GB2294245A

GB2294245A - Tilt triggered driver restraint for an industrial truck.

Info

Publication number: GB2294245A
Application number: GB9521389A
Authority: GB
Inventors: Theodor Abels
Original assignee: Linde GmbH
Current assignee: Linde GmbH
Priority date: 1994-10-20
Filing date: 1995-10-18
Publication date: 1996-04-24
Anticipated expiration: 2015-10-18
Also published as: GB9521389D0; GB2294245B

Abstract

A restraint device to prevent the driver falling from a toppling industrial truck with a partially open driver's cab, the device comprising at least one displaceable and/or pivotable arm which, in the retracted position, is behind the driver in the area of the backrest (4) of the driver's seat and closes from the rear around the torso (2) of the driver. A device detecting tipping of the truck is connected to a tripping device (3) moving at least one restraint means out of a retracted position into a restraining position and locking it there. A pre-loaded spring is provided for movement of the restraint means from the retracted position into the restraining position. The restraint means is locked in its restraining position by means of a ratchet construction. In another embodiment (Fig. 8) the restraint means exhibits a moving belt ring (11) which is secured to belts (13) which can be wound up and are attached to the pillars of the cab. The driver need not strap himself into the seat and may therefore leave and return to the vehicle easily. … <IMAGE> …

Description

1 2294245 DRIVER RESTRAINT DEVICE FOR AN INDUSTRIAL TRUCK The present

invention concerns driver safety devices, and particularly concerns restraint devices for the drivers of industrial trucks whose driver's cabs are at least partially open.

Industrial trucks such as fork-lift trucks for example are mainly manufactured and operated with at least partially open driver's cabs. Closed driver's cabs are firstly unnecessary when the industrial trucks are used predominantly under cover in at least partially enclosed buildings, and secondly undesirable since they hinder access to and egress from the driving position and can impair the driver's field of view.

However, in the case of industrial trucks with at least partially open driver's cabs there is the problem that 9 the industrial truck tips sideways, the driver can fall out of the cab and be trapped between parts of the truck body, in particular the driver-protecting roof, and the ground. Quite often, accidents of this kind prove to be serious or even fatal for the driver. The most important factors which can lead to tipping of the industrial truck are cornering too rapidly, failure to lower the load when driving, and driving over or into obstructions.

Known driver restraint devices are at least partially suitable for preventing the driver failing out of the driver's cab if the industrial truck tips over. These driver restraint devices consist of a combination of a safety belt with fixed restraint arms disposed on both sides of the driver.

However, in practical use, this embodiment of a driver restraint system has serious drawbacks. The safety belt is an impediment to the driver when getting on and off the truck, so that often the belt is not worn and hence the protective effect of the restraint device is eliminated. In addition, the fixed restraint arms restrict the freedom of movement of the driver, e.g. freedom to turn round when reversing, and also lead to a reduction in the driver's field of view.

The underlying object of the present invention is to provide a driver restraint device which prevents the driver from failing out of the driver's cab if the industrial truck tips over, but does not impede him while working and does not restrict the driver's field of view.

2 According to the invention this object is achieved in that a measuring device detecting tipping of the industrial truck is in operative connection with a tripping device moving at least one restraint means out of a retracted position into a restraining position and locking it there.

During normal operation of the industrial truck the restraint means is in a retracted position in which it does not impede the driver in any way. After the measuring device detects tipping of the industrial truck and signals this to the tripping device, the restraint means is moved into its restraining position and locked there, to prevent the driver from failing out of the driver's cab.

One advantageous embodiment of the driver restraint device is characterised in that the restraint means comprises at least one displaceable andlor pivotable arm.

In one particularly advantageous arrangement of a driver restraint device, the restraint means is disposed behind the driver in the area of the backrest of the driver's seat in its retracted position, and closes from the rear around the torso of the driver R the industrial truck tips over. Therefore, it is possible for the driver to get on and off unhindered by the restraint means in its retracted position.

In one expedient arrangement the restraint means is secured to the driver's seat, preferably to the backrest of the driver's seat.

In a further expedient embodiment, the restraint means is disposed by the side of the driver's seat cushion in its retracted position, and essentially closes from the side around the torso of the driver if the industrial truck tips over. Here, the driver restraint device is expediently designed so that if the industrial truck tips over, the restraint means is initially moved away from the driver's seat in a sideways direction, then moved upwards and then closes from the side around the torso of the driver. This arrangement ensures that the driver is not hindered when getting on and off the truck, and that the restraint means is brought into the restraining position with a short pivoting movement in the event of the truck tipping over.

3 In order to define the pivoting movement of the restraint means precisely, it is advantageous if at least one slide guiding the movement of the restraint means is present. Advantageously the tripping device is disposed in the area of the backrest of the driver's seat.

A further advantageous embodiment of the invention is characterised in that the retracted position the restraint means is disposed by the side of the driver's seat cushion, and is pivoted upwardly about a substantially horizontal pivot axis K the industrial truck tips over. Here, the pivoting movement of the restraint means can be guided by simple design measures.

In one advantageous development, the pivot axis of the restraint means is disposed essentially horizontally and extends in the longitudinal direction of the driver's seat. With this arrangement of the pivot axis, in the retracted position the restraint means is located beside the seat cushion of the driver's seat so that the driver is not hindered when getting on and off.

Expediently, in the restraining position the restraint means is disposed in the area of the pelvis of the driver. Here, the centre of gravity of the body of the driver is located in the area of the restraint means so that the driver is unlikely to topple out over the restraint means.

It is particularly advantageous if the restraint means is formed such that the driver is restrained on the driver's seat both in the lateral direction and in the forward direction. Thus, the driver restraint device acts in the lateral and in the frontal direction if the industrial truck tips over.

One advantageous embodiment is characterised in th ' at for movement of the restraint means from the retracted position into the restraining position, at least one pre-loaded spring is provided, containd in the tripping device.

A particularly simple embodiment of the driver restraint device is one in which access to the driver's cab is from one side only. In such a case, a fixed restraint means is provided on the side opposite the cab access and on the cab access side the restraint means is disposed so as to 4 be moveable from a retracted position into the restraining position. Since the driver always gets on and off the industrial truck on the same side, that the driver is not impeded by a restraint means disposed rigidly on the other side. Where access to the cab is afforded from both sides, the restraint means on both sides of the seat are disposed so as to be moveable from a retracted position into the restraining position.

Expediently for locking the restraint means in the restraining position at least one ratchet construction is provided, contained in the tripping device.

A further expedient embodiment of a driver restraint device according to the invention is characterised in that the restraint means exhibits at least one moving belt ring.

Here, advantageously, in the retracted position the restraint means is disposed above the driver in the area of the roof of the driver's cab.

Advantageously, the driver restraint device can be formed so that for movement of the restraint means from the retracted position into the restraining position at least two beft reels are provided, contained in the tripping device, which wind up automatically and lock in the opposite direction and to which the restraint means is secured with the belts which can be wound up.

Moreover, it is advantageous if belt guides are provided as part of the tripping device, which belt guides are releasable electrically and release the belts holding the restraint means K the industrial truck tips over. When the belts are released, they are wound up by the automatically winding beft reels and thus the restraint means is drawn into its restraining position and locked there.

One particularly advantageous driver restraint device ccording to the invention can be formed so that a switch in operative connedon with the tripping device is provided for releasing the lock of the restraint means in the restraining position.

As a further embodiment, it is possible for a net to be provided as the restraint means.

Another advantageous embodiment is characterised in that the measuring device is embodied as an electrical sensor detecting the angle of inclination about a vehicle longitudinal axis and/or the angle of inclination about a vehicle transverse axis and/or the transverse acceleration of the industrial truck.

It is particularly advantageous if the measuring device is disposed in the area of the driver's seat. Thus, the driver restraint device constitutes a compact unit which can be fitted as an addition to existing seats.

Further advantages and features of the invention are described in greater detail with reference to the exemplary embodiments shown diagrammatically in the accompanying drawings, in which:

Figure 1 shows a side view of a driver's cab with two arms as restraint means.

Figure 2 shows a plan view of a driver's seat with two arms as restraint means.

Figure 3 shows a side view of a tripping device for an arm.

Figure 4 shows a plan view of an arm in the retracted position behind the driver's seat.

Figure 5 shows a side view of a driver restraint device with side arms.

Figure 6 shows a driver restraint device with pivotable arms.

Figure 7 shows a driver restraint device with one rigid and one pivotable arm.

Figure 8 shows a driver's cab with a belt ring as the restraint means.

Referring now to the drawings, Figure 1 shows a side view of the laterally open driver's cab of an industrial truck. The driver sits on a seat and leans against a backrest 4. A restraint means has two arms 1 which, in the restraining position, extend to the left and right bout the torso 2 of the driver. The arms 1 are secured to the backrest 4 of the driver's seat by means of the tripping device 3.

6 Figure 2 shows a plan view of the driver's seat of an industrial truck, wherein the restraint means embodied as arms 1 grip around the torso 2 of the driver. In the process, the tripping device 3 secured to the backrest 4 presses the arms 1 against the torso 2 of the driver. In addition, an arm mounting 10 is shown in which the arms 1 are located in their retracted position. The arms remain in the retracted position behind the backrest 4 of the drivers seat until the tripping mechanism is activated. The arms then move first laterally outwards, and then pivot about substantially vertical axes at the sides of the backrest 4 into the restraining position wherein the arms 1 grip the torso 2 of the driver.

Figure 3 is a side view of a tripping device 3 of one of the arms 1, showing the mounting 5 of a helical spring, an electrical trip 6, a ratchet construction 7 for locking the arm in the restraining position, and a switch 8 for releasing the lock.

Figure 4 shows a plan view of an arm 1 with the tripping device 3 in its retracted position. The spring 9 is a band of resilient material, preferably spring steel, which in its unstressed condition forms a tight roll about a vertical spindle. The spring 9 is pre-loaded by straightening it out as the arm 1 is slid through a pivoting bearer to place the arm 1 in the retracted position. A detent holds the arm in the retracted position, and is releasable by an electrical signal.

When the detent is released, the arm 1 slides through the bearer to an intermediate position in which it extends laterally outward from the seat back 4. The arm 1 then swings forward about the spindle axis to embrace the torso 2 of the driver. Alternatively, the sliding and swinging movements may occur simultaneously. An inclinometer or an accelerometer provides the signal to release the detent when tipping of the truck is detected.

Figure 5 shows a side view of an alternative driver restraint device with lateral arms, showing the arms 1 is in the restraining position in solid lines. The retracted position 16 of the arms 1 is shown by the chain lines, the arms moving from the retracted to the restraining position by pivoting about a generally transverse horizontal axis. If the industrial truck tips over, the arms are moved into the restraining 7 position by the tripping device 3, the movement being guided by the slide 17.

Figures 6 and 7 show a driver restraint device with one fixed arm 19 and one pivotable arm 1. The restraining position of the arm 1 is shown in chain lines. The pivot axis 18 of the arm 1 is oriented in the longitudinal direction of the vehicle and disposed essentially horizontally alongside the seat cushion of the driver's seat.

The pivotable arm 1, in its retracted position, extends down from the pivot axis 18 and forward below the driver's seat. A detent holds the arm 1 in this position against the force of a spring or the like which urges the arm to pivot upwardly about the pivot axis 18 into a restraining position in which the arm 1 extends forwardly from the seat back 4 alongside the driver's torso 2. The front ends of the arms 1 and 19 are turned inwardly, to prevent the driver from moving forward off the seat.

An inclinometer or accelerometer, or other device for detecting tipping of the truck, is operatively connected to the detent so as to release the detent 9 the truck tips. the arm 1 then pivots upwards into the restraining position. The two arms 19 and 1 are shaped so that the driver cannot move sideways or forwards away from the driver's seat.

Figure 8 shows a third alternative embodiment of the present invention. In this embodiment, the driver's cab is fitted with a belt loop 11 as the restraint means. In the retracted position, the belt loop 11 is held adjacent the roof 12 of the driver's cab, as shown by the dashed line. The belt loop 11 is secured to tour belts 13 which can be wound up onto belt reels 14. In the retracted position the belts 13 are held with electrically releasable belt guides 15 mounted at roof height. A tipping detector controls the belt guides 15, causing them to release the belts 13 if the truck tips. Belts 13 are then wound onto belt reels 13, the tension in the belts 13 holding the belt loop 11 open. The belt loop 11 fails down over the driver's head to extend round th upper body of the driver, and ratchet means in the belt reels prevent the belts 13 from unrolling. The driver is thus secured against lateral and forward movement. Although four belts 13 are shown, it is foreseen that three retractable belts may be used, or a combination of one or more fixed and one or more retractable belts may be used, provided that the loop is held open so as to pass over the driver's head.

8

Claims

1. A driver restraint device for an industrial truck with an at least partially open driver's cab having a driver's seat therein, the restraint means being movable between a retracted position and a restraining position, in which it acts to prevent movement of the driver's body relative to the seat, a measuring device detecting tipping of the industrial truck being in operative connection with a tripping device capable of moving the restraint means out of its retracted position into the restraining position and locking it therein.

2. A driver restraint device according to claim 1, wherein the restraint means comprises at least one displaceable arm.

3. A driver restraint device according to claim 2, wherein the displaceable arm is pivotable.

4. A driver restraint device according to one of claims 1, 2 or 3, wherein in the retracted position the restraint means is disposed behind the driver in the area of the backrest of the driver's seat and closes from the rear around the torso of the driver if the industrial truck tips over.

5. A driver restraint device according to one of claims 1 to 4, wherein the restraint means is secured to the driver's seat, preferably to the backrest of the driver's seat.

6. A driver restraint device according to claim 5, wherein the restraint means is secured to the backrest of the driver's seat.

7. A driver restraint device according to one of claims 1, 2 or 3, wherein in the retracted position the restraint means is disposed beside the driver's seat cushion and closes around the torso of the driver from the side if the industrial truck tips over.

8. A driver restraint device according to claim 7, wherein the restraint means is initially moved away from the driver's seat in a sideways direction and then closes around the torso of the driver essentially from the side.

9 9. A driver restraint device according to one of claims 1 to 8, wherein at least one slide guiding the movement of the restraint means is provided.

10. A driver restraint device according to one of claims 1, 2 or 3, wherein in the retracted position the restraint means is disposed beside the driver's seat cushion and is pivoted upwardly about a generally horizontal pivot axis.

11. A driver restraint device according to claim 10, wherein the pivot axis of the restraint means is essentially oriented in the longitudinal direction of the driver's seat.

12. A driver restraint device according to one of claims 1 to 11, wherein in the restraining position the restraint means is disposed in the area of the pelvis of the driver when in the restraining position.

13. A driver restraint device according to one of claims 1 to 12, wherein the restraint means is formed such that the driver is restrained on the driver's seat both in the lateral direction and in the frontal direction.

14. A driver restraint device according to one of claims 1 to 13, wherein the tripping device is disposed in the area of the backrest of the driver's seat.

15. A driver restraint device according to one of claims 1 to 14, wherein for movement of the restraint means from the retracted position into the restraining position at least one pre-loaded spring is provided, contained in the tripping device.

16. A driver restraint device according to one of claims 1 to 15, wherein for locking the restraint means in the restraining position at least one ratchet construction is provided, contained in the tripping device.

17. A driver restraint device according to one of claims 1 to 16, wherein a first restraint means is provided on the left-hand side of the driver's seat and a second restraint means is provided on the right-hand side of the driver's seat, one of the restraint means being secured rigidly in the restraining position and the other restraint means being moveable from a retracted position into the restraining position.

18. A driver restraint device according to claim 1, wherein the restraint means exhibits at least one moving beft loop.

19. A driver restraint device according to claim 18, wherein in the retracted position the beft loop is disposed above the driver in the area of the roof of the driver's cab.

20. A driver restraint device according to claim 18 or claim 19, wherein movement of the restraint means from the retracted position into the restraining position is achieved by at least two beft reels, constituting the tripping device, which wind up automatically and include ratchet means to prevent unwinding, the restraint means being secured to the belts.

21. A driver restraint device according to claim 19, wherein beft guides are provided as part of the tripping device, which beft guides are releasable electrically and release the belts holding the restraint means if the industrial truck tips over.

22. A driver restraint device according to one of claims 1 to 21, wherein a switch in operative connection with the tripping device is provided for releasing the lock of the restraint means in the restraining position.

23. A driver restraint device according to claim 1, wherein a net is provided as the restraint means.

24. A driver restraint device according to one of claims 1 to 23, wherein the measuring device is embodied as an electrical sensor detecting the angle of inclination about a vehicle longitudinal axis and/or the angle of inclination about a vehicle transverse axis and/or the transverse acceleration of the industrial truck.

25. A driver restraint device according to one of claims 1 to 24, wherein the measuring device is disposed in the area of the driver's seat.

26. A driver restraint device substantially as described herein with reference to Figures 1 to 4, Figure 5, Figures 6 and 7, or Figure 8 of the accompanying drawings.