GB2390842A

GB2390842A - Lifting device

Info

Publication number: GB2390842A
Application number: GB0216523A
Authority: GB
Inventors: Philip Charles Compton
Original assignee: Balfour Beatty PLC
Current assignee: Balfour Beatty PLC
Priority date: 2002-07-16
Filing date: 2002-07-16
Publication date: 2004-01-21
Also published as: GB0216523D0

Abstract

A device for lifting an elongate fixing element (20, fig 5) out of a support (16) has a leverage arm 30, a first support arrangement 40 at a first location along the arm defining a first pivot location for the arm and a second support arrangement 44 at a second location along the arm, further from the head than the first location, and defining a second pivot location for the arm. One of the first and second support arrangements can be selected such that the device has two modes of operation with different mechanical leverages. This device enables a two-stage removal process to be applied. In a first stage, a large initial lifting force can be applied and in a second stage a lower force is applied but over a greater length. The device can be used for lifting railway lock spikes from a rail fastening clamp.

Description

LIFTING DEVICE

This invention relates to a lifting device, particularly but not exclusively for lifting a lockspike which secures a rail fastening clamp to a railway sleeper.

s In conventional railway systems, the rails are secured to sleepers by fastening clips mounted on the sleepers. Typically, a shoulder is mounted onto the sleeper, and a clip part attaches to the shoulder and bears down upon the rail base.

10 The shoulders are attached to the sleepers by so-called "lockspikes", which are retaining pins driven through the sleeper and into the ballast beneath. A lockspike has two arms which are sprung apart, so that once inserted into place, the lockspike is very difficult to remove. This is essential as the rail is subjected to significant lifting forces during normal traffic flow.

The shoulders are therefore difficult to remove, as a result of the difficulty of removing the lockspikes.

According to the invention, there is provided a device for lifting an elongate fixing 20 element out of a support, comprising: a leverage artn having a handle portion at one end and a head for attachment to the fixing element at the other end; a first support arrangement at a first location along the arm defining a first pivot location for the arm; and 25 a second support arrangement at a second location along the arm, further from the head than the first location, and defining a second pivot location for the arm, wherein one of the first and second support arrangements can be selected such that the device has two modes of operation with different mechanical leverages.

30 This device enables a two-stage removal process to be applied. In a first stage, with a fulcrum near the head of the leverage arm, a large initial lifting force can be applied, to lift the fixing element a short way out of the support. In a second stage, with a fulcrum further from the head, a lower force is applied but over a greater length (for a given

( 2 movement of the handle portion) so that the fixing element can be fully removed from the support. The support may be a sleeper and the fixing element may be a lockspike of a rail clamp, but the device of the invention can be used for removing other fixing elements from their support (for example the ground).

The first support arrangement may provide a first contact portion (for contacting the support in which the fixing element is retained, i.e. the sleeper) and the second support arrangement may provide a second contact portion, the first contact portion being closer to the arm than the second contact portion. The first contact portion then 10 provides support for the leverage of the arm at a low position, so that the head can engage the fixing element in its fully inserted position. The second contact portion then provides support for the leverage of the arm at a higher position, so that the head can engage the fixing element after it has been partially lifted.

15 The second support arrangement preferably comprises a second support arm pivotally mounted to the leverage arm. This pivoting movement provides two advantages.

Firstly, the pivoting of the leverage arm is about this pivot point rather than about the point where the support arm contacts the fixing element support (for example. the sleeper). This means the support am, is less likely to slip. It also means the movement 20 of the head is closer to perpendicular to the leverage arm. Secondly, the pivotable connection of the second support arm means it can be pivoted out of the way when the I other support arrangement is to be used.

The first support arrangement may comprise a first support arm pivotally mounted to 25 the leverage arm. With the second support arm longer than the first support arm, the first contact portion (for contacting the sleeper) is made closer to the arm than the second contact portion.

By allowing the second support arm to be moved out of the way, the two arms can be 30 arranged in one plane on one side of the leverage ann. This means the two-stage lifting process can be performed without needed to change the orientation of the leverage arm.

( 3 The invention also provides a method of removing a lockspike which secures a rail fastening clamp to a sleeper of a railway track, the method comprising: attaching the head of a leverage arm to the top of the lockspike; levering the leverage arm about a first location to partially lift the lockspike 5 with a first mechanical advantage; levering the leverage arm about a second location further from the head than the first location, to further lift the lockspike with a second mechanical advantage less than the first mechanical advantage.

10 Preferably, levering the leverage arm about the second location comprises rotating a support arm into place to provide a support for the leverage arm, the support arm defining the pivot point for the leverage arm.

An example of the invention will now be described in detail with reference to the 15 accompanying drawings, in which: Figure] shows a known rail mounting system; Figure 2 shows a lockspike used to mount the shoulder in Figure I to the sleeper; Figure 3 shows in greater detail the shoulder in the system of Figure 1; 20 Figure 4 shows a device of the invention; Figure 5 shows the device of Figure 4 in a first mode of operation; and I Figure 6 shows the device of Figure 4 in a second mode of operation.

Figure I shows a conventional rail fastening system in which a rail 10 is mounted on 25 sleepers by a clip arrangement 14. The clip arrangement has a shoulder 1G attached to the sleeper 12 (on each side of the rail, although only one is shown in Figure 1) and a sprung clip 18 which bears down on the rail base.

The shoulder 16 is mounted to the sleeper with one or more pins 20, called lockspikes, 30 shown in Figure 2. These pass through the sleeper and into the ballast beneath. The lockspike has two arms 22 which are sprung apart, so that once inserted into place, the lockspike is very difficult to remove. The head of the lockspike has an opening 24. t

f 4 Figure 3 shows in greater detail the shoulder 16 and shows three openings 26 each for a respective lockspike.

The invention provides a device for removing the lockspikes, although there are many other possible applications for the device. The device is shown in Figure 4, and 5 comprises a leverage arm 30 having a handle portion 32 at one end and a head 34 at the other end for attachment to lockspike 20.

The device is used to lever the lockspike out of the ground, by pivoting the arm 30 about a point along its length. Thus, by pushing down on the handle portion 32, the 10 head is raised. The position of the fulcrum dictates the mechanical advantage of the lever. In accordance with the invention, a first support arrangement 36 is at a first location along the arm defining a first pivot location for the arm, and a second support 15 arrangement 38 is at a second location along the arm, further from the head 34 than the first location, and defines a second pivot location for the arm. Each support arrangement thus provides different leverage properties, and together they enable a two-stage removal process.

20 The first support arrangement 36 comprises a support arm 40 pivotably mounted to the leverage arm 30. The base of the arm 40 is for providing stationary contact with the sleeper, and the pivoting of the leverage arm 30 is then about the pivot 42. Similarly, the second support arrangement 38 comprises a support arm 44 pivotably mounted to the leverage arm 30, further away from the head 34. The base of the arm 44 is also for 25 providing stationary contact with the sleeper, and the pivoting of the leverage arm 30 is then about the pivot 46. The second support arm is longer than the first, so that support for the leverage of the arm is at a higher position.

The use of the device will now be explained with reference to Figures 5 and 6. 1 Figure 5 shows the initial lifting operation. In this mode, the second support arm 44 is pivoted out of the way, and the leverage arm 30 is pivoted about the pivot point 42.

The length of the support arm 40 is selected so that the head 34 can be engaged with

( 5 the top of the lockspike 20 with the handle 32 in a raised position. The head has an opening 50, and a pin can be pushed through the opening 50 and through the opening 24 in the top of the lockspike. The mechanical advantage is high, so that a high initial force can be applied to release the lockspike.

By allowing the second support arm 44 to be moved out of the way, the two arms can be arranged in one plane on one side of the leverage arm 30, so that no change in! orientation of the leverage arm is required. Once the lockspike has been lifted as far as possible using the first support arrangement, the second arm 44 is used, as shown in 10 Figure 6.! In this mode, the fulcrum is further from the head, so that a lower force is applied but over a greater length so that the fixing element can be fully removed from the support (i.e. the sleeper). The position of the second arm 44 along the leverage arm is selected 15 to provide sufficient movement to remove the lockspike. The length of the arm 44 is approximately equal to the length of the lockspike, and it is positioned such that the head can engage the lockspike when it has been removed as far as possible in the first stage with the handle 32 at a suitable height.

20 The leverage arm may be 1.5m to 3m in length and the two support arrangements may be within 50cm of the head 34.

Although both arms 40,44 are shown as pivoting, this is not essential. For example, the first arm 40 may be fixed, and the base of the aml may then be shaped to allow rocking 25 about the base of the arm 40, which then acts as the fulcrum. Pivoting is preferred because this puts the fulcrum in a better position for vertical lifting.

The main advantage of the second arm 44 pivoting is that it can be moved out of the way. However' it can be mounted on an opposite side of the arm 30, so that this is not 30 required. The arm would then need to be turned around between lifting phases, although a rotatable head would be an alternative to avoid the need to detach the device from the lockspike.

f 6 Other variations will be apparent to those skilled in the art.

Claims

( 7 CLAIMS

1. A device for lifting an elongate fixing element out of a support, comprising: 5 a leverage arm having a handle portion at one end and a head for attachment to the fixing element at the other end; a first support arrangement at a first location along the arm defining a first pivot location for the amp; and a second support arrangement at a second location along the aTrn, further from 10 the head than the first location, and defining a second pivot location for the arm, wherein one of the first and second support arrangements can be selected such that the device has two modes of operation with different mechanical leverages.

2. A device as claimed in claim 1, wherein the first support arrangement provides 15 a first contact portion and the second support arrangement provides a second contact portion, the first contact portion being closer to the arty than the second contact portion.

3. A device as claimed in any preceding claim, wherein the second support arrangement comprises a second support arm pivotally mounted to the leverage arm.

4. A device as claimed in claim 3, wherein the first support arrangement comprises a first support arm pivotally mounted to the leverage arm.

5. A device as claimed in claim 4, wherein the second support arm is longer than 25 the first support and.

6. A device as claimed in any preceding claim 4 or 5, wherein the support arms are arranged in one plane on one side of the leverage arm.

30

7. A device as claimed in any preceding claim, wherein the leverage arm is l to 3m long.

r

8 8. A device as claimed in claim 7, wherein the first and second locations are within SOcm of the head.

9. A method of removing a lockspike which secures a rail fastening clamp to a 5 sleeper of a railway track, the method comprising: attaching the head of a leverage am1 to the top of the lockspike; levering; the leverage arm about a first location to partially lift the lockspike with a first mechanical advantage; levering the leverage arm about a second location further from the head than the 10 first location, to further lift the lockspike with a second mechanical advantage less than the first mechanical advantage.

10. A method as claimed in claim 9, wherein levering the leverage arm about the second location comprises rotating a support arm into place to provide a support for the 15 leverage arm, the support arm defining the pivot point for the leverage arm.