JPS5852101B2 - push pull chain - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in push-pull chains.

Conventionally, a protrusion is provided on the link plate of the chain to restrict the chain from bending to one side, allowing the chain to be used for push-pull movements or for supporting objects by placing it on the side where the chain is restrained from bending. This chain is known as a push-pull chain or a no-back bend chain.

FIG. 4 shows a conventional push-pull chain, which consists of a plurality of inner links 10 and outer links 20, each link being connected by a pin 11, and protrusions 12 and 21 of each link mutually extending. When engaged, the external force that biases it to one side in the direction of travel is suppressed, and it can be bent only to the opposite side.

In this chain, when the applied load changes from a tensile load to a compressive load, the position of the pin 11 of the chain may be above or below the pitch line L due to a slight difference in the direction of force or other external factors. I come to.

As shown in FIG. 4, when the bank bends to the lower side, the amount of bank bend becomes large, the compressive load can be resisted, and the desired function can be obtained.

On the other hand, when it reaches the upper side as shown in Figure 5, the chain is at pin 1.
It bends in 10 places, causing a so-called buckling phenomenon and ceases to function.

The rate at which this buckling occurs can be said to be approximately 50%.

In order to always prevent buckling that occurs at such a ratio, as shown in Fig. 6, give the chain a backbend amount A from the beginning and position the pin 11 below the pitch line L. The shape of the end fitting 25, the link 10.2G, etc. must be taken into consideration, and this method has the disadvantage that the chain becomes curved because it requires a backbend amount A.

The present invention has been made in view of the above points, and provides a push-pull chain that can always maintain a straight state.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

The push-pull chain according to the present invention consists of a plurality of first link plates 30 and second link plates 40, each of which engages with each other to prevent the chain from bending downward. It has protrusions 32 and 41.

The second link plate 40 is provided with a pair of oblique elongated holes 42 that are inclined with respect to the pitch line L and converge toward each other upward, and each of the oblique holes 42 is formed in an upper portion located below the end of the protrusion 41. It has a center 43 and a lower center 44.

The pin 31 is slidably fitted into the inclined hole 42 and
The pin 31 is tightly fitted into the hole 33 of the link plate 30 so that the center of the pin 31 does not substantially move relative to the center of the hole 33.

One embodiment of the present invention is constructed as described above, and when a tensile load is applied to the push-pull chain as shown in FIG. 2, the pin 31 moves to the position of the lower center 44 of the inclined hole 42 and becomes condition, allowing tension to be transmitted from one end of the chain to the other.

Next, when a compressive load is applied, the pin 31 moves to the upper center 43 of the inclined hole as shown in FIG. The compressive or suppressing load applied to is transmitted to each link plate 30 and 40 in turn and to the other end of the chain.

Thus, when the load acting on the push-pull chain changes from a tensile load to a compressive load, the pin 31 moves within the inclined hole 42, so the chain does not buckle.

As explained above, the push-pull chain according to the present invention includes a first link plate and a second link plate having a pair of inclined holes, and the pin is slidably fitted into the inclined hole of the second link plate. Since the top of each link plate is provided with interlocking protrusions, the chain will not buckle when the load acting on the push-pull chain changes from tension to compression.

Furthermore, the chain itself can prevent buckling and maintain a straight posture without using any auxiliary means other than the chain.

Therefore, due to the linear posture of the chain, the driven body moved by the chain always moves in a straight line, eliminating the need for a guide and the need for backbend space.

[Brief explanation of drawings]

1A and 1B are respectively a front view and a side view of the link plate of the push-pull chain according to the present invention, FIGS. 2 and 3 are front views of the push-pull chain in the operating state, and FIGS. FIG. 6 is a front view of a conventional push-pull chain.

Claims (1)

[Claims] 1 First and second link plates are alternately connected so that the protrusions attached to the upper sides engage with each other and cannot be bent upward, and the first link plate has a pair of round holes in the front and rear. , the second link plate has a pair of oblique long holes in the front and rear, so that the connecting round pin fits tightly into the round hole of the first link plate and can freely slide into the oblique long hole of the second link plate. A push-pull chain that features a snap-fitting feature.