NL2011367C2 - In-ground lifting system for lifting a vehicle and method there for. - Google Patents

Description

In-ground lifting system for lifting a vehicle and method there for

The invention relates to an in-ground lifting system and more specifically to a system comprising one or more movable lifts or lifting devices. These in-ground lifting systems are specifically used for lifting trucks, buses and other vehicles.

In known in-ground vehicle lifting systems with a movable lifting device this movable lifting device is manoeuvred under an axle of the vehicle, like a bus or truck, in accordance with the specific axle distance of the vehicle. In practice, different types of vehicles, and more specifically different lengths of such vehicles with different axle distances need to be dealt with by moving the movable lifting device. This requires moving of the movable lifting device in a pit. A cover is provided to cover the opening of the pit and to provide a safe working place when performing service or maintenance operations such as tire or brake replacement, or other tasks that require access to the underside of the motor vehicle. It is not uncommon that companies using an in-ground lifting system are confronted with over 200 types of vehicles that have different dimensions. This requires moving the carriage with the movable lifting device over the length of the pit by a drive. Every time the lifting device is repositioned, the cover moves accordingly. In practice, this results in problems when repositioning the cover. For example, due to dirt and trash that moves around in the work place where the in-ground lift is installed, moving the cover may become problematic possibly resulting in unsafe working conditions. Furthermore, when moving the cover it may not run smoothly such that the cover or cover elements may become damaged thereby hindering the operation of the in-ground lift and resulting in additional maintenance and repair costs.

An objective of the invention is to obviate or at least reduce the above problems to improve safety when lifting a vehicle.

This objective is achieved with an in-ground lifting system for lifting a vehicle according to the invention, the in-ground lifting system comprising: - one or more movable lifts; - a support structure for mounting the one or more lifts in a pit; - a carriage for supporting the lift from the support structure and being movable within the support structure, wherein the lift is capable of moving between an extended position in which a portion of the lift extends from the support structure, and a retracted position in which a substantial entirety of the lift is positioned within the support structure; - a cover connected to the carriage for covering the pit; and - a cover drive for driving the cover such that the cover moves the carriage and the lift can be moved between the extended and retracted positions at any location within a range of travel of the carriage within the support structure.

The invention relates to a so-called in-ground lifting system. Such vehicle lifting system preferably comprises a first lift with a stationary position and is used for lifting the front, or alternatively the rear, of the vehicle. The system further comprises at least one moveable lift for lifting the other part of the vehicle. The one or more moveable lifts of such lifting system are preferably provided in a pit. The pit enables a translational movement for the moveable lifting device in the length of the vehicle to be lifted. The moveable lift moves in a pit such that can be dealt with a wide range of vehicle dimensions. The pit is covered with a pit cover. Preferably, the moveable lift is connected to the pit cover such that the pit remains covered during the operation. Depending on the dimensions of the vehicle, for example the amount of axles or axles, more than one moveable lift according to the invention may be provided.

The vehicle lifting system according to the invention may comprise lifts of a scissor type or alternatively of a telescopic (piston) type. The scissor type lift has the additional advantage that a relatively shallow pit construction can be used which can be applied beneficially to situations with bedrock, water table or unstable soil conditions. Both types accommodate vehicles with relatively low ground clearance.

Preferably, the vehicle is lifted by the lift engaging one of the wheel axles or axles of the vehicle. The one or more moveable lifts are positioned based on the distance as determined between two vehicle axles. In case more than two vehicle axles need to be lifted, a further movable lift is steered to the movable desired position.

This achieves an effective and efficient positioning of the movable lift reducing the time required for positioning a vehicle relative to the lifting system according to the invention .

According to the invention, the carriage for supporting the lift that is movable within the support structure of the pit of the in-ground lifting system is moved by pulling the cover that is connected to the carriage. A cover drive is provided that is capable of driving the cover such that the cover moves the carriage so that the lift can be moved between the extended and retracted positions at any locations between the range of travel of the carriage within the support structure. Driving the cover is according to the invention preferably performed by pulling the cover towards the desired direction of travel of the moveable lift. The cover connected to the carriage of the moveable lift is being pulled such that the carriage moves in the desired direction. On the other side of the carriage the cover is jointly pulled with a carriage. Moving the cover is achieved by applying pulling forces only. By pulling the cover, the cover can be moved jointly and blocking and/or undesired upward folding of the cover, or cover part thereof, is substantially prevented. This provides an effective in-ground lifting system that can be used efficiently with a substantial reduction of the number of malfunctions and associated maintenance and repair costs. A further advantage of pulling the cover(s) to move a moveable lift is the simplification of the drive or drive system that can be achieved. This may reduce investment costs. In addition, this may reduce the risk of malfunctions and associated maintenance and repair costs.

While lifting a vehicle, at least two of the wheel axles of the vehicle have to be positioned over the lifts of the lifting system. The wheel base distance defines the distances between axles of the vehicle. The wheel base distance is a measure for correct positioning of the lifts.

Preferably, the front wheels are positioned in a wheel positioning hatch or wheel recess, preferably adjacent to the stationary lift. One or more movable lifts are positioned under some or all of the other vehicle axles.

Different configurations are possible for the position of the vehicle relative to the lifting system.

In a first preferred configuration, when positioning the vehicle, the vehicle rides past or over the movable lifts and the front axle is positioned over or on top of the stationary lift. The other wheel axles are positioned relative to the moveable lifts.

In a second preferred configuration, when positioning the vehicle, the vehicle rides past or over the stationary lift and the front axle is positioned over or on top of a movable lift. In case the lifting system comprises more than one movable lift, the front axle is preferably movable over the lift at the largest distance from the stationary lift. The rear axle to be lifted is positioned over or on top of the stationary lift.

The in-ground lifting system according to the invention is preferably provided according to a so-called flush type wherein the bolster of the lift in a retracted position is more or less even or "flush" with the floor of the work place. This has advantages when working with relatively low vehicles having a relatively small distance between the work floor and the vehicle bottom. Such flush type system can be achieved by providing pockets at a specific location such that in the retracted position the lifting system has to provide the moveable lift at this specific location, or with a continuous system wherein the bolster can move over the entire moving distance of the carriage in the pit and be retracted at any desired position. In practice, this continuous type requires a pit whereof at the least the upper side is provided with a larger width capable of receiving the bolster. These flush type systems have the advantage that the floor surface can be flat or even when the in-ground lifting is not in use. As an alternative system, the non-flush type system provides a bolster that in the retracted position remains above the floor surface.

In an advantageous preferred embodiment according to the present invention the cover drive comprises a drive roll for driving the cover.

By providing the cover drive comprising a drive roll the cover parts can be stored efficiently on a roll or roller. Preferably, the drive roll is provided in the pit structure of the in-ground lifting system.

In an advantageous preferred embodiment according to the present invention the cover drive of the in-ground lifting system comprises a spring-element for driving the cover .

By providing a spring-element a continuous pulling force is put on the cover, acting as a sort of pretension, such that the cover moves gently and malfunctioning is prevented.

In an advantageous preferred embodiment according to the present invention the cover drive of the in-ground lifting system according to the invention comprises a second drive roll. Preferably, the second drive roll is situated on the opposite end of the pit as compared to the first drive. By providing a second drive roll a pulling force can be provided to the cover for pulling the lift in the desired direction. This means that moving the cover for driving the carriage of the lift device can be performed with a pull force. This prevents malfunctioning of the lifting system according to the present invention.

In a presently preferred embodiment according to the present invention the system further comprises a pulling element connected to the drive for moving the cover.

By providing a pulling element that is connected to the drive, the drive is only indirectly connected to the cover or cover parts thereof. Using such pulling element enables locating the drive at a desired position, such that more space is available for the lifting system.

Preferably, the pulling element comprises a cable. Such cable may be a steel cable, for example. This cable provides the pulling force of the drive on the cover.

In a presently preferred embodiment the in-ground lifting system comprises a wheel base measuring system.

By providing a wheel base measuring system a wheel axle can be positioned accurately. Preferably, the wheel base measuring system comprises distance measuring means determine the distance of the vehicle to a reference point. The distance measuring means may comprise a camera, (near) infra-red sensor, ultrasound sensor and/or another appropriate sensor for directly or indirectly determining the vehicle dimensions, and more specifically the axle position(s). Using the sensor(s) the wheel position can be defined accurately. As the wheel axle is accurately positioned with the positioning means, either directly or indirectly through defining the wheel position, the distance from this vehicle to a reference point is measured. By performing a separate measurement for every wheel axle that needs to be lifted the control means are capable of determining the distance between two vehicle axles by calculating the difference between the distances of the vehicle to a reference point for different wheel axles.

After the distance between two vehicle axles is calculated the control means steer one or more movable lifts to the correct position.

By measuring the actual wheel base distance between individual wheel axles, automatically the desired lifting position for the lifts of the lifting system is detected. This is achieved by first positioning one of the wheel axles, preferably the front axle, in a defined position, for example with a wheel positioning edge or recess. By comparing the distance measurement with the measurement (s) for other wheels and wheel axles the desired wheel axles distances can be determined. Using the determined distances between the wheel axles the movement of the moveable lifting device is controlled and the lifts are positioned correctly for the type of vehicle that needs to be lifted.

The measuring means involve a sensor preferably comprising a type of transmitter and a type of receiver.

This involves the use of RF, IR etc. More particularly the sensor may involve a laser including infra-red lasers, ultraviolet lasers, X-ray lasers and the like.

In addition, by providing a contactless sensor the robustness of the system is further improved. No physical contact between the detection means and the vehicle is required for determining the desired lifting position.

Preferably, the control means comprise a process controller. More preferably, the process controller is the overall lifting system controller that integrates the wheel base measuring system with the lifting system to provide an integrated wheel based lifting system for lifting a vehicle. Optionally, the process controller is used to control the cover drive for moving the cover. This also enables to start moving covers pulling the movable lift to its desired lifting position while manoeuvring the vehicle relative to the lifting system. This reduces the time required for positioning a vehicle on the lifting system.

Furthermore, the integrated process controller enables performing additional safety checks to see whether the measured and/or calculated distances are in an expected range and to provide an operator with an alarm in case the measured and/or calculated distance is outside such range.

Preferably, the lifts lift the vehicle by engaging the vehicle axles. Alternatively, the vehicle can be lifted by the lifts engaging on another part of the vehicle.

Automatically detecting the desired lifting position and next, preferably fully automatic, moving the moveable lift or lifts by pulling the cover by the cover drive to the desired position, guarantees a correct positioning of the lifts under the vehicle independent of the vehicle type. Furthermore, the system according to the invention guarantees a correct and safe lifting operation. A further advantage of the lifting system according to the invention is that the operation of the vehicle lifting system does not depend on the type of vehicle that needs to be lifted. New vehicle types can be lifted as easily as known conventional vehicles.

The invention further relates to a method for lifting a vehicle, the method comprising the steps of: - positioning the motor vehicle with the above lifting system, so that a first axle of the motor vehicle is located directly above a first lift and a second axle of the motor vehicle is located over a pit having a second lift located in the pit with a support structure; - positioning the second lift by driving the cover with a cover drive thereby moving the carriage with the lift, so that the second lift is located directly beneath the second axle; and - extending the first and second lifts so that the first and second lifts urge the respective first and second axles upward.

The same effects and advantages apply for the method as described for the system. The method according to the invention involves at least one cover drive preferably pulling the cover for positioning the lift. In a presently preferred embodiment according to the present invention the method further comprises determining wheel base distances using a wheel base measuring system.

Further advantages, features and details of the invention will be elucidated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying drawings, in which: - Figure 1 shows a system according to the present invention; - Figure 2A-C show a piston-type lifting system; - Figure 2D shows a scissor-type lifting system; - Figures 3A-B show a first embodiment with the cover drive according to the invention; - Figure 4 shows a second embodiment according to the invention; - Figure 5 shows a third embodiment according to the invention; - Figure 6 shows a fourth embodiment according to the present invention; and - Figure 7 shows a schematic diagram of the method and system according to the invention. A lifting system 2 (figure 1) comprises a stationary lifting column 4 and a moveable lifting column 6 that are located on or in floor 8. The front lifting column 4 is provided in cassette or box 10 with a telescopic lifting cylinder 12. On top of cylinder 12 there is provided carrier 14 with axle carriers 16. In the illustrated embodiment wheel edges or wheel recesses 18 are provided. Recesses 18 define the position of the front wheels of the vehicle. Furthermore, in the illustrated embodiment a hatch 20 is provided in front of the front lifting column 4 for maintenance, for example.

The moveable lifting column 6 moves in cassette or box 22. Box 22 provides a pit with a slot or recess 24 for guiding the moveable lifting column 6. Moveable lifting column 6 is provided with carrier 26 whereon axle carriers 28 are mounted. Depending on the type of vehicle additional adapters can be provided that cooperate with carriers 14, 26 to enable engagement with different axle dimensions.

Cover 27 covers box 22. Cover drive 29 drives cover 27 such that moveable lift 6 moves in box 22.

Lifting column 6 is optionally provided with camera 30 that enables a safety check when system 2 is about to lift the vehicle and allows the operator to additionally check the engagement of the carrier 26 on the axle of the vehicle .

Using system 2 enables positioning the moveable lifting column 6 with accuracy of at least 2.5 cm and preferably within the range of about 1.25 cm.

Further details of conventional parts of system 2 are disclosed in WO 2006/112857 which is included by reference herein. WO 2006/112857 specifically discloses a scissor type lifting device that is positioned in a pit.

This pit with a pit cover and lifting means involving auxiliary adapters engaging the axle of the vehicle have been described in detail herein.

Wheel base measuring system 32 comprises sensor 34, 36. In the illustrated embodiment sensor 34, 36 is positioned on or against wall 38 to provide a stable reference point for the measurement. Sensor 34, 36 provides a signal 40 when performing a distance measurement. Signal 40 may use infrared, ultrasound and/or another signal. The use of such signal 40 prevents physical contact between the sensor 34, 36 and the wheels or axles of the vehicle. Measurement signal 42 is provided to controller 44. Controller 44 steers the required sensor activities and performs the desired calculations. Controller 44 starts a measurement when a wheel of the vehicle is in recess 46, 48. Recesses 46, 48 can be provided with a sensor 50, for example a load sensor. Sensor 50 provides a measurement signal 52 to controller 44 indicative of the presence of a wheel in recess 46, 48. Controller 44 may optionally also control cover drive 29 for driving cover 27. Optionally, recess 46 can be combined with wheel recesses 18 to provide one recess adjacent to stationary lift 4. It will be understood that one recess 46, 48 will suffice for the wheel base measuring system 32 included in lifting system 2. In one of the preferred embodiments recess 46 is combined with wheel recess 18 such that no additional recesses are required .

In the illustrated embodiment controller 44 provides a steering command 54 to cover drive 29. A vehicle 78 (figures 2A-C) is positioned over or relative to system 2. Moveable lifting device 6 is positioned under rear axle 80 of vehicle 78 using wheel base measuring system 32 that is integrally provided with lifting system 2 in the illustrated embodiment, and cover drive 29 using cover 27 for positioning lift 6.

Rear axle 80 is lifted by movable lifting column 6, while front axle 82 is lifted by stationary lifting column 4. In the illustrated embodiment movable lift 6 moves from starting position 84 to the desired lifting position 86 .

In the illustrated embodiment lifts 4, 6 engage axles 80, 82 directly, such that lifting position 86 corresponds to the rear axle 80 location. As described earlier, carriers 14, 26 may engage other parts of the vehicle. Furthermore, in the illustrated embodiments one moveable lifting column 6 is shown. Alternatively, more than one, for example two, moveable lifting columns 6 can be provided for system 2. Preferably, the individual lifts 6 are provided with a corresponding cover drive 29.

When engaging the axles of the vehicle for lifting, the number of lifting devices 4, 6 may depend on the size of the vehicle and/or number of axles of the vehicle. It will be understood that either the front wheel axle or a rear wheel axle can be lifted by the stationary lift during a lifting operation.

In an alternative lifting system 88 of the in-ground type (figure 2D) the telescopic lifting cylinders 12 of lifting system 2 are replaced by scissor type lifts 90.

It will be understood that operation of lifting systems 2, 88 of the in-ground type is similar.

In a first embodiment 92 (figure 3A-B) a cover drive 94 comprises a first roller drive 96 for pulling cover 27. Guiding roller 98 guides the movement of cover 27. On one side 100 of movable lifting device 6 first cover partition 102 is provided and connected to roller drive 96. On the other side 104 of moveable lift 6 second cover partition 106 runs over a further guide roller 108 and is connected to a second drive roller 110. Cover 27 comprises a number of cover elements 112 that are attached to each other. At the ends of cover 27 cable 114 is provided that connects the ends of cover 27 with the respective drive rollers 96, 110 .

It will be understood that the drive rollers 96, 110 can be provided at the end of the pit. However, in alternative embodiments the roller drive can be located at other positions. Furthermore, the drive rollers receive the cover 27. It will be understood that alternative configurations according to the invention will also be possible. For example, cover 27 can be provided between additional buffer rollers that behave as a buffer for receiving cover parts 112. In such embodiment cover parts 112 are buffered in (vertical) layers hanging in loops from the additional buffer rollers. This prevents cover 27 being wound on roller 96, 110.

In a second embodiment 116 (figure 4) on one side an additional spring element 118 is provided. As is schematically illustrated, the (spriral) spring element 118 is connected to the axis of roller 110. This provides a continuous tensioning force on cover partition 112. This improves movement of cover 27. In addition, this may require the use of only one drive 96 on one side of cover 27. This provides a cost effective embodiment. In such alternative embodiment a continuous pulling force acts on cover 27.

In a third embodiment (figure 5) system 120 is provided with a cover 27 that is directly connected to drive rollers 96, 110. In this embodiment the shape of rollers 96, 110 preferably is adapted to receive cover parts 112.

In a fourth embodiment (figure 6) system 122 is provided with a drive 124 pulling cover 27 from horizontal surface position and pushes cover parts 112 inside the pit using roller 126 and guides 128 to buffer a row of cover parts 112.

Lifting operation 202 (figure 7) first performs an initialization step 204. Then a first axle of a vehicle is positioned by providing a wheel in a recess in positioning step 206. Thereafter, measurement step 208 is performed to measure the distance between the vehicle and a reference point. The vehicle is moved forward in step 210 and a second wheel is positioned in the recess in step 212 such that a further measuring step 214 can be performed. In case more than two axles need to be lifted the vehicle is moved further and steps 210, 212, 214 are performed again.

Finally, the vehicle moves towards the lifting system in step 216. The wheels are positioned in positioning step 218 relative to the stationary lift 4. Thereafter, or alternatively at the same time, the one or more movable lifts 6 are positioned by driving cover 27 in positioning step 220 such that the vehicle is positioned relative to the lifting system and is ready for lifting operation 222. At the end of the lifting operation the vehicle is removed from lifting system 2.

The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged. For example, it is explicitly mentioned that combinations of the illustrated embodiments, or features thereof, are possible. In the illustrated embodiments axle carriers have been shown. Alternatively, other carriers engaging other parts of the vehicle to be lifted can be applied.

CLAUSES 1. In-ground lifting system for lifting a vehicle, comprising : - one or more movable lifts; - a support structure for mounting the one or more lifts in a pit; - a carriage for supporting the lift from the support structure and being movable within the support structure, wherein the lift is capable of moving between an extended position in which a portion of the lift extends from the support structure, and a retracted position in which a substantial entirety of the lift is positioned within the support structure; - a cover connected to the carriage for covering the pit; and - a cover drive for driving the cover such that the cover moves the carriage and the lift can be moved between the extended and retracted positions at any location within a range of travel of the carriage within the support structure. 2. In-ground lifting system according to clause 1, wherein the cover drive comprises a drive roll for driving the cover . 3. In-ground lifting system according to clause 1 or 2, wherein the cover drive comprises a spring-element for driving the cover. 4. In-ground lifting system according to clause 2 or 3, wherein the cover drive comprises a second cover drive. 5. In-ground lifting system according to one or more of the foregoing clauses, further comprising a pulling element connected to the cover for moving the cover. 6. In-ground lifting system according to clause 5, wherein the pulling element comprises a cable. 7. In-ground lifting system according to one or more of the foregoing clauses, wherein at least one of the movable lifts is a scissors lift. 8. In-ground lifting system according to one or more of the foregoing clauses, wherein at least one of the movable lifts is a piston lift. 9. In-ground lifting system according to one or more of the foregoing clauses, further comprising a wheel base measuring system. 10. A method for lifting a vehicle, comprising: - positioning the motor vehicle with the system according to one or more of the foregoing clauses, so that a first axle of the motor vehicle is located directly above a first lift and a second axle of the motor vehicle is located over a pit having a second lift located in the pit with a support structure; - positioning the second lift by driving the cover with a cover drive thereby moving the carriage with the lift, so that the second lift is located directly beneath the second axle; and - extending the first and second lifts so that the first and second lifts urge the respective first and second axles upward.

Claims (10)

An underground lifting system for lifting a vehicle, comprising: - one or more movable lifting devices; - a support structure for mounting therein the one or more movable lifting devices in a well; - a carriage for supporting the lifting device from the support structure and movable within the support structure, the lifting device being adapted to move between an extended position, in which a part of the lifting device extends from the support structure, and a retracted position, in which a substantial part of the lifting device is positioned within the support structure; - a cover connected to the carriage for covering the well; a cover drive for driving the cover such that the cover causes the carriage to move and the lifting device can be moved between the extended and retracted position at any location within a range of movement of the carriage in the support structure. 2. Underground lifting system as claimed in claim 1, wherein the cover drive comprises a drive roller for driving the cover. 3. Underground lifting system as claimed in claim 1 or 2, wherein the cover drive comprises a spring element for driving the cover. 4. Underground lifting system as claimed in claim 2 or 3, wherein the cover drive comprises a second cover drive. 5. Underground lifting system according to one or more of the preceding claims, further comprising a pulling element connected to the cover for moving the cover. 6. Underground lifting system as claimed in claim 5, wherein the pulling element comprises a cable. 7. Underground lifting system as claimed in one or more of the foregoing claims, wherein at least one of the movable lifting devices is a scissor lift. 8. Underground lifting system as claimed in one or more of the foregoing claims, wherein at least one of the movable lifting devices is a telescopic lift. 9. Underground lifting system according to one or more of the preceding claims, further comprising a wheel base measuring system. Method for lifting a vehicle comprising: - positioning the motor vehicle with the system according to one or more of the preceding claims, such that a first axle of the motor vehicle is positioned directly above a first lifting device and a second axle of the vehicle motor vehicle is positioned above a well with a second lifting device positioned in the well with a support structure; - positioning the second lifting device by driving the cover with a cover drive thereby moving the carriage with the lifting device, such that the second lifting device is positioned directly below the second axle; and - extending the first and second lifting device such that the first and second lifting devices push the respective first and second axes upwards.