Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D21/00—Understructures, i.e. chassis frame on which a vehicle body may be mounted
  • B62D21/18—Understructures, i.e. chassis frame on which a vehicle body may be mounted characterised by the vehicle type and not provided for in groups B62D21/02 - B62D21/17
  • B62D21/186—Understructures, i.e. chassis frame on which a vehicle body may be mounted characterised by the vehicle type and not provided for in groups B62D21/02 - B62D21/17 for building site vehicles or multi-purpose tractors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G21/00—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces
  • B60G21/02—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces permanently interconnected
  • B60G21/04—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces permanently interconnected mechanically
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D21/00—Understructures, i.e. chassis frame on which a vehicle body may be mounted
  • B62D21/14—Understructures, i.e. chassis frame on which a vehicle body may be mounted of adjustable length or width

Definitions

• This invention relates to off-road vehicles, agricultural implements, earthworking machines, • • tractors and other moveable apparatus of the kind comprising a warpable chassis supported, for example, by ground wheels or tracks and a rigid platform supported by said warpable chassis.
• the purpose of the warpable chassis is to enable the ground wheels or tracks to rise and fall independently to maintain good contact with uneven ground while maintaining the rigid platform in a more or less stable disposition.
• the latter effect is achieved by pivotally supporting the platform on the chassis by means of pivotal connections defining two mutually perpendicular substantially horizontal pivotal axes, and positioned at points on the chassis intermediate (preferably mid-way between) the points of attachment of the wheels or tracks.
• the platform corresponds to the normal rigid chassis of conventional mobile apparatus.
• the warpable chassis of mobile apparatus of the kind concerned has usually comprised four chassis members, namely two side members and two end members, disposed in a rectangular array with four corner connectors respectively interconnecting the side members and the end members at each corner of the chassis.
• the pivotal connections to the platform are robust enough, one chassis member not directly attached to the wheels or tracks, say one end member, may be omitted.
• the chassis it would be preferable for the chassis to present no resistance to warping, that is to say ideally the said corner connectors, while maintaining the integrity of the chassis and transferring load and drive forces from platform to ground, should not introduce any resistance to rotational movement of the chassis members about the axes of their respective pivotal connections to the platform, throughout the entire intended operating range of such movement. This would eliminate warping stresses in the chassis components and so minimise the overall stresses therein. That ideal situation has not been realised hitherto.
• any apparatus of the kind under discussion in which stress in the chassis members is lessened by permitting free variation of the effective length of any chassis member or chassis member/corner connector combination and/or free variation of the bodily position of a chassis member is referred to hereinafter as apparatus wherein the chassis is dimensionally variable.
• the invention is based on the realisation that when a chassis is warped the included angle between its chassis members at the corner is less than the corresponding angle when the chassis is unwarped, and on the discovery that, small as the change in angle is, its enforcement requires the establishment of considerable stresses in the chassis components.
• the invention consists in a mobile apparatus of the kind comprising a warpable chassis, itself comprising a plurality of chassis members and corner connectors, characterised in that the chassis is dimensionally variable , and in that each of said corner connectors permits free variation of the included angle between the chassis members interconnected by it.
• Figure 1 is a perspective view of the warpable chassis 5 and associated components of a prior art tractor according to applicant's said earlier International patent application.
• Figure 2 is a diagrammatic perspective view of the right hand front corner portion of a warpable chassis 10 according to the invention of a tractor which in its non- inventive features may be generally similar to the tractor of figure 1.
• Figure 3 is an exploded perspective view of the subject matter of figure 2.
• Figure 4 is a perspective view from below of the corner portion of figure 2 ; when the corner is depressed, drawn to a larger scale, and showing the acute angle then pertaining between the side and end members of the chassis.
• the prior art tractor of figure 1 comprises a rigid box-like platform 4 surrounded by a warpable chassis 25 comprising tubular side members 5, front and rear end members 6 and 7 respectively, and four corner connectors 8.
• the chassis is supported by four ground wheels (not shown) mounted at the bottom ends of four, splayed, tubular legs 9 extending downwardly from the chassis side members 5.
• the platform 4 is supported by the chassis by pivotal connections 10 and 11 respectively.
• the pivotal connections 10 each comprise a tubular cantilever 12 extending into a gear box 13 whereby drive from a main, change-speed gear box 14 is transmitted to the wheels by shafts within the cantilevers 12, side members 5 and legs 9.
• the pivotal connections 11 each ' comprise a tubular stub projecting from the platform 4 through a plain bushed bearing in the end member 6 or 7 as the case may be. Therefore, the end m%mbers 6 and 7 may freely and independently rotate about the axis Y-Y and slide laterally along that axis. Thus the effective spacing between the end members 6 and 7 may freely vary within design limits.
• Each corner connector 8 comprises an elbow piece 15 comprising two projecting pivot pins 16 and 17 respectively entering bushes within the side members 5 and end member 6 or 7, as the case may be.
• the arrangement is such that the pivot pins 17 are unable to move longitudinally within the side members 5 whereas the pivot pins 16 may slide freely within the end members 6 and 7.
• the effective lengths of the end members 6 and 7 are variable within design limits depending on the extent to which the pivot pins 16 protrude into those end members.
• figure 1 prior art chassis is dimensionally variable, but it will be noted that its corner connectors make no provision for departure of the included angle between side and end members from 90°, leading to constraint on the warping of the chassis which requires that angle to become progressively more acute as warping increases.
• the corner connector between the chassis side member 5 and end member 6 of figures 2, 3 and 4 comprises a shackle 20, itself comprising a strap 21, two annular housings 22 integral with the strap 21 and two eye members 23, each of which may be a ball pierced by a diametral bore or a symmetrical segment of such a ball having a central plane perpendicular to the axis of the bore.
• the inner peripheral surface of each housing 22 is part-spherical to suit its eye member 23-
• Each eye member 23 is trapped in its housing 22 but may rotate and swivel therein.
• a pivot pin 24 projects from the side member 5 through the bore of the upper eye member 23.
• a clevis pin 25 extends through the bore of the lower eye member 23 and two cheek plates formed on the end of the end member 6.
• the shackle 20 is actually a short tension link connected at its ends by universal joints to the respective chassis members tied together by the shackle.
• each housing 22 and its eye member 23 are essentially the same as the so-called ball joints provided on the lifting arms of the standard 3-point linkage provided on conventional agricultural tractors for the reception of support pins projecting from implements carried by the tractor.
• Those ball joints are of three kinds, namely ones in which the inner circumferential margins of the housing are swaged over the eye member after it has been positioned within the housing so that the eye member is permanently trapped within the housing, others in which the housings are split and the two parts brought together about the eye member and then secured by fasteners, and still others in which minor portions of the finished housing and eye member are cut away to enable the eye member to be inserted into the housing after which a cotter pin is passed through the housing to prevent the eye member coming into a position where it may escape from the housing.
• pin/housing/eye member combination at either end of the shackle may be replaced by any other conventional universal joint, for example a ball and socket joint of the kind wherein a pin projects rigidly from a ball trapped in a cup-like part-spherical socket.
• the strap 21 When the chassis is unwarped the strap 21 is substantially vertical but as the chassis warps, for example because the illustrated corner rises above the plane, of the axes ⁇ -X and Y-Y, the ends of the members 5 and 6 move apart along diverging arcuate paths as the members themselves rotate about those axes, and the strap 21 adopts a more nearly horizontal disposition to maintain the connection between the members.
• the strap 21 may adapt in that way partly as a result of rotation of the eye members 23 on the pins 24 and 25 and partly as a result of rotation of the housings 22 on the eye members 23.
• the change in the disposition of the shackle may be said to have increased their effective lengths.
• the illustrated chassis is fully dimensionally variable, as that term is used herein, notwithstanding that neither side members 5 nor end members 6 and 7 may move bodily along their pivotal axes with the platform 12.
• the shackle illustrated in figures 2, 3 and 4 provides for the transmission of vertical loads between the members 5 and 6, while leaving them free to adapt in a stress-free manner to all warping requirements, including the crucial change in angularity between the chassis members, which change occurs as a result of the eye members swivelling in their housings.
• elbow pieces similar to those of figure 1 but comprising two half elbows hinged together for articulation about a vertical axis may be employed.
• the hinge connection may be by way of a hinge pin piercing each half elbow or it may be by way of an elastomeric body interposed between the two halves and bonded thereto.
• one piece elbows may be used engaging bushes which are moveable in the chassis members, for example elastomer mounted bushes or trunnion mounted bushes.
• a single ball and socket joint may be used if it provides sufficient articulation in all directions and provided there is an appropriate combination of movements between joint components and chassis members and/or between chassis members and platform to ensure dimensional variability.
• both chassis member may move bodily along its pivotal axis with the platform then both the ball component and the socket component of the joint would require to be slideable along the chassis member to which it is attached, if only one chassis member may move bodily along its pivotal axis then only the joint component attached to that member would be required to slide therealong, whereas if both chassis members could move bodily as aforesaid then both joint components could be fixed to the respective chassis members.
• the shackle 20 is subjected to tension loading in so far as the static loads on the vehicle are concerned, and therefore in some slow speed vehicles could be replaced in its entirety by a pliable link or short chain.
• the shackle may be inverted with the strap 21 then becoming a strut under compression loading.
• the illustrated disposition of the universal joints at the ends of the illustrated shackle may be varied, for example, the axis .of the housing and pivot pin at one end of the shackle may be perpendicular or at some other orientation to the axis of the pin and housing at the other end instead of parallel thereto as shown.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Architecture (AREA)
• Structural Engineering (AREA)
• Body Structure For Vehicles (AREA)
• Pivots And Pivotal Connections (AREA)
• Vehicle Body Suspensions (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=3773306

Family Applications (1)

Country Status (4)

Cited By (4)

Families Citing this family (1)

Citations (8)

• 1989
  • 1989-08-17 WO PCT/AU1989/000351 patent/WO1990002072A1/en unknown
  • 1989-08-18 CN CN89106637A patent/CN1040548A/zh active Pending
  • 1989-08-18 ES ES8902893A patent/ES2014869A6/es not_active Expired - Lifetime
• 1990
  • 1990-04-17 KR KR1019900700785A patent/KR900701594A/ko not_active Application Discontinuation

Patent Citations (8)

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