AU2004203164B2 - Adhesive Applicator - Google Patents

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL TO BE COMPLETED BY APPLICANT Name of Applicant: Dominic Victor Costa Actual Inventor: Dominic Victor Costa Address for Service: A.P.T. Patent and Trade Mark Attorneys PO Box 222, Mitcham, SA 5062 Invention Title: Adhesive Applicator Details of Associated Provisional Application No 2003903707 dated 18 July 2003 The following statement is a full description of this invention, including the best method of performing it known to me:- 2 This invention relates to an adhesive applicator, and in one specific form an adhesive applicator suitable for applying wood glues to articles of wood including wooden boards. In applying adhesive to boards to, for example, make laminate structures of boards end to 5 end, there is a desire to apply adhesive in an even fashion and in an amount that does not result in excess adhesive forming beads of set adhesive protruding from joints between abutting boards. Such spillover of adhesive requires additional work to remove in finishing a surface of the laminate product. Laminate products of particular interest are where multiple boards are adhered edge to edge to form a wide end product such as cabinet doors, 10 table tops and the like. A further difficulty in laminating boards is that generally the edges have grooves formed in them. These grooves may be 2 or 3 mm in depth and may be V shaped, or they may be deeper in the order of 4 to 6 mm and may have straight sides. In order for the boards to be 15 adhered properly adhesive must penetrate as deep as possible into the grooves and evenly so that a uniform bond is formed over the length of two adjacent boards. In practice it is found that deficiencies in adhering boards particularly with deeper grooves lead to a high rate of defective product. Additionally it is desired that excessive adhesive is not used in adhering adjacent boards with deep grooves because even though use of a larger quantity of adhesive 20 might lead to some enhancement of adhesion between the boards there is the problem of cleaning up as well as the difficulty of finishing the laminated product as referred to above, and finally the additional cost of the wasted adhesive. It is an object of the present invention to ameliorate or reduce one or more of the above 25 problems or at least provide the public with a useful choice. For the purposes of this specification the word "comprising" means "including but not limited to", and the word "comprises" has a corresponding meaning. Also a reference within this specification to a document is not to be taken as an admission that the disclosure therein 30 constitutes common general knowledge in Australia.

3 In a first broad aspect the invention might be said to reside in an adhesive applicator including an adhesive delivery means for delivery of adhesive to an applicator roller, the applicator roller having a outer compressible layer for carrying adhesive, a compressing 5 means to compresses the compressible layer of the roller to regulate the thickness of adhesive carried by the applicator roller. Preferably the compressing means can be adjusted to vary the amount of compression of the roller. The adhesive delivery means also preferably includes an adhesive delivery adjustment means to vary the amount of adhesive delivered. Preferably the applicator is held within a housing having one or more sealable closures 10 including an openable lid for providing access for the article to which adhesive is applied, said housing being otherwise sealable to ingress of air. In a second broad aspect the invention might be said to reside in an adhesive applicator including 15 an adhesive reservoir, a driven pick-up roller a lower surface path of which is immersed in the reservoir to pick up adhesive held therein, a scraper positioned adjacent an upward path of the pick up roller, an edge of the scraper spaced from the roller surface path to define a thickness of adhesive carried upwards 20 on the surface of the roller, and a driven applicator roller trailing the scraper blade and positioned to contact the pick up roller to pick up adhesive carried on the pick-up roller. This then provides a means of regulating the thickness of adhesive on the applicator roller. 25 The above form of the invention envisages carriage of the adhesive by the pick-up roller after contact with adhesive in a reservoir. Other forms of the invention might however envisage, a compressing surface, which might be the surface of a compressing roller, or might be the surface of a skid plate, or perhaps the edge of a scraper blade to compress the applicator roller to determine the thickness of adhesive on the applicator roller. The compressing 30 surface in these alternatives are not envisioned as carrying adhesive to the applicator roller, 4 instead there is provided other adhesive delivery means whereby adhesive is delivered to the surface of the applicator roller. This may be by reason of adhesive carried from a reservoir to a delivery slot whereby gravity or a pump expels a measured quantity of adhesive through the slot. 5 Preferably the position of the applicator roller is adjustable relative to the pick-up roller. Preferably the position of the scraper is adjustable relative to surface of the roller. 10 Access to the roller is preferably clear of obstructions from above, so that the article to which glue is applied can be lowered onto the applicator roller, with the applicator roller positioned above the pick-up roller. Alternative arrangements might include, however, the roller positioned at an upper portion of the pick-up roller but not above the pick-up roller, rather to one side. The article to be glued might then contact the applicator roller from one side. It is 15 thus envisaged that the article to which adhesive is to be applied can be brought in radially with respect to the applicator roller to the normal contacting position for application of the adhesive. The invention might additionally contemplate the article to be glued being brought in generally tangentially to the normal contact position for application of the adhesive. Thus where the article to be glued is a plank and the applicator roller is above the pick-up roller 20 the article can be inserted from a side of the glue applicator, and this could occur even where an obstruction existed to radial positioning of the article to be glued. The applicator roller preferably includes an applicator roller shaft and a removable applicator sleeve. The removable applicator sleeve contacts the workpiece and may include an outer 25 sponge or fibrous layer for carrying adhesive thereon. Preferably the cross sectional dimension of the applicator roller shaft is such that a standard paint roller sleeve can be fitted thereto. This has the advantage that no special coverings need to be manufactured and a range of off the shelf rollers sleeves can be purchased with varying nap length to provide for varying capacity to penetrate grooves of a range of depths or other patterns for gluing. 30 5 Preferably the applicator includes a housing encasing the applicator. The housing preferably includes a lid that closes the housing. More preferably a seal is provided between the housing and the lid, and any other closures that might be provided for access inside the housing to maintain the housing and adhesive in a sealed state. This then allows, particularly 5 with wood adhesives, the capacity to do piecemeal work and close the housing between jobs without the adhesive setting. Preferably a drive to the pick-up roller has a sprung clutch to release the drive should an object interfere with the free rotation of the pick-up roller. 10 Preferably the adhesive reservoir is a removable receptable preferably removable from a sealable opening at a lower portion of the housing. Preferably the applicator roller is driven at a speed to match the surface traverse of the pick 15 up roller. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding the invention will be described with reference to one embodiment wherein 20 Figure 1 is a somewhat schematic perspective view of the illustrated embodiment of the invention, Figure 2 is schematic cross sectional view through approximately II-II of figure 4 25 but with the lid of the housing being shown, Figure 3 is a similar schematic cross sectional view of figure 2 with the lid not shown, 30 Figure 4 is a longitudinal cross sectional view through IV - IV of figure 2, and 6 Figure 5 is a schematic cross sectional view substantially as in figure 2 showing details of a second embodiment of scraper blade. 5 DETAILED DESCRIPTION OF THE ILLUSTRATED AND EXEMPLIED EMBODIMENTS OF THE INVENTION The illustrated embodiment of the adhesive applicator according to this invention is held within a sealable housing (1) including a lid (2) and a tub (3). The tub supports a pickup roller (10) which is partly immersed in an adhesive reservoir (11) rotation of the pick up 10 roller carries adhesive up from the reservoir. A scraper (12) is positioned spaced apart from an upward path of the surface of the pick up roller to define the thickness of the adhesive carried thereon. A driven applicator roller (13) trails the scraper and is held in a position to contact the adhesive carried on the surface of the pickup roller so that adhesive is transferred to the applicator roller for transfer to the article to which it is to be applied. 15 The tub is made generally box shaped from steel and has elongate side walls (20, 21) end walls (22, 23) and a floor (24). The end walls extend beneath the floor to form a respective foot (25, 26) at either end of the tub. An upper edge of side and end walls forms a peripheral flange (27) extending outwardly to form a seat onto which a seal (28) in a corresponding 20 flange (29) of the lid can be pressed to assist in forming a seal therewith. A reservoir access door (30) is provided at a front of the tub. This is pivotal about a reservoir door hinge (31) formed at a lower part of the front foot (25). Two catches (32, 33) can be secured to fasten the door in a closed position. These are releasable to open the 25 reservoir door (30) for removal of the adhesive reservoir when desired. The reservoir access door overlaps a reservoir access aperture (35) extending over adjacent portions of the front wall (25). A reservoir door seal (36) in the form of a foamed rubber strip is adhered adjacent a peripheral edged of the inside of the door to seal the inside of the tub when the reservoir door is closed. 30 7 A motor support (40) extends from the rear end wall (23) of the tub. The motor support on which is supported an electric motor (41) and a gear box (42) to drive the pick up roller (10) and the applicator roller (13). The motor support is generally box shaped and formed from metal plate, and is bolted to the rear end wall of the tub. The motor and gear box are 5 similarly bolted to the motor support. The speed of the motor can be varied by electronic control. The inside of the tub is divided into two chambers by a dividing wall (49). A drive chamber (50) of the tub houses pick up roller drive shaft (51) which extends directly from the gear 10 box (42) through to the pick up roller (10). A pick up roller sprocket (52) is supported on drive shaft (51). An applicator drive shaft begins at a position spaced above the upper most part of the tub but is aligned with the pick up roller sprocket, with an end applicator roller sprocket (53). A chain (54) is entrained around sprockets (52, 53) as well as a sprocket supported on an expansion spring which acts to release the chain from the applicator roller 15 sprocket (53) should significant resistance be encountered, for example, caused by entrapment of the fingers of an operator of the applicator, or alternatively should the applicator roller shaft be shifted out of the way. Details of this sprung clutch arrangement are not shown. A cover (55) is provided to fit over the drive chamber to cover the various sprockets, shafts and the chain. The ensures, for safety reasons, that an operator of the 20 applicator is not injured. The adhesive reservoir (11) is supported at a lower region of the tub (3) by a reservoir support (60) that can be raised and lowered. The reservoir support comprises a front leg (61) and a rear leg (62), each pivoted at a lowermost part to the floor (24) of the tub, and at an 25 uppermost part to a tray (63). The construction of the front and rear legs (61, 62) and the tray is of sheet metal which may be of stainless steel. The front and rear legs are made of a web of material extending substantially the width of the tray. The tray is generally flat with side walls to locate the adhesive reservoir (11) laterally, the tray however does not have a front or rear wall. The reservoir is not fastened to the tray and is slidable from the front to 30 the rear of the tray. To remove the adhesive reservoir, the reservoir access door is opened by 8 undoing the catches (32, 33) and opening the door forward and resting it on a bench top or other adjacent surface. The legs are pivoted forward with the front leg pivoting through the reservoir access aperture (35). The adhesive reservoir (11) moves downwardly with the reservoir support, sliding backwards relative to the tray (63) until it is clear of the pick-up 5 roller, whereupon it moves forward with the tray. The adhesive reservoir (11) can then be slid out of the reservoir access aperture (35). The adhesive reservoir can be cleaned, filled, repaired or otherwise dealt with. To return the adhesive reservoir the reverse of the above steps is performed. 10 Where considerable adhesive is utilised it may be desirable to provide a feed nozzle (not shown) extending through the front wall, whereby adhesive can be pumped from the outside through the feed nozzle which leads to a tube directing adhesive into the adhesive reservoir. A cap is preferably provided over the feed nozzle to close the feed nozzle and prevent ingress of air into the housing when closed. 15 The adhesive reservoir is made of stainless steel. The reservoir comprises two end walls (71, 72) which are generally rectangular in shape, and a curved, semi cylindrical body (73). The curved body ensures that there is no "dead space" where adhesive stays for extended times without movement, such as would be present where significant corners were provided. The 20 shape of the end walls facilitates the interaction of the external part of the reservoir with the tray (63) of the reservoir support (60). The flat bottom of the end walls of the reservoir rest on the flat upper surface of the tray and allow sliding thereon. Sides of the end walls are positioned adjacent to the side walls of the tray and limit lateral movement of the reservoir on the tray. 25 The pick-up roller (10) is rotatable with the pick-up roller shaft (51) relative to the tub. The pick up roller shaft is supported by two bearings (80, 81) one on the front wall of the tub (22) and the other on the dividing wall (49) of the tub. As can be seen, the pick-up roller shaft is directly connected with gear box (42). Rotation of the pick up roller is thus driven by motor 30 (41) via the gear box (42). The pick-up roller is a substantial diameter and is made of 9 stainless steel. The outer surface of the pick-up roller is generally smooth, or what might be described as having a brushed finish. The direction of rotation of the pick-up roller can be seen by arrow (82) that can be see in figures 2 and 4. 5 The scraper (12) is elongate and extends for the length of the roller so that it exerts its effect over the entire length of the roller. The scraper is made of flat stainless steel and might be described as a blade. The scraper is pivotably supported relative to the tub at a position generally level with the top of the tub (3) about an axis of rotation of the scraper hinge (85). In the illustrated embodiment two hinges are provided either side of the scraper blade, the 10 first hinge is positioned close to the front wall (22) of the tub and the second is supported adjacent the dividing wall (49). The position of an edge of the scaper (86) relative to the peripheral surface (83) of the pick up roller determines the thickness of adhesive that is carried by the pick-up roller downstream of the scraper and therefore how much comes in contact with the applicator roller. Adjustment of the position of the scraper blade is by 15 adjusting the pivotal position of the blade using a scraper adjustment screw (87). The scraper adjustment screw includes a handle (88) a screw threaded stem (89) and a stop (90). The screw threaded stem engages with a complementary threaded aperture in the scraper. It will be appreciated that by turning the scraper adjustment screw clockwise the scraper is carried closer to the surface of the pick-up roller, whereas turning the screw anticlockwise 20 will carry the scraper further away from the surface of the pick-up roller. A second embodiment of scraper blade is shown in figure 5. The applicator is substantially the same as for the first embodiment, as is the adjustment of the scraper blade relative to the pick-up roller. The scraper blade comprises two parts. A metal plate (200) which is attached 25 in a like manner to the first embodiment of scraper blade, with the same adjustment means. This extends across the length of the pick-up roller and beyond the roller. The metal plate is bent over to form a scraper receiving flange (201). The scraper receiving flange has a plurality of spaced apart screw threaded apertures formed therethrough. The scraper blade takes the general form of an inverted U shape, an upper part (202) of which forms a straight 30 edge which is spaced apart from the pick-up roller to regulate the thickness of adhesive 10 carried by the pick-up roller. On either side of the scraper blade are to downwardly extending legs one of which is shown at (203), these are positioned on either side of the ends of the pick-up roller and extend adjacent a bottom of the reservoir. It will be appreciated that whilst the general layout of the adhesive applicator shown in Figure 4 is relevant to this 5 embodiment of scraper blade, that the pick-up roller is more centrally positioned in the reservoir than is shown therein. The scraper blade of this second embodiment is formed of a nylon material, and fastened to the scraper receiving flange by screws. The benefits of using nylon is that any risk of scoring the pick-up roller is alleviated, the wear being principally to the scraper blade which can readily be replaced. The benefits of the downwardly extending 10 legs is that carriage of adhesive up the sides of the pick-up roller is minimised, additionally the adhesive held in the reservoir is in majority contained to the pick-up side of the reservoir when in use. The applicator roller (13) comprises an applicator roller shaft (100) and an applicator roller 15 sleeve (101). The applicator roller shaft is rotatably support on an applicator support plate (102), a first end of which is pivotally supported on one side of the tub by a hinge (103). A second end of the applicator support plate (104) is supported by an applicator adjustment screw (105). The applicator adjustment screw comprises a handle (106), and a screw threaded stem (107) and a stop (108). The screw threaded stem engages with a 20 complementary threaded aperture in the applicator support plate. Turning the handle clockwise or anticlockwise adjusts the angle of the applicator support plate and thus the relative distance between the applicator roller and the pick-up roller (82). The applicator roller shaft is supported at a first end portion by two bearing (110, 111) 25 spaced apart on the applicator support plate (102). The applicator roller sprocket (53) is supported at the first end of the applicator roller shaft and engages with chain (54), which drives sprocket and the applicator roller shaft in the direction indicated by arrow (112).

11 The sprockets driving the applicator roller (13) and the pick-up roller (10) are such that the surface traverse of the applicator roller and the pick up roller are the same. There is accordingly no skidding of one relative to the other. 5 The second, free end of the applicator roller shaft includes a sleeve retaining disc (113) and a sleeve retaining disc bolt (114). The sleeve retaining disc bolt engages a screw threaded bore in the applicator roller shaft and passes through a central aperture in the sleeve retaining disc to fasten the disc in place when secured. The sleeve retaining disc extends past the diameter of the applicator roller shaft and acts to retain the applicator roller sleeve (101) in place on 10 the applicator roller shaft. This then allows for ready removal of the applicator roller sleeve by unfastening the bolt, removing the retaining disc and the removing the sleeve by sliding it off of the free end of the applicator roller shaft. Replacing a sleeve is achieved by the reverse steps. 15 The diameter of the applicator roller shaft is chosen to coincide with the diameter of a standard paint roller, so that a standard paint roller sleeve can be fitted onto the applicator roller shaft. Paint rollers provide a source of applicators and a range of nap thicknesses that are readily available. Longer nap rollers may be preferred where adhesive is to be applied to deeper grooves because longer nap can extend into deeper grooves than can a shorter nap 20 roller sleeve. Typically the applicator roller (13) is adjusted so that the nap of the roller sleeve (101) is somewhat compressed onto the pick-up roller. Typically the construction of the roller sleeve is such that fibres are embedded into or adhered to a plastics cylinder and oriented to extend 25 peripherally away from the cylinder. A contact surface of the roller is formed by the fibres a distance from the plastics cylinder, and the distance between the contact surface and the plastics cylinder determines the potential thickness of adhesive applied to a board or other workpiece. It will be understood that compression or expansion of the fibres of the roller sleeve (101) against the pick up roller will regulate the amount of adhesive that can be 30 applied to a board passing thereover.

12 As can be seen from the drawings, the applicator roller (13) sits generally above the upper surface of the tub of the housing. At very least the upper surface of the applicator roller does so. Additionally the applicator roller is freely accessible from above so that a board can 5 readily be placed onto the roller and be drawn over the adhesive applicator by the applicator roller to thereby apply a controlled amount of adhesive. The board might be drawn end on or on the flat so that adhesive can be applied thereon. To give a better understanding of the invention dimensions of the illustrated embodiment are 10 as follows. The applicator roller sleeve (100) is a commercially available paint roller sleeve with outside diameter of approximately 50mm, and a length of 270mm. The pickup roller (10) has an axial length of 280mm and an outside diameter of 140mm. The overall length of the apparatus is 550mm, the tub (3) having a length of 410mm and the drive chamber has a length of 140mm. The depth of the tub is 200 mm and the depth of the lid (2) is 100mm. The 15 width of the tub is 300mm. The reservoir has an overall height of 50mm, a width of 280mm and is 400mm long. As indicated earlier the lid (2) of the housing is able to close over the tub (3). The lid comprises side walls (120, 121) and end walls (122, 123) generally in line with those of the 20 tub. A lower end of the side walls and end walls are formed into a continuous outwardly extending flange (29). A foamed rubber strip (28) is fastened to a lower surface of the flange (29). A lowermost part of the rear end wall (123) is pivotable about the axis of rotation of lid 25 hinge (124), to allow for the lid to pivot from a closed position shown in figure 2 to an open position shown in figure 1. A strut (125) is positioned between the lid and the tub to limit the extent to which the lid can open. Two lid closure catches (126, 127) are provided on the front wall of the tub to engage with two tongues (128, 129) extending from the lid. The catches are overcentre catches that apply a measure of pressure on the closure, providing 30 thereby a compressive force on the seal to thereby seal the housing. Similar compressive 13 force is exerted on the seal of the reservoir access door (30). It can thus be seen that minimal exchange of air occurs between the inside of the housing and the external milieu. It has been found that adhesive can be kept inside the glue applicator of the present invention for periods of a week or more when the lid is closed, and the housing is sealed. That then provides for a 5 very convenient adhesive applicator where adhesive is to be applied in a piecemeal fashion. When the adhesive applicator is not in use the electronic variable speed regulator on the motor can allow the pick up roller to run at a speed of less than 1 revolution per minute. This prevents the adhesive on the rollers from drying when the lid is closed, and obviates any 10 need to clean the rollers where the adhesive applicator is not used over an extended period. Various features of the invention have been particularly shown and described in connection with the exemplified embodiments of the invention, however, it must be understood that these particular arrangements merely illustrate and that the invention is not limited thereto 15 and can include various modifications falling within the spirit and scope of the invention.

Claims (20)

1. An adhesive applicator including an adhesive delivery means for delivery of adhesive to an applicator roller, the applicator roller having a outer compressible layer for carrying adhesive therein, a compressing means to compresses the compressible layer of the roller to 5 regulate the thickness of adhesive carried within the outer layer of the applicator roller, the compressing means acting on the applicator roller upstream of contact made with a surface to which the adhesive is applied, the compressing means adapted to be adjusted to vary the amount of compression of the roller. 10

2. An adhesive application of claim 1 wherein the outer compressible layer is fibrous.

3. An adhesive application of claim 1 wherein the outer compressible layer is a sponge.

4. An adhesive application as in any one of claims 1 to 3 wherein the applicator roller 15 includes an applicator shaft roller and a removable applicator sleeve.

5. The adhesive applicator of any one claims 1 to 4 wherein the adhesive delivery means include an adhesive delivery adjustment means to vary the amount of adhesive delivered. 20

6. The adhesive applicator of any one of claims 1 to 4 5 wherein the applicator roller comprises an applicator roller shaft and a removable applicator sleeve, an outer part of the removable applicator roller being the outer compressible layer. 25

7. The adhesive applicator of claim- 6 wherein the applicator roller shaft is driven from a fixed end and the applicator roller shaft having a free end so that the applicator sleeve can be fitted over the sleeve from the free end.

8. The adhesive applicator of any one of claims 1 to 7 wherein the applicator is held 30 within a housing having one or more salable closures including an openable lid for 15 providing access for the article to which adhesive is applied, said housing being otherwise salable to ingress of air.

9. The adhesive applicator of claim 1 further including 5 an adhesive reservoir, the delivery means comprising a driven pick-up roller a lower surface path of which is immersed in the reservoir to pick up adhesive held therein, a scraper positioned adjacent an upward path of the pick up roller, an edge of the scraper spaced from the pick-up roller surface path to define a thickness of adhesive carried 10 upwards on the surface of the roller, and the applicator roller being driven and trailing the scraper blade and positioned to contact the pick up roller to pick up adhesive carried on the pick-up roller.

10. An adhesive application as in claim 9 wherein the applicator roller has an outer 15 compressible layer for carrying adhesive, and is held against the pick up roller so as to compress the compressible layer to thereby regulate the thickness of adhesive carried by the applicator roller thereby acting as the compressing means the position of the applicator roller being adjustable relative to the pick-up roller whereby to vary the degree of compression of the compressible layer. 20

11. An adhesive application as in either claim 9 or 10 wherein the position of the scraper is adjustable relative to the surface of the pick-up roller.

12. The adhesive applicator of any one of claims 9 to 11 wherein the applicator is held 25 within a housing consisting of a tub with one or more salable closures including an openable lid for providing access for the article to which adhesive is applied, said housing being otherwise salable to ingress of air.

13. An adhesive application as in claim 12 wherein the tub is upwardly open when said 30 lid is opened to thereby provide access from above, the applicator being positioned above the 16 pick-up roller and protruding above an upper surface of the tub so that an elongate article can be drawn across the top of the applicator roller.

14. An adhesive application as in any one of claims 9 to 13 wherein a drive to the pick-up 5 roller has a sprung clutch to release the drive should an object interfere with the free rotation of the pick-up roller.

15. An adhesive application as in any one of claims 9 to 14 wherein the adhesive reservoir is a removable receptable preferably removable from a salable opening at a lower 10 portion of the housing.

16. An adhesive application as in any one of claims 9 to 15 wherein the applicator roller is driven at a speed to match the surface traverse of the pick up roller. 15

17. An adhesive application as in any one of claims 9 to 16 wherein the motor speed is variable, there being provided speed control means to control the speed of the motor.

18. An adhesive application as in any one of claims 9 to 17 the reservoir is removable from beneath the pick-up roller through a salable access door. 20

19. An adhesive application as in any one of claims 9 to 13 wherein the reservoir has an arcuate floor aligned with the curvature of the pick-up roller and generally upright side walls.

20. An adhesive application as in any one of claims 9 to 13 wherein two downwardly 25 extending legs are provided one adjacent either side of the pick-up roller on the upward moving half of the pick up roller to contain a majority of adhesive scraped by the scraper blade. 30