Tipping wheelbarrow

Abstract

A wheelbarrow (100) has a support structure (102) mounted for rotation about a tip axis (119). A bucket is mounted on the support structure (102) for rotation about a bucket axis (124). The centre of gravity (134) of the bucket when loaded is normally behind the bucket axis (124). Rotation of the support structure (102) about the tip axis (119) upwards moves the centre of gravity (134) forward and when the centre of gravity (134) is forward of the bucket axis (124) the bucket tips and discharges its contents.

Description

[0001] 5664-20251112-specification

[0002] - 1 -

[0003] Tipping Wheelbarrow

[0004] Field of Invention

[0005] This invention relates to wheelbarrows and more particular to manually moved and tipped wheelbarrows.

[0006]

[0007] >

[0008] Manually moved and tipped wheelbarrows are used to move relatively small quantities of material, typically soil and building materials.

[0009] Wheel barrows typically have one or more wheels mounted for rotation about an axis. A support structure, typically a frame, is mounted for rotation relative to the wheel(s) with handles, feet and a bucket for material to be moved. The bucket is fixed to the frame and, in a fore-aft direction, is located between the wheel(s) and handles used for manipulating the wheelbarrow. Emptying the bucket typically requires the frame and fixed bucket to be rotated about the axis so that any material slides out of the front of the bucket. Because the bucket is fixed, this usually requires the frame to be rotated a significant amount. This in turn requires the ends of handles to be raised a significant amount.

[0010]

[0011] of the Invention

[0012] In one broad form the invention provides a wheelbarrow comprising:

[0013] at least one wheel:

[0014] a support structure connected to the wheel and mounted for rotation about a tip axis;

[0015] a bucket mounted to the support structure for rotation about a bucket axis relative to the support structure between a load position and a discharge position;

[0016] the wheelbarrow having a rest state when the at least one wheel and the 5664-20251112-specification

[0017] - 2 -

[0018] support structure sit on a horizontal surface;

[0019] the wheelbarrow having a front and a rear;

[0020] the bucket having a centre of gravity when loaded with a homogeneous material, the centre of gravity being located between the bucket axis and the rear of the wheelbarrow when the wheelbarrow is at the rest state and the bucket is in the load position;

[0021] the support structure rotatable about the tip axis to a tip state in which the centre of gravity is between the bucket axis and the front of the wheelbarrow, whereby the bucket rotates about the bucket axis to the discharge position, to discharge said material from the bucket.

[0022] The tip axis may be an axis of rotation of at least one of the at least one wheel but may be independent of the axis of rotation of a wheel.

[0023] The at least one wheel may be mounted for rotation about multiple axes of rotation.

[0024] The tip axis is preferably a wheel axis.

[0025] The angle of rotation from the rest state to the tip state may be between about 18 and about 43 degrees, preferably between about 25 and about 38 degrees, more preferably between about 28 and 33 degrees and most preferably is about 28 degrees.

[0026] In a preferred embodiment the support structure comprises at least one arm whereby a user can rotate the support structure about the tip axis.

[0027] The support structure may have a longitudinal axis. In a preferred embodiment, in the rest state the longitudinal axis may extend at about 12 degrees to the horizontal and about 22 degrees to the horizontal when rotated to a movable state, when only the at least one wheel supports the remainder of the wheelbarrow. The support structure may include at least one handle portion. The at least one handle portion may extend generally parallel to the longitudinal axis. 5664-20251112-specification

[0028] - 3 -

[0029] In a preferred embodiment in which the longitudinal axis extends at about 12 degrees to the horizontal in the rest state, in the tip position, the longitudinal axis will be between about 30 and about 55 degrees (, corresponding to rotation from the rest state of about 18 to 43 degrees), more preferably between about 35 and about 45 degrees and most preferably about 40 degrees to the horizontal.

[0030] The bucket may be biased to the load position.

[0031] The wheelbarrow may include retaining means to retain the bucket in the load position.

[0032] The wheelbarrow bucket may have a base portion and an inner surface of the base along a fore-aft centreline may be generally vertical when the bucket is at the discharge position and the support structure is at the tip state.

[0033] At least one location on the inner surface of the base portion along the fore-aft centreline may be between plus or minus 10 degrees of the vertical when at the discharge position and the support structure is at the tip state.

[0034] The inner surface of the base portion may be rectilinear along the fore-aft centreline.

[0035] The wheelbarrow may have a retainer member movable between a retaining position and a release position mounted on one of the support structure and the bucket, that, when the bucket is in the load position and the retainer member is in the retaining position, the retainer engages the other of the support structure and the bucket and prevents the bucket moving to the discharge position.

[0036] The retainer member may engage the other of the support structure and the bucket when the bucket returns to the load position.

[0037] The retainer may be biased to the retaining state.

[0038] The wheelbarrow may comprise a release mechanism on the support structure adapted to move the retainer member from the retaining position to the 5664-20251112-specification

[0039] - 4 -

[0040] release position.

[0041] The release mechanism may include a release member operable by the user to cause the retainer member to move from the retaining position to the release position.

[0042] The support structure may comprise at least one handle portion adapted to be engaged by a user to rotate the support structure about the tip axis

[0043] The release member may be at or adjacent at least one handle portion.

[0044] The release member may be operable by the user whilst the at least one handle portion is engaged by the user

[0045] The at least one wheel may comprise wheels mounted for rotation about multiple axes of rotation.

[0046] The support structure may comprise a forward end and a rearward end with the tip axis between the forward and rearward ends and wherein when the support structure is in the tip state and the bucket is in the discharge state the forward end is clear of a notional horizontal surface tangent to the at least one wheel.

[0047] Brief

[0048]

[0049] of the

[0050]

[0051] Figure 1 is a side view of a wheelbarrow according to an embodiment of the invention in a rest state.

[0052] Figure 2 is a side view of the wheelbarrow of figure 1 in a tipping state.

[0053] Figure 3 is a side view of the bucket of the wheelbarrow of figure 1.

[0054] Figure 4 is a rear view of the bucket of the wheelbarrow of figure 1.

[0055] Figure 5 is a schematic side view of a releasable retaining mechanism for the wheelbarrow of figure 1.

[0056] Detailed Description of Preferred and other Embodiments Referring to the drawings there is shown a wheelbarrow 100 according to an 5664-20251112-specification

[0057] - 5 -

[0058] embodiment of the invention. The wheelbarrow 100 comprises support structure 102, which includes and feet 108, bucket 104, wheel 106.

[0059] The wheel 106 is mounted to the support structure, in this embodiment by brackets 110 of support structure 102. The support structure comprises two arms 112 that extend either side of the wheel 106, joined by cross bar 114. Each arm 112 has a handle portion 116.

[0060] The brackets 110 hold wheel axle 118 on which wheel 106 is mounted, whereby the wheel 106 and support structure 102 can rotate relative to each other. Thus the support structure 102 is rotatable about the axis 119 of the axle 118. Axis 119 is hereinafter referred to as the tip axis.

[0061] The feet 108 support the rest of the support structure 102 on the ground. The feet 108 are sized and positioned so that, in this embodiment, the arms 112 are at an angle 120 of about 12 degrees to the ground. The size and positioning depend partly on the size of the wheel 106, the size of the feet 108 and the size of the brackets 110. The angle 120 of about 12 degrees to the ground is not critical and other angles may be used.

[0062] The bucket 104 is mounted on the support structure via bucket axle 122 and is rotatable about the bucket axis 124 of bucket axle 122 relative to support structure 102. The bucket has two spaced lugs 128 through which the axle 122 passes. In this embodiment the bucket axle 122 is mounted on brackets 129 which are then connected to the rest of the support structure 102. The bucket axle 122 may mount directly to the support structure and / or the brackets may be part of the support structure. The bucket may rotate about bucket axle 122, with bucket axle 122 fixed to support structure 102 or may be fixed to bucket axle 122 with the bucket axle rotating relative to the support structure. Rotation of both the bucket relative to the bucket axle 122 and the bucket axle 122 relative to the support structure 102 is within the scope of the invention. The bucket 104 may rotate forwards (anticlockwise in figure 1 ) relative to support structure 102, with stop 130 engaging support structure 102 to limit rotation. Rotation backwards (clockwise in figure 1) relative to support 5664-20251112-specification

[0063] - 6 -

[0064] structure 102 is limited by supports 132 of arms 112.

[0065] In the preferred embodiment, when resting on a horizontal surface, the centre of bucket axle 122 (the bucket axis 124) is located about 280 mm above the wheel axle 118 and about 150 mm rear of the wheel axle 118. In this embodiment the centre of bucket axle 122 is located about 445 mm above the ground. The height is determined partly by the diameter of the wheel 106, the brackets 110, 114 and the feet 108.

[0066] When resting on a horizontal surface the centre of gravity of both an empty bucket and a loaded bucket is located rearwards of the bucket axle 122 (and bucket axis 124) and so the weighty of empty bucket and a loaded bucket urges the bucket clockwise against the support structure 102. A centre of gravity of a loaded bucket is schematically shown at 134. The location of the point 134 is not to be considered to be the actual centre of gravity of a loaded bucket and is merely provided to explain the working of the invention. It will be appreciated that the actual centre of gravity depends on the shape of the bucket, the amount in the bucket, how the material is distributed in the bucket, material density (or densities) and how varied (non-homogenous) it is. When loaded and the user lifts the handles 116 to rotate support structure 102 about tip axis 119 and lift the feet 108 off the ground, to a movable state, the arms 112 and handle portions 116 are at an angle around 22 degrees, depending on the user’s size. In the movable state the wheelbarrow may be wheeled over the ground to a destination. This angle of around 22 degrees is not critical and when in a movable state the centre of gravity of both an empty bucket and a loaded bucket just needs to remain located rearwards of the axis 124 of bucket axle 122. It will be appreciated that the support structure may have a different construction and need not have two straight elongate arms 112. The support structure and / or the arms 112 may be constructed with metal tubing or the like that has handle portions 116 extending from a support structure portion at an angle to the adjacent support structure portion. The arms may be joined by a transverse handle portion. 5664-20251112-specification

[0067] - 7 -

[0068] Figure 2 shows the wheelbarrow 100 in a tipping state. The support structure 102 has been rotated anticlockwise relative to tip axis 129 / wheel axle 118 to a tip position. The tip position depends on the shape of the bucket, the amount the bucket has been loaded and if it is homogeneous or not, but typically for the preferred embodiment the tip position will only require rotation of about 28 degrees around tip axis 119 compared to the rest state, i.e. about an extra 18 degrees compared to the movable state. In this embodiment the angle 120 of the arms 112 to the horizontal is about 40 degrees when the support structure is at the tip position.

[0069] Depending on the implementation of the invention, when the bucket is filled with a homogenous material, such as sand, preferably the tipping state occurs when the support structure has rotated between about 23 and about 43 degrees compared to the rest state (in this embodiment the handle portions 116 will be between about 35 and about 55 degrees to the horizontal), more preferably between about 28 and about 38 degrees (in this embodiment the handle portions 116 will be between about 40 and about 50 degrees to the horizontal) and most preferably about 33 degrees (in this embodiment the handle portions 116 will be at about 40 degrees to the horizontal).

[0070] As the arms 112, and hence support structure 102 as a whole, are rotated anticlockwise the centre of gravity 134 moves forward relative to the bucket axis 124. Once the centre of gravity 134 passes a vertical plane 136 passing through the bucket axis 124 the weight of the loaded bucket urges the bucket 104 anticlockwise and the bucket rotates anti clockwise to the discharge position shown in figure 2. Rotation may be aided by jerking (a small, short and sharp motion of) the wheelbarrow forwards or upwards, so that when stopped the momentum of the bucket moves the centre of gravity past the vertical plane 136. Rotation is limited by the stop 130. Preferably the front 138 of the support structure is cleared by front lip 140 of bucket 104. Because the support structure has not needed to be rotated as much as a conventional wheelbarrow, the front 138 of the support structure 102 is higher above the 5664-20251112-specification

[0071] - 8 -

[0072] ground when unloading compared to a conventional wheelbarrow. With many conventional wheelbarrows to fully discharge the bucket the user needs to rotate the wheelbarrow so it is resting on the front 138 of the support structure and not the wheel. This makes it difficult to move the wheelbarrow backwards as the load discharges. In contrast, because the front 138 of the support structure remains clear of the ground, as the load discharges the user may easily wheel the wheelbarrow backwards away from the pile of the discharged load.

[0073] The amount of rotation of the support structure required from the rest state to the tip state to cause the bucket to rotate about the bucket axis to discharge loaded material depends on the actual centre of gravity. The actual centre of gravity depends on the shape of the bucket, the amount in the bucket, how the material is distributed in the bucket, material density (or densities) and how varied (non-homogenous) it is. As such the actual rotation required may be outside the ranges mentioned, despite a bucket loaded with a homogenous material rotating to the discharge position with a rotational angle within the ranges specified.

[0074] In the preferred forms of the invention the bucket is located nearer to the wheel than conventional wheelbarrows. This results in reduction of the upwards force required to raise the feet off the ground and so the load appears to the user to be lighter.

[0075] Where a bucket with the same shape is mounted on a support structure with the support structure members and / or the handle portions 116 extending at a different angle, the amount of rotation of the support structure from a rest stage to the point at which the centre of gravity 134 passes a vertical plane 136 passing through the bucket axis 124 will be unchanged where the bucket orientation at the rest position is unchanged. However, because the support structure members and / or the handle portions 116 at the rest state are at a different angle, their angle will be different. Thus, for example, use of a smaller wheel with the same size feet 108, the support structure members will 5664-20251112-specification

[0076] - 9 -

[0077] be angled upward more. Assuming supports 132 are modified to keep the base 142 of the bucket at the same angle, the support structure members will still rotate the same amount but will be at a greater angle to the ground and the handles higher. Similarly a larger wheel will result in the support structure members being at a smaller angle relative to the ground and the handles will be lower when tipping.

[0078] Preferably the inner surface 143 of the base 142 of the bucket along a fore-aft centreline 148 is generally vertical at this discharge position when the support structure is at the tip state, aiding discharge of any material in the bucket. This includes the base 142 being slightly off vertical, as seen in figure 2. The inner surface 143 of the base 142 along a fore-aft centreline may be between plus or minus about 10 degrees of the vertical when at the discharge position when the support structure is at the tip state.

[0079] It will be appreciated that the base 142 need not be planar and, for example, may be curved in a fore-aft direction. If so, in the discharge position, preferably the inner surface of a curved base is also generally near vertical, but because of the fore-aft curvature the angle relative to vertical will differ along the inner surface. Once the material in the bucket has been discharged the user lowers the wheelbarrow, either to the movable state or the rest state. The bucket may initially remain in the discharge position. Depending on the location of the centre of gravity 134 of the empty bucket in that discharge position, the centre of gravity 134 may return to be rearwards of the vertical plane 136, in which case the bucket will automatically rotate to the load state and rest against the supports 132.

[0080] If, in the discharge position as shown in figure 2, the centre of gravity 134 of the empty bucket is forwards of the vertical plane 136 it may be brought to be rearwards of the plane 136 by the user by jerking the wheelbarrow forwards or downwards (and using the bucket’s momentum) or merely by gently lowering the arms (such as to the movable position) until the centre of gravity 134 of the empty bucket is rearwards of the vertical plane 136 and the bucket rotates 5664-20251112-specification

[0081] - 10 -

[0082] to the load state, resting on the stops 132. The user may also manually rotate the bucket back to the load state.

[0083] It will be appreciated that in use a user may rotate the support structure more than needed to initiate rotation of the bucket to the discharge position, i.e. past the tip state, so the centre of gravity of the empty bucket may be forward of the vertical plane 136 even if it would be rearwards of the vertical plane 136 when the support structure is at the tip state as in figure 2.

[0084] If, in the tipping state, the centre of gravity 134 remains forward of the vertical plane 136 at the rest state, the bucket will not rotate automatically to the load state. The user may manually rotate the bucket back to the load state or other means may be provided to cause or assist in return to the load state.

[0085] A spring or other biasing member may be provided to assist in return of the bucket to the load state. It will be appreciated that if the bucket is biased toward the load state the biasing should preferably not significantly in impact on the ability of the bucket to rotate to the discharge position.

[0086] Preferably the user does not need to touch the bucket and preferably it returns to the load state merely on lowering the wheelbarrow to the movable state.

[0087] As shown in figures 4 and 5, a retainer may be provided to retain the bucket in the load state and prevent tipping until the retainer has been released by the user. The retainer may be mounted on the support structure or the bucket and engage the other of the support structure and the bucket.

[0088] Bucket 104 may be provided with a fixed retainer member, flange 144. Flange 144 may be provided with an aperture 146 whereby a movable retainer mounted on the support structure 102 may engage with the flange and retain the bucket in the load state and prevent tipping until the retainer has been released from engagement with the flange 144 by the user. This can be advantageous when moving downhill to prevent unplanned tipping of the 5664-20251112-specification

[0089] - 11 -

[0090] bucket or when moving over rough ground where sudden stopping of the wheelbarrow may cause the bucket to rotate relative to support structure 102 due to its momentum. Use of an aperture is not essential and other means of retaining the bucket in its loaded state may be used.

[0091] The retainer may be a pawl (a rotatable curved or hook like member) that engages within the aperture 146. The aperture may be omitted and a pawl or other retainer may merely engage a side of a retainer member. The retainer, such as a pawl, may be moved directly or via one or more linkages that extend to the handles, so that the user can move the retainer and release the bucket without taking their hands from the handles. Preferably the linkages are positioned so that a user’s thumb can move the retainer, such as a pawl. The retainer is preferably shaped and biased to engage in the aperture (or other part of the retainer member) when the bucket returns to the load state, securing the bucket in the load state without user action.

[0092] The movable retainer may be mounted on the bucket and engage the support structure. A release mechanism may be provided that is mounted on the support structure that is operable by the user to selectively move the retainer on the bucket to allow the bucket to move relative to the support structure. Figure 5 schematically shows a side view of a support structure member 112 with a latch mechanism generally indicated by 150. The latch mechanism includes retainer, in this case pawl 152, that passes into aperture 146 of retainer member 144. The pawl is mounted for rotation about axis 154. A release lever 156 is mounted on the support structure member at or near the handle portion 116 for rotation about axis 158. Link member 160 connects the pawl 152 and release lever 156 together. The user may push down on lever 156, as indicated by arrow 162, drawing the pawl 152 out of the aperture 146, as indicated by arrow 164. A spring or other biasing member 166 may bias the mechanism 150 to the retaining position shown in figure 5. The lever 156 is preferably positioned so that the user may push down on the lever with their thumb or other finger whilst lifting the wheelbarrow. 5664-20251112-specification

[0093] - 12 -

[0094] It will be appreciated that there are many different configurations of wheelbarrow support structures and buckets and the invention is not limited to the specific support structure arrangement shown or the specific bucket arrangement shown.

[0095] Whilst the invention has been described with reference to an embodiment with a single axis of rotation for a single wheel it will be appreciated that it is applicable to wheelbarrows with multiple wheels, whether mounted for rotation about a single axis of rotation or multiple axes of rotation, such as a wheel barrow with two pairs of wheels with each pair mounted on separate axes of rotation.

[0096] Unless the context clearly requires otherwise, it is to be understood that, if any prior art is referred to herein, such reference does not constitute an admission that the prior art forms a part of the common general knowledge in the art, in Australia or any other country.

[0097] Unless the context clearly requires otherwise, throughout the description and any claims the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

[0098] The features of the invention described or mentioned in this document may be combined in any combination of features where features are not mutually exclusive.

[0099] It will be apparent to those skilled in the art that many obvious modifications and variations may be made to the embodiments described herein without departing from the spirit or scope of the invention.

Claims

5664-20251112-specification- 13 - The claims defining the invention are as follows:

1. A wheelbarrow comprising:at least one wheel:a support structure connected to the wheel and mounted for rotation about a tip axis;a bucket mounted to the support structure for rotation about a bucket axis relative to the support structure between a load position and a discharge position;the wheelbarrow having a rest state when the at least one wheel and the support structure sit on a horizontal surface;the wheelbarrow having a front and a rear;the bucket having a centre of gravity when loaded with a homogeneous material, the centre of gravity being located between the bucket axis and the rear of the wheelbarrow when the wheelbarrow is at the rest state and the bucket is in the load position;the support structure rotatable about the tip axis to a tip state in which the centre of gravity is between the bucket axis and the front of the wheelbarrow, whereby the bucket rotates about the bucket axis to the discharge position, to discharge said material from the bucket.

2. The wheelbarrow of claim 1 wherein the angle of rotation from the rest state to the tip state is between about 18 and about 43 degrees.

3. The wheelbarrow of any one of the previous claims wherein the angle of rotation from the rest state to the tip state is between about 25 and about 38 degrees.

4. The wheelbarrow of any one of the previous claims wherein the angle of rotation from the rest state to the tip state is between about 28 and 33 degrees.5664-20251112-specification- 14 -5. The wheelbarrow of any one of the previous claims wherein the angle of rotation from the rest state to the tip state is about 28 degrees.

6. The wheelbarrow of any one of the previous claims wherein the bucket has a base portion and an inner surface of the base along a fore-aft centreline is generally vertical when the bucket is at the discharge position and the support structure is at the tip state.

7. The wheelbarrow of claim 6 wherein at least one location on the inner surface of the base portion along the fore-aft centreline is between plus or minus 10 degrees of the vertical when at the discharge position and the support structure is at the tip state.

8. The wheelbarrow of claim 6 or claim 7 wherein the inner surface of the base portion is rectilinear along the fore-aft centreline.

9. The wheelbarrow of any one of the previous claims wherein the bucket is biased to the load position.

10. The wheelbarrow of any one of the previous claims comprising a retainer member movable between a retaining position and a release position mounted on one of the support structure and the bucket, that, when the bucket is in the load position and the retainer member is in the retaining position, the retainer engages the other of the support structure and the bucket and prevents the bucket moving to the discharge position.

11. The wheelbarrow of claim 10 wherein the retainer member engages the other of the support structure and the bucket when the bucket returns to the load position.

12. The wheelbarrow of claim 10 or claim 11 wherein the retainer is biased to the retaining state.

13. The wheelbarrow of any one of claims 10 to 12 comprising a release mechanism on the support structure adapted to move the retainer member from the retaining position to the release position.5664-20251112-specification- 15 -14. The wheelbarrow of any one of claims 10 to 13 wherein the release mechanism includes a release member operable by the user to cause the retainer member to move from the retaining position to the release position.

15. The wheelbarrow of any one of the previous claims wherein the support structure comprises at least one handle portion adapted to be engaged by a user to rotate the support structure about the tip axis16. The wheelbarrow of claim 15 when dependent on claim 14 wherein the release member is at or adjacent at least one handle portion.

17. The wheelbarrow of claim 15 or claim 16 when dependent on claim 14 wherein the release member is operable by the user whilst the at least one handle portion is engaged by the user.

18. The wheelbarrow of any one of the previous claims wherein the tip axis comprises an axis of rotation of at least one of the at least one wheel.

19. The wheelbarrow of any one of claims 1 to 17 wherein the tip axis is independent of the axis of rotation of a wheel.

20. The wheelbarrow of any one of the previous claims wherein the at least one wheel comprises wheels mounted for rotation about multiple axes of rotation.

21. The wheelbarrow of any one of the previous claims wherein the support structure comprises a forward end and a rearward end with the tip axis between the forward and rearward ends and wherein when the support structure is in the tip state and the bucket is in the discharge state the forward end is clear of a notional horizontal surface tangent to the at least one wheel.

Images