inserted into the larger tubular portion 40 of another connecting bar 32 to make the connection between two subpanels 14a placed end to end referring again to fig2 other general components which are used to either secure two subpanels 14a together or to secure and mount one end or another of a subpanel 14a to track 22 fig1 include respective right and left end caps 42 44 and junction cap 46 right and left end caps 42 44 each include respective rollers 20 21 it will be appreciated that when subpanel 14a is used as an end subpanel of door panel 12a on the left side of door 10 as viewed in fig1 end cap 44 will be connected to the left end of subpanel 14a to supply rollers 21 for mounting the left side of door 10 to track 22 likewise when subpanel 14a is used as an end subpanel of door panel 12a on the righthand side of door 10 end cap 42 will be used to similarly supply rollers 20 for mounting the righthand side of door 10 to a track not shown in this regard end caps 42 44 connect and function in the same manner as the caps disclosed in related application ser no 08 241 288 in a manner to be detailed below junction caps 46 are used between adjacent subpanels 14a to provide a.