EP0343041B1 - Electrical motor-powered ladder - Google Patents

Description

The present invention relates to a ladder of the industrial type comprising two wheels making it possible to move it and a trolley provided with four castors sliding on an IP N. We already know such ladders either with bare feet or equipped with wheels, in the case which we are interested in moving by pushing with the arm, forwards or backwards. This maneuver is painful since once placed in the desired location the user must each time descend the steps to repeat the first operation. These trips all day long become tiring and create a significant loss of time.

The object of the present invention is to avoid these drawbacks by producing a motorized ladder of a new type which eliminates any fatigue on the part of the user: he can at his will perform his work at the desired height no longer needing to go down, these movement operations are done with the right hand which activates the push buttons to start at the exact place where it is: forward, reverse. The non-negligible advantage of this invention consists in starting and stopping without any sudden, securing the user for the risk of falls, this achievement is due to the installation of an electronic frequency converter from 0 to 120 hertz him even controlled by a microprocessor which regulates the rise and fall times of the motor supply.

Another advantage for the user, it has a safety ramp specially designed to enlarge its working place allowing it to move without narrowness when it is occupied, and high enough so that it can lean while taking thus a good working position.

When the ladder advances with its user, a safety device is fixed by two movable yokes, called a hanging bar provided with a limit switch which automatically cuts the power to the motor, this in case a third party is busy working in the passage of the ladder. The wiring along the handrail is 10 volts, eliminating the risk of electric shock. Thus thanks to the invention all the ladders of this type can be motorized, the cited elements are all removable since they are fixed by bolted yokes.

The transformation of a manual ladder into a motorized ladder can therefore take place by adapting a set of elements ready to assemble.

• la figure 1 est une vue en perspective d'une échelle selon l'invention en position d'utilisation.
• la figure 2 est identique en vue de face qui la représente telle qu'elle est réalisée.
• la figure 3 est le descriptif du chassis moteur.
• la figure 4 est le descriptif du chariot et de la gaine d'alimentation.
• les figures 5 et 6 sont des vues de détails du montage du moteur, références à ce dessin; les longerons (1) marches (2) roues (3) courroie (4), chassis moteur (5), moteur (6) réducteur (7), carter supérieur de protection et d'aération (8) poulie moteur (9), poulie d'entrainement (10). rampe de la main courante (11), boutons poussoirs (12) chapes de fixation (13), cadre formant barre pendante (14) avec deux plat horizontaux de protection (30), boitier électronique (15), chariot (16) contacteur rail (17), contacteur barre pendante (18), IPN (19) câblage (20) sur figure 4, gaine d'alimentation en pcv (21), pattes de fixation sur IPN (22), charnière (23), alimentation (24).

An embodiment of the invention is shown by way of example with reference to the accompanying drawings in which:

• Figure 1 is a perspective view of a ladder according to the invention in the use position.
• Figure 2 is identical in front view which represents it as it is produced.
• Figure 3 is the description of the engine chassis.
• Figure 4 is the description of the carriage and the supply sheath.
• Figures 5 and 6 are detail views of the engine mounting, references to this drawing; the side members (1) steps (2) wheels (3) belt (4), motor chassis (5), motor (6) reducer (7), upper protection and ventilation casing (8) motor pulley (9), drive pulley (10). handrail ramp (11), push buttons (12) fixing brackets (13), hanging bar frame (14) with two horizontal protection plates (30), electronic unit (15), carriage (16) rail contactor (17), hanging bar contactor (18), IPN (19) wiring (20) in Figure 4, PVC supply duct (21), mounting lugs on IPN (22), hinge (23), supply (24 ).

With reference to the drawings, the subject of the invention is a motor assembly of a ladder provided in the upper part of a carriage moving along a rail and in the lower part of two wheels integral with each of the two uprights, characterized in what it consists of a motor assembly comprising belt pulley (4), gearmotor (6) (7) mounted on a support frame (5) allowing it to be fixed to the uprights (1) of the ladder by housing bolts under said ladder and supplied by a supply cable (20) and by a conductive sheath (21) connected or rail (19) by supports (29) and in which are received friction rollers arranged at the top of the supply cable, the control being ensured by contactors (12) forward, reverse according to other characteristics:

an electronic variator (15) is provided placed in a metal box at the top of the scale and fixed by flat iron flanges incorporating a microprocessor controlling the ascents and descents of the speed of rotation of the gearmotor group (6) (7) in forward and reverse.

Safety means are further provided in the form of a square tube frame (14) provided with two horizontal protection plates (30) articulated on two movable yokes (13) fixed by screws under the uprights (1) of the ladder for actuating a limit switch (18) which cuts the supply as soon as there is an obstacle.

It comprises a protection formed by a ramp (11) forming a railing through which passes the power cable (20) held by arms (13) superimposed connection support. An engine ventilation casing (8) is provided in expanded metal fixed by screws on the casing (5).

The pushers (12) are arranged on three levels at the connecting arms (13) of the ramp (11) grouped by two with indication carriers in insulating material and indicating forward and reverse.

A belt tensioning system (4) by a winged or hexagonal screw (25) acting on the fixing frame of the mostor (6) connected transversely by an axis (27) thus making it possible to tension and relax the latter.

The manual scale is transformed into a motorized scale by dismantling the two wheels (3) and adding a grooved pulley (9) fixed to the spacer tube on which two large ones have been welded 5 mm sheet washers pierced with three holes and fixed to the two flanges of the two wheels by bolts making them drive. The chassis structure is of robust design, the assembly made of 5 mm sheet steel and assembled by bolts, an axis (27) of 18 mm placed transversely between the two flanges (5) positions the support sheet (26) on which is fixed the motor (6) and the reduction gear (7), this element being movable around said axis (27) allows the tension of the belt (4) by a locking screw with wings (25) connecting the element mobile attachment of the engine to the frame (28).

Motor characteristics: Triphase 220/380, 0kw37, 1370 T / Mi

Characteristics of the reducer: 1: 28.

The power supply is obtained by mounting a PVC sheath (21) spaced 0 m 25 from the IPN (19) and fixed by supports (29) as shown in Figure 4.

Depending on the importance of the length of the IPN rail, several scales can follow one another; each of the scales is then adjusted to cover a rolling distance of, for example, 10 meters.

For bearing on telescoping a device in rectangular tube (31) 40 × 20 × 2 with articulation (32) and mounted on a roller (35) as shown in FIG. 7 provided with an antenna (33) of 0 , 40 m and on the other side of a contractor (34) is fitted to the bottom of the upper carriage (16) by screwing; thus at the end of the travel the tip of the antenna (33) of a ladder touches the limit switch (34) with rod opposite the ladder which cuts the supply.

To clear the ladder, the user must simultaneously press a reset button and then press the AR button to restore power. This safety means was provided in front of the ladder in the form of a hinged square tube frame coming to meet as soon as there is an obstacle a limit switch which cuts the power supply and at the end of the rail ( 19) is provided a fixed antenna (33) actuating the contractor (34) of the first scale, similarly at the end of the rail a fixed antenna (33) is provided intended to actuate a second contractor (34) provided on the last ladder opposite.

The invention also provides a rear safety device in the form of a flexible cover (36) illustrated in FIG. (8) fixed on the protective cover (5) of the existing engine assembly coming to meet as soon as there is an obstacle a limit switch (37) thus securing the reverse of the ladder.

To avoid overheating of the components of the electronic variator, a time switch is attached near the electrical connection box; this being set for the daily working time is cut in the evening and is reset in the morning.

Claims (10)

1. Set of motorization of a ladder of type, on the upper part equipped with a truck which is moving along the rail and on the lower part equipped with two wheels attached to each of the two uprights characterized by its constitution of a motor including a pulley, a belt, an automatic reductor put on a support's subframe allowing its fastening on the uprights of the ladder bolts and which goes under this ladder and supplied with a power cable and a conducting sheath linked to the rail by supports and which the rollers in friction are received, equipped with a power cable at the top, the control being provided by a forward and backward motion's contactor.

2. Set of motorization according to the first claiming characterized by an electronic transmission in a metallic box placed at the top of the ladder and fixed by flat iron's strags holding a microprocessor controlling the rotation speed's raisings and fells of the automatic reductor's group in forward and backward motion.

3. Set according to the first claiming characterized by means of security provided by a frame with a square pipe fitted with a protection of two horizontal surfaces, joined to two moving shells fixed by screws under the uprights of the ladder to activate a contactor at the end which turn the power off as soon as there is a problem.

4. Set of motorization according to the first claiming characterized by a protection provided by a ramp forming a quadrial in which is going through the power cable hold by handle's linked supports superposed.

5. Set of motorization according to the first claiming characterized by a ventilation crank-case made of fine expanded metal fixed by screws on the crank-case.

6. Set of motorization according to the first and the fourth claiming characterised by the push button placed in three levels to the handdle's linked supports of the ramp with guide supports of insulation material and indicating forward and backward motion.

7. Set of motorization according to the first claiming characterized by the present system of selt's tension by a wing nut or hexagonal acting between the fixed frame and the frame's fastening of the motor linked accross with an axle which allows in this way to tighten or to loosen this one.

8. Set of motorization according to the first claiming characterized by a system to bear the ladder's telescoping, a mechanism with a connected rectangular pipe 40 × 20 × 2 and assembled on roller as showed in picture 7, on one side with an aerial of 0,40 m and on the other side with one contactor which is fitted to the lower part of the upper truck by screwing. In this way, when it comes completly off, the point of the aerial of the ladder touchs the end's part of the contactor, in line with the ladder which cuts the power off.

9. Set of motorization according to the first claiming characterized by a security system, the mecanism provides a device appliance forward and backward motion under a flexible bonnet showed in picture 8 linked to the cover of the set of the motor which meets the end's part of the contactor as soon as there is a problem, securing this way the forward and backward motion of the ladder.

10. Set of motorization according to the first claiming, in order to avoid the overheating of the electronic transmission's components, characterized by the present system of a time clock switch placed hear the connecting electric torch, this one fixed up for the daily work's time, is off in the evening and reengaged the next day.

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