Devices for working of an object and especially its edges are previously known in several variants which incorporate means for moving the object which is to be worked in the x and y directions. In the case of large objects, for example boards, but relatively thin ones, working of these edges imposes heavy strains on fastenings for the object with an accompanying risk of disturbing vibrations when carrying out the working, especially where there is a larger distance between the point of working and point of attachment, which larger distance obviously is the case when dealing with larger board-shaped objects.

Moreover in working of objects it is often a matter of large variations with regard to shapes of the objects in different portions thereof.

For example an object may consist of several straight sides with narrow transitions (= short radii) between them. Such workings are usually managed today in that the straight stretches are worked in one machine and the corner radii in another machine together with, when appropriate, supplementary manual working.

Apart from this to work objects with different shapes in one and the same machine has hitherto proved difficult. The primary reason for this is not only that the objects have different shapes in relation to one another but

also as a rule have different appearances in different portions thereof, for example different radii in different portions of the respective objects.

The primary object of the present invention is to provide a device with the aid of which objects with the same or different shapes can be worked, preferably finished, in one and the same machine to the desired shape with good repeatability. It is especially intended to provide a device with the aid of which working can be carried out essentially at a right angle to the object regardless of the position of the object.

The above tasks and objects have been solved in accordance with the present invention by means of the device mentioned in the descriptive preamble in that the said control system is arranged to be fed with the intended shape and orientation of the object in relation to the device and to emit corresponding control signals for movement of the said slide, in that in the close vicinity of the said machine for working of the object the device is provided with a second means for retention, steering and feeding of the object, which second means, preferably via the said control system, is controlled by a sensor which is arranged to mainly continuously sense the current position of the said object in relation to the position of the said machine and to emit a corresponding control signal to the said second means and/or to the control system. The invention is especially characterized in that the said sensor consists of an angle sensor and in that the second means is located at a distance from the slide and consists of two mutually oppositely directioned rollers on either side of the said objects, at least one of which rollers is driven and the other is counter-holding.

The present invention will be described in greater detail hereinbelow, with particular reference to an embodiment chosen by way of example and with particular reference to the accompanying drawing, wherein Fig. 1 shows a view from above of a device according to the present invention for carrying out in a controlled manner working of the edges with varying shapes of an essentially board-shaped object or of several

objects which are placed along a varying line which is adapted to the shapes taken together of the said object, Fig. 2 shows a cross-section through an object which is to be worked and sketchedly indicated driving and counter-holding rollers working on either side of for example the board-shaped object, and Fig. 3 illustrates an example of different rotational directions and different rotational speeds for the said rollers, depending on the shape of the object which for example is to be edge-worked with for example different existing corner radii.

The device according to the present invention will and can be used together with different types of working machines, for example grinding, polishing and milling machines, and also with machines for puttying, painting, surface treatment, edging, edge trimming, bending of thin materials etc. The device can also be embodied as a fed and controlled fixture for retention and working of one or several workpieces located one after another.

The present invention is nevertheless primarily intended to be used for edge- working of board-or sheet-shaped objects and therefore will be described hereinbelow in connection with working of such objects with the aid of a belt polishing machine, for example of the type described in my own Swedish patent No. 9002666-7 (publ. No. 466 642), which belt polishing machine provides a controlled and aligned belt with, in appropriate cases, several pressure shoes to carry out working of the different edges of a board 1. In the case shown in Fig. 1 the said board 1 has a shape where three sides are straight and at right-angles relative to each other with a transitional or corner radius, whereas the fourth side is arc-shaped, i. e. has a given, essentially larger radius than the said transitional radius, which board is indicated with continuous lines in Fig. 1 and with broken lines illustrating different working positions in relation to the working machine 4.

The board 1 is fixed by means of for example a number of vacuum suckers or corresponding fastening means 3 in relation to the device and this

fastening means 3 is preferably located under the board 1 close to or in its centre of gravity on a movable slide 2.

In order for the position of the said board 1 to be exactly determined in relation to the device two beams 23 and 24 are provided which, in themselves, are located in a plane which viewed in the vertical direction is located below the plane in which it is intended that the said board 1 will be moved. One or both beams 23,24 can also be arranged movable and/or turnable if this should be desired or required. The said beams 23 and 24 are also provided with stop means 231,232 and 241, for example pneumatically activatable, preferably movable along the beams 23 and 24 and lockable, which stop means on activation articulated in one end move in the vertical direction, for example the part which is located closest to the said board 1 so high that they act as a stop for the said board 1 in both a direction to the left i n the plane of the paper in Fig. 1 and in a direction upwards in the plane of the paper in Fig 1. The said two directions are hereinafter designated the x and y directions for the device according to the invention. The said stop means 231, 232 and 241 thus determine the starting position for the board 1 which is to be worked and the aforesaid fastening means 3 fixes the board 1 in this position essentially in the centre of gravity of the board 1 with the aid of vacuum suckers or corresponding fastening means 3 and all programming, steering and feeding of the device thus emanates from the starting position of the object 1 according to the said stop means 231,232 and 241 and the shape of the object 1 in different portions thereof. When the starting point for the board 1 is determined the said stop means 231,232 and 241 are deactivated whereupon the board 1 is freely movable above the said beams 23 and 24 in relation to the said stop means 231,232 and 241.

The shape and the appearance which the said board 1 is intended to be imparted by means of working-here preferably along its edges and parts/portions adjacent to the edges of the board 1-are first fed in as set-point values to a control system 7 by primarily specifying the data which are relevant for the board 1, in applicable cases for example the respective lengths

of the straight sides, the corner radii to be generated between the straight edges and which radius of bend the bent edge of the board 1 is to have. These data are subsequently translated by a program incorporated in the said system into x and y positions for the position of the fastening means 3 relatively to and to the angular position for the object 1 or the board 1 which is to be worked.

This control system 7 is furthermore connected to an angle sensor 6 the angle value of which emanates from the centre of turning and which is located to advantage in or beside the slide 2 on which the said fastening means 3 is also advantageously located. The slide 2 with fastening means 3 and angle sensor 6 is thus fixed in relation to the board 1 which is to be worked in the starting position as above. The slide 2 is in its turn movable in the aforesaid positive and negative x and y directions with the aid of for example gear belts driven by electric step motors located in a first beam 21 respectively in a second beam 22 and controlled in terms of speed and direction by the said control system 7 via the said (not shown) step motors placed in the said beams 21 and 22. The second beam 22 of the slide 2 is also- as indicated sketchedly in Fig 1.-designed advantageously wider in one end thereof in relation to its other end in order to be able to support more firmly larger objects for working and carries on its upper side above its top surface distributed easily rotatable linkage rollers (not shown), which are arranged rotatably in all directions and which carry and distributedly support the said board 1 which is to be worked along its edges over a not unessential portion of the surface of the board 1.

The narrower end of the said second beam 22 is located in the position indicated sketchedly in Fig. 1-downwards in Fig. 1-near the machine 4 which is intended to work the object or the board 1 along its edges and is in its narrower end preferably also provided with a second means 5, see especially Fig. 2, which second means 5 incorporates two rollers 8 and 9, one of which, for example 9, is driven in terms of speed and direction by a motor not shown on the drawings and is arranged movably to and from an appropriately pressurized engagement with one, in this case the lower, side of the board 1

the edge of which is to be worked and the other, for example 8, acts primarily also as a pressurized counter-roller against the other, in this case the upper, side of the board 1. The driven roller 9 is controlled by the said control system with regard to both choice of rotational direction in one or the other rotational direction as is also the direction of its axis of rotation in relation to the object 1 and to the rotational speed in order to make possible adjustment of any positional or angular error when dealing with primarily long and narrow objects. Moreover either the driven roller 9 and possibly also the counter-roller 8 can be elaborated with a relatively soft surface coating, for example of polyurethane, or with a high coating viewed in the vertical direction according to Fig. 2 or be elaborated in some other suitable manner so that a certain torsion is permitted in the surface coatings of the rollers 8 and 9 in relation to the object 1 so as thereby to retain a certain grip when turning the object 1 without risking generation of potential turning damage in the surface of the object 1 and/or in the contact surfaces of the rollers.

This second means 5 is located in principle and advantageously close to the working machine 4 and far from the first fastening means 2 with also counter-holding rollers in between as above. By this means it is ensured that the object 1 which is to be worked is always and securely held and supported, especially near the point of working, whereby a minimal risk exists that the working machine 4 will for example generate throw and oscillations in the board 1 on account of clamping of the board 1 and thereby possibly disturb the working by the machine 4 of the edges of the board 1.

A working of an object 1 can take place in the following way: The starting position of the board 1 is first determined as above, whereafter the control system 7 by means of a basic programme following for example manual infeed of all relevant data with regard to the board 1 in terms of size, shape, bending radii etc. takes over the handling of the board 1. It is appropriate but not required that working of the edges of the board 1 commences roughly in the middle of one long side of the board 1, whereafter the board 1 is rotated and moved-guided by the control system 7-under

control, monitoring and steering of the high-resolution angle transmitter 6 so that one long side of the board 1 with for example its middle point becomes located opposite the rotating polishing belt (in the present example) of the working machine 4, which belt in this position is activated by the control system so as to engage with the edge la of the board 1 and start to work this edge, whereupon the drive roller 9 is rotated at a certain speed with its axis of rotation located in the y direction as above, at the same time as the slide 2 is moved in the x direction as above with the same speed, all controlled by the said control system 7, whereby the board 1 moves straight during simultaneous working of its edge la by means of the said rotating polishing belt of the machine 4. When the half edge side la of the board 1, in the present example, has been worked it is presupposed here that the board 1 is to be worked to an essentially right-angled corner with a relatively large corner radius. If this is the case the driving roller 9 respectively the counter-roller 8 can be driven relative to the board 1 along a broken line b according to Fig. 3, i. e. between the edge la of the board 1,11,111 which is to be worked and the rotational centre of the board 1, which rotational centre in this case coincides with the desired relatively large radius for the said corner, the centre of which radius is marked here with an x in Fig 3. This corner rotation of the said board 1 is controlled by the said control system 7 and is monitored by the angle sensor 6 and is driven partly by the rotational direction of the driving roller 9 and in relevant cases with varying rotational speed and partly by the movement of the slide 2 in directions x and y, which movement in the present case is short or none at all in the case of for example circular objects.

During this corner movement machining by the machine 4 of the corner of the board 1 obviously takes place.

If in contrast the said corner of the board 1 is given a radius which is so short or narrow that room for the driving roller 9 and in applicable cases the counter-roller 8 cannot be provided between the middle point of the radius and the corner because the swing radius is all too short the movement pattern must be solved in some other way, this way being sketchedly

intimated in Fig. 3. When narrow curve radii are to be worked the driving roller 9 and preferably also the counter-roller 8 are located to work against the board 1 along the lines which are marked with c or d in Fig. 3, i. e. on the side of the centre of the radius of bend which lies inwards towards the centre of the board 1. The driving roller 9 thus here follows to begin with the direction indicated with cl in Fig. 3 and when it arrives at a level with the centre of the radius of bend but-according to Fig. 3-above this the driving roller 9 is instead caused by the control system 7 to switch rotational direction at the same time as its axis of rotation can be turned and/or that the slide 2, by the control system 7 and by the angle sensor 6 via the control system 7, rotates the board 1 so that the course which is indicated with c2 in Fig. 3 is followed by the driving roller 9, whereafter when the driving roller 9 arrives at a level with the centre of the radius of bend but-acording to Fig. 3-to the right thereof the rotational direction of the driving roller 9 is switched to that indicated with c3 and its rotational axis is in this position located in the x direction, whereupon the driving roller 9 is now caused by the control system to rotate with a peripheral speed which agrees with the simultaneous movement of the slide 2 parallel with the rotational direction of the driving roller 9. With a different -in the present case narrower or shorter-corner radius, for example the driving roller 9 and in applicable cases the counter-roller 8, can follow the course relative to the board 1 which is indicated with d in Fig. 3.

After this working by the machine 4 of the following straight edge of the board 1 continues in that the slide 2 moves in the x direction with a speed which agrees with the speed with which the driving roller 9 with its rotational axis located in the said y direction now feeds the edge of the board 1, controlled by the said control system 7 and by the angle sensor 6 of the slide 2 as far as the next corner which is steered in the same way as indicated above depending on the size of the corner radius. The following straight side edge of the board 1 is subsequently moved and worked in the same way as described above. After this the machine 4 in relevant cases meets the edge la of the board 1 which according to Fig. 1 is to worked a relatively long distance to a

relatively large radius and in this case there is no doubt that the driving roller 9 will have room between the edge la of the board 1 and the centre of the large radius. In this case the control system 7 must thus adapt the speed and rotational direction of the driving roller 9 and also the movement of the slide 2 in the x and y directions during sensing by the angle sensor 6. There now remains finally the other half of the first straight edge la where the machine started to work and the slide 2 moves in the x direction with a speed which agrees with the speed with which the driving roller 9 with its rotational axis located in the said y direction now feeds the edge of the board 1, steered by the said control system 7 and by the angle sensor 6 of the slide on to half of the straight edge la, whereupon the wanted working is completed.

The steering and movement of the board or the objects 1 which are to be worked thus takes place depending on the shape of the object 1 in its edges in that the peripheral speed and feed direction of the driving roller 9 is caused by the control system 7 to co-vary with movement of the slide 2 in x and y directions during superior control of the angle sensor 6. In certain types of working, for example working of the edges of round objects, the slide 2 stays still in the x and y directions and in this case the driving roller 9 and counter- roller 8 in principle and in the first place feed the board 1 round close to the working machine 1.

It should be noted that the working by the machine 4 may in certain cases need individual adjustment, for example in little working of a narrow corner radius, which reduced working can be accomplished in that for example the control system 7 initiates near the corners of the board 1 a reduced speed of the belt of the polishing machine 4 or a lower contact pressure.

The machine 4 can obviously work several"rounds"of the object 1 with the aid of for example one or more pressure shoes additionally.

For safety reasons the entire device is also furnished with a suitable machine-stopping light curtain 25 if the said curtain is

unintentionally broken by a person or an object. A start and stop button is located to advantage outside the said light curtain 25.