GB2342073A

GB2342073A - Wheelbarrow with suspension

Info

Publication number: GB2342073A
Application number: GB9820034A
Authority: GB
Inventors: Peter William Bothwell
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-09-16
Filing date: 1998-09-16
Publication date: 2000-04-05
Anticipated expiration: 2018-09-16
Also published as: GB2342073B; GB9820034D0

Abstract

A wheelbarrow comprises a load carrying body (10), handle means (15), support means (16), a wheel (20), and suspension means (21,23) providing for sprung and damped movement of the wheel upwardly and downwardly relative to the load carrying body. The axis of rotation of the wheel is positioned so that when the wheelbarrow is empty it lies a small distance forward of the centre of gravity (19) of the wheelbarrow. When the wheelbarrow is loaded the arcuate path of movement of the wheel causes the axis of rotation to move rearwardly closer to the centre of gravity, thus reducing the force required in lifting the handles. The spring means (23) may be such as a rubber in torsion spring, a telescopic spring-damper unit, or a pivot bearing and separate spring. The trailing arm nature of the suspension could be replaced with a leading arm wheel support, which could be capable of being locked against vertical movement.

Description

2342073 PATENTS ACT 1977 GMD/A9524GB Title: WHEELBARROW

Description of Invention

This invention relates to a wheelbarrow.

The wheelbarrow is a familiar item of equipment for use in gardens, on building sites, and elsewhere, and in its most usual form has remained substantially unchanged for generations. Such traditional form of barrow comprises a load-carrying body, a wheel at one end thereof, and a pair of handles extending longitudinally from the other end of the body for holding by a user to enable the barrow to be controlled, propelled and tilted when required for discharging the barrow's load. At the end of the body from which the handles extend there are supports such as legs which are rested on the ground when the barrow is to be parked, and when the barrow is supported on level ground by such supports and its wheel it is normally arranged that the loadcai-ryMg body of the barrow will be substantially level. Front and rear walls of the load-carrying body are inclined with the fi-ont wall usually at a relatively C shallow angle to the horizontal and extending at least pailly over the wheel, for 0 facilitating load discharge by tilting the barrow forwards.

0 Whilst a conventional wheelbarrow is a robust piece of equipment, it requires considerable strength to be operated when it is full of a dense substance such as earth. The centre of gravity of the laden body is a substantial distance rearwardly of the balTOW'Swliecl, and the leverage about such wheel afforded by the handles, whilst significant, is not sufficient to reduce to a very low level the lifting force which has to be exerted by the user 1 of the barrow. Tipping the barrow forwardly to empty it also requires exertion C) of considerable force by the operator.

2 Accordingly it is an object of the present invention to provide a wheelbarrow which overcomes or reduces the above-described disadvantages of conventional barrows. Further advantages of a barrow in accordance with the invention will be described hereafter.

According to the invention, 1 provide a wheelbarrow comprising a loadcarrying body; handle means extending from one end of the body; a wheel disposed beneath the body, at a position in the vicinity of the centre of gravity of the body when uniformly loaded; and suspension means providing for sprung and damped movement of the wheel upwardly and downwardly relative to the body.

When we refer to the wheel being in the vicinity of the centre of gravity C of the body when uniformly loaded, we mean the disposition in plan View of the barrow. It will be appreciated that in side view of the barrow the centre of gravity of the loaded body will lie a substantial distance above the axis of rotation of the wheel, whatever the position of the wheel is within its range of movement relative to the body provided by the suspension means.

By virtue of having the wheel in the vicinity of the centre of gravity of the body when loaded uniformly, a user lifting the handle means of the barrow does not have to exert a great force to lift the end of the barrow having the handle means.

Preferably there is support ineans at the end of the body of the barrow havine, the handle means, for providing "parking" support of the barrow with its 0 C1 c body in a more or less horizontal orientation (when parked on level ground) for loading purposes. Preferably the wheel is positioned so as to lie slightly forwardly of the centre of gravity of the body when uniformly loaded, so that the barrow will rest on its support means.

Conveniently the support means comprises tx,,,o leg members or leg C1 structures, as for a conventional barrow.

3 The body of the barrow may have a base which is flat or substantially flat, or may have a base with a recess extending upwardly into it and into which the wheel moves in the course of its movement relative to the body provided by the suspension means.

The wheel is preferably carried by a pivoted arm or fork. Such a pivoted arm or fork may be mounted on the body of the barrow or on a chassis member or structure, e.g. of one or more tubular elements appropriately shaped, which may also carry other pails of the barrow. Any convenient spring means and damping means may be provided in association therewith: examples are described hereafter.

The invention will now be described by way of example with reference to the accompanying drawing, which is a diagrammatic side elevation of a 0 wheelbarrow in accordance with the invention.

Referring to the drawings, a wheelbarrow comprises a load-carrying body indicated generally at 10, in the form of an open-topped pan having a base 11, front and rear walls 12, 13 respectively, and opposite side walls as indicated at 14. The front and rear walls are, as illustrated, inclined to the vertical when the wheelbarrow is the orientation illustrated, the front wall being inclined to a greater extent than is the rear wall.

At the rear of the body 10 there is a pair of handles for holding by a user and as illustrated such handles may be secured to the body 10: one such handle is shown at 15 in the drawings and it extends rearwardly generally in line with the upper boundary of the body. Also at the rear of the body there is a pair of parking legs one of which is indicated at 16. in this embodiment the parking leg 16 is a generally U-shaped tubular member secured to the rear wall and base of the body as indicated at 17, 18.

The approximate position of the centre of gravity of the body 10 when it is uniformly loaded to or near its capacity is indicated at 19.

4 Beneath the body 10 the barrow has a wheel 20. The wheel is carried by a pivoted arm or fork 21 which is mounted on a plate 22 at the front end of the base 11 of the barrow's body. The arm or fork 21 is carried relative to the support plate 22 by a pivot arrangement 233 incorporating a rubberin-torsion 0 spring so that upwards movement of the wheel relative to the body of the barrow is resisted by such spring. The wheel 20 is shown primarily in the drawing in a lower or lowermost position relative to the body of the barrow: it C1 can move against the force of the spring 23) to a position of maximum deflection as shown in broken lines at 24. A bump stop 25 engaging the arm or fork 21 prevents movement beyond this point.

A damper unit 26 is secured beneath the base 11 of the barrow above the arm or fork- 21 and has an aligularly movable arm 27 pivotally connected to a link 28 which is in turn pivotally conriected to the arm or fork 21. It will be appreciated that pivotal movement of the arm or fork 21 correspondincr to upwards and downwards movement of the wheel 20 relative to the body of the barrow causes angular movement of the damper arm 27 and the damper causes such movement to be resisted. The damper 26 may be a fluid operated type. As an alternative to the damper 26 a damper may be incorporated in the pivot arrangement 23).

The position of the wheel relative to the body of the barrow 1S such that when the barrow is unloaded and the wheel is in the position in which it is primarily shown in the drawing it lies in the vicinity of the centre of gravity 19 of the barrow: in fact the axis of rotation of the wheel 20 lies a small distance forwardly of the centre of gravity. When the barrow is laden, the arcuate path of movement of the wheel 20 ineans that the axis of rotation of the wheel moves rearwardly more closely to approach the centre of gravity 19.

Because of the disposition of the wheel as above described, die user of the barrow does not have to exert a great force to lift its handles as 15 when it is fully loaded. The damper 26 controls any tendency of the body of the barrow to bounce up and down in an uncontrolled manner, which if it were allowed to occur could cause spillage of a liquid load such as liquid concrete or of a particulate load such as sand. The exertion required of the operator to control any such bouncing is significantly reduced by the presence of the C 0 damper. The position of the centre of gravity 19 relative to the wheel renders the barrow stable when being pushed.

It will be noted that the base 11 of the body of the barrow is domed upwardly above the wheel 20, to accommodate upwards movement of the wheel relative to the body without requiring the body as a whole to be mounted high above the wheel. The base 11 may be inclined upwardly as illustrated from both ends to a central region above the wheel or it may be provided with a more pronounced recess: a recess into which the wheel can move may also be present when the body is viewed in transverse cross-section. The shape preferably affords no narrow "pocket" or recess in which material being carried can become lodged.

By way of example, the wheel of a barrow as illustrated may have a diameter of the order of 20-25cins. A smaller wheel would require less of a recess or no recess at all to be provided in the base of the barrow to accommodate it, but would travel less readily over rough ground. The wheel may be of any appropriate type, e.g. of plastics or metal liaving a rubber tyre, possibly a pneumatic tyre, or it could be of the type generally in the configuration of an inflated ball. Preferably the wheel provides a broad contact patch with the ground.

Other suspension arrangements could be utilised while remaining within C 0 the broadest scope of the invention. For example, instead of the incorporation of a rubber-in-torsion spring at the point where the wheel carryl rig an-ri or fork is pivoted to the body of the barrow, there could be a simple pivot bearing at such point and a separate spring could be utilised. A telescopic spring-damper 0 unit could be used to provide both spi.maing and damping functions, such a unit 0 D 6 being connected between the wheel-carrying arm or fork and the body of the barrow at an appropriate position away from the pivotal connection of the arm or fork to the body. Instead of a trailing arm or fork aiTangement, having C regard to the normal direction of travel of the barrow, a leading arm or fork could be utilised, pivoted to the barrow at or adjacent the rear end of the body thereof. It would be possible to provide for the suspension of the barrow to be locked against upwards and downwards wheel movement relative to the body, if the barrow is to be used on level ground. This could be done by use of a strut or struts able to be placed in a suspension-locking position.

In any event, the invention provides a wheelbalTOWwhich is easy for an operator to use.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any

C combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

7 CLAIMS

1. A wheelbaiTow comprising a load carrying body; handle means extending from one end of the body; a wheel disposed beneath the body, at a C position in plan view in the vicinity of the centre of gravity of the body when uniformly loaded; and suspension means providing for sprung and damped movement of the wheel upwardly and downwardly relative to the body.

2. A wheelbarrow according to Claim 1 wherein the wheel is disposed C) towards the end of the body opposite to that from which the handle means extends, relative to the centre of gravity of the body when uniformly loaded.

A wheelbarrow according to Claim 2 fui-ther comprising suppoil means 0 at the end of the body having the handle means, for supporting the baiTow with 0 its body in a generally horizontal orientation.

4. A wheelbarrow according to Claim 33 wherein the suppon means C) comprises two]cc,, members or structures.

5. A wheelbaiTow according to any one of the preceding claims wherein 0 0 the body has a base which is flat or substantially flat.

6. A wheelbarrow according to any one of Claims 1 to 4 wherein the body Z-> 1 has a base having a recess extending upwardly into it, and into which the wheel moves in the course of its movement i.elati,,.,e to the body afforded by the suspension means.

7. A wheelbarrow according to any, one of the preceding claims wherein 0 0 the wheel is carried by a pivoted ann or fork.

9

8. A wheelbarrow according to Claim 7 wherein said arm or for k is pivoted Z:) in the region of the end of the body opposite that from which the handle means extends.

9. A wheelbarrow according to Claim 7 or 8 wherein said arm or fork is C, pivoted by a pivot arrangement including a rubber-in-torsion spring.

10. A wheelbarrow according to Claim 7 or 8 comprising a telescopic spring-damper unit cooperating with said arm or fork.

C)

11. A wheelbarrow substantially as hereinbefore described with reference to the accompanying drawings.

12. Any novel feature or combination of features described herein and/or in the accompanying drawings Z: 0 1