Abstract: A construction set including a set of interlocking blocks and a container for the set which can be constructed so that at least a part of the container interlocks with the blocks. As a consequence, a structure may be erected using both the blocks and the container. Such a structure is desirable because it is significantly larger than a structure which could be created from the set of blocks alone.

Abstract: Structures including a platform and a slide located adjacent to the platform which are primarily useful for play purposes can be constructed so as to fold into an essentially small, flat configuration for storage and shipment purposes. Such structures are constructed utilizing a support including two normally upright sections connected by a plurality of links or link-type structures, one of which extends between the sections and serves as the platform. The links or link-type structures used are connected to the sections so that the sections can be manipulated between an open position in which they are spaced from one another and a folded position in which the sections are adjacent to one another.

Abstract: A wheeled vehicle primarily useful for play purposes can be constructed so that it can be manipulated or folded between an open position in which the vehicle can be used and a folded, relatively flat position in which it can conveniently be shipped and stored. The vehicle described includes sides or side panels which are connected by a front hinge and which are also connected by back and bottom panels. These back and bottom panels are hinged relative to one another and relative to the sides so as to permit folding and unfolding. Preferably the front hinge has a pivot pin which carries one of the wheels used to support the vehicle and which also carries a handle used in steering the vehicle. Other wheels are provided on the extremities of the sides remote from the front hinge.

Abstract: Hollow, generally rectilinear structures having a top, a bottom, sides and ends can be constructed so as to be capable of being manipulated between a "normal" or unfolded type configuration and a collapsed or folded configuration in which the ends extend generally parallel to and beneath the top and in which the sides are folded so as to be located next to the ends generally between the bottom and the top. Such a structure includes hinges connecting the ends to the top so that they can be pivoted so as to lie generally parallel to the top. Such a structure also includes a frame or frame-type elements forming a part of the top and extending adjacent to the ends when the ends are folded into such a collapsed position.

Abstract: A folding structure useful as a "climber" or climbing type play equipment for children can be constructed so as to utilize an odd number of sides located in side edge to side edge relation. One of the sides used can be referred to as an end side; the remainder of the sides consist of an even number of pairs of sides, the sides on each of the pairs having identical external dimensions. Hinges are utilized to connect the adjacent edges of all of the sides to one another so as to form a continuous "band" type structure. The sides are of such external dimensions as to permit them to be folded between an open position in which all of the sides define a hollow structure and a collapsed position in which the sides of the pairs of sides extend adjacent to one another in a stacked relationship and in which the end side extends along side edges of the sides as they are located in this stacked configuration.

Abstract: Two-wheeled carts can be constructed so that their bodies can be manipulated between a normal, expanded configuration in which such carts can be used and a folded, relatively compact configuration in which such carts may be easily and conveniently stored. Such foldable carts include side walls, at least one of which is constructed so as to include two panels and a hinge connecting such panels in edge-to-edge relationship. A connector pivotally connects the side walls so that they can be manipulated so as to be moved generally toward one another as the structure is manipulated from the unfolded to the folded configuration. The extremities of these side walls are connected by end walls each of which consist of two wall sections connected in edge-to-edge relationship by center edge hinges. The wall sections have side edges which are connected to the sides by side edge hinges.

Abstract: Folding structures useful for a variety of different utilitarian and play purposes can be constructed so as to utilize a Sarrus linkage modified so as to include an overcenter toggle mechanism to reinforce the linkage against inadvertent or undesired folding from an expanded position. As used in accordance with the invention such a Sarrus linkage includes two non-folding members or walls which are connected by two separate folding wall structures. Each of such wall structures includes two non-folding parts, an intermediate hinge connecting such parts, and edge hinges connecting such parts to the non-folding members or walls.

Abstract: A structure such as a doghouse can be constructed so as to be capable of being folded between an expanded configuration in which parallel side walls are connected by a top, a bottom, and parallel ends and a folded configuration in which the side walls are adjacent to one another. In order to achieve a folding action the top, the bottom and the ends each consists of a set of two parts. The parts of each of these sets extend between the side walls. A first group of hinges are used to pivotally connect the parts of each of the sets to the side walls. A second group of hinges are employed to connect the parts of each set midway between the side walls. All of the hinges of both groups which are secured to the top and the bottom have parallel axes and all of the hinges of both groups secured to the ends have parallel axes. Further, all of the axes of the hinges of the second group are located in a common plane midway between the side walls.

Abstract: A folding wheelbarrow can be constructed so as to utilize a wheelbarrow body which is adapted to be folded or manipulated from a normal position into a folded position. Such a body is attached to a wheel support serving to carry a normal wheel and handles. In order to achieve a satisfactory folding action each such body is constructed so as to have a bottom wall including at least two bottom panels, a front wall having at least two front wall panels and sides connected by the bottom wall panel and the front wall panel. A plurality of separate linkage hinges connect the bottom and front wall panels and the sides so as to permit Sarrus-type motion of the panels and the sides during manipulation of the body from a normal position into a folded position. A latch or latch-type structure is preferably used to connect at least two parts which pivot relative to one another during such folding so as to hold the body in its normal position.

Abstract: A folding, rigid tent-like structure useful for a variety of play purposes can be constructed so as to utilize a pair of sides. These sides have top edges which are preferably connected by a connector and appropriate hinges so that the sides may be pivoted relative to one another. A pair of bottom walls are located between these sides adjacent to the bottom edges of these sides. The bottom walls have pivotally connecting adjacent edges and side edges which are pivotally connected to the sides. At least one folding link structure is secured to the sides beneath the bottom wall. This folding link structure serves to support the bottom walls against sagging. The tent-like structure may be folded to a flat position by concurrently folding the link structure between the sides and folding the bottom walls so that they are adjacent to one another between the sides as the sides themselves are pivoted so as to be adjacent to one another.