JP2019078110A - Step width expander - Google Patents

Abstract

To provide a step width expander which can be removably attached to a lifting device having a plurality of steps between columns such as ladders, stepladder, and tripods, can be attached to steps of different lengths and which can be stably operated regardless of where on the step surface.SOLUTION: The present invention comprises a first step 20 which has a substantially rectangular step plate portion, a pair of side plate portions extending substantially vertically downward from both long sides of the step plate portion, and a pair of projecting pieces extending in the direction approaching each other substantially perpendicularly from extending lower sides of the pair of side plate portions, a first abutment support 21 provided at an end of the first step 20 in the longitudinal direction, a second step 30 slidable in the longitudinal direction inside the first step 20, a second abutment support 31 provided at an end of the second step 30 in the longitudinal direction, and sliding locking means 40 for locking the sliding of the first step 20 and the second step 30 relative to each other.SELECTED DRAWING: Figure 1

Description

  The present invention is a tread width expander which is detachably attached to a lifting device such as a ladder, a stepladder or a tripod having two columns and a plurality of treads installed between them, and extends the width of the tread. About.

  When performing work at heights that can not be reached, a ladder or stepladder should be provided, and the worker should rise above it to perform work, but generally the width of the steps of the ladder or stepladder is narrow. It is difficult for the worker to maintain a stable posture on the treads, it is difficult to improve the working efficiency when working with unstable feet, and it is likely that the treads will fall off during the work and fall. There is also such a danger.

  In order to cope with the above-mentioned circumstances, there has been proposed an appliance which is detachably attached to the ladder and extends the width of the tread so that a sufficient tread surface can be obtained to work stably. There is. For example, in Patent Document 1, two rod-like arm bodies having hooks formed at their tips, and an L-shaped rod-like support rotatably attached to each of the two rod-like arm bodies, 2 A ladder footboard is disclosed having a footplate supported on the long side of a rod-like support of a book. The ladder footboard is hooked to a ladder of a ladder by hooks of two rod-like arm bodies and attached, and work can be performed on a tread plate having a sufficient tread surface. Further, in Patent Document 2, a scaffold main body provided on both sides with abutment portions capable of abutting on a pillar of a forceps, a hook body provided so as to be movable back and forth on the lower surface of the scaffold main body, and advancing and retracting the hook body There is disclosed an auxiliary scaffold having an operating means. This auxiliary scaffolding is attached by hooking the hook body to the step of the ladder and causing the hook body to move back and forth by the operation means to abut the abutment portion on the side of the scaffold body to the pole of the ladder and has a sufficient tread Work can be done on the scaffold body.

Unexamined-Japanese-Patent No. 2007-032133 Japanese Patent Application Publication No. 09-203203

  The ladder footboard disclosed in the above-mentioned Patent Document 1 is attached to the ladder of the ladder by the hooks of two rod-like arm bodies, and although the ladder is attached regardless of the length of the tread, the tread plate is Since the two rod-like arm members are supported by being mounted on the long side of the L-shaped rod-like support rotatably mounted, the worker works on the tread plate When the weight is applied to the end of the tread plate out of the area between the two rod-like supports that support the tread plate, the hooks of the distant rod-like arm body may float off the treads or may come off And there is a risk of falling. In addition, the auxiliary scaffold disclosed in Patent Document 2 has a hook of the lower part of the scaffold main body hooked on the step of the ladder and makes the hook move forward and backward by the operation means, and the abutment part of the side of the scaffold main body It is stable because it is attached in contact, but when the length of the tread is long, the length between the abutments on both sides of the scaffold main body is not butted against the support, and If the length is short, there is a problem that the scaffold main body can not be inserted and attached, and it can be attached only to a ladder with a specific tread length.

  The present invention has been made in view of the above circumstances, and can be detachably attached to a lifting device having a plurality of treads between columns such as ladders, stepladders and tripods, and can be attached to treads of different lengths. Therefore, it is an object of the present invention to provide a tread width extending device which can be stably operated regardless of where on the tread surface.

  In order to solve the above-mentioned subject, the step width expansion device concerning the present invention is removably attached to the rise-and-fall device which has two pillars and a plurality of treads installed between the two pillars. A tread width expanding device, which is attached to one of the plurality of treads, the length in the longitudinal direction is shorter than the length of the treads, and the length in the short direction is wider than the width of the treads. A rectangular first tread plate portion, a first front plate portion and a first rear plate portion extending substantially vertically downward from both long sides of the first tread plate portion, and the first front plate portion and the first front plate portion. The first front projection and the first rear projection that extend in the direction approaching each other substantially perpendicularly from the lower extension of the rear plate and form a first longitudinal opening wider than the width of the tread. A first footstep having a portion, and a longitudinal end of the first footstep provided in contact with one of the two columns A second front side plate portion and a second rear side plate portion extending substantially vertically downward from both long sides of the first contact support portion, the substantially rectangular second step plate portion, and the second long step plate portion, and the second step plate portion A second front projection forming a second longitudinal opening which extends from the lower front sides of the front side plate portion and the second rear side plate portion so as to approach each other substantially perpendicularly from each other and extends therebetween; And a second rear projection, and the second tread plate, the second front side and the second rear side, and the second front and second rear projections. The portions are in sliding contact with the first tread plate portion, the first front side plate portion and the first rear side plate portion, and the first front projection piece portion and the first rear projection piece portion respectively inside the first step board. A second step which can slide in the longitudinal direction inside the first step, and a longitudinal end of the second step, which is in contact with the other of the two columns A second abutment support portion, the first back side plate portion and the second back side plate portion, and the first footrest provided on at least one of the first front side plate portion and the second front side plate portion; And a sliding locking means for locking the mutual sliding of the second step.

  The step width expander according to the present invention comprises a first step mounted on one of the steps of a lifting device having two columns and a plurality of steps bridged between the two columns; A first abutment support portion provided at an end of the first step in the longitudinal direction to abut on one of the two columns, a second step which is slidable in the longitudinal direction inside the first step, and a second step A second contact support portion provided at an end in the longitudinal direction of the step and contacting the other of the two columns; and a slide locking means for locking the first step and the second step from sliding relative to each other , So that the first step and the second step can be slid and locked to each other, and the distance between the first and second contact supports can be freely expanded and contracted. it can. Therefore, it is possible to attach even when the width of the support and the length of the treads installed between them are not limited to specific ones but various lengths. In addition, the first step board and the second step board may be mounted such that the first step board portion and the second step board portion are mounted on the upper surface of the step via the first longitudinal opening portion and the second longitudinal opening portion. And the first contact support and the second contact support at both ends are brought into contact with the columns, respectively, so that the entire surface of the upper surface of the tread is covered by the first tread plate and the second tread plate. Since the width of the tread is extended as it is, it is possible to provide a tread having a larger area than the tread of the original tread. Further, the load applied to the first tread plate portion and the second tread plate portion is supported by the first contact support portion and the second contact support portion at both end portions and the tread of the lower surface extending in the longitudinal direction. The work can be stably performed anywhere on the upper surfaces of the first tread plate portion and the second tread plate portion which are tread surfaces. In addition, the first tread plate portion and the first front side plate portion and the first front projection piece portion of the first tread, and the second tread plate portion and the second front side plate portion and the second front projection piece portion of the second tread, or the first tread step The first tread plate portion and the first rear side plate portion and the first rear projection portion, and the second tread plate portion and the second rear side plate portion and the second rear projection portion portion of the second tread are respectively formed in a substantially U-shaped hook shape Since the hook-like portion is hooked from the side and hooked on the tread when it is attached to the tread, it is hard to be removed and it is safe.

It is a perspective view showing a tread spreader according to an embodiment of the present invention. (A) is an assembly drawing, (B) is an exploded view. It is a perspective view which shows a mode that the step width expansion apparatus which concerns on embodiment of this invention was attached to one of the steps of a stepladder. It is a side view which shows the CC cross section of FIG. It is a perspective view which shows a mode that the step width expansion apparatus which concerns on embodiment of this invention was attached to the step of different length of a stepladder.

  Hereinafter, the best embodiment of the present invention will be described based on the drawings. In FIG. 2, the example which attached the step width expansion tool 10 which concerns on this embodiment to the stepladder 90 is shown. In the stepladder 90, a ladder body having two pillars 91 arranged in a substantially V shape, the distance of which becomes narrower toward the upper side, and a plurality of treads 92 installed between them, is joined from two sides The upper part is connected, and the lower part can be opened and closed by using the connected part as a fulcrum, and it is the raising / lowering instrument which can be independent. The step width expansion device 10 is detachably attached to one of the step bars 92 of the stepladder 90, and as shown in FIG. And one second support portion 31 having one end slidably fitted in the other end of the first step 20 and having the other end in contact with the other of the columns 91. The second step 30 and the slide locking portion 40 that locks the sliding of the first step 20 and the second step 30 relative to each other.

  For the first step 20, a lip channel steel which is a longitudinal member having a substantially C-shaped cross section is used. The length of the longitudinal direction is shorter than the length of the tread 92, and the length of the lateral direction is longer than the width of the tread 92. A substantially rectangular plate-like first tread plate portion 20a and both long sides of the first tread plate portion 20a A direction from which the first front side plate portion 20b1 and the first rear side plate portion 20b2 extending substantially vertically downward respectively, and the lower sides of the first front side plate portion 20b1 and the first rear side plate portion 20b2 approach each other substantially vertically. Between the first front projection 20c and the first rear projection 20c2 than the width of the tread 92. The first front projection 20c and the first rear projection 20c2 A wide first longitudinal opening 20d is formed. Although the lip channel steel is used here, it may be formed into a similar shape from a single plate or the like.

  At one end of the first step 20 in the longitudinal direction, a first contact support 21 that contacts the support post 91 when attached to the stepladder 90 is provided. The first contact support portion 21 is fixed to the first front side plate portion 20b1 inside the end portion of the first tread plate portion 20a in the longitudinal direction by using a rectangular steel pipe which is a longitudinal member having a substantially rectangular cross section. The other end side extends so as to project toward the first longitudinal opening 20d. The contact surface 21a of the end on the other end side is covered with a flat plate, and as shown in FIG. 3, the angle α between the contact surface 21a and the first tread plate portion 20a is approximately 75 degrees. . As shown in FIGS. 2 and 3, when the first step support 20 is attached to the step bar 92, the first contact support portion 21 contacts one of the columns 91 at the contact surface 21 a, so that the first contact is made. The end portion of the first step support 20 to which the first contact support portion 21 is fixed so that the support portion 21 and the support column 91 can be in contact with each other on the first rear side plate portion 20b2 side. Notches in width are provided.

  In this embodiment, the angle α between the contact surface 21a and the first tread portion 20a is approximately 75 degrees, but this is the angle β of the elevation surface of the stepladder 90 of this embodiment with respect to the ground, that is, in FIG. This is because an angle β of 75 degrees between the support column 91 and the horizontal surface is used. The JIS S1121 of the Japanese Industrial Standard (JIS) stipulates that the inclination angle of the elevation and back surfaces of the stepladder with respect to the ground shall be 75 degrees or less. It is defined that the angle of the angle of 75 degrees or less. In addition, it is known that it is generally safest to lay the ladder so that the angle between the ground and the elevating surface is about 75 degrees for the ladder used on the wall or the like. Therefore, since it is thought that the angle with respect to the ground with respect to the raising / lowering surface of a general ladder or a stepladder is often used in the vicinity of 75 degrees, angle beta with respect to the ground of the raising / lowering surface of stepladder 90 is 75 degrees. If the formed angle α and the angle β of the elevation surface of the stepladder 90 with respect to the ground are substantially the same, the first step support 20 is attached to the step 92 and the first contact support portion 21 is mounted as shown in FIG. When it abuts on the support column 91, the first tread plate portion 20a becomes substantially horizontal. Therefore, the formed angle α may be appropriately changed to be approximately equal to the angle β by the angle β to the ground of the elevation surface of the stepladder used. Preferably, it is in the range of 65 degrees to 75 degrees.

  In the present embodiment, a square steel pipe is used as the first contact support portion 21. However, the present invention is not limited thereto, and a round steel, an L-shaped steel, or the like may be used. Since the contact surface 21a at the end abuts against the support column 91 to support a part of the load applied to the first tread plate portion 20a, it is better to make a flat plate by fixing a flat plate to the contact surface 21a, etc. Good. In addition, although one end of the first contact support 21 is fixed inside the end of the first step plate portion 20a, the present invention is not limited thereto, and depending on the size of the first contact support 21 used, the first front It may be fixed to the side plate portion 20b1 or may be fixed to straddle the first tread plate portion 20a and the first front side plate portion 20b1. In addition, it may be fixed to the end side surface of the first step 20 in the longitudinal direction. In that case, it is not necessary to provide the first step 20 with a notch. The attachment of the first step 20 to the step bar 92 may not be disturbed, and the first step block 20 may be in contact with the support post 91 when the first step block 20 is attached to the step bar 92.

  The second step 30 also uses a lip channel steel which is a longitudinal member having a substantially C-shaped cross section. Similar to the first step 20, a substantially rectangular plate-like second step-plate portion 30a whose length in the longitudinal direction is shorter than the length of the step 92 and whose length in the short direction is longer than the width of the step 92; Second lower side plate portion 30b1 and second rear side plate portion 30b2 extending substantially vertically downward from both long sides of second tread plate portion 30a, and lower lower sides of second front side plate portion 30b1 and second rear side plate portion 30b2 And a second front projection 30c and a second rear projection 30c2 extending substantially perpendicularly to each other, and between the second front projection 30c1 and the second rear projection 30c2 A second longitudinal opening 30d is formed wider than the width of the tread 92. The length in the longitudinal direction of the second step 30 is substantially the same as the length in the longitudinal direction of the first step 20, and the width of the second longitudinal opening 30d of the second step 30 is the second length. The width is substantially the same as the first longitudinal opening 20 d of the first step 20. Here, the length in the longitudinal direction of the second step 30 is substantially the same as the length in the longitudinal direction of the first step 20, but may be different. Further, the width of the first longitudinal opening 20 d and the second longitudinal opening 30 d needs to be wider than the width of the tread 92. According to the Japanese Industrial Standard (JIS), JIS S1121 specifies that the depth to the elevating surface of the tread, that is, the width of the tread, be 20 mm or more for ladders and 30 mm or more for stepladders. The temporary equipment approval standard by the temporary construction industry stipulates that the width of the stepladder must be 50 mm or more, so the width of the first longitudinal opening 20 d and the second longitudinal opening 30 d is at least 20 mm. It is above. Preferably it is 50 mm or more.

  The second step 30 has a first cross-section side opening 20e at the end opposite to the side on which the first contact support portion 21 in the longitudinal direction of the first step 20 is provided. The second longitudinal opening 30 d and the first longitudinal opening 20 d of the first step 20 are inserted into the first step 20 in the same direction. In that state, the second step plate portion 30a, the second front side plate portion 30b1 and the second rear side plate portion 30b2 of the second step board 30, and the second front protruding piece portion 30c1 and the second rear protruding piece portion 30c2 are respectively the first Inside the step 20, the first step plate portion 20a, the first front side plate portion 20b1, the first rear side plate portion 20b2, and the first front projection 20c1 and the first rear projection 20c2 are in sliding contact with each other. Is slidable in the longitudinal direction inside the first step 20.

  A second contact support 31 is provided at an end opposite to the side of the second step 30 to be inserted into the first step 20 in the longitudinal direction, which abuts on the column 91 when attached to the stepladder 90 . Similar to the first contact support portion 21, the second contact support portion 31 uses a rectangular steel pipe which is a longitudinal member having a substantially rectangular cross section, and one end side is an inner side of an end portion of the second tread plate portion 30 a in the longitudinal direction. It is fixed to the second front side plate portion 30b1 side, and the other end side is extended so as to project toward the second longitudinal direction opening 30d. The contact surface 31a of the end on the other end side is covered with a flat plate, and the angle between the contact surface 31a and the second tread plate portion 30a is the first contact support 21 as shown in FIG. Of the contact surface 21a and the first tread plate portion 20a, which is approximately 75 degrees. As shown in FIG. 2 and FIG. 3, when the second step support 30 is attached to the step bar 92, the second contact support portion 31 abuts on one of the columns 91 at the contact surface 31a. The end of the second step support 30 to which the second contact support portion 31 is fixed so that the support portion 31 and the support column 91 can abut on the second contact support portion 31 on the second rear side plate portion 30b2 side. Notches in width are provided. Similarly to the first step 20 and the first contact support portion 21, the second step 30 and the second contact support portion 31 can be appropriately changed.

  The mutual sliding of the first step 20 and the second step 30 is locked by the slide locking means 40. The slide locking means 40 includes a bolt hole 41 provided in the vicinity of the end on the first cross-section side opening 20 e side of the first back side plate portion 20 b 2 of the first step 20 and the second back side plate of the second step 30. The lateral groove hole 42 extending in the longitudinal direction with a width substantially the same as the diameter of the bolt hole 41 provided in the portion 30b2 and the lateral groove hole from the inside of the second step 30 with the second step 30 inserted in the first step 20 A low-head bolt 45 inserted to the outside of the first step 20 through the bolt hole 42 and the bolt hole 41 and a wing nut 46 screwed to the low-head bolt 45 are provided. The low head bolt 45 is a bolt with a thin head. The wing nut 46 is a nut with a handle that can be turned by hand. When the wing nut 46 is tightened, the mutual sliding of the first step 20 and the second step 30 is locked, and when the wing nut 46 is loosened, it is possible to slide again. When sliding the first step 20 and the second step 30, the low head bolt 45 can pass through the lateral slot 42 of the second step 30, so the low head bolt 45 and the wing nut 46 can be used as the first step 20 and the second step. There is no need to remove it from 30.

  By sliding the first step 20 and the second step 30, the first contact support 21 provided at the end of the first step 20 and the second contact provided at the end of the second step 30 The distance between the supports 31 can be adjusted. The distance of the length of the longitudinal slot 42 minus the diameter of the threaded portion of the low head bolt 45 is adjustable.

  In the present embodiment, the bolt holes 41 are provided in the first rear side plate portion 20b2, and the lateral groove holes 42 are provided in the second rear side plate portion 30b2. However, the lateral groove holes 42 in the first rear side plate portion 20b2 and the bolts are provided in the second rear side plate portion 30b2. The hole 41 may be provided. Further, the bolt holes 41 and the lateral groove holes 42 may be provided in the first front side plate portion 20b1 and the second front side plate portion 30b1 instead of the first rear side plate portion 20b2 and the second rear side plate portion 30b2, It may be provided on both sides. However, when provided on the first front side plate portion 20b1 and the second front side plate portion 30b1, since the treads 92 do not interfere as shown in FIG. 3 at the time of attachment, ordinary bolts may be used instead of the low head bolts 45. You may use a butterfly bolt and a nut, but it is possible that the foot may be hooked to the low head bolt 45 and the wing nut 46 when going up and down to the tread spreader 10 because it is the front side with respect to the elevation surface. There is. Further, although the wing nut 46 is used here, a normal nut may be used. However, the wing nut 46 is easier because it can be turned by hand and does not require a tool.

  Next, a flow of attaching the step width extension device 10 according to the present embodiment to the stepladder 90 will be described. As shown in FIG. 2, the stepladder 90 is disposed at a target work place. Then, the tread width expander 10 is attached to one tread 92 at a height corresponding to the work place. First, the wing nut 46 of the sliding lock means 40 is loosened so that the length between the inner sides of the first contact support portion 21 and the second contact support portion 31 is shorter than the length of the tread 92 attached. 1. Slide the tread 20 and the second tread 30 to adjust the length. Then, the first tread plate portion 20 a and the second tread plate portion 30 a are mounted on the tread 92 through the first longitudinal opening 20 d and the second longitudinal opening 30 d. Then, the first step support 20 and the second step support 30 are slid to adjust the length, and the first contact support portion 21 and the second contact support portion 31 are respectively brought into contact with the support columns 91. At this time, it is safe to keep the first step 20 and the second step 30 in contact with the insides of the columns 91, since they do not shift laterally during use. After that, if the wing nuts 46 of the slide locking means 40 are tightened to stop the sliding of the first step 20 and the second step 30, the installation of the step spreader 10 on the stepladder 90 is completed. An operator gets on the first tread plate portion 20 a and the second tread plate portion 30 a of the tread width expansion device 10 attached and performs work.

  When the first step 20 and the second step 30 of the step width extension device 10 are attached to the step bar 92, the first back side plate portion 20b2 and the second back side plate portion 30b2 are put between the two columns 91 When the first step 20 and the second step 30 are slid to adjust the length between the inner sides of the first contact support 21 and the second contact support 31 to a minimum. The length of the support must be equal to or less than the inner width of the support 91, that is, the length of the tread 92 between them. According to the Japanese Industrial Standard (JIS), JIS S1121 stipulates that the inner width of the pillar of the ladder, that is, the length of the step is 300 mm or more, and the inner width of the top of the stepladder be 280 mm or more. Further, according to the temporary equipment qualification standard by the temporary association of the general association, it is stipulated that the length of the uppermost step of the stepladder be 300 mm or more and the length of the first step be 550 mm or less. Therefore, the length when the length between the inner widths of the first contact support 21 and the second contact support 31 is minimized may be in the range of 280 mm to 550 mm.

  In the present embodiment, the lengths in the longitudinal direction of the first step 20 and the second step 30 are substantially the same, and the widths of the first contact support portion 21 and the second contact support portion 31 are also substantially the same. The length when the length between the inner widths of the first contact support portion 21 and the second contact support portion 31 is minimized is equal to the length from the end of the first cross-section side opening 20e of the first tread plate portion 20a. The length in the longitudinal direction up to the contact support portion 21, that is, the length in the longitudinal direction of the first rear side plate portion 20b2 and the first rear projecting piece portion 20c2 after the notch is equal. Similarly, the lengths in the longitudinal direction of the second rear side plate portion 30b2 and the second rear protruding piece portion 30c2 after the notch are also equal. Therefore, when the length between the inner widths of the first contact support portion 21 and the second contact support portion 31 is maximized, the length of the overlapping portion of the first step 20 and the second step 30 should be at least 20 mm. If the lengths of the first back side plate portion 20b2 and the first back protruding piece portion 20c2 as well as the second back side plate portion 30b2 and the second back protruding piece portion 30c2 after the notch are in the range of 150 mm to 550 mm. Good. In the case of the range from 285 mm to 300 mm, it is more preferable because it can be attached to any step of a stepladder that satisfies the temporary equipment qualification criteria by the Temporary Incorporated Industry Association.

  In the state where the step width extension device 10 is attached to the stepladder 90, the widths of the first step plate portion 20a and the second step plate portion 30a are wider than the width of the step bars 92, as shown in FIG. It is shaped to cover the entire surface of the tread. And as shown in FIG. 3, the 1st tread plate part 20a of the 1st tread 20, the 1st back side board part 20b2, the 1st back projection piece part 20c2, and the 2nd tread plate part 30a of the 2nd tread 30 and the 2nd back A substantially U-shaped hook-shaped portion formed by the side plate portion 30b2 and the second rear projection portion 30c2 is shaped so as to be hooked on the tread 92. Then, with the first contact support 21 and the second contact support 31 in contact with the support 91, the first front plate 20b and the second front plate 30b1 of the first tread plate 20a and the second tread plate 30a are on the side. It is shaped to be supported from below. Therefore, the width of the tread surface of the tread 92 is expanded toward the front side with respect to the elevating surface, and a tread surface sufficient for the worker to get on and work stably can be provided. When you get on it, the upper step is not in the way. And, even if the worker put weight on the side of the first front side plate portion 20b1 and the second front side plate portion 30b1 side of the first tread plate portion 20a and the first tread plate portion 30a, the first The abutment support portion 21 and the second abutment support portion 31 support the first front side plate portion 20b1 and the second front side plate portion 30b1 of the first tread plate portion 20a and the first tread plate portion 30a, and also the first rear projection Since the piece portion 20c2 and the second rear protruding piece portion 30c2 are caught on the tread 92, it is difficult to be removed and it is safe. In addition, also in the middle part of the longitudinal direction of the tread width expander 10 considered to be weak, the strength is sufficient because the first tread 20 and the second tread 30 are partially overlapped, and the first tread portion The work can be stably performed regardless of where on the 20a and the second step board portion 30a.

  In addition, the angle α between the contact surface 21 a of the first contact support portion 21 and the contact surface 31 a of the second contact support portion 31 with the first tread plate portion 20 a and the second tread plate portion 30 a moves up and down the stepladder 90 The first tread plate portion 20a and the second tread plate portion 30a are kept substantially horizontal since they are substantially the same as the angle β of the surface to the ground. Therefore, it is difficult for the worker to slide down and work can be performed in a stable posture.

  Further, the first step 20 and the second step 30 can slide relative to each other in the longitudinal direction, and the distance between the first contact support portion 21 and the second contact support portion 31 provided at their respective end portions is It can be adjusted, and as shown in FIG. 4, it can be attached also to the treads 92 of different lengths in the stepladder 90 in which the distance between the columns 91 is different on the upper stage side and the lower stage side.

  In this embodiment, as shown in FIG. 3, an example is shown in which the step width expander 10 is attached to a stepladder 90 having a step 92 having a substantially rectangular cross section, but the step width expander 10 has a first length. The first tread plate portion 20a and the second tread plate portion 30a are mounted on the tread so as to be mounted on the tread via the directional opening 20d and the second longitudinal opening 30d, and the first tread portion 20a, the first back side plate portion 20b2 and the first back protruding piece portion 20c2, and the second tread plate portion 30a, the second back side plate portion 30b2, and the second back protruding piece portion 30c2 are formed in a substantially U-shaped hook shape Since the hook-shaped part is attached in a form to be hooked from the side of the tread so as to be hooked, not only the cross-sectional shape of the tread is substantially rectangular, but also the hook-shaped part can be hooked Can also be installed on treads with a cross-sectional shape such as Can.

  Although the example in which the step width extension device 10 has been attached to the step 90 has been described above, the same is applied to a lifting device having a plurality of step beams between other two columns such as a ladder and a tripod. be able to.

  Since the above only shows one embodiment of the step width expansion device according to the present invention, it can be suitably modified without departing from the concept of the present invention.

DESCRIPTION OF REFERENCE NUMERALS 10 tread width expanding device 20 first tread 20a first tread plate portion 20b1 first front side plate portion 20b2 first rear side plate portion 20c1 first front projecting piece portion 20c2 first rear projecting piece portion 20d first longitudinal opening portion 21 1 Abutment support portion 30 Second tread 30a Second tread plate portion 30b1 Second front side plate portion 30b2 Second rear side plate portion 30c1 Second front projection piece portion 30c2 Second rear projection piece portion 30d Second longitudinal opening portion 31 second Abutment support 40 Slide locking means 90 Legs (raising and lowering equipment)
91 pillars 92 trams

Claims (1)

A tread spreader which is removably attached to a lifting apparatus having two columns and a plurality of treads installed between the two columns,
A substantially rectangular first tread plate portion attached to one of the plurality of treads, the length in the longitudinal direction being shorter than the length of the treads, and the length in the lateral direction being wider than the width of the treads; A first front side plate portion and a first rear side plate portion extending substantially vertically downward from both long sides of the first tread plate portion, and an extending lower side of the first front side plate portion and the first rear side plate portion A first step base having a first front projection and a first rear projection which extend in a direction substantially close to each other and form a first longitudinal opening wider than the width of the tread in between; ,
A first abutment support portion provided at a longitudinal end of the first step and abutting on one of the two columns;
A substantially rectangular second tread plate portion, a second front side plate portion and a second rear side plate portion extending substantially vertically downward from both long sides of the second tread plate portion, and the second front side plate portion and the second front side plate portion (2) A second front projection and a second rear projection which extend in the direction approaching each other substantially perpendicularly from the extension lower side of the rear plate and form a second longitudinal opening wider than the width of the tread. And the second tread plate portion, the second front side plate portion and the second rear side plate portion, and the second front protrusion portion and the second rear protrusion portion respectively have the first portion. The first tread plate portion, the first front side plate portion, the first rear side plate portion, and the first front projection piece portion and the first rear projection piece portion are in sliding contact with the inside of the step pedestal, and the inside of the first step pedestal And a second step which can slide in the longitudinal direction,
A second contact support portion provided at a longitudinal end of the second step and contacting the other of the two columns;
The sliding movement between the first step board and the second step board provided on at least one of the first rear side plate portion and the second rear side plate portion, and the first front side plate portion and the second front side plate portion Sliding locking means for locking;
A tread extension device characterized by having.

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