To provide an opening motion auxiliary device for an entrance door which facilitates opening of the entrance door when, for example, it becomes very heavy to open the entrance door in the opening direction because of a difference in air pressure between indoors and outdoors or the like.
The opening motion auxiliary device is installed on the upper frame of an entrance facing to the entrance door. The interior of a casing 7 is provided with a pressing part, a male screw shaft 10, and an operation plate 18. The pressing part is constituted by a cylinder 11 having a built-in spring 12 for shock absorption, which transfers the power in the door-opening direction, and the male screw shaft is connected to the output shaft 8a of a motor 8 via a gear wheel for letting the cylinder 11 reciprocate for moving forward/backward. The operation plate 18 can freely slide in the longitudinal direction of the male screw shaft 10. The cylinder 11 is slidably supported and a large-diameter cylindrical body 11a of the cylinder 11 is joined to the operation plate 18. Also the operation plate 18 and the cylinder 22 are moved integrally in the longitudinal direction of the male screw shaft 10 by the rotation of the male screw shaft 10, so that one end side of a small-diameter cylindrical body 11b of the cylinder 11 can move backward and forward from an opening 20a of the casing 7.
NAGAMITSU KAZUYUKI
HARUTA DAISUKE
FUJISASH CO
JEO PRINCE TAKESHITA KK
Yoshihiro Morimoto
Toshiji Sasahara