AU2007221937A1 - Elevator system - Google Patents

Description

Australian Patents Act 1990 Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title "Elevator system" The following statement is a full description of this invention, including the best method of performing it known to me/us:- P/00/011 Q\OPER\DH\October 2007\0356556 0 Oa 07 divdoc 10/10/07 P OPERIDHU035656 ,l Jo..Sfl(O, 7 -1o ELEVATOR SYSTEM 0 Field This invention relates to an elevator system.

Background A known form of elevator system 1, as shown in Figure 1, is disclosed in European C)Patent No. 1216949. The system 1 includes a cantilevered elevator car assembly 2 which is driven up and down an elevator shaft 3 by a motor 4 which is positioned at a top end 5 of the shaft 3. The motor 4 has a drive sheave 6 which engages and drives a rope or cable 7, which passes over the sheave 6 and interconnects a counterweight 8 at one end 9 and a top cross-beam 10 of a frame 11 of the car assembly 2 at the other end 12. Such a system 1 provides a space saving advantage in that positioning of the motor 4 at a top end of the elevator shaft 3 dispenses with the need for a separate motor room at a base of the shaft 3.

Obiect The present invention seeks to provide an improved elevator system.

Summary of the Invention In accordance with the invention, there is provided an elevator system including: an elevator car assembly for travel within an elevator shaft; a cable interconnecting the assembly with a counterweight; and a motor for driving the cable, wherein the cable is coupled to the assembly at a lower region thereof; and the motor is positioned in spaced relation to a roof of the elevator shaft, so as to be laterally adjacent to the car assembly when the assembly is at a top terminal landing serviced by the system.

Preferably, the elevator car assembly is cantilevered.

Preferably, the cable is connected to a lower structural beam of the assembly.

P 'OPER'DH\303 6556 J oc -2ll:r,7 -2o Preferably, the motor is arranged in a position lower than a roof of the assembly when a floor of the elevator car assembly is level with the top terminal landing.

Preferably, the motor is arranged in a position laterally adjacent a central region of Sthe assembly when the floor of the elevator car assembly is level with the top terminal landing.

More preferably, the motor is able to be reached by a person standing on the roof of the elevator car assembly when the roof of the elevator car assembly is level with the top terminal landing.

Preferably, the elevator car assembly travels within the elevator shaft at speeds in the order of 1 m/s, such as between 1.0 m/s and 1.6 m/s.

Preferably, the system includes a second motor and a second cable coupled to the elevator car assembly.

Preferably, the first and second cables are coupled to opposite sides of the elevator car assembly.

Preferably, the cables are connected to a common structural beam which extends across an underside of the elevator car assembly.

Preferably, the motors are synchronised by a common inverter.

In another aspect, there is provided an elevator system which includes an elevator car assembly and two motors for driving associated first and second cables coupled to the assembly.

In another aspect, there is provided an elevator system which includes an elevator car assembly with guideshoes supporting the assembly for travel along respective guiderails, wherein the guideshoes engage the guiderails externally of the guiderails in order to travel past a motor positioned internally and between the guiderails.

%OPERIDF3C]656 doc: A -3o Brief Description of the Drawinqs The invention is described in more detail with reference to the accompanying drawings, in which: -Figure 1 is a diagrammatic side view of a known elevator system; Figure 2 is a diagrammatic side view of another elevator system; c Figure 3 is a diagrammatic perspective cut-away view of the system of Figure 2; and 1 Figure 4 is a diagrammatic side view of another elevator system.

Detailed Description An elevator system 20 is now described with reference to Figure 2. The system has features similar to those shown in Figure 1 and like reference numerals are used to denote like parts.

The elevator system 20 shown is a commercial-type elevator system, for example, a passenger and/or goods elevator system capable of transporting passengers and/or goods at speeds in the order of 1.0 to 1.6 m/s.

Similarly to system 1, the elevator system 20 includes a cantilevered elevator car assembly 2 coupled to a counterweight 8 via a rope or cable 7, which is driven by a motor 4, to allow the car assembly 2 to travel up and down elevator shaft 3. The cable 7 is, however, coupled to the elevator car assembly 2 at a lower region 23 of the assembly 2, as compared to the top cross-beam 10 shown in Figure 1. More particularly, the cable 7 is connected to sockets 24 which are in turn coupled to a lower structural beam 25 of the assembly 2 so as to provide a length of cable 'L' between the motor 4 and the sockets 24.

A further difference between the systems 1 and 20 is that the motor 4 is supported in spaced relation to the top end 5 of the shaft 3. The motor 4 can, in fact, be positioned further away from the end 5 of the shaft 3 such as in the location shown in dashed outline 30, where the motor 4 is below a roof 26 of the assembly 2 and laterally adjacent a central region of the assembly when level with a top floor 22 serviced by 'OPSRDYM03W56 j, I.-Zi 191 -CIO, -4o the system In relation to the positioning of the motor 4 relative to the car assembly 2, a certain minimum distance needs to be maintained between the motor 4 and the end 12 of the cable connected to the car assembly 2, to accommodate overrun of the car assembly and the like. The specific length of cable required to accommodate the overrun is calculated by Staking into consideration a number of factors such as a counterweight buffer stroke, which 0is the displacement distance of a buffer at a base of the elevator shaft, which is used to c arrest downward displacement of the counterweight. Since the cable 7 is connected to the car assembly 2 at the lower region 23, the relevant overrun can be readily accommodated within the length of cable 7. The motor 4 may be placed at a substantially lower location as a result, as compared to the location of the motor 4 of Figure 1, where the placement of the motor needs to be above the car assembly 2 itself.

The relative positioning of the motor 4 in the system 20, relative to the roof 5 and top floor 22, is perhaps more clearly shown in the cut-away perspective view of Figure 3.

It can be seen that placement of the motor 4 below a top 27 of guiderails 28 and adjacent the elevator car assembly 2, when the assembly is at a top terminal landing, is achieved by positioning the motor 4 intemally and between the guiderails 28 themselves. Such an arrangement leads to a related aspect of the invention in so far as the guideshoes 29 supporting the assembly 2 must necessarily engage from and travel extemally of the guide rails 28, in order to travel past the motor, as required. It is believed such a configuration of guiderails 28 and guideshoes 29 represents novel subject matter as compared with existing guideshoe arrangements which travel intemally of the guiderails.

The arrangement of the system 20 may thereby provide a number of advantages.

Flexibility exists in the specific placement of the motor 4 and the motor 4 may be more readily accessed by a person standing on the roof 26, particularly when the roof 26 is level with the top floor 22. Also, the overall height requirements for the shaft 3 may be reduced which could perhaps result in some economic advantage in the form of space and construction savings, such as by allowing the top end 5 of the shaft 3 to be lowered, or in the form of allowing an additional floor to be added and serviced by the system 20, whilst OPER'OhAO3356 J ,o C09,ON O ci o still complying with initial building height restrictions.

To further illustrate the potential height advantage provided by the system 20, a standard minimum lift shaft overrun calculation was made for comparison with the system 1. Lift Soverrun is taken as being the distance between the top floor 22 served and the top end 5 of the shaft 3. The calculations were conducted for a system intended to carry 13 c passengers at 1.0 m/s with a counterweight buffer stroke of 80 mm; a counterweight 0 buffer clearance of 450 mm, below the motor or its support; and a top-of-car person C clearance of 1570 mm, which is a clearance required for a maintenance person standing on top of the car assembly 2. The minimum lift shaft overrun for the system shown in Figure 1 was found to be 4680 mm while that required for system 20 was only 3960 mm (as a top-of-car person clearance above the car assembly when at the top landing is effectively increased by obviating the overhead motor and by replacing same with the motor laterally adjacent the car assembly when at the top landing), which indicates a clear height advantage may be realised utilising the present invention.

Another elevator system 40 is shown in Figure 4. The system 40 has features similar to those shown in Figures 1 to 3 and like reference numerals are used to denote like parts.

A difference between the system 40 and the system 20 is that a second motor 41 is provided together with an associated second cable 42. Like cable 7, the second cable 42 couples a counterweight 8 to the car assembly 2 at its end 12, via sockets 24. Both cables 7, 41 are attached to a common structural beam 43 which extends across an underside 44 of the car assembly 2.

In order to operate the system 40 effectively, power to the two motors 4, 41, which are preferably in the form of two permanent magnet synchronous motors of the same size, is synchronised through one common inverter (not shown) such that power is provided to the motors 4, 41 equally. The load carrying capacity of the system is doubled as a result and the elevator car assembly frame 11 can be increased in width as it is supported on both sides, allowing versatility in the use of P OPEaODHIo;56356 JXc21.Oi9W'Y -6o the lift with possible application to large passenger lifts, large goods lifts and car lifts, etc. Despite the increased capacity of system 40 the top and bottom overruns remain low and shallow, as per the single motor arrangement of Figures 2 and 3, due to the placement of the motors and the location of the pick-up of the cables 7, 41 with the assembly 2.

C Overall power consumption is expected to be considerably less, in the order of as compared to a conventional lift with equivalent load carrying capacity.

c Also the potential for reduced maintenance and damage may be realised with the system 40, as compared to a conventional cantilevered car arrangement, as a tandem guiding system with twin sets of guiderails (not shown) is used, which serves to balance the car assembly within the guiderails to thereby reduce load on the guide shoes to thereby also reduce friction, etc. Safety switches would, however, still be installed to detect any out of level movement of the car frame 11.

The invention has been described by way of non-limiting example only and many modifications and variations may be made thereto without departing from the spirit and scope of the invention described.

Claims (9)

1. An elevator system including: an elevator car assembly for travel within an elevator shaft; c 5 a cable interconnecting the assembly with a counterweight; and a motor for driving the cable, Swherein the cable is coupled to the assembly at a lower region thereof; and the motor is positioned in spaced relation to a roof of the elevator shaft, so as to be laterally adjacent to the car assembly when the assembly is at a top terminal landing serviced by the system.

2. An elevator system as claimed in claim 1, wherein the cable is connected to a lower structural beam of the assembly.

3. An elevator system as claimed in claim 1 or claim 2, wherein the motor is arranged in a position lower than a roof of the assembly when a floor of the elevator car assembly is level with the top terminal landing.

4. An elevator system as claimed in claim 3 wherein the motor is arranged in a position laterally adjacent a central region of the assembly when the floor of the elevator car assembly is level with the top terminal landing. An elevator system as claimed in claim 1, wherein the motor is able to be reached by a person standing on the roof of the elevator car assembly when the roof of the elevator car assembly is level with the top terminal landing.

6. An elevator system as claimed in any one of claims 1 to 5, wherein the elevator car assembly travels within the elevator shaft at speeds in the order of 1 m/s.7. An elevator system as claimed in claim 1 including a second motor and a second cable coupled to the elevator car assembly.

8. An elevator system as claimed in claim 1, wherein the first and second cables are coupled to opposite sides of the elevator car assembly. ?'OPERaDh'\303656 Jl Ioc-.2309/'CO O-8- o 9. An elevator system as claimed in claim 1, wherein the cables are connected to a common structural beam which extends across an underside of the elevator car assembly. An elevator system as claimed in claim 1, wherein the motors are synchronised by a common inverter.

11. An elevator system as claimed in claim 1, wherein which includes an 0 elevator car assembly and two motors for driving associated first and second cables coupled to the assembly.

12. An elevator system as claimed in claim 1, which includes an elevator car assembly with guideshoes supporting the assembly for travel along respective guiderails, wherein the guideshoes engage the guiderails externally of the guiderails in order to travel past a motor positioned internally and between the guiderails.

13. An elevator system, substantially as described with reference to the drawings and/or examples.