JPS6246795Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a ladder with a safety device that prevents the ladder from being used at angles other than the normal installation angle.

Most accidents that occur during ladder work are due to improper installation of the ladder. In particular, if the installation angle becomes smaller than a certain value (approximately 75 degrees), the anti-slip effect attached to the bottom end of the ladder will become weaker.
In some cases, the supports may slip, causing workers to fall, resulting in serious accidents. However, conventional ladders can be installed at any angle and have a structure that allows them to be raised and lowered, so the only way to use them at a safe installation angle is to be careful on the part of the user.

The purpose of this invention is to eliminate the drawbacks of conventional ladders as described above, and to provide a ladder with a safety device that makes it physically impossible to climb the ladder if the ladder is installed at an angle other than the set angle.

This invention will be explained below based on drawings showing examples. FIG. 1 is a perspective view of a ladder 1 according to this invention. Reference numeral 2 denotes left and right pillars, and 3 represents a plurality of step bars horizontally fixed between the pillars 2. Numeral 4 is a non-slip member, which is attached to the lower end of the support column 3 by a pin 5 so as to be rotatable back and forth, and has a foot portion 4a having a certain length.
Anti-slip measures have been taken on the back side, such as by adding rubber material. 6 is the blocking frame, the bottom 2 of ladder 1
It has a frame shape in which horizontal members 6a, 6a located along the opposing inner sides of step bars 3, 3 of the steps are connected by vertical members 6b, 6b. As long as the parallel shape of the horizontal members 6a, 6a can be maintained, the vertical member 6b may only be provided on one side. A rotation shaft 7 is fixed approximately at the center of the vertical member 6b, and inserted into a bearing 8 fixed to the corresponding support column 2 side. The horizontal members 6a, 6a, the rotation shaft 7, and the bearing 8 are arranged so as to correspond to the three step bars 3, respectively, as shown in FIG. , 3, the rotation shaft 7 and the bearing 8 may be located at intermediate positions therebetween.
Reference numerals 9 and 10 denote two conductive wires, the lower ends of which are fixed to fixing pins 11 and 12 at the front and rear ends of the foot 4a of the anti-slip 4, respectively, and the upper ends of which are wound around the outer circumference of the rotating shaft 7 in opposite directions. Fixed (see Figure 2). 13 and 14 are pulleys, and wires 9 and 10
It is attached to a support post 2 to facilitate smooth movement. The attachment lengths of the wires 9 and 10 are adjusted so that the blocking frame 6 is parallel to the support column 2 when the ladder 1 is erected at the most appropriate installation angle θ (approximately 75 degrees).

When the ladder 1 configured as described above is installed at an angle θa other than the normal angle, for example, if θa is smaller than the normal angle θ as shown in FIG. 6 rotates and the tension returns to its original state. As a result, the horizontal member 6a protrudes from the step 3, and the operator notices that the installation angle θa of the ladder 1 is inappropriate, and corrects the installation angle of the ladder 1 so that the blocking frame 6 is parallel to the column 2. do.

As explained above, this idea is based on the bottom two of the ladder.
A blocking frame formed by vertically connecting horizontal members located along the opposite inner sides of the step treads is rotatably attached to the column, and a slip stopper rotatably attached to the lower end of the column and the blocking frame are rotatably attached to the column. By installing a simple safety device that links the frame with conductive wire,
If the ladder is installed at an angle other than the set angle, it has the effect of making it impossible to physically climb up the ladder, and as a result of correction, the correct installation angle can be easily confirmed, allowing safe ladder work. There is an effect that can be done.

[Brief explanation of the drawing]

The figures show an embodiment of this invention, in which Fig. 1 is a perspective view of the lower part of a ladder with a safety device, Fig. 2 is an enlarged view of the main part of Fig. 1, and Fig. 3 is an explanatory view of the operation. 3... Step rung, 4... Anti-slip, 6... Blocking frame, 6a... Horizontal member, 6b... Vertical member, 7... Rotating shaft, 8... Bearing, 9, 10... Conductive wire.

Claims (1)

[Scope of utility model registration request] A blocking frame formed by vertically connecting horizontal members located along the opposite inner sides of the lower two rungs of the ladder, a rotation axis provided approximately in the center of the vertical member, and a rotation axis of the vertical member. a bearing that rotatably attaches the shaft to the support of the ladder; a non-slip member having a foot that is rotatably attached to the lower end of each of the supports of the ladder and maintains constant contact with the installation surface; conductive wires that are fixed to the front and rear ends of the slider, respectively, and whose upper ends are wound and fixed in opposite directions around the rotating shaft of the blocking frame, so that the blocking frame rotates as the non-slip member rotates. A ladder with a safety device.