JP3181963U - Ladder or stepladder with auxiliary legs - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively and inexpensively lock an auxiliary leg made of a square pillar or the like slidably inserted inside a fixed leg made of a circular pipe while preventing rotation around an axis at any lift position. Provide ladders or stepladders with extra support legs.
A side surface of a fixed leg 11 is pressed and deformed to form a flat surface portion 11a, and an auxiliary leg 12 is inserted between the flat surface portion and the inner surface of the fixed leg. After the enlarged diameter portion 33b provided at the tip of the bolt 33 is slidably inserted into the internal space 34a of the brake pad 34 together with the washer 36, the edge of the opening 34b in the internal space is reduced in diameter. A bolt 33 is screwed into a knurled nut 35 provided on the bolt support portion 31, and a brake pad 34 is slidably inserted into an opening hole 11 b provided in the fixed leg 11, and this bolt support portion is attached to the outer surface of the fixed leg. Weld.
[Selection] Figure 4

Description

  The present invention relates to a ladder or a stepladder with an auxiliary leg capable of adjusting a leg length, and more particularly to a ladder or a stepladder in which an auxiliary leg made of a quadrangular column or a square pipe is attached to a fixed leg made of a circular pipe.

  Conventionally, ladders and stepladders have been proposed in which auxiliary legs that can be raised and lowered are provided on fixed legs, and the lengths of the left and right legs can be changed. As such a ladder or stepladder, an auxiliary leg made of a square pole is slidably inserted inside a fixed leg made of a square pipe, and a pin is inserted into a through-hole provided at each predetermined interval to insert the auxiliary leg of the auxiliary leg. There is one that adjusts the elevation height (for example, see Patent Document 1). Further, an auxiliary leg having a U-shaped cross section is slidably fitted to an outer surface of a fixed leg having a U-shaped cross section, and through an opening hole provided at a predetermined interval in the auxiliary leg. In some cases, the height of the auxiliary leg is adjusted by screwing a screw into a screw hole screwed into the fixed leg at predetermined intervals (see, for example, Patent Document 2).

  Furthermore, a slide auxiliary leg made of a square pole is slidably inserted inside the fixed leg made of a square pipe, and the slide leg provided in parallel to the slide auxiliary leg is engaged with a step of the fixed leg by a hook. In some cases, the height of the slide leg is adjusted (for example, see Patent Document 3). In addition, a cylindrical auxiliary leg is slidably inserted into a circular hole provided in the locking plate, and the circular plate is opened at an arbitrary height by tilting the locking plate diagonally with a spring force. There has been proposed a structure in which an edge is crimped to the outer periphery of a cylindrical auxiliary leg and the auxiliary leg is locked to the locking plate (see, for example, Patent Document 4).

  In addition, a guide with a U-shaped cross section is provided inside the fixed leg made of a square pipe, and an auxiliary leg made of a square pole is slidably inserted into the guide, and a thumbscrew is inserted into a screw hole screwed into the guide. , And the tip of the thumbscrew is crimped to the outer surface of the auxiliary leg to lock the auxiliary leg at an arbitrary height position (see, for example, Patent Document 5).

Japanese Utility Model Publication No. 61-098199 JP 07-259461 A Actual No. 3076713 Japanese Utility Model Publication No. 04-055998 JP 2006-328855 A

  However, in the ladders and stepladders described in Patent Documents 1 to 3, since the auxiliary legs are locked at predetermined intervals, the raising / lowering position of the auxiliary legs cannot be adjusted steplessly. Therefore, when installing on an inclined ground or the like, it is difficult to install the ladder or stepladder so as not to tilt in the left-right direction in accordance with the inclination angle of the ground or the like.

  Further, in the structure described in Patent Document 4, the raising / lowering position of the auxiliary leg can be adjusted steplessly, but the opening edge of the circular hole provided in the locking plate is strongly pressure-bonded to the outer peripheral surface of the auxiliary leg. The auxiliary leg is easily damaged at the crimping point, and the opening edge of the circular hole is easily worn out. If the auxiliary leg is damaged, not only the view is deteriorated, but also when changing the raising / lowering position of the auxiliary leg, the opening edge of the circular hole is caught by this scratch, and it becomes difficult to slide the auxiliary leg. Further, if the opening edge of the circular hole is worn out, the auxiliary leg becomes slippery, which may cause the ladder or the like to fall over. Further, when changing the raising / lowering position, the columnar auxiliary leg freely rotates around the axis. However, when the auxiliary leg rotates, when a non-slip spike or the like is provided obliquely at the lower end of the auxiliary leg, it becomes difficult to install the spike or the like so as to be substantially perpendicular to the ground.

  Further, in the structure described in Patent Document 5, a guide having a U-shaped cross section is provided inside a fixed leg made of a square pipe, and an auxiliary leg made of a square pipe is slidably inserted into the guide. If both the fixed leg and the auxiliary leg are formed of square pipes as described above, it is advantageous in the following points. That is, when the auxiliary leg is slidably inserted inside the fixed leg, the auxiliary leg does not rotate around the axis inside the fixed leg. For this reason, when the anti-slip spike or the like as described above is obliquely provided at the tip of the auxiliary leg, it is possible to prevent the fixed leg from rotating and deviating from an angle at which the spike or the like is substantially perpendicular to the ground. . Further, when the auxiliary leg is pressed with a screw or the like, the outer surface of the auxiliary leg and the inner surface of the fixed leg are pressed against each other by a flat surface, so that it becomes difficult to slip and the pressed surface is hard to wear out.

  However, when the cross-sectional shape of the fixed leg is a square, when the ladder or stepladder is carried or lifted, the square corner hits and feels pain when held by hand. For this reason, there is a strong demand from orchards and the like that the legs should be round pipes. However, if a circular pipe is used for the fixed leg, the advantages of the fixed leg composed of the square pipe described above are lost. For this reason, the inventor fixed a rectangular flat plate with screws on the inner surface of a fixed leg made of a circular pipe, and slidably inserted an auxiliary leg made of a square pole between the flat plate and the inner surface of the circular pipe. I tried a means to do. That is, the advantage of the fixed leg made of the above-described square pipe is that the flat plate becomes a pedestal for the auxiliary leg made of the square pillar, and the auxiliary leg made of the square pillar is pressed on the flat plate with a screw screwed to the fixed leg. Turned out to be able to get back.

  However, a structure in which a rectangular flat plate is fixed with screws on the inner surface of a fixed leg made of a circular pipe increases the manufacturing cost. Further, in order to prevent the flat plate from being deformed when the auxiliary leg is pressed against the flat plate with a screw, it is necessary to increase the thickness and length of the flat plate to some extent and increase the weight. Furthermore, it is not always easy to fix the flat plate with high accuracy so as to be parallel to the axis of the circular pipe. When the flat plate is fixed in an inclined state, the flat plate and the auxiliary leg are in surface contact with each other. It becomes difficult, it becomes slippery and wear easily occurs.

  Therefore, the purpose of the present invention is to be able to securely lock the auxiliary leg made of a square pillar or a square pipe slidably inserted inside the fixed leg made of a circular pipe while preventing rotation at any lift position. The object is to provide an inexpensive and lightweight ladder or stepladder with auxiliary legs.

  In order to solve the above-described problems, a ladder or a stepladder with an auxiliary leg according to the present invention has the following characteristics. That is, the fixed leg is formed of a circular pipe and the auxiliary leg is formed of a quadrangular column or a quadrangular pipe. Further, a locking means for locking the auxiliary leg to the fixed leg is provided. A flat portion is formed on the fixed leg by pressing and deforming the side surface of the circular pipe flatly inward. The auxiliary leg is slidably inserted between a flat part formed on the fixed leg and an inner side surface of the fixed leg facing the flat part. The locking means includes a bolt support portion provided at a location facing the flat portion on the outer surface of the fixed leg, and a bolt that is screwed into a female screw provided on the bolt support portion. Then, by screwing the bolt into the female screw, the tip of the bolt presses the auxiliary leg and comes into pressure contact with the flat portion formed on the fixed leg.

  Here, the “circular pipe” means a hollow tube having a circular cross section, and the material is preferably aluminum, but other metals such as magnesium and duralumin are also included. “Fixed leg” means the original leg that constitutes the ladder or stepladder. In the ladder, the left and right two legs, in the stepladder, the front and rear and left and right four legs, or the front left and right two legs and the rear One leg in the center of the side corresponds. “Square column” means a solid bar having a square or rectangular cross section, and the material includes a material equivalent to a fixed leg. “Rectangular pipe” means a hollow tube having a square or rectangular cross section, and includes materials equivalent to fixed legs. “Auxiliary leg” means a leg that is attached to all or at least one of the above-described ladder or stepladder fixed legs so as to be movable up and down.

  The “flat portion deformed by pressing flatly” means a portion having a predetermined length and width formed by denting one outer surface of a circular pipe of a fixed leg with a press jig or the like. . It is desirable that two “plane portions” be provided on one fixed leg with a predetermined length interval, but also includes cases where there are one or three or more locations. In the “bolt support part”, for example, an opening hole through which the bolt penetrates is formed in the side surface of the fixed leg, and the bracket is fixed to the fixed leg by welding or the like so as to cover the opening hole, or directly to the opening hole by welding or the like. Applicable to fixed nuts.

  The above-described ladder or stepladder with auxiliary legs is preferably configured as follows. That is, an opening hole is provided on a side surface of the fixed leg that faces the flat portion. The locking means includes a brake pad that is slidably inserted into an opening hole provided in a side surface of the fixed leg. The female screw is provided at a portion of the bolt support portion that faces the opening hole with a certain distance. Then, the tip of the bolt is pressed against the auxiliary leg through the brake pad.

  Here, the shape of the “brake pad” corresponds to, for example, a cylindrical shape having a circular cross section, a square shape or a polygonal shape, and the material corresponds to, for example, aluminum or stainless steel or iron. “With a brake pad” means that the tip of the bolt is pressed against one end surface of the brake pad or the bottom surface of the internal space that opens to one end surface of the brake pad, and the other end surface of the brake pad The case where it press-contacts to the plane part formed in the fixed leg corresponds. In order to prevent the brake pad from dropping into the fixed leg when the auxiliary leg is removed from the fixed leg, it is desirable to connect the tip of the bolt to one end surface of the brake pad with a wire or the like.

  Furthermore, it is desirable to configure the ladder or stepladder with auxiliary legs as described above as follows. That is, an enlarged diameter portion is provided at the tip of the bolt. An internal space that opens to one end surface of the brake pad is formed inside the brake pad. The enlarged diameter portion provided at the tip of the bolt is slidably inserted into the internal space formed in the brake pad. A locking portion is provided at the opening where the internal space is open to prevent the enlarged diameter portion provided at the tip of the bolt from coming out.

  As used herein, the term “expanded portion” means a portion having a diameter larger than the male screw diameter provided at the tip of the bolt, and a hemispherical shape is desirable. Also includes trapezoids. The “internal space” is preferably a cylindrical space, but also includes a quadrangular columnar space or a polygonal columnar space. As described later, in the “locking portion”, after the diameter-expanded portion is slidably inserted into the internal space formed in the brake pad, the diameter of the edge of the opening where the internal space opens is reduced, For example, a flat plate having a through hole slightly larger than the outer diameter of the male screw of the bolt is divided into two at a surface passing through the center of the through hole, and divided into two at a position above the enlarged diameter portion provided at the tip of the bolt. This includes a case where the flat plate is fixed to the brake pad with welding or a screw in a state where the bolt is sandwiched from the left and right by the through hole of the flat plate.

  More preferably, in the bolt described above, an insertable washer is inserted into the inner space formed in the brake pad at the upper portion of the enlarged diameter portion, and the locking provided in the opening portion where the inner space of the brake pad opens. The portion is formed by inserting the enlarged diameter portion and the washer provided at the tip of the bolt into the internal space and then reducing the diameter of the edge of the opening.

  More preferably, the above-mentioned enlarged diameter portion provided at the tip of the bolt is formed in a hemispherical shape, the washer inserted into the bolt is formed into a disk shape, and the brake pad is concentric with the cylindrical inner space inside the cylinder. The opening hole provided in the fixed leg is formed in a circular hole.

  By forming the fixed leg by the circular pipe, it is possible to prevent the hand holding the fixed leg from being painful when carrying the ladder or the stepladder or when moving up and down. By inserting an auxiliary leg formed of a square pole or a square pipe slidably between a flat part formed on the fixed leg and an inner surface of the fixed leg facing the flat part, Since the parts can be pressed against each other on a flat surface, rotation of the auxiliary leg around the axis can be reliably prevented. In addition, since the auxiliary leg is surrounded by a cylindrical outer wall of the fixed leg having a predetermined axial length over a predetermined length, the structure is extremely strong against a lateral load.

  Here, the flat part is formed by pressing and deforming the side surface of the circular pipe of the fixed leg flat inward, so that no other parts are required for forming the flat part, and the production cost is accordingly reduced. Reduction and weight reduction can be achieved. Further, the flat portion can be easily and accurately formed so as to be parallel to the central axis of the fixed leg. Therefore, the outer peripheral surface of the auxiliary leg can be pressed against the flat portion so as to be in contact with each other in parallel. For this reason, the auxiliary leg can be more reliably locked to the flat surface portion, and it is possible to suppress the occurrence of scratches, abrasion, or the like on the pressure contact surface.

  Furthermore, since the flat portion can be formed continuously and integrally with the circular pipe, the strength and rigidity are extremely high, and it is possible to prevent the locked auxiliary leg from being shaken or displaced. In addition, since the length and width of the flat part can be easily increased, the pressure contact surface with the auxiliary leg can be widened, whereby the auxiliary leg can be more securely locked to the flat part and the pressure contact surface can be damaged. It is possible to suppress the occurrence of wear and the like.

  By pressing the tip of the bolt against the auxiliary leg via the brake pad, it is possible to prevent scratching or abrasion of the pressing surface of the auxiliary leg, which is likely to occur when the tip of the bolt directly presses the auxiliary leg. For this reason, it can avoid that the view of an auxiliary leg worsens. Further, since the auxiliary leg is pressed with a large area via the brake pad, the auxiliary leg can be more reliably locked. By inserting the brake pad into the opening hole provided on the side of the fixed leg in a freely swingable manner, the brake pad can always be brought into pressure contact with the outer surface of the auxiliary leg in a flat contact with each other, and the brake pad is fixed. It is possible to prevent the leg from moving and dropping in the length direction and the width direction.

  By providing an enlarged diameter part at the tip of the bolt, forming an internal space that opens at one end face of the brake pad inside the brake pad, and inserting the enlarged diameter part into the internal space so that the bolt can be freely moved. The brake pad can be prevented from coming off from the tip in the lateral direction. By providing a locking part to prevent the enlarged diameter part provided at the tip of the bolt from coming out at the opening where the internal space opens, when the auxiliary leg is removed from the fixed leg, the brake pad is It is possible to prevent the bolt from coming off in the axial direction and falling into the fixed leg. By providing the enlarged diameter portion at the tip of the bolt, it becomes easy to form a locking portion that prevents the tip of the bolt from coming off at the opening.

  Insert a washer that can be inserted into the inner space formed in the brake pad at the upper part of the bolt's enlarged diameter part, insert the enlarged diameter part and the washer into the inner space, and then reduce the edge of the opening. First, the locking part can be easily formed. Second, even if the degree of diameter reduction is small, the brake pad can be prevented from falling off from the tip of the bolt in the axial direction of the bolt.

  Bolt tip diameter-enlarged part is formed in a hemispherical shape, washer is formed in a disk shape, brake pad is formed in a cylindrical inner space concentrically inside the cylinder, and an opening provided in the fixed leg By making the hole into a circular hole, these parts and parts can be easily manufactured, and the edge of the opening of the brake pad can be more easily reduced in diameter.

It is a front view of a stepladder. It is a side view of a stepladder. It is a side view of the latching means which latches an auxiliary leg to a fixed leg. It is front sectional drawing of the latching means which latches an auxiliary leg to a fixed leg. It is a side view of the other latching means which latches an auxiliary leg to a fixed leg. It is front sectional drawing of the other latching means which latches an auxiliary leg to a fixed leg. It is side sectional drawing of the other latching means which latches an auxiliary leg to a fixed leg. It is a top view of the other latching means which latches an auxiliary leg to a fixed leg. It is side sectional drawing of another latching means. It is a front view of another latching means. It is side sectional drawing of the front-end | tip part of an auxiliary leg.

  The structure of a ladder or stepladder with auxiliary legs according to the present invention will be described with reference to FIGS. 1 to 4 by taking a stepladder having three legs as an example. As shown in FIGS. 1 and 2, the stepladder with auxiliary legs according to the present invention has two left and right legs 1 and 1 on the near side and one leg 2 on the center on the rear side. . The three legs 1, 1, 2 are fixed legs 11, 11, 21 each formed by a circular pipe, and auxiliary legs 12, 12 formed by square pillars attached to lower portions of these fixed legs, respectively. , 22 and locking means 3, 3, 3 for locking these auxiliary legs to each other.

  The left and right fixed legs 11, 11 on the front side are configured such that the upper half is opened in parallel and the lower half is opened left and right. The steps 4a, 4b, 4c, 4d, and 4e are arranged in five steps at almost equal intervals. However, both ends thereof are fixed by welding. The upper ends of the left and right fixed legs 11, 11 are fixed to both side surfaces on the front side of the top plate part 5 by welding. Furthermore, the tip of the fixed leg 21 is attached to the center of the rear end of the top plate 5 so as to be rotatable in the front-rear direction. One end of the chain 6 is connected to the center of the uppermost step 4a, and the other end can be locked to a locking hole of the rear fixed leg 21 with a hook (not shown). Yes.

  Further, at the lower ends of the auxiliary legs 12, 12, 22, non-slip disks 7, 7, 7 are provided so that their central axes are vertical. Note that the fixed legs 11 and the like, the auxiliary legs 12 and the like, the step 4a and the like, the top plate 5 and the anti-slip disc 7 are all made of aluminum.

  Next, referring to FIG. 3 and FIG. 4, one of the three legs 1, 1, 2 is taken as an example, and the auxiliary leg 12 is attached to the fixed leg 11 so as to be movable up and down. The structure which latches in the raising / lowering position is demonstrated. The other legs 1 and 2 have the same configuration. As shown in FIGS. 1 to 4, at the lower part of the fixed leg 11, there are two flat portions 11a obtained by pressing and deforming the side surface of the circular pipe inwardly at two points spaced apart by a predetermined axial distance. It is formed. The auxiliary leg 12 is slidably inserted between a flat portion 11a formed at two positions on the fixed leg 11 and an inner surface of the fixed leg facing the flat portion.

  The flat surface portion 11a sandwiches the fixed leg between a jig having flat surfaces facing each other and a jig having an arc concave cross section that fits to the cylindrical outer surface of the fixed leg 11, and slowly narrows the distance therebetween. In this way, it is molded.

  As shown in FIGS. 3 and 4, the locking means 3 includes a bolt support portion 31 provided at a position facing the flat portion 11 a on the outer surface of the fixed leg 11, and a female screw provided on the bolt support portion. And a brake pad 34 slidably coupled to the tip of the bolt.

  The bolt support part 31 forms an aluminum plate in a U-shaped cross-sectional shape, and fixes the lower ends of both side walls to the outer surface of the fixed leg 11 by welding. A through hole is opened at the center of the U-shaped cross section of the bolt support portion 31, and a knurled nut 35 having a female screw 32 is inserted and fixed in the through hole. Further, guide plates 37 made of aluminum flat plates are fixed inside the both side walls of the bolt support portion 31 by welding. The guide plate 37 has a circular hole into which a later-described columnar brake pad 34 is slidably inserted.

  By providing a guide plate 37 on the bolt support portion 31 and inserting a columnar brake pad 34 into a circular hole opening in the guide plate so as to be freely slidable, lateral displacement of the brake pad can be reliably prevented. As a result, it is possible to reliably avoid the brake pad 34 riding on the opening hole 11 b provided on the side surface of the fixed leg 11.

  A hemispherical enlarged diameter portion 33 b is integrally provided at the tip of the male screw 33 a of the bolt 33. Further, a disc-shaped washer 36 made of aluminum is inserted in a freely swingable manner with the bolt 33 above the enlarged diameter portion 33b, that is, in the male screw 33a connected to the enlarged diameter portion. The other end of the male screw 33a of the bolt 33 is screwed into a female screw threaded at the center of the handle 33c, and both are soldered to prevent rotation.

  The brake pad 34 has a cylindrical shape made of an aluminum material, and a cylindrical inner space 34a that opens to one end face of the brake pad is formed concentrically on the inner side. An enlarged diameter portion 33 b provided at the tip of the bolt 33 is inserted into the cylindrical inner space 34 a together with the washer 36. The depth of the cylindrical inner space 34a is slightly larger than the combined thickness of the enlarged diameter portion 33b provided at the tip of the bolt 33 and the washer 36, for example, about 5 mm, and the inner diameter is The outer diameter of the washer 36 is slightly larger, for example, about 0.3 mm. Moreover, the thickness of the surrounding wall of the cylindrical internal space 34a is formed around 2 mm. The bottom surface of the cylindrical inner space 34a is formed in a flat shape, but may be formed in a conical shape or a spherical shape.

  An opening hole 11b made of a circular hole is provided on the side surface of the fixed leg 11 facing the flat surface portion 11a. The inner diameter of the opening hole is such that the columnar brake pad 34 can be freely inserted. Furthermore, the outer diameter of the brake pad is slightly larger, for example, about 2 mm.

  Next, the procedure for assembling the locking means 3 will be described with an example. A washer 36 is inserted into the male thread 33a of the bolt 33 provided with a hemispherical enlarged portion 33b at the tip from the other end opposite to the enlarged portion. Next, the enlarged diameter portion 33b of the bolt 33 is inserted into the cylindrical inner space 34a of the brake pad 34 together with the washer 36, the edge of the opening 34b of the cylindrical inner space is reduced in diameter, and this washer falls off. Do not. Note that this diameter reduction is achieved by pressing a jig having a cylindrical inner space whose tip is expanded conically against one end surface of the brake pad 34, so that the thin peripheral wall of the opening 34b opening on the one end surface faces inward. Deform. Next, the female screw 32 of the knurled nut 35 is screwed into the male screw 33a of the bolt 33 from the other end opposite to the enlarged diameter portion 33b.

  Next, the brake pad 34 slidably attached to the enlarged diameter portion 33 b of the bolt 33 is inserted into an opening hole opened in the guide plate 37 provided in the bolt support portion 31, and the through hole opened in this bolt support portion Then, a knurled nut 35 screwed into the bolt is press-fitted and fixed. A brake pad 34 slidably connected to the tip of the bolt 33 is inserted into an opening hole 11b provided on a side surface of the fixed leg 11 and opposed to the flat surface portion 11a to support a bolt having a U-shaped cross section. The lower ends of both side surfaces of the portion 31 are fixed to the outer surface of the fixed leg by welding. Finally, the handle 33c is screwed to the other end of the male screw 33a of the bolt 33, and both are soldered to prevent rotation. In this way, the locking means 3 is attached to the fixed leg 11.

  After the locking means 3 is mounted on the fixed leg 11, the handle 33 c is turned and the bolt 33 is pulled outward to increase the distance between the pressing surface 34 c of the brake pad 34 and the flat portion 11 a of the fixed leg 11. The auxiliary leg 12 can be inserted between the two. When the handle 33c is turned in the opposite direction to push the bolt 33 back inward, the tip of the bolt presses the bottom surface of the internal space 34a of the brake pad 34, and the pressing surface of the brake pad pushes the auxiliary leg 12 down. The auxiliary leg is pressed against the flat surface portion 11a of the fixed leg 11, and the auxiliary leg is locked to the fixed leg.

  As described above, when using a stepladder with an auxiliary leg according to the present invention, the handle 33c of the bolt 33 is loosened, the auxiliary leg 12 is slid to a predetermined elevation position, and the bolt is screwed by this handle at the elevation position. Thus, the auxiliary leg is locked to the fixed leg 11.

  Next, another embodiment of the locking means for locking the auxiliary leg to the fixed leg will be described with reference to FIGS. The locking means 103 shown in FIG. 5 opens a through hole at a position facing the flat surface portion 111a in the fixed leg 111, and a nut 108 is directly fixed to the through hole by welding, and a male screw 133a of a bolt 133 is fixed to the nut. Are screwed together. The tip 133 d of the bolt 133 is formed in a hemispherical shape, and the hemispherical tip is directly pressed against the auxiliary leg 112, and the auxiliary leg is pressed against the flat portion 111 a of the fixed leg 111 and locked.

  Next, the locking means 203 shown in FIG. 6 is different from the locking means 3 shown in FIG. 4 in that the mounting direction of the knurled nut 235 provided on the bolt support portion 231 is reversed, and the tip of the knurled nut is the brake pad. 234 is slidably inserted into a cylindrical inner space 234a, the diameter of the bolt 233 is not formed, the washer 36 is not provided, and the brake pad is provided. The difference is that the edge of the opening of the internal space is not reduced in diameter. In order to prevent the auxiliary leg 212 from falling off the fixed leg 211, for example, a leaf spring as will be described later is provided at the tip of the auxiliary leg.

  If the locking means 203 is configured in this way, it is necessary to reduce the diameter of the opening of the brake pad 234 or to form the enlarged diameter portion at the tip of the bolt 233 as shown in FIGS. The manufacturing cost can be reduced. Further, since the male screw 233a of the bolt 233 is covered with the knurled nut 235 between the bolt support portion 231 and the one end surface of the brake pad 234, the appearance is improved. As described above, since the means for preventing the auxiliary leg 212 from falling off the fixed leg 211 is provided, the brake pad 234 does not fall into the fixed leg.

  If the appearance does not matter, it is not necessary to insert the tip of the knurled nut 235 into the cylindrical inner space 234a provided in the brake pad 234, and further, the bolt can be provided without providing an inner space in the brake pad. The tip of 233 can also be configured to press one end surface of the brake pad.

  Next, the locking means 303 shown in FIGS. 7 and 8 is configured by connecting the tip 333 d of the bolt 333 to one end face of the brake pad 334 with a wire 338. That is, as shown in FIGS. 3 and 4, the locking means 303 includes a bolt support portion 331 having a U-shaped cross section provided at a position facing the flat portion 311 a on the outer surface of the fixed leg 311 at 180 degrees. And a bolt 333 screwed into a female screw 332 of a knurled nut provided in the bolt support portion, and a brake pad 334 slidably connected to the tip of the bolt.

  A tip 333d of the male screw 333a of the bolt 333 is formed in a hemispherical shape, and a through hole 333e perpendicular to the axis is provided in the vicinity of the tip. The brake pad 334 has a cylindrical shape, and a spherical concave portion 334e is formed on one end surface thereof, and protruding portions 334d having through holes project from both sides centering on the concave portion. .

  Next, the assembly procedure of the locking means 303 described above will be described. That is, with the spherical tip of the bolt 333 in contact with the recess 334e formed on one end surface of the brake pad 334, the wire 337 is passed through the through hole 333e provided in the vicinity of the tip of the bolt. Both ends are wound around a through hole provided in a projection 334d projecting from the brake pad and soldered. Next, the bolt 333 is screwed into a female screw 332 of a knurled nut provided on the bolt support portion 331. Then, a brake pad 334 slidably connected to the tip of the bolt 333 by a wire 338 is slidably inserted into an opening hole 311 b provided on a side surface of the fixed leg 311 and opposed to the flat surface portion 311 a to support the bolt. The part 331 is fixed to the outer surface of the fixed leg by welding.

  Next, the locking means 403 shown in FIG. 9 and FIG. 10 inserts a hemispherical enlarged diameter portion 433 a provided at the tip of the bolt 433 into a cylindrical inner space 434 a provided in the brake pad 434 so as to be freely slidable. Next, a flat plate 439 having a through hole 438a slightly larger than the outer diameter of the male screw 433a of the bolt 433 is divided into two by a surface 439b passing through the center of the through hole. Then, at a position above the hemispherical enlarged portion 433a provided at the tip of the bolt 433, four bolts are mounted on the brake pad in a state where the bolt is sandwiched from the left and right by the through holes 439a of the flat plate 439 divided into two. Fix with screws. Other parts are the same as those shown in FIGS.

  Finally, referring to FIG. 11, an example of means for preventing the auxiliary leg inserted into the fixed leg from falling off the fixed leg is shown. The locking means shown in FIG. 11 uses a locking means 503 equivalent to the locking means 3 shown in FIGS. 3 and 4 as a representative means. However, a groove 512a is formed along the axial center on the outer surface of the tip of the auxiliary leg 512, and a leaf spring 519 is provided in the groove. That is, as shown in FIG. 11, the leaf spring 519 has a side cross section similar to the side cross section of the tip end portion of the spoon, and the handle portion is a screw (not shown) near the rear wall of the groove 512a. Etc.) etc.

  When the auxiliary leg 512 is inserted into the fixed leg 511, the curved portion of the leaf spring 519 is pushed and bent at the entrance of the flat portion 511a formed on the fixed leg, and is stored in the groove 512a. The leaf spring passes through the flat portion while sliding. And if the leaf | plate spring 519 passes the plane part 511a, this leaf | plate spring will protrude again from the inside of the groove | channel 512a. Accordingly, when the auxiliary leg 512 is to be pulled out of the fixed leg 511, the leaf spring 519 comes into contact with the outlet portion of the flat portion 511a, and this leaf spring acts as a brake to prevent the auxiliary leg from falling off the fixed leg. If the auxiliary leg 512 is pulled strongly, the leaf spring 519 is bent into the groove 512a and can be pulled out from the fixed leg 511.

  The ladder or stepladder with an auxiliary leg according to the present invention is inexpensive and lightweight, and can be reliably locked while preventing rotation around an axis at an arbitrary lift position, so that it can be widely used in industries related to ladders and stepladders. .

DESCRIPTION OF SYMBOLS 1 Leg 11, 111-511 Fixed leg 11a, 111a, 411a, 511a Plane part 11b, 211b, 411b, 511b Opening hole 12, 112-512 Auxiliary leg 2 Leg 21 Fixed leg 22 Auxiliary leg 3, 103-503 Locking means 31, 231, 431, 531 Bolt support part 32, 232, 432, 532 Female thread 33, 133-533 Bolt 33a, 133a-533a Male thread 33b, 333b-533b Expanded diameter part 34, 234-534 Brake pad 34a, 334a, 434a Internal space 34b Opening 35, 235, 435, Knurled nut 36 Washer

Claims (5)

A fixed leg formed of a circular pipe, an auxiliary leg formed of a square pole or a quadrangular pipe, and a locking means for locking the auxiliary leg to the fixed leg,
The fixed leg is formed with a flat portion obtained by pressing and deforming the side surface of the circular pipe flat toward the inside.
The auxiliary leg is slidably inserted between a flat portion formed on the fixed leg and an inner surface of the fixed leg facing the flat portion,
The locking means includes a bolt support portion provided at a location facing the flat surface portion on the outer surface of the fixed leg, and a bolt that is screwed into a female screw provided on the bolt support portion,
A ladder or a stepladder with an auxiliary leg, wherein a bolt is screwed into the female screw so that a tip of the bolt presses the auxiliary leg and comes into pressure contact with a flat portion formed on the fixed leg. An opening hole is provided at a position on the side surface of the fixed leg facing the flat surface portion.
The locking means includes a brake pad that is slidably inserted into an opening hole provided in a side surface of the fixed leg,
The female screw is provided in a portion facing the opening hole at a certain distance in the bolt support portion,
The ladder or stepladder with an auxiliary leg according to claim 1, wherein the bolt presses the auxiliary leg through the brake pad. An enlarged diameter portion is provided at the tip of the bolt,
Inside the brake pad, an internal space that opens to one end face of the brake pad is formed,
The enlarged diameter portion provided at the tip of the bolt is slidably inserted into the internal space formed in the brake pad,
The ladder with an auxiliary leg according to claim 2, wherein a locking portion for preventing an enlarged diameter portion provided at a tip of the bolt from slipping out is provided in an opening portion in which the internal space is opened. Or a stepladder. In the bolt, an washer that can be inserted into an internal space formed in the brake pad is inserted into the upper portion of the enlarged diameter portion,
The locking portion provided at the opening where the internal space of the brake pad opens is formed by reducing the edge of the opening after inserting the enlarged diameter portion and the washer provided at the tip of the bolt into the internal space. The ladder or stepladder with auxiliary legs according to claim 3, wherein the ladder or stepladder is provided. The enlarged diameter portion provided at the tip of the bolt is hemispherical,
The washer inserted into the bolt is disc-shaped,
The brake pad has a cylindrical inner space formed concentrically inside a cylinder,
The ladder or stepladder with auxiliary legs according to claim 4, wherein the opening hole provided in the fixed leg is a circular hole.

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