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Step apparatus for heavy construction equipment and tree harvester having leveling system

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Step apparatus for heavy construction equipment and tree harvester having leveling system


A step apparatus for heavy construction equipment and tree harvester having a leveling system for controlling a horizontal level of a cab and an upper frame is provided, which includes a step protector including a main body fixedly installed on one side of an upper frame, a step guide hole opened from an inside of the main body to an outside, a guide rail formed along a length direction of an inner side wall of the main body, and an insert hole formed on one side of the guide rail and open toward a vertically upward direction of the guide rail; a side step including a plurality of foot steps arranged at specified intervals on a step frame to form stairs, a step drawer formed on an upper part of the step frame and seated in the step guide hole, and a guide pin positioned adjacent to the step drawer and projected toward the side wall of the main body, wherein when the guide pin is slid along the guide rail, the step frame is seated in the main body or is drawn out from the inside of the main body; and a folding actuator including a cylinder rod coupled to the step drawer to be extended and contracted, the folding actuator drawing the step drawer to the inside of the main body of the step protector.


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USPTO Applicaton #: #20140174852 - Class: 182 88 (USPTO) -
Fire Escape, Ladder, Or Scaffold > Wall- Or Floor-attached >Retractable Or Collapsible Beneath Floor, Track-mounted

Inventors: In Woo Kim, Young Ok Park

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The Patent Description & Claims data below is from USPTO Patent Application 20140174852, Step apparatus for heavy construction equipment and tree harvester having leveling system.

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CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority from Korean Patent Application No. 10-2008-0048976 and 10-2008-0052641, filed on May 27, 2008 and Jun. 4, 2008, respectively in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a step apparatus for heavy construction equipment and tree harvester having a leveling system, and more particularly to a step apparatus for heavy construction equipment and tree harvester having an improved leveling system, which can prevent a collision with an external obstacle or a lower driving structure by making the step apparatus in a step protector drawn out and seated in foldable steps even if an upper swing structure is tilted in an inclined workplace or is in a tilted state against the lower driving structure through operation of the leveling system.

2. Description of the Prior Art

Conventionally, heavy construction equipment and tree harvester having a leveling system, e.g. an excavator and tree harvester having a leveling system, can safely perform logging works or engineering works in a workplace having severe inclination or on the inclined ground, such as a slop, a hill, and the like.

If an upper frame including a cab and a working device is tilted at a specified angle due to the inclination of the workplace, a leveling system lifts up or pulls one lower side of the upper frame to offset the inclination, and thus the cab and the upper frame is kept roughly in a parallel state to a horizontal surface.

According to the heavy construction equipment and tree harvester having a leveling system as described above, since the height of structures mounted on the upper frame, such as the cab, engine room, and the like, is relatively high, the operator\'s approach to such structure for getting on or off the equipment is lowered, and the maintenance and repair work becomes difficult.

In consideration of the above-described drawbacks, a fixed step apparatus having foot steps or a step plate provided on one side of the upper frame to form stairs for getting on or off the equipment, has been widely used.

The conventional fixed step apparatus is a kind of step structure in which the step frame and foot steps hang down from one side of the upper frame, and are in a standing posture toward the lower driving structure or the upper swing structure.

Accordingly, the conventional fixed step apparatus is always in an exposed state as a step structure, without being affected by the change of the operation position of a safety lever typically installed in the cab, and thus an operator can keep the approach to various structures mounted on the upper swing structure, such as the cab, engine room, and the like.

FIG. 1 is a perspective view illustrating the use state of a conventional fixed step apparatus installed in heavy construction equipment and tree harvester having a leveling system, and FIG. 2 is a schematic perspective view of a conventional fixed step apparatus.

According to the heavy construction equipment and tree harvester having a leveling system as illustrated in FIG. 1, a leveling device 14 is installed between an upper frame 1 and a lower driving structure 2, and a cab 9, a boom 12 having a working device 13 such as a logging device or a bucket, and an engine room 11 are installed on an upper part of the upper frame 1. Also, in order for an operator to approach the cab 9, a step apparatus 10 is fixed to one side surface of the upper frame 1.

The conventional fixed step apparatus 10, as illustrated in FIG. 2, has a structure in which a stopper unit 3 is provided on one side of the upper frame 1, and a step frame hanger 6 having foot steps 5 hangs on the stopper unit 3.

Also, pinholes 4 for fixing the position of the step frame are formed on the step frame hanger 6. In the case of selectively fixing the step frame 7 in a standing posture so that the step frame 7 is headed upward from the upper part of the upper frame 1, stoppers 8 of the stopper unit 3 are inserted into the pinholes 4 of the step frame hanger 6, and thus the step frame 7 on the upper part of the upper frame 1 is kept in a standing posture.

Typically, in the case where the equipment such as an excavator having a leveling system performs work in an inclined area, the upper frame 1 is kept in a horizontal state that substantially corresponds to a horizontal surface H for prevention of overturn and work safety of the equipment, while the lower driving structure 2 is in an inclined state.

Also, the step apparatus 10 is fixed to be exposed from the upper frame 1, and if it is intended to adjust the exposed state of the step apparatus 10, the fixing position of the step frame 7 should be adjusted in a state where a safety lever is set to an operation mode.

However, the conventional step apparatus has the problem that, although the fixing position of the step frame 7 is adjusted, the step apparatus 10 is still exposed to an outside, and thus interference or collision may occur between the step apparatus and an external object or the lower driving structure.

For example, the conventional fixed step apparatus has severe problem that, when the upper swing structure and the upper frame are inclined or tilted at a preset angle due to an inclined ground surface, the step frame is projected toward the lower driving structure, and thus collision occurs between one side of the step frame and the lower driving structure to cause damage of the step frame and the lower driving structure.

Also, even in the case where the conventional step apparatus is fixed to the upper part of the upper frame in a standing posture by the stoppers to prevent collision between the step frame and the lower driving structure, collision may still occur between the step frame and an external object during working of the equipment.

The conventional fixed step apparatus also has severe problems that, in the case of adjusting the setting position of the step apparatus before leveling control of the upper frame or during working of the equipment, an operator should manually adjust the positions of the step frame and the steps up and down in a state where the operator directly hangs on the upper frame, and thus the manipulation performance is lowered with the operator\'s safety threatened.

SUMMARY

OF THE INVENTION

Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art while advantages achieved by the prior art are maintained intact.

One object of the present invention is to provide a step apparatus for heavy construction equipment and tree harvester having a leveling system, which can prevent a collision with a lower driving structure even if an upper frame is tilted by making a step frame kept in a step protector in a foldable manner and making the step frame form stairs on an outer side of the upper frame when in use.

Another object of the present invention is to provide a step apparatus for heavy construction equipment and tree harvester having a leveling system, which can remove interference or conflict between the step apparatus and the lower driving structure and collision between the step apparatus and an external object even if the upper frame is tilted by forming inclined steps that are projected to a side of the upper frame to secure the visual field of an operator.

Still another object of the present invention is to provide a step apparatus for heavy construction equipment and tree harvester having a leveling system, which can selectively adjust the keeping and exposing of a step frame by hydraulic pressure when a safety lever is set to a safety mode.

In the following description of the present invention, it could be commonly understood by those ordinary skilled in the art to which the present invention belongs that the term “folding” includes a process in which the step frame is rotated or folded and is drawn out from or seated in the step protector, and the term “exposure” includes a process in which the step frame and foot steps are drawn out from the step protector or are set in the form of stairs on the outside of the step protector.

In order to accomplish these objects, there is provided a step apparatus for heavy construction equipment and tree harvester having a leveling system, according to an embodiment of the present invention, which includes a step protector including a main body fixedly installed on one side of an upper frame, a step guide hole opened from an inside of the main body to an outside, a guide rail formed along a length direction of an inner side wall of the main body, and an insert hole formed on one side of the guide rail and open toward a vertically upward direction of the guide rail; a side step including a plurality of foot steps arranged at specified intervals on a step frame to form stairs, a step drawer formed on an upper part of the step frame and seated in the step guide hole, and a guide pin positioned adjacent to the step drawer and projected toward the side wall of the main body, wherein when the guide pin is slid along the guide rail, the step frame is seated in the main body or is drawn out from the inside of the main body; and a folding actuator including a cylinder rod coupled to the step drawer to be extended and contracted, the folding actuator drawing the step drawer to the inside of the main body of the step protector.

A slit may be formed adjacent to the step guide hole on a main body bottom part of the step protector, and one side of the step frame may be slid up and down by the slit.

The step guide hole may be penetratingly formed on a side part in the length direction of the main body of the step protector.

A step support may be attached to one side of the main body bottom part of the step protector, and may have an inclined support part adjacent to the slit, wherein when the step frame stands up toward a lower part of the main body of the step protector, the step frame is supported at specified inclination by the inclined support part.

The inclined support part may be formed to be tilted in an angle range of about 65° to 80° against a horizontal surface formed in the length direction of the main body bottom part of the step protector.

The folding actuator may be rotatably fixed to a first mounting flange formed inside the main body, and the cylinder rod may be rotatably fixed to a second mounting flange formed on one side of the step drawer.

A handle may be formed on one side of the step frame.

A safety cover may be installed on a lower part of the step frame.

The step apparatus according to an embodiment of the present invention may further include a safety lever installed inside the cab to change a present mode to a safety mode or an operation mode, wherein if the safety lever is in the safety mode, the step frame is folded outside the main body of the step protector by the driving of the folding actuator, while if the safety lever is in the operation mode, the step frame is unfolded and seated inside the main body of the step protector by the driving of the folding actuator.

In another aspect of the present invention, there is provided a step apparatus for heavy construction equipment and tree harvester having a leveling system, which includes a step protector including a cylinder fixing holder formed inside a protector housing, first and second fixing lugs respectively formed apart from the cylinder fixing holder along a length direction of the protector housing, and a step protection cover attached to a lower part of the protector housing and having a step receiving hole penetratingly formed thereon to communicate with an inner part of the protector housing, the step protector being fixedly installed on one side of an upper frame; a first step frame including a first lug support flange coupled to the first fixing lug, and a plurality of step support flanges formed apart from the first lug support flange, wherein the first lug support flange and the first fixing lug are rotatably fixed to each other; a second step frame including a second lug support flange coupled to the second fixing lug, a plurality of step support flanges formed apart from the second lug support flange, and a fixing cam formed adjacent to the second lug support flange to support a rotating force generated about a rotating shaft formed on the second lug support flange, wherein the second lug support flange and the second fixing lug are rotatably fixed to each other; foot steps fixed to the plurality of step support flanges formed in the first step frame and the second step frame, respectively; and a folding actuator including a rod that can be extended and contracted, and having one side connected to the cylinder fixing holder and the other side connected to the fixing cam, the folding actuator providing the rotating force to the fixing cam by a predetermined pressure.

At least one of the first and second step frames may have a projection angle θ2 and may be fixed with an inclination so that at least one of the foot steps is projected to an outside of an outer wall of the step housing when the first and second step frames are exposed to an outside of the step protector at maximum.

The projection angle θ2 of the step frame may be in the range of 5° to 40°.

The fixing cam may be formed in a body with the second step frame.

The fixing cam may be formed in a body with the second lug support flange.

The foot step may be supported on one side of a support link that is rotatably shaft-engaged with the step support flange.

A safety cover may be further installed on a lower part the foot step.

The step apparatus according to an embodiment of the present invention may further include a safety lever installed inside the cab to change a present mode to a safety mode or an operation mode, wherein if the safety lever is in the safety mode, the second step frame is drawn out to an outside of the step protector by the driving of the folding actuator, while if the safety lever is in the operation mode, the second step frame is rotated and folded inside the step protector by the driving of the folding actuator.

The folding actuator may include a hydraulic cylinder that is extended and contracted.

The first step frame may be installed on the step receiving hole when the second step frame is folded and fixed inside the protector housing.

The safety cover may be installed on the step receiving hole when the second step frame is folded and fixed inside the protector housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating the use state of a conventional fixed step apparatus installed in heavy construction equipment and tree harvester having a leveling system;

FIG. 2 is a schematic perspective view of a conventional fixed step apparatus;

FIG. 3 is an exploded perspective view of a step apparatus for heavy construction equipment and tree harvester having a leveling system, in which a step frame is folded inside a step protector, according to an embodiment of the present invention;

FIG. 4 is an enlarged perspective view illustrating an inside of a guide hole of a step protector main body, from which a step frame as illustrated in FIG. 3 has been removed;

FIG. 5A is a perspective view illustrating a sliding state of a step frame that moves by extension and contraction operation of a folding actuator as illustrated in FIG. 3;



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stats Patent Info
Application #
US 20140174852 A1
Publish Date
06/26/2014
Document #
14189479
File Date
02/25/2014
USPTO Class
182 88
Other USPTO Classes
International Class
/
Drawings
18




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