Hydraulic actuating device

A hydraulic actuating device for moving an object comprising:

• a reservoir for hydraulic fluid,
• a pump having at least one pressure port for delivering pressurized hydraulic fluid,
• a double-acting hydraulic actuator for moving the object, which actuator has an actuator housing with a space inside which a piston is moveable, which piston, in the said space, delimits a first working chamber and a second working chamber, the actuator furthermore having an object-coupling member, which is connected to the piston and is adapted to be coupled to the object, and for each of the first and second working chambers an associated first and second connection respectively for supplying and discharging hydraulic fluid,
• a throttling assembly which is in communication with the first connection of the hydraulic actuator, which throttling assembly is adapted to provide, for hydraulic fluid passing through the first connection, either a controllable throttling opening or a clear passage opening which is larger than the throttling opening,
• wherein the throttling assembly comprises a pressure-detection means for detecting a second working chamber hydraulic pressure in the second working chamber, and wherein a predetermined switching pressure corresponding to a force on the piston indicating a final part of a movement of the piston is associated with said throttling assembly, and wherein the throttling assembly is designed such that—when pressurized hydraulic fluid is being supplied to the said second working chamber—the throttling assembly provides for hydraulic fluid passing through the clear passage opening if the detected second working chamber hydraulic pressure is above the predetermined switching pressure and provides the throttling opening if the detected second working chamber hydraulic pressure is below the predetermined switching pressure,
• and wherein the throttling assembly has a housing with a first passage, which is in communication with the first connection, in which an associated controllable throttling member is provided at the first passage, and in which the controllable throttling member is operatively coupled to the pressure-detection means, so that the first passage has an effective opening corresponding to the clear passage opening if the detected second working chamber hydraulic pressure is above the predetermined switching pressure, and the first passage has an effective opening corresponding to the throttling opening with a controllable dimension if the detected second working chamber hydraulic pressure is below the switching pressure, and in which the throttling assembly comprises a main bore, in which a throttling piston, which is operatively coupled to the pressure-detection means, is moveable to and fro, which throttling piston, depending on its position, delimits the clear passage opening or the throttling opening, and in which the main bore, on one side of the throttling piston, is connected to the first working chamber, and in which on another side of the throttling piston at least one side port is connected to the main bore, and in which the first passage also extends through the throttling piston, in such a manner that the first passage extends through the side port and the throttling piston and in such a manner that the throttling piston can be displaced under the influence of the flow of fluid through the throttling piston.

A hydraulic actuating device for moving an object comprising:

• a reservoir for hydraulic fluid,
• a pump having at least one pressure port for delivering pressurized hydraulic fluid,
• a double-acting hydraulic actuator for moving the object, which actuator has an actuator housing with a space inside which a piston is moveable, which piston, in the said space, delimits a first working chamber and a second working chamber, the actuator furthermore having an object-coupling member, which is connected to the piston and is adapted to be coupled to the object, and for each of the first and second working chambers an associated first and second connection respectively for supplying and discharging hydraulic fluid,
• a throttling assembly which is in communication with the first connection of the hydraulic actuator, which throttling assembly is adapted to provide, for hydraulic fluid passing through the first connection, either a controllable throttling opening or a clear passage opening which is larger than the throttling opening,
• wherein the throttling assembly comprises a pressure-detection means for detecting a second working chamber hydraulic pressure in the second working chamber, and wherein a predetermined switching pressure corresponding to a force on the piston indicating a final part of a movement of the piston is associated with said throttling assembly, and wherein the throttling assembly is designed such that—when pressurized hydraulic fluid is being supplied to the said second working chamber—the throttling assembly provides for hydraulic fluid passing through the clear passage opening if the detected second working chamber hydraulic pressure is above the predetermined switching pressure and provides the throttling opening if the detected second working chamber hydraulic pressure is below the predetermined switching pressure,
• and wherein the pressure-detection means comprises a control piston, which is moveable in an associated bore in a housing of the throttling assembly, which bore is in communication with the second working chamber, so that the control piston is subjected to load by the second working chamber hydraulic pressure in the said second working chamber, in which the throttling assembly has a housing with a first passage, which is in communication with the first connection, in which an associated controllable throttling member is provided at the first passage, and in which the controllable throttling member is operatively coupled to the pressure-detection means, so that the first passage has an effective opening corresponding to the clear passage opening if the detected second working chamber hydraulic pressure is above the predetermined switching pressure, and the first passage has an effective opening corresponding to the throttling opening with a controllable dimension if the detected second working chamber hydraulic pressure is below the switching pressure, and in which the throttling assembly comprises a main bore, in which a throttling piston, which is operatively coupled to the pressure-detection means, is moveable to and fro, which throttling piston, depending on its position, delimits the clear passage opening or the throttling opening, and in which the control piston and the throttling piston are in line with one another, and in which a spring is disposed between the throttling piston and the control piston.

A hydraulic actuating device for moving an object comprising:

• a reservoir for hydraulic fluid,
• a pump having at least one pressure port for delivering pressurized hydraulic fluid,
• a double-acting hydraulic actuator for moving the object, which actuator has an actuator housing with a space inside which a piston is moveable, which piston, in the said space, delimits a first working chamber and a second working chamber, the actuator furthermore having an object-coupling member, which is connected to the piston and is adapted to be coupled to the object, and for each of the first and second working chambers an associated first and second connection respectively for supplying and discharging hydraulic fluid,
• a throttling assembly which is in communication with the first connection of the hydraulic actuator, which throttling assembly is adapted to provide, for hydraulic fluid passing through the first connection, either a controllable throttling opening or a clear passage opening which is larger than the throttling opening,
• wherein the throttling assembly comprises a pressure-detection means for detecting a second working chamber hydraulic pressure in the second working chamber, and wherein a predetermined switching pressure corresponding to a force on the piston indicating a final part of a movement of the piston is associated with said throttling assembly, and wherein the throttling assembly is designed such that—when pressurized hydraulic fluid is being supplied to the said second working chamber—the throttling assembly provides for hydraulic fluid passing through the clear passage opening if the detected second working chamber hydraulic pressure is above the predetermined switching pressure and provides the throttling opening if the detected second working chamber hydraulic pressure is below the predetermined switching pressure,
• and wherein the pressure-detection means comprises a control piston, which is moveable in an associated bore in a housing of the throttling assembly, which bore is in communication with the second working chamber, so that the control piston is subjected to load by the second working chamber hydraulic pressure in said second working chamber, in which the throttling assembly has a housing with a first passage, which is in communication with the first connection, in which an associated controllable throttling member is provided at the first passage, and in which the controllable throttling member is operatively coupled to the pressure-detection means, so that the first passage has an effective opening corresponding to the clear passage opening if the detected second working chamber hydraulic pressure is above the predetermined switching pressure, and the first passage has an effective opening corresponding to the throttling opening with a controllable dimension if the detected second working chamber hydraulic pressure is below the switching pressure, and in which the throttling assembly comprises a main bore, in which a throttling piston, which is operatively coupled to the pressure-detection means, is moveable to and fro, which throttling piston, depending on its position, delimits the clear passage opening or the throttling opening, and in which the control piston and the throttling piston are in line with one another, and in which a spring is disposed between the throttling piston and the control piston, and in which the throttling piston has an open cavity, into which the spring fits, on one side of the control piston.

A hydraulic actuating device for moving an object comprising:

• a reservoir for hydraulic fluid,
• a pump having at least one pressure port for delivering pressurized hydraulic fluid,
• a double-acting hydraulic actuator for moving the object, which actuator has an actuator housing with a space inside which a piston is moveable, which piston, in the said space, delimits a first working chamber and a second working chamber, the actuator furthermore having an object-coupling member, which is connected to the piston and is adapted to be coupled to the object, and for each of the first and second working chambers an associated first and second connection respectively for supplying and discharging hydraulic fluid,
• a throttling assembly which is in communication with the first connection of the hydraulic actuator, which throttling assembly is adapted to provide, for hydraulic fluid passing through the first connection, either a controllable throttling opening or a clear passage opening which is larger than the throttling opening,
• wherein the throttling assembly comprises a pressure-detection means for detecting a second working chamber hydraulic pressure in the second working chamber, and wherein a predetermined switching pressure corresponding to a force on the piston indicating a final part of a movement of the piston is associated with said throttling assembly, and wherein the throttling assembly is designed such that—when pressurized hydraulic fluid is being supplied to the said second working chamber—the throttling assembly provides for hydraulic fluid passing through the clear passage opening if the detected second working chamber hydraulic pressure is above the predetermined switching pressure and provides the throttling opening if the detected second working chamber hydraulic pressure is below the predetermined switching pressure,
• and wherein the pressure-detection means comprises a control piston, which is moveable in an associated bore in a housing of the throttling assembly, which bore is in communication with the second working chamber, so that the control piston is subjected to load by the second working chamber hydraulic pressure in the said second working chamber, in which the throttling assembly has a housing with a first passage, which is in communication with the first connection, in which an associated controllable throttling member is provided a the first passage, and in which the controllable throttling member is operatively coupled to the pressure-detection means, so that the first passage has an effective opening corresponding to the clear passage opening if the detected second working chamber hydraulic pressure is above the predetermined switching pressure, and the first passage has an effective opening corresponding to the throttling opening with a controllable dimension if the detected second working chamber hydraulic pressure is below the switching pressure, and in which the throttling assembly comprises a main bore, in which a throttling piston, which is operatively coupled to the pressure-detection means, is moveable to and fro, which throttling piston, depending on it s position, delimits the clear passage opening or the throttling opening, and in which the control piston and the throttling piston are in line with one another, and in which a spring is disposed between the throttling piston and the control piston, and in which the throttling piston has an open cavity, into which the spring fits, on one side of the control piston, and in which the throttling piston has a stop for the control piston.