may be moved away from contact with the teeth 92 of the ratchet wheel 90 against the force of the spring 110 when the tip of the screwdriver is removed the pawls 88 of the pawl member 82 will move back into contact with the teeth 92 of the ratchet wheel 90 the apparatus may then be adjusted again to preload the bias on the torsion tube 160 as previously described while a conventional tool not shown may be used to adjust the display pivot member 130 by using the notches 134 in the adjustment wheel 132 of the display pivot member 130 fig1 a custom tool such as the custom tool 170 illustrated in fig1 may also be utilized the custom tool 170 has a curved section 172 sized to fit around approximately half of the adjustment wheel 132 at one end of the curved section 172 of the custom tool 170 is a radially inwardly extending tooth 174 which will fit into one of the notches 134 in the adjustment wheel 132 the other end of the curved section 172 of the custom tool 170 is attached to a handle 176 referring now to fig1 and 19 a door retainer clip 180 for installation on the door is illustrated the display door not shown is installed by the engagement member 136 of the display pivot member 130 into the machined passage 94 of the ratchet wheel 90 in the base member 120 by lowering the display door slightly the door retainer clip 180 has a c shaped portion 182 which is designed to snap onto the cylinder 154 in the space between the bottom of the top door frame member and the top of the display door thus the door.