Smoothing/brushing machine for wooden articles and relative operating method

Abstract

 A machine for smoothing or brushing flat surfaces of wooden articles which are in the raw state or to the surface of which one or more paint layers have been previously applied, comprising at least one smoothing/brushing unit (3), each comprising a smoothing/brushing device (4) and means for moving each unit (3) at least relative to the article flat surface to be smoothed. Each smoothing device (4) comprises a motorized head (5) rotatable about a main axis (13) perpendicular to the flat surface to be smoothed or brushed, said smoothing/brushing device (4) being provided with suction means (14) to maintain a smoothing or brushing element (6) rigid with the motorized head (5) during its rotation, said smoothing or brushing element (6) being provided with an abrasive surface or a brushing surface, respectively, both surfaces facing the article and being parallel to the surface to be smoothed or brushed.

Description

[0001] The present invention relates to a machine for smoothing or brushing flat surfaces wooden articles and the relative operating method in accordance with the introduction to the main claims.

[0002] Smoothing machines able to smooth flat articles, even presenting recessed and/or relief shapings, are known.

[0003] These machines comprise a horizontal conveyor device (in particular a conveyor belt) for conveying the articles to be smoothed, and a smoothing device or several smoothing devices in succession above the conveyor belt, each smoothing device being movable vertically in both directions relative to the conveyor device. Each smoothing device comprises a motorized smoothing element, rotatable about an axis perpendicular to that flat surface of the article to be smoothed, each smoothing element presenting an abrasive flat surface facing the article and parallel to that surface of this latter to be smoothed.

[0004] Each of these rotating elements comprises a rigid part provided with a flat face facing the surface to be smoothed, to this flat face there being fixed, for example by hook and eye connecting means, a layer of elastic material the lower face of which is abrasive. A machine of this type is described for example in EP1790433 in the name of the same proprietor.

[0005] Although advantageous in various aspects, the rotating elements of these known machines present the drawback of requiring the intervention of an operator located in proximity to the smoothing element to perform the operations involved in applying the abrasive surface and its removal when requiring replacement.

[0006] An object of the present invention is therefore to provide a smoothing/brushing machine which does not present the aforedescribed drawbacks, and more precisely allows more rapid and efficient replacement of a smoothing or a brushing element.

[0007] This object is attained by a smoothing/brushing machine, the inventive characteristics of which are defined in the accompanying claims.

[0008] The invention will be more apparent from the ensuing detailed description of one embodiment thereof provided by way of non-limiting example and illustrated in the accompanying drawings, in which:

Figures 1-4 are partially sectional side views of the machine of the invention during some stages of its operation,

Figure 5 is a schematic view from above showing one embodiment of smoothing/brushing devices of the machine of Figure 1,

Figure 6 is a schematic view from above showing a modified embodiment of smoothing/brushing devices of the machine of Figure 1,

Figure 7 is an enlarged schematic view from below showing a rotating head of the machine of Figure 1,

Figure 8 is a section on the line II-II of the rotating head of Figure 7,

Figure 9 is an exploded schematic view of a smoothing element of the machine of Figure 1,

Figure 10 is an exploded schematic view of a brushing element of the machine of Figure 1.

[0009] With reference to Figure 1, this shows a smoothing/brushing machine 1 comprising a conventional conveyor belt 2 which extends horizontally, with its advancement direction parallel to the plane of the sheet, and serves mainly to bring into position an article the upper flat surface of which is to be treated.

[0010] These smoothing machines comprise, in known manner, a frame comprising two lateral columns along which two mutually parallel horizontal connection crosspieces move vertically in a rigid manner, they being provided one for each side of the plane in which the two columns lie. In said figure neither these elements nor the base of the machine 1 have been shown for simplicity.

[0011] The two crosspieces also act as runways for a carriage carrying a smoothing unit 3 comprising at least one smoothing device 4 provided with a rotating head 5, which is disc-shaped in the illustrated example.

[0012] It is however apparent that depending on the articles to be treated and the specific requirements, the smoothing unit can comprise one or more smoothing devices 4, and even present more than one smoothing unit 3.

[0013] The smoothing device 4 hence comprises a motorized head 5 rotatable about a main axis 13 perpendicular to the flat surface to be smoothed or brushed. According to the invention, the smoothing unit 3 is provided with suction means 14 to maintain a smoothing or brushing element 6 rigid with the motorized heads 5, at least during its rotation, said element being provided with an abrasive surface or a brushing surface both facing the article and parallel to the surface to be smoothed or brushed.

[0014] Specifically, as shown in Figures 7 and 8, the motorized head 5 comprises in its interior a suction chamber 10 connected by a hollow vertical shaft 13a to a device able to draw in/expel air.

[0015] For example, the motorized head 5 is keyed onto the lower end of the vertical shaft 13a driven by a gearmotor supported by the carriage.

[0016] Further keying means 17 are provided between the gearmotor and the motorized head 5.

[0017] Advantageously, the keying means 17 do not rigidly secure the head 5 to the gearmotor but enable it to tilt slightly about a plane perpendicular to the shaft 13a.

[0018] The vertical movement of the pair of crosspieces, and hence of the carriage, and the horizontal movement of the carriage, i.e. of the smoothing device mover means, and consequently of the smoothing unit 3, are achieved in conventional manner.

[0019] The disc-like smoothing or brushing element 6 comprises in this specific case (as best seen observing the discoidal smoothing element 6a shown in Figure 9) a rigid carrier disc 7 (for example of steel) and a disc-shaped layer of elastic material 8 (for example sponge rubber) applied (for example glued) to the lower face of the rigid disc 7. To the lower face of the elastic layer 8 there can be applied a circular sheet of abrasive paper having substantially the same diameter as this latter, or a circular blanket of abrasive material, both being conveniently applied using hook and eye means allowing rapid application and removal (in particular the means known by the trademark VELCRO).

[0020] The machine 1 of the invention can also support a brushing element 6b, shown in Figure 10, comprising a rigid disc 11, on the lower face of which there can be applied a brushing element 12, which is conveniently applied still using said hook and eye means. The free ends of filiform element 12 of the brush elements form the brushing surface of the brushing element 6b.

[0021] For certain operations it can be useful to provide between the drive shaft 13a and the movable head 5 a joint (for example a universal joint) enabling the element 5 to tilt slightly about a plane perpendicular to the shaft 13.

[0022] Advantageously, according to the invention each smoothing device 4 comprises at least one centering element 15 movable along an axis parallel to the main axis 13 such as not to interfere with the rotating head 5 and to enable the smoothing or brushing element 6 to be aligned coaxially to the rotating head 5.

[0023] For example this centering element 15 comprises a pair of pneumatic cylinders, shown in Figures 1-5, positioned to the side of the smoothing/brushing device 4.

[0024] There is nothing to prevent this centering element 15 from being a profiled guide element 15a, shown in Figure 6, which enables the smoothing or brushing elements to be centered.

[0025] With reference to Figures from 1 to 4, the operation of the smoothing/brushing machine shown therein will now be described, in particular with reference to the automatic loading of the smoothing or brushing elements 6.

[0026] The machine 1 comprises (as stated) a horizontal conveyor belt 2 extending in a direction perpendicular to the plane of the sheet of Figure 1. Smoothing or brushing elements 6 are positioned on this conveyor belt, which normally allows positioning of the article to be treated. During this stage the smoothing/brushing unit 3 evidently lies at an elevation such as not to hinder the positioning of the smoothing or brushing element 6 by the movement of the conveyor belt 2. The centering elements 15 are then lowered to interfere with the edge of the smoothing or brushing elements 6 conveyed by the conveyor belt.

[0027] The smoothing or brushing element 6 is made to advance until it abuts against the centering elements 15 in order to align itself coaxially with the rotating head 5.

[0028] With the centering elements 15 raised, as shown in Figure 2, the smoothing/brushing unit 3 is then lowered to bring the head 5 into contact with the upper surface of the smoothing or brushing elements 6.

[0029] At this point the suction means 14 are activated to also maintain the smoothing or brushing elements 6 in contact with the head 5 during its rotation.

[0030] The head 5 is then positioned at its working level to enable the articles to be positioned in conventional manner and then treated.

[0031] By suitably combining, in known manner, the movement of the conveyor belt 2 and the movement of the carriage along the pair of crosspieces, the entire upper surface of the article can be brushed, or even just a part thereof, this being useful when a face of the article presents several flat surfaces disposed in parallel planes or separated and/or defined by relief shapings.

[0032] When the smoothing or brushing element 6 has to be changed, the suction means 15 are halted, the smoothing or brushing element 6 then falling onto the conveyor belt 2, as shown in Figure 3, to be removed by the conveyor belt itself (Figure 4).

[0033] Clearly if the machine 1 is provided with several smoothing or brushing units 3, the loading, the aligning, the setting-up of the smoothing or brushing elements 6 and their removal are all effected much more rapidly and functionally than in conventional smoothing machines in which the abrasive surface is removed manually by an operator for each smoothing unit.

[0034] The smoothing/brushing machine can be conveniently provided with sensors, connected to the control unit, able to sense the entry and exit of the smoothing or brushing elements.

[0035] It is also evidently possible to provide a smoothing/brushing machine of the invention in which the smoothing/brushing unit is maintained fixed and conventional means are provided to move the article and the smoothing or brushing elements both vertically and horizontally, in two perpendicular directions, to hence effect the operation of smoothing/brushing the entire article surface to be treated or to change the smoothing or brushing element 6.

[0036] In conclusion according to the invention, by virtue of the presence of the suction means, a very versatile smoothing/brushing machine can be obtained enabling the smoothing or brushing elements 6 to be loaded and aligned automatically, and be rapidly replaced.

Claims

1. A machine for smoothing or brushing flat surfaces of wooden articles which are in the raw state or to the surface of which one or more paint layers have been previously applied, comprising at least one smoothing/brushing unit (3), each comprising a smoothing/brushing device (4) and means for moving each unit (3) at least relative to the article flat surface to be smoothed;
characterised in that each smoothing/brushing device (4) comprises a motorized head (5) rotatable about a main axis (13) perpendicular to the flat surface to be smoothed or brushed, said smoothing/brushing device (4) being provided with suction means (14) to maintain a smoothing or brushing element (6) rigid with the motorized head (5) during its rotation, said smoothing or brushing element (6) being provided with an abrasive surface or a brushing surface, respectively, both surfaces facing the article and being parallel to the surface to be smoothed or brushed.

2. A smoothing/brushing machine (1) as claimed in claim 1,
characterised in that said smoothing element (6) comprises a rigid part (7) provided with a flat face facing the surface to be smoothed, to said flat face there being fixed a layer of a material (8) the outer face of which presents an abrasive surface.

3. A smoothing/brushing machine (1) as claimed in claim 1,
characterised in that the abrasive surface of the smoothing element (6) is obtained by applying an abrasive paper (9) or a blanket of abrasive material.

4. A smoothing/brushing machine (1) as claimed in claim 1,
characterised in that the abrasive paper (9) or the blanket of abrasive material is applied to the remaining parts of the smoothing element using hook and eye means.

5. A smoothing/brushing machine (1) as claimed in claim 1,
characterised in that said brushing element (6) comprises a rigid part (11) provided with a flat face facing the surface to be brushed, to said flat face there being fixed a brushing element (12).

6. A smoothing/brushing machine (1) as claimed in claim 1,
characterised in that each smoothing/brushing device (4) comprises centering elements (15) movable along an axis (16) parallel to the main axis (13) such as not to interfere with the rotating head (5) and to enable the smoothing or brushing element (6) to be aligned coaxially with said rotating head (5) during the loading stage.

7. A smoothing/brushing machine (1) as claimed in claim 1,
characterised in that said rotating head (5) comprises a suction chamber (10).

8. A method for automatically loading a smoothing or brushing element (6) of a smoothing/brushing machine described in claim 1, comprising the steps of:

- aligning the smoothing or brushing element (6) coaxially with the rotating head (5),

- lowering the rotating head (5) to bring it into contact with an upper surface of said smoothing or brushing elements (6),

- causing the smoothing or brushing element (6) to adhere to the rotating head (5) by suction.

9. Automatic loading method as claimed in claim 8, characterised in that the alignment step comprises the steps of:

- positioning the smoothing or brushing element (6) on a conveyor belt (2) used to bring into position an article the upper flat surface of which is to be smoothed or brushed.

- lowering the centering elements (15) with which the smoothing or brushing device is provided such that they are able to interfere with the edge of the smoothing or brushing elements (6),

- advancing the smoothing or brushing element (6) until it abuts against said centering elements (15).

Drawing