CLOSURE FOR SLEEPING BAG

Description

CROSS-REFERENCE TO RELATED APPLICATION1. FIELD OF THE I NVENTION

[0001] The field of the present invention relates to sleeping bags. In particular, disclosed herein are various closure arrangements for a sleeping bag.2. BACKGROUND

[0002] US4217662 discloses a comforter having a blanket-like body member which is provided with closure members for enclosing a lower portion thereof so that one lower side edge is secured to a corresponding opposite lower side edge and the bottom edge is secured together to define a sack-like robe configuration. A snap fastener is disposed at each upper corner for attachment to associated snap fasteners disposed adjacent to but slightly above the closure member on the side edges so that the upper half side edges can be held in a folded condition to provide a pair of sleeve portions on the body member, each sleeve portion having a predetermined maximum sleeve opening. At least two additional snap fasteners are disposed at intermediate positions on each upper half side edge for securement together to obtain a preselected sleeve opening smaller than the maximum sleeve opening. Preferably, several snap fasteners are disposed along the top edge of the body member for engagement therebetween to enclose the body member around the wearer's chest.3. SUMMARY

[0003] A first inventive article comprises a quilt usable as a sleeping bag, first and second pairs of discrete, mating bottom fastener elements, an inner set of one or more quilt fastener elements, an outer set of one or more quilt fastener elements, and a draw cord. The bottom fastener elements are attached to the quilt along the quilt bottom edge; one discrete bottom fastener element of the first pair is positioned between the discrete bottom fastener elements of the second pair, and one discrete bottom fastener element of the second pair is positioned between the discrete bottom fastener elements of the first pair. The bottom fastener elements thereby define a first quilt bottom edge lateral segment between the first pair of bottom fastener elements but not between the second pair of bottom fastener elements, a second quilt bottom edge lateral segment between the second pair of bottom fastener elements but not between the second pair of bottom fastener elements, and a quilt bottom edge central segment between both pairs of bottom fastener elements. The inner set of quilt fastener elements is attached to the quilt inner surface along at least a portion of a linear or curved inner quilt attachment path; the outer set of quilt fastener elements is attached to the quilt outer surface along at least a portion of a linear or curved outer quilt attachment path. The inner quilt attachment path extends from the first quilt lateral edge to the first quilt bottom edge lateral segment and defines on the quilt inner surface an inner quilt- overlap areal segment bounded by the inner quilt attachment path, the quilt bottom edge, and the first quilt lateral edge. The outer quilt attachment path extends from the second quilt lateral edge to the second quilt bottom edge lateral segment and defines on the quilt outer surface an outer quilt-overlap areal segment bounded by the outer quilt attachment path, the quilt bottom edge, and the second quilt lateral edge.

[0004] With the quilt wrapped in an overlapping footbox-wrapped arrangement, (i) the outer quilt-overlap areal segment faces a portion of the quilt inner surface, (ii) the inner quilt-overlap areal segment faces a portion of the quilt outer surface, (iii) each quilt fastener element of the inner set is substantially aligned with a corresponding, mating quilt fastener element of the outer set, and (iv) engagement of the corresponding mating quilt fastener elements of the inner and outer sets with each other retains at least a footward portion of the quilt in the overlapping footbox-wrapped arrangement. With the quilt wrapped in the overlapping footbox-wrapped arrangement, (i) the first pair of mating bottom fastener elements is positioned so as to engage each other, (ii) the second pair of mating bottom fastener elements is positioned so as to engage each other, and (iii) engagement of the first pair of bottom fastener elements with each other and engagement of the second pair of bottom fastener elements with each other retain at least the quilt bottom edge in the overlapping footbox-wrapped arrangement with the first and second quilt bottom edge lateral segments overlapping each other. The draw cord is engaged with the quilt bottom edge. With the quilt retained in the overlapping footbox-wrapped arrangement by engagement of the first pair of bottom fastener elements with each other, engagement of the second pair of bottom fastener elements with each other, and engagement of the corresponding quilt fastener elements of the inner and outer sets with each other, pulling the draw cord gathers the quilt bottom edge to form a closed, wrapped footbox of the sleeping bag.

[0005] A second inventive article comprises a sheet adapted for use with a sleeping bag, a first set of one or more sheet fastener elements, and a second set of one or more sheet fastener elements. The sheet is structurally arranged to be secured to a sleeping pad. The first and second sets of sheet fastener elements are attached to an outer surface of the sheet and structurally arranged along corresponding linear or curved first and second sheet attachment paths on the sheet outer surface. The first and second attachment paths are structurally arranged generally longitudinally along at least corresponding footward portions of respective first and second lateral edges of the sheet. The sheet fastener elements and the first and second sheet attachment paths are structurally arranged so as to enable (i) the first set of sheet fastener elements and a corresponding first set of quilt fastener elements of a quilt usable as a sleeping bag to engage each other, and (ii) the second set of sheet fastener elements and a corresponding second set of quilt fastener elements of the quilt to engage each other. With the quilt in an unwrapped arrangement with the first and second sets of quilt fastener elements disengaged from each other, and with the quilt positioned over the sheet with a quilt inner surface facing the sheet outer surface, (i) each quilt fastener element of the first set is substantially aligned with a corresponding, mating sheet fastener element of the first set, (iii) each quilt fastener element of the second set is substantially aligned with a corresponding, mating sheet fastener element of the second set, and (iv) engagement of the corresponding mating quilt and sheet fastener elements of the respective first sets with each other, and engagement of the corresponding mating quilt and sheet fastener elements of the respective second sets with each other, retain at least a footward portion of the quilt secured to the sheet in a footbox-expanded arrangement.

[0006] Objects and advantages pertaining to sleeping bags may become apparent upon referring to the example embodiments illustrated in the drawings and disclosed in the following written description or appended claims.

[0007] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0008] The scope of the invention is limited by the appended claims.(a) BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figs. 1A and 1B are schematic outer and inner views, respectively, of an example quilt of an inventive sleeping bag in a flattened arrangement. Figs. 2A and 2B are schematic inner and bottom views, respectively, of the example quilt of Figs. 1A / 1B in an overlapping footbox-wrapped arrangement. Fig. 2C is a schematic bottom view of the example quilt of Figs. 2A / 2B with the bottom edge gathered by the draw cord to form a closed, wrapped footbox of the sleeping bag. Figs. 3A and 3B are schematic outer and inner views, respectively, of another example quilt of an inventive sleeping bag in a flattened arrangement. Figs. 4A and 4B are schematic outer and inner views, respectively, of another example quilt of an inventive sleeping bag in a flattened arrangement. Fig. 5A is a schematic outer view of an example sheet of an inventive sleeping bag secured to a sleeping pad. Fig. 5B is a schematic bottom view of the example quilt of Figs. 4A / 4B attached in a footbox-expanded arrangement to the example sheet of Fig. 5A. Fig. 5C is a schematic bottom view of the example quilt of Fig. 5B with the bottom edge gathered by the draw cord to form a closed, expanded footbox of the sleeping bag. Figs. 6A and 6B are schematic outer and inner views, respectively, of another example quilt of an inventive sleeping bag in a flattened arrangement. Figs. 7A and 7B are schematic outer views of another example quilt and another example sheet of an inventive sleeping bag. Fig. 8A is a schematic bottom view of the example quilt of Fig. 7A in an open footbox-wrapped arrangement. Fig. 8B is a schematic bottom view of the example quilt of Fig. 7A in a closed footbox-wrapped arrangement. Fig. 9A is a schematic bottom view of the example quilt of Fig. 7A attached in an open footbox-expanded arrangement to the example sheet of Fig. 7B. Fig. 9B is a schematic bottom view of the example quilt of Fig. 7A attached in a closed footbox-expanded arrangement to the example sheet of Fig. 7B. Figs. 10A and 10B are schematic outer views of another example quilt and another example sheet of an inventive sleeping bag. Fig. 11A illustrates schematically partly engaged half-zipper fastener elements. Fig. 11B illustrates schematically engaged cord loop and hook fastener elements.

[0010] The embodiments depicted are shown only schematically; all features may not be shown in full detail or in proper proportion, certain features or structures may be exaggerated relative to others for clarity, and the drawings should not be regarded as being to scale. The embodiments shown are only examples, and should not be construed as limiting the scope of the present disclosure or appended claims.4. DETAILED DESCRIPTION OF EMBODIMENTS

[0011] An inventive sleeping bag is illustrated schematically in Figs. 1A / 1 B and includes a quilt 100 usable as a sleeping bag, a first pair of bottom fastener elements 121a / 121 b, a second pair of bottom fastener elements 122a / 122b, an inner set of one or more quilt fastener elements 131, an outer set of one or more quilt fastener elements 141, and a draw cord 160 (omitted from Figs. 1A / 1 B so as to avoid cluttering the drawing). If only a single inner quilt fastener element is present it is referred to herein as inner quilt fastener element 131; if multiple inner quilt fastener elements are present, they are referred to individually as inner quilt fastener elements 131a / 131 b / ... and collectively as inner quilt fastener elements 131. Similarly, if only a single outer quilt fastener element is present it is referred to herein as outer quilt fastener element 141; if multiple outer quilt fastener elements are present, they are referred to individually as outer quilt fastener elements 141a / 141 b / ... and collectively as outer quilt fastener elements 141.

[0012] The quilt has a headward top edge 100a, a footward bottom edge 100b, a first lateral edge 100c, a second lateral edge 100d, an outer surface 100e, and an inner surface 100f. In some examples, the quilt 100 is substantially trapezoidal with the top and bottom edges 100a / 100b substantially parallel and the bottom edge 100b shorter than the top edge 100a; in other examples, the quilt 100 is substantially rectangular; other suitable shapes can be employed. The quilt 100 typically includes a quilted construction, i.e., two layers of fabric with some soft substance (e.g., wool, down, or other natural or synthetic insulation) between them and stitched in patterns or tufted through all thicknesses in order to prevent the filling from shifting (light dashed lines in the drawings indicate stitching). The stitching shown in the drawings notwithstanding, the term "quilt" is used generically herein to indicate any quilt-like or blanket-like article suitable for use as all or part of a sleeping bag; use of the term "quilt" is not intended to imply that the article so named must necessarily include quilting or be wholly or partly quilted, although such articles are encompassed by the term "quilt" as employed herein. The quilt 100 can be made in any suitable way from any one or more suitable materials. Any one or more materials ( e.g., fabrics or insulators) suitable for constructing a conventional sleeping bag can be employed for constructing an inventive sleeping bag (or inventive sheet; see below). Examples of such materials include, but are not limited to: nylon, polyester, silk, cotton, taffeta, ripstop, pongee, flannel, microfiber, Gore-Tex, or fleece; natural down, synthetic insulation, or other insulating material; or metal-coated polymer film or other thermally shielding or thermally reflective material. If needed or desired, the quilt (and / or a sheet; see below) can include heating elements, e.g., electrical or chemical heating elements.

[0013] The discrete bottom fastener elements 121a / 121 b / 122a / 122b are attached to the quilt along the quilt bottom edge 100b; the first pair comprises mating bottom fastener elements 121a / 121 b, and the second pair comprises mating bottom fastener elements 122a / 122b. "Along the quilt bottom edge 100b" encompasses arrangements wherein the bottom fastener elements 121a / 121 b / 122a / 122b are attached at the quilt bottom edge 100b as well as arrangements wherein those fastener elements are displaced slightly from the quilt bottom edge 100b to leave a narrow strip of the quilt along the quilt bottom edge 100b to act as a baffle. "Discrete" fastener elements are to be contrasted with "continuous" fastener elements. A continuous fastener element attaches together different portions of a quilt or a sheet along a continuous line of attachment, leaving no significant gaps along that line of attachment. Examples of continuous fastener elements include but are not limited to, e.g., mating halves of a zipper 701 (Fig. 11A), mating strips of hook material and loop material of a hook-and-loop fastener ( e.g., Velcro ®< ), or strips of magnetic plastic ( e.g., such as is used for refrigerator magnets). Discrete fastener elements attach together different portions of a quilt or sheet at only localized attachment points or areas along an attachment path, leaving gaps between those localized attachment points or areas. Examples of discrete fastener elements include but are not limited to, e.g., a cord loop 801 and a hook 802 to retain the cord loop (Fig. 11B), mating male and female snap elements, mating button and button hole, mating male and female buckle or clasp elements, mating circumscribed patches of hook material and loop material of a hook-and-loop material, or pairs of magnets. Note the difference between a cord loop 801 and a hook 802 (i.e., a single loop 801 of an elastic or inelastic cord material, and a hook 802 arranged to engage and retain the cord loop 801; as in Fig. 11B) versus a hook-and-loop material ( e.g., Velcro ®< ) that includes myriad tiny loops and tiny hooks arranged on strips or patches. In drawings showing all or portions of a quilt or sheet, fastener elements of a mating or corresponding pair are indicated by an "X" for one fastener element (e.g., a hook) and an "O" for the other fastener element (e.g., a cord loop). It is not intended that every "X" or that every "O" in a given drawing necessarily indicates the same type of fastener element, although that can sometimes be the case.

[0014] The two pairs of discrete bottom fastener elements 121a / 121 b and 122a / 122b are arranged along the quilt bottom edge 100b so that only one discrete bottom fastener element 121b of the first pair is positioned between the discrete bottom fastener elements 122a / 122b of the second pair, and only one discrete bottom fastener element 122b of the second pair is positioned between the discrete bottom fastener elements 121a / 121 b of the first pair. The bottom fastener elements 121a / 121 b / 122a / 122b thus divide the quilt bottom edge 100b into a first quilt bottom edge lateral segment 100b-1, a quilt bottom edge central segment 100b-2, and a second quilt bottom edge lateral segment 100b-3. The first quilt bottom edge lateral segment 100b-1 lies between the first pair of bottom fastener elements 121a / 121 b but not between the second pair of bottom fastener elements 122a / 122b (thus between bottom fastener elements 121a and 122b); the second quilt bottom edge lateral segment 100b-3 lies between the second pair of bottom fastener elements 122a / 122b but not between the first pair of bottom fastener elements 121a / 121 b (thus between bottom fastener elements 121b and 122a); the quilt bottom edge central segment 100b-2 lies between both pairs of bottom fastener elements 121a / 121 b and 122a / 122b (thus between bottom fastener elements 121b and 122b). In some examples, the bottom fastener element 121a is positioned where the first quilt lateral edge 100c meets the quilt bottom edge 100b ( e.g., at one bottom corner of a rectangular or trapezoidal quilt 100), and the bottom fastener element 122a is positioned where the second quilt lateral edge 100d meets the quilt bottom edge 100b (e.g., at the other bottom corner of a rectangular or trapezoidal quilt 100). In such examples, the quilt bottom edge segments 100b-1, 100b-2, and 100b-3 encompass the entire quilt bottom edge 100b.

[0015] The footward portion of the quilt 100 can be wrapped or folded into an overlapping footbox-wrapped arrangement ( e.g., as in Figs. 2A / 2B / 2C; stitching omitted to avoid cluttering the drawings). In that arrangement, the quilt bottom edge lateral segments 100b-1 and 100b-3 overlap each other. Also in that arrangement, the mating discrete bottom fastener elements 121a / 121 b are positioned opposite each other, and the mating discrete bottom fastener elements 122a / 122b are positioned opposite each other. Engagement of the bottom fastener elements 121a / 121 b with each other and engagement of the bottom fastener elements 122a / 122b with each other retain at least the quilt bottom edge 100b in the overlapping footbox-wrapped arrangement with the first and second quilt bottom edge lateral segments 100b-1 and 100b-3 overlapping each other (may be referred to herein as a spiral or corkscrew arrangement of the quilt bottom edge 100b; seen most clearly in Fig. 2B).

[0016] The inner set of one or more quilt fastener elements 131 is attached to the quilt inner surface 100e along at least a portion of a linear or curved inner quilt attachment path 130. The inner quilt attachment path 130 extends from the first quilt lateral edge 100c to the first quilt bottom edge lateral segment 100b-1 and defines on the quilt inner surface 100e an inner quilt-overlap areal segment 103 bounded by the inner quilt attachment path 130, the quilt bottom edge 100b, and the first quilt lateral edge 100c (Fig. 1B). The outer set of one or more quilt fastener elements 141 is attached to the quilt outer surface 100f along at least a portion of a linear or curved outer quilt attachment path 140 that extends from the second quilt lateral edge 100d to the second quilt bottom edge lateral segment 100b-3 and defines on the quilt outer surface 100f an outer quilt-overlap areal segment 104 bounded by the outer quilt attachment path 140, the quilt bottom edge 100b, and the second quilt lateral edge 100d (Fig. 1A). Note that portions of the attachment paths 130 and 140 that extend to edges of the quilt 100 can in some examples be only virtual extensions of the attachment path defined by the corresponding fastener elements. In other examples a fastener element can be positioned at an edge of the quilt 100. In some examples wherein the quilt 100 is quilted, the attachments paths 130 and 140 can optionally lie along seams of the quilted pattern. In some examples the inner and outer quilt attachment paths 130 / 140 are substantially linear; in some examples the inner and outer quilt-overlap areal segments 103 / 104 are substantially triangular. When the quilt 100 is wrapped or folded into the overlapping footbox-wrapped arrangement, the outer quilt-overlap areal segment 104 faces a portion of the quilt inner surface 100e, and the inner quilt-overlap areal segment 103 faces a portion of the quilt outer surface 100f (shown in Fig. 2A although those areal segments would not be visible; most clearly seen in Fig. 2B). In that arrangement, each quilt fastener element 131 of the inner set is substantially aligned with a corresponding, mating quilt fastener element 141 of the outer set. Engaging the corresponding mating quilt fastener elements 131 / 141 of the inner and outer sets with each other retains at least a footward portion of the quilt 100 in the overlapping footbox- wrapped arrangement (locations of the engaged quilt fastener elements 131 / 141 indicated in Figs. 2A / 2B although they would not be visible).

[0017] The draw cord 160 is engaged with the quilt bottom edge 100b; in some examples the draw cord 160 extends substantially entirely across the quilt bottom edge 100b. The draw cord 160 can be of any suitable or conventional type or arrangement. With the quilt 100 retained in the overlapping footbox-wrapped arrangement by (i) engagement of the bottom fastener elements 121a / 121 b with each other, (ii) engagement of the bottom fastener elements 122a / 122b with each other, and (iii) engagement of the corresponding quilt fastener elements 131 / 141 of the inner and outer sets with each other, then pulling the draw cord 160 gathers the quilt bottom edge 100b to form a closed footbox of the sleeping bag (Fig. 2C). To secure the closed footbox of the sleeping bag, one or both of the draw cord 160 or the quilt bottom edge 100b can in some examples be structurally arranged so as to secure the draw cord 160 with the quilt bottom edge 100b gathered. In some of those examples, the draw cord 160 can include a retaining member 161 that secures the draw cord 160 with the quilt bottom edge 100b gathered. An example of such a retaining member 161 is a conventional cord lock of any suitable type that can slide along the draw cord 160 and then be locked into place at a chosen position along the draw cord 160.

[0018] In some examples, the inner set of quilt fastener elements 131 comprises a continuous quilt fastener element 131 attached to the quilt inner surface 100e along at least a portion of the inner quilt attachment path 103 (Fig. 3B). Similarly, in those examples the outer set of quilt fastener elements 141 comprises a continuous quilt fastener element 141 attached to the quilt outer surface 100f along at least a portion of the outer quilt attachment path 140 (Fig. 3A). The continuous fastener elements 131 / 141 can in some examples extend to the respective quilt side edges 100c / 100d, or can in other examples extend only partly toward those edges. The continuous fastener elements 131 / 141 typically do not extend all the way to the quilt bottom edge 100b; instead their respective footward ends are displaced in a headward direction from the quilt bottom edge 100b. The continuous fastener elements 131 / 141 can be of any suitable type or arrangement, including those described above (e.g., mating zipper halves, mating hook-and-loop material strips, or strips of magnetic plastic).

[0019] In some examples, the inner set of quilt fastener elements 131 comprises an inner set of multiple discrete quilt fastener elements 131a / 131 b / ... attached to the quilt inner surface 100e along at least a portion of the inner quilt attachment path 130 (Fig. 1B). Similarly, in those examples the outer set of one or more quilt fastener elements 141 comprises an outer set of multiple discrete quilt fastener elements 141a / 141 b / ... attached to the quilt outer surface 100f along at least a portion of the outer quilt attachment path 140. The inner and outer sets of quilt fastener elements 131 / 141 and the inner and outer quilt attachment paths 130 / 140 are structurally arranged so that, with the quilt 100 wrapped in the overlapping footbox-wrapped arrangement, each discrete quilt fastener element 131a / 131 b / ... of the inner set is substantially aligned with a corresponding, mating, discrete quilt fastener element 141a / 141 b / ... of the outer set. In some examples the topmost discrete quilt fastener element 131a of the inner set is positioned on the first quilt lateral edge 130, and the topmost discrete quilt fastener element 141a of the outer set is positioned on the second quilt lateral edge 100d. In other examples the topmost quilt fastener elements 131a / 141 a are displaced from the respective quilt lateral edges 130 / 140. The bottommost discrete quilt fastener elements of the inner and outer sets (quilt fastener elements 131c / 141 c in the example in the drawings) typically are displaced in a headward direction from the quilt bottom edge 100b. The discrete quilt fastener elements 131 / 141 can be of any suitable type or arrangement, including those described above (e.g., a cord loop and a hook, mating male and female snap elements, mating button and button hole, mating male and female buckle or clasp elements, mating circumscribed patches of hook material and loop material of a hook-and-loop material, or pairs of magnets).

[0020] In many examples, all of the discrete quilt fastener elements 131 of the inner set are of one type (e.g., all cord loops, or all male snap elements), and all of the discrete fastener elements 141 of the outer set are of the one corresponding other type that mates with or corresponds to that of the inner set (e.g., all hooks if the inner set is all cord loops, or all female snap elements if the inner set is all male snap elements). In addition, in many of those examples the fastener element types chosen for the quilt fastener elements 131 / 141 are the same as those chosen for the bottom fastener elements 121a / 121b / 122a / 122b, although that need not be the case. Such arrangements can be advantageous, e.g., by simplifying the manufacturing processes employed to produce the inventive sleeping bag, however, those conditions are not required. The only requirement is that, for each pair of corresponding inner and outer quilt fastener elements (131a / 141 a, 131b / 141b, and so forth), the two fastener elements are of mating or corresponding types that can engage and retain each other. It is therefore possible to "mix-and-match" inner quilt fastener elements 131a / 131 b / ... of any desired mixture and sequence of fastener element types along the inner attachment path 130 with outer quilt fastener elements 141a / 141 b / ... of a mixture and sequence of mating or corresponding fastener element types. Such mixed-type sets of inner and outer quilt fastener elements 131 / 141 can be advantageous, e.g., by guiding a user toward engaging the correct pairs of inner and outer quilt fastener elements with each other when deploying the sleeping bag. Such mixed-type sets of inner and outer quilt fastener elements 131 / 141 shall fall within the scope of the present disclosure or appended claims.

[0021] The inventive closure arrangement described above for the footward portion of the quilt 100 is used to form a closed footbox of the sleeping bag formed by the quilt 100. That inventive closure arrangement can be particularly advantageous when multiple discrete fastener elements are employed instead of continuous fastener elements. A common problem that arises with the use of discrete fasteners in a sleeping bag closure is that the sleeping bag portions joined by the discrete fastener elements can still separate from each other along the gaps between adjacent engaged pairs of fastener elements. Movement of an occupant of the sleeping bag tends to cause intermittent separations along those gaps, and those separations allow heat to escape from the sleeping bag, degrading its performance. The inventive arrangement, including the overlapped arrangement of the bottom quilt edge lateral segments 100b-1 and 100b-3 (i.e., the so-called spiral or corkscrew arrangement; seen most clearly in Figs. 2B / 2C), the inner and outer sets of quilt fastener elements 131 / 141 arranged along attachment paths 130 / 140 that slant inward and downward from the quilt lateral edges 100c / 100d, the quilt-overlap areal segments 103 / 104 facing the respective quilt outer / inner surfaces 100f / 100e, and the draw cord 160 along the quilt bottom edge 100b, all act together to form the closed footbox of the sleeping bag in a way that resists, reduces, and in some instances eliminates separation of the joined portions of the quilt 100 that form the footbox of the sleeping bag, even when the occupant moves around in it.

[0022] Weight is an important constraint in designing outdoor gear, particularly if that gear is to be carried by person traveling on foot over a significant distance ( e.g., during a backpacking outing). Lightweight materials and specialized construction techniques have been developed over the years to produce ever lighter gear items such as tents and sleeping bags. As weight limits are pressed lower and lower, finding ways to cut further weight becomes correspondingly more difficult.

[0023] In a so-called ultralight sleeping bag or quilt, the zippers account for a significant percentage of the overall weight, in some cases about 10% to about 20% or even more. A zipper-less sleeping bag arrangement could potentially eliminate that weight, thereby enabling further overall weight reduction of the sleeping bag, or replacement of the zipper weight with, e.g., more or denser fill for enhancing the thermal performance of the sleeping bag, or heavier cover material for improved durability. Unfortunately, as noted above, simply replacing the zippers (i.e., a continuous fastener) with a lighter set of discrete fasteners in conventional sleeping bag closure arrangement can allow the connected portions of the sleeping bag to separate from one another between the discrete fasteners as the occupant of the sleeping bag moves around. Such separation allows heat to escape from the sleeping bag and can seriously degrade its performance in cold conditions. It would be desirable to provide a zipper-less sleeping bag, comprising a quilt and various discrete fasteners, that is structurally arranged so that portions of the quilt that are joined by the discrete fasteners do not separate, or separate less, or separate less readily, when the occupant of the sleeping bags moves around. The inventive sleeping bag footbox closure arrangement described above provides that new and useful functionality.

[0024] The inventive sleeping bag footbox closure arrangement described above (referred to herein as the overlapping footbox-wrapped arrangement) can be employed when the sleeping bag is used without its footward portion being attached to another article (e.g., such as a sheet of sleeping pad). In some instances a user might want to expand the footbox of the sleeping bag and attach it to a sleeping pad, typically by attaching it to a sheet on the sleeping pad. The inventive sleeping bag described above can be further adapted to provide that additional new and useful functionality.

[0025] An additional set of one or more quilt fastener elements 151 can be attached to the quilt outer surface 100f along at least a portion of a linear or curved additional quilt attachment path 150 (Figs. 4A / 4B). The additional attachment path 150 extends from the first quilt lateral edge 100c to the first quilt bottom edge lateral segment 100b-1 and defines on the quilt outer surface 100f an additional quilt-overlap areal segment 105 bounded by the additional outer quilt attachment path 150, the quilt bottom edge 100b, and the first quilt lateral edge 100c. The additional quilt attachment path 150 typically, but not necessarily, follows on the quilt outer surface 100f the same path that the inner quilt attachment path 130 follows on the quilt inner surface 100e; in that case the additional quilt-overlap areal segment 105 reproduces on the quilt outer surface 100f the size, shape, and position of the inner quilt-overlap areal segment 103 on the quilt inner surface 100e. A sheet 200 (Figs. 5A / 5B / 5C) is structurally arranged in any suitable way to be secured to a sleeping pad 299 of any suitable type, size, and shape, e.g., by being arranged as a fitted sheet, or by including straps or ties for wrapping around the sleeping pad 299, or by enclosing the entire sleeping pad 299 in a manner similar to a pillowcase enclosing a pillow. The sheet 200 includes on its outer surface a first set of one or more sheet fastener elements 241 that are structurally arranged along a corresponding linear or curved first sheet attachment path 240, and a second set of one or more sheet fastener elements 251 that are structurally arranged along corresponding linear or curved second sheet attachment path 250. The first and second attachment paths 240 / 250 are structurally arranged generally longitudinally along at least corresponding footward portions of respective first and second lateral edges of the sheet 200. In some examples the first and second sheet attachment paths 240 / 250 are positioned on respective first and second sheet lateral edges; in other examples the first and second sheet attachment paths 240 / 250 are displaced medially from the respective first and second sheet lateral edges.

[0026] To use the quilt 100 in a footbox-expanded arrangement, the bottom fastener elements 121a / 122b are disengaged from each other, the bottom fastener elements 122a / 122b are disengaged from each other, and the inner and outer sets of quilt fastener elements 131 / 141 are disengaged from each other. With all of those fastener elements disengaged, the quilt 100 can be unwrapped or unfolded into a footbox- expanded arrangement and positioned over the sheet 200 with the quilt inner surface 100e facing the sheet outer surface (Figs. 5B / 5C). The quilt-overlap areal segments 104 and 105 on the quilt outer surface 100f are tucked or folded under to face corresponding portions of the sheet outer surface (Figs. 5B / 5C). Thus positioned and arranged, each quilt fastener element 141 of the outer set is substantially aligned with a corresponding, mating sheet fastener element 241 of the first set, and each quilt fastener element 151 of the additional set is substantially aligned with a corresponding, mating sheet fastener element 251 of the second set. By engaging the corresponding mating quilt and sheet fastener elements 141 / 241 of the respective outer and first sets with each other, and engaging the corresponding mating quilt and sheet fastener elements 151 / 251 of the respective additional and second sets with each other, at least a footward portion of the quilt 100 is retained and secured to the sheet 200 in the footbox-expanded arrangement (Figs. 5B / 5C). In cooler conditions when a closed footbox might be desired, the draw cord 160 can be pulled to gather the bottom edge 100b and form a closed, expanded footbox of the sleeping bag (Fig. 5C). Alternatively, in warmer conditions when an open footbox might be desired, the quilt bottom edge 100b can be left ungathered so that the footbox is left open in its footbox-expanded arrangement (Fig. 5B). To convert back to the closed overlapping footbox-wrapped arrangement, the quilt fastener elements 141 and the sheet fastener elements 241 are disengaged from each other and the quilt fastener elements 151 and the sheet fastener elements 251 are disengaged from each other. The quilt 100 can then be returned to the overlapping footbox-wrapped arrangement as described above.

[0027] The type(s) and arrangement of the sheet fastener elements 241 are chosen to mate with or correspond to the type(s) and arrangement of the outer quilt fastener elements 141, so that those fasteners can be engaged with each other (e.g., a cord loop corresponds to a hook and vice versa, or a button corresponds to a buttonhole and vice versa, and so on for other fastener element types). The type(s) and arrangement of the sheet fastener elements 251 are chosen to mate with or correspond to the type(s) and arrangement of the additional quilt fastener elements 151, so that those fasteners can be engaged with each other. The type(s) and arrangement of the additional quilt fastener elements 151 can in principle be arbitrarily chosen from among any of the continuous or discrete fastener element types, including any one or more of those described above. Alternatively, the sheet fastener elements 251 can be arbitrarily chosen, and then additional quilt fastener elements 151 can be chosen to mate or correspond. More typically, however, the additional quilt fastener element(s) 151 are chosen to have the same type(s) and arrangement as either the inner quilt fastener element(s) 131 or the outer quilt fastener element(s) 141.

[0028] If the outer and additional quilt fastener elements 141 / 151 are of the same types(s) and arrangement as each other, then the sheet fastener elements 241 / 251 must also be of the same type(s) and arrangement as each other and correspond to the quilt fastener elements 141 / 151. In one such example, the inner quilt fastener elements 131 are all cord loops, the outer and additional quilt fastener elements 141 / 151 are all hooks, and the first and second sheet fastener elements 241 / 251 are all cord loops. Such arrangements can be advantageous for simplifying manufacture of the sheet 200 and quilt 100.

[0029] If the inner and additional quilt fastener elements 131 / 151 are of the same types(s) and arrangement as each other, then the sheet fastener elements 241 / 251 will differ from each other with respect to fastener type(s) and arrangement, while mating with or corresponding to the respective quilt fastener elements 141 / 151. In one such example, the inner and additional quilt fastener elements 131 / 151 are all cord loops, the outer quilt fastener elements 141 are all hooks, the first sheet fastener elements 241 are all cord loops, and the second sheet fastener elements 251 are all hooks). Such an arrangement can be advantageous for guiding assembly of the quilt 100 with the sheet 200 (because they can only go together one way). Also in some examples of such an arrangement that employ discrete quilt fastener elements, the topmost inner quilt fastener element 131a can also be the topmost additional quilt fastener element 151a (Figs. 4A / 4B).

[0030] Any of the various continuous or discrete type(s) and arrangements described above for the inner / outer quilt fastener elements 131 / 141 can be employed for the additional quilt fastener elements 151 and the first / second sheet fastener elements 241 / 251, including, e.g., continuous fastener elements (Figs. 6A / 6B and 10B), discrete fastener elements (Figs. 4A / 4B and 5A), sets of only a single fastener element type, mixed-type sets of fastener elements, and so forth.

[0031] The arrangement of the additional quilt fastener elements 151 and the sheet fastener elements 241 / 251 provides the new and useful functionality that a quilt 100 usable as a sleeping bag can be readily converted between (i) an arrangement having a self-contained, closed footbox and (ii) an arrangement having an expanded footbox that is attached to a sheet 200 (and therefore usually also indirectly attached to a sleeping pad 299 on which the sheet 200 is deployed). The new and useful sheet-attached, expanded-footbox functionality is provided in the examples described above in combination with the inventive overlapping, footbox-wrapped arrangement of the closed footbox. However, the sheet-attached expanded-footbox arrangement can be implemented independently of the overlapping, footbox-wrapped arrangement, and can in some examples be employed with a conventional quilt usable as a sleeping bag in combination with an inventive sheet. A sheet thus usable to provide the sheet-attached expanded-footbox arrangement can be provided together with the quilt as a set, or can be provided separately from the quilt as an accessory or a retrofit.

[0032] A sheet 300 adapted for use with a sleeping bag is illustrated in Fig. 7B. The sheet 300 is structurally arranged to be secured to a sleeping pad 399 of any suitable type, size, and shape in any suitable way, including those described above. A first set of one or more sheet fastener elements 341 is attached to an outer surface of the sheet 300; the sheet fastener elements 341 are structurally arranged along a linear or curved first sheet attachment path 340 on the sheet outer surface. A second set of one or more sheet fastener elements 351 is attached to the sheet outer surface; the sheet fastener elements are structurally arranged along a linear or curved second sheet attachment path 351 on the sheet outer surface. The first and second attachment paths 340 / 350 are structurally arranged generally longitudinally along at least corresponding footward portions of respective first and second lateral edges of the sheet 300. In some examples the first and second sheet attachment paths 340 / 350 can be positioned on respective first and second sheet lateral edges; in other examples the first and second sheet attachment paths 340 / 350 can be displaced medially from the respective first and second sheet lateral edges. The sheet attachment path 340 and the sheet fastener elements 341 are arranged so that the sheet fastener elements 341 and a corresponding first set of quilt fastener elements 441 (attached along an attachment path 440 on a quilt 400 usable as a sleeping bag; Fig. 7A) can engage each other. Similarly, the sheet attachment path 350 and the sheet fastener elements 351 are arranged so that the sheet fastener elements 351 and a corresponding second set of quilt fastener elements 451 (attached along a second quilt attachment path 450 on the quilt 400; Fig. 7A) can engage each other.

[0033] The quilt fastener elements 441 / 451 typically are arranged to engage each other and hold at least a footward portion of the quilt 400 in a wrapped, folded, or closed arrangement (optionally but not necessarily overlapping) when not being used in conjunction with the sheet 300 (as in Fig. 8A, with an open, expanded footbox, or as in Fig. 8B, with a closed footbox formed by pulling the draw cord 460). With the quilt 400 in an unwrapped arrangement with the first and second sets of quilt fastener elements 441 / 451 disengaged from each other, the quilt 300 can be positioned over the sheet 400 with a quilt inner surface facing the sheet outer surface (Figs. 9A / 9B). Each quilt fastener element 441 of the first set is then substantially aligned with a corresponding, mating sheet fastener element 341 of the first set, and each quilt fastener element 451 of the second set is substantially aligned with a corresponding, mating sheet fastener element 351 of the second set. Engaging the corresponding mating quilt and sheet fastener elements 341 / 441 with each other, and engaging the corresponding mating quilt and sheet fastener elements 351 / 451 with each other, retain at least a footward portion of the quilt 400 secured to the sheet 300 in a footbox-expanded arrangement (Figs. 9A / 9B; similar to that described above for the quilt 100 and sheet 200 and shown in Figs. 5B / 5C).

[0034] Any of the various continuous or discrete type(s) and arrangements described above for the inner / outer quilt fastener elements 131 / 141 can be employed for the first / second sheet fastener elements 341 / 351 and the first / second quilt fastener elements 441 / 451, including, e.g., continuous fastener elements (Figs. 10A / 10B), discrete fastener elements (Figs. 7A / 7B), sets of only a single fastener element type, mixed-type sets of fastener elements, and so forth.

[0035] As noted above, the sheet 300 and quilt 400 can be provided together as a set. Alternatively, the sheet 300 can be provided as an accessory or a retrofit for a quilt 400 that may or may not have been intended for use with the sheet 400.

[0036] If the quilt 400 includes a draw cord 460 across its bottom, footward edge, that draw cord typically is used, with the quilt fastener elements 441 / 451 engaged with each other, to gather the quilt bottom edge into a closed footbox of the sleeping bag (Fig. 8B); a draw cord retaining member 461 can be employed. When the quilt 400 is not attached to the sheet 300, that closed footbox can include a wrapped arrangement as described above, or can include non-overlapped attachment of the attachment paths 440 / 450 to form the closed footbox (Figs. 8A / 8B). With the quilt fastener elements 441 / 451 disengaged from each other and the quilt 400 attached to the sheet 300 in the footbox-expanded arrangement as described above (Figs. 9A / 9B), pulling the draw cord 460 gathers the quilt bottom edge to form a closed, expanded footbox of the sleeping bag (Fig. 9B). Depending on the conditions, the user may prefer to leave the expanded footbox open by not pulling the draw cord 460 (Fig. 9A).

[0037] The arrangements described enable a quilt 400 usable as a sleeping bag, including conventional quilts not necessarily intended for such use, to be readily converted between (i) an arrangement with a self-contained, closed footbox, and (ii) an arrangement having an expanded footbox that is attached to a sheet 300 (and therefore usually to a sleeping pad 399 on which the sheet 300 is deployed).

[0038] In the foregoing Detailed Description, various features may be grouped together in several example embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that any claimed embodiment requires more features than are expressly recited in the corresponding claim. Rather, as the appended claims reflect, inventive subject matter may lie in less than all features of a single disclosed example embodiment. Therefore the present disclosure shall be construed as implicitly disclosing any embodiment having any suitable set of one or more features - which features are shown, described, or claimed in the present application - including those sets that may not be explicitly disclosed herein. A "suitable" set of features includes only features that are neither incompatible nor mutually exclusive with respect to any other feature of the set.

[0039] For purposes of the present disclosure and appended claims, the conjunction "or" is to be construed inclusively (e.g., "a dog or a cat" would be interpreted as "a dog, or a cat, or both"; e.g., "a dog, a cat, or a mouse" would be interpreted as "a dog, or a cat, or a mouse, or any two, or all three"), unless: (i) it is explicitly stated otherwise, e.g., by use of "either ...or," "only one of," or similar language; or (ii) two or more of the listed alternatives are mutually exclusive within the particular context, in which case "or" would encompass only those combinations involving non-mutually-exclusive alternatives. For purposes of the present disclosure and appended claims, the words "comprising," "including," "having," and variants thereof, wherever they appear, shall be construed as open ended terminology, with the same meaning as if the phrase "at least" were appended after each instance thereof, unless explicitly stated otherwise. For purposes of the present disclosure or appended claims, when terms are employed such as "about equal to," "substantially equal to," "greater than about," "less than about," and so forth, in relation to a numerical quantity, standard conventions pertaining to measurement precision and significant digits shall apply, unless a differing interpretation is explicitly set forth. For null quantities described by phrases such as "substantially prevented," "substantially absent," "substantially eliminated," "about equal to zero," "negligible," and so forth, each such phrase shall denote the case wherein the quantity in question has been reduced or diminished to such an extent that, for practical purposes in the context of the intended operation or use of the disclosed or claimed apparatus or method, the overall behavior or performance of the apparatus or method does not differ from that which would have occurred had the null quantity in fact been completely removed, exactly equal to zero, or otherwise exactly nulled.

[0040] The Abstract is provided as required as an aid to those searching for specific subject matter within the patent literature. However, the Abstract is not intended to imply that any elements, features, or limitations recited therein are necessarily encompassed by any particular claim. The scope of subject matter encompassed by each claim shall be determined by the recitation of only that claim.

Claims

1. A quilt (100) selectively usable as a sleeping bag, the quilt comprising: an inner surface (100f), an outer surface (100e) opposed to the inner surface, a top edge (100a), a bottom edge (100b), a first lateral edge (100c), and a second lateral edge (100d) spaced from the first lateral edge; a first pair of discrete, mating bottom fastener elements (121a / 121b) attached along the bottom edge, the first pair of discrete, mating bottom fastener elements being adapted for selective engagement and disengagement with each other; a second pair of discrete, mating bottom fastener elements (122a / 122b) attached along the bottom edge, the second pair of discrete, mating bottom fasteners being adapted for selective engagement and disengagement with each other, one discrete, mating bottom fastener element of the first pair of discrete, mating bottom fastener elements being positioned laterally between the second pair of discrete, mating bottom fastener elements, and one discrete, mating bottom fastener element of the second pair of discrete, mating bottom fastener elements being positioned laterally between the first pair of discrete, mating bottom fastener elements; at least one inner quilt fastener element attached to the quilt inner surface (131); and at least one outer quilt fastener element attached to the quilt outer surface (141); characterised in that the inner and outer quilt fastener elements are cooperatively arranged so that, with the quilt wrapped in an overlapping footbox-wrapped arrangement, each inner quilt fastener element is configured to be substantially aligned with and engaged to a corresponding, mating outer quilt fastener element; wherein the quilt bottom edge defines a first quilt bottom edge lateral segment (100b-1), a quilt bottom edge central segment (100b-2), and a second quilt bottom edge lateral segment (100b-3); wherein the at least one inner quilt fastener element comprises a set of multiple discrete quilt fastener elements disposed on the inner surface along an inner quilt attachment path (130), the inner quilt attachment path (130) extending from the first quilt lateral edge to the first quilt bottom edge lateral segment, wherein the at least one outer quilt fastener element comprises a set of multiple discrete quilt fastener elements disposed on the outer surface along an outer quilt attachment path (140), the outer quilt attachment path (140) extending from the second quilt lateral edge to the second quilt bottom edge lateral segment, wherein the first quilt bottom edge lateral segment overlaps the second quilt bottom edge lateral segment in the overlapping footbox-wrapped arrangement.

2. The quilt of Claim 1, further comprising a draw cord (160) disposed adjacent the bottom edge.

3. The quilt of Claim 2, wherein, where the at least one inner quilt fastener element and the at least one outer quilt fastener element are engaged with each other, the draw cord (160) is configured to gather the bottom edge into a closed, wrapped footbox in the overlapping footbox-wrapped arrangement.

4. The quilt of Claim 1, wherein at least one of the first pair of discrete, mating bottom fastener elements and the second pair of discrete, mating bottom fastener elements includes a cord loop and a hook structurally arranged so as to engage and retain the cord loop.

5. The quilt of Claim 1, wherein each of the at least one inner quilt fastener elements and the at least one outer quilt fastener elements comprises a continuous quilt fastener element.

6. The quilt of Claim 5, wherein the at least one inner quilt fastener element comprises a first zipper half and the at least one outer quilt fastener element comprises a second zipper half adapted for engagement with the first zipper half.

7. The quilt of Claim 1, wherein each discrete quilt fastener element disposed on the inner surface comprises a cord loop, and each discrete quilt fastener element disposed on the outer surface comprises a hook structurally arranged so as to engage and retain a respective one of the cord loops.

8. The quilt of Claim 1, wherein each discrete quilt fastener element disposed on the outer surface comprises a cord loop, and each discrete quilt fastener element disposed on the inner surface comprises a hook structurally arranged so as to engage and retain a respective one of the cord loops.

9. The quilt of Claim 1, wherein each discrete quilt fastener element disposed on the outer surface comprises a first snap element, and each discrete quilt fastener element disposed on the inner surface comprises a second snap element that mates with the first snap element of the corresponding quilt fastener element disposed on the outer surface.

10. The quilt of Claim 1, wherein the set of discrete quilt fastener elements disposed on the outer surface comprises at least one quilt fastener element of a first fastener element type and at least one quilt fastener element of a second fastener element type, and each discrete quilt fastener element disposed on the inner surface comprises a quilt fastener element of the same fastener element type as the corresponding fastener element disposed on the outer surface.