Bush fitting machine

The present invention relates to a machine for delivering supplied hollow bushes and for fitting individual hollow bushes to a cable, and to a corresponding method. The apparatus has a picking apparatus which can pick up hollow bushes and arrange said hollow bushes so as to be axially aligned in front of the fitting tube, and a bush fitting apparatus for fitting individual hollow bushes to a cable, wherein the bush fitting apparatus has a fitting tube which can receive and hold, on the outer surface of said tube, the hollow bushes on the inner surface thereof, and in which the cable for fitting the hollow bushes can be arranged. Furthermore, the apparatus has a delivery apparatus with a slip-over device which is capable of moving relative to the picking apparatus and by means of which the hollow bushes can be delivered from the picking device to the fitting tube, and a filling mandrel, which can protrude through the fitting tube in order to deliver the hollow bush from the picking apparatus onto the bush fitting apparatus and can withdraw from the fitting tube in order to fit the hollow bush to the cable.

FIELD OF THE INVENTION

The present invention relates to a machine for delivering hollow bushes supplied by this machine and for fitting individual hollow bushes to a cable. Furthermore, the present invention relates to a method for delivering and fitting hollow bushes.

PRIOR ART

In the prior art different apparatuses and machines for fitting bushes are known. Bushes—also called “seals”—are used for the assembly of cable ends and are generally made of rubber or a material similar to rubber.

Bushes/hollow bushes are used to guarantee the moisture-proof passage of cables, e.g.

through housing walls of electrical appliances. For this purpose such a bush is generally applied to a stripped cable so that the bush remains on the cable. A tight connection is thus established between the cable jacket and the hollow bush. The hollow bush itself can then be fastened within the housing of an electrical appliance.

European Patent EP 0 881 720 B1 is known as prior art. The apparatus has a picking apparatus (reference number 50) with a mandrel the tip of which has a smaller diameter than the other mandrel, a radial inner groove being provided partially between the tip and the other mandrel (see FIGS. 9 and 10 of EP 0 881 720 B1). The structure and the production of such a mandrel are therefore complex.

This picking apparatus 50 is used to pick up a bush/hollow bush in an axial movement of the picking mandrel and to press it onto a fitting tube in the same direction of movement. For this purpose the tip of the mandrel of the picking apparatus plunges into the fitting tube, and the outer circumference of the fitting tube is introduced at least partially into the radial inner groove between the tip and the other mandrel (see FIG. 2 of EP 0 881 720 B1). The end region of the mandrel, which forms a step for the tip extending further, serves here to push the bush onto the fitting tube.

Next the mandrel moves back into its initial position and a further hollow bush is then delivered so as to later also “strike” the fitting tube.

Once the bush is located on the fitting tube and the mandrel has been moved back into its initial position, the fitting tube is turned and aligned in the direction of a stripped cable.

Next the hollow bush is applied to the cable by the movement of the fitting tube in the direction of the stripped cable. Furthermore, the fitting tube is moved back, and then a stop holding the hollow bush on the cable is opened. If the fitting tube then turns in alignment with the mandrel, the slip-away device moves back.

It is a disadvantage of the apparatus of EP 0 881 720 B1 here that the mandrel and the fitting tube must be aligned precisely to one another in order to be able to “strike” a hollow bush. Due to the complex configuration of the mandrel this alignment must be as accurate as possible so as to damage neither the mandrel nor the fitting tube. Furthermore, the hollow bushes are not separated, but are used directly from the conveyer. The delivery of the hollow bushes must accordingly coordinate with the “striking” so that, for example, there is no catching with the next hollow bush in the conveyor. Furthermore, it has proved to be disadvantageous that the conveyor device is blocked during the delivery of the hollow bush from the picking apparatus to the fitting tube, and no other procedural steps can be implemented in parallel.

Document EP 1 022 821 A1 is known as further prior art. With this apparatus a hollow bush is picked up and held with a mandrel by means of a picking apparatus. The mandrel is then guided to a bush holding part into which the hollow bush is introduced. After the mandrel of the picking apparatus has been moved away, a further mandrel is positioned over the bush holding part. This other mandrel is then used to push the hollow bush through the bush holding part and to place it on a fitting tube. The other mandrel thereby penetrates at least partially into the fitting tube.

This apparatus is turn has the disadvantage that the bush holding part is provided as an additional component. Moreover, the apparatus has a first mandrel as a fitting on the bush holding part, and optionally a further mandrel for delivering the hollow bush from the bush holding part onto the fitting tube. By means of this structure the hollow bushes are separated and then applied to the fitting tube, but a plurality of individual elements are required for this, and so the structure of the apparatus of EP 1 022 821 A1 is complex.

DESCRIPTION OF THE INVENTION

It is the aim of the present invention to provide a machine for delivering and fitting hollow bushes to a cable which simplifies the picking up of bushes without requiring a plurality of parts. In contrast to the prior art, one should moreover avoid having numerous components corresponding to one another in order to be able to fit hollow bushes of different sizes and distinctive in other ways. The hollow bushes in question are in fact characterised substantially by their inner and outer diameters so that hollow bushes with the same inner diameter do not necessary have to have the same outer diameter.

The aforementioned aims are achieved by a machine according to claim1and a method according to claim9. Preferred embodiments of the invention are specified in the sub-claims.

An apparatus according to claim1offers the advantage that a minimum number of delivery components/fitting components is provided, and any slight deviations in the alignment of the pick-up apparatus and of the fitting tube do not cause damage to any of the components, but can be evened out mechanically. Moreover, the individual elements/components of the apparatus according to claim1have a simple structure, and this in turn leads to inexpensive production.

Furthermore, the present invention is also advantageous in that independent movements are provided by it and a subsequent bush can therefore be delivered sooner. In this way the fitting is accelerated. In the prior art, however, individual movements of elements of the fitting apparatus are dependent upon one another, and so a new bush can only be provided when the fitting apparatus is totally clear again.

According to a preferred embodiment the picking apparatus of the present apparatus is provided with a picking mandrel which can pass into a hollow bush and pick up and hold, on the outer surface of said mandrel, the hollow bush on the inner surface thereof.

By means of the picking mandrel the hollow bushes can be picked up particularly easily and practically by one feed device. By picking up the hollow bushes on their inner surface, a sufficient holding force is provided in order to hold the hollow bushes and to convey them further. Moreover, the provision of a picking mandrel offers the advantage within the framework of the picking apparatus that the delivery of a hollow bush from the picking apparatus to a fitting tube is facilitated.

In the machine according to the invention it is advantageous that the longitudinal axes of the picking mandrel, the fitting tube and the filling mandrel extend substantially in a same axial direction. The picking mandrel and the fitting tube with the filling mandrel can thus be aligned with one another easily, and among other things, no further pivot movement of the components in relation to one another is necessary.

In a further preferred embodiment the slip-away device, by means of which the hollow bushes can be delivered from the picking apparatus to the fitting tube, is arranged coaxially to the picking mandrel. In this way an exceptionally compact structure is made possible, and the slip-away device can grasp the hollow bush well for delivery from the picking apparatus to the fitting tube.

Furthermore, the machine according to the invention can be characterised in that the tip of the filling mandrel is formed in the shape of a truncated cone (with a rounded edge) in order to support the delivery of the hollow bushes from the picking apparatus to the fitting tube.

In a further embodiment the slip-over device can be moved in the direction of the fitting tube for the delivery of the hollow bushes such that the slip-over device at least partially also surrounds the fitting tube. In this way complete application of the hollow bushes on the fitting tube is guaranteed. Consequently, the hollow bushes are also applied so far over the fitting tube that when subsequently drawing back the slip-over device, the hollow bushes also remain securely on the fitting tube.

According to a further embodiment the fitting tube is fastened to a fitting tube base and is held by the latter. Provision is made here such that the fitting tube base has a larger diameter than the outer surface of the fitting tube. Furthermore, the fitting tube is preferably designed with a step at one end. If a sufficiently large bush is used, the fitting tube can also be designed without a step, i.e. flush.

The machine according to the invention can be further characterised in that the bush fitting apparatus is attached pivotally to the secure base. Thus, after the hollow bush has been applied to the fitting tube, the bush fitting apparatus can be pivoted so as then to be able to deliver the hollow bush to the cable. In this way a compact structure of the machine according to the invention is achieved.

The present application further relates to a method that offers the same advantages as the apparatus according to the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

In the following the apparatus according to the invention and the method according to the invention are described by means ofFIGS. 1-11. In the following the features relating to the apparatus will first of all be described.

The apparatus according to the invention comprises a feed rail1in which bushes3are conveyed. InFIG. 1a number of bushes3are illustrated which are conveyed along the arrow shown to a stop2and are then separated.

The apparatus further comprises a picking apparatus10which in turn comprises a holder11and a picking mandrel12. The picking mandrel12has a cylindrical mandrel12aand a picking mandrel body12bwhich is also cylindrical. On the end of the picking mandrel12opposite the mandrel12aa profile12cis provided in order to receive and hold the picking mandrel12in the picking apparatus10. The profile12ccan be a component connected to the picking mandrel body12bor is formed integrally with the latter. Therefore the picking mandrel12can be exchanged in the picking apparatus10.

The picking mandrel apparatus10further comprises a slip-over device13. As is explained in more detail over the course of the description of the method, the holder11, fastened to the slip-over device13, is capable of moving relative to the picking mandrel12. Both the picking mandrel12and the holder11are received on and attached to the picking mandrel apparatus10, but are capable of moving relative to one another.

The apparatus according to the invention further comprises a bush fitting apparatus20. In the figures a control curve12is indicated diagrammatically in order to illustrate the moveability of a filling mandrel apparatus22. The moveability of the filling mandrel apparatus22along the control curve21is demonstrated in the present embodiment by pivotability and translatory displaceability. For this reason there are provided on the control curve21guide tracks21a,21balong which the filling mandrel apparatus22can be pivoted and optionally moved translatorily.

The filling mandrel apparatus22further comprises a fitting tube24through which the filling mandrel23extends. In other words, the fitting tube24is arranged concentrically to the filling mandrel23. Here, in a basic position, the tip23aof the filling mandrel23projects at one side of the fitting tube, whereas the pencil-shaped region23bof the filling mandrel23extends on the other side of the fitting tube24. The basic position described is illustrated inFIG. 1. In this situation the bush fitting apparatus20is ready to receive a bush3.

The fitting tube24has a fitting tube end24that is designed like a sleeve. The fitting tube24further comprises a fitting tube body24bwhich is integrally formed with the fitting tube end24aand which is cylindrical in form. The fitting tube24is capable of moving relative to the filling mandrel apparatus22and relative to the filling mandrel23.

The apparatus according to the invention further comprises a slip-away mask30in the region of the bush fitting apparatus20. The slip-away mask30, which is shown inFIG. 1in an open position, is capable of moving relative to the bush fitting apparatus20. The slip-away mask30further comprises a bush slip-away mask31which is set up to pick up and optionally enclose a bush. The inner region31aof the bush slip-away mask31is of a form substantially corresponding to a bush to which a funnel-shaped insertion mask32is applied, which is also called an insertion funnel. At the tapered section (the section facing toward the fitting tube24and facing away from the delivered cable4) the insertion mask32has a smaller inner diameter than the inner diameter of the fitting tube24in the region of the fitting tube end24a. However, the insertion mask32can also be formed integrally with the bush slip-away mask31. The insertion mask32has an inner bore hole32awhich is formed in a funnel shape so that, as will be explained in detail later, a cable4can be threaded in.

As can be seen, however, the slip-away mask30is set up to surround and pick up a bush3, the slip-away mask30being able to touch the bush3, but does not have to touch it. The slip-away mask30is designed in a number of parts and in the corresponding procedural step, as described in more detail below, is moved such as to enclose the bush3. The slip-away mask30further comprises a stop33which is provided on the side of the bush slip-away mask opposite the insertion mask32.

In the following an exemplary procedure for fitting a bush3on a cable4is described by means of which the features of the apparatus already described will become more comprehensible. The basic procedure follows the sequence according toFIGS. 1-11.

InFIG. 1a situation is shown in which a bush3is delivered by means of the feed rail1and rests against the stop2. The picking mandrel12has been guided through the bush3. The bush is picked up from the picking mandrel by the profile of the picking mandrel12or by spreading apart. The picking mandrel can rest flat against the inside of the bush, or also with line or point contact.

In the following, as can be seen by consideringFIGS. 1 and 2together, the picking mandrel12moves away in a translatory direction perpendicular to the feed rail1and thereby guides the bush3from the feed rail1to the picking mandrel apparatus10. In the embodiment shown, the picking mandrel12moves until the bush3touches the slip-over device13. Alternatively, a certain distance can be provided between the end of the bush3and the slip-over device13. It is only important that the bush “catches” on the picking mandrel12when separated.

As can be gathered fromFIG. 2in comparison toFIG. 1, the picking mandrel12moves a little further after the bush3has touched the slip-over device13. In other words, the bush3is already slipped away somewhat from the picking mandrel13, a sufficient length of the picking mandrel12projecting over the bush3, however, so that the bush3is furthermore held by the picking mandrel12.

InFIG. 3the next step of the exemplary procedure is shown. As indicated by the arrow, the picking mandrel apparatus10has been moved relative to the feed rail1. This movement corresponds approximately to the feed direction of the bushes3in the feed rail1.

After the picking mandrel apparatus10has been moved in this way, the picking mandrel12is located opposite the filling mandrel23, the respective axes being aligned substantially equally. The filling mandrel23and the picking mandrel12do not touch one another here, but they can be brought together sufficiently in order to be able to deliver the bush3. The situation just described is shown in an enlarged view inFIG. 4.

As shown inFIG. 4, the bush3is now delivered by a movement of the slip-over device13in the direction of the bush fitting apparatus20. After the picking mandrel12and the filling mandrel23have been aligned substantially linearly in relation to one another, when the slip-over device13is moved, the bush is slipped away from the picking mandrel12and delivered via the tip23aof the filling mandrel to the fitting tube24on which the bush can in turn either lie flat or be held with line or point contact.

After the bush3is now slipped away from the picking mandrel12, the slip-over device13moves, as shown inFIG. 5, away from the bush fitting apparatus20. This movement is substantially opposite to the movement described above for delivering the bush. Subsequently the slip-over device13no longer prevents the picking mandrel apparatus10from moving away from the bush fitting apparatus20.

As shown inFIG. 6, the bush fitting apparatus20is now pivoted, and in the present exemplary embodiment by <90°, preferably by 87°. During this pivot movement the filling mandrel23draws back a little, and the fitting tube24moves towards a stop (not detailed) of the slip-away mask30. This process can be seen clearly by consideringFIG. 5andFIG. 6together.

As is to be understood clearly within this context, the slip-away mask30is moved in the direction of the bush3held on the fitting tube24such that the bush slip-away mask31surrounds the bush3.

As can be seen inFIG. 6, the filling mandrel23is drawn back with respect to the fitting tube24so that the outer end of the fitting tube end24aforms the outermost position, and the tip23aof the filling mandrel23disappears in the fitting tube24.

As can be seen furthermore inFIG. 7, a cable4has been delivered that already has an exposed wire4band a cable jacket4a. In another embodiment, however, the cable4can also be provided without an exposed wire. The filling mandrel23, the fitting tube24and the cable4are located in approximate linear alignment to one another.

In the following, as can be seen inFIG. 8, the fitting tube24is moved further in the direction of the cable4. The slip-away mask30is moved together with the movement of the fitting tube24. On the other hand, the filling mandrel23remains in exactly the same drawn back position.

As can be seen inFIG. 8, the bush3has now been drawn up with the fitting tube24moved forwards and the slip-away mask30moved at the same time over the cable4.

Then the fitting tube24is moved back, by means of which the bush3held back from the slip-away mask30is slipped away from the fitting tube24. InFIG. 9the filling mandrel apparatus22is shown already back in the pivoted back position when delivering a new bush3. Over the course of this pivot movement the filling mandrel23is moved again such that it projects out of the fitting tube24(basic position), and so supports the delivery of a bush3from the picking mandrel12.

While the further bush3is now delivered from the picking mandrel12to the fitting tube24, the slip-away mask30opens, as shown inFIG. 10. Next the slip-away mask30moves in the direction of the bush fitting apparatus20and forms a stop for the bush fitting apparatus20which is pivoting and moving forwards. In this way the bush fitting apparatus can be moved independently until the latter comes into contact with the stop. They then move together over the rest of the stroke.FIG. 11then shows a position of the described apparatus which corresponds substantially to that ofFIG. 5.

As already described, the bush fitting apparatus20is pivoted by <90°, preferably 87°, in order to be aligned with the cable4. Consequently, the picking mandrel12also forms a corresponding angle, preferably of 87°, relative to the cable4. The picking mandrel12in turn is aligned perpendicularly to the feed rail1. Before pivoting, the picking mandrel deviates by approximately 3° from a perpendicular to the ground (direction of gravity). The slight deviation is produced by the feed rail being inclined by approximately 3° in relation to a horizontal direction so that a constant supply of bushes is guaranteed and supported. The tip23aof the filling mandrel23can adopt different shapes. It is important here that the tip23ais designed in order to support the delivery of the bush3from the picking mandrel12to the fitting tube24.

By dividing the bush fitting apparatus20into a picking mandrel23and a filling mandrel24, the number of different diameter pairings can be drastically reduced. In this way a wide variety of combinations of bushes and cable cross-sections can be processed by the bush fitting apparatus20. For this purpose it is necessary for the picking mandrel12and the filling mandrel23, and also the fitting tube24, to be interchangeable. However, different bushes3with different inner diameters, which only vary by a relatively small amount, can be drawn onto a common fitting tube24with the aid of a filling mandrel23according to the present invention so that excessive changing of fitting tubes24is eliminated.