JP3253286B2 - Ladder with fall prevention mechanism - 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 that can be easily and reliably fixed to a pillar when the ladder is leaned against a pillar such as a telephone pole. The present invention relates to a ladder with a fall prevention mechanism that can be released from below from below.

[0002]

2. Description of the Related Art For example, when a ladder has to be leaned on a telephone pole and work must be performed on the ladder, another worker must support the ladder from below so that the ladder does not fall down during the work. Must.

[0003] In the conventional ladder, the uppermost stage of the ladder which comes into contact with the telephone pole is provided with a simple bar-like horizontal bar constituting a step, or a modified rubber member is provided on the step. Is only a thing. In the former case, the contact part with the utility pole is slippery at the point contact, and in the latter case, it is a linear contact.Because it is possible to obtain the frictional resistance by the rubber member, the worker is better than the former, When the user leans on the ladder to work on the upper part, the rubber member overcomes the frictional force with the utility pole and shifts in the direction that the rubber member rotates around the utility pole, and in extreme cases, the ladder falls down It is something.

Therefore, if the upper end of the ladder in contact with the utility pole is fixed to the utility pole, a fall accident can be prevented. However, since the fixed portion is located at an extremely high point at the tip of the ladder, the fixed portion is located above the ladder from above the ground. It was extremely difficult to easily attach and detach the parts.

[0005]

SUMMARY OF THE INVENTION The present invention has the following advantages. (1) The tip portion can be easily and securely fixed to a pillar when leaned against a pillar such as a telephone pole. The development of a ladder with a fall prevention mechanism that can be easily performed on the ground from underneath.

[0006]

A ladder (A) with a fall prevention mechanism according to claim 1 comprises a ladder main body (1) and a ladder main body.
It is provided at the upper end of (1) and abuts one side of the pillar (3)
Fixed side holding member (2a) and opposite of the fixed side holding member (2a)
Opening / closing side holding member (2b) that comes into contact with the pillar (3) on the side
A pair of holding members (2) for holding the outer periphery of the object (3), and
Opening and closing machine for opening and closing the holding member (2b) on the opening and closing side of the holding member (2)
Anti-tip mechanism comprising out with structure (C) (B) and de Configured overturning
A ladder with a prevention mechanism (A), the opening and closing mechanism (C) is fixed
It is disposed rotatably with respect to the holding member (2a),
The rotating cylinder (7), which forms part of the member (2b),
Part of the member (2a), one-way clutch inside
(4) is housed in the fixed cylindrical portion (9),
The latch (4) and the rotating cylinder (7) rotate together with the rotating cylinder.
(7) and operation to move axially in the one-way clutch (4)
The operating shaft (8) has a one-way
The large diameter part (10) and the small diameter part (11)
The one-way clutch (4) has an operating shaft
When the large diameter part (10) is inserted by inserting and removing the part (8),
The opening and closing side holding member (2b) is only rotated in the closing direction.
Allow, when the small diameter part (11) is inserted, the inner diameter is reduced
Rotate the holding member on the open / close side only in the open direction or in both open / close directions.
To allow it " .

According to this, the columnar object (3) is held by the holding member (2).
To prevent the ladder body (1) from overturning.
Once (B) is fixed to the pillar (3), the fall prevention mechanism (B) does not come off from the pillar (3) even when the worker leans out of the ladder body (1) and works. There is no such thing as falling down. In addition to this, the operating shaft (8) is connected to the one-way clutch (4).
One-way clutch by simply moving it in the axial direction
(4) One-way clutch operation (rotates in one direction, reverses
Operation that does not rotate) and release thereof. Therefore, it works
If the string (12) is attached to the shaft (8) or described later
`` Lever member (13) or (13a) '' for operating shaft (8)
If you attach the ladder (A)
Just pull the string (12) with the one-way clutch (8).
(4) can be moved in and out of the ladder (A).
Work on the ground can release the fall prevention mechanism (B).
Become.

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

Claim 2 is a further limitation of the opening / closing mechanism (C). "An opening / closing side holding member (2b) is provided between the fixed side holding member (2a) and the opening / closing side holding member (2b). A spring member (6) for applying a force to the normally open side is provided. "

According to this, when the one-way clutch (4) is released and the opening / closing-side holding member (2b) becomes free, it is automatically opened by the action of the "spring member (6)", and the lower part of the ladder (A) is opened. , The release work on the ground becomes easy.

[ Claim 3 ] is another mechanism for operating the operating shaft (8). "The operating shaft (8) is a lever member (13) or (11) attached to the fixed side holding member (2a). 13a).
If the string (12) is attached to (13) or (13a) ", the operating shaft (8) can be operated with a small force.

Claim 4 is a further limitation of the ladder (A) with an overturn prevention mechanism according to any one of claims 1 to 3 , wherein the columnar member comprises a fixed-side holding member (2a) and an opening / closing-side holding member (2b). Pads (14) and (15) for increasing frictional resistance are provided on the contact surface with (3). "

According to this, the frictional resistance of the sandwiched portion is increased by the action of the pads (14) and (15), so that the sandwiched portion becomes less slippery and safety is enhanced.

A fifth aspect of the present invention is a further improvement of the ladder (A) having the overturn prevention mechanism according to the first to fourth aspects.
(B) is attached to the ladder main body (1) so that it can be turned upside down. '' By doing so, the fall prevention mechanism (B) is stored in the ladder main body (1) during storage. The ladder body (1) can be woken up when used, and the ladder body (1) does not become bulky when stored even if it is newly equipped with a fall prevention mechanism (B).

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to illustrated embodiments. The ladder body (1) is used by leaning on a tall pillar-shaped object such as a telephone pole, and varies from long to short, depending on the application. Here, a long ladder that can be folded in three steps is typical. This will be described as an example, but is not limited to this.

A tumbling prevention mechanism (B) is provided at the upper end of the ladder body (1). The fall prevention mechanism (B) includes a pair of holding members (2) for holding the outer periphery of the columnar object (3), and a holding member.
And an opening and closing mechanism (C) for opening and closing (2). In this embodiment, the holding member (2) includes a fixed-side holding member (2a),
One end is rotatable by the opening / closing mechanism (C).
And an opening / closing side holding member (2b) supported by the opening / closing side.

The fixed-side holding member (2a) is a plate-shaped fixed-side main body.
(20) and a fixed cylindrical portion (9) welded and fixed to the upper surface of one end of the fixed side main body (20), the uppermost step (1a) of the ladder main body (1) and the vertical member ( 1b) directly on the reinforcing member (1c) provided at the corner portion, or the
6) is mounted via. On the surface of the fixed side body (20) opposite to the ladder body (1), a fixed side recess (21) into which the columnar object (3) is fitted is formed, and a curved plate is formed on the inner periphery thereof.
One pad (14) is attached via (22).

The opening / closing mechanism (C) comprises a one-way clutch (4) housed in the fixed cylinder (9) and an operating shaft (8). Is the opening / closing side clamping member (2b)
The rotary cylinder part (7) which constitutes a part of is mounted.
The rotating cylinder (7) is fixed via a stationary body (20).
It is arranged on the opposite side (lower side) of (9), and the fixed side body
The working shaft (8) is inserted into the communicating part through a through hole (23) formed in the (20), and moves in the axial direction with respect to the one-way clutch (4). It has become.

A large-diameter portion (10) and a small-diameter portion (11) are formed in a portion where the operating shaft (8) is inserted into and removed from the one-way clutch (4). Large diameter part (1
(0) is inserted, the inner diameter of the one-way clutch (4) is enlarged to allow only the rotation of the opening / closing side holding member (2b) in the closing direction, and when the small diameter portion (11) is inserted, the inner diameter is increased. The opening and closing side holding member (2b) is allowed to rotate only in the opening direction or in both the opening and closing directions.

A stopper (24) is attached to the top end of the operating shaft portion (8), and a stopper (25) provided on the upper surface of the fixed cylindrical portion (9). A coil spring (26) is provided. The coil spring (26) constantly urges the operating shaft (8) in the pulling direction, so that the large diameter portion (10) of the operating shaft (8) is located in the one-way clutch (4), and therefore the small diameter ( 11)
Is located at the escape position, and the one-way clutch (4) is always operated so that the opening / closing-side holding member (2b) rotates only in the closing direction.

Next, a description will be given of the rotary cylinder part (7) which constitutes a part of the opening / closing side holding member (2b). The rotating cylinder (7) is disposed on the back side of the fixed side body (20) as described above, is inserted into the through hole of the holding plate (28), and the outer flange of the rotating cylinder (7).
(20a) is held between the holding plate (28) and the fixed-side main body (20), and is configured to rotate.

The lower part of the operating shaft (8) is
A non-rotating pin (17) slidably inserted into (7) and inserted transversely through the rotary cylinder (7) into a slit (27) formed in the lower part of the operating shaft (8). ) Is inserted,
The operating shaft (8) is formed so as to rotate together with the rotary cylinder (7).

Therefore, the rotating cylinder (7) rotates about the operating shaft (8) together with the operating shaft (8) with respect to the stationary body (20), and the operating shaft (8) is It will slide further to (7). The operating shaft (8) is located at the lower end of the operating shaft (8).
A cord (12) for pulling in the axial direction is attached. The lever member that moves the operating shaft (8) in the axial direction is
(13) or (13a) ”will be explained again.

The opening / closing side holding member (2b) is provided with the rotary cylinder (7).
And the open / close side clamping arm (2
9), the opening / closing side recess (30) is formed on the surface of the opening / closing side holding arm (29) on the fixed side holding member (2a) side corresponding to the fixed side recess (21). The pad (15) is provided via a curved plate (31).

Further, between the opening / closing side holding arm (29) and the fixed side body (20), the opening / closing side holding arm (29) is always open side (that is, the opening / closing side holding arm (29) is fixed side). A spring member (6) pulling in a direction away from the main body (20) is provided.

Next, the lever (5) will be described. One end of the lever (5) is rotatably attached to the fixed body (20) via a fulcrum shaft (32), and the free end is connected to the fixed body (2).
It is disposed so as to cross the front of the fixed side recess (21) at a position below the pad (0) so as not to be hooked on the pad (14). The lever (5) and the opening / closing side holding arm (29)
It is connected via a connecting member (33), and is arranged such that when the lever (5) moves, the opening / closing side holding arm (29) also moves via the connecting member (33).

The uppermost step (1) of the ladder body (1)
The member disposed between the vertical members (1b) above the a) is a rubber attachment (34), and the contact surface with the columnar object (3) is formed in a concave curved shape. It is formed so as to easily follow the columnar object (3).

Next, the operation of the present invention will be described. First, the opening / closing side holding arm (29) is kept open, the ladder main body (1) is extended, and its tip is leaned against the columnar object (3). Then, the attachment (34) comes into contact with the side surface of the columnar object (3), and at the same time, the lever (5) is pushed by the side surface of the columnar object (3) and moves to the fixed side recess (21) side, and the pad (14). ) Below to reach the concavely curved bottom of the pad (14).

Then, the open / close side holding arm (29) connected via the connecting member (33) moves to the fixed side concave portion (21) side,
Close the space between the fixed side recess (21) and the opening and closing side recess (30),
The pillar (3) is sandwiched between the inside and the outside by both pads (14) and (15). The rotation of the opening / closing side holding arm (29) in the closing direction is due to the one-way clutch operation of the one-way clutch (4).
The one-way clutch (4) does not rotate any longer even if it tries to open in addition to (9), and the tightened state is not released because the position is maintained.

As described above, since the columnar object (3) is sandwiched between the inside and the outside by the pads (14) and (15), even if a force is applied to the ladder (A), the columnar object (3) ) And both pads (1
4) Even if force is applied in a direction that rotates (15), both pads
(14) The rotation is prevented by the frictional force and the tightening force of (15), and the upper end portion of the ladder (A) is firmly fixed to the columnar object (3).

In this state, the worker climbs on the ladder (A) and performs high-place work on the pillar. During this time, the worker leans out of the ladder (A) and works, as described above. (14) (1
Since the columnar object (3) is gripped in 5), the ladder (A) does not fall down, of course, and does not shake.
Therefore, there is no need for the operator to support the ladder (A) under the ladder (A).

When the work on the pole is completed, the worker moves to the ladder (A).
Get off and pull the string (12) connected to the operating shaft (8) on the ground under the ladder (A). Then, the operating shaft (8) is pulled against the coil spring (26), the small-diameter portion (11) is retracted into the one-way clutch (4), the inner diameter of the clutch is enlarged, and the operating shaft (8) is expanded. ) Is released, and the opening / closing side holding arm (29) is pulled by the pulling action of the spring member (6).
Rotates together with the rotating cylinder (7) and the operating shaft (8) in the opening direction to release the holding of the columnar object (3). After that, remove the ladder (A) from the pillar (3) and fold it to complete the work.

Next, a first embodiment of the "lever member (13)" will be described with reference to FIG. In the above embodiment, the string (12) is directly connected to the operating shaft (8) without using the lever member (13), and the string (12) is pulled to directly operate the operating shaft (8). In this case, the tension of the string (12) is directly applied to the fixed body (20) through the operating shaft (8), and a large moment is applied to the mounting base of the fixed body (20). And may cause the mounting base to flex or bend in some cases.

Then, one end of the lever member (13) is connected to the fixed side main body.
(20) is rotatably attached to a fulcrum (44), the other end is attached with the string (12), and a roller (46) provided in the middle is attached to the stopper (24) of the operating shaft (8) or As shown in the figure, the engaging flange (45) protruding from the side surface of the operating shaft (8) is in contact with the operating shaft (8). Thus, when the string (12) attached to the lever member (13) is pulled, the operating shaft (8) is pushed down by the principle of leverage, and the large diameter part (10) is moved from the one-way clutch (4). Withdrawal,
The small diameter portion (11) enters and enters the release state as described above.
In this case, since the "lever member (13)" is used, not only can the string (12) be pulled with a smaller force, but also the force applied to the fixed side main body (20) is reduced.

FIG. 9 is the reverse of FIG. 8, in which the lever member (13a) is brought into contact with the stopper (24) of the operating shaft (8), and is provided on the upper surface side of the fixed body (20). Pivoted to the fulcrum (44a),
The stopper (24) is pushed from above. The effect is shown in FIG.
Is the same as

Next, a case will be described in which the fixed-side holding member (2a) is attached to the uppermost step (1a) via the elevating member (16) so as to be able to be turned upside down. In this case, the raising / lowering operating member (16) is firmly fixed to the uppermost step (1a) by the rivet (16a). Further, a fixed-side holding member (2a) is pivotally connected to a rotation support shaft (40) protruding from a casing (16b) of the raising / lowering operation member (16).

On the other hand, a moving pin (43) is provided adjacent to the rotation support shaft (40) and moves in parallel with the rotation support shaft (40), and is slidably supported by the support member (43a). And
The moving pin (43) has a handle portion (43b) protruding therefrom, and protrudes outside from a slide through hole (16c) formed in the casing (16b). A coil spring (43c) is provided between the handle portion (43b) and the support member (43a) to urge the moving pin (43) toward the fixed side holding member (2a). I have. The tip of this moving pin (43) is
It is designed to protrude / retract from a through hole (16d) formed in the facing surface of the fixed side holding member (2a) of 6b).

On the other hand, the casing (1) of the fixed side holding member (2a)
On the surface facing 6b), locking holes (2a1) and (2a2) are drilled on a circle of a certain radius around the rotation support shaft (40),
The angle (θ) formed by the straight line connecting the locking holes (2a1) (2a2) and the rotation support shaft (40) is, when the fixed side holding member (2a) is caused,
It is substantially horizontal and ready for use, and is set at an angle along the ladder body (1) when it is folded down, that is, at an angle of 75 °.
In this embodiment, the raising and lowering member (16) is a fixed-side holding member.
The movable pin (43) is installed on both sides of (2a). The movable pin (43) is inserted into and removed from the fixed-side holding member (2a) from both sides to maintain a horizontal use position or a folded storage position during use.

In use, when the handle (43b) is held and the moving pin (43) is moved in a direction to deflect the spring (43c), the tip of the moving pin (43) is held in a folded and stored state. It is pulled out from the locking hole (2a2) and further immerses into the casing (16b) through the through hole (16d) to release the locked state. Thereby, the fixed side holding member (2a) can be raised from the ladder main body (1a).

A locking hole that raises the fixed-side holding member (2a) from the ladder body (1a) and raises the horizontal holding state.
When the (2a1) and the through hole (16d) match, the handle (43
When the hand is released from b), the tip of the moving pin (43) protrudes from the through hole (16d) due to the elastic force of the spring (43c), and the locking hole
(2a1) and locked in the locking hole (2a1). Thereby, when the ladder main body (1a) is leaned against the columnar object (3), the fixed-side holding member (2a) is held so that it can be used substantially horizontally. And in this state, the ladder (A)
Is attached to the column (3).

After using the ladder (A), the ladder (A) is removed from the pillar (3) by the method described above, and then the handle (4) is used.
3b) and move the pin in the direction to flex the spring (43c).
(43) is moved, and the tip of the moving pin (43) is pulled out from the locking hole (2a1) holding the horizontal use state. Subsequently, the fixed side holding member (2a) is pulled down, and when the locking hole (2a2) for holding the folded storage state matches the through hole (16d), the handle portion is
When the hand is released from (43b), the tip of the moving pin (43) protrudes from the through-hole (16d) due to the elastic force of the spring (43c), is inserted into the locking hole (2a2), and the locking hole (2a2 ).

Thus, the folded and stored state is maintained. In addition, when the ladder (A) is long, after use, it is folded or folded in three, and is stored.
a) is stored in the ladder main body (1) in a folded storage state, so that this does not interfere.

Although there are various lock methods, a pin fixation can be adopted as a simple method here. Although not shown, a method is used in which a fixing pin is inserted at a place where a fixing pin hole formed in the holding member is aligned with a fixing operation hole, and both are fixed. When not using the fall prevention mechanism, pull out the fixing pin and fold and store the fall prevention mechanism along the ladder main body. Thus, even if the overturn prevention mechanism is provided, the ladder does not become bulky as described above.

Reference numeral (48) denotes a hook attached to the tip of the ladder main body (1), which is used by hooking on an overhead wire stretched between pillars (3) such as telephone poles. An opening / closing member (49) for opening and closing the opening of at least one hook (48) is provided, and by pulling a string (50) attached to the opening / closing member (49) from under the ladder (A). The opening / closing member (49) is pulled down to open the opening of the hook (48).

[0050]

As described above, according to the method of the present invention, when the ladder is leaned against the pillar, the pillar is clamped by the clamping member of the overturn prevention mechanism. Even when working, the ladder does not fall off the pillar and fall down. Therefore, it is not necessary for another worker to support the ladder during the work, and the labor can be saved.

In addition, by using a one-way clutch for the opening / closing mechanism, the opening / closing-side holding portion always rotates only in the direction of tightening the opening / closing-side holding portion to the fixed-side holding member side while the ladder is in use, so that the columnar object can be securely mounted. The ladder does not fall down during use.

Further, by using a lever located in front of the fixed-side holding member and connected to the opening-and-closing-side holding member, the ladder main body is automatically held on the pillar by simply leaning the ladder body on the pillar. Since no special operation is required for the clamping operation, the operation is very simple.

The one-way clutch can operate and release the one-way clutch by inserting and removing an operating shaft having a large-diameter portion and a small-diameter portion. Simply pulling the string from under the ladder enables the work to release the fall prevention mechanism.

If a spring member is provided between the fixed side holding member and the opening / closing side holding member, the spring member constantly applying a force to the opening side of the opening / closing side holding member. The opening / closing-side holding member is opened to facilitate the release operation from below the ladder on the ground.

When the lever is used for operating the operating shaft, the operating shaft can be operated with a small force.

Further, by arranging a pad for increasing frictional resistance on the contact surface between the fixed-side holding member and the columnar member of the opening / closing-side holding member, the frictional resistance of the holding portion can be increased. Is less slippery and more secure.

[Brief description of the drawings]

FIG. 1 is a front view of a ladder of the present invention.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a bottom view of the overturn prevention mechanism of a portion (X) in FIG. 1;

FIG. 4 is a rear view of FIG. 3;

FIG. 5 is a side view of FIG. 3;

FIG. 6 is an enlarged sectional view of an operation state of the opening / closing mechanism according to the present invention.

FIG. 7 is an enlarged sectional view of a release state of the opening / closing mechanism according to the present invention.

FIG. 8 is an enlarged sectional view of an operating state of the opening / closing mechanism using a lever according to the present invention.

FIG. 9 is another enlarged cross-sectional view of the operating state of the lever-operated opening / closing mechanism according to the present invention.

10 is a side view of the overturning prevention mechanism of part (X) shown in FIG.

FIG. 11 is a rear view of FIG. 10;

FIG. 12 is a bottom view of FIG. 10;

FIG. 13 is a sectional view of a tilting operation member of the overturn prevention mechanism of FIG. 10;

14 is a vertical sectional view of FIG. 13;

[Explanation of symbols]

 (A) Ladder (B) Overturn prevention mechanism (C) Opening / closing mechanism (1) Ladder body (2) Holding member (2a) Fixed side holding member (2b) Opening / closing side fixing member (3) Columnar object (4) One-way clutch ( 5) Lever (6) Spring member (7) Rotating cylinder (8) Operating shaft (9) Fixed cylinder (10) Large diameter part (11) Small diameter part (12) String (13) Lever member (14) Pad (15) Pad (16) Lifting member

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E06C 1/00-7/00 E04G 1/30

Claims (5)

(57) [Claims] 1. A ladder main body, which is provided at an upper end portion of the ladder main body and abuts one side of a columnar object.
Fixed side holding member and the opposite side of the fixed side holding member
The outer periphery of the column is sandwiched by the opening / closing side holding member that contacts the column.
A pair of holding members to be held, and an opening and closing side of the holding member
A ladder with a tip-over prevention mechanism, comprising: an opening / closing mechanism for opening and closing the holding member; and the opening / closing mechanism is rotatably disposed with respect to the fixed-side holding member.
The rotating cylinder that forms a part of the opening / closing side
A part of the side clamping member, with a one-way clutch inside
And the one-way clutch
And rotate with the rotating cylinder, and one-way with the rotating cylinder
And an operating shaft that moves in the clutch in the axial direction.
The operating shaft has a large diameter part that can be inserted and removed from the one-way clutch.
The one-way clutch is formed with a small-diameter part.
When the is inserted, the inner diameter is enlarged and the open / close side holding member is closed.
Direction rotation only, and when the small diameter part is inserted,
Is reduced so that the opening / closing side
A ladder with a fall prevention mechanism, characterized in that it allows rotation in any direction . Wherein between the fixed side holding member and the opening and closing side holding member according to claim 1, the spring member which applies a force to the opening and closing side holding member always open side, characterized in that it is arranged A ladder with a fall prevention mechanism according to item 1. Wherein actuating shank, characterized in that is operated by lever member mounted to the fixed side holding member 請
The ladder with a fall prevention mechanism according to claim 1 or 2 . 4. A fall prevention device according to claim 1 , wherein a pad for increasing frictional resistance is provided on a contact surface between the fixed side holding member and the columnar member of the opening / closing side holding member. Ladder with mechanism. 5. The anti-tip mechanism ladder with anti-tip mechanism of claim 1, wherein it is raised or lowered freely attached to the ladder body.