarriage 10 to virtually any type of mechanism by connections at selected points along the entire length and around the entire periphery of frame 12. A related feature of this structure is greater load carrying capacity. Furthermore, frame 12 can be of sealed construction so that it can serve as a lubricant reservoir, if desired, as well as a structural member.

Drain pluts 14 and 16 are located at the bottom and outside surfaces, respectively, of frame 12 to facilitate draining or replenish ing of lubricants therein.

The undercarriage 10 is supported by three tired wheels 18; the three wheels including a forward wheel 20, a middle wheel 22, and a rear wheel 24. The wheels 18 are of equal diameter and include tires of either a solid or a pneumatic type. Wheels 18 rotate about axles 26. Preferably all three wheels 18 are positioned on the same side of frame 12; however, depending on the particular adverse terrain vehicle, it may be desirable to locate one wheel 18 on the opposite side of frame 12. Preferably, axles 26 extend completely through frame 12 and are rotatably supported within both adjacent vertical surfaces of frame 12.

Also included in undercarriage 10 is drive assembly 28. Drive assebly 28 incorporates a motor 30 which can be of a dual speed variety in that structure is provided within motor 30 for selecting either a high or low speed range of operation. Such selection is effected by manipulation of lever 32. Alternatively, motor 30 can be of the constant speed variety. In addition, motor 30 can be of the electric or the hydraulic types. Referring momentarily to Figure 6 in conjunction with Figures 1 and 2, undercarriage 10 is provided with a fluid operated cylinder 34 having a piston 36 connected to lever 32 by means of link 38. Cylinder 34 is adapted for operation from a remote point, such as the operator's compartment of an adverse terrain vehicle incorporating undercarriage 10, to selectively place motor 30 in the desired operational range.

Referring again to Figures 1 and 2, motor 30 is connected directly to speed reducer 40, which can be a multiple or constant speed type. Speed reducer 40 is slidably mounted on frame extension 42 by means of bolts 44.

Frame extension 42 extends upwardly from the inside rearward top surface of frame 12 and speed reducer 40 is bolted substantially perpendicular thereto. Speed reducer 40 has output shaft 46 to which drive sprocket 48 is attached by means of setscrew 49, as is best shown in Figure 3a. If, for example, motor 30 is of the hydraulic type, motive energy is received from the output of remotely located hydraulic pumps (not shown) driven by an engine mounted on the adverse terrain vehicle to which undercarriage 10 is attached.

The power transmission by means of the pressurized hydraulic fluid from the aforementioned pumps, or from a remote power source (not shown) in the case of an electric motor, to motor 30 and hence to drive sprocket 48 through speed reducer 40 comprises the hydrostatic drive system which functions to both propel and steer undercarriage 10.

Motive power is first applied to drive sprocket 48 which is constrained to second sprocket 50 by means of chain 52. Chain 52, which is constrained around drive sprocket 48 and second sprocket 50, serves to transfer rotative movement to axle 26, upon which first sprocket 50 is mounted. Sprockets 48 and 50 and chain 52 are totally enclosed in a sealed housing 54 which is detachably secured to both frame extension 42 and frame 12. Housing 54 serves not only to protect these parts of the drive system, but more importantly, can constitute a reservoir for lubricant in which chain 52 and sprockets 48 and 50 continuously operate. Accordingly, drain plug 56 is provided at the rearward lower end of housing 54.

A tension adjusting means for chain 52 is provided in bolt 58. Bolt 58 is threadably mounted on brace 60 and acts in compression directly against the collar of speed reducer 40, which is slidably mounted on frame extension 42. Thus, by either clockwise or counterclockwise rotation of bolts 58, tension in chain 52 may be varied.

Motor 30 is in direct operative relationship with the forward, middle and rearward wheels, 20, 22, and 24, respectively, of undercarriage 10. Constituting part of the drive system, axle 26 of rear wheel 24 receives power by means of first sprocket 50 which is connected to drive sprocket 48 by means of chain 52. Also attached to axle 26 of rear wheel 24 is sprocket 62. Sprocket 62 is coupled by means of chain 64 to sprocket 66, which is connected to the axle 26 of middle wheel 22. Sprocket 68 is also attached to the axle 26 of the middle wheels 22 of the set, and in turn is coupled by means of chain 70 to sprocket 72. Sprocket 72 is secured to the axle 26 of the forward wheel 20 of the set, whereby motor 30 is operatively connected to all three wheels 18 on undercarriage 10.

Tension adjustment assemblies 74 are provided for assuring proper tension in chains 64 and 70.

In order to arrest movement of undercarriage 10, brake assembly 76 is provided.

Brake assembly 76 consists of a brake disc 78 and three caliper assemblies 80. Turning momentarily to Figure 3b in conjunction with Figures 1 and 2, caliper assemblies 80 (only one of which is shown) are anchored to frame extension 82 by means of bolts 84.

Consequently, the caliper assemblies 80 remain stationary at all times, while the brake disc 78, which is secured to axle 26 of the middle wheel 22, rotates therewith. Specifically, brake disc 78 rotates within the slots of the three caliper assemblies 80 which house the brake pucks and their hydraulic actuating cylinders. To arrest movement of the undercarriage 10, the actuating cylinders cause the pucks to frictionally engage discs 78. By means of chains 64 and 70, this braking force is directly transmitted to the rearward and forward wheels, 24 and 20, respectively. In this manner, the force of one brake assembly 76 is simultaneously applied to all wheels on the undercarriage 10. It will be noted that brake assembly 76 is disposed to the interior of axle spindle 86, to which wheel rim 88 is secured by threaded lugs 90. This location for brake assembly 76 is advantageous in that it affords protection from dirt, rocks, mud, or other debris typically encountered by an adverse terrain vehicle.

Middle wheel 22 protrudes below a plane 92 extending tangent to the bottom surfaces of the wheels 18 comprising the forward wheel 20 and the rear wheel 24. This fact embodies a significant feature of the present invention. A relatively short wheelbase is desirable because it facilitates skid steering of the vehicle. However, this advantage is offset by decreased overall vehicle stability, which is especially troublesome in the case of an adverse terrain vehicle with variable loading arrangements. In contrast, a longer wheelbase affords maciximum vehicle stability but does not permit effective skid steering.

The present invention economically and simply accomplishes the objectives of both short and long wheelbases by means of a lower middle wheel 22. For example, when operated over a hard, smooth surface, undercarriage 10 will be able to rock either forwardly or backwardly, depending upon the location of the center of gravity and the loading characteristics of the particular adverse terrain vehicle. The vehicle rests on only two wheels at any given moment, while an end wheel remains available for stabilization. Therefore, the wheelbase of the vehicle will comprise the distance between the middle wheel 22 and one of the endmost wheels, either 20 or 24. Consequently, the effort required to effect skid steering of the vehicle is substantially reduced over that which would be required if the wheelbase always comprised the distance between the endmost wheels 20 and 24. At the same time, the rocking feature of undercarriage 10 allows instant utilization of the stability inherent in a longer wheelbase.

Assume now that the vehicle to which undercarriage 10 is attached is operated over a softer surface, such as sand, mud or loose dirt. All three tired wheels 18 will engage the adverse surface because they will sink into the adverse surface until vehicle flotation occurs. Superior traction, stability and maneuverability will be achieved since each wheel 18 directly contacts the surface, and all wheels 18 are drivingly interconnected.

Furthermore, total pressure under any individual wheel is substantially reduced, which lessens surface rutting as well as the vehicle's susceptibility to bogging down.

Turning now to Figures 3a and 3b, there is shown in detail the drive system for undercarriage 10. Motor 30 is coupled to speed reducer 40. Speed reducer 40 is attached to frame extension 42 by means of bolts 94 in conjunction with nuts 96. By means of slots 98, speed reducer 40 is adapted for slidable movement relative to frame extension 42 when acted upon by tension adjusting bolt 58, which is best shown in Figure 1. Attached to the output shaft 46 of the speed reducer 40 is sprocket 48. Setscrew 49 secures sprocket 48 to output shaft 46. Chain 52 in turn connects sprocket 48 to sprocket 50. Sprocket 50 is affixed to axle 26 of rear wheel 24 by means of nut 100. It will be noted that all three axles 26 are rotatably supported by the inner bearing assemblies 102 and outer bearing assemblies 104. Inner bearing assemblies 102 are supported by cups 106 which are detachably secured to frame 12 by means of bolts 108. In contrast, outer bearing assemblies 104 are permanently affixed to frame extensions 82 of frame 12.

Sprocket 62 is also attached to axle 26 of rear wheel 24 by means of keyway 110, thus sprocket 62 rotates in unison with sprocket 50. Sprocket 62 in turn is connected by means of chain 64 to sprocket 66, which is secured to axle 26 of middle wheel 22 by means of a keyway 112. Located substantially adjacent to sprocket 66 and also attached to axle 26 of middle wheel 22 by means of keyway 112 is sprocket 68. Chain 70 is constrained for rotation around sprockets 68 and 72. Sprocket 72 is affixed to axle 26 of forward wheel 20 by means of keyway 114. Consequently motor 30 is directly connected by a series of sprockets and chains to each wheel 18 of undercarriage 10.

The tension in chains 64 and 70 is adjusted by means of forward and rear tension adjustment assemblies 74. Tension adjustment assemblies 74 include idler sprocket 116 which engage the slack or return sides of either chain 64 or 70. Idler sprocket 116 is rotatably connected to pin 118 by means of journal bearing 120. The pin 118 which rotatably supports idler sprocket 114 is disposed and secured between two vertical adjacent wall surfaces of slider assembly 122.

Slider assembly 122 is constrained for vertical movement by stops 124 and 126. Vertical movement of slider assembly 122 is accomplished by means of adjustable screws 128.

Either clockwise or counterclockwise movement of adjustable screws 128 serves to displace slider assembly 122 vertically, whereby idler sprocket 116 engages idler chains 64 or 70 so as to change the tension therein. For example, if idler sprocket 116 of forward tension adjustment assembly 74 were manipulated in a vertical direction, it would engage chain 70 so as to cause a small but significant increase in the effective travel distance thereof. This in turn would cause chain 70 to experience an increase in tension, because it is of substantially fixed length.

Protective covers 130 are provided to protect the inward ends of axles 26 of forward wheel 20 and middle wheel 22. Covers 130 are secured to bearing cup 106 by means of screws 132. Consequently, all inward ends of axles 26 on undercarriage 10 are shielded from rocks, dirt, mud, or other hazards to be found in the terrain over which the adverse terrain vehicle is likely to operate.

The foregoing description was directed to the preferred construction of undercarriage 10 wherein each wheel 18 is interconnected by a series of sprockets and chains. However, it will be understood that undercarriage 10 can be operated with other transmission means, such as gears or other means; and such that motor 30 is drivingly connected to less than all of the wheels 18. For example, motor 30 can be drivingly connected to rear wheel 24 and middle wheel 22 only, thereby eliminating the need for sprockets 68 and 72, chain 70, and forward tension adjustment assembly 74 all of which serve to intercon nect forward wheel 20 and middle wheel 22.

Referring now to Figures 4 and 5, there are shown two modifications of the three wheel undercarriage for an adverse terrain vehicle 10. Referring particularly to Figure 4, there is shown an alternative position for the hydrostatic drive assembly 28. The position illustrated in Figure 4 is higher and more rearward than that depicted in Figures 1 and 2, but still disposed substantially between rear wheel 24 and middle wheel 22. The wheel spacing in Figure 4 is relatively closer than that shown in Figures 1 and 2. Figure 5 illustrates another alternative position for hydrostatic drive assembly 28 which permits reduced wheel spacing of undercarriage 10 over that shown in Figure 4. In this modification, drive assembly 28 is mounted on rear frame extension 134. The closer wheel placement permitted by the modifications appearing in Figures 4 and 5 facilitates skid steering of undercarriage 10 because the effort required is substantially reduced over that which would be required if the wheel base were longer. Accordingly, not only are the power requirements for steering the vehicle lowered, but overall vehicle response is improved. Moreover, the feature of being able to vary the wheel spacing and/or the hydrostatic drive housing location consider ably enhances the adaptability of undercar riage 10 to virtually any type of adverse terrain vehicle.

Referring now to Figures 15 and 16, there is shown another modification of the three wheel undercarriage for an adverse terrain vehicle 10. At least two significant features attend this modification. First, instead of supporting hydrostatic drive assembly 28 with a frame extension attached to the top surface of frame 12, drive assembly 28 is slidably mounted directly on the rear portion of frame 12. Frame 12 in Figures 15 and 16 includes an integral raised rear portion which serves to house and protect sprockets 48 and 50, and drive chain 52. Besides eliminating the need for a separate housing to protect these parts of the drive system, placement of drive assembly 28 on the side of frame 12 opposite wheels 18 makes it less vulnerable to flying rocks, dirt, mud and objects likely to be picked up by the wheels of the vehicle. In addition, this location for drive assembly 28 allows a lower profile which further enhances ,adaptability of undercarriage 10 to various types of adverse terrain vehicles. Bolt 58 is threadably mounted on brace 60 which is now attached directly to the rear top and side portions of frame 12. Bolt 58 acts in tension directly on the collar of speed reducer 40 to serve as a tension adjusting means for chain 52. The absence of brake assembly 76 secured to middle wheel 22 comprises the second feature of the modification illustrated in Figures 15 and 16. Instead, brake assembly 133 is positioned directly between motor 30 and speed reducer 40. Brake 133 may be of the AUSCO brand fail-safe type produced by Auto Specialties Manufacturing Co. of St.

Joseph, Michigan. It has been found that placement of brake 133 in drive assembly 28 requires lower braking effort which results in increased brake efficiency. If desired, access plates (not shown) can be located in the upper surface of frame 12 above the axles for wheels 18. In all other respects undercarriage 10 with the modification shown in Figures 15 and 16 operates as was described above.

Referring now to Figures 7 and 8, there is shown an undercarriage for an adverse ter rain vehicle 136 incorporating a second embodiment of the invention. The undercar riage 136 incorporates numerous component parts which are substantially identical in con struction and operation to the component parts of undercarriage 10 illustrated in Figures 1 and 2. Such identical component parts are designated in Figures 7 and 8 with the same reference numeral utilized in the description of the undercarriage 10, but are differentiated therefrom by means of a prime prime (') designation.

The primary differentiation between undercarriage 10 and undercarriage 136 is the fact of a four tired wheel embodiment, wherein wheel 138 is the fourth wheel. The extra wheel 138 is in fact another middle wheel. The middle wheels 22' and 138 extend below plane 92' which is tangent to the bottom surfaces of wheels 20' and 24'.

All wheels 18' are of equal diameter and includes tires of either a solid or a pneumatic type. However the addition of lower middle wheel 138 requires the addition of two more sprockets, 140 and 144, and another chain 142, and may necessitate an additional brake assembly 76' In many respects similar to the three wheel configuration, the transmission of power in the four wheel configuration shown in Figures 7 and 8 proceeds as follows. The hydrostatic drive assembly 28' is mounted on the rearmost upper surface of undercarriage 136 and includes motor 30'. Motor 30' is connected directly to speed reducer 40'.

Attached to the output shaft 46' of speed reducer 40' is sprocket 48'. Chain 52' is constrained for rotation about sprockets 48' and 50'. Sprocket 50' in turn is secured to the axle 26' of rear wheel 24'. Also attached to the axle 26' of rear wheel 24' is sprocket 62'.

Connected by chain 64', sprocket 66' is constrained to rotate in unison with sprocket 62'.

Sprocket 66' is mounted on axle 26' of middle wheel 22', as is sprocket 68'. Chain 142 in turn connects sprocket 140, which is affixed to axle 26' on second middle wheel 138, and sprocket 68'. Sprocket 144, which is also attached to axle 26' of second middle wheel 138, is connected by means of chain 70' to sprocket 72' which is mounted on axle 26' of forward wheel 20'. Thus, it is apparent that motor 30' is in direct mechanical communication with all four wheels of undercarriage 136 by virtue of the aforementioned arrangement of sprockets and chains. It will be understood that undercarriage 136 can be operated where motor 30' is drivingly connected to fewer than all four wheels. Note also that hydrostatic drive guard 146 is provided at a rearward lower position on undercarriage 136 adjacent to drive assembly 28' so as to protect it from the hazards of operation over adverse terrain. In all other aspects, the four wheel embodiment illustrated in Figures 7 and 8 operates substantially the same as the three wheel embodiment shown in Figures 1 and 2.

In certain applications, it may be desirable to adjust the height of an end wheel of undercarriage 10, or one or both end wheels of undercarriage 136. Referring now to Figure 10, there is shown a wheel height adjustment assembly 148. Adjustment assembly 148 comprises a subframe 150 which is pivotally attached to frame 12 at pin 152. The outside vertical walls of subframe 150 are interposed between the inside vertical walls of frame 12 so as to allow connection at, and pivotal movement about, pin 152. A hydraulic cylinder 154 is attached at one end to a frame 156 mounted on frame 12, and at the other end to a frame 158 mounted on subframe 150. A boot 160 of highly resilient, flexible material is securely attached to seal the gap existing between frame 12 and subframe 150. When actuated, cylinder 154 causes subframe 150 to pivot downwardly about pin 152 so as to bring into alignment the axes of rotation of wheels 18. Turning momentarily to Figures 1 and 2 in conjunction with Figure 10, it will be seen that provision has been made for the incorporation of one wheel height adjustment assembly 148 in the three wheel embodiment shown therein, at the location indicated by arrow 148a. Wheel height adjustment assembly 148 is positioned between forward wheel 20 and middle wheel 22. Upon actuation of hydraulic cylinder 154, subframe 150 will pivot downwardly about pin 152 so as to bring the axes of rotation of wheels 20, 22 and 24 into alignment.

In contrast to the three wheel embodiment of undercarriage 10, two wheel height adjustment assemblies 148, indicated by arrows 147 and 149, can be incorporated in the four wheel embodiment of undercarriage 136. Having reference momentarily to Figures 7 and 8 in conjunction with Figure 10, it will be seen that forward wheel height adjustment assembly 148 is located between forward wheel 20' and middle wheel 138, while rear wheel height adjustment assembly 148 is positioned between rear wheel 24' and middle wheel 22'. Upon actuation of hydraulic cylinder 154 of forward wheel height adjustment assembly 148, subframe 150 will pivot downwardly to bring into alignment the axes of rotation of the forward three wheels of undercarriage 136. Similarly, the axes of rotation of the rearward three wheels of undercarriage 136 embodiment of the invention. The undercarriage 210 includes numerous component parts which are substantially identical in construction and operation to the component parts of undercarriage 10 illustrated in Figures 1 and 2. Such identical component parts are designated in Figure 17 with the same reference numeral utilized in the description of undercarriage 10, but are differentiated therefrom by means of a double prime (") designation.

The primary distinction between undercarriage 210 and undercarriage 10 is the fact of a three tired wheel embodiment wherein the diameters of the wheels 18" are not identical. More particularly, middle wheel 22" is of relatively larger diameter than are the endmost wheels 20" and 24". Additionally, each wheel 18" rotates about an axle lying on a common line of centers, which is denoted by line 212. Thus, larger middle wheel 22" still protrudes below the plane 92" extending tangent to the bottom surfaces of forward wheel 20" and rear wheel 24", but for completely different reasons than its counterpart in undercarriage 10.

The fact of an aligned larger center wheel comprises a significant feature of this embodiment. The objectives of both a short and a long wheel base is accomplished by means of larger middle wheel 22". For example, when operated over a hard, smooth surface undercarriage 210 will be able to rock either forwardly or backwardly, depending upon the location of the center of gravity and the loading characteristics of the particular adverse terrain vehicle. The vehicle rests on only two wheels at any given moment, while the other wheel remains available for stabilization. Consequently, the wheel base of the vehicle when operated over a hard, smooth surface is the distance between wheel 22" and one of the endmost wheels, either 20" or 24". The effort required to effect skid steering of the vehicle is substantially reduced with a shorter wheel base, while the rocking feature of undercarriage 210 allows recourse to the stability inherent with a longer wheel base. It wil be noted that if middle wheel 22" includes a pneumatic tire, the partial deflation thereof wil serve to neutralize the rocking feature and bring all three wheels 18" into contact with the hard, smooth surface to improve vehicle traction and stability. Conversely, greater inflation of middle wheel 22" will serve to augment the rocking feature, if desires. Of course, during operation of undercarriage 210 over a softer surface, all three tired wheels 18" engage the adverse surface because they will sink into the surface until vehicle flotation occurs. Moreover alignment of the axles of wheels 18" improves the vehicle performance over both hard and soft surfaces by reducing porpoising and other control problems associated with multiple nonaligned drive wheels. The power transmission and other aspects of the aligned three wheel embodiment ilustrated in Figure 17 are substantially identical to that of the nonaligned three wheel embodiment shown in Figures 1 and 2, and the modification thereof, which were discussed hereinbefore.

Turning now to Figure 18, there is shown an undercarriage for an adverse terrain vehicle 230 incorporating a fourth embodiment of the invention. The undercarriage 230 includes numerous component parts which are substantially identical in construction and operation to the component parts of undercarriage 136 illustrated in Figures 7 and 8. Such identical component parts are designated in Figure 18 with the same reference numeral utilized in the description of undercarriage 136, but are differentiated therefrom by means of a triple prime ("') designation.

The primary distinction between undercarriage 230 and undercarriage 136 is the fact of a four tired wheel embodiment wherein the diameters of the wheels 18"' are not identical. More particularly, middle wheels 22"' and 232 are of relatively larger diameter than are the endmost wheels 20"' and 24"'. Additionally, each wheel 18"' rotates about an axle lying on a common line of centers, which is denoted by line 234.

Thus, larger middle wheels 22"' and 232 protrude below the plane 92"' extending tangent to the bottom surface of forward wheel 20"' and rear wheel 24"', but for completely different reasons than their counterparts in undercarriage 136.

The fact of aligned larger center wheels comprises a significant feature of this embodiment. The objectives of both a short and a long wheel base is accomplished by means of larger middle wheels 22"' and 232. For example, when operated over a hard, smooth surface, undercarriage 230 will be able to rock either forwardly or backwardly, depending upon the location of the center of gravity and the loading characteristics of the particular adverse terrain vehicle. The vehicle rests on only three wheels at any given moment, while the other wheel remains available for stabilization. Consequently, the wheel base of the vehicle when operated over a hard, smooth surface is the distance between wheels 22"' and 232 and one of the endmost wheels, either 20"' or 24"'. Therefore, the effort required to effect skid steering on the vehicle is substantially reduced with a shorter wheel base, while the rocking feature of undercarriage 230 allows recourse to the stability inherent with a longer wheel base. It will be noted that if the center wheels 18"' include pneumatic tires, the partial deflation thereof will serve to neutralize the rocking feature to bring all four wheels 18"' into contact with the hard, smooth surface improving vehicle traction and stability.

Conversely, greater inflation of middle wheels 22"' and 232 will serve to augment the rocking feature, if desired. Of course, during operation of undercarriage 230 over a softer surface, all four tired wheels 18"' engage the adverse surface because they will sink into the surface until vehicle flotation occurs. Moreover, alignment of the axles of wheels 18"' improves the vehicle performance over both hard and soft surfaces by reducing porpoising and other control problems associated with multiple nonaligned drive wheels. The power transmission and other aspects of the aligned three wheel embodiment illustrated in Figure 18 is substantially identical to that of the nonaligned four wheel embodiment depicted in Figures 7 and 8, and the modifications thereof, which were discussed previously.

Referring now to Figure 9, there is shown a T-handle 162 which can be mounted in the cockpit of the adverse terrain vehicle to which the invention is attached. T-handle 162 performs the function of controlling the flow of energy from a remote source (not shown) to the motor(s) of the hydrostatic drive system. The T-handle 162 is supported for pivotal movement about horizontal and vertical axes 164 and 166, respectively. The handle 162 includes a pair of handle grips 168 and a lower portion 170 extending parallel to handle grips 168. Thus, manipulation of the handle grips 168 relative to axles 164 and 166 results in a directly corresponding motion in lower handle portion 170.

The lower handle portion 170 of the T-handle 162 is coupled to a pair of levers 172 by means of a pair of links 174. The levers 172 serve to control the energy flowrate to the motors. In this way, the T-handle 162 is operable to provide complete control over the direction. speed, and steering of the vehicle incorporating the invention. Manipulation of the T-handle 162 solely about the horizontal axis 164 causes movement of both the levers 172 in the same direction by the same amounts. By this means, the motors are actuated in synchronism for propulsion of the vehicle either forwardly or rearwardly along a straight line.

Similarly, manipulation of T-handle 162 solely about the vertical axis 166 causes equal and opposite flow of motive energy to the motors whereby the vehicle pivots about its center, but does not move either forward or rearward. Of course, any combination of manipulations about axes 164 and 166 is possible to effect complete control of the adverse terrain vehicle. A pair of springs 176 are provided for returning the levers 172 to their center or nil position wherein the remote power source (not shown) provides no output to the motors.

In reference now to Figures 11 - 14, there are shown several vehicles to which either the lowered center wheel(s) or larger center wheel(s) embodiments of the undercarriage of the present invention can be adapted.

Although each vehicle has a different operational loading profile, the present invention is equaly compatible with all. It will be understood that wheel height adjustment assemblies 147 and 149, or 148 can be adapted to each vehicle utilizing lowered center wheels to impart additional stability, if desired.

Figure 11 illustrates application of the undercarriage 10 to a front-end loader 188.

The heaviest component of the machine, the engine 180, is located to the rear of the vehicle. In the unloaded condition, with the bucket 182 retracted and empty, the center of gravity is located rearward near the engine 180 so that the vehicle rests on its rear and middle pairs of wheels. After loading and upon extension of the unloaded bucket 182, the center of gravity shifts forward, which causes the vehicle to rock forward to rest upon its forward and middle pairs of wheels.

Shown in Figure 12, born by undercarriage 10, is a front-end loader 188 equipped with a backhoe 184. The engine 186 is mounted forward. The center of gravity will be located forward near the engine 186 when the empty front-end loader 188 is retracted, and the empty backhoe 190 is tucked in. The vehicle in the unloaded configuration will thus be supported by its forward and middle sets of wheels. If the front-end loader 188 alone is loaded and extended, the vehicle's center of gravity remains forward and the vehicle will continue to rest on its forward and middle pairs of wheels. If only the backhoe 190 is manipulated, the center of gravity will shift rearward causing the vehicle to rock back and rest on its rearward and middle pairs of wheels. Of course, during combined operation of the front-end loader 188 and the backhoe 190, the vehicle may rock either forwardly or rearwardly depending on the relative loads manipulated.

Figure 13 depicts undercarriage 136 as applied to a mobile drilling rig 192. During transportation, the drilling mast 194 lies substantially parallel to the vehicle. The weight of the mast 194 when added to that of the forwardly located engine 196 causes the vehicle to rest upon its forward and middle pairs of wheels. Upon raising mast 194 into drilling position, the center of gravity shifts rearward to reposition the vehicle on the rearward and middle sets of wheels.

Another backhoe 198 is shown in Figure 14 supported on undercarriage 136. Owing to the rearward engine 200 location, the vehicle rests on its rearward and middle pairs of wheels when the bucket 202 is tucked in and empty. During manipulation of the bucket 202, the vehicle rocks forward to be sup ported by the forward and middle pairs of wheels.

While each of the example applications of the invention appearing in Figures 11-14 was discussed above as though the vehicle were operating over hard, smooth terrain, it will be understood that while operating over softer terrain, all wheels would contact the surface, achieving better flotation and traction.

Turning now to Figure 19, there is shown in detail a modified drive system for undercarriage 10. Whereas the drive system 28 shown in Figure 2 and further shown in detail in Figures 3a and 3b has a speed reducer 40 attached to a frame extension 42 such that motor 30 is located outboard of frame 12, the modified drive system of Figure 19 is arranged such that a motor and speed reducer 40' are disposed inboard of frame 12. Speed reducer 40' is mounted on frame extension 42' which extends upwardly from the inside rearward top surface of frame 12.

Speed reducer 40' has an output shaft 46' to which a drive sprocket 48' having two sets of teeth 48a' and 48b' is attached by means of bolts 49a' and 49b'. Chain 52' connects sprocket 48a' to sprocket 62' attached to axle 26' of rear wheel 24. Accordingly, sprocket 62' rotates in unison with sprocket 48a'.

It will be noted that axle 26' of rear wheel 24 is rotatably supported by an inner bearing assembly 102' and an outer bearing assembly 104'. A protective cover 130' is provided to protect the inward end of axle 26' of rear wheel 24. Cover 130' is secured to bearing holder 103' by screws 132'. Accordingly, the inward end of axle 26' is shielded in the drive system arrangement of Figure 19.

A chain 64' connects sprocket 48b' to sprocket 68a' and provides a driving connection between speed reducer 40' and axle 26' of middle wheel 22. Located substantially adjacent to sprocket 68' and also connected to axle 26' of middle wheel 22 is sprocket 66'.

A chain 70' is constrained for rotation around sprocket 66' for driving axle 26 of the forward wheel 20.

In accordance with the drive system of Figure 19, axles 26' of the rear wheel 24 and the middle wheel 22 are each driven directly from the speed reducer. Such an arrangement reduces the amount of chain required by the arrangement of Figures 3a and 3b.

Although the tension adjustment assemblies shown in Figures 3a and 3b have not been shown in Figure 19, it is to be understood that such mechanisms could be utilized with the drive system of Figure 19. Also, although the brake mechanism shown in Figure 3b for axle 26 of middle wheel 22 is not shown in Figure 19, it is to be further understood that such brake mechanism could be utilized with the drive system shown in Figure 19.

In reference now to Figures 20-24, there is shown several additional vehicles to which the undercarriage of the present invention can be adapted.

Figure 20 illustrates the application of the undercarriage 10 to a hydraulic power loader 211. The power loader vehicle utilizes a three wheeled version of undercarriage 10.

Power loader 211 comprises an hydraulically actuated, articulated arm 213 having hydraulically actuated claws 214 mounted on the end thereof. The undercarriage of power loader 211 is further provided with hydraulic stabilizers 216 at the front and rear ends.

Shown in Figure 21 is a hydraulic power loader 220 supported on a four wheeled version of undercarriage 136. The configuration of power loader 220 is substantially identical to loader 211 of Figure 20, except the undercarriage has been replaced by the more heavy duty undercarriage. Hydraulic loader 220 also comprises a hydraulically operated, articulated arm 222 having a set of hydraulically actuated scrap grabbers 224 mounted on the end thereof.

Another power loader 231 is shown in Figure 22 supported on undercarriage 10.

Power loader 231 is provided with a knuckle boom crane 233 comprising an articulated arm with a hydraulically operated hand 235 on the end. As shown, loader 231 incorporates stabilizers 236 at the front and rear.

Figures 23 and 24 show undercarriage 10 as applied to a mobile rotary drilling vehicle 240. During transportation, the drilling mast 242 is carried in a down position, wherein the mast is substantially parallel to the road surface 244 over which the vehicle travels.

As shown in Figure 24, the drilling mast 242 when raised into the vertical drilling position is disposed at one end of vehicle 240.

The rotary drilling head 246 is raised and lowered by a chain 248. Rotation of drilling head 246 is through the application of controlled hydraulic pressure in lines 249. Vehicle 240 is stabilized in the drilling position by stabilizers 250 mounted at the front and rear of the vehicle.

Thus, it is apparent that there has been provided, in accordance with the invention, an undercarriage for an adverse terrain vehicle that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in view of the foregoing description.

Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the appended

Claims

claims. WHAT WE CLAIM IS:

1. An undercarriage assembly for supporting and propelling a mechanism, comprising an elongate hollow load-bearing frame adapted for connection to the mechan ism; at least three axle members each having a wheel receiving member at one end thereof; at least three wheel members each mounted on and secured to the wheel receiving end of one of the axle members; means rotatably supporting the axle members at longitudinally spaced points along the frame with each of the axle members extending through the frame and being rotatably supported in opposite sides of the frame; the middle wheel member or members extending below a plane lying tangent to the bottoms of the endmost wheel members to facilitate, when fixed to the mechanism and in use, skid steering of the mechanism; transmission means including sprockets and chains positioned within the frame and drivingly interconnecting at least two of the axle members; and drive means including a motor mounted on the frame and operably connected to the transmission means for actuation thereof whereby the drive means and the transmission means cause concurrent rotation of the interconnected axle members.

2. The undercarriage assembly according to claim 1, wherein the elongate hollow frame is rectangular in cross-section and comprises structural members around its entire periphery and along its entire length so as to cacilitate attachment of the mechanism at any point thereon.

3. The undercarriage assembly according to claim 1 or claim 2, wherein the means rotatably supporting the axle members comprise bearing means mounted on opposite sides of the frame and rotatably supporting the axle members with the axle members extending through the frame.

4. The undercarriage assembly according to any one of claims 1 to 3, wherein the middle axle members are mounted for rotation about axes lying in a plane positioned substantially below a plane extending through the rotational axes of the endmost two axle members thereby facilitating skid steering of the mechanism.

5. The undercarriage assembly according to any one of claims 1 to 3, which includes means for selectively varying the vertical positioning of at least one of the axle members and thereby either positioning the axle members for rotation about axes lying in the same plane, or effectively positoning the center axle members for rotation about axes located substantially below a plane extending through the axes of rotation of the endmost two axle members to facilitate skid steering of a mechanism carried by the undercarriage assembly.

6. The undercarriage assembly according to any one of claims 1 to 5, wherein the frame comprises a lubricant reservoir so that the transmission means can be continuously operated in a lubricant bath.

7. The undercarriage assembly according to any one of claims 1 to 3, wherein the middle axle members are mounted for rotation about axes lying in a plane extending through the axes of rotation of the endmost two wheel members, said middle wheel members having diameters substantially larger than the diameters of the endmost wheel members thereby facilitating skid steering of a mechanism supported by the undercarriage assembly.

8. The undercarriage assembly according to any one of claims 1 to 7, wherein the transmission means comprises a plurality df sprocket means positioned within the frame and each connected to one of the axle members for rotation therewith; and chain means positioned within the frame and constrained around the sprocket means whereby at least two of the axle means are drivingly interconnected.

9. The undercarriage assembly according to any one of claims 1 to 7, wherein the transmission means comprises a plurality of sprocket means, each connected to one of the axle members for rotation therewith; a plurality of chains each constrained around sprocket means mounted on an adjacent pair of axle members to drivingly interconnect all of the axle members.

10. The undercarriage assembly according to any one of claims 1 to 9, wherein the drive means comprises motor means mounted on the frame; first drive sprocket means mounted for rotation by the motor means; second drive sprocket means mounted on one of the axle members; and drive chain means constrained around the two drive sprocket means for effecting rotation of said one of the axle members under the action of the motor means.

11. The undercarriage assembly according to any one of claims 1 to 10, further including brake means mounted on at least one of the axle members for selective actuation to arrest rotation of said axle member whereby the transmission means concurrently arrests rotation of the interconnected axle members.

12. The undercarriage assembly according to any one of claims 1 to 10, further including brake means mounted between the drive means and the transmission means for selective actuation to arrest rotation of said drive means whereby the transmission means concurrently arrests rotation of the interconnected axle members.

13. The undercarriage assembly according to any one of claims 1 to 7, wherein the transmission means and the drive means include: a plurality of sprocket means each positioned within the frame and each mounted on and secured to one of the axle members; motor means mounted on the frame between one endmost axle member and the middle axle member; first drive sprocket means having two sets of teeth thereon positioned within the frame and mounted for rotation by the drive means; second drive sprocket means mounted on the middle axle member; first drive chain means constrained around the first drive sprocket means on one set of teeth and the sprocket means on the endmost axle member adjacent the drive means; second drive chain means constrained around the first drive sprocket means on the other set of teeth and the sprocket means on the middle axle member; and third drive chain means constrained around the second drive sprocket means and the sprocket means on the other endmost axle member; the first and second drive chain means drivingly connecting the endmost axle member adjacent the drive means and the middle axle member to the output of the drive means for rotation under the action thereof.

14. The undercarriage assembly of any one of claims 1 to 13, including a power loader mechanism, comprising a frame; means supporting the frame on the undercarriage assembly for pivotal movement with respect thereto about a normally vertically extending axis; a knuckle boom crane comprising an articulated arm mounted on the frame at one end thereof; a clamp mounted at the opposite end of the articulated arm for receiving, lifting and carrying materials therein; hydraulic cylinder means for extending and retracting the knuckle boom crane and for actuating the mechanical clamp; an operator's compartment mounted on the frame; and an engine mounted on the frame.

15. The undercarriage assembly of any one of claims 1 to 13, including a mobile drilling rig mechanism with a rotary digging tool, which comprises a frame; a boom; means supporting the boom on the frame for pivotal movement between a travelling orientation wherein the boom extends substantially horizontally and in operating orientation wherein the boom extends substantially vertically; means mounted on the boom for effecting rotation of a drilling tool; and means for moving the drilling tool rotating means axially with respect to the boom from a position adjacent one end thereof to a position adjacent the other end.

16. An undercarriage assembly for supporting and propelling a mechanism, comprising an elongate hollow load bearing frame adapted for connection to the mechanism; at least three axle members each having a wheel receiving member at one end thereof; at least three wheel members each mounted on and secured to the wheel receiving end of one of the axle members; means rotatably supporting the axle members at longitudinally spaced points along the frame with each of the axle members extending through the frame and being rotatably supported in opposite sides of the frame; the middle wheel member extending below a plane lying tangent to the bottoms of the endmost wheel members to facilitate, when fixed to the mechanism and in use, skid steering; a plurality of sprocket means each positioned within the frame and each mounted on one of the axle members; drive means comprising motor means and transmission means mounted on the frame between one endmost axle member and the middle axle member; first drive sprocket means having two sets of teeth thereon positioned within the frame and mounted for rotation by the drive means; second drive sprocket means positioned within the frame and mounted on the middle axle member; first drive chain means constrained around the first drive sprocket means on one set of teeth and the sprocket means on the endmost axle member adjacent the drive means; second drive chain means constrained around the first drive sprocket means on the other set of teeth and the sprocket means on the middle axle member; and third drive chain means constrained around the second drive sprocket means and the sprocket means on the other endmost axle member; said first and second drive chain means drivingly connecting both the endmost axle member adjacent the drive means and the middle axle member directly to the output of the drive means for concurrent rotation under the action thereof.

17. An undercarriage assembly, substantially as hereinbefore described with reference to the accompanying drawings.

18. A vehicle including an undercarriage assembly as claimed in any one of claims 1 to 17.