Coating implements with material supply – Including ball – roller or endless-belt tool – Engageable with feed roller
Reexamination Certificate
2000-03-13
2002-05-28
Walczak, David J. (Department: 3751)
Coating implements with material supply
Including ball, roller or endless-belt tool
Engageable with feed roller
C401S197000, C401S208000, C401S193000
Reexamination Certificate
active
06394681
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a liquid applicator assembly. In particular, although not exclusively, the invention relates to a liquid applicator assembly for topically administering herbicide to weeds by the use of a hand held device with a long stem held at one end by the user, with a roller applicator at the other end. The applicator assembly is not limited to manual applicator devices. Additionally, while the applicator assembly illustrated in the drawings is intended for domestic use, the device may be adapted for commercial and agricultural use.
BACKGROUND TO THE INVENTION
Weeds have long been the scorn of the home gardener and manual removal is time consuming and tedious. Chemicals applied by spraying weeds is effective and less time consuming but there are health risks associated with applying herbicides in this manner. Additionally, plants not intended to be destroyed by the herbicide can unintentionally be damaged or destroyed. The application of herbicides by spraying also results in wastage of the herbicide, particularly where the spraying is conducted to eradicate weeds growing sparsely up through cracks in concrete or roadways,
As an alternative method of applying liquid herbicides, International Patent Specification No. WO98/42187 assigned to Green Management Limited describes a roller applicator having an elongate tubular stem able to be held by the user at one end with a roller applicator provided at the other end in the shape of a large ball. The roller applicator is constructed of porous resiliently compressible foam material. The tubular stem acts as a reservoir for the liquid herbicide. The liquid herbicide is delivered in a controlled manner to the ball for surface application of the herbicide to weeds as the ball is rolled along the ground surface.
This product suffers from a number of shortcomings. Since the ball has a large surface area which is in direct contact with the ground surface, the ball delivers a large amount of herbicide to the ground/concrete/road etc irrespective of whether there are weeds present on the surface. Additionally, continual contact with the ground surface causes substantial wear on the ball.
Another shortcoming is that the shape of the ball precludes it from gaining access to tight corners. Consider for example garden beds and other densely growing garden areas.
Also, its size and shape make it difficult to accurately effect spot weeding by simply dabbing herbicide from the applicator onto plants/weeds which the user decides to eradicate. Moreover, in view of the awkward shape of the ball applicator, it is difficult for the user to be selective about the plants to which the herbicide is applied. The applicator will likely kill all in its path. The large ball is also expensive to manufacture, partly because of its awkward shape requiring it to be moulded into shape and partly because of the large amount of compressible foam material required for its construction.
Another shortcoming is the difficulty in draining the liquid contained in the tubular stem. An air valve is provided to avoid a vacuum being formed in which case the stem will not drain. However this air valve is ineffective to enable full drainage of the stem and the stem requires continual filling to maintain the flow rate. This can be resolved with the stem opened to the atmosphere but with the consequent risk of spilling the contents and losing the cap. No air valves are known to resolve this problem at a reasonable cost. Moreover, it has been found that the valve provided in the above device is not temperature stable and does not operate below about 8 degrees Celsius.
Yet another problem with the above device is caused by the glue used to connect some of its component parts. The glue gives off solvents in vapour form which attack some of the plastics in the device. Especially vulnerable is a valve which controls the flow to the applicator ball.
It is therefore an object of the present invention to address at least some of the foregoing disadvantages or at least provides the public with a usefuil choice.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention there is provided an applicator assembly including:
a liquid applicator which is rotatably mounted on the applicator assembly, the liquid applicator having a substantially cylindrical applicator surface for applying liquid from a source thereof;
a spacer means extending radially beyond the applicator surface in a manner effective to space the applicator surface from any flat surface with which the spacer means is engaged, wherein the liquid applicator is provided with an external edge defined between the substantially cylindrical applicator surface and an end surface of the applicator, said applicator surface and said end surfaces being exposed at least adjacent to the external edge along at least a portion of the external edge.
The invention thus defines a free edge not encumbered by either the spacer means or any other part of the applicator assembly, enabling the free edge to be used as a spot applicator. This increases the versatility of the applicator assembly whose primary function is as a roller applicator.
In a preferred form of the invention, the spacer means is provided at the end of the applicator opposite the exposed end surface. The spacer means may extend radially only a short distance (2-5 mm) beyond the applicator surface. Preferably, the spacer means is a substantially planar member. The spacer means may present a continuous peripheral surface extending radially beyond the applicator surface. Alternatively, the spacer means may be discontinuous like teeth provided on a gear wheel.
The spacer means may be in the form of a spacer wheel rotatably mounted on the applicator assembly. Moreover, a gripping surface may be provided along the peripheral edge of the spacer wheel to engage with the ground for rotation of the spacer wheel. The spacer means is preferably a wear resistant material such as a polycarbonate plastic. In a preferred form of the invention, the liquid applicator and the spacer wheel move in unison. Accordingly, the spacer wheel and the liquid applicator may be attached to each other. In a most preferred form of the invention, the spacer wheel has inwardly extending spikes to penetrate the liquid applicator to enable the spacer wheel and the liquid applicator to move as a unitary assembly.
Preferably, the liquid applicator and the spacer means have coaxial rotatory axes. For this purpose, the spacer means may include an integral bush with the liquid applicator seated on the external periphery thereof, Preferably, the internal periphery of the bush is rotatably mounted on an axle of the applicator assembly.
The liquid applicator is preferably a unitary porous foam mass. Furthermore, the applicator may be resiliently compressible. High density polyurethane foam is the preferred material.
In accordance with a second aspect of the present invention there is provided an applicator assembly including:
a liquid applicator having an applicator surface to apply liquid from a source thereof;
an elongate stem having the liquid applicator arranged at one end, the stem being of sufficient length to enable the assembly to be grounded at the end with the applicator and held in the hand of an upright user at the other end; and
a guard extending proximate the applicator surface such that with the stem arranged in an operative, substantially upright position with the guard disposed forwardly of the applicator, the guard extends beyond the applicator surface in the forward direction.
The guard preferably extends past the applicator surface when the stem is disposed at a substantially upright angle of 15° or less to the vertical.
Thus if the applicator assembly is used in the above manner for the administration of liquid herbicide, the guard will serve to protect the upright stem of any plants in the vicinity of the applicator assembly to guard against the likelihood of herbicide being applied to the stem of the plant. On the other hand, in the ca
Walczak David J.
Workman & Nydegger & Seeley
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