Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
  • B62B3/00—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor
  • B62B3/04—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment
  • B62B3/06—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground
  • B62B3/0625—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground using rigid mechanical lifting mechanisms, e.g. levers, cams or gears
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
  • B62B2203/00—Grasping, holding, supporting the objects
  • B62B2203/20—Grasping, holding, supporting the objects using forks or tines
  • B62B2203/28—Guiding the forks into the pallets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
  • B62B2205/00—Hand-propelled vehicles or sledges being foldable or dismountable when not in use
  • B62B2205/12—Collapsible wheels

Definitions

• the present invention relates generally to a pallet carrier trolley and more specifically a pallet trolley essentially comprising a main body mounted on an elevating rear steering wheel, two horizontal lifting arms connected to the main body and each of which is provided with a corresponding elevating front wheel, a rear wheel actuation means mounted on the main body and actuating the elevation of the elevating rear steering wheel, two front wheel actuation mechanisms each of which is mounted in one of the lifting arms and actuates the elevation of one of the front elevating wheels and of control bars, each of which connects the rear wheel actuation means and the corresponding front wheel actuation mechanism.
• This blockage is caused by the blocking of one of the front wheels of the carriage, caused by a small hard object strewn on the ground, for example a pebble or a bolt, or by a very low step situated on the ground between two consecutive flat surfaces.
• An object of the present invention is to provide a pallet carriage in which the front wheels can roll more easily on hard foreign bodies present on the ground.
• Another object of the present invention is to provide such a pallet carriage in which the front wheels can easily pass irregularities or steps of low height present on the ground.
• Another object of the present invention consists in proposing such a pallet-carrying trolley which can also comply with the dimensional constraints resulting from the use of standardized pallets.
• the invention therefore relates to a rolling mechanism intended to support and transport a load.
• each of the two front wheel actuation mechanisms has kinematics which transforms the longitudinal displacement of the control bar into a corresponding displacement of the axis of rotation of the front wheel, this displacement being the combination: - of a rotation of the front wheel rotation axis around an axis substantially perpendicular to this front wheel rotation axis and oriented substantially in the longitudinal direction of the lifting arm, - and of a displacement of the center of the front wheel in a plane substantially perpendicular to the longitudinal direction of the lifting arm, whereby the point of contact between the front wheel and the ground remain substantially in a longitudinal vertical plane when said front wheel actuation mechanism changes from a lowered position to a raised position and vice versa.
• this displacement of the wheel axis results from a combination of a rotation of the rotation axis (3) of the wheel (2) and a displacement of the center (C) of the wheel (2), this displacement having at least one vertical component.
• the invention also relates to a pallet carriage comprising: a main body mounted on a rear steering and elevating wheel; two lifting arms connected to the main body and each of which is provided with a lifting front wheel; a rear wheel actuation mechanism mounted on the main body and actuating the elevation of the steerable and elevating rear wheel; two front wheel actuation mechanisms each of which is mounted in one of the lifting arms and actuates the raising of one of the front lifting wheels; and a control bar connecting the rear wheel actuation mechanism and the front wheel actuation mechanism.
• said wheel actuation mechanism has kinematics which transforms the longitudinal displacement of the control bar into a corresponding displacement of the axis of rotation of the wheel, this displacement being the combination: - d 'a rotation of the wheel rotation axis about an axis substantially perpendicular to this wheel rotation axis and oriented substantially in the direction of travel, - and of a displacement of the center of the wheel in a plane substantially perpendicular to the direction of advance, where it follows that the point of contact between the wheel and the ground remains substantially in a vertical plane along the direction of advance when said wheel actuation mechanism changes from a lowered position to a raised position and vice versa.
• this displacement of the wheel axis results from a combination of a rotation of the rotation axis (3) of the wheel (2) and a displacement of the center (C) of the wheel (2), this displacement having at least one vertical component.
• each of the two front wheel actuation mechanisms is constituted by: a first wheel support on which the front wheel is rotatably mounted; a second wheel support on which the first wheel support is rotatably mounted; a third wheel support which is connected to the second wheel support by means of a first articulation whose articulation axis is substantially longitudinal and which is mounted movable relative to the lifting arm so that the first articulation moves along a first substantially transverse trajectory (X; Y); and a pivoting control means, the pivot axis of which is substantially transverse, this control means being actuated by said control bar and comprising a free end connected to the first wheel support by means of a ball-type connection.
• the third wheel support is slidably mounted along guide bars arranged in a substantially transverse manner.
• the third wheel support is pivotally mounted about a second articulation axis fixed relative to the lifting arm.
• said first trajectory (X; Y) is inclined relative to a horizontal plane so that said first articulation moves towards down and transversely when said front wheel actuation mechanism moves from a lowered position to a raised position.
• said first trajectory (X; Y) is inclined relative to a transverse vertical plane so that the longitudinal position of said first articulation approaches said pivot axis of said pivoting control means when said front wheel actuation mechanism changes from a lowered position to a raised position.
• said pivot axis of said pivoting actuating means is inclined with respect to a horizontal plane so that the position of said ball-type connection along a transverse line and the position of said first articulation along this transverse line move in the same direction when said front wheel actuation mechanism passes from a lowered position to a raised position.
• said pivot axis of said pivoting actuating means is inclined with respect to a transverse vertical plane so that the position of said ball-type connection along a transverse line and the position of said first articulation along this transverse line moves in the same direction when said front wheel actuation mechanism passes from a lowered position to a raised position.
• Figures 1 and 2 are the same cross-sectional views of part of a pallet carriage according to the invention, this part of the pallet carriage including a device according to the invention, the rest of the pallet carriage not being shown because it can be of any conventional type;
• Figure 1 showing the carriage in the lowered position and Figure 2 showing the same carriage in the raised position;
• Figure 3 is a simplified bottom view of the pallet carriage portion of Figure 1;
• Figure 4 is a simplified side view of the pallet carriage portion of Figure 1;
• Figures 5 to 7 are the same perspective views, from below, of another embodiment of a part of a pallet carriage according to the invention, this part of the pallet carriage including a device according to the invention, the rest of the pallet carriage not being shown because it can be of any conventional type;
• Figure 5 showing the carriage in the lowered position and Figure 6 showing the same carriage in the intermediate position and Figure 7 showing the same carriage in the fully raised position;
• FIGS. 8 are the same cross-sectional views of part of a pallet carriage according to the invention, this part of the pallet carriage
• FIG. 1 there can be seen, in cross section, a lifting arm 1 of a pallet-carrying carriage in which a front wheel 2 of the carriage is mounted, this wheel 2 being able to rotate about a wheel articulation axis 3.
• the lifting arm 1 has an inverted U-shaped cross section.
• the wheel 2 and the whole mechanism for rotating and controlling the position of the wheel 2 is housed inside the lifting arm 1.
• This mechanism is hereinafter called "front wheel actuation mechanism”.
• a control bar 4 (more visible in FIGS. 3 and 4) can move longitudinally between a position offset towards the rear of the carriage (position corresponding to FIGS. 1, 3 and 4) and a position offset towards the front of the carriage (position corresponding to figure 2).
• This control bar 4 makes it possible to control the lowering or raising of the wheel 2.
• the front end of the control bar 4 is connected by a hinge 6 to the free end of a first control arm 8 of which 1 the other end is fixed to a rotating hub 10 which can pivot around a fixed support bar 12.
• One end of a second control arm 14 (visible essentially in FIGS. 2, 3 and 4) is also fixed to the hub 10 and this second control arm 14 is connected, at its free end, by a ball-type joint 16 to a third control arm 18 of a part constituting a first wheel support 20, the latter being described more in detail below.
• first wheel support 20 On this first wheel support 20, the wheel 2 is mounted for free rotation by means of a ball bearing 22.
• This first wheel support 20 is mounted for free rotation on a second wheel support 24.
• a third support wheel 26 is connected, at one of its ends, to the lifting arm 1 by means of an articulation 28, so as to be able to pivot relative to the lifting arm 1 about a pivot axis substantially longitudinal 30 (visible in Figure 3).
• the other end of the third wheel support 26 is connected to a fourth control arm 32 fixed to the second wheel support 24, by means of another articulation 34, so as to be able to pivot relative to the second support wheel 24 around a substantially longitudinal pivot axis 36 (visible in Figure 3).
• This front wheel actuation mechanism operates as follows.
• this wheel 2 has its axis of rotation 3 which is situated substantially in a vertical plane perpendicular to the longitudinal direction of the lifting arm 1 (that is to say a plane situated in the plane of the sheet of Figure 1), and this axis of rotation is further inclined relative to the horizontal at a relatively large angle ⁇ l, for example between 50 ° and 80 °. It is understood that this wheel 2 can in these conditions be housed between the surface of the ground 40 and the inner face 42 of the lifting arm 1 so that the distance dl separating these two surfaces 40 and 42 is less than the diameter d2 of the wheel 2.
• this wheel 2 has its axis of rotation 3 which is situated substantially in a vertical plane perpendicular to the longitudinal direction of the lifting arm 1 (that is to say a plane situated in the plane of the sheet of Figure 2), and this axis of rotation is also substantially horizontal.
• the articulations 16 and 34 are raised (brought closer to the surface 42 of the lifting arm 1), so that the center C of the wheel 2 is relatively close to the surface 42 of the lifting arm lifting 1 and relatively distant from the longitudinal median plane 44 of the lifting arm 1, and in the raised position (FIG. 2), the joints 16 and 34 are lowered (distant from the surface 42 of the lifting arm 1) and brought back towards the plane longitudinal median 44 of the lifting arm 1, so that the center C of the wheel 2 is relatively distant from the surface 42 of the lifting arm 1 and relatively close to the longitudinal median plane 44 of the lifting arm 1.
• the wheel 2 rolls without sliding on the plane from the ground 40 during the lowering or raising of the lifting arm l while this lifting arm 1 is lowered or raised by following a vertical path. To obtain this, one can play on the profile of the surface of the wheel 2 which can come into contact with the ground 40.
• FIGS. 5 to 7 show another embodiment of the invention.
• FIGS. 5 and 6 therefore show the lifting arm 1, the wheel 2 with its axis of rotation 3, the ground 40 and the control bar 4.
• the bar 4 is connected to a lever 50.
• the lever 50 comprises a first branch 51 and a second branch 52 substantially perpendicular.
• the bar 4 is connected by ball joint to the free end of the branch 51.
• a second lever 53 comprises three branches 54, 55, 56 and is pivotally mounted around an axis 57 along the branch 54.
• the lever 50 is mounted pivoting about an axis 58 along the branch 56.
• Two arms 59, 60 are mounted pivoting around the branch 55.
• a wheel support piece 61 is pivotally mounted on the free ends of the two arms 59, 60 and supports a hub 62 on which the wheel 2 is pivotally mounted and on which a wheel arm 63 is pivotally mounted, the free end of which is connected by a ball joint 64 to the free end of the branch 52.
• the mechanism works as follows. We start arbitrarily from the lowered position of FIG. 5. The bar 4 is then pushed, which causes the pivoting of the lever 50. (like the length of the branch 51 is larger than that of branch 56, only the lever 50 starts to pivot about its axis 58 and therefore the lever 53 does not pivot around its axis 57. This movement brings the ball joint 64 closer to the branch 55, which causes the wheel support 61 to pivot while approaching the arms 59, 60 and becomes substantially vertical (FIG. 6). The wheel 2 has its axis 3 which therefore passes from a substantially vertical position (fig. 8) to a substantially horizontal position (fig. 9).
• the trajectory Y is an arc of a circle situated in a plane inclined relative to the vertical, this inclination being in the same direction than the inclination of the path X relative to a longitudinal vertical plane.
• the invention is not limited to the embodiments which have just been described but encompasses all the variants in which a control mechanism for the front wheel of a pallet carriage performs the same functions as those of the invention, in that which concerns the combined movements of the axis 3 of the front wheel 2 and its center C.
• a third wheel support which would be constituted by a deformable parallelogram mechanism, a cam mechanism, a hydraulic cylinder mechanism, or the like.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Handcart (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9435611

Family Applications (1)

Country Status (4)

Families Citing this family (3)

Family Cites Families (5)

• 1992
  • 1992-11-13 FR FR9213801A patent/FR2698063A1/fr not_active Withdrawn
• 1993
  • 1993-11-15 WO PCT/FR1993/001172 patent/WO1994011229A1/fr not_active Ceased
  • 1993-11-15 AU AU55672/94A patent/AU5567294A/en not_active Abandoned
  • 1993-11-15 EP EP94900887A patent/EP0707548A1/de not_active Withdrawn

Non-Patent Citations (1)

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