Add-on device to be attached to a lifting vehicle, and method for actuating said add-on device

1. Attachment device ( 1 ), which is to be attached to a lifting vehicle, with a movable fork apparatus ( 2 ) comprising at least one fork ( 3 ), with at least two devices ( 4 ) for driving of a lateral movement of the fork apparatus ( 2 ), in particular each comprising at least one driving chain ( 6 ), in particular arranged for opposite movement, wherein the said driving chain is in particular associated with one fork ( 3 ) respectively, each with at least one oil motor ( 11 ), with which the device is to be driven, wherein for a lateral rectified movement of the forks ( 3 ) the oil motors ( 11 ) of two devices ( 4 ) can be arranged in a parallel connection and/or for a lateral oppositely directed adjustment of the forks ( 3 ) the oil motors ( 11 ) of two devices ( 4 ) can be arranged in a series connection; and

wherein characterized by that in series connection of the oil motors ( 11 ) a valve is provided for limiting the pressure built-up in the oil motors ( 11 ) arranged in particular in the lifting vehicle.

2. Attachment device according to claim 1 , characterized by that in parallel connections of the oils motors ( 11 ) an hydraulic end-switch for the oil motors is provided.

3. Attachment device according to claim 1 , characterized by that the device ( 4 ) has at least one tensioning device ( 5 ), comprising at least one hydraulic piston ( 8 ), which is acted on by oil of the oil motor ( 11 ), which is associated with the fork ( 3 ), through which the driving chain ( 6 ) is to be held at a predetermined tension, wherein in particular the device ( 4 ) is associated with a deflection roller ( 7 ), on which the driving chain ( 6 ) is deflected and which is stretched by the hydraulic piston ( 8 ).

4. Attachment device according to claim 1 , characterized by that the hydraulic piston is a plunger cylinder, wherein the tension of the device is to be held by pressure force of the plunger cylinder and/or the hydraulic piston is a differential cylinder, wherein the tension of the device is to be held by tensile force of the differential cylinder.

5. Attachment device according to claim 1 , characterized by that the pressure generated in the hydraulic piston ( 8 ) is held by a pressure-holding device, in particular a non-return valve.

6. Attachment device according to claim 1 , characterized by that a pre-tensioning valve is provided in front of at least one hydraulic piston ( 8 ) , wherein in particular the pre-loading valve is provided in combination with a non-return valve.

7. Attachment device according to claim 1 , characterized by that a pressure limiting valve is provided, via the oil from the hydraulic piston ( 8 ) can escape, in particular in the case of a damage.

8. Attachment device ( 1 ), which is to be attached to a lifting vehicle, with a movable fork apparatus ( 2 ) comprising at least one fork ( 3 ), with at least two devices ( 4 ) for driving of a lateral movement of the fork apparatus ( 2 ), in particular each comprising at least one driving chain ( 6 ), in particular arranged for opposite movement, wherein the said driving chain is in particular associated with one fork ( 3 ) respectively, each with at least one oil motor ( 11 ), with which the device is to be driven, wherein for a lateral rectified movement of the forks ( 3 ) the oil motors ( 11 ) of two devices ( 4 ) can be arranged in a parallel connection and/or for a lateral oppositely directed adjustment of the forks ( 3 ) the oil motors ( 11 ) of two devices ( 4 ) can be arranged in a series connection; and

characterized by that a longitudinal transport device for longitudinal transport of goods is provided arranged along at least one fork ( 3 ), wherein the longitudinal transport device in particular comprises a transport chain, wherein in particular a tensioning device ( 5 ) with a hydraulic piston ( 8 ) is provided for tensioning the transport chain actuated by the oil in the oil motor ( 11 ), wherein the longitudinal transport device, is in particular connectible by means of a solenoid valve.

9. Method for actuating an attachment device ( 1 ), which is to be attached to a lifting vehicle, with a movable fork apparatus ( 2 ) comprising at least two forks ( 3 ), with at least two devices ( 4 ) by which a lateral movement of the fork apparatus ( 2 ) is driven, in particular each comprising at least one driving chain ( 6 ), in particular arranged for opposite movement, wherein the said driving chain is in particular associated with one fork ( 3 ) respectively, each with at least one oil motor ( 11 ), with which the device is driven, wherein for a lateral rectified movement of the forks ( 3 ) the oil motors ( 11 ) of two devices ( 4 ) are arranged in a parallel connection and/or for a lateral oppositely directed adjustment of the forks ( 3 ) the oil motors ( 11 ) of two devices ( 4 ) are arranged in a series connection; and

characterized in that in series connection of the oil motors ( 11 ) a valve arranged in particular in the lifting vehicle limits the built-up pressure in the oil motors ( 11 ) and/or in a parallel connection of the oil motors ( 11 ) a hydraulic end switch respectively switches off the oil motors ( 11 ) in the end position.