Mobile Lifting Column, Lifting System Comprising One or More of Such Lifting Columns, and Method for Lifting a Vehicle

Abstract

The invention relates to a mobile lifting column, a lifting system including one or more of such lifting columns, and a method for lifting a vehicle. The mobile lifting column includes a frame with a moveable carrier. The carrier includes a carrier part and a guiding part with the carrier configured for carrying the vehicle. The mobile lifting column also includes a drive system which acts on the carrier and is configured for raising and/or lowering the carrier relative to the frame, and a lifting controller configured for controlling movement of the carrier. The guiding part of the carrier includes a U-shaped guiding part.

Claims

1-53. (canceled)

54. A mobile lifting column for lifting a vehicle, the column comprising: a frame with a moveable carrier, wherein the carrier comprises a carrier part and a guiding part with the carrier being configured for carrying the vehicle; a drive system which acts on the carrier and is configured for raising and/or lowering the carrier relative to the frame; and a lifting controller configured for controlling movement of the carrier, and further comprising a displacement mechanism configured for positioning the lifting column, wherein the displacement mechanism comprises: a displacement frame comprising a housing, and a wheel that is provided at a first end of the housing, wherein the wheel is moveable relative to the frame between a displacement position where the lifting column can be displaced and a stationary position where the lifting column is in a stationary position; a counter force element that is providing in or on the frame; and a steering handle that is operatively coupled to the wheel with a linkage mechanism that is configured for moving the wheel relative to the frame, wherein the steering handle is connected to the displacement frame at a second end of the housing.

55. The mobile lifting column of claim 54, wherein the guiding part of the carrier comprises a U-shaped guiding part.

56. The mobile lifting column according to claim 54, further comprising a position sensor that is configured for detecting the position of the displacement mechanism.

57. The mobile lifting column according to claim 54, further comprising a lifting column position detector.

58. The mobile lifting column according to claim 56, wherein the sensor comprises an induction detector that is provided in or on the housing.

59. The mobile lifting column according to claim 58, wherein the sensor further comprises a metal bush that moves with the wheel relative to the housing and the detector when moving the wheel between the displacement and stationary positions.

60. The mobile lifting column according to claim 56, wherein the controller comprises a displacement mode that is directly or indirectly activated by the position sensor detecting an intended displacement of the lifting column.

61. The mobile lifting column according to claim 56, further comprising an indoor positioning detector configured for detecting an absolute and/or relative position of the lifting column.

62. The mobile lifting column according to claim 56, further comprising a shock absorber or a damper.

63. The mobile lifting column according to claim 54, wherein the counter force element is a spring element substantially extending along a displacement frame axis between the wheel and the steering handle, and wherein the counter force is preferably adjustable.

64. The mobile lifting column according to claim 54, wherein the linkage mechanism comprises a rod that extends between the wheel at the first end of the housing and the handle at the second end of the housing, and is connected to the handle, wherein the handle is preferably pivotally connected to the housing at a hinge and the displacement mechanism further comprises a lever or balance with the linkage mechanism being pivotally connected to the lever or balance, and wherein the handle preferably acts as the lever or balance.

65. The mobile lifting column according to claim 54, further comprising an energy supply with one or more batteries, and further comprising a charging device, wherein the controller preferably comprises a charging monitor configured for monitoring a regenerative charging process when lowering a load.

66. The mobile lifting column according to claim 54, wherein the drive system further comprises connectors such that the drive cylinder of the drive system can be positioned in a first configuration and a second configuration, and wherein the first and second configurations have the bottom and top ends of the cylinder reversed.

67. The mobile lifting column according to claim 54, further comprising a locking system for locking and unlocking the moveable carrier relative to the frame, wherein the locking system comprises: a lock actuator and a locking rail that both extend over at least a part of the height of the frame; a locking drive configured for moving the lock actuator between a locked state and an unlocked state; and a lock that is provided at or on the moveable carrier and is configured for engaging and/or disengaging the locking rail in response to a movement of the lock actuator.

68. The mobile lifting column according to claim 67, wherein the lock actuator and the locking rail are provided in or at the frame, and wherein the locking actuator is provided in the frame with a connection such that the locking actuator may rotate around its axis when moving between the locked and unlocked states.

69. The mobile lifting column according to claim 67, wherein the locking system comprises a locking mechanism that further comprises a rod extending between the lock and the carrier, wherein the rod is preferably connected to the carrier with a hinged connection and substantially extends in a vertical direction, and wherein the hinged connection is configured such that it automatically moves the lock in the locked state when the lock actuator is not activated.

70. The mobile lifting column according to claim 54, further comprising a light pipe element configured for indicating a battery status.

71. A lifting system for lifting a vehicle, the lifting comprising a number of mobile lifting columns for lifting a vehicle, the column comprising: a frame with a moveable carrier, wherein the carrier comprises a carrier part and a guiding part with the carrier being configured for carrying the vehicle; a drive system which acts on the carrier and is configured for raising and/or lowering the carrier relative to the frame; and a lifting controller configured for controlling movement of the carrier, and further comprising a displacement mechanism configured for positioning the lifting column, wherein the displacement mechanism comprises: a displacement frame comprising a housing, and a wheel that is provided at a first end of the housing, wherein the wheel is moveable relative to the frame between a displacement position where the lifting column can be displaced and a stationary position where the lifting column is in a stationary position; a counter force element that is providing in or on the frame; and a steering handle that is operatively coupled to the wheel with a linkage mechanism that is configured for moving the wheel relative to the frame, wherein the steering handle is connected to the displacement frame at a second end of the housing.

72. The lifting system according to claim 18, wherein the lifting system comprises a central controller for centrally controlling the one or more lifting columns, the central controller comprising: a transmitter/receiver for communication with individual lifting columns; and computing means, such as a processor, for determining required control actions for individual lifting columns; wherein at least one of the central controller or at least one of the lifting columns comprises user input means configured for providing the central controller with input, and wherein the central controller controls one or more groups of selected lifting columns.

73. A method for lifting a vehicle with a lifting system comprising a number of mobile lifting columns, the method comprising the steps of: positioning a vehicle into a lifting position relative to the lifting system; and lifting the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0175] Further advantages, features and details and of the embodiment will be elucidated on the basis of preferred embodiments therefor, wherein reference is made to the accompanying drawings, in which:

[0176] FIG. 1A shows a mobile lifting column according to a first embodiment of the invention;

[0177] FIG. 1B shows a mobile lifting column according to a second embodiment of the invention;

[0178] FIG. 2A shows a lifting system with a group of lifting columns according to the first embodiment of FIG. 1A;

[0179] FIG. 2B shows a lifting system with a group of lifting columns according to the second embodiment of FIG. 1B;

[0180] FIG. 2C shows an alternative lifting system comprising a central group controller controlling multiple groups of lifting columns;

[0181] FIG. 2D shows a display that can be used for a lifting column according to the present invention;

[0182] FIG. 3 shows an embodiment of a carrier for a lifting column according to the present invention;

[0183] FIG. 4 shows a view of an embodiment of a lifting column according to the present invention;

[0184] FIG. 5 shows a further view of the lifting column of FIG. 4;

[0185] FIG. 6 shows one of the preferred configurations of the drive system for a lifting column according to the present invention;

[0186] FIG. 7 shows details of the drive system of FIG. 6 with motor and integrated motor controller;

[0187] FIG. 8 shows details of the hydraulic reservoir of the drive system of FIGS. 6 and 7;

[0188] FIG. 9 shows a foot of a column according to the present invention with modular cartridge;

[0189] FIG. 10 shows a carrier and locking system for a lifting column according to the present invention;

[0190] FIGS. 11 A-B, 12 show details of embodiments of the lock actuator and locking drive for a locking system of FIG. 10;

[0191] FIGS. 13-16 show an embodiment of a displacement system for a lifting column according to the present invention;

[0192] FIGS. 17 A-B and 18 A-C show details of an alternative embodiment of a displacement system for a lifting column according to the present invention;

[0193] FIG. 19 A-B shows details of a measurement system for detecting movement of the carrier for a lifting column according to the present invention;

[0194] FIG. 20 shows an indicator for the status of the recharger of batteries for a lifting column according to the present invention;

[0195] FIG. 21 A-B shows a cable drum and connectors for a lifting column according to the present invention; and

[0196] FIG. 22 A-B shows alternative mounting configurations of a cylinder in a lifting column according to the present invention.

DESCRIPTION OF THE INVENTION

[0197] The following description is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. While the disclosure is described as having exemplary attributes and applications, the present disclosure can be further modified. This application is therefore intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice of those skilled in the art to which this disclosure pertains and which fall within the limits of the appended claims. Accordingly, the following description of certain embodiments and examples should be considered merely exemplary and not in any way limiting.

[0198] The mobile lifting column of the present invention is suitable for use with lift systems comprising any number of lifting columns, including systems having one, two, four or another number of columns. The columns may achieve lifting and lowering capability by any means known to those of skill in the art, including hydraulically, electrically, mechanically, and electromechanically. Lift systems compatible with the present mobile lifting column may be stationary and/or permanently affixed or attached to a certain location or may be mobile, capable of being transported via wheels or any other suitable means known to those in the art. With reference to the figures, like element numbers refer to the same element between drawings.

[0199] Lifting column 4 (FIG. 1A) is positioned on ground surface 8 of for instance a floor of a garage or workshop, and comprises foot 10 which can travel on running wheels 12 a,b over ground surface 8. Running wheel(s) 12 is/are part of a pallet truck mechanism enabling easy maneuvering of lifting column 4. Lifting column 4 furthermore comprises mast 14. A carrier 16 is moveable upward and downward along mast 14. Optionally, adapters can be used to adjust carrier 16 to specific wheel dimensions. Carrier 16 is driven by motor/drive system 18 that is provided in housing 17 of lifting column 4. In one embodiment, the motor of system drive 18 is a 3-phase low voltage motor controlled by a separate controller. In another embodiment, the motor of system 18 is a 3-phase low voltage motor with integrated controller. Such motor with integrated controller can also be used in combination with conventional lifting columns with conventional height measurement systems. Motor 18 is supplied with power from the electrical grid or by one or more batteries 19 that is provided on lifting column 4 in the same housing as motor 18, or alternatively on foot 10 (not shown). Display unit 20 may provide the user with information about the lifting system.

[0200] In an alternative embodiment lifting column 4′ (FIG. 1B) the same or similar components are applied as illustrated and/or described for lifting column 4. Same elements are indicated with same reference numbers.

[0201] Lifting column 4′ comprises housing 17′ with a different shape and size. In particular housing 17′ is provided with a smaller height as compared to housing 17. This affects the required amount of material, the inner space for receiving and holding further components, and the esthetical appearance of lifting column 4, 4′.

[0202] Optionally, column 4, 4′ is provided with moving system 13 (configured for moving or displacing column 4, 4′ using wheels 12 a,b with drive 13a. In the illustrated embodiment drive 13a is powered by batteries 19 acting as power system for moving system 13. It will be understood that other embodiments of moving system 13 can also be envisaged, for example comprising a separate power system.

[0203] Further embodiments will be illustrated with the use of lifting column 4 and/or lifting column 4′. It will be understood that most features and effects can be exchanged between the different embodiments of lifting columns 4, 4′.

[0204] Lifting system 2 (FIG. 2A), 2′ (FIG. 2B) comprises four mobile lifting columns 4 in the illustrated embodiment. Lifting columns 4 lift passenger car 6 from ground 8. In the illustrated embodiment car 6 is lifted over distance D. It will be understood that other heights can also be envisaged in accordance with the present invention.

[0205] Lifting columns 4 are connected to central controller 22 by wireless communication means 24 on individual lifting column 4 and wireless communication means 26 on central controller 22. Optionally, controller 22 is provided with display 23. In the illustrated embodiment communication means 24 are provided in (local) mobile lifting column controller 28 in control box 30. Central controller 22 can be provided as a separate unit at a desired location in the workshop and/or can be provided in or at one or all of mobile lifting columns 4. Wireless communication means 24, 26 involve one ore more transmitters and/or receivers.

[0206] The illustrated lifting system 2 includes at least two lifting columns 4. Each of the lifting columns has at least one ascent mode and one descent mode, and is under the influence of central controller 22. In the illustrated embodiment controller 22 is positioned centrally above lifting columns 4 assuring a good communication path between the individual lifting columns 4 and the central controller 22.

[0207] Central controller 22 determines the desired control actions. In one of the embodiments of the invention this may involve receiving a measurement signal measuring the actual height of carrier 16 of individual lifting column 4 that is measured with height or movement sensor 32 attached to an individual lifting column 4. Sensor 32 is capable of measuring position and/or speed of carrier 16. In the illustrated embodiment sensor 32 is a potentiometer and/or an inclinometer. Optionally, pressure or load sensor 33 may be used for monitoring, control and indication of the correct positioning of the load that is lifted with lifting system 2. Optionally, vehicle detector 31 is provided to detect the presence of vehicle 6. It will be understood that alternative sensors can be used in combination or as an alternative.

[0208] In presently preferred embodiments of the invention central controller 22 determines the desired control actions using measurement signals representing the status and/or actions of drive 16. In an embodiment of the invention controller 22 involves directly and/or indirectly measuring the hydraulic liquid level, pressure, or volume and/or a change thereof. This provides an effective control of the lifting operation. In addition, or as an alternative thereto, the flow between drive 18 of carrier 16 and the hydraulic liquid reservoir can be measured. Several embodiments of such measurement signal will be described in this description in relation to further figures (for example in relation to FIG. 8).

[0209] In the illustrated embodiment, central controller 22 may communicate with external system 34. Several embodiments of such measurement signal will be described in this description in relation to further figures (for example in relation to FIG. 2C).

[0210] Furthermore, the illustrated embodiment shows lock sensor 29a (FIG. 2A, 11B). Lock sensor 29a detects/measures the status of locking mechanism 29b. Optional load sensor 33 detects the presence of a load and/or the actual load that is supported by carrier 16. In this embodiment, sensor signals are provided to controller 22.

[0211] In the illustrated embodiment, in addition, or as an alternative, remote control 21a (FIG. 2A) is provided with display 21b. Preferably, displays 20, 21b, 23 are touchscreens. Light 25 is schematically illustrated and is provided with one or more signaling lights 25a, preferably LED lights. Optionally, acoustic signal generator 25b is provided to assist the signaling function of light 25. It will be understood that light 25a and generator 25b can be positioned at or adjacent system 2 and/or at a central location in a workshop, for example.

[0212] Lifting system 2′ with lifting columns 4′ (FIG. 2B) comprises the same or similar components as illustrated and/or described for lifting system 2 with lifting columns 4. Same elements are indicated with same reference numbers.

[0213] In a further embodiment of the invention, central controller 22 (FIG. 2C) is configured to control multiple groups of lifting systems 2a, 2b. Such multi-group controller is described in US 2017/0174484 A1 which is incorporated herein by reference. It will be understood that features of the different embodiments of lifting systems 2, 2′ can be exchanged and applied in different combinations and configurations. Central controller 22 detects height differences between lifting columns and/or differences between the status and/or actions of drive 16, calculates the required control actions with computing means 36, such as a processor, for individual lifting columns, and communicates the control actions to the relevant individual lifting columns 4, 4′. In the illustrated embodiment battery 38 provides power to central controller 22. Alternatively, or in addition, power is provided through connection 40 to the electrical grid. Data can be stored in memory/storage 42. Optionally, indoor positioning system 43 is provided to determine position and/or height of carrier 15 with transmitters/sensors 43a and optionally making use of further sensors 62 attached to or or provided in control box 30 and/or sensor 33 attached to carrier 16 that optionally provides a dual function as load sensor and position sensor. Central controller 22 is optionally provided with a wired and/or wireless connection 44 to enable connection between communication module 46 of central controller 22 to internal and/or external networks, involving internal company networks for workshop control 48, financial control 50 and maintenance 52, for example, and external networks 54 of suppliers and/or customers, for example. Optionally, central controller 22 is provided with displacement means 22a, such as wheels and/or guides to enable displacement of central controller 22 in a room. Optionally, in an alternative embodiment central controller 22 comprises a portable housing. In a displaceable and/or portable embodiment central controller 22 can be positioned efficiently and effectively in relation to the relevant mobile lifting columns 4, 4′. Central controller 22 can be positioned and moved along a ceiling, wall and/or workshop floor depending on the specific circumstances and embodiment of controller 22.

[0214] Individual lifting columns 4 are provided with display 20 that is provided in or at control box 30. Display 20 preferably relates to a touch screen. Control box 30 optionally comprises a number of buttons 56 to provide additional input means for a user, an RFID antenna 58 enabling a user to identify himself with an ID-key 60 and/or pay for a number of lifts with a pre-paid card. In the illustrated embodiment control box 30 further comprises position determining means 62 and communication means 24, preferably providing wireless functionality to communicate in one or more environments such as LAN, WAN, VPN intranet, internet etc. that are schematically shown in the illustrated embodiments. Control box 30 is further provided with input/output ports, such as USB, SD card reader, smart phone communication possibilities etc. to improve the functionality. Display 20 may provide warning signals to the user. Display 20, preferably a TFT-LCD, is protected by a display lens cover of a resilient material, preferably scratch-resistant.

[0215] Transmitter/receivers 24, 26 provide user instructions to central system controller 22. On a central level controller 22 determines the individual control actions to be taken for all lifting columns 4 in system 2 a,b (FIG. 2C). Transmitter/receivers 24, 26 provide the control actions from central controller 22 to the individual lifting column 4. Information about the actual position of carrier 16 and/or drive (system) 18 and/or other relevant data is measured. The measurement data is provided to central controller 22 that determines if and what control actions are required. In this illustrated embodiment no direct communication between individual lifting columns 4 is required. This significantly contributes to the robustness of lifting system 2.

[0216] In an advantageous embodiment according to the invention, central controller 22 (FIG. 2C) can be used to control a first group 2a of lifting columns 4 and a second group 2b of lifting columns 4. Operation and control of a single group 2a, 2b is substantially similar to the operation and control of a single system 2 with lifting columns 2. Optionally, first computing means 36 involving a first processor is provided with second or further computing means 64 involving second processor. Furthermore, central controller 22 can be provided with additional multiple components to improve overall control operation and robustness.

[0217] Optionally, central controller 22 is provided with a number of communicators/distributors 66, such as an RF-host, that send and/or receive signals 68 between lifting columns 4 and communicator 66, and signals 70 between communicator/distributor 66 and central controller 22. Communicators/distributors 66 provide additional robustness to the overall operation of the groups 2a, 2b of lifting columns 4.

[0218] In a presently preferred embodiment lifting column 4 is provided with release system 72 (schematically illustrated in FIG. 2C, most right lifting column). In the illustrated embodiment central controller 22 provides a clearance signal to an individual lifting column 4 involving a release signal enabling the effective use of carrier 16. The release signal may release a software lock preventing motor 74 and/or pump 76 of lifting column 4 to operate. Alternatively, or in addition thereto, release signal may release a hardware lock, for example a clamp locking carrier 16. Payments can be received via card 60, for example, generating payment instructions and sending the instructions to the accounting department of the user and/or receiving an authorization signal authorizing the system and user to perform a number of lifts and/or use lifting system 2 for a specific period of time. Sensor 78 can be used to inform controller 22 of lifting activities of carrier 16. Alternatively, or in addition thereto, motor run time sensor 80 may provide controller 22 with motor run time information of motor 74 and/or pump activity sensor 82 may provide controller 22 with pump activity information of pump 76 and/or load sensor 33 (for monitoring, control and indication of the correct positioning of the load that is lifted with lifting system 2) may provide central controller 22 with information on the actual loads carried by carrier 16, preferably in combination with the time period the carrier 16 is exposed to the load.

[0219] Display 20, 21b, 23 (FIG. 2D) schematically shows screen background 27a, text box 27b and visual elements 27c that represent lifting columns 2. With changing colours and/or text, elements 27a-c indicate a safe or unsafe situation, optionally assisted by light 25a and/or generator 25b (FIG. 2A).

[0220] When lifting vehicle 6 the vehicle is positioned relative to carriers 16. When raising carriers 16 relative to frame 4 of mobile lifting columns the actual height is preferably measured with a type of height or movement sensor 32 and/or status of drive system 18. When the desired height and/or status is reached and all carriers 16 are equally positioned, in the illustrated embodiment the carriers 16 are lowered into their lock with locking mechanism 29b. For example, this requires changing of the actual position of locking element 202 (FIG. 12) that can be detected by sensor 29d and/or cam 29c (FIG. 11B) that can be detected by sensor 29a. The signal of sensor(s) 29a,c is/are preferably provided to controller 22 that enables a visual indication on display 20, 21b, 23, optionally assisted by further assisting signals with light 25a and acoustic generator 25b. Optionally, a central controller 22, remote control 21a, chief operator etc. is provided with the measurement signal. Visualization of a safe or unsafe working situation can be performed by changing the color of the screen background 27a (FIG. 2D) and/or indicating in text box 27b that all columns are safe to use. Screen background 27a helps a user to be informed of a safe or unsafe situation even from a distance. The condition of individual columns can be provided with visual elements 27c. For example, green background color indicates a locking situation wherein a user can perform operations on vehicle 6, while a red background indicates an unsafe situation and an orange background indicates that some but not all lifting columns are locked. It will be understood that other configurations can also be envisage in accordance with the invention.

[0221] Carrier 16 (FIG. 3) comprises two forks 84. In the illustrated embodiment forks 84 have claws 86 that engage front part 88 of carrier 16. Plates 90 connect front part 88 with carrier frame 92. Frame 92 has four guiding wheels 94. In the illustrated embodiment claws 86 are fixated relative to front part 94 with fixation element 96, for example a pen or other suitable element. Frame 94 has a U-shape profile with connecting rod 98 and connecting plates 100 a,b. The U-shaped profile allows for a controllable (reduction of) torsional stiffness to enhance the contact between wheels 94 and mast 14. This prevents an overload on wheels 94 due to (small) misalignments between wheels 94, carrier 16 and mast 14. It will be understood that alternatively forks 84 can also be provided in an integrated manner with carrier 16.

[0222] Carrier 18 (FIG. 4) comprises forks 84 and guiding frame 94. Frame 94 extends over length d.sub.1 along guide rail 102 of mast 14 in a substantial vertical direction. Guide rail 102 is provided with cylinder 104. Guide rail 102 extends over length d.sub.2 along mast 14. It is noted that this length d.sub.2 is mostly related to the length or height of cylinder 104. Mast 14 also houses locking system 106 and locking rail 108. In the illustrated embodiment locking rail 108 extends over a substantial part of the length or height of mast 14.

[0223] Lifting column 4 comprises pallet truck mechanism 110 (FIG. 5) for displacing/positioning lifting column 4. An operator is provided with information and/or provides input to lifting column 4 with control box 30 that comprises display 20. Lifting column 4 further comprises cover 17, 17′. Cover 17, 17′ protects a number of components against fouling and damage. For example, charger 112 and connector 114 are provided behind cover 17, 17′. This provides an integrated design.

[0224] Mounting rail 116 (FIG. 6) enables a robust connection of cover 17, 17′ to mast 14 of lifting column 4, 4′. In the illustrated embodiment energy system 118 comprises first battery 120 and second battery 122. Drive system 18 is in the illustrated embodiment provided above energy system 118. An overcharge monitor 124 is provided in control box 30 that also comprises an integrated switch circuit 30a and resistance 30b for a safety measure to prevent overcharging of batteries 120, 122. Connectivity module 126 is also provided in control box 30 to connect lifting column 4 with other (external) systems. Optionally, sensor 32 is provided at mast 14 of lifting column 4 to detect the velocity of a moving carrier 16.

[0225] Drive system 18 comprises integrated system 128 (FIG. 7) comprising motor and pump assembly 130 and motor controller 132. Assembly 130 comprises pump and valve 134 and PM motor 136. Motor controller 132 comprises plate 138, print 140 and cover 142.

[0226] Drive system 18 further involves reservoir 144 (FIG. 8). In the illustrated embodiment reservoir 144 has bottom part 146 with opening 148 and pump connection 150. Reservoir 144 is further provided with vertical extending part 152. In use, reservoir 144 is filled with hydraulic oil 154 defining oil level 156. In the illustrated embodiment several sensors have been illustrated. It will be understood that these relate to exemplary embodiments of the invention and other configurations of one or more of these sensors or further alternative sensors can also be envisaged in accordance with the invention. In the illustrated embodiment ultrasonic sensor 158 is mounted at the top of the vertical part 152 of reservoir 144. Sensor 158 provides signal 160 that is reflected by oil level 156. This indicates the position of oil level 156. Float 162a also measures oil level 156. Load cell 162b measures the amount of oil in reservoir 144. Pressure sensor 162c measures pressure differences indicating the position of oil level 154. Flow sensor 162d measures the amount of flow from and/or to reservoir 144. Furthermore, in addition or as an alternative to the aforementioned sensor(s), a flow sensor can be provided in hydraulic circuit, for example in suction pipe. It will be understood that other locations for flow sensor can also be envisaged in accordance with the present invention. Reservoir 144 is provided with connection 164 to connect sensors 158, 160, 162a-d to control box 30.

[0227] In an alternative embodiment lifting column 4 is provided with a further measurement system 178 (schematically illustrated in FIG. 4) that measures displacement of a piston that drives carrier 18. Such measurement system is disclosed in U.S. Patent Application Publication No. 2016/0052757 and incorporated herein by reference. In this illustrated measurement system a hydraulic circuit is operatively connected to hydraulic cylinder with the piston.

[0228] Foot 10 of lifting column 4 (FIG. 9) comprises connecting part 166 having height h.sub.1, curve part 168 with height h.sub.2 and front part 170 having height h.sub.3, with decreasing height from h.sub.1 to h.sub.3. This provides maximum strength at connecting part 166 and maximum space for manoeuvring front part 170.

[0229] Front running wheel or additional wheel 12b is provided in cartridge 172 that is located in front part 170 of foot 10. Cartridge 172 (detail of FIG. 9) comprises frame 174 and spring element 176. Cartridge 172 is designed that it may be replaced as a whole, including additional wheel 12b.

[0230] One or more of controllers 22, 28 receive measurement signals from sensors 158, 160, 162a-d and/or other sensors. Controller(s) 22, 28 determine(s) movement and/or height of carrier 16 and/or actions/status of drive system 18, for example. Preferably, local controller 28 is connected to central controller 22 configured for controlling the lifting columns, optionally communicating with (local) controllers of lifting columns. Central controller 22 and/or local controller 28 determine movement, height and/or speed differences between individual carriers 16 of a lifting system 4, 4′ (FIG. 1) and determine required control actions. These control actions may result in sending control signals/actions to motor/pump assembly 128 of drive system 18.

[0231] When lifting car 6 a number of mobile lifting columns 4,4′ are positioned around vehicle 6. When the lifting operation is approved carriers 16 start moving along masts 14. As soon as the desired height D above ground surface 8 of carriers 16 is reached carriers 16 are stopped. Preferably, carriers 16 are locked when working on the (lifted) vehicle.

[0232] Locking system 180 (FIG. 10) comprises lock actuator 182 that extends over a substantial part of the length or height of mast 14. Lock 184 comprises a block/blocking element capable of engaging with locking rail 108 (FIG. 4), and optionally a pawl with pen 186. Lock 184 is provided at one end of rod 188. Rod 188 is connected to lock or block 184 with connection 190. Furthermore, rod 188 is connected to guiding/frame part 92 of carrier 16 at upper connection 192. Carrier 16 moves along mast 14 with upper guide wheels 94a and lower guide wheels 94b.

[0233] Lock actuator 182 (FIG. 11A) comprises aluminium profile or frame 194 and polyethylene anti-wear strip 196 that may contact block 184. In the illustrated embodiment actuator 198 comprises an electromagnet.

[0234] Locking mechanism 29b (FIGS. 2A, 11B) is schematically illustrated and comprises in this illustrated embodiment (locking) rail 108 with supporting surfaces 200. Locking element/pawl 202 is provided with support surface 204. In a locked position, support surface 204 of pawl 202 engages one of the supporting surfaces 200 of rail 108. On the other side of locking element 202 a secondary support surface 206 can be supported by support 208. Lock actuator 210 acts as drive for locking element 202 and moves element 202 between a locked state and an unlocked state using plunger or shaft 212, with bolt 214 allowing the movement between both states. It will be understood that an alternative locking mechanism 29b can also be envisaged in accordance with the present invention. In the illustrated embodiment lock sensor 29a comprises an inductive sensor that measures the position of cam 29c. In a first embodiment rail 108 is provided on carrier 16 and locking element 29b is provided on frame/mast 4 of lifting column 2. In a second embodiment rail 108 is provided on frame/mast 4 of lifting column 2 and locking element 29b is provided on carrier 16.

[0235] Profile 194 (FIG. 12) comprises hole or opening 216 with a number of protrusions or nocks 218. The other end profile frame 194 is provided with hole or opening 220 having a number of protrusions or nocks 222, with hole 220 capable of receiving PE strip 196. Sensor 29d is attached to plate or frame 29e of the lifting system and is capable of detecting the position of profile 194.

[0236] When lifting car 6 a number of mobile lifting columns 4 are positioned around vehicle 6. When the lifting operation is approved carriers 16 start moving along masts 14. As soon as the desired height D above ground surface 8 is reached, locking system 29b is activated. Locking system 29b activates lock actuator 182 to rotate, with lock actuator 182 comprising profile 194 and anti-wear strip 198. Lock actuator 182 rotates between a locked state and an unlocked state. Lock actuator 182 is pivotally connected at its outer ends to mast 14 or other parts of the lifting column. When rotating lock actuator 182 block or pawl 184 will engage or disengage from locking rail 108. Rail 108 preferably extends along mast 14. As a further advantage, as the length of lock actuator 182 corresponds to the length of stroke of cylinder 104, carrier 16 can be locked at any desired height along mast 14. This further improves the operation of lifting column of the present invention.

[0237] Preferably, in case of a power failure, the electromagnet of actuator 210 is turned off and profile 194 returns to its inactive position wherein block 184 engages locking rail 108. Optionally, a user may manually operate rod 188 to disengage block 184 from locking rail 108 to lower carriers 16, for example. This contributes to providing a safe working environment with an effective lifting column. It will be understood that other embodiments or configurations for locking mechanism 29b can also be envisaged in accordance with the present invention.

[0238] Pallet truck mechanism/displacement system 224 (FIGS. 2A, 13) comprises wheel 12a that is capable of rotating around shaft 13 (FIGS. 13-18C). Wheel 12a is connected to displacement housing 226. Connecting block 228 is configured for connecting displacement system 224 to column 4. Rod or shaft 230 extends through housing 226 between wheel 12a and steering handle 232. Handle 232 is pivotally connected to rod 230 at hinge 234. Connector 236 connects steering handle 232 at hinge 238 and connects to rod 230 at hinge 240.

[0239] Attached to rod or shaft 230 is adjustment screw 242 (FIGS. 13-15). In the illustrated embodiment adjustment screw 242 enables adjustment of the counter force. Connecting rod 244 (FIG. 15) is connected to shaft 13 of wheel 12a and to rod 230. Connecting rod 244 extends along rod 230, optionally moving with a separate metal bush 246. In the illustrated embodiment spring 248 is provided between rod 230 and connecting rod 244 or bush 246. Adjustment screw 242 enables setting the counter force that is achieved by spring 248 by positioning piston like element 250 relative to spring 248 with screw 242. Stop 252 prevents fouling of spring 248, for example. Sensor 254 is configured for detecting the position of bush or profile 246. This provides a measure for the actual position of displacement system 224.

[0240] Optionally, damping element 256 (FIG. 16) is provided below steering handle 232. In the illustrated embodiment damping element 256 comprises an oil damper that damps the movement of handle 232 from the stationary to the displacement position. When moving handle 232 from the displacement to the stationary position damping element 256 preferably has no substantial effect. Damping element 256 is optionally applied in all illustrated and/or described embodiments.

[0241] When positioning lifting column 4, displacement system 224 is in the displacement position (FIG. 13) wherein mobile lifting column 4 can be moved relative to passenger car 6 and/or another lifting column 4. When lifting column 4 has reached its desired position, steering handle 232 is moved downwards, with the overcenter linkage, to the stationary position (FIG. 14). In this stationary position, lifting column 4 is ready for a lifting operation wherein foot 10 rests on ground surface 8 of a carriage or workshop floor.

[0242] In a situation wherein lifting column 4 is unintentionally in a displacement position (FIG. 13), while the lifting operation with passenger car 6 is started, its load will exceed the counter force of spring 248. This forces displacement mechanism 224 to move from the displacement position to the stationary position, thereby providing a safer environment. Optionally, sensor 254 detects that displacement mechanism 224 is in the wrong position, thereby blocking operation of lifting column 4.

[0243] After the lifting operation has ended, displacement mechanism 224 can be brought from the stationary position to the displacing position by moving steering handle 232 in upwards direction. This enables moving lifting column 4 to another position/location.

[0244] In an alternative embodiment displacement mechanism/pallet truck mechanism 258 (FIGS. 2A, 17A-B) comprises handle 232. In the displacement position (FIG. 17B) handle 232 can be positioned in an upright position. When manoeuvring with column 4 stopping/braking is achieved by pulling handle 232 such that wheel 12a is retracted. This improves the overall safety when working with column 4 and makes manoeuvring easier. Furthermore, when storing column 4, handle 232 can be placed in an upright position such that less space is required. Also, displacement mechanism 258 can be used effectively when loading/unloading lifting columns 4, 4′ from a truck with handle 232 in an upright position. In the illustrated embodiment, unlocking handle 232 is achieved by pulling button 260, preferably in an upward or outward direction such that lock 262 is pushed by spring 264 in opening 266. Preferably, mechanism 258 (FIGS. 18A-C) comprises position detector 268 that is attached to the frame of column 4. Detector 268 detects the position of metal bush or pen 270. This configuration has the advantage that mechanism 258 can be removed from column 4 without removing any wiring. Optionally, damper 272 is mounted between metal bush or pen 270 and displacement housing 226 to damp movements when handle 232 is brought into the displacement position. Pen 270 moves along slotted opening 274 in connecting block 228.

[0245] Optionally, movement sensor system 276 (FIGS. 19A-B) comprises sensor 278 that detects movement of wheel 280. Wheel 280 is mounted on shaft 282. Cord 284 initiates movement of wheel 280. Cord 284 is at first end 286 connected to carrier 16 with hook 288, or other suitable connecting means, and at a second end provided with a weight. In the illustrated embodiment cord 284 runs through pipe 290 with weight 291. Detector 278 detects openings 292 in wheel 280. This provides an additional safety measure and/or measurement system to monitor desired and/or undesired movements of carrier 16.

[0246] In a presently preferred embodiment, batteries 120, 122 (FIG. 6) can be recharged with charger 282 (FIG. 20). This also applies to charger 112 (FIG. 5). Outputs 284, 286 (FIG. 20) indicate the status of charger 282 and/or batteries 120, 122. To enable an operator to check this status outputs 284, 286 are connected to wires 288, 290 acting as light pipes, preferably a fiber optic cable (PMMA). This enables checking the status of charger 282 and/or batteries 120, 122 directly at the outside of column 4. It will be understood that alternatives for wires 288, 290 can be envisaged, for example using LEDs.

[0247] Column 4, 4′ is preferably provided with cable drum 292 (FIGS. 21A-B) with cable 294 in housing 17, 17′. This also applies to cable/connector 114 (FIG. 5). In the illustrated embodiment cable 294 (FIGS. 21A-B) is provided with IEC14 connector 296 that is extendable with adapter cable 298, preferably with a locking mechanism. At the other side of drum 292 connectors 300 are provided to enable connecting other lifting columns 4, 4′ and/or other parts of column 4, 4′. In the illustrated embodiment one of connectors 300 is provided with connector chassis 302 enabling another column to connect. One of the other connectors 300 is connected to charger 282 and another connector 300 acts as spare, optionally for connecting socket-outlet(s). This enables charging batteries 120, 122, preferably without relocating columns 4, 4′.

[0248] In a further preferred embodiment cylinder 104 (FIG. 4) comprises housing 304 (FIG. 22A) that in a first configuration is attached to carrier 16 and plunger 306 that is provided at the bottom of housing 304. In an alternative embodiment in a second configuration (FIG. 22B) housing 304 is mounted at plate 308 and plunger 306 moves cover 310 of (additional) pipe 312. In the illustrated embodiments the attachments are made with connectors 314.

[0249] It will be understood that other embodiments, combinations of illustrated features, and configurations can be envisaged in accordance with the present invention.

[0250] The present invention is by no means limited to the above described preferred embodiments. The rights sought are defined by the following claims within the scope of which many modifications can be envisaged. For example, lifting columns according to the invention include wired or wireless mobile type lifting columns, lifting columns of the two-post lift type with pivoting support arms, the four-post lifting column types with runways, the, in-ground lifts etc.

[0251] Furthermore, height differences between individual lifts within one set are detected and corrected by the controller. This correction can be performed by increasing the speed of the “slowest” lift(s) that is behind while ascending or descending. Alternatively, the “fastest” lift(s) can be corrected. For example, the lift that ascends or descends faster than the other lifts can be adjusted. This adjustment may involve sending an adjusting steering signal to the (lifting) drive of the carrier of the specific lift. The lift may relate to different types of lifts, including mobile lifting columns and stationary and/or moveable lifts of an in-ground lifting system. It will be understood that this approach for adjustment can be also be applied to sets of only mobile lifting columns.

[0252] In addition, it will be understood that communication between lifting devices and/or with a (central) controller may involve the use of wireless communication. This reduces the amount of cables in a workshop, thereby improving the safety of working in such workshop. Wireless communication can be performed at different bandwidths, for example in the radio spectrum such as within a bandwidth of 300-430 kHz. It will be understood that the use of other bandwidths can also be envisaged. It will be understood that this wireless communication, preferably within this specific bandwidth, can be also be applied to sets of only mobile lifting columns.

[0253] Furthermore, a fuel cell based power supply (for example using hydrogen, ethanol or formic acid as fuel) to provide power for the column can be envisaged, for both lifting the column (carriage) and/or moving (driving) the column. The capacity of the fuel cell can be relatively small. For example, the “off” time of the column can be used to (slowly) charge the batteries. The batteries will act as an energy buffer and will be discharged when power is needed by the column. Also, a drive for moving the lifting column can be provided that uses one or more of a hydrogen powered drive, electric drive, or other suitable drive, optionally in combination with another drive such as a fuel cell.