The invention relates to an electro-hydraulic device for moving a jib for a tower crane, in which device the motor of the hydraulic unit is switched off when the position of the jib is not altered for a predetermined time period.

A device for conveying thick matter including a thick matter pump; a feed line which leads away from the pump; a boom which receives the feed line and which includes at least one boom arm and which is arranged on a swivel bogie, wherein the swivel bogie is rotatable for angular orientation of the boom through a drive, in particular a hydraulic motor with a transmission arranged thereon, and a measuring device which includes rotation angle sensors for measuring the rotation angle of the swivel bogie, wherein the rotation angle of the swivel bogie is measured through direct measurement of a rotation angle of the drive or of the transmission arranged between the motor and swivel bogie.

A device for conveying thick matter including a thick matter pump; a feed line which leads away from the pump; a boom which receives the feed line and which includes at least one boom arm and which is arranged on a swivel bogie, wherein the swivel bogie is rotatable for angular orientation of the boom through a drive, in particular a hydraulic motor with a transmission arranged thereon, and a measuring device which includes rotation angle sensors for measuring the rotation angle of the swivel bogie, wherein the rotation angle of the swivel bogie is measured through direct measurement of a rotation angle of the drive or of the transmission arranged between the motor and swivel bogie.

Device and process for braking rotating and/or slewing gears of work machines comprising at least one dynamic service brake for decelerating a rotating and/or pivotal movement of the rotating and/or slewing gear, and at least one static holding brake (16), by means of which the rotating and/or slewing gear can be locked in one position, wherein at least one sensor (14) is assigned to the dynamic service brake (11a) and/or to the static holding brake (16), said sensor detecting the current movement of the rotating and/or slewing gear, and the sensor (14) being connected to a controller (13, 19) that detects an actuation of the dynamic service brake (11, 11a) said controller actuating the static holding brake (16) when in case of continued rotating and/or pivoting movement of the rotating and/or slewing gear when a dynamic service brake (11a) is still actuated.

Device and process for braking rotating and/or slewing gears of work machines comprising at least one dynamic service brake for decelerating a rotating and/or pivotal movement of the rotating and/or slewing gear, and at least one static holding brake (16), by means of which the rotating and/or slewing gear can be locked in one position, wherein at least one sensor (14) is assigned to the dynamic service brake (11a) and/or to the static holding brake (16), said sensor detecting the current movement of the rotating and/or slewing gear, and the sensor (14) being connected to a controller (13, 19) that detects an actuation of the dynamic service brake (11, 11a) said controller actuating the static holding brake (16) when in case of continued rotating and/or pivoting movement of the rotating and/or slewing gear when a dynamic service brake (11a) is still actuated.

A hydraulic circuit for use on a construction machine includes a first valve, a second valve, and at least a third valve. The second and third valve each includes at least one inlet port connected to a first outlet port of the first valve. The first outlet port of each of the second and third valves are configured to reduce a first pressure to a second pressure and/or a third pressure downstream of the second valve and the third valve, respectively. The second valve and the third valve also include at least a second outlet port connected to a reservoir tank. A hydraulic motor is connected to the first outlet port of the second valve, which operates the hydraulic motor in a first direction. The hydraulic motor also is connected to the first outlet port of the third valve, which operates the hydraulic motor in a second direction.

A hydraulic circuit for use on a construction machine includes a first valve, a second valve, and at least a third valve. The second and third valve each includes at least one inlet port connected to a first outlet port of the first valve. The first outlet port of each of the second and third valves are configured to reduce a first pressure to a second pressure and/or a third pressure downstream of the second valve and the third valve, respectively. The second valve and the third valve also include at least a second outlet port connected to a reservoir tank. A hydraulic motor is connected to the first outlet port of the second valve, which operates the hydraulic motor in a first direction. The hydraulic motor also is connected to the first outlet port of the third valve, which operates the hydraulic motor in a second direction.

A slewing control device is used for a crane that includes an upper slewing body, a lower travelling body, a slewing drive unit, and an attachment. A controller in the slewing control device enables the slewing drive unit to operate based on feedforward control to slew the upper slewing body at a target slewing speed. The controller generates a corrected command signal by correcting a reference command signal set in advance in response to a predetermined target slewing speed, based on information about a variation factor causing the slewing speed to vary. The controller inputs the corrected command signal to the slewing drive unit.

A slewing control device is used for a crane that includes an upper slewing body, a lower travelling body, a slewing drive unit, and an attachment. A controller in the slewing control device enables the slewing drive unit to operate based on feedforward control to slew the upper slewing body at a target slewing speed. The controller generates a corrected command signal by correcting a reference command signal set in advance in response to a predetermined target slewing speed, based on information about a variation factor causing the slewing speed to vary. The controller inputs the corrected command signal to the slewing drive unit.

Provides is a crane in which the manipulation according to an operator's intention is more easily performed. The crane includes a manipulating member capable of performing at least one of an accelerator manipulation for increasing or decreasing a rotational speed of an engine and a turning manipulation of a turning body. A predetermined operation is stopped in a case where an operator is not touching the manipulating member and the predetermined operation (turning operation, traveling operation, or the like) of the crane is performed.