|20060195985||BEDDING HEM WITH ASSOCIATED INTERIOR SPACE INTERLINING||September, 2006||Keith|
|20080109963||Inflatable bed having a built-in electric air pump unit for inflating a mattress assembly||May, 2008||Wang et al.|
|20050125903||Fabric sheet retaining device and method of use||June, 2005||Tapanes|
|20080271245||Inflatable mattress with uniform restraint||November, 2008||Flick|
|20060000024||Mattress having a flammable core and a nonwoven cellulose flame retardant fabric||January, 2006||Mcguire et al.|
|20070192955||Shelter bed||August, 2007||Matoba|
|20090188047||Body support system for a variety of purposes||July, 2009||Morse|
|20010027574||Device and method for raising or moving a person||October, 2001||Bouhuys|
|20040163179||Folding of a protective cover article||August, 2004||Trefethren et al.|
|20070199152||Baby sleeping receptacle||August, 2007||Askaroff|
|20020116763||Bed covering securing system||August, 2002||Weir et al.|
 The present invention relates to a rail device which has a frame inserted below the mattress and the bars of the rail device can be folded to be a compact assembly.
 A conventional playpen is used to let a baby sleep or crawl therein so that it has a bottom and four side rails. The side rails are cooperated with fabrics so that the baby can not crawl over the side rails and is safe in the playpen. When the baby grows, the playpen is small for the baby so that the adults could put the baby on a bed and keep an eye on the baby who is vigorous and tries to crawl out from the bed. It is necessary to have a rail device that can be connected to a side of the bed so that the baby cannot crawl out from the bed. However, the conventional rail device involves a complicated structure and a lot of parts. The size of the conventional rail device is so huge that the mother of the baby feels inconvenient to install or removed the rail device from the bed.
 In accordance with one aspect of the present invention, there is provided a rail device which comprises a U-shaped frame having two ends thereof respectively connected to two respective connection devices. Each of the connection devices has a first plate and a second plate between which a first tube is pivotally connected. Each of the first plate and the second plate has a notch defined therein. A first transverse bar is pivotally connected between the two second plates of the two connection devices, and a second transverse bar is pivotally connected between the two first tubes. Each of the first tubes has a first pin extending therethrough and two aligned slots defined through a wall of each of the first tubes. A spring is received in each of the first tubes and a first end of the spring contacts the first pin and a second end of the spring is engaged with a stop member. A second pin extends through the stop member and two ends of the second pin movably extend through the two slots in each of the first tubes. The two ends of the second pin are engaged with the two notches in the first plate and the second plate.
 The primary object of the present invention is to provide a rail device that can be easily folded and is installed with or disengaged from the bed.
 The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
 Referring to FIGS.
 Each of the first tubes
 A second transverse bar
 While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.