Energy guiding chain

The invention relates to an energy guiding chain for guiding cables, hoses and the like between two connecting points that move relative to each other, comprising a plurality of tubular chain links (1), which are connected to each other in articulated fashion and made of plastic, and each of which displays a bottom wall (2), adjoining, opposite side walls (3, 4), and a cover wall (5), where the cover wall (5) is or can be detachably connected to the side walls (3, 4), the side walls (3, 4) each display a pivot pin (6) and a joint opening (7) for the articulated connection of adjacent chain links (1), the pivoting angle is limited by stops (8) in both pivoting directions, and the cover walls (5), side walls (3, 4) and bottom walls (2) overlap over the entire pivoting angle. On an energy guiding chain of this kind, the protection of the interior is to be even further improved, and handling during opening and closing of the energy guiding chain facilitated. According to the invention, this is made possible by the fact that the cover wall (5) displays at least one fastening tab (11) on each side, in that the fastening tabs (11) reach over the outer surfaces of the side walls (3, 4), in that snap-in elements (12) are provided on the inner surfaces of the fastening tabs (11) facing towards the outer surfaces of the side walls (3, 4), in that mating snap-in elements (13) are provided on the outer surfaces of the side walls (3, 4), interacting with the snap-in elements (12) of the fastening tabs (11), and in that the snap-in elements (12) and mating snap-in elements (13) form a hinge on at least one side of the energy guiding chain.

The invention relates to an energy guiding chain for guiding cables, hoses and the like between two connecting points that move relative to each other, comprising a plurality of tubular chain links, which are connected to each other in articulated fashion and made of plastic, and each of which displays a bottom wall, adjoining, opposite side walls, and a cover wall, where the cover wall is or can be detachably connected to the side walls, the side walls each display a pivot pin and a joint opening for the articulated connection of adjacent chain links, the pivoting angle is limited by stops in both pivoting directions, and the cover walls, side walls and bottom walls of adjacent chain links overlap over the entire pivoting angle.

Energy chains of this kind, which are very largely closed over their entire circumference, are particularly used in environments where there is a risk of foreign bodies getting into the chain, e.g. on metal-cutting machine tools, where chips can fall onto the surface of the energy chain and get into the interior between the chain links during pivoting in the area of a bend.

In a known energy chain of the aforementioned type (DE 20 2009 005 605 U1), protection of the interior is already largely ensured by the fact that the surface of the cover walls, the bottom walls, and at least of the transitional zones of these walls and the side walls, has a convex curvature in the circumferential direction. Owing to this curvature of the individual wall areas, it is already very effectively ensured that unwanted foreign bodies cannot stick to the energy chain so easily, and thus not get into the interior. In this respect, the known energy guiding chain already ensures extensive protection of the interior.

The object of the invention is, while retaining the advantages of the prior art, to even further secure the protection of the interior of the energy guiding chain, and to facilitate handling when opening and closing the energy guiding chain.

According to the invention, this object is solved in that the cover wall displays at least one fastening tab on each side, in that the fastening tabs reach over the outer surfaces of the side walls, in that snap-in elements are provided on the inner surfaces of the fastening tabs facing towards the outer surfaces of the side walls, in that mating snap-in elements are provided on the outer surfaces of the side walls, interacting with the snap-in elements of the fastening tabs, and in that the snap-in elements and mating snap-in elements form a hinge on at least one side of the energy guiding chain.

As a result of this design, where the fastening tabs reach over the outside of the side walls, optimum protection of the interior against the penetration of foreign bodies is ensured, this requiring extremely little design effort.

The snap-in elements provided on the inner surfaces of the fastening tabs are preferably designed as projections pointing inwards towards the side walls, while the mating snap-in elements located on the outer surfaces of the side walls have the form of projecting snap-in lugs, the snap-in connection being created in that the projections of the fastening tabs snap over the snap-in lugs, the interacting components undergoing slight elastic deformation in the process.

The features according to the invention make it possible to very easily create a structural design where the snap-in connections on both sides function in the manner of a hinge. This is advantageously achieved in that the projections provided on the fastening tabs are located on the lower ends of the fastening tabs and of circular cylindrical design, in that hollow cylindrical receptacles, which are open towards the outside and whose inside diameter corresponds to the outside diameter of the circular cylindrical projections, are provided below the snap-in lugs provided on the outer surfaces of the side walls, and in that, in snapped-in state of the corresponding cover wall, the projections are mounted in the hollow cylindrical receptacles of the side walls in the manner of a hinge.

A connection of this kind can be designed as a simple snap-in connection, where the cover wall is simply placed on the upper ends of the side walls, where it snaps into position.

For the hinge structure, the outer opening area of the receptacles is expediently slightly smaller than the diameter of the circular cylindrical projections, such that a reliable hinge is created on both sides of the cover wall, and the cover wall can optionally be swung open to either wide, without the cover wall having to be detached from the energy guiding chain.

The snap-in connection between the side walls and the cover wall can be provided in a recessed area of the outer surface of the respective side wall.

The recessed area of the respective side wall is preferably dimensioned in such a way that, in snapped-in state of the snap-in connection, the outer side of the fastening tab lies flush with the outer surface of the respective side wall. This creates a relatively smooth outer surface of the energy chain, without interfering, lateral protrusions.

In a preferred embodiment of the invention, the middle area of the snap-in lugs provided on the side walls displays an interruption, while a rib is provided above the circular cylindrical projections located on the cover wall, where, in snapped-in state of the cover wall, the rib positively engages the respective interruption in the snap-in lug. This measure additionally secures the snap-in connection against unintentional transverse shifting.

To achieve reliable engagement of the fastening tabs, said tabs can be provided with lateral bevels, which interact with insertion bevels provided on the side walls when closing the cover wall.

For convenient release of the snap-in connections, a recess having at least the width of the working end of a screwdriver can be provided, roughly in the middle area of the circular cylindrical projections located on the fastening tabs. It is then easily possible to lever open the corresponding snap-in connection by inserting a screwdriver, or some other suitable tool, such that the cover wall can be swung open to the desired side, or completely detached.

Alternatively or additionally, a recess having at least the width of the working end of a screwdriver can likewise be provided at the lower edge of the area of the hollow cylindrical receptacle that is open towards the outside.

The outside of the lateral edges of the cover wall adjoining the fastening tabs preferably lies flush with the outer surface of the side wall, such that a smooth lateral surface is obtained.

In a preferred embodiment of the invention, the lateral edges of the cover wall adjoining the fastening tabs can display a downward-pointing flange, where the flange is provided with a bevel over its length, and where a corresponding mating bevel is formed on the upper edges of the side walls, against which the corresponding bevel of the cover wall lies flush in snapped-in state. These bevels and mating bevels serve to center the cover wall on the side walls, and also to reliably seal off the interior.

FIGS. 1 to 12show an embodiment of the energy guiding chain according to the invention, which serves to guide cables, hoses and the like between two connecting points that move relative to each other. An energy guiding chain of this kind comprises a plurality of tubular chain links1, which are connected to each other in articulated fashion and made of plastic, and each of which displays a bottom wall2, adjoining, opposite side walls3and4, and a cover wall5.

In the embodiment illustrated in the drawing, bottom wall2and side walls3and4are of one-piece design, whereas cover wall5can be detachably connected to the side walls.

According to a further embodiment, not shown in the drawing, bottom wall2could, of course, optionally also be detachable.

As can particularly be seen fromFIG. 6, side walls3and4each display a pivot pin6on their outer sides and, at a distance from it, a joint opening7on the inner side. Pivot pins6snap into the respective joint opening7during assembly of the link chain or when elastically sliding chain links1into each other. This creates an articulated connection between adjacent chain links1. The pivoting angle of chain links1relative to each other is limited in both directions by stops8, which are located on the respective outer sides of side walls3and4, and interact with corresponding mating stops9, which are located on the inner surfaces of side walls3and4.

Cover walls5, side walls3and4, and bottom walls2of adjacent chain links1overlap each other over the entire envisaged pivoting angle, such that, even when the direction of movement of the energy guiding chain changes, a closed interior10is ensured for the hoses, cables and the like guided in the energy guiding chain.

In the embodiment illustrated in the drawing, only cover wall5is detachable from the duct comprising side walls3,4and bottom wall5. In this context, cover wall5displays a fastening tab11on either side. In assembled state, the two fastening tabs11reach over the outer surfaces of side walls3and4. To fix cover wall5on side walls3and4, the inner sides of fastening tabs11facing towards the outer surfaces of side walls3and4are provided with snap-in elements12, which interact with mating snap-in elements13, provided on the outer surfaces of side walls3and4.

Snap-in elements12, provided on the inner surfaces of fastening tabs11, are designed as projections14, pointing inwards towards side walls3and4. The mating snap-in elements located on the outer surfaces of side walls3and4have the form of projecting snap-in lugs15. The snap-in connection is then created in that projections14on fastening tabs11snap over snap-in lugs15, fastening tabs11undergoing slight elastic deformation in the process.

Projections14, provided on fastening tabs11, are located on the lower ends of fastening tabs11and are of circular cylindrical design. Provided below snap-in lugs15, located on the outer surfaces of side walls3and4, are hollow cylindrical receptacles16, which are open towards the outside and whose inside diameter corresponds to the outside diameter of circular cylindrical projections14.

In snapped-in state of the corresponding cover wall5, circular cylindrical projections14are mounted in hollow cylindrical receptacles16in the manner of a hinge. The respective cover wall5can then be swung open and closed again like a hinged lid, both to the one side and to the other.

To ensure that the cover wall remains firmly anchored in the respective side wall when swung open, outer opening area17of hollow cylindrical receptacles16is designed to be slightly smaller than the outside diameter of circular cylindrical projections14.

As can particularly be seen fromFIGS. 2 and 3, the snap-in connection between side walls3,4and cover wall5is formed in a recessed area18of the outer surface of the respective side wall3or4. In this context, recessed area18of the respective side wall3or4is dimensioned in such a way that, in snapped-in state of the snap-in connection, the outer side of the respective fastening tab11lies flush with the outer surface of the respective side wall3or4. This measure creates a smooth outer surface of the energy guiding chain when the individual chain links1are assembled.

The hinge-like engagement of circular cylindrical projections14, provided on fastening tabs11, in hollow cylindrical receptacles16, provided on side walls3and4, is extremely stable and reliable. To ensure additional protection against transverse shifting, the middle area of snap-in lugs15, provided on side walls3and4, is provided with a recess or interruption19, as can particularly be seen fromFIGS. 6 and 8. Provided above each circular cylindrical projection14, located on cover wall5, is a rib20, which positively engages the respective interruption19in snap-in lug15in snapped-in state of cover wall5.

The closing of cover walls5, following the insertion of hoses, cables and the like into the energy guiding chain, is facilitated by the fact that fastening tabs11are provided with lateral bevels21, which interact with corresponding insertion bevels22, provided on side walls3and4.

In snapped-in state of the snap-in connection, cover walls5sit relatively tightly on chain links1. To facilitate opening of cover walls5, a recess23is provided, roughly in the middle area of circular cylindrical projections14, located on fastening tabs11. Said recess23is at least wide enough to permit application of the working end of a screwdriver in order to lever open cover wall5.

For the same purpose, a corresponding recess24, having at least the width of the working end of a screwdriver, is provided at the lower edge of the area of the respective hollow cylindrical receptacle16that is open towards the outside. As can particularly be seen inFIG. 1, the two recesses23and24are located directly one above the other in snapped-in state of cover wall5, such that the respective cover wall5can conveniently be levered open on one side with the help of a screwdriver, in order to swing open cover wall5on one side.

Lateral edges25of cover wall5, adjoining fastening tabs11, lie flush with the outer surface of the respective side wall3or4on the outside. In this context, the respective lateral edge25, illustrated inFIGS. 1 and 10, lies exactly in the plane of the area of the side wall3illustrated inFIG. 1that lies on the outside in assembled state of the energy guiding chain. In finally assembled state of the energy guiding chain, the right-hand, slightly recessed area26, illustrated inFIG. 1, is overlapped by the respective side wall of the subsequent chain link, such that a smooth surface is created on the outside of the energy guiding chain.

As can particularly be seen fromFIGS. 2 and 11, the lateral edges of cover wall5, adjoining fastening tab11, display a downward-pointing flange27, which is provided with a bevel28over its entire length. The upper edges of side walls3and4are provided with a corresponding mating bevel29, as can particularly be seen fromFIG. 6. In fitted and snapped-in state of cover wall5, bevel28of cover wall5lies firmly and flush against mating bevel29, such that good guidance of cover wall5on the upper edges of side walls3and4is thus obtained, and additional sealing of interior10of the energy guiding chain is created.

LIST OF REFERENCE NUMBERS

17Outer opening area of receptacle16

29Mating bevel on the side walls