1. Field of the Invention
The present invention relates to the scientific technology of automatic shutting pull door, and in particular, to a damped closing mechanism for automatic shutting pull door in which the automatic closing mechanism can perform a varied damping effect to alleviate the closing force and retard the travelling speed when the moving door panel is about to reach the final shut position so as to avoid the door panel to collide with the door post too forcibly that might result in damaging the door.
2. Description of the Prior Art
For the purpose of performing closing and opening operation of the door efficiently and silently, an automatic door closing mechanism is employed. For example, in order to avoid too loud bumping noise and accidental disruption of a door when closing it too forcibly, an automatic closing mechanism is provided for a revolving or a pull door to alleviate the closing impulse or retard closing speed. As for a pull door in which the door panel makes transverse displacement, there have been disclosed many kinds of automatic closing mechanism with a variety of functions, namely, “Speed Governor for Automatically Shutting Pull Door” (Taiwan Pat. No. 445340), “Locking Device of Pull Door” (Taiwan Pat. No. 1295335), and “Automatic Closing Device for Pull Door” (Taiwan Pat. No. 200743717) etc.
Take the last one for example, it has successfully eliminated the prior flaw of employing a bulky and awkward rack rail in its automatic closing device, however, it has not been liberated form the conventional disadvantage of lacking damping effect of the helical spring in the closing device that results in failing to lower the travelling speed of the door panel, and causing a loud bumping noise or even disruption of the mechanism or door itself when the door is closed.
In view of the foregoing situation, the inventor of the present invention herein has gone to great length of intensive research based on many years of experience gained through professional engagement in the manufacturing of the related products, with continuous experimentation and improvement culminating in the development of the present invention.
Accordingly, the object of the present invention is to provide a damped closing mechanism for automatic shutting pull door having a change over device capable of changing the damping effect generated nearby the closing position of the door so as to alleviate colliding speed and impulse of the moving door panel with the door post when shutting without affecting pulling of the door panel before closing.
To achieve the afore said object, the gist of the present invention is to provide a damped closing mechanism essentially comprising a base, a screw wheel, a change over device and a brake gear.
The screw wheel is erected on the base and having a coil spring to produce a restoring resilient force. The screw wheel is able to wind back and stretch out a rope whose exposed end is fasten to a door panel or door frame where the damped closing mechanism being not installed so as to stretch out the rope when the door panel is away form the shut position; and when liberating the door panel, the screw wheel winds back the rope to move the door panel to approach the shut position.
The change over device is erected on the base and having a first and a second rocking bars radially extended with an angle therebetween. The size of opened angle depends on the predetermined retarding distance for the screw wheel to go. There is a brake member provided at the nearby door closing position on the door frame or door panel to where the exposed end of the rope is fastened for stirring up the first and the second rocking bars.
The brake gear erected on the base revolves simultaneously with the screw wheel. There is a damping element contained in the brake gear to provide a damping effect. Corresponding with the first and second rocking bars, there are a first and a second positioning dents formed on the brake gear, and a corresponding ball button is provided on the sidewall of the base for the change over device to vary the damping effect of the brake gear.
With this scheme, when the door panel approaches the door closing position, the change over device actuates the brake gear to vary its position to begin damping so as to alleviate the colliding force and speed of the door panel with the door post yet without affecting pulling back of the door panel before closing.
Other objects and purposes of the invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspection of the accompanying drawings.
Referring to
Referring further to shaped frame member having a fence 15 to enclose the bottom and side opening around the base 10 such that an upwardly opened accommodation space is formed between the base 10 and the fence 15.
The screw wheel 20 is erectly housed in the accommodation space between the base 10 and the fence 15. The screw wheel 20 contains a coil spring (not shown) capable of producing a restoring resilient force when recoiling and making the screw wheel 20 to wind back or extend the rope 50. The screw wheel 20 is provided with an elastic limit member 24 for limiting its revolution and an adjustable mechanism 26 to adjust resilience of the coil spring. The forward rotation of the adjustable mechanism 26 coils up the coil spring and strengthen its resilient force, and vice versa. A driving gear wheel 21 is attached to the shaft of the screw wheel 20 and mated with a gear unit 22 (see
Here, the change over device 30 is erectly housed in the accommodation space between the base 10 and the fence 15 and located in a position at the opposite side of the guide rolling wheel 25 of the screw wheel 20. The change over device 30 has a first and a second rocking bars 31 and 32 extended radially outward with and angle formed therebetween (see
Meanwhile, the size of a door panel 2 must allow at least one damper 35 installed around the vicinity of those component parts of the change over device 30, e.g. the driving gear 33, conversion gear 34, or the paired driving gear 33 and conversion gear 34 to conjoin with so as to provide the retarding effect for the change over device 30.
In an embodiment of the present invention, the brake gear 40 is in mesh with the conversion gear 34, but it is not limited only as such. As shown in
The brake gear 40 has at least two positioning dents formed along its own edge at a position opposite to the screw wheel 20. In this embodiment two dents, a first and a second dents 41 and 42 are formed, and a corresponding ball button 45 is provided on the side fence surface of the base 10. There is a cavity 451 with a spring 452 and a rolling element 453 formed inside of the ball button 45. At the side of the ball button 45 is an adjuster 455 to adjust the resilience of the spring 452 to provide the rolling element 453 with an adjustable pre-pressure thereby bringing the rolling element 453 to be trapped into the first or the second dents 41, or 42 and positioned thereat.
With this scheme, a damped closing mechanism for automatic shutting pull door can be operated to retard the travelling speed of the door panel when shutting through the use of the change over device 30.
In practical application, reference can be made to
By so, when the door panel 2 is pushed in the opening direction, the rope 50 will be extended by the guide rolling wheel 25, the screw wheel 20 rotates to coil up the coil spring to store the resilient force towards the shutting direction. At the time the door panel 2 goes apart from its shut position, the brake member 60 will actuate the first rocking bar 31 of the change over device 30 on time (see
On the contrary, when the door panel 2 is liberated, screw wheel 20 will use its restored resilient force to wind up the rope 50 thereby urging the door panel 2 to move towards closing direction. The screw wheel 20 themselves contains a damper 23 to avoid sudden movement of the door panel 2. The travelling speed of the door panel 2 in closing direction is greater than the winding up speed of the rope 50 by the screw wheel 20. When the second rocking bar 32 of the change over device 30 is in touch with the brake member 60 (see
In the present invention, the cooperated function of the ball button 45 and the second dent 42 of the brake gear 40 further serves to alleviate the restoring resilient force of the coil spring in the screw wheel 20 and retards the moving speed of the door panel 2 towards closing direction so as to restrain bumping impulse and the noise when door is shut but without delaying the returning time of the door to the shut position too long.
It is apparent to a person skilled in the art that the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are thus not restricted to the examples described above, but may vary with the scope of the following claims.