GB2421535A

GB2421535A - A lifting clamp for lifting sleepers

Info

Publication number: GB2421535A
Application number: GB0525438A
Authority: GB
Inventors: Otto Widlroither
Original assignee: Robel Bahnbaumaschinen GmbH
Current assignee: Robel Bahnbaumaschinen GmbH
Priority date: 2004-12-22
Filing date: 2005-12-14
Publication date: 2006-06-28
Anticipated expiration: 2025-12-14
Also published as: WO2006074668A1; GB0525438D0; GB2421535B

Abstract

A lifting clamp (5) for lifting sleepers (s) comprises a clamp carrier (7), vertically adjustable by means of a lifting drive (9) with two clamp parts (11) which are squeezable towards one another by a drive (13) and each has a contact part (12), positioned underneath a pivot axis (10), for gripping the sleeper (2). The clamp carrier (7) is provided with a limiting stop (14), underneath the pivot axes (10) and between the same, which is elongated as centring legs (15) in the direction of lower ends (16) of the two clamp parts (11). Clamp parts have contact parts (12) which have V-shaped indentation. The lifting clamp is provided with a centring rod (21), extending parallel to the lifting drive (9) and is vertically adjustable in a guide (23).

Description

1 2421535 A lifting clamp for lifting sleepers.

The invention relates to a lifting clamp for lifting sleepers according to the introductory clause of claim 1.

According to US 5,125,345, a lifting clamp of this type is already known in which the contact parts of the vertically adjustable clamp parts, squeezable towards one another, are provided for application to the vertical side faces of the sleepers.

It is the object of the present invention to create a lifting clamp of the specified type with which bi-block sleepers, in particular, can be lifted without problems.

According to the invention, this object is achieved with a lifting clamp of the type mentioned at the beginning by means of the features cited in the characterizing clause of claim 1.

With a lifting clamp having a limiting stop designed in this way, it is now possible to simply and safely set the clamp down upon the bar of a biblock sleeper.

During this, the centering legs ensure that, when the clamp is lowered, there is an automatic and exact centering thereof with regard to the sleeper while, as a result of the limiting stop coming to rest on the bar, the correct vertical positioning of the clamp is provided automatically, before the latter is closed for lifting the sleeper. A particular advantage of the arrangement according to the invention also lies in the small number of individual parts and the structural robustness made possible thereby, as well as in the simplicity of operation.

With the further development according to claim 2, it is possible to securely grip a bi-block sleeper regardless of the particular orientation of the steel angle forming the bar, without necessitating a turning around of the clamp in the process. As a result of the feature according to claim 3, it is possible to reliably preclude an undesired twisting of the clamp arrangement with respect to the lifting drive.

Additional advantages and features of the invention become apparent from the

drawing and the description.

The invention will be described in more detail below with reference to embodiments represented in the drawing in which Fig. 1 shows a side view of a lifting clamp arrangement for lifting a sleeper, Fig. 2 shows an enlarged detail view in the longitudinal direction of the sleepers, according to arrow II in Fig. 1, of a lifting clamp according to the invention, and Fig. 3 shows a view of the lifting clamp in the transverse direction of the sleeper.

Depicted in Fig. 1 is a device 1 for lifting a sleeper 2. Said sleeper 2 designed in particular as a bi-bloclç sleeper - consists of two individual sleeper blocks 3 which are connected to one another by means of a bar 4 formed by a steel angle. The device 1 is composed of two lifting clamps 5 which are arranged spaced from one another with regard to the longitudinal direction of the sleeper 2 and are fastened to a machine frame 6 of a track maintenance machine (not shown). For joint operation, the two lifting clamps 5 are hydraulically coupled to one another.

As becomes clear also from Figs. 2 and 3, the lifting clamp 5 comprises a clamp carrier 7 which is fastened to the lower end of a piston rod 8 of a vertically oriented hydraulic lifting drive 9 and thus is vertically displaceable relative to the machine frame 6. Arranged on the clamp carrier 7 are two clamp parts 11 - each rotatable about a pivot axis 10 which in each case comprise a contact part 12, positioned underneath the pivot axis 10, for gripping the sleeper 2 or the bar 4 thereof, and which are squeezable toward one another by means of a drive 13.

The clamp carrier 7 comprises a limiting stop 14 which is arranged underneath the pivot axes 10 and between the same, and which is designed elongated in the direction of lower ends 16 of the two clamp parts 11 by means of two centering legs 15. In this, the two centering legs 15 are spaced from one another - as seen Perpendicularly to the pivot axes 10 by such a distance that there is adequate space between them for accommodating the bar 4 of the sleeper 2.

The distance between the two centering legs 15 is smaller than the distance of the contact parts 12 of the lifting clamp 5 to one another when the clamping parts 11 are in the opened position. Furthermore, lower ends 17 of the centering legs 15 are bevelled toward one another in such a way so as to improve a centering operation with regard to the bar 4.

As is visible particularly in Fig. 2, the two contact parts 12 are designed symmetrically, with regard to their surfaces 18 facing one another, and each comprise a V-shaped indentation 19. The latter is positioned in such a way that - after the lowering of the lifting clamp 5 until the limiting stop 14 touches the bar 4 - the indentation 19 comes to lie vertically exactly in the region of the corner of the steel angle of the bar 4. Additionally, two further indentations 20, spaced from one another in the vertical direction, may be provided at either side of the indentation 19, serving to receive the free ends of the steel angle of the bar 4.

Thus it is ensured that, after the closing of the lifting clamp 5 by means of the drive 13, the bar 4 - and thus the sleeper 2 - is fixed formfittingly in the clamp, so that the sleeper 2 is reliably prevented from slipping or falling out of the lifting clamp 5 during the lifting operation. Due to the symmetrical arrangement of the indentations 19, 20 on the two contact parts 12, the lifting clamp 5 may be employed independently of the orientation of the bar 4.

Additionally fastened to the clamp carrier 7 is a centering rod 21 extending parallel to a longitudinal axis 22 of the lifting drive 9. For vertically guiding the centering rod 21, a guide 23 is provided which is connected to the lifting drive 9.

Thus, a rotation of the piston rod 8 or of the lifting clamp 5 about the longitudinal axis 22 is precluded.

Claims

Claims 1. A lifting clamp for lifting sleepers (2), including two clamp

parts (11) squeezable towards one another by means of a drive (13) on a clamp carrier (7), with each clamp part (11) having a contact part (12), positioned underneath a pivot axis (10), for gripping the sleeper (2), wherein the clamp carrier (7) is vertically adjustable by means of a lifting drive (9), characterized in that the clamp carrier comprises a limiting stop (14), situated underneath the pivot axes (10) and between the same, which is elongated in the direction of lower ends (16) of the two clamp parts (11) by means of two centering legs (15) spaced from one another as viewed Perpendicularly to the pivot axes (10).
2. A lifting clamp according to claim 1, characterized in that each contact part (12) has a V-shaped indentation (19).
3. A lifting clamp according to claim 1 or 2, characterized in that a centering rod (21), extending parallel to a longitudinal axis of the lifting drive (9) and vertically adjustable in a guide (23) connected thereto, is fastened to the clamp carrier (7).
4. A lifting clamp according to claim 1, 2 or 3, characterized in that the distance between the two centering legs (15) is smaller than the distance of the contact parts (12) of the lifting clamp (5) to one another when the clamp parts (11) are in the open position.
5. A lifting clamp substantially as described with reference to, and as shown in, the accompanying drawings.