A WELDING UNIT FOR WELDING TWO RAILS OF A TRACK

GROUPE DE SOUDAGE DESTINE A SOUDER DEUX RAILS D'UNE VOIE DE CHEMIN DE FER

English Abstract

Each electrode (6) of a flash-butt welding unit comprises two contact surfaces
(7)
which are separate from one another. Of these, the upper contact surface (7) -
-
with regard to a vertical - is designed for application to a bottom flank (9)
of a rail
head (10), and the lower contact surface (7) is designed for application to a
rail
base shoulder (8). Thus, improved current flow is possible.

French Abstract

Chaque électrode (6) d'un groupe de soudage par étincelage présente deux surfaces de contact (7) séparées l'une de l'autre. La surface de contact (7), supérieure par rapport à la verticale, est conçue pour s'appuyer contre un flanc inférieur (9) d'une tête de rail (10), et la surface de contact inférieure (7) est conçue pour s'appuyer contre un flanc de base de rail (8). Ceci permet une meilleure circulation du courant.

Claims

4
Claims
1. A welding unit for welding two rails (2) of a track (3), consisting of
two unit
halves (5) which are displaceable towards one another in the longitudinal
direction
of the rails, wherein a respective pair of electrodes (6) is associated with
each unit
half (5), the electrodes (6) having contact surfaces (7) for application to
the rail (2)
which are provided for current transmission, wherein each electrode (6) has
two
contact surfaces (7), separate of one another, of which an upper said contact
surface (7) - with regard to a vertical - is engageable with a bottom flank
(9) of a rail
head (10), and a lower said contact surface (7) is engageable with a rail
shoulder
(8).
2. A welding unit according to claim 1, characterized in that the two
contact
surfaces (7) enclose an acute angle a with one another which depends on the
type
of rail to be welded.
3. A welding unit according to claim 1, characterized in that each
electrode (6)
is mounted for pivoting about an axis (11) extending parallel to the
longitudinal
direction (4) of the rails.
4. A welding unit according to claim 3, characterized in that each
electrode (6)
is fastened to a lower end (13) ¨ with regard to a vertical ¨ of an electrode
lever
(12) for rotation about the axis (11), the electrode lever (12) being
pivotable by
means of a drive (14) about a lever axis (15).

5
5. A welding unit according to claim 4, characterized in that the lever
axis (15)
of the electrode lever (12) is positioned parallel to the axis (11).
6. A welding unit according to claim 4, characterized in that a pivot bolt
(17)
forming the axis (11) is designed to be displaceable along a vertical
direction
relative to the electrode lever (12) against the resistance of a spring (19).
7. A welding unit according to claim 1, characterized in that the electrode
(6) is
connected to the unit half (5) via a universal joint (20).
8. A welding unit according to claim 1, characterized in that the electrode
(6) is
connected to the electrode lever (12) via a universal joint (20).

Description

CA 02695639 2015-01-22
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A WELDING UNIT FOR WELDING TWO RAILS OF A TRACK.
[0001] The invention relates to a welding unit for welding two rails of a
track,
consisting of two unit halves which are displaceable towards one another
in the longitudinal direction of the rails, wherein a respective pair of
electrodes is associated with each unit half, the electrodes having contact
surfaces for application to the rail which are provided for current
transmission.
[0002] A welding unit of this type is known from US 6 762 390, in which the
electrodes provided for current transmission are pressed to the rail web
between the rail head and -base. This has the disadvantage that
embossings containing various rail production data, which might be
present on the rail in this region, must first be ground away.
[0003] It is the object of the present invention to provide a welding unit of
the type
mentioned at the beginning with which an optimal rail contact can be
established independently of rail embossings.
[0004] This object is achieved, according to the invention, with a welding
unit of
the specified type in that each electrode has two contact surfaces,
separate of one another, of which the upper contact surface ¨ with regard
to a vertical ¨ is designed for application to a bottom flank of a rail head,
and the lower contact surface is designed for application to a rail base
shoulder.
[0005] With a contact surface being configured in this manner, rail embossings
on
the rail web have no influence whatsoever on the electrodes or the weld

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quality. Furthermore, as a result of the inclined arrangement of the contact
surfaces forming a wedge, as it were, it is possible to achieve an excellent
clamping effect with the rail, and thus an optimal current flow.
[0006] The invention will be described in more detail below with reference to
an
embodiment represented in the drawing in which
[0007] Fig. 1 shows a simplified side view of a welding unit,
[0008] Fig. 2 shows a view of a pair of electrodes, and
[0009] Figs. 3, 4 each show a detail of an electrode fastening.
[0010] A welding unit 1, represented in Fig. 1, for welding two rails 2 of a
track 3
comprises two unit halves 5 arranged one following the other in a
longitudinal direction 4 of the rails. Associated with each unit half 5 is a
respective pair of electrodes 6 (see also Fig. 2) which, for the purpose of
current transmission, are provided for application to the rails 2 to be
welded. Numerous welding units 1 of this type for flash-butt welding are
already known; therefore, further details will not be elaborated upon.
[0011] As visible in Fig. 2, each electrode 6 has two contact surfaces 7 which
are
separate from one another. Of these, the upper contact surface 7 ¨ with
respect to a vertical ¨ is designed for application to a bottom flank 9 of a
rail head 10. The oppositely positioned lower contact surface 7 is provided
for application to a rail base shoulder 8 of the rail 2. The two contact
surfaces 7 of an electrode 6 enclose an acute angle a. The latter depends
upon the type of rails 2 to be welded. When the electrode 6 is applied to
the rail 2, a surface of the said electrode lying between the two contact
surfaces 7 is spaced from a rail web 16.
[0012] Each electrode 6 is mounted to a lower end 13 of an electrode lever 12
and pivotable about an axis 11 extending parallel to the longitudinal

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direction 4 of the rails. Both electrode levers 11, positioned opposite one
another in a direction extending perpendicularly to the longitudinal direction
4 of the rails, are fastened to the respective unit half 5 for pivoting by
means of a drive 14 about a lever axis 15. The lever axis 15 and the axis
11 of the electrode 6 extend parallel to one another.
[0013] In Fig. 3, a variant of a mounting of the electrode 6 is shown. In
this, a pivot
bolt 17 forming the axis 11 is mounted in a vertically extending oblong hole
18 and displaceable relative to the electrode lever 12 against the
resistance of a spring 19. This ensures a small degree of freedom of
movement of the electrode 6 for better adaptation to the two rail ends to be
welded.
[0014] According to Fig. 4, the electrode 6 is connected to the electrode
lever 12
by means of a universal joint 20.

Representative Drawing