Current Collector Head Manufacturing Method and Current Collector Head

Abstract

A method for manufacturing a current collector head for a current collector consisting of an electrically conductive contact shoe and an electrically insulating contact shoe holder includes the following steps: inserting a section of the contact shoe into an outwardly open cavity in the contact shoe holder dimensioned to match this section; clamping the contact shoe in the cavity of the contact shoe holder by acting on the contact shoe holder with at least an external force directed onto the inserted section of the contact shoe; heating the contact shoe to a temperature sufficient to form a bonded connection with the contact shoe holder; and cooling the current collector head formed from the contact shoe and the contact shoe holder.

Claims

1. A method for manufacturing a current collector head for a current collector having an electrically conductive contact shoe and an electrically insulating contact shoe holder, the method comprising: inserting a section of the contact shoe into an outwardly open cavity in the contact shoe holder dimensioned to match the section; clamping the contact shoe in the cavity of the contact shoe holder by acting on the contact shoe holder with at least an external force directed onto the inserted section of the contact shoe; heating the contact shoe to a temperature sufficient to form a bonded connection with the contact shoe holder; cooling the current collector head formed from the contact shoe and the contact shoe holder.

2. The method of claim 1, wherein the action of the external force after completion of heating is maintained for a predetermined time sufficient for permanent stabilization of the bonded connection.

3. The method of claim 1, wherein heating of the contact shoe occurs inductively by an alternating magnetic field.

4. The method of claim 1, wherein heating of the contact shoe occurs by mechanical contact with at least one heated body.

5. The method of claim 1, wherein the cavity in the contact shoe holder has a form of a groove with two parallel longitudinal sides, the length of which is a multiple of a spacing between the sides, and wherein a main direction of the external force lies perpendicular to the longitudinal sides of the groove.

6. The method of claim 5, wherein action of the external force on the contact shoe holder directed onto the contact shoe occurs on one or several individual sites along the groove of the contact shoe holder.

7. The method of claim 5, wherein action of the external force on the contact shoe holder directed onto the contact shoe occurs extensively along the entire groove of the contact shoe holder.

8. The method of claim 5, wherein heating of the contact shoe occurs on a section of the contact shoe protruding from the groove in the contact shoe holder.

9. The method of claim 5, wherein heating of the contact shoe occurs on one or several individual sites along the groove of the contact shoe holder.

10. The method of claim 5, wherein heating of the contact shoe occurs extensively along the entire groove of the contact shoe holder.

11. The method of claim 6, wherein both the action of the external force on the contact shoe holder directed onto the contact shoe, as well as the heating of the contact shoe on an identical site or several identical individual sites occur relative to the longitudinal direction of groove of the contact shoe holder.

12. The method of claim 9, wherein both the action of the external force on the contact shoe holder directed onto the contact shoe, as well as the heating of the contact shoe on an identical site or several identical individual sites occur relative to the longitudinal direction of groove of the contact shoe holder.

13. The method of claim 1, wherein the contact shoe is heated to a temperature sufficient to form a bonded connection between the surfaces of the contact shoe holder pressed together by the clamping force and the contact shoe.

14. The method of claim 1, wherein the electrically insulating contact shoe holder includes a thermoplastic.

15. A current collector head for a current collector, comprising an electrically conductive contact shoe and an electrically insulating contact shoe holder, wherein the current collector head is produced by the method of claim 1.

16. The current collector head of claim 14, wherein the electrically insulating contact shoe holder includes a thermoplastic.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] An embodiment example of the disclosed method and current collector head are described below with reference to the drawings.

[0025] FIG. 1 shows a side view of a current collector head product according to the disclosure,

[0026] FIG. 2 shows a front view of the current collector head of FIG. 1,

[0027] FIG. 3 shows a sectional view of the current collector head of FIG. 1 along line B-B with clamping jaws and induction coils and

[0028] FIG. 4 shows a top view of the current collector head of FIG. 1 with clamping jaws and induction coils and

[0029] FIG. 5 shows a sectional view of the current collector head of FIG. 1 along line B-B with clamping jaws and heating jaws.

DETAILED DESCRIPTION

[0030] FIGS. 1 and 2 show a current collector head 1 produced according to the invention, consisting of an electrically conducting contact shoe 2 and an electrically insulating contact shoe holder 3. The top 4 of the contact shoe 2 is intended to slide along a contact wire during operation on a live rail. A lower section 2A of the contact shoe 2, indicated by the dashed lines in FIG. 1, is accommodated in the contact shoe holder 3 in a groove 5 formed on its top, which is apparent in the sectional view of FIG. 3. The contact shoe holder 3 in the front view has a narrow upper section 3B and a significantly wider lower section 3A, where the locations “bottom” and “top” only refer to the depiction in FIGS. 1 to 3 and not to the spatial orientation of the current collector head 1 during operation on the current collector of a conductor rail system.

[0031] An upper section 2B of contact shoe 2 protrudes upwardly from the upper section 3B of the contact shoe holder 3. The current collector head 1 during operation on a current collector of a vehicle, which is supplied current through a contact line, is fastened by means of a pin extending through-hole 6 in the lower section 3A of the contact shoe holder 3 so that it can rotate around the center axis of hole 6 by a predetermined angle. The movement direction of current collector head 1 along the live rail of a contact line during operation corresponds to the direction of the arrow visible at the left next to through-hole 6 in FIG. 1 or the direction opposite thereto.

[0032] The groove 5 is wide enough in cross section that the lower section 2A of the contact shoe 2 can be introduced to it from above and is situated in opposite longitudinal sides of the groove 5 in contact with the longitudinal sides of the lower section 2A of the contact shoe 2. At one location, the base of groove 5 has an opening extending to the bottom of contact shoe holder 3, through which a plug connector formed on contact shoe 2, which is suitable for connection of the cable, extends in the direction of the bottom of contact shoe holder 3. This plug connector is not visible in the figures and is insignificant to the invention.

[0033] In order to fasten the contact shoe 2 to the contact shoe holder 3, according to the depiction in FIGS. 3 and 4, after introduction of the lower section 2A of the contact shoe 2 into groove 5 in the upper section 3B of the contact shoe holder 3, lateral clamping forces F are exerted by means of several opposite clamping jaws 7 and 8 in an opposite direction on the upper section 3B of the contact shoe holder 3 in the direction of the lower section 2A of the contact shoe, so that the longitudinal sides of groove 5 are forced against the longitudinal sides of the lower section 2A of the contact shoe 2 and the contact shoe 2 is fixed in this manner in the contact shoe holder 3.

[0034] An arrangement of inductors 9 is then positioned in the embodiment of the invention shown in FIGS. 3 and 4 in the form of a combination of a magnetic core 10 of ferromagnetic material with a coil 11 on the upper section 2B of the contact shoe 2, so that the alternating magnetic fields generated by coils 11 when coils 11 are supplied an alternating current penetrate the upper section 2B of the contact shoe 2. The magnetic cores 10 in the embodiment example depicted in FIGS. 3 and 4 are largely closed C-shaped cores with an air gap that is somewhat wider than the upper section 2B of the contact shoe 2, so that it fits into the air gap in the lateral direction and a spacing still remains on both sides between the contact shoe 2 and magnetic core 10. The inductors are thus brought close to the contact shoe 2, so that the magnetic cores 10 enclose its upper section 2B.

[0035] The initial heating of the upper section 2B of the contact shoe 2 occurs by means of the electrical eddy currents generated by the alternating magnetic fields in the conducting contact shoe 2, which propagates quickly as a result of the high thermal conductivity of the contact shoe 2 into its lower section 2A, especially in the areas directly beneath the magnetic cores 10. The magnitude of the current and duration of the energization of coils 11 is chosen so that, by means of heating, a softening of the upper section 3B of the contact shoe holder 3, which consists of thermoplastic, occurs on the longitudinal sides of the groove 5, and a bonded connection is formed between the surfaces of the contact shoe holder 3 and the contact shoe 2 forced together by the clamping jaws F. After the end of energization of coils 11, cooling occurs, followed by solidification of the formed connection between the contact shoe 2 and the contact shoe holder 3. It is expedient here that the clamping force is maintained for a time sufficient for said solidification after the end of energization.

[0036] In the depicted embodiment example according to FIG. 4, three inductors 9 are equidistantly arranged along the upper section 2B of the contact shoe 2 and three pairs of clamping jaws 7 and 8 along the upper section 3B of the contact shoe holder 3, so that one inductor 9 and one clamping jaw pair 7, 8 each are found at the same position with reference to the common longitudinal direction of the contact shoe 2 and the contact shoe holder 3. The clamping forces F are thereby introduced into the contact area between the contact shoe 2 and the contact shoe holder 3 that lies closest to the area of introduction of the thermal power into contact shoe 2.

[0037] The number of three inductors 9 and three clamping jaws pairs 7, 8 shown in FIG. 3 is merely an example. In principle, one inductor 9 and one clamping jaw pair 7, 8 would also be sufficient in order to bring about bonding of the contact shoe 2 to the contact shoe holder 3 at a location, but more than the number of three inductors 9 and three clamping jaw pairs 7, 8 shown in FIG. 4 could also be used. One larger clamping jaw pair 7, 8 and one larger inductor 9, which each extend along a significant part of the length of the contact shoe 2 and the contact shoe holder 3, could also be used.

[0038] The C-shape of the inductor 9 is an expedient shape, but is in no way the only possible shape. The spatial orientation of the current collector head 1, the clamping jaw 7, 8 and the inductor 9 during the thermal joining process need not correspond to the arrangement according to FIG. 3, but the entire arrangement, for example, could also be rotated 180°. In this case, the inductor 9 could be configured so that it has a housing that functions as a base, on which the components of the current collector head 1 to be joined together are initially placed in the assembled state and through which they are held in a defined position before they are fixed together by means of clamping jaws 7, 8.

[0039] Another embodiment of the invention is shown in FIG. 5 with reference to a view of a current collector head as in FIG. 3. Components coinciding with FIG. 3 are marked in FIG. 5 with the same reference numerals as in FIG. 3. The only difference relative to the arrangement of FIG. 3 is that an additional clamping jaw pair 12, 13 is provided instead of the inductors 9 there for heating of the contact shoe 2, which functions in this embodiment as heat source for heating of contact shoe 2. For this purpose, the additional clamping jaw pair 12, 13 is initially heated to a predetermined temperature and then brought in contact with the upper section 2B of the contact shoe 2 by a movement in the direction marked by arrows in FIG. 5 and forced against it, so that the contact shoe 2 is heated starting from the areas of the surface of the upper section 2B situated in contact with the additional clamping jaw pair 12, 13.

[0040] Just as with the inductive heating in the first embodiment, heat here propagates vertically downward into the lower section 2A of the contact element 2. By exposing the upper section 3B of the contact shoe holder 3 to a clamping force F directed against the lower section 2A of the contact shoe 2 through the first clamping jaw pair 7, 8, as in the first embodiment, a bonding connection is produced between the upper section 3B of the contract strip holder 3 and the lower section 2A of the contact shoe 2. The difference relative to the first embodiment therefore only consists of a different origin of the heating of the contact shoe 2.

[0041] Just as in the first embodiment, heating of the upper section 2B can also occur in the second embodiment both point-like at one or more sites along the contact shoe 2 or extensively along the entire length of contact shoe 2. This can be achieved by a corresponding arrangement and shaping of one or more heated additional clamping jaw pairs 12, 13, similar to the arrangement of one or more inductors 9 in the first embodiment. Heating of the clamping jaw pair 12, 13 or additional clamping jaw pairs 12, 13 can occur, for example, electrically by means of heating wires embedded in the additional clamping jaws 12 and 13, as are used in the heating plates of electric stoves. Further conceivable types of heating of the additional clamping jaws 12 and 13 would be corresponding channels in the additional clamping jaws 12 and 13 through which a heated liquid is passed, or targeted irradiation of the additional clamping jaws 12 and 13 by an infrared radiation source.

[0042] In the embodiment examples, two clamping jaws 7 and 8 are provided on opposing sides of the upper section 3B of the contact shoe holder 3, each of which exerts an identical force F, i.e., a total of two forces in opposite directions on the upper section 3B and fastens the lower section 2A of the contact shoe 2 inserted in them, which is a preferred solution of clamping. In principle, however, only one force F could also be exerted by a single movable clamping jaw 7 or 8 from one side on the upper section 3B of the contact shoe holder 3, and thus forced against an unmovable holder on its other side.

LIST OF REFERENCE NUMERALS

[0043] 1 Current collector head [0044] 2 Electrically conductive contact shoe [0045] 2A Lower section of contact shoe [0046] 2B Upper section of contact shoe [0047] 3 Electrically insulating contact shoe holder [0048] 3A Lower section of contact shoe holder [0049] 3B Upper section of contact shoe holder [0050] 4 Top of contact shoe [0051] 5 Groove [0052] 6 Hole [0053] 7 Clamping jaw [0054] 8 Clamping jaw [0055] 9 Inductors [0056] 10 Magnetic core [0057] 11 Coil [0058] F Clamping forces