The present invention refers to a flexible member for transmitting pressure media, and of the type intended and 05 adapted to contact against and to follow movements of a movable supporting member, particularly a robot arm, where the flexible member at least at movable portions of the supporting member is preformed into creased portions.

10 It is earlier known to form flexible hoses, and particularly ho.ses for compressed air in such a manner that they allow a flexible transmittin of pressure media to tools , spray guns etcetera . The technique almost solely used herefore is the use of coiled

15 hoses .

The drawback of this technique is primarily that it gives a limited movability over short distances. Especially limiting are rotational movements about the symmetry line of the coil 20 where the coil has big radial variations at a small number of convolutions .

The coiled form gives un unacceptable limitation of its movability in relation to its "bulkiness" or space-requiring

25 properties, especially for transmitting pressure media to tools, and spray guns at robots, where often a plurality of hoses are required. Some machine members furthermore do not give possibility of being entirely enclosed by one or more coiled hoses, and they therefore must be mounted on the

3.0 outside of the machine component resulting in a still more space-requiring installation.

There are furthermore solutions using swivel fittings between the hose portions allowing rotational transfer, but these 35 require big structural operations in the machine member in question and it therefor does not provide a flexible and adaptive problem solution from the user's point of view.

DE-A1 26 29 032 describes a vacuum cleaner hose with an

electric cord fitted thereto and being bent in creased form in order not to subject the cord to too big tensile forces due to movements of the vacuum cleaner hose. At this design the electric cord is fixed to the hose along its entire extension by means of an outer casing enclosing the hose and the cord. Such a fixing method is not suitable for hoses conveying pressure medium as even such a type of fixation can imply a non-desirable limitation of the mobility and it is furthermore required -.- possibility of visual watch of the hoses, at the same time, as a more flexible and less costly design is desired:.

The purpose and most important features of the invention

The purpose of the present invention is to provide a flexible member, which with a mimimum of space requirement and with an extremely high mobility, which is substantially unhampered by fixing means movability, via a. machine member with high mobility may transmit pressure media to a tool, e.g. a tool on an industrial robot, whereby there is a possibility of visual watch of the flexible member over its entire length.

This is obtained, at a flexible member of the type described above, in that the flexible member is preformed with a double- curved shape, which makes tthe member strive to contact against and at least partly to enclose its movable supporting member .

At a pressure air hose arranged in Z-shape the individual folds will be able to slide freely along the machine member. There will be no radius reduction at rotational movements. By preforming the hose with a double curvature, thus that it partly or entirely forms an almost completely closed coil without the individual creases being interconnected, it is possible to guide the built-in mobility tendencies of the hose, thus that it strives to be "buckled" inwards against the machine member upon which it is arranged, and hereby the need for special fixing devices is eliminated.

Description of the drawings

The invention hereinafter will be further described with reference to non-limiting embodiments shown in the accompanying drawings.

Figure 1 shows in perspective the outmost part of a robot arm, which carries a spray gun, to which are connected pressure media hoses according to the invention. Figure 2 is a similar view of an complete industrial robot with pressure media hoses according to the invention.

Figure 3 shows a portion of an alternative pressure media hose according to the invention.

Figure 4 shows schematically the hose according to Fig. 3 fitted upon a robot arm.

Figure 5 shows a pressure media hose substantially of the type shown in Fig. 1 arranged upon another type of robot arm.

Figure 6 is an explanatory view illustrating a portion of a pressure medium hose, which is preformed in order to be pressed against its associated machine member.

Figures 7a - 7f show schema ically a portion of a hose according to the invention and its mobility when exerted to different loads.

Description of embodiments

Figure 1 shows in perspective an outer end portion of a robot arm 1 , carrying a spray gun 2, which is connected to pressure medium hoses 3 according to the invention. Those pressure medium hoses 3 are preformed to Z- or sine-creased shape along the movable portions of the machine component - the robot arm - whereby the hose becomes highly adaptive to motions axially, transversally as well as to rotational movements in all directions .

In Fig. 2 is shown at a corresponding application upon a complete industrial robot how the crease-shaped pressure medium hoses 3 are arranged only along the movable portions of the robot arm, whereas the rigid portions of the robot arm

have straight hose portions 4, which are integrated with the creased hose portions or are connected to these in any proper manner. As can be seen from this view, the crease-shaped pressure medium hoses are attached to the machine member only at their end portions via particular connecting members 5, whereas the entire creased portion is arranged along the machine member only and therefore gets a very high mobility and adaptability to the movement of the machine member.

In Fig. 3 is shown in perspective a portion of a pressure medium hose 6 according to the invention, which has another type of creases than that according to Fig. 1 and 2, whereby the loop-formed creases are double-curved in such a manner that the hose strives to contact against the machine member about which it is arranged, and thereby eliminating the need for attachment means.

In figure 4 is schematically shown the hose according to Fig. 3 arranged upon a robot arm. *

Figure 5 shows another type of robot arm 7, which is movable in its entire extention and in this case the robot arm is equipped with several hoses 3 creased to a substantial sine- shape, which hoses without being interconnected surround the robot arm like a stocking.

Figure 6 shows a portion of a hose 3 according to the invention , and as shown the hose is preformed with a radius of curvature R, which gives the hose a buckling direction, which goes inwards against the machine member on which the hose shall be applied. In this manner the hose will get a pretension towards the machine member under all movements subjected to the machine component, and this also eliminates the need for individual attachment means.

Fig.s 7a - 7f schematically show a hose 3 according to the invention in unloaded condition, exerted to axial thrust, to rotational movement, to lateral bending and to axial compressing strain and simultaneous bending laterally resp. ( Fig . s 7e and 7f) .

It is advantageous that the flexible member - the pressure medium hose - has a double-curvature where the centre of one of the radii of curvature mainly coincides with the geometrical centre of the machine member.

The invention is not limited to the embodiments shown in the drawing and described in connection thereto but other applications and designs are possible within the scope of the inventive concept.

The ^* flexible members thus have been described as applied to robot arms of different types, but they of course also can be applied to manipulators or other machine members of different types having high mobility. The flexible member may be designed in one or more Z- or sine-shaped creases, and several flexible members can be connected in such a manner that they form a stocking surrounding the machine member.