EP2275380A1

EP2275380A1 - A vehicle lift

Info

Publication number: EP2275380A1
Application number: EP09165305A
Authority: EP
Inventors: Johannes Jan Nijmeijer
Original assignee: Ingenieursbureau Moderniek BV
Current assignee: Ingenieursbureau Moderniek BV
Priority date: 2009-07-13
Filing date: 2009-07-13
Publication date: 2011-01-19

Abstract

A vehicle lift (1) comprises a platform (3) for supporting a vehicle (2) and three actuators (6, 7) for lifting the platform (3). The three actuators (6, 7) can be operated independently from each other. The actuators (6, 7) are engaged to the platform (3) such that the actuators (6, 7) support the platform at three resultant support locations (11).The resultant support locations (11) form corners of a virtual triangle as seen from above.

Description

The present invention relates to a vehicle lift.
Several types of vehicle lifts are known in the art, for example scissors lifts and other lifts that are applied in car repair garages. One of the requirements of a vehicle lift is that the vehicle is maintained in a stable position during lifting.
The object of the invention is to provide a vehicle lift which fulfils the mentioned requirement and that can be controlled in a simple way.
This is achieved by the vehicle lift according to the invention, which comprises a platform for supporting a vehicle, three actuators for lifting the platform, which actuators can be operated independently from each other, wherein the actuators are engaged to the platform such that the actuators support the platform at three resultant support locations, wherein the resultant support locations form corners of a virtual triangle as seen from above.
This means that the platform can be lifted by exerting three upwardly directed resultant forces at the resultant support locations of the platform. Since the actuators can be operated independently from each other the resultant forces can be controlled independently from each other. Because of the three-point support that is formed by the resultant support locations a relatively simple lifting control is possible since basically a deviation of the inclination between the resultant support locations should be monitored and adjusted during operation of the vehicle lift.
In a practical embodiment at least one of the actuators may comprise at least two upwardly displaceable elements which are spaced from each other in horizontal direction and operatively coupled to each other. This is advantageous in case of a heavy load, since it may be desirable to have an actuator that comprises more than one upwardly displaceable element in order to spread the resultant force over different sub-actuators or displaceable elements. The displaceable elements together still support the platform at one of the resultant support locations.
Each of the displaceable elements may be engaged to the platform at engaging locations which are spaced from each other in horizontal direction. In this case each of the displaceable elements exerts a force on the platform and the forces together form the resultant force which acts on the resultant support location.
The displaceable elements can be located along at least a longitudinal side of the platform and/or the displaceable elements can be located at opposite sides of the platform as seen in lateral direction of the platform extending perpendicularly to a longitudinal direction thereof. This typically depends on the expected concentrations of the load on the platform.
The displaceable element may comprise a hydraulic cylinder/piston combination, but alternative displaceable elements are also conceivable.
In a specific embodiment a rotatable wheel is mounted to the hydraulic piston and a belt is attached to both the hydraulic cylinder and the platform and guided by the wheel. This appears to be a robust and reliable structure of the vehicle lift.
The vehicle lift may be provided with at least an inclination sensor for detecting an inclination angle between two resultant support locations and a controller for controlling at least an actuator so as to synchronize the actuators during a vertical displacement of the platform. Due to this feature the platform, orientation can be controlled accurately during lifting.
In a preferred embodiment the vehicle lift comprises at least two inclination sensors for measuring the inclinations of the platform in a longitudinal and lateral direction, since this provides the opportunity to lift the platform in a stable orientation on the basis of the sensor signals.
The invention will hereafter be elucidated with reference to the very schematic drawings showing an embodiment of the invention by way of example.

Fig. 1a is a top view, Fig. 1b is a side view and Fig. 1c is a front view of an embodiment of the vehicle lift according to the invention.
Fig. 2 is a perspective view of the embodiment of Figs 1a-1c on a different scale, illustrating the control thereof.
Figs. 1a-1c show different views of an embodiment of a vehicle lift 1 according to the invention. In these Figs. a truck including a trailer 2 on the vehicle lift 1 is shown. Nevertheless the vehicle lift 1 is also suitable for lifting other vehicle types. Fig. 2 shows the embodiment of the vehicle lift 1 without a vehicle thereon so as to clarify its functioning.

The embodiment of the vehicle lift 1 as shown comprises a platform 3 for supporting the vehicle 2. The platform 3 has a rectangular shape as seen from above. The vehicle 2 is able to drive onto the platform 3 in a longitudinal direction thereof. In front of the platform the roadway is adapted to create a gradual transfer for driving the vehicle 2 onto the platform 3. This is also the case at the back side of the platform 3 as seen in longitudinal direction thereof. Of course, it is also possible that the platform 3 is only accessible at one short side thereof as illustrated in Figs. 1a and 1b.
The vehicle lift 1 as shown in Figs. 1a-1c and 2 is provided with six pillars 4 which extend substantially vertically. Three pillars 4 are located at one side of the platform 3 and three pillars 4 are located at the opposite side of the platform 3. The platform 3 is moveable in vertical direction between the pillars 4. Adjacent pillars 4 in longitudinal direction of the platform 3 are attached to each other by longitudinal bars 5.
Each of the pillars 4 comprises a displaceable element, which, in the present embodiment, comprises a hydraulic cylinder 6 and piston 7 which is moveable with respect to the hydraulic cylinder 6. As can be seen in Fig. 2 a freely rotatable wheel 8 is mounted to the piston 7. Furthermore, a belt in the form of a chain 9 is engaged to the hydraulic cylinder 6 and the platform 3 at an engaging location 10, and guided by the wheel 8. When the piston 7 is moved upwardly with respect to the hydraulic cylinder 6 the chain 9 will pull the platform 3 at the engaging location 10 upwardly, whereas the wheel 8 will guide the chain 9. Alternatively, the displaceable element may be an electrically driven screwable element or a winch, for example.
The embodiment as shown in the Figs. comprises three pairs of hydraulic cylinder/piston combinations 6, 7. In each pair the hydraulic cylinder/piston combinations 6, 7 are spaced from each other in horizontal direction. Furthermore, the hydraulic cylinder/piston combinations 6, 7 of a pair are operatively coupled to each other such that their hydraulic pressure is equal. Due to their coupling each pair forms a resultant support location 11 which will be located between the engaging locations 10 of the respective corresponding hydraulic cylinder/piston combinations 6, 7. Each of the three pairs of hydraulic cylinder/piston combinations 6, 7 can be operated independently from each other such that exactly three resultant support locations 11 are present. In other words the platform 3 is supported by three actuators in the form of three pairs of hydraulic cylinder/piston combinations 6, 7 at three resultant support locations 11.
According to the invention the resultant support locations 11 form corners of a virtual triangle as seen from above. This is illustrated in Fig. 1a. Due to the symmetric dimensions of the embodiment as shown the virtual triangle has two sides of substantially equal lengths, but alternative shapes are conceivable.
Since the embodiment of the vehicle lift 1 as shown is suitable for lifting a truck including a trailer 2 two pairs of hydraulic cylinder/piston combinations 6, 7, which pairs are each located along a longitudinal side of the platform, are disposed at opposite sides of the platform 3 in lateral direction, which is in practice near the location where the wheels of the trailer will be present. Thus, this region of the platform 3 is supported by four hydraulic cylinder/piston combinations 6, 7 in total. At the front side of the truck 2 less lifting power is required, which means that only one pair of hydraulic cylinder/piston combinations 6, 7 is applied. In this pair the hydraulic cylinder/piston combinations 6, 7 are located at opposite sides of the platform 3 as seen in lateral direction of the platform 3.
Fig. 2 shows a hydraulic fluid control system of the vehicle lift 1. Each pair of hydraulic cylinder/piston combinations 6, 7 are in fluid communication with each other and also with a source of hydraulic fluid 12 via a pump 13 and a valve 14. The hydraulic fluid circuit also comprises fluid line leakage protection valves 15. Furthermore, a pressure sensor will indicated the end of lowering or jamming conditions.
Due to the three resultant support locations 11 which form corners of a virtual triangle it is relatively simple to control the hydraulic fluid control system for synchronizing the three pairs of hydraulic cylinder/piston combinations 6, 7 during a vertical displacement of the platform 3 on the basis of signals from inclination sensors which are able to detect an inclination angle between two resultant support locations 11. Additionally, the platform orientation can be controlled during vertical displacement by a rough height control in the form of a balancer and a more accurate control on the basis of a signal from two inclination sensors, one for measuring an inclination of the platform 3 in longitudinal direction and one for measuring an inclination thereof in lateral direction.
From the foregoing, it will be clear that the invention provides a vehicle lift which can be operated in a relatively simple way.
The invention is not limited to the embodiment shown in the drawings and described hereinbefore, which may be varied in different manners within the scope of the claims and its technical equivalents. The platform may have alternative shapes instead of a rectangular flat type. Pairs of hydraulic cylinder/piston combinations may also be replaced by one, or three or more hydraulic cylinder/piston combinations so as to form a resultant support location. Furthermore, the wheel and chain may be replaced by a gear and toothed belt, for example.

Claims

A vehicle lift (1) comprising
a platform (3) for supporting a vehicle (2),
three actuators (6, 7) for lifting the platform (3), which actuators (6, 7) can be operated independently from each other,
the actuators (6, 7) being engaged to the platform (3) such that the actuators (6, 7) support the platform at three resultant support locations (11), wherein the resultant support locations (11) form corners of a virtual triangle as seen from above.
A vehicle lift (1) according to claim 1, wherein at least one of the actuators comprises at least two upwardly displaceable elements (6, 7) which are spaced from each other in horizontal direction and operatively coupled to each other.
A vehicle lift (1) according to claim 2, wherein each of the displaceable elements (6, 7) is engaged to the platform at engaging locations (10) which are spaced from each other in horizontal direction.
A vehicle lift (1) according to claim 2 or 3, wherein the displaceable elements (6, 7) are located along at least a longitudinal side of the platform (3).
A vehicle lift (1) according to claim 2 or 3, wherein the displaceable elements (6, 7) are located at opposite sides of the platform (3) as seen in lateral direction of the platform extending perpendicularly to a longitudinal direction thereof.
A vehicle lift (1) according to one of the claims 2-5, wherein the displaceable element comprises a hydraulic cylinder/piston combination (6, 7).
A vehicle lift (1) according to claim 6, wherein a rotatable wheel (8) is mounted to the piston (7) and wherein a belt (9) is attached to both the hydraulic cylinder (6) and the platform (3) and guided by the wheel (8).
A vehicle lift (1) according to one of the preceding claims, wherein the vehicle lift (1) is provided with at least an inclination sensor for detecting an inclination angle between two resultant support locations (11) and a controller for controlling at least an actuator (6, 7) so as to synchronize the actuators (6, 7) during can vertical displacement of the platform (3).
A vehicle lift (1) according to one of the preceding claims, wherein the vehicle lift (1) comprises at least two inclination sensors for measuring the inclinations of the platform (3) in a longitudinal and lateral direction.