Coating implements with material supply – Including means to apply material-moving force – In or at feeder
Patent
1996-08-23
1999-08-03
Bratlie, Steven A.
Coating implements with material supply
Including means to apply material-moving force
In or at feeder
401197, 401218, 401220, B05C 1703
Patent
active
059315954
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a device for applying a liquid product, in particular paint, comprising an applicator with at least one roller provided for applying the product on a surface and a supply unit provided with a pump and an at least partially flexible duct connecting the pump to the applicator, said pump being connected to a control unit provided for controlling the flow of the liquid to be supplied based upon a measured speed of the roller on the surface.
Such a device is known from U.S. Pat. No. 3,549,267. According to the known device, the paint is supplied from a container by means of a pump via the duct towards the roller, in order to be applied on the surface. The speed at which the roller moves on the surface on which the paint is applied, is measured by means of a detector which generates the control signal indicative for that roller speed. The control signal, formed by a sequence of switching pulses, is supplied to a control unit, which under control of that control signal, regulates the flow rate of paint towards the roller. In such a manner, the supply of paint is controlled by the roller speed.
A drawback of the known device is that for controlling the flow rate of paint, use is made of a flow switch, which is switched on or off in function of the sequence of the switching pulses, which form the control signal. Consequently, the pressure within the duct varies in an asymptotic manner which causes a non-linear throughout of the liquid within the duct, leading to an unequal thickness of the paint applied on the surface.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a device for applying a liquid product to a surface which enables the product to be applied on the surface with a substantially equal thickness.
A device according to the present invention is therefore characterized in that a volumetric pump, provided for operating at an adjustable pump speed, is used in combination with a control unit comprising a regulator for setting at least one linear relationship between said roller speed (V.sub.r) and said pump speed (V.sub.p). The use of a volumetric pump enables one to control the pump speed (V.sub.p) and thus one can obtain a flow of liquid which is proportional to that pump speed. Upon setting a linear relationship between the roller speed (V.sub.r), which is measured by the detector, and the pump speed, it is possible to have the pump speed changed linearly in relation to the measured change of the roller speed. So, a change of the roller speed will cause a proportional change of the pump speed, thus causing a proportional change in the flow rate of the supplied liquid. The set linear relationship causes a constant ratio between the pump speed and the roller speed so that the liquid supply will follow the roller speed enabling an application with a substantially equal thickness of the liquid product on the surface.
It has to be noted that the patent application GB-A-2.263.508 describes a device wherein the supply of liquid is determined as a function of the speed of the movement. However, the roller which measures that speed is not the one which applies the liquid. The only task of that roller is to measure the speed. The liquid is applied by means of an ejector. Moreover, that device does not comprise a control unit enabling adjustment of the ratio between the flow and the speed of the roller. In that device, the pump is driven by the movement of the roller which is not compatible with strongly fluid liquids which are sucked and not pushed towards the applicator.
The patent application DE-A-3,526,257 also describes a device for applying a liquid product on a surface. In that device a buffer zone is adjacent to the application roller. The liquid, in particular paint, is pumped in that buffer zone which then supplies the roller. The rotation of the roller provokes a suction which brings the paint from the buffer zone on the roller. The suction force is a function of the roller rotation speed. The solution described in DE-A-3,526,257 does not comprise th
REFERENCES:
patent: 2722029 (1955-11-01), Barnes et al.
patent: 3138814 (1964-06-01), Carrona
patent: 3149365 (1964-09-01), Adair, Jr.
patent: 3549267 (1970-12-01), Wurzer et al.
patent: 4175300 (1979-11-01), McGlew et al.
patent: 4217062 (1980-08-01), Trp et al.
patent: 4422789 (1983-12-01), Charney et al.
patent: 4537522 (1985-08-01), Charney et al.
patent: 4588318 (1986-05-01), O'Brien et al.
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