JPS6215413Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement to the latch of a security chain, which makes it easy to lock and unfasten the chain, and is also resistant to clever illegal lock-opening methods such as "string pulling." It is intended to provide a security chain with great crime prevention power.

Conventional safety chains have a rectangular metal plate with a narrow longitudinal groove in the center, with one end of the groove enlarged.
It was of the type in which a hook fixed to one end of the chain was slid into the narrow groove.

This type of safety chain is a rectangular metal plate that provides the greatest crime prevention effect when installed horizontally, and is a hardware that is designed to be installed in that way. However, in recent architecture, there are many steel doors and flat doors, and since there are no horizontal bars to horizontally attach the rectangular metal plate of the guard chain, it has become common to have no choice but to attach the metal plate vertically to the vertical stile. However, this method of attachment had the disadvantage that the chain could be easily removed illegally using a wire or the like by opening the door slightly and looking at the latch through the gap. Therefore, in order to improve crime prevention as much as possible,
By moving the attachment position of the chain downwards and positioning the chain base so that the door is fully closed and the chain is fully extended and the stopper can be hung, it is considered to be complete. It is normal to have one.

However, if the chain is attached in such a way that there is no room for chain extension, a new drawback arises in that it becomes extremely difficult to hang and remove the chain.

In addition, even if the installation is carried out strictly like this, it is possible to open the door slightly, tie a thin and strong nylon string to the stopper at the end of the chain, close the door completely, and attach the nylon string to the door. The stopper can be easily removed by passing it from the vertical stile to the upper stile and pulling the string. This illegal unlocking technique is called ``string pulling''.

If the rectangular metal plate is horizontally attached to the door, you can easily and illegally attach the stopper from the outside of the door by pulling the nylon string along the door's upper frame and toward the hinge side. It can be removed.

In the case of a guard chain with a single metal rod protruding from the mounting plate instead of a rectangular metal plate, the same method as above was used, and the same drawbacks occurred.

The present invention is a guard chain used for doors of architectural openings, which includes a base rod that protrudes from the mounting seat and is fixed to the mounting seat, a spring that is housed in the base lever, and the spring.
It is characterized by having a latch consisting of a slide rod that is always pressed so as to protrude above the base rod and is slidably held within the base rod, and a chain ring to be hooked to the latch. By providing a security chain that is convenient to use and has a high crime prevention ability, it is free from the above-mentioned drawbacks.

An example of implementing the present invention will be described with reference to the drawings. 1 is a mounting seat, and 2 is a latch. The latch fitting 2 is the base rod 3
and a slide rod 4, the slide rod 4 is slidably held internally by the base rod 3, and is always pressed outward by a spring 5. 6 is slide rod 4
It is a stop pin planted and fixed at the bottom of the base rod 3, and is fitted into the guide groove 7 of the base rod 3. Therefore, slide rod 4
Although its upper part protrudes from the base rod 3, when the head of the slide rod 4 is pushed down, the spring 5 is compressed.
The slide rod 4 descends and sinks into the base rod 3. When the external force is removed, the slide rod 4 protrudes due to the elastic force of the spring 5, but the slide rod is locked at the position where the stop pin 6 hits the upper edge of the guide groove 7.

8 is a chain, 9 is a chain seat, 10 is a hanging ring, and 11 is a hanging hole.

Note that 12 is a pillar, 13 is a door, and 14 is a stile for the door.

The safety chain of this invention has the structure as shown in the drawings and the above description, and is installed and used as follows.

First, hold the latch 2 vertically and place the mounting seat 1 on the door 1.
Attach it to the vertical stile 14 of 3. Next, with the slide rod 4 still retracted, the hanging ring 10 of the chain 8 is placed on the top of the base rod 3, and the chain 8 is allowed to hang down.With the chain 8 extending in a straight line, the chain seat 9 is moved toward the pillar 12. move it,
A chain seat 9 is firmly screwed to approximately the center of the pillar 12. The state is as shown in FIGS. 4 and 5.

In this case, in the proposed precautionary chain, the chain 8 is slightly slackened so that the hanging ring 10 can be easily hung on the base rod 3.
You may also raise the position of the chain seat 9 a little higher.

To hang the safety chain attached in this way, all you need to do is press down the slide rod 4 with your fingers or the hook ring 10, hook the hook hole 11 of the hook ring 10 onto the base rod 3, and drop it in. is extremely easy. When the engagement is completed, the slide rod 4 automatically pops out to its original position by the pressure of the spring 5.

To release the engagement, it is sufficient to first push in the slide rod 4 with fingers and then pull out the hanging ring 10 from the base rod 3, and this operation is also extremely easy.

Next, when comparing the conventional safety chain in which a single metal rod is curvedly protruded from the mounting plate and the proposed safety chain, in FIG. 4, when the door 13 is closed, the mounting plate 1
If the center of the chain is Q, the center of the chain seat 9 is R, and the upper end of the base rod 3 is S, then with the conventional safety chain, the length of the chain 8 = It is extremely difficult to attach and remove the hanging ring 10, so the actual installation is difficult. In order to do so, it is necessary to lengthen the chain 8 a little so that the length of the chain 8 = , so that the chain 8 can be easily hung. In the case of actual installation, everything is installed like this.

Therefore, if the length of chain 8 is , the conditions under which chain 8 can be removed are as follows:
The point where the arc with radius intersects the horizontal line passing through S
Chain 8 can be removed until base rod 3 moves to S'.

In other words, the conventional security chain, which has enough room for the chain 8, can be removed not only when the door is closed, but also when the door is slightly opened.

On the other hand, in the proposed safety chain, the sliding rod 4 further protrudes from the base rod 3, so the sliding rod 4 can be moved not only when the door is slightly opened, but also when the door is completely closed. Because of its protrusion, the chain 8 is characterized in that it cannot be illegally removed.

Furthermore, there is a criminal technique called ``string pulling'' that involves illegally removing security chains from the outside of the door.

In this method, as shown in FIG.
Slightly open the door, tie a thin and strong string 15 such as a nylon string to the ring 10, close the door 13 completely, and then tie the string 15 along the gap between the door 13 and the pillar 12. When the door 13 is completely closed, the hanging ring 10 can be removed from the base rod 3, and the guard chain door 13 can be removed. It can be illegally removed from the outside.

Even if the main body of the safety chain is installed horizontally as shown in FIG.
If you pull it while sliding it to the hinge 17 side along the
It can be illegally removed from the outside of the security chain door.

Due to this "string pulling", the slide rod 4 protrudes from the base rod 3 even if an attempt is made to illegally unlock the lock, and even if the chain 8 is extended to the maximum, the hanging ring 10
The lock cannot be pulled out from the slide rod 4, so it cannot be illegally unlocked.

As described above, the safety chain in question has the characteristics that the locking ring 10 is extremely easy to operate due to the length of the chain 8, and that it cannot be illegally unlocked from the outside. , which is extremely practical.

[Brief explanation of drawings]

Figure 1 is a front view of the proposed safety chain, Figure 2 is a side view showing the main parts in cross section, Figure 3 is a front view showing how to use it, and Figure 4 is FIG. 5 is a schematic diagram for explaining the function, and is a perspective view of the door showing the security function. In the figure, 2... Latch fitting, 3... Base rod, 4...
...Slide rod, 5...Spring, 10...Kake ring, 15
...It's a string.

Claims (1)

[Scope of utility model registration request] In a guard chain used for a door in a building opening, a base rod 3 protrudes from the mounting seat 1 and is fixed to the mounting seat 1.
A latch consisting of a spring 5 housed in the base rod 3, and a slide rod 4 which is always pressed by the spring 5 so as to protrude above the base rod 3 and is slidably held within the base rod 3. A safety chain characterized in that a hook 10 at the tip of a chain 8 whose rear end is irremovably fixed to a chain seat 9 is hung on the tool 2.