JP2020084414A - Ladder body lock structure and ladder body - Google Patents

Abstract

To provide a ladder body locking mechanism capable of suppressing displacement of a lock pin in a lock releasing direction even if friction occurs between the lock pin and a support pillar when a plurality of support pillars are used at elongated positions, and a ladder body.SOLUTION: A locking mechanism 20 comprises a plurality of ladder members 10 equipped with a pair of support pillars 11 and a rung 13, and fixes the continuous support pillars 11 to each other in a ladder 1 in which the support pillars 11 can be expanded and contracted. The locking mechanism comprises a lock pin 23 fixed to the rung 13 assembled to the support pillars 11 and inserted into an insertion hole 11b formed in a support pillar 11i in a state where the other support pillar 11i inserted between the pillars 11, 11 are expanded and contracted. In an outer peripheral surface of the lock pin 23, a tapered surface 23c is formed as a release regulation part closer to a tip side of the lock pin 23 than an abutted part against which an inner peripheral surface of the insertion hole 11b in a state where the lock pin 23 is inserted into the insertion hole 11b.SELECTED DRAWING: Figure 7

Description

The present invention relates to an extendable and retractable ladder body and a lock structure thereof.

Conventionally, a ladder, a stepladder, a step, a tripod, a scaffold, etc. are known as an elevating tool including a ladder body having a pair of columns and a stepped bridge spanned between the pair of columns. In such a ladder body, a technique is used in which a plurality of pillars are connected in a nested manner and continuous pillars are fixed at an extended position by a locking mechanism (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2007-186898

In the ladder body described in Patent Document 1, a lock mechanism including a lock pin (stopper pin) is provided on one of two continuous columns. Then, when the columns are in the extended position, the lock pin is inserted into the other column by the urging force of the coil spring, so that the relative displacement of the columns is regulated.

In the ladder body configured as described above, when the plurality of columns are used in the extended position, the lock pin may be gradually retracted toward the base end side (direction of the coil spring) due to friction with the columns. That is, the lock pin may be displaced in the unlocking direction when the ladder body is in use.

The present invention has been made in view of the above circumstances, and the problem to be solved by the present invention is that when a plurality of columns are used in extended positions, friction occurs between the lock pin and the columns. Another object is to provide a ladder body locking mechanism and a ladder body that can suppress the lock pin from being displaced in the unlocking direction.

Below, the means for solving the said subject is demonstrated.

A locking mechanism of a ladder body according to the present invention includes a plurality of ladder members including a pair of columns formed in a tubular shape, and a cross rail bridged between the pair of columns, and the columns are nested. In a ladder body that is expandable and contractible by being connected to a ladder lock mechanism for fixing the continuous columns to each other at a predetermined position, the lock mechanism is attached to one column. And a lock pin fixed to the step rail and inserted into an insertion hole formed in the other column in a state where the one column and the other column inserted into the one column are extended, Urging means for urging the lock pin toward the tip end side of the pin, and a lock release portion for displacing the lock pin toward the base end side against the urging force of the urging means, In the outer peripheral surface of the lock pin, the use of the ladder body on the tip end side of the lock pin with respect to the contact portion with which the inner peripheral surface of the insertion hole abuts when the lock pin is inserted into the insertion hole. In this state, a release restricting portion that restricts the release of the lock pin from the insertion hole by being positioned above the contact portion is formed.

Further, in the ladder lock mechanism according to the present invention, a recess is formed on the outer peripheral surface of the lock pin, the abutting portion is located inside the recess, and the tip side of the recess of the lock pin is the release. It is formed as a regulation portion.

Further, in the ladder lock mechanism according to the present invention, an inclined surface that is inclined along the axial direction of the lock pin is formed on the outer peripheral surface of the lock pin, and the contact portion is on the inclined surface. And the tip end side of the lock pin is formed as the release restricting portion with respect to the contact portion of the inclined surface.

In the ladder lock mechanism according to the present invention, the release restricting portion is formed over the entire circumference of the lock pin.

Further, the ladder body according to the present invention includes a pair of columns formed in a tubular shape, a step bridge bridged between the pair of columns, and the continuous columns provided on the step bars, which are continuous with each other. A ladder body that includes a plurality of ladder members including a lock mechanism that is fixed at a predetermined position, and that is capable of expanding and contracting by connecting a plurality of the pillars in a nested shape, wherein the lock mechanism is one pillar. It is fixed to the assembled cross rail, and is inserted into an insertion hole formed in the other column in a state where the one column and the other column inserted into the one column are extended. A lock pin, a biasing unit that biases the lock pin toward the tip side of the lock pin, and a lock release unit that displaces the lock pin toward the proximal end side against the biasing force of the biasing unit. And, on the outer peripheral surface of the lock pin, on the tip end side of the lock pin with respect to the contact portion with which the inner peripheral surface of the insertion hole abuts in a state where the lock pin is inserted into the insertion hole, A release restricting portion that restricts release of the lock pin from the insertion hole by being positioned above the abutting portion when the ladder body is in use is formed over the entire circumference of the lock pin, A concave portion is formed on the outer peripheral surface of the pin, an inclined surface that is inclined along the axial direction of the lock pin is formed on the tip end side of the concave portion of the lock pin, and the contact portion is the surface of the inclined surface. It is located above, and the tip end side of the lock pin is formed as the release restricting portion with respect to the contact portion of the inclined surface.

According to the ladder body lock mechanism and the ladder body according to the present invention, even when friction is generated between the lock pin and the column when the plurality of columns are used in the extended position, the lock pin is unlocked in the unlocking direction. There is an effect that it is possible to suppress the displacement.

The perspective view which shows the use condition of the ladder which concerns on one Embodiment. The perspective view which shows the contraction state of a ladder. The perspective view which shows the lowermost ladder member. (A) is a perspective view showing an example of a ladder member in the middle, and (b) is a perspective view showing a pillar provided at the top of the ladder. FIG. 3 is an enlarged perspective view showing a positional relationship between one of the columns and the cross rail. The disassembled perspective view which shows a lock mechanism. Sectional drawing which shows a locking mechanism. Sectional drawing which shows the unlocking method in a lock mechanism. Sectional drawing which shows the reduction method of a ladder. Sectional drawing which shows the locking mechanism in a contracted state. Sectional drawing which shows the locking mechanism of the lowest stage.

Hereinafter, a schematic configuration of the ladder 1 including the lock mechanism 20 and the lower lock mechanism 30, which is the lock mechanism of the ladder body according to the present invention, will be described with reference to FIGS. 1 to 4. In the present embodiment, the ladder 1 is described as an example of the ladder body. That is, the lock mechanism 20 and the lower lock mechanism 30 according to the present invention are ladder bodies in which a step rail for a user to move up and down is bridged between a pair of columns, and a plurality of columns are connected in a nested manner. In addition to the ladder 1, it can be used in other configurations such as a stepladder, a step, a tripod, and a scaffolding.

As shown in FIG. 1 and FIG. 2, the ladder 1 according to the present embodiment includes a lower ladder member 10</b>L that constitutes the lowermost portion of the ladder 1 and a plurality of (15 The individual ladder members 10 and a pair of upper columns 11U and 11U that form the uppermost portion of the ladder 1 are provided as main components.

As shown in FIG. 2 and FIG. 3, the lower ladder member 10L is a tubular member bridged between a pair of lower pillars 11L and 11L formed in a rectangular tube shape and the lower pillars 11L and 11L. It is provided with two lower cross rails 13L and 13L. In the ladder 1 according to this embodiment, the lower pillar 11L (similarly to the pillar 11 and the upper pillar 11U described later) is formed in the same polygonal shape in cross section, so that the positioning of holes can be easily performed. In addition to that, the relative rotation around the axis that occurs between the support 11 and the pillar 11 connected to the upper side is restricted.

The lower step rails 13L are fixed one by one to the upper end portion and the lower middle portion of the lower support column 11L. In this embodiment, a light metal material made of aluminum or an aluminum alloy is adopted for the lower support 11L and the lower rail 13L (also for the later-described pillar 11, upper pillar 11U, and rail 13). As well). Both ends of each of the lower step rails 13L are fixed to each of the two lower support columns 11L and 11L by a resin lower connection member 12L. Resin grounding members 14, 14 are fixed to the lower ends of the lower columns 11L, 11L.

Lower lock mechanisms 30 and 30 are provided at both ends of the upper lower step rail 13L between the lower columns 11L and 11L, respectively. As shown in FIG. 3, insertion holes 11a are formed inside (on the side of the adjacent lower columns 11L) at the upper ends of the lower columns 11L and 11L. A lock pin 33 (see FIG. 11) is inserted into the insertion hole 11a from a lower lock mechanism 30 provided outside the lower support 11L. As a result, the insertion portion 33b formed at the tip of the lock pin 33 extends inside the lower support 11L.

As shown in FIG. 4A, the ladder member 10 includes a pair of pillars 11 and 11 formed in a rectangular tube shape, and a step bar 13 which is a cylindrical member bridged over the upper ends of the pillars 11 and 11. , Is provided. Both ends of the cross rail 13 are fixed to the columns 11 by a resin connecting member 12. Specifically, as shown in FIG. 6, the insertion tube portion 12 a of the connecting member 12 is inserted into the step rail 13. Further, the connecting member 12 is fixed to the support 11 by tightening the fixing portion 12e with the screw S in a state where the support 11 is inserted inside the main body portion of the connecting member 12. As a result, the pillar 11 and the step rail 13 are connected by the connecting member 12. A total of four stopper members 16 are fixed to the outer peripheral surface of each of the columns 11 and 11 at the upper and lower positions on the front surface and the rear surface.

Locking mechanisms 20 and 20 are provided at both ends of the cross rail 13 between the columns 11 and 11 (see FIGS. 8 and 9). An insertion hole 11a is opened inside (on the side of the adjacent support 11) at the upper end of the support 11. A lock pin 23 (see FIGS. 8 and 9) is inserted into the insertion hole 11a from a lock mechanism 20 provided outside the support 11. As a result, the insertion portion 23b formed at the tip of the lock pin 23 extends inside the column 11. In addition, an insertion hole 11b is opened inside (on the side of the adjacent columns 11) at a midpoint of the columns 11, 11 at the same height as the upper end of the upper stopper member 16.

As shown in FIGS. 1 and 4B, the upper support 11U is a rod-shaped member that constitutes the uppermost portion of the ladder 1. The respective upper columns 11U, 11U are inserted into the columns 11, 11 of the ladder member 10 one step below. A cap member 15 made of resin is covered on the upper end of the upper support 11U. On the outer peripheral surface of the upper column 11U, a total of four upper stopper members 16U are fixed at two positions, that is, a front surface and a rear surface.

As shown in FIGS. 1 and 2, in the ladder 1, the lower pillar 11L of the lower ladder member 10L, the pillars 11 of the plurality of ladder members 10, and the upper pillar 11U are connected in a nested manner. In other words, the ladder 1 is configured such that the upper pillars (upper pillars 11U and pillars 11) are continuously housed inside the lower pillars (pillars 11 and lower pillars 11L). For this reason, the pillar 11 of the ladder member 10 is configured such that the inner diameter thereof gradually decreases from the lower side toward the upper side.

As a result, the step bars 13 bridged between the columns 11 and 11 of each ladder member 10 are configured such that the length in the longitudinal direction (left-right direction) gradually increases from the lower side to the upper side. There is. In this way, the ladder 1 is expanded and contracted between the extended state shown in FIG. 1 and the shortened state shown in FIG. 2 by connecting the lower support 11L, the plurality of support 11 and the upper support 11U in a nested manner. It is possible.

Next, the configuration of the lock mechanism 20 will be described in detail with reference to FIGS. 5 to 10. As shown in FIGS. 7 and 8, the lock mechanism 20 is a mechanism for fixing the vertically continuous columns 11 of the ladder 1 in the extended state to each other at a predetermined position (extended position).

As described above, the lock mechanism 20 is provided at both ends of the step rail 13. Specifically, as shown in FIG. 6, the lock mechanism 20 is housed inside the insertion tube portion 12 a of the connecting member 12. In this embodiment, the lock mechanism 20 includes a spring support member 21, a spring 22, a lock pin 23, and a lock release member 24.

As shown in FIG. 7, the spring support member 21 is fixed to the end of the insertion cylindrical portion 12a in a state where the spring 22 which is the urging means is accommodated inside the cylindrical body which is the main body. The cylindrical lock pin 23 made of iron is housed in the cylindrical body of the spring support member 21 at the base end (the left end in FIG. 7) and abuts on the spring 22. The spring 22 biases the lock pin 23 toward the tip side (right side in FIG. 7) of the lock pin 23.

The urging force of the spring 22 causes the insertion portion 23b, which is the tip of the lock pin 23, to extend from the pin extension hole 12b of the connecting member 12. In this way, the lock pin 23 can be advanced and retracted in the axial direction inside the insertion tube portion 12a against the biasing force of the spring 22. An engaged portion 23a having a smaller diameter than the surroundings is formed in the middle of the lock pin 23.

The lock pin 23 can be displaced toward the base end side by the lock release member 24. The lock releasing member 24 is formed by including a rotating shaft 24a, an engaging portion 24b, an abutting portion 24c, and a restricting portion 24d. The lock releasing member 24 can be vertically slidable in the connecting member 12 by inserting the rotating shaft 24a into the first engaged recess 12c which is a notch formed in the connecting member 12.

The engagement portion 24b of the lock release member 24 engages with the engaged portion 23a of the lock pin 23. As a result, the unlocking member 24 receives the biasing force of the spring 22 via the lock pin 23 and is biased downward. The contact portion 24c formed in the lower portion of the unlocking member 24 receives the biasing force of the spring 22 and extends downward from the opening portion 13a formed in the lower surface of the step rail 13. Further, the regulating portion 24d formed at the end of the unlocking member 24 comes into contact with the inner peripheral surface of the step rail 13, whereby the downward swinging of the unlocking member 24 is regulated.

As described above, the lock pin 23 is urged toward the tip end side by the urging force of the spring 22, and the insertion portion 23b passes through the pin extension hole 12b of the connecting member 12 and the insertion hole 11a of the support column 11 inside the support column 11. Be extended to. At this time, the support column 11 and the support column 11i (hereinafter referred to as "second support column") inserted into the support column 11 are in the extended position, and the insertion hole 11b in the second support column 11i is located in the support column 11. When it matches the insertion hole 11a, the insertion portion 23b of the lock pin 23 is inserted into the insertion hole 11b of the second support column 11i as shown in FIG. Thereby, the column 11 and the second column 11i are fixed to each other in the extended position. That is, in the pillars 11 connected to each other, the second pillars 11i inserted therein are pulled up to the extended position, and the insertion holes 11b of the second pillars 11i are aligned with the insertion holes 11a of the pillars 11. The lock pin 23 is forcibly inserted into the insertion hole 11b by the biasing force of the spring 22, and the support 11 and the second support 11i are locked to each other (hereinafter, this state is referred to as a "locked state"). ..

At this time, as shown in FIG. 8, the second strut 11i is displaced at the extension position with respect to the strut 11 by the stopper member 16i fixed to the outer peripheral surface coming into contact with the connecting member 12 fixed to the strut 11. Regulated. In other words, the user of the ladder 1 can pull the second support column 11i from the support column 11 until the displacement is restricted, so that the second support column 11i can be in the extended position with respect to the support column 11.

The user of the ladder 1 pulls up the columns 11 of the ladder member 10 in order from the top, starting with the upper column 11U, when moving from the shortened state shown in FIG. 2 to the extended state. As a result, the upper columns 11 are sequentially locked at the extended position, and the ladder 1 can be finally brought into the extended state.

The lock release member 24 can displace the lock pin 23 toward the base end side against the biasing force of the spring 22. Specifically, as shown in FIG. 8, when the unlocking member 24 receives a turning force from below as shown by an arrow R, the unlocking member 24 rotates upward (counterclockwise in FIG. 8). .. When the lock releasing member 24 rotates, the lock pin 23 is displaced toward the base end side as indicated by an arrow M against the biasing force of the spring 22 by the force received from the engaging portion 24b of the lock releasing member 24.

When the lock pin 23 of the unlocking member 24 is displaced toward the base end side, the insertion portion 23b of the lock pin 23 comes out from the insertion hole 11b of the second support column 11i as shown in FIG. 9, and the support column 11 and the second support column 11i are separated from each other. Is unlocked. At this time, friction occurs between the lock pin 23 and the second support column 11i, but since the support column 11 is made of an aluminum-based material that is softer than the iron lock pin 23, the lock pin 23 is worn. There is no such thing. By releasing the locked state of the second support column 11i with the ladder 1 standing on the ground, the second ladder member 10i including the second support column 11i descends by its own weight as shown by an arrow D in FIG. ..

Then, as shown in FIG. 10, the lock releasing member 24i provided in the lock mechanism 20i of the second ladder member 10i abuts on the step bar 13 of the ladder member 10 to cause the second support column 11i and the second support column to be contacted. The locked state with the third support 11s inserted in 11i is released. In this way, the lock releasing member 24 is configured to operate when the step rail 13 below the step rail 13 including the lock releasing member 24 contacts. In this way, the locked state of the columns 11 is sequentially released from the lower side, whereby the ladder 1 in the extended state can be brought into the shortened state.

Next, the configuration of the lower lock mechanism 30 provided on the lower ladder member 10L will be described with reference to FIG. As shown in FIG. 11, the lower lock mechanism 30 is a mechanism for fixing the lower support 11L and the support 11 inserted into the lower support 11L in a predetermined position (extended position) in the ladder 1 in the extended state. ..

As described above, the lower lock mechanism 30 is provided at both ends of the lower step bar 13L provided on the upper side of the lower column 11L. Specifically, as shown in FIG. 11, the lower lock mechanism 30 is housed inside the insertion tube portion 12a of the lower coupling member 12L. In this embodiment, the lower lock mechanism 30 includes a spring support member 31, a spring 32, a lock pin 33, and a lock release member 34.

As shown in FIG. 11, the spring support member 31 is fixed to the end portion of the insertion cylindrical portion 12a in a state where the spring 32 that is the urging means is accommodated inside the cylindrical body that is the main body. A cylindrical lock pin 33 made of iron has a base end portion (left end portion in FIG. 11) housed in a cylindrical body of the spring support member 31 and abuts on the spring 32. The spring 32 urges the lock pin 33 toward the tip side (right side in FIG. 11) of the lock pin 33. The lock pin 23 may be formed in a prismatic shape.

The urging force of the spring 32 causes the insertion portion 33b, which is the tip of the lock pin 33, to extend from the pin extension hole 12b of the lower coupling member 12L. In this way, the lock pin 33 can be advanced and retracted in the axial direction inside the insertion tube portion 12a against the biasing force of the spring 32. A small-diameter engaged portion 33a is formed at a middle portion of the lock pin 33 on the tip side.

The lock pin 33 can be displaced toward the base end side by the lock release member 34. The unlocking member 34 is formed to include a rotating shaft 34a, an engaging portion 34b, a hook portion 34c, and a restricting portion 34d. The unlocking member 34 can be swung up and down in the lower connecting member 12L by inserting the rotation shaft 34a into the second engaged recess 12d which is a notch formed in the lower connecting member 12L. It The hook portion 34c, which is rotatably connected to the lower portion of the lock releasing member 34, hangs downward from an opening portion 13a formed in the lower surface of the lower step bar 13L.

The engagement portion 34b of the lock release member 34 engages with the engaged portion 33a of the lock pin 33. Since the engaged portion 33a is located closer to the tip end side than the second engaged recess 12d, the lock release member 34 is biased upward by the biasing force of the spring 32 via the lock pin 33.

As described above, the lock pin 33 is urged toward the tip side by the urging force of the spring 32, and the insertion portion 33b is moved downward from the pin extension hole 12b of the lower coupling member 12L and the insertion hole 11a of the lower support 11L. It extends inside the pillar 11L. At this time, the lower support 11L and the support (second support) 11i inserted into the lower support 11L are in the extended position, and the insertion hole 11b in the second support 11i is the insertion hole 11a of the support 11. If it coincides with, the insertion portion 33b of the lock pin 33 is inserted into the insertion hole 11b of the second support 11i as shown in FIG. As a result, the lower support 11L and the second support 11i are fixed to each other in the extended position.

The lock release member 34 can displace the lock pin 33 toward the base end side against the biasing force of the spring 32. Specifically, when the hook portion 34c of the lock releasing member 34 is pulled downward by the user, the lock releasing member 34 rotates downward (counterclockwise in FIG. 11). When the lock releasing member 34 rotates, the lock pin 33 is displaced toward the base end side against the biasing force of the spring 32 by the force received from the engaging portion 34b of the lock releasing member 34.

When the lock pin 33 of the unlocking member 34 is displaced toward the base end side, the insertion portion 33b of the lock pin 33 is pulled out from the insertion hole 11b of the second support column 11i, and the lower support column 11L and the second support column 11i are locked. Is released. By releasing the locked state of the second support column 11i with the ladder 1 standing on the ground, the ladder member 10 connected to the lower ladder member 10L descends due to gravity. In this way, by unlocking the lower pillar 11L located at the lowermost stage, the locked states of the pillars 11 are sequentially released from the lower side, so that the ladder 1 in the extended state can be shortened. In other words, the user of the ladder 1 can automatically shorten the ladder 1 by manually unlocking the lower ladder member 10L in the extended ladder 1.

In the ladder 1 according to the present embodiment, the lock pin 23 is inserted into the insertion hole 11b on the outer peripheral surface of the lock pin 23 of the lock mechanism 20 (the same applies to the lock pin 33 of the lower lock mechanism 30). In the state, a tapered surface 23c (33c) is formed as a release restricting portion on the tip end side of the lock pin 23 with respect to the contact portion with which the inner peripheral surface of the insertion hole 11b abuts.

The taper surface 23c is an inclined surface that is inclined such that the tip end thereof has a larger diameter along the axial direction of the lock pin 23. The inner peripheral surface of the insertion hole 11b is in contact with the surface of the tapered surface 23c. In the present embodiment, the tip end side of the lock pin 23 is formed as the release restricting portion with respect to the contact portion of the inner peripheral surface of the insertion hole 11b in the tapered surface 23c. Specifically, as shown in FIG. 7, the tip end side of the lock pin 23 in the tapered surface 23c is located above the contact portion with the inner peripheral surface of the insertion hole 11b when the ladder 1 is in use. As a result, the tapered surface 23c regulates the release of the lock pin 23 from the insertion hole 11b.

Although the tapered surface 23c is formed as the release restricting portion in the present embodiment, the protrusion may be formed upward at the tip of the lock pin 23 to configure the protrusion as the release restricting portion. It is possible.

Further, in the present embodiment, a concave portion is formed on the outer peripheral surface of the lock pin 23, and the contact portion with which the inner peripheral surface of the insertion hole 11b abuts when the lock pin 23 is inserted into the insertion hole 11b is a concave portion. It is configured to be located inside. That is, the taper surface 23c is formed on the tip side of the concave portion of the lock pin 23 as a release restricting portion. However, it is also possible to form the lock pin 23 without forming the concave portion and simply form the release restricting portion on the tip side of the abutting portion.

In the lock mechanism 20 of the ladder 1 according to the present embodiment, the release restricting portion is formed on the outer peripheral surface of the lock pin 23 by the taper surface 23c, so that the lock pin 23 can be used when the plurality of columns 11 are used in the extended position. Even if friction occurs between the column 23 and the column 11, the lock pin 23 can be prevented from being displaced toward the base end side which is the unlocking direction. That is, as shown in FIG. 7, since the inner peripheral surface of the insertion hole 11b of the second support column 11i is located inside the recessed portion of the lock pin 23, the lock pin 23 is difficult to separate from the second support column 11i. More specifically, due to the gravity of the second support column 11i, the second support column 11i exerts a force that presses the tapered surface 23c downward, so that the lock pin 23 has a tip end side (right side in FIG. 7). A force is generated toward. Therefore, the lock pin 23 can be prevented from being displaced toward the base end side.

Further, the release restricting portion of the lock pin 23 is formed as a taper surface 23c that is inclined so that the tip side expands in diameter. Accordingly, even when the continuous columns 11 are in the locked state, the inner peripheral surface of the insertion hole 11b can be gradually lifted along the tapered surface 23c when the lock release member 24 is actuated. 23 can be pulled out from the insertion hole 11b. That is, when the step rail 13 located one step lower abuts on the lock releasing member 24, the lock releasing member 24 can be automatically operated.

Further, in the present embodiment, the lock pin 23 is formed in a cylindrical shape, and the tapered surface 23 c forming the release restricting portion is formed over the entire circumference of the lock pin 23. Thereby, even when the lock pin 23 rotates about the axis, the lock pin 23 can be restrained from being displaced toward the base end side which is the unlocking direction, and the lock pin 23 can be locked when the lock releasing member 24 is actuated. It can be pulled out from the insertion hole 11b.

That is, since the lock pin 23 in the lock mechanism 20 has the release restricting portion formed by the tapered surface 23c, the inner peripheral surface of the insertion hole 11b may be caught by the release restricting portion when the lock pin 23 is pulled out from the insertion hole 11b. There is no. Therefore, the ladder 1 according to the present embodiment can operate the lock mechanism 20 without impeding the function of automatically changing from the extended state to the shortened state.

1 Ladder (ladder body) 10 Ladder member
10L Lower ladder member 11 Support
11a insertion hole 11b insertion hole
11i Second support 11s Third support
11U Upper strut 11L Lower strut
12 connecting member 12a insertion cylinder part
12b Pin extension hole 12c First engaged recess
12d Second engaged recess 12e Fixed part
12L Lower connection member 13 Step rail
13a opening 13L lower cross rail
14 Grounding member 15 Cap member
16 stopper member 16U upper stopper member
20 Lock mechanism (Ladder lock mechanism)
21 spring support member 22 spring
23 Lock Pin 23a Engagement Part
23b insertion part 23c taper surface
24 Lock release member (lock release section)
24a rotating shaft 24b engaging portion
24c abutting part 24d regulating part
30 Lower lock mechanism (Ladder lock mechanism)
31 spring support member 32 spring
33 Lock Pin 33a Locked Part
33b Insertion part 33c Tapered surface
34 Lock release member (lock release section)
34a Rotating shaft 34b Locking part
34c Hook part 34d Control part
S screw R rotation direction
M displacement direction D descending direction

Claims (5)

A plurality of ladder members each including a pair of cylindrical columns and a cross rail bridged between the pair of columns are provided, and the columns are telescopically connected so that they can be expanded and contracted. In the ladder body, a locking mechanism of the ladder body for fixing the continuous columns to each other at a predetermined position,
The lock mechanism is fixed to the cross rail assembled to one support column, and is formed on the other support column in a state in which the one support column and another support column inserted into the one support column are extended. A lock pin inserted into the insertion hole, an urging means for urging the lock pin toward the tip side of the lock pin, and the lock pin on the proximal side against the urging force of the urging means. And a lock release part for displacing toward
In the outer peripheral surface of the lock pin, the use of the ladder body on the tip end side of the lock pin with respect to the contact portion with which the inner peripheral surface of the insertion hole abuts when the lock pin is inserted into the insertion hole. In the state, a lock mechanism for the ladder body is provided, in which a release restricting portion that restricts release of the lock pin from the insertion hole by being positioned above the contact portion is formed. A recess is formed on the outer peripheral surface of the lock pin,
The abutting portion is located inside the recess,
The ladder lock mechanism according to claim 1, wherein a tip end side of the concave portion of the lock pin is formed as the release restricting portion. An inclined surface that is inclined along the axial direction of the lock pin is formed on the outer peripheral surface of the lock pin,
The abutting portion is located on the surface of the inclined surface,
The ladder lock mechanism according to claim 1, wherein a tip end side of the lock pin is formed as the release restricting portion with respect to an abutting portion of the inclined surface. The lock mechanism for a ladder body according to any one of claims 1 to 3, wherein the release restricting portion is formed over the entire circumference of the lock pin. A pair of cylindrically formed stanchions, a step rail bridged between the pair of stanchions, and a lock mechanism for fixing the continuous stanchions provided on the step rail to each other at predetermined positions, A ladder body comprising a plurality of ladder members, comprising: a plurality of the pillars connected in a nested manner to allow expansion and contraction,
The lock mechanism is fixed to the step rail assembled to one support column, and is attached to the other support column in a state where the one support column and another support column inserted into the one support column are extended. A lock pin inserted into the formed insertion hole, a biasing means for biasing the lock pin toward the tip side of the lock pin, and a base end of the lock pin against the biasing force of the biasing means. A lock releasing portion that is displaced toward the side,
In the outer peripheral surface of the lock pin, the use of the ladder body on the tip end side of the lock pin with respect to the contact portion with which the inner peripheral surface of the insertion hole abuts when the lock pin is inserted into the insertion hole. In the state, a release restricting portion that restricts release of the lock pin from the insertion hole by being positioned above the contact portion is formed over the entire circumference of the lock pin,
A recess is formed on the outer peripheral surface of the lock pin,
An inclined surface inclined along the axial direction of the lock pin is formed on the tip side of the recess in the lock pin,
The abutting portion is located on the surface of the inclined surface,
A ladder body in which a tip end side of the lock pin is formed as the release restricting portion with respect to an abutting portion of the inclined surface.

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