SE1450933A1

SE1450933A1 - Lifting device, in particular patient lifter, with an unrolling prevention device

Info

Publication number: SE1450933A1
Application number: SE1450933A
Authority: SE
Inventors: Lutz Pahlke; Andreas Wolfrum
Original assignee: Ebm Papst Zeitlauf Gmbh & Co Kg
Priority date: 2012-02-15
Filing date: 2013-02-15
Publication date: 2014-08-12
Also published as: WO2013120981A1; CA2864970A1; DE102012202257B4; SE539653C2; DE102012202257A1; DK201470459A; DK179579B1; SE1450933A2

Description

10 15 20 25 _2_ depending on the rotational speed, the locking lever being controlled due to gravity.

The problem With this unrolling prevention device is the fact that a speciﬁc rotational speed - in other Words a relatively high falling speed of the lifted person - firstly has to be reached until the blocking mechanism sets in Suddenly. This may entail serious injuries in terms of health for injured people moved with the aid of the patient lifter.

A rolling door securing device is known from DE 20 2004 0l2 024 Ul, the engagement of Which takes place by means of a mechanical centrifugal force control. The advantages mentioned of the prior art also apply here.

The invention is based on the object of disclosing a lifting device, Which ensures a gently responding but effective unrolling prevention device in all the phases of application.

This object is achieved by the features disclosed in the characterising part of the claim and is characterised by - a mounting of the Winding coil that can be rotated relative to the output shaft, - an abutment body non-rotatably connected to the Winding coil, - at least one clamping body, which can be displaced radially With respect to the output shaft between the inner abutment body and an outer locking ring, said clamping body being coupled by means of a coupling arm, Which is articulated to the output shaft, to the latter in such a Way that = in the event of a torque produced by the output shaft both in the Winding and in the unwinding direction, the clamping body can 10 15 20 25 _3_ be transferred from its locking position resting on the looking ring into a torque transmission position resting on a wedge face of the abutment body to rotate the abutment ring with the winding coil independently of the load-induced counter-torque acting on the winding coil, and = in the event of a torque-free output shaft, owing to the load- induced counter-torque on the winding coil, the at least one clamping body is loaded by the wedge face of the abutment body radially outwardly into the looking position resting on the looking ring with rotary blooking of the abutment body with the winding coil.

Because of this concept, the lifting device according to the invention is designed with a complete functional range as a lifting, lowering, stopping and securing unit. In this case, a separate motor brake for stopping and a separate securing unit, such as is also used, for example, in the form of an electromagnetically activated looking element in the known unrolling prevention device according to EP O 940 134 A2, is avoided, as is a disadvantageous, centrifugal force-controlled brake or lock. Because of the release and looking of the lifting device acting both in the winding and in the unwinding direction, the latter acts like a switchable freewheel acting in both directions, which reacts selectively to a torque introduction on the drive and output side. To this extent its function is, in particular, independent of the rotational direction of the drive side, on the one hand, and the output side, on the other hand. As no components operating due to gravity are present, the function of the lifting device with the unrolling prevention device is also independent of its installation position. 10 15 20 25 _4_ A further important advantage is furthermore that because of the arrangement of the unrolling prevention device between the output shaft and winding coil, the electric motor itself can also be exchanged under load on the lifting mechanism. Equally, an emergency lowering can be carried out by a direct emergency actuation of the output shaft if the drive fails.

The latter is also released by means of the unrolling prevention device according to the invention of the lifting device.

Preferred embodiments of the invention are given in the dependent claims, the features, details and advantages of which are described in more detail in the following description of an embodiment with the aid of the accompanying drawings, in which: Fig. l shows a partially broken away, perspective view of the lifting device, Fig. 2 shows a vertical rotational axial section of the lifting device according to Fig. l and Figs. 3 and 4 show sections along the section line A-A according to Fig. 2 in different functional positions of the lifting device.

As emerges from the accompanying drawings, the lifting device designated 1 as a whole is fastened to a solid U-shaped bow 2, which is either stationarily attached to a ceiling of a room or to a travelling trolley of a ceiling rail system. In the case first mentioned, the lifting device l is merely used to lift and lower a patient and in the case mentioned second, the patient can additionally be brought to a different location with the aid of the rail system. 10 15 20 25 _5_ The lifting device 1, as the central drive part, has a gear motor 3 with an electrically operated motor unit 4 and an upstream planetary gear 5. The gear motor 3 is ﬂanged to the U-shaped bow 2 laterally on the outside. Its output shaft 6 projects by way of a bore 7 into the interior 8 between the limbs 9, 10 of the bow 2, where the remaining components of the lifting device 1 with the unrolling prevention device are accommodated. A winding coil ll is thus provided, between the cheeks 12 of which a belt 13 indicated in Fig. 2 layerwise and running out to the bottom can be wound and unwound. The winding coil ll is rotatably mounted relative to the output shaft 6 by means of ball bearings 14 relative thereto. This winding coil ll is rigidly connected by one of its cheeks 12 -the right-hand one in relation to Fig. 2 -to an abutment body 15 by means of ﬁxing screws 16, said abutment body being substantially disc-shaped. Three bearing extensions 17, which are rotatably supported at their ends in a pivot bearing 18 in an annular bearing body 19, project in the axially parallel direction from the abutment body 15 from the side remote from the winding coil 11.

The bearing body 19 is screwed to the inside of the second limb 10 of the bow 2 opposing the gear motor 3 by means of screws 20. On its side facing the winding coil 1 1, the bearing body 19 has a proj ecting annular shoulder that forms a locking ring 21 of the unrolling prevention device in the lifting device 1. The abutment body 15 is arranged radially within this locking ring 21, said abutment body forming, with corresponding recesses, three receivers 22 arranged angle-symmetrically with respect to the rotational axis R of the lifting device, said receivers in each case having, on the inside, wedge faces 23 adopting a large obtuse angle W of about l50° with respect to one another. Said wedge faces are symmetrical with respect to a radial line passing through the apex of the angle. 10 15 20 25 _6_ Congruently formed clamping bodies 24, the radially outer side 25 of which is arc of a circle-shaped With an external diameter corresponding to the internal diameter of the locking ring 2l, are inserted in the receivers 22, in each case. The two clamping bodies 24 radially inwardly have contact faces 26 in each case, which are at the angle W to one another and cooperate with the wedge faces 23 of the receivers 22 in the abutment body l5 in a manner still to be described in more detail.

The clamping bodies 24 are in each case coupled to the output shaft 26 by means of a coupling arm 26 articulated to the end face of the output shaft 6 by means of pivot bolts 28. The connection between the coupling arm 27 and clamping body 24 takes place here by means of a sliding connection that is radially affected by play, which is realised by a connecting bolt 29 on the side face of the clamping body 24 in a radially directed slot 30 in the coupling arm 27.

Finally, each coupling arm 27 is spring-loaded by paired tension springs 31 clamped between its inner end and the abutment body l5, which will be functionally described in more detail below.

The mode of functioning of the lifting device l with an unrolling prevention device is now to be described as follows: In the locking position of the lifting device shown in Fig. 3, the output shaft 6 is torque-free and, without further securing measures, in the event of a load-induced counter-torque G, upon the exceeding of the inner inhibition of the gear motor 3, would lead to an uncontrolled unwinding of the belt l3. 10 15 20 25 _7_ In order to prevent this, the lifting device has the unrolling prevention device formed from the abutment body 15, clamping body 24 and locking ring 21. The counter-torque G is transmitted by the Winding coil ll to the abutment body 15, which therefore exhibits the tendency to rotate clockwise in relation to Fíg. 3. Owing to this introduction of force, the clamping bodies 24 are pressed radially outwardly by means of their contact faces 26 by means of the wedge faces 23 of the receivers 22 in the abutment body 15, so they come into braking engagement With the clamping ring 21 and therefore prevent a further, uncontrolled rotation of the abutment body 15 With the Winding coil 1 l. The coupling arms 27 are therefore radially erected and are symmetrical to a radial line running through the pivot bolts 28. The lifting device l is therefore reliably rotationally blocked.

In the event of an actuation of the gear motor 3, for example to lift a load counter to the counter-torque G, the drive torque D produced by the gear motor Will ensure a rotation of the output shaft 6 in the anti-clockwise direction in relation to Fig. 4. This rotary movement is transferred to the coupling arms 27, Which, figuratively speaking, “bend in” and are drawn radially inwardly by their outer ends. As a result, the connecting bolt 29 in the slot 30 comes to abut the radially outer end thereof. Upon a further rotation of the output shaft 6, the clamping bodies 24 are drawn radially inwardly so they leave the locking position on the locking ring 21. Owing to the abutment of the contact faces 26 of the clamping bodies 24 pointing in the direction of the drive torque D on the corresponding wedge faces of the receivers 22 in the abutment body 15, the latter is entrained in the direction of the drive torque D and the Winding body 10 is correspondingly made to carry out the rotary movement. A patient suspended on the belt is thus draWn upWardly. 10 15 20 25 _g_ When the gear motor 3 is switched off, the counter-torque G is active again, so the coupling arms 27 are erected again under the influence of the abutment body 15 on the clamping bodies 24 and the latter are pressed radially outwardly onto the locking ring 21 into the blocking position.

Thus the position shown in Fig. 3 is adopted again.

To let down the patient- as is not shown in more detail in the drawings - the output shaft 6 is made to rotate parallel to the counter-torque G, so the coupling arms 27 “bend in” in the opposite direction in relation to Fig. 4 and thus pull the clamping bodies 24 radially inwardly again. As a result, the rotary blocking of the lifting device 1 is eliminated again and the load can be safely let down under the control of the gear motor 3 The mentioned tension spring pairs 31 in this case assist the erecting movement of the coupling arms 27 and the aligning connected therewith of the output shaft 6 and abutment body 15 in relation to one another into the blocking position shown in F ig. 3. The interaction between the two rotational directions of the drive torque D to wind and unwind the belt 13 is configured overall in the manner of dead centre kinematics, in which the coupling arms 27 bend in once in the unwinding or winding direction, in other words in opposite directions, depending on the torque direction.

Instead of the planetary gear 5, a spur gear may also be provided for the output shaft 6, the motor unit 4 then not being arranged aligned with the output shaft in the axial direction, but being arranged laterally adj acent thereto with a parallel offset.

Finally, as indicated in Fig. 2, the bow 2 may have a central through-bore 33 in its limb 10 remote from the gear motor 3, by way of which through- 10 15 _9_ bore a tool connection 34 rests on the output shaft 6 in the access region.

The tool connection 34 may, for example, be formed by the extended pivot bolts 28, on Which a rotary handle With its tool head having three corresponding receiving bores can be placed. Thus, an emergency lowering can take place if the gear motor 3 fails by manual rotation of the output shaft 6 with the aid of this rotary handle.

Because of the mode of construction shown of the lifting device l, a modular system can advantageously be realised, in that the output shaft 6 can be equipped With the most varied gear motors. Owing to the symmetric construction of the lifting device l, many identical parts are produced here, Which involves a small diversity of parts in the construction.

Overall, a very compact, reliably operating lifting device l With an unrolling prevention device is provided.

Claims

10 15 20 25 _10- Claims

1. Lifting device, in particular patient lifter, comprising a drive motor (3, 4) with an output shaft (6), and a winding coil (11) to wind and unwind a lifting mechanism, in particular a lifting belt (13), characterised by a mounting of the winding coil (1 1) that can be rotated relative to the output shaft (6), an abutment body (15) non-rotatably connected to the winding coil (11), at least one clamping body (24), which can be displaced radially with respect to the output shaft (6) between the inner abutment body (15) and an outer locking ring (21), said clamping body being coupled by means of a coupling arm (27), which is articulated to the output shaft (6), to the latter in such a way that = in the event of a torque (D) produced by the output shaft (6) both in the winding and in the unwinding direction, the clamping body (24) can be transferred from its locking position resting on the locking ring (21) into a torque transmission position resting on a wedge face (23) of the abutment body (15) to rotate the abutment ring (15) with the winding coil (11) independently of the load-induced counter-torque (G) acting on the winding coil (11), and = in the event of a torque-free output shaft (6), owing to the load- induced counter-torque (G) on the winding coil (11), the at least one clamping body (24) is loaded by the wedge face (23) of the abutment body (15) radially outwardly into the locking position resting on the locking ring (21) with rotary blocking of the 10 15 20 25 _11- abutment body (15) with the winding coi1 (11).

. Lifting device according to c1aim 1, characterised in that three clamping bodies (24) with a respectively associated coupling arm (27) are arranged in receivers (22) forming the wedge faces (23) in the abutment body (15).

. Lifting device according to c1aim 1 or 2, characterised in that the clamping bodies (24) with the associated coupling arm (27) and receiver (22) are arranged ang1e-symmetrica11y with respect to the rotational axis (R) of the output shaft (6).

. Lifting device according to any one of the aforementioned c1aims, characterised in that each clamping body (24) has two contact faces (26), which are at an obtuse angle (W) to one another, to the associated wedge faces (23) of the abutment body (15).

. Lifting device according to any one of the preceding c1aims, characterised in that each coupling arm (27) is coup1ed to the associated c1amping body (24) by means of a shear connection (29, 30) radia11y affected by play.

. Lifting device according to c1aim 5, characterised in that the shear connection is formed by a s1ot-guided connecting bo1t (29) between the clamping body (24) and coupling arm (27 ).

. Lifting device according to any one of the preceding c1aims, characterised in that each coupling arm (27) is articulated in a spring- 1oaded manner on the output shaft (6) in such a way that each coupling _12- arm (27) is erected from a bent-in position upon a torque transmission between the output shaft (6) by Way of each clamping body (24) to the abutment body (15) into an erected position in the locking position. 5

8. Lifting device according to claim 7, characterised in that each coupling arm (27), in the manner of dead centre kinematics, upon a torque applied by the output shaft (6), depending on the torque direction in the unwinding or winding direction, bends in in opposite directions. 10

9. Lifting device according to any one of the preceding claims, characterised in that the drive motor (3) has a transmission gear, in particular planetary gear (5) or spur gear.

10. Lifting device according to any one of the preceding claims, 15 characterised in that the output shaft (6) has a tool connection (34) for a manual emergency lowering.