FR3121416A1 - Load transport trolley - Google Patents

Abstract

TITLE: Load transport trolley Load transport trolley comprising a frame (1) carried by two caterpillar modules (3), motorized and carrying a load carrier (2). The frame (1) is pivotally connected to the crawler modules (3), and also to each crawler module (3) by an adjustable spacer (5). Figure 1

Description

Load transport trolley

FIELD OF THE INVENTION

The present invention relates to a load transport trolley or handling comprising: a chassis carried by two crawler modules, motorized and carrying a load carrier, the chassis being pivotally connected to the crawler modules and, also to such a carriage in the form of a motorized devil comprising a frame housing the motor and its transmission and connected by a pivot to the two caterpillar modules, which are free to pivot; each module is connected to the pivot by a bearing not coaxial with the wheels defining the support surface of the module and projecting onto this support surface; the load support formed by a backrest ends at one end with a maneuvering handle and at the other with a shovel, being connected by a hinge to the frame at a point different from the pivot of the two modules.

STATE OF THE ART

Multiple embodiments of such load transport carriages equipped with a running gear consisting of two motorized caterpillar modules are known.

These carts in different forms are used to transport different loads including disabled people. Thanks to their caterpillar module, these trucks can travel on terrain that is impassable for wheeled trucks and, if necessary, they can overcome slopes, obstacles or stairs. However, the passage of stairs is generally relatively difficult.

There is also known a trolley in the form of such a very efficient motorized devil for transporting loads on both flat and irregular surfaces or for passing steps.

However, if the load to be transported is very heavy, the user encounters difficulty in tilting the trolley from its substantially vertical position for taking up the load into an inclined transport position.

This difficulty limits the use of this motorized hand truck to loads that the driver can easily take, that is to say tilt the hand truck from its position for taking up the load to its transport position and vice versa for setting down the load. .

PURPOSE OF THE INVENTION

The object of the present invention is to develop a handling trolley, motorized, with accompanying driver, facilitating the transport of loads and also the passage of obstacles such as steps, uphill and downhill, being used in the manner of a wheelbarrow while facilitating maneuvers and reducing the load imposed on the user by the guide arms of the trolley and facilitating the picking up and setting down of a heavy load by the single maneuver of the load carrier of the hand truck.

The invention also aims to facilitate the passage of curves with such caterpillar module trolleys.

DESCRIPTION AND ADVANTAGES OF THE INVENTION

To this end, the subject of the invention is a load transport carriage comprising: a frame carried by two caterpillar modules, motorized and carrying a load support, the frame being pivotally connected to the caterpillar modules, this carriage being characterized in that the frame is connected to each crawler module by an adjustable spacer.

This carriage thus makes it possible to pass safely over obstacles such as steps without risking the imbalance of the carriage both during the ascent and the descent. This even makes it possible to stop the trolley during ascent, blocking the drive motor, the transmission being irreversible so that the trolley whose wheels are blocked will thus remain positioned in a stable manner on the geometric surface in the form of a ramp formed by the steps of the stairs.

The possibility of stopping is extremely advantageous from the point of view of safety, depending on the type of trolley used, for example, in the case of a trolley transporting stretchers or people seated on an armchair constituting the support surface.

The possibility of blocking the articulation by the spacer of adjustable length also facilitates the circulation of the truck on horizontal or slightly inclined surfaces because the driver does not have to support the weight of the load or at least he does not have to support only a fraction of the weight of the load, the rest being transmitted by the stabilized assembly to the support surface of the caterpillar modules.

The flexibility of the truck's operation thanks to the control of the adjustable spacer, allows this function to be activated and deactivated immediately, without prior preparation, which makes it possible to use this function of the adjustable spacer, when passing obstacles of low height, for example, a difference in level on a traffic surface, the passage between the roadway and the sidewalk which, however, is of considerable importance for the transport of heavy loads and does not require occasional unloading of the support of charge to pass the obstacle.

According to another characteristic, the spacer is continuously adjustable, which allows precise adjustment of the position of the handle and the comfort of driving the trolley.

According to another characteristic, the load support integral with the frame comprises an auxiliary support that slides and is adjustable with respect to the load support. This auxiliary support thus makes it possible, on the one hand, to facilitate the picking up of certain loads and their removal and, on the other hand, to move the center of gravity of the load on the load support and to adapt it to the operation of the truck in order to the center of gravity, for example, as close as possible to the vertical plane passing through the axis of articulation of the chassis to the tracked modules, or even to move the center of gravity to bring it closer to the vertical plane of the axis of the front wheels to relieve the track and support the load mainly on the front wheel of each track and thus facilitate the turning movement of the trolley by preventing the modules from shifting.

According to another advantageous characteristic, the carriage comprises a control for adjusting the spacer or the auxiliary support. This integrated control, preferably in the handle, allows the driver to visually follow the movement of the load support or the auxiliary support to position the load as advantageously as possible for driving and overcoming obstacles.

According to another characteristic, the adjustable spacer is a hydraulic cylinder comprising a piston subdividing it into two chambers whose sum of volumes is constant, a bypass connecting the two bottoms of the cylinder and provided with a controlled valve to allow the exchange of liquid between the two chambers by moving the piston and blocking it by cutting off the passage of liquid in the bypass, the piston rod and the cylinder being connected to the frame and to the track modules, to adjust the gap between the frame and crawler modules.

This particularly simple and effective embodiment of the adjustable spacer promotes the continuous adjustment of the spacer and thus of the configuration of the carriage.

According to an advantageous characteristic, the piston is carried by a piston rod with an extension which protrudes from the second chamber and projects into the extension of the cylinder beyond the second chamber.

According to another characteristic, the module is equipped with a support wheel at least partially above the rear wheel of the module and projecting from the latter, which facilitates the initiation of the passage of a step, in particular in the case of heavy loads that do not allow the driver of the truck to slightly lift the rear of the latter to initiate the passage of a step or a first step of a set of steps.

According to another characteristic, the subject of the invention is a trolley in the form of a motorized hand truck of the type defined above, characterized in that it comprises,

- a frame housing the engine and its transmission, connected by a pivot to the two caterpillar modules, free to pivot,

- each module is connected to the pivot by a bearing not coaxial with the wheels defining the support surface of the module and projecting onto this support surface,

- the load support is made up of a backrest ending at one end with a handle and at the other with a shovel,

- the load support is connected by a hinge to the chassis at a point different from the pivot of the two modules,

- a support of the module receives the joint in the first phase of tilting of the load support and,

- a frame support receives the load support at the end of the first tilting phase to continue the tilting of the integral frame in support of the support around the pivot of the modules and release the support from the joint.

The hand truck according to the invention has the advantage of facilitating the taking of a heavy load and the tilting of the hand truck to pass from its position for taking up the load to its transport position. The decomposition of the tilting movement into two successive movements with different lever arms allows the driver to initially maneuver a relatively heavy load to bring it into a tilted position from which the lever arm to continue the tilting is reduced from fact of the displacement of the position of the center of gravity of the load then facilitating the driving of the hand truck while benefiting from the mobility of the two modules. In particular, the support of the module is substantially vertical to the axis of the wheel of the module, on the load support side and this support makes it possible to receive, in a stable manner, the effort to maneuver the hand truck for its start of tipping.

According to another advantageous characteristic, the support of the load support on the frame is a support which surrounds the pivot around which each caterpillar is mounted. This support makes it possible to receive the weight of the load during this second phase of the movement and then during the transport of the load while leaving the two modules free to pivot according to the relief of the surface on which the modules circulate.

According to another feature, the subject of the invention is a handling truck of the type defined above, characterized in that it comprises a frame provided with a transverse pivot located substantially vertically to the center of gravity of the loaded load support. in a balanced manner, each module has a transverse bearing receiving the transverse pivot of the carriage in the vertical plane passing through the support surface of the crawler module, and an adjustable spacer connecting the load support to each module, blocking the two modules or releasing their pivoting relative to the load support.

The handling trolley according to the invention has the advantage of being particularly simple to make and very easy to drive both on flat surfaces, inclined in the downward or upward direction or when passing obstacles such as a sidewalk or step curb. The trolley is very space-saving and practically only takes up the space of the loading surface. This cart is easy to drive in both forward and reverse. The lockable swivel of the two modules makes it easier to use and reduces the effort required of the driver.

According to an advantageous characteristic, the lock is composed of two legs each connected by an axis to the side of the frame facing a module and pivoting between a blocking position and a position for unlocking the pivoting of the module relative to the frame, by hooking to the module , the two legs being integrally connected in movement by a transverse rod. The lock blocks or releases the two modules at the same time so that the symmetry of operation is respected. This symmetry is important for the passage of steps.

The lock is advantageously maneuvered with the foot by acting on the transverse rod connecting the two legs, which allows the driver to keep his hands on the tiller or the handle of the tiller while maintaining the balance of the load and facilitating the engagement or the release of the tabs constituting the lock.

According to another advantageous characteristic, the carriage comprises a drive system composed of an electric motor housed in the chassis and connected by a differential to two axle elements each connected to a module through the bearing of the module to drive the wheel motor of the module.

The weight distributed on the tracks results in low pressure on the ground or other surface and the differential allows the truck to be maneuvered to follow curved paths.

According to a variant, the carriage drive system is formed by a motor integrated in each module and controlled by an electric differential. This motor can also be directly integrated into the drive wheel of the module.

The front end of the module being constituted by the driving wheel of larger diameter than the rear wheels, the module combines the advantage of a wheel of a certain diameter which makes it possible to easily absorb low-height obstacles in forward motion. and obstacles of greater height or of more difficult passage such as the steps thanks to the ramp at the rear end of the module, the direction of passage of such obstacles being reverse.

According to a structural feature, the frame is provided with two uprights forming a backrest carrying the drawbar. The two uprights can thus constitute the backrest of the support surface, whether the latter is a tray or another support surface adapted, for example, to the shape of the objects to be transported.

Finally, according to an advantageous characteristic, the drawbar is connected by a joint to the backrest, this joint locking in the position selected by the operator according to the maneuver to be carried out with the trolley.

In summary, the carriage, according to the invention, is of a particularly simple construction; its use is in particular that of a wheelbarrow with the advantage of a reduction of the efforts to be provided by the operator who drives this trolley and by the possibility of passing on steps, going up and down stairs and maneuvering in narrow spaces , since the maneuver can be done on the spot in the space occupied by the single platform.

The present invention will be described below in more detail with the aid of embodiments of a carriage represented very schematically in the accompanying drawings in which:

side view of a carriage according to a first embodiment circulating on a flat surface,

side view of the carriage suitable for crossing steps,

diagram of an adjustable spacer fitted to the carriage according to figures 1 and 2,

diagram of a load carrier variant,

diagram of another variant of the carriage.

block diagram of another embodiment of a devil-shaped cart

simplified diagram of the geometry of the motorized hand truck in the initial loading position and in the end position of the first tilting phase,

diagram of the motorized hand truck showing its position at the end of the first tilting and an end position for the second phase of tilting,

diagram of the structure of the motorized hand truck showing the end position of the second tipping.

schematic side view of an embodiment in the form of an industrial truck,

schematic plan view of the carriage of the ,

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

According to , the invention relates to a load transport carriage 100 consisting of a frame 1 shown schematically by a line, connected to a load support 2 in the form of a surface terminated at one end by a relief such as the shovel of a Devil. The other end of the load carrier 2 is the handle 24 used to maneuver and drive the cart. This handle 24 is equipped with a control 241.

A load CH is placed on the load support 2; it has a CG center of gravity.

Insofar as the load support 2 is solidly connected to the frame 1 as described above, this assembly will be considered identical to the frame 1.

The chassis 1 is connected in an articulated manner by a pivot 4 to two track modules 3, identical, in symmetrical positions with respect to the median plane which is the plane of symmetry (plane of the ).

The description will be limited to that of a single module 3. Depending on the case, the expression “the module” may designate the two modules in symmetrical operation.

To facilitate the description, by convention the rear rear of the carriage 100 is located on the right, on the side of the handle 24 and the front AV is on the opposite side.

The caterpillar modules 3 are schematized by a front wheel 31 and a rear wheel 32 over which the caterpillar 33 passes. One or both wheels are driven.

The space between the wheels 31, 32 is occupied either by an internal support for the caterpillar 33, or by a succession of intermediate wheels, not shown, resting on the caterpillar 33.

The support surface SA of the carriage 100 via its caterpillar 33 on the ground S corresponds to the spacing of the axes 311, 312 of the wheels 31, 32 of each module.

According to the representation, the load support 2 is inclined at an angle (α) with respect to the support surface SA of the caterpillar. The trolley handle 24 is at a height H relative to the surface S on which the trolley and its driver circulate. This adjustable height H generally corresponds to the height for driving the carriage by holding the handle 24 and moving the carriage 100 forwards or backwards.

According to the embodiment, each caterpillar module 3 is equipped with a motor, if necessary, each wheel 31, 32 of the module is equipped with an electric motor and the motors of the two modules are associated so as to operate as one. differential.

In the case of a single motor installed in frame 1, this is connected to the two modules 3 by a transmission incorporating a differential. The transmission is done in this case through the joint 4 between the frame 1 and each module 3.

These various details are not shown in figures 1, 2 and 4.

According to the invention, the carriage 100 comprises a spacer 5, by definition "a part which connects two others to maintain a determined spacing" connecting the frame 1 (here the load support 2 secured to the frame 1), to each of the two modules caterpillar 3 by an articulation 511, 512. This spacer 5 is continuously adjustable in length by the control 241 actuated by the driver. The latter can, in fact, release the blocking of the spacer 5 and tilt the chassis 1 (the load support 2) as it sees fit depending on the difficulties or obstacles of the route and the height H at which the handle 24 then block the length.

This reversible adjustment can be made at any time and is not final. It is renewable if necessary, when passing each obstacle requiring a modification of the length of the spacer 5, or even a release of the spacer to allow the spacer to function as a shock absorber, to be neutral without effect on the joint between frame 1 and track modules 3 and allow the joint to play freely.

The adjustable spacer 5 connects the frame 1 to the two modules 3. As in general the modules 3 must pivot in the same way, a single spacer 5 can be connected by its end 512 to the two modules 3 by a transverse bar.

A variant consists in installing two adjustable spacers 5, controlled in synchronism. In this variant, the control 241 simply acts on the opening of the valve 55 of the respective bypass 54 to allow the exchange of the hydraulic fluid according to the "request" of each module 3 then the blocking of the two spacers 5 according to the desired inclination for the carriage 1 and its handle 24. This variant leaves the two modules 3 mechanically independent so that their damping by their respective spacer 5 can act independently when the valve 54 of their spacer 5 is in the partially closed position (reduced section) slowing the exchange of hydraulic fluid between the chambers C1, C2 of their respective spacer 5.

The support surface SA of modules 3 corresponds to the stride F of a staircase, i.e. a support on three nosings Nm in the case of a regular staircase, which is the norm.

The geometry of the steps M can be different from one staircase to another, but on average, the tread g and the height h of a step are linked by relatively simple geometric relations such as the sum of these two lengths (g + h) corresponds to a total length which, depending on the country or construction habits, is within known dimensional ranges; the interval of three nosings to define the minimum length of the bearing surface SA of a caterpillar module 3 solves this problem of geometry.

The shows the carriage 100 in the position for passing the steps.

The noses of these steps M correspond to a slope angle β that the tracked module 3 follows. The articulation 4 between the chassis 1 and each tracked module 3 is blocked by the blocking of the length L0 of the adjustable spacer 5 This adjustment followed by the blocking of the length of the spacer is made at the start of the passage of steps M by the driver; this first releases the blocking of the spacer 5 to tilt the chassis 1 with its load support 2 to the appropriate height H1 which suits it, then it blocks the adjustment thus made and the assembly made up of the track modules 3 and frame 1 with its load carrier 2 constitutes a regulated assembly which is then rigid.

The carriage 100 can thus pass over the steps M continuously, as if it were traversing a ramp R corresponding to the angle of slope B.

This adjustment results in the modification of the length L1 of the spacer 5 and of the angle α1 between the theoretical surface (the ramp R) on which the carriage 100 and the frame 1/support 2 circulate for the position chosen for the handle 24.

It should be noted that on horizontal or slightly inclined surfaces, the carriage 100 is usually driven by walking behind the carriage whereas for climbing the steps M the driver stands in front of the carriage 100 in the direction of passage of the steps.

According to a variant shown in , the load CH is not carried directly by the load support 2, but by an auxiliary support 21 sliding and adjustable longitudinally relative to the load support 2. This movement is controlled by the driver with the control 241.

The auxiliary support 21 makes it possible to position the load CH (its center of gravity CG) with respect to the support surface SA and in particular with respect to the vertical VV passing through the articulation 4 connecting the chassis 1 to the caterpillar modules 3 and to balance the load with respect to the articulation 4 of the chassis.

Such an adjustment can also be made when passing steps to put the center of gravity of the load in an appropriate position, corresponding to the balance of the whole.

The is a schematic sectional view of the adjustable spacer 5 consisting of a hydraulic cylinder 52 with two chambers C1, C2 separated by a piston 53 carried by a piston rod 531 passing through the first bottom 521 of the chamber C1. This piston rod 531 extends beyond the piston 53 and the extension 532 passes through the second bottom 522 of the second chamber C2.

The extension 532 is housed freely in the extension 523 of the cylinder 52 which thus protects it. The volume beyond the second chamber C2 leads to the open air. This volume only serves to protect the extension 532 of the piston rod.

The section of the rod 531 and that of its extension being the same, the sum of the volumes of the two chambers C1, C2 is constant whatever the position of the piston 53 in the hydraulic cylinder 52.

The first chamber C1 and the second chamber C2 are connected by a branch line 54, the two ends of which open out via the branches 541, 542 in the two bottoms 521, 522 of the chambers C1, C2 to allow the exchange of liquid between the two bedrooms.

Bypass 54 is equipped with a controlled valve 55 which, when open, allows free exchange of liquid between chambers C1, C2 or which, when closed, blocks the exchange of liquid and blocks the position of the piston in cylinder 52 and thus the angle α.

By partially opening this valve 55, this makes it possible to adjust the flow of hydraulic fluid in one direction or the other and the spacer 5 can thus function as a shock absorber. When valve 55 is closed, piston 53 is blocked between the two chambers C1, C2 in the position in which it was when the valve was closed.

According to the variant shown in , to facilitate the turning movements of the carriage 100 and avoid causing the two caterpillar modules 3 to slip over their entire support surface SA, it may be advantageous to move the load CH so that its center of gravity CG is as close as possible from the vertical V1V1 passing through the axis 311 of the front wheel 31 of each caterpillar module 3. This makes it possible to transfer the weight of the load to a point on the support surface SA of the caterpillar modules 3 close to the projection of the axis 311 of the front front wheel of the two modules 3.

It is then possible to slightly lift the handle 24 so that the carriage no longer rests on the ground except by the two front wheels 31 of its tracks 33. This avoids the bearing surface SA of each of the two tracks 33 d have to skid and complicate the direction change movement of the trolley.

The shows another trolley variant that can be combined with the variant of the .

According to this variant, the module 3 is completed by a support wheel 35 coming at least partially above the rear wheel 32 of the module 3 and projecting from the latter. At the beginning of the passage of a step M, this support wheel 35 meets the top of the riser or the nose of the step and the thrust of the module causes this wheel 35 to pass over the top of the step by a leverage effect. The attachment of caterpillar 33 to the riser and the nose of the step initiates the passage of module 3 on step M and its inclination to pass the next step; the module can thus take the inclination of the inclination slope of the steps. This support wheel 35 is important in the case of heavy loads and when the center of gravity of the load on the load support 2 can be shifted sufficiently towards the front wheel 31 of the modules to allow the driver to raise the rear sufficiently modules to initiate the passage of the nose of the first step.

According to , the embodiment of the trolley is in the form of a motorized hand truck 100a comprising a frame 1a to which is articulated a load support 2a having an auxiliary support in the form of a backrest 21a provided with a shovel 211a as well as two caterpillar modules 3a connected to a pivot 4a of the frame 1a through which passes the drive of the two modules 3a, symmetrical with respect to the mid-plane of the frame.

Frame 1a houses the engine, battery and transmission including the differential. The transmission is unidirectional so that the hand truck remains stationary when the engine is stopped; the weight of the hand truck cannot drive the tracks, which is a safety feature.

The caterpillar module 3a has a ground support surface SA, delimited by the caterpillar segment between the vertical projection of the axis 311a of the front wheel 31a and the axis 321a of the rear wheel 32a of the module, delimiting this track segment forming the support surface. The front wheel 31a is on the side of the load support 2a and the rear wheel 32a is at the start of a ramp starting from this wheel 32a which is still resting on the ground or even a few wheels forming the ramp with the caterpillar on the rear side Rear of the carriage.

The bearing of the module 3a which receives the pivot 4a of the frame 1a is in the interval between the end wheels 31a, 32a defining the support surface SA of the module 3a on the ground so that the axis of the pivot 4a projects onto the support surface SA and not at either end of this surface or beyond it.

Frame 1a is represented by a rectangle containing pivot 4a and joint 7a from support 2a to frame 1a. Frame 1a pivots freely around pivot 4a; this pivoting is limited by the support of the frame 1a on the modules 3a as will be described, to avoid the collapse of the frame 1a around its pivot 4a.

The articulation 7a of the load support 2a connected to the frame 1a is by construction at a fixed distance from the pivot 4a and does not exceed in vertical projection the ends of the support surface SA of the module.

The load support 2a is connected to its articulation 7a by a lever arm B1 which must be as short as possible, without the articulation 7a projecting beyond the bearing surface SA; it is advantageous for the articulation 7a to be as forward as possible and therefore at most vertical to the axis 311a of the front wheel 31a and can come on a support 312a which is on the axis 311a of the wheel 31a or the vertical of this axis; this has, moreover, the advantage of applying the weight of the support 2a directly by the articulation 7a to the wheel 31a without requiring any particular or reinforced structure of the module 3a to receive this weight.

So that the driver can initiate the pivoting of the load support 2a engaged under the load CH by his shovel 211a, the joint 7a is supported by the support 312a.

The load support 2a is connected to each module 3a or jointly to the two modules 3a by an adjustable spacer 5a connected to the support 2a by the joint 512a and to each of the modules 3a, 3b by a joint 511a. This adjustable spacer 5a is controlled by the control 241a equipping, if possible, the handle 240 to manage the operation of the carriage in the form of a devil 100a.

This adjustable spacer 5a works as already described above:

- in step passage mode in which the length of the spacer 5a is adjusted to the appropriate length by the driver when passing the steps,

- damping mode making it possible to attenuate pendular or oscillating movements when the hand truck is circulating normally,

- in damping mode consisting of slowing the exchange of hydraulic fluid between the two chambers of the adjustable spacer,

- in free mode in which the bypass 54 between the two chambers C1, C2 is open and allows the module to pivot freely around the axis 4a,

the adjustable spacer 5a has continuous operation. The different elements of this solution have been described extensively above and will not be mentioned in the following figures.

The first phase of the rocking movement continues with the load support 2a coming into contact with an abutment 6a of the frame 1a, thus making the support 2a and the frame 1a integral. From this moment, the tilting continues according to a different trajectory which now takes place around the axis of the pivot 4a. The pivot 4a, which is also that of the bearing of the module 3a, is a fixed point. The tilting then takes place with the lever arm B2 which is the distance separating the pivot 4a and the line schematizing the support 2a or its backrest 21a; this distance is also that of the pivot 4a of the module 3a which is a fixed point: the tilting takes place with the lever arm B2 which is the distance separating the pivot 4a and the line schematically representing the support 2a or the backrest 21a.

During this second tilting movement, the weight of the load CH is applied to the pivot 4a which is projected onto the bearing surface SA.

While in the initial phase of the tilting, the load support 2a is supported by the joint 7a against the support 312a of the module 3a, from the start of the second phase of tilting, that of the assembly (chassis 1a - support 2a), integral, around the pivot 4a, the joint 7a takes off from the support 312a; the module 3a is then free to pivot relative to the frame 1a, which is essential so that the hand truck can move easily on its tracks.

The end of this first tilting phase is schematized by the support 2a coming into contact with the pivot 4a. The support 2a could bear against another element of the frame 1a. However, as by this bearing all the weight of the support 2a must be transmitted, it is preferable to apply this weight directly to the pivot 4a which transmits this force to the support surface SA and leaves free the pivoting of the two modules 3a.

In practice, the center of gravity CG of the support 2a with its load CH being at a certain distance from the support 2a and from its backrest 21a, the lever arm for calculating the torque exerted by the load on the articulation 7a is the product of the distance B1 between the joint 7a in support and the vertical passing through the center of gravity CG of the load CH. This distance corresponds to only a fraction of the distance of the center of gravity with respect to the pivot 4a so that the torque is thus divided according to the same ratio, by two or by three, depending on the location of the center of gravity of the load , if the tilting was initially around the pivot 4a.

When the center of gravity CG passes vertically to joint 7A, the torque is canceled and then changes direction.

Already before this passage, the handle 24a at the end of the backrest 21a passes beyond the vertical of the joint 7a, and the truck driver can then play his weight so that the initial tilting movement is greatly facilitated and even accentuated by the change in direction of the torque of the load that the driver can then easily retain for reasons of distance from his point of application (the handle 24a) with respect to the vertical passing through the articulation 7a.

The first tilting phase ends with support 2a coming into contact with pivot 4a so that the torque of the load now depends on the distance from pivot 4a; this distance is generally much smaller than the distance between the vertical passing through the handle 24a and the pivot 4a. This makes it considerably easier to lower the load support 2a and hold it while moving the hand truck; this is all the more true as the center of gravity of the load CH on the support 2a is generally maintained close to the vertical passing through the pivot 4a.

The shows the initial loading position of the hand truck to tilt the load support 2a and the case of two centers of gravity CGo, CG'o allowing to see by way of example, how the position of the center of gravity evolves after the tilting of the support load 2a during the first failover phase. The load support at the end of tilting around joint 7a bears the reference 2aA (and its elements, the references 21aA, 22aA).

During this first phase, joint 7a remains in contact with support 312a.

The shows the second phase of tilting of support 2a passing from its position 2aA to its position 2aB.

The support 2a has a stop member 23a shown schematically by a rod which comes against the support 6a of the frame at the end of the first phase of tilting of the support 2a. This phase begins with support 2a coming into abutment against support 6a of frame 1a.

The support member 23a could extend as far as the pivot 4a and the support 6a coincide with the pivot 4a, the design of the is simply made to explain this support function of the support 2a on the frame 1a.

From this beginning of the second phase of movement, the assembly formed by the support 2a and the frame 1a, that is to say the elements 1a, 7a, 6a, 23a, 2a, 21a, 22a tilt around the pin 4a.

The shows such a tilting position integral with the support 2a and the frame 1a around the pivot 4a. In this position, the tilted elements carry the numerical references supplemented by the reference B.

This position is not an end position and the assembly 1a, 2a can freely tilt around the pivot 4a during the transport movement of the load.

According to Figures 10 and 11, the subject of the invention is a motorized handling trolley 100b for transporting loads, in particular heavy and compact, solid, fluid or liquid loads (CH). It is driven by an accompanying driver, walking behind or in front of the trolley depending on the direction of traffic.

The trolley 100b consists of a frame 1b to which is attached the load carrier 2b such as a tray, a tank or other receptacle for transporting rigid loads or fluid loads such as sand or liquids or other building materials. .

The carriage 100b is carried by two caterpillar modules 3b, connected on each side to the frame 1b by a transverse pivot 4b. The transverse pivot 4b (according to the forward, reverse direction of the carriage) is located substantially vertical to the center of gravity CG of a load CH regularly distributed on the load support 2b such as a tray so that the load CH can be maintained substantially in balance by the driver holding the drawbar 12b.

To allow this balance, the transverse pivot 4b is connected to a bearing 35b of each module 3b, located in the vertical plane VV passing through the middle of the bearing surface SA of the caterpillar 33b, taken in the longitudinal direction.

The two modules 3b are identical or at least symmetrical with respect to the median plane of the frame 1b. Each module 3b consists of a driving front wheel 31b, a low rear wheel 32b and a high rear wheel 34b, offset from the low front wheel 32b over which the caterpillar 33b passes.

The support surface SA substantially corresponds to the part of the caterpillar 33b between the front wheel 31b and the low rear wheel 32b. The segment between the two rear wheels 32b, 34b forms a ramp 36b to facilitate the passage of obstacles or steps.

According to a variant, the caterpillar module 3b has a front wheel and a rear wheel 32b without forming a ramp.

The support surface SA of the caterpillar 33b can be supported inside the module by a series of wheels or intermediate rollers, not shown.

The transverse axis 4b for the pivoting mounting of the modules 3b with respect to the frame 1b is, for example, produced by an axis element 83b coming from each side of the frame 1b and housed in a bearing 35b of each module 3b.

According to one embodiment, each module 3b has at least one driving wheel 31b integrating an electric motor or connected by a transmission to such a motor housed in the module. According to another embodiment, the carriage 100b has a central motor in the chassis 1b and driving by a differential 82b, the two axle elements 83b each connected to a respective module 3b. Each axis element 83b comes out of the frame 1b by a bearing 11b and passes into the module by the bearing 35b; it carries a pinion 84b, connected in the module 3b, to the drive wheel 31b.

The frame 1b or the support 2b integral with the frame 1b is connected by an adjustable spacer 5b to each module 3b. This spacer 5b can be common to the two modules 3b or be separate for each module; it is controlled from command 241b.

The schematic plan of the shows more particularly the drive system 8b of the two modules 3b by an electric motor 81b connected by a differential 82b to two shaft elements 83b, coaxial, forming the pivots passing through bearings 35b of each module 3b and carrying a pinion 84b meshing with a pinion 312b of each driving wheel 32b.

In this embodiment, the transverse pivot 4b coming out of the frame 1b, taken in the general sense, is replaced here by the axis element 83b of the differential 82b which comes into the two bearings of the module and allows the pivoting of the module, not blocked and at the same time drive the module.

Motor 81b is reversible for forward or reverse. The differential 82b at the output of the motor (or more exactly of the geared motor) can be blocked. In the case of electric motors integrated in the modules, these are controlled by an electric differential. A particularly important mode of operation of the carriage 100b for maneuvering in reduced spaces is that of the pivoting of the frame 1b on itself around a vertical axis CC which passes substantially through the center CC of the chassis ( ), one 3b module, advancing while the other 3b module is retreating.

The mounting of the two modules 3b on the frame 1b allows them to pivot freely which is useful for certain modes of movement, for example, the passage of steps. But, in general, it is preferable, for movement on flat ground, to block this free pivoting by an adjustable spacer 5b or a lock 9b blocking each module 3b to the frame 1b. When the 3b modules are locked to the chassis, the driver does not have to support the load as is the case with a wheelbarrow.

The frame 1b carries a backrest 21b formed by two uprights 211b provided with an easel to which the drawbar 12b is connected, the inclination of which can be adjusted by the joint 121b connecting the drawbar 12b to the easel carried by the folder. This articulation 121b, with a horizontal axis, makes it possible, for example, to choose and block the inclination of the drawbar 12b between a vertical position or close to a vertical position and a horizontal position or even an inclination below the horizontal orientation. , depending on the conditions of use of the carriage 100b.

The tubular drawbar 12b is provided at its end with a non-detailed handle 24b comprising control elements 241b for:

- activate forward or reverse and variable speed,

- lock the differential 82b,

- rotate the carriage on itself in the direction of rotation to the right or to the left.

NOMENCLATURE OF THE MAIN ELEMENTS

100 Trolley

1 chassis

2 charging stand

21 Auxiliary support

211 Auxiliary support shovel

24 Handle

241 Command

3 Crawler module

31 Front wheel

311 Front wheel axle

32 Rear wheel

321 Rear wheel axle

33 Caterpillar

35 Support wheel

4 Swivel

5 Adjustable spacer

511 Articulation to module

512 Chassis articulation

52 cylinder

521 First bottom

522 Second bottom

523 Cylinder extension

53 Plunger

531 Piston rod

532 Piston rod extension

54 Derivation

54 Controlled valve

541 Connection at the bottom 521

542 Connection at the bottom 522

Forward forward / forward direction

AR Reverse / reverse direction / stair climbing

F Stride

M On

Nm Stair nosing

R Ramp

S Floor area

SA Track module bearing surface

g Giron

h Step height M

H Handle height 24

α Angle of inclination of the load carrier relative to the running surface

β Slope angle

VV Vertical plane passing through joint 4

V1V1 Vertical plane passing through axis 311 of wheel 31

100a Motorized Hand Truck

1a Chassis

2a Charging stand

21a backrest / auxiliary support

211a Excavator

23a Stop device

24a Handle

3a Crawler module

31a Front wheel

311a Axis

312a Support

32a Rear wheel

321a Axis

37a Support

4a Pivot

41a Pivot axis

5a Adjustable spacer

511a Articulation fixing in adjustable spacer to the module

512a Articulation fixing the adjustable spacer to the frame

7a Articulation of support 2a to frame 1a

6a Chassis support

B1 Support lever arm 2a connected to frame 1a

B2 Support lever arm 2a connected to module 3a

100b Trolley

1b Chassis

11b Cross pivot bearing 4b

12b Drawbar

121b Drawbar joint

2b Charging Stand / Tray

21b Folder

211b Amount

24b Handle

241 Command

3b Crawler module

31b Drive wheel / front wheel

311b Front wheel axle

312b Drive wheel sprocket

32b Low rear wheel

321b Rear wheel axle

33b Caterpillar

34b High rear wheel

35b Transverse pivot bearing on module 3b

36b Ramp

4b Cross frame pivot

5b Adjustable spacer

511b Spacer joint

512b Spacer joint

8b Drive system

81b Engine

82b Differential

83b Shaft element

84b Transmission gear

9b Lock connecting frame 1b to each module 3b

Claims (17)

Load transport trolley including:
- a chassis (1) carried by two caterpillar modules (3), motorized and carrying a load support (2),
- the chassis (1) being pivotally connected to the caterpillar modules (3),
trolley characterized in that
- the chassis is connected to each caterpillar module (3) by an adjustable spacer (5). Trolley according to claim 1,
characterized in that
the spacer (5) is continuously adjustable. Trolley according to claim 1,
characterized in that
the load support (2) integral with the frame (1) comprises an auxiliary support (21) sliding and adjustable relative to the load support (2). Trolley according to claim 1,
characterized in that
it comprises a control (241) for adjusting the spacer (5) or the auxiliary support (21). Trolley according to claim 1,
characterized in that
the adjustable spacer is a hydraulic cylinder (52) comprising a piston (53) subdividing it into two chambers (C1, C2) whose sum of volumes is constant,
- a bypass (54) connecting the two bottoms (521, 522) of the cylinder (52) and provided with a controlled valve (55) to allow the exchange of liquid between the two chambers (C1, C2) by moving the piston (53) and blocking of the piston (53) by cutting off the passage of liquid in the bypass (54),
- the piston rod (531) and the cylinder (52) being connected to the chassis (1) and to the track modules (3), to adjust the spacing between the chassis (1) and the track modules (3). Trolley according to claim 5,
characterized in that
the piston (53) is carried by a piston rod (531) with an extension (532) which protrudes from the second chamber (C2) and projects into the extension (523) of the cylinder (52) beyond the second bedroom (C2). Trolley according to claim 1,
characterized in that
the module (3) is equipped with a support wheel (35) at least partially above the rear wheel (32) of the module (3) and projecting therefrom. Trolley (100a) according to any one of claims 1 to 7, in the form of a motorized hand truck carried by two caterpillar modules (3a),
characterized in that it comprises
- a frame (1a) housing the engine and its transmission, connected by a pivot (4a) to the two caterpillar modules (3a), free to pivot,
- each module (3a) is connected to the pivot (4a) by a bearing not coaxial with the wheels (31a, 32a) delimiting the bearing surface (SA) of the module (3a) and projecting onto this bearing surface (SA ),
- the load support (2a) is formed by a backrest (21a) ending at one end with a handle (24a) and at the other with a shovel (22a),
- the load support (2a) is connected by a joint (7a) to the frame (1a) at a point different from the pivot (4a) of the two modules (3a),
- a support (312a) of the module (3a) receives the articulation (5a) in the first tilting phase of the load support (2a) and,
- a support (6a) of the frame (1a) receives the load support (2a) at the end of the first phase of tilting to continue the tilting of the frame (1a) integral in support of the support (2a) around the pivot (4a ) modules (3a) and release the support (312a) of the joint (5a). Motorized hand truck according to claim 8,
characterized in that
the support (312a) is substantially vertical to the axis (311a) of the wheel (31a) of the modules (3a) on the load support side (2a). Motorized hand truck according to claim 8,
characterized in that
the support (6a) of the support (2a) on the frame (1a) surrounds the pivot (4a). Trolley according to any one of claims 1 to 10,
trolley characterized in that it comprises
- a frame (1b) provided with a transverse pivot (4b) located substantially vertical to the center of gravity (CG) of the load support (2b) loaded in a balanced manner,
- each module (3b) has a transverse bearing (36b) receiving the transverse pivot (4b) of the carriage (1b) in the vertical plane passing through the support surface (SA) of the caterpillar module (3b), and
- an adjustable spacer (5b) connecting the load support (2b) to each module (3b), blocking the two modules (3b) or releasing their pivoting relative to the load support (2b). Trolley according to claim 1,
characterized in that it comprises
a lock (9b) composed of two lugs each connected by a pin (82b) to the side of the frame (1b) facing a module (3b) and pivoting between a blocking position and a position for unlocking the pivoting of the module (3b) relative to the frame (1b), by hooking to the module (3b), the two legs being integrally connected in movement by a transverse rod. Trolley according to claim 1,
characterized in that
it comprises a drive system (8b) composed of an electric motor (81b) housed in the chassis (1b) and connected by a differential (82b) to two axle elements (83b) each connected to a module (3b ) through the bearing (4b) of the module to drive the drive wheel (31b) of the module (3b). Trolley according to claim 1,
characterized in that it comprises
a drive system formed by a motor integrated in each module (3b) and controlled by an electric differential. Trolley according to claim 1,
characterized in that
the caterpillar (33b) module (3b) forms a ramp (36b) at its rear end. Trolley according to claim 11,
characterized in that
the frame (1b) is provided with two uprights (121b) forming a backrest (21b) and carrying the drawbar (12b). Trolley according to claim 16,
characterized in that
the drawbar (12b) is connected by an articulation (121b) to the backrest (21b), this articulation locking in the selected position.