Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
  • B66F11/00—Lifting devices specially adapted for particular uses not otherwise provided for
  • B66F11/04—Lifting devices specially adapted for particular uses not otherwise provided for for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations
  • B66F11/042—Lifting devices specially adapted for particular uses not otherwise provided for for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations actuated by lazy-tongs mechanisms or articulated levers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
  • B66F17/00—Safety devices, e.g. for limiting or indicating lifting force
  • B66F17/006—Safety devices, e.g. for limiting or indicating lifting force for working platforms
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
  • E04G1/00—Scaffolds primarily resting on the ground
  • E04G1/18—Scaffolds primarily resting on the ground adjustable in height
  • E04G1/22—Scaffolds having a platform on an extensible substructure, e.g. of telescopic type or with lazy-tongs mechanism

Definitions

• the present invention relates to the field of mobile elevating work platforms (also referred to as PEMP) still commonly referred to as aerial work platforms. It relates more particularly wheeled aerial work platforms by means of which the aerial platform is supported on the ground and movable on it.
• PEMP mobile elevating work platforms
• aerial work platforms still commonly referred to as aerial work platforms. It relates more particularly wheeled aerial work platforms by means of which the aerial platform is supported on the ground and movable on it.
• Aerial work platforms are machines designed to allow one or more people to work at height. They include a frame, a work platform and a lifting mechanism of the work platform.
• the work platform includes a tray surrounded by a railing. It is intended to accommodate one or more people and possibly also loads such as tools or other material, materials such as paint, cement, etc.
• the work platform is supported by the lifting mechanism which is mounted on the chassis. In this case, the chassis rests on the ground through the aforementioned wheels.
• the lifting mechanism lifts the work platform from a lowered position on the frame to the desired working height, usually by means of one or more hydraulic cylinders.
• the motorization for moving the aerial platform to the ground is usually mounted directly on the chassis.
• aerial work platforms There are several types of work platform lifting mechanisms which are referred to as aerial work platforms.
• the invention primarily relates to, but is not limited to, scissor lifts and aerial work platforms with vertical poles.
• the lifting mechanism comprises centrally scissor-shaped beams, which scissors mechanisms are mounted one above the other at their ends which are pivotally connected to each other. reach the desired working height.
• Figures 1 and 2 illustrate an example of a scissor lift: the chassis is referenced 1, the scissor lift mechanism 2, the work platform 3, the front wheels 4, the rear wheels 5 and the hydraulic cylinder. Actuation of the lifting mechanism of the working platform 6.
• the maximum working height generally varies between 6 and 18 meters.
• the lifting mechanism is designed in the form of an extensible mast comprising vertical parts sliding on one another. others to extend vertically to the desired working height.
• Their lifting mechanism sometimes comprises a turret on which are mounted the vertical sliding parts, the turret being pivotally mounted on the frame about a vertical axis in order to vary the orientation of the work platform relative to the frame.
• the work platform is mounted on the uppermost vertical part sometimes by means of a pendulum arm - that is to say an arm articulated to the vertical mast around a horizontal axis - in order to give more flexibility to the user to reach the working position.
• the maximum working height generally varies between 6 and 12 meters.
• the ground clearance is large enough to allow the aerial platform to cross, during its movement, obstacles such as potholes or curbs without the frame does not contact the ground.
• a first approach is to use a mechanical connection between the lifting mechanism of the work platform and the bars, as well as springs.
• the operating energy of the lifting mechanism of the work platform is used to move the bars from the raised position to the lowered position. Examples of this approach are described in US 6,425,459 B1, WO 2005/068347 A1 and CA 2 646 412 A1.
• These solutions are mechanically complex, especially since they must include a bar locking system in their lowered position to maintain this position if an external force tending to return to the raised position is applied to them.
• the second approach is to use actuators assigned only to the actuation of the bars; they are therefore independent of that or those of the lifting mechanism of the work platform.
• Each bar is actuated by a respective actuator to move it from the raised position to the lowered position and vice versa, in particular according to the signal of a position sensor detecting whether the work platform is in the lowered position or not.
• FIG. 3 illustrates this approach as it is implemented on the machines of the Optimum range marketed by the applicant.
• Each bar 10 is secured to each of its longitudinal ends to a support 11 which is pivotally mounted to the frame 1 about an axis 12.
• the bars 10 move from the raised position to the lowered position and vice versa by pivoting about the axes 12.
• Each bar 10 is moved between these two positions by a corresponding hydraulic cylinder 13 whose rod is mounted in pivot connection on the support 11 about an axis 14 and whose body is mounted in pivot connection on the frame around
• This solution is simpler than those of the first approach and provides reliable protection against the overturning of the aerial work platform, but it is still expensive because of the cost of the cylinders.
• US 2002/0185850 A1 discloses another implementation of this second approach.
• Each bar is mounted to the frame by a first pair of links articulated together forming a first toggle mechanism and a second pair of links articulated together forming a second toggle mechanism.
• the bar When the two toggle mechanisms are folded, the bar is in the raised position while the bar is in the lowered position when the toggle mechanisms are in the unfolded position.
• An actuator specific to each bar is mounted between the two toggle mechanisms to move them from the folded position to the unfolded position and vice versa. In unfolded position, the links of the toggle mechanisms are placed in abutment beyond the alignment position of their axes.
• EP 831,054 A2 discloses yet another implementation of this second approach, but using only one hydraulic cylinder to actuate the two bars.
• the jack is mounted under the frame and extends parallel to mid-distance between the two bars, the body of the jack being fixed to the frame while its rod actuates pivotally the two bars through a mechanism of kneepad angle return which converts the movement of the rod parallel to the bars in a movement perpendicular to the bars.
• this solution is still complex and cumbersome because of the knee-lever angle mechanism.
• An object of the present invention is to provide a technical solution for protection against potholes for aerial work platforms that at least partially overcomes the aforementioned drawbacks.
• the invention aims to provide a solution that is both reliable while being simpler and more economical.
• the present invention proposes a lifting platform, comprising: a chassis mounted on wheels for moving the aerial platform to the ground; a work platform;
• a lifting mechanism mounted on the frame and supporting the work platform to move it upwards;
• an actuator assigned solely to actuating the two lateral bars to move them from the raised position to the lowered position and vice versa.
• the lowered position of the side bars makes it possible to limit the risk that the aerial platform will overturn if a wheel rolls in a pothole during its displacement on the ground with the work platform raised.
• the fact that the actuator is assigned solely to the actuation of the two lateral bars is advantageous because, being distinct from the actuator or actuators of the lifting mechanism of the working platform, it avoids resorting to a complex mechanical connection between the mechanism. lifting the platform and the side bars as is the case of the prior arts implementing the first approach described above. Furthermore, the fact of using a single actuator to operate both bars is more economical and limits assembly operations compared to the prior art using two actuators as is the case of those implementing the second one. approach described above.
• the actuator has two opposite ends through which it actuates the two lateral bars by varying the distance between the two ends, the actuator acting on each of the two side bars through another of the two ends and the actuator being maintained only through the two ends.
• the actuating mechanism of the bars is simpler, more economical and more compact compared to the teaching of EP 831 054 A2 mentioned above.
• the invention includes one or more of the following features:
• each of the bars is mounted to the frame by means of connecting elements and the actuator is held to the frame only through said connecting elements;
• the bars are mounted to the frame in pivotal connection
• the actuator biases each bar in the lowered position against a respective fixed stop of the chassis
• each bar in the lowered position, is offset relative to a vertical passing through the pivot axis so that the external forces to the aerial platform which are exerted vertically upwards on the lower edge of the bar are countered by the respective fixed stop of the chassis;
• each bar is horizontal and extends between two lateral wheels substantially along the entire length separating the two lateral wheels;
• the actuator is a cylinder
• the actuator is a hydraulic cylinder
• the jack extends horizontally and perpendicularly to the longitudinal direction of the frame;
• each of the two ends of the actuator is preferably mounted in pivot connection on a respective one of the two bars or on a part on which is secured one respective of the two bars;
• each of the two ends of the actuator is pivotally mounted on a respective support which is secured to another of the two side bars, the support being pivotally mounted to the frame;
• Each of the lateral bars is secured to the respective support (21) towards one of its longitudinal ends, each of the lateral bars being further secured towards the other of its longitudinal ends to a second respective support pivotally mounted to the frame.
• the actuator actuates each of the two side bars through a respective locking mechanism, each locking mechanism having an unlocked position and a locked position, the actuator actuating the locking mechanisms to move them from their unlocked position to their locked position and reciprocally, the transition to the unlocked position having the effect of moving the side bars in the raised position and the passage in the locked position having the effect of moving the bars in the lowered position, the locking mechanisms in the locked position counteracting independently of the actuator any force external to the aerial platform exerted on the bars which tend to move them from the lowered position to the raised position;
• the aerial work platform is a scissor lift or vertical mast aerial work platform.
• FIG. 1 represents a perspective view of a scissor lift with the working platform in a lowered position on the chassis, the platform having side bars for protection against potholes which are not visible because in position raised under the chassis.
• Figure 2 shows the same perspective view of the aerial work platform of Figure 1, but with the work platform raised and the side bars of protection against potholes in the lowered position (only one is visible).
• FIG. 3 represents, for a scissor lift platform, FIGS. 1 and 2, the frame and a system for actuating the pothole protection lateral bars according to the prior art of the applicant's Optimum range, the bars being in the raised position, it being specified that the part of the chassis corresponding to the front wheels is fictitiously omitted to make visible the actuation system of the pothole protection side bars which is located at a level of the chassis a little behind the wheels before.
• FIG. 4 represents, for a scissor lift platform, FIGS. 1 and 2, an exploded view of the frame and the system for actuating the lateral bars according to a preferred embodiment of the invention.
• Figures 5 and 6 show respectively a perspective view and a front view of the frame and the actuating system of the side bars for protection against potholes, the bars being in the raised position, it being specified that a part of the frame is fictitiously omitted to make visible the system of actuation of the side bars of protection against the potholes.
• Figures 7 and 8 are similar to those of Figures 5 and 6, but with the side bars of protection against potholes in the lowered position.
• Figures 9 and 10 show schematically a variant according to the invention of the operating system of the side bars of protection against potholes, the bars being in the lowered position and in the raised position respectively.
• FIGS. 1, 2 and 4 to 8 The description made above of the aerial platform of FIGS. 1 and 2 remains applicable in the context of the present mode. of realization.
• the aerial platform comprises an elongated frame mounted on wheels to allow the displacement of the aerial platform.
• the two narrow ends define the front AV and the rear rear of the aerial platform with regard to the direction of ground travel that two front wheels 4 and two rear wheels 5 give to the aerial platform.
• the lifting platform comprises on each side side a bar 10 for protection against potholes.
• One of these two bars is visible in Figure 2 where it is in the lowered position while they are not visible in Figure 1 because they are in the raised position under the frame 1.
• Each side bar 10 is arranged under the frame 1 and extends horizontally over substantially the entire length between the front wheel and the rear wheel, whether in the lowered position or in the raised position. The system for actuating the bars 10 to move them in the lowered position and in the raised position will be described with reference to FIGS. 4 to 8.
• Each bar 10 is secured to each of its longitudinal ends to a support 21 which is pivotally mounted to the frame 1 about a respective axis 22.
• the bars 10 pass from the raised position to the lowered position and vice versa by pivoting about the axes 22.
• Each bar 10 is moved between these two positions by the same actuator, in this case a hydraulic cylinder 30.
• This is assigned only to the actuation of the bars 10.
• the body of the jack 30 is mounted in pivot connection about an axis 33 on a support 21 of one of the bars 10.
• the body of the jack 30 has been lengthened by a rod 32 which is fixedly arranged on the body of the jack 30.
• the rod 31 of the jack 30 is mounted in pivot connection about an axis 34 on a support 21 of the other bar 10.
• the rod 31 of the jack 30 and / or the body of the jack 30 are mounted - preferably in pivot connection - directly to the corresponding bar 10 or to a piece other than a support 21 to which the corresponding
• the jack 30 can be mounted to the supports 21 so that it is the output of the rod 31 which causes the displacement of the bars 10 in the lowered position and the retraction of the rod 31 which causes their displacement 10 in the raised position. .
• the jack 30 extends horizontally and perpendicularly to the longitudinal direction of the frame 1, which limits the space necessary for housing the jack 30.
• the jack 30 is only held to the frame by the supports 21 to which it is mounted, which simplifies assembly operations.
• the hydraulic supply of the jack 30 is made by flexible hoses, which allows the cylinder body to move relative to the frame 1 when the rod 31 out or retracts.
• the cylinder 30 is a double-acting cylinder. It is supplied with hydraulic fluid by means of two connectors 36, 37 mounted in our example on a housing 35.
• the housing 35 is itself mounted on the body of the jack 30 by two rigid tubes feeding each of the chambers of the jack 30 from the fittings 36, 37 via a respective nonreturn valve contained in the housing 35.
• each bar 10 As a safety measure, a position sensor 50 is provided for each bar 10 to verify that it is in the lowered position. This makes it possible to trigger an alarm and prevent the platform from moving on the ground if one of the bars 10 is not in the lowered position when it should be. In this case, each sensor 50 cooperates with a surface of the support 21 of the bar 10.
• the lower edge 10a of the bars 10 when in the lowered position, to be offset towards the outside of the frame with respect to the vertical V passing through the axis 22 of pivoting of the support 21.
• the forces Fv external to the aerial platform exerting vertically upwards on the lower edge 10a of the bars 10 are countered directly by the frame 1 at 41 where the bar 10 is supported. It is therefore not the jack 30 against the vertical forces.
• the system for actuating the bars 10 is preferably dimensioned so as to be able to keep the bars 10 in the lowered position for vertical forces Fv exerted on each of them by at least half the weight of the aerial lift with his work platform loaded to his maximum allowed load.
• the system for actuating the bars 10 is preferably dimensioned so as to be able to keep the bars 10 in the lowered position for lateral forces FLE, FLI exerted on each of them by at least a quarter of the weight of the aerial platform. with his work platform loaded to his maximum allowed load.
• the jack 30 may be powered by the hydraulic supply circuit of the aerial platform which serves to supply the actuators of the lifting mechanism 2 and / or the actuators controlling the orientation of the steering wheels 4 of the nacelle lift.
• the jack can be classically controlled by a hydraulic distributor preferably electrically controlled.
• the dispenser can then be controlled by an electrical circuit depending for example on a position sensor - not shown - which detects whether the lifting mechanism 2 of the work platform 3 and / or commands triggered by the operator at the station control of the aerial work platform.
• the control circuit can cause the raising of the bars 10 in the case where a control movement of the aerial platform on the ground is triggered by the operator and that the aforementioned position sensor detects that the lifting mechanism 2 is in the lowered position.
• the control circuit can cause the lowering of the bars 10 in the case where a lifting control of the work platform 3 is triggered by the operator. If the position sensor of the lifting mechanism signals that the work platform 3 is raised and one of the position sensors 50 indicates that a bar is not in the lowered position, the control circuit prohibits the movement to the the platform and triggers an alert to the operator, for example by lighting a fault light on the control station.
• FIGS 9 and 10 schematically illustrates a variant of the embodiment described above. Only the left part of the actuating system is shown, it being specified that the right part not shown is made in the same way, except that it is the body of the jack 30 which is connected to the corresponding support 21 in the same way that the cylinder rod 31 for the left part of the actuating system.
• the bars 10 are mounted pivotally connected to the frame about an axis 22.
• the jack 30 actuates each bar 10 by means of a respective locking mechanism. It is constituted in this example by two links 61 and 62.
• the rod 61 is mounted in pivot connection to the support 22 about the axis 63.
• the rod 61 is pivotally mounted about the axis 64 at a end of the rod 62.
• the other end of the rod 62 is pivotally connected to the frame about the axis 65.
• the rod 31 is linked in pivot connection to the locking mechanism to the axis 64.
• Figure 10 illustrates the unlocked position of the locking mechanism in which the links 61 and 62 are in a folded position while the bar 10 is raised.
• the jack 30 moves the locking mechanism and the bar 10 when it leaves its rod 31.
• the locking mechanism When the jack 30 retracts its rod 31, it moves the locking mechanism in the locked position which is illustrated in FIG. 9.
• the axis 64 has exceeded the alignment position with the pins 63, 65 and one of the rods 61, 62 is in abutment against a stop 66 of the frame 1.
• the rods 61, 62 are in a position self-locking relative to any external force to the aerial platform exerted on the bar 10 which tend to rotate it from the lowered position to the raised position.
• the locked position the locking mechanism against these forces independently of the cylinder.
• the jack 30 Since the jack 30 does not intervene in maintaining the position of the bar 10 vis-à-vis these efforts, it can be a much lower power since it must only be able to actuate the locking mechanisms . In this case, it is possible to replace the hydraulic cylinder 30 with a pneumatic cylinder, see an electromechanical actuator.
• the actuator may be of any suitable type other than a hydraulic cylinder. Although particularly suitable for scissor lifts and vertical boom lifts, the invention can be applied to any other type of mobile elevating work platforms, including towed or pushed aerial work platforms to move them to the ground.

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• Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Mechanical Engineering (AREA)
• Forklifts And Lifting Vehicles (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2015
  • 2015-04-18 FR FR1553476A patent/FR3035099A1/fr active Pending
• 2016
  • 2016-04-15 WO PCT/FR2016/050893 patent/WO2016170255A1/fr active Application Filing
  • 2016-04-15 CN CN201680022429.8A patent/CN107531471B/zh active Active
  • 2016-04-15 EP EP16720460.1A patent/EP3286128B1/de active Active
  • 2016-04-15 CA CA2982883A patent/CA2982883C/fr active Active
  • 2016-04-15 AU AU2016252094A patent/AU2016252094B2/en active Active
  • 2016-04-15 US US15/567,369 patent/US10676334B2/en active Active

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