JP4763647B2 - Tripod stepladder - Google Patents

Description

  The present invention relates to a tripod stepladder comprising a top plate at the upper end and a front ladder-like leg that is opened in a substantially C shape and a single rod-like leg on the rear side that are openably and closably connected. is there.

  This kind of tripod stepladder is a three-point support unlike a normal quadruped stepladder, so it can stand up stably even if the support surface is not flat, and even if the obstacle is complicated and complicated The rear rod-like legs can be used for these obstacles, and are therefore widely used for harvesting fruit trees such as oranges, and for pruning garden trees.

As a conventional tripod stepladder, a specific publicly known document such as a patent publication cannot be cited, but a currently used tripod stepladder B is shown in FIG. 7 (a) is a front view of the tripod stepladder B folded into a closed leg posture from the rear side, FIG. 7 (b) is a side view of the tripod stepladder B, and FIG. A side view in a state of being opened to a posture, (d) is a front view of the same open leg posture as viewed from the front side. The tripod stand B has a top plate 3 fixedly installed at the upper end, a ladder-like leg 1 that is open in a substantially C-shape on the front side, and the above-mentioned ladder-like leg 1 that is fixedly installed on the ladder-like leg 1. The upper end of the top plate 3 is connected to the top end of the top plate 3 so that it can be opened and closed. The ladder-shaped leg body 1 is composed of a pair of left and right support columns 4 and 4 arranged in a substantially C-shape, and a traverse 5 which is horizontally mounted between the support columns 4 and 4 at appropriate intervals in the height direction. As described above , the top plate 3 is fixedly attached to the support columns 4 and 4 at the upper end portions of the support columns 4 and 4 so that the top plate 3 is in a horizontal posture when used. The upper end portion of the leg 2 is pivotally connected, and reinforcing frames 6 and 6 are disposed along the support columns 4 and 4. Reference numeral 7 denotes a rope body that holds the ladder-like leg body 1 and the rod-like leg body 2 in a predetermined open leg posture.

  When the tripod stand B is manufactured at the factory and shipped, both legs 1 and 2 are folded into a closed leg posture as shown in FIG. It is transported to a place, and when used, both legs 1 and 2 are opened and used in a predetermined open leg position as shown in (c).

  By the way, in the conventional tripod stepladder B, the top plate 3 is fixed at a predetermined angle so that the top plate 3 is in a horizontal position when used with respect to the ladder-like leg 1, so that the leg is closed as shown in FIG. In the folded state, the thickness in the front-rear direction becomes thicker and bulky, and the thickness of the end of the top plate 3 is thicker than that of the opposite end, so that the state of loading when stacked is very poor. In addition to being stable and prone to collapse, there is a problem that loading capacity is limited when loading into a container or the like at the time of shipment, and loading performance is poor.

  The present invention has been made in view of the above problems, and provides a tripod stepladder capable of improving stability during stacking to prevent load collapse and improving loadability and load capacity. For the purpose.

Means for solving the above problems will be described with reference numerals in the embodiments described later. The invention according to claim 1 includes a top plate 3 at the upper end and opens in a substantially C-shape on the front side. In a tripod stepladder in which a ladder-like leg 1 and a single rod-like leg 2 on the rear side are connected so as to be openable and closable,
A base end portion of the top plate 3 is pivotally attached to the upper end portion of the ladder-like leg 1 and a tip end portion of the top plate 3 is pivotally attached to the upper end portion of the rod-like leg 2 so that the ladder-like leg is supported. A locking means 8 is provided between the ladder-shaped leg body 1 and the top board 3 for locking the top board 3 in a horizontal position when the body 1 and the rod-like leg body 2 are opened in a predetermined leg position. Ri name and,
In the ladder-like leg 1, the rod-like leg 2 is placed in the ladder-like leg 1 when the ladder-like leg 1 and the rod-like leg 2 are closed in the closed posture at the center of the rear side of each step bar 5. It is characterized in that a fitting recess 9 into which the rod-like leg 2 is fitted is provided.

Claim 2 is a tripod stepladder according to claim 1 , wherein the lower leg of the ladder-like leg 1 has a fitting recess of the rod-like leg 2 fitted in the fitting recess 9 of the ladder 5. The stoppers 21 and 31 are provided so as to be prevented from coming out of the stopper 9, and the stoppers 21 and 31 are integrally formed by a leaf spring, and the dent recess that enters when the rod-like leg 2 is fitted into the fitting recess 9. 22, projecting pieces 23, 23 projecting opposite to each other at an interval narrower than the diameter of the rod-like leg 2 on both sides of the entrance of the entry recess 22, and outside the projecting pieces 23, 23, when the rod-like leg 2 enters. It comprises taper guide portions 24 and 24 for guiding the protrusions 23 and 23 so as to widen the distance between them.

A third aspect of the present invention is the tripod stepladder according to the first or second aspect , wherein the locking means 8 includes a horizontal pivot shaft 10 worn on the top plate pivoted horizontally on the upper end portion of the ladder-like leg 1, and a ceiling. It is provided in the base end part of the board 3, and is interposed between the hollow member 11 worn by the top plate pivotably fitted to the horizontal support shaft 10, and is attached to the outer periphery of the horizontal support shaft 10. A locking spring member is provided with a locking protrusion 16 extending in the direction, and biased so that a locking claw 18 a at the distal end is in contact with the outer peripheral surface of the horizontal support shaft 10 on the inner periphery of the hollow member 11. 18, and the claw 18 a of the locking spring member 18 is rotated by rotating the top plate 3 from the closed state of the ladder-shaped leg 1 and the rod-shaped leg 2 to the horizontal posture in use. When the overhanging protrusion 16 is overcome, the engaging claw 18a engages with the protrusion 16 to lock the top plate 3 in a predetermined horizontal posture. And wherein the Rukoto.

According to a fourth aspect of the present invention, in the tripod stepladder according to the third aspect , the locking claw 18a of the locking spring member 18 is locked to the locking projection 16 of the horizontal support shaft 10 so that the top plate 3 has a predetermined horizontal position. An operating tool for inserting an operating tool for operating the locking spring member 18 so that the locking claw 18a stands up from the locking position with the locking protrusion 16 and is unlocked in the locked state in the posture. The insertion opening 20 is provided at a required portion of the hollow member 11.

The effect of the invention by the above solution will be described with reference numerals of the embodiments described later. According to the tripod stepladder of the invention according to claim 1, the base end portion of the top plate 3 is connected to the ladder-like leg 1 according to the invention. rotatably pivoted to the upper end, as well as rotatably pivoted the front end portion of the top plate 3 to the upper end of the rod-shaped leg 2, the ladder leg 1 and the rod-shaped leg 2 and a predetermined open leg posture The locking means 8 that locks the top board 3 in a horizontal position with the top board 3 open is interposed between the ladder-like leg body 1 and the top board 3 so that the ladder-like leg body 1 and the rod-like leg body 2 are closed. When folded into a state, the thickness of the tripod stepladder can be flattened as thin as possible, improving stability during stacking and preventing load collapse, and improving loadability and load capacity it can.

Further , according to the tripod stepladder of the present invention , the ladder-like leg 1 is provided by providing the fitting recess 9 into which the bar-like leg 2 is fitted at the rear center part of each step 5 of the ladder-like leg 1. The rod-like leg 2 can be accommodated in the ladder-like leg 1 when the leg and the leg-like leg 2 are closed in the closed leg posture, thereby making it possible to further reduce the thickness of the tripod stand in the front-rear direction and flatten it. And the load capacity can be further improved.

According to the tripod stepladder according to the second aspect of the present invention, the rod-like leg 2 fitted to the fitting recess 9 of the step bar 5 is fitted from the fitting depression 9 to the lower step beam 5 of the ladder-like leg 1. Since stoppers 21 and 31 are provided to prevent slipping out, the rod-like leg 2 can be fixed in a state where it is fitted into the fitting recess 9 of the ladder-like leg 1 when the leg is closed, which is extremely effective when transporting a tripod stand. It is. Further, the stoppers 21 and 31 are integrally formed by a leaf spring, and a rod-like leg body is formed on the both sides of the entry recess 22 and the entrance of the entry recess 22 when the rod-like leg body 2 is fitted into the fitting recess 9. And projecting pieces 23 and 23 that face each other at intervals smaller than the diameter of 2 and tapered guide portions 24 and 24 that guide the rod-shaped leg 2 so as to widen the distance between the projecting pieces 23 and 23 when the rod-like leg 2 enters. The structure is simple and easy to manufacture, and the rod-like leg 2 is easy to attach and detach.

According to the tripod stepladder according to the third aspect of the present invention, once the top plate 3 is opened to the horizontal posture at the time of use, the lock means 8 is made into a locked state and does not return to its original state. In addition, since it is already in a horizontal position during use, it is easy to use and has good workability.

According to the tripod stepladder according to the fourth aspect of the present invention, in the case of being erroneously locked at the time of assembly, the operation tool 19 is inserted, and the locking claw 18a is moved from the locking position with the locking projection 16 to the hollow member. 11 is raised to the inner peripheral surface side, the locking claw 18a can get over the locking projection 16 downward and can be unlocked. Therefore, the top plate 3 is folded at the time of shipment. The ladder-like leg 1 and the rod-like leg 2 can be folded into the closed leg posture.

  A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 (a) is a front view of the tripod stepladder A according to the present invention folded in a closed leg posture, as viewed from the rear side. ) Is a side view of the closed leg posture, (c) is a plan view of the top plate 3 portion viewed from arrow X in (b), (d) is an enlarged cross-sectional view along line YY in (b), FIG. 2 (a) is a side view of a state in which the rod-like leg 2 is folded with respect to the ladder-like leg 1 in a state where the top board 3 is locked to the ladder-like leg 1 in a horizontal position when used. ) Is a side view of the rod-shaped leg 2 opened from the folded state shown in (a) to the open leg position, (c) is a front view of the open leg position, and (d) is viewed from the arrow Z in (b). It is the enlarged plan view of the top plate 3 part. The tripod stand A includes a top plate 3 at the upper end, and a ladder-like leg body 1 that is open in a substantially C-shape on the front side, and a rear-side one connected to the ladder-like leg body 1 so as to be openable and closable. The ladder-like leg 1 is composed of a pair of left and right support columns 4 and 4 arranged in a substantially C shape, and an appropriate interval in the height direction between the support columns 4 and 4. It is formed by the step rails 5.

  The top plate 3 is pivotally attached to the upper end of the ladder-like leg 1 at the base end, and is pivotally attached to the upper end of the rod-like leg 2 at the base end, and the ladder-like leg 1 and the rod-like leg A locking means 8 is provided between the ladder-like leg 1 and the top plate 3 so as to lock the top plate 3 in a horizontal posture when in use with the top 2 being opened to a predetermined open posture. In addition, the rod-shaped leg 2 can be expanded and contracted.

  The above structure will be described in more detail. As can be seen from FIG. 1 (d), each step bar 5 of the ladder-like leg 1 includes a front side step bar 5a horizontally mounted between the left and right support columns 4, 4. The rear step 5b includes a rear step 5b that is formed in a plan view so as to project integrally from both ends of the front step 5a to the rear of the ladder-like leg 1, and the rear step 5b includes a ladder. The rod-like leg 2 is fitted to the center part of the rear side pedestal 5b so that the rod-like leg 2 fits in the ladder-like leg 1 when the leg-like leg 1 and the rod-like leg 2 are closed in the closed leg posture. A concavity 9 is provided.

  Reinforcing frames 6 and 6 are disposed on the rear sides of the left and right struts 4 and 4 of the ladder-shaped leg body 1, and each reinforcing frame 6 is fixed to the rear tread bar 5 b of each tread bar 5. The upper and lower ends of each reinforcing frame 6 are fixed to the upper and lower ends of the column 4. Further, as shown in FIGS. 2 (d) and 3 (d) and 3 (e), a horizontal support shaft worn by the top plate pivot is provided between the upper ends of both supports 4 and 4 of the ladder-like leg 1. 10 is mounted non-rotatably.

  As can be seen from FIG. 2 (d) and FIG. 3 (d), the top plate 3 is located on the base end side of the top plate 3 and is attached to the top end of the ladder-like leg 1 at the horizontal support shaft 10 attached to the top plate. A hollow member 11 that is pivotably fitted to the top plate, a U-shaped frame 12 that is integrally attached to the hollow member 11 and forms the top plate peripheral frame 3a together with the hollow member 11, and It is composed of a plurality of middle rails 13 provided in a U-shaped frame 12, and is centered on a hollow member 11 on the proximal end side that is fitted to a horizontal pivot 10 that is attached to the top plate of the ladder-like leg 1. It can be turned up and down.

  Further, as shown in FIGS. 2D and 3A, a cylindrical member 14 that is pivotally attached to a rod-shaped leg is rotatable at the distal end side frame portion 12a of the U-shaped frame 12 of the top plate 3. And the upper end of the rod-like leg 2 is fixed to the central part of the cylindrical member 14, whereby the rod-like leg 2 is attached to the tip of the top plate 3 as shown in FIG. It is possible to pivot around. A reinforcing member 15 is interposed between the upper end portion of the rod-like leg 2 and the cylindrical member 14.

  The locking means 8 for locking the top board 3 in the horizontal position with the ladder-like leg 1 and the rod-like leg 2 opened in the open-leg position is shown in FIGS. 3 (d) and 3 (e). It is provided at the base end of the top plate 3 and is mounted on the horizontal support shaft 10 so as to be rotatable. While being provided between the hollow member 11 worn by the top plate pivot, two locking projections 16 extending in the axial direction are provided on the outer periphery of the horizontal support shaft 10 at intervals of 180 ° in the circumferential direction, On the inner periphery of the hollow member 11, a locking step portion 17 that engages with a locking protrusion 16 of the horizontal support shaft 10 to limit the rotation of the hollow member 11 within approximately 90 °, and a locking claw at the tip portion A locking spring member 18 is provided to bias 18a so as to be in contact with the outer peripheral surface of the horizontal support shaft 10, and the top plate 3 is used when the ladder-like leg 1 and the rod-like leg 2 are closed. water When the locking claw 18a of the locking spring member 18 gets over the locking projection 16 of the horizontal support shaft 10 by rotating to the posture, the locking claw 18a is locked to the projection 16 and the top plate 3 is moved. It is designed to lock in a flat position.

  FIG. 3A shows a state in which the top plate 3 is folded downward from the horizontal posture in use. At this time, the locking step 17 on the hollow member 11 side is the locking projection 16 on the horizontal support shaft 10 side. Therefore, it is not possible to rotate downward any more, and can be rotated up and down within a range of about 90 ° from the folded position to the horizontal position when used (see FIG. 3). (See (b)). When the top plate 3 is rotated so as to be lifted upward from the folded position shown in FIG. 3 (d), the locking claw 18a of the locking spring member 18 on the hollow member 11 side is moved to the horizontal spindle 10 side. When the latching claw 18a gets over the latching projection 16 by elastic deformation of the latching spring member 18 after the latching projection 16 is latched, the latching claw 18a is as shown in FIG. The top plate 3 is locked in a horizontal position during use (see (c) and (e) of FIG. 3).

  As described above, the top plate 3 cannot be folded once it is locked in the horizontal posture at the time of use. However, measures are taken so that the lock can be released if it is accidentally locked during assembly. That is, as shown in FIG. 3 (f), an operation tool insertion opening 20 for inserting a nail raising operation tool 19 for operating the locking spring member 18 is provided at a required portion of the hollow member 11. The nail raising operation tool 19 is inserted from the opening 20 as shown in the figure, and the locking claw 18a is raised from the locking position with the locking projection 16 to the inner peripheral surface side of the hollow member 11. If it does, the latching claw 18a can get over the latching projection 16 in the downward direction and can be unlocked.

  The operation of the tripod stepladder A configured as described above will be described below with reference to FIGS.

  FIG. 1 shows a tripod stand A that is manufactured in a factory and ready for shipment at any time. At this time, as can be seen from FIG. 1 (b), the tripod stand A has the ladder-like leg 1 and the rod-like leg 2 in a closed leg position with the top 3 folded downward. Compared with FIG. 7 (b) showing a conventional tripod stepladder B because the rod-like leg 2 is fitted in the fitting recess 9 of each step rail 5 and is accommodated in the ladder-like leg 1. As can be seen, the thickness in the front-rear direction is considerably thin and flat.

  In this way, the tripod stepladder A has a thin thickness in the front-rear direction and is folded into a flat shape. Therefore, when loading into a container or the like at the time of shipment, it does not cause collapse even if it is stacked in a multi-stage shape. While being able to stack well, since the thickness in the folded state is thin and flattened, it is possible to increase the load capacity as well as the loadability.

  When using the tripod stand A in which the ladder-like leg 1 and the rod-like leg 2 are folded as thinly as possible in the closed leg position at the time of shipment as shown above, the rod-like leg 2 is pushed up as shown in FIG. Then, the top plate 3 pivotally attached to the upper end portion of the rod-like leg 2 rotates upward and is locked in the horizontal posture at the time of use by the lock means 8. That is, when the top plate 3 is rotated so as to be lifted from the folded position shown in FIG. 3 (d), the locking claw 18a of the locking spring member 18 on the hollow member 11 side is used for locking on the horizontal support shaft 10 side. When the locking claw 18a gets over the locking projection 16 due to the elastic deformation of the locking spring member 18 after locking to the protrusion 16, the locking claw 18a moves in the reverse direction as shown in FIG. It will not return, and the top 3 is locked in the horizontal position at the time of use.

  After the top plate 3 is locked in the horizontal position at the time of use, the ladder-like leg 1 and the rod-like leg 2 are opened to each other, and a predetermined opening as shown in FIGS. 2 (b) and 2 (c). Leg posture may be used. At this time, the legs 1 and 2 are held in a predetermined open leg posture by the rope 7.

  In the above-described embodiment, the lock means 8 is fitted to the horizontal support shaft 10 worn on the top plate pivoted so as not to rotate on the upper end portion of the ladder-shaped leg 1 and to the horizontal support shaft 10 so as to be rotatable. A locking projection 16 extending in the axial direction is provided on the outer periphery of the horizontal support shaft 10, and a tip is provided on the inner periphery of the hollow member 11. A locking spring member 18 is provided to urge the locking claw 18a of the portion so as to abut against the outer peripheral surface of the horizontal support shaft 10, and the top plate is opened from the state where the ladder-like leg 1 and the rod-like leg 2 are closed. When the locking claw 18a of the locking spring member 18 gets over the locking projection 16 of the horizontal spindle 10, the locking claw 18a is locked to the projection 16. The top plate 3 is locked in a predetermined horizontal posture, and once the top plate 3 is opened to the horizontal posture at the time of use, it becomes a locked state. Back not because it is configured, it is possible to have a structure in which less bulky and with a compact locking means 8, because it is already in the horizontal position at the time of use, good usability, workability is good.

  FIG. 4 shows an embodiment in which a bar-like leg slip-out prevention stopper 21 is provided on the step 5 of the ladder-like leg 1. In other words, a fitting recess 9 into which the rod-like leg 2 is fitted is provided on the stepping bar 5 of the ladder-like leg 1 so that the rod-like leg 2 is accommodated in the ladder-like leg 1 when the leg is closed. In this case, as shown in FIG. 1 (d), if the rod-like leg 2 is simply fitted into the fitting recess 9, the rod-like leg 2 will come out of the fitting recess 9 when the tripod stand A is transported. Because of the inconvenience such as the state of rattling or rattling, a bar-like leg slip-out prevention stopper 21 is provided on the stepped foot 5 on the lowermost side of the ladder-like leg 1 so that the leg-like leg 2 is closed when the leg is closed. Can be fixed in a state of being fitted in the respective fitting recesses 9 of the ladder-like leg 1.

  The stopper 21 is formed integrally with a leaf spring having a width of, for example, about 15 mm. As can be seen from FIG. 5, the stopper 21 has a substantially C-shape that enters when the rod-like leg 2 is fitted into the fitting recess 9. A projecting recess 22, projecting pieces 23, 23 projecting on both sides of the entrance of the projecting recess 22 at an interval narrower than the diameter of the rod-like leg 2, and outside the projecting pieces 23, 23. Tapered guide portions 24, 24 for guiding the protrusions 23, 23 so as to widen the distance between the protrusions 23, 23 when the body 2 enters, and attachment portion pieces 25, 25 connected to the tip portions of the taper guide portions 24, 24, respectively. For mounting, both the mounting pieces 25 and 25 are fitted into the fitting recess 9 of the rear stepping bar 5b in a state in which the indentation recess 22 is fitted into the fitting recess 9 of the rear stepping bar 5b as shown in the figure. On the both sides of the entrance portion of the door, and the central portion of the indentation recess 22 is the fitting recess of the rear side crosspiece 5b. It may be attached at each example blind rivets 26 to 9 side.

  Therefore, when the ladder-like leg body 1 and the rod-like leg body 2 are closed, when the rod-like leg body 2 is fitted into the fitting recess 9 of each stepping bar 5, the lower end portion of the rod-like leg body 2 is at the lowest level. The rod-like leg 2 is prevented from coming out of the fitting recesses 9 by being fitted into the fitting recesses 22 of the stoppers 21 in the fitting recesses 9 of the step bars 5. When the rod-like leg 2 enters the entry recess 22, if the rod-like leg 2 hits the taper guide portions 24, 24, the entry recess is caused by the wedge action of the taper guide portions 24, 24 and the elastic deformation of the leaf spring. Both projecting pieces 23 and 23 at the inlet 22 are pushed open, and the rod-like leg 2 enters the entering recess 22. After entering, both projecting pieces 23 and 23 return to their original positions by the urging force of the leaf spring. Thus, the rod-like leg 2 is held by the two projecting pieces 23 and 23 to be prevented from coming out.

  In the embodiment of FIG. 4, the stopper 21 is attached to the rear side of the step bar 5 b, but FIG. 6 shows an embodiment in which the stopper 31 is attached to the front side of the step bar 5 a. The stopper 31 is formed of a leaf spring similar to the stopper 21, and has a substantially U-shaped indentation recess 22 that enters when the rod-shaped leg 2 is fitted into the fitting recess 9, and the indentation recess 22. On both sides of the entrance of the rod-shaped leg 2, and projecting pieces 23, 23 that face each other at a distance narrower than the diameter of the rod-shaped leg 2, and outside the two projecting pieces 23, 23. Taper guide portions 24 and 24 for guiding the gap to be widened, and the central portion of the indentation recess 22 is attached to the front side traverse 5a of the traverse 5 with, for example, a blind rivet 26. The action of the stopper 31 is the same as that of the stopper 21. As shown in FIG. 6, the stopper 31 is attached to the front side rail 5a below the rear side rail 5b so that the use of the rail 5 is not hindered.

  The stoppers 21 and 31 may be provided on the lowermost step rail 5 of the ladder-like leg 1, but may be provided on the second or third step rail 5 from the lowermost step, and such lower step side. You may provide in two or more of the crosspieces 5 of.

(a) is a front view of the tripod stepladder according to the present invention folded in a closed leg position, viewed from the rear side, (b) is a side view of the closed leg position, and (c) is viewed from an arrow X in (b). The top view of a top-plate part, (d) is the YY line expanded sectional view of (b). (a) is a side view of a state in which the bar-shaped leg is folded with respect to the ladder-shaped leg while the top plate is locked in a horizontal position when used with respect to the ladder-shaped leg, and (b) is shown in (a). The side view of the state which opened the rod-shaped leg to the open leg posture from the state, (c) is a front view of the same open leg posture, and (d) is a plan view of the top plate portion viewed from the arrow Z in (b). . (a) is an enlarged view of the part indicated by the arrow V in FIG. 2 (b), and (b) is an enlarged view of the part indicated by the arrow W in FIG. 2 (b). (C) is an enlarged view similar to (b), showing a state in which the top plate is locked in a horizontal position, and (d) is a top plate pivot in a state in which the top plate shown in (b) is rotatable. (E) is an enlarged cross-sectional view of the top plate pivot part in a state where the top plate is locked in a horizontal position, and (f) is an opening for inserting the operation tool into the hollow member for unlocking the locking means. It is a perspective view which shows embodiment which provided the part. It is a top view of a foot cross provided with a rod-like leg body slip-out prevention stopper. (a) is an enlarged view of the stopper of FIG. 4, and (b) is a cross-sectional view taken along the line QQ of (a). It is a top view similar to FIG. 4 which shows other embodiment of a rod-shaped leg body withdrawal prevention stopper. (a) is a front view of a conventional tripod stepladder folded into a closed leg position, as viewed from the rear side, (b) is a side view of the same leg position, and (c) is a position in which the tripod stepladder is opened to a predetermined open leg position. (D) is a front view of the open leg posture as seen from the front side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ladder-like leg body 2 Rod-like leg body 3 Top plate 4 Column 5 Step rail 5a Front side rail 5b Rear side rail 8 Locking means 9 Fitting recessed part 10 provided in the rear side rail Horizontal support shaft 11 Hollow member 16 Locking Protrusion 17 Locking step 18 Locking spring member 21 Bar-shaped leg slip-out prevention stopper 31 Bar-shaped leg slip-out prevention stopper

Claims (4)

In a tripod stepladder with a top plate at the upper end, and a ladder-like leg that opens in a substantially C-shape on the front side and a single rod-like leg on the rear side that are openably and closably connected,
The base end portion of the top plate is rotatably pivoted to the upper end of the ladder leg, the distal end portion of the top plate with rotatably pivoted to the upper end of the rod-like leg, ladder leg and the rod-shaped legs Ri locking means for locking the body in a horizontal posture while using the top plate in opened to a predetermined open leg posture name and interposed between the ladder leg and the top plate,
The ladder-shaped legs are fitted in the center of the rear side of each pedestal so that when the ladder-shaped legs and the rod-shaped legs are closed in the closed position, the rod-shaped legs fit into the ladder-shaped legs. A tripod stepladder characterized in that a fitting recess is provided . The lower leg of the ladder-like leg is provided with a stopper that prevents the rod-like leg fitted in the fitting recess of the ladder from coming out of the fitting recess, and this stopper is formed integrally with a leaf spring. A protruding recess that protrudes when the rod-like leg is fitted into the fitting recess, a protruding piece that protrudes on both sides of the inlet of the protruding recess at an interval narrower than the diameter of the rod-shaped leg, The tripod leg stand according to claim 1 , further comprising a taper guide portion which is provided outside and guides so as to widen a distance between both projecting pieces when the rod-like leg enters. The locking means are provided at the top end of the ladder-like leg that is horizontally mounted on the top end of the ladder-shaped leg, and at the base end of the top board, and is rotatably fitted to the horizontal support shaft. It is interposed between the hollow member worn by the top plate pivot, and a locking projection extending in the axial direction is provided on the outer periphery of the horizontal support shaft, and the tip end is locked on the inner periphery of the hollow member. A locking spring member is provided to urge the claw so that it comes into contact with the outer peripheral surface of the horizontal support shaft, and the top plate is rotated from the closed state to the horizontal position when it is used. When the latching claw of the latching spring member gets over the latching projection on the horizontal support shaft, the latching claw latches on the projection and locks the top plate in a predetermined horizontal posture. A tripod stepladder according to claim 1 or 2 , characterized in that: When the locking claw of the locking spring member is locked to the locking projection of the horizontal support shaft and the top plate is locked in a predetermined horizontal posture, the locking claw is locked to the locking projection. claim 3, characterized in that provided operation instrument insertion opening for inserting the operating tool to operate the locking for spring member so as to unlock by rising from the position in the predetermined position of the hollow member Tripod stepladder as described in.

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