US3407901A | 1968-10-29 | |||
US20090020360A1 | 2009-01-22 | |||
FR2799424A1 | 2001-04-13 |
[Claims] [Claim 1 ] Stairs for construction vehicle, comprising: main supports spaced from a vehicle body at a certain distance to be fixed to one side of the vehicle body and comprising a first upper hole penetrated in the top and a first lower hole penetrated in the bottom; second supports spaced from, the main supports towards the exterior of the vehicle body at a certain distance to be parallel and comprising a second upper hole penetrated in the top and a second lower hole penetrated in the bottom; an upper step comprising a first hinge shaft coupled to the first upper hole of the main support and a second hinge shaft coupled to the second upper hole of the second support, whereby the upper step is rotatabiy coupled to the main supports; and a lower step comprising a third hinge shaft coupled to the first lower hole of the main support and a fourth hinge shaft coupled to the second lower hole of the second support, whereby the lower step is rotatabiy coupled to the main supports. [Claim 2] The stairs for construction vehicle as claimed in claim. 1, further comprising: a lever coupled to one side of the upper step or the lower step to allow the upper step to rotate clockwise or counterclockwise on the first hinge shaft. [Claim 3] The stairs for construction vehicle as claimed in claim. 1, further comprising a securing means for fixing the upper step to retain the unfolded or folded condition. [Claim 4] The stairs for construction vehicle as claimed in claim 3, wherein the securing means comprises: a first pin hole provided to the first hinge shaft; a second pin hole provided to the second hinge shaft; a pin being capable of penetrating the first pin hole and the second pin hole; and a pin control unit for inserting or releasing the pin into or from, the second pin hole. [Claim 5] The stairs for construction vehicle as claimed in claim 1, further comprising: a cylinder, one side of which is fixed to the vehicle body and the other side of which is connected to one side of the upper step or the lower step, wherein the length of the cylinder is variable. [Claim 6] The stairs for construction vehicle as claimed in claim 5, wherein the other side of the cylinder is spaced from, the third hinge shaft to be connected to the lower step. [Claim 7] The stairs for construction vehicle as claimed in claim 5, wherein the other side of the cylinder is spaced from the first hinge shaft towards the vehicle body to be connected to the upper step. [Claim 8] The stairs for construction vehicle as claimed in claim 1, wherein the first lower hole and/or the second lower hole are/is in the shape of an elongated hole, which is vertically long. [Claim 9] The stairs for construction vehicle as claimed in claim 1, wherein at least one sub- step is provided between the upper step and the lower step. |
TITLE OF THE INVENTION Foldable stairs for construction vehicle
TECHNICAL FIELD
The present disclosure relates to stairs for construction vehicle and, more particularly, to foldable stairs for construction vehicle such as wheel loaders, compactors and graders.
BACKG ROUND OF THE INVENTIO
Generally, it is essential to use construction vehicle at the civil engineering and construction site. Accordingly, there has been continuous development of the construction vehicle for improving its performance and efficiency. As such construction vehicle becomes larger, the work efficiency has been improved. Thus, large-size construction vehicle is preferred except under special circumstances, such as use for special purposes or use in narrow areas.
Such construction vehicle is large in size and the operator's cabin is disposed in a high position from the ground. Accordingly, in order for the operator to get in and out of the cabin for the operation of the construction vehicle, stairs are required. These stairs are normally attached to the lateral side of the vehicle body and are in a fixed type. As an advanced type, detachable stairs are also used.
FIG. 1 shows a grader 1 equipped with conventional fixed stairs. As shown in FIG. l, fixed stairs 11 are attached to one side of the grader 1, and the operator can get in and out of the operator's cabin 20, which is disposed in a considerably high position from the ground, using such stairs 11. Such fixed stairs 11 always protrude from, one side of the vehicle body and are exposed during the operation of the grader 1. Due to this, the protruding stairs 11 are frequently damaged during the operation. For example, when the operator moves a blade 30, specifically, when the blade 30 rotates up to the limit position, the stairs 11 protruding from the lateral side of the vehicle body are bumped against the blade 30. The strong bumping of the stairs 11 and the blade 30 or the frequent collision of the stairs 11 by the blade 30 may result in breaking stairs. The broken stairs may be dangerous to the operator in getting in and out of the cabin, and thus, are required to be repaired. It is necessary to minimize the protrusion of the stairs from, the vehicle body in order not to prevent the operation of the construction vehicle. However, a certain space for the stairs is needed so that the operator can easily get in and out of the operator's cabin. For this reason, a certain size of protrusion from the vehicle body is unavoidable. SUMMARY OF THE INVENTIO
According to one aspect of the present disclosure, there provide stairs for construction vehicle. The stairs for construction vehicle comprise: main supports, which are spaced from the vehicle body at a certain distance to be fixed to one side of the vehicle body and comprise a first upper hole penetrated in the top and a first lower hole penetrated in the bottom; second supports, which are spaced from the main supports at a certain distance towards the exterior of the vehicle to be parallel and comprise a second upper hole penetrated in the top and a second lower hole penetrated in the bottom; an upper step, which comprises a first hinge shaft coupled to the first upper hole of the main support and a second hinge shaft coupled to the second upper hole of the second support, whereby the upper step is coupled to the main supports rotatably; and a lower step, which comprises a third hinge shaft coupled to the first lower hole of the main support and a fourth hinge shaft coupled to the second lower hole of the second support, whereby the lower step is coupled to the main supports rotatably. Preferably, the stairs for the construction vehicle according to the present disclosure further comprise: a lever, which is coupled to one side of the upper step or the lower step to allow the upper step to rotate clockwise or counterclockwise on the first hinge shaft.
Preferably, the stairs for the construction vehicle according to the present disclosure further comprise a securing means for fixing the upper step to retain the unfolded or folded condition. According to the present disclosure, preferably, the securing means comprises: a first pin hole provided to the first hinge shaft; a second pin hole provided to the second hinge shaft; a pin configured to penetrate the first pin hole and the second pine hole; and a pin control unit for inserting or releasing the pin into or from the second pin hole.
Preferably, the stairs for the construction vehicle according to the present disclosure further comprise: a cylinder, one side of which is fixed to the vehicle body, and the other side of which is connected to one side of the upper step or the lower step, wherein the length of the cylinder is variable.
According to the present disclosure, preferably, the other side of the cylinder is spaced from the third hinge shaft to be connected to the lower step. According to the present disclosure, preferably, the other side of the cylinder is spaced from the first hinge shaft towards the vehicle body to be connected to the upper step.
According to the present disclosure, preferably, the first lower hole and/or the second lower hole are/is in the shape of an elongated hole, which is vertically long.
According to the present disclosure, preferably, at least one sub-step is further provided between the upper step and the lower step.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing a fixed step in conventional practices;
FIG. 2 is a perspective view showing a construction vehicle with unfolded stairs according to one embodiment of the present disclosure;
FIG. 3 is a perspective view showing a construction vehicle with folded stairs according to one embodiment of the present disclosure;
FIG. 4 is a perspective view showing stairs in unfolded condition according to a second embodiment of the present disclosure;
FIG. 5 a perspective view showing stairs in folded condition according to a second embodiment of the present disclosure;
FIG. 6 is a perspective view showing stairs in unfolded condition according to a third embodiment of the present disclosure;
FIG. 7 is a perspective view showing the stairs in folded condition according to third embodiment of the present disclosure;
FIG. 8 is a perspective view showing stairs in unfolded condition according to a fourth embodiment of the present disclosure;
FIG. 9 is a perspective view showing stairs in unfolded condition according to a fifth embodiment of the present disclosure;
FIG. 10 is a perspective view showing stairs in folded condition according to a fifth embodiment of the present disclosure;
FIG. 11 is a perspective view showing stairs in unfolded condition according to a sixth embodiment of the present disclosure;
FIG. 12 is a perspective view showing stairs in folded condition according to a sixth embodiment of the present disclosure; and
FIG. 13 is a perspective view showing stairs in folded condition according to a seventh embodiment of the present disclosure.
DETAILED DESCRIPTIO OF THE INVENTION
Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. While the present disclosure will be described in conjunction with the following embodiments, it will be understood that they are not intended to limit the present disclosure to these embodiments alone. On the contrary, the present disclosure is intended to cover alternatives, modifications, and equivalents which may be included within the spirit and scope of the present disclosure as defined by the appended claims. Furthermore, in the following detailed description of the present disclosure, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, embodiments of the present disclosure may be practiced without these specific details.
FIGS. 2 and 3 show a construction vehicle 1 in its entirety having stairs 10 according to an embodiment of the present disclosure, with stairs 10 in different conditions or positions. The construction vehicle 1 may be a wheel loader, a compactor, a grader or any other type of construction vehicle. As shown in FIGS. 2 and 3, the stairs 10 include main supports 100, second supports 200, an upper step 300 and a lower step 400.
The main supports 100 are bar-shaped support structures spaced from the vehicle body at a certain distance to be fixed to one side of the vehicle body 1 by a securing member 105. A first upper hole 110 formed to be penetrated is provided in the top of the main support 100, and a first lower hole 120 formed to be penetrated is provided in the bottom, thereof. A pair of such main supports 100 may be provided by being spaced from each other to be parallel.
The second supports 200 are bar-shaped support structures similar to the main supports 100, are parallel to the main supports 100 and are spaced from the main supports 100 at a certain distance towards the exterior of the vehicle body. A second upper hole 210 formed to be penetrated is provided in the top of the second supports 200, and a second lower hole 220 formed to be penetrated is provided in the bottom thereof. A pair of such second supports 200 may be spaced from, each other to be parallel.
An upper step 300 is provided at the position corresponding to the first upper hole 110 between the main supports 100. A first hinge shaft 310 coupled to the first upper hole 110 is provided to the upper step 300. Further, a second hinge shaft 320 parallel to the first hinge shaft 310 is provided to the upper step 300 at the position corresponding to the second upper hole 210 by being spaced from the first hinge shaft 310 at a certain distance. The first hinge shaft 310 is coupled to the first upper hole 110 of the main supports 100 to allow the upper step 300 to rotate clockwise or counterclockwise on the first hinge shaft 310. The second hinge shaft 320 is coupled to the second upper hole 21.0 of the second supports 200.
Similarly, a lower step 400 is provided at the position corresponding to the first lower hole 1.20 between a pair of main supports 100. A third hinge shaft 410 coupled to the first lower hole 120 is provided to the lower step 400. Further, a fourth hinge shaft 420 parallel to the third hinge shaft 41.0 is provided to the lower step 400 at the position corresponding to the second lower hole 220 by being spaced from the third hinge shaft 410 at a certain distance. The third hinge shaft 410 is coupled to the first lower hole 120 of the main supports 100 to allow the lower step 400 to rotate clockwise or counterclockwise on the third hinge shaft 400. The fourth hinge shaft 420 is coupled to the second lower hole 220 of the second supports 200.
Since the upper step 300 and the lower step 400 are linked by the second support 200, if one of the upper step 300 and the lower step 400 rotates, the other step will be in communication with it to rotate.
Herein, the stairs 10 may further comprise at least one sub-step 800above the lower step 400. At least one sub-step 800 may be added in the construction vehicle based on the height of the operator's cabin 20. FIG. 2 or FIG. 3 shows an embodiment of comprising an additional, sub-step 800 between the upper step 300 and the lower step 400. Such sub-step 800 comprises two hinge shafts spaced from, each other similarly to the upper step 300 or the lower step 400, wherein one hinge shaft is connected to the main support 100 to allow the sub-step 800 to rotate, and the other hinge shaft is connected to the second support 200 to allow the upper step 300 and the lower step 400 to rotate together when one of the two steps rotates.
The embodiment in the attached drawings discloses, but is not limited to, stairs having three steps. The aforesaid structure can continuously apply, and thus, is available for all stairs for construction vehicle regardless of the number of steps.
FIG. 2 shows stairs in the unfolded condition according to an embodiment of the present disclosure. As shown in FIG. 2, when the operator gets in or out of the operator's cabin 20, the main supports 100 and the second supports 200 are maximally spaced from each other to unfold the upper step 300 to be parallel to the ground surface. Accordingly, the other steps, i.e. the sub-step 800 and the lower step 400, retain the same condition as the condition of the upper step 300. Such configuration enables the operator to easily get in and out of the operator's cabin using the steps.
On the other hand, FIG. 3 shows stairs in the folded condition according to an embodiment of the present disclosure. As shown in FIG. 3, during the operation after the operator gets in the operator's cabin 20, the main supports 100 and the second supports 200 can be maximally adjacent to each other so that the stairs 10 can be folded. In this case, the upper step 300 rotates counterclockwise on the first hinge shaft to be inclined. The other steps, i.e. the sub-step 800 and the lower step 400 also retain the inclined condition, similarly to the upper step 300. Such configuration maximally reduces the width of the stairs protruding from the exterior of the vehicle body, thereby eliminating the interference with the stairs when the blade rotates during the operation to produce an effect of enlarging the operation radius. Due to this, damages caused by frequent collision of the conventional stairs and the blade can be prevented.
Such conversion of the condition of the stairs, i.e., from the unfolded condition to the folded condition or from the folded condition to the unfolded condition, can be conducted by various means.
As an embodiment of such conversion means, a lever 500, which is coupled to one side of the upper step 300 to allow the upper step 300 to rotate clockwise or counterclockwise on the first hinge shaft 310, is provided as shown in FIG. 4 and FIG. 5. If the lever 500 rotates clockwise, i.e., in the arrow direction, the unfolded condition of stairs as shown in FIG. 4 can be converted to the folded condition of stairs as shown in FIG. 5. On the contrary, if the lever 500 rotates counterclockwise, i.e., in the arrow direction, the folded condition of stairs as shown in FIG. 5 can be converted to the unfolded condition of stairs as shown in FIG. 4.
Although not shown in the drawings, if the lever 500 rotates counterclockwise, the unfolded condition of stirs as shown in FIG. 4 can also be converted to the folded condition of stairs. Meanwhile, the stairs 10 in the unfolded condition may comprise a securing means
600 preventing the conversion of the stairs' condition to support the operator's weight. According to an embodiment of the present disclosure, the securing means 600 comprises a first pin hole 312 provided to the first hinge shaft 310, a second pine hole 322 provided to the second hinge shaft 320, a pin 610 configured to penetrate through the first pin hole 312 and the second pine hole 322, and a pin control unit 620 for inserting or releasing the pin 610 into or from the second pin hole 322, as shown in FIG. 6 and FIG. 7. As shown in FIG. 6, in order to retain the unfolded condition of stairs, the pin 610 is inserted by penetrating through the first pin hole 312 and the second pin hole 322. Due to this, the upper step 300 is prevented from rotating on the first hinge shaft, and thus, is retained in the horizontal condition. The sub-step 800 and the lower step 400, which are linked by the second supports 200, are also retained in the same condition as the condition of the upper step 300. Accordingly, the rotation of the stairs is prevented despite the operator's weight, and the operator can safely get in and out of the operator's cabin.
In order to convert the condition of stairs to the folded condition, a pin control unit 620 is operated, i.e., a lever connected to the pin 610 is pulled so that the pin 610 can be escaped from the second pin hole 322, as shown in FIG. 7. Due to this, the upper step 300 is capable of rotating on the first hinge shaft 310, and thus, rotates counterclockwise as shown in FIG. 7 or clockwise although not shown in the drawings. Consequently, the condition of stairs can be converted to the folded condition. In the meantime, in order to convert or retain the condition of the stairs 10 to the unfolded condition or the folded condition, a conversion means can be used, as shown in FIG. 8 to FIG. 12.
Such conversion means comprises a cylinder 700, the length of which is variable, and a cylinder control unit 710 for controlling the change in the length of the cylinder 700. The cylinder may be a gas pressure spring, which is compressed and expanded by gas. One side of such cylinder 700 is fixed to the vehicle body, and the other side thereof is connected to one side of the upper step 300 or the lower step 400.
As an embodiment, a cylinder 700 may be used as shown in FIG. 8. One side of the cylinder 700 is fixed to the vehicle body, and the other side thereof is connected to the bottom of the lower step 400. The other side of the cylinder 700 is connected at the position spaced from the third hinge shaft 410 of the lower step 400 at a certain distance such that the lower step 400 can rotate on the third hinge shaft according to the change in the length of the cylinder 700. A cylinder control unit 710 for controlling the length of the cylinder 700 is in the form, of a pedal, and the pedal may be disposed inside the operator's cabin 20, see FIG. 2.
As shown in FIG. 9 to FIG. 12, two cylinders 700 are spaced from each other to be parallel. As an embodiment, one side of each of the two cylinders is fixed to the vehicle body, and the other side thereof is connected to the bottom of the lower step 400, as shown in FIG. 9 and FIG. 10. The other side of the cylinder 700 is connected at the position spaced from, the third hinge shaft 410 of the lower step 400 at a certain distance such that the lower step 400 can rotate on the third hinge shaft 410 of the lower step 400 according to the change of the length of the cylinder 700. When the operator gets in or out of the operator's cabin, under the condition that the cylinder 700 is lengthened, the lower step 400 is retained to be horizontal, and the upper step 300 and the sub-step 800, which are linked together with the lower step 400, are also retained to be horizontal, so that the stairs 10 are in unfolded condition. During the operation after the operator gets in the operator's cabin, in order to fold the stairs, the length of the cylinder 700 is minimized to allow the lower step 400 to rotate clockwise on the third hinge shaft 41.0, thereby giving a slope to the upper step 300, the lower step 400 and the sub-step 800 such that the main supports 100 and the second supports can be maximally adjacent to each other, as shown in FIG. 10.
Similarly, as an embodiment, one side of each of the two cylinders may be fixed to the vehicle body, and the other side thereof may be connected to one side of the upper step 300, as shown in FIG. 11 and FIG. 1.2. The other side of the cylinder 700 is connected at the position spaced from the first hinge shaft 31.0 of the upper step 300 at a certain distance such that the upper step 300 can rotate on the first hinge shaft 310 according to the change in the length of the cylinder 700. That is, the other end of the cylinder 700 is preferably connected to the portion adjacent to the vehicle body in the upper step 300. When the operator gets in or out of the operator's cabin, under the condition that the length of the cylinder 700 is minimized, the upper step 300 is retained to be horizontal, and the lower step 400 and the sub-step 800, which are linked together with the upper step 300 by the second supports 200, are also retained to be horizontal, and therefore, the stairs are in the unfolded condition, as shown in FIG. 11. During the operation after the operator gets in the operator's cabin, in order to fold the stairs 10, the cylinder 700 has the longest length to allow the upper step 300 to rotate counterclockwise on the first hinge shaft 310, thereby making the upper step 300, the lower step 400 and the sub-step 800 inclined such that the main supports 1.00 and the second supports 200 can be maximally adjacent, as shown in FIG. 12.
Meanwhile, the first lower hole 120 in the main supports 100 and the second lower hole 220 in the second supports 200 may be in the shape of an elongated hole, which is vertically long. Due to the elongated hole shape of the first lower hole 120 and/or the second lower hole 220, a clearance is generated in the connection of the third hinge shaft 310 or the fourth hinge shaft 420 of the lower step 400. In the event that unexpected obstructions, such as rock with a considerable height, hit the bottom, of the vehicle body, the lower step 400, which is disposed in the lowest end of the stairs 10, under the folded or unfolded condition or stairs, can ascend by the length of the elongated hole. Accordingly, such clearance can prevent damages caused by unexpected obstructions. As stated above, the stairs for construction vehicle are simple and easy to assemble and are foldabie, thereby minimizing the width thereof protruding from the exterior of the vehicle body to secure a larger working space for the working tool. Further, it is avoided that the stairs are interfered by working tools, such as a blade, during the operation, which results in extending the life span of stairs. The aforesaid stairs are used for a grader among construction vehicles as an example, and are also applicable to other construction vehicles.
Although the invention has been described with reference to the preferred embodiments in the attached figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.
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