Patent Publication Number: US-9408484-B2

Title: Sleeping bag with self-sealing, vented footbox

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This nonprovisional application claims priority to U.S. Provisional Patent Application Ser. No. 61/902,628, filed on Nov. 11, 2013, which is incorporated in its entirety by reference. 
    
    
     FIELD 
     The field of this disclosure relates generally to sleeping bags, and more particularly to sleeping bags having a self-sealing vent opening selectively moveable from a closed configuration to an opened configuration for venting an inner volume of the sleeping bags. 
     BACKGROUND 
     Typically, sleeping bags are used when conventional bed and bedding are unavailable. For example, sleeping bags are used by backpackers, hikers, campers, mountaineers, and other users as portable beds or coverings. Sleeping bags are often durable sleeping coverings that provide a soft surface, insulation, and weather resistance. 
     Consumers face a difficult task in finding a sleeping bag that is thermally efficient, comfortable, and lightweight. One type of sleeping bag is referred to as a “mummy bag”, which tends to be shaped with a lateral taper to approximate the contour of the body of a user and thereby minimize the internal volume of the bag. Mummy bags attempt to conserve heat by minimizing air movement within and from the bag. As a result, mummy bags are often suited for use in outdoor, colder ambient temperatures. One drawback to the mummy bag is that some users may feel discomfort due to the tight fit of the bag. Some users may become too warm or the air within the bag may become stagnant. Such feeling of discomfort may be increased in the foot portion of the bag due to its distance from the opening of the bag. Thus, some users are unable to sleep comfortably in mummy bags. 
     Other sleeping bags, such as rectangular-type sleeping bags, are shaped with a generally constant lateral dimension and provide a greater range of motion for the user. Such bags also typically have a zippered portion to allow the user to more easily enter the bag. However, although rectangular bags are often more spacious than mummy bags, one drawback is that the larger internal volume reduces the thermal efficiency of the bag. Moreover, rectangular bags often do no insulate the head, and are typically too large to be thermally efficient. As a result, rectangular bags tend to be better suited for use indoors or in milder outdoor temperatures. When used in outdoor, colder ambient temperatures, air within the bag can more easily become chilled, especially in the foot portion of the bag. 
     Accordingly, a need exists for a sleeping bag that is both comfortable, thermally efficient, and allows the warm, stagnant air within the bag to escape and be replaced with fresh, ambient air. 
     BRIEF DESCRIPTION 
     In one aspect, a sleeping bag generally comprises an elongate shell defining an inner volume sized and shaped to receive a user therein. The shell has a head portion, a foot portion, a middle portion extending longitudinally between the head and foot portions, an overlying portion adapted to overlie the user during use, an underlying portion adapted to underlie the user during use, and a vent. The vent is selectively moveable between a closed configuration and an opened configuration to enable the user to access the exterior of the sleeping bag from within the bag. The vent comprises an inner panel and an outer panel. The inner panel is positioned in overlapping face-to-face engagement with the outer panel in the closed configuration. The outer panel is spaced from the inner panel in the opened configuration to define a passage to enable the user to extend his or her feet through the vent. 
     In another aspect, a sleeping bag generally comprises an elongate shell defining a longitudinal centerline and an inner volume sized and shaped to receive a user therein. The shell has an overlying portion adapted to overlie the user during use, an underlying portion adapted to underlie the user during use, and a vent. The vent has an opening selectively moveable between a closed configuration and an opened configuration to enable the user to access the exterior of the sleeping bag from within the sleeping bag. The opening extends substantially perpendicular to the longitudinal centerline. The vent is fastener free. 
     In yet another aspect, a sleeping bag generally comprises an elongate shell defining a longitudinal centerline and an inner volume sized and shaped to receive a user therein. The shell has a head end panel, a foot end panel, and a pair of spaced side panels extending longitudinally between the head end panel and the foot end panel, an overlying portion adapted to overlie the user during use, an underlying portion adapted to underlie the user during use, and a pair of vents. Each of the vents is selectively moveable between a closed configuration and an opened configuration to enable the user to access the exterior of the sleeping bag from within the sleeping bag. Each of the vents comprises an inner panel and an outer panel. The inner panel is positioned in overlapping face-to-face engagement with the outer panel in the closed configuration. The inner panel and the outer panel are generally perpendicular to the underlying portion in the closed configuration. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of a sleeping bag having a vent; 
         FIG. 2  is a top plan view of the sleeping bag of  FIG. 1 ; 
         FIG. 3  is a bottom plan view of the sleeping bag of  FIG. 1 ; 
         FIG. 4  is an end view showing a foot end panel of the sleeping bag of  FIG. 1 ; 
         FIG. 5  is an end view showing a head end panel of the sleeping bag of  FIG. 1 ; 
         FIG. 6  is a right side elevation of the sleeping bag of  FIG. 1 ; 
         FIG. 7  is an enlarged top plan view of the foot portion of the sleeping bag of  FIG. 1  illustrating the interior portion of a ventable foot portion in a closed configuration; 
         FIG. 8  is an enlarged perspective view of the foot portion of the sleeping bag of  FIG. 1  illustrating the interior portion of a ventable foot portion in an opened configuration; 
         FIG. 9  is an enlarged top plan view of the foot portion of the sleeping bag of  FIG. 1  illustrating the exterior portion of a ventable foot portion in a closed configuration; 
         FIG. 10  is an enlarged perspective view of the foot portion of the sleeping bag of  FIG. 1  illustrating the exterior portion of a ventable foot portion in an opened configuration; 
         FIG. 11  is an enlarged section view of the foot portion of the sleeping bag of  FIG. 1  taken along the longitudinal centerline; 
         FIG. 12  is an enlarged perspective view of the foot portion of the sleeping bag of  FIG. 1  showing a user&#39;s feet inside the sleeping bag and the ventable foot portion in a closed configuration; 
         FIG. 13  is an enlarged perspective view of the foot portion of the sleeping bag of  FIG. 1  showing a user&#39;s feet extending through the ventable foot portion external of the sleeping bag; 
         FIG. 14  is a perspective view of another embodiment of a sleeping bag having a vent; 
         FIG. 15  is a perspective view of yet another embodiment of a sleeping bag having a pair of vents. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring now to the drawings and in particular to  FIGS. 1-6 , one suitable embodiment of a sleeping bag is designated in its entirety by the reference number  10 . The sleeping bag  10  comprises an elongate shell  12  that defines an inner volume that is sized and shaped to receive a user therein. The shell  12  has a head portion  14 , a foot portion  18 , and a middle portion  16  that extends longitudinally between the head portion  14  and foot portion  18 . In addition, the shell  12  has an overlying portion  20  that is configured to overlie the user and an underlying portion  22  that is configured to underlie the user during use of the sleeping bag  10 . In the illustrated embodiment, the sleeping bag  10  is a “zipperless” sleeping bag, i.e., is free from any zippers. In other suitable embodiments, the sleeping bag  10  may have a zipper configured to selectively attach and detach at least a portion of the overlying portion  20  to at least a portion of the underlying portion  22  of the sleeping bag  10 . In the illustrated embodiment, the sleeping bag  10  is a “regular” size sleeping bag configured to fit users up to about 6 feet tall. It is understood, however, that the sleeping bag  10  may have any suitable size (e.g., shorter, longer, wider, narrower) and may be configured specifically for men, women, or youths. It is also contemplated that the sleeping bag  10  can be sized and shaped to receive more than one individual (e.g., two individuals). 
     In the illustrated embodiment, the shell  12  comprises a head end panel  24  located in the head portion  14 , a foot end panel  26  located in the foot portion  18 , and a pair of spaced side panels  28  located in the middle portion  16 . The side panels  28  extend longitudinally between the head end panel  24  and the foot end panel  26  and are symmetrical about a longitudinal centerline CL of the sleeping bag  10 . The head end panel  24 , the foot end panel  26 , and the side panels  28  are stitched into the shell  12  between the overlying portion  20  and underlying portion  22 . As a result, the panels  24 ,  26 ,  28  collectively provide vertical expansion of the shell  12 , thus adding inner volume to the sleeping bag  10 . It is contemplated that in some embodiments, the panels  24 ,  26 ,  28  can be omitted. 
     In the illustrated embodiment, the shell  12  is tapered toward the foot portion  18  to generally conform to the contours of the user, being broadest in the head portion  14  corresponding to the shoulders of the user and narrowest in the foot portion  18  corresponding to the feet of the user. The tapered shell  12  thus provides the user a generally snug fit. By generally conforming to the contours of the user and substantially receiving the user therein, air movement within the sleeping bag  10  is substantially reduced, thus making the bag thermally efficient. The illustrated sleeping bag  10  can be generally categorized as a semi-rectangular bag or a tapered bag. It is understood, however, that in other embodiments the sleeping bag  10  could have less taper (e.g., a rectangular-type bag) or have greater taper (e.g., a mummy type bag). 
     The shell  12  comprises an inner layer  30  that defines the inner volume of the shell  12  and an outer layer  32  that defines an exterior of the shell  12 . The inner layer  30  is configured to receive the user occupying the inner volume of the sleeping bag  10 . The inner and outer layers  30 ,  32  can be any suitable material (e.g., polyester). In some embodiments, the inner layer  30  can be made from a material different than the outer layer  32 . The shell  12  also comprises an insulation material (not shown) that is located between the inner layer  30  and the outer layer  32  to facilitate providing warmth and softness to the sleeping bag  10 . The insulation material can be attached to the inner and outer layers  30 ,  32  of the shell  12  using stitch-lines. It is understood that the insulation material can be any suitable material (e.g., goose down, CLOUDLOFT insulation, DRIDOWN insulation) and that the amount of insulation material can be selected to achieve the desired warmth and softness. The inner and outer layers  30 ,  32  are stitched together along their periphery edges to enclose the insulation material between the layers  30 ,  32 . 
     In one suitable embodiment, the sleeping bag  10  has a hood  34  located at the head portion  14  of the shell  12 . The hood  34  is configured to receive the head of the user. In addition, the shell  12  has a vent  40  for selectively opening and closing the foot portion  18  of the shell  12 . The vent  40  is formed in the shell  12  at the foot portion  18  in the underlying portion  22 . The vent  40  enables venting of the inner volume at the foot portion  18  of the sleeping bag  10 . 
     With reference to  FIGS. 7-13 , the illustrated sleeping bag  10 , and more specifically, the underlying portion  22  includes the vent  40 , which defines a passage  42  through the shell  12  to enable the user to access the exterior of the sleeping bag from within the sleeping bag  10 . The vent  40  of the illustrated sleeping bag  10  is located in the underlying portion  22  such that the user can selectively extend his or her feet through the vent  40  ( FIG. 13 ). The vent  40  includes an inner panel  44  and an outer panel  46 . A closed configuration, as illustrated for example in  FIGS. 7, 9 , and  11 , is defined by the outer panel  46  overlapping in direct face-to-face relationship the inner panel  44 . The overlapping relationship of the outer panel  46  and the inner panel  44  inhibits air from entering the inner volume of the sleeping bag  10  and enables the vent  40  to be self-sealing, i.e., to automatically seal without the use of fasteners. Moreover, the outer panel  46  and inner panel  44  are configured to inhibit the vent  40  from unintentionally opening during use of the sleeping bag  10 . In another suitable embodiment, the vent  40  may include a fastener to facilitate maintaining the vent  40  in the closed configuration. For example, without limitation, the vent  40  may include a zipper, snaps, hook and loop fasteners, magnets, or any other suitable fasteners to allow the vent  40  to be held in the closed configuration. 
     As illustrated for example in  FIGS. 8, 10, and 13 , an opened configuration is defined by the outer panel  46  being at least in part in spaced relationship to the inner panel  44 . In the opened configuration, the user is able to extend his or her foot or feet through the passage  42  of the vent  40  to a location that is external to the inner volume of the sleeping bag  10  ( FIG. 13 ). When the user draws his or her foot or feet back into the sleeping bag  10 , the outer panel  46  and inner panel  44  are configured to move back to a face-to-face relationship wherein the vent  40  is moved back to the closed configuration without any additional effort by the user ( FIG. 12 ), i.e., upon the foot or feet being withdrawn from one the vent  40 , the outer panel  46  will automatically return to position overlying the inner panel  44 . 
     As illustrated in  FIG. 11 , in the closed configuration, the outer panel  46  and the inner panel  44  cooperate to define part of the underlying portion  22 . The inner panel  44  has an inner free edge  48  and the outer panel  46  has an outer free edge  50 . In the illustrated embodiment, the inner panel  44  overlaps the outer panel  46  such that the inner free edge  48  of the inner panel  44  is spaced a predetermined distance L from the outer free edge  50  of the outer panel  46 . Distance L is long enough to seal out drafts while still enabling the user to slide his or her foot or feet through the vent  40 . 
     In the illustrated embodiment, the outer panel  46  and the inner panel  44  are made from the same material as the shell  12  (i.e., an inner layer, an outer layer, and an insulation material between the inner and outer layers). It is understood, however, that the outer and inner panels can be made from any suitable material or materials. The illustrated inner and outer panels  44 ,  46  have a width that is generally the entire width of the underlying portion  22 , such that an opening  52  of the vent  40  extends the entire width of the underlying portion  22 , substantially perpendicular to the longitudinal centerline CL. It is understood however that the width of the outer panel  46  and the inner panel  44  may be any width that enables the outer and inner panels to function as described herein. 
     In operation, the vent  40  provides ventilation to the foot portion  18  of the sleeping bag  10  without the need for fasteners (e.g., zippers, snap fasteners, or buttons). It is understood, however, that a fastener may be used to close the vent  40  in other suitable embodiments. The user slides his or her foot or feet under the inner panel  44 , passing it through the passage  42  to the exterior of the sleeping bag  10 , thereby moving the vent  40  to the opened configuration “hands free,” i.e., the user can move the vent  40  to the opened configuration from inside the sleeping bag  10  without the use of his or her hands. In the opened configuration, the user&#39;s foot or feet are exterior to the sleeping bag  10  whereby they are exposed to the ambient air, and the passage  42  is at least partially opened enabling ambient air to circulate through the sleeping bag  10  ( FIG. 13 ). To close the vent  40 , the user draws his or her foot or feet inside the sleeping bag  10  and places his or her foot or feet on top of the inner panel  44 . The inner panel  44  and the outer panel  46  are moved to a face-to-face relationship and the vent  40  is closed to create a seal. In the closed configuration, the user&#39;s feet rests on the inner panel  44 , wherein the weight of his or her feet facilitates maintaining the vent  40  in the closed configuration ( FIG. 12 ). 
     In another suitable embodiment illustrated in  FIG. 14 , the inner panel  44  and the outer panel  46  extend to the foot end panel  26 . That is, the underlying portion  22  is continuous and extends longitudinally between the head end panel  24  and the foot end panel  26 , and the vent  40  is located in the foot end panel. The passage  42  extends through the shell  12  to enable the user to access the exterior of the sleeping bag from within the sleeping bag  10 . As described above, the closed configuration of the vent  40  is defined by the outer panel  46  overlapping in direct face-to-face relationship with the inner panel  44 . The opened configuration is defined by the outer panel  46  being at least in part in spaced relationship to the inner panel  44 . As illustrated in  FIG. 14 , in the closed configuration, the outer panel  46  and the inner panel  44  cooperate to define part of the foot end panel  26  and the underlying portion  22 . The inner panel  44  has an inner free edge  48  and the outer panel  46  has an outer free edge  50 . The inner panel  44  overlaps the outer panel  46  forming an L-shaped passage  42  such that the inner free edge  48  of the inner panel  44  is spaced a predetermined distance L from the foot end panel  26 , and the outer free edge  50  is spaced a predetermined distance H from the underlying portion  22 . The combined distance of L and H is long enough to seal out drafts while still enabling the user to slide his or her foot or feet through vent  40 . 
     As previously described, the outer panel  46  and the inner panel  44  are made from the same material as the shell  12  (i.e., an inner layer, an outer layer, and an insulation material between the inner and outer layers). It is understood, however, that the outer and inner panels can be made from any suitable material or materials. The illustrated inner and outer panels  44 ,  46  have a width that is generally the entire width of the underlying portion  22  and the foot end panel  26 , such that an opening  52  of the vent  40  extends the entire width of the underlying portion  22  and the foot end panel  26 , substantially perpendicular to the longitudinal centerline CL. It is understood however that the width of the outer panel  46  and the inner panel  44  may be any width that enables the outer and inner panels to function as described herein. 
     In another suitable embodiment illustrated in  FIG. 15 , a pair of outer panels  46  is positioned in the foot portion  18  of the side panels  28  along with the inner panel  44 . In this embodiment, the underlying portion  22  is continuous and extends longitudinally between the head end panel  24  and the foot end panel  26 , and the sleeping bag comprises a pair of vents  40 , one located in each side panel  28 , generally perpendicular to the underlying portion  22  in the closed configuration. The vents  40  are symmetrical about the longitudinal centerline CL of the sleeping bag  10 . In the illustrated embodiment, the passage  42  extends through the shell  12  to enable the user to access the exterior of the sleeping bag from within the sleeping bag  10 . As described above, the closed configuration of the vent  40  is defined by the outer panel  46  overlapping in direct face-to-face relationship the inner panel  44 . The opened configuration is defined by the outer panel  46  being at least in part in spaced relationship to the inner part  44 . 
     As illustrated in  FIG. 15 , in the closed configuration, one of the outer panels  46  and the inner panel  44  cooperate to define part of one side panel  28  and the underlying portion  22 . The other outer panel  46  cooperates with the inner panel  44  to define part of the opposite side panel  28  and the underlying portion  22 . The inner panel  44  has an inner free edge  48  and each of the outer panels  46  has an outer free edge  50 . The inner panel  44  overlaps the outer panels  46  forming a U-shaped passage  42  such that the inner free edge  48  of the inner panel  44  is spaced a predetermined distance L from the foot end panel  26 , and the free edges  50  are spaced a predetermined distance H from the underlying portion  22 . The overlap distance of L and H is long enough to seal out drafts while still enabling the user to slide his or her foot or feet through the opening  52  of the vent  40 . The openings  52  of the vents  40  are substantially parallel to the longitudinal centerline CL of the shell  12 . As previously described, the outer panels  46  and the inner panel  44  are made from the same material as the shell  12  (i.e., an inner layer, an outer layer, and an insulation material between the inner and outer layers). It is understood, however, that the outer and inner panels can be made from any suitable material or materials. 
     An advantage of the above embodiments is that the vents are lightweight because they do not require any fasteners for closure. Furthermore, the vents are self-sealing vents and enable the user to operate the vents from the inside of the sleeping bag using only his or her feet. In addition, the above disclosed vents provide a tortuous path to inhibit the introduction of air into the interior of the sleeping bag causing loss of heat. 
     When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.