JPH0240709Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a door closing device, and an object thereof is to reliably prevent a door from closing suddenly.

Hereinafter, the present invention will be explained based on drawings showing an example of implementation. In the figure, 1 is the entrance/exit part 2 of the building.
4 is a door closing device main body fixed to the upper end of the door 1, and 5 is a guide member fixed to the upper end of the doorway 2. be. The door closing device main body 4 includes a main cam 7 fixed to a shaft 6.
and a sub-cam 8 rotatably supported on the shaft 6.
, a coil spring 9 that presses the main cam 7 and the sub cam 8 , and a slide member 11 that wraps around the coil spring 9 and has one end abutted via a metal plate 10 . The slide member 11 is divided into two parts and has protrusions 16 and 17 that are slidably fitted into elongated holes 14 and 15 formed in the upper and lower plate parts 12 and 13 of the main body 4. The pressing force of the coil spring 9 is transmitted to the cams 7 and 8 via the front end and the metal plate 10. Note that the slide member 11 is connected to the protruding portion 1.
6 and 17 are fitted into the elongated holes 14 and 15, and the elongated holes 14 and 15 are opened and closed by opening and closing of the door 1, which will be described later.
Slide along. By the way, the main cam 7 is fixed to the shaft 6 with a screw 18, and the sub-cam 8 is free with respect to the shaft 6. A coil spring 19, which is engaged with the main cam 4 and whose other end is engaged with the sub cam 8, applies a rotational force in the direction of rotation of the main cam 7 when it is opened. The shaft 6 passes through the main body 4 vertically, and its lower end is supported by a bearing 20 that is fitted and fixed into the hole 13a of the plate 13 on the lower side of the main body 4. One end of the link 22 is supported by a screw 23 at the upper end of the shaft 6, which is supported by a bearing 21 that is fitted and fixed in the hole 12a of the shaft 6, and further projects upward from the bearing 21. At the other end of the link 22 is a screw 2.
A guide roller 25 rotatably supported by 4
The guide roller 25 is slidably engaged inside an elongated hole 26 formed in the lower part of the guide member 5 along the elongated hole 26. The elongated hole 26 faces in the same direction as the width direction of the entrance/exit portion 2.

Further, to describe the main cam 7 and the sub cam 8 in detail, when the door 1 is opened or closed, the main cam 7 rotates together with the link 22 to convert the force of the coil spring 9 into a force in the closing direction. The main cam 7 has an oblique surface 7a that faces the metal plate 10 in the door closed state, and a cam surface 7b that gradually increases in diameter from the oblique surface 7a in the door opening direction. The sub cam 8 also has a flat surface 8 that comes into contact with the metal plate 10 when the door is closed.
a and a cam surface 8b whose diameter gradually increases from the flat surface 8a in the opposite direction to the door opening direction, and this sub cam 8 is biased by the coil spring 19 in the door opening direction. The structure is such that the biasing force of the coil spring 19 disappears at the maximum opening angle of the door 1, for example, 90 degrees. Further, this sub-cam 8 is connected to the metal plate 10 when the door 1 is open, as shown in FIGS. 8a to 8d.
It separates from the door and comes into contact with the metal plate 10 while the door is being closed, and then as the door 1 closes, it rotates in the opposite direction to the door closing direction due to friction with the metal plate 10 against the biasing force of the coil spring 19. This secondary cam 8 fills the gap between the flat surface 7 of the main cam 7 and the metal plate 10 by having its cam surface 8b abut against the metal plate 10 while the door is being closed as shown in FIG. 8C. This is to prevent the flat surface 7a from coming into contact with the metal plate 10 impactfully, and from the middle of the door closing shown in FIG. 8C to the final door closing state shown in FIG. 8D, the cam surface 8b of the sub cam 8 and Oblique plane 8a
Since the connection portion with the sub-cam 8 has a smooth arc shape, the oblique surface 8a of the sub-cam 8 smoothly contacts the metal plate 10, and the door 1 is prevented from being blocked by an impact.

In short, the main cam 7 converts the force of the coil spring 9 into a force in the closing direction and transmits the same to the door 1, and the sub cam 8 serves as the main cam when the sub cam 8 is not provided. It serves to prevent impactful contact between the cam 7 and the metal plate 10, and ultimately the flat surface 8a of the sub-cam 8
comes into contact with the metal plate 10 and the door 1 is closed. In the final closed state, the flat surface 7a of the main cam 7 does not come into contact with the metal plate 10. Note that when the door 1 is opened and closed, the link 22 is connected to the guide roller 25 at the other end.
is engaged with the elongated hole 26 of the guide member 5 and slides along the elongated hole 26.

The door closing device of the present invention can be implemented as described above, and the secondary cam can reliably prevent the door from closing suddenly due to the spring force, and the door can be automatically and quietly closed.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention.
The figure is a schematic perspective view seen from the front with the door open, Figure 2 is an enlarged perspective view of the main part of Figure 1, Figure 3 is an enlarged perspective view of the main part seen from the rear with the door open, and Figure 4 is A perspective view of the door closing device, FIG. 5 is an exploded perspective view of the same, FIG. 6 is a cross-sectional view of the main body of the door closing device,
FIG. 7 is a rear view of the same, and FIGS. 8 a to 8 d are explanatory views of the operation. DESCRIPTION OF SYMBOLS 1... Door, 2... Entrance/exit part, 4... Door closing device main body, 5... Guide member, 6... Shaft, 7
...Main cam, 7a...Flat surface, 7b...Cam surface,
8... Sub-cam, 8a... Flat surface, 8b... Cam surface, 9... Coil spring, 10... Metal plate, 11...
...Slide member, 19...Coil spring, 22...
Link, 25... Guide roller, 26... Long hole.

Claims (1)

[Scope of utility model registration request] A door closing device that automatically closes a door that is rotatably installed around a vertical axis at the entrance/exit of a building, and includes a main cam that is fixed to a shaft inside and rotates, and a main cam that is loosely fitted to the shaft and rotates. A first spring that presses the secondary cam and the main cam to bias the door in a direction to close the door via the shaft, and a second spring that biases the secondary cam in a direction opposite to the door closing direction are housed. a main body, a link whose one end is connected to one end of the shaft, and a guide member which slidably engages the other end of the link, and the sub cam is connected to the first spring just before the door is closed. A door closing device characterized in that the door closing device is brought into contact with the first spring side to create a gap between the door closing device and the cam.