Clamp device and a mobile lift system with the clamp device

Abstract

A clamp device for a mobile lift system and a mobile lift system is provided, where the clamp device has a supporting part and two gripper arms movably connected to the supporting part. An actuating system is arranged on the supporting part, where an actuator is connected to each of the gripper arms. The actuators functions as a main cylinder and a slave cylinder respectively. At least one accumulator is connected to the slave cylinder where the accumulator creates an opposing pressure as a result of the gripper arms' position.

Claims

1. A clamp device for a mobile lift system comprising: a supporting part with an interface configured to be connected to a corresponding interface on a lift unit in the lift system; a gripper arm arranged in each end of the supporting part, where the one end of the gripper arm is movable connected to the supporting part and the second end is configured to grab an article; an actuating system arranged on the supporting part and connected to at least one of the gripper arms, where the actuating system comprises at least one actuator configured to move the at least one gripper arm between an open position and at least one clamping position; wherein the actuator system is configured to grab an article with a clamping pressure and to adjust the clamping pressure based on a position of the gripper arm, wherein the clamping pressure is gradually adjusted between the open position and the at least one clamping position, and wherein the actuating system is configured to apply a substantially constant pressure in a grip direction and to create an opposing pressure which combined create a resulting clamping pressure.

2. The clamp device according to claim 1, wherein the actuating system comprises a main cylinder and slave cylinder so that a first medium flow between the main cylinder and the slave cylinder.

3. The clamp device according to claim 2, wherein the actuating system comprises at least one accumulator connected to at least one of the main and slave cylinders, where the at least one accumulator is configured to generate the opposing pressure by compression of a second medium.

4. The clamp device according to claim 2, wherein at least one of the first and second mediums is a hydraulic fluid or a type of gas.

5. The clamp device according to claim 1, wherein at least one position sensor is arranged relative to the at least one gripper arm and registers the position of the gripper arm, wherein the output of the at least one position sensor is electrically inputted to a control unit, which adjusts the clamping pressure based on the position of the gripper arm.

6. The clamp device according to claim 1, wherein the clamping pressure is at its highest when the gripper arms is in an outer clamping position and the clamping pressure is at its lowest when the gripper arms is in an inner clamping position.

7. A mobile lift system comprising: a base; a lift unit arranged at the base, where the drive unit is configured to lift or lower a clamp device in a lift direction; a drive unit connected to the lift unit, where the drive unit is configured to run the lift unit, eventually with the help of an internal energy source; a control unit connected to the lift unit, where the control unit is configured to control at least the lift unit; and wherein the clamp device is configured according to claim 1.

8. The mobile lift system according to claim 7, wherein a rotation unit is arranged between the clamp device and the lift unit, where the rotation unit is configured to rotate the clamp device in a rotational direction around an axis of rotation.

9. The mobile lift system according to claim 7, wherein at least one sensor is arranged on the lift system and configured to at least measure the clamping pressure either directly or indirectly, where the at least one sensor is connected to the control unit.

10. The clamp device according to claim 1, wherein the one end of the gripper arm is rotatable connected to the supporting part.

11. The clamp device according to claim 1, wherein the actuating system is configured to rotate the at least one gripper arm around an axis of rotation on the supporting part via the at least one actuator.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows a draft of an exemplary lift system according to embodiments of the invention;

(3) FIG. 2 shows the lift system shown in FIG. 1 with the clamp device locked in a vertical position;

(4) FIG. 3 shows the lift system shown in FIG. 1 as seen from the top with the gripper arm in an open position;

(5) FIG. 4 shows the clamp device with the gripper arms in an outer clamping position and in an inner clamping position;

(6) FIG. 5 shows an exemplary embodiment of the clamp device;

(7) FIG. 6 shows the piston's position within the slave cylinder shown in FIG. 5 in the outer clamping position;

(8) FIG. 7 shows the piston's position within the slave cylinder shown in FIG. 5 in the inner clamping position;

(9) FIG. 8 shows an exemplary configuration of the actuator system; and

(10) FIG. 9 shows an alternative configuration of the actuator system.

REFERENCES

(11) TABLE-US-00001 Lift system 1 Base 2 Lift unit 3 Control unit 4 Drive unit 5 Clamp device 6 Lift direction 7 Rotational unit 8 Rotational direction 9 Central axis, axis of rotation 10 Supporting part 11 Gripper arms 12 Grip direction 13 Actuator system 14 Initial pressure, constant pressure 15 Secondary pressure, opposing pressure 16 Clamping pressure, resulting clamping 17 pressure Article 18 Supporting plate 19 Clamp device interface 20 Lift unit interface 21 Axis of rotation 22 First actuator, cylinder 23 Second actuator, cylinder 24 First accumulator 25 Second accumulator 26 The piston 27 First chamber 28 Second chamber 29 First medium 30 Second medium 31 Accumulator 32 Third medium 33 Fourth medium 34

DETAILED DESCRIPTION

(12) FIG. 1 shows a draft of an exemplary lift system 1 according to embodiments of the invention, encompassing a base 2 with wheels, a lift unit 3 arranged at the base, a control unit 4 connected to the lift unit 1, and a drive unit 5 connected to the lift unit 3.

(13) The lift unit 3 is configured to raise or lower a clamp device 6 in a lift direction 7. The drive unit 5 is configured to drive the lift unit 3 through an internal energy source, e.g., a battery.

(14) The control unit 4 is configured to control at least the lift unit 3. Here, the control unit 4 is also configured to control the clamp device 6. The control unit 4 in this case comprises a handle and at least one control panel.

(15) A rotational unit 8 is arranged between the clamp device 6 and the lift unit 3. The rotational unit 8 is attached to interfaces (not shown) on the lift unit 3 and clamp device 6 respectively.

(16) FIG. 2 shows the lift system 1 with the clamp device 6 locked in a vertical position where the lift unit 3 is raised and locked in a flip position. The rotational unit 8 is configured to rotate the clamp device 6 in a rotational direction 9 around an axis of rotation 10. Here, the axis of rotation 10 is a central axis on the clamp device 6.

(17) The rotational unit 8 can comprise a handle to manually flip the clamp device 6, alternatively the rotational unit 8 can comprise an actuator e.g., an electric actuator to automatically flip the clamp device 6.

(18) FIG. 3 shows the lift system 1 shown from the top with the clamp device 6 in an open position. The clamp device 6 comprises a supporting part 11 and two gripper arms 12 rotatably connected to the supporting part 11. The gripper arms 12 can be rotated in grip direction 13 around an axis of rotation (see FIG. 5).

(19) The gripper arms 12 can be rotated between an open position (see FIG. 1) and at least one clamping position (see FIG. 4). The gripper arms 12 can be rotated with the help of an actuator arranged in the clamp device 6.

(20) FIG. 4 shows the clamp device 6 with the gripper arms 12 in an outer clamping position (indicated as max) and an inner clamping position (indicated as min).

(21) The clamp device 6 comprises an actuator system (see FIG. 5) configured to inflict an initial pressure 15 e.g., a constant pressure in the grip direction 13. The actuator system further configured to create a second pressure 16 e.g., an opposing pressure in the grip direction 13 as a function of the gripper arm's 12 position. The first and second pressure 15, 16 combined create a resulting clamping pressure 17 upon the article 18.

(22) Hereby the clamping pressure 17 placed upon the article 18 as a function of the gripper arms' 12 positioning is adjusted. The clamping pressure 17 is highest when the gripper arms 12 are in an outer clamping position (max) and the clamping pressure 17 is lowest when the gripper arms 12 are in an inner clamping position (min).

(23) A supporting plate 19 is arranged in the opposite end of the gripper arm 12 where the supporting plate is adjusted to press up against the article 18. The supporting plate 19 has a particular length and width and is connected to the gripper arm 12 that allows for tilting so that it can accommodate the article 18.

(24) FIG. 5 shows an exemplary embodiment of the clamp device 6 where the front plate and top plate and supporting plates 19 have been removed for illustrative purposes. The supporting part 11 has an interface 20 adjusted for installation to a corresponding interface 21 on the lift unit 3. The supporting part 11 is designed to provide support for the gripper arms 12 and house the actuator system 14.

(25) The gripper arms 12 connected to the supporting part 11 in a way that allows for rotation, so that they can rotate in the grip direction 13 around the axis of rotation 22. A first actuator 23 is connected to the one gripper arm 12 and a second actuator 24 is connected to the second gripper arm 12. The actuator 23, 24 is configured to move, e.g., rotate, the gripper arms 12 in the grip direction 13 between an open position and at least one clamping position. The actuators 23, 24 are hydraulic cylinders and generate an initial pressure 15 in the grip direction as indicated in FIG. 4. One of the cylinders 23, 24 functions as a main cylinder while the other cylinder 23, 24 functions as a slave cylinder.

(26) A first accumulator 25 and a second accumulator 26 are further connected to one of the cylinders 23, 24, e.g., the slave cylinder. The accumulators 25, 26 are hydraulic accumulators and generate a second pressure 16 opposite of the grip direction 13 as shown in FIG. 4.

(27) In this configuration the clamping pressure 17 is adjusted as the actuators 23, 24 rotate the gripper arms 12 in a grip direction 13 while simultaneously creating an opposing pressure in the accumulators 25, 26.

(28) FIG. 6 shows the piston's 27 position within the slave cylinder in the outer clamping position while FIG. 7 shows the piston's 27 position within the slave cylinder in the outer clamping position. Here the second cylinder 24 functions as a slave cylinder.

(29) The cylinders 23, 24 have an inner chamber divided into a first chamber 28 and a second chamber 29, wherein the two chambers are separated by the piston's 27 head. A first medium 30 is transported from the main cylinder and into the first chamber 28 in the slave cylinder. A third medium 33 is transported from the second chamber 29 within the slave cylinder and into an accumulator 32 containing a second medium 31.

(30) In the outer clamping position, the compression of the second medium 31 within the accumulator 25, 26 will be minimal. This leads to the resulting pressure 17 which is inflicted by the piston 27 upon the article 18 through the gripper arm 12 will be highest, given that the pressure in the first medium 30 from the main cylinder will be constant.

(31) In the inner clamping position, the compression of the second medium 31 within the accumulator 25, 26 will be maximal. This leads to the resulting pressure 17 which is inflicted by the piston 27 upon the article 18 via the gripper arm 12 will be at its lowest, given that the first medium 30 from the main cylinder will be constant.

(32) Here the first medium 30 and/or third medium 33 is a hydraulic fluid while the second medium 31 is a type of gas.

(33) FIG. 8 shows an exemplary circuitry diagram concerning the actuator system 14 shown in FIG. 5. There the first accumulator 25 is similar to the second accumulator 26. Alternatively, they can have two different configurations/sizes. Here the two accumulators 25, 26 are connected to a series of slave cylinders.

(34) A fourth medium 34 is led into the first chamber 28 within the main cylinder from a hydraulic unit, e.g., a pump, when the gripper arms 12 are rotated towards the article 18. The hydraulic unit can be installed upon the lift system 1.

(35) The piston 27 within the main cylinder is pushed out of the main cylinder and the first medium 30 is transferred over to the slave cylinder. Hereby the piston 27 within the slave cylinder is pushed out of the slave cylinder and the third medium 33 is transferred to the accumulators 25, 26. This leads to the second medium 31 being compressed and creating an opposing pressure. When the gripper arms 12 are rotated away from the article 18 the pistons 27 will then push back the cylinders and the opposing pressure will decrease.

(36) At least one sensor arranged on the lift system 1 and configured to either directly or indirectly measure at least the clamping pressure 17, where the at least one sensor is connected to the control unit 4.

(37) FIG. 9 shows an alternative circuitry diagram concerning the actuator system 14 for operating the gripper arms 12. Here, a position sensor 35 is arranged on the supporting part 11 of the clamp device 6. The position sensor 35 is electrically connected to the controller 36 in the control unit 4, wherein the position sensor 35 registers the position of the gripper arm 12.

(38) Further, a pressure sensor 37 is electrically connected to the controller 36, wherein the pressure sensor 37 registers a local pressure within the actuator system. Here, the pressure of the fourth medium 34 is registered and inputted to the controller 36.

(39) The controller 36 is also electrically connected to at least one pressure limiting valve 38, which is controlled by the controller 36 to ensure that the pressure supplied by the hydraulic system 39 remains within safe operating limits.

(40) Hydraulic fluid is pumped via the pump to the actuators 23, 24 in the clamp device and further to the lift actuator 40. Any bypassed hydraulic fluid from the pressure limiting valves 38 is returned to the supply tank 41.

(41) Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(42) For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements. The mention of a unit or a module does not preclude the use of more than one unit or module.