DE4337737C1 - Process for connecting the ends of toothed belts - Google Patents

Abstract

A process for connecting the ends of toothed belts provided with elongate tension inserts, in which the toothed belt ends to be connected are laid one over the other and, by being cut together, are divided into sections which fit exactly one end to the other, is to be designed such that it can be used to produce a connection with which the greatest possible forces can be transferred uniformly. For this purpose it is provided according to the invention that, after the separating cut, the ends of the elongate tension inserts are at least partially exposed and that, after exposure, every second protruding elongate tension insert end is cut off, the cut-off ends and the interspaces between the remaining ends lying in line with one another, whereupon additional elongate tension inserts are incorporated in the interspaces formed by the cutting off. These additional inserts reach from the interspace of one end into the interspace of the other end and span the respective separating point, whereupon the connection area is filled again with plastic in a mould, so that the two ends of the toothed belt are fused to each other.

Description

The invention relates to a method for connecting the ends of toothed belt provided with tension cord inserts, in which the The toothed belt ends to be connected are placed one above the other and by means of of a common cut in precisely fitting interlocking Sections can be split.

In a known method of this type (DE 22 51 454 C3) are cutouts and tongues on the Belt ends formed, which are nested and together get connected. The common cut runs here to some extent meandering, so that in the same cross section several consecutive separation points of the tensile cord deposits occur.  

The cut thus formed is then through the pull cord insert encapsulating plastic material closed by the plastic is melted in a mold.

A disadvantage of this known method is that the so created connection point much less force transferred than the rest of the belt, so that this over must be dimensioned to the necessary forces over to be able to wear.

The invention is accordingly based on the object, a Ver drive the type mentioned in such a way that with a connection can be made with which, if possible large forces can be transferred evenly.

This object is achieved in that after the separating cut at least the ends of the tension cord inserts to be partially exposed and that after the exposure of each second protruding tension cord insert end is cut off, the cut ends or spaces between the remaining ends are in alignment with each other, leading to additional tension cord inserts in the resulting by cutting interstices that are stored by the intermediate space of one end into the space of the other end range and bridge the respective separation point, whereupon the Connection area re-opened in a mold with plastic is filled, so that the two ends of the toothed belt together to be merged.  

With this method it is achieved that on both sides next to the between the remaining ends of the tension cord inserts the separating point is where the additional tension cord inserts lie, so that the separation point is reinforced from both sides is, which gives an even strength and strength distribution in the connection area results. This even Force distribution is in the arrangement according to the invention guaranteed especially when it comes to the Manufacture of annular endless timing belts.

The inventive attachment of additional train strand inserts for double-sided reinforcement of separation points between remaining tension cord inserts, as above led to a good power transmission and the same moderate load distribution in the belt. The junction is usually about 30 to 35 cm long. That way it is possible to use relatively long tension cord inserts, so that the forces are still the same over the length of the belt distribute more moderately.

It is known from DE 25 11 671 A1 for connecting the ends of conveyor belts or power transmission belts, for example to expose the ends of the tensile cord inserts at least partially and after joining the ends the connection area refill in a mold with plastic. From the DE-C 30 42 600 A1 it is also known to have additional tension members in the form of overlapping tapes that the respective  Bridge the separation point.

However, it can be particularly advantageous if the separating cut is inclined at an angle and common by the superimposed ends of the toothed belt sam performed straight cut, which is at an angle for longitudinal extension of the tensile cord insert from approximately 15 to 30 °, is preferably attached from 30 °. That way  namely the respective separation point of the individual train deposits opposite the respective separating point in Longitudinal direction of the toothed belt offset, this offset the larger the smaller the above angle is. However, this must not be chosen too small either because otherwise the connection point becomes too long. So that is in each case perpendicular to the longitudinal direction of the toothed belt running cross-sectional plane of the toothed belt only a single severed tension cord insert, so that the front parts of those achieved with the additional tension cord inserts Reinforcement with the advantages of the offset of the separation points is combined.

In the method according to the invention, it is possible to pull to completely expose strand insert ends after the cut, then both the tooth partially removed in this way refill profile as well as the toothed belt back.

In a preferred embodiment of the method, it can but on the other hand be advantageous if from the back of the toothed belt, So from the side facing away from the teeth, only that Plastic material is worked away until the train strand inserts at least half free towards the back lie so that they can be grasped and cut off. This procedure has the advantage that the teeth themselves  working away of the plastic is not damaged, so that the initial state after filling in the mold of the removed toothed belt back very easily can be produced.

To restore the toothed belt back at this off leadership form, it can also be advantageous if a Back intermediate piece is used, which additional Includes tension cord inserts that are described in the above Free spaces fit.

When using the intermediate piece, these additional Train cable inlays automatically to these vacant places, if the back adapter together with the rest of the tooth belt part is inserted into the mold. The back between piece is then attached to the existing plastic material Melted timing belt.

The invention is based on execution examples explained in more detail in the drawing.

Fig. 1 shows a schematic and greatly shortened representation of two toothed belt ends that are to be connected together.

Fig. 2 are the toothed belt ends of Fig. 1 after performing the separating cut.

Fig. 3 are the toothed belt ends according to Fig. 1 and 2 after removing every second tension cord insert (here the tension cord inserts 2 and 4 ).

Fig. 4 are the toothed belt ends of FIG. 3 after the use of two additional and the separating point cross-train insert.

Fig. 5 are the toothed belt ends of Fig. 3 in a slightly modified embodiment.

Fig. 6 are the toothed belt ends according to Fig. 5 with additional tension cord inserts used.

Fig. 7 shows a perspective view of the exposure of the tension cord insert ends of a toothed belt end, a larger number of tension cord deposits being chosen here for the sake of clarity.

Fig. 8 is the toothed belt end of Fig. 7 after removal of every second tension cord insert end.

FIG. 9 shows a toothed belt end in which the tension cord inserts are exposed from the back of the toothed belt.

Fig. 10 shows the finished connection in a way work according to FIG. 9.

Fig. 11 shows the introduction of additional Zugstrangeinlagen via a toothed belt between back piece.

Fig. 12 shows a perspective view of the introduction of the back intermediate piece.

According to Fig. 1 are two ends 8 a and 9 a of one or more toothed belts 8 and 9 are connected to each other. The toothed belts each have tension cord inserts 1 to 5 . The number of tension cord inserts in FIG. 1 has been kept low for the sake of clarity; the number of tension cord inserts is usually higher for the timing belts actually used.

To prepare the connection, the two ends 8 a and 9 a are placed one above the other in such a way that the tension cord inserts and the other parts of the toothed belt are aligned with one another in the connection area, whereupon a straight cut S is made, with which the toothed belt lying beyond the cut ends 8 b and 9 b are separated. Here, both the plastic material and the tension cord inserts are cut in the area of the cut S.

Fig. 2 shows the through the rectilinear and at right angles to the longitudinal extension of the toothed belt cuts S and the resulting separation of the remaining ends 8 b and 9 b from the toothed belt ends 8 a and 9 a, which are generally designated z tensile cord inserts at Initial shape of the toothed belt ends 8 a and 9 a enclosed by plastic material 10 . The plastic material is closed to the outside by an outer skin 11 formed by the material itself, the skin being formed by the contact of the mold wall.

In order to be able to carry out the connection, the toothed belt ends must be freed from at least part of the plastic material, wherein, as indicated in FIG. 2, this free space is formed beyond the line F. The free space F extends, as indicated by the arrow 12 , from the full toothed belt in the direction of the section S.

According to FIG. 3, after the cut through the section S, every second tension cord insert z is removed, so that in the area of the separation point 13 after the removal of every second tension cord insert, empty spaces 14 remain open, in which additional tension cord deposits 15 (cf. FIG. 4) are used can, which bridge the intermediate separation point 13 on both sides and thus largely compensate for the weakening of the belt caused by the separation point 13 .

In the embodiment according to FIG. 4, however, the force transmission in the area of the connection point is only taken up by two additional tension cord inserts 15 , because the counting starts from the middle tension cord insert 3 (cf. FIG. 4). In order to avoid this, according to the exemplary embodiment shown in FIGS . 5 and 6, an odd number of additional tension member inserts 15 should always be used, so that the free spaces 14 created according to FIG. 5 for the additional tension member inserts 15 (cf. Fig. 6) are always in the area of the junction in the over number.

Fig. 7 shows an embodiment of the working away of the plastic material 10 from the tensile insert z, wherein seven tensile insert z are provided in Fig. 7. The so-called back 16 of the toothed belt 8 or 9 , which contains the tension cord inserts z, is also completely worked away in the connection area in this embodiment, as are the teeth 17th

Fig. 8 shows the result of the work, with every second tension cord insert 2 , 4 and 6 removed by cutting. As he can see, gaps 18 have thus formed between the remaining tension member inserts 19 , in which the ends of the additional tension member inserts 15 (see FIG. 6) can occur in the manner described. The embodiment according to FIGS. 7 and 8 is, as can be seen, not particularly expedient; According to the above statements, an embodiment should be selected in which the number of additional tension member deposits exceeds that of the remaining tension member deposits by at least 1.

FIG. 9 shows a modified embodiment in which the tension cord inserts z are only freed from the plastic material 10 from the back 16 to such an extent that they are at least half exposed, as shown in FIG. 9. This method has the advantage that the teeth 17 are not worn in the cutting area, but that, as can be seen from FIG. 10, the cut toothed belt ends 8 and 9 , as indicated at 20 , the teeth 17 abut each other in the tooth area so that their original Form is maintained and only an approximately ent gap between 20 must be filled in the form.

According to FIG. 11, the additional tension cord inserts can currently be contained in a back intermediate piece 21 , from which, as shown in FIG. 11, they also look down at least in half, that is, in the direction of the teeth 17 . The additional tension member inserts zz are arranged so that they are opposite the free spaces formed by cutting away this second tension member insert (cf. in particular FIG. 5). If the back intermediate piece 21 according to FIG. 11 is used in the direction of the arrow, its length L corresponding to the distance A between the two edges of the toothed belt ends delimiting the free space, then the train strand inserts zz automatically get into the correct position in the spaces 14 between the two remaining deposits tension cord, so that the intermediate piece 21 is melted under precise incorporation of the Zugstrangeinlagen upon actuation of the mold. A particular advantage here is that the intermediate back pieces can be kept prefabricated in the warehouse, their use being effortless and precise, and the labor-intensive insertion of the individual pull cord deposits eliminated.

Fig. 12 shows a perspective view of the back intermediate piece 21 with the contained and half protruding tension member inserts zz, which can be used in the spaces 22 and 23 between the remaining tension member inserts 1 , 3 and 5 so that it is between the vertical walls 24 , which is open to the rear of the toothed belt, can be used very precisely.

All representations are compared to the actual ver ratios greatly shortened to ver the essence of the invention clear. In fact, the joints are 30 to 35 cm long.

Claims (9)

1. A method for connecting the ends of toothed belts provided with tension cord, in which the toothed belt ends to be connected are placed one on top of the other and divided into precisely fitting interlocking sections by means of a common cut, characterized in that after the separating cut, the ends of the tension cord deposits are at least partially exposed and that after the exposure of every second protruding tension member insert is cut off, the cut ends or the spaces between the remaining ends being in alignment with one another, whereupon additional tension member deposits are stored in the spaces formed by the cutting, which are separated from the space by one end extend into the space between the other end and bridge the respective separation point, whereupon the connection area is filled up in a mold with plastic, so that the two ends of the toothed belt are fused together en. 2. The method according to claim 1, characterized in that it in the separating cut at an angle inclined and through the superimposed ends of the timing belt jointly performed straight cut. 3. The method according to claim 2, characterized in that the Cut at an angle to the longitudinal extension of the tension cord insert from about 15 to 30 °. 4. The method according to claim 3, characterized in that the Angle is about 30 °. 5. The method according to any one of the preceding claims, characterized characterized that after the cut and the complete Exposure of the ends of the tensile cord that partially ent removed tooth profile is replenished as well as the Back of the timing belt. 6. The method according to any one of claims 1 to 4, characterized records that from the toothed belt back, that of the teeth  away from the plastic material so far away is worked until the Zugstrangeinlagen at least half exposed to the rear so that it grips and can be cut. 7. The method according to claim 5 or 6, characterized in that that a back to restore the timing belt back intermediate piece is used, which additional train contains strand deposits that are described in the above Free spaces fit. 8. The method according to claim 7, characterized in that the Back intermediate piece together with the rest of the timing belt part is inserted into the mold. 9. The method according to any one of the preceding claims, characterized characterized in that the number of additional pull cords deposits is at least 1 greater than the number of Toothed belt part remaining tension cord insert ends