PAINT ROLLER CLEANING DEVICE This invention relates to the cleaning of paint applicators of the kind comprising a roller rotatably mounted on a frame which carries a handle.
It is known to clean paint from roller-type applicators after use by repeatedly wetting the roller with a suitable solvent and then rotating the roller at high speed, whereby the solvent containing dissolved paint residues is discharged from the roller under centrifugal force.
United States Patent Specification No. 4 130 443 discloses a device which can be used for cleaning a roller-type paint applicator, the device comprising a cylindrical housing having a side door through which the roller is placed into the housing. A notch in the edge of the door opening receives the frame of the applicator, and supports permanently mounted inside the housing engage opposite ends of the roller, one of which is rotatably driven by an external motor. A further proposal is described in GB-A 2219732, in which a roller-type paint applicator is placed within a generally box-shaped casing having a slidable lid, the casing containing a mounting for the elbow of the roller frame adjacent the roller at one end, the other end of the roller being engaged by a coupling member carried on a spindle which passes through the casing wall for engagement with the chuck of a pistol drill. However, such prior devices are considered either to be relatively expensive to manufacture or to be inconvenient in use.
An object of the present invention is to produce apparatus for use in cleaning a roller-type p~ιint
applicator, which overcomes problems inherent with known such apparatus.
According to the present invention, apparatus for cleaning a roller-type paint applicator comprises an elongate housing for receiving the roller rotatably mounted on a support, a drive shaft rotatably mounted in one end of the housing and carrying a drive head for driving engagement with one end of the roller, the housing being provided at the other end with closure means containing an opening for receiving the roller support.
Preferably, the roller support comprises the frame of the paint applicator, about a spindle portion of which the roller rotates in use in applying paint. In such an arrangement, the roller need not be separated from the handle before cleaning and the distal portion (with respect to the roller) of the handle extends outside the housing through the opening. However, in an alternative arrangement, the soiled roller is detached from the handle before cleaning and is mounted in the cleaning apparatus on a separate support spindle which may be sized to be received either within the bore of the roller which receives the handle or within the internal diameter of the roller body itself.
The drive shaft may be coupled to a hand crank or to a drive motor which may conveniently be in the form of an electric pistol drill. Preferably, at least the coupling end of the drive shaft is facetted, for example to provide a triangular cross-section, to ensure non-slip engagement with the chuck or other coupling means of the drive motor or hand crank. the hand crank may include a mechanism whereby driving
force is provided by the handle of the roller.
The closure means preferably includes a drain passage for conducting fluid out of the housing. The closure means is preferably longitudinally divided into two halves, each including a portion of the opening. The closure means may be in the form of a closure member which engages the main body of the housing or it may be formed integrally with the housing, in which case the housing too would be longitudinally divided. The opening may include an axial inlet portion which leads from the interior of the housing to the mid region of a radial portion which opens at opposite sides of the closure member. There may conveniently be two drain passages disposed on opposite sides of the inlet portion and leading from the interior of the housing to a respective radial portion of the opening, each half of the closure member including a portion of each drain passage.
The drive head preferably includes means for positive driving engagement with the roller, such as a plurality of projections for engagement with the free end of the roller and which, in use, allow fluid within the housing access to substantially the entire surface area of the roller, without any portion of the soiled roller surface being masked from solvent by elements of the drive head. The projections may comprise radially-disposed fins which may in use engage with corresponding formations on the free end of the roller, for the purpose of positive roller drive. The fins are preferably angled such that on rotation they generate a frusto-conical portion which engages the free end of the roller, which may be formed as or with a recess to receive the tapered or frusto-conical portion, whereby
the roller is automatically positioned and maintained in co-axial relationship with the drive shaft and rollers of different diameters' may be accommodated. The fins may be resilient to absorb axial and radial vibration or displacement of the roller. Additionally or alternatively, the engagement means between the drive head and roller includes a gearing arrangement; this would permit an increase in rotational speed of the roller relative to to the drive shaft which would particularly be advantageous with a hand-crank drive. The housing preferably comprises a substantially cylindrical inner surface, and the drive head may have an outer bearing surface which engages the said inner surface of the housing, to ensure that the drive shaft is maintained substantially axially within the housing and to transmit any vibrations to the housing.
The end of the housing opposite the closure means (that is, the end through which the drive shaft passes) is preferably provided with a blanking means which may include a bearing surface for the drive shaft. One or both of the closure means and blanking means may be formed so as to provide for shock- and vibration-absorption, for example by being adapted for radial and/or axial resilient flexure. One way of providing such flexure is for the closure or blanking means to include an annular outer relatively convex portion and an annular inner relatively concave portion adjoined thereto, optionally with variations in thickness, although other means for providing flexure may be comtemplated. Furthermore, the closure means and/or blanking means may be separately formed from the housing or integrally formed therewith. The housing may be formed in two or more portions, for example, as two longitudinally- divided portions which may be
hinged together, retainer means being provided to hold the portions together for use and sealing means being included to minimize loss of solvent. The retainer means may be removable and may comprise the aforementioned closure and/or blanking means, which may for example be provided with a peripheral axially-disposed flange or with tabs to clasp the housing portions together, or the retainer means may be integrally formed and comprise interengageable parts, for example snap-action studs or toggle clips. Alternatively, the retainer means may comprise bands, collars, straps or sleeve elements.
The invention also includes a roler for a roller-type paint applicator in which at least one end of the roller is adapted for driving engagement with the drive head of a centrifugal paint roller cleaning apparatus such as described and claimed herein. The roller may for this purpose include an end cap which may be removable and which includes projections or apertures suitable for engagement with a roller drive head, whether specifically intended to mate with the said roller end cap or otherwise.
Apparatus according to the invention may be formed from any suitable material although a plastics material may be preferred for reasons of expense. The housing may, for example, be formed from a length of extruded plastics tube or by injection moulding, although the former would be cheaper. Alternatively, the housing could be formed by bending a flat plastics sheet around a mandrel and the blanking means may be secured thereto by staples, contact adhesive, hot melt adhesive, ultrasonic welding or any other suitable means.
Another suitable production method is vacuum forming. According to this method, the housing may be formed in two longitudinally divided parts which may be identical and could, therefore, be formed in the same mould. The two parts of each housing could be formed with hinge parts which are joined by a hinge pin inserted therethrough, or they could be joined by an integral plastics hinge. For example, the housing parts may be formed from a single flat sheet of a thermoplastic material as two longitudinally-split half cylinders lying parallel and laterally spaced apart, and having a peripheral land area of flat thermoplastics material surrounding them and connecting them together, a longitudinal groove bisecting the connecting zone to act as an integral hinge, whereby the respective halves on either side of the groove may be folded together so that the land areas abut, thereby forming a complete cylinder with a surrounding edge flange which may conveniently serve to receive clips or other retainer means. In the unfolded or open state, the land area on the external side of each half cylinder may be formed with a slot which constitutes in the folded or closed state, together with the other slot, a finger-recess which facilitates the two halves being held together by the user. The external parts of the land areas may also comprise the opening for receiving the roller support, the said opening being a channel to receive at least a part of the angled portion of the roller handle, thereby to hold the roller with both axial and lateral stability within the housing. The channel may be formed as an open trough or depression in at least one of the said land area parts, to be closed to surround the handle portion axially by the other said land area part on joining together of the two halves in the folded or closed state. A groove may be formed in
the land zone around at least part of one half cylinder and a corresponding projection around the other, whereby in the folded or closed state the projection is received within the groove to effect a liquid-tight seal. Optionally, the groove may carry a resilient sealing element or material. Such a vacuum-formed product would be easy to clean when opened, economical to produce, stackable in the open or unfolded state and hence cheap to transport and store, and would be suitable for shrink-wrap packaging.. Injection moulding would also be suitable for producing such apparatus.
As discussed hereinabove, the closure means is preferably provided in two halves and these halves may be separately formed for insertion within the housing by the user or they may, where the housing is formed as two or more parts, be integrally formed with the housing parts.
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which
Figure 1 is a longitudinal section through one form of a roller-type paint applicator cleaning apparatus;
Figure 2 is a perspective view of a closure member suitable for use with the apparatus of Figure 1;
Figure 3 shows an alternative closure means for use when cleaning applicator rollers when removed from their handle;
Figure 4 is a side elevation of another form of cleaning apparatus;
Figure 5 is a cross-sectional view along the line IV-IV of Figure 3 and, viewed in the direction of the arrows; and
Figure 6 is a longitudinal cross-section through a drive shaft and associated drive head and through a removable roller end cap suitable for use with apparatus according to Figure 1 or Figure 3.
The apparatus described with reference to Figure 1 is intended primarily for cleaning paint applicators of the kind comprising a roller rotatably mounted on a frame which projects from one end of the roller and which carries a handle. For convenience, the end of the roller from which the frame extends will be referred to below as "the handle end" and the opposite end of the roller will be referred to as "the free end".
The apparatus includes an elongate housing 1 which may be formed inexpensively of a plastics material. The housing 1 comprises a hollow cylinder 2, one end of which may be closed by an end cap of Nylon or other suitable bearing material, but which as shown is formed integrally with the cylinder and consists of an outer annular convex part 3 and an inner annular concave part 4 merged thereto with a reduction in wall thickness in the merge zone, whereby to absorb vibrations from the cylinder wall and drive shaft. The end cap contains an axial bore 5 which rotatably receives a drive shaft 6. (The cap could also be of other material and may have a tubular insert to act as a bearing for the shaft 6.) The shaft 6 is a fairly close fit in the bore 5 whilst permitting axial movement of the shaft within the bore. One end of the drive shaft 6 projects from the housing
and terminates in a portion 7 of triangular section for reception in the chuck of a pistol drill (not shown) . The opposite end of the shaft 6 is integrally formed with a moulded plastics drive head 8, or the shaft may be of metal and knurled or otherwise keyed to a plastics drive head. The drive head 8 comprises an axially projecting frusto-conical portion 9 and a generally cylindrical portion 10. The radially outermost surface of the cylindrical portion 10 provides a cylindrical bearing surface 11 which contacts the inner surface of the cylinder 2 in order radially to locate the drive head 8 whilst still allowing free rotation and axial movement of the drive head. The frusto-conical portion 9 carries a series of circumferentially spaced radially projecting fins 12 for driving engagement with the free end of a paint roller (see below) . The drive head 8 includes an internal boss 13 which is engaged with the shaft 6 and which has an annular end face 14 to act as a stop and bearing surface for contact with the end cap 3 when the drive shaft 6 is pulled to its outermost position.
The device may be manufactured to accommodate rollers of different lengths by suitably varying the length of the cylinder 2 and of the drive shaft 6.
The opposite end of the cylinder 2 to the cap 3 is provided with a closure member 20 which is longitudinally divided into two equal halves 20a and 20b (See Fig. 2) . The closure member 20 includes a spigot 21 having a number of external circumferentially extending ribs or flanges 22 which enable the spigot to be a fluid-tight push fit into the cylinder 2. The spigot 21 leads into an intermediate portion 23 of greater diameter and having a smooth cylindrical
external surface. This intermediate portion 23 in turn leads into a shorter cylindrical hand grip portion 24 of still greater diameter having a textured external surface for gripping purposes. The closure member contains a generally T-shaped internal opening, indicated generally at 25, which includes two substantially identical conjoined portions formed in the two halves 20a and 20b of the closure member. The opening 25 includes an axial inlet portion 26 formed in the spigot 21 and which opens into the interior of the cylinder 2. The inlet portion leads via a divergent portion 27 into the centre of a radial outlet portion 28 which extends completely through the intermediate portion 23 of the closure member. In addition, a pair of drain passages 29 and 30 extend axially through the spigot 21 on opposite sides of the inlet portion 26, to meet the outlet portion 28. Each drain passage is again formed in two conjoined halves provided in the respective halves of the closure member 20. The drain passages may be formed inset from the outer surface of the spigot 21 as shown in Fig. 1 or they may merge into the outer surface of the spigot, as in the modified arrangement of Fig. 2. Drain passages may also be provided in the wall of the cylinder 2 instead of, or in addition to, the drain passages 29 and 30.
The device just described is particularly intended for cleaning a paint applicator of the kind which comprises a roller R rotatably mounted on a frame F which extends from one end only of the roller. The frame F carries a handle (not shown) and includes a first part F' which extends axially from the roller R and which leads into a second part F" disposed at 90° to the first part F*. In most roller designs, the second frame part F" will lead to a third part (not shown in Figure 1) which is
formed at an oblique angle and which extends from the end of the roller to a medial position at which the handle is carried. In a typical cleaning operation the closure member 20 is removed from the cylinder 2 and the two halves 20a and 20b are placed around the frame F of an applicator having a paint-soiled roller such that the first part F1 of the shaft is received in the inlet portion 26 of the opening 25 and the second part F" projects from one end of the outlet portion 28. (See Fig. 1.) The divergent portion 27 accommodates frames with different radii of curvature between the two parts F' and F". The roller R is now inserted through the open end of the cylinder 2 and the spigot 21 of the closure member is manually pushed into the end of the cylinder so that the two halves 20a and 20b are held firmly together. A small quantity of a suitable solvent is now trickled into the housing 1 directly onto the roller R via the open portion of the outlet portion 28 and the adjacent drain passage 29 or 30. The housing can now be gently shaken to distribute the solvent about the roller R. With the triangular portion 7 of the drive shaft firmly held in the chuck of a pistol drill, the hand grip portion 24 of the closure member is held in one hand whilst the other hand grips the pistol drill. By holding the device thus the shaft 6 can be urged into the housing so that the fins 12 of the drive head engage in the free end of the roller. The frusto-conical portion of the drive head tends to centre the roller in the housing, and also readily accommodates rollers of different diameters. The housing is normally held in use with the free end of the roller uppermost, and the drill is actuated rotatably to drive the shaft 6 and hence spin the roller at a sufficient speed centrifugally to discharge the solvent and any dissolved paint from the
roller. It is important to note that the internal diameter of the cylinder 2 should be such that the paint-absorbing coat of the roller should not touch the cylinder even when it becomes fully extended during high speeds of rotation, to ensure that the solvent can be optimally discharged from the roller. The fins 12 of the drive head drivably engage the roller whilst permitting fluid to pass freely between them into the free end of the roller. Highly effective fluid seals are not required in the region of the end cap 3 since the fluid does not in practice travel past the drive head 8. Since the pressure applied by the hands acts between the ends of the roller, the roller cannot inadvertently be pushed out of the housing during the cleaning process, although toggles, catches or other devices could be provided to maintain the end cap 3 or the closure member 20 in position if desired. The paint-solvent solution can drain from the housing via the drain passage 29/30 and the outlet portion 28.
Trickling a small quantity of solvent directly onto the roller R uses only a small quantity of solvent and is therefore highly economical. The first washings are very high in paint content and can be re-added to the paint so that the solvent is not wasted.
If required, further solvent can be trickled into the housing and the procedure repeated until all traces of paint have been removed from the roller. Instead of trickling paint through the closure member 20 the roller and closure member can be removed from the cylinder and a minimum quantity of solvent trickled directly onto the roller, or the roller can be immersed in a suitable container of solvent, but the above-described procedure has the advantage that a
minimum quantity of solvent is required. In fact, apart from the initial washings as noted above, all the solvent could be used for thinning the paint as required so that there need be no wastage of solvent.
A modified form of closure member, not specifically illustrated, will now be described with reference to Figure 2. In the modified closure member, the hand-grip portion 24 is formed as a whole portion and the spigot 21 extends to portion 24 without the intermediate portion 23. The spigot 21 is formed in two generally D-shaped halves, one half being attached to or formed integrally with portion 24 and the other half being either formed separately from or hinged to the said one half at respective corners, whereby the two D-shaped halves can be placed or pivotted together with their straight edges facing to constitute the spigot. Each half is additionally formed with a recess in the centre of the straight edge, the recesses cooperating to form a central axial passageway for receiving the part F' of the frame. The said other half of the spigot and the inner face of the hand-grip portion 24 should cooperate to receive the part F" of the frame, either by providing a suitable notch or recess in the said face and/or by reducing the thickness of the said other half of the spigot to provide a gap therebetween in which the part F" of the frame can be accommodated. The cylinder 2 is a push-fit over the spigot when the two halves thereof are together and enclosing the parts F' and F" of the frame, the edge of the cylinder abutting the peripheral edge of the inner face of the hand grip portion 24, suitable edge slots being formed in the cylinder to accommodate the part F" of the frame and/or to provide for entry and exit of cleaning solvent.
14
The apparatus could be formed as a longitudinally divided cylinder 2 which, preferably, is also integral with two halves of the end cap 3, as mentioned above. Indeed, the latter arrangement could be used with rollers of the kind having a frame which projects from both ends. The two halves of the housing may be joined by an integral plastics hinge, or they could be formed with parts of a hinge which are joined by a hinge pin inserted therethrough. Alternatively, the two halves could be joined by moulded collars which can be slid over tapering regions at each end of the housing, or they could have a snap engagement with the housing which can be disengaged by depressing part of the collars. Metal clips formed from round wire could also be used in place of the collars. These could be made on the circlip principle, but with round portions formed at each end which, when squeezed between the fingers, increase the diameter of the clip enabling it to be fitted into and similarly removed from a recess in the outside of the housing. Other methods of securing the two halves include plastics self-locking straps or elongate mouldings which, when rotated through 90 , engage in recesses in the outside of the housing to lock the two halves together.
Since the device is used in the hands it is under the direct control of the user. Additional advantages of the device are that the housing is easy to clean and inexpensive to manufacture. The housing also takes up a small amount of space, and in fact provides an ideal storage space for the paint applicator where it will remain clear.
If desired, the paint roller may be removed from its frame for cleaning purposes. To support the roller
within the cylinder, a bearing pin may be inserted in one end of the roller; the other end of the pin is journalled in a modified closure member as shown in Figure 3. In Figure 3, the bearing pin P is retained by a collar C in the nose of a cap M which is a push-fit within the end of the cylinder 2. The interior of the closure member may be concealed by way of a plate D having a peripheral raised formation which engages with an inner annular groove by snap action. The pin P is retained in the cap M by the pressure of the roller R, which in the embodiment illustrated has a foamed plastics paint-application covering F. In this arrangement, the pin P is freely rotatable both in the cap M and within the end cap E of the roller R. As an alternative, however, the pin P could be fixedly mounted to the nose of the cap M, the roller R being rotatable thereon. Yet again, the diameter of the nose of the cap M could be chosen so that the peripheral annular surface thereof acts as a bearing surface within the inner shoulder of the end cap E.
Figure 4 shows a side elevation of a vacuum-formed embodiment with an integral support for the frame of the roller. Figure 5 is a cross-section on the line V-V. The housing is formed from a single sheet of flat thermoplastic material having a central groove which constitutes an integral hinge. The apparatus is shown in the drawing with the parts on either side of the hinge folded together; the hinge constitutes the lower edge 41. Each part has a half-cylinder 42 formed therein and a drain channel 43 at a lower corner. The half-cylinders are surrounded by a land area 44; the upper portion of the land area is formed with a passage 45 for receiving the angled part 46 of the roller frame, thereby utilizing the obliquely-angled part of
the frame to hold the said roller centrally in the cylinder with lateral and axial stability. A hand-holding recess 47 and mating grooves/projections
48 to effect a liquid seal are also provided. A passage
49 is also formed co-axially with the cylinder to accommodate the roller drive shaft. The two halves may be held in the closed condition by a resilient cylinder having a longitudinal slot formed therein along its entire length and which is sleeved around the housing with the land regions 50 (delineated by dashed lines) being received within the slot.
Figure 6 illustrates in cross section the drive head for a cleaning apparatus according to the invention, and a removable roller end cap for driving engagement therewith. The drive shaft 51 is provided with a drive head consisting of a boss 52 and a plurality (five in this case) of radial arms 53 spaced equi-angularly apart and supporting an outer rim 54 for turning within the housing.The outer surface of the rim 54 is provided with endless circumferential troughs and projections which act to reduce the area of contact with the housing and hence to reduce frictional forces and heat generation in use. The radial elements are angled rearwardly to generate on rotation the frustum of a cone and to absorb vibrations. The drive head is formed from a plastics material, for example Nylon, to combine strength with resilience. The removable paint roller end cap 55 includes inwardly-directed radial projections 56 which are received in use within the spaces between the arms 53 and are drivingly engaged thereby.
It will be appreciated that the arms 53 may be replaced by a solid frusto-conical surface which includes
interengagement means for positive driving engagement with the roller end cap which for this purpose may be provided with mating formations other than the projections 56 specifically described.