EP4719956A1 - Elevator pulley arrangement, elevator, and method of suspending elevator car - Google Patents

Abstract

An elevator pulley arrangement, an elevator, and a method for supporting an elevator car. The arrangement comprises at least two supporting pulleys (12) mounted at a lower part of an elevator car (3) and at least one suspension element (5) passing via them. The supporting pulleys are mounted to pulley control units (13) comprising independent control arms (14) supported to the elevator car by means of a turning joints (15). The control arms are provided with spring elements (16) allowing the control arms to turn, whereby the supporting pulleys are movable in relation to the elevator car.

Description

Elevator pulley arrangement , elevator , and method of suspending elevator car

Background of the invention

The invention relates to an elevator pulley arrangement of an elevator comprising suspension pulleys mounted at a lower part of an elevator car .

The invention further relates to an elevator provided with an elevator pulley arrangement and to a method for suspending an elevator car inside an elevator shaft .

The field of the invention is defined more speci fically in the preambles of the independent claims .

An elevator comprises an elevator car which is moved vertically in an elevator shaft and is stopped at landings . A bottom of the elevator shaft comprises a pit and at a top of the shaft is typically a machine room . There is a desire to develop elevators which require as little space as possible in the elevator shaft in both vertical and horizontal directions so as to allow ef ficient shaft space utili zation . Therefore , elevator pulley arrangements are developed wherein elevator car pulleys are placed at a bottom part of the elevator car structure instead mounting them on the top of elevator car . However, the known solutions for placing the pulleys to the bottom part of the elevator car have shown to contain some disadvantages .

Brief description of the invention

An obj ect of the invention is to provide a novel and improved elevator pulley arrangement , and an elevator provided with such pulley arrangement . A further obj ect is to provide a new and improved method for suspending an elevator car to an elevator shaft .

The elevator pulley arrangement according to the invention is characteri zed by the characteri zing features of the first independent apparatus claim . The elevator according to the invention is characteri zed by the characteri zing features of the second independent apparatus claim .

The method according to the invention is characteri zed by the characteri zing features of the independent method claim .

An idea of the disclosed solution i s that the elevator pulley arrangement compri ses at least two supporting pulleys mounted at a lower part of an elevator car and at least one suspension element , such as a rope , is conveyed via the supporting pulleys . The supporting pulleys are mounted to pulley control units comprising independent control arms . Each control arm is supported at a first end portion to the elevator car by means of a turning j oint . The supporting pulleys are located at opposite second end portions of the control arms . Further, the control arms are suspended in relation to the elevator car by means of one or more spring elements allowing the control arms to turn in relation to the turning j oints . Thereby, the supporting pulleys are movable in relation to the elevator car .

An advantage of the disclosed solution is that the movable supporting pulleys are capable to stabili ze loadings and they can also dampen vibrations and noise . The disclosed solution also facilitates maintenance work since the pulling arrangement is a bigger entity which is easier to handle , repair and change .

According to an embodiment , the control arm is an elongated rigid piece comprising a hinge structure at its first end . The supporting pulley is mounted to the distal second end . The hinge structure serves as the turning j oint and may comprise a transverse bolt or pivot pin .

According to an embodiment , the arrangement comprises two control arms facing away from each other . The turning j oints are located at a middle part of a bottom part of the elevator car . The elongated control arms extend to lateral sides of the elevator car so that the supporting pulleys are located at the sides of the bottom part . Placing the turning j oints at the middle part of the bottom of the elevator car is advantageous for the maintenance operations .

According to an embodiment , movement range of the supporting pulleys is typically 5-30 mm in vertical direction .

According to an embodiment , the suspens ion element passing via the supporting pulleys may be a wire rope , a composite rope , or a belt , for example .

According to an embodiment , the pulley control units comprise one common spring element . An advantage of this solution is that number of components may be reduced and the structure may be simple .

According to an embodiment , the common spring arranged between the two control arms may be a leaf spring . The leaf spring may be supported from its middle section to a frame structure of the elevator car and both end portions of the leaf spring may be directly or indirectly in contact with the control arms .

According to an embodiment , the pulley control units comprise dedicated spring elements whereby the control arms are provided with independent suspension . An advantage of this embodiment is that the pulley control units may be separate compact and independent units which are easy to mount and dismount for maintenance and replacement purposes , for example .

According to an embodiment , the spring elements are helical springs . The helical springs can be mounted between the control arms and bottom part or frame of the elevator car, for example .

According to an embodiment , resi lient compressible material is configured to serve as the spring element . The compressible spring material may be made of polyurethane , for example . The compressible and resilient material may serve also well as a dampening element dampening vibrations and noise . According to an embodiment , the spring elements may be polyurethane blocks , or plate-like compressible elements , arranged between an upper surface of the control arm and a support surface above the control arm . Thus , the spring element block may be a relatively simple , durable , and inexpens ive element . Further, it is easy to adj ust the suspension by selecting suitable block material .

According to an embodiment , a further alternative to be used as the spring element are torsion springs .

According to an embodiment , the control arm is suspended by means of a torsion bar suspension mechanism wherein the control arm is connected to a first end of a transverse torsion bar which is an elongated obj ect . An opposite second end of the torsion bar is mounted fixedly, such as to a bottom structure of the elevator car . The torsion bar is subj ected to torsion forces when the suspension pulley and the control arm are moved . The tors ion forces cause the bar to twist around its axis and is resisted by the bar ' s torsion resistance . The ef fective spring rate of the bar is determined by its length, cross section, shape , material , and manufacturing process .

In addition to the disclosed mechanical springs , it may be possible to utili ze hydraulic or pneumatic actuators as the spring elements .

According to an embodiment , the spring elements may be integrated to be inseparable parts of the control arms .

The type of the spring implemented in the disclosed solution can be selected case by case .

According to an embodiment , the turning j oints are provided with bushings made of resilient material . The bushings may form a separating material layer between the control arms and the elevator car . Then the bushings can serve as dampeners dampening vibrations and noise , whereby the use of the bushings can improve traveling comfort . The bushings may break metal against metal connections between the mating components . According to an embodiment , the bushings may be made of polyurethane material , rubber, rubber-like material , or resilient polymer material .

According to an embodiment , the turning j oint may be provided with one single bushing, or alternatively, there may be two bushing components .

According to an embodiment , a hinge pin is arranged to pass through the bushing .

According to an embodiment , there may be an inner sleeve element inside the bushing . The inner sleeve may be made of steel or bearing metal , for example .

According to an embodiment , the arrangement comprises at least one stabili zing element connecting two opposite directed control arms together for transmitting forces between the connected control arms .

According to an embodiment , the stabi li zer element is a stabili zer bar, or a sway bar, connecting the two pulley control units together and transmitting vertical forces between them . Then the forces can be divided for two control arms whereby more stable operation may be provided . The stabil i zer bar is a rigid bar connected to the control arms by means of link systems .

When one of the connected control arms moves towards the bottom of the elevator car in relation to the turning j oint , then the force transmitted by the stabili zer element forces the connected other control arm to also move towards the bottom o f the elevator car . This way the operation and movements of the control arms are stabil i zed since the movement occurs in both control arms simultaneously . Then the total spring force of the two springs elements of the control arms can be taken into consideration in the dimensioning of the spring system .

According to an embodiment , the turning j oints are located on a bottom side of the elevator car and are mounted to a frame of the elevator car . The control arms are orientated to extend towards sides of the elevator car bottom . The frame of the elevator car may comprise a beam structure and the turning j oints may be mounted to the beams of the frame .

According to an embodiment , the bottom of the elevator car comprises at least one openable and closable opening at the pulley control units for providing access to the pulley control units from the inside of the elevator car . An advantage of this embodiment is that services , inspections , and component changes can be executed without entering to an elevator shaft . The required maintenance operations can be executed through the opening . This way safety and ef fectivity of the maintenance operations can be improved . Furthermore , depth of a pit of the elevator shaft can be decreased and overall space utili zation can be improved .

According to an embodiment , the opening on the bottom of the elevator car is provided with at least one hatch . The hatch may be of removable or slidable type , or it may be hinged to a floor structure of the elevator car .

According to an embodiment , the pulley control unit may be designed and dimensioned to be an entity which is easy to remove and remount through the opening on a floor of the elevator car . The entity or unit may be handled in one piece .

According to an embodiment , the disclosed solution relates also to an elevator utili z ing the embodiments disclosed above . The elevator compri ses : an elevator shaft ; an elevator car supported vertically movably inside the elevator shaft ; a hoisting machinery and suspension means for moving and supporting the elevator car ; and wherein the suspension means comprise at least two supporting pulleys mounted at a lower part of an elevator car and at least one suspension element passing via the supporting pulleys . Further, the supporting pulleys mounted to pulley control units are in accordance with the embodiments and features disclosed in this document . According to an embodiment , the disclosed solution suits well for elevators wherein depth of a pit below a lowermost landing is 500 mm or less . This kind of elevators may be called as low pit elevators .

According to an embodiment, the elevator is a traction elevator comprising a counterweight assembly .

According to an embodiment , the disclosed solution relates al so to a method for suspending an elevator car of an elevator . The method comprises : suspending the elevator car vertically movably inside an elevator shaft by means of suspension elements or means ; providing the suspension elements or means with at least two supporting pulleys mounted at a lower part of the elevator car ; and conveying at least one suspension element via the supporting pulleys . The method further comprises mounting the supporting pulleys to pulley control units with movable control arms and thereby allowing the supporting pulleys to move vertically in relation to the elevator car .

According to an embodiment , the method further comprises suspending the control arms by means of one or more spring elements .

According to an embodiment , the method further comprises connecting the control arms to the elevator car by means of dedicated turning j oints and providing the turning j oints with bushings made of resil ient material and serving as vibration dampening elements .

According to an embodiment , the method further comprises providing access from inside of the elevator car to the pulley control units through at least one openable and closable opening and executing maintenance operations for the pulley control units without entering the elevator shaft .

The above disclosed embodiments may be combined to form suitable solutions having those of the above features that are needed . Brief description of the figures

Some embodiments are described in more detail in the accompanying drawings , in which

Figure 1 is a schematic and highly simpli f ied side view of a traction elevator,

Figure 2 is a schematic side view of a lower part of an elevator car provided with two pulley control units with independent control arms and supporting pulleys ,

Figures 3 - 5 are schematic s ide views of some alternative pulley control units and di f ferent spring systems used,

Figure 6 is a schematic s ide view of a pul ley control unit wherein compressible material is used as a spring element ,

Figure 7 is a schematic view of a turning j oint of a pulley control unit ,

Figure 8 is a schematic side view of pulley control units connected together by means of a stabili zing element , and

Figure 9 is a schematic view of a pulley control system provided with torsion bars as spring elements .

For the sake of clarity, the figures show some embodiments of the disclosed solution in a simpli fied manner . In the figures , like reference numerals identi fy like elements .

Detailed description of some embodiments

Figure 1 discloses a traction elevator 1 mounted to an elevator shaft 2 of a building . The elevator 1 comprises an elevator car 3 for receiving load to be transported . The car 3 and a counterweight assembly 4 are suspended from a suspension rope or element 5 passing via a hoisting machinery 6. The hoisting machinery 6 comprises a traction sheave 7 driven by means of an electric motor M . Between the suspension element 5 and the traction sheave 7 occurs friction which is utili zed for transmitting li fting power to the elevator system . The suspension element 5 may be mounted to fastening points 8 . The hoisting machinery 6 may be located at an upper machine room 9, or alternatively the system may be a so called machine room les s elevator . A compensation chain or rope may, or may not , be connected between the counterweight assembly 4 and a bottom of the elevator car 3 .

The elevator car 3 can be driven to desired landings L or f loors under control of one or more control units CU . Below a first or lowermost landing LI there is a pit 11 of the shaft 2 .

Below the elevator car 3 are two supporting pulleys 12 and the suspension element 5 running via them . Figure 1 discloses a prior art solution wherein the supporting pulleys are fixedly mounted to the structure of the elevator car 3 . It has been found out that maintenance of the supporting pulleys 12 is di f ficult especially when the elevator 1 is provided with the pit 11 with limited height .

Figure 2 discloses that there are two supporting pulleys 12 mounted to pulley control 13 units . Each pulley control unit 13 comprises an independent control arm 14 supported at a first end portion to the elevator car 3 by means of a turning j oint 15 . The supporting pulleys 12 are located at opposite second end portions of the control arms 14 . The control arms 14 are suspended in relation to the elevator car 3 by means o f at dedicated spring elements 16 so that the control arms 14 can turn in relation to the turning j oints 15 whereby the supporting pulleys 12 are movable in relation to the elevator car 3 . The turning j oint 15 may be connected to a supporting structure 17 beneath a bottom 18 of the elevator car 3 . In Figure 2 the supporting structure 17 is shown in simpli fied manner for clarity reasons . In practice , the supporting structure 17 may comprise beams or structures of a frame of the elevator car 3 .

The supporting pulleys 12 are kept at a distance from the bottom 18 of the elevator car 3 by means of spring forces generated by dedicated spring elements which may be for example helical springs shown in Figure 2 . Depending on required supporting forces , the supporting pulleys 12 can move vertically in relation to the elevator car 3 .

For executing required inspections and other maintenance operations , the elevator car can be driven to the lowermost landing . Then the pulley control units 13 are close to a bottom 19 of a pit of an elevator shaft . The bottom 18 o f the elevator car 3 may be provided with openings 20 which are located at the pulley control units 13 so that maintenance operations can be executed from the inside of the elevator car 3 and there is no need to enter the shaft or the pit . Figure 2 further shows that the openings 20 may be provided with hatches 21 openable in relation to hinges . Di f ferent opening positions of the hatches 21 are indicated in Figure 2 by means of broken lines .

Figure 3 di scloses a solution which di f fers from the one shown in Figure 2 in that the pulley control units 13 are provided with separate dampening actuators 22 . The dampening actuators 22 may be for example hydraul ic, pneumatic, or hydro-pneumatic cylinders . The dampening actuators 22 may stabili ze movements of the control arms 14 .

A further di fference in the solution of Figure 3 is that there is only one large openable hatch 21 providing access to both pulley control units 13 .

Figure 4 shows a slightly di f ferent solution compared to the solutions of Figures 2 and 3 and discloses that the control arms 14 may comprise extens ions 14a which extend to other sides of the turning j oints 15 . Then the spring elements 16 may be placed at the extensions 14a .

In Figures 2 - 4 helical springs are disclosed but it is of course possible to implement any other spring type disclosed in this document or being suitable for the purpose .

Figure 5 di scloses that instead o f us ing dedicated spring elements for both control arms 14 , one common spring element 16 may serve them both . The common spring element 16 may be a leaf spring supported at its central part to the structure of the elevator car 3 by means of a spring support 23 . However , other spring types may also be implemented as common spring elements when being equipped with suitable force transmitting elements or mechanisms .

Figure 6 discloses a pulley control unit 13 wherein a compressible resilient material is arranged to serve as the spring element 16 . The compressible spring element 16 may be placed between an upper surface of the control arm 14 and a spring support 24 . The spring element 16 may be a block, disk, sheet , or any formed piece made of material that can compress under stress and return to its original form when the stres s is removed . The spring element 16 may be of polyurethane or rubber-like material , for example .

Figure 7 discloses a turning j oint 15 for coupling a control arm 14 movably to a frame beam 25 or a frame structure of an elevator car . There may be a hinge pin 26 , such as a bolt , which is arranged to pass an inner first sleeve 27a . There may also be a second sleeve 27b surrounding a bushing 28 . The bushing 28 may be made of resil ient material , such as polyurethane or rubber, so that that it can serve as a vibration and noise dampener . The second sleeve 27b may provide support for the bushing 28 and may serve as a bearing element against surfaces of the control arms 14 . The bushing 28 may comprise two bushing components 28a, 28b both provided with sleeve parts and flange parts . The bushing components 28a, 28b are easy to mount from opposite lateral sides so that their sleeve parts are inside the first sleeve 27a and the flange parts separate the frame beam 25 and the control arm 14 in lateral direction . The bushing 28 may alternatively be construed to be a one single piece with a sleeve part and one flange at one end . Then it is possible to use a separate resilient ring at the other end, or the s leeve part may extend longer than the s leeves 27a and 27b and may form a separating lateral structure . It is also possible to provide a bushing arrangement with only one of the sleeves 27a or 27b, or without either of them .

Figure 8 discloses an arrangement wherein two pulley control units 13 are connected to each other by means of a stabili zing element 29 . The stabili zing element 29 may comprise a rigid stabi li zing bar 30 connected by link systems 31 to control arms 14 of the pulley control units 13 . The link systems 31 may comprise vertical bars with articulated ends , for example . The stabili zing bar 30 and the link systems 31 can transmit forces between the control arms 14 and can thereby stabili ze movements of the supporting pulleys 12 . In a simpli fied illustration 32 it is shown that torque 33 is generated to the stabilizing bar 30 when force is directed to one pulley control unit 13 , and the transmitted turning moment 33 makes the control arm 14 of the other pulley control unit 13 to move into the same direction . There may be one or more bearing points 34 for supporting the stabili zing bar 30 to the structure of the elevator car 3 in a turnable manner . End portions of the stabili zing bar 30 may comprise transverse portions 30a, 30b for generating the torque 33 .

Figure 9 discloses an arrangement wherein pulley control units 13 are provided with torsion bars 35 serving as spring elements 16 . Movement of a supporting pulley 12 is transmitted by a control arm 14 to the torsion bar 35 which is mounted rigidly at its oppos ite end to a frame beam 36 o f an elevator car . There is a rigid connection without a turning j oint between a free end of the torsion bar 35 and the control arm 14 . As can be noted, the tors ion bars 35 may have relative great lengths and minor space requirement in vertical direction .

It should be noted that the type and operating principle of the elevator 1 may be di fferent from the one shown in Figure 1 . For example , a roping system of the elevator may di f fer from the exemplary one shown . Furthermore , Figures show the elevator, the pulley control units , and the openings and hatches of the elevator car in a highly simpli fied manner .

Thus , the disclosed solution can be implemented in a versatile manner in elevator cars wherein car rope pulleys or supporting pulleys are placed in the lower part of the elevator car near its bottom .

The drawings and the related description are only intended to illustrate the idea of the invention . In its details , the invention may vary within the scope of the claims .

In a further solution, which is not in accordance with the independent claims of this document , the pulley arrangement may be without the above disclosed features turning j oint and spring element . It may be possible to use bendable control arms , for example .

Further , a leaf spring can be arranged to serve as the control arm . One more option i s to provide the control arms with other type of integrated spring mechanisms .

Claims

Claims

1. An elevator pulley arrangement comprising; at least two supporting pulleys (12) mounted at a lower part of an elevator car (3) ; and at least one suspension element (5) passing via the supporting pulleys (12) ; char ac t e r i z e d in that the supporting pulleys (12) are mounted to pulley control units (13) wherein each pulley control unit (13) comprises an independent control arm (14) supported at a first end portion to the elevator car (3) by means of a turning joint (15) ; the supporting pulleys (12) are located at opposite second end portions of the control arms (14) ; and wherein the control arms (14) are suspended in relation to the elevator car (3) by means of at least one spring element (16) allowing the control arms (14) to turn in relation to the turning joints (15) whereby the supporting pulleys (12) are movable in relation to the elevator car .

2. The arrangement as claimed in claim 1, char ac t e r i z e d in that the pulley control units (13) comprise one common spring element (16) .

3. The arrangement as claimed in claim 1, char ac t e r i z e d in that the pulley control units (13) comprise dedicated spring elements (16) whereby the control arms (14) are provided with independent suspension.

4. The arrangement as claimed in any one of the preceding claims 1 - 3, char ac t e r i z e d in that the turning joints (15) are provided with bushings

(28) made of resilient material.

5. The arrangement as claimed in any one of the preceding claims 1 - 4, char ac t e r i z e d in that the arrangement comprises at least one stabilizing element (29) connecting two opposite directed control arms (14) together for transmitting forces between the connected control arms (14) .

6. The arrangement as claimed in any one of the preceding claims 1 - 5, char ac t e r i z e d in that the turning joints (15) are located on a bottom side of the elevator car (3) and are mounted to a frame of the elevator car (3) .

7. The arrangement as claimed in any one of the preceding claims 1 - 6, char ac t e r i z e d in that the bottom (18) of the elevator car (3) comprises at least one openable and closable opening (20) at the pulley control units (13) for providing access to the pulley control units (13) from the inside of the elevator car (3) .

8. An elevator (1) comprising: an elevator shaft (2) ; an elevator car (3) supported vertically movably inside the elevator shaft (2) ; a hoisting machinery (6) and suspension means for moving and supporting the elevator car (3) ; and wherein the suspension means comprise at least two supporting pulleys (12) mounted at a lower part of an elevator car (3) and at least one suspension element (5) passing via the supporting pulleys (12) ; char ac t e r i z e d in that the supporting pulleys (12) are mounted to pulley control units (13) which are in accordance with the previous claims 1 - 7.

9. A method for suspending an elevator car (3) of an elevator ( 1 ) ; wherein the method comprises: suspending the elevator car (3) vertically movably inside an elevator shaft (2) by means of suspension means; providing the suspension means with at least two supporting pulleys (12) mounted at a lower part of the elevator car (3) ; and conveying at least one suspension element (5) via the supporting pulleys; char ac t e r i z e d by mounting the supporting pulleys (12) to pulley control units (13) with movable control arms (14) and thereby allowing the supporting pulleys (12) to move vertically in relation to the elevator car (3) .

10. The method as claimed in claim 9, cha r ac t e r i z e d by suspending the control arms (14) by means of at least one spring element (16) .

11. The method as claimed in claim 9 or 10, char ac t e r i z e d by connecting the control arms (14) to the elevator car (3) by means of dedicated tuning joints (15) ; and providing the turning joints (15) with bushings (28) made of resilient material and serving as vibration dampening elements.

12. The method as claimed in any one of the preceding claims 9 - 11, char ac t e r i z e d by providing access from inside of the elevator car (3) to the pulley control units (13) through at least one openable and closable opening (20) ; and executing maintenance operations for the pulley control units (13) without entering the elevator shaft (2) .