Abstract:
An expandable sleeping bag or bunting bag includes features in which the size of the bag is adjustable to accommodate the growth of the child. To expand or contract the sleeping bag in width, one or more additional tapes of zipper teeth are sewn to the front of the garment adjacent to, and parallel to, the regular zipper. To expand or contract the sleeping bag in length, a pair of parallel zippers permits the removal or insertion of a length expansion strip extending around the circumference of the sleeping bag.

Description:
This application claims the benefit of priority from provisional patent application No. 60/871,199, filed Dec. 21, 2006. 

   FIELD OF INVENTION 
   The present invention relates to improvements in the field of adjustable size sleeping bags. 
   BACKGROUND OF THE INVENTION 
   A sleeping bag is a large padded bag design to be slept in. A bunting bag, similar to a sleeping bag, is a thick, warm garment for a baby that is shaped like a sleeping bag to cover the baby&#39;s body and legs, and usually includes a hood. Sleeping bags (or bunting bags) for use by children may have slits or openings in the back through which harnesses (such as from strollers and car seats) or seatbelts may pass through in order to allow safe use of the sleeping bag in child strollers, car seats and automobiles. Such sleeping bags for children are typically used as outer garments in cold weather. 
   A bunting bag or sleeping bag is generally chosen to fit the size of the child. Typically, a child starts with a small sleeping bag. Eventually, the child outgrows the small sleeping bag, in which case a larger sleeping bag must be purchased. Thus, is not uncommon for a child to require use of several successively larger sleeping bags as the child grows. 
   Adjustable size bunting bags are known. A baby robe with an adjustable length is shown in U.S. Pat. No. 4,773,101 to Kapp et al. A one-piece infant bunting with Velcro fasteners to accommodate the size of the infant is shown in U.S. Pat. No. 4,897,885 to Lunt. 
   Adjustable size sleeping bags are known. Maguire (in U.S. Pat. Nos. 4,079,472 and 4,197,601) shows a sleeping bag with a longitudinally extensible and laterally expandable foot section. Maguire shows a sleeping bag constructed of a single rectangularly-shaped sheet of bed-sheet fabric having an accordion fold at the feet thereof, to permit the foot portion of the sleeping bag to be longitudinally extensible to permit the length of the bag to be comfortably utilized by a slightly taller person. 
   U.S. Pat. No. 6,175,976 to Cantwell also shows a sleeping bag with an adjustable foot space. The sleeping bag by Cantwell is selectively convertible between a compact foot space configuration (mummy bag) and an expanded foot space configuration (rectangular type sleeping bag). 
   U.S. Pat. No. 6,216,290 Zemitis et al. show a sleeping bag that is expandable in width by having an access zipper and expansion zipper. The expansion zipper has a draft tube expansion segment, which is used to expand the circumference of the sleeping bag&#39;s interior lining and outer shell. 
   U.S. Pat. No. 6,438,774 to Michaelis et al. shows a convertible sleeping bag using a pair of zippers to allow users to adjust the bag between a conventional rectangular bag and a narrowed mummy style bag. 
   SUMMARY OF THE INVENTION 
   The present invention is embodied in a sleeping bag (or bunting bag) in which the size of the bag is adjustable to accommodate the growth of the child. The sleeping bag in accordance with the present invention may be expanded (or contracted) in width and/or expanded (or contracted) in length. 
   In order to expand (or contract) the width of the sleeping bag, an additional tape of zipper teeth is attached to the front of the garment adjacent to, and parallel to, the (regular) first zipper. When one of the tapes of zipper teeth from the first (regular) zipper is meshed with the additional tape of zipper teeth, the width of the bag is reduced, i.e., the circumference of the bag is reduced. Further additional tapes of zipper teeth may be provided adjacent to, and parallel to, the first additional tape of zipper teeth. When the one of the tapes of zipper teeth from the first zipper is meshed with one of the further additional tapes of zipper teeth, the width of the bag is further reduced. 
   In order to expand (or contract) the length of the sleeping bag, a pair of parallel zippers around the circumference of the sleeping bag is provided, which define a strip of material forming a length expansion strip extending around the circumference of the sleeping bag. The pair of parallel zippers permits the removal or insertion of such length expansion strip. To shorten the length of the sleeping bag, the length expansion strip extending around the circumference of the sleeping bag is removed. The remaining bottom portion of the sleeping bag is joined to the remaining top portion of the sleeping bag by meshing the tape of zipper teeth on the bottom portion of the sleeping bag to the tape of zipper teeth on the top portion of the sleeping bag. To further increase the length of the sleeping bag, and additional length expansion strips may be added, such additional length expansion strip having tapes of zipper teeth attached to the edges thereof that mesh with the tapes of zipper teeth on the edge of each respective adjacent length expansion strip. 
   In such matter, the length and width of a sleeping bag in accordance with the present invention may be adjusted to fit the child. As the child grows, the sleeping bag of the present invention may be expanded in width and/or length to accommodate the growth and fit properly. Therefore, the sleeping bag of the present invention is economical because it is not necessary to purchase additional sleeping bags as the child grows. Furthermore, because the sleeping bag of the present invention is adjustable to fit the child better (i.e. fit more closely) the sleeping bag will be warmer. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front view of an expandable sleeping bag in accordance with the present invention. 
       FIG. 2  is a back view of an expandable sleeping bag in accordance with the present invention. 
       FIG. 3  is an exploded isometric view of the bottom portion of an expandable sleeping bag in accordance with the present invention. 
       FIG. 4  is a front view of an expandable sleeping bag expanded to a larger configuration in accordance with the present invention. 
       FIG. 5  is a front view of an expandable sleeping bag contracted to a smaller configuration in accordance with the present invention. 
       FIG. 6  is a front view of an expandable sleeping bag expanded to a longer configuration in accordance with the present invention. 
       FIG. 7  is a cross-sectional view of an expandable sleeping bag expanded to a larger width configuration in accordance with the present invention. 
       FIG. 8  is a cross-sectional view of an expandable sleeping bag contracted to a smaller width configuration in accordance with the present invention. 
       FIG. 9  is an exterior view of an open (i.e. an unzipped) expandable sleeping bag in accordance with the present invention. 
   

   DETAILED DESCRIPTION 
   An expandable sleeping bag  10  shown in  FIG. 1  includes a hood  12 , a hood zipper  14 , a blanket body  16 , a length expansion strip  20  and a bottom piece  22 . A pocket  17  is provided on the blanket body  16  for utility storage. A regular zipper  18  is used to close the sleeping bag around the wearer. 
   As shown in the back view of  FIG. 2 , the expandable sleeping bag  10  further includes slits or openings  24 ,  26  and  28  to accommodate a seatbelt or harness straps as may be found in an automobile, car seat or stroller. The expandable sleeping bag of the present invention may be tucked into a car seat or stroller, while the straps of the restraining device (seatbelt or harness) are passed through the slits  24 ,  26 ,  28  to hold a child safety in place. The front of the expandable sleeping bag is then enclosed around the child. 
     FIG. 3  shows the arrangement facilitating the expansion of the sleeping bag  10  in both width and length. A first tape of zipper teeth  18  and a second tape of zipper teeth  30  form a first zipper (the regular zipper). A third tape of zipper teeth  19  is attached to the blanket body  16  of the sleeping bag  10 . 
   When the first tape of zipper teeth  18  is meshed to the second tape of zipper teeth  30  the width of the garment blanket body  16  is maximized. When the first tape of zipper teeth  18  is meshed to the third tape of zipper teeth  19  the width of the blanket body  16 , is reduced. The arrangement is illustrated in cross-sectional form in  FIGS. 7 and 8 . In  FIG. 7 , slider  21  meshes the first tape of zipper teeth  18  to the second tape of zipper teeth  30 , in which case the width of the garment blanket body  16  is maximized. In  FIG. 8 , slider  21  meshes the first tape of zipper teeth  18  to the third tape of zipper teeth  19 , in which case the width of the garment blanket body  16  is reduced. 
   The arrangement facilitating the expansion of the sleeping bag  10  in length is also illustrated in  FIG. 3 . In particular, a pair of parallel zippers ( 23 ,  25  and  27 ,  29 ) around the circumference of the sleeping bag  10  defines a length expansion strip  20 . For a longer sleeping bag, the length expansion strip  20  is attached to zippers above and below to become part of the sleeping bag. The length expansion strip  20  is secured at the front by using Velcro (hook and loop) fasteners  32 A and  32 B, one of which will attach to a corresponding hook and loop fastener ( 37  in  FIG. 9 ). To complete the sleeping bag configuration, the tape of zipper teeth  29  on the bottom piece  22  is meshed to the tape of zipper teeth  27  on the length expansion strip  20 . The bottom piece  22  is a strip of material extending around us a conference of the sleeping bag. In order to close the bottom piece  22  in the front, hook and loop fasteners  34 A and  34 B, one of which will attach to a corresponding hook and loop fastener ( 35  in  FIG. 9 ) and bottom snaps  40 A are provided. 
   Different configurations of the expandable sleeping bag are shown in  FIG. 4 ,  FIG. 5  and  FIG. 6 . In  FIG. 4  the expandable sleeping bag is made wider as compared to the configuration shown in  FIG. 1 . In the latter configuration, the additional tape of zipper teeth  19  is visible. Also, the Velcro hook and loop fasteners  32 B,  34 B on the additional length expansion strip  20  and the bottom piece  22 , respectively, are visible. 
   In  FIG. 5  the expandable sleeping bag is made shorter as compared to the configuration in  FIG. 1 . In the latter configuration the length expansion strip extending around the circumference of the sleeping bag ( 20  in  FIG. 1 ) has been removed. 
   In  FIG. 6  the expandable sleeping bag is made both wider and longer as compared to the configuration shown in  FIG. 1 . In the latter configuration yet another length expansion strip  20 B extending around the circumference of the sleeping bag has been added. 
   Consistent with the present invention, further additional tapes of zipper teeth may be attached to the front of the garment adjacent to, and parallel to, the other tapes of zipper teeth  18 ,  19 . Similarly, the expandable sleeping bag may be made yet longer by adding additional length expansion strips extending around the circumference of the sleeping bag. 
     FIG. 9  shows an outside view of the expandable sleeping bag  10  with all of its zippers open. Hood zipper  14  is opened so that the hood portion  12  lies flat. On the left side, a first tape of zipper teeth  18  is sewn to the edge of the garment. On the right side a second tape of zipper teeth  30  is sewn to the other edge of the garment. An additional tape of zipper teeth  19  is attached to the front of the garment adjacent to, and parallel to, the first tape of zipper teeth  18 . 
   The additional length expansion strip  20  extending around the circumference of the sleeping bag includes fasteners  32 A and  32 B, which correspond in position to zippers  18  and  19  respectively. The length expansion strip  20  further includes a fastener  37 , which corresponds in position to zipper  30 . Similarly, the bottom piece  34  includes fasteners  34 A and  34 B, which correspond in position to zippers  18  and  19  respectively. The bottom piece  34  further includes a fastener  35 , which corresponds in position to zipper  30 . 
   The bottom piece  34  further includes fasteners  40 A,  42 A,  42 B,  40 B,  42 C,  42 D and  40 C at the bottom edge thereof so that the bottom edge can be sealed when the zippers of the expandable sleeping bag are meshed so as to form a sleeping bag. In particular, a series of hook and loop fasteners  42 A,  42 B,  42 C and  42 D are available to seal the bottom of the expandable sleeping bag. In addition, a series of snaps  40 A,  40 B and  40 C are available to seal the bottom of the expandable sleeping bag. The length expansion strip  20  and the bottom piece  34  are similar in function in that each is a strip that functions to expand the length of the sleeping bag. The primary difference between the two is that the bottom edge of the bottom piece  34  is configured with fasteners to seal to itself while the bottom edge of the length expansion strip  20  is configured with fasteners to receive yet another length expansion strip or a bottom piece. 
   The fasteners  32 A and  32 B permit the length expansion strip  20  to be expandable in width in the same manner that fasteners  18  and  19  permit the sleeping bag to be expanded or contracted in width. In particular, fastener  37  meshes with fastener  32 A to expand the width of the sleeping bag. Alternatively fastener  37  meshes with fastener  32 B to contract the width of the sleeping bag. The fasteners  34 A and  34 B permit the bottom piece  22  to be expandable in width in the same manner that fasteners  18  and  19  permit the sleeping bag (along with one or more length expansion strips  20 ) to be expanded or contracted in width. In particular, fastener  35  meshes with fastener  34 A to expand the width of the sleeping bag. Alternatively fastener  35  meshes with fastener  34 B to contract the width of the sleeping bag. 
   As a result, the sleeping bag of the present invention may be independently expanded in width and length. It should be understood that while some of the fasteners described herein are specifically indicated as either zippers, Velcro (hook and loop) and/or snaps, these fasteners may be interchanged with each other or other types of fasteners (e.g. buttons) may be substituted without departing from the spirit of the invention.