EP0830903A2

EP0830903A2 - Paint system applicator

Info

Publication number: EP0830903A2
Application number: EP97306741A
Authority: EP
Inventors: Nicholas Ian Mounteney
Original assignee: Black and Decker Inc
Current assignee: Black and Decker Inc
Priority date: 1996-09-07
Filing date: 1997-09-02
Publication date: 1998-03-25
Also published as: GB2309183B; EP0830903A3; GB9618721D0; GB2309183A

Abstract

A paint applicator (80) comprises a body (82,82'), and a roller (84), journalled in the body for rotation about a longitudinal axis of the roller, the roller having an external application surface (272). The body has a paint supply input (250). A cover (87,87') is mounted in the body in communication with said input, the cover having a wall whose lips (254) are adapted to abut the roller application surface around at least a part thereof to define a plenum (256) between said wall and surface bounded by said lips. The cover is movable in said body in a radial direction with respect to the roller and is resiliently biased against the roller by leaf springs (258).

Description

This invention relates to an applicator for a paint system of the type broadly disclosed in GB 2142386. In such a system, a machine is supplied which contains a bellows, or other pressurising means, arranged to squeeze a bag of paint and force the paint to exit the bag through a tube to a paint applicator, such as a brush or roller.

In a conventional roller application, the roller comprises a handle, a link connecting the handle to a shaft on which is rotatably mounted a roller arrangement comprising a circular cylindrical sleeve on which is formed a paint applying surface. This is usually a flock material of some description, whether natural wool or artificial, but it may also be of sponge material, or even some form of cloth. Indeed, it is increasingly the case that various different surface materials are used in order to achieve different and distinctive surface finishes. But all of them require the use of a paint tray into which a volume of the chosen paint is poured and the roller is first saturated in the paint before being applied, and rolled over, the surface desired to be painted (hereinafter called, for the sake of convenience, "the wall").

The problem with such an arrangement is that when first applied to the wall, the roller is laden with paint, meaning that this part of the wall gets heavily loaded with paint, but, in a short time, the roller is depleted of paint, meaning that the heavily loaded area has to traversed again with the roller to soak up some paint from it and to spread the paint to other areas of the wall. Finally, once an even coat is achieved, the user starts again by reloading the paint roller from the tray. This may involve climbing down a ladder, or balancing the tray on the ladder. Also the tray needs cleaning. These and other reasons have lead various manufacturers to propose a paint system, where the roller is continuously supplied with paint from a machine incorporating a supply of paint and delivering the paint to the machine through a tube connected at one end to the machine and at its other end to the roller. The present applicants describe such a system in their copending application filed under the title "Paint System".

Such machines have inherent problems of paint wastage, however. They all involve some form of pump having a pressure side and a supply side. Once the supply side of the pump is exhausted of paint, usually the pressure side can no longer be employed. If the volume of paint on that side is large, particularly in comparison with the total volume of paint used, then the amount of wasted paint questions the whole value of the system. Consequently, it is desirable to reduce that volume to a minimum. One such source of pressure side volume is in the roller. One known arrangement provides the paint supply tube connected to the handle, the link and shaft being hollow and forming a conduit for the paint to the interior of the cylindrical sleeve of the roller. The sleeve has perforations which permit the paint to seep through and wet the flock coating. Such an arrangement is beneficial in the even coating of the roller surface can be ensured. However, such an arrangement suffers a number of disadvantages. Firstly is the large volume of paint inside the roller which exacerbates the wastage problem mentioned above. But there is also another problem. This is that the handle normally has some kind of switch on it to control flow of paint to the roller. It goes without saying that the reaction time between the moment of activating the switch to stop flow and the moment when paint ceases to appear on the roller surface should be as short as possible. With a large volume of paint inside the roller, this objective will seldom be realised, because paint seeps naturally through the roller, despite lack of driving pressure. While this might reduce the wastage, it does nothing for the user's perception of the control he or she has over the system.

Thus it has been proposed to feed paint directly, or indirectly, on to the outside surface of the roller and DE-A-3308829, CH-A-480198 and EP-A-0073522 all disclose potential arrangements. The latter describes a system where paint is fed to a feed roller which rolls against the application roller and supplies it with paint. The position of the application roller appears to be adjustable to cater for different diameter application rollers. CH-A-480198 describes a system where paint is sprayed onto the outside surface of the roller, and DE-A-3308829 describes a system in which a plenum is defined by the roller support which has edges abutting the roller, paint being supplied to the plenum. Sealing such a plenum is a particular difficulty, especially if different rollers having different surfaces and different diameters might be used. In this regard, it is quite common to have a short haired roller where a smooth paint surface is required of the finished wall, and a longer haired roller where a stippled effect is required. In either case the diameter varies slightly with paint loading of the roller surface.

It is an object of the present invention to provide a paint roller of simple construction and which meets the objectives set out above, or at least goes some way towards achieving them.

In accordance with this invention there is provided a paint applicator for a paint system, wherein the applicator comprises:-

a) a body;

b) a roller, adapted to be journalled in the body for rotation relative to the body about a longitudinal axis of the roller, the roller having an external circular cylindrical application surface;

c) a paint supply input to the body;

d) a cover mounted in the body in communication with said input, the cover having a wall whose edges are adapted to abut the roller application surface around at least a part thereof to define a plenum between said wall and surface bounded by said edges; and

e) the cover being movable in said body in a radial direction with respect to the roller and being resiliently biased against said roller.

Preferably, said biassing comprises a spring between said body and cover, ideally a pair of leaf springs mounted in the body one on either side of said input. The roller preferably comprises a sleeve mounted on a carrier journalled in the body, the sleeve having coating material thereon, and wherein the radius of curvature of the lips lying against arcs of the circumference of the roller is larger than the radius of the sleeve and smaller than the radius of the coating material. The capacity for movement of the cover is preferably at least as much as the thickness of the coating material. The cover may be closed above the plenum by a baffle to form a chamber in the cover, a window being formed in the baffle permitting entry of paint under pressure in the chamber into the plenum.

Two such windows are preferably provided in the baffle, one on either side of said input and wherein the width of the windows increase with distance from said input.

Preferably, the paint supply input to the body passes centrally through the body and the cover is slidably mounted in said input, the input being radially arranged with respect to said axis. Alternatively, the cover may be slidable within the body radially with respect to said axis, an opening in the cover being connected to said input by a resilient material bellows tube.

The invention is further described hereinafter with reference to the accompanying drawings, in which:-

Figure 1 is a perspective view of a paint system;

Figure 2 is a schematic view of a paint bag and roller arrangement connected thereto;

Figure 3 is a side section through a handle;

Figure 4 is a side section through a paint applicator according to the present invention, along the line X-X in Figure 5;

Figure 5 is a section along the line Y-Y in Figure 4;

Figure 6 is a side section through another embodiment of the present invention, in reverse view to that of Figure 4;

Figure 7 is a section through the cover of Figure 6, along the lines VII-VII in Figure 10b;

Figure 8 is an underneath view of the body of the applicator, with roller and cover removed and taken in the direction of arrow VIII in Figure 6;

Figure 9 is a side view of the cover, in the direction of arrow IX in Figure 6; and

Figures 10a and b are views of the cover of Figure 7, respectively an underneath view in the direction of arrow A in Figure 10b, and a section on the line B-B in Figure 10a.

In Figure 1 is shown a paint application machine 10 which comprises a hollow container 12, having a back 18 and a closing handle 16. The container includes a bellows (not shown) pressurised with fluid by a pump unit (also not shown).

In Figure 2, a paint bag 24 contains paint and is inserted in the container 12 next to the bellows. When the pump is operated, the bellows squeezes the bag 24 and paint therein is forced through an opening 40 to which a connector 50 has been attached. The connector 50 is at one end of a flexible tube 60 which leads to a handle arrangement 70, having a flow control button 72. A paint applicator 80 is connectible to the handle 70. The tube 60 is protected by a flexible portion 160 of the connector as it exits the container 12 and connector 50.
Turning to Figure 3, the tube 60 at its end remote from the connector 50 is connected by a screwed adaptor to an input element 210 of handle 70. At its other end, handle 70 has an output 220 having a sleeve element 222 with a circumferential groove to receive an elastomeric O-ring 223. Output 220 has a tapering mouth 224 to receive correspondingly tapering input 250 to applicator 80 (see Figure 4). The O-ring 223 is adapted to seal against circular cylindrical surface 252 of input 250.

Between its input and output, handle 70 comprises a body 230 including a resiliently elastic tube element 232. Tube element 232 passes over an anvil 234 formed in the body. Above the anvil and tube element is the head 236 of a squeeze lever 238, which head is pressed against anvil 234, squeezing and sealing the tube element 232 therebetween, by a spring 240, mounted in the body 230. Squeeze lever 238 is pivoted in the body about axis 242, and its other end 244 is actuated by switch lever 246, also pivoted in the body about axis 248. Switch lever 246 has knob 72 which extends through an opening 214 in the body 230, and which knob is actuable by the user. The handle is therefore a deadman's handle, the spring 240 serving to close flow of paint in the tube element 232 and through the handle 70 until the knob 72 is pressed by the user. Pressing the knob 72 pivots the switch lever, clockwise in Figure 3, about axis 248, which in turn pivots squeeze lever 238 anti-clockwise about axis 242. Such pivoting is against the restoring force of spring 240, but opens tube element 232 to permit flow of paint while the knob is pressed.

The lever arrangement is such that only a small movement of head 236 results from a large movement of the knob 72. This is desirable on two counts. Firstly the spring 240 needs to be quite strong to ensure adequate sealing under the working pressure when the knob 72 is released, so the extra leverage provided by the arrangement minimises user fatigue. Secondly, although in practice it is found that a handle which is a mere on/off switch to paint flow is more than adequate to satisfy the requirement of a user to be able to keep the applicator sufficiently loaded with paint (the flow merely being turned on and off on a periodic basis as required), the small movement of the head 236 for a large movement of the knob 72 means that an intermediate position of the knob can be found to achieve a flow rate somewhere between nothing and maximum which satisfies the ongoing paint loading requirement as the system is used.

Referring now to Figure 5, applicator 80 according to the present invention comprises a roller arrangement having a body 82 mounting a flossed roller 84 which is journalled for free rotation about its long axis 86 in the body 82. The roller 84 has pips 88 at its ends which rotate in eyes 89 in body 82. The roller 84 comprises a sleeve 270 on which flock 272 is attached. The sleeve 270 is slid over a carrier 274 which comprises two boat-like mouldings 276,278 connected together edge to edge to form the carrier 274. The space within the carrier 274 is sealed so that paint cannot enter it. The carrier has longitudinal ribs 282 spaced around its circumference.

A cover 87 has a central sleeve 85 which is a close sliding fit in a bore 83 formed in the body 82 and communicating with input 252. Around the sleeve 85, the cover is substantially rectangular having a rectangular lip 254 (having curved short ends to correspond with the circumference of the roller 84) adapted to lie against the roller surface. The lip 254, the cover inside the lip, and the surface of the roller bounded by the lip, between them define a paint plenum 256 into which paint is supplied from handle 70 when it is connected to applicator 80.

No absolute seal is required between facing

surfaces

83,85, because paint can be permitted to find its way around the outside of the cover without causing any problem. If it were a substantial amount, it would in any event end up on the roller, but it will not be such an amount because here the paint pressure is substantially atmospheric.

The cover 87 is biased towards the roller by two leaf springs 258 disposed in the body 82. The facing surfaces 83,85 permit the cover to slide in and out slightly to maintain contact of the lip 254 with the roller as it changes diameter with wear or degree of paint loading. Indeed, rollers 84 having different flock lengths can be employed, for achieving different surface finishes, or even having different surfaces such as wool, cloth or sponge, or indeed just about any presently available material used for applying paint to walls. To this end the radius of curvature of the lip 254, where it lies over an arc of the circumference of the roller 84, is arranged to be as small as the diameter of the roller is likely to be. That is to say, its radius should be slightly larger than the radius of sleeve 270, because larger diameter rollers are larger because of the thickness of the pile 272 of the roller, rather than because of the diameter of their base sleeve 270. Thus with thicker piles, the edge 254 can more easily dig into the pile to form a seal between lip and roller, although this is not a terribly important important point, since paint is wanted to flow to the outsides of the roller in any event. Moreover, the cover is constructed from thin (about 0.3mm thick) flexible plastics material such as high impact polystyrene, so that it adapts easily to the shape of the roller.

The cover has two waves 260 outside the long sides of the lip 254. These are adapted to capture paint on the surface of the roller as the roller feeds under the leading lip 254, depending on the direction of roll of the roller, and to feed such paint back into the plenum 256.
Preferably there is no leak permitted at the connection between the body input 83 and the plenum 256. In this event, the embodiment described below with reference to Figures 6 to 10 is preferred. Like components have the same reference numerals, but with the addition of a prime where there are differences in construction.

Thus in Figure 6, body 82' of applicator 80' has a short sleeve 83' on which a resilient bellows tube 290 is connected. The other end of the bellows 290 is engaged over sleeve 85' of the cover 87'. This arrangement permits movement of the cover relative to the body without leakage. However, different guidance for the cover is then required.

This guidance is provided by

ribs

292, 294 in the body which restrain the cover against sideways movement in the directions of the

arrows

2,2 and 4,4 respectively in Figure 8.

In Figure 7 there is clearly visible a baffle 296 which is elongate and closes a chamber 298 in the cover above the plenum 256. The baffle is clipped into the cover by pips 300 on the cover snapping into engagement with corresponding detents 302 in the baffle 296. Ribs 304 in the cover locate the baffle. The baffle 296 has two elongate windows 306 which widen away from the opening of sleeve 85'. These windows permit entry of paint under pressure in the chamber 298 into the plenum 256. Where the paint is under maximum pressure near its entry to the chamber 298 from sleeve 85', the windows 306 have a narrow width, but as the pressure drops further way from the sleeve 85', the window width increases to permit greater flow. The result is an even distribution of paint into the plenum 256 along its length.

On the top side of the cover 87', ribs 308 are formed against which the leaf springs 258 bear. In Figure 9, three positions of the leaf spring are shown, first (i) under maximum compression where the widest diameter roller 84 is employed, second (ii) under minimum compression where the narrowest diameter roller is employed, and third (iii) under no compression. Figure 6 shows the two

possible diameters

84a and 84b of roller 84 corresponding to maximum (i) and minimum (ii) compressions of the springs 258.

Although not shown clearly in the embodiment of Figures 4 and 5, the cover there is likewise provided with a baffle. Thus the present invention is of simple construction and yet provides for efficient distribution of paint to the surface of the roller, whatever diameter (within limits) the roller has.

Although the word "paint" is used exclusively herein, it should be understood to include any liquid, which in this context includes other surface coating compositions such as varnishes, stains and lacquers. Moreover, while the paint system described employs a bellows arrangement, any paint delivery system could be employed.

Claims

A paint applicator for a paint system, wherein the applicator comprises:-

a) a body;

b) a roller, adapted to be journalled in the body for rotation relative to the body about a longitudinal axis of the roller, the roller having an external circular cylindrical application surface;

c) a paint supply input to the body;

d) a cover mounted in the body in communication with said input, the cover having a wall whose lips are adapted to abut the roller application surface around at least a part thereof to define a plenum between said wall and surface bounded by said lips; and

e) the cover being movable in said body in a radial direction with respect to the roller and being resiliently biased against the roller.
A paint applicator as claimed in claim 1, wherein said biassing comprises a spring between said body and cover.
A paint applicator as claimed in claim 2, wherein said biassing comprises a pair of leaf springs mounted in the body one on either side of said input.
A paint applicator as claimed in any preceding claim, wherein the lips of the cover lying parallel the longitudinal axis of the roller have waves beyond the plenum adapted to catch paint on the roller surface and feed it back into the plenum as the roller rolls along a surface.
A paint applicator as claimed in any preceding claim, wherein the roller comprises a sleeve mounted on a carrier journalled in the body, the sleeve having coating material thereon, and wherein the radius of curvature of the lips lying against arcs of the circumference of the roller is larger than the radius of the sleeve and smaller than the radius of the coating material.
A paint applicator as claimed in any of claims 1 to 5, wherein the capacity for movement of the cover is as least as much as the thickness of the coating material.
A paint applicator as claimed in any preceding claim, wherein the cover is closed above the plenum by a baffle to form a chamber in the cover, a window being formed in the baffle permitting entry of paint under pressure in the chamber into the plenum.
A paint applicator as claimed in claim 7, wherein two windows are provided in the baffle, one on either side of said input and wherein the width of the windows increase with distance from said input.
A paint applicator as claimed in any preceding claim, wherein the paint supply input to the body passes centrally through the body and the cover is slidably mounted in said input, the input being radially arranged with respect to said axis.
A paint applicator as claimed in any of claims 1 to 8, wherein the paint supply input to the body passes centrally through the body, the cover is slidable within the body radially with respect to said axis, an opening in the cover being connected to said input by a sealed flexible connection.
A paint applicator as claimed in claim 10, wherein said flexible connection comprises a resilient material bellows tube.