and 107 which serve to partially confine and support ball bearings 108 only one of which is so designated positioned within the channel 105 and between the ball bearings 108 is a hanger member 109 along its vertical sides the hanger member 109 is equipped with grooves or raceway defining portions 110 only one of which is designated the grooves 110 cooperate with the raceway portions 106 107 to confine the ball bearings 108 thus the hanger member 109 is slidably supported for horizontal movement on the ball bearings 108 as also described in the 39 898 patent a closure member 111 is provided at the ends of the raceways to confine the ball bearings 108 against inadvertent displacement reference is now made to fig4 where the hanger bar 109 is depicted in side elevational and each end thereof is equipped with a horizontal bore at 112 and 113 the bores 112 and 113 provide for an advantageous connection of the novel hanger bar 101 previously referred to now referring to fig4 it will be seen that in the illustrated embodiment the hanger bar 101 includes a pair of pivot block elements 114 and 115 connected by a bar portion 116 for ease of manufacturing i cast the pivot block elements 114 and 115 and weldably secure thereto the bar portion 116 the left pivot block element 114 is seen to be equipped with a threaded bore as at 117 for.