WO1993023202A1

WO1993023202A1 - Apparatus for the buffing of edges on an elongated item

Info

Publication number: WO1993023202A1
Application number: PCT/DK1993/000164
Authority: WO
Inventors: Anders Erik Hjort Jeppesen
Original assignee: Bodilsen Hodling A/S
Priority date: 1992-05-14
Filing date: 1993-05-14
Publication date: 1993-11-25

Abstract

The apparatus according to the invention is equipped with two pairs of counter-rotating brushes (6, 6a, 7, 7a) for the buffing of elongated, curved items of wood (4). For the feeding of the item, there is provided a flat holder provided with a driving belt (9) and a roller (8), and between which means (8, 9) the item (4) can be fed between the brushes (6, 6a, 7, 7a) in an inclined direction in relation to the buffing directions (14, 14a) of the brushes. Consequently, all edges (15, 16, 17, 18) on the item (4) can thus be buffed in one operation, even though the item (4) is curved.

Description

APPARATUS FOR THE BUFFING OF EDGES ON AN ELONGATED ITEM

STATE OF THE ART

The invention concerns an apparatus for the buffing (trimming, smoothing, deburring) of edges on an elongated item. By "elongated" is meant an item with relatively constant cross-section and with much larger extension in the dimension at right-angles to the cross-section than the cross dimensions, regardless of whether the item curves during the course of its extension.

The apparatus comprises two rotatable buffing brushes and is arranged with a buffing area between the brushes where the peripheries of the buffing brushes can touch the item. For the guiding of the item through the buffing area, mechanical means with endless periphery are provided, one of said means being a roller. The guiding means are arranged to feed the item forward in such a manner that the item's longitudinal edges extend obliquely in relation to a tangent to the periphery of the brushes. The tangent is contained within a plane parallel with the extension of the item length in the buffing area. The mutually closest-lying parts of the guiding means are placed so that a straight line extends obliquely in relation to the tangent.

An apparatus with the above features, but intended for the handling of the plane surfaces of an item, is known from GB patent 1,543,395, the contents of which form part herewith by reference. The known apparatus has two rollers which, when in contact with two remaining sides of the item, can guide the item during its passage of the buffing area. During the buffing, the item is driven through the buffing area by separate, external means of feeding. The known apparatus is described for the handling of linearly extended items.

Within the woodworking industry, an apparatus is known which consists of a vertical stand with a rotatable buffing brush disposed in the upper end, in that the axis of rotation of the brush is horizontal. The apparatus can comprise two brushes which are disposed on the same spindle on each side of the stand. When the apparatus is used, an operator leads the item past the buffing brush so that the edges on the item are chamfered by the brush bristles. Not only is the work time-consuming, but the result depends on the skill and the care of the operator.

Another apparatus for the buffing of edges on items is described in EP A2 137,859. The apparatus comprises a conveyor belt having an upwardly-facing, horizontal surface on which the item can rest. Above the belt there are two parallel buffing brushes having axes of rotation which are inclined in relation to the belt's direction of movement. In order to hold the item in position during the buffing, a number of rollers are provided at the side of the item nearest to the brushes, in that said rollers are able to press the item in the direction towards the belt. With the belt, the item can be moved forwards and backwards under the brushes, whereby fraze and sharp edges on the underside of the item can be processed. The apparatus is arranged primarily for relatively flat items on which punching operations have been carried out. Since the belt serves as support surface for the items, the size of the items is limited by the dimensions of the belt, and the shape of the items is limited.

EXPLANATION OF THE INVENTION

The special feature of the apparatus according to the invention is that the guiding means also function as feeding means, and that the means comprise an endless belt which together with a roller can feed the item through the buffing area between roller and belt. The belt extends around wheels suspended in a holder which is pivotably mounted around an axis close to the one end of the holder, so that the holder with the belt can be swung in different angles in relation to the tangent.

By squeezing the item between the belt and the roller, while at the same time driving either the belt or the roller by means of a motor, the edges of the item will pass the buffing area where the bristles or buffing means on the brushes can work on the edges which face towards the brushes, while at the same time the displacement of the item is effected solely in a direction parallel with the item edges. Due to the configuration of the feeding means, it is possible to feed curved items, preferably single- curved items, through the buffing area, whereby the edges of the item are worked on by the brushes.

It is preferred that the conveyor belt is connected to a driving unit as disclosed in claim 2. The axis of rotation of the holder can hereby coincide with the spindle of the driving unit, whereby the construction is simplified.

To ensure the squeezing of the item between belt and roller, and herewith ensure the feeding of the item, it is preferred to include at least one force-exercising element to influence the holder so that it turns around its axis in the direction towards the roller. The same arrangement ensures a sure grip for the feeding means if there are variations in the cross-sectional width of the item.

By configuring the apparatus as disclosed in claim 4, two edges which face towards the same side in relation to the feeding means can be buffed simultaneously.

When the apparatus comprises at least four buffing -brushes, which are disposed in pairs on opposite sides of the buffing area, all outwardly-facing, longitudinal edges can be buffed in one operation.

It is also preferred to make the apparatus with a plane supporting surface which the item can be displaced along with during feeding through the buffing area, see claim 6.

Out of regard for the thickness of the item, adjustment of the position of the brushes in relation to the supporting surface can be ef ected when the apparatus is constructed as disclosed in claim 7.

Further adjustment out of regard for the width of the item can be effected by means of the arrangements mentioned in claim 8.

THE DRAWING

An embodiment of the apparatus according to the invention will now be described in more detail with reference to the drawing, where

fig. 1 shows a side view of the apparatus according to the invention,

fig. 2 shows an enlarged section of the apparatus according to the invention along the line II-II in fig. 3,

fig. 3 shows the principle construction of the apparatus in a horizontal section along the line III- III in fig . 2,

fig. 4 shows a section along the line IV-IV in- fig. 3,

fig. 5 shows a section along the line V-V in fig. 3,

fig. 6 shows a section along the line VI-VI in fig. 5, and

fig. 7 shows a section of the apparatus along the line VII-VII in fig. 1.

DESCRIPTION OF EMBODIMENTS

The apparatus according to the invention is constructed as an edge trimming or edge buffing machine which is used for furniture parts, i.e. items of wood. The items can be straight, even though the apparatus is particularly advantageous in the processing of curved items as shown. In the examples described, the item is of rectangular cross- section, but items with other cross-sections can also be processed.

The apparatus consists of a lower part 1 and an upper part 2, said lower part 1 being provided with a table surface 3 on which an item 4 can slide. The upper part 2 can be displaced upwards and downwards, as it 2 is suspended between and guided by columns 30. The columns 30 are mutually connected at each side with a transverse beam 31, which with a not-shown bearing at its centre supports a screw spindle 32. The thread 33 of the spindle is in engagement with a threaded bush placed in a second transverse beam 34 which supports the upper part 2. The spindles 32 can be turned by means of handwheels 35, whereby the upper part 2 can be moved up or down. In a preferred embodiment of the apparatus, the buffing area 5 between the parts 1 and 2 is provided with two pairs of cylindrical, rotating brushes 6,6a and 7,7a which can process the item 4. The brushes 6,6a are suspended in the upper part 2 and the brushes 7,7a in the lower part 1 under the -table surface 3. In the table surface or the table top 3 there is an opening 3a which allows the brushes 7,7a to extend above the plane which is defined by the surface 3. The brushes 6,6a,7,7a are provided in a known manner with sandpaper flaps supported by and alternating with bristles which support the sandpaper flaps during the processing. By turning the handwheels 35, the upper brushes 6,6a can be raised or lowered and fixed at different distances in relation to the table top 3 for adjustment in accordance with various item thicknesses. The lower brushes 7,7a have fixed axes of rotation 21 and 22 in relation to the table top 3 apart from a possibility of slight adjustment out of regard for wear on the brushes. The brushes 6 and 6a are mounted on the ends of stub axles 24 and 25 which have mutually opposite directions of rotation as shown in fig. 2. The brushes 7 and 7a are mounted on corresponding counter-rotating axles 27 and 28. The brushes 6,6a,7,7a are each driven by their own electric motors which are secured in a manner not shown in the upper part 2 and the lower part 1 respectively.

For the feeding of the item 4, a roller 8 is mounted in a fixed manner and a conveyor belt 9 is configured as a V- belt extending between a drive wheel 10 and a carrier wheel 11. The belt 9 is of a rubber composition with high surface friction on its outwardly-facing side, and it is reinforced with textile thread.

The rollers 10,11 are built into and suspended in a relatively flat holder 40 which in principle is configured like the "sword" on a power chain saw, and as shown in fig. 5. The holder 40 is supported via the built-in bearing for the drive roller 10 of the drive shaft 41 which is ^• connected to an electric motor 42. The holder 40 is hereby pivotably suspended around a vertical axis 12 which coincides with the axis of rotation of the roller 10. The holder 40 is provided with a cylindrical collar 43 which surrounds the shaft 41. To the collar 43 there is secured two pins 44 and 45 which extend in diametrically opposite directions. The one pin 44 is secured to the piston for a double-acting compressed air cylinder 46, whereby the collar 43 and therewith the holder 40 can be swivelled. The belt 9 can thus be swung from the position shown with the fully-drawn line to the position shown with the stippled line in fig. 3. The second pin 45 can be influenced by pressure forces from the ends of two compressed air cylinders 47 with relatively short stroke length. During operation, the cylinders 47 serve as an elastic influence on the pin 45 and therewith the holder 40 and the belt 9 in such a manner that the holder 40 is given a torque in the direction towards the roller 8, whereby a squeezing and herewith a reliable feeding of the item 4 can be effected. In order to be able to adjust the squeezing force, the cylinders 47 are adjustable (movable) in their longitudinal direction in relation to the underlayer, e.g. in a not- shown manner with elongated holes around mounting screws.

As shown in figs. 5 and 6, the holder 40, the motor 42 and the cylinders 46 and 47 are all suspended on a movable carriage 48 which on two ball liners 49 can be displaced along cylindrical guides 50. The guides 50 are secured to the underside of the table 3 by aprons 51. A screw spindle 52 provided with a handwheel 53 is pivotably suspended in the one bracket 51 and is in engagement with a not shown threaded bush in the carriage 48. The carriage 48 with motor 42 and other parts can thus be moved in directions towards and away from the roller 8, and the holder 40 with its axis 12 is movable in directions towards and away from the roller 8, whereby the holder 40 can be adjusted with regard to different item breadths.

The belt 9 has a constant direction of rotation as shown by the arrow 13.

The brushes 6,6a,7,7a have constant direction of rotation as shown in fig. 2, where the resulting brushing directions in the buffing area 5 are shown with the number 14 and 14a.

The item 4 has four longitudinal edges 15, 16, 17, 18. With reference to fig. 3, the apparatus according to the invention is used as follows. The item 4 is introduced into position as shown in fig. 3 in the direction indicated by the arrow 19, whereby the item 4 is gripped between the belt 9 and the roller 8 and is driven forwards in the direction 19. During this operation, the edges 16 and 17 are processed by the brushes on the rollers 6 and 7 respectively.

As will be seen in fig. 3, the edges 16, 17 on the item extend obliquely in relation to the brushing direction 14, which at the same time indicates the direction of a tangent to the periphery of the brushes 6, 7 in a plane parallel with the extension of the item in the buffing area. It is also seen in fig. 3 that the mutually closest-lying parts of the roller 8 and the belt 9 determine a line 20 which extends at an angle in relation to the brushing direction 14 and thus at an angle in relation to the above-mentioned tangent. Corresponding conditions apply with regard to the edges 15 and 18, the brushes 6a and 7a and the brushing direction 14a respectively.

When an item 4 is passed through the machine, all of the edges 15,16,17 and 18 are thus buffed by the brushes 6a, 6, 7 and 7a respectively. Moreover, all edges on both end surfaces of the item 4 will be buffed.

With the edge buffing machine, items with cross-sections other than rectangular, e.g. trapezoidal and polygonal cross-sections, possibly items with varying cross-sections, can be buffed in one operation. In special cases, the feeding means can have a yielding surface which can take up irregularities.

In a second and more simple but original embodiment of the invention, there is only one brush 6 in the upper part and one brush 7 in the lower part.

When the item 4 has passed completely through the buffing area and is free of the belt 9 and the roller 8, the item can be turned 180° around its longitudinal axis and thereafter be fed through in the same manner as earlier. With this second operation, the edges 15 and 18 will be processed by the brushes 6 and 7.

Claims

1. Apparatus for the buffing of edges on an elongated item (4) and comprising two rotatable buffing brushes (6,7), said apparatus having a buffing area (5) disposed between the brushes (6,7), in which area (5) the peripheries of the brushes can touch the item (4), and where for the guiding of the item (4) through the buffing area (5) the apparatus has mechanical guiding means (8,9) with endless periphery, one of said means being a roller (8), and where the guiding means are arranged to feed the item through the apparatus in such a way that the item's longitudinally extending edges (16,17) extend obliquely in relation to a tangent (14) to the brushes' periphery, said tangent (14) being contained in a plane parallel with the extension of the item in the buffing area (5), and where the mutually closest-lying parts of the guiding means for the feeding of the item are placed so that a straight line (20) through the parts extends at an angle in relation to the tangent (14), characterized in that the guiding means are also feeding means, and that the means comprise an endless belt (9) which, together with the roller (8), can feed the item through the buffing area (5) between roller (8) and belt (9), where the belt (9) extends around wheels (10,11) that are suspended in a holder (40) which is pivotably mounted around an axis (12) close to the holder's one end in such a way that the holder with the belt (9) can be swung into different angles in relation to the tangent (1 ).

2. Apparatus according to claim 1, characterized in that the holder comprises two wheels (10,12) which carry the belt (9), where the wheel (10) which is located closest to the axis (12) is connected by means of a spindle to a drive unit (42).

3. Apparatus according to claim 2, characterized in that it is provided with at least one force-exerting element which keeps the holder biased to turn around its axis (12) in the direction towards the roller (8).

4. Apparatus according to any of the claims 1-3, characterized in that the apparatus comprises two mutually counter-rotating buffing brushes (6,6a,7,7a) which have substantially coaxial axes of rotation (21,22), where the ends of the brushes mutually face each other.

5. Apparatus according to any of the claims 1-4, characterized in that the apparatus comprises at least four buffing brushes (6,6a,7,7a) which are disposed in pairs on opposite sides of the buffing area (5).

6. Apparatus according to any of the claims 1-5, characterized in that it comprises a substantially horizontal surface (3) for supporting the item, and where in relation to said surface (3) the axes of rotation of the buffing brushes (6,6a,7,7a) are disposed at a distance from and on each their side of the surface (3) .

7. Apparatus according to claim 6, characterized in that a buffing brush (6,6a) which is disposed above the support surface (3) is suspended in such a manner that the brush can be fixed at different distances from the surface (3).

8. Apparatus in accordance with any of the foregoing claims, characterized in that the roller (8) is mounted in a fixed manner, and in that the holder (40) is suspended with its axis of rotation (12) linearly movable in the direction towards the roller (8).