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(11) | EP 1 790 607 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Safety device for automatically checking the weight of the load present on one or more lifting groups of an elevator, of a platform, of a lift or of other similar apparatuses |
| (57) The present finding concerns a safety device for automatically checking the weight
present on one or more lifting groups of an elevator, of a platform, of a lift or
of other similar apparatuses. Such a device is of the type in which the mobile platform
or the cabin (1), able to slide on the column (2), consists of a board (3) on which
the load rests and a motorisation group (4), formed from a welded structure (5), which
supports the motor group, consisting of a geared motor (6) or another work device,
which takes care of moving the aforementioned platform on the aforementioned column.
Such a safety device is characterised in that it foresees that the two components
of the platform (1), i.e. the board (3) on which the load is rested and the motorisation
group (4) consist of two distinct and separate work groups, between which an intermediate
element (8) is inserted that, as well as acting as connection means between the aforementioned
groups, to allow the entire platform to be moved vertically, also detects the weight
value of the material loaded onto the board.
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[0001] The present finding concerns a safety device for automatically checking the weight of the load to be mounted on a lifting group of an elevator, of a platform, of a lift or of other similar apparatuses, according to the general part of claim 1.
[0002] The use of apparatuses, known by the generic term "elevators", which lift things and/or people along a supporting column is widespread in all sectors of industry and in particular in building.
[0003] The elevator essentially consists of a base equipped with large adjustable screws, from which a column made up of modular elements rises up.
[0004] The load platform, which is preferably motorised through a rack and pinion coupling, slides vertically on the column.
[0005] The elevator is completed with safety devices, such as an emergency brake, which is automatically activated in the case in which the speed of descent exceeds the values set by the safety standards.
[0006] In particular, safety standards and instructions recommend that the machine (elevator, platform or lift) be equipped with devices that continuously check the weight of the load lifted so that when there is an "overload", i.e. when the maximum weight value is exceeded, the shut down procedure is immediately activated and the apparatus is automatically blocked.
[0007] In the current state of the art numerous devices are known that detect the weight loaded onto the machine, but most of them have numerous constructive and operative drawbacks.
[0008] The purpose of the present finding is to make a safety device for automatically checking the weight of the load on the machine (elevator, platform, lift or other similar apparatus), which does not have the drawbacks of similar known products.
[0009] Such a purpose is obtained by making a loading platform or cabin, characterised in that the two components thereof, i.e. the board on which the load is rested and the motorisation group that moves it vertically on the column, consist of two distinct and separate work groups, between which an intermediate element is inserted that, as well as acting as connection means between the aforementioned two groups, to allow the entire platform or the cabin to be moved vertically, also detects the weight value of the material loaded onto the board on which the load is rested.
[0010] In greater detail, the board, through a horizontal bracket, rests or is held on an intermediate element and this rests on the frame of the motorisation group consisting of a tubular structure equipped with a series of guide rollers, which are moved through a self-braking geared motor or another device suitable for the purpose.
[0011] Constructively, such an intermediate element can consist of load cells, which cause the machine to automatically block when they detect that the weight acting upon the platform on the cabin exceeds the set limit.
[0012] Alternatively, such an intermediate element can consist of a plurality of elastic elements, consisting of springs (coil or another type) that operate under compression or traction, so as to hold the platform in the correct use position, up to the set maximum value of the load.
[0013] When the value of the load exceeds the set value, the springs undergo a minimal compression or a minimum traction, respectively, which in both cases causes a minimal lowering of the platform and such a minimal movement is detected by a limit switch or by another device suitable for the purpose, applied to the structure of the motorisation group, which takes care of shutting down the machine.
[0014] The finding shall be better understood through the description of a possible embodiment thereof, given just as a non-limiting example, with the help of the attached tables of drawings, where:
- figs. 1 and 2 (tables I-II) represent two views, in front and side elevation respectively, of an elevator group equipped with the safety device according to the finding, in a first embodiment;
- figs. 3 and 4 (tables III-IV) represent two views, in front and side elevation respectively, of an elevator group equipped with the safety device according to the finding, in a second embodiment.
[0015] As can be seen in the figures, the mobile platform, wholly indicated with 1, able to slide on the column 2, consists of a board 3 on which the load is rested and a motorisation group, wholly indicated with 4, consisting of a welded structure 5, which supports the geared motor 6, which through the rack and pinion coupling 7 takes care of moving the aforementioned platform on the aforementioned column, all according to per se known configurations.
[0016] The novelty characteristic of the finding consists of the fact that the board 3 is connected to the motorisation group 4, through the interposition of an elastic means, preferably consisting of a plurality of springs or another similar device, wholly indicated with reference numeral 8.
[0017] As can be seen in figures 1 and 2, in a first embodiment the board 3 is equipped with a frame 9, from which a plate 10 projects, which rests on the springs 8, supported through the cross member 11, belonging to the welded structure 5.
[0018] Said frame 9 is also equipped with small wheels 12, engaged to slide in guides 13, applied to the frame 5 so that the board 3, as well as resting on the springs 8, is also vertically fixed to the motorisation group 4.
[0019] In operation, as can easily be seen by observing figures 1 and 2, when overloading accidentally occurs, i.e. the weight of the products and/or people loaded on the board 3 exceeds the predetermined maximum, the springs 8, being calibrated up to the aforementioned predetermined weight, undergo a compression that exceeds such a value, for which reason a relative sliding between the board 3 and the motorisation group 4 occurs, i.e. the board lowers with respect to the motorisation group.
[0020] In a second embodiment, as can be seen in figures 3 and 4, the board 3 is equipped with a frame 9, from which a plate 10.1 projects, which fastens at the bottom to the springs 8.1, in turn hung at the cross member 11.1, belonging to the welded structure 5.
[0021] In operation, as can easily be seen by observing figures 3 and 4, when overloading accidentally occurs, i.e. the weight of the products and/or people loaded on the board 3 exceeds the predetermined maximum, the springs 8.1, being calibrated up to the aforementioned predetermined weight, undergo a traction that exceeds such a value, for which reason a relative sliding between the board 3 and the motorisation group 4 occurs, with the board lowering with respect to the motorisation group.
[0022] In both cases, as can be seen in figures 1 and 3, the millimetric lowering of the board 3 is detected through a detector 14, limit switch or other device suitable for the purpose, fixed onto the upright 15 of the frame 5, which is activated by the lowering of the sliding block 16 applied, instead, onto the upright 17 of the frame 9.
[0023] Finally, thanks to the constructive solution according to the finding, i.e. with the board mounted mobile on the motorisation group, it is possible to avoid damaging the load plane, caused by an accidental presence of foreign bodies on the ground, when it reached the end of the bottom stroke.
[0024] This is obtained by applying a limit switch 18 onto the upright 15 of the frame 5, which is activated and stops the machine in contact with the sliding block 19 applied to the upright 17 of the frame 9 in the case in which, during the final descent step of the platform, there are bodies on the ground that are taller than the predetermined height of the load plane from the ground.
1. SAFETY DEVICE FOR AUTOMATICALLY CHECKING THE WEIGHT OF THE LOAD PRESENT ON ONE OR
MORE LIFTING GROUPS OF AN ELEVATOR, OF A PLATFORM, OF A LIFT OR OF OTHER SIMILAR APPARATUSES,
of the type in which it is foreseen that the mobile platform or the cabin (1), able
to slide on the column (2), consists of a board (3) on which the load rests and a
motorisation group (4), formed from a welded structure (5), which supports the motor
group, consisting of a geared motor (6) or another work device, which, through a rack
and pinion coupling or with another type of connection (7), takes care of moving the
aforementioned platform on the aforementioned column, said safety device being characterised in that it foresees that the two components of the platform (1), i.e. the board (3) on which
the load is rested and the motorisation group (4) consist of two distinct and separate
work groups, between which an intermediate element (8) is inserted that, as well as
acting as connection means between the aforementioned two groups, to allow the entire
platform to be moved vertically, also detects the weight value of the material loaded
onto the board.
2. SAFETY DEVICE, according to claim 1, characterised in that the intermediate element (8) consists of load cells.
3. SAFETY DEVICE, according to claim 1, characterised in that the intermediate element (8) consists of an elastic body.
4. SAFETY DEVICE, according to claim 3, characterised in that the elastic intermediate element (8) consists of preloaded springs, which operate
under compression.
5. SAFETY DEVICE, according to claim 4, characterised in that the board (3) is equipped with a frame (9), from which a plate (10) projects, which
rests upon the springs (8), supported by the cross member (11), belonging to the welded
structure (5).
6. SAFETY DEVICE, according to claim 3, characterised in that the elastic intermediate element (8.1) consists of preloaded springs, which operate
under traction.
7. SAFETY DEVICE, according to claim 6, characterised in that the board (3) is equipped with a frame (9), from which a plate (10.1) projects, which
attaches at the bottom on the springs (8.1), hung from the cross member (11.1), belonging
to the welded structure (5).
8. SAFETY DEVICE, according to one or more of the previous claims, characterised in that the frame (9) is equipped with small wheels (12) engaged to slide in guides (13),
applied onto the frame (5) so that the board (3), as well as being rested on the intermediate
element (8), is also vertically fixed to the motorisation group (4).
9. SAFETY DEVICE, according to claim 5, characterised in that, in overloaded condition, when the weight of the products loaded on the board (3)
exceeds a predetermined maximum weight value, the springs (8) undergo a compression
deformation, for which reason a relative sliding occurs between the board (3) and
the motorisation group (4), with the lowering of the aforementioned board with respect
to the aforementioned motorisation group and said micrometric lowering is detected
by at least one apparatus (14) such as a limit switch or another similar device, fixed
to the upright (15) of the frame (5) and that is activated by the lowering of the
sliding block (16) applied to the upright (17) of the frame (9).
10. SAFETY DEVICE, according to claim 5, characterised in that, in overloaded condition, when the weight of the products loaded on the board (3)
exceeds a predetermined maximum weight value, the springs (8.1) undergo an extension
deformation, for which reason a relative sliding occurs between the board (3) and
the motorisation group (4), with the lowering of the aforementioned board with respect
to the aforementioned motorisation group and said micrometric lowering is detected
by at least one apparatus (14) such as a limit switch or another similar device, fixed
to the upright (15) of the frame (5) and that is activated by the lowering of the
sliding block (16) applied to the upright (17) of the frame (9).
11. SAFETY DEVICE, according to one or more of the previous claims, characterised in that it foresees at least one limit switch (18), applied to the upright (17) of the frame
(9), during the final descent step of the platform, when there are bodies on the ground
that are taller than the predetermined height of the load plane from the ground.