Land vehicles – Wheeled – Extensible
Reexamination Certificate
1998-02-02
2001-02-27
Johnson, Brian L. (Department: 3618)
Land vehicles
Wheeled
Extensible
C280S047310
Reexamination Certificate
active
06193265
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to wheelbarrows, and in particular, to readily maneuverable wheelbarrows with ergonomic handle designs and requiring small leverage to lift a load.
Wheelbarrows are well known as a tool for moving heavy loads for a short distance. Typically, a wheelbarrow has a container made from sheet metal supported by a forward wheel and two rear legs. The handles are typically formed as a pair of parallel pipes extending to the rear of the container.
The conventional wheelbarrow handle design suffers from a number of disadvantages. Although the conventional handle design is relatively comfortable to lift, the forward directed force required to move the wheelbarrow must be directed along the length of the handles. This applies transverse stress on the wrists of the user, rapidly leading to tiredness and aching joints. The conventional wheelbarrow handle design is also inconvenient for tipping-up the wheelbarrow, typically requiring at least one change of hand position during the lifting action.
Various other features of the conventional wheelbarrow design also have drawbacks. The single, forwardly-placed wheel makes the wheelbarrow unstable when the rear legs are raised. This instability is further aggravated by the positioning of the center of gravity of the container well above the wheel. Finally, the forward positioning of the wheel relative to the center of gravity leaves a large proportion of the loaded weight to be supported at the handles by the user.
Some of the aforementioned shortcomings have been addressed by a number of two-wheel wheelbarrows designs, typically made form molded plastic. An example of such a wheelbarrow is described in U.S. Pat. No. 5,615,903. Clearly, such a design is considerably more stable than a single-wheeled design. However, the high center of gravity, forwardly placed wheels, and poor handle design still present considerable disadvantages. Linkage between the two wheels may also make it difficult to steer the wheelbarrow in tight turns.
There is therefore a need for a wheelbarrow which has ergonomic handle design, and which is stable and easy to lift and maneuver.
SUMMARY OF THE INVENTION
The present invention is a readily maneuverable wheelbarrow with ergonomic handle designs and requiring small leverage to lift a load.
According to the teachings of the present invention there is provided, a wheelbarrow comprising a container, a pair of handles rigidly connected to the container, and a support system for supporting the container, the support system including at least one wheel assembly, wherein the container has a longitudinal-vertical plane of symmetry, each of the handles having an extensional direction angled rearwardly outwards such that, in a horizontal projection, the extensional direction forms an angle of between about 65° and about 85° with the plane of symmetry.
According to a further feature of the present invention, the container is divided by an intermediate wall into a front container and a rear container, the rear container being smaller than the front container.
According to a further feature of the present invention, the rear container has a rear wall, the handles being integrally formed with the rear wall.
According to a further feature of the present invention, the front container has side walls, the side walls having a plurality of shaped recesses, the wheelbarrow further comprising a plurality of clips configured to be received within the shaped recesses.
According to a further feature of the present invention, the shaped recesses have features configured to abut edges of the clips so as to prevent the clips from swiveling.
According to a further feature of the present invention, the at least one wheel assembly includes: (a) a support region integrally formed with the container, the support region having a transverse hole; (b) an axle passing through the transverse hole; (c) a wheel having a central bore; and (d) a sleeve element for positioning within the central bore, the sleeve element having: (i) an axial recess extending along a major part of the length of the sleeve element, the recess being shaped to receive the axle, (ii) an end wall for defining an extent of full insertion of the axle within the axial recess, and (iii) a substantially cylindrical external surface for rotatably engaging within the bore.
According to a further feature of the present invention, the sleeve element also has: (a) an outwardly extending radial flange for abutting an external surface of the wheel; (b) a first resilient catch for abutting an internal surface of the wheel; and (c) a second resilient catch for engaging an edge of the transverse hole.
According to a further feature of the present invention, the sleeve element also has a shoulder for abutting a surface of the support region adjacent to the transverse hole so as to space the wheel from the support region.
REFERENCES:
patent: D. 327350 (1992-06-01), Brown et al.
patent: D. 337409 (1993-07-01), Maple et al.
patent: D. 370326 (1996-05-01), Chapmane et al.
patent: D. 389972 (1998-01-01), Grosfillex
patent: D. 393129 (1998-03-01), Yemini
patent: D. 404870 (1999-01-01), Van Rhienen
patent: 1560164 (1925-11-01), Jarnagin
patent: 3740100 (1973-06-01), Perego
patent: 3822437 (1974-07-01), Screen
patent: 3913946 (1975-10-01), Valentine et al.
patent: 4234203 (1980-11-01), Johnson
patent: 4530543 (1985-07-01), Keane
patent: 5318315 (1994-06-01), White et al.
patent: 5358314 (1994-10-01), Spadotto
patent: 5415421 (1995-05-01), Godwin
patent: 5598605 (1997-02-01), Tomasiak
patent: 5603555 (1997-02-01), Dickey et al.
patent: 5615903 (1997-04-01), Spear et al.
patent: 5687979 (1997-11-01), Plevka
patent: 5692761 (1997-12-01), Havlovitz
patent: 5845916 (1998-12-01), Stroud
patent: 5884982 (1999-03-01), Yemini
patent: 2 292 713 (1994-09-01), None
Avery Bridget
Johnson Brian L.
Pillsbury & Winthrop LLP
ZAG Industries Ltd.
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