LIFT DEVICE

Abstract: A lift device including a lift shaft (1) and a lift cage (2) movable in said lift shaft, elongated guide means (3, 4), a supporting frame (6, 29) movable along said guide means (3, 4) and driving means (17) for moving said supporting frame (6) along said guide means (3, 4). A pulley (9) is rotatably mounted to said supporting frame (6), the supporting frame being connected with said lift cage (2) by means of at least one lifting cable (10) attached at one end to said lift cage (2) and extending over said pulley (9) to form a tackle loop so that movement of said supporting frame (6) a distance along the guide means (3, 4) by said tackle loop is transformed to a movement of said lift cage (2) a multiple of said distance. A drive rod (16) is fixedly mounted with respect to said means (3, 4) and extends along the guide means in the moving direction of the supporting frame (6). A drive element is further supported on said supporting frame (6), said drive element positively engaging the drive rod (16).

Description: LIFT DEVICE The present invention relates to a lift device including a lift shaft and a lift cage movable in said lift shaft, elongated guide means, a supporting frame movable along said guide means, and driving means for moving said supporting frame along said guide means, a pulley rotatably mounted to said sup¬ porting frame, the supporting frame being connected with said lift cage by means of at least one lifting cable attached at one end to said lift cage and forming a tackle loop extending over said pulley so that movement of said supporting frame a distance along the guide means, by said tackle loop is trans- formed to a movement of said lift cage a multiple of said distance. In known lift devices of this kind the sup¬ porting frame is movable on guide rails in the ver- ticle direction in said lift shaft, the supporting frame being attached at the upper end of the piston rod of a vertically extending hydraulic cylinder, the opposite end of which being supported on a base structure at the bottom of said lift shaft. Ex¬ tending or retracting the hydraulic cylinder unit thus causes the supporting frame, to move vertically in the lift shaft, and since the supporting frame is connected with the lift cage by lifting cables form¬ ing a loop over a pulley supported on the supporting frame, the lift cage is caused , to move vertically in the lift shaft over the double distance and with the double velocity compared to the movement of the sup¬ porting frame. In the known lift devices of this kind the hydraulic cylinder units extends from the bottom of the lift shaft past the lift cage in a re- cess at the side of the lift cage to the supporting frame to which the piston end of the hydraulic cylinder is articulately attached. The hydraulic cylinder is supplied with pressure medium from a hydraulic pump unit disposed in a suitable space in the vicinity of the lift shaft. The length of the hydraulic cylinders used is thus considerable since the hydraulic cylinder unit extends from the bottom of the lift shaft past the lift cage up to the supporting frame. The length of the hydraulic cylinder units and the fact that the cylinders are subject to buckling stress, results in big dimen¬ sions of the hydraulic cylinders and consequently in a need for large quantities of pressure fluid to be supplied to said cylinders, which in turn influences the space required for accomodating the hydraulic power unit and the associated pressure fluid tank. One object of the present invention is to pro¬ vide a lift device of the kind mentioned initially in which the need for hydraulic cylinders and asso- ciated hydraulic pressure units is eliminated. An¬ other object of the invention is to provide a lift device vΛiich is particularly well adapted to be manufactured, assembled, tested and finished at the factory, to be ready for delivery as a complete lift device including lift shaft, lift cage and associ¬ ated drive arrangement, which as a unit may be transported to the building in which the lift device may be installed by lowering the complete unit ver¬ tically through an opening in the roof of the build- ing just above the hoist shaft therein. Still an¬ other object of the invention is to provide a lift device in which the main power transmitting con¬ structive parts substantially are subject to trac¬ tion forces instead of buckling forces thus reducing the dimensions of said parts. Still another object of the invention is to provide a lift device of the kind mentioned initially which is simple to install, the installation only requiring that the lift device be connected to the electricity supply system of said building. These and other objects of the present inven¬ tion are achieved by a lift device having the char¬ acteristics specified in the appended claims. The invention will now be described with reference to embodiments illustrated on the appended drawings, on which fig 1 is a schematic vertical front sectional view of a lift device in accordance with the inven¬ tion, - fig 2 is a schematic sectional side view of the lift device shown in fig 1, - fig 3 is a schematic sectional view correspond¬ ing to fig 1 of a second embodiment according to the invention, - fig 4 is a schematic sectional side view of the lift device shown in fig 3, - fig, 5 is a schematic sectional view of a lift device in an alternative embodiment in accordance with the invention, - fig 6 is a schematic partial view taken as in¬ dicated by lines I-I in fig 5, - fig 7 is a vertical sectional view through the upper portion of the lift shaft and the drive unit in another embodiment according to the invention, - fig 8 is a partial top view taken as indicated by II-II in fig 7, and - fig 9 is a schematic transverse sectional view through the guide frame of the drive unit shown in fig 7, said transverse section taken as indicated by III-III in fig 7. The lift device schematically illustrated in figures 1 and 2 includes a vertical lift shaft 1, preferably having a rectangular cross section. The lift shaft 1 includes a supporting frame work, not shown in the figures, said frame work being covered by thin plating so that a closed lift shaft is formed. Vertically movable in said lift shaft is a lift cage 2, including a frame work covered with thin plating and preferably sound insulated in a conventional manner. One side the lift cage 2 is provided with a vertical recess for the lifting cables of the drive unit. In the upper portion of the lift shaft, on the side thereof facing the re¬ cess in the lift cage, are rigidly " attached two ver- tically extending guide rails 3, 4 for guiding en¬ gagement with a supporting frame 5, supporting the lift cage 2 and being movable along said guide rails. The supporting frame 5 includes an upper horizontal frame portion 6 and a lower horizontal frame portion 7 disposed at a distance below said upper frame portions 6, the upper and lower frame portions* 6, 7 being interconnected by means of ver¬ tical struts 8. Rotatably supported on the upper frame portion 6 is a pulley 9 having a number of parallel pulley grooves for a corresponding number of parallel lifting cables 10, preferably three lifting cables. The end of each one of said lifting cables 10 is attached at the upper part of the frame work of the lift cage 2, said lifting cables ex- tending from the lift cage in a direction vertically upwards over the pulley 9 and from this in a direc¬ tion vertically downwards to the bottom of the lift shaft, where the lifting cables are attached via equalizing means known per se for equalizing of tensions in order to secure that the tension in each one of said lifting cables is substantially the same. The portions of the lifting cables 10 extending to the bottom of the lift shaft thus extend through the recess of the lift cage 2. The guide rails 3 and 4 extend from the upper portion of the lift shaft in a direction downwards at least a short distance past half the height of said lift shaft, but may also be extended to the bottom of the lift shaft in case said guide rails are used as guides also for the lift cage 2. This is not necessary, however. The lift shaft 1 may instead be provided with separate guide rails (not shown in the figures) for the lift cage. As appears from the figures the lift arrange- ment described results in that when the supporting frame 5 is caused to move over a certain distance, a movement is also imparted to the lift cage, said lift cage moving in the vertical direction of the lift shaft over the double distance and with the double velocity compared to the movement of the sup¬ porting frame 5. The * displacement of the supporting frame 5 along the guide rails 3, 4 is obtained by means of a vertical screw spindle 11 extending from the upper part of the lift shaft in the • vertical direction downwards over a distance which is somewhat greater that half the height of the lift shaft. The screw spindle 11 is rigidly secured in the upper part of said lift shaft and cooperates 'positively with a nut 12 supported by the supporting frame 5 and being rotatively attached to said supporting frame. The nut 12 is provided with a gear ring 13 positively engaging a pinion 14 which is rotatably driven by a drive motor 15. When driving the electrical motor 15 and thus causing the pinion to rotate, the nut 12 also rotates, at the same time being displaced ver¬ tically along the screw spindle 11. When driving the electrical motor 15 for rotation in one direction, the nut 12 and thus also the supporting frame 5 is caused to move in a direction upwards. The lift cage 2 supported by the supporting frame 5 via lifting cables 10 is thus caused to move in a direction up¬ wards with the double velocity compared to the vel¬ ocity of said supporting frame. If the electrical motor 15 is made to rotate in the opposite direc¬ tion, the direction of movement of the frame and thus of the lift cage is the opposite. The lift shaft 1 and the lift cage 2 are nat¬ urally in a conventional manner provided with lift doors and lift door openings disposed just opposite and in level with the respective floor plan of the building in which the lift device is to be in¬ stalled, and further in a conventional manner equipped with an electrical control system for con- trol of the driving of the lift device and of the stop positions just in level with the desired floor plan. Figures 3 and 4 illustrate very schematically a modification of the embodiment illustrated in fig- ures 1 and 2. The embodiment according to figures 3 and 4 differs from the embodiment shown in figures 1 and 2 mainly in that the screw spindle 16 disposed vertically in the lift shaft is rotatably supported at the upper end of the lift shaft, and is driven by means of an electrical gear motor drive for rotation about its longitudinal axis. In this embodiment the nut is rigidly secured to the supporting frame 5. In other respects the lift device construction corre¬ sponds to the embodiment described in connection with figures 1 and 2. The movement of the supporting frame 5 along the guide rail 3 and 4, and thus the movement of the lift cage 2 in the lift shaft is obtained by driving the electrical drive motor, which via the gear 17 causes the screw spindle 16 to rotate either in a direction for lifting the supporting frame 5 and thus the lift cage 2 or in a direction for lowering of supporting frame and lift cage. Figures 5 and 6 very schematically illustrate an alternative embodiment of the lift " device in ac¬ cordance with the invention. With respect to lift shaft, lift cage, supporting frame and the arrange¬ ments of lifting cables also this embodiment corre¬ sponds to the embodiments previously described. The main difference is that the screw spindle has been replaced by two racks 19, 20 rigidly mounted on each one of guide rails 3, 4 respectively. Mounted on the supporting frame 5 adjacent each one of guide rails 3, 4 is an electric drive motor 21, 22 respectively, for driving a pinion 23, 24 which permanently en¬ gages rack 19 and 20 respectively. Synchronous driving of electrical motors 21, 22 thus causes pin¬ ions 23, 24 to rotate and consequently to move in a direction upwards or downwards along said racks, de- pending of the rotational direction of drive motors 21, 22. Drive motors 21, 22, which are rigidly at¬ tached to the supporting frame 5, are thus caused to move together with the supporting frame in the ver¬ tical direction and thus, in • the manner previously described, causing the lift cage to move vertically in the lift shaft with the double velocity of the supporting frame 5. Figures 7-9 illustrate a furhter embodiment of the invention * The main difference compared with the embodiments previously described is that the guides, the supporting frame, drive rod, drive element and drive means are assembled to form a separate drive unit entirely disposed at a level above the lift shaft, said drive unit being designed so as to im- part to the lift cage a movement in the lift shaft which corresponds to the movement of the supporting frame along the guide frame multiplied by three. As appears from figures 7-9 the drive unit 25 comprises a main frame formed by guide rails 3, 4 and girders 26, 27, e.g. in the form of elongated tubes with square section, which are disposed in the corners of a rectangel, as seen in fig 9. The guide rails 3, 4 and the girders 26, 27 are interconnected by a number of rectangular frame sections 28 equally spaced to form an elongated frame for said drive unit 25. The guide rails 3, 4 are disposed diagonal¬ ly opposite each other for guiding cooperation with the supporting frame 29 by engagement with guiding blocks 30 disposed on said supporting frame. The supporting frame 29 is thus movable along said guide rails 3, 4. Rotatably supported on said supporting frame is«a pulley 9 for lifting cables 10. The drive unit 25 is disposed with one end just above and op¬ posite the upper opening of the vertical lift shaft 1 as best seen in fig 7. Rotatably supported at this end of the drive unit 25 are two intermediate pul¬ leys 31, 32, one of said intermediate pulleys 31 de¬ viating the lifting cables 10 towards the pulley 9 supported on the supporting frame 29, said lifting cables further extending over said pulley 9 to form a tackle loop. From the pulley 9 the lifting cables further extend to and over the second intermediate pulley 32 to form a second tackle loop, the lifting cables extending back to the supporting frame, to which the ends of the lifting cables are fixedly attached by an attachment 33. Fixedly attached to the supporting frame 29 is a drive element in the form of a nut 34 which positively engages an elongated screw spindle 35 extending through said nut 34 and being rotatably supported by a thrust bearing 36 at the end of the drive unit 25 which faces away from the lift shaft. The thrust bearing 36 in turn is supported by a yoke 37 interconnecting the girders 26, 27 at the ends thereof. At the opposite end the screw spindle 35 is connected to an electrical gear drive motor 38 by means of a coupling 39. When the screw spindle 35 is rotaded by means of the drive motor 38, the nut 34, which is in posi- tive engagement with the screw spindle, is displaced along the screw spindle 35, and since the nut 34 is rigidly attached to the supporting frame 29, said supporting frame is caused to move along the guide rails 3, 4. The direction of said movement depends on the rotational direction of the screw spindle 35. By the lifting cables 10 the movement of the sup¬ porting ' frame 29 along the guide rails 3, 4 is transformed to a movement of the lift cage 2 verti¬ cally in the lift shaft 1 over a distance and with a velocity that is three times the distance and veloc¬ ity of the movement of the supporting frame 29. In the embodiment illustrated in fig 7 the drive unit 25 extends substantially perpendicularly with respect to the lift shaft. The drive unit 25 may, however, extend in any desired inclination with respect to the lift shaft, including an arrangement in which the drive unit 25 extends axially above the lift shaft 1, or an arrangement in which the drive unit 25 extends close to and in parallel with the upper part of the lift shaft and having the end. which is provided with said intermediate pulleys 31, 32 disposed close to the upper opening of the lift shaft. In this latter case an additional intermedi¬ ate pulley should be arranged for deviating the lift cables 10 from the lift cage 2 over said additional pulley to said intermediate pulleys 31, 32 at the end of the drive unit and further to the pulley 9 on the supporting frame 29. The invention is not limited to the embodiments described above but may be subject to modifications within the scope of the appended claims. The screw spindle used in the embodiments according to figures 1, 2, 3, 4, and 7-9 may be of the self-breaking type or the non-self-breaking type. In the latter case the driving means of the lift should be provided with a brake which is automatically actuated in case of interruption in electricity supply to the elec¬ trical drive motor. The embodiments according to figures 5 and 6 include two racks and two synchron- ously driven electrical motors. Said drive arrange¬ ment may instead include only one rack and one elec¬ trical dsive motor including a pinion positively en¬ gaging said rack. .In the embodiments including rack and pinions the lift device should be provided with a brake which is automatically actuated in case of interruption in electricity supply to the drive motor. In the embodiments described above the lift¬ ing cables 10 and the pulleys 9, 31, 32 are arranged so that the resulting movement' of the lift cage 2 is a multiple by two or three of the movement of the supporting frame 6, 29 along the guide rails 3, 4. Within the scope of the present invention it is also possible, using the principles described, to design the arrangement of lifting cables 10 and pulleys 9 so that the resulting movement of the lift cage is a multiple by four, five ....etc of the movement of the frame.

Claims: CLAIMS 1. Lift device including a lift shaft (1) and a lift cage (2) movable in said lift shaft, elongated guide means (3, 4), a supporting frame (6, 29) movable along said guide means (3, 4) and driving means (12, 17, 21, 22, 38) for moving said support¬ ing frame (6, 29) along said guide means (3, 4), a pulley (9) rotatably mounted to said supporting frame, the supporting frame (6, 29) being connected with said lift cage (2) by means of at least one lifting cable (10) attached at one end to said lift cage (2) and forming a tackle loop extending over said pulley (9) so that movement of said supporting frame (6, 29) a distance along the guide means (3, 4) by said tackle loop is transformed to a movement of said lift cage (2) a multiple of said distance, c h a r a c t e r i z e d by a drive rod (11, 16, 19, 20, 35) fixedly mounted with respect to said guide means (3, 4) and extending along the guide means in, the moving direction of the supporting frame (6, 29), and by a drive element (12, 18, 23, 24, 34) on said supporting frame (6, 29) positively engaging the drive rod, said drive rod and said drive element being relatively rotatable by said driving means for displacement of the supporting frame (6, 29) along the guide means (3, 4) by said positive engagement. 2. Lift device as claimed in claim 1, c h a r ¬ a c t e r i z e d in that said drive rod is a screw spindle (11, 16, 35) and said drive element is a nut (12, 18, 34) positively engaging the screw spindle. 3. Lift device as claimed in claim 2, c h a r a c t e r i z e d in that said screw spindle (11) is immovably fixed with respect to the guide means (3, 4), the nut (12) being rotatably mounted to said supporting frame (6) and drivingly connected to driving means (14, 15) mounted on the supporting frame (6). 4. Lift device as claimed in claim 2, c h a r ¬ a c t e r i z e d in that the screw spindle (16, 35) is rotatably fixed with respect to the guide means (3, 4) and drivingly connected to driving means (17, 38) for rotatably driving the screw spindle (16, 35) in positive engagement with said nut (18, 34), said nut being immovably mounted to said supporting frame (6, 29). 5. Lift device as claimed in claim 1, c h a r - a c t e r i z e d in that said drive rod includes a rack (19, 20) which is immovably fixed with respect to the guide means (3, 4), said drive element in¬ cluding a pinion (23, 24) mounted on said supporting frame (6) and positively engaging said rack (19, 20), said pinion (23, 24) being drivingly connected to driving means (21, 22) mounted on the supporting frame (6). 6. Lift device as claimed in any of claims 1-5, c h a r a c t e r i z e d in that the other end of said lifting cable (10) being fixedly secured in the lower part of said lift shaft (1), preferably at the bottom thereof. 7. Lift device as claimed in any of claims 1-5, c h a r a c t e r i z e d in fchat the lifting cable (10) further extends over a rotatably fixed inter¬ mediate pulley (32) to form a second tackle loop, the other end of said lifting cable (10) being attached to said supporting frame (29). 8. Lift device as claimed in any of claims 1-7, c h a r a c t e r i z e d in that said elongated guide means (3, 4) are mounted vertically in the up¬ per part of said lift shaft. 9. ψ Lift device as claimed in any of claims 1-7, c h a r a c t e r i z e d in that the elongated guide means (3, 4), the supporting frame (29), the drive rod (35), the drive element (34) and the driving means (38) are included in an independent drive unit (25) which is mounted independently of the lift shaft (1), one end of said drive unit (25) being disposed close to the top opening of said lift shaft (1). 10. Lift device as claimed in claim 9, c h a r ¬ a c t e r i z e d in that said end of the drive unit (25) is provided with two rotatably mounted in- termediate pulleys (31, 32), one of which (31) devi¬ ating the lifting cable (10) from the lift cage (2) to the pulley (9) mounted on said supporting frame (29) to form said first tackle loop, the other in¬ termediate pulley (32) further deviating the lifting cable (10) to form said second tackle loop, the end of the lifting cable (10) being fixedly secured to said supporting frame (29).

Inventors: SARNIK STANISLAW, SARNIK, STANISLAW
Applicants: KOCKUMS MARINE AB, KOCKUMS MARINE AKTIEBOLAG
Application year: 1987
Main classification: B66B9
IPC codes: B66B9