The invention relates to a mechanical handling or tool holding apparatus of the kind de ined in the first part of claim 1.

Such apparatus is previously known from SE-B-8205268-9 , wherein a number of profile sections are partially telescopically dis¬ placeable relative to one another so- as to form an extendable arm, which carries a handling means. Each such profile section or linearly movable element is coupled to an adjacent linearly movable element by means of an endless drive loop.

Owing to the partially telescopical arrangement in the known apparatus, the mutually cooperating profile sections must be given a different structural shape, which implies a relatively complicated and costly structure.

With this background, an object of the present invention is to provide an improved apparatus of the kind defined in the first part of claim 1, in such a way that the same profile cross- section can be used in the profile sections constituting the arm, so that one obtains a simple and inexpensive structure, which nevertheless enables repeatable, exact movement of the objects in question. A further object is to permit development from a simple basic structure to a combined system operating with a relatively complex movement pattern. The mechanical con¬ struction shall also enable a simple drive with a standard type of electric motor, which can be easily controlled in accordance with a selectable program. In addition, it is desirable that the structure shall enable simple exchange of handling or tool holding means for adapting to specific production conditions.

These objects are achieved in accordance with the invention by means of the characterizing features disclosed in the following claim 1.

The profile element embodiment in the form of a box section with a substantially rectangular, closed cross-section will give the structure a good torsional and bending strength.

Furthermore, by placing the box sections included in the arm in juxtaposition and not telescopically one inside the other, there is obtained sufficient space inside the respective box section for a drive loop, preferably in the form of a toothed belt driven by an electric motor, such as to achieve in a simple manner exact mutual displacement of the juxtaposed box sections. The closed separate box sections will also provide a space for building in power and signal cables to the particular handling or tool holding means .

The drive loop or loops can be arranged in different ways for achieving a desired drive function, cf . claims 2 - 5. In such cases each pair of juxtaposed box sections can be driven separately with its associated motor and drive loop, or a drive loop can be "passively" connected between two box sections separated by an additional box section so that a mutual movement between two sections is transmitted to the additional box section (claim 4).

By using an electric motor in combination with a toothed belt as a drive loop (claims 6 and 7> , a linear movement can be con¬ trolled very accurately with a repeatability of about ± 0.2 mm and a movement speed of about 0.5 - 1.5 m/s.

Suitable cross-sectional shapes and embodiments of the sliding guide flanges, which inter alia give good stability and mutual guidance, are disclosed in claims 8 - 12.

Production of the box sections by extruding aluminium (claim 13) gives low manuf cturing costs as well as considerable possi¬ bilities for adapting the apparatus to specific production condi ions .

The basic components, namely the mutually displaceable box sections with associated drive means, can be arranged in many different ways as a modular constructional system, and some principle variants are disclosed in claims 14 - 23.

The invention will now be described in more detail below and with reference to the accompanying drawings, which schematically illustrate a plurality of embodiments.

Figs, la and lb illustrate two different cross-sectional shapes for box sections coupled together mutually displaceably and included in an apparatus in accordance with the invention.

Figs. 2a, 2b, 3a, 3b, 4a, 4b and 5a, 5b illustrate in side view and cross section, respectively, different embodiments of an arm included in an apparatus in accordance with the invention, the arm having mutually, linearly displaceable box sections with associated drive means;

Figs. 6a, 6b, 7a, 7b and 8a, 8b illustrate in side view (6a) front view (7a, 8a) and cross section (6b, 7b, 8b), respectively different embodiments of vertically displaceable suspension means for an arm, e.g. according to any one of the of the Figs. 2 - 5;

Fig. 9 illustrates in side view a rotatable base, on which a column stand with vertical guidance is arranged, e.g. according to any one of Figs. 6 - 8;

Figs. 10a, 10b, 11a, lib and 12a, 12b illustrate in side view and cross section, respectively, different accessories for connecting to an arm and carrying different gripping means; and

Figs. 13 - 18, finally, schematically illustrate different com¬ binations of stand and arm in accordance with the invention.

A mechanical handling apparatus in accordance with the invention includes in principle a stand with a preferably horizontally oriented arm fitted to it, this arm carrying handling or tool- holding means which are discplaceable in the longitudinal di¬ rection of the arm, C . Figs. 13 - 18 which illustrate some possible combinations.

In accordance with the invention, such an arm comprises at least two box sections, which are juxtaposed, e.g. one above the other, are mutually displaceable and have complementary sliding glide flanges, the different box sections being mutually dis¬ placeable with the aid of one or more motor-driven drive loops, as will be described in more detail below with reference to Figs. 2 - 5.

A preferred embodiment of such box sections is illustrated in Fig. la, and a simplified variant is illustrated in Fig. lb.

Accordingly, Fig. la is a cross section of two interconnected box sections la and lb, which are mutually displaceable linear¬ ly, have exactly the same cross-sectional shape and are produced by extruding an aluminium alloy.

The cross section of the extruded section is formed for obtain¬ ing large torsional and bending stiffness with simple but exact mutual connection of two or more sections. For the purpose, each section has a closed, substantially rectangular, preferably approximately quadratic cross section, with two opposing top and bottom walls 10 and 11 and two opposing side walls 12 and 13. The side walls 12,13 are joined at their central portions by a web 14 dividing the interior of the box section la or lb into two chambers 15 and 16.

Intrinsic with the corner portions between the top wall 10 and side walls 12,13 there are two top flanges 17,18, each having a

side portion 17a, 18a extending substantially as an extension of the respective side wall 12,13, each flange also including an inwardly curved top portion 17b or 18b which, at its free end, has an end portion 17c or 18c tapering obliquely inwards and downwards towards the top wall 10. This end portion 17c pr 18c forms, together with a longitudinal ridge 17d or 18d directly opposite it on the upper side of the top wall 10 a pincer-like or C-shaped opening 17e och 18e in- cross section, where the openings 17e and 18e are disposed facing towards each other.

The end portions 11a, lib of the bottom wall 11 merging with the respective side wall 12,13 have been moved up with a small distance, although still parallel to the bottom wall 11. A bottom flange 19 or 20 projects downwards from the junction between the straight portion 11 of the bottom wall and the respective end portion 11a, lib. This flange 19 or 20 has a portion 19a or 20a extending perpendicularly downwards from the bottom wall 11, the respective portion curving away substantially at right angles to 19a or 20a and outwards laterally into a bottom portion 19b or 20b, to forming at the free end a solid, substantially cylindrical guide flange 19c or 20c. Both these flanges 19c and 20c are thus directed in opposite directions and are dimensioned to fit with clearance into the respective C-shaped top flange 17 or 18 of a juxtaposed box section, as will be seen from Fig. la.

The diameters of the flanges 19c, 20c are greater than the pincer-like openings 17e and 18e, so that the guide flanges 19c, 20c are securely retained in the fitted position (the box sections are interconencted by thrusting together in the lon¬ gitudinal direction. To enable mutual, linear displacement with low friction there is a slide body 21,22 with a substantially annular cross section fitted externally on the respective guide

flange 19c,20c. This slide body 21,22 comprises a plastics material e.g. polya ide, preferably with the addition of a lubricant such -as an oil molecule mixture, so that permanent low friction against the surrounding aluminium flange 17,18 is obtained. The slide body 21,22 can suitably comprise a hose which has been slit longitudinally and is thrust onto the respective guide flange 19c,20c so that the hose surrounds at least the greater part of its circumferential surface.

The fit between the sliding guide flanges 17,18 and 19,20 as well the slide bodies 21,22 is such that one guide flange 19c is kept well fixed in position (upwards, downwards and laterally) inside the C-shaped flange 17, while the other guide flange 20c has a slight lateral clearance, as will be seen from the air gap between the slide body 22 and the side portion 18a of the C-shaped flange 18. Unavoidable manuf cturing tolerances can thus be compensated and sticking avoided in the mutual linear movement of the box sections la, lb.

Since the top and bottom flanges 17,18,19,20 serving as sliding guide surfaces projects a distance upwards and downwards, re¬ spectively, from the appropriate section wall 10,11, there is formed a free internal space 23 between the top and bottom walls 10,11 of the interconnected box sections la, lb, between the en¬ gaging flanges 17,19 and 18,20. As will be seen from below, this space 23 is utilized, as well as the internal chambers 15 and 16 for providing protected space to the different parts of one or more drive belts, with the aid of which the mutual, linear dis¬ placement of the box sections is achieved.

There are side flanges 24a, 25a, 26a and 24b,25b,26b formed on the outside of the respective side wall 12,13, and these flanges together form T-slots 27a, 28a and 27b,28b, respectively, which can be utilized for attaching different equipment details, e.g. for fixing a box section to a stand, attaching a drive motor for

a drive belt or mutually fixing two box sections arranged at an angle to each other (see drawing Figs. 2 - 18).

Adjacent on to the lower corner edges and side flanges 26a, 26b, the box sections la, lb according to fig. la further have downwardly projecting, outer covering flanges 29a or 29b, which have their outer planes coincident with those of the side flanges 24a, 25a, 26a or 24b, 25b, 6b, and exteriorly with play partially surround the adjacent C-shaped top flanges 17 or 18 of the interconnected, respective box section. In this way the inter- connected box sections la, lb have common, flat external side surfaces (with slots 27 , 28a , 27b, 28b) and the mutually engaging sliding guide flanges 17,19 and 18,20 lie well protected inside the common side walls.

A modified box section lc, corresponding to the upper portion (including the intermediate wall 14) of the element la or lb is illustrated in Fig. lb. Such a section lc with top flanges 17,18, top wall 10, side walls 12,13 with side flanges 24a,25'aand 24b,25'b and bottom wall 14' can be connected by its upper side to the underside of a box section la, lb according to Fig. la. A complete unit having a substantially smooth bottom side thus being obtained .

The mutually connected box sections, e.g. la, lb and/or ic can have the same or different lengths. In Fig. 2a there is illus¬ trated a side view of two equally as long box sections la and lb and a substantially shorter box section lc .

The drive is achieved by an electric, pulse controlled motor 30 (Fig. 2b), which is attached to one side of the section la and with the aid of an unillustrated drive shaft, projecting into the upper chamber 15 (see Fig. la) of the element la drives a gear wheel 31, which is m mesh with a first toothed belt 40 serving as a drive loop. This belt 40 has an upper part 40a

extending substantially along the entire length of the upper chamber 15 of the element la (adjacent a top wall 10) to a return pulley 32 arranged freely rotatably at the other end, from where the belt is taken back over an adjacent jockey pulley 33 freely rotatably mounted on a shaft in the lower chamber 16, the belt extending from this pulley with a first end part 40b in the space 23 between the sections la and lb to the right hand end of the section lb in Fig. 2a, where the belt is fastened to the top wall 10 of the element lb at the point 41.

From the underside of the drive wheel 31 the belt extends over a freely rotatable idler pulley 34 mounted in the chamber 15 in the vicinity of the drive wheel 31 (adjacent the upper side of the intermediate wall 14) with an intermediate part 40c taken over a return pulley 35 placed at some distance from the jockey pulley 33, and from the underside of the return pulley 35 the other end part 40d of the belt extends in the space 23 to the other end of the section lb (see left-hand end in Fig. 2a), where it is fastened to the top wall 10 of the element lb at the point 42.

The necessary openings are drilled or milled from the appropriate side in the box sections for fitting the driving gear wheel and the different idler, jockey and return pulleys 31-35 as well as to enable the passage of the belt in the region of the intermediate wall 14.

As the driven gear wheel 31 is driven by the motor 30, the end parts 40b and 40d will become extended or foreshortened, the section lb being displaced linearly in the respective direction in relation to the section la. By controlling the motor 30 the section lb can thus be set into any desired position between two end positions corresponding to the location of the point 41 adjacent to the jockey pulley 33 and the location of the point. 42 adjacent to the return pulley 35 ,

A second toothed belt 50 is arranged in the box section lb to form a practically closed loop. The ends of the belt 50 are thus fastened in adjacents points 43,44 between the jockey pulley 33 and return pulley 35 in the bottom wall 11 of the section la. From these points 43,44 two upper parts 50a and 50b depart through the space 23 to the respective return pulleys 60 and 61, which are freely rotatably mounted at the ends of the section lb. A lower part 50c extends between idler pulleys 62 and 63, which are situated adjacent associated return pulleys 60 and 61. The part 50c extends on the underside of the bottom wall 11 of the section lb and through the space 23 between the section lb and the substantially shorter box section lc, where the belt is attached at the point 45 on the top wall 10 of the section lc.

The belt 50 is not driven by any driving gear wheel and only serves to give the box section lc a corresponding movement for the mutual movement of the sections la and lb. When the section lb is displaced a given distance relatively section la, the section lc will be displaced an equally as long a distance in the same direction relative the section lb. The section lc is thus moved at double the speed and with double the stroke compared with the mutual displacement of the sections la, lb.

If so desired, the shorter, third box section lc can of course be driven independently of the mutual drive of the sections la, lb. Such an arrangement is illustrated in Figs. 3a and 3b, where a first motor 30 drives the box section lb in relation to the section la by a first endless belt loop 40' extending around a driving gear wheel 31' and a return pulley 32' placed at either end of the section la, the belt being attached to the section lb at a point 46, while a second motor 30b drives the section lc in relation to the section lb by a second, similarly endless belt loop 50' which extends around a drive wheel 60' and a return wheel 61' placed at either end of the section lb, the belt being attached to the section lc at a point 47.

In Figs. 4a and 4b there is illustrated a simpler embodiment with only two box sections, namely a longer section la and a short section lc, which is driven by a motor 30 via an endless belt loop 40' arranged in the section la and attached to the section lc at the point 48.

In Figs. 5a and 5b there is shown an embodiment which is similar to the one in Fig. 2a, although somewhat modified. The difference is that the upper section 1'a is shorter than the section lb and that the first belt 40" is taken over a driving gear wheel 31' situated between and somewhat above the two jockey pulleys 33,35.

The arms provided with a longitudinally movable section lc and illustrated in Figs. 2a - 5a are normally intended for use horizontally. In many applications it is desirable to raise and lower such an arm. For this purpose there is provided a vertical guide arrangement with one or more vertically displaceable slides on which a horizontal arm can be mounted.

A first embodiment of such a vertical guide arrangement is il¬ lustrated in Fig. 6a, and here a vertically oriented box section 70, of the same kind as the section la in Fig. la, is included in a stand, the section 70 having connected to it a slide 71 corresponding to the section lb in Fig. la. The drive is arranged in a corresponding manner to that for the horizontal arms, namely by a motor 30 (see Fig. 6b) which drives an endless toothed belt loop 40' via a driving gear wheel 31', the belt being taken over a return pulley 32' and attached to the slide 71 at a point 49. A counterweight 72 is mounted on the part 40 'a of the belt 40' facing away from the slide 71 for balancing the weight of the arm 1 (denoted in Fig. 6a by dashed lines) and possible load. The counterweight 72 is flat and elongate, and moves in the interior chamber of the section 70 corresponding to the chamber 15 m Fig. la.

A second embodiment of the vertical guide arrangement is illus¬ trated in Figs. 7a and 7b. In this case two box sections 70a and 70b are disposed mutually spaced and each has its slide 71a or 71b corresponding to the section lc in Fig. lb. The units 70a, 71a and 70b, 71b have the slides situated in differents planes, so that an arm 1' (illustrated with dashed lines in Fig. 7b) can be fastened between them at different positions in the longitudinal direction of this arm 1', thus obtaining good stability, and the secondarily driven slide 71a achieves counterbalancing of the forces in the slide 71b. The slides 71a and 71b are driven synchronously by a motor 30 which is coupled directly to a toothed belt loop 40'b in the unit 70b, 71b and via a toothed belt 72 and a transmission shaft 73 to a toothed belt loop 40'a in the unit 70a, 71a.

In Figs. 8a and 8b there is illustrated a third embodiment of the vertical guide arrangement with two box sections 70c, 70d, which are sufficently close together for each of them to be connected to each of a slide 71c, which is driven vertically with the aid of two synchronously driven motors 30c, 30d, which are each in driving mesh with its toothed belt loop connected to the slide 71c.

Fig. 9 illustrates an apparatus for rotating a column stand PS, denoted by dashed lines, about a vertical axis P. This column PS carries a horizontal arm, e.g. where the arm is mounted on a vertical guide arrangement of the kind described above. A base plate 81 is screwed for horizontal orientation to a substructure 80, eg. a workshop floor, and a footplate 82 is rotatably mounted on this base plate 81 with the aid of a bearing. The bearing has a stationary part 83 fixed to the base plate 81 and inside the fixed part 83 there is a rotatable bearing part 84. The stationary bearing part 83 carries a radially outwardly situated toothed ring 85. The upper rotatable foot plate 82 has a motor 86 mounted on it with a drive wheel 87, and round the

toothed ring 85 and drive wheel 87 three is mounted an endless toothed belt 88. With this arrangement, the foot plate 82 provided with the motor 86 can be caused to rotate about the vertical axis P, together with the column stand PS carried by the foot plate.

Figs. 10a and 10b show a portion of an arm, e.g. according to Figs. 2a,3a,4a or 5a-, where the relatively short box section lc in these Figs being now removably connected longitudinally with a further box section 1'c engaging with the section la or lb, and this section 1'c carries a schematically illustrated handling or tool holding means 90. The mechanical connection between the sections lc and 1'c is provided by cheek plates 91, which are screwed onto both sections, while electrical and/or pneumatic connections are achieved automatically by push-on connections 92 CFig. 10b) .

In Fig. 11a there is illustrated an example with a rotatable holder plate 93, which is mounted on one -end of the section 1'c and which is settable in a desired rotational position with the aid of a toothed belt transmission 94 and an electric motor 95. The holder plate 93 carries an unillustrated gripping means which can thus be rotated as desired.

In the variant according to Figs. 12a and 12b the holder plate 93 has been replaced by a holder arm 96, which carries an operating cylinder 97, the rod 97' of which can also swing a holder body 98 about a pivot 99. In this case the holder body carries two holder plates 93a, 93b, each of which in turn carries an unillustrated gripping means.

The units described so far can be combined m a plurality of ways and some such combinations are illustrated in Figs. 13 - 18.

The arrangement illustrated in Fig. 13 includes a frame stand RSI with four legs lOOa-d, each carrying a rectangular frame lOla-d. A box section l'a is suspended in two opposing frame sides 101a arid 101c, this box section l'a beiing included in an arm of the kind illustrated in Figs. 5a, 5b. The schematically illustrated gripping means 90 on the section lc can thus be moved linearly to a desired position and move an unillustrated object along the linear movement path.

The arrangement according to Fig. 14 has a frame stand RS2 with four legs lOOa-d, two longitudinal frame beams 102a, b, a cross¬ beam 103 connecting these with a pivot bearing means 104, and slopingly upwardly directed beams 105a-d from the respective leg, these upwardly directed beams being upwardly connected in pairs to an upper crossbeam 106. A sloping operating arm 107 corresponding to that in Fig. 4a is pivotably mounted in the crossbeam 106, the box section lc of the operating arm being pivotably connected to an operating arm 108 pivotably mounted on the bearing means 104. The operating arm 108 similarly corresponding to that in Fig. 4a and having a gripping means 90 on its section lc. The gripping means 90 can thus be moved as desired in a vertical plane in the two angular sectors defined by the pivoting motion of the arm 108 between two end positions.

The arrangement according to Fig. 15 includes a stationary column stand PS1 with vertical guide arrangements 108a, 108b according to Figs. 6a, 6b, with slides 71 which are driven synchronously, and with the aid of brackets 109a, 109b carry two parallel, horizontal operating arms 110a, 110b which are mutually synchronized and corresponding to those in Figs. 5a, 5b. The sections lc of the arms 110a, 119b are connected to an operating arm 111 at right angles to the arms 110a, 110b, where this arm also corresponds to that in Figs. 5a, 5b. The operating arm 111 has a combined box section lc.l'c with an exchangeable holder part 1'c for a desired gripping means, e.g. according to one of

the Figs. 10a, 11a, 12a. It will be understood that, although it is not illustrated, the optionally rotatable and/or swingable gripping means can thus be moved as desired in all three dimensions. An arrangement according to Fig. 15 can suitably be used as a feeder to a machine tool, such as a press or the like.

The arrangement according to Fig. 16.includes a stationary column stand PS2 with a vertical guide arrangement 112 according to Figs. 7a, 7b and an operating arm 113 according to Fig. 4a (in combination with Fig. 10a, 11a or 12a), so that the unillustrated gripping means on the holder part i'c can be moved as desired in a vertical plane. A desired pattern of movement can be programmed via an operating panel 114 to an unillustrated micro computer, which controls the motors of the different drive means. The arrangement can be used as a simple picking robot.

The arrangement according to Figs. 17a and 17b includes a rotatable column stand PS3 , which is mounted on a rotation means 115 corresponding to that in Fig. 9, and with the aid of a vertical guide arrangement according to Figs. 7a, 7b carries an operating arm 113 according to Fig. 4a (in combination with Fig. 10a, 11a or 12a), so that the arm 113 can be swung about the vertical axis P, raised or lowered along the vertical guide arrangement 112 and set (the section lc,l'c) horizontally to a desired position. The gripping means 90' can thus be moved in three dimensions within a cylindrical working range. This arrangement can be used, e.g. as a robot for moving workpieces in combination with one or more machine tools, conveyors and/or storage positions. In this case as well, the desired movement pattern can be programmed via an operating panel 114. As will be seen from Fig. 17b, the gripping means 90' consists in this case of two gripping elements 116a, 116b, each mounted on a swingable arm 117a or 117b. The gripping means is easily exchanged, how¬ ever, since the holder section 1'c can easily be replaced with another holder section having the desired handling or tool holding means.

The arrangement according to Fig. 18 substantially corresponds to the arrangement according to Figs. 17a, 17b. However, the operating arm 118 is made according to Fig. 2a (in combination with Figs. 10a, 11a or 12a) and in addition the rotatable column stand PS4 can be displaced on rails 119a, 119b along a predetermined path, e.g. on a workshop floor.

Apart from further combinations of stands and arms, the inventive concept can be applied in different ways with respect to the implementation of the box sections and the drive means.

The box sections can thus be provided with differently formed sliding guide flanges, which can also be placed in a different way. For example, it can be sufficient with a centrally placed flange which is situated upwards, and a complementary formed flange placed downwards on the respective section, the necessary stability being achieved with the aid of sliding surfaces or sliding rails on either side of the respective flange, so that the central flanges ensure that the box sections cannot be moved apart, and the outer sliding guides prevent mutual skewing between the sections. In addition, the web 14 can be excluded in simplier embodiments, or can be replaced by several intermediate walls, if it is desired to have a plurality of internal chambers in the box sections, e.g. for guiding a plurality of different drive loops or loop parts.

The drive loop or loops can also be replaced by other loop elements other than toothed belts, e.g. cables, chains or some form of belt, providing that these do not stretch.