WO2011051885A1

WO2011051885A1 - Stability control device of a ladder or mobile scaffold

Info

Publication number: WO2011051885A1
Application number: PCT/IB2010/054847
Authority: WO
Inventors: Ottorino Franzoni; Domenico Franzoni
Original assignee: Sicos S.R.L. A Socio Unico
Priority date: 2009-10-28
Filing date: 2010-10-26
Publication date: 2011-05-05
Also published as: ITBS20090194A1

Abstract

The present invention relates to an electronic stability- control device of a lift apparatus able to allow a person to raise him/herself in relation to a support surface, such as a ladder or mobile scaffold, he device comprises at least one inclination sensor able to detect the inclination of the apparatus at least in relation to two orthogonal axes (X, Y) defining a horizontal reference plane and to provide in output at least one digital control signal showing the value of such inclination detected, a microprocessor control unit able to receive said control signal from the inclination sensor, compare said control signal with at least one predefined reference value and provide in output a stability indicator signal showing said comparison, and at least one visual and/or audio indicator which can be activated by said stability indicator signal.

Description

DESCRIPTION

"Stability control device of a ladder or mobile scaffold"

[0001] The present invention relates to a stability control device of ladders, mobile scaffolds and similar apparatus able to allow a person to raise him/herself from an initial position defined by a support surface of the apparatus .

[0002] Various types of ladders and mobile scaffolds having the most varied characteristics, for both domestic and professional use are known of .

[0003] The ladder is an apparatus comprising at least one pair of uprights between which steps or rungs extend enabling ascent or descent along said uprights. Among the types found are folding ladders, step ladders, fixed ladders, extension ladders etc. In any case, the characteristic feature of ladders is their inclination in relation to a horizontal plane during use and their stability and therefore safety depends on the value of such inclination. The inclination of the ladder may depend both on the planarity of the surface which the uprights rest on, and on the angle chosen by the user between the ladder and the support wall or between the two pairs of uprights hinged to each other.

[0004] If one considers the main axis of the steps, it is clear that this must be as close as possible to horizontal to prevent the ladder from overturning laterally under the weight of the user or to prevent objects, such as tools, from sliding off the support surface (if provided) and falling dangerously from a height .

[0005] Furthermore, the inclination of the pair of uprights must be within a predefined range, for example form 65° to 75°, as required by legislations of the field of art. In fact, an inclination above such range makes the support base of the ladder overly limited, thereby making the equipment unstable; an inclination below such range imposes elevated strain on the ladder, which could jeopardise its integrity and therefore safety for the user.

[0006] A mobile scaffold rather, is a scaffold obtained by means of a girder structure composed of crossbeams, usually used to reach elevated heights in the professional sphere.

[0007] Mobile scaffolds usually have wheels at the base to facilitate movement of the same, generally so as to continue work laterally as it advances.

[0008] In any case, whatever the use and whatever the type of these apparatuses, all ladders and mobile scaffolds need to be stable to enable their safe use.

[0009] Currently, the correct positioning of ladders or mobile scaffolds is left to the expertise of the user, who, especially in the domestic sphere, does not fully perceive the risk of non optimal positioning and pays little attention to the problem. While a person is using a ladder or mobile scaffold, moreover, initial working conditions could change, either due to environmental circumstances or to errors or carelessness of the user, so that the user might find him/herself operating in hazardous working conditions not only in his/her own regard but also that of the people in the area surrounding the ladder or mobile scaffold.

[0010] Both in the domestic and professional sphere therefore the need to prevent situations of instability of the ladder or scaffold from occurring and/or to immediately signal the occurrence of such situations is deeply felt .

[0011] Stability control instruments currently available to a user, such as air bubble devices, are not immediately comprehended, especially by some types of user, and in any case are hardly ever used.

[0012] The purpose of the present invention is to propose a stability control device of a ladder, mobile scaffold or similar apparatus which is able to satisfy the aforementioned requirements detecting and immediately indicating to the operator, in an intuitive manner, if conditions are right for performing the job safely.

[0013] The characteristics and advantages of the device according to the invention will be evident from the following description, made by way of a non-limiting example, with reference to the attached drawings wherein:

[0014] Figure 1 is a block scheme of a stability control device according to the invention; and

[0015] Figure 2 is an example of a ladder to which the stability control device has been applied.

[0016] The block scheme in figure 1 shows, in one embodiment, the main functional components of an electronic stability control device 10 of a lift apparatus able to allow a person to raise him/herself in relation to a support surface 1, such as a ladder 2 or mobile scaffold.

[0017] In one general embodiment, the stability control device 10 comprises at least one inclination sensor 12 able to detect the inclination of the apparatus 2 at least in relation to two orthogonal axes X, Y defining a horizontal reference plane and to provide in output at least one digital control signal 14 showing the value of such inclination detected.

[0018] The control signal 14 is sent to a microprocessor control unit 16 able to receive said control signal from the inclination sensor, to compare said control signal with at least one predefined reference value and to provide in output a stability indicator signal 18 showing said comparison.

[0019] The control device 10 comprises at least one visual indicator 20 and/or audio indicator 22 which can be activated by said stability indicator signal 18, 18' .

[0020] In one embodiment, particularly suitable for application to a mobile scaffold, which can reach considerable heights, the inclination sensor 12 is also able to measure the inclination of the apparatus in relation to a vertical axis Z. In fact, a situation could occur in which the mobile scaffold is resting on a horizontal surface, but its summit is not, for example on account of the wind, in line with said base.

[0021] In the case of application to a ladder 2, the microprocessor control unit 16 is programmed to verify whether the inclination (angle a in figure 2) of the apparatus in relation to one (in this case the Y axis) of the two horizontal axes is within an admissible inclination range, for example between 65° and 75°.

[0022] In one embodiment, which advantageously takes into account the fact that the stability control device 10 is applied to a step 3 which, for example when the ladder is opened for use, is not perfectly horizontal, but is inclined towards the inside by an angle β, the microprocessor control unit 16 is programmed to correct said admissible inclination range by an angle equal to the inclination of the step.

[0023] In a preferred embodiment, the inclination sensor 12 comprises an accelerometer with at least two axes (X, Y) , preferably three orthogonal axes (X, Y, Z) , with a digital interface.

[0024] In one embodiment, the stability indicator signal 18' is a signal which can have two values ("ladder stable" and "ladder unstable") . In this case, the visual indicator 20 comprises a pair of LEDs 20a and 20b of different colours, which can be activated alternately depending on the value of the stability indicator signal. For example, lighting of a red LED indicates a situation of the ladder being unstable, while lighting of a green LED indicates a situation of the ladder being stable.

[0025] In one embodiment variation, the stability indicator signal 18' is able to show the difference of inclination of the apparatus compared to at least one reference value, for example compared to one or more of the axes X, Y and Z. In this case, the visual indicator comprises a display 24 able to show said difference in a numerical and/or graphic form. In this embodiment solution, the user can control the entity of the difference from a situation of stability, and thus assess whether and how to return the ladder or mobile scaffold to a condition of safety.

[0026] In one embodiment, at least the inclination sensor 12, control unit 16 and visual and/or audio indicator 20, 22, 24 are powered electrically by a battery 26.

[0027] Advantageously, the battery is rechargeable by means of a renewable source of energy, in particular a photovoltaic panel 27.

[0028] In a further embodiment, the microprocessor control unit 16 is operatively connected to a communication interface 28 towards external equipment. For example, in the case of using several ladders and/or mobile scaffolds contemporarily, for example on a building site, such apparatus may advantageously be connected and controlled by a centralised processor, for example dedicated to controlling on site safety.

[0029] Figure 2 shows an example of practical application of the stability control device 10 to a ladder 2.

[0030] The control device is preferably incorporated or built-in to one of the steps or rungs 3, so as not to obstruct or alter the dimensions of the ladder.

[0031] Advantageously, the visual and/or audio indicator faces the user and in particular is placed in an aperture made in the front wall of the step 3. In figure 2, a photovoltaic panel 27 for the autonomous power supply of the control device can also be seen beside the LEDs 20a, 20b and the loudspeaker 22.

[0032] Advantageously, moreover, the stability control device is inserted so as to be hermetic in its seat made in a portion of the ladder or mobile scaffold, for example in the step 3, so as to be suitable for outdoor use .

[0033] In conclusion, the stability control device according to the invention makes it possible to indicate, even to the non-professional user, in an immediate and intuitive manner, whether the ladder or mobile scaffold is positioned correctly and therefore if it can be used in total safety.

[0034] Advantageously, the device warns the user with visual and audio signals if the ladder is not used correctly in such a way as to function both in conditions of poor visibility and in particularly noisy environments .

[0035] Advantageously, the solution with the display also indicates the inclination of the ladder, and by how many degrees it should be inclined to achieve optimal conditions,

[0036] Advantageously, the device signals a danger in the event that conditions of safety should come to be lacking even during use, for example as a result of gusts of wind.

[0037] Advantageously, even domestic use of the device will prove safe .

[0038] Advantageously, the use of an electronic control device makes it possible to incorporate the apparatus in a digital communication network controlled by a centralised processor unit.

[0039] Advantageously, the use of a photovoltaic panel installed on the step of the ladder itself enables the device to function autonomously, without limiting in any way the ease of handling or transport of the ladder or mobile scaffold.

[0040] A person skilled in the art may make modifications, adaptations and replacements of elements with other functionally equivalent to the embodiments of the ladder and mobile scaffold according to the invention to satisfy contingent requirements, while remaining within the sphere of protection of the invention. Each of the characteristics described as belonging to a possible embodiment may be realised independently of the other embodiments described.

Claims

1. Electronic stability control device of a lift apparatus (2) able to allow a person to raise him/herself in relation to a support surface, such as a ladder or mobile scaffold, comprising:

- at least one inclination sensor (12) able to detect the inclination of the apparatus at least in relation to two orthogonal axes (X, Y) defining a horizontal reference plane, and to provide in output at least one digital control signal showing the value of such inclination detected;

- a microprocessor control unit (16) able to receive said control signal from the inclination sensor, to compare said control signal with at least one predefined reference value and to provide in output a stability- indicator signal showing said comparison;

at least one visual (20, 24) and/or audio (22) indicator which can be activated by said stability indicator signal .

2. Device according to claim 1, wherein the inclination sensor (12) is also able to measure the inclination of the apparatus in relation to a vertical axis (Z) .

3. Device according to claim 1 or 2 , wherein the microprocessor control unit (16) is programmed to verify whether the inclination of the apparatus in relation to one (Y) of the two horizontal axes is within an admissible inclination range, for example between 65° and 75° .

4. Device according to the previous claim, wherein the microprocessor control unit is programmed to correct said admissible inclination range by an angle equal to the inclination of the step to which the control device is associated in relation to the horizontal reference axis .

5. Device according to any of the previous claims, wherein the inclination sensor comprises an accelerometer with at least two axes (X, Y) with a digital interface.

6. Device according to any of the previous claims, wherein the stability indicator signal is a signal which can only have two values and wherein said visual indicator comprises a pair of LEDs (20a, 20b) of different colours, which can be alternately activated depending on the value of the stability indicator signal.

7. Device according to any of the previous claims , wherein the stability indicator signal is able to show the difference of inclination of the apparatus compared to at least one reference value, and wherein said visual indicator comprises a display (24) able to show said difference in a numerical and/or graphic form.

8. Device according to any of the previous claims, wherein the inclination sensor, control unit and visual indicator are powered electrically by a battery (26) .

9. Device according to claim 8, wherein the battery is rechargeable by means of a renewable source of energy, such as a photovoltaic panel (27) .

10. Device according to any of the previous claims, wherein the microprocessor control unit is operatively connected to a communication interface (28) towards external equipment .

11. Ladder, mobile scaffold or similar apparatus having a support base suitable for being positioned on a support surface and at least one pair of parallel uprights between which a number of rungs or steps (3) extend so to allow a person to raise him/herself from said support surface, comprising a stability control device (1) according to any of the previous claims .

12. Ladder or mobile scaffold according to claim 11, comprising at least one photovoltaic panel (27) for the electric power supply of the stability control device.

13. Ladder according to claim 11 or 12, wherein the stability control device is incorporated or built-in to one of the rungs or steps and wherein the visual and/or audio indicator faces the person using the ladder.

14. Ladder or mobile scaffold according to any of the claims 11-13, wherein the stability control device is inserted so as to be airtight in a seat for the purpose made in a portion of the ladder or mobile scaffold.