EP1547964A1

EP1547964A1 - A lifting apparatus

Info

Publication number: EP1547964A1
Application number: EP04425801A
Authority: EP
Inventors: Antonio Bonita
Original assignee: Vima Impianti Srl
Current assignee: Vima Impianti Srl
Priority date: 2003-10-27
Filing date: 2004-10-27
Publication date: 2005-06-29
Also published as: CN1611442A; ITBO20030634A1

Abstract

An apparatus (1) for lifting loads (11), for use in particular in the pharmaceutical and/or chemical and/or food sector, comprises a column (3) extending along its own longitudinal axis (A1) from a base (2), a pick up arm (10) for the loads (11) able to slide along the column (3), a belt (13) connected to the pick up arm (10), a motor unit designed to feed the belt (13) forward and retract it so as to move the arm (10) along the column (3).

Description

The present invention relates to an apparatus for lifting loads.
In particular, the present invention relates to an apparatus for lifting loads by means of flexible lifting parts, which can be used in the pharmaceutical and/or chemical and/or food sector.
The lifting apparatus according to the present invention is of the column type.
The present invention also relates to a system for conditioning products comprising the above-mentioned lifting apparatus.
Column type lifting apparatuses for use in the pharmaceutical sector are known, which are used to handle bulky, heavy containers, for example to transfer containers between two successive processing and/or treatment steps in a system for the production of pharmaceutical products.
Another habitual use of said apparatuses is for handling operating machines to be used in the different steps for the treatment of the above-mentioned pharmaceutical and/or food products. These machines may be, for example, extractors or pneumatic conveyors used to transfer powders, liquids and/or loose materials between different containers and which, therefore, must be correctly positioned at the containers.
The known apparatuses indicated above comprise a base, a vertical column along which a load pick up arm slides and an actuator device operatively connected to the arm to move it along the column.
The use of different types of actuator devices to move the arm is known, and the choice depends on a variety of factors: the size of the load, the speed of movement, the precision required in movements.
Amongst the devices normally used, especially for larger loads, there are hydraulic or pneumatic cylinders which, however, following micro-leaks or leaks of operating fluid, often have the disadvantage of not guaranteeing that the position will be held stable after the arm subject to the load has been lowered.
Other known devices are those which use a nut screw - worm screw coupling for pick up arm movement.
Such types of lifting apparatuses are normally expensive, large, and mechanically rather complex, therefore also requiring laborious, costly maintenance.
With reference to the above description, the use of the above-mentioned types of lifting apparatuses has the disadvantage of not being particularly advantageous if the loads to be handled are small or if large investments are to be avoided.
To make up for the limited usefulness of the devices described, lifting apparatuses have been developed with a more simple structure, which use actuator devices comprising flexible lifting parts such as chains, metal cables or belts. In other words, the pick up arm, which can slide along the vertical column, is suspended from the flexible lifting part which is fed forward or retracted by a motor, in order to respectively lower or lift the load supported by the pick up arm.
To guarantee operator safety, apparatuses with flexible lifting parts have been fitted with braking devices designed to ensure that the arm stops if necessary.
A first type of braking device is relative to those devices acting directly on the motor parts which feed the flexible part forward or retract it. One example is the electromagnetic brakes fitted on the winches used to wind steel cables.
A second type of braking devices comprises a kinetically activated device. These operate substantially when the lifting apparatus pick up arm reaches an excessive sliding speed along the vertical column.
The above-mentioned types of devices, although often useful, are not without disadvantages.
A first disadvantage is, in particular, linked to use of the above-mentioned first type of devices which, operating directly and exclusively on the motor parts, basically do not guarantee any safety in the event that the flexible part should break.
Another disadvantage is, in particular, linked to use of the above-mentioned second type of braking devices which, only operating when the arm has reached a predetermined speed, do not guarantee an effective response in those situations in which even a small movement of the arm could prove dangerous.
A further disadvantage relative to both of the above-mentioned types of braking devices is the significant structural complexity of the devices.
The aim of the present invention is to provide an apparatus for lifting loads which is equipped with a braking device that is free of the above-mentioned disadvantages and which is, at the same time, functional, simple and economical to make and practical and efficient to use.
The technical features of the present invention, in accordance with the above-mentioned aim, are set out in the claims herein, in particular claim 1 and, preferably, any of the claims directly or indirectly dependent on claim 1.
The advantages of the present invention are more clearly described in the detailed description below, with reference to the accompanying drawings, which illustrate preferred embodiments of the invention, without limiting the scope of its application, and in which:

Figure 1 is a schematic side elevation view of a first embodiment of an apparatus for lifting loads made according to the present invention;
Figure 2 is a schematic side elevation view, with some parts in cross-section and other parts cut away for greater clarity, of a detail of the apparatus illustrated in Figure 1;
Figure 3 is a top plan view of the detail illustrated in Figure 2, according to section III in Figure 2;
Figures 4 and 5 are respectively schematic side elevation views, with some parts cut away and other parts in cross-section for greater clarity, of a detail of an alternative embodiment of the apparatus made in accordance with the present invention, in two different operating configurations;
Figure 6 is a top plan view, with some parts cut away and other parts in cross-section for greater clarity, of the detail illustrated in Figures 4 and 5.

With reference to the accompanying drawings, the numeral 1 denotes as a whole a first embodiment of an apparatus for lifting loads.
As illustrated in Figure 1, the apparatus 1 comprises a supporting base 2 on the floor, from which there extends, vertically, a column 3 with a longitudinal axis A1.
A control unit 4 for the apparatus 1 is connected to the base 2.
The column 3 has a first, lower end 3a and a second, upper end 3b, longitudinally opposite.
As is better illustrated in Figure 3, the column 3 has a quadrangular cross-section and has a first, front face 5 and a second, rear face 6 which are opposite one another, and two side faces 7, 8.
With reference to Figure 1, at its first, lower end 3a, the column 3 is fixed to the base 2 and, at its second, upper end 3b, the column is connected to a guard 9 which houses a motor unit, of the type substantially known and therefore not further illustrated or described in this text.
The apparatus 1 also comprises a pick up arm 10 for a load, illustrated in Figure 1 as a drum 11, for example containing a pharmaceutical product.
The pick up arm 10 is slidably connected to the column 3 using methods which are better described below.
The arm 10 is operatively connected to the above-mentioned motor unit, not illustrated, housed in the guard 9, by a flexible lifting part 12 which, in the embodiment illustrated in Figure 1, is a belt 13.
The pick up arm 10 is fitted with a handwheel 14 which operates a gear, not illustrated and advantageously of the worm type, on whose output shaft 16 there are parts 17 which grip the drum 11. The shaft 16 has a central axis of extension 16a perpendicular to the axis A1 of the column 3.
The above-mentioned gear, not illustrated, allows, in ways which are known and not described in further detail, drum 11 rotation about the axis 16a of the shaft 16.
With reference to Figure 2, the pick up arm 10 comprises a first, upper pair 18 and a second, lower pair 19 of rollers 20 which engage in a rolling motion with the front and rear faces 5, 6 of the column 3.
The rollers 20 pivot on respective pins 21, with bearings 22 of the known type inserted between them, so that they turn about respective axes A2 of rotation.
The arm 10 also comprises two pairs 23, 24, respectively upper and lower, of rollers 25 designed to engage in a rolling motion with the side faces 7, 8 of the column 3. The rollers 25 have respective axes A3 of rotation, these axes A3 being perpendicular to the axes A2 of the rollers 20.
The apparatus 1 comprises a braking part 26 pivoting on the pin 21 of the roller 20 in the lower pair 19, the roller 20 engaging in a rolling motion with the front face 5. The braking part 26 is, therefore, connected to the pick up arm 10, so that it oscillates about the axis A2 of the pin 21.
The braking part 26 comprises two substantially triangular plates 27 arranged side-by-side and distanced from one another in the direction of the axis A2 of the pin 21. The two plates 27 are connected to one another by a bar 28 and by a first and a second peg, respectively labelled 29 and 30 which respectively have axes A4, A5 and are arranged parallel with the pins 21 of the rollers 20.
As already indicated, the plates 27 are triangular and have the two pegs 29, 30 located close to two respective vertices of the triangle whilst, at the third vertex, each plate 27 pivots on the pin 21 of the roller 20.
The bar 28 connects the two plates 27 close to the first peg 29.
One end 13a of the belt 13 is fixed to the first peg 29 of the braking part 26.
The braking part 26 comprises a pad 31 pivoting on the second peg 30, the pad 31 having a portion 32, made of a material with a high friction coefficient, designed to engage with and adhere to the front face 5 of the column 3.
As illustrated in Figure 2, the arm 10 is also fitted with two elastic pushers 33, of which only one is illustrated. Each of the two pushers 33 comprises an upper adjusting portion 34 fitted on a block 35 integral with the arm 10, and an elastic lower portion 36 with a partially compressed helical spring 37. As already indicated, the apparatus 1 comprises two pushers 33 acting on the braking part 26 and each positioned close to a respective plate 27.
The spring 37 of the lower portion 36 of each pusher 33 engages with the bar 28.
Fixed to the pick up arm 10 there are two first L-shaped brackets 38 which, together with the respective screws 39, form as many adjustable contact elements 40, each designed to make contact with a portion of a respective plate 27 of the braking part 26, during normal movement of the arm 10 along the column 3.
A second bracket 41 is stably fixed on the braking part 26. The second bracket is fitted with a part 42 for pulling the pad 31. The pulling part 42 holds the pad 31 substantially detached from the front face 5 of the column 3 during normal sliding of the pick up arm 10 along the column 3.
An alternative embodiment of the lifting apparatus 1 described above is illustrated in Figures 4, 5 and 6 in which it is labelled 1'.
As illustrated in Figure 4, the apparatus 1' comprises, as the flexible lifting part 12, a chain 43 of the known type and therefore only schematically illustrated in the drawing.
The apparatus 1' comprises a braking part 44 with a rocker arm configuration, pivoting on a pin 45 connected to the pick up arm 10, so that it oscillates about an axis A6 of the pin 45.
The braking part 44 has a first and a second end 44a, 44b on opposite sides of the pin 45.
At its first end 44a, the braking part 44 is connected, at the top, to one end 43a of the chain 43 and, at the bottom, to an upper end 46a of a spring 46, schematically illustrated in the accompanying drawings.
The spring 46 has a second end 46b which is stably connected to the pick up arm 10.
In particular with reference to Figure 6, at its second end 44b, opposite the first end 44a, the braking part 44 comprises a forked portion 47 with two teeth 48 at its two ends.
As illustrated in Figure 4, at its second end 44b, below the forked portion 47, the braking part 44 comprises an adjustable contact element 49, designed to make contact with a portion 50 integral with the pick up arm 10.
Two rack portions 51 are stably fixed to the column 3 and each of them is positioned with its toothing facing a respective tooth 48 of the forked portion 47 of the braking part 44. The rack portions 51 may comprise teeth and/or gripping elements having any shape and arrangement.
In practice, with reference to the first embodiment of the lifting apparatus disclosed, labelled 1, during normal operation the apparatus 1 moves the pick up arm 10, and therefore the drum 11 connected to it, along the column 3 in a direction D1 parallel with the axis A1 of the column 3.
To move the pick up arm 10 along the column 3, the motor unit, not illustrated, feeds the belt 13 which forms the flexible lifting part 12 forward and retracts it.
Basically, in accordance with methods that are known and therefore not described in detail in this text, the belt 13 is wound on a drum to retract it and lift the arm, and it is unwound from the drum to feed it forward and so lower the pick up arm 10.
During the above-mentioned arm 10 movements, the belt 13 is tensioned longitudinally by two opposing forces: the pull of the motor unit and the combined weight of the pick up arm 10 and the load it supports. The compensation of said forces and of the resulting moments at the braking part 26 guarantee the latter, under normal operating conditions, equilibrium as regards rotation about its own pivoting axis A2.
In the above-mentioned condition of equilibrium, the braking part 26 assumes its first stable home position.
By means of the respective springs 37, the pushers 33 normally exert an action on the braking part 26 which opposes the pull of the belt 13, relative to part 26 rotation about the axis A2.
If the belt 13 breaks or loses tension, the pushers 33 are no longer opposed by the pull of the belt 13 and, therefore, are free to push the braking part 26 so that it performs a partial rotation about its pivoting axis A2, clockwise in Figure 2.
Following such a rotation, the pad 31 is pushed with its portion 32 of material with a high friction coefficient into contact with and adhering to the front face 5 of the column 3, in this way exerting a braking action on pick up arm 10 movements relative to the column 3.
In the configuration just described, the braking part 26 assumes its second stable operating position, braking the pick up arm 10.
Therefore, if the belt 13 breaks, the elastic pushers 33, push and stably hold the braking part 26 in its second, braking operating position.
In practice, with reference to the second embodiment of the lifting apparatus disclosed, labelled 1', during normal operation the apparatus 1', similarly to the above description with reference to the apparatus 1, moves the pick up arm 10 along a column not illustrated in Figures 4 to 6, in the direction D1.
In order to move the pick up arm 10 along the column, the motor unit feeds the chain 43 which forms the flexible lifting part 12 forward and retracts it.
Basically, in accordance with known methods not described in detail in this text, the chain 43 is moved, for example, by means of a toothed pinion, to retract it and lift the arm or to feed it forward, lowering the pick up arm 10.
As illustrated in Figure 4, during the above-mentioned arm 10 movements, the chain 43 is longitudinally tensioned by two opposing forces: the pull of the motor unit and the combined weight of the pick up arm 10 and the load it supports. The compensation of said forces and of the resulting moments at the braking part 44 guarantee the latter, under normal operating conditions, equilibrium as regards rotation about its own pivoting axis A6.
In the above-mentioned condition of equilibrium, the braking part 44 assumes its first stable home position.
The spring 46 normally exerts on the braking part 44 an action which opposes the pull of the chain 43, relative to part 44 rotation about the axis A6.
As illustrated in Figure 5, if the chain 43 should accidentally break, the spring 46 is no longer opposed by the pull of the chain 43 and, therefore, is free to push the braking part 44 so that it performs a partial rotation about its pivoting axis A6, anti-clockwise in Figure 5.
Following such a rotation, each of the two teeth 48 of the forked portion 47 is pushed so that it engages with a relative rack portion 51, forming a stop zone 52 on the column, in this way having an immediate braking action on pick up arm 10 movements relative to the column.
For the braking part 44, the teeth 48 form coupling means 53 designed to engage with the column stop zone 52.
In the configuration just described, the braking part 44 assumes its second stable operating position, braking the pick up arm 10.
Therefore, if the chain 43 breaks, the spring 46 brings the braking part 44 into its second, braking operating position, in which it is easily held by the teeth 48 coupling with the respective rack portions 51.
The braking parts 26, 44, elastic pushers 33, elastic lower portion 36 and rack portion 51 form, for the apparatus 1, braking means 54 designed to have a braking action on pick up arm 10 sliding along the column 3.
With reference to Figure 2, the pad 31 is substantially wedge-shaped. This configuration can be used advantageously, according to suitable sizing and positioning of the braking part 26 to ensure that the pad 31 can be at least partially inserted between the column 3 and the adjacent roller 20 when the braking part 26 assumes its second stable operating position, braking the pick up arm 10.
In alternative embodiments of the present invention, not illustrated but covered by the same inventive concept, the action of the elastic elements 33, 36 may be substituted by that of a weight.
The accompanying drawings illustrate the flexible lifting part by way of example and without in any way limiting any flexible lifting part to which the inventive concept of the present invention naturally extends.
Advantageously, in the lifting apparatus 1, 1' disclosed, the braking action does not depend on the speed of pick up arm 10 movement along the column 3.
In this description, the term break refers not just to actual breakage of the flexible lifting part 12, but also to its detachment from the respective elements which fix it to the parts of the apparatus 1, 1' or, as indicated, a loss of tension of any kind, for example if the load supported by the arm 10 is set down.
According to the present invention, a lifting apparatus 1, 1' is included in a system, not illustrated, for conditioning pharmaceutical or chemical or food products.
The invention described is suitable for evident industrial applications and may be subject to modifications and variations without thereby departing from the scope of the inventive concept. Moreover, all details of the invention may be substituted by technically equivalent elements.

Claims

An apparatus for lifting loads (11), in particular in the pharmaceutical and/or chemical and/or food sector, comprising:

a column (3) extending along its longitudinal axis (A1),

a pick up arm (10) for the loads (11), able to slide along the column (3),

a flexible lifting part (12) connected to the pick up arm (10), the arm (10) being suspended from the flexible lifting part (12),

motor means designed to feed the flexible lifting part (12) forward and retract it so as to move the arm (10) along the column (3), the lifting apparatus being characterised in that it comprises braking means (54) for braking the sliding movement of the pick up arm (10) along the column (3), the braking means (54) being activated automatically by breakage of the flexible part (12).
The apparatus according to claim 1, characterised in that the braking means (54) comprise a braking part (26; 44) connected to the pick up arm (10) and mobile integral with the arm (10) along the column (3).
The apparatus according to claim 2, characterised in that the braking part (26; 44) pivots on a respective axis (A2; A6) so that it oscillates at least between a first stable home position, corresponding to normal movement of the pick up arm (10) along the column, and a second stable operating position, braking the arm (10) relative to the column (3), corresponding to breakage of the flexible lifting part (12).
The apparatus according to claim 3, characterised in that the braking part (26; 44) is connected to one end (13a; 43a) of the flexible lifting part (12), the lifting part (12), tensioned by the weight of the pick up arm (10), holding the braking part (26; 44) in its first stable home position.
The apparatus according to claim 3 or 4, characterised in that the braking (54) means comprise elastic means (33; 46) designed to move the braking part (26; 44) into its second stable, braking operating position.
The apparatus according to any of the claims from 2 to 5, characterised in that the braking part (26) comprises at least one portion (32) made of a material with a high friction coefficient, said portion (32), with the braking part (26) in its second stable, braking operating position, being designed to engage with and adhere to the column (3).
The apparatus according to any of the claims from 2 to 5, characterised in that the braking part (44) comprises coupling means (53) designed to engage with a relative column stop zone (52).
The apparatus according to claim 7, characterised in that the coupling means (53) comprise at least one tooth (48) and the braking means (54) comprise at least one rack portion (51) extending longitudinally along the axis (A1) of the column (3), the tooth (48) being designed to engage with the rack portion (51) in the second stable, braking operating position.
The apparatus according to claim 6, in which the pick up arm (10) slidably engages with the column (3) by means of at least one roller (20), characterised in that the braking part (26) comprises a wedge-shaped pad (31) which can be at least partially inserted between the column (3) and the roller (20) in the second stable, braking operating position of the braking part (26).
The apparatus according to any of the claims from 1 to 9, characterised in that the flexible lifting part (12) is a belt (13).
The apparatus according to any of the claims from 1 to 9, characterised in that the flexible lifting part (12) is a chain (43).
A system for conditioning pharmaceutical or chemical or food products, characterised in that it comprises an apparatus for lifting loads according to any of the claims from 1 to 11.