GB2169867A - Lifting method and apparatus - Google Patents

Abstract

Lift apparatus for a multi-floor building has twice as many lift cars 10 as there are floors 16 to be serviced, evenly spaced along an endless loop 12, consisting of vertical up and down paths 20/22 joined by upper and lower transfer paths 24/26, moving and stopping in unison when any one car is commanded to be stopped, and doors 28 openable whilst cars are stopped at floors. In a variant, each of the four paths has a separate travel system, movement along transfer paths being not continuous with vertical movement. Levelling adjustment means for each lift car comprise hydraulic means (44 in Fig. 4) or a sprocket wheel 52 (Fig. 5) around which drive chain 50 loops. <IMAGE>

Description

SPECIFICATION Lifting method and apparatus The invention relates to a method and apparatus for raising and lowering persons or goods by lift or elevator.

A lift conventionally moves in a vertical shaft to convey persons or goods between the floors of a building, ship or other multistorey structure. The passenger or freight car has to be summoned and there is a wait for it to arrive. If the car has only just been missed, the maximum wait could be as long as the time for the car to travel twice the total height of the stucture plus two sojourns of the car on each floor, once on the way up and once on the way down.

In tall or very busy buildings, long waiting periods have been minimised by providing two or more synchronised lift cars moving in neighbouring shafts. In theory, a car can be summoned while the other or another car is completing a previously started journey but, even under optimum conditions, it will be known that much time is wasted in waiting.

Also, the provision and operation of several lift cars, each travelling in its own shaft, is a costly affair, which is a disadvantage that also appertains to express cars in some very tall buildings. An express car accelerates to a particular elevation before it can be halted floor by floor, the idea being that each car or set of cars services only particular floors. Yet another system involves a first lift or set of lifts which moves through only part of the height of the structure, it being necessary to change cars to complete the journey. Whatever system may be used, the disadvantages of long waiting periods and multiple lift shafts have not yet been avoided, except perhaps in the case of a continuously moving chain of cars known as a paternoster which is suitable only as a passenger lift and has been banned by most authorities because of the obvious danger of jumping on and off.

According to one aspect of the present invention, a method of carrying passengers or goods up and down multi-floor buildings or other structures comprises the steps of moving a plurality of evenly spaced lift cars, preferably at least twice the number of cars as there are floors to be serviced, in a loop consisting of a vertical up path and a vertical down path joined by upper and lower transfer paths, and stopping all cars along the up and down paths when any one car is commanded to be stopped, doors being openable to gain access to and egress from the cars whilst stopped at respective floors.

Preferably the loop is continuous and the cars are moved in unison, the distance travelled by each car along each transfer path of the loop being preferably substantially equal to the vertical distance between successive floor levels (herein mostly called "the floor height").

Alternatively however, the lift cars may be carried along the loop by separate travel or transfer systems, namely along the up path by an up travel system, along the down path by a down travel system, and be transferred from the up travel system to the down travel system along the upper transfer path by an upper transfer system and from the down travel system to the up travel system along the lower transfer path by a lower transfer system.

Preferably each car is levelled with its respective floor when stopping at that floor.

According to another aspect of the present invention, a lift or elevator apparatus for a multi-floor building or other structure, comprises a plurality of lift cars mounted for movement in a loop consisting of a vertical up path and a vertical down path joined by upper and lower transfer paths, the pitch between successive cars along the up path and along the down path being substantially equal to, or an integral multiple or a vulgar fraction of, the floor height, means for simultaneously stopping the cars at respective floors, and doors that are openable to gain access to and egress from the cars while stopped at respective floors.

Preferably the cars are accommodated in a single shaft. They may be mounted back to back with doors at opposite ends; or they may be mounted side by side with a door at one end or doors at both ends.

Preferably there are twice the number of cars as there are floors to be serviced; but for e.g. buildings having many floors an equal number or two-thirds or an even smaller fraction may suffice; conversely for e.g. a goods lift four times or in the case of e.g a building having a large spacing between successive floors an even larger multiple may be appropriate.

In a preferred form of the invention, the up and down paths and the transfer paths form a continuous loop and the cars are mounted for movement in unison. And preferably also, the length of each tranfer path of the loop is equal to the floor height. To minimise the horizontal offset between the vertical up and down paths the transfer paths may diverge from the rectilinear horizontal and may e.g. be V-shaped or U-shaped.

Desirably, one or more endless chains or cables may be disposed at one side only of the cars, to carry the cars by way of carriages, from which they are cantilevered.

In an alternative form of the invention, the up path, the down path, the upper transfer path and the lower transfer path may comprise separate travel systems (not involving movement of all cars in unison). Thus, the up path may comprise an endless chain or cable carrying carriages which support the cars along the up path, the down path an endless chain or cable carrying carriages which support the cars along the down path, the upper transfer path has means for transversely conveying the cars at the top from the up path to the down path and the lower transfer path has means for transversely conveying the cars at the bottom from the down path to the up path.

In lift apparatus embodying the invention, therefore, a lift car no longer reciprocates in its own shaft. Instead, two or more cars move discontinuously in the same direction along a loop, being both or all intermittently stopped simultaneously whenever commanded by the needs of a passenger or goods in or for any one of the cars. Calculations will show that in this way the waiting periods can be reduced considerably for certain conditions of operation. For example, in the case of passenger lifts in department stores and in other crowded buildings, it is most likely that passengers will wish to embark or alight at practically every floor level but there is usually a long wait for the car to arrive.Also, in apparatus embodying the invention, a car may be stopped at each floor along each of the vertical paths, thereby reducing the maximum period to the time it takes a car to travel between two adjacent floors. Of course the sojourn times at each floor and the travelling times between floors are the same as for conventional lifts. Should there be no demand for a car to stop at a particular floor level, all the cars may be allowed to continue to move along the loop to the appropriate next floor commanded.

To allow for slight variations in floor height, it is preferred that each car be provided with individual levelling means allowing for independent fine height adjustment of the car with respect to the carrying chains or cables after it has been moved a nominal or coarse distance in unison with the other cars.

Alternatively, the paths of the carrying chains or cables can be made to diverge from the vertical (as e.g. by use of jockey sprocket wheels) thereby permanently compensating for height differences in the spacing of floors: the pitch of the cars along the chains or cables is selected by reference to the greatest spacing between successive floors and the travel of a lift car along its vertical rails between more closely spaced floors is appropriately reduced consequently on the divergence of the chains or cables. This is suitable not only for compensation of slight differences in floor level but can also cater for substantial intentional differences in room height.

Some preferred forms of the invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 diagrammatically shows a first lift apparatus designed to serve a three storey building; Figs. 2a and 2b show the apparatus of Fig.

1 with minor modifications but in greater detail, in front elevation and side view respectively; Figs 3a and 3b are representations of an alternative form of lift apparatus again in front elevation and side view respectively; and Figs 4 and 5 show two arrangements for levelling cars when stopped at a floor.

Turning to Figs. 1 and 2, six lift cars 10 represented by boxes (albeit the position of five of them is indicated in Fig. 1 by crosses) are carried at both sides by an endless chain or cable 12 by means of which they can travel in an endless loop 14. The lift apparatus is installed in a three storey building, of which the floor levels are designated 16. Each lift car has a pair of bars 18 guided in appropriate guide rails (not shown). The cars are evenly spaced along the chain by a distance equal to the height from floor level to floor level (the floor height).

In Fig. 1, the vertical up path 20 and the vertical down path 22 of the continuous loop travelled by all the lift cars are spaced apart by a distance such that the cars on the up run adjoin those on the down run, the lengths of the upper and lower transfer paths 24 and 26 being substantially equal to the height between floor levels, but diverging from the horizontal by being U-shaped as shown. The lift cars being mounted back to back, each of course requires a door 28 in each of two opposite sides, one door being openable on the up run and the opposite door on the down run when the lift cars are stopped at a floor. The lift cars in this construction can share a common lift shaft.

It will be evident from the sketch that, in moving from the up path to the down path, and vice versa, each lift car should be suitably guided along the transfer path without being turned upside down.

In Fig.2, the upper and lower transfer paths 24 and 26 extend horizontally so that the horizontal distance between the up and down paths 20 and 22 equals the height between floor levels. Here, separate lift shafts will be required but of course the horizontal floor space between them can provide for access to the lift cars by way of their openable doors both on the up run and the down run.

Comparing the time of the six cars in the sketch with a two-car conventional lift installation will show that the invention facilitates a faster passenger flow. Also, the lift installation of the invention can take up less space.

The invention is particularly applicable to goods lifts. For example, all the cars of one loop can be successively filled at the storeroom level during the closed times of a department store and used as a mobile store for calling up to a particular level during working hours for unloading. For this application, there could even be more than two cars per floor level, (at a pitch equal to a vulgar fraction of the floor height) thereby increasing the total storage capacity.

Conversely for very tall buildings a ratio of one car to every two or three floors (at a pitch equal to a multiple of the floor height) might suffice.

Turning to Fig. 3, there is shown an installation for a four storey building. Here, movement along the continuous loop is not by a single system of chains or cables, but separate travel systems are provided for the several elements that go to make up the loop, namely lower tansfer system 30 for horizontal travel along the lower transfer path 26, an up travel system 32 for the run along the up path 20, upper transfer system 34 for horizontal travel along the upper transfer path 24, and a down travel system (not shown) for the down run along the down path 22. It will be appreciated that movement along the loop is not continuous, in that during horizontal travel of cars along the upper and lower transfer paths, there is no travel along the up and down paths.

The up travel system 32 has an endless chain or cable 36 carrying spaced L-shaped lifting carriages 38 which carry the cars releasably along the up path, the shorter-limb of the L supporting the floor of a car and the longer limb being secured to the chain 36. At the top of the up path the cars are released from their carriages and transferred by the upper transfer system 34 (by way of hydraulic cylinders-not shown) to the down travel system. The latter is of like construction as the up travel system. Similarly, at the bottom of the down path the cars are released from their carriages and transferred by the lower transfer system 30 to the up travel system.

The carriages of the up and down travel systems of course make their return journeys empty (with their respective carriages upside down). The distance separating the up and the down travel systems can be quite small, a larger spacing being shown in Fig. 3a merely for ease of illustration. Thus, the up and down travel systems can share a common shaft, each car requires but a single door, so that pairs of doors adjoin when stopped at any given floor, in alignment.

Fig. 4 shows another form of lifting carriage, generally designated 40, suitable for incorporation in the apparatus of Figs. 1 and 2.

Each carriage is carried by the chains or cables, and in turn carries a lift car 10, cantilevered from it by way of arms 42 (as shown). This construction (like that of Fig. 3) necessitates but a single door for each car enabling them to be mounted flank to flank (rather than back to back).

Additionally, the carriage 40 is provided with a hydraulic levelling actuator 44. The lift car, though captive, is vertically slidable with respect to its carriage along guides 46, enabling fine vertical adjustment by extension or retraction of the actuator, one operative end whereof is secured to the carriage and the other to the lift car (as shown). Upper and lower extreme positions of the car relative to the carriage are indicated in broken line. This enables accurate levelling of the cars on arrival at respective floors, the actuators being operated by conventional position sensing means (also not shown). Similar actuators can be incorporated in the L-shaped carriages of Fig. 3, interposed between the longer limb of the L and its attachment to the chain.

In the alternative construction of Fig. 5, levelling means is provided at each floor for fine height adjustment. The line of the car guides is designated 48, and the lifting chain 12 is diverted laterally from its normal line 50, by way of sprocket wheel 52. The reduction in height travelled by the lift cars along guide line 48 is of course determined by the extent of the diversion of the chain from its own line 50. The lift cars are connected to the chain by way of swinging links 54 indicated in broken line.

On each floor there is of course an opening giving access to the lift shaft, generally fitted with a door openable when a lift car is stopped at that floor. These can be in place of the lift car doors though generally will be in addition to those doors.

Some advantages of the forms of the invention described above have been mentioned already. Additionally it should be noted that no balance weights would normally be required.

In the load free condition the system is completely balanced and the only power to operate it is that required to overcome friction and inertia. When the lift cars are loaded, the situation is different, but as the system is intended for high traffic situations it is likely that all or most of the cars would be at least partly loaded. Use of the invention should therefore lead to an energy saving.

Moreover, each lift car can have a much smaller floor area than would normally be required for a given traffic handling capacity, and this should lead to savings in floor space accommodation and cost.

Claims (14)

1. A method of carrying passengers or goods up and down multi-floor buildings or other structures comprising the steps of moving a plurality of regularly spaced apart lift cars, preferably at least twice the number of cars as there are floors to be serviced, in a loop consisting of a vertical up path and a vertical down path joined by upper and lower transfer paths, and stopping all cars along the up and down paths when any one car is commanded to be stopped, doors being openable to gain access to and egress from the cars whilst stopped at respective floors.

2. The method according to claim 1 wherein the loop is continuous and the cars are moved in unison, the distance travelled by each car along each transfer path of the loop being preferably substantially equal to the floor height.

3. The method according to claim 1 wherein the cars are carried along the up path by an up travel system, along the down path by a down travel system, and are transferred from the up travel system to the down travel system along the upper transfer path by an upper transfer system and from the down travel system to the up travel system along the lower transfer path by a lower transfer system.

4. The method according to any preceding claim which includes the further step of levelling each car with its respective floor when stopping at that floor.

5. A lift or elevator apparatus for a multifloor building or other structure, comprising a plurality of lift cars mounted for movement in a loop consisting of a vertical up path and a vertical down path joined by upper and lower transfer paths, the pitch between successive cars along the up path and along the down path being substantially equal to, or an integral multiple or a vulgar fraction of, the floor height, means for simultaneously stopping the cars at respective floors, and doors that are openable to gain access to and egress from the cars while stopped at respective floors.

6. Apparatus according to claim 5 wherein the up and down paths and the transfer paths form a continuous loop, the cars are mounted for movement in unison, and the length of each transfer path of the loop is substantially equal to, or an integral multiple of the pitch between successive cars.

7. Apparatus according to claim 6 wherein one or more endless chains or cables disposed at one side only of the cars carry the cars by way of carriages from which they are cantilevered.

8. Apparatus according to claim 6 or claim 7 wherein the transfer paths diverge from the rectilinear horizontal so as to reduce the horizontal offset between the up and down paths.

9. Apparatus according to claim 5 wherein the up path, the down path, the upper transfer path and the lower transfer path comprise separate travel systems.

10. Apparatus according to claim 9 wherein the up path comprises an endless chain or cable carrying carriages which support the cars along the up path, the down path comprises an endless chain or cable carrying carriages which support the cars along the down path, the upper transfer path has means for transversely conveying the cars at the top from the up path to the down path and the lower transfer path has means for transversely conveying the cars at the bottom from the down path to the up path.

11. Apparatus according to any of claims 5 to 10 wherein, to allow for slight variations in floor height, each car is provided with individual levelling means allowing for independent fine height adjustment of the car with respect to the carrying chains or cables after it has been moved a nominal or coarse distance in unison with other cars.

12. Apparatus according to any of claims 5 to 10 wherein the paths of the carrying chains or cables diverge from the vertical (as by the use of jockey sprocket wheels) thereby permanently compensating for differences in floor height, the pitch of the cars along the chains or cables being selected by reference to the greatest floor height and the vertical travel of a car along its guides between floors of lesser floor height being appropriately reduced consequently on the divergence of the chains or cables.

13. A method of carrying passengers or goods up and down multi-floor buildings or other structures substantially as herein described with reference to Figs. 1 and 2 or Fig.

3 of the accompanying drawings, with or without the refinements of Figs. 4 or 5.

14. A lift or elevator apparatus for a multifloor building or other structure, substantially as shown in and herein described with reference to Figs. 1 and 2 or Fig. 3 of the accompanying drawings, with or without the refinements of Figs. 4 or 5.