JPH089938B2 - Ladder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ladder, and more particularly to a retractable ladder.

[0002]

2. Description of the Related Art Conventionally, on a ladder, a plurality of horizontal rails are fixed at right angles to a pair of relatively long rod-shaped columns at appropriate intervals in the lengthwise direction. There is something. There is also a structure in which a pair of support columns can be bent at their intermediate portions.

[0003]

However, the rod-shaped support as described above has a problem in that its length becomes long and a large amount of space is required for storage. . In addition, although the column that can be bent at the middle portion has a smaller storage space than the rod-shaped column, it still requires a considerable space. In addition, there is a problem that the work of extending the bent portion and bending the extended portion is considerably troublesome.

An object of the present invention is to provide a ladder that solves the above problems.

[0005]

In order to achieve the above object, the present invention forms one unit with a pair of support columns and cross rails. The pair of support columns are arranged in parallel with each other with a space therebetween and have a hollow interior. The horizontal cross section is
It is arranged between the upper ends of the support columns at substantially right angles to them. This unit is provided as n units (n is a positive integer of 2 or more) units.

Then, these n units are m (2≤m
≤ n) The m-th unit's strut part can be moved to the m-th unit's strut part so that the horizontal cross-sections of the m-th and m-1'th units can move from the contacting state to the distant state. It is inserted so that it can move forward and backward.

Further, in a state where the horizontal rails of the m-th and m-1th units are in contact with each other, they are engaged with the support columns of the m-th unit, which are below the horizontal rails of the m-1th unit. A hole is formed.

Engaging means, urging means, and releasing means are provided on the horizontal rail of the (m-1) th unit. The engaging means is arranged so as to be able to advance and retreat toward the column part, and is capable of engaging with the engaging hole of the m-th unit. The urging means urges the engaging means toward the column. The releasing means is rotatably supported midway around an axis that straddles the advancing / retreating direction of the engaging means, and one end thereof comes into contact with the engaging means or the urging means, and the horizontal cross section of the m-th and (m-1) th units. In the contact state, the other end portion is located inside the horizontal rail portion, and the other end portion is in the horizontal state when the engaging means of the m-1th unit is engaged with the engaging hole of the mth unit. It projects below the cross section.

[0009]

According to the present invention, in the state where the cross rails of each unit are in contact with each other, that is, in the contracted state, the engagement hole of the m-th unit is lower than the engagement means of the (m-1) -th unit. , The engaging means of the (m-1) th unit is not engaged with the engaging hole of the mth unit. Therefore, m
The th unit can be drawn from the m-1 th unit. Then, when the m-th unit is pulled out and the engagement hole of the m-th unit reaches the position corresponding to the engagement means of the m-1st unit, the biasing force of the biasing means causes the m-1st unit. The unit engaging means is m
It engages with the engagement hole of the th unit and prevents the further m th unit from being pulled out. In this way, each unit is sequentially drawn out. At this time, the other end of the release means of each unit projects below the horizontal rail.

In this state, when the other end of the releasing means of the lowermost unit is pushed into the cross rail, one end of the releasing means causes the biasing means or the engaging means to move in the direction opposite to the moving direction of the engaging means. Since it is pushed in the direction of, the engaging means comes out of the engaging hole. Therefore, the second unit falls due to its own weight and is in a contracted state. Then, the release means of the second unit comes into contact with the cross rail of the first unit and is pushed inside. Thereafter, in the same manner, all units are automatically reduced.

[0011]

EXAMPLE This example comprises n units 2-1 to 2-n as shown in FIG. Each unit 2-1
2 to 2-n are provided with support columns 4 and 4 and a horizontal cross section 6. The support columns 4 and 4 are formed in a hollow columnar shape, and are arranged in parallel with each other with a constant interval. A horizontal rail portion 6 is arranged between the upper ends of the pillar portions 4 and 4 at right angles to them.

The support columns 4 and 4 of the unit 2-1 have the support columns 4 and 4 of the unit 2-2 inserted therein so as to be movable back and forth in the longitudinal direction. In addition, the support columns 4 and 4 of the unit 2-2
The column portions 4 and 4 of the unit 2-3 are inserted in the column so as to be able to advance and retreat in the length direction. Hereinafter, the same as the unit 2
The support columns 4 and 4 of the units up to -n are inserted through the support columns 4 and 4 of the unit that is one stage lower than itself.

That is, the support columns 4 and 4 of the m (2 ≦ m ≦ n) th unit are the support columns 4 and 4 of the m−1th unit.
Has been inserted into. Therefore, the diameter of each of the columns 4, 4 is
The upper one is smaller, and the distance between the columns 4 and 4 is
The upper one is narrower.

From unit 2-2 to unit 2-n,
That is, as shown in FIG. 1, engagement holes 8 are formed in the support columns 4 and 4 of the m-th (2 ≦ m ≦ n) unit. Each engagement hole 8 is provided on the side facing the horizontal rail portion 6. For example, the engagement hole 8 of the unit 2-2 is the horizontal rail portion 6 of the unit 2-2. The pillar portions 4 and 4 of the unit 2-1 positioned below the horizontal rail portion 6 of the unit 2-1 in a state of being in contact with the horizontal rail portion 6.
Is formed in. Also in other units, the engaging hole 8
Are formed at similar positions.

Engaging means 10 is provided in the horizontal rail portion 6 of the units 2-1 to 2- (n-1), that is, in the horizontal rail portion 6 of the m-1 (2≤m≤n) th unit. A biasing means 12 and a releasing means 14 are provided.

The engaging means 10 has a cylindrical body 16 having a diameter substantially the same as the diameter of the engaging hole 8, and a cylindrical neck having a diameter smaller than that of the body 16 on one end side thereof. 18, and a head portion 20 having a short columnar shape having substantially the same diameter as the body portion 16 is provided on one end side of the neck portion 18. The body portion 16 is the horizontal rail portion 6
Through hole 2 formed in support wall 22 extending downward from the upper surface of
4 and can be moved forward and backward toward the support column 4. A guide groove 26 is formed in the side wall 25 of the horizontal rail portion 6 on the side of the support column 4 toward the support column 4 side, and the other end of the body 16 is inserted into the guide groove 26. Incidentally, 28 is a protective rubber provided on the other end of the body 16.

A washer 30 is fixed to the body portion 16 at a position closer to the support columns 4 and 4 than the support wall 22. Between the washer 30 and the support wall 22, a biasing means 12 is provided. The coil having a reduced length is arranged so as to surround the body 16.

Therefore, the engaging means 10 is pressed toward the column 4 by the force of the coil 12 extending. Note that, in FIG. 1, the rubber 28 of the engaging means 10 is drawn so as not to come into contact with the support column 4 of the m-th unit, but actually, it does not contact the support column 4 of the m-th unit. There is.

The releasing means 14 is a lever having an intermediate portion pivotally supported by a rotary shaft 32. The rotating shaft 32 is the engaging means 1
It is provided in a direction perpendicular to the moving direction of 0, that is, in the front and back direction of the paper surface in FIG. One end 34 of this lever 14
Is divided into two as shown in FIG.
It is arranged so as to contact the body portion 16 and the head portion 20 on both sides of the neck portion 18, respectively.

The other end 36 of the lever 14 is shown in FIG.
In the state where the engaging means 10 is not engaged with the engaging hole 8 as shown in FIG. 3, the engaging means 10 is positioned horizontally in the cross rail portion 6, and the engaging means 10 engages with the engaging hole 8 as shown in FIG. In the combined state,
It rotates about the rotary shaft 32 as a center of rotation and projects below the horizontal cross section 6. The lower surface of the horizontal rail portion 6 is entirely open.

In the ladder thus constructed, when not in use, the columns 4 and 4 of each of the units 2-2 to 2-n are arranged one stage below each of the units 2-1 to 2-.
It is stored in (n-1). When this ladder is used, the horizontal rail portion 6 of the uppermost unit 2-n is held and pulled upward.

By this pulling up, the engaging hole 8 of the unit 2-n moves to the position of the engaging means 10 of the unit 2- (n-1). At this time, the engaging means 10 is moved to the support column 4 side by the urging force of the urging means (coil spring) 12, and engages with the engaging hole 8 as shown in FIG. Note that FIG.
Shows a part of the movement of the engaging means 10, and finally moves until the washer 30 comes into contact with the side wall 25. At this time, the other end of the releasing means (lever) 14 is
As shown in FIGS. 2 and 3, it projects below the horizontal cross section 6.

Because of the engaged state, the supporting columns 4 of the units 2-n and 2- (n-1) are connected, so when the unit 2-n is further pulled up, the unit 2- (n- The support column 4 of 1) is also pulled up, and the unit 2- (n-1) and the unit 2- (n-
The support column 4 of 2) is joined. Hereinafter, in the same manner, all the units 2-1 to 2-n are connected in the pulled out state.

When the ladder thus extended is returned to the housed state again, the releasing means (lever) 14 projecting from the horizontal rail portion 6 of the lowermost unit 2-1 is indicated by an arrow A in FIG. Push it into the horizontal cross section 6 as shown by. As a result, one end of the lever 14 causes the head of the engaging means 10 to move toward the arrow B.
When pushed in the direction, the body portion 16 of the engaging means 10 comes out of the engaging hole 8.

As a result, the unit 2-2 falls downward due to its own weight. This drop causes unit 2
-2, the lever 14 protruding downward from the horizontal rail portion 6 comes into contact with the upper surface of the horizontal rail portion 6 of the unit 2-1, and the unit 2-
It is pushed into the cross rail portion 6 of 2. Therefore, in the same manner as described above, the column portion 4 of the unit 2-3 and the unit 2-2
Is disengaged from the support column 4, and the unit 2-3 falls. Thereafter, the engagement between the units is sequentially released in the same manner, and the storage state is automatically restored.

In the above embodiment, the lever 14 pushes the engaging means 10 in the direction of the arrow B. However, the biasing means (coil spring) 12 forms an engaging portion with the lever 14, and the lever 14 biases the engaging means 10. The means 12 may be pushed in the direction of arrow B. Further, in the above embodiment, the urging means 12 is provided on the body portion 16 of the engaging means 10, but the receiving portion is formed on the right side of the head portion 20 in FIG. 1 or FIG. The biasing means 12 may be provided between the head 20 and the head 20. Further, although the coil spring is used as the urging means, a leaf spring or the like can also be used.

[0027]

As described above, in the ladder according to the present invention,
Since the column portion of the m-th (2 ≦ m ≦ n) -th unit among the n units is inserted into the column portion of the m−1-th unit, it is very small in the housed state. Also, m
In the extended state in which the engaging means of the -1st unit is engaged with the engaging hole of the mth unit, the end portion of the releasing means of the m-1th unit projects below the cross rail. Therefore, by simply pushing the releasing means of the lowermost unit into the horizontal rail portion, the storage state is automatically established, and the storage work can be performed very easily.

[Brief description of drawings]

FIG. 1 is a partially omitted vertical cross-sectional view showing a state in which one unit has begun to be pulled out in one embodiment of a ladder according to the present invention.

FIG. 2 is a partially omitted front view of the embodiment.

FIG. 3 is a partially omitted vertical sectional view showing a state in which one unit has been pulled out in the embodiment.

FIG. 4 is a cross-sectional view taken along the line CC of FIG.

[Explanation of symbols]

 2-1 to 2-n unit 4 support part 6 lateral rail part 8 engaging hole 10 engaging means 12 biasing means 14 releasing means

Claims (1)

[Claims] 1. A unit having a pair of support columns, which are spaced apart from each other and are substantially parallel to each other, and whose inside is hollow, and cross rails, which are disposed between the upper ends of the support columns and are substantially perpendicular to them. , N (n is a positive integer greater than or equal to 2) units are provided, and the horizontal rails of the m (2 ≦ m ≦ n) th and m−1th units can move from a state where they are in contact with one another Insert the column of the m-th unit into the column of the m-1th unit so that it can move back and forth in the length direction, and in the state where the cross rails of the mth and m-1th units are in contact, Of the m-th unit located below the horizontal cross section of the unit is formed with an engaging hole, and the horizontal cross section of the (m-1) th unit is arranged so as to be able to move forward and backward toward the above-mentioned cross section. Engaging means capable of engaging with the engaging hole of the m-th unit, and the engaging means Is rotatably supported midway around an axis straddling the advancing / retreating direction of the engaging means, and one end thereof is in contact with the engaging means or the urging means. In the state where the horizontal rail portion of the (th) -th unit and the (m-1) th unit are in contact with each other, the other end portion is located inside the horizontal rail portion, and the engaging means of the (m-1) th unit engages with the mth unit. A ladder comprising: a release means having the other end protruding below the cross rail in a state of being engaged with the hole.