FR2759049A1 - Shopping trolley - Google Patents

Abstract

The shopping trolley comprises a lower chassis (1) which can be fitted into the rear of a similar trolley chassis. It has four directional wheels (3,4, 7, 8) and a transport basket with a manoeuvring handle at its upper rear end. The handle, which can be fitted into a similar handle of another trolley, is connected to the lower chassis by uprights. An intermediate pivot assembly composed of an intermediate wheel in contact with the ground swivels around a horizontal intermediate axis of rotation (131). The intermediate pivot also rotates about a vertical axis and is associated with selective locking means (50). This locking means enables either unlocking its free rotation around the vertical axis or its locking with the intermediate rotation axis in the fixed transverse direction. The locking means are activated by a lever and are aided by a return spring, automatically returning them into the locking position, and a manoeuvring part activated by the pressure of an adjacent trolley fitted into the trolley in order to unlock the pivot. The trolley which can be easily fitted into the rear of a similar trolley and by automatic neutralising of its intermediate pivot a stack of trolleys is easily manoeuvred.

Description

UNLOCKABLE PIVOT TROLLEY
The present invention relates to shopping carts, which are in particular made available to customers in self-service stores for transporting products and goods chosen by customers.

 The shopping carts usually used, for example such as that described in document FR-A-2 610 273, comprise a lower chassis comprising a set of two rear wheels swiveling around two horizontal rear axes of rotation, a set of two front wheels swiveling around two horizontal front axes of rotation themselves carried by respective individual supports pivotally mounted under the lower frame along two vertical pivot axes. The lower chassis has an interlocking shape, for example consisting of a front cross member and two slightly oblique side members progressively moving away from the front cross member towards the rear, allowing it to fit behind a similar lower frame of another carriage.

 A transport basket, with an operating handle at its upper rear end and with tilting rear wall, has a generally interlocking shape, for example frustoconical with small anterior base, allowing it to be nestled behind a similar basket of an anterior carriage. During an interlocking, the tilting rear wall of the front carriage allows the penetration of the rear carriage. The basket is connected to the lower chassis by rear side uprights.

 When such trolleys are small, their operation does not generally pose any particular problem.

 On the other hand, with larger trolleys, such as they tend to become widespread in big box stores, the operation of the trolley is much more difficult when the trolley is full of relatively heavy goods such as bottles water or other liquids. It is indeed difficult to rotate the carriage, by pushing the handle on one side and pulling the handle on the other, to change direction. For this, we have already imagined central pivot trolleys.

 For example, document EP-A-0 267 817 describes a shopping trolley with fixed central pivot, the lower chassis of which comprises two longitudinal side bars fixed at their front ends to two central bars, the rear ends of which are connected by a bar. transverse. An intermediate transverse tube joins the side and central bars. Steerable wheels are attached to the front and rear ends of the side bars, while two central wheels with fixed transverse axes are fitted under the rear ends of the central bars. The intermediate transverse tube limits the nesting of the carriages.

 Document GB-A-2 218 053 also teaches a structure with a fixed central pivot formed by two non-orientable lateral wheels held directly on the longitudinal members of the lower chassis.

 Document EP-A-0 513 839 teaches another structure with a fixed central pivot. The system lacks stability and is expensive.

 Document EP-A-0 403 202 teaches a central wheel trolley with a complex and expensive device for raising the central wheel out of contact with the ground by actuation of a lever. The device significantly reduces the possibilities of nesting of the carriages between them, and is not compatible with existing car parks.

 The problem proposed by the present invention is to design a new shopping trolley structure with an effective central pivot, having a good capacity for stacking the trolleys one behind the other, and ensuring neutralization of the central pivot for operating the batteries. of carts.

 Preferably, the invention also aims to design such a carriage structure which is compatible with existing car parks, thus avoiding premature renewal of existing carts not provided with the central pivot according to the invention.

 In addition, the invention aims to make automatic neutralization of the central pivot when the carriages are stacked, as well as the return to service of the central pivot as soon as the carriage is separated from the stack.

 To achieve these and other objects, a shopping trolley according to the invention comprises - a lower chassis having an interlocking shape allowing its nesting behind a similar lower chassis of another trolley, and comprising four orientable peripheral rolling wheels on the ground, - a transport basket, with an operating handle at its upper rear end, the basket having a generally interlocking shape allowing its nesting behind a basket similar to another carriage, the basket being connected to the lower chassis by uprights, - an intermediate pivot assembly, consisting of at least one intermediate wheel, disposed in contact with the ground under the lower chassis in an intermediate longitudinal position substantially along the median longitudinal plane of the carriage, said intermediate wheel journalling around an axis of horizontal intermediate rotation which in progress position ion of the carriage, is arranged in a fixed transverse orientation, - the intermediate pivot assembly being mounted for rotation about a vertical axis of the lower chassis and associated with selective locking means allowing either its unlocking in free rotation around said vertical axis , or its locking with the intermediate axis of rotation in said fixed transverse orientation.

 According to one embodiment, the locking means of the intermediate pivot assembly are actuable by a lever accessible by the user. As a variant, the locking means of the intermediate pivot assembly can be actuated by a tool such as a rod engaged by the user on an operating member.

 As an alternative or in addition, the locking means of the intermediate pivot assembly are urged by automatic return means returning them to the locking position, and by an operating member actuated by the pushing of an adjacent carriage fitted on said carriage. to bring the locking means to their unlocked position in the presence of said adjacent carriage.

 Other objects, characteristics and advantages of the present invention will emerge from the following description of particular embodiments, made in relation to the attached figures, among which: - Figure 1 illustrates, in top view, a traditional chassis structure lower shopping cart without intermediate pivot assembly - Figure 2 illustrates, in top view, a lower chassis structure according to an embodiment of the present invention - Figure 3 illustrates, in side view, the structure lower chassis according to the embodiment of Figure 2 - Figure 4 is a front view in cross section along the plane AA of Figure 7 - Figure 5 is a detail view from below in partial section along the plane BB of a pivot assembly structure in the embodiment of Figure 2 - Figure 6 is a detail view in longitudinal section from the side of the pivot assembly of Figure 5 - Figure 7 is a side view in longitudinal section of an automatic locking and unlocking mechanism of the pivot assembly according to an embodiment of the invention, in the locked position - FIG. 8 is a side view in longitudinal section of the mechanism of the Figure 7, in the unlocked position - Figures 9 and 10 illustrate in side view the state of the pivot assembly locking mechanism when two carriages are fully engaged - Figures 11 and 12 illustrate in side view the state of the pivot assembly locking mechanism when at least two carriages are engaged, tensioned link chain - Figure 13 illustrates in side view the state of the pivot assembly locking mechanism on an insulated carriage - Figures 14 to 17 illustrate , in top view, possible nesting configurations of different or similar carriages - Figure 18 is a top view illustrating a lower chassis structure according to another e embodiment of the invention; and FIG. 19 is a side view in longitudinal section on a larger scale of the front part of the chassis of FIG. 18.

 As illustrated in FIGS. 9 and 11, a shopping trolley 100 according to the invention comprises a lower frame 1 supporting a transport basket 2. The transport basket 2 comprises an operating handle 19 at its rear upper end, and a tilting rear wall 20, for example tilting about an upper horizontal axis 21 as illustrated by the arrow 122. The basket 2 has a generally interlocking shape, for example a frustoconical shape with small anterior base 22, the tilting rear wall 20 constituting the great base. In known manner, such a shape allows the nesting, in the basket 2, of a similar basket 202 of another carriage 200, by tilting of the tilting rear wall 20.

 The basket 2 is connected to the lower chassis 1 by rear lateral uprights such as the uprights 23 and 123.

 As illustrated in FIGS. 2 and 3, the lower chassis 1 is formed by two lateral longitudinal members 27 and 28 converging towards the front, the rear ends of which are separated from one another, and the front ends of which are connected to the moon. to the other by a V-shaped connecting structure 32 and an anterior thrust cross member 132. The lower chassis 1 comprises a set of at least two rear wheels 3 and 4 which can be oriented, swiveling around two rear horizontal axes of rotation 5 and 6, and a set of at least two front wheels 7 and 8 which can rotate around two front horizontal axes of rotation 9 and 10.

 The rear horizontal axes of rotation 5 and 6 are carried by two respective individual supports 11 and 12 pivotally mounted under the lower frame along two vertical pivot axes 13 and 14. Similarly, the front axes of rotation 9 and 10 are carried by two respective individual supports 15 and 16 allowing their pivoting under the lower chassis 1 along two vertical pivot axes 17 and 18.

 The lower chassis 1 itself has an interlocking wedge shape in top view (Figures 2 and 3), allowing it to fit behind a similar lower chassis of another carriage. The desired nesting rate can be obtained by choosing the angle of convergence of the lateral beams 27 and 28 of the lower chassis, and the width of said beams 27 and 28. At the end of nesting, the beams of the rear carriage bear against the side members of the front carriage.

 According to the invention, an intermediate pivot assembly 24 is disposed under the lower chassis 1 in an intermediate longitudinal position substantially along the median longitudinal plane I-I of the carriage.

 In the embodiment illustrated in FIGS. 2 and 3, the intermediate pivot assembly 24 comprises a single intermediate wheel 31, placed along the median longitudinal plane II of the carriage, and journalling around an horizontal intermediate axis of rotation 131 which, in normal rolling operation on the ground, is fixed in transverse orientation.

 The intermediate wheel 31 is carried at the top of the V-shaped connecting structure 32 formed of two generally horizontal oblique beams 33 and 34 connecting the intermediate pivot assembly 24 to the intermediate wheel 31 at the respective anterior ends of the two lateral side members 27 and 28 of the chassis lower 1. Preferably, the V-shaped connection structure 32 is slightly elastically deformable, by longitudinal bending of the oblique beams 33 and 34, to promote the elastic support of the intermediate wheel 31 on the ground.

 The intermediate wheel 31 is slightly lowered relative to the front wheels 7 and 8 and to the rear wheels 3 and 4, to form a privileged point of contact on the ground.

 By way of example of comparison, FIG. 1 represents, in top view, a lower chassis structure 300 of a traditional shopping cart. We find side rails 327 and 328 similar to beams 27 and 28, with two generally parallel rear sections and carrying two rear wheels 303 and 304 which can be oriented, connecting by two bent portions to anterior sections converging towards the front to the front ends. connected to each other by a front cross member 332 and a set of two front wheels 307 and 308 orientable. The traditional carriage has no intermediate pivot.

 The lower frame 1 according to the invention can advantageously be formed from a continuous monobloc bent profile. For example, as illustrated in FIGS. 2 and 3, the monobloc profile can be formed of two bars 25 and 26 offset vertically and connected to each other by spacers, such as the spacer 29.

 The V-shaped connecting structure 32 forms a central portion of lower chassis 1. Preferably, to improve the nesting capacities of the carriages one inside the other, the central portion of lower chassis 1 is lowered relative to the plane of the side rails 27 and 28, as best seen in FIG. 3. In this way, the lowered central portion of the lower chassis 1 can engage below the front crossmember 132 of the lower chassis of a traditional carriage or another trolley according to the invention which would be fitted behind the trolley considered. This ensures nesting compatibility between the carts according to the invention and traditional carts.

 For reasons of mechanical strength, the bars 25 and 26 are offset vertically and connected by vertical spacers 29.

 However, in the central portion of lower chassis 1, forming the V-shaped connection structure 32, the two bars 25 and 26 have posterior portions which become offset horizontally with respect to each other to produce a flat posterior structure which is thus lowered to the maximum.

 As indicated previously, in normal use of rolling on the ground, the intermediate axis of rotation 131 of the intermediate wheel 31 is fixed in transverse orientation. The wheel 31 thus constitutes a central pivot around which the user can pivot the carriage, the four peripheral wheels 3, 4, 7 and 8 being freely orientable around their vertical axes.

 However, according to the invention, the intermediate pivot 24 carrying the intermediate wheel 31 is mounted for rotation about a vertical axis 13 and is associated with selective locking means allowing either its locking with the intermediate axis of rotation 131 in said fixed transverse orientation, ie unlocking it in free rotation around the vertical axis 13.

 For this, in the embodiment illustrated in Figures 4 to 8, the intermediate pivot assembly 24 comprises a turret 40, integral with the caliper 41 carrying the axis 131 of the intermediate wheel 31, and pivotally mounted along the vertical axis 13 under the lower chassis 1. A housing 42 is secured to the rear ends of the oblique beams 33 and 34 of the V-shaped structure 32, and carries two upper 43 and lower 44 raceways on which roll balls such as the balls 45 and 46 on either side of a horizontal flange 47 of the turret 40. The turret 40 is retained on the housing 42 by a shaft 48.

 The turret 40 has a peripheral passage 49 in which a radial locking rod 50 can engage, constituting the selective locking means allowing either the locking of the turret 40 and of the intermediate pivot assembly 24 in the normal rolling position, or its unlocking for free pivoting around the vertical axis 13.

 The radial lock rod 50 is pushed back towards the turret 40 by a return spring 51. Thus, in the orientation of the fixed transverse intermediate axis of rotation 131, the return spring 51 causes the engagement of one end of the latch rod 50 in the peripheral passage 49 to prevent the rotation of the turret 40. In the orientations of the intermediate axis of rotation 131 other than the fixed transverse orientation, the return spring 51 causes the said spring to bear radially by sliding support end of the lock rod 50 against the cylindrical peripheral face 52 of the turret 40, allowing the turret 40 to pivot freely around the vertical axis 13.

 In the embodiment illustrated in the figures, the radial lock rod 50 is mounted in anteroposterior sliding on guides of the lower carriage frame, with its rear end 53 disposed opposite the turret 40 of intermediate pivot assembly 24, and with its front end 54 oriented towards the front end of the carriage.

For example, the latch rod 50 slides in rear guides 55 and 56 of the housing 42, and slides in an anterior guide 57 of the lower chassis structure.

 In FIGS. 7 and 8, for example, the front end of the latch rod 50 is free, overhanging beyond the front guide 57.

 More advantageously, in the variant of FIGS. 18 and 19, the front end of the latch rod 50 remains slidably permanently engaged in a tube 157 of longitudinal axis fixed to the front crosspiece 132. The length of the tube 157 is chosen greater than the distance between the two anterior 150 and posterior 250 extreme positions of the latch rod 50.

 According to a first embodiment of the invention, the lock rod 50 can be actuated by a lever accessible by the user.

For example, one can imagine a lever arranged in the vicinity of the operating handle 19, and connected by a cable to the lock rod 50.

 Preferably, according to the invention, the lock rod 50 is biased by automatic return means returning it to the locked position by the return spring 51, and is actuated by an operating member itself actuated by the push of 'An adjacent carriage fitted on the carriage considered to bring the latch rod 50 to its unlocked position in the presence of the adjacent carriage. The operating member is preferably actuated by the thrust of the lower chassis of a rear carriage fitted behind the carriage in question.

 For this, in the embodiment illustrated in the figures, the operating device comprises a slider 58 mounted with antero-posterior sliding on the lower frame 1 between a recoil position illustrated in FIG. 7 and an advanced position illustrated in FIG. 8. The slider 58 is biased towards its recoil position by a spring 59 engaged between the slider 58 and the latch rod 50. The spring 59 has a stiffness greater than that of the return spring 51 of the latch rod 50. The slide 58 has a rear support wall 160, arranged so that, when engaging a rear carriage, the front transverse stop 232 of the rear carriage comes to push the rear support wall 160 and the slide 58 towards the forward against the spring 59 and the return spring 51. At the start of the thrust stroke of the anterior transverse stop 232, the slider 58 moves forward, causing the latch rod 50 and by compressing the return spring 51, but without still compressing the spring 59, the rear end 53 of the latch rod 50 being quickly released from the passage 49 of the turret 40 for unlocking the pivot assembly intermediate 24 which can then pivot freely. After compression of the return spring 51, the thrust of the front transverse stop 232 of the rear carriage further displaces the slide 58 forwards, compressing the spring 59 but without driving the latch rod 50 which is retained by the return spring 51 fully compressed, or by a fixed stop.

 FIGS. 9 to 13 illustrate the advantage of the slide arrangement 58 and two springs 59 and 51. It is known that the shopping carts can be nested and retained one behind the other by a chain such as the chain 400. In FIG. 9, the chain 400 is relaxed, the carriages 100 and 200 being brought closer to one another, while, in FIG. 11, the chain 400 is tensioned, the carriages 100 and 200 being further apart. one of the other.

 In the close position of FIG. 9, the front transverse stop 232 of the rear carriage 200 pushes the slider 58 back to the front position, compressing the two springs 59 and 51 and moving the latch rod 50 forwards to unlock the pivot assembly intermediate of the front carriage 100. In the separated position of FIG. 11, chain 400 tensioned, as can be seen in FIG. 12, the slider 58 is slightly retracted from the advanced position of FIG. 10, and the spring 59 is slightly relaxed.

However, by the fact that the spring 59 has a greater stiffness than the return spring 51, the return spring 51 remains compressed and the latch rod 50 remains in the advanced position, to unlock the intermediate pivot 24. Thus, as long as the carriages are stacked, the anterior carriages such as the carriage 100 remain in the unlocked position of the intermediate pivot 24. Only the rear carriage 200 is possibly in the locked position of the intermediate pivot 24. It is then possible to provide that the locking or locking means unlocking of the intermediate pivot assembly of the rear carriage 200 can be actuated by a tool such as a rod engaged by the user on the operating member such as the slider 58. By a rod, the user can thus push the slider 58 in the anterior position, causing the intermediate pivot of the posterior carriage 200 to be unlocked.

 In the service position, as illustrated in FIG. 13, the springs 59 and 51 push the slide 58 and the lock rod 50 respectively backwards, causing the locking of the intermediate pivot assembly 24 as soon as the central wheel 31 is in a fixed transverse orientation position with its intermediate axis of rotation 131 oriented transversely.

 As seen in Figures 4, 7 and 8, the latch rod 50 has two successive elbows 60 and 61, respectively separating a rear section 62 carrying the return spring 51 and sliding in the guides 55 and 56, an intermediate section 63 carrying the spring 59, and a front section 64 sliding in the front guide 57. The rear section 62 is slightly lowered relative to the plane of the rear portions of the oblique beams 33 and 34, while the intermediate section 63 is substantially in the plane posterior portions of oblique beams 33 and 34, the anterior section 64 being raised and substantially in the plane of the lateral beams 27 and 28.

 These arrangements allow the carriages to be fitted one behind the other, while retaining freedom of pivoting of the peripheral wheels around their respective vertical axes. These nesting possibilities according to the invention are illustrated in Figures 14 to 17 in Figure 14, there is illustrated the nesting of three identical successive carriages according to the previously described embodiment of the present invention, comprising a front carriage 100 , an intermediate carriage 200, and a rear carriage 200a. These different sockets between four- or five-wheeled carriages are also made possible thanks to the particular position chosen for the front wheels 7 and 8 of the carriages according to the invention. This position is shown in Figures 2, 14 to 18.

 In Figure 15, there is illustrated the fitting of a front carriage 100 according to the invention, a traditional intermediate carriage 300, and a rear carriage 200 according to the invention.

 In Figure 16, there is illustrated the fitting of a front carriage 100 according to the invention, an intermediate carriage 200 according to the invention, and a traditional rear carriage 300.

 In Figure 17, there is illustrated the fitting of a traditional front carriage 300, an intermediate carriage 100 according to the invention, and a rear carriage 200 according to the invention.

 Thus, according to the invention, the central wheel 31 forming a pivot is mounted on an intermediate pivot assembly 24 pivoting around a vertical axis 13 which is locked in the user position and which is unlocked when parking, respecting the constraints. following additional - the mechanism does not interfere with the stacking of the carriages, - the intermediate pivot assembly 24 locks automatically when the trolley is taken in a parking lot, and unlocks automatically when the trolley is placed in the parking lot - the unlocking is operational whatever the tension of the chain connecting the carriages, - preferably, when stacking, it is the next carriage which unlocks the intermediate pivot of the preceding carriage; when the last cart in the stack is a four-wheel cart, all of the carts are unlocked; when the last carriage in the stack is an intermediate pivot carriage, the latter is not unlocked, and the unlocking can be obtained simply by hand with a tool, it being observed that unlocking the last carriage does not seem essential for handling a queue of stacked carts.

 Thus, in a stack of carts, they can be moved in all directions by technical service agents, and in particular in the transverse direction. On the other hand, when the carriages are independent, for use by the buyer in a store, the intermediate pivot is locked and facilitates the handling of the carriage by opposing the transverse movement of the pivot.

 The intermediate pivot carts according to the invention are compatible with traditional shopping carts with four steerable wheels or two front steerable wheels.

 The present invention is not limited to the embodiments which have been explicitly described, but it includes the various variants and generalizations thereof contained in the field of claims below.

Claims (10)

 1 - Shopping trolley, in particular for use by customers in self-service stores, comprising - a lower chassis (1) having an interlocking shape allowing its nesting behind a similar lower chassis of another trolley, and comprising four wheels peripherals (3, 4, 7, 8) orientable for rolling on the ground, - a transport basket (2), with an operating handle (19) at its upper rear end, the basket having a generally interlocking shape allowing it to be nested behind a basket similar to another carriage, the basket (2) being connected to the lower chassis (1) by uprights (23, 123), - an intermediate pivot assembly (24), consisting of at least one intermediate wheel ( 31), disposed in contact with the ground under the lower chassis (1) in an intermediate longitudinal position substantially along the median longitudinal plane (II) of the carriage, said intermediate wheel (31) rotating in an aut or of a horizontal intermediate axis of rotation (131) which, in the carriage advancing position, is arranged in a fixed transverse orientation, characterized in that - the intermediate pivot assembly (24) is rotatably mounted around a vertical axis (13) and associated with selective locking means (50) allowing either its unlocking in free rotation around said vertical axis (13), or its locking with the intermediate axis of rotation (131) in said fixed transverse orientation.  2 - Trolley according to claim 1, characterized in that the locking means of the intermediate pivot assembly (24) can be actuated by a lever accessible by the user.  3 - Trolley according to claim 1, characterized in that the locking means of the intermediate pivot assembly (24) can be actuated by a tool such as a rod engaged by the user on an operating member.  4 - Trolley according to any one of claims 1 to 3, characterized in that the locking means (50) of the intermediate pivot assembly (24) are biased by automatic return means (51) returning them to the position of locking, and by an operating member (58) actuated by the pushing of an adjacent carriage (200) fitted on said carriage (100) to bring the locking means (50) to their unlocked position in the presence of said adjacent carriage (200 ).  5 - Trolley according to claim 4, characterized in that the operating member (58) is actuated by the thrust of the lower chassis (1) of a rear carriage (200) fitted behind said carriage (100).  6 - Trolley according to any one of claims 1 to 5, characterized in that the intermediate pivot assembly (24) comprises a turret (40) pivoting along said vertical axis (13) under the lower frame (1) and comprising a peripheral passage (49) into which a locking rod (50) can engage radial locking means.  7 - Trolley according to claim 6, characterized in that the radial locking rod (50) is pushed back towards the turret (40) by a return spring (51) to bear radially against a cylindrical peripheral face (52) of turret (40) in the intermediate axis of rotation orientations (131) other than said fixed transverse orientation, and to engage in said peripheral passage (49) and prohibit the rotation of the turret (40) in said fixed transverse orientation of the intermediate axis of rotation (131).  8 - Trolley according to claim 7, characterized in that the radial locking rod (50) is mounted in antero-posterior sliding on guides (55-57) of the lower chassis (1) of the trolley, with its rear end (53 ) disposed opposite the turret (40) of an intermediate pivot assembly (24), and the operating device comprises a slide (58) with anteroposterior movement itself urged forward by an anterior portion (232) of lower chassis (1) of rear carriage (200) against a spring (59) and engaged on the radial lock rod (50) to drive it in translation during the front portion of its travel anteroposterior.  9 - Trolley according to any one of claims 1 to 8, characterized in that - the lower chassis (1) is formed by two lateral beams (27, 28) converging towards the front, the rear ends of which are separated from one another. the other and carry a set of at least two rear wheels (3, 4) which can be oriented, and the front ends of which are connected to each other by a connecting structure and carry a set of at least two wheels front (7, 8) orientable, - the intermediate pivot assembly (24) is carried by a lowered central portion of the lower chassis (1), so as to engage below the front crossmember (132, 232) of the chassis lower (1) of a traditional carriage (300) fitted behind said carriage (100), - the locking means comprise a radial locking rod (50) having a lowered rear section (62) connected by at least one elbow (60 , 61) to an anterior section (64) relie , Structure promoting the socket one behind the other carriages.  10 - Trolley according to claim 9, characterized in that the lowered central portion of the lower chassis (1) comprises a V-shaped structure (32) formed by two oblique beams (33, 34) generally horizontal connecting the intermediate pivot assembly (24 ) at the respective anterior ends of the two side rails (27, 28) of the lower chassis (1).