JP4007972B2 - How to remove a pedestal in a rivet joint structure between a support and a pedestal on a ladder - Google Patents

Description

The present invention provides a ladder which is formed by laterally placed the踏桟the appropriate intervals between a pair of posts, the rivet joint structure ladder each踏桟is riveted to the strut, from the ladder The present invention relates to a method for removing a pedestal. In addition, a ladder shall include ladder parts, such as a stepladder and a work bench | platform, besides what consists of a ladder structure as a whole.

  In manufacturing a ladder formed by horizontally laying a plurality of step bars between a pair of struts at appropriate intervals, aluminum extruded molds are generally used as struts and step bars, and both end portions of each step bar are both struts. Are joined by rivets. Thus, in the ladder in which each of the steps is rivet-bonded to the support, when one of the steps is damaged and replaced, the damaged support and the support are joined. Pull out the rivets, remove the damaged pedestals, and install new ones.

  In order to remove the rivet when replacing the pedestal as described above, the rivet head (preformed head) and the caulking head (caulked at the time of rivet joining) projecting on both sides of the column at the rivet joint If one of the heads is removed, the rivet can be removed by pulling the other head outward. For example, using a grinder or a cutter, the rivet head When the head or the caulking head is to be excised, there is a problem in that the rotating grindstone or the rotating blade hits the side of the column of the rivet joint at the stage where the head is cut off and damages the side of the column.

In the present invention, when removing the pedestal from the column, the rivet can be easily extracted from the rivet junction of the ladder so as not to damage the rivet junction on the side of the column, etc. It is to provide a method of removing a crosspiece that can easily remove the crosspiece.

Means for solving the above problems will be described with reference numerals in the embodiments described later. In the invention according to claim 1, the crosspiece 2 is horizontally mounted between the pair of columns 1 and 1 at appropriate intervals. In the rivet joining structure of the ladder A in which the pedestal 2 is rivet-bonded to the support column 1 with the ladder A formed as described above, a rivet in which a rivet head 3b is formed in advance at one end of the shaft portion 3a of the rivet 3 The shaft portion 3a is passed through the through-holes 1a and 2a of the support column 1 and the treadle 2 that are overlapped with each other, and the other end portion of the rivet shaft portion 3a is caulked to form a caulking head 3c, and the rivet head 3b A metal washer 4 is fitted into the rivet shaft 3a on the side or the caulking head 3c side, and a small hole 5 for drill guide is provided at the center of the rivet head 3b or caulking head 3c on the side where the metal washer 4 is fitted. Forming the drill The tip of the drill is engaged with the small guide hole 5, and in this state, a hole having substantially the same diameter as the rivet shaft 3a is formed coaxially so that the rivet head 3b or the caulking head 3c is connected to the rivet shaft. This relates to a method of removing the stepped bar that is cut out from 3a, withdrawing the rivet 3, and removing the stepped bar 2.

The effect of the invention by the above solution will be described with reference numerals of the embodiments described later. According to the invention according to claim 1, for example, when the damaged tram 2 is removed from the column 1 and replaced with a new one In addition, by using the drill 6 to cut out the rivet head 3b or the caulking head 3c on the side where the washer 4 is fitted, the rivet 3 can be pulled out and the step rail 2 can be removed. When the rivet head 3b or the caulking head 3c is excised, the rivet joint is protected by the washer 4 fitted to the rivet head 3b or the caulking head 3c. The crosspiece 2 is not damaged.

When drilling the rivet head 3b or the caulking head 3c with the drill 6, the drill guide small hole 5 is formed in the center of the rivet head 3b or the caulking head 3c. easy cutting edge 6a of 6 a nip and the center of the rivet head 3b or staking head 3c, thereby can be drilled coaxially, can be accurately ablate rivet head 3b or staking head 3c.

Therefore, according to the present invention, the support 1 and the traverse 2 are not damaged, and the rivet head 3b or the caulking head 3c can be cut out very easily, and the removal operation of the traverse 2 can be performed quickly. Can be done.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (a) is a front view of a ladder A having a rivet joint structure according to the present invention as viewed from the front side, and FIG. 3 is an enlarged horizontal sectional view of a portion indicated by an arrow X. FIG. 2A is an enlarged view of a portion indicated by an arrow X in FIG. 1A, and FIG. 2B is an enlarged view of the same portion as viewed from the back side of the ladder A. FIG. 3 (a) is a side view of the portion shown in FIG. 2 (a), and FIG. 3 (b) is a longitudinal side view of the same portion showing the rivet joint structure according to the present invention.

  As shown in FIG. 1 (a), this ladder A is composed of a pair of struts 1, 1 and a plurality of traversing bars 2,... As shown in FIG. 1 (b), each support column 1 is formed by an aluminum extruded mold member having a U-shaped cross section, and each crosspiece 2 is formed by a hollow aluminum extruded mold member having a trapezoidal cross section as shown in FIG. Thus, as shown in FIG. 1B, each crosspiece 2 is fitted with a rivet 3 with both end portions thereof fitted into a column 1 having a U-shaped cross section.

The rivet joint structure in which the ladder 2 of the ladder A is rivet-joined to the column 1 is shown in FIG.
As can be seen from the drawing, the rivet shaft portion 3a is overlapped with each other in a state in which the metal washer 4 is fitted to the base portion of the rivet head 3b formed in advance on one end portion of the shaft portion 3a of the rivet 3. A caulking head 3c is formed by penetrating through the through holes 1a and 2a of the column 1 and the traversing rail 2 and caulking the other end of the rivet shaft 3a with a riveter (caulking device) (not shown). is there.

  In this case, a drill guide small hole 5 is formed at the center of a rivet head 3b formed in advance at one end of the rivet shaft 3a, as can be seen from FIGS. 2 (a) and 3 (b). Is formed. As will be described later, the small hole 5 is formed so that when the rivet head 3b is drilled by the drill 6 in order to remove the rivet 3 when the step rail 2 is removed from the column 1, the cutting edge 6a of the drill 6 is placed at the center of the rivet head 3b. It is intended to be able to perforate precisely and thereby to be able to drill precisely in a coaxial manner.

  The rivet 3 is formed of a suitable metal material such as steel, iron, or aluminum. The washer 4 is a flat washer formed of a suitable metal material such as steel, iron, or aluminum.

  In the ladder A in which each step rail 2 is fixed by rivet bonding to the column 1 as described above, if one of the step rails 2 is damaged and the step rail 2 needs to be replaced, it is damaged. The rivet 3 joining the step rail 2 and the column 1 is pulled out, the damaged step rail 2 is removed, and a new step rail 2 is attached. A method of removing the step rail 2 in this case will be described with reference to FIG.

  First, as shown in FIG. 4 (a), of the rivet head portion 3b and the caulking head portion 3c at both ends of the rivet shaft portion 3a of the rivet 3 that joins the traverse 2 and the support column 1, the metal A portable electric drill 6 is coaxially opposed to the rivet 3 on the rivet head 3b on the side where the washer 4 is fitted, and the tip of the cutting edge 6a of the drill 6 is riveted as shown in FIG. It engages with a small hole 5 for drill guide formed at the center of the head 3b. In this case, the drill 6 can drill a hole having the same diameter as or slightly larger than the outer diameter of the rivet shaft portion 3a. This is because the rivet head 3b cannot be separated if the diameter of the hole to be drilled is smaller than the rivet shaft 3a.

  In this manner, the drill 6 is rotated in a state where the tip of the cutting edge portion 6a of the drill 6 is engaged with the drill guide small hole 5 of the rivet head 3b, and as shown in FIG. 4 (c), the rivet head 3b. Then, a hole 7 having the same diameter as the rivet shaft portion 3a is drilled. When the hole 7 is drilled in the rivet head 3b as shown in (c) of the figure, the rivet head 3b is separated from the rivet shaft 3a as shown in (d) of the figure. In this state, the caulking head 3c opposite to the rivet head 3b separated from the rivet shaft portion 3a in this state is pulled outward, and the rivet 3 is inserted into the through holes 1a and 2a of the column 1 and the traverse 2 By pulling it out of the rail, the step rail 2 can be removed from the column 1.

  When the hole 7 is drilled in the rivet head 3b by the drill 6 as described above, the hole 7 penetrates the rivet head 3b and the rivet head 3b is separated from the rivet shaft portion 3a. Since the blade edge portion 6a protrudes into the rivet shaft portion 3a, unless the washer 4 is fitted into the base portion of the rivet head 3b, the through-hole 1a of the support column 1 is deeply scraped off and the support column 1 side is damaged. However, since the washer 4 is fitted on the rivet head 3b side of the rivet shaft portion 3a, the cutting edge portion 6a of the drill 6 bites into the washer 4 after the hole 7 of the rivet head 3b has been drilled. Therefore, if the rotation of the drill 6 is stopped at this stage, even if the washer 4 is damaged, the support 1 is not damaged.

  FIG. 5 (a) shows a structure in which the ladder 2 of the ladder A is rivet-bonded to the column 1 in the same manner as the rivet-bonding structure shown in FIG. 3 (a). In this rivet joint structure, a rivet shaft portion 3a having a rivet head 3b formed in advance at one end is passed through the through-holes 1a and 2a of the strut 1 and the treadle 2 overlapped with each other. A caulking head 3c is formed by caulking the other end of the rivet shaft 3a with a similar metal washer 4 fitted into the other end of 3a.

  Also in this case, a small hole 5 for drill guide is formed at the center of the caulking head 3c formed by caulking the other end of the rivet shaft 3a.

  In the case of the ladder A having the rivet joint structure shown in FIG. 5 (a) as described above, when it is necessary to replace one of the step rails 2, the rivet 3 that joins the step rail 2 and the column 1 to each other. 4 is coaxial with the rivet 3 on the caulking head 3c on the side where the metal washer 4 is fitted, of the rivet head 3b and the caulking head 3c at both ends of the rivet shaft 3a. The tip of the drill blade tip 6a is engaged with a small hole 5 for drill guide formed at the center of the rivet head 3c. In this state, the drill 6 is rotated, and holes 7 having the same diameter as or slightly larger than the rivet shaft head 3a are drilled in the caulking head 3c as shown in FIG. 5 (b). When the hole 7 has been drilled, the caulking head 3c is separated from the rivet shaft 3a. In this state, the rivet 3 is placed on the side opposite to the separated caulking head 3c. By pulling it toward the head 3 b and pulling it out from the through holes 1 a and 2 a of the support column 1 and the tread bar 2, the tread bar 2 can be removed from the support column 1.

  Also in this case, when the hole 7 is drilled in the caulking head 3c with the drill 6, the cutting edge of the drill 6 is in a state where the hole 7 penetrates the caulking head 3c and the caulking head 3c is separated from the rivet shaft 3a. Since the portion 6a protrudes into the rivet shaft portion 3a, unless the washer 4 is fitted into the base portion of the caulking head 3c, the through-hole 1a of the post 1 is deeply scraped off and the post 1 side is damaged. However, since the washer 4 is fitted to the caulking head 3c side to be drilled, the cutting edge portion 6a of the drill 6 bites into the washer 4 after the hole 7 of the caulking head 3c has been drilled. Since the rotation of the drill 6 can be stopped at this stage, the support column 1 is not damaged.

  In the embodiment described above, the electric drill 6 is used to cut the rivet head 3b or the caulking head 3c on the side where the washer 4 is fitted, and the hole 7 having the same diameter as the rivet shaft portion 3a is formed. The method of drilling coaxially has been described. However, in order to cut the rivet head 3b or the caulking head 3c from the rivet shaft portion 3a, not only the above-described drilling method but also an electric cutter, a grinder, a sander, or the like is used. The rivet head 3b or the caulking head 3c may be cut or scraped off. However, as shown in this embodiment, according to the method in which a hole having substantially the same diameter as the rivet shaft portion 3a is coaxially drilled by the electric drill 6, the rivet head 3b or the caulking head 3c is cut off very easily. Therefore, it is possible to quickly remove the step rail 2.

(a) is the front view which looked at the ladder of the stepladder which has a rivet joining structure of this invention from the front side, (b) is the expanded horizontal sectional view of the part shown by the arrow X of (a). (a) is the enlarged view of the part shown by the arrow X of (a) of FIG. 1, (b) is the enlarged view which looked at the part from the back side of the ladder. FIG. 2A is a side view of the portion shown in FIG. 2A, and FIG. 2B is a longitudinal side view of the portion showing a rivet joint structure according to the present invention. (a)-(d) is explanatory drawing explaining the removal method of the crosspiece which concerns on this invention. (a) is a longitudinal side view showing another embodiment of the rivet joint structure according to the present invention, and (b) is an enlarged view for explaining a method for removing the ladder crosspiece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support | pillar 1a Through-hole 2 Foot cross 2a Through-hole 3 Rivet 3a Rivet shaft part 3b Rivet head part 3c Caulking head 4 Washer 5 Small hole 6 for drill guidance Drill 7 hole

Claims (1)

In a ladder rivet joint structure in which a step rail is horizontally mounted between a pair of struts at appropriate intervals, and the step rail is rivet-bonded to the strut, a rivet is preliminarily attached to one end of the shaft portion of the rivet. The rivet shaft portion on which the head is formed is passed through the through-holes of the struts and the treads that overlap each other, and the other end portion of the rivet shaft portion is caulked to form a caulking head, and the rivet head side or A metal washer is fitted into the rivet shaft on the caulking head side, and a small hole for drill guidance is formed in the center of the rivet head or caulking head on the side where the metal washer is fitted, The tip of the drill is engaged with the small hole, and in this state, a hole having the same diameter as the rivet shaft is formed coaxially, so that the rivet head or caulking head is cut off from the rivet shaft and the rivet is pulled. Without ,踏桟removal method of which is to remove the踏桟.

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