response to rightward movement of link 46 caused by pushing of the push bar 23 as can be seen in fig4 this occurs in response to clockwise pivoting movement of link 47 about axis 98 in this regard link 46 is coupled at 49 to rotor 50 rotate it clockwise to displace 47 to fig4 position causing 45 to be displaced downwardly and plate 45 a to be displaced upwardly if external rotor 24 is rotated manually it likewise causes rotor 50 to rotate clockwise however the handle cannot rotate if the actuator coupled to 50 is blocked as at location 52 in fig4 by lever 53 turning of the key 26 in slot 26 a serves to unblock rotation of 51 by limited rightward rotation of lever 53 if rotation of handle 24 is blocked and excess torque is applied provision is made for disengagement of a coupler in the handle torque transmission path this is shown schematically by coupler 66 in fig4 coupled to handle 24 at 67 and to rotor 50 in fig8 a modified door 160 has front and rear vertical panels 161 and 162 and door interior 163 channel shaped receptacles 164 and 165 u shaped in section fit between the panels and open oppositely endwise to receive sealing structure as shown in fig6 fig9 also shows the receptacles as well as adjustable door edge sealing elements 32 and 32 a and sealing walls 164 a and 165 a the receptacles are box shaped as shown and move toward or away from frame edges as threaded adjusters 32 and 32 a are rotatably adjusted a hinge 166 has plate connection at 167 to receptacle 164 and at 168 to door frame 169.