The present invention relates to an inclination indicator for loading machines having gripping means which are adjust¬ able to an arbitrary angle of inclination in relation to a reference plane, for instance the fork on a fork truck. The purpose of this is to enable the driver of the loading machine to adjust the inclination of the gripping means to a position which is most suitable for gripping the goσds.

When loading piled goods as boards with a fork truck the fork is entered into spaces in the pile of goods. It is then important that the fork has the same inclination as Ijhe spaces, or otherwise the fork may damage the boards where it is entered.

When loading cylindrical objects as paper rolls with a clamping truck, the clamping means bearing on the cylind- rical surface of the roll, it is important that the contact of the clamping means with the roll is parallel to the axis of the roll. If the clamping occurs at an angle to the axis the roll is damaged by the shearing in the outer layers of the roll which is- caused when the roll during .the continued clamping movement strives to turn towards a position where the axis of the roll is parallel to the clamping contact line.

In both these cases there is a great risk of damaging the goods because the inclination of the clamping means can not be judged with sufficient accuracy from the driver's seat.

The present invention solves this problem by means of an inclination indicator, suitably of an electronic type, consisting of a sensor, for instance a potentiometer, which detects the angular position of the fork in relation to a reference plane, for instance the plane defined by the supporting surfaces of the wheels, and a pointer which shows the position detected by the sensor.

The invention is described more in particular in the following specification with appended drawings showing the following:

Fig. 1 shows a fork lift truck with a fork for piece goods or piled goods and an inclination indicator according to the invention.

Fig. 2 shows a clamping truck with clamping means for grip ping a paper roll or similar and an inclination indicator according to the invention. The figure shows the clamping means in their correct position.

Fig. 3 shows the same clamping truck as in Fig. 2 but with the clamping means in an incorrect position. The truck 10 shown i Fig. 1 is in a known way provided wit a fork 11 which is vertically adjustable on a lifting fram 12. The fork is placed at 90 angle to the frame. The fram can be inclined to different angles and in the figure an inclination forwards is marked x and an inclination rear- wards is marked y . The angles are related to the line 15 which is perpendicular to the plane 16 of the ground. When the lifting frame is inclined a certain angle forwards or rearwards the fork 11 is inclined by the same angle down¬ wards respectively upwards in relation to the plane 16 of the ground, the plane 16 thus being the reference plane fo the inclination of the fork.

The inclination of the frame and the fork is detected by the sensor 13 and registered on the pointer device 1 , so that the truck driver can adjust the fork to the desired position. The horizontal position is used when the fork is entered between the boards in a pile, an inclination upwar is used in order to prevent the goods from sliding off, an an inclination downwards is used for unloading.

Figs. 2 and 3 show another type of loading machine, a truc with a clamping device for gripping objects. In the illust rated case the clamping device has two clamping arms 20 adapted to grip on opposite sides of a paper roll 21 place with its axis vertically. Fig. 2 shows the clamping device adjusted to the correct angular position so that the clam- ping contact surfaces of the clamping arms are parallel to the axis of the paper roll and thus bear on the surface of the roll. Fig. 3 shove an incorrect angle of the gripping

device, which results in a point contact between the clamping surfaces and the paper roll, with subsequent damage on the roll at the contact points.

In the described examples it is assumed that the ground is the reference plane. In case the truck stands on a sloping ground the indicator will thus register the inclination in relation to the sloping plane. If instead it is desired to register a horzontal position independently of the possible inclination of the truck, this can be achieved by means of a plummet device to which the indicator is related.

In the examples described it is shown how the angular position of the gripping means is adjusted by changing the position of the lifting frame in relation to the truck. Naturally this adjustment can also be made by making the gripping means angularly adjustable in relation to the lifting frame.