GB2292366A

GB2292366A - Excavator and Safety Stop

Info

Publication number: GB2292366A
Application number: GB9416833A
Authority: GB
Inventors: Robert Wilson
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-08-19
Filing date: 1994-08-19
Publication date: 1996-02-21
Anticipated expiration: 2014-08-19
Also published as: GB2292366B; GB9416833D0

Abstract

All excavator of the type having a backhoe (1, Fig. 1) mounted between supporting telescopic legs (4), comprises a support (7) detachably mounted and extending rearwardly from, one of the legs and carrying a laterally adjustable stop member (13 - 16) arranged so that engagement of the boom with the stop member provides resistance to further movement of the boom and an audible warning to the operator of the excavator. The stop may have a further support arm (9) and a telescopic rest (11). The support (7) may carry a link (17, Fig. 3) to prevent the backhoe moving during transport. <IMAGE>

Description

EXCAVATOR AND SAFETY STOP THEREFOR Field of the Invention This invention relates to an excavator, and to a safety stop for an excavator.

Background to the Invention A typical excavator has a rear excavating boom and bucket, usually referred to as a "backhoe", used for trenching operations and the like. The boom can be rotated in a horizontal plane to permit excavated material to be dumped to one side of the vehicle, for example, and may also be arranged so that its mounting on the vehicle permits sliding of the backhoe transversely of the vehicle to permit variations in alignment of excavation without the need to reposition the whole vehicle.

Manoeuvring the boom and bucket is a skilled operation, because the hydraulic controls are designed to permit heavy loads to be lifted, rather than permitting fine precision of movement; the movements of the bucket tend to be rather jerky, especially when the components of the excavator have become worn with prolonged use. In many instances, the excavator will be used in relatively confined spaces where manual operations are carried out alongside, or where road traffic passes close to the excavation site, for example in roadworks. Sudden jerky movements of the boom and bucket in such circumstances can be dangerous. For example, when manual work is being carried on adjacent to the excavator, there is a risk of workers being struck and injured by the bucket.For this reason, it is necessary for some operations to wait until the excavator has completed its work, thus delaying the overall building work. Where the excavator is used in roadworks, the sudden movement of the bucket and boom in the direction of the traffic, even if it is unlikely to encroach on the traffic space, can cause motorists to swerve away from the perceived danger, and this can lead to accidents, especially in the confined space of a contraflow system. It therefore becomes necessary either to suspend the traffic flow while the excavations close to the carriageway are carried out, or to delay the roadworks while provision is made to divert the traffic away from proximity with the excavation site. In either case, the disruption caused can be costly.

It is difficult for the operator of the excavator to prevent the boom moving too far to the side of the machine in use.

Summary of the Invention According to the invention, there is provided an excavator of the type having a backhoe mounted between supporting telescopic legs, and a support detachably mounted on, and extending rearwardly from, one of the legs and carrying a laterally adjustable stop member arranged so that engagement of the boom with the stop member provides resistance to further movement of the boom and an audible warning to the operator of the excavator.

The support preferably comprises a pair of arms with vertically spaced mounting points on the leg, joining at or adjacent to the mounting for the adjustable stop member. The arms are suitably connected to mounting brackets on the leg by means of pins. Each of the legs may be provided with mounting brackets so that the support and stop member may readily be transferred from one side of the excavator to the other, according to the position in which it is to be used. In certain circumstances, it may be desirable for two stops, each with its associated support, to be mounted on the excavator at the same time, one on each side thereof.

In a preferred embodiment of the invention, the stop member also carries an electrical contact switch electrically connected to a visible and/or audible warning device in the operator's cab.

The support may comprise a third arm, pivotable at a position adjacent to the stop member and having the free end thereof arranged to be engageable with the ground to provide additional stability for the support. The third arm may be telescopically extendible, with a locking pin being passed through aligned holes in the telescoping sections to lock it at any particular extension. A fourth arm may extend generally horizontally from a position adjacent to the mounting for the stop member to the knuckle on the swivel for the boom used during transport of the excavator, for example when driving on the roads, to stabilise the boom.

The stop member may be adjustable by sliding relative to the support, with a pin to lock it in the desired position, or by being screw-threaded into the support.

The invention also provides a safety stop for an excavator, comprising a support detachably mountable on one of the rear telescopically-extensible legs of an excavator of the type having a backhoe, whereby the support extends rearwardly from the leg, and a laterally adjustable stop member mounted on the support and arranged so that engagement of the boom with the stop member provides resistance to further movement of the boom and an audible warning to the operator of the excavator, The safety stop is preferably capable of being dismantled for convenience of transport.

Brief Description of the Drawings In the drawings: Figure 1 is a side view of the rear part of an excavator of the type with which the invention is concerned, before installation of the safety stop; Figure 2 is a diagrammatic side elevation of the safety stop according to one embodiment of the invention, mounted on the telescopic supporting leg of the excavator; and Figure 3 is a diagrammatic top plan view of the rear part of an excavator with the safety stop installed.

Detailed Description of the Illustrated Embodiments Referring first to Figure 1, which shows the rear portion of a typical excavator before installation of the safety stop of the invention, the hydraulically operated backhoe comprises a boom 1 which can be extended outwardly from the excavator, elevated and lowered, and rotated or slewed in a horizontal plane to move the bucket 2 from side to side of the main body 3 of the excavator. In addition, the mounting for the boom is slidable laterally of the excavator body 3 to adjust alignment of excavation, for example. Hydraulically-operated telescopically-extensible legs 4 are driven downwards before digging begins, to stabilise the excavator.

As may be seen from Figure 2, each of the legs is provided, in accordance with the invention, with a vertically-spaced pair of mounting brackets 5, each consisting of two flanges with a hole 6 therethrough. A first arm 7, in the form of a steel tube with a spaced pair of tongues 8 extending from one end thereof; is connected to the upper mounting bracket 5a by a pin, which is retained in position by a spring clip or the like (not shown). A second arm 9, of similar construction, is connected to the lower bracket 5b by a second pin and clip arrangement. The first arm 7 has adjacent to its free end a bracket 10 to which is connected the other end of the second arm 9, again by means of a pin and clip. A third arm 11, having two telescoping parts, is also connected to the bracket 10 using the same pin.The third arm 11 extends downwardly and has at its free end a spike 12 which can be urged into the ground to afford additional stability to the assembly, and to ensure that, when the boom is operated close to the ground, it cannot pass inadvertently under the first arm and the stop.

The free end of the first arm 7 has a transverse short length of tube 13 welded thereto, inside which a second tube 14 is a sliding fit. The second tube has a steel disc 15 welded thereto to serve as a stop for the boom of the excavator. The tube 13 is provided with a hole through its walls, and the second tube 14 has a series of holes alignable with the hole in the outer tube 13. A pin 16 is passed through the holes to lock the second tube in its desired position so that the disc 15 is at the correct position to limit the movement of the boom according to the circumstances of use of the excavator.

The fourth arm 17 can be seen in Figure 3. This extends from a bracket 18 on the side of the first arm 7, again being fixed by a pin and clip, and has at its other end an eye 19 which can be located on the boss 20 provided on the centre yoke 21 of the excavator for locking the boom 1 (shown only partially and diagrammatically) against movement during transporting of the excavator, under its own power or otherwise.

This serves to ensure that the operator does not slide the yoke transversely and thus possibility of reach beyond the limits imposed by the stop.

In each case where a pin and clip arrangement is used to secure components together, it will be found convenient to secure the pin to one of the arms by a short chain to ensure that it is always available for use.

The broken lines in Figure 3 illustrate the extreme position of the boom, in which it engages the stop member 15, indicating by sound and visually to the operator that further movement in that direction is not permitted.

Claims

1. An excavator of the type having a backhoe mounted between supporting telescopic legs, comprising a support detachably mounted on, and extending rearwardly from, one of the legs and carrying a laterally adjustable stop member arranged so that engagement of the boom with the stop member provides resistance to further movement of the boom and an audible warning to the operator of the excavator.

2. An excavator according to Claim 1, wherein the support comprises a pair of arms with vertically spaced mounting points on the leg, joining at or adjacent to the mounting for the adjustable stop member.

3. An excavator according to Claim 2, wherein the arms are connected to mounting brackets on the leg by means of pins.

4. An excavator according to Claim 3, wherein each of the legs is provided with mounting brackets whereby the support and stop member may readily be transferred from one side of the excavator to the other.

5. An excavator according to any preceding claim, comprising two stop members, each with its associated support mounted on a respective one of the legs.

6. An excavator according to any preceding claim, wherein the stop member also carries an electrical contact switch electrically connected to a visible and/or audible warning device in the operator's cab.

7. An excavator according to any preceding claim, wherein the or each support comprises a third arm, pivotable at a position adjacent to the stop member and having the free end thereof arranged to be engageable with the ground to provide additional stability for the support.

8. An excavator according to Claim 7, wherein the third arm is telescopically extendible.

9. An excavator according to Claim 8, wherein the third arm is provided with a locking pin passed through aligned holes in the telescoping sections to lock it at any of a plurality of different extended lengths.

10. An excavator according to any preceding claim, comprising a fourth arm extending generally horizontally from a position adjacent to the mounting for the stop member to the knuckle on the swivel for the boom, for use during transport of the excavator to stabilise the boom.

11. An excavator according to any preceding claim, wherein the stop member is adjustable by sliding relative to the support.

12. An excavator according to Claim 11, wherein a pin is provided to lock the stop member in any desired position.

13. An excavator according to Claim 11, wherein the stop member is screwthreaded into the support.

14. An excavator, substantially as described with reference to, or as shown in, the drawings.

15. A safety stop for an excavator, comprising a support detachably mountable on one of the rear telescopically-extensible legs of an excavator of the type having a backhoe, whereby the support extends rearwardly from the leg, and a laterally adjustable stop member mounted on the support and arranged so that engagement of the boom with the stop member provides resistance to further movement of the boom and an audible warning to the operator of the excavator.

16. A safety stop for an excavator, substantially as described with reference to, or as shown in, the drawings.