GB2059335A

GB2059335A - Tractor-drawn baler

Info

Publication number: GB2059335A
Application number: GB8030360A
Authority: GB
Original assignee: Claas KGaA mbH
Current assignee: Claas KGaA mbH
Priority date: 1979-09-22
Filing date: 1980-09-19
Publication date: 1981-04-23
Also published as: GB2059335B; DE2938475A1; FR2465404B1; FR2465404A1; DE2938475C2

Abstract

A tractor-drawn baler with a bale ejecting belt 3 driven by a hydraulic motor 17 connected to a hydraulic pressure supply means, the belt being pivotable about a substantially vertical axis by means of a hydraulic piston- cylinder unit wherein the hydraulic piston cylinder unit 10, 11 is of dual-action construction in that a first hydraulic connection 15 of the hydraulic piston- cylinder unit 10, 11 communicates with a separate hydraulic pump 13 with a control valve 14 interposed, and a second connection 16 communicates with the pressure side of the hydraulic motor 17, and wherein the piston force of the side impinged on by the separate hydraulic pump 13 is arranged to be greater than that of the side impinged on by the hydraulic motor 17. Such an arrangement permits the belt to be positively held in a desired ejection direction. <IMAGE>

Description

SPECIFICATION Tractor-drawn baler The invention relates to a tractor-drawn baler (i.e. a baler designed to be drawn by a tractor) with a bale ejection belt driven by a hydraulic motor, the melt being pivotable about a substantially vertical axis by means of a hydraulic piston-cylinder unit.

In known balers with bale ejectors the harvester material from the pick-up means is fed to the compression passage. The material which is pressed and formed into bales in this passage is thrown by the bale ejector onto a transporting vehicle hitched onto the tractor. Bale throwing means with throwing buckets and belts are known, the latter being predominant. The fixing of the bale ejecting belts to the end of the compression passage is in most cases achieved by a construction pivotable about a vertical axis, so that the trailing vehicle can be loaded evenly. The pivoting movement itself is provided in most cases by single-action hydraulic pistoncylinder units with a return spring, controlled by a single-action control valve on the tractor.However, hydraulic adjusting mens of this type have the disadvantage that when the bale ejector has been pivoted into a desired position it cannot be stopped quite still in that position because of the return spring.

According to the invention, there is provided a tractor-drawn baler with a bale ejecting belt driven by a hydraulic motor connected to a hydraulic pressure supply means, the belt being pivotable about a substantially vertical axis by means of a hydraulic piston-cylinder unit, wherein the hydraulic piston-cylinder unit is of dual-action construction, in that a first hydraulic connection of the hydraulic piston-cylinder unit communicates with a separate hydraulic pump with a control valve interposed, and a second connection communicates with the pressure side of the hydraulic motor, and wherein the piston force of the side impinged on by the separate hydraulic pump is arranged to be greater than that of the side impinged on by the hydraulic motor.

The control valve is advantageously a singleaction control valve fitted between the separate hydraulic pump and the hydraulic piston-cylinder unit, to connect the first hydraulic connection either to a tank pipe or to the separate pump, depending on the position of the valve. Afurther preferred feature of the invention is that the hydraulic piston-cylinder unit is connected at one end to the ejection end of the baler and at the other end to a pivotable guide member, the bale ejecting belt being mounted on the latter.

A baler may thus be constructed so that the ejection belt may be securely arrested in any desired position.

An example of the invention will now be described in greater detail with reference to the accompanying diagrammatic drawing. In the drawing 1 is the rear end of an agricultural baler (not shown), from which the finished bales are fed through a guide member 2 to discharge (ejection) conveyor belts 3 fixed to the member 2. The guide member 2 has two cross bars 4 and 5 with holes extending right through them. Bolts 6 and 7, which engage in these holes, are fixed to brackets 8 and 9 carried by the baler rear end 1. The guide member 2, with the belts 3 fixed to it, is pivotable about the bolts 6 and 7 by means of a hydraulic piston-cylinder unit. The cylinder 10 of the unit is fixed to the baler rear end 1 and the piston rod 11 to plates 12 which are in turn welded to the cross bar 4.Forthis purpose a separate hydraulic pump 13 is provided, communicating with an oil connection 15 on the cylinder 10 by way of a single-action valve 14. The other oil connection 16 of the cylinder 10 communicates with the pressure side of a hydraulic motor 17, which drives the pair of conveyors 3 in known manner. The connections are chosen so that the force on the side of the piston impinged on by oil from the hydraulic motor is weaker than the force on the side of the piston impinged on oil from the hydraulic pump 17. The oil supplied from the motor 17 through the pipe 18 therefore constantly presses against the annular surface of the piston fixed to the rod 11, but cannot force it back so long as the valve 14 is in the neutral (closed) position.This forcing back happens only when the valve 14 is moved into a first position in which the pipe 19 communicates with the tank 21 via pipe 20. In this case the guide member 2 pivots in the direction of the arrow A together with the belts 3. If pivoting movement in the opposition direction is required, the valve 14 is switched over so that the pipe 19 is connected to the pump line 22. By virtue of the area ratios at the piston of the hydraulic piston-cylinder unit 10, 11 the oil in front of the annular surface of the piston is then forced back. As soon as the valve 14 is moved into the neutral position the piston and thus the guide member are stopped absolutely still in the chosen position.Obviously the oil motor 17 also communicates with a tank pipe 23 and a pressure pipe 24, and the latter communicates with the hydraulic means for discharging (centrifuging) the bales, but the discharging means is not connected to the separate oil pump except by the pipe 18.

The term 'belt' is used herein in a wide sense and includes chain and transverse slat conveyors and the like.

1. A tractor-drawn baler with a bale ejecting belt driven by a hydraulic motor connected to a hydraulic pressure supply means, the belt being pivotable about a substantially vertical axis by means of a hydraulic piston-cylinder unit, wherein the hydraulic piston-cylinder unit is of dual-action construction, in that a first hydraulic connection of the hydraulic piston-cylinder unit communicates with a separate hydraulic pump with a control valve interposed, and a second connection communicates with the pressure side of the hydraulic motor, and wherein the piston force of the side impinged on by the separate hydraulic pump is arranged to be greater than that of the side impinged on by the hydraulic motor.

2. A baler according to claim 1, wherein the control valve is arranged to connect the first hydraulic connection either to a tank pipe or to the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Tractor-drawn baler The invention relates to a tractor-drawn baler (i.e. a baler designed to be drawn by a tractor) with a bale ejection belt driven by a hydraulic motor, the melt being pivotable about a substantially vertical axis by means of a hydraulic piston-cylinder unit. In known balers with bale ejectors the harvester material from the pick-up means is fed to the compression passage. The material which is pressed and formed into bales in this passage is thrown by the bale ejector onto a transporting vehicle hitched onto the tractor. Bale throwing means with throwing buckets and belts are known, the latter being predominant. The fixing of the bale ejecting belts to the end of the compression passage is in most cases achieved by a construction pivotable about a vertical axis, so that the trailing vehicle can be loaded evenly. The pivoting movement itself is provided in most cases by single-action hydraulic pistoncylinder units with a return spring, controlled by a single-action control valve on the tractor.However, hydraulic adjusting mens of this type have the disadvantage that when the bale ejector has been pivoted into a desired position it cannot be stopped quite still in that position because of the return spring. According to the invention, there is provided a tractor-drawn baler with a bale ejecting belt driven by a hydraulic motor connected to a hydraulic pressure supply means, the belt being pivotable about a substantially vertical axis by means of a hydraulic piston-cylinder unit, wherein the hydraulic piston-cylinder unit is of dual-action construction, in that a first hydraulic connection of the hydraulic piston-cylinder unit communicates with a separate hydraulic pump with a control valve interposed, and a second connection communicates with the pressure side of the hydraulic motor, and wherein the piston force of the side impinged on by the separate hydraulic pump is arranged to be greater than that of the side impinged on by the hydraulic motor. The control valve is advantageously a singleaction control valve fitted between the separate hydraulic pump and the hydraulic piston-cylinder unit, to connect the first hydraulic connection either to a tank pipe or to the separate pump, depending on the position of the valve. Afurther preferred feature of the invention is that the hydraulic piston-cylinder unit is connected at one end to the ejection end of the baler and at the other end to a pivotable guide member, the bale ejecting belt being mounted on the latter. A baler may thus be constructed so that the ejection belt may be securely arrested in any desired position. An example of the invention will now be described in greater detail with reference to the accompanying diagrammatic drawing. In the drawing 1 is the rear end of an agricultural baler (not shown), from which the finished bales are fed through a guide member 2 to discharge (ejection) conveyor belts 3 fixed to the member 2. The guide member 2 has two cross bars 4 and 5 with holes extending right through them. Bolts 6 and 7, which engage in these holes, are fixed to brackets 8 and 9 carried by the baler rear end 1. The guide member 2, with the belts 3 fixed to it, is pivotable about the bolts 6 and 7 by means of a hydraulic piston-cylinder unit. The cylinder 10 of the unit is fixed to the baler rear end 1 and the piston rod 11 to plates 12 which are in turn welded to the cross bar 4.Forthis purpose a separate hydraulic pump 13 is provided, communicating with an oil connection 15 on the cylinder 10 by way of a single-action valve 14. The other oil connection 16 of the cylinder 10 communicates with the pressure side of a hydraulic motor 17, which drives the pair of conveyors 3 in known manner. The connections are chosen so that the force on the side of the piston impinged on by oil from the hydraulic motor is weaker than the force on the side of the piston impinged on oil from the hydraulic pump 17. The oil supplied from the motor 17 through the pipe 18 therefore constantly presses against the annular surface of the piston fixed to the rod 11, but cannot force it back so long as the valve 14 is in the neutral (closed) position.This forcing back happens only when the valve 14 is moved into a first position in which the pipe 19 communicates with the tank 21 via pipe 20. In this case the guide member 2 pivots in the direction of the arrow A together with the belts 3. If pivoting movement in the opposition direction is required, the valve 14 is switched over so that the pipe 19 is connected to the pump line 22. By virtue of the area ratios at the piston of the hydraulic piston-cylinder unit 10, 11 the oil in front of the annular surface of the piston is then forced back. As soon as the valve 14 is moved into the neutral position the piston and thus the guide member are stopped absolutely still in the chosen position.Obviously the oil motor 17 also communicates with a tank pipe 23 and a pressure pipe 24, and the latter communicates with the hydraulic means for discharging (centrifuging) the bales, but the discharging means is not connected to the separate oil pump except by the pipe 18. The term 'belt' is used herein in a wide sense and includes chain and transverse slat conveyors and the like. CLAIMS

2. A baler according to claim 1, wherein the control valve is arranged to connect the first hydraulic connection either to a tank pipe or to the separate pump depending on the position of the valve.

3. A baler according to claim 1 or 2, wherein the hydraulic piston cylinder unit is connected at one end to the ejection end of the baler and at the other end to a pivotable bale guide member, and wherein the bale ejecting belt is mounted on the bale guide member.

4. A baler substantially as hereinbefore described with reference to the accompanying draw ing.