Patent Publication Number: US-2022219588-A1

Title: Tipper assembly

Description:
BACKGROUND 
     The disclosure relates to the field of tipper assemblies, more particularly tipper assemblies for use in dump trucks, tipper trucks and/or the like. 
     Dump trucks, also known as tipper trucks, can be fitted with a tailgate to close off the end of the truck body to increase payload volume and reduce spillage during hauling. 
     It is known to provide a separate tailgate actuation mechanism, powered independently from the truck body tipping mechanism. This adds cost and complexity to the system. 
     Alternatively, a pivoting arm mechanism actuated by a single tie or chain may be used to open the tailgate. The chain or tie may be connected to an end of the pivoting arm and to the chassis. The chain or tie causes the arm to move relative to the truck body as the truck body is pivoted into the raised tipping position relative to the chassis by the tipping actuators, thereby opening the tailgate. Such mechanisms may be limited by the geometry of the tailgate, the truck body and the chassis and may result in a restricted opening rate. 
     SUMMARY 
     Against this background there is provided a tipper assembly configured to open the tailgate quickly and efficiently to avoid interfering with the free flow of the payload as the truck body is raised into a raised “tipping” position, to avoid damage and destabilisation of the machine. 
     In embodiments of the present disclosure, a tailgate lift assembly is configured to lift the tailgate from a closed position to the open position on movement of the body from the lowered position to the raised position. The dump truck or the like comprises a chassis and a truck-bed/dump-body, and the truck-bed is pivotally attached to the chassis about a truck-bed pivot axis. The truck-bed is configured to contain a load to be carried by the truck and is coupled with the chassis so that it can be moved between a lowered position for transporting the load and a raised position for emptying the load from the truck-bed. The truck-bed includes a tailgate that is designed to maintain the load within the truck-bed during transport. 
     In accordance with embodiments of the present disclosure, the tailgate is moveable between a closed position, in which the tailgate closes an end opening of the truck-bed and an open position in which the tailgate is pivoted away from the end opening leaving an opening through which the load can be emptied from the truck-bed. 
     In embodiments of the present disclosure, the tailgate is coupled with a tailgate lift assembly. The tailgate lift assembly is configured to lift the tailgate from the closed position to the open position when the truck bed is raised from the lowered position to the raised position. 
     In embodiments of the present disclosure, the tailgate lift assembly includes arms on either side of the truck bed that extend from the tailgate, to which the arms are coupled, to a linkage point. The arms are each pivotally attached to the truck-bed at a pivot point, where the pivot point is disposed between the tailgate and the linkage point. 
     In embodiments of the present disclosure, a first tailgate lift assembly comprises a first arm having a tailgate end fixedly attached to the tailgate and a first arm linkage point, the first arm being pivotally attached to the body about an arm pivot axis, the arm pivot axis being arranged between the tailgate end and the first arm linkage point. 
     In embodiments of the present disclosure, a first linkage assembly connects the first arm linkage point to the first chassis linkage point, the first linkage assembly comprising an arm link and a rapid opening assembly having a first end attached to the body or chassis and a second end attached to an intermediate portion of the first arm link. The rapid opening assembly is configured to create a v-shape in the arm link, drawing the first arm linkage point closer to the first chassis linkage point on rotation of the body about the body pivot axis from the lowered to the raised position. 
     The linkage assembly is configured to draw the linkage point closer to the chassis linkage point when the truck-bed is raised. The drawing of the tailgate linkage point closer to the chassis linkage point causes the tailgate-opening assembly to increase the rate at which the tailgate is opened. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the disclosure are now described with reference to the accompanying drawings, in which: 
         FIG. 1  shows a schematic representation of a tipper assembly according to the prior art in a lowered position; 
         FIG. 2  shows a schematic representation of the tipper assembly of  FIG. 1  in an intermediate position during raising of the tailgate; 
         FIG. 3  shows a schematic representation of a tipper assembly according to the present disclosure in a lowered position; and 
         FIG. 4  shows a schematic representation of the tipper assembly of  FIG. 3  in an intermediate position during raising of the tailgate; 
         FIG. 5  shows a schematic representation of the tipper assembly of  FIG. 3  in an intermediate position, showing the locus of movement of the tailgate and arm linkage point and a tipper assembly as in  FIG. 1  showing the locus of movement of the tailgate and arm linkage point of the tipper assembly of  FIG. 1 ; 
         FIG. 6  shows a schematic representation of the tipper assembly of  FIG. 3  in a raised position, showing the locus of movement of the tailgate and arm linkage point and a tipper assembly as in  FIG. 1  showing the locus of movement of the tailgate and arm linkage point of the tipper assembly of  FIG. 1 ; 
         FIG. 7  shows a schematic representation of a further tipper assembly according to the present disclosure in a lowered position; and 
         FIG. 8  shows a schematic representation of the tipper assembly of  FIG. 7  in an intermediate position during raising of the tailgate; 
         FIG. 9  shows a schematic representation of the tipper assembly of  FIG. 7  in an intermediate position, showing the locus of movement of the tailgate and arm linkage point and a tipper assembly as in  FIG. 1  showing the locus of movement of the tailgate and arm linkage point of the tipper assembly of  FIG. 1 ; 
         FIG. 10  shows a schematic representation of the tipper assembly of  FIG. 7  in a raised position, showing the locus of movement of the tailgate and arm linkage point and a tipper assembly as in  FIG. 1  showing the locus of movement of the tailgate and arm linkage point of the tipper assembly of  FIG. 1 ; 
         FIG. 11  shows a schematic representation of a further tipper assembly according to the present disclosure in a lowered position. 
     
    
    
     DETAILED DESCRIPTION 
     A tipper truck comprising a tipper assembly  100  in accordance with the prior art is shown in  FIGS. 1 and 2 . The tipper assembly may comprise a chassis  110  and a body  120  for receiving a load of material. The body  120  may be pivotably attached to the chassis  110  at a body pivot axis  122  such that the body can be pivoted about a body pivot axis  122  from a lowered position as shown in  FIG. 1  to a raised or lifted position in which the load of material can flow out of an end opening  121  of the body  120  as shown in  FIG. 2 . 
     In the lowered position, a tailgate  130  may be arranged in a closed position across the end opening  121 . The tailgate  130  may be attached to an arm  140 . The arm  140  may be pivotably attached to the body  120  about an arm pivot axis  141  arranged in an intermediate portion of the arm  140 , such that the arm  140  and the tailgate  130  may be pivoted relative to the body  120 , lifting the tailgate  130  to an open position away from the end opening  121 . A chain or tie  150  may be attached to an arm linkage point  142  arranged at a distal end of the arm  140  to the tailgate  130 . The chain or tie  150  may be further attached to a chassis linkage point  111  on the chassis  110 , thereby attaching the chassis linkage point  111  to the arm linkage point  142 . 
     As the body  120  is pivoted into its lifted position under the action of a tipper actuator  160 , the arm pivot axis  141 , being in a fixed position relative to the body  120 , may move in an upwards arc. The chain or tie  150  may hold the arm linkage point  142  of the arm at a fixed distance relative to the chassis  110 , thereby causing the arm  140  to pivot relative to the body  120  about the arm pivot axis  141  and lifting the tailgate  130  into the open position. 
     The tailgate  130  may therefore be lifted into the open position by the tipper actuator  160  as a result of the action of the chain or tie  150  and the tipper actuator  160  lifting the body to the open position. The pivoting action may result in an arcuate motion of the tailgate  130  outwards and upwards from its original position. The shape of the arc may therefore be dictated by the fixed length and pivoting motion of the chain or tie  150 . Where a chain  150  is used, any slack in the chain is taken up by initial movement of the body such that the arm linkage point  142  first moves away from and then at a fixed distance to the chassis linkage point  111  as the body is lifted from the lowered to the raised position. 
     A tipper assembly  200  in accordance with a first aspect of the present disclosure is shown in  FIGS. 3 to 6 . In  FIGS. 3 and 4 , the tipper assembly  200  is shown in the context of a tipper truck. The tipper assembly  200  may comprise a chassis  210  and a body  220  suitable for receiving a load of material to be tipped out by the tipper assembly. The body may be, for example, a truck bed or body, or a container body. The body  220  may be pivotable between a lowered position and a raised position. The body  220  may be pivotably attached to the chassis  210  at a body pivot axis  222  such that the body can be pivoted about a body pivot axis  222  from the lowered position as shown in  FIG. 3  to the raised or lifted position (as shown in  FIG. 6 ) in which the load of material can flow out of an end opening  221  of the body  220 . The body pivot axis  222  may be arranged in a fixed position on the chassis  210  and may be arranged at or near a first end of the chassis  210 , adjacent to the end opening  221  of the body  220 . 
     A tipper actuator  160  may be arranged to act on and lift a free end of the body  220 , distal to the end opening  221  of the body, thereby pivoting the body  220  about the body pivot axis  222  to move the body  220  into the raised position (i.e. the tipping position). 
     When the body  220  is arranged in the lowered position, shown in  FIG. 3 , a tailgate  230  may be arranged in a closed position across the end opening  221 . The tailgate  230  may be fixedly attached to an arm  240 . The arm  240  may be pivotably attached to the body  220  about an arm pivot axis  241  arranged in an intermediate portion of the arm  240 , such that the arm  240  and the tailgate  230  may be pivoted together relative to the body  220 . 
     A first linkage assembly  250  may comprise an arm link  251  attached to an arm linkage point  242 , the arm linkage point  242  arranged at or near an end of the arm  240  distal to the tailgate  230 . The arm link  251  may be non-extensible. The arm link  251  may be further attached to a chassis linkage point  211  on the chassis  210 , thereby connecting the chassis linkage point  211  to the arm linkage point  242 . The arm link  251  may be formed from a first element  251   a  pivotally attached to the arm linkage point  242  and a second element  251   b  pivotally attached to the chassis linkage point  211 . The first element  251   a  may be pivotally attached to the second element  251   b , thereby allowing bending or folding of the arm link  251  at the joint  251   c  of the first element  251   a  and the second element  251   b , the joint  251   c  being arranged at an intermediate portion  253  of the arm link  251 . 
     The first linkage assembly  250  may further comprise a rapid opening assembly comprising offset link  252 . The offset link  252  may extend between a body linkage point  223  on the body  220  and the arm link  251 . The body linkage point  223  may be disposed on a side of the body between the arm pivot axis and the tailgate opening. A first end of the offset link  252  may be pivotably attached to the body  220  and a second end of the offset link  252  may be attached to the arm link  251  at or near the joint  251   c  at the intermediate portion  253  of the arm link  251 . The offset link  252  may be non-extensible. 
     As the body  220  is pivoted into its lifted position under the action of a tipper actuator  160 , the arm pivot axis  241 , being in a fixed position relative to the body  220 , may move in an upwards arc relative to the chassis  210 . The direction of movement of the tailgate  230  and the rotation of the body  220  about the body pivot axis  222  are illustrated by arrows in  FIG. 4 . 
       FIGS. 5 and 6  show a locus of movement  231  of the tailgate  230  and a locus of movement  243  of arm linkage point  242  of tipper assembly  200  as the body moves to the raised position. For comparison,  FIGS. 5 and 6  also show the locus of movement  131  of a tailgate  130  and the locus of movement  143  of arm linkage point  142  as moved by a chain or tie  150  as shown in  FIGS. 1 and 2 . The locus of movement  143  remains at a fixed distance from the chassis linkage point  211 . 
     In tipper assembly  200 , on rotation of the body  220  about the body pivot axis  222  from the lowered to the raised position, the offset link  252  may pull the intermediate portion  253  of the arm link  251  to displace the intermediate portion  253  laterally such that the arm link  251  is curved, bent or folded. The rapid opening assembly may thereby be configured to create a v-shape in the arm link  251 . The arm linkage point  242  and the chassis linkage point  211  may thereby be drawn closer together, as illustrated by locus of movement  243  in  FIGS. 5 and 6 . An effective length of the arm link  251 , being the shortest distance between the arm linkage point  242  and the chassis linkage point  211 , may thereby be reduced. 
     The above configuration of the first linkage assembly  250  may draw the arm linkage point  242  closer to the chassis linkage point  211  on rotation of the body  220  about the body pivot axis  222  from the lowered to the raised position. The tailgate  230  may therefore be lifted by the tipper actuator  160  as a result of the action of the first linkage assembly  250 . The pivoting action may result in an arcuate motion of the tailgate  230  outwards and upwards from its original closed position to an open position as shown in  FIG. 6 . The shape of the arc of the locus of movement  243  may therefore be dictated by arc of movement of the body  220  and the shortening of the distance between the arm linkage point  242  and the chassis linkage point described above under the effect of the first linkage assembly  250 . As shown in  FIGS. 5 and 6 , this may result in an increase in vertical movement of the tailgate  230  at the beginning of the motion of the body  220  from the lowered position, such that the tailgate  230  clears the open end of the body  220  faster, as shown by the increased angle of locus of movement  231  of the tailgate  230  compared to locus of movement  131  of the tailgate  130  in the known system. This may also result in an increased final height of the tailgate  230 . 
     In this way, as the body  220  is tipped relative to the chassis  210 , the speed of rotation of the tailgate  230  away from the end opening  221  is faster than the speed of rotation of the prior art tailgate  130  relative to the end opening  121 . Consequently, other than in the lowered position, for any angular position of body  220  relative to the chassis  210 , the tailgate  230  is further from the end opening  221  than for the same angular position (other than the lowered position) of the prior art body  120  relative to the chassis  110 . 
     Further embodiments of the disclosure are described below. Features of the first embodiment and the following embodiments may be interchanged and combined as desired. In addition, in the following description only differences between the embodiments will be described in detail. In other respects the reader is directed to the description of the prior embodiment. 
       FIGS. 7 to 10  show a further tipper assembly  300  according to the present disclosure. In  FIGS. 7 and 8 , the tipper assembly  300  is shown in the context of a tipper truck. 
     In this tipper assembly a first linkage assembly  350  may comprise an arm link  351  attached to an arm linkage point  242 , the arm linkage point  242  arranged at or near an end of the arm  240  distal to the tailgate  230 . The arm link  351  may be non-extensible. The arm link  351  may be further attached to a chassis linkage point  211  on the chassis  210 , thereby connecting the chassis linkage point  211  to the arm linkage point  242 . The arm link  351  may be formed from a first element  351   a  pivotally attached to the arm linkage point  242  and a second element  351   b  pivotally attached to the chassis linkage point  211 . The first element  351   a  may be pivotally attached to the second element  351   b , thereby allowing bending or folding of the arm link  351  at a joint  351   c  of the first element  351   a  and the second element  351   b , the joint  351   c  being arranged at an intermediate portion  353  of the arm link  351 . 
     The first linkage assembly  350  may further comprise a rapid opening assembly comprising an offset link  352 . The offset link  352  may extend between a body linkage point  323  on the body  220  and the arm link  351 . The body linkage point may be disposed on a side of the body between the arm pivot axis and the tailgate opening. A first end of the offset link  352  may be pivotably attached to the body  220  and a second end of the offset link  352  may be attached to the arm link  351  at or near the joint  351   c  at the intermediate portion  353  of the arm link  351 . The offset link  352  may therefore have a first end having a fixed position relative to the body. The offset link  352  may be non-extensible. 
     As the body  220  is pivoted into its lifted position under the action of a tipper actuator  160 , the arm pivot axis  241 , being in a fixed position relative to the body  220 , may move in an upwards arc. The direction of movement of the tailgate  230  and the rotation of the body  220  about the body pivot axis  222  are illustrated by arrows in  FIG. 8 . 
       FIGS. 9 and 10  show a locus of movement  331  of the tailgate  230  and a locus of movement  343  of arm linkage point  242  of tipper assembly  300  as the body moves into the raised position. For comparison,  FIGS. 9 and 10  also show the locus of movement  131  of a tailgate  130  and the locus of movement  143  of arm linkage point  142  as moved by a chain or tie  150  as shown in  FIGS. 1 and 2 . The locus of movement  143  remains at a fixed distance from the chassis linkage point  211 . 
     On rotation of the body  220  about the body pivot axis  222  from the lowered to the raised position, the offset link  352  may push the intermediate portion  353  of the arm link  351  to displace the intermediate portion  353  laterally such that the arm link  351  is curved, bent or folded. The rapid opening assembly may thereby be configured to create a v-shape in the arm link  351 . The arm linkage point  242  and the chassis linkage point  211  may thereby be drawn closer together, as illustrated by locus of movement  343  in  FIGS. 9 and 10 . An effective length of the arm link  351 , being the shortest distance between the arm linkage point  242  and the chassis linkage point  211 , may thereby be reduced. The offset link  352  may be a strut suitable for withstanding compressive loading. 
     The above configuration of the first linkage assembly  350  may draw the arm linkage point  242  closer to the chassis linkage point  211  on rotation of the body  220  about the body pivot axis  222  from the lowered to the raised position. The tailgate  230  may therefore be lifted by the tipper actuator  160  as a result of the action of the first linkage assembly  250 . The pivoting action may result in an arcuate motion of the tailgate  230  outwards and upwards from its original closed position to an open position as shown in  FIG. 10 . The shape of the arc of the locus of movement  343  may therefore dictated by arc of movement of the body  220  and the shortening of the distance between the arm linkage point  242  and the chassis linkage point described above under the effect of the first linkage assembly  350 . As shown in  FIGS. 9 and 10 , this may result in an increase in vertical movement of the tailgate  230  at the beginning of the motion of the body  220  from the lowered position, such that the tailgate  230  clears the open end of the body  220  faster, as shown by the increased angle of locus of movement  331  of the tailgate compared to locus of movement  131  of the tailgate  230  of the known system. This may also result in an increased final height of the tailgate  230 . 
     In this way, as the body  220  is tipped relative to the chassis  210 , the speed of rotation of the tailgate  230  away from the end opening  221  is faster than the speed of rotation of the prior art tailgate  130  relative to the end opening  121 . Consequently, other than in the lowered position, for any angular position of body  220  relative to the chassis  210 , the tailgate  230  is further from the end opening  221  than for the same angular position (other than the lowered position) of the prior art body  120  relative to the chassis  110 . 
       FIG. 11  shows a further tipper assembly  400  according to the present disclosure in the context of a tipper truck. In this tipper assembly, the first linkage assembly  450  comprises an arm link  451  connecting the arm linkage point  442  and the body linkage point  423 . The arm link  451  may be formed from a first element  451   a  pivotally attached to the arm linkage point  442  and a second element  451   b  pivotally attached to a body linkage point  423 . The first element  451   a  may be pivotally attached to the second element  451   b , thereby allowing bending or folding of the arm link  451  at the joint  451   c  of the first element  451   a  and the second element  451   b , the joint  451   c  being arranged at an intermediate portion  453  of the arm link  451 . 
     The rapid opening assembly comprising offset link  452  may connect an intermediate portion  453  of the arm link  451  with the chassis linkage point  411 . The offset link  452  may have a fixed overall length. On raising of the body  420  by the tipper actuator, the offset link  452  may resist movement of the intermediate portion  453  of the arm link away from the chassis  410  and may thereby draw the arm linkage point  442  down relative to the body  120  as the body  120  moves upwards. The rapid opening assembly may thereby be configured to create a v-shape in the arm link  451 . An effective length of the first linkage assembly  450 , being the shortest distance between the arm linkage point  442  and a distal end of the arm link  451 , may thereby be reduced. 
     Whilst preferred embodiments of the present invention have been described above and illustrated in the drawings, these are by way of example only and non-limiting. It will be appreciated by those skilled in the art that many alternatives are possible within the ambit of the invention. For example, any one or more of the features of any embodiment may be combined and/or used separately in a different embodiment with any other feature or features from any of the embodiments. 
     In any embodiment, the arm link may be inextensible. 
     In any embodiment of the present disclosure the arm link may alternatively comprise a chain or wire or other similar element that is bendable or foldable at an intermediate point under the action of the offset link. If first element and second element of the arm link are replaced by a single bendable tie or chain, the joint may be replaced by a bending point or attachment point for the offset link, arranged at an intermediate portion of the arm link. 
     In any embodiment in which the offset link is configured to pull on the intermediate portion of the arm link, the offset link may comprise a flexible element such as a wire, chain, rope or similar tie suitable for carrying a tensile load, or a rigid element, for example a bar or rod or other similar tie suitable for carrying a tensile load. In any embodiment in which the offset link is configured to push on the intermediate portion of the arm link, the offset link may comprise a rigid element, for example a bar, rod or similar strut suitable for carrying a compressive load. 
     In any embodiment, on lowering of the body from the raised to the lowered position, the tailgate returns to the closed position under the action of the linkage assembly as a result of a lowering action of the tipper actuator. 
     In any embodiment the offset link may be configured to act (push or pull) the intermediate portion of the arm link on movement of the body into the raised position to displace the intermediate portion laterally such that the arm link is curved, bent folded. An effective length of the first linkage assembly, being the shortest distance between the arm linkage point and a distal end of the arm link, may thereby be reduced. 
     In any embodiment, the tailgate lift assembly may consist of simple mechanical links and connections (i.e. does not comprise actuators, motors, or hydraulic components). 
     In any embodiment, the tailgate lift assembly may be actuated by the movement of the body under the action of the tipper actuator. 
     In any embodiment, the first and/or second arm link may be arranged in a straight line or in a v-shape when the body is in the lowered position. For example, the arm link may be arranged with two elements or sections arranged at an angle to each other, or in a straight line when the body is in the lowered position. The creation of a v-shape in an arm link may therefore include creating a v-shape in a previously straight arm link or deepening an existing v-shape (for example by reducing an angle between two elements or sections of the arm link). The term v-shape may include u-shapes or similar curved shapes. 
     In the present disclosure, the term fixedly attached is used to refer to an attachment with little or no relative movement between the components. This may include the components in question being welded or bolted together, or being integrally produced as a single component. For example, in any embodiment of the present disclosure, the arm may be fixedly attached to the tailgate. 
     In any embodiment, the tipper assembly may comprise a second tailgate lift assembly configured to lift the tailgate from the closed position to the open position on movement of the body from the lowered position to the raised position. The first tailgate lift assembly may be arranged on a first side of the body and the second tailgate lift assembly may be arranged on a second side of the body. 
     The second tailgate lift assembly may be of the same construction as the first tailgate lift assembly. For example, the second tailgate lift assembly may comprise a second arm having a tailgate end fixedly attached to the tailgate and a second arm linkage point, the second arm being pivotally attached to the body about the arm pivot axis, the arm pivot axis being arranged between the tailgate end and the second arm linkage point, and a second linkage assembly connecting the second arm linkage point to the second chassis linkage point, the second linkage assembly comprising a second arm link and a second rapid opening assembly, the second rapid opening assembly having a first end attached to the body or chassis and a second end attached to an intermediate portion of the second arm link. The second rapid opening assembly may be configured to create a v-shape in the second arm link, drawing the second arm linkage point closer to the second chassis linkage point on rotation of the body about the body pivot axis from the lowered to the raised position. 
     INDUSTRIAL APPLICABILITY 
     In this way, it may be possible for the tailgate to be moved away from the opening more quickly, as it follows a different arc to that in the prior art, gaining height relative to the chassis more quickly in the initial phase of the movement. There may therefore be less chance of obstruction of the flow of material out of the body as the assembly moves to a tipping position.