Charging technique for a shopping trolley

Abstract

One aspect of the present disclosure relates to a pushable trolley, in particular shopping trolley, having a contacting system. The contacting system comprises a first contact pair having at least two contact elements for a first connection pole of an electrical charging voltage and a second contact pair having at least two contact elements for a second connection pole of the electrical charging voltage. The first and the second contact pair are configured in such a way that, by pushing the pushable trolley into a second, structurally identical trolley having a second, structurally identical contacting system, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair establish electrically effective contact with a respective mating contact element of the second trolley. In addition, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair are designed and / or arranged in such a way that, at least during part of the pushing-in process, sliding and / or rolling contact is established between the contact elements and the mating contact elements.

Description

[0001] CHARGING TECHNOLOGY FOR A SHOPPING CART

[0002] 1. Field of the invention

[0003] The present invention generally relates to push carts, in particular "smart" / digitally equipped, manually pushable, possibly motor-assisted carts, such as those used for shopping in retail or wholesale stores, for picking items in a warehouse, or as panel carts in hardware stores. These carts may be equipped with a permanently or detachably installed tablet computer / smartphone or the like, or have a holder for a user's own smartphone or other smart device, either borrowed or owned by the user. In particular, the present invention relates to the field of shopping carts in supermarkets.

[0004] 2. Technical background

[0005] The tablet computer or, if applicable, the customer's own device is used to facilitate shopping by automatically or manually scanning the items placed in the shopping cart by the customer. For example, this can simplify the payment process, significantly reduce customer waiting times, and increase the effectiveness and efficiency of the retailer's checkout area. To achieve this, it must be ensured that the battery of the tablet computer or, if applicable, the customer's own device has sufficient power to ensure that the purchase is not interrupted due to a lack of power.

[0006] German patent application DE 10 2022 103520 Ai discloses a shopping cart in which the power supply is provided via a conventional deposit lock and chain attached to the handle of the cart in the shopping cart house, where the shopping carts are pushed together, usually overnight. The battery of the cart at the front of a row is charged using a special device permanently installed in the house. This device contains a powered plug that is inserted into a socket on the deposit lock of the first cart. The battery of the next shopping cart and the batteries of all other nested shopping carts are charged via a contact system integrated into the deposit lock, which also electrically connects the carts to one another via the chain. The disadvantage of this system is that the contact system becomes quite complex because the mechanical coupling also includes the electrical coupling.There is no guarantee that the system will function reliably for years to come, as customers often pull or tug on the shopping cart handle even though the cart is still mechanically connected via the deposit lock. This puts strain on both the mechanical components and the relatively sensitive electrical contacts, which can be damaged. Furthermore, the chain must be insulated, as customers can touch this part of the cart directly and need to be protected from electric shocks. Moreover, not every shopping cart has a chain. Many retail chains deliberately opt for shopping carts without a deposit lock or chain to save customers from having to bring a shopping cart token or coin with them. Many customers also have key fobs, which can be inserted into a deposit lock to open it and then immediately removed again.When returning the shopping cart, the customer doesn't have to close the deposit lock again because there's neither a chip nor a coin inside. This interrupts the flow of electricity. A solution using electronic deposit lock opening also presents a further hurdle for the customer when shopping, something many retailers want to avoid.

[0007] The European patent EP 3 252913 Bi describes a contacting system in which the contacts are arranged on the right and left outside of the handle bar of the shopping trolley and are functionally separated from the mechanical coupling of the trolleys to each other.

[0008] The disadvantage of this system is that the shopping cart building requires a relatively high level of technical and structural effort, as it requires two railings with rails and contact rails located within them, which accommodate the contacts on the right and left outer edges. These devices are also expensive and space-consuming. Customers are therefore required to carefully push their way into the contact rails. This can result in customers pinching their fingers if they are careless when pushing them in. Since the task of removing empty shopping carts is often carried out by children, who are naturally more careless than adults, this risk is further increased.

[0009] European patent application EP 3 644474 Ai discloses a system that charges shopping cart batteries without mechanical contact via induction surfaces attached to the sides of the cart. However, the counter surfaces must be installed separately for each shopping cart in the cart house, which requires a high level of technical effort and incurs high costs. The carts must also be precisely positioned; otherwise, the induction surfaces are too far apart or spaced unevenly from one another, making battery charging inefficient, expensive, and unsustainable. Therefore, rails must be installed in the floor of the cart houses, into which the carts must be precisely guided. These rails represent an additional technical and structural effort; they are potential tripping hazards and can be blocked by garbage. However, the willingness to clean up other people's garbage is generally quite low.

[0010] The object of the present invention is therefore to create a trolley, in particular a shopping trolley, that can be pushed manually or with motorized assistance. It has a contact system that is independent of the existence of a deposit lock, requires little technical infrastructure in the shopping trolley depot or at the respective stacking point of the trolleys, and does not present any tripping hazards or a risk of injury to the fingers of the customer or user when returning the shopping trolley. Summary of the Invention

[0011] The subject matter according to the invention with the features of claim i solves this problem, but can also be used for the other vehicles mentioned at the beginning.

[0012] The subclaims contain advantageous developments and improvements of the respective subject matter of the invention.

[0013] Hand-pushed trolleys according to the invention are, in particular, shopping trolleys, so-called cash & carry trolleys or rolling trolleys, transport trolleys, and panel trolleys that can be pushed into one another, also referred to as nestable, with or without motorized assistance from one or more drive wheels. Particularly in the form of shopping trolleys, they can be equipped with a shopping basket and with or without an additional shelf for goods located beneath the shopping basket. The present invention is described below based on its use for shopping trolleys, along with its features and advantages, which are at least largely transferable to the other trolley types mentioned.

[0014] A first aspect of the present invention relates to a pushable cart, in particular a shopping cart, which is equipped with a contacting system. The contacting system comprises a first contact pair with at least two contact elements for a first connection pole of an electrical charging voltage and a second contact pair with at least two contact elements for a second connection pole of the electrical charging voltage. The first and second contact pairs are designed such that when the pushable cart is pushed into a second, identically constructed cart with a second, identically constructed contacting system, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair establishes an electrically effective contact with a respective counter-contact element of the second cart.

[0015] The contact system thus comprises a plurality of contact elements assigned to the corresponding contact pairs. In particular, the contact elements of a contact pair are related to the connection pole belonging to the contact pair. The counter contact elements are part of the contact system of the second, identically constructed trolley, so that electrically effective contact only occurs between contact elements that relate to the same connection polarity. Since the contact pairs and the corresponding contact elements are configured in such a way that electrical contact with a respective counter contact element of the second trolley is created when the pushable trolley is pushed into a second, identically constructed pushable trolley, this contact system is independent of the existence of a deposit lock. Nevertheless, a conventional deposit lock with a chain can be used.

[0016] Furthermore, the contacting system is based solely on establishing contact between the contact pairs and corresponding mating contact pairs, so minimal technical infrastructure is required in the shopping cart building or at the respective cart stacking point. In particular, no guide rails are required in the floor, as the carts are simply pushed into each other as usual. Thus, the present invention eliminates tripping hazards in the shopping cart building. Furthermore, the risk of injury to the customer's or user's fingers when returning the shopping cart is minimized, as no railings with potentially hazardous contact rails are required.This is due to the fact that the electrically active contacts can be placed relatively far forward on the chassis or basket of the shopping cart, or at other locations outside the operating range of the cart. They are reliably far away from the customer when the carts are stacked together, and they are not exposed to contact even in the case of clumsy behavior (e.g., children). These are significant advantages, because tripping hazards and possible injuries can often lead to liability issues. Furthermore, contact between the contact elements and the counter-contact elements is established automatically when the carts are stacked together, so no additional action is required on the part of the customer.Furthermore, no inductively effective contact surfaces are necessary in the house, because the contacting system according to the invention can be based on touching contacts, and the cars can each charge themselves on the contact elements of the car in front of it.

[0017] In addition, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair can be designed and / or arranged such that a sliding and / or rolling contact is established between the contact elements and the counter-contact elements at least during part of the insertion process and / or a stationary contact is established when the contact elements are fully inserted.

[0018] If contact is made between the contact elements and the counter contact elements during part of the insertion process, contact between the corresponding contact systems is guaranteed, even if the trolleys are not in the fully inserted position. This means that the electrical charging voltage is also transmitted to trolleys which have not been fully inserted by the customer or user upon return. If the trolley is not fully inserted, this can be due, among other things, to an insufficiently forceful insertion process and / or a customer in a hurry. The use of sliding and / or rolling contacts minimizes the force required during the insertion process, maximizes the probability that the trolley will be returned in the fully inserted position, and optimizes the transmission of the charging voltage to all trolleys nested in a row.The fixed contact established in the fully retracted position allows the charging voltage to be transmitted to the pushable trolley for the entire period in which the trolley is in the fully retracted position, i.e., during a period in which the trolley is not actively used by the customer. This leads to efficient allocation of the trolley's usage time. The part of the retraction process in which contact is established between the contact elements and the counter-contact elements is preferably located in the second half of the retraction process and immediately precedes the establishment of the fixed contact.

[0019] However, it is emphasized that a sliding, rolling and / or stationary contact as described above is not mandatory, and other embodiments described herein may do without this aspect.

[0020] In particular, the contacting system can be configured to supply power to the pushable trolley, preferably to supply power to a battery of the pushable trolley and / or an electrical device connected to the battery.

[0021] The first and second connection terminals of the electrical charging voltage can be used to charge a battery belonging to the pushable cart. This battery can be mounted on the cart and used to power an electrical, power-consuming device connected to the battery. This device can be permanently connected to the shopping cart or a customer-owned or loaned device that can be reversibly coupled to the shopping cart, e.g., a tablet computer, smartphone, and / or barcode scanner. Alternatively or additionally, the battery can be used to operate a drive motor for the cart.

[0022] In particular, it is primarily irrelevant which power-consuming device the contact system according to the invention is used for, as it can be used for any power-consuming device present on the trolley. From today's perspective, all types of "smart devices" such as tablet computers, mobile phones, etc. are particularly suitable, but also trolleys that are not equipped with these smart devices, where only the battery for an electric drive motor for one or more wheels is present on the trolley and is charged according to the invention. The contact system is part of the electrical system on the shopping trolley. Other components are connecting cables, if necessary.with plug-in and / or soldered contacts that lead from the contact elements to a battery and / or to a tablet computer and / or to a charging or storage cradle for a customer's own smartphone that may be additionally located on the handle or basket of the shopping cart, if charging the smartphone is offered as a free service or the customer uses a shopping app that is intended to support the purchasing process in some way.

[0023] Furthermore, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair can be configured such that they each serve as a counter-contact element for a third, identically constructed carriage when the third, identically constructed carriage is inserted into the carriage. Thus, if two or more sliding carriages are nested in series, the contact elements of the respective contact pairs configured as counter-contact elements effectively allow continuous contacting of all carriages nested in series. Thus, the electrical charging voltage can be transferred from one carriage to the next.

[0024] Additionally or alternatively, it may be a cart that can be pushed manually or with motor assistance, in particular a shopping cart, with a battery for operating a power-consuming device that is permanently connected to the shopping cart, or a customer-owned device or one that is loaned to the customer and can be reversibly coupled to the shopping cart, or for operating a drive motor for the cart, wherein the shopping cart has a contact system that is designed to supply the battery with power by contacting it with an identical contact system of another cart that is already supplied with power, wherein the contact system of the cart has at least one pair of contacts for a first connection pole of an electrical charging voltage and at least one pair of contacts for a second connection pole of the charging voltage,wherein at least two contact elements of a contact pair are each conductively connected to one another, and wherein at least one of the at least two contact elements is configured to establish a mechanically and electrically effective contact with a counter-contact element of another carriage having an identical contact system when the carriage is pushed into the other carriage from behind, wherein the contact elements and the counter-contact elements are designed and arranged such that they already create a sliding or rolling contact during the pushing-in process, which remains as a stationary contact when fully pushed in.

[0025] The charging voltage is preferably a direct voltage in the low voltage range below 24 volts.

[0026] Preferably, exactly two contact elements are provided per contact pair and terminal pole. Despite the term "contact pair," a contact pair can optionally have more than two contact elements.

[0027] According to the invention, the contact elements of a contact pair are provided at such locations on the chassis, on storage surfaces or on a possibly present shopping basket of the trolley, which, when a trolley is pushed into another trolley in front of it, approach each other in a sufficiently predictable manner so closely that the contact elements and the associated counter-contact elements reliably form the desired electrical contact and / or a mechanically effective contact with each other.

[0028] In the following, some preferred mounting locations for the contact elements are explained, which are particularly suitable for the formation of sliding contacts in which an exemplary contact directed from the inside outwards or a contact directed from the bottom upwards is created.

[0029] In some embodiments, the first and / or second contact pair may be attached directly to the pushable carriage. For example, the first and / or second contact pair may directly contact and / or be connected to at least a portion of the pushable carriage. For example, at least one of the two contact elements of the first contact pair may be attached directly to the pushable carriage. Additionally or alternatively, at least one of the two contact elements of the second contact pair may be attached directly to the pushable carriage. Direct attachment to the pushable carriage may include there being substantially no spacing between at least a portion of the pushable carriage and the first and / or second contact pair.Substantially no spacing can comprise a distance between the at least part of the pushable carriage and the first and / or second contact pair being less than 1 cm, preferably less than 0.5 cm, more preferably less than 0.2 cm, most preferably less than 0.1 cm. In other words, the first and / or the second contact pair, in particular at least one of the contact elements of the first and / or second contact pair, can bear against at least part of the pushable carriage. For example, the first and / or second contact pair can bear against a chassis of the pushable carriage. Alternatively, or additionally, the first and / or second contact pair can bear against a shopping basket and / or a storage level of the pushable carriage.

[0030] In general, the contacting system can be attached to the pushable cart such that at least part of the contacting system is located below a handlebar of the pushable cart. An arrangement below a handlebar of the pushable cart can include the at least part of the contacting system being located below a (horizontal) plane defined by the handlebar. For example, at least part of the first contact pair and / or at least part of the second contact pair can be arranged below the handlebar of the pushable cart. In particular, at least one of the contact elements of the first and / or second contact pair can be arranged below the handlebar.

[0031] In certain embodiments of the sliding carriage, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair can be directed toward the inside of the sliding carriage. Furthermore, at least one of the contact elements of the first contact pair and / or at least one of the contact elements of the second contact pair can be directed toward the outside of the sliding carriage, wherein the contact element directed toward the outside of the sliding carriage is conductively connected to the contact element of the respective contact pair directed toward the inside of the sliding carriage.

[0032] The outward-facing contact elements serve to make contact with the second, identically constructed carriage, whereby the outward-facing contact elements come into contact with the inward-facing contact elements of the second carriage. The inward-facing contact elements of the carriage can further form an electrically effective contact with the outward-facing contact elements of a third, identically constructed carriage, which is inserted into the carriage in a nesting manner. The conductive connection between the inward-facing and outward-facing contact elements serves to transmit the electrical charging voltage from the second, identically constructed carriage to the third, identically constructed carriage.

[0033] The contact elements of the first contact pair can be mounted on a left side of the carriage, preferably on a chassis of the carriage, and / or the contact elements of the second contact pair can be mounted on a right side of the carriage, preferably on the chassis. Alternatively or additionally, the contact elements of the first contact pair can be mounted on a left front edge of the carriage, preferably on the chassis of the carriage, and / or the contact elements of the second contact pair can be mounted on a right front edge of the carriage, preferably on the chassis.

[0034] The contacting system can have a first, outwardly directed contact element and an inwardly directed second contact element as a contact pair on a left and a right outer side and / or on a left or right front edge of the chassis or the shopping cart, wherein the contact elements of one side are each conductively connected to one another.

[0035] In general, an outwardly directed contact element can be oriented such that a contact surface of the contact element is directed outwards. For example, a normal vector perpendicular to the contact surface of the contact element can be directed outwards. In particular, an outwardly directed contact element can comprise a laterally outwardly directed contact element. Additionally, or alternatively, an inwardly directed contact element can be oriented such that a contact surface of the contact element is directed inwards. For example, a normal vector perpendicular to the contact surface of the contact element can be directed inwards. In particular, an inwardly directed contact element can comprise a laterally inwardly directed contact element.

[0036] Under normal circumstances, the outer sides of the chassis or basket, located to the right and left in the direction of travel, and their respective inner sides always come so close to each other during nesting that contact is reliably achieved with the contact elements described below. <see previous figures> Furthermore, the contact elements facing the outside of the pushable trolley can each be configured to extend around a front edge of the trolley, so that they form part of a left or right side and part of a front side of the chassis and / or a basket of the trolley.

[0037] If the outward-facing contact elements are each designed to go around the front edge of the lower frame member or basket, so that they form part of the outside and part of the front of the chassis member or basket, the advantage is that the contact is particularly reliable, especially when the carriages are not pushed completely parallel into one another during nesting.

[0038] In certain embodiments of the pushable carriage, the first and second contact pairs can be arranged such that at least one of the contact elements of the first contact pair and / or at least one of the contact elements of the second contact pair is directed upwards, and at least one of the contact elements of the first contact pair and / or at least one of the contact elements of the second contact pair is directed downwards. The contact elements of a contact pair are each conductively connected to one another.

[0039] Furthermore, the pushable trolley can have a, preferably pivotable, storage level, wherein the first and / or second contact pair are arranged on the storage level. Alternatively or additionally, the trolley can have a shopping basket, wherein the first and / or second contact pair are arranged on the shopping basket.

[0040] The contact system can – if, for example, a pivoting lower shelf is present – ​​comprise two contact pairs mounted at a sufficient lateral distance from each other, namely a first, upward-facing contact element and a second, downward-facing contact element, with the contact elements of each pair being conductively connected to each other. This contact system can be advantageously used not only for typical "plate trolleys," but also for shopping carts, where the pivoting lower shelf is located below the shopping cart.

[0041] As an alternative to or in combination with one of the two attachments described above, if a shopping cart is present, the contacting system can have two contact pairs mounted there, e.g., at the basket base, with sufficient lateral spacing from one another, each contact pair having a first, upward-facing contact element and a second, downward-facing contact element, the contact elements of a pair being conductively connected to one another. Here, too, the underside of the basket base of the rolling-in cart comes sufficiently close to the top side of the basket base of the cart in front during nesting, both vertically and in its right-left orientation.

[0042] Furthermore, at least one of the contact elements of the pushable carriage can have a contact surface, preferably a contact strip with a predetermined length and width.

[0043] For example, in the case of contact directed from the inside outwards, the outwards-facing contact elements can advantageously each be designed as a flat contact strip with a predetermined length and width, whereby the length and width should be adapted to the specific installation location. The contact strips are preferably attached to the lower frame of the shopping trolley, to which the holders for the trolley's wheels are also attached. These are often bars with a rectangular cross-section, an external lateral height of around 30 mm and a hollow interior. In this case, the outwards-facing contact element would preferably be a strip less than 30 mm wide and approximately 15 cm long if attached purely laterally, and preferably 20 cm long if the contact strip is continuous along the side of the bar and at the front of the bar. These dimensions are to be understood as examples.For example, contact surfaces can generally be provided with a width of at least 2 mm, at least 5 mm, and / or at most 20 mm, or at most 30 mm. A length can generally be at least 2 cm, at least 5 cm, at least 15 cm, or at least 20 cm.

[0044] If the outward-facing contact elements are attached to the shopping cart, they can have similar length and width dimensions. They are then best placed near the bottom of the cart to minimize interference with the mating contact elements inside the cart.

[0045] In certain embodiments of the pushable carriage, at least one section of at least one of the contact elements of the first contact pair can be flexible and / or at least one section of at least one of the contact elements of the second contact pair can be flexible, such that the at least one flexible section exerts permanent pressure on the respective counter-contact element in the at least partially inserted state. The at least one flexible section is preferably directed inward and / or downward.

[0046] This creates the advantage of reliable and robust contact, which is present even if the trolley is not parked perfectly symmetrically or not fully pushed forward in the row of trolleys. The flexibility can be achieved in a variety of ways depending on the shape used, material thickness and size of the inward-facing contact elements. If elongated strips are also used as the shape, which have a certain degree of rigidity and robustness due to the material, then the flexibility can be advantageously achieved by firmly attaching one end of the strip to the pole or basket, and allowing the remaining part of the contact strip to extend freely overhanging at the same height further inwards. The inward-projecting end section is preferably bent outwards in a round shape to prevent it from causing scratching contact on the outward-facing mating contact element.A sliding contact when pushed together is preferred. If the inner contact element is less rigid but also has an elongated structure, it can also be attached to a second point on the beam. Semi-oval or oval shapes are suitable in this case, which are pressed into a more elongated shape when pushed together. The advantage is that such a closed shape is more robust against vandalism because it cannot be bent as easily and therefore does not lose its flexibility.

[0047] Alternatively, or in combination with the material's inherent flexibility, flexibility can also be achieved through suitable spring elements mounted between the contact element and the frame beam or basket, preferably secured on both sides. Springs, clips, and buffers made of plastic or rubber are advantageously used in this case. Relatively strong, non-corrosive pairs of flat magnets can also be mounted between the beam or basket and the contact element in such a way that they repel each other and press the contact element against the mating contact element.

[0048] With bottom-up contact on the basket base or on the pivoting lower product storage area, the upward-facing contact elements are located in an area where goods can be placed. Therefore, the upward-facing contact elements are advantageously designed as contact strips with a predetermined length and width, approximately as described above, and the edges of the contact elements do not protrude upward, thus eliminating any risk of injury to the customer. The same principles apply to the downward-facing contact elements on the underside of the basket base or on the underside of the lower, pivoting storage area as previously explained for the inward-facing contact elements.They are either designed to be flexible due to their material properties or are constructed using a spring or a magnet with a certain restoring force, so that a sliding contact and a permanent restoring contact are created in the fully inserted position.

[0049] The contact elements can be made of an electrically conductive, homogeneous material that is as corrosion-resistant as possible and has a low tendency to break due to its repeated bending. Possible materials include stainless steel, preferably chrome-plated, galvanized or chrome-plated copper, or aluminum. However, composite materials can also be used, preferably a plastic carrier that provides flexibility and a conductive layer of a suitable material applied to it. The connection can be mechanical, for example, with rivets or screws, or it can be adhesively bonded.

[0050] The contact elements are attached to the chassis beam using a permanent, low-vulnerability connection such as adhesive bonding, a screw connection that prevents loosening, or welding, if appropriate. All of these connections should ensure a secure position of the contact elements without any risk of the contact element swinging loosely. The connection must ensure that no charging current flows from the contact element into the metal of the frame beam.

[0051] The contact element preferably has an extension made of the same material as the shopping cart, with which it can be inserted through an opening in the frame member or in a cable duct on the shopping cart. This has the advantage that an electrically effective connection of the extension to a cable is located inside the member or the cable duct by means of a plug connection or as a soldering point and is thus protected from external access and from the effects of the weather. The pushable cart can comprise a system for maintaining contact, wherein the system for maintaining contact comprises at least a first and at least one second system element such that a positive connection is established between the at least one first system element of the cart and a second counter system element of the second, identically constructed cart when the second cart is pushed into the first cart and the electrically effective contact is established in the process.

[0052] Preferably, a contact-maintaining system is provided on a chassis or a cart. Such a contact-maintaining system largely prevents an electrical contact, once established between two carts in a row during nesting, from being broken again by the removal of the rearmost cart in the row.

[0053] Furthermore, the pushable carriage can have a chassis with at least one beam, wherein a male system element is provided on an inner side of the beam and a female system element is provided on an outer side of the beam.

[0054] Preferably, the form fit is achieved by providing a male system element on the inside of a chassis pillar and a matching female system element on the outside of the pillar. This has the advantage that the outer contour of the trolley is not altered by protruding individual parts that could cause collisions with customers.

[0055] Furthermore, the system for maintaining contact can be provided by shaping contact elements that fit together and are in contact with each other.

[0056] The contact-holding system can be mounted on the shopping cart independently of the contact-holding system. It can also be integrated into the contact-holding system, as follows:

[0057] The contact elements then have a shape that ensures that after the trolley has been pushed into the trolley in front of it, the newly pushed trolley remains in contact. Accidental rolling back and thus a loss of the electrical contact is therefore preferably prevented by a positive connection between the two contacting contact elements. The positive connection can be created, for example, by a corresponding, gentle indentation in one contact element, into which a corresponding bulge in the other contact element engages upon contact. On the other hand, the positive connection should be easy to overcome when the next customer retrieves the shopping trolley. Both of these can be achieved by the relatively gentle design of the indentation and bulge as well as by the contact elements being sufficiently rigid.

[0058] Alternatively, the system for maintaining mechanical contact can be achieved independently of the electrical contact by a magnetically induced force connection between one or two pairs of magnets, one attached to the front of the chassis's front beam and the other to the rear of a cross beam located slightly behind it, which is already present on the trolley. This creates a defined position in which one trolley is pushed into another to the maximum extent. The magnetic force should be adjusted so that the trolley is secured against rolling away, but can also be pulled towards the customer without excessive resistance.

[0059] In certain embodiments, the pushable trolley can include a power connection that is electrically connected to the contacting system. Preferably, the trolley has a power connection, e.g., a DC connection, in the form of a plug that is electrically connected to the contacting system, as described above. It can be used after business hours for the last trolley in the row of trolleys if a faulty contact occurs somewhere within the row, by connecting a supply cable belonging to the trolley housing with a live socket to the plug of the last trolley. In this way, the rear trolleys are at least supplied with power until the faulty contact occurs.

[0060] According to a further aspect, the present invention comprises a device for inserting into a rearmost carriage of a nested row of pushable carriages, wherein the device has a contacting system. The contacting system of the device contains contact elements such that, by inserting the device into a pushable carriage according to the invention, electrical contact can be established with respective counter-contact elements of the pushable carriage according to the invention.

[0061] The device according to the invention can further comprise a power connector that is conductively connected to the contacting system. The device can be inserted into the rearmost trolley of a nested row of push-to-use trolleys after the store closes or when generally needed, with the power connector being connected to a corresponding power source or voltage source. This allows the trolleys nested in series to be supplied with power from both sides, i.e., from the front and rear. This can not only speed up the charging process itself, but also minimizes the risk of some of the trolleys nested in series not being charged if no electrically conductive contact has been established between two trolleys in the row.

[0062] The present invention further comprises a docking station configured to supply power to a foremost, push-along cart nested in a row. The docking station preferably has a power connection that can be connected to a power grid. In certain embodiments, the docking station is a permanently installed element, for example, in and / or on a wall, on the floor, or the docking station is part of a cart housing. Alternatively, the docking station can also be portable, so that it can be used in locations where push-along carts have been nested in a row. The docking station comprises a contacting system, wherein the contacting system contains contact elements such that by pushing the push-along cart according to the invention toward and / or into the docking station, electrical contact can be established with respective counter-contact elements of the push-along cart according to the invention.The electrical contact established between the docking station and the pushable trolley according to the invention allows the trolley to be supplied with power, preferably a battery connected to the trolley being supplied with power.

[0063] According to a further aspect, the present invention comprises a contacting system for mounting on a push-to-use cart, e.g., a cart described herein. This contacting system comprises a first contact pair with at least two contact elements for a first connection pole of an electrical charging voltage and a second contact pair with at least two contact elements for a second connection pole of the electrical charging voltage.The first and the second contact pair are arranged in such a way that the first and the second contact pair each have at least two contact elements and, by means of a sliding operation of the sliding carriage into a second, identical carriage with a second, identical contacting system, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair establishes an electrically effective contact with a respective counter-contact element of the second carriage.

[0064] Furthermore, the present invention comprises a retrofit kit for a pushable trolley (as described herein), in particular a shopping trolley, with the contacting system according to the invention.

[0065] The retrofit kit according to the invention enables the cost-effective integration of push carts without a contact system into the corresponding charging system of push carts with the contact system according to the invention. Push carts without a contact system can, for example, be older existing carts in a store. In particular, the retrofit kit allows for quick and efficient repair of push carts.

[0066] The retrofit kit and / or the (separate) contacting system may be designed as described herein with respect to a contacting system already mounted on the vehicle.

[0067] According to a further aspect of the present invention, the shopping cart according to the invention can be used in conjunction with a charging logic system. This charging logic can be used to coordinate the charging current of the shopping carts connected in series and can preferably be used in a supermarket. The charging logic can be software-based and / or hardware-based.

[0068] In certain embodiments, the charging logic comprises a control unit located on the trolley. By means of this control unit, the trolley can, for example, set the charging current to be consumed. The control unit can have at least one processor and / or microcontroller and / or at least one storage medium, wherein at least one processor and / or microcontroller can be operatively connected to at least one storage medium. The storage medium can contain a predetermined charging configuration and / or an algorithm which is set up for the coordination and / or regulation of the charging current and is executed accordingly by the processor (or microcontroller). The predetermined charging configuration can be fixed in such a way that the trolley can control or regulate the charging current autonomously, i.e., the trolley does not rely on any external, additional data and / or commands for the control or regulation.In further embodiments, the charging configuration can depend at least partially on the registration of a third, identically constructed car nested in the car. If the car registers the third car, the car can adjust the charging configuration such that, thanks to the contact system, the third car is also still supplied with sufficient power. This sufficient power supply to the third car can lead to a reduction in the power supply to the car. In a preferred embodiment, the car therefore draws the maximum available amount of charging current if no third car is registered.

[0069] In general, the pushable cart can be connected to a backend permanently, at least during the charging process, via at least one docking station using a wireless transmission method. The pushable cart and / or the docking station can be equipped with a corresponding interface to establish the connection to the backend. The wireless transmission method can be a WLAN connection, for example. The backend can be implemented on a computer belonging to the supermarket and / or in a cloud solution. Each of the shopping carts can send data to the backend using the wireless transmission method. This data can be shopping cart-specific and can include, for example, at least the current battery level of the respective shopping cart. Furthermore, the data can include a temperature.The backend can collect and summarize the data received from the shopping carts and / or create a charging prioritization for the nested shopping carts. The charging prioritization shows, for example, which shopping carts need to be charged most urgently and / or which do not. The backend can send the charging prioritization back to the shopping carts, which can then determine their corresponding charging prioritization, e.g., whether the shopping cart should be charged or not and / or the charging voltage or charging current available to the shopping cart. The shopping carts themselves can control the consumption of charging current according to the charging prioritization. This control can include the consumption of charging current from the series connection as well as the passing of the charging current to the nested following cart.

[0070] As already explained, during the charging process the shopping carts can be in contact with at least one docking station, which supplies the nested shopping carts with power. This leads to the shopping carts at the back of the row being used more frequently than the shopping carts at the front. Consequently, the shopping carts at the back generally have a lower battery level and should therefore be prioritized for charging in order to enable the battery to be charged as quickly as possible. If the battery level of the rear carts is below a threshold, the backend can configure the charging prioritization such that all shopping carts with a battery level above the threshold receive no charging current and the rear carts (e.g. two, three or four) below the threshold receive the maximum possible charging current. The threshold can be set to a maximum of 20% of the maximum battery level, preferably a maximum of 40% of the maximum battery level.

[0071] Furthermore, at least one of the shopping carts can be equipped with a temperature sensor such that it sends temperature data to the backend. The temperature data can be transmitted to the backend together with the battery level data. Based on the received temperature data, the backend can determine a temperature, which can be the minimum, the maximum, the mean, the median, or a function of the received temperature data. If this temperature is below a threshold, the backend can inform the shopping carts that they should not draw any charging current. The threshold can be at least 10°C, preferably at least 5°C, since at such temperatures the battery could be damaged during the charging process. Alternatively or additionally, there can also be another, stationary thermometer that is not attached to one of the shopping carts.

[0072] In addition, the backend can also send data to the shopping carts which includes a time. The time can include the time at the time the time is sent, the date and / or the day of the week, whereby the time can refer to the time at the location of the supermarket. Furthermore, the time can include the closing time of the supermarket. The time signal can be sent by the backend continuously and / or at intervals. For example, the time signal can be sent at least every 10 minutes, preferably at least every 20 minutes. Furthermore, the time signal can be sent periodically. If the time is in a time window before the closing time of the supermarket, this can lead to a change in the configuration of the charge level LEDs and / or contact status LEDs described herein. The time window can, for example, include a period of at least 30 minutes, preferably at least 15 minutes.In a first configuration, which can be active during shopping operations, the charge level LEDs are either off or light up green to signal to the customer that the corresponding shopping cart is ready for use. In a second configuration, which can be activated by a time signal, the charge level LEDs can be set up to indicate whether the battery of the corresponding shopping cart is charging. For example, the charge level LEDs can light up red if the shopping cart is connected to the power grid. This display technology allows a supermarket employee to directly see whether all the carts nested in a row are supplied with power. In particular, the employee can immediately identify an interruption and / or defect. In other examples, the configurations mentioned can also be used independently of one another and, for example, permanently.

[0073] Additionally or alternatively, the shopping carts can also exchange data directly with each other without involving a backend. In this case, each shopping cart can receive data from other shopping carts, whereby preferably only data from shopping carts in the shopping cart's vicinity is received. This environment can have a maximum extent of 20 m, preferably a maximum of 10 m. Limiting the environment to a maximum extent of 20 m leads to a reduction in the communication overhead. Based on the received data, each shopping cart determines for itself, for example, whether it is entitled to charging current and / or how much charging current it is entitled to. For this purpose, control units of the shopping carts, for example, can be equipped with a corresponding algorithm.

[0074] In a further embodiment, the backend is further connected to a solar system, which supplies at least part of the charging current. The solar system can consist of one or more solar panels and is preferably installed on the supermarket and / or on buildings close to the supermarket. If the solar system supplies enough power to charge all shopping carts, all shopping carts are charged with the maximum available power. This can occur, for example, during a period in which the sun is shining and thus sufficient solar power is produced. If the solar system supplies less power than is needed to charge all shopping carts, each shopping cart only draws enough power to maintain its operation. In general, the shopping carts' power consumption can be controlled depending on a current sunshine parameter and / or a current electricity price. 4.Short description of the drawings.

[0075] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

[0076] Figure 1 shows a smart shopping cart on wheels in a schematic side view, with a lower and a rear frame member, with a shopping cart on a support frame, and with a tablet computer, as well as with a contact system according to the invention with a pair of contact elements per side (right-left) including cable routing to the tablet computer.

[0077] Figure 2 shows a simplified representation of the chassis with the side beams and the front beam, as well as with a contact system according to Figure 1, schematically from above, whereby for the sake of clarity only the chassis with the contact system according to the invention are shown.

[0078] Figure 3 shows a simplified representation of two shopping trolleys nested one inside the other according to Figure 2, but omitting the contact pairs 32, 42, whereby for the sake of clarity only the chassis with the contacting systems according to the invention are shown.

[0079] Figure 4 shows a simplified representation of the first shopping cart inserted into a contacting system of a base adapter, wherein the base adapter is connected to a DC power supply and establishes electrical contact with the contact elements of the shopping cart shown in the drawing above.

[0080] Figure 5 shows a shopping cart according to Figure 1 with a holding device located on the floor in coupling with the base adapter from Figure 4, in a schematic side view.

[0081] Figure 6 shows a nested row of shopping carts where the third cart from the top is not fully inserted into the second, resulting in the desired electrical contact not being established (see detail on the right). Figure 7 shows a cart that has been inserted at an angle but still achieves sufficient charging contact thanks to its redundant contact elements on the front right and left.

[0082] Figures 8a to 8e show several shapes for the design of the internal contact elements 42 or 44 from Figure 2 as variants in a schematic view.

[0083] Figure 9 shows an external contact element 34 from Figure 2, which is guided around the front edge, for the right side of the shopping cart, schematically in several perspectives, omitting the contact to a socket of the cable inside the pole, wherein Figure 9a shows a side view from the outside, Figure 9b a side view from the inside, Figure 9c a perspective view from the rear outside above and Figure 9d a plan view from above.

[0084] Figure 10 shows an internal contact element 42 or 44 from Figure 2 for the right side of the shopping cart schematically in several perspectives, omitting the contact to a socket of the cable inside the pole, wherein Figure 10a shows a side view of the rear side adjacent to the pole, Figure 10b shows a view from the rear, Figure 10c shows a perspective view from the rear outside above and Figure 10d shows a plan view from above.

[0085] Figure 11a shows an example of contacting an internal contact element with a connecting cable piece that is to be connected to a cable by means of a plug connection that runs inside the spar; Figure 11b correspondingly shows an example of contacting an external contact element.

[0086] Figure 12 shows an example of contact between an internal contact element and a cable running inside the spar by means of a plug connection, as well as the contact for an external contact element, both on the right side in the assembled state for making contact and on the left side in the fully assembled state screwed to the spar 12 after making the electrical contacts.

[0087] Figure 13 shows two shopping carts according to the invention pushed into each other in a

[0088] Top view of the chassis, in which, according to a variant of the present invention, the horizontal spar has a first, small bulge on its inner side, and the spar has a second small bulge on its outer side.

[0089] Figure 14a shows a "dummy" shopping cart frame provided according to the invention in a schematic view from above, which has an additional power connection installed on the shopping cart housing and intended for the last cart in a nested row, in a schematic partial view from above in the nested state, Figure 14b shows the "dummy" shopping cart frame schematically in perspective from the front above without cable, and Figure 14c shows the "dummy" shopping cart frame schematically from above with connection cable.

[0090] Figure 15 shows a shopping cart equipped according to the invention with a cable duct leading from the lower bar to the tablet.

[0091] Figure 16 shows a shopping cart equipped according to the invention entirely without hollow bars, with a cable duct leading from the front contact elements to the tablet.

[0092] Figure 17 shows a schematic side view of a shopping cart equipped according to the invention, in which the contact elements are attached to the bottom right and left sides of the shopping cart.

[0093] Figure 18 shows a schematic plan view of the shopping cart from Figure 17.

[0094] Figure 19 shows a schematic side view of a shopping cart equipped according to the invention, in which the contact elements are attached to the top right and left sides of the shopping cart.

[0095] Figure 20 shows a schematic side view of a shopping cart equipped according to the invention without a lower storage level, with a chassis which has four bars extending diagonally downwards from the shopping cart, which connect to the rollers, and in which the contact elements are attached to the bottom of the shopping cart.

[0096] Figure 21 shows a schematic side view of a shopping cart equipped according to the invention without a lower storage level, with a chassis which has four bars extending diagonally downwards from the shopping cart, which connect to the rollers, and in which the contact elements are attached to the two front inclined bars above the rollers.

[0097] Figure 22 shows the shopping cart from Figure 21 in a schematic view from above, with only the outline of the basket exposed.

[0098] Figure 23a shows two shopping carts from Figure 21, fully nested, in a schematic top view with only the outline of the basket exposed.

[0099] Figure 23b shows a section of the right front inclined beam in the direction of travel with the contact pairs in a schematic side view from the outside at the front and above.

[0100] Figure 23c shows the attachment point of the contact pairs from the front.

[0101] Figure 23d shows a schematic, side view from the outside of the inclined beam with the contact pairs.

[0102] Figure 23c shows a schematic top view of the inclined beam with the contact pairs.

[0103] Figure 23t shows the section from Fig. 23a from the inside.

[0104] Figure 24 shows a schematic side view of a shopping cart with a lower, pivotable storage level, in which two contact pairs arranged next to each other with sufficient lateral distance from each other - only one contact pair is shown because of the side view - are arranged under the shopping cart on a lower storage level, each contact pair having a first contact element directed upwards and a second contact element directed downwards.

[0105] Figure 25 shows two nested shopping carts according to Figure 24 in a side view, illustrating the contact between the upwardly directed contact element of the rear shopping cart (shown on the left) and the downwardly directed contact element of the front shopping cart. Figure 26 shows a schematic side view of a shopping cart with a shopping basket, with two contact pairs attached to the basket base with sufficient lateral spacing from one another - although only one contact pair is shown due to the side view - each contact pair having a first, upwardly directed contact element and a second, downwardly directed contact element.

[0106] Figure 27 shows two nested shopping carts according to Figure 26 in a side view, showing the contact between the upwardly directed contact element of the rear shopping cart (shown on the left) and the downwardly directed contact element of the front shopping cart.

[0107] Figure 28 shows a schematic side view of a shopping trolley with a shopping basket, with two contact elements attached to the upper edge of the basket - only one contact element being shown because of the side view - and two contact elements attached to the pivoting rear wall of the basket - also only one contact element being shown because of the side view - which together form a contact pair.

[0108] Figure 29 shows two nested shopping trolleys according to Figure 28 in a side view, showing the contact between the upwardly directed contact element on the basket edge of the rear shopping trolley (shown on the left) and the downwardly directed contact element on the pivoting basket rear wall of the front shopping trolley.

[0109] Figure 30 shows a schematic side view of a shopping cart with an electric motor-driven fifth wheel and a battery which, in addition to the tablet, is also supplied with power by the contacting system according to the invention, which has been omitted for reasons of improved clarity.

[0110] Figure 31 shows the shopping cart from Figure 30 exposed without a basket in a schematic view from above.

[0111] 5. Detailed description of preferred embodiments

[0112] Below, some preferred embodiments of shopping carts are explained in more detail with reference to Figures 1-31. It is emphasized that the aspects explained therein can also be applied to other types of push carts, for example, those described above.

[0113] In the figures, the same reference symbols denote the same or functionally identical components.

[0114] Figure 1 shows a smart shopping cart 10 on wheels in a schematic side view, with a lower, horizontal frame member 12 and a rear vertical frame member 14, with a shopping cart 16 on a support frame 18, and with a tablet computer 20, as well as with a contacting system 30 according to the invention with two redundantly effective pairs 32, 34 of contact elements per side (right-left) including cable 36 with cable routing within the hollow members 12, 14 to the tablet computer.

[0115] Figure 2 shows a simplified representation of the chassis with the side beams 12 and the front beam 13, as well as with a contacting system 30 according to Figure 1, with two redundantly effective pairs 32, 34 or 42, 44 of contact elements per side (right-left) schematically from above, whereby for the sake of better clarity only the chassis with their beams with the contacting system 30 according to the invention are shown.

[0116] With common reference to Figures 1 and 2, the frame members 12, 14 are constructed as square tubes made of stainless steel of standard thickness. They are used to route the cables 36 from the contact system 30 to the tablet computer 20. This protects the cables 36 from damage.

[0117] Figure 2 shows two contact pairs on the right and left, providing redundancy for the contact. One pair is contact pair 34, 44, and the other is contact pair 32 and 42. Only one of the two pairs is required for proper operation; using both increases contact reliability.

[0118] The external contact elements 32 and 34 are strip-shaped and attached to the outside of the uprights 12. The contact element 34 extends around the rounded front edge on the right and left of the trolley, so that it can contact a counter contact element from the sides and from the front. Internal contact elements 42, 44 are provided on the inside of the uprights 12, on the right and left of the chassis. These contact elements are intended to establish and maintain mechanical and electrical contact with the corresponding contact elements 32 and 34 on the two outer sides of the next shopping trolley when the trolley is pushed in and placed in a nested position after shopping is completed.The inner contact element 42 on the right-hand rail 12 establishes contact with the contact 32, also located on the right but on the outside, of a carriage of the same design and with the same contacting system that is inserted next into the carriage shown. The inner contact element 44 on the right-hand rail 12 establishes contact with the contact 34, also located on the right but on the outside and surrounding the front right edge, of a carriage that is inserted next into the carriage shown.

[0119] In this example, the contact elements on the right side of the shopping cart are connected to the positive pole of the DC supply voltage. The contact elements on the left side of the shopping cart are connected to the negative pole of the DC supply voltage. The reverse is also possible.

[0120] In order to transfer the charging current from the shopping cart in front, which is already supplied with charging current, to the next cart pushed in, the contact elements 32, 34, 42 and 44 on the right side are connected to each other by contact lines (not shown).

[0121] Likewise, the contact elements 32, 34, and 42 and 44 on the left side are connected to each other by contact lines not shown.

[0122] Since the contact elements on the right side are connected to the positive pole of the DC voltage in this exemplary embodiment and the contact elements on the left side are connected to its negative pole, there is no contact between the contact elements on the right side and those on the left side. Those skilled in the art will understand that only a single pair of contacts per side, i.e. 32 with 42, or 34 with 44, can be used if one is willing to forgo the redundancy of the contacts. In the exemplary embodiment, the contact elements 32 and 34 are strips of chrome-plated copper, approximately 10 to 15 cm long and slightly less wide than the lateral height of the square bar 12, for example 25 mm wide with a thickness of 2 mm. They are each attached to the bar 12 by means of a non-conductive adhesive layer.

[0123] The cable 36 runs through the lower beam 12 and further through the connected vertical beam 14 upwards to a hollow upper cross beam (not shown), which also carries a holder for the tablet, and in which the cable 36 is guided further to the tablet 20.

[0124] Figure 3 shows a simplified representation of two shopping carts pushed into one another, i.e., nested, as shown in Figure 2, but with the contact pairs 32, 42 omitted. For the sake of clarity, only the chassis with the contact systems 30 according to the invention are shown. The front outer contact elements 34 of the pushed-in cart, which surround the front edges, always touch the front inner contact elements 44 of the cart in front of them, which are flexibly bent outward upon insertion and thus, due to their mechanical flexibility, establish a mechanically stable electrical contact.

[0125] Figure 4 shows, in a simplified representation according to Figure 3, the chassis of the first shopping cart, which is inserted into a contacting system of a base adapter 46, wherein the base adapter 46 is connected to a DC power supply and establishes an electrical contact with the contact elements 44 of the shopping cart shown in the drawing above, as already described above.

[0126] Figure 5 shows a shopping cart according to Figure 3 with a holding device located on the floor in coupling with the base adapter from Figure 4 in a schematic side view.

[0127] With common reference to Figures 4 and 5, the shopping cart in this position is ready to be charged and serve as a power source for charging the next cart inserted. The supply voltage must be adjusted to the voltage required for the tablet 20 (Figure 1) and requires a DC voltage. This is illustrated by the symbols at the top of Figure 4. The charging voltage is in the low range of 5V to 24V DC, which is typical for tablets.

[0128] In this exemplary embodiment, the mechanical coupling of the first shopping cart to the base adapter 46 is only achieved via the front upright 13 and the side uprights 12. In other exemplary embodiments, this coupling can also be achieved via the front of the shopping cart. Preferably, the front wheels of the first cart in the row of carts to be nested are releasably locked in the fully inserted position, thus preventing accidental, incomplete insertion of the cart into the first cart. In this exemplary embodiment, this is achieved by a threshold 48 screwed to the floor of the cart housing, which is shown exaggerated in Figure 5 for improved clarity, and which both front wheels must roll over to ensure stable mechanical and electrical contact.

[0129] The threshold 48 is preferably low enough that it can easily be rolled over by the customer during a normal adjustment procedure. It is preferably positioned so that electrical contact is established even if the trolley is pushed directly up to the threshold without rolling over it.

[0130] Figure 6 shows a nested row of shopping trolleys in which the third trolley from the top has not been fully pushed into the second and the desired electrical contact is not made at the front contact elements 34, 44, see detail on the right.

[0131] However, due to a preferably existing, redundant power connection, which can be established via the last trolley pushed into the row of trolleys after business hours, and which is described further below in connection with Figures 14a, 14b, 14c, it is nevertheless guaranteed that the trolley that has not been pushed in far enough and all the trolleys pushed in behind it are successfully electrically contacted and their batteries are charged.

[0132] Figure 7 below shows a carriage inserted at an angle. Due to its front contact elements 34 extending around the front edge of the chassis, it still achieves sufficient charging contact via contact pairs 34 / 44 at the front right. The same applies to the left side. Figures 8a to 8e show several configurations for the internal contact elements 42 or 44 from Figure 2—only their right side—as variants in schematic view, each of which creates the flexibility of the contact element in different ways. Details regarding the attachment to the frame member 12 and the contact with the cable 36 are explained further below.

[0133] The contact element 42 in Figure 8a derives its flexibility solely from its shape and material properties. For example, this example is an electrically conductive metal strip made of chrome-plated copper, 25 mm wide, approximately 15 cm long, and 1.5 mm thick.

[0134] The contact element 81 in Figure 8b is constructed from a metal strip that transitions into the protruding part via a hinge 83. The protruding part derives its flexibility from an elongated compression spring 82, which is attached to it and to the post 12 and pushes it away from the post 12, thus holding it to the mating contact element. The contact element 81 is, for example, an electrically conductive metal strip made of chrome-plated copper with a width of 25 mm, a protruding length of approximately 8 cm, and a thickness of 1.0 mm.

[0135] The contact element 84 in Figure 8c is constructed from a metal strip, which also connects to the protruding part via a hinge. The protruding part derives its flexibility from a torsion spring 85, which pushes it away from the beam 12 and thus holds it to the mating contact element. The contact element 84, for example, is an electrically conductive metal strip 25 mm wide, approximately 8 cm long, and 1.0 mm thick, made of chrome-plated copper.

[0136] The contact element 84 in Figure 8d is constructed from a metal strip, which also hinges into the protruding part. The protruding part derives its flexibility from a pair of plastic-coated permanent magnets 87—additionally marked with a horseshoe symbol—which push it away from the beam 12 and thus hold it to the mating contact element. The contact element 86, for example, is an electrically conductive metal strip 25 mm wide, approximately 8 cm protruding, and 1.0 mm thick, made of chrome-plated copper.

[0137] Contact element 88 in Figure 8e is a closed, oval-shaped, electrically conductive metal strip, 25 mm wide, with a long semi-axis of approximately 10 cm and a short semi-axis of approximately 5 cm, and a thickness of approximately 1.5 mm, made of chrome-plated copper. Its flexibility derives solely from its shape and material properties.

[0138] Figure 9 shows an external contact element 34 from Figure 2, which is guided around the front edge, for the right side of the shopping cart, schematically in several perspectives, omitting the contact to a socket of the cable inside the pole, wherein Figure 9a shows a side view from the outside, Figure 9b a side view from the inside, Figure 9c a perspective view from the rear outside above and Figure 9d a plan view from above.

[0139] In this embodiment, the contact element 34 is an elongated composite body adapted to the curvature of the rounded front edge of the chassis, consisting of an insulating body 90 made of electrically insulating material and a contact strip 92 made of aluminum or chrome-plated copper, which establishes the electrical contact.

[0140] In order to ensure that the contact elements 32, 34 remain robustly connected to the bar 12 even against accidental contact with the customers' shoes, the edges of the contact strips are preferably recessed in notch-like depressions on the insulating body 90, which prevents the edges from bending outwards over time and then tearing further, or from posing a risk of injury to the feet or legs of customers.

[0141] The insulating body 90 also serves the function of securely and robustly attaching the contact strip to the uprights 12, 13 of the chassis. In the example, it is made of a break-resistant polymer material, for example ABS, with a thickness of approximately 7.5 mm and has a tab-like area 93 projecting beyond the longitudinal ends of the insulating body on both sides, each with a hole with which it can be screwed to the upright 12 or the front upright 13. The insulating body 90 preferably has a longitudinally extending base area 94, which has a shape that matches a corresponding curvature present in the upright 12, so that the contact element thus formed is robustly constructed as a whole and can be attached to the chassis of the shopping cart in a way that is resistant to external mechanical stress.

[0142] The insulating body 90 and the contact strip 93 are strip-shaped, arranged one above the other with mutually parallel longitudinal edges and glued together. The left-hand contact element 34 has a structure analogous to the right-hand one. The contact to the cables located in the upright 12 will be discussed in more detail below. Figure 10a shows an internal contact element 42 or 44 from Figure 2 for the right-hand side of the shopping cart schematically in several perspectives, omitting the contact to a socket of the cable inside the upright, wherein Figure 10a shows a side view of the rear side adjacent to the upright, Figure 10b a view from the rear, Figure 10c a perspective view from the rear outside above and Figure 10d a plan view from above.

[0143] In this exemplary embodiment, the contact element 42, 44 is an elongated, strip-shaped composite body consisting of an insulating body 100 made of electrically insulating material and the actual metal body 102 made of aluminum or chrome-plated copper, which serves as the electrical contact and establishes the electrical contact, as described in connection with Figure 8.

[0144] The insulating body 100 also serves to securely and robustly attach the metal body 102 to the chassis spar 12. In this example, the insulating body 100 is made of a break-resistant polymer material, such as ABS or a comparable material with a thickness of approximately 5.0 mm, and has a hole on both sides of the longitudinal ends, with which it can be screwed to the spar 12.

[0145] The metal body 102 has two holes at the end where it rests against the insulating body, through which two brass contact pins 106 pass. These pins lead to a cable connecting to a plug. The plug is located in a sufficiently large maintenance opening in the beam 12 and can be connected there to a suitable socket to establish the desired electrical contact.

[0146] The left-side contact element 42, 44 has a structure analogous to the right-side one. The contact to the cables located in the beam 12 will be discussed in more detail below.

[0147] Figure 11a shows an example of contacting an internal contact element 44, which is contacted and fastened to an insulated contact lug 112 of a connecting cable piece by means of two screws made of electrically conductive material and by means of matching nuts, wherein the connecting cable piece contains two cables 114 and 116, wherein the cable 114 can be connected to the cable 36 by means of a plug connection, which runs inside the spar and leads to the outer contact element 34 located at the front, and wherein the other cable 116 leads to a plug connection which leads on the one hand to the tablet and on the other hand to the other external contact 32 (see Figure 2).

[0148] Figure 11b accordingly shows an exemplary contacting of an external contact element 34 with the cable 114, which leads to a plug connection that leads to the tablet and to the internal contact 44.

[0149] Figure 12 shows an example of contact between an internal contact element and a cable running inside the spar by means of a plug connection, as well as the contact for an external contact element, both on the right side in the assembled state for making contact and on the left side in the fully assembled state screwed to the spar 12 after making the electrical contacts.

[0150] The cables are laid in the spar 12 with a length excess of approximately 20 cm, so that the connecting cable piece can easily be manually connected to the cable 36 outside the spar, and the electrically connected contact element can then be screwed tight to the outside of the spar.

[0151] Figure 13 shows two shopping carts according to the invention pushed into one another in a top view of the chassis. According to a variant of the present invention, the left and right bars 12 each have a first, small bulge 122 on their inner side, and the bar 12 also has a second, small bulge 124 on its outer side. The bulges are installed on the bar in a stable and durable manner. They are dimensioned such that a slight mechanical resistance must be overcome during the pushing-in process when the cart is pushed into the vehicle in front of it, and electrical contact is maintained thereafter. The bulges 122, 124 engage with one another with their curves, as shown in Figure 12, thereby forming "locking lugs."The mechanical resistance during locking is intended to prevent the newly inserted carriage from rolling back on its own, for example on uneven terrain or due to careless handling, which could result in the loss of the previously established electrical contact. The bulges 122, 124 can be made as buffer bodies from a slightly flexible plastic, for example, a somewhat softer ABS, and can be glued or screwed to the rail, with the screws countersunk into the material if necessary. The surface of the buffer bodies is preferably smooth.

[0152] Instead of a second locking lug, a concavity can also be provided in the bars 12, preferably on their outer sides, into which the locking lugs on the right and left engage. The material of the individual locking lugs should then be slightly less flexible to ensure the same locking effect.

[0153] Figure 14a shows a "dummy" shopping cart frame 140 provided according to the invention in a schematic view from above, which has an additional power connection with a connecting cable 144 installed on the shopping cart housing and intended for the last cart 142 of a nested row, in a schematic partial view from above in the nested state, Figure 14b shows the "dummy" shopping cart frame 140 schematically in perspective from the front above without cable, and Figure 14c shows the "dummy" shopping cart frame schematically from above with connecting cable 144.

[0154] The “dummy” shopping cart frame 140 can be moved to the last shopping cart in a nested row of carts after the store closes and can be connected with its connecting cable 144 to a second, redundant DC power supply provided stationary in the cart house.

[0155] The "dummy" shopping cart frame 140 has the same external contact elements 34 as described above and supplies power to the internal contact elements 44 of the last cart 142 in the row. Thus, in the event that there is no electrical contact between two shopping carts at a leak point in the row that is difficult for staff to detect, this last cart 142 can supply power to the carts in front of it up to the leak point, and the associated batteries can thus be charged. In the event that there is no leak point at all, the contacts 34 of the dummy 140 and the contacts 44 of the last cart are at the same voltage potential, and the additional power connection is simply not used, but it cannot cause any damage.

[0156] Figure 15 shows a shopping cart equipped according to the invention with a cable duct 140, which leads from the lower hollow upright 12 to a not-shown upper, hollow crossbar, which also supports a holder for the tablet, and in which the cable 36 is routed further to the tablet 20. The cable duct 140 is also present on the left side of the cart. It is preferably used for shopping carts that do not have a hollow vertical upright on both sides as shown in Figure 1, but rather only a stable wire frame that connects the lower upright 12 to the handlebar and / or the shopping cart. The cable duct 140 preferably consists of a hollow aluminum tube that follows the contour of the shopping cart as closely as possible. For this reason, corresponding bending points are provided in the tube at the bends 142, 144.The attachment to the trolley's wire frame can be achieved using suitable, irreversible click connections or other suitable connecting elements commonly used in the art to prevent tampering or wear by customers. The cable duct 140, when the cable is in place, can be pushed into a separate opening (not shown) provided in the upright 12 to prevent the cable from being exposed and tampered with on the surface.

[0157] Figure 16 shows a shopping cart equipped according to the invention entirely without hollow uprights, with a cable duct 160 that runs from the foremost contact elements 34 to the tablet. Its upper, vertical section is constructed and secured as described above, and its lower section 162 runs outside on the underside of the chassis so that it is exposed to as little mechanical stress as possible that occurs when the carts are pushed together. In its lower section 162, the cable duct has a cross-section large enough to accommodate the previously described cables, including excess length and plugs. The outer contact elements 34 are secured against rotation to the outside of the wire frame and have no protruding corners or edges. The inner contact elements are secured against rotation to the inside of the wire frame.

[0158] Figure 17 shows a schematic side view of a shopping cart equipped according to the invention in which the contact elements 34, 44 are attached to the bottom of the shopping cart.

[0159] Figure 18 shows a schematic plan view of the shopping cart from Figure 17.

[0160] With common reference to Figures 17 and 18, the right- and left-side contact elements 34 in this exemplary embodiment are each an elongated, strip-shaped composite body consisting of an insulating body made of electrically insulating material and a contact strip made of aluminum or chrome-plated copper, which establishes the electrical contact, analogously to that shown and described in Figures 9a-d, only in a flat form. The internal contact elements 44 are constructed as described in Figure 10. In the example shown, however, the contact elements 34, 44 are located directly opposite one another and not longitudinally offset as in the example in Figure 2. The material of the wall of the shopping cart lies between them.Contacting each other and the cable leading to the tablet 20 takes place in a somewhat more voluminous contacting section 172 of the cable duct, which is connected to the actual cable duct 170, which is also shown schematically, and contains the necessary plug connections. The cable duct 170 is preferably arranged in the interior of the shopping cart. As described above, it is preferably made of plastic or metal. The internal contact elements 44 have rounded edges and are preferably so strong that it is impossible for a user to cut themselves on them. They preferably have a bent shape at a freely projecting end section, as illustrated in Fig. 8a, or have a longitudinally oval closed shape, as explained in connection with Fig. 8e, so that the shape is robust enough and is not changed by the goods placed in the shopping cart.A non-conductive plastic plate 174 is preferably arranged beneath the internal contacts, which is large enough to prevent direct contact between contact element 44 and the material of the basket itself. This ensures that no leakage current flows through the basket during charging.

[0161] When the shopping carts constructed in this way are pushed into one another, the front section of the shopping cart of the newly inserted cart protrudes into the interior of the cart in front of it, as the rear wall of the shopping cart is pivoted upwards as usual. The contact pairs 34, 44 are arranged on both sides in such a way that the outer contact elements 34 of the newly inserted cart and the inner contact elements 44 of the cart in front of them are in permanent contact over the desired surface of the inner contact element 44.

[0162] The coupling of the first cart to the base adapter 46 (see Fig. 4 with description) is carried out analogously using a base adapter that is structurally adapted to the changed height of the contacts. Figure 19 shows a schematic side view of a shopping cart equipped according to the invention, in which the contact elements are attached to the top of the cart. Here, the cable duct 170 runs approximately below the upper edge of the cart into its interior.

[0163] Figure 20 shows a schematic side view of a shopping cart equipped according to the invention without a lower storage level, with a chassis having four bars extending diagonally downwards from the rear of the shopping cart—also referred to here as "slanted bars"—which connect to the respective rollers, and in which the contact elements are attached to the bottom of the shopping cart. Reference can be made to the description of Figures 17 and 18 for this purpose, since the contacting system is completely independent of the chassis, as long as it is ensured that the contact elements 34, 44 are in sufficiently close and continuous contact during nesting.

[0164] With reference to Figures 21 to 23t, a further variant for shopping carts without a lower shelf is described, in which the four wheels of the cart are individually mounted on slanted, downwardly extending beams, referred to as inclined beams 210. Here, the contact elements according to the invention are attached to the cart in the area of ​​the front rollers:

[0165] Figure 21 shows a schematic side view of a shopping cart equipped according to the invention without a lower storage level, with a chassis having four inclined beams extending diagonally downwards from the shopping cart, connecting to the rollers, and in which the contact elements 34, 44 are attached to the two front inclined beams 210 above the rollers. The cables are routed in a cable duct 170 similar to that described above in Figure 17.

[0166] Figure 22 shows the shopping cart from Figure 21 in a schematic view from above, with only the outlines of the basket exposed, with the contact elements 34, 44.

[0167] The inwardly directed contact elements 34 are strip-like and are attached, preferably glued, to rigid, self-supporting, elongated, strip-like plastic supports 212. The plastic support, in turn, is attached to the inclined beam 210 and projects freely to the rear. The outwardly directed contact elements 44 are also attached to the inclined beam 210, preferably close to the beam 210 on its outwardly facing surface at the same height above the floor, so that the corresponding contact pairs of nested carriages touch each other (see Figure 23a).

[0168] Figure 23a shows two shopping carts from Figure 21 or 22, fully nested, in a schematic top view with only the outline of the basket exposed. The contact elements 34 and 44 are shaped such that they already touch each other during the nesting process, well before a predetermined mechanical stop that defines the fully nested position. They remain in mechanical and electrical contact all the way to the stop, with the outwardly projecting ends 214 of the plastic supports 212 being pushed further and further outward. The contact elements 34 and 44 continue to maintain mechanical and electrical contact in the fully nested position of the carts.

[0169] To further clarify the attachment of the contact elements 34 and 44, Figure 23b shows a section of the right front inclined beam 210 in the direction of travel with the contact pairs 34, 44 in a schematic side view obliquely from the outside front and above.

[0170] Figure 23c shows the fastening point of the contact pairs 34, 44 from the front in a position approximately 10 cm above the holder for the roller.

[0171] Figure 23d shows a schematic, side view from the outside of the inclined beam with the contact pairs 34, 44.

[0172] Figure 23c shows a schematic view from above of the front inclined beam 210 located on the right in the direction of travel with the contact pairs 34, 44.

[0173] Figure 23t shows the section from Fig. 23b from the inside.

[0174] In the exemplary embodiment, the fastening of the plastic carrier 212 for the inwardly directed contact elements 34 is provided by a sleeve 230 that surrounds the inclined beam 210 and is screwed to the inclined beam 210. The sleeve 230 has receptacles on its outer side for the outwardly directed contact elements 44. The sleeve 230 and the plastic carrier 212 are manufactured as injection-molded parts from a suitable plastic that has the required mechanical robustness and is UV-stable.

[0175] The cables are connected in the inclined beam 210, provided it is hollow, in the same manner as described above. If the inclined beam is not hollow or has a cross-section that is too small, the cables run upwards in a cable duct along the two inclined beams 210, as shown and described in Figure 17 or 21.

[0176] Figure 24 shows a side view of a shopping cart with a pivotable storage level 240 arranged below the shopping cart, in which two contact pairs arranged next to one another with sufficient lateral distance from one another - only one of which is shown in the figure - are arranged on the lower storage level, each contact pair having a first, upwardly directed contact element 241 and a second downwardly directed contact element 242 with the electrical connections as described above.

[0177] The lower storage level consists of a wire frame with four longitudinal struts running in the direction of travel and a few cross struts connected to them made of thick aluminum wire, about 8 mm thick, as is often found in the state of the art.

[0178] The two downward-facing contact elements 242 are constructed as composite bodies analogously to the contact elements described in Figure 9, but with an elongated shape of approximately 30 cm in length and 5 cm in width, again consisting of an insulating body made of electrically insulating material and a contact strip made of aluminum or chrome-plated copper, which establishes the electrical contact.

[0179] The downward-facing contact elements 242 are fastened with their insulating bodies to the two middle longitudinal struts of the storage level 240 in a rotationally secure manner, for example by screwing. They have a free distance between them of approximately 8 to 10 cm, depending on the distance between the two middle longitudinal struts. They run parallel to one another. The two upward-facing contact elements 241 are arranged in this exemplary embodiment in the region of the approximately 40 cm long front edge of the storage level 240 and are fastened there in its middle area with a lateral distance from one another that corresponds to that of the contact elements 242. For details of the contacts, the wiring of the electrical cables, and the routing in a cable duct, reference can be made to the description above. The cables are preferably guided through the front strut and the two side struts, orIf no hollow posts are present, in appropriate cable ducts. Thus, the end section 243 (see Figure 25) of the lower storage level, which extends freely upwards during nesting, remains unoccupied with a cable.

[0180] Figure 25 shows two nested shopping carts according to Figure 24 in a side view, illustrating the contact between the upwardly directed contact element 241 of the rear (left-shown) shopping cart and the downwardly directed contact element 242 of the front shopping cart. Preferably, the upwardly directed contact element 241 is slightly obliquely flattened at its front, upwardly directed edge so that the electrically effective contact area with its downwardly directed mating contact element 242 is as large as possible.

[0181] Advantageously, in this embodiment, in which the contact strip of the downwardly directed contact element 242 is approximately 30 cm long, the mechanical and electrical contact is maintained even when the carriages are pushed into one another very messily, even when they are a considerable distance apart in the direction of travel, since the weight of the pivoting storage level 240 presses the upper contact element onto the lower one in practically any position.

[0182] Figure 26 shows a schematic side view of a shopping cart with a shopping basket, with two contact pairs attached to the basket bottom with sufficient lateral distance from each other - only one contact pair is shown because of the side view - each contact pair having a first, upwardly directed contact element 261 and a second downwardly directed contact element 262.

[0183] Figure 27 shows two nested shopping carts according to Figure 26 in a side view, showing the contact between the upwardly directed contact element of the rear shopping cart (shown on the left) and the downwardly directed contact element of the front shopping cart.

[0184] With common reference to Figures 26 and 27, the basket base 260 consists of a relatively fine-meshed wire frame made of aluminum wire, approximately 3 mm thick, as is often found in the prior art.

[0185] The two downward-facing contact elements 262 are constructed as composite bodies analogously to the contact elements described in Figure 9, but with an elongated shape of approximately 20 cm in length and 5 cm in width, again consisting of an insulating body made of electrically insulating material and a contact strip made of aluminum or chrome-plated copper, which establishes the electrical contact.

[0186] The two downward-facing contact elements 262 are attached, for example, by screwing, with their insulating bodies to the underside of the basket base in the front area, symmetrically to the longitudinal axis. The contact elements 262 run parallel to each other and have a free distance between them of approximately 10 cm.

[0187] The two upward-facing contact elements 261 are approximately the same length and width as the downward-facing contact elements 262 and, in this exemplary embodiment, are arranged slightly in front of the center of the basket base and secured there with a lateral spacing corresponding to that of the contact elements 262. For details of the contacts, the wiring of the electrical cables, and the routing in a cable duct, please refer to the description above. The upward-facing contact elements 261 are positioned so that they come into contact with the downward-facing contact elements of the front member over as large a surface as possible when pushed together.

[0188] To prevent the contact elements from jamming together in the nested position when the carriages are pushed into one another up to their stop as provided in the prior art, at least one of the two contact elements, preferably the downward-facing one, is spring-mounted or has a preload formed by the shape or suspension of the contact element. Here, too, reference can be made to the description above in connection with Figure 8, in particular Figure 8e. The preload ensures that the contact pressure between the contact surfaces remains within a predefined range, even when the carriages are pushed into one another up to their mechanical stop, whether perfectly aligned or with a deviation of several degrees.

[0189] Figure 28 shows a schematic side view of a shopping cart with a shopping basket, with two contact elements 281 attached to the upper basket edge 280 - only one contact element being shown due to the side view - and two contact elements 282 attached to the pivotable basket rear wall 285 - also only one contact element being shown due to the side view - which together form a contact pair and are electrically connected to one another.

[0190] Figure 29 shows two nested shopping trolleys according to Figure 28 in a side view, showing the contact between the upwardly directed contact element on the basket edge of the rear shopping trolley (shown on the left) and the downwardly directed contact element on the pivoting basket rear wall of the front shopping trolley.

[0191] With common reference to Figures 28 and 29, the pivoting basket back wall 280 also consists of a wire frame, constructed in a grid-like manner, made of aluminum wire with a thickness of approximately 3 mm, with its edge 286 being formed by a somewhat stronger wire.

[0192] The two contact elements 282, which are directed downwards in the nested position, are constructed as a composite body analogously to the contact elements described in Figure 9, but with an elongated shape of approximately 10 cm in length and 5 cm in width, again consisting of an insulating body made of electrically insulating material and a contact strip made of aluminum or chrome-plated copper, which establishes the electrical contact.

[0193] The downward-facing contact elements 282 are secured with their insulating bodies to the two outer right and left struts of the basket rear wall 285 in a rotationally secure manner, for example, by screwing. They extend slightly diagonally to each other, at the same angle as the right and left upper basket edges converge.

[0194] In this embodiment, the two upward-facing contact elements 281 are arranged in the front third of the right- and left-hand edges 280 of the basket and are secured there in a rotationally secure manner. For details of the contacting, the wiring of the electrical cables, and the routing in a cable duct, please refer to the description above. Preferably, the connecting cables between the contact elements of a pair are routed along the top edge of the basket and then along the outer edge of the pivoting rear wall of the basket in corresponding cable ducts.

[0195] Advantageously, in this embodiment, in which the contact strip of the upwardly directed contact element 281 is approximately 30 cm long, the mechanical and electrical contact is maintained even when the trolleys are pushed into each other very messily, even when they are a considerable distance apart in the direction of travel, since the weight of the pivoting rear wall 280 of the basket presses the upper contact element onto the lower one in practically any position.

[0196] Figure 30 shows a schematic side view of a shopping cart with an electric motor-driven fifth wheel 301 and a battery 303, which is also supplied with power by the contacting system according to the invention, which has been omitted for reasons of improved clarity, in addition to the tablet 20.

[0197] Figure 31 shows the shopping cart from Figure 30 exposed without a basket in a schematic view from above.

[0198] The battery 303 is attached to a front cross member of the chassis. It is supplied with power by the connecting cables of the contacting system (not shown) located on the right and left sides of the shopping cart. The battery is connected to the drive motor on the drive roller via a supply cable 305. The exemplary embodiment shows that even a battery that is not part of the tablet 20 can be supplied with charging current via the contacting system according to the invention, since its attachment does not interfere with the fastening and functioning of the contacting system according to the invention, and the contacting system itself is also fundamentally suitable for supplying a correspondingly higher charging capacity with the aforementioned supply voltages.

[0199] Although the present invention has been described above using a preferred exemplary embodiment, it is not limited thereto but can be modified in many ways. In one variant, the outward-facing contact elements are each designed to be flexible in such a way that, when in contact, they exert a certain permanent pressure on their respective counter-contact element, namely the inward-facing contact elements. The flexibility can be achieved by the means mentioned above, depending on the shape, material thickness, and size of the outward-facing contact elements used. Advantageously, the outward-facing contact elements do not protrude beyond the outer contour of the lower beams 12, but are attached, for example, beneath the beams.However, it is also possible that the inward-facing contact elements are each designed to be flexible and accordingly exert a certain permanent pressure on the outward-facing contact elements in the nested state when they are in contact.

[0200] In another variant, in addition to the front contact elements 34 and 44, the side contact elements 32 and 42 are also installed. This can be advantageous if you want to increase the redundancy of the contacts and thus the reliability of the contact.

[0201] In one variant of the present invention, the cart according to the invention, and specifically the shopping cart, is equipped with a radio module for a beacon connection. This can be implemented via the Wi-Fi of the associated store or via a Wi-Fi-independent wireless radio connection between each cart and a stationary beacon base station located in a cart house. As soon as the cart is pushed into the cart house, the base station registers this due to the spatial proximity to the base station, and a beacon-based control of the charge level of the tablet computer's battery is activated. The charge level of the battery to be charged is queried and displayed, for example, via a multi-color LED. Green can mean "sufficiently charged," red or the absence of the LED can mean "battery needs to be charged," and yellow can mean "charging not absolutely necessary."This ensures that store staff can determine at a glance whether a shopping cart in a nested row needs to be charged immediately or later. This "charging status LED" is preferably mounted separately near the top of the Tablet 20 or integrated into the tablet, for example, on its left edge.

[0202] In another variant equipped with beacon technology, which can optionally include the aforementioned variant, a so-called "contact status LED" is provided on the shopping cart. This can also be a multi-color LED. This LED indicates the status "can be charged" or "cannot be charged." It is wired to glow green when current is flowing across both charging contacts (for positive and negative) of a cart in a nested row, meaning the battery can be charged if it is properly nested in the cart housing. The LED glows red or off at all when no charging current is flowing, for example because the cart was pushed in crookedly and only one pair of charging contacts is touching, or because it was not pushed far enough into the cart in front of it. This "contact status LED" is preferably mounted separately at the top near the tablet 20 or integrated into the tablet, for example, on its right edge.In this example, it is connected in parallel to the shopping cart's charging current and therefore receives power when the cart is being charged - even if the charging current is very low and the cart's battery is already almost fully charged. This has the advantage that store staff, for example after closing time, only have to briefly look at the nested rows of carts in a cart bay to check the contacts. As soon as they see a red LED light up on the right edge of the tablet, they know that the contact there is broken. They can then, standing at the end of the row, push the last cart in a little, along with the carts in front of it, and if necessary, touch the cart with the poor contact individually and adjust it so that it makes contact.

[0203] If the beacon is connected to the store's Wi-Fi, this query of the contact status can then also be used to send a message to a pre-programmed mobile number of an employee, stating that a manual check of a specific car garage should be carried out.

[0204] In a further variant of the present invention equipped with beacon technology, the shopping carts are equipped with a beacon and the entrance area of ​​a store is equipped with several stationary beacons. If a customer now drives through the entrance area in the wrong direction, they pass from one stationary beacon to the next - albeit in an unexpected direction. This can be easily registered and monitored accordingly. For example, a warning LED on the affected shopping cart can be switched to flashing mode and / or an acoustic alarm can be triggered if the customer has crossed the entrance barrier in the wrong direction. In a variant of the present invention, a retrofit kit is disclosed: The part of the cable duct 162 intended for the lower area of ​​the shopping cart, together with its cables, cable connecting elements and the contact elements 32, 34, as well as 42 and 44, orThe other contact elements described above are manufactured as a prefabricated set, ready for attachment to the chassis of a shopping cart. This allows existing shopping carts constructed solely from wire frames to be easily retrofitted. The connection to a Tablet 20 can then be customized, depending on the design of the rear frame and handlebar, as well as the availability of a tablet-compatible mount for the shopping cart to be retrofitted.

[0205] Finally, the features of the subclaims may be combined essentially freely with each other and not by the order in the claims, provided that they are independent of each other.

Claims

CLAIMS 1. A pushable trolley, in particular a shopping trolley, with a contacting system, the contacting system comprising: a first contact pair with at least two contact elements for a first connection pole of an electrical charging voltage; a second contact pair with at least two contact elements for a second connection pole of the electrical charging voltage; the first and second contact pairs being configured such that: by pushing the pushable trolley into a second, identically constructed trolley with a second, identically constructed contacting system, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair establishes an electrically effective contact with a respective counter-contact element of the second trolley;wherein at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair are designed and / or arranged such that a sliding and / or rolling contact is established between the contact elements and the counter-contact elements during at least part of the insertion process; 2. Pushable trolley according to claim i, wherein the contacting system is configured to supply power to the trolley, preferably to supply power to a battery of the pushable trolley and / or an electrical device connected to the battery.

3. Pushable trolley according to one of claims 1 or 2, wherein at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair is arranged such that this each serves as a counter-contact element for a third, identically constructed carriage when the third, identically constructed carriage is inserted into the carriage.

4. A pushable carriage according to any one of claims 1-3, wherein: at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair is directed towards the inside of the pushable carriage; at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair is directed towards the outside of the pushable carriage; wherein the contact element directed towards the outside of the pushable carriage is conductively connected to the contact element of the respective contact pair directed towards the inside of the pushable carriage.

5. A pushable trolley according to any one of claims 1-4, wherein: the contact elements of the first contact pair are mounted on a left side of the trolley, preferably on a chassis of the trolley, and / or the contact elements of the second contact pair are mounted on a right side of the trolley, preferably on the chassis; and / or the contact elements of the first contact pair are mounted on a left front edge of the trolley, preferably on the chassis of the trolley, and / or the contact elements of the second contact pair are mounted on a right front edge of the trolley, preferably on the chassis.

6. A push cart according to claim 4 or claim 5 when dependent on claim 4, wherein: the contact elements directed towards the outside of the push cart are each formed around a front edge of the cart so as to form part of a left or right side and part of a front side of a chassis and / or a basket of the cart. 7- Pushable trolley according to one of claims 1-6, wherein the first and second contact pairs are arranged such that: at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair is directed upwards; at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair is directed downwards; wherein the contact elements of a contact pair are each conductively connected to one another.

8. A pushable trolley according to claim 7, wherein: the trolley has a, preferably pivotable, storage level, and the first and / or second contact pair are arranged on the storage level; and / or the trolley has a shopping basket, and the first and / or second contact pair are arranged on the shopping basket.

9. Pushable trolley according to one of claims 1-8, wherein at least one of the contact elements has a contact surface, preferably a contact strip with a predetermined length and width.

10. Pushable trolley according to one of claims 1-9, wherein at least a portion of at least one of the contact elements of the first contact pair is flexible and / or at least a portion of at least one of the contact elements of the second contact pair is flexible such that: the at least one flexible portion exerts permanent pressure on the respective counter-contact element in the at least partially inserted state; wherein the at least one flexible portion is preferably directed inwards and / or downwards.

1. Pushable trolley according to one of claims 1-10 with a system for Maintaining contact, wherein the system for maintaining contact comprises at least a first and at least a second system element such that: a positive connection is established between the at least one first system element of the carriage and a second counter-system element of the second, identically constructed carriage when the second carriage is pushed into the first carriage and the electrically effective contact is established in the process.

12. A pushable cart according to claim 11, wherein the cart comprises a chassis with at least one beam, wherein: a male system element is provided on an inner side of the beam; a female system element is provided on an outer side of the beam.

13. A push-cart according to claim 11 or 12, wherein the contact-maintaining system is provided by forming matching contact elements in contact with one another.

14. A push-along cart according to any one of claims 1-13, wherein: the cart includes a power connector electrically connected to the contacting system.

15. A pushable cart according to any one of claims 1-14, wherein the contacting system is arranged: on a left and / or a right outer side of the chassis or the shopping cart; and / or on a left and / or right front edge of the chassis or the shopping cart.

16. Device for inserting into a rearmost carriage of a nested row of pushable carriages, the device comprising a contacting system, the contacting system containing contact elements such that: by inserting the device into a carriage according to claim 1, an electrical contact can be established with respective counter-contact elements of the carriage according to claim i.

17. Contacting system for mounting on a push-along carriage, comprising: a first contact pair with at least two contact elements for a first connection pole of an electrical charging voltage; a second contact pair with at least two contact elements for a second connection pole of the electrical charging voltage; wherein the first and second contact pairs are configured such that: the first and second contact pairs each have at least two contact elements; and by pushing the push-along carriage into a second, identically constructed carriage with a second, identically constructed contacting system, at least one of the contact elements of the first contact pair and at least one of the contact elements of the second contact pair establishes an electrically effective contact with a respective counter-contact element of the second carriage.

18. Retrofit kit for a push-along trolley, in particular a shopping trolley, with a contact system according to claim 17.

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