JPS6042088B2 - Automatic tension adjustment mechanism of film feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanism for stably supplying film, particularly film in a packaging pool supply device.

When feeding the film, it is required to feed the film while applying slight tension to the film.

Also, since the film is rolled onto a bobbin, the diameter of the roll changes as the film is fed, so in order to feed the film at a constant speed, it is essential to adjust the rotational speed of the bobbin, that is, the strength of the brake force. It will be about. However, with conventional devices of this type, it is difficult to make delicate adjustments to the tension, or because the range for adjusting the tension of the film is narrow, the adjustment cannot be completed at once but must be repeated, which is extremely troublesome.

Therefore, the present invention has a wide range of film tension adjustment, and once adjusted, it can be automatically adjusted regardless of the size of the film roll diameter, and has a simple structure, making it inexpensive and easy to manufacture. It is something that provides something. Next, an embodiment of the present invention shown in the drawings will be described.

The film 1 is rolled onto a bobbin holder 2 having a rotating shaft, and the film sent out from there is pivoted to a pulley 3 that is pivoted to the device and a floating arm 8 that rotates coaxially with this pulley 3. the pulley 4, which is attached to the device, the pulley 6, which is pivoted to the device, and then the floating arm 8.
It is supplied through a pulley 5 which is pivoted on the machine and finally through a bobbin 7 which is also pivoted on the device.

A brake drum 17 is provided on the bobbin holder 2 so as to protrude in the axial direction, and a brake belt 9 is wound around this drum. One end 9a of this belt is connected to the other end 11b of a balancer arm 11 having a weight 10 which is detachable and slidably adjustable, and this balancer arm 11 is supported by a bearing 12 in the center of the apparatus. A tension spring 1 is attached to the other end 9b of the brake belt 9.
3 to one end of the floating arm 8, i.e. the pusher 4,
The end 8b in the direction opposite to the side where 5 is pivoted is connected.

At the other end 8a of the floating arm 8, a tension spring 14, one end of which is fixed to the device, is attached to the pulley 3 of the tension spring 13.
The floating arm 8 is fixed with an acting force in a direction that resists the force that attempts to rotate the floating arm 8 about the axis. Tension spring 13
, 14 are provided with adjustment bolts 15, 16 for adjusting the respective springs. The present invention is configured as described above.

Furthermore, when the film tension becomes large, the brake force on the film bobbin must be weakened to facilitate film feeding. On the other hand, if the film tension becomes small, the brake force must be strengthened to apply a slight tension to the film. For this purpose, when the film tension becomes large, the pulleys 4 and 5 pivoted on the floating arm 8 are pulled in the direction of arrow A by the tension of the wound film, so that the floating arm 8 is pulled by the spring 14. The arm 8 rotates counterclockwise (in the direction of arrow A) using the pulley 3 as a fulcrum against this, and one end 8b of the arm 8 moves in the direction of the brake belt 9 (in the direction of arrow B) to loosen the tension on the belt 9. Therefore, the equilibrium of the balancer arm 11 connected to one end 9a is broken, and the weight 10 direction of the balancer arm descends, and the part of the balancer arm 11 that is supported by the bearing 12 on the device acts as a fulcrum, and therefore the opposite side 11b conversely rises, and the balancer arm 11 changes to the dotted line position.

Accordingly, one end 9a of the brake belt 9 is also lifted, and the contact surface with the brake drum 17 is separated from the portion C.
This reduces the contact area between the brake belt 9 and the brake drum 17, which weakens the brake force, speeds up the rotation of the film roll, and promotes the feeding of the film. Conversely, if the tension of the film is weak, the tension spring 1 fixed to the floating arm 8
4 prevails, the arm rotates clockwise, and one end 8b of the arm pulls the brake belt 9, so the balancer arm 11 connected to this belt returns to the state shown by the solid line.

As a result, the contact surface between the brake belt and the brake drum 17 increases, the brake force is strengthened, the rotation of the film roll is slowed down, and the tension of the film is restored to its original state. In this manner, according to the present invention, if the tension springs 13 and 14 are adjusted in advance using the adjustment bolts 15 and 16 and the balance of the weight 10 is adjusted, the film feeding can be performed according to the tension. It is automatically adjusted.

[Brief explanation of the drawing]

The drawings are schematic illustrations of embodiments of the invention. 1... film, 8... floating arm, 9
...Brake belt, 11...Balancer arm, 13, 14...Tension spring, 17
...Brake drum.

Claims (1)

[Claims] 1. A balancer arm 11 equipped with an adjustable weight 10 at one end of a brake belt 9 wound around a brake drum 17 provided on a bobbin holder 2 on which a film is rolled.
The fulcrum position of this balancer arm is a bearing 12 in the device, and the other end of this belt 9 has at least one pulley 5 attached to one side, and a shaft 3 serving as a fulcrum. The other end of the floating arm 8 is fixed, and the film is attached to the pulley 5.
The pulley 5 moves up and down depending on the tension of the film, and the other side moves up and down by the floating arm 8, and the brake belt 9 connected to the other side moves up and down depending on the tension of the film.
An automatic tension adjustment mechanism for a film supply device that changes the balance position of the balancer arm by increasing or decreasing the tension.