JP2008297705A - Stepladder serving also as ladder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stepladder capable of preventing an accident of a worker falling down from a top plate as much as possible by preventing the worker from stepping on the top plate when using the stepladder. <P>SOLUTION: In this stepladder serving also as the ladder constituted by supporting upper end parts of a pair of front and rear leg bodies 1, 1 pivotally and connecting them mutually by rotary fittings 2 and forming each leg body 1 by stretching step crosspieces 4 between a pair of right and left support columns 1 and 1 at the predetermined interval in the vertical direction, upper end parts of both of inner and outer side wall parts 7, 8 form an unstable surface US1 for making worker's feet unstable even if the worker attempts to step on it and preventing the worker from stepping on it. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stepladder in which upper ends of a pair of front and rear ladder-like legs are rotatably connected.

  As a conventional stepladder, specific publicly known documents such as patent gazettes cannot be cited, but the stepladder used in the past is shown in a perspective view in FIG. 5, and FIG. 6 (a) is a partial front view of the stepladder. , (B) is a side view thereof, (c) is an enlarged cross-sectional view taken along line EE of (a), and (d) is a plan view viewed from an arrow F of (b). In this stepladder 10K, the upper ends of a pair of front and rear legs 1, 1 are pivotally connected by a rotating metal fitting 2, and each leg 1 has a step rail 4 between a pair of left and right columns 3, 3 at a required interval in the vertical direction. When the stepladder is used, it is only necessary to open both legs 1 and 1 at a predetermined angle and lock the opening stopper 5 when the stepladder is used. The stepladder 10K is a stepladder stepladder that can also be used as a ladder by releasing the stopper metal fitting 5 and further opening both legs 1, 1 to extend both legs 1, 1 in a straight line. .

  And in this conventional stepladder 10K, the upper surface 10 has a wide flat plate so that the top plate 4o at the upper end of each leg 1 which becomes a top plate when using the stepladder can be used as a temporary placement of a work tool or the like. It is formed in a shape.

  In the conventional stepladder, as described above, the upper surface of the step rail 4o on the upper end side of each leg 1 is widely formed in a flat plate shape, so that an operator can relatively easily ride on the top plate when using the stepladder. For this reason, in recent years, there have been frequent accidents in which an operator rides on the top plate during work and falls off the foot or falls from the top plate due to loss of balance.

  In view of the above circumstances, the present invention provides a stepladder that minimizes accidents such as dropping from the top plate by making it difficult or impossible for an operator to step on the top plate when using the stepladder. The purpose is that.

  Means for solving the above problems will be described with reference numerals of the embodiments described later. In the invention according to claim 1, the upper ends of the pair of front and rear legs 1, 1 are pivotally supported by the rotating metal fitting 2. Each leg 1 is a ladder at the upper end of each leg 1 in a ladder-supporting stepladder that is formed by laying a leg 4 between a pair of left and right support columns 1 and 1 at a required interval in the vertical direction. 4o is formed of a profile formed into a substantially U-shaped cross section by an inner side wall portion 7, an outer side wall portion 8, and a bottom wall portion 9 connecting both side wall portions 7, 8, and both inner and outer side wall portions are formed. 7 and 8 are characterized in that they form unstable surfaces US1 and US2 such that even if an operator tries to get on, the feet become unstable and the rider cannot get on.

  A second aspect of the present invention is the stepladder according to the first aspect, wherein the unstable surface US1 is formed at an upper end portion of the inner and outer side wall portions 7 and 8, respectively, or an upper end portion of the inner or outer side wall portion 7 or 8. Characterized by comprising uneven portions 11 and 12

  A third aspect of the present invention is the stepladder according to the second aspect, in the unstable surface US1 in which the concave and convex portions 11 and 12 are formed on the upper end portions of the inner and outer side wall portions 7 and 8, respectively, The concavo-convex portions 11 and 12 and the concavo-convex portions 11 and 12 of the outer side wall portion 8 are formed so that the concave portions 11 or the convex portions 12 do not face each other in the direction crossing the step rail 4o.

  A fourth aspect of the present invention is the stepladder according to the first aspect, wherein the unstable surface US2 is different in height between the inner and outer side walls 7 and 8 when the stepladder is used, and has a large step between the side walls 7 and 8. 15 is formed.

  The effect of the invention by the above solution will be described with reference numerals of the embodiments described later. According to the stepladder of the invention according to claim 1, the step rail 4o at the upper end of each leg 1 is provided on the inner side. The upper end of the inner and outer side walls 7, 8 is made of a profile formed in a substantially U-shaped cross section by a side wall 7, an outer side wall 8 and a bottom wall 9 connecting both side walls 7, 8. The part is formed with unstable surfaces US1 and US2 that make the feet unstable and unable to get on when the operator tries to get on it. Even if it tries to get on the step rail 4o at the upper end of the leg 1 to be formed, it gives up that it gets scared and gives up, so that accidents such as dropping from the top plate can be minimized.

  In the invention according to claim 2, the unstable surface US1 is formed from the concavo-convex parts 11 and 12 formed on the upper end part of the inner and outer side wall parts 7 and 8, respectively, or the upper end part of either the inner or outer side wall part 7 or 8. In this case as well, even if an operator tries to get on the stepping rail 4o forming the top board, his / her feet become unstable and he / she cannot get on.

  In the unstable surface US1 in which the uneven portions 11 and 12 are formed at the upper end portions of the inner and outer side wall portions 7 and 8, respectively, the invention according to claim 3 has the uneven portions 11 and 12 and the outer side wall portion 8 of the inner side wall portion 7. The concave and convex portions 11 and 12 are formed so that the concave portions 11 or the convex portions 12 do not face each other in the direction crossing the step rail 4o, so that the worker can Even if you put your foot on 8, it will be very unstable and will give up actively on the top board.

  In the invention according to claim 4, the unstable surface US <b> 2 is formed of a structure in which the heights of the inner and outer side walls 7, 8 are different when the stepladder is used and a large step 15 is formed between the side walls 7, 8. In this case as well, even if the operator tries to get on the crosswalk 4o forming the top board, his / her feet become unstable and he can not get on, and as a result, accidents such as dropping from the top board are minimized. be able to.

  A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 (a) shows an upper end portion of a ladder and stepladder K similar to the conventional stepladder 10K shown in FIGS. (B) is a side view when the ladder is in use, (c) is a front view of the ladder and stepladder K as viewed from the arrow A in (a), and (d) is (a) It is a BB sectional view taken on the line. In this ladder combined stepladder K, like the conventional stepladder 10K shown in FIGS. 4 and 5, the upper ends of the pair of front and rear legs 1, 1 are pivotally connected to each other by the rotating metal fittings 2, 2 and the pivot pin 6. Each leg body 1 is formed by laying step rails 4 made of aluminum extruded shape material between the right and left support columns 3 made of a pair of left and right aluminum extruded shape materials at a predetermined interval in the vertical direction. The

  As shown in FIGS. 2 and 3, the crosspiece 4 o at the upper end of each leg 1 is crossed by an inner side wall portion 7, an outer side wall portion 8, and a bottom wall portion 9 that connects both side wall portions 7, 8. It consists of an aluminum extruded profile formed in a substantially U-shape, and the upper ends of the inner and outer side walls 7 and 8 are unstable even if an operator tries to get on them. Such an unstable surface US1 is formed.

  The unstable surface US1 is composed of uneven portions 11 and 12 formed on the upper end portion of the inner and outer side wall portions 7 and 8, respectively, or the upper end portion of either the inner or outer side wall portion 7 or 8. That is, as can be seen from FIG. 2, the concave portions 11 and the convex portions 12 are alternately formed in the longitudinal direction on the upper end portion of the inner side wall portion 7, and the concave portions 11 and the convex portions 12 are also formed on the outer side wall portion 8. Are alternately formed in the longitudinal direction so that an operator cannot get on the step rail 4o at the upper end as much as possible.

  Further, in the unstable surface US1, the concave and convex portions 11 and 12 of the inner side wall portion 7 and the concave and convex portions 11 and 12 of the outer side wall portion 8 are opposed to each other in the concave portions 11 or the convex portions 12 in the direction crossing the step rail 4o. It is formed so as not to. This is because the concave portion 11 of the inner side wall portion 7 and the concave portion 11 of the outer side wall portion 8 do not face each other with respect to the direction crossing the step rail 4o, and the convex portion 12 of the inner side wall portion 7 and the outer side wall portion. In other words, the concave portion 11 of the inner side wall portion 7 and the convex portion 12 of the outer side wall portion 8 are opposed to each other. In other words, the convex portion 112 of the inner side wall portion 7 is formed so as to face the concave portion 11 of the outer side wall portion 8.

  As shown in FIGS. 3 (b) and 3 (c), this tram 4o has both struts so that the upper end of the inner side wall portion 7 and the upper end of the outer side wall portion 8 are positioned at the same horizontal level when the stepladder is used. 3 and 3 are attached. In order to attach the step rail 4o to the left and right support columns 3 and 3, as shown in FIGS. 3 (a) to 3 (c), the end of the step rail 4o is fitted to the upper end portion of the support column 3 and With the collar 13 fitted to the end of the cross 4o, an aluminum rivet 14 is driven into the collar 13 on the side of the step 4o from the side wall 3a side of the post 3 so that the left and right posts 3, 3 Fixed against.

  According to the ladder-supporting stepladder K having the above-described configuration, the bottom rail 4o is connected to the inner side wall 7, the outer side wall 8, and the both side walls 7, 8 by the step rail 4o at the upper end of each leg 1. 9, the upper end portions of the inner and outer side wall portions 7 and 8 are unstable even if an operator tries to get on the upper end portions of the inner and outer side wall portions 7 and 8, so that they cannot get on. Since the unstable surface US1 is formed, when using the stepladder, the worker gives up fear of getting on the treadle 4o and gives up accidents such as dropping from the top plate. It can be eliminated as much as possible.

  In particular, the unstable surface US1 is such that the concave and convex portions 11 and 12 of the inner side wall portion 7 and the concave and convex portions 11 and 12 of the outer side wall portion 8 are opposed to each other with respect to the traverse 4o. In other words, the step rail 4o at the upper end is formed so that the concave portion 11 of the inner side wall portion 7 and the convex portion 12 of the outer side wall portion 8 are opposed to each other in the direction crossing the step rail 4o. Since the concave portion 11 of the side wall portion 8 outside the convex portion 112 of the side wall portion 7 faces the concave portion 11 of the side wall portion 7, even if the operator puts his / her foot on the step rail 4o at the upper end portion of the leg 1, Since the ground cannot be grounded, it is not possible to ride on the step 4o forming the top board, and the ride on the top board is actively stopped.

  In the unstable surface US1 of this embodiment, the concavo-convex portions 11 and 12 are formed on the upper end portions of the inner and outer side wall portions 7 and 8 that form the step rail 4o, respectively. It may be formed only on the outer side wall portion 8 or only on the outer side wall portion 8.

  FIG. 4 shows an unstable surface US2 of the upper end side rail 4o of the leg 1 according to another embodiment. The unstable surface US2 has the heights of the inner and outer side walls 7, 8 when the stepladder is used. Differently, a large step 15 is formed between the side wall portions 7 and 8. In this case, in the posture when using the stepladder, the height of the outer side wall 8 is higher than the height of the inner side wall 7 in FIG. You may make it make it higher than the height of the part 8. FIG. Such an unstable surface US2 also has the same effect as the unstable surface US1 of the above-described embodiment, and even if an operator tries to get on the upper end portions of the inner and outer side wall portions 7 and 8, the step 15 As a result, the feet become extremely unstable, giving up riding, and as a result, accidents such as dropping from the top plate can be minimized.

  In the above-described embodiment, the ladder-ladder stepladder has been described, but the present invention is also applicable to a dedicated stepladder.

(a) is a side view showing the upper end portion of the ladder combined stepladder according to an embodiment of the present invention in a stepladder use state, (b) is a side view in a ladder use state, and (c) is from an arrow A in (a). The front view of the ladder-ladder stepladder K which was seen, (d) is a cross-sectional view taken along the line BB of (a). It is a perspective view which shows the step rail of the upper end part of a leg. (a) is a plan view seen from an arrow X in FIG. 1, (b) is a cross-sectional view taken along the line CC of (a), and (c) is a cross-sectional view taken along the line DD of (a). It is sectional drawing which shows the upper end side crosspiece of the ladder by other embodiment. It is a perspective view which shows the stepladder used conventionally. (a) is a partial front view of a conventional stepladder, (b) is a side view thereof, (c) is an enlarged sectional view taken along line EE of (a), and (d) is viewed from an arrow F in (b). It is a top view.

Explanation of symbols

K Stepladder 1 Leg Body 2 Rotating Bracket 3 Post 4 Foot Cross 4o Top End Step 7 Upper Side Side Side Wall 8 Upper End Side Side Side Wall 9 Upper End Step Bottom wall US1 Unstable surface 11 Recess 12 Convex US2 Unstable surface 15 Step 10K Conventional stepladder

Claims (4)

  The upper ends of a pair of front and rear legs are pivotally connected by a rotating metal fitting, and each leg is a stepladder formed by laying a step rail between a pair of left and right columns at a required interval in the vertical direction. The crosspiece at the upper end of the slab is made of a shape formed in a substantially U-shaped cross section by an inner side wall part, an outer side wall part, and a bottom wall part connecting both side wall parts. The stepladder is characterized in that the upper end portion is formed with an unstable surface that makes the feet unstable and unable to get on even if an operator tries to get on.   2. The stepladder according to claim 1, wherein the unstable surface includes an uneven portion formed at an upper end portion of each of the inner and outer side wall portions or an upper end portion of one of the inner and outer side wall portions.   In the unstable surface in which the concavo-convex portion is formed at the upper end of each of the inner and outer side wall portions, the concavo-convex portion on the inner side wall portion and the concavo-convex portion on the outer side wall portion are each a concave portion or a convex portion in the direction crossing the step rail The stepladder according to claim 2, wherein the stepladders are formed so as not to face each other.   2. The stepladder according to claim 1, wherein the unstable surface is formed by forming a large step between the both side wall portions with different heights of the inner and outer side wall portions when the stepladder is used.

Images