Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
191 words
A driving unit for a feed pump, comprising a hydraulic cylinder including a piston separating said cylinder into a piston-sided chamber and a piston-rod-sided chamber, said piston alternatively performing an upstroke and a downstroke of the pump, a driven variable displacement pump, said pump including a pressure port and a suction port, said suction port being connected through a check valve to a reservoir, a first line, and a second line the improvement comprising directional control valve means for connecting said pressure port of said pump via said first line to said piston-rod-sided chamber to perform an upstroke and for connecting said piston-rod-sided chamber to said second line in which a relatively low pressure prevails to perform a downstroke including means connecting said second line to the suction port of said pump upon downstroke operation for flow through said pump from said suction port to said pressure port upon said downstroke operation to drive said pump to recover energy, said pump being adjusted in the same direction of adjustment for the upstroke as well as for the downstroke for flow therethrough in the same direction during both upstroke and downstroke operation.
Claim 2
Dependent Claim
191 words
A driving unit for a feed pump, comprising a hydraulic cylinder including a piston separating said cylinder into a piston-sided chamber and a piston-rod-sided chamber, said piston alternatively performing an upstroke and a downstroke of the pump, a driven variable displacement pump, said pump including a pressure port and a suction port, said suction port being connected through a check valve to a reservoir, a first line, and a second line the improvement comprising directional control valve means for connecting said pressure port of said pump via said first line to said piston-rod-sided chamber to perform an upstroke and for connecting said piston-rod-sided chamber to said second line in which a relatively low pressure prevails to perform a downstroke including means connecting said second line to the suction port of said pump upon downstroke operation for flow through said pump from said suction port to said pressure port upon said downstroke operation to drive said pump to recover energy, said pump being adjusted in the same direction of adjustment for the upstroke as well as for the downstroke for flow therethrough in the same direction during both upstroke and downstroke operation.
Claim 3
Dependent Claim
36 words
The driving unit of claim 1, comprising a hydraulic accumulator and a directional control valve for connecting the accumulator to the second line for the piston-up stroke and to the first line for the piston-down stroke.
Claim 4
Dependent Claim
21 words
The driving unit of claim 2, wherein said first line is connected to the reservoir through a piloted pressure relief valve.
Claim 5
Dependent Claim
23 words
The driving unit of claim 2, wherein a directional control valve is provided for connecting said cylinder and said accumulator to said pump.
Claim 6
Dependent Claim
22 words
The drive unit of claim 1, wherein the first line is connected to the reservoir for performing the downstroke of the piston.
Claim 7
Dependent Claim
21 words
The drive unit of claim 5, wherein said first line is connected to said reservoir through a piloted pressure relief valve.
Claim 8
Dependent Claim
56 words
The drive unit of claim 6, wherein a directional control valve is provided in both said first line between the pressure port of the pump and the cylinder chamber and the reservoir and wherein a further directional control valve is provided in said second line between the suction port of the pump and the cylinder chamber.