Field of invention

The invention relates to a lift system for elevation of persons or goods.

Background of the Invention

Lift or elevator systems are normally used as a vertical transportation means for moving people and goods, for example between floors in a building. Lifts are conventionally positioned in shafts and are guided by rails that span the entire shaft and powered by a motor that drive a traction cable. These lift systems are required to have some part of the system positioned at the highest point reachable for the lift. That can be the motor itself or a pulley which is used to change the direction of the traction cable that connects the motor and the cabin. Lifts used for persons requires measures ensuring the security of the persons.

Accordingly, making sure, that in case of a malfunction the lift does not fall to the ground and cause injury. This can be ensured by emergency brakes on the cabin, which brakes against the rails or a brake on the traction cable. It is usually preferred that a lift system has means which will enable persons to leave the lift in case of a malfunction.

A lift system is known from US 3,954,157 which disclose a hydraulic elevator installation for vertically transporting an elevator cab up and down in a hoistway comprising a piston, fixedly mounted in a vertical position in the hoistway and a lifting frame for carrying the elevator cab. The lifting frame includes a cylinder, forming a vertical support member of the lifting frame and slidably mounted on the piston for vertical reciprocating movement thereon.

A lift system is also known from US 4,041 ,845 which disclose a hydraulic elevator apparatus, including a cylinder and a fluid actuated plunger, which supports an elevator car. A cylinder head seals against fluid leakage to the outside, and it guides the plunger as it moves relative to the cylinder. The cylinder head includes a travel limit structure for the plunger which generates a hydraulic retarding force programmed by a resilient device which adjusts the hydraulic retarding force during a travel limit stop. The resilient device also adds its own retarding force to the plunger, to smoothly decelerate and stop the plunger with minimal impact forces on the cylinder head.

Summary of the invention

Considering the prior art described above, it is an object of the present invention to provide a lift system wherein there are no requirements for parts of the system to be positioned at a substantially greater height than the cabin.

The object can be achieved by means of a lift system for elevation of persons or goods, comprising elevation means and a cabin that at least at times can move in a vertical direction and be positioned at different vertical positions, the cabin comprises an outer surface with a bottom area defining a footprint for the cabin and an inner compartment with a floor, the footprint comprises an inner area where the footprint and the floor overlaps, and an outer area where the footprint and the floor does not overlap, the elevation means comprises at least one lifting column, which is able to move the cabin in the vertical direction wherein the at least one lifting column penetrate the bottom of the outer area.

Thus, it is possible to have a lift system where there is no need to have a part of the system at an elevated position above the cabin to pull the cabin upwards. Additionally, the lifting column is outside the inner compartment, making sure that the person using the lift system does not get in contact with the moving parts of the lift system. The lift system can, so to speak, be made as a self-contained entity that can easily be installed and if necessary moved. The footprint can, preferably, be square, round, oval or super elliptic

In an embodiment, the at least one lifting column comprise a telescopic member. The telescopic member can be a telescopic member with multi-stage units of two, three, or more stages. Preferably, the telescopic member comprises at least two metal or plastic profiles which enable the telescopic motion. This expands the movable vertical distance of the cabin.

Preferably, the telescopic member can at least at time be retracted to be substantially enclosed within the outer surface of the cabin. This makes the system compact and very easy to install as the lift system can be delivered and installed as a single unit requiring little or no extra space to incorporate parts of the system. In an embodiment, the telescopic member comprises a wire pulley system that secures the extending of the telescopic member is facilitated. Using multiple linear actuators can be expensive and they can be difficult to calibrate to get a smooth speed of the cabin. If the lift system only uses one or a small number of actuators then the moving parts can be connected by a wire pulling system to lower the costs. This is especially advantageously when using a telescopic member, as it is sufficient to have only one actuator and a number of wires and pulleys, depending on the number of telescopic members and the number of stages in each telescopic member.

Advantageously, the elevation means comprises linear actuator, preferably a hydraulic actuator. Hydraulic actuators have the benefit of no need for additional security as the cabin will not fall after a hydraulic malfunction. If for example the pump stops working, it will be impossible to ascend the lift, but neither will it descend. By opening a valve and releasing hydraulic fluid (e.g. oil) from the hydraulic system, it is possible to descend the lift in a controlled manner. The valve can be an extra security valve installed for this purpose. If alternatively, a linear actuator with a spindle and nut is used, the lift will simply stop moving during a malfunction.

In an embodiment, the outer surface of the cabin comprises a top defining a

substantially vertical top-plane wherein the at least one lifting column does not extend through the top plane. Accordingly, the lifting column does not extend through the roof of the cabin. Constructing the lift system this way, ensures a compact construction and easy installation of the lift system. Further, it is easy to install this lift in buildings not prepared for lifts. This is the case in old buildings where, during construction, no lift was installed. Subsequent installation of the lifts often require extensive modifications of the building, whereas the present invention require very little modifications.

Preferably, the elevation means comprises two, three or four lifting columns. Using two or more lifting columns secures the stability of the lift system. The Cabin can, so to speak, be situated on at least two feet. The task to be considered when using more than one lifting column is the synchronisation of the columns. The extension needs to be in sync, to ensure that the floor of the inner chamber keeps a vertical position. This can be done by using only one actuator and connect at least one of the lifting columns to the actuator via a column wire pulley system. In other words, letting the lifting columns be actuated by a shared actuator. In an embodiment, the at least one lifting column extends through a plane having a vertical position similar to the floor of the inner compartment. In other words, the lifting columns go further up than the floor of the inner compartment. Using this embodiment ensures the lifting columns can have a larger part inside the cabin, and that the cabin is constructed to provide space for the lifting columns.

Preferably, the inner compartment comprises at least one wall and a door, wherein the floor of the inner compartment is only limited by the at least one wall and the door of the inner compartment. Accordingly, that the floor is unbroken. For example that it is not possible to circumscribe the lifting columns from within the inner chamber.

In an embodiment, the lift system further comprises means for rotating the cabin. This can for example be a rotating floor plate, situated under the elevation means so that when the floor plate is rotated, the entire cabin and elevation means are rotated. It is preferred that the footprint is circular as rotation of the cabin will not require additional modification of the surroundings. It is especially advantageously to have a rotating cabin if the cabin has two doors. This can for example be an entrance door and an exit door, which means that a wheelchair user can enter the cabin and then exit front first without turning the wheelchair inside the cabin. This makes it possible to use a smaller cabin as there is no need for space to manoeuvre the wheelchair inside the cabin. Further, a rotating cabin can, with ease, be installed between floors having different layout as less consideration for keeping the door easily accessible e.g. by keeping them away from walls.

In an embodiment, the elevation means comprise a timing belt connected to a pulley system and drive means adapted to facilitate the movement of the cabin. This is an advantageously embodiment because a timing belt is a reasonably simple construction and can be made compact.

Description of the drawings

The invention will in the following be described in greater detail with reference to the accompanying drawings: Fig. 1 a schematic view of a lift system according to a first embodiment of the invention.

Fig. 2 a schematic view of a lift system according to a second embodiment of the invention in a first position.

Fig. 3 a schematic view of a lift system according to a second embodiment of the invention in a second position.

Fig. 4 a schematic views of top cross-sectional view of a second embodiment of the invention with the doors open.

Fig. 5 a schematic views of top cross-sectional view of a second embodiment of the invention with the doors closed.

Fig. 6 a schematic view of a lifting column.

Fig. 7. a schematic view of a second embodiment of lifting columns

Fig. 8. a schematic view of an embodiment of means for rotating the cabin. Description of a preferred embodiment

Fig. 1 shows a lift system 1 according to a first embodiment of the invention with a top or roof 5, a floor 4, outer walls 5 and inner doors 3 which define a cabin. The doors 3 are positioned on tracks so that is can slide to the side and not occupy any

considerable space neither outside nor inside the cabin. Although the doors can be of any type as long as they provide access to the cabin. The lift system 1 can be of any form such as rectangular or circular, in the present case the lift system 1 has an elliptic shape. Generally it is preferred to have an elliptic or circular shape (see fog. 2 to 5 for a embodiment with circular shape) as that ensures that sliding doors can follow the outer shape of the lift. This provide the benefit that the lift doors can be made relatively large compared to the cabin and at the same time not occupy cabin space or require space outside the cabin. This is especially beneficial, as it makes the installation of the lift easier and the cabin can be relatively small leading to fewer requirements for the surroundings compared to a lift system with rectangular shape.

The cabin can also have two sets of doors one on each "side". Then the person using the lift does, for example not need to turn around between entering at one level and exiting at another level. This is beneficial for people with reduced mobility such as people in wheel chairs. The cabin can have a control panel, wherein the vertical position of the cabin can be controlled. This lift control panel is well known in the art.

The first embodiment shown in fig. 1 has two lifting columns 2. The lifting columns are positioned within the footprint of the lift system 1. They do in a way limit the space inside the cabin because parts of them are enclosed within the outer shape of the lift 1. The lift columns 2 are telescopic and actuated 8 by a hydraulic actuator as described below. The telescopic lifting column 7 has three telescopic members 12, 13, 14 on each lifting column 2. This enables the cabin to be elevated to a position that is about three times the height of the cabin. The number of telescopic members required, is dictated by the height that the cabin must reach. In principle any height can be reached with the use of telescopic members.

Fig. 2 and 3 shows a second embodiment of a lifting system 1. In fig. 2 the doors are open and in fig. 3 the doors are closed. The lifting system 1 is similar to the first embodiment, it has a top or roof 5, a floor 4, outer walls 5 and inner doors 3 which define a cabin. The lift system 1 functions the same way as the first embodiment shown in fig. 1. Additionally the ground or the floor 15, where the lift system is positioned and the horizontal division 18 between building levels is schematically shown. The cover 19 of the hole 20 where through the lift moves is also shown.

Fig. 1 shows the lift in a first position which can be ground level or in any case the lowest level where the lift can be positioned. Fig. 2 shows the lift in a second position where it is at the first floor.

The second embodiment is installed in a building, where a hole 20 in the horizontal division 18 between the levels is needed. It is constructed in such a way that the hole 20 is closed with a cover 19. At some point, when the cabin is at the lower level (see fig. 2) and when the cabin ascends, it will reach the cover and then the cover can ascend together with the cabin, lying on top of the cabin, as shown in fig 3. In this way, the area occupied by the lift system on higher levels is kept to a minimum when the lift is in its lower position.

In some cases, lift systems are, due to safety, required to have dual doors and measures, securing nothing gets under the lift while it is descending. This can be ensured by using an extra wall 16 surrounding the lift system, as shown in the second embodiment. This extra wall 16 should have security doors 17 corresponding to inner doors 3 in the cabin, so that when both doors 3, 17 are open the inner compartment is accessible. The security doors 17 in the extra wall 16 should preferably be sliding doors, as shown in the second embodiment. These sliding security doors 17 use the same principles as the inner doors 3 of the cabin.

Installation of any one of the embodiments is especially easy, as it can be placed anywhere and lift a person up to the height desired. This is important, especially when the lift is to be installed in a building, which initially was not designed for lifts. The lift can for example be positioned inside a house and provide transportation between floors. It can for example be positioned anywhere on the lowest floor and then a hole in the horizontal division between the levels is the only modification needed in the building. Alternatively, the lift can be installed where there already is access between the levels. This can for example be in a stairway.

In fig. 4 and 5 the footprint of the cabin, according to the second embodiment, can be seen. The floor 4 is smaller than the footprint of the lift system 1. This is because there is a column space 6 for the lifting column 2 that occupies part of the area of the bottom of the lift 1. When using the word footprint, it should be interpreted as the area taken up by lift system 1. Preferably, lifting columns 2, mechanics and hydraulics are positioned within this area. Although, some of the parts, such as the pump arrangement for the hydraulic, can be positioned outside the footprint, it is preferred to enclose as many of the parts as possible within the column space 6.

Fig. 4 and 5 show the principle of the sliding doors. In fig. 4 both the inner doors 3 and the security doors are open. Here is can be seen that the doors are sliding in such a way that they follow the shape of the lift and the extra wall 16. The security doors 17 are, in this specific embodiment, stationary in the same way as the security wall 16. In fig. 5 the doors 3, 17 are closed.

Referring to fig. 6, a telescopic lifting column 7 is shown to have three telescopic members 12, 13, 14. It is however clear for the skilled person, that any number of telescopic members can be used when applying these principles. It is also clear, that the telescopic members can be of any form or that the telescopic members 12, 13, 14 can be enclosed in an outer telescopic members for aesthetic and security purposes, as it will secure that nothing will get caught in the lifting columns. The telescopic lifting column 7, comprises a hydraulic actuator 8, a first telescopic member 12, a second telescopic member 13, a third telescopic member 14 and a wire pulley system 9 with a pulley 10 and a wire 1 1. The telescopic members 12, 13, 14 fit into each other in such a way that they can slide out from each other, a principle well known in the art. The hydraulic actuator 8 is connected in one end to the first telescopic member 12 and in the other end with the second telescopic member 13 in such a way that when the hydraulic actuator 8 is extended and retracted so is the second telescopic member 13 in relation to the first telescopic member 12. The wire 11 is in one end connected to the first telescopic member 12 and in the other end connected to the bottom of the third telescopic member 14, wherein the direction is altered by the pulley 10, which is positioned at the top of the second telescopic member 13. In this way the third telescopic member 14 is raised when the second telescopic member 13 is raised by the hydraulic actuator 8. A wire pulley system 9 as described can be used to add any desired number of additional telescopic members. Among the benefits of the wire pulling system is that it is cheap and easy to implement.

The principle of the wire pulley system ensures that the third telescopic member 14 extends simultaneously as the second telescopic member 13.

When two lifting columns 2 are used, it can be beneficial to use only one hydraulic actuator. Then one of the lifting columns can be arranged as shown in fig. 6 and a further wire pulley system is arranged, so that the second lifting columns is actuated. The further wire pulley system is connected in similar fashion, as the wire pulley system 9 on the lifting column with the hydraulic actuator. This is an advantage because if more that one hydraulic actuator is used, one needs to ensure that they are correlated and lift precisely at the same time, where as this problem does not occur when there is only one hydraulic actuator.

Alternatively to the hydraulic actuator 8 shown in fig. 6, there can be used another actuator for example screw or wheel and axle actuators. If a wheel and axle actuator is used the wire pulley principle shown in fig.6 can be used.

The hydraulic actuator 8 needs a pump for the hydraulic fluid and control means for the pump (not shown). The principle of a hydraulic actuator is well known in the art. One special benefit, as described above, when using a hydraulic actuator, is that it provides security. The worst case for a hydraulic system is if oil (or another hydraulic fluid) leaks. In that case the lift will descend as the oil leaks and hydraulic pressure decreases. If, for some reason, the control means stop working there can be installed a security valve that can open and release the hydraulic pressure which then lowers the cabin. This security arrangement is very cheap and easy to install and makes it possible for the cabin to securely reach the lowest level in case of a malfunction.

While specific and preferred embodiments of the invention have been shown and described in detail above to illustrate the inventive principles, it will be understood that variants to these embodiments may be provided without departing from the scope of the invention as set forth in the accompanying claims.

Fig. 7 disclose an example of interconnected lifting columns according to the invention. The embodiment comprises two interconnected lifting columns 2A and 2B. In principle the lifting column 2A has a similar function to the lifting column disclosed in fig. 6. However, the lifting column 2A is driven with a motor 21 and a timing belt 22 and there are additional wire pulley systems which are described below.

This system can be used in the lift system 1 disclosed in fig. 4 and 5, where two lifting columns are used. The motor 21 is fixed to the first telescopic member 12A and drives a drive pulley 24. The drive pulley 24 moves the timing belt 22 and connects it with the timing pulley 25. A timing fitting 23 is fixed to the timing belt 22 so when the belt is driven, the timing fitting 23 is moved up or down depending on the rotational direction of the drive pulley. The timing fitting 23 is also fixed to the second telescopic member 13A so it will follow the movement of the timing belt 22. In similar fashion as described for the lifting column 2 disclosed in fig. 6, the lifting column 2A has a wire pulley system 9A which ensures that the third telescopic member 14A raises when the second telescopic member 13A raises.

The lifting column 2A further comprise a second wire pulley system 26A comprising a wire 27A which connects the first telescopic member 12A via the pulley 28A with the third telescopic member 14A. This second wire pulley system 26A ensures that the third telescopic member 14A is lowered when the motor 21 lowers the second telescopic member 13A. This second wire pulley system 26A is not essential as the weight of the cabin will, in most cases, ensure that the lifting column 2A will be contracted when the second telescopic member 13A is lowered by the timing belt 22 and motor. The interconnected lifting columns 2A and 2B disclosed in fig. 7 comprise a lifting column 2B. This lifting column 2B is actuated via wire pulley systems connected to the lifting column 2A. A extend wire pulley system 27 is connected to the timing fitting 23 at one end and is guided via pulleys 28, 29, 30 and connected with the lower part of the second telescopic member 13B in such a way, that when the timing fitting 23 is raised the second telescopic member 13B will also raise.

The lifting column 2B has a wire pulley system 9B similar to the wire pulley system 9A of the lifting column 2A. This ensures that the third telescopic member 14B raise when the second telescopic member 13B is raised.

The lifting column 2B also has a second wire pulley system 26B similar to the second wire pulley system 26A of the lifting column 2A. This ensures that the third telescopic member 14B is lowered when the second telescopic member 13B is lowered. The interconnected lifting columns 2A and 2B also have a contracting wire pulley system 31 , which ensures that the lifting column 2B is lowered when the lifting column 2A is lowered. The contracting wire pulley system 31 has a wire connected to the timing belt 22, on the opposite side of the timing fitting 23. The wire is connected to the lower part of the second telescopic member 13B via pulleys 32, 33. This ensures that the second telescopic member 13B is forced downwards when the second telescopic member 13A is lowered.

Fig 8 disclose a cross sectional view of a part of an embodiment of means for rotating the cabin 34. The figure only shows part of the means for rotating the cabin 34 a more elaborate view can be seen in fig 9. However, on fig 9 fitting for the fitting 35 is not present.

The means for rotating the cabin 34 is to be placed on the floor or accommodated in a compartment in the floor. The lifting columns 2 are then placed on the means for rotating the cabin 34, whereby it is possible to rotate the cabin together with the lifting columns 2. Preferably, the means for rotating the cabin 34 has a footprint no larger than the footprint for the cabin.

The means for rotating the cabin 34 has in the present embodiment a circular form with a footprint in the same size as the cabin so it can fit under the lifting columns 2 and cabin as seen on fig 4 and 5. The means for rotating the cabin 34 comprise a fitting 35 for fixating the lifting columns 2 to the plane member 36 and a frame 37, which is stationary. The plane member 36 is connected to the frame 37 via a roller bearing 38, making it possible to rotate the plane member 36 any desired angle. A toothed bar 39, having a circular form, is fixed to the plane member 36 and engages a toothed wheel 40, which is connected to a motor for rotation 41 via gearing 42 in such a way that the motor controls the rotation of the plane member 36.

By use of the disclosed means for rotating the cabin 34, it is possible to rotate the entrance/exit of the cabin in any desired angle.

Reference list:

lift system 1

lifting columns 2, 2A, 2B

inner doors 3

floor 4

top or roof 5

column space 6

telescopic lifting column 7

hydraulic actuator 8

wire pulley system 9

pulley 10

wire 1 1

first telescopic member 12, 12A, 12B second telescopic member 13, 13A, 13B third telescopic member 14, 14A, 14B floor 15

extra wall 16

security doors 17

horizontal division 18

cover 19

hole 20

motor 21

timing belt 22

timing fitting 23

drive pulley 24

timing pulley 25

second wire pulley system 26 extend wire pulley system 27 pulleys 28, 29, 30

contracting wire pulley system 31 pulleys 32,33

means for rotating the cabin 34 fitting 35

plane member 36

frame 37 roller bearing 38 toothed bar 39 toothed wheel 40 motor for rotation 41 gearing 42