Abstract:
The present invention includes a cart which includes: a chassis connected to a plurality of wheels; a basket mounted on the chassis and adapted to store one or more items therein; and a bridge element which is formed as an integral part of the cart and is adapted to fit onto an edge of a vehicular trunk, wherein the bridge element of the cart is at an area of the cart located between the basket and the wheels.

Description:
FIELD 
     Some embodiments are related to the field of carts, and more particularly to shopping carts. 
     BACKGROUND 
     Many stores and supermarkets provide shopping carts which may be used by customers. For example, a shopping cart includes an open basket which is rigidly connected to a bottom frame having four wheels. The customer puts inside the shopping cart items that the customer wishes to purchase. At the checkout point, the customer takes the items out from the shopping cart, and allows the cashier to scan the items so that the customer may pay for the purchase. Then, the purchased items are placed back into the shopping cart, either directly or optionally using one or more shopping bags. 
     Unfortunately, some stores do not allow the customer to take the shopping cart out of the store, for example, towards the customer&#39;s vehicle which may be parked outside the store or in a nearby parking lot. Accordingly, the customer may be required to hand-carry the purchased items, which may be heavy or cumbersome to carry, from the checkout point within the store to the vehicle. 
     Some stores allow the customer to take the shopping cart out of the store, for example, towards the customer&#39;s vehicle. Unfortunately, once the customer arrives at his vehicle, the customer has to manually unload the shopping cart, by transferring each purchased item (or each bag containing one or more purchased items) from the shopping cart to the customer&#39;s vehicle, e.g., to the trunk or compartment of the vehicle. This process may be inconvenient, effort consuming and/or time-consuming, particularly when the customer purchases a relatively large number of items or one or more relatively heavy items. 
     SUMMARY 
     Some embodiments include, for example, carts, collapsible carts and/or foldable carts, 
     In some embodiments, for example, a cart includes: a collapsible or non-collapsible chassis connected to a plurality of wheels; a basket mounted on the chassis and adapted to store one or more items therein; and a bridge element adapted to fit onto an edge of a vehicular trunk, wherein the bridge element is connected at a point located between said basket and said wheels. 
     In some embodiments, for example, the bridge element is moveable on one or more rails connected underneath the basket substantially in parallel to a long axis of the basket. 
     In some embodiments, for example, the bridge element is moveable on one or more rails connected to the chassis substantially in parallel to a long axis of the basket. 
     In some embodiments, for example, the bridge element has a general shape of an upside-down U. 
     In some embodiments, for example, the basket extends forward relative to the chassis. 
     In some embodiments, for example, the bridge element is adapted to reach a position extending beyond the length of the chassis. 
     In some embodiments, for example, the cart includes: one or more wheels connected at a bottom of a front end of the basket (or at a front end of a bottom of the basket, or in proximity to the front-end of the basket and/or the bottom of the basket, or at other suitable places), to smoothly glide the basket on a bottom of the vehicular trunk. 
     In some embodiments, for example, the cart includes: one or more wheels connected at a front end of a bottom of a of the basket, to smoothly glide the basket on a bottom of the vehicular trunk. 
     In some embodiments, for example, the chassis comprises: a first set of one or more collapsible beams, connecting a right side of the basket with a right side of the chassis; and a second set of one or more collapsible beams, connecting a left side of the basket with a left side of the chassis. 
     In some embodiments, for example, the first set of collapsible beams comprises one or more pivot brackets able to collapse said first set of collapsible beams; and the second set of collapsible beams comprises one or more pivot brackets able to collapse said second set of collapsible beams. 
     In some embodiments, for example, at least one of the first and second sets of collapsible beams is connected through to a pullable cable adapted to collapse said at least one set of collapsible beams upon pulling of said cable. 
     In some embodiments, for example, an end of the cable is connected to a handle adapted to be pulled by a hand of a human being. 
     In some embodiments, for example, the cable passes through a one-way roll-up mechanism adapted to maintain the cable partially pulled upon release of said handle. 
     In some embodiments, for example, a height of the basket from the ground is user-modifiable by modifying an angle of one or more of the pivot brackets. 
     In some embodiments, for example, the cart includes: a multi-step locking mechanism adapted to lock the height from the ground of the basket at a particular height set by a user. 
     In some embodiments, for example, the multi-step locking mechanism comprises: a set of ratchets; and a sliding pole, adapted to be moveable along a downward direction along said set of ratchets, and adapted to be unmovable along an upward direction along said set of ratchets. 
     In some embodiments, for example, the multi-step locking mechanism is lockable to avoid folding of the chassis, and is unlockable to allow folding of the chassis. 
     In some embodiments, for example, the basket is detachably attached to said chassis through one or more connectors. 
     In some embodiments, for example, the chassis comprises an extendable rail; and the basket is adapted, upon its release from said chassis, to glide along said extendable rail into said vehicular trunk. 
     In some embodiments, for example, the cart includes: one or more wheels connected at a bottom of a front end of the basket, to smoothly glide the basket on a bottom of said vehicular trunk. 
     In some embodiments, for example, one or more rails are connected underneath the basket and are connected to said bridge element; the basket is detachable from the chassis; and the basket is forward-movable along said one or more rails and relative to said bridge element when said bridge element is positioned over the edge of said vehicular trunk. 
     Some embodiments may provide other and/or additional benefits and/or advantages. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity of presentation. Furthermore, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. The figures are listed below. 
         FIG. 1A  is a schematic illustration of a three-dimensional isometric top-view of a cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 1B  is a schematic illustration of a three-dimensional isometric bottom-view of the cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 1C  is a schematic illustration of a side-view of the cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 2A  is a schematic illustration of a three-dimensional isometric top-view of the cart in a folded state, in accordance with some demonstrative embodiments. 
         FIG. 2B  is a schematic illustration of a three-dimensional isometric bottom-view of the cart in a folded state, in accordance with some demonstrative embodiments. 
         FIG. 2C  is a schematic illustration of a side-view of the cart in a folded state, in accordance with some demonstrative embodiments. 
         FIG. 3  is a schematic illustration of a three-dimensional isometric view of a portion of the cart, showing in greater detail a multi-step locking mechanism, in accordance with some demonstrative embodiments. 
         FIG. 4A  is a schematic illustration of a three-dimensional isometric top-view of another cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 4B  is a schematic illustration of a three-dimensional isometric bottom-view of the cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 4C  is a schematic illustration of another three-dimensional isometric bottom-view of the cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 4D  is a schematic illustration of a side-view of the cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 4E  is a schematic illustration of a front-view of the cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 4F  is a schematic illustration of a rear-view of the cart in an unfolded state, in accordance with some demonstrative embodiments. 
         FIG. 5  is a schematic illustration of a three-dimensional isometric top-view of another cart in an unfolded state, in accordance with some demonstrative embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of some embodiments. However, it will be understood by persons of ordinary skill in the art that some embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, units and/or circuits have not been described in detail so as not to obscure the discussion. 
     Although portions of the discussion herein may relate, for demonstrative purposes, to a shopping cart or to a supermarket car, some embodiments (or some features thereof) may be used in conjunction with various other types of carts and/or devices, for example, a stroller, a baby stroller, a carriage, a baby carriage, a cart used for carrying tools, a farm cart, a cart used for carrying one or more pre-defined items, an airport cart, a cart used typically in airports or train stations or central bus stations, or the like. 
     As an overview, some embodiments may provide a collapsible or foldable shopping cart, which may be inserted, with a significantly small effort, into a car trunk or a car compartment while the cart is loaded with items. The cart may subsequently be unload from the car trunk with its contents, and may expand to an open position and serve to deliver the content of the cart to the final destination (e.g., a home or other residence). 
     In some embodiments, the cart includes two components: a collapsible chassis, and a load box or a basket able to store items therein. The basket is a generally rectangular container, and is connected to the chassis. In some embodiments, the basket is non-detachable or non-separable from the chassis, and vice versa. 
     In some embodiments, the cart may optionally include an (optionally collapsible) “trunk invasion component” or “trunk penetration component”. When the cart is extended and erect, the trunk invasion component invades into the car trunk in order to provide support for the front side of the cart when its wheels and chassis are folded. In some embodiments, the trunk invasion component may be equipped with wheels or other sliding surfaces, for example, to reduce friction and/or to provide safe and smooth movement. The trunk invasion component may be connected to the front of the cart. In some embodiments, in a collapsed or folded state, the trunk invasion component does not extend, or only slightly extends, beyond the general outline of the cart or of the basket. In other embodiments, the trunk invasion component may extend beyond the general outline of the cart or of the basket; for example, by approximately one percent, by approximately two percent, by approximately five percent, by approximately ten percent, or by other suitable dimension ratio. 
     In some embodiments, for example, the bottom side of the basket may include an upside-down U-shape protective component or bridge element, which may be movable using one or more rails along the elongated axis of the basket. The protective component or bridge is attached to the bottom of the basket (or to other suitable part of the cart, for example, to the chassis beneath the basket, or to the front side of the cart) and may slide from the front to the rear side of the basket, and vice versa. In some embodiments, for example, the protective component may support the load of the basket and items stored therein; may prevent harm to the trunk or the car; and may further operate as a safety measure to prevent the cart from slipping to the ground when taking the cart out of the trunk. 
     In some embodiments, the chassis may include one double-leg on each side of the cart (namely, on the right side and on the left side). Each double-leg may include two (or more) beams, and may further include multiple pivot brackets or joins. In some embodiments, the two double-legs may be interconnected; and the two double-legs may be collapsed and expended from a single point. 
     Reference is now made to  FIG. 1A , which is a schematic illustration of a three-dimensional isometric top-view of a cart  100  in an unfolded state, in accordance with some demonstrative embodiments; to  FIG. 1B , which is a schematic illustration of a three-dimensional isometric bottom-view of cart  100  in an unfolded state, in accordance with some demonstrative embodiments; and to  FIG. 1C , which is a schematic illustration of a side-view of cart  100  in an unfolded state, in accordance with some demonstrative embodiments. Reference is further made to  FIG. 2A , which is a schematic illustration of a three-dimensional isometric top-view of cart  100  in a folded state, in accordance with some demonstrative embodiments; to  FIG. 2B , which is a schematic illustration of a three-dimensional isometric bottom-view of cart  100  in a folded state, in accordance with some demonstrative embodiments; and to  FIG. 2C , which is a schematic illustration of a side-view of cart  100  in a folded state, in accordance with some demonstrative embodiments. 
     In some embodiments, cart  100  may include a basket  110 , which may be connected to or mounted on a mount or a chassis  150 . In some embodiments, basket  110  may be generally elongated and generally box-shaped or generally rectangular, or may have other suitable shape (e.g., oval, ellipse shaped, egg shaped, circular, a box having rounded or smooth or non-sharp corners, a hexagon, an octagon, or the like). For example, basket  110  may have a generally horizontal bottom wall  111 , which may be generally parallel to the ground. Basket  110  may further have two smaller side walls  112 - 113 , for example, a front side wall  112  and a rear side wall  113 , which may be generally vertical or generally perpendicular to the ground. Basket  110  may further have two longer, or elongated, side walls  114 - 115 , for example, a right side wall  114  and a left side wall  115 , which may be generally vertical or generally perpendicular to the ground. 
     In some embodiments, basket  110  may have an open upper side or an open upper end, namely, basket  110  may not have a sixth wall or a cover, and may be open at its top in order to allow unobstructed insertion of items into basket  110 . In other embodiments, basket  110  may optionally include, or may be associated with, a top cover which may be used to cover the top side of basket  110 , or a portion thereof. For example, a removable cover may be used, or a foldable cover may be used, to allow a user to cover and uncover the top side of basket  110 , e.g., in order to protect items from rain, snow, sunlight, dust, or the like. In yet other embodiments, the upper side of basket  110  may be partially covered with a removable or non-removable cover, and may be partially non-covered, in order to allow the user to store some items under the partial cover and some items without the protection of the partial cover. 
     In some embodiments, basket  110  may be connected to one or more handles; for demonstrative purposes, a generally horizontal handle  120  is shown. Other types of handles may be used. Handle  120  may allow the user to conveniently grip the handle  120  in order to push and/or maneuver the cart  100 . 
     In some embodiments, basket  110  may be rigidly connected or attached to the chassis  150  such that basket  110  may not be separated or disconnected from chassis  150 . In other embodiments, basket  110  may be detachably-attached to chassis  150  (or vice versa), using one or more clips or locks, such that basket  110  may optionally be detached, separated or disconnected from the chassis  150 . 
     In some embodiments, the chassis  150  may be collapsible or foldable, as described herein. In some embodiments, the chassis  150  may include multiple wheels in order to allow the user to conveniently push, propel and/or maneuver the cart  100 , by applying directional force on the handle  120 . For example, two rear wheels  151 - 152  may be directionally locked and may be able to rotate (e.g., forward and backward, or clockwise and anti-clockwise) but may not be able to turn (e.g., left or right); whereas two front wheels  153 - 154  may be directionally unlocked and may be able to both rotate as well as turn. 
     For demonstrative purposes, four wheels  151 - 154  are shown; yet some embodiments may utilize other number of wheels or other configuration of wheels. In some embodiments, for example, a tricycle configuration may be used, in which a single front wheel is used (e.g., able to rotate and to directionally turn) together with two directionally-locked rear wheels. In other embodiments, six wheels may be used at the bottom part of chassis  150 , e.g., similar to a six-wheel configuration of some buses or some trucks. In some embodiments, other suitable configurations may be used. 
     In some embodiments, front wheels  153 - 154  may be connected through a generally horizontal front axle  155 . In some embodiments, a generally horizontal rear axle  156  may be used to connect the rear wheels  151 - 152 . 
     In some embodiments, the right-front wheel  153  may be connected to the right-rear wheel  151  through a right-side bar  161 ; and the left-front wheel  154  may be connected to the left-rear wheel  152  through a left-side bar  162 , which may be generally parallel to the right-side bar  161 . In some embodiments, each one of bars  161 - 162  may be generally horizontal at one end (e.g., at the front end), and may have an S-shape or a J-shape at the other end (e.g., at the rear end), in order to connect to the corresponding wheel from the top of the wheel (e.g., using a horizontal pivot or axis) and thereby allowing directional movement of the wheel in addition to wheel rotation. 
     In some embodiments, the front side of the basket  110  may extend forward beyond the front wheels  153 - 154 . For example, in some embodiments, approximately 25 percent or 33 percent or 40 percent of the length of basket  110  may extend forward beyond the front wheels  153 - 154 . 
     The chassis  150  may include one or more generally vertical and collapsible or foldable beams. For demonstrative purposes, two sets of beams are shown; other number of beams or sets of beams may be used. The first set of beams may include a right-side shorter beam  171 A and a left-side shorter beam  171 B. The second set of beams may include a right-side longer beam  172 A and a left-side longer beam  172 B. 
     In some embodiments, for example, the right-side shorter beam  171 A may be generally C-shaped, and may connect the right-side bar  161  (e.g., at approximately 25 or 33 percent of its length measured from the right-front wheel  153 ) with the front side of the right wall  114  of basket  110 . Similarly, the left-side shorter beam  171 B may be generally C-shaped, and may connect the left-side bar  162  (e.g., at approximately 25 or 33 percent of its length measured from the left-front wheel  154 ) with the front side of the left wall  115  of basket  110 . 
     For example, the right-side longer beam  172 A may be generally S-shaped, and may connect the front end of the right-side bar  161  with the right wall  114  of basket  110  (e.g., at approximately 30 or 35 percent of the length of the right wall  114  measured from the front side wall  111 ). Similarly, the left-side longer beam  172 B may be generally S-shaped, and may connect the front end of the left-side bar  162  with the left wall  115  of basket  110  (e.g., at approximately 30 or 35 percent of the length of the left wall  115  measured from the front side wall  111 ). 
     In some embodiments, each one of the beams  171 A,  171 B,  172 A and  172 B may include one or more joints or pivot brackets. For demonstrative purposes, each one of the beams  171 A,  171 B,  172 A and  172 B is shown with one pivot bracket; yet in some embodiments, each one of the beams  171 A,  171 B,  172 A and  172 B may include two or more joints or pivot brackets, for example, in order to increase the flexibility of collapsing or expanding the cart  100 . 
     In some embodiments, for example, the right-side shorter beam  171 A may have a pivot bracket  181 A, which allows the right-side shorter beam  171 A to fold or collapse. The pivot bracket  181 A may be in an extended position, in which the right-side shorter beam  171 A is fully extended; or may be in a closed position, in which the right-side shorter beam  171 A is folded or collapsed, partially or substantially entirely. In some embodiments, the right-side shorter beam  171 A may optionally include more than one pivot bracket  181 A. 
     Similarly, the left-side shorter beam  171 B may have a pivot bracket  181 B, which allows the left-side shorter beam  171 B to fold or collapse. The pivot bracket  181 B may be in an extended position, in which the left-side shorter beam  171 B is fully extended; or may be in a closed position, in which the left-side shorter beam  171 B is folded or collapsed, partially or substantially entirely. In some embodiments, the left-side shorter beam  171 B may optionally include more than one pivot bracket  181 B. 
     In some embodiments, the right-side longer beam  172 A may have a pivot bracket  182 A, which allows the right-side longer beam  172 A to fold or collapse. The pivot bracket  182 A may be in an extended position, in which the right-side longer beam  172 A is fully extended; or may be in a closed position, in which the right-side longer beam  172 A is folded or collapsed, partially or substantially entirely. In some embodiments, the right-side longer beam  172 A may optionally include more than one pivot bracket  182 A. 
     Similarly, the left-side longer beam  172 B may have a left-side pivot bracket (not shown), which allows the left-side longer beam  172 B to fold or collapse. The left-side pivot bracket may be in an extended position, in which the left-side longer beam  172 B is fully extended; or may be in a closed position, in which the left-side longer beam  172 B is folded or collapsed, partially or substantially entirely. In some embodiments, the left-side longer beam  172 B may optionally include more than one pivot bracket. 
     In some embodiments, a portion of the right-side longer beam  172 A may optionally pass through a portion of the pivot bracket  181 A of the right-side shorter beam  171 A. Similarly, a portion of the left-side longer beam  172 B may optionally pass through a portion of the pivot bracket  181 B of the left-side shorter beam  171 B. In some embodiments, the right-side longer beam  172 A may be connected to the right-side shorter beam  171 A through a joint or a pivot bracket; and similarly, the left-side longer beam  172 B may be connected to the left-side shorter beam  172 B through another joint or pivot bracket. 
     In some embodiments, the bottom side of the bottom wall  111  of basket  110  may have an upside-down U-shaped bridge element  116  (or “n” shaped bridge element) connected thereto. The bridge element  116  may be able to move back and forth, along a portion of the elongated axis of basket  110 , over one or more guideways or rails  117  (e.g., two rails  117  as shown). In some embodiments, the bridge element  116  may be used in order to protect the trunk of a vehicle once the basket  110  is placed thereon; and the motion of the bridge element  116  over the rails  117  may allow a controlled and scratch-free sliding motion of the basket  110  into the trunk of the vehicle. In some embodiments, the width of the bridge element  116  (e.g., from the right side to the left side) may be smaller or slightly smaller than the width of the basket  110 , such that bridge element  116  may be smaller or slightly smaller, in its long dimension, than the length of front axle  155 . For example, in some embodiments, the width of the bridge element  116  may be approximately 5 percent smaller, 10 percent smaller, 15 percent smaller, 20 percent smaller, 30 percent smaller, 40 percent smaller, or 50 percent smaller than the width of the basket  110 . In other embodiments the width of the bridge element  116  may be similar or substantially identical to the width of the basket  110 . In other embodiments, the width of the bridge element  116  may be greater or slightly greater than the width of the basket  110 , for example, approximately one percent greater, two percent greater, three percent greater, five percent greater, ten percent greater, or the like. Other suitable size ratios may be used. 
     In some embodiments, the rails  117  may be connected to the basket  110 , for example, underneath the basket  110 . In other embodiments, the rails  117  may be connected to the chassis  150 . In some embodiments, the rails  117 , or at least a portion thereof, may be substantially parallel or generally parallel to a long axis of the basket  110 ; may be substantially parallel or generally parallel to the longest dimension of the basket  110 ; may be substantially perpendicular to the rear side wall  113  and/or to the front side wall  112 ; may extend from the rear side wall  113  (or from a position relatively close to the rear side wall  113 ) to the front side wall  112  (or to a position relatively close to the front side wall  112 ); may be substantially parallel or generally parallel to the ground; may be substantially perpendicular or generally perpendicular to the front axle  155  and/or to the rear axle  156 ; may be substantially parallel or generally parallel to the right-side bar  161 , or to the left-side bar  162 , or to a line or a bar connecting the right-front wheel  153  with the right-rear wheel  151 , or to a line or a bar connecting the left-front wheel  154  with the left-rear wheel  152 ; or may be otherwise suitably positioned. 
     Optionally, one or more guiding wheels  118 - 119  may be located at the front side of the basket  110 , to allow smoother and substantially scratch-free and/or friction-free sliding motion of the basket  110  into the trunk of the vehicle. In some embodiments, sliding surfaces or other sliding components or guiding components may be used, instead of or in addition to the guiding wheels  118 - 119 . 
     In some embodiments, cart  110  may be implemented such that the distance between the ground and the bottom wall  111  of basket  110  ground may be higher, or slightly higher (e.g., approximately 5 or 10 or 15 or 20 percent higher) than a typical and/or average height of a trunk of a car. For example, in some embodiments, data may be collected in order to determine the average or typical height from the ground of trunks of top-selling or most-common vehicles (e.g., Toyota Camry, Toyota Corolla, Honda Accord, GMC Impala, Ford Taurus, or the like), and the collected and analyzed data may be used in order to determine the height from the ground to the bottom wall  111  of basket  110  (e.g., approximately 70 centimeters in Toyota Camry, approximately 73 centimeters in Toyota Corolla, approximately 76 centimeters in GMC Malibu, or the like). 
     In some embodiments, the height from the ground of the bottom wall  111  of basket  110  may be fixed and pre-defined, for example, based on typical and/or average heights from the ground of trunks (or edges of trunks, which are higher than the bottom of the trunk). In other embodiments, cart  100  may include a mechanism or one or more components which allow the user to modify the height from the ground of basket  110 , for example, by further extending or by partially collapsing one or more of the beams (e.g., beams  171 A,  171 B,  172 A and/or  172 B), or using other suitable height-changing mechanisms, height-increasing mechanisms, or height-reducing mechanisms. 
     In some embodiments, the user may push the cart  100  towards the open trunk of the vehicle, such that the front side of the basket  110  extends over the edge of the trunk. Then, the user may further delicately push or slightly maneuver the cart  100  such that the bridge element  116  is above the edge of the trunk. The user holds the handle  120 , and collapses or folds the beams  171 A,  171 B,  172 A and  172 B, such that the beams  171 A,  171 B,  172 A and  172 B become collapsed and folded beneath the basket  110  and in proximity to the basket  110 , or such that the  171 A,  171 B,  172 A and  172 B become substantially parallel to the bottom wall  111  (or in a small angel relative to the bottom wall  111 ), in contrast to being substantially perpendicular to the bottom wall  111  when the cart  100  is erect. The cart  110  is now temporarily held and balanced in place, for example, by the bridge element  116  which is held by the trunk edge, and by the handle  120  which is held by the user. The user may now slightly lift the handle  120 , which is connected to the basket  110 , and may thereby slide gently the basket  110  forward into the trunk, as the bridge element  116  slides backwards over the rails  117 . Once the bridge element  116  traverses the entire length of the rails  117  (e.g., which may be corresponding substantially to the entire length of the basket  110 ), the user slightly further lift the handle  120  and may push the portion of basket  110  which is still outside the trunk, into the trunk; optionally utilizing the guiding wheels  118 - 119  which may allow a smooth and scratch-free motion within of the basket  110  within the trunk. Once the rear side wall  113  traverses the edge of the trunk, and the entire basket  110  is located beyond the edge of the trunk, the user may delicately lower the basket  110  using the handle  120 , such that the basket  110  (and the chassis  150  which is collapsed and folded underneath it) lies within the trunk. It is noted that the basket  110  may remain in a substantially horizontal position during the entire insertion process, or at a relatively low angel (e.g., approximately 10 or 20 degrees relative to the ground), such that items within the basket  110  remain therewith and do not “spill out” of the basket  110  during the insertion process. It is further noted that in some embodiments, the wheels  151 - 154  of cart  110  may be implemented such that they do not interfere with folding of cart  100 ; for example, once cart  100  is folded, wheels  151 - 154  may be protruding externally (e.g., sideways) to basket  110 , or may be beneath basket  110 . 
     A substantially reversed order of operations may be used for removal of the cart  100  from the trunk of the vehicle. The user opens the trunk, and holds the handle  120  of the cart  100 . The user lifts the handle  120 , and pulls the basket  110  upward and backward (towards the user), such that the bridge element  116  is placed on the edge of the trunk. The guiding wheels  118 - 119  may assist the user to perform a smooth and scratch-free backward pulling motion. The user than proceeds to pull backwards the basket  110 , such that the bridge element  116  slides forward over the rails  117 . The upside-down U-shape of the bridge element  116  operates as a brake to prevent the user from accidentally pulling back the basket  110  beyond the edge of the trunk prior to unfolding or extending the folded chassis  150 . Once the basket  110  (or a major portion thereof) is external to the trunk, the chassis  150  is extended or unfolded to be in an erected position, in order to support the weight of the basket  110  and its contents once the entire basket  110  is pulled backward out of the trunk. 
     Reference is now made to  FIG. 3 , which is a schematic illustration of a three-dimensional isometric view of a portion of cart  100 , showing in greater detail a multi-step locking mechanism  121 , in accordance with some demonstrative embodiments. 
     In some embodiments, due to differences between the heights of trunks of various vehicles, cart  100  may include the multi-step locking mechanism  121  which allows the user to lock the chassis  150  of the cart  100  to accommodate the height of the particular vehicle trunk of the user. This allows the user to take out the cart  100  (e.g., substantially empty of any stored items) out of his vehicle trunk; to lock the cart  100  on a particular height; to utilize the cart  100  by filling it with items; and to return with the cart  100  to the vehicle, while the height of cart  100  is maintained due to the multi-step locking mechanism  121  and accommodates the height of the particular vehicle trunk of the user. In some embodiments, this may avoids a situation in which the cart  100  has a relatively large height (e.g., to accommodate the highest of common vehicle trunks), which may result in a “free fall” of possibly several centimeters when the cart  100  is folded into the car; the multi-step locking mechanism  121  thus avoids such “free-fall”, as well as safety concerns and user concerns associated therewith. In some embodiments, the multi-step locking mechanism  121  may further provide stability to cart  100 , for example, along the horizontal axis, thereby improving the durability and/or the performance of the chassis  150  and its components. 
     In some embodiments, the multi-step locking mechanism  121  may include, for example, a rigid clip or sleeve  123 , a sliding pole  124 , and a set of teeth or ratchets  122 . In some embodiments, for example, the rigid sleeve  123  may provide strength and horizontal stability; the sliding pole  124  may be able to slide downward along the set of teeth or ratchets  122 , such that a sliding upward is not available or not easily available due to a locking provided by the sliding pole  124  in the upward direction. The length of the set of teeth or ratchets  122  may allow a variety of locking positions, thereby providing a variety of heights into which the cart  100  may be locked. 
     Referring now back to  FIGS. 1A-1C  and  2 A- 2 C, in some embodiments, cart  100  may include a cable  125  to facilitate the folding of the cart  100 . For example, the user may arrive with the cart  100  to her vehicle; the user may place the cart  100  such that the basket  110  extends into the open trunk, and such that the bridging element  116  is placed above or on top of panel of the trunk; the user may unlock the locked chassis  150 , and may pull back the cable  125  in order to pull-up and fold the chassis  150  into a folded position under the basket  110 . The cable  125  may be connected to a non-returning rolling mechanism  126  and may end with a pull handle  127 , similar to or resembling (from a visual point of view, and/or from an external point-of-view) a cable and rolling mechanism of a lawn mower starter: for example, pulling of the handle  127  rotates an internal rolling component (e.g., a round or circular drum-shaped unit) which in turn rolls-up the cable  125 , which in turn pulls up the folding components of the chassis  150 . In some embodiments, the rolling mechanism  126  includes two rolling components that share a common axis or axle. For example, a first rolling component is a “user roller”, having a spiral spring and a free return mechanism; the first rolling component operates, upon the user pulling of the handle  127 , to rotate around the common axel and squeeze the spring; when the user releases the handle  127 , the first rolling component returns to its default position due to the power of the spring. As a result of the common axel, the rotation of the first rolling component also rotates the second rolling component, for example, a “legs roller” which may be a cylinder having a non-return mechanism. This split mechanism allows the user to practice several relatively short pulling operations in order to perform a full collapse operation. In some embodiments, the user may apply multiple pulls to handle  127  in order to completely fold the folding components of chassis  150 . In some embodiments, the folding process may commence at the particular height in which the cart  100  is positioned, e.g., based on the multi-step locking mechanism  121 . 
     In some embodiments, cart  100  may be implemented or manufactured by taking into account, for example, the average, the mean, or the common dimensions and/or heights and/or characteristics of popular vehicles in a particular market for which the cart  100  is intended; and by taking into account an average, a mean or a common cumulative volume of shopping items (e.g., for implementing an appropriate volume of basket  110 ). Some implementations may emphasize safety of operation, ease of operation, ability to operate the cart  100  (e.g., including the ability to fold and unfold the cart  100 ) by utilizing a minimal amount of physical force (e.g., to accommodate senior citizens), and the elimination of damage or scratches to the vehicle or its trunk. 
     In some embodiments, the chassis  150  may be implemented using multiple bars and beams, having multiple joints or pivot brackets. In some embodiments, each bar or beam (or a set of bar and beam) may support a pair of wheels (e.g., a front wheel and a corresponding rear wheel). In some embodiments, each bar or beam may be anchored to one or more (e.g., to two) anchoring points, in order to allow flexible folding. In some embodiments, bars or beams that are located at the right and left sides of the cart  100 , may be interconnected using one or more horizontal axles, in order to increase the stability of the cart  100  and the chassis  150 , and to avoid an instable “shaking” of the cart  100  sideways. In some embodiments, such bars and beams may be implemented to minimally protrude beyond the basket  110 , in order to allow a small form factor of the cart  100  once folded. 
     In some embodiments, cart  100  may be implemented in order to allow convenient folding of cart  100  into a collapsed or folded cart  100  having a relatively-small form factor. For example, the rear wheels  151 - 152  (and the horizontal rear axle  156  connecting them) may fold towards the rear side of the cart  100 , such that upon folding of cart  100  they are located behind the basket  110  and/or externally to basket  110 . In some embodiments, a gap  199  may be introduced into rails  117 , dividing each one of rails  117  into two rail-portions separated by the gap  199 . The gap  199  may be implemented as a cavity able to accommodate the horizontal front axle  155  upon folding of cart  100 . The gap  199  may be sufficiently small to allow the bridge element  116  to be able to continuously glide or move along the two rail-portions of each rail  117 , including over the gap  199 . Other suitable implementations may be used. 
     In some embodiments, cart  100  may be implemented using suitable dimensions and/or angles in order to allow stacking and/or nesting of multiple carts, or of multiple chassis components (e.g., if the basket  110  is detachable from the chassis  150 ). In some embodiments, for example, chassis  150  may be implemented to have a front side which is narrower and/or smaller then the rear side of chassis  150 , in order to facilitate stacking or nesting of multiple units of chassis  150 . 
     In some embodiments, other suitable combinations of basket, chassis, beams or bars, and wheels may be used. For example, in some embodiments, the basket  110  may be sufficiently strong and/or rigid to directly connect with a collapsible or foldable set of bars and/or beams, substantially without a chassis or through a relatively small or light-weight chassis. In some embodiments, the bridge element  116  may be connected to other suitable portions of the cart  100 , for example, to the basket  110 , to the bottom of basket  110 , underneath the basket  110 , in front of the basket  110 , to the chassis  150 , to one or more of the bars and/or beams of cart  100 , to multiple components of cart  100 , or the like. Other suitable implementations may be used. 
     In some embodiments, cart  100  may be implemented using other mechanisms. For example, in some embodiments, basket  110  may be detachable from chassis  150 , and a particular mechanism may be used (e.g., instead of the folding mechanism described above) for safe insertion of basket  110  into a trunk of a vehicle. For example, a sliding mechanism may include a first sliding member attached to basket  110 , and/or a second sliding member attached to chassis. The chassis may include a collapsible or extendable track or rail which guides the basket  110  (once detached) safely into the trunk of the vehicle. The basket  110  may include one or more rollers or gliding wheels which allow the basket  110  to move smoothly along its trail into the trunk. One or more connectors may be used to attach the basket  110  to the chassis  150 , and to selectively detach (by the user) the basket  110  from the chassis  150 . For example, when the user wishes to transfer the basket  110  into the vehicle trunk, the user pulls the rail from the chassis  150  towards the car trunk; the user unlocks the basket  110  (namely, detaches the basket  110  from the chassis  150  by releasing one or more clips or locks of connectors); and the user pushes the basket  110  along the extended rail. After the safe landing of the basket  110  in the vehicle trunk, the user returns the rail back to its original folded place. In contrast, when the user wishes to transfer the basket  110  from the vehicle trunk to be attached to the chassis  150  which stands outside of the vehicle, the user pulls the rail from the chassis  150  into to the vehicle trunk, and then pushes the basket  110  towards the chassis  150  along the rail. When the basket  110  reaches the rear end on the chassis  150 , the basket  110  is locked, for example, manually by the user, or automatically due to a locking mechanism or a clip or other component of connectors which auto-activates once the basket  110  reaches the rear end of the chassis  110 ; and the rail may then be put back to its original folded state. In some embodiments, other suitable implementations may be used. 
     Reference is now made to  FIG. 4A , which is a schematic illustration of a three-dimensional isometric top-view of a cart  200  in an unfolded state, in accordance with some demonstrative embodiments; to  FIG. 4B , which is a schematic illustration of a three-dimensional isometric bottom-view of cart  200  in an unfolded state, in accordance with some demonstrative embodiments; to  FIG. 4C , which is a schematic illustration of another three-dimensional isometric bottom-view of cart  200  in an unfolded state, in accordance with some demonstrative embodiments; to  FIG. 4D , which is a schematic illustration of a side-view of cart  200  in an unfolded state, in accordance with some demonstrative embodiments; to  FIG. 4E , which is a schematic illustration of a front-view of cart  200  in an unfolded state, in accordance with some demonstrative embodiments; and to  FIG. 4F , which is a schematic illustration of a rear-view of cart  200  in an unfolded state, in accordance with some demonstrative embodiments. 
     Cart  200  may include components which may be similar to the components of cart  100  described above, for example, a basket  210  and a chassis  250 . In accordance with some embodiments, in cart  200 , the basket  210  is attachable and detachable from chassis  250  (e.g., using one or more connectors, clips or locks). 
     In some embodiments, basket  210  and chassis  250  may include one or more front-side connectors  299 , as well as one or more rear-side connectors  298 , allowing the user of cart  200  to attach basket  210  to chassis  250 , and to detach or release or separate basket  210  from chassis  250 . Connectors  298  and  299  may be of a common type or of different types. For example, connectors  298  and/or  299  may include a connection mechanism in which a pin, a tooth, or a protrusion is insertable to (and removable from) a corresponding hole, recess, tunnel, cavity, corner holder, or other suitable member; as well as other suitable attachment/detachment mechanisms or locking/unlocking mechanisms. 
     In some embodiments, basket  210  and/or chassis  250  may include one or more guiding rails  297  or other suitable guiding components, in order to guide and/or to facilitate the insertion of the basket  210  into its corresponding place on top of chassis  250 . For example, the guiding rails  297  may guide the basket  210  (e.g., when pushed towards the chassis  250  or along the chassis  250 ) towards the center of the chassis  250  and/or towards the rear-side connectors  298 . 
     In some embodiments, chassis  250  includes a set of bars and beams, as well as four wheels  251 - 254 ; other suitable number of wheels may be used. In some embodiments, rear wheels  251 - 252  may be larger, or significantly larger (e.g., at least 50 percent larger), than front wheels  253 - 254 ; this may improve the stability of cart  200 , and/or may allow efficient pulling backwards of cart  200  (e.g., onto a stair, a set of stairs, a ramp, a pavement, or the like). Chassis  250  may further include one or more handles  220 , as well as a hook  231  for hanging a bag or purse. 
     In some embodiments, cart  200  may be implemented using suitable dimensions and/or angles and/or characteristics in order to allow stacking and/or nesting of multiple carts, or of multiple chassis components (e.g., once the basket  210  is detached from the chassis  250 ). In some embodiments, for example, chassis  250  may be implemented to have a front side which is narrower or smaller then the rear side, in order to facilitate stacking or nesting of multiple units of chassis  250 . 
     The bottom side of basket  210  may include, or may be connected to, one or more tracks or rails  217 , on which an upside-down U-shaped bridge element  216  may be connected and may be movable thereon. 
     A user may utilize cart  200  by placing items inside the basket  210  (e.g., in a store or a supermarket), and may push the cart  200  from the checkout point to the user&#39;s vehicle. The user may open the trunk of the vehicle, and may gently push the cart  200  forward until the front side of cart  200  reaches the elevated edge of the vehicular trunk. In some embodiments, chassis  250  may include a reaching bar  232 , for example, located at the front of chassis  250  and under the plane of bridge element  216 . The reaching bar  232  may block the user of cart  200  too hard into the vehicle, and may indicate to the user that the edge of the chassis  250  reached the edge of the vehicular trunk. In some embodiments, one or more portions of the reaching bar  232  may be covered or coated with a sleeve  233 , for example, made of plastic or foam or a non-rigid material, which may absorb force applied by the user who may push the cart  200  forward towards the trunk, and/or may avoid scratching or damaging the vehicle upon contact between the chassis  250  and the vehicle. 
     In some embodiments, cart  200  may be implemented, for example, such that when bridge element  216  is located slightly higher than the trunk edge of the vehicle, or slightly higher than an average or common height of vehicular trunks. For example, once the reaching bar  232  touches the vehicle or its trunk, the bridge element  216  may be located above the edge of the vehicular trunk. The user may detach the basket  210  from the chassis  250  (or vice versa), using the suitable clips, locks or other connectors of cart  200 . Optionally, the user may assist the basket  210  to drop gently a few centimeters, such that bridge element  216  is mounted on the edge of the vehicular trunk. At this point in time, the basket  210  is still held by the chassis  250  (from which basket  210  was already detached), and by the bridge element  216  which lays on the edge of the vehicular trunk. 
     Then, the user pushes forward the basket  210 , applying force in a forward direction, while maintaining the bridge element  216  static and non-moving. In some embodiments, cart  200  may include two separate handles  220  (e.g., in contrast with the single horizontal handle  120  discussed above), in order to facilitate the access of the user to the basket  210  and to facilitate the pushing forward of the basket  210  without obstruction by the handles  220  (e.g., the user optionally standing between the two handles  220 ). In some embodiments, cart  200  may include a set of handles, for example: two separate side-handles  220 ; as well as a horizontal handle or a “n” shaped handle or a central handle  296 , which may be slightly narrower than the distance between the two separate side-handles  220 , and may have chamfered corners or rounded corners or diagonally-cut corners, in order further facilitate the user&#39;s access to the basket  210 , and/or to facilitate the user-controlled lifting and/or releasing of basket  210 , and/or to further facilitate the guiding or centering of the basket  210  relative to the rear side of chassis  250  (e.g., further to the guiding provided by the guiding rails  297 ). Other suitable handle combinations may be used. 
     Due to the rails  217 , basket  210  glides or slides forward towards and/or into the trunk; during this forward motion of basket  210 , the bridge element  216  remains substantially static and non-moving relative to the trunk. Optionally, one or more guiding wheels  218  may be connected to the bottom-front section of basket  210 , and may help the user to produce a smooth and scratch-free guiding of the detached basket  210  into the trunk. 
     In some embodiments, optionally, chassis  250  may be implemented using a suitable set of beams and/or bars, for example, one or more “L” shaped or “n” shaped support bars  234 , which may support the detached basket  210  during its gliding into the trunk, and to ensure that the detached basket  210  does not fall to the ground (e.g., through a vertical “cavity” within the chassis  250 . 
     Once the rear end of the rails  217  reaches the bridge element  216 , the user may finalize the insertion of the basket  210  into the vehicular trunk. For example, the user may slightly lift the rear side of the basket  210  by a few centimeters (e.g., to release the bridge element  216  from the edge of the trunk); the user may gently push forward the basket  210 , thereby guiding the basket  210  (using the guiding wheels  218 ) a few centimeters forward to traverse the trunk edge; and the user may then gently lower the rear end of the basket  210  until the entire basket  210  rests firmly within the trunk. 
     Upon placement of the basket  210  within the trunk, the user may handle the chassis  250  which is outside the trunk. In some embodiments, the chassis  250  may be non-collapsible or non-foldable, and the user may return the chassis  250  to the shop, or the user may push the chassis  250  to a designated storage place for chassis units (e.g., optionally nesting multiple chassis units). In other embodiments, chassis  250  may be collapsible or foldable, for example, using one or more joints or pivot brackets (e.g., as described above), and the user may fold or collapse the chassis  250  and may then place the folded chassis  250  inside the trunk or inside the vehicle&#39;s passenger cabin. 
     In some embodiments, removal of the basket  210  from the vehicular trunk may be performed using a set of reversed operations. In some embodiments, for example, the user may lift the rear end of the basket  210 , and may pull it back a few centimeters, in order to position the bridge element  216  over the edge of the trunk. The user may then pull back the basket  210  relative to the static bridge element  216 , and the basket  210  may move outward using the rails  217 . Once the front side of the rails  217  reaches the bridge element  216 , the user connects or attaches the basket  210  to the chassis  250  located outside the trunk and underneath the pulled-back basket  210 ; and optionally, the user slightly lifts the front side of the basket  210  in order to release the bridge element  216  from the trunk edge. Other suitable operations or sets of operations may be used. 
     In some embodiments, the rear end of basket  210  may include, or may be connected to, a gripping handle to facilitate the lifting or lowering of the rear end of basket  210 . In some embodiments, the top portion of chassis  250  may include bars and beams that are substantially horizontal or substantially parallel to the ground; in other embodiments, bars and beams in the top portion of chassis  250  may be diagonal or slightly diagonal relative to the ground (e.g., going down towards the front side of the chassis  250 , at an angel of 10 degrees), for example, in order to accommodate insertion of the basket  210  into low-height trunks, and/or in order to allow nesting of multiple chassis units. 
     In some embodiments, basket  210  (or basket  110  described above) may be implemented to include sub-baskets or other sub-containers, e.g., to allow orderly placement or storage or grouping of various items (e.g., fruits and vegetables, or chilled items, or frozen items), and/or to allow convenient and selective partial removal of one or more sub-containers independently of the removal of other sub-containers. 
       FIG. 5  is a schematic illustration of a three-dimensional isometric top-view of a cart  500  in an unfolded state, in accordance with some demonstrative embodiments. Cart  500  and its components may be generally similar to cart  100  of  FIG. 1A  and its components. 
     Cart  500  may include a trunk penetration component  501  (or other trunk invasion component) which may be used in addition to a bridge element or instead of a bridge element. Cart  500  includes a basket  510  and a chassis  550  (e.g., a collapsible or foldable chassis). For demonstrative purposes, cart  500  is shown without a bridge element, and with a trunk penetration component  501  implemented using two curved legs  502  extending from the front side of the basket  510 , or from the bottom-front side of basket  510 . In other embodiments, a single leg, or three or more legs, may be used; for example, one central leg may be used, or two side-legs may be used as shown, or other suitable combinations may be used. In still other embodiments, the legs need not be curved, and may be substantially linear, may be diagonal (e.g., extending diagonally downward and forward from the basket  510 ), may be S-shaped, may be L-shaped, or the like. In some embodiments, the one or more legs  502  may terminate with one or more wheels  503 , in order to allow smooth and substantially scratch-free and/or friction-free sliding motion of the basket  510  into the trunk of the vehicle (e.g., upon collapsing or folding of the cart  500  and/or of the chassis  550 ). In some embodiments, the one or more legs  502  may be rotatable or retractable using a hinge  504 , in order to allow the folding backwards (e.g., towards the basket  510 ) of the one or more legs  502  upon complete insertion of the cart  500  into the vehicular trunk; and optionally allowing the one or more legs  502  to enter, partially or entirely, into one or more corresponding cavities or recesses or leg-holders, which may be included in basket  510  or externally to basket  510  in order to contain or hold the one or more legs  502 . Other suitable mechanisms may be used for invasion or penetration of vehicular trunks, and/or for allowing smooth insertion of the collapsible cart  500  into the vehicular trunk. 
     The terms “plurality” or “a plurality” as used herein include, for example, “multiple” or “two or more”. For example, “a plurality of items” includes two or more items. 
     The word “comprising” as used herein includes, for example, the term “including at least but not limited to”. The term “comprises” as used herein includes, for example, the term “includes at least but not limited to”. 
     Functions, operations, components and/or features described herein with reference to one or more embodiments, may be combined with, or may be utilized in combination with, one or more other functions, operations, components and/or features described herein with reference to one or more other embodiments, or vice versa. 
     While certain features of some embodiments have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. Accordingly, the following claims are intended to cover all such modifications, substitutions, changes, and equivalents.