JPS6049751B2 - Feeding and winding mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feeding and winding mechanism for feeding and winding up a roll-blind projection screen, a map for teaching materials, etc., or stopping it at an arbitrary position.

Conventionally, this type of winding mechanism generally includes a torsion spring or the like interposed between the shaft center and the core tube, and a predetermined blind, screen, etc., wrapped around the core tube.

If you extend the blinds, screens, etc., or stop them at any point along the way, the lower end of the extended blinds, screens, etc. must be hooked to a separately provided locking part, as there is no stop mechanism. I was using it. In addition, some machines do not have a winding function using a torsion spring, or even if they do have a winding function using a torsion spring, there is a stop mechanism in the middle that allows the steel ball to be removed from the groove by centrifugal force from the rotation of the core tube. This method had many practical problems, such as unreliable operation, frequent failures, and high cost. This invention has been made in order to solve the above-mentioned problems, and is a feed-out/wind-up device that is configured to be able to reliably feed out and wind up blinds, screens, etc. with a single touch, and to be able to stop at any position. There is also a mechanism that provides a locking mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In the figure, reference numeral 1 denotes a bearing frame body, and brackets 2 having a predetermined width are extended from both ends thereof. One end of the bracket 2 is formed with a square hole 2a in which one end of the shaft core 3 is formed into a square shape and is supported so as not to rotate, and the other end is formed with a square hole 2a in which one end of the shaft 4 is rotatably supported. A hole 2b is formed. The other end of the shaft 4 is a free end, and the other end of the shaft core 3 is rotatably supported on this free end. A shaft 5 is rotatably supported on a non-rotating shaft core 3 whose one end is supported in the square hole 2a of the bracket 2, at an end opposite to the shaft 4.

A slit groove 3a is formed at the end of the shaft core 3 on the shaft 4 side to lock one end of a torsion spring 6 inserted on the shaft core 3, and the other end of the torsion spring 6 is connected to the shaft 4, The winding core cylinder 7 is press-fitted between the shafts 5 and 5 and is locked from the shaft 5 side. That is, the winding core cylinder 7 is a hollow cylinder, and the fixed shaft core 3 is different from the shaft 4,
It is rotatably mounted via 5. Moreover, the above-mentioned winding core tube 7
A blind or screen 8 having a predetermined length and having one end surface fixed is wound around the outer periphery of the screen.

On the other hand, a cam 9 having a plurality of engagement grooves 9a formed on its outer periphery is integrally formed on the bracket 2 side of the shaft 4 which is pivotally supported in the round hole 2b of the bracket 2.

The cam 9 may be formed separately and fixed concentrically to the outer surface of the shaft 4. The cam engagement groove 9a is formed as shown in FIG. has been done.

The opening of the engagement groove 9a is biased in the biasing direction P1 of the torsion spring 6.
A first protrusion a is connected to the side thereof, and a second protrusion b is connected to the opposite side thereof. The separation distances La and Lb between the two protrusions A and b from the rotation center 0 of the cam are longer for the first protrusion a! (La>Lb).
Further, the groove 9a is formed to be inclined in the direction opposite to the biasing direction of the torsion spring 6. That is, in the above-mentioned configuration, as shown in FIG. The shafts 4 and 5 rotate on the shaft core 3, and the torsion spring 6 interposed between the winding core tube 7 and the shaft core 3 is rotated in the tightening direction P (the opposite direction to the P direction in FIG. 4). , accumulates return repulsive force.

At this time, the stop pin 11a of the stop lever 11 pivotally connected to the pin 10 of the bracket 2 moves into the engagement groove 9 of the cam 9.
It is pushed up along the slope from a (Fig. 5, 11a
-1→11a-2) and is pushed out from the opening, so the rotation is not restricted and the core cylinder 7 rotates smoothly. In this way, when the blind or screen 8 is pulled out to an arbitrary position and slowly returned to its original position while being stopped,
The lever 11 descends under its own weight and falls into the engagement groove 9a of the stop pin 11a, and the cam 9 is about to return in the P1 direction due to the repulsive force of the torsion spring 6, so it is locked. Therefore, even when the blind or screen 8 is fully extended, the same operation as described above can be performed, and the same applies when the blind or screen 8 is once stopped midway and then extended again. In addition, when the cam 9 is unlocked from the above-mentioned stopped state and the blind or screen 8 is to be rolled up, once the blind or screen 8 is pulled out downward, the stop pin 11a of the stop lever 11 moves into the engagement recess of the cam 9. The cam 9 comes off the groove 9a and becomes rotatable, and when you release your hand, the cam 9 is moved by the repulsive force of the torsion spring 6.
rotates, and the blind or screen 8 is rolled up vigorously. At this time, as shown in FIGS. 6A to 6B, the opening of the engagement groove 9a is provided with a first protrusion a and a second protrusion b having different distances from the rotation center 0 of the cam 9. Therefore, in the process in which the stop pin 11a of the stop lever 11 climbs over the first protrusion a with a long separation distance and falls into the groove 9a, the cam 9 is moved so that the second protrusion b with a short distance above the stop pin 11a. It rotates so that it passes below.
That is, the engagement groove 9a passes before the stop pin 11a of the stop lever 11 enters the groove from the opening of the engagement groove 9a, and the cam 9 is not locked and rotates smoothly, catching the screen, etc. It is.

In this way, when the cam 9 rotates at high speed, the stop pin 11a jumps over the engagement groove 9a and slides into contact with the outer periphery of the cam, thereby making it possible to freely rotate the winding core tube 7 in two directions: feeding out and winding in.
When the cam 9 rotates slowly, it engages with the engagement groove 9a to lock the rotation of the core tube in the winding direction. Note that 12 in the figure is an edge provided at the lower end of the blind or screen 8, and a handle 13 is fixed to the center.

As explained in detail above, the feeding according to this invention,
The winding mechanism has a simple structure and is easy to handle.

Moreover, since it can be operated with a single touch, operations such as extending and winding up the blind or screen, and stopping the unfolding at an arbitrary position are easy. Furthermore, since it is a simple mechanism, there are few failures and it can be made at low cost, which has practical effects. The engaging groove of the present invention has a first protrusion and a second protrusion that are separated from each other by a different distance from the center of rotation of the cam at its opening, so that the engagement groove can overcome the first protrusion that has a long distance from the center of rotation of the cam. Even if the rotational speed of the cam is not very high, the stop pin can easily jump over the concave groove and reach the second protrusion with a short distance, so that the winding operation of the blind or screen can be performed smoothly.

Furthermore, since the cam of the present invention is rotated, the engagement groove can be formed over the entire outer circumference of the cam, and the stopping position of the winding core cylinder can be adjusted to any desired position depending on the number of engagement grooves formed. It is possible to make fine adjustments by making the intervals finer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a left side view of FIG. 1, FIG. 3 is a right side view of FIG. 1, and FIG. 4 is a main part. The enlarged side view of FIG. 5 and FIGS. 6A to 6B are explanatory diagrams illustrating the operation of the main parts of the same.

1...Bearing frame body, 2...Bracket,
2a...square hole, 2b...round hole, 3...
Axial core, 4, 5... shaft, 6... torsion spring, 7
... Winding core cylinder, 8 ... Blind or screen, 9 ... Cam, 9a ... Engagement groove, 10 ... Zen, 11. ... Stop lever, 11a ... Stop pin, 12 ... Edge, 13 ... Handle.

Claims (1)

[Claims] 1 A first shaft with one end rotatably supported by one bracket and the other end being a free end, and one end rotatably supported by the free end side of the first shaft and the other end supported by the other bracket. A shaft core whose rotation is restrained and supported by a shaft, a second shaft rotatably extrapolated to the shaft core on the other bracket side, and a shaft between the first shaft and the second shaft. A winding core tube around which a fixed blind or screen, etc. is wound, a torsion spring interposed between the shaft core and the winding core tube, and an outer side of either the first shaft or the second shaft. It consists of a cam with a plurality of engagement grooves formed on the outer periphery formed concentrically on the side surface, and a stop pin whose one end is pivotally attached to a bracket and whose other end slides on the outer periphery of the cam. The mating groove has a first protrusion on the biasing direction side of the torsion spring of the opening, and a second protrusion on the opposite biasing direction side of the opening thereof, and extends from the center of rotation of the cam. The distance between the first and second protrusions is longer than that of the first protrusion, and the concave groove is formed to be inclined in the direction opposite to the biasing direction of the torsion spring, and the stop pin is connected to the cam. During fast rotation, the cam slides over the engagement groove and slides on the outer periphery of the cam, allowing free rotation in two directions for feeding out and winding the winding core cylinder, and when the cam rotates slowly, it engages in the engagement groove and winds. A feeding and winding mechanism characterized by locking the rotation of the core cylinder in the winding direction.