WO1994021507A1

WO1994021507A1 - Device providing monoeuvrability and sideslip-free directional steering stability for trolleys

Info

Publication number: WO1994021507A1
Application number: PCT/FR1994/000304
Authority: WO
Inventors: Robert Maloeuvre; Bernard Gallee
Original assignee: Robert Maloeuvre; Bernard Gallee
Priority date: 1993-03-22
Filing date: 1994-03-21
Publication date: 1994-09-29
Also published as: FR2703016A1; AU6285494A

Abstract

A device providing manoeuvrability and sideslip-free directional steering stability for trolleys (10), preferably but not exclusively trolleys with four wheels (14) swivelling freely about a swivel shaft (15), wherein at least the swivel shaft (15) of the rear wheels is tilted through β or α degrees so that said shaft and the respective pivotable plate (19) are at a caster angle which enables sideslip-free operation of the wheel. The device is particularly suitable for use in supermarket trolleys.

Description

DEVICE FOR MANEUVERABILITY AND ANTI-DRIFT TRACK TRACKING FOR HANDLING TROLLEYS

The invention relates to a device for maneuverability and anti-drift trajectory tracking for handling trucks, in particular those used for the transfer of goods or foodstuffs available to users in self-service. We already know from the French patent N ° 89 08745 in the names of the applicants a trajectory guidance device for basket-handling carts, of the type nestable in guarding stations, four-wheel carts of which at least two can be steered in all directions but also trolleys with four wheels that can be freely rotated in all directions.

This guide device is constituted by a fixed additional wheel carrier at the bottom part of the basket of the trolley or of its loading platform, this anti-drift wheel carrier being located, in the driving phase of the trolley, preferably at the plumb with the truck's center of gravity.

Thanks to this arrangement, the maneuverability of the trolley is considerably increased in maneuvers of the U-turn type, but also, especially when the trolley is loaded, the taking of curves with a small turning radius even on uneven ground. Although this device provides definite progress in driving comfort for trolley users, its distribution is still modest due to the additional cost due to the anti-drift wheel and its wheel carrier system. We also know from the French patent _T ° 92 I02I0 in the names of the applicants another anti-drift device for industrial trucks having a new architecture compared to the first cited patent, which significantly improves the anti-drift effect in the trajectory tracking chosen by the user. In this device, the anti drift effect of the rear wheels of the carriage is canceled in reverse and in the so-called pivoting maneuvers on site.

This improved device is entirely satisfactory, but its manufacturing cost is added to the cost of the trolley, which does not encourage, in times of economic recession, the generalization of such a device despite the comfort and safety of use provided to users. .

Yet another generation of anti-drift device is known which adjusts to the normally freely pivoting rear wheels. in all directions, in a manner which has been known per se for a very long time and to which is added a mechanism controlled by a roller applied temporarily on said wheel to immobilize it when the carriage is pushed in a straight line or in curves with a large radius at l 'using a locking finger which, engaged in a notch prevents any angular displacement of pivoting. The ^' locking finger maintaining the fixity of the rear wheels can be unlocked from its position of engagement with the stationary plate of the wheel'. The unlocking of the locking finger is obtained by the user by exerting a reversing maneuver, that is to say reversing on the carriage. It is understood that by this dis¬ position it gives freedom of pivoting to the rear wheels only when one performs the backward movement on the carriage. This technical solution leads to an additional manufacturing cost due to the presence of the locking and unlocking mechanism for the normally pivoting wheels, but also does not improve the maneuverability in very winding routes as long as the carriage is pushed, as long as the carriage is pushed in. forward the usually swiveling rear wheels are locked in orientation.

The present invention therefore aims to an anti drift device for handling carts which eliminates the adjonc¬ tion of an additional wheel as in the first two examples described but which also eliminates the locking mechanisms unlocking wheels usually freely pivoting third example, but also which improves the maneuverability and maneuverability both in so-called on-the-spot maneuvers but the maneuverability in a winding course with a small turning radius in all conditions of forward pushing and which still has an anti drift effect in a straight line and in curves canceling out in so-called on-site maneuvers without adding a mechanism.

To this end, the invention relates to a maneuverability and anti-drift trajectory tracking device for nestable handling trolleys, of the type preferably comprising four wheels pivoting freely at 3ό5 ° around a carrying axis connected in any manner. , preferably removable, at the trolley, characterized in that at least the bearing axis of the rear wheels PI, P2 of the trolley, but not limiting, is inclined by a value of B or L degrees to give this axis a hunting angle applying correspondingly to the pivoting plate of the wheel in such a way that on the one hand the free pivoting of the wheel is counteracted in proportion to the value of the load transported in the carriage when it is pushed in a straight line or on a journey sinuous, but on the other hand, the pivoting of the wheels remains authorized without the addition of a mechanism when the carriage is pulled in reverse or pivoted in place or pushed laterally.

According to an arrangement of the invention, the carrier axis and the associated pivoting plate can occupy two angular positions passing through a vertical plane, one inclined A corresponding to the hunting angle chosen for the anti-drift function, the other vertical A 'when the user moves the carriage backwards which completely cancels the anti-drift effect of the wheel which can pivot freely. when the carriage is pivoted in place or pushed laterally. Other characteristics and advantages will become apparent on reading the following detailed description of embodiments of the invention, given here by way of example and shown in the accompanying drawings in which: FIG. I is a view in elevation of a handling trolley equipped with a maneuverability device according to the invention. FIG. 2 is a top view of a carriage showing the kinematics of modification of orientation of the wheels during an on-site pivoting of a carriage. Figures 3 and 4 show in detail an alternative embodiment of the device.

FIG. 5 is a top view of the device equipped with stops for limiting the pivoting of the wheels.

According to the invention, as shown in FIG. I, the handling trolley, of the type which can be fitted into a guard station is designated by the general reference 10, this trolley is made up, in the example shown, of a chassis II, a carrying basket 12 or a platform, a pipe handle 13 for users. The carriage rests on four wheels 14, of the wheel type, with a carrying axle 15 extended by a fork 16 carrying the wheel, the horizontal wheel axle 17 being offset relative to the supporting axle 15 to constitute a wheel which aligns naturally parallel to the longitudinal axis of the carriage when the latter is pushed in a straight line.

There is provided, in a manner known per se an orientation plate 19 between the axis 15 e the fork 16 wheel carrier. It is understood that when a directional pivoting force FI, F2 is exerted on the carriage, for the rear wheels PI, P2, an angular movement occurs in the direction DI, D2, while the front wheels P3, P4 , are oriented in the directions D3, D4. This natural kinematics is taken advantage of in the maneuverability and trajectory tracking device described in more detail below.

At least the bearing axis 15 of the rear wheels PI, P2 of the carriage 10 is inclined by a value B or ou_ degrees in a vertical plane, preferably parallel to the longitudinal axis 20 of the carriage, which gives this axis an angle hunting B or CL, positive or negative. This hunting angle applies to the pivoting plate whose pivot plane passes from a horizontal position to an inclined position along Y - Y '.

Thanks to this arrangement, an anti-drift or anti-pivoting effect is obtained on the wheels PI, P2 which is proportional to the weight of the load transported in the carriage, the maximum anti-drift effect is obtained when the carriage is pushed in a straight line. This effect is also obtained on winding routes. When the trolley is free, therefore empty in a guard station, the wheels, under the action of a reverse gear, will pivot around the inclined axis 15, the anti-drift effect then being neutralized, the wheels pivot without torque when exerted, the carriage rises by a low value equal to the degree of inclination of the plates 19. It is then possible to easily carry out all the maneuvers said on site, recoil, pivoting, thrust transverse to the longitudinal axis 20.

As soon as a thrust action is exerted on the trolley, in straight or curved trajectory, the rear wheels are automatically realign with anti drift effect. In the exemplary embodiment, shown in FIGS. 3 and 4, the carrying axis 15 and the pivoting plate 19 can occupy two angular positions passing through a vertical plane, one inclined, shown in FIG. 3, and corresponding to the angle of chas¬ se B or Ct chosen for the anti drift function when the user pushes the carriage forward, in a straight line or in a curve. In the other position, obtained by recoil action on the carriage, the axis 15 passes into a vertical position which completely cancels the anti-drift effect on the wheel which can then pivot angularly freely over 3 ° 0 °. This position allows free movement of the carriage on site, such as pivoting, lateral thrusts. In this embodiment the support axis 15 pivots a vertical plane between its two angular positions between the walls 20 of a vertical guide by means of a horizontal axis 21 located between the ends of the support axis 15. L the carrier axis advantageously has an inclined plane 22 to allow its debate within the guide 20. Advantageously the thinned upper end of the axis 15 comprises an elastic element 23 which has the function of maintaining the vertical position axis 15 in its guide especially during pivoting maneuvers on the spot or lateral thrusts exerted on the carriage. The invention is not limited to the embodiments described above and shown for which other variants can be provided. Thus, for example for carriages with fixed rear wheels, they can be partially released from their fixed position, using an orientation plate as described in 19, the deflections as shown in FIG. 5, are limited by stops 24 located on either side of the natural position of alignment of the wheels.

Claims

1 °) - Maneuverability and anti-drift path tracking device for nestable handling carriages (10) of the type preferably comprising four wheels (14) pivoting freely at 365 ° around a load-bearing axis (15) connected any way, preferably removable, to the chassis (II) of the carriage, in which at least the bearing axis (15) of the rear wheels PI, P2 of the carriage, but not limited to, is inclined by a value of β or α degrees, to give this axis (15) a caster angle applying correspondingly to the pivoting plate (19) of the wheel so that on the one hand, the free tilting of the wheel either. thwarted in proportion to the value of the load transported in the carriage when it is pushed in a straight line or in sinuous course, but that on the other hand, the pivoting of the wheels remains authorized without addition of mechanism when the carriage is pulled in reverse or pivoted on the spot or pushed laterally, characterized in that the carrying axis (15) and the associated pivoting plate (19) can occupy two angular positions passing through a vertical plane, one inclined A corresponding to the hunting angle chosen for the anti-drift function, the other vertical A 'when the user moves the carriage back (10) which completely cancels the anti-drift effect of the wheel which can pivot freely when the carriage is swiveled in place or pushed laterally. 2 °) - Device according to claim 1 characterized in that the carrier axis (15) pivots in a vertical plane between its two angular positions A - A 'between the walls (20) of a vertical guide via a horizontal axis (21) located between the ends of the carrying axis, an elastic element (23) being preferably arranged in the vicinity of the free end of said axis (15) to hold it in position vertical in its guide for on-site pivoting or lateral pushing operations. 3 °) - Device according to claims 1 and 2 applied to trolleys with fixed rear wheels characterized in that the wheels are partially released from their fixed position, using an orientation plate (19) whose deflections on either side of the natural alignment position are limited by stops (24).