JPH0447358Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a telescoping ladder that is installed on a large construction machine and is used by drivers, workers, etc. to ascend and descend.

(Prior art) Some large construction machines have an upper revolving body that has a driver's cab, etc., and has a height of 2 meters or more.
A ladder is provided for the driver and workers to ascend and descend from the upper revolving structure and the operator's cab. This ladder is attached to the upper rotating body, but when traveling or working, there is a risk that a long ladder may collide with rocks or structures on the ground and be damaged, and it may also get in the way of the rotating operation. Therefore, a structure is adopted in which the ladder is made telescoping and the telescoping portion of the ladder is pulled up when not in use. As described in Utility Model Application Publication No. 60-4649, a telescoping ladder for construction machinery is equipped with a balance weight that balances the weight of the movable ladder in order to facilitate the ascent and descent of the movable ladder, which weighs several kilograms. There is something I used. However, in the case of using this balance weight, the balance weight running part must be installed on the ladder frame for climbing up and down the ladder.
A sheave is required at the top of the ladder frame to hang a rope with both ends connected to the movable ladder and balance weight, which increases the height of the ladder frame and requires a large-scale upper structure. The problem is that it has no choice but to become

In addition, in Japanese Utility Model Application Publication No. 58-163000, a cylindrical rotating drum wrapped with a torsion coil spring is attached to the movable ladder side, a winding drum with a rope wrapped concentrically with the drum is attached, and the rope is attached to the fixed ladder. A telescoping ladder is disclosed that is connected to the top of the ladder and configured to constantly apply a pulling force to the movable ladder.

However, with this known telescopic ladder, the higher the movable ladder is, the weaker the force to pull it up.
The pulling force becomes uneven depending on the height of the movable ladder, such that the lower the ladder is, the stronger the pulling force becomes. For this reason, if this is applied to large construction machinery where the movable ladder has a large weight, when the movable ladder approaches the upper limit position, there will be insufficient lifting force, resulting in the problem of having to push it up with a large force. .

Further, in order to make the pulling force as uniform as possible with the above-mentioned known configuration, the number of turns of the torsion coil spring must be increased and the wire diameter must be increased, making it unavoidable to increase the size.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned problems, and is made by reducing the height of the ladder frame fixed to the upper revolving body and by using lightweight members to make it inexpensive and compact. To provide a telescoping ladder for construction machinery which can be used in construction machinery and which can apply a uniform lifting force to the movable ladder regardless of the ascending/descending position of the movable ladder.

(Means for Solving the Problems) The present invention is characterized in that a movable ladder is mounted so as to be able to rise and fall freely along a ladder frame fixed to an upper rotating body of a construction machine, and a mainspring built in the upper rotating body or the ladder frame is installed. A rope winder is installed, the rope wound on the rope winder is connected to the lower part of the movable ladder, the rope winder comprises a grooved conical drum around which the rope is wound, and the rope winder is provided with a grooved conical drum for winding the rope; The ladder frame is characterized by having a configuration in which the ladder is fed out from the small diameter side of the drum, and there is no need to provide a sheave or the like for hanging a balance weight and a rope connected to the movable ladder on the upper part of the ladder frame. The ladder frame can be made of lightweight materials because it is short in height, and there is no need to provide a running section for the balance weight and there is no need to support the load. In addition, since the rope is paid out from the small diameter side of the drum, when the movable ladder is in the upper position and the spring force of the main spring is weak, the radius from the center of the drum to the part where the wire is paid out is small. On the other hand, when the movable ladder is in the lower position and the spring force of the main spring is strong, the radius from the center of the drum to the part where the wire is fed out increases, so the pulling force acting on the wire is equal to the force of the movable ladder. It becomes uniform regardless of height.

(Example) FIG. 5 shows an example of a large construction machine equipped with a ladder according to the present invention, in which an upper revolving structure 1 has a driver's cab 2, and a passage 3 to the driver's cab 2 is provided. In this example, a ladder 4 according to the present invention is provided at a position at the rear of the passageway 3.

FIG. 1 is an enlarged side cross-sectional view of the telescopic ladder 4, and FIG. 2 is a view of the ladder seen from the mounting surface side, where 5 is a ladder frame, and the ladder frame 5 is a handrail member. It consists of left and right frames 5A and 5B to which 5C is attached, and is fixed to a mounting frame 6 fixed to the upper revolving body 1 with mounting metal fittings and bolts (none of which are shown).

Reference numeral 8 denotes a movable ladder, and the movable ladder 8 has a plurality of footrest members 8C integrally installed between left and right frames 8A and 8B to which handrail members 8D are attached.
As shown in FIG. 3, the left and right frames 5A and 5B constituting the ladder frame 5 have a substantially U-shaped cross section, and sliders 7 made of synthetic resin are attached to three inner surfaces of the frames by screws 9 in the longitudinal direction. Left and right frames 8A and 8B of a movable ladder 8 having a rectangular cross section are slidably fitted so as to be surrounded by these sliders 7.

1 and 4, reference numeral 15 is a rope winding machine with a built-in spring that applies force in the pulling direction to the movable ladder 8 and pulls up the movable ladder 8 when the ladder 4 is not in use. Machine 15 is
Ladder mounting frame 6 fixed to upper revolving body 1
, attach the winder mounting frame 1 with the bolt 11.
2 is fixed, the hook 16 of the winder 15 is hung on the mounting pin 12a provided on the frame 12, and the upper and lower auxiliary hangers 18, 19 of the winder case 31 are fixed to the auxiliary frame 13 fixed to the frame 12. A hook 28 is attached to the lower end of the rope 20 wound around the winder 15.
is hung on a U-shaped hanger 14 fixed to a footrest member 8C at the lower end of the movable ladder 8, and the load of the movable ladder 8 is supported by a mainspring built into the winder 15.

As shown in FIG. 6, the rope winding machine 15 has one end of a shaft 22 rotatably supported by a case 31 having the hook 16 and auxiliary hangers 18, 19, and the other end of the shaft 22. A circular scale plate 23 for displaying a rotation angle is fitted, and the scale plate 23 is rotatably fitted into a circular opening 25a of a cover 25 fixed to the opening surface of the case 31 with bolts 24,
A grooved conical drum 27 is rotatably attached to the shaft 22 via a bearing 26, a rope 20 is wound around the drum 27 along the groove, and one end of the rope 20 is attached to the large diameter end of the drum 27. bolt (not shown)
The rope 20 is fixed with A case 32 is fixed with a bolt 33, a mainspring 30 is housed in the mainspring case 32, and the outer peripheral end of the mainspring 30 is fixed, and the inner peripheral end of the mainspring 30 is connected to the shaft 22 via a bush 34. . By fitting a worm wheel 35 to one end of the shaft 22 and engaging it with a spring force adjusting worm 36 mounted on the case 31, the shaft 22 can be rotated over a certain rotation angle range. The rotation angle is also displayed on the scale plate 23, and a lock mechanism (not shown) for fixing the shaft 22 to the case 31 is provided.

In Figures 1 and 4, 37 is in case the rope 2
This is a safety device that prevents the movable ladder 8 from falling when the movable ladder 8 is cut, etc. The safety device 37 has a safety rope 38 wound around a built-in drum, and the safety rope 38 The safety rope 38 is hung on a U-shaped hanger 39 fixed to the member 8C in parallel with the hanger 14, and the safety rope 38 is attached to the rope 20.
At the same time, the safety rope 38 is wound up and let out, and when the safety rope 38 is let out at a predetermined speed or higher by cutting the rope 20 or the like, the safety rope 38 is locked and the movable ladder 8 is prevented from falling. It has a mechanism.

As shown in FIGS. 1 and 2, at the lower part of the mounting surface side of one frame 5B of the movable ladder 5, there is an automatic locking mechanism that locks the U-shaped striker 40 provided at the upper end of the frame 8B of the movable ladder 8. A lower limit stopper 41 is fixed, and an upper limit stopper 43 with an automatic locking mechanism for locking a U-shaped striker 42 provided at the lower end of the frame 8A of the movable ladder 8 is fixed to the lower part of the mounting surface side of the other frame 5A. The range in which the movable ladder 8 can be moved up and down is regulated. The automatic locking mechanism built into each stopper 41, 43 is such that the rod portion of each U-shaped striker 40, 42 resists the force of the spring and locks the stopper's locking plate (both not shown).
This is a mechanism that rotates the lock plate by pressing and engages a separately provided lock pawl (not shown) with the lock plate to maintain the locked state.The movable ladder 8 is pulled up when traveling or working. The movable ladder 8 is fixed in the lowered state to prevent it from falling due to rattling, and when the movable ladder 8 is lowered,
The goal is to maintain that attitude. Reference numerals 44 and 45 indicate operation handles for operating the lock release levers 41a and 43a of the lower limit stopper 41 and upper limit stopper 43, respectively, from above the passage 3 in the lock release direction;
Reference numerals 6 and 47 are suspension rings that are also operated from the ground.

Unlike conventional ladders, this ladder 4 does not require a balance weight and a sheave for hanging a rope connected to the movable ladder on the upper part of the ladder frame 5, so the ladder frame 5 can be short in height. Therefore, when the movable ladder 8 is pulled up, as shown in FIGS. 1 and 2, the movable ladder 8 protrudes upward from the ladder frame 5, unlike the conventional ladder. In the conventional type, it is necessary to provide the sheave at a higher position than the upper end of the movable ladder 8 shown in FIGS. 1 and 2, so the ladder frame 5 must be elongated.

On this ladder 4, the driver etc.
When getting on top, pull the suspension ring 47 from the ground to release the automatic lock of the stopper 43, thereby allowing the movable ladder 8 to descend, and grasp the handle 48 (see Fig. 4) attached to the movable ladder 8. Pull it, then put your hand on the footrest member 8C and release the striker 40.
is engaged with the stopper 41 and pulled down until it is automatically locked. At this time, the movable ladder 8 is
The state shown in FIG. 1 is reached, and the upper end of the movable ladder 8 is at the position shown in E of FIG. After the driver, etc. climbs onto the aisle 3, hold the handle 49 and climb the movable ladder 8.
Pull up the striker 4 as shown in Figures 1 and 2.
2 comes into pressure contact with the upper limit stopper 43 and is automatically locked.

Here, in the rope winding machine 15, when the rope is paid out, as the rope 20 is paid out, the spring force of the mainspring 30 becomes stronger. At this time, since the rope 20 is configured to move from the small diameter side groove of the drum 27 to the large diameter side groove, the movable ladder 8
can be lowered with equal force over the entire range from the top to the bottom of the ladder frame 5. The movable ladder 8 is lowered and the driver etc.
When the driver or the like pulls the handle 44 after ascending to the passageway 3 via the 8 is pulled up by the force of the mainspring 30 and the force of the driver, and the striker 42 is pulled up by the upper limit stopper 43.
It stops by coming into contact with and is automatically locked. Note that depending on the force of the mainspring 30, the movable ladder 8 may be automatically pulled up by the force of the mainspring 30. When a driver or the like gets off the passage 3, the driver or the like pulls the handle 45 to release the lock by the stopper 43, and pushes the movable ladder 8 down until the striker 40 is automatically locked by the stopper 41.

When adjusting the spring force of the mainspring 30 of the rope winder 15, the adjustment is made by unlocking the shaft 22, turning the worm 36, and then rotating the shaft 22 relative to the case 31. In addition, when using a conventional balance weight as a lifting means, the balance weight must be removed from the ladder frame to attach and detach the balance weight, but by having a spring force adjustment means as in the above example, it is possible to The pulling force of the ladder 8 can be easily adjusted.

Note that in the above embodiment, the rope winding machine 15
Although an example is shown in which the rope winder is attached to the upper revolving structure 1 side, the rope winder may be attached to the ladder frame 5 side via an appropriate bracket. Also, instead of the slider 7 or together with the slider 7, a movable ladder 8 may be used.
Rollers for sliding may also be provided.

(Effect of the invention) As described above, the telescoping ladder for construction machinery of the present invention is provided with a movable ladder that is movable up and down along the ladder frame fixed to the upper revolving body of the construction machine. A rope winder with a built-in spring is attached to the ladder frame, and the rope wound by the rope winder is connected to the lower part of the movable ladder, so that the balance weight and the rope connected to the movable ladder are attached to the upper part of the ladder frame. Since there is no need to provide a hanging sheave, etc., the ladder frame can be short in height.Also, there is no need to provide a running part for the balance weight, and there is no need to support the load of the balance weight, so the ladder frame is lightweight. It can be constructed from several parts, and the extension ladder can be manufactured at low cost.

In addition, compared to a torsion coil spring wrapped around a cylindrical drum, a uniform pulling force can be obtained regardless of the height of the movable ladder, and the movable ladder can be moved up and down with a small force regardless of the position of the movable ladder. Therefore, it is possible to provide a telescopic ladder suitable for application to large-scale construction machinery where the weight of the ladder is large. Also, compared to the case of using a torsion coil spring, the use of a mainspring spring and a conical drum allows
A device with uniform pulling force can be constructed in a small size.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing one embodiment of the telescopic ladder of the present invention in the installed state, Fig. 2 is a view of the ladder of the embodiment as seen from the mounting surface side, and Fig. 3 is the A of Fig. 1.
-A enlarged sectional view, Figure 4 is a view of the attachment part of the rope winder of the embodiment as seen from the rear of the working machine, Figure 5
The figure is a side view of a construction machine to which the present invention is applied, and FIG. 6 is a sectional view showing an example of a rope winder used in the present invention.

Claims (1)

[Scope of utility model registration request] A movable ladder is mounted so as to be able to rise and fall freely along a ladder frame fixed to an upper revolving body of a construction machine, a rope winding machine with a built-in spring is attached to the upper revolving body or the ladder frame, and winding is performed on the rope winding machine. The rope winding machine has a grooved conical drum around which the rope is wound, and the rope is unwound from a small diameter side of the drum. A telescopic ladder for construction machinery featuring: