阅读说明：本技术 高架行进系统 (Overhead traveling system ) 是由 金都铉 张普舜 崔重吉 辛允瑆 任赫淳 于 2019-07-24 设计创作，主要内容包括：一种高架行进系统包括固定到天花板并在X轴方向上延伸的上轨道；沿所述上轨道行进的上部车辆,所述上部车辆中的每一个在所述上轨道中接收并传送盒子；固定到所述天花板、设置在所述上轨道的下方并在所述X轴方向上延伸的下轨道；沿所述下轨道行进的下部车辆,所述下部车辆中的每一个在所述下轨道中接收并传送盒子；以及设置在所述下轨道的上方并用作脚踏板的板,所述脚踏板被配置为允许操作者移动以进行所述上轨道和所述上部车辆的维护。(An overhead traveling system includes an upper rail fixed to a ceiling and extending in an X-axis direction; upper vehicles traveling along the upper track, each of the upper vehicles receiving and transporting a cassette in the upper track; a lower rail fixed to the ceiling, disposed below the upper rail, and extending in the X-axis direction; lower vehicles traveling along the lower track, each of the lower vehicles receiving and transporting a cassette in the lower track; and a plate disposed above the lower rail and serving as a foot board configured to allow an operator to move for maintenance of the upper rail and the upper vehicle.)

1. An overhead traveling system, comprising:

an upper rail fixed to the ceiling and extending in the X-axis direction;

upper vehicles traveling along the upper track, each of the upper vehicles receiving and transporting a cassette in the upper track;

a lower rail fixed to the ceiling, disposed below the upper rail, and extending in the X-axis direction;

lower vehicles traveling along the lower track, each of the lower vehicles receiving and transporting a cassette in the lower track; and

a plate disposed above the lower track and serving as a foot rest configured to allow an operator to move for maintenance of the upper track and the upper vehicle.

2. The overhead traveling system of claim 1, wherein the plate has a plurality of openings through which downward airflow passes.

3. The overhead traveling system according to claim 2, wherein the plate has an aperture ratio of 60 to 80%.

4. The overhead traveling system according to claim 1, wherein the plate is made of a transparent material.

5. The overhead traveling system according to claim 1, further comprising a passage structure provided at one side of the upper rail and configured to extend in the X-axis direction and allow an operator to move for maintenance of the upper rail and the upper vehicle.

6. The overhead traveling system according to claim 1, further comprising:

mold bars fixed to the ceiling and having a lattice shape;

an upper raceway provided below the die rods and having a lattice shape to disperse a load applied to the die rods; and

a securing member for securing the raceway to the mold bar at an intersection of the raceway and the mold bar;

wherein the upper rail is fixed to the upper raceway.

7. The overhead traveling system according to claim 6, further comprising:

a lower raceway provided below the upper raceway and having a lattice shape; and

a connecting member for connecting the lower raceway with the upper raceway,

wherein the lower track is fixed to the lower raceway.

8. The overhead traveling system of claim 7, wherein the plate is fixed to an upper surface of the lower raceway.

9. The overhead traveling system according to claim 7, wherein the mold bar includes a plurality of first mold bars extending in the X-axis direction and a plurality of second mold bars extending in a Y-axis direction perpendicular to the X-axis direction;

the upper raceway and the lower raceway respectively include a plurality of first raceways extending in the X-axis direction and a plurality of second raceways extending in the Y-axis direction; and is

The first raceway of the upper raceway is fixed to the second die bar, and the second raceway of the upper raceway is fixed to the first die bar.

10. The overhead traveling system according to claim 9, wherein the connecting member connects the second raceway of the upper raceway and the second raceway of the lower raceway to prevent interference with the upper rail.

Technical Field

The present invention relates to an overhead traveling system, and more particularly, to an overhead traveling system having a multi-deck track structure.

Background

Generally, the raceway unit is disposed on a ceiling in a building and transports an object, such as a box, using a travel rail and a vehicle.

The overhead traveling system may have a single-layer track structure or may have a multi-layer track structure to increase the transfer efficiency of the object.

When the overhead traveling system has a single-layer track structure, maintenance of the traveling track may be performed using an elevator.

However, when the overhead traveling system has a multi-story track structure, it is difficult for an operator to access the upper traveling track using the elevator due to interference of the lower traveling track. Therefore, it is difficult to maintain the upper traveling rail.

Disclosure of Invention

The present invention provides an overhead traveling system having a multi-deck track structure, which allows an operator to easily access an upper track.

According to an example embodiment of the present invention, an overhead traveling system includes an upper rail fixed to a ceiling and extending in an X-axis direction; upper vehicles traveling along the upper track, each of the upper vehicles receiving and transferring the cassette in the upper track; a lower rail fixed to the ceiling, disposed below the upper rail, and extending in the X-axis direction; lower vehicles traveling along the lower track, each of the lower vehicles receiving and transferring the cassette in the lower track; and a plate disposed above the lower track and serving as a foot board configured to allow an operator to move for maintenance of the upper track and the upper vehicle.

In one example embodiment, the plate may have a plurality of openings through which the downward airflow passes.

In one example embodiment, the plate may have an aperture ratio of 60 to 80%.

In one example embodiment, the plate may be made of a transparent material.

In one example embodiment, the overhead traveling system may further include a passage structure provided at one side of the upper rail and configured to extend in the X-axis direction and allow an operator to move for maintenance of the upper rail and the upper vehicle.

In one example embodiment, the overhead traveling system may further include a mold bar fixed to the ceiling and having a lattice shape; an upper raceway provided below the die rods and having a lattice shape to disperse a load applied to the die rods; and a fixing member for fixing the raceway to the die bar at an intersection of the raceway and the die bar, the upper rail being fixable to the upper raceway.

In one example embodiment, the overhead traveling system may further include a lower raceway disposed below the upper raceway and having a lattice shape; and a connecting member for connecting the lower raceway with the upper raceway, the lower raceway being fixable to the lower raceway.

In one example embodiment, a plate may be secured to an upper surface of the lower race.

In one example embodiment, the mold bar may include a plurality of first mold bars extending in an X-axis direction and a plurality of second mold bars extending in a Y-axis direction perpendicular to the X-axis direction, the upper and lower raceways may include a plurality of first raceways extending in the X-axis direction and a plurality of second raceways extending in the Y-axis direction, respectively, and the first raceways of the upper raceway may be fixed to the second mold bars and the second raceways of the upper raceway are fixed to the first mold bars.

In one example embodiment, the connecting member may connect the second race of the upper race and the second race of the lower race to prevent interference with the upper track.

According to an example embodiment of the present invention, the overhead traveling system includes a plate disposed above the lower rail such that an operator can easily access the upper rail and the upper vehicle using the plate. Therefore, maintenance of the upper rail and the upper vehicle can be stably performed.

Since the plate has openings, the downward airflow generated by the fan filter unit can pass through the openings of the plate. Thus, the plate does not interfere with the flow of the downward air flow.

Further, since the plate is made of a transparent material, the plate transmits light irradiated from the lighting fixture provided in the ceiling without blocking the light. Therefore, the illuminance can be prevented from falling below the lower rail.

Since the die bars and the raceways have a lattice shape in the overhead traveling system, respectively, the number of intersections of the die bars and the raceways and the fixing members for fixing the raceways to the die bars can be increased. As the number of the fixing members increases, the load applied to each of the fixing members may be reduced. Therefore, the overhead traveling system can support a large load.

Further, a flange is formed on each of the raceways, and the die bar and the raceways are joined to each other in a multipoint support manner of two or more points using the flange. Therefore, the load applied to the connection point of the die bar and the raceway is dispersed, so that the die bar can stably support the raceway.

The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The following detailed description and claims more particularly exemplify these embodiments.

Drawings

Exemplary embodiments can be understood in more detail from the following description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a front view illustrating an overhead traveling system according to an exemplary embodiment of the present invention;

fig. 2 is a partially enlarged view illustrating the overhead traveling system as shown in fig. 1;

FIG. 3 is a schematic plan view showing the arrangement of the die rods and upper race as shown in FIG. 1;

fig. 4 is a front view showing a fixing structure of the second mold bar and the first raceway as shown in fig. 1;

fig. 5 is a side view showing a fixing structure of the second mold bar and the first raceway as shown in fig. 1;

FIG. 6 is a perspective view showing the nut and bolt with a T-shaped head as shown in FIG. 1; and

fig. 7 is a plan view showing the plate as shown in fig. 1.

Detailed Description

While various embodiments are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the claimed invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims.

Hereinafter, specific embodiments regarding the overhead traveling system will be described in more detail with reference to the accompanying drawings. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout. In the drawings, the size of layers and regions may be exaggerated for clarity.

Terms such as first, second, etc. can be used to describe various elements, but the elements should not be limited by the terms. The above terms are only used to distinguish one element from another. For example, the present invention may be similarly named without departing from the scope of the first component to the second component, which may also be named after the first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the inventive concepts. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the concepts of the present invention belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Fig. 1 is a front view illustrating an overhead traveling system according to an exemplary embodiment of the present invention, fig. 2 is a partially enlarged view illustrating the overhead traveling system as shown in fig. 1, fig. 3 is a schematic plan view illustrating an arrangement of a mold bar and an upper raceway as shown in fig. 1, fig. 4 is a front view illustrating a fixing structure of a second mold bar and a first raceway as shown in fig. 1, fig. 5 is a side view illustrating a fixing structure of a second mold bar and a first raceway as shown in fig. 1, fig. 6 is a perspective view illustrating a bolt and a nut having a T-shaped head as shown in fig. 1, and fig. 7 is a plan view illustrating a plate as shown in fig. 1.

Referring to fig. 1 to 7, an overhead traveling system 100 includes a mold bar 110, an upper raceway 120, a fixing member 130, an upper rail 140, an upper rail fixing member 150, an upper vehicle 160, an extension member 170, a lower raceway 180, a lower rail 190, a lower rail fixing member 200, a lower vehicle 210, a plate 220, and a passage structure 230.

The mold bars 110 have a lattice shape and are fixed to the ceiling. The mold bars 110 may be directly fixed to the ceiling or separately fixed from the ceiling using an additional member. When the mold bar 110 is directly fixed to the ceiling, the mold bar 100 may be embedded in the ceiling or protrude from the ceiling.

In particular, the mold bar 110 includes a first mold bar 110a and a second mold bar 110 b.

The first mold bars 110a may extend along the X-axis and may be spaced apart from each other at predetermined intervals along the Y-axis.

The second mold bars 110b may extend along the Y-axis and may be spaced apart from each other at predetermined intervals along the X-axis.

A groove 112 is formed in a lower portion of each of the mold bars 110. The groove 112 is elongated in the extending direction of each of the mold bars 110. Here, the grooves 112 may be formed to extend to both ends of each of the mold bars 110. That is, the groove 112 of each of the first mold bars 110a is formed along the X-axis, and the groove 112 of each of the second mold bars 110b is formed along the Y-axis.

When the groove 112 is cut in a vertical direction perpendicular to the extending direction of the mold bar 110, the cross section of the groove 112 is substantially T-shaped.

Specifically, the groove 112 has a lower groove portion 112a and an upper groove portion 112 b.

The lower groove portion 112a is provided in a lower surface portion of the mold bar 110 and has a first width.

The upper groove portion 112b is disposed on the lower groove portion 112a and connected to the lower groove portion 112 a. The upper groove portion 112b has a second width larger than the first width.

The upper raceway 120 is disposed below the die bar 110 and has a lattice shape.

In particular, the upper raceway 120 includes a first upper raceway 120a and a second upper raceway 120 b.

The first upper raceways 120a may extend along the X-axis and may be spaced apart from each other at predetermined intervals along the Y-axis.

The second upper raceways 120b may extend along the Y-axis and may be spaced apart from each other at predetermined intervals along the X-axis. The second upper raceway 120b contacts a lower surface of the first upper raceway 120a and supports the first upper raceway 120 a.

Alternatively, the first upper raceway 120a may contact a lower surface of the second upper raceway 120b and support the second upper raceway 120 b.

The spacing of the upper raceways 120 may be the same as or different from the spacing of the mold bars 110.

When the mold bar 110 and the upper raceway 120 respectively have a lattice shape, the intersection point of the mold bar 110 and the upper raceway 120 can be increased as compared with the case where the mold bar 110 and the upper raceway 120 respectively extend along any one of the X-axis and the Y-axis.

Each of the upper raceways 120 includes a flange 122. A flange 122 is provided on an upper portion of each of the upper raceways 120. The width of the flange 122 is greater than the width of each of the upper raceways 120. The flanges 122 are used to secure each of the upper raceways 120 to each of the mold bars 110.

On the other hand, additional grooves may also be formed on both side surfaces and the lower surface of the upper raceway 120, respectively. Turnbuckles, hanger bolts, etc. may be installed on the additional grooves.

The fixing member 130 is provided at an intersection of the mold bar 110 and the upper race 120 to fix the upper race 120 to the mold bar 110.

The first mold bar 110a extending in the X-axis direction crosses the second upper raceway 120b extending in the Y-axis direction, and the second mold bar 110b extending in the Y-axis direction crosses the first upper raceway 120a extending in the X-axis direction. Accordingly, the fixing member 130 fixes the first upper raceway 120a to the second mold bar 110b and fixes the second upper raceway 120b to the first mold bar 110 a.

As the intersection point of the mold bar 110 and the upper race 120 increases, the number of the fixing members 130 also increases. As the number of the fixing members 130 increases, a load due to the structure fixed to the overhead traveling system 100 may be dispersed, and a load applied to each of the fixing members 130 may be reduced. Therefore, the overhead traveling system 100 can support a large load.

The fixing member 130 includes a bolt 132 and a nut 134.

Bolts 132 and nuts 134 may secure each of the upper raceways 120 to each of the mold bars 110. Here, it is preferable that two bolts 132 and two nuts 134 are provided at each intersection, but more than two bolts 132 and two nuts 134 may be provided.

Specifically, as shown in fig. 6, the bolt 132 is a T-shaped bolt having a T-shape to include a head portion extending in one direction. A width in a short direction of the head of the bolt 132 may be equal to or less than a first width of the lower groove portion 112a, and a width in a long direction of the head of the bolt 132 may be greater than the first width of the lower groove portion 112a and equal to or less than a second width of the upper groove portion 112 b.

In a state where the extending direction of the head of the bolt 132 is aligned with the extending direction of the groove 112, the head of the bolt 132 is inserted into the upper groove portion 112b through the lower groove portion 112a, and then the bolt 132 is rotated by 90 degrees so that the bolt 132 can be mounted in the T-shaped groove 112 of the die bar 110.

Each of the bolts 132 also passes through the flange 122 of the upper race 120.

After each of the bolts 132 is mounted in each of the grooves 112 of the mold bar 110 and passes through the flange 122 of the upper race 120, the nuts 134 are fastened to the bolts 132, respectively.

The process of fixing the mold bar 110 and the upper race 120 to each other using the bolt 132 and the nut 140 will be explained in detail below.

The bolts 132 are inserted downward through the flanges of the first and second upper raceways 120a and 120 b. After the mold bars 110 and the upper raceways 120 having the lattice shapes, respectively, are aligned to cross each other, the first upper raceway 120a is brought into close contact with the lower surface of the second mold bar 110b, and the second upper raceway 120b is brought into close contact with the lower surface of the first upper raceway 120 a. Subsequently, the bolts 132 are respectively brought into contact with the grooves 112 of the first mold bar 110a and the grooves 112 of the second mold bar 110 b. Here, the direction of extension of the head of the bolt 132 is aligned with the direction of extension of the groove 112.

The head of the bolt 132 is lifted up to the upper groove portion 112b by the lower groove portion 112a, and then the bolt 132 is rotated by 90 degrees so that the bolt 132 is installed in the groove 112 of the first mold bar 110a and the groove 112 of the second mold bar 110 b.

Next, nuts 132 are fastened to the bolts 132, respectively, the bolts 132 being installed in the grooves 112 of the first mold bar 110a and the grooves 112 of the second mold bar 110b, respectively, and arranged to pass through the flanges 122 of the first upper raceway 120a and the flanges 122 of the second upper raceway 120b, respectively, so that the first upper raceway 120a can be fixed to the second mold bar 110b and the second upper raceway 120b can be fixed to the first mold bar 110 a.

Meanwhile, although not shown in the drawings, unlike fig. 4 and 5, the bolts 132 and nuts 134 may fix the raceways 120 to the mold bars 110.

Specifically, the nut 134 may be inserted into the upper groove 112b through both side surfaces of the mold bar 110. Here, the width of the nut 134 may be greater than the first width of the lower groove portion 112a and may be equal to or less than the second width of the upper groove portion 112 b. Therefore, the nut 134 inserted into the upper groove portion 112b is not released downward from the mold bar 110 through the lower groove portion 112 a.

After aligning the mold bar 110 and the upper raceway 120, the lower surface of the mold bar 110 and the upper surface of the upper raceway 120 are in close contact with each other. Next, the bolts 132 may pass upward through the flanges 122 of the raceway 120, and then the bolts 132 are fastened to nuts 134 inserted into the upper groove portions 112b, respectively. Here, the bolt 132 may be a T-bolt or a general bolt.

The die bar 110 and the upper race 120 can be simply and quickly fastened by using the T-shaped groove 112 of the die bar 110 and the bolt 132 having a T-shaped head and passing through the flange 122 of the upper race 120. Therefore, the overhead traveling system 100 can be quickly and easily installed on the ceiling.

Since each of the upper raceways 120 has the flange 122, the mold bar 110 and the upper raceway 120 can be fixed in a multi-point supporting manner of two or more points instead of a one-point supporting manner using the flange 122, the bolts 132, and the nuts 134. Accordingly, the load applied to the intersection of the mold bar 110 and the upper raceway 120 is dispersed, so that the mold bar 110 can stably fix the upper raceway 120.

The upper rail 140 extends in the X-axis direction. The upper vehicle 160 may travel along the upper track 140. The upper track 140 is located below the upper raceway 120.

The upper rail fixing member 150 fixes the upper rail 140 to the upper raceway 120. Since the upper rail 140 extends in the X-axis direction, the upper rail fixing member 150 fixes the upper rail 140 to the first upper raceway 120a of the upper raceway 120. Accordingly, the upper rail 140 may include a pair of rails, and a distance between the pair of rails of the upper rail 140 may be substantially the same as a distance between the first upper raceways 120a of the upper raceways 120.

A T-shaped groove is formed on an upper surface of the upper rail 120 in the X-axis direction, and the upper rail fixing member 150 fixes the upper rail 140 to the upper raceway 120 using the T-shaped groove. Examples of the upper rail fixing member 150 include turnbuckles, hanger bolts, and the like.

The upper vehicle 160 travels along the upper rail 140 and receives and transfers the cassette therein. The detailed description of the upper vehicle 130 is substantially the same as that of a general vehicle, and thus is omitted.

The upper rail 140 and the upper vehicle 160 are provided in plurality, and the upper vehicle 160 can simultaneously transfer the objects.

The extension member 170 extends downward from the upper raceway 120. Here, the lower end of the extension member 170 may be located below the lower surface of the upper vehicle 130. Examples of the extension member 170 include turnbuckles, hanger bolts, and the like.

Alternatively, the extension member 170 may extend downward from the mold bar 110.

The lower raceway 180 is fixed to the extension member 170 and has a lattice shape.

In particular, the lower raceway 180 includes a third raceway 180a and a fourth raceway 180 b.

The third raceways 180a may extend along the X-axis and may be spaced apart from each other at predetermined intervals along the Y-axis. Here, the distance between the third raceways 180a may be substantially the same as the distance between the first raceways 120a and the distance between a pair of rails of the upper rail 140.

The fourth raceways 180b may extend along the Y-axis and may be spaced apart from each other at predetermined intervals along the X-axis.

The third raceway 180a contacts a lower surface of the fourth raceway 180b and is mounted to the fourth raceway 180 b.

Alternatively, although not shown in the drawings, the fourth raceway 180b may contact a lower surface of the third raceway 180a and may support the third raceway 180 a.

The third and fourth raceways 180a and 180b may be fixed to each other. For example, a flange may be provided on the upper surface of the third raceway 180a, and a flange may be provided on the lower surface of the fourth raceway 180 b. The flange of the third raceway 180a and the flange of the fourth raceway 180b are fastened with bolts and nuts so that the third raceway 180a and the fourth raceway 180b can be fixed to each other.

Alternatively, the third and fourth raceways 180a and 180b may be fixed to each other using an additional fixing member.

The distance between the pair of rails of the upper rail 140 is substantially the same as the distance between the first upper raceway 120a of the upper raceway 120 and the distance between the third raceway 180a of the lower raceway 180. Thus, when the extension member 170 is connected between the first upper raceway 120a of the upper raceway 120 and the third raceway 180a of the lower raceway 180, the extension member 170 may interfere with the upper rail 140.

The second upper raceway 120b of the upper raceway 120 and the fourth raceway 180b of the lower raceway 180 extend in a Y-axis direction perpendicular to the X-axis. The extension members 170 are fixed to the second upper raceway 120b of the upper raceway 120 and the fourth raceway 180b of the lower raceway 180, respectively. Accordingly, the extension member 170 may be prevented from interfering with the upper rail 140.

Like the upper rail 140, the lower rail 190 extends in the X-axis direction. The lower vehicle 210 may travel along the lower track 190. The lower track 190 may be located below the lower raceway 180.

The lower rail 190 may include a pair of rails, and a distance between the pair of rails of the lower rail 190 may be substantially the same as a distance between the pair of rails of the upper rail 140.

The lower rail fixing member 200 fixes the lower rail 190 to the lower raceway 180. Since the lower rail 190 extends in the X-axis direction, the lower rail fixing member 200 fixes the lower rail 190 to the third raceway 180a of the lower raceway 180.

A T-shaped groove is formed on an upper surface of the lower rail 190 in the X-axis direction, and the lower rail fixing member 200 fixes the lower rail 190 to the lower race 180 using the T-shaped groove. Examples of the lower rail fixing member 200 include turnbuckles, hanger bolts, and the like.

The lower vehicle 210 travels along the lower track 190 and receives and transports cassettes therein.

The lower rail 190 and the lower vehicle 210 are provided in plurality, and the lower vehicle 210 can simultaneously transfer the objects.

Since the overhead traveling system 100 includes the mold bars 110, the upper raceway 120, and the fixing members 130, the overhead traveling system 100 can support a large load. Accordingly, the overhead traveling system 100 can stably form a multi-layered rail including the upper rail 140 and the lower rail 190.

Further, since the upper and lower vehicles 160 and 210 can travel through the upper and lower rails 140 and 190 at the same time, the transfer efficiency of the overhead traveling system 100 can be improved.

The plate 220 is disposed above the lower rail 190. Specifically, plate 220 may be secured to the upper surface of lower race 180. More specifically, the plate 220 may be fixed to an upper surface of an upper one of the third and fourth raceways 180a and 180 b.

The plate 220 may be provided on the entire upper surface or a portion of the upper surface of the lower race 180.

Although not shown in the drawings, the plate 220 may be fixed to the upper surface of the lower race 180 using additional fastening members, such as bolts and nuts.

The board 220 has a substantially rectangular board shape. For example, a plurality of plates 220 may be used to form a foot pedal on which an operator may move. Even if a plurality of upper rails 140 and upper vehicles 160 are provided, an operator can easily access the upper rails 140 and upper vehicles 160 using the plate 220 regardless of the positions of the upper rails 140 and upper vehicles 160. Therefore, maintenance of the upper rail 140 and the upper vehicle 160 can be stably performed.

The plate 220 has a plurality of openings 222. A fan filter unit (not shown) is provided on the ceiling to create a downward airflow. Since the downward airflow may pass through the openings 222 of the plate 220, the plate 220 does not interfere with the flow of the downward airflow.

When the aperture ratio of the plate 220 is less than about 60%, the total area of the openings 222 is relatively narrow, so that the downward airflow may not be sufficiently transmitted under the plate 220. Therefore, it is difficult to sufficiently remove particles existing under the plate 220.

When the aperture ratio of the plate 220 exceeds about 80%, the total area of the openings 222 is relatively wide, so that the strength of the plate 220 may be weakened. Thus, the plate 220 may not be able to withstand the load of the operator and may be damaged.

The aperture ratio of the plate 220 may be about 60% to about 80% so that the plate 220 sufficiently transmits the downward air flow and has a strength sufficient to withstand the load of the operator. More preferably, the aperture ratio of the plate 220 may be about 70%.

The plate 220 may be made of a transparent material. Examples of transparent materials include plastic, glass, and the like.

Since the plate 220 is made of a transparent material, light irradiated from a light source disposed on the ceiling may be transmitted through the plate 220 without being blocked by the plate 220. Therefore, the illuminance can be prevented from falling below the plate 220.

The via structure 230 is disposed on one or both sides of the upper rail 140 and the lower rail 190 in the Y-axis direction, and extends in the X-axis direction. The access structure 230 is secured to the ceiling. Specifically, the access structure 230 may be secured to the ceiling by being secured to the upper raceway 120.

The access structure 230 includes a foot board 232 and a foot board securing member 234.

The foot board 232 has a flat plate shape and extends in the X-axis direction. The operator may move along the foot pedal 232.

The footrest 232 may also include a plurality of openings (not shown) for the downward airflow to pass through.

A footrest securing member 234 may secure the footrest 232 to the upper race 120. Since the foot board 232 extends in the X-axis direction, the foot board fixing member 234 fixes the foot board 232 to the first race 120a of the upper race 120.

A T-shaped groove is formed on the upper surface of the pedal plate 232 in the X-axis direction, and the pedal plate fixing member 234 is fixed to the upper raceway 120 using the T-shaped groove. Examples of the pedal fixing member 234 include turnbuckles, hanger bolts, and the like.

The access structure 230 provides access to the operator for movement so that the operator can stably maintain the upper rail 140 and the upper vehicle 160.

When the upper rail 140 and the upper vehicle 160 are provided in plurality, the upper rail 140 and the upper vehicle 160 located outside the upper rail 140 and the upper vehicle 160 can be easily accessed by the operator in the Y-axis direction through the passage structure 230. Further, the operator can easily access the upper rails 140 and the upper vehicles 160 located inside the upper rails 140 and the upper vehicles 160 through the panel 220. Therefore, the upper rail 140 and the upper vehicle 160 can be easily accessed and stably maintained using the plate 220 and the passage structure 230 regardless of the positions of the upper rail 140 and the upper vehicle 160.

Meanwhile, although not shown in the drawings, the overhead traveling system 100 may further include a lifting structure. A lifting structure may be provided between the upper rail 140 and the lower rail 190 to lower the upper vehicle 160 to the lower rail 190 or to raise the lower vehicle 210 to the upper rail 190.

As described above, the overhead traveling system according to the present invention can stably perform maintenance on the upper rail and the upper vehicle because an operator can easily access the upper rail and the upper vehicle using the panel and the passage structure.

Further, since the overhead traveling system has a structure capable of distributing a load, the overhead traveling system can endure a high load. Therefore, the overhead traveling system can stably constitute a multi-deck track structure.

Although the overhead traveling system has been described with reference to the specific embodiment, it is not limited thereto. Accordingly, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention as defined by the appended claims.