JP2019167693A - Extendable leg device of ladder body - Google Patents

Abstract

To provide an extendable leg device of ladder body which can operate extension and contraction of the extendable leg member with more comfortable posture, has no risk that ladders, and the like collapse during extending-contracting work of the extendable leg member therefore is excellent at safety.SOLUTION: An extendable leg device of ladder body 5 has left and right extendable leg members 6 which are inserted freely slidably inside each of the left and right poles 3 and a lock mechanism 7 which locks the extendable leg members at any given positions. The lock mechanism consists of a rack 71 provided on the extendable leg members and a locking member 72 including a locking part 721 which is freely rotatably provided near the lower end of the pole and has a rack tooth 711 and a meshing tooth 721a. On the left and right two upper operation levers 8 are swingably arranged on the back of the first upper step 4C of the third step counted from below, and a transmission member 9 for interlocking each of the upper operation levers and the locking member is provided along the poles. When the upper control lever is swung in the direction approaching the back of the first upper step 4C, the locking member is switched to the unlocked position via the transmission member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a telescopic leg device provided on a ladder body in which a plurality of step bars are held in a step shape between two right and left columns.

In a structure for working at a high place such as a ladder provided with a ladder body, a dedicated stepladder, a ladder stepladder, a scaffolding platform, etc., as disclosed in, for example, Patent Document 1 below, an extendable leg device is provided at the lower part of the pillar of the ladder body. What is provided is known.
This telescopic leg device includes an extendable leg member that is slidably inserted from the lower end into each hollow pillar of the ladder body and has a grounding portion at the end on the non-insertion side. And a locking mechanism that locks at the sliding position.
As the locking mechanism, for example, a rack having a large number of teeth arranged on the inner side surface of the telescopic leg member and aligned along the length direction of the telescopic leg member, and a swing extending in the front-rear direction near the lower end of the support column. A locking member that is mounted so as to be swingable around a moving shaft and that has a locking portion made of teeth that mesh with the teeth of the rack at one end, and the teeth of the locking portion of the locking member are racks And an urging member such as a spring that urges toward the direction of meshing with the teeth of the engagement member, and against the urging force of the urging member by pressing upward on the other end of the locking member. A member provided with an operation lever portion that swings the locking member in a direction in which the teeth of the locking portion are disengaged from the teeth of the rack is used (see Patent Document 1 below).
According to the structure for working at a high place such as a ladder provided with the above-mentioned telescopic leg device, even if it is installed on a stepped or inclined ground, the telescopic leg member under one or both struts of the ladder body is required to slide. By locking with the locking mechanism at the position, it can be used safely in a stable state where the central axis is almost vertical, as in the case of installation on a horizontal plane.

JP 2003-193780 A

However, in the telescopic leg device described above, the locking member of the locking mechanism is provided in the vicinity of the lower end portion of the column of the ladder body. While the unlocking operation is being performed by pressing the operation lever portion upward, it is necessary to hold the telescopic leg member with the other hand and slide it in the required direction.
For this reason, for example, in order to extend and retract the telescopic leg member in a state in which a working structure such as a ladder is standing on the installation surface, it is necessary to perform the above work in a deeply crouched posture, which is difficult to work. In addition, both hands were blocked by the same operation, and the ladders and the like were in an unstable state, and there was a risk of falling down.

  The present invention has been made in view of the above-described problems, and can easily perform an expansion / contraction operation of the expansion / contraction leg member in a more comfortable posture, and a ladder or the like falls down during the expansion / contraction operation of the expansion / contraction leg member. It is an object of the present invention to provide a ladder-type telescopic leg device that is superior in safety.

  In order to achieve the above object, the present invention comprises the following aspects.

1) In a ladder body in which a plurality of step bars are held in a step-like manner between two left and right hollow struts, each ladder is slidably inserted from the lower end into each strut and at the end on the side opposite to the insertion side. It has two left and right telescopic leg members having a grounding part and two left and right locking mechanisms that can lock each telescopic leg member to the ladder body at an arbitrary slide position. A locked portion formed along the length direction of the leg member, a locking position provided near the lower end portion of each column in the ladder body and engaged with the locked portion of each telescopic leg member and A ladder body telescopic leg device having a locking member that is switchable between unlocking positions where the engagement with the locking portion is released,
An upper operation member for releasing the lock of each telescopic leg member by each lock mechanism is provided on the back surface of the first upper stepped bar located at the required multiple steps from the bottom so as to perform a predetermined operation. In addition, two left and right transmission members for interlocking the upper operation member and each locking member are provided along each column, and the upper operation member is operated to perform a predetermined operation. A ladder body telescopic leg device in which each locking member is switched to the unlocked position via each transmission member.

2) The left and right upper operation members are provided on the rear surfaces of the left and right sides of the first upper step rail and can switch the locking member of each lock mechanism to the unlock position via each transmission member by a predetermined operation. The ladder body extendable / contracting leg device according to 1), comprising two upper operation members.

3) The left and right upper operation members are mounted so as to be swingable around the axis extending in the left-right direction and in close proximity to each other on the rear surfaces of the substantially left half and the right half of the first upper step rail. The upper and lower flap-shaped upper control levers are pivoted in the unlocking operation direction approaching the back surface of the first upper step rail so that each locking member is engaged via each transmission member. The ladder body extendable leg device according to 2), which is adapted to be switched to the unlocking position.

4) When the left and right ends of the lowermost step pier and the first upper step pedestal are the third step or more from the bottom, between the lowermost step pedestal and the first upper step pedestal, The left and right ends of the second upper stepped pedestal that are positioned are attached via brackets so that the required gaps are formed between each column,
Each transmission member has an elevating bar that is passed through the gap and is slidable along the length direction of each column.
An upper interlocking mechanism is provided at the upper end of each lifting bar and each upper operating lever, which allows each lifting bar to slide downward as each upper operating lever is swung in the unlocking operation direction.
Each locking member is attached to the vicinity of the lower end portion of each column in the ladder body so as to be rotatable about an axis extending in the front-rear direction, and when the locking member is rotated in a required locking direction, It has a locking part to be engaged and is biased in the locking direction by the biasing member so that the engaged state between the locked part and the locking part is maintained.
When the upper / lower bar is slid downward as the upper operating lever swings in the unlocking operation direction, the required position of each locking member is pressed to the lower end of each lifting / lowering bar. 3. The ladder leg extendable leg device according to 3) above, wherein a pressing member that rotates in a direction in which the engagement between the portion and the locking portion is released is attached.

5) Each strut has a substantially U-shaped cross section that opens inward in the left-right direction.
A slider is slidably received through the opening in a lower portion of the first upper step in each column, and the slider is connected to the upper end of each lifting bar,
An arm portion extending in the front-rear direction is provided at the outer end in the left-right direction of each upper operation lever so as to protrude into the lower space of the first upper step rail,
The upper interlocking mechanism has a cam surface inclined in the front-rear direction on the slider, moves from the arm part into the opening of each support column, and moves on the cam surface as each upper operation lever swings. 4. The ladder extendable / contracting leg device according to 4) above, which is a cam mechanism including a cam shaft.

6) Each upper operation lever has a lever body made of a metal shape, the first upper step bar is made of a metal shape, and the upper edge of the lever body of each upper operation lever and the first upper step bar A hinge-forming fitting groove extending in the left-right direction is formed on either one of the upper edges of the rear surface of the back surface of the rear surface, and the other is inserted into the hinge-forming fitting groove from its opening. The telescopic leg device of the ladder body according to any one of 3) to 5) above, wherein a hinge-forming fitting ridge that is movably fitted is formed.

7) The slider is provided so as to be positioned above the cam shaft when each upper operation lever is swung away from the back surface of the first upper step rail, and the slider and the lifting bar slide downward. The ladder body extendable / contracting leg device according to the above 5) or 6), which has a lock state holding stopper for preventing the above.

8) A swing stopper that is swingable about an axis extending in the left-right direction is provided at the arm portion of each upper operation lever. The swing stopper is determined by its own weight when the ladder body is turned upside down. The upper operation lever can be prevented from swinging in the unlocking operation direction by swinging in the direction and being positioned between each upper operation lever and the back surface of the first upper step rail. The extendable leg device of the ladder body according to any one of 5) to 7).

9) A lever return biasing member for biasing each upper operation lever in a direction away from the back surface of the first upper step bar is interposed between each upper operation lever and the back surface of the first upper step bar. The extendable leg device of the ladder body according to any one of 3) to 8) above.

According to the ladder extendable leg device of 1), a predetermined operation is performed by operating the upper operation member provided on the back surface of the first upper stepped rail located at the required plurality of steps from the bottom. As a result, each locking member can be switched to the unlocked position via each transmission member.For example, in a state where the ladder body is erected, it can be expanded and contracted in a comfortable posture while standing deeply. The leg member can be easily expanded and contracted with one hand, and the ladder can be supported by the other hand and prevented from falling down, so that the work can be performed safely.
Moreover, according to the ladder body extendable leg device of 1) above, since the upper operation member is provided on the back surface of the first upper step rail, the upper operation member does not get in the way when using the ladder body, Furthermore, even when the ladder body is used in a state where the ladder body is turned upside down as in the ladder combined use stepladder, the upper operation member does not appear on the front surface or the upper surface (tread surface) of the first upper step rail. There is no risk of disturbing use.

  According to the ladder body extendable leg device of 2) above, the upper operation member is composed of the left and right upper operation members, and the left and right extendable leg members can be individually expanded and contracted by operating these members, respectively. Can be done.

  According to the ladder body telescopic leg device of 3) above, the left and right upper operation members are composed of two left and right flap-shaped upper operation levers, and each upper operation lever is moved to the back of the first upper step rail. Since each locking member can be switched to the unlocking position via each transmission member by swinging in the direction, the lever can be operated together with the first upper step rail with one hand. It can be done very easily. In addition, since the left and right upper operation levers are arranged close to each other, if the left and right upper operation levers are simultaneously held with one hand together with the first upper step rail, the left and right telescopic leg members can be simultaneously unlocked. It is convenient and convenient.

According to the ladder extendable leg device of 4), since the elevating bar is provided as the transmission member, the structure is simple and the cost is reduced, and the elevating bar is connected to each strut and the lowermost step. Since it can be slidably arranged along the length of each column only by passing through the gap between the left and right ends of the rail and the left and right ends of the second upper step rail, it can be incorporated into the ladder body. In addition, no special construction or structure is required, and assembly work can be easily performed.
Further, according to the telescopic leg device of 4) above, the upper operation levers are swung in the unlocking operation direction, so that the upper and lower bars and the upper interlocking mechanisms provided on the upper operation levers are moved. When each lifting bar is lowered, the pressing member provided at the lower end of the lifting bar presses the required portion of each locking member to release the engagement between the locked portion and the locking portion. Thus, the mechanism for unlocking by remote control is simplified, the mechanism can be easily incorporated into the ladder, and the unlocking operation is performed reliably.

According to the ladder extendable leg device of 5), as the upper interlocking mechanism, the slider cam surface connected to the upper end of each lifting bar and the cam shaft provided on the arm portion of each upper operation lever. Therefore, the structure is simple, the cost is reduced, the lifting bar is lowered by swinging the upper operation lever, and the unlocking leg member is unlocked smoothly by the lock mechanism. And excellent operability is obtained.
Further, according to the telescopic leg device of the above 5), since the slider is accommodated through the opening in the substantially U-shaped cross section, the assembling work to the ladder body can be performed more easily. it can.

  According to the ladder extension / contraction leg device of 6), one of the upper edge of the lever main body made of a metal member of each upper operation lever and the upper edge of the back surface of the first upper stepped rail made of a metal member. A hinge-forming fitting groove is formed on the other side, and a hinge-forming fitting groove is formed on the other side, and the hinge-forming fitting groove is inserted into the hinge-forming fitting groove from its opening. Since both are hinge-coupled by simply fitting together, it is possible to attach each upper operation lever to the first upper rail of the ladder body by retrofitting without using any special hinge coupling means. Excellent in properties.

  According to the ladder extendable leg device of 7) above, when each upper operation lever is swung in a direction away from the back surface of the first upper step rail, above the cam shaft of the arm portion in each upper operation lever. Because the slider lock state holding stopper is positioned, the camshaft can be locked from above even when an unintended downward external force is applied to the lift bar by, for example, hitting the lift bar. When the stopper portion is in contact, the slider and the lift bar are prevented from sliding downward to unlock the telescopic leg member, and can be used safely.

  According to the ladder body extendable leg device of the above 8), when the ladder body is used with the ladder body turned upside down, such as a ladder-supporting stepladder, the swing stopper provided on the arm portion of each upper operation lever is provided. Since it swings in a predetermined direction by its own weight and is positioned between each upper operation lever and the back surface of the first upper step rail, each upper operation lever swings in the unlocking operation direction by the same swing stopper. Therefore, there is no fear that the telescopic leg member with the tip upward facing will be inadvertently unlocked and expanded or contracted, and the ladder / ladder can be used safely as a ladder.

  According to the ladder body telescopic leg device of 9) above, when the hand is released from each upper operation lever rotated in the unlocking operation direction approaching the back of the first upper step rail, each upper operation lever is moved to the lever. The telescopic leg member is locked by the lock mechanism so that it can be rotated back in the direction away from the back surface of the first upper step by the urging force of the return urging member to reliably return to the standby position when the unlocking operation is not performed. Is done more reliably.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention, and is an overall perspective view of a ladder and stepladder including an extendable leg device according to the present invention. The locked state of the expansion-contraction leg apparatus is shown, Comprising: (a) is a partial front view, (b) is sectional drawing which follows the BB line of (a). It shows the unlocking state of the telescopic leg device, (a) is a partial front view, (b) is a cross-sectional view taken along line BB of (a). It is a perspective view which shows the lower part of the expansion-contraction leg apparatus. It is a perspective view which decomposes | disassembles and shows the lower part of the expansion-contraction leg apparatus. (A) is a vertical longitudinal cross-sectional view which shows the lower part of the expansion-contraction leg apparatus, (b) is sectional drawing which follows the BB line of (a). It is a perspective view which shows the upper part of the expansion-contraction leg apparatus. It is a perspective view which decomposes | disassembles and shows the upper part of the expansion-contraction leg apparatus. It is a perspective view which decomposes | disassembles and shows the upper operation lever of the expansion-contraction leg apparatus. It is the vertical cross-sectional view which shows the upper part of the expansion-contraction leg apparatus, Comprising: (a) shows the state in which an upper operation lever is in a lock release non-operation position, (b) shows the state in which an upper operation lever is in a lock release operation position (C) shows a state when the ladder body is turned upside down.

Next, an embodiment of the present invention will be described with reference to FIGS.
As shown in the figure, this embodiment is an embodiment in which the ladder body extendable leg device according to the present invention is applied to a ladder and stepladder.
In the following description, the right side of FIGS. 2 (b), 3 (b), and 10 is referred to as “front”, the left side is referred to as “rear”, and “left and right” are as viewed from the front. The left and right (for example, left and right in FIGS. 2A, 3A, and 6) are assumed.

As shown in FIG. 1, the ladder-supporting stepladder (1) has two upper and lower ladder bodies (2F) and (2R) that are connected to each other by hinge brackets (201) so that they can be opened and closed. For example, it can be used as a ladder by rotating the front ladder body (2F) so as to be turned upside down.
Each of the front and rear ladder bodies (2F) (2R) has two hollow struts (3) on the left and right sides, and a plurality of ladders (here, spaced in a vertical direction between both struts (3)) Then, there are 5 pedestals (4A) (4B) (4C) (4D) (4E). When used as a stepladder, the top step (4E) constitutes a top plate.
Opening stoppers (202) are secured between the upper portions of the left struts (3) of the front and rear ladder bodies (2F) (2R) and between the upper portions of the right struts (3). The stop fitting (202) is composed of two links whose one ends are rotatably connected, and a hook provided on the other end of one link is provided on a support pin (3). It is designed to be detachably latched on the top.
The telescopic leg device (5) according to the present invention is provided below the left and right columns (3) of the front and rear ladder bodies (2A) and (2B).

2 to 10 show the detailed structure of the front ladder body (2F). Since the rear ladder body (2R) is substantially symmetrical with the front ladder body (2F), detailed illustration and description are omitted.
The left and right struts (3) of the front ladder body (2F) are made of a metal shape such as an aluminum alloy shape, and have a substantially U-shaped cross section that opens inward in the left-right direction.
Each of the crosspieces (4A), (4B), (4C), (4D), and (4E) is also made of a metal shape such as an aluminum alloy shape, and has a hollow shape having a substantially rectangular cross section.
The left and right ends of the bottom pedestal (4A) and the second pedestal (second upper pedestal) (4B) from the bottom are connected via a pair of front and rear brackets (101) and (102), respectively. Attached to the left and right struts (3). A required gap (S) is formed between the left and right ends of the step bars (4A) and (4B) and the left and right columns (3). The left and right ends of the third step rail from the bottom (first upper step rail) (4C) and the upper step rails (4D) and (4E) are inserted into the left and right columns (3). For example, the rivets (11) are directly attached to the front and rear side walls of the column (3).

  The telescopic leg device (5) provided at the lower part of the left and right struts (3) of the front ladder (2F) is slidably inserted into each strut (3) from the lower end and grounded to the end on the non-insertion side The telescopic leg member (6) having the portion (61) and the lock mechanism (7) for locking the telescopic leg member (6) at an arbitrary slide position are provided.

  The telescopic leg member (6) is made of a metal shape such as an aluminum alloy shape and has a substantially rectangular cross section. The front and rear wall portions of the telescopic leg member (6) are curved in a substantially U shape so as to protrude toward each other. Slide guide ridges (63) are formed in an extended shape on the front and rear edges of the left and right outer side walls of the telescopic leg member (6), and these ridges (63) are formed in each column (3). It is slidably fitted in a vertical groove (31) formed in the left and right outer edges of the inner surfaces of the front and rear walls (see FIG. 6 (b)). An internal enlarged groove (62) that opens inward in the left-right direction is formed in the left-right inner wall portion of the telescopic leg member (6).

The locking mechanism (7) is a rack (locked portion) having a large number of teeth (711) provided on the inner surface in the left-right direction of each telescopic leg member (6) and arranged in the length direction of the telescopic leg member (6). ) (71) and near the lower end of each strut (3) in the front ladder (2F), more specifically, to attach the left and right ends of the bottom step (4A) to the strut (3) A tooth (721a) is attached to the front and rear bracket (101) so as to be swingable about a swing shaft (720) extending in the front-rear direction and meshed with the teeth (711) of the rack (71) at the outer end in the left-right direction. The locking member (72) having the formed locking portion (721), and the locking member (72) are connected to the teeth (721a) of the locking portion (721) by the teeth (711) of the rack (71). ) And a spring (biasing member) (73) that urges in a direction (counterclockwise direction in FIG. 6A).
An operating lever portion (722) is provided at the inner end of the locking member (72) in the left-right direction. By pressing the operating lever portion (722) upward, the spring elastic force of the spring (73) ( The locking member (72) in a direction (clockwise direction in FIG. 6A) in which the teeth (721a) of the locking portion (721) are disengaged from the teeth (711) of the rack (71) against the biasing force). Is swung.
That is, the locking member (72) includes the locking position where the teeth (721a) of the locking portion (721) mesh with the teeth (711) of the rack (71), and the teeth (721a) of the locking portion (721). It is possible to switch between the unlocking positions where the engagement with the teeth (711) of the rack (71) is released.
The spring (73) is interposed in the up-down direction between the inner side portion in the left-right direction of the locking member (72) and the lower surface of the lowermost step rail (4A). A spring holding portion (724) extending upward in a branch shape is formed at the middle position of the lengthwise inner portion of the locking member (72), and this spring holding portion (724) and the swing shaft ( The lower end of the spring (73) is inserted and held between the central portion (723) through which the 720) is inserted.
A metal cover member (103) having a substantially U-shaped cross section is fitted on the lower end of each column (3) so as to cover the opening of each column (3). The front and rear brackets (101) are attached to the front and rear wall portions of the support column (3) by rivets or the like from above the front and rear wall portions of the cover member (103). The cover member (103) is formed with a vertical rectangular communication window (103a) for exposing a part of the teeth (711) of the rack (71). The teeth (721a) of the locking portion (721) of the locking member (72) are engaged with the teeth (711) of the rack (71) through the communication window (103a).
The lock mechanism (7) is not limited to the illustrated one, and can be changed as appropriate. For example, the locking member (72) is provided below the lowermost step rail (4A) as described above, or incorporated in the upper portion of the same step rail (4A) or above the same height of the step rail (4A). It may be provided.

The telescopic leg device (5) is provided with a remote control mechanism having the following configuration.
That is, the left and right telescopic leg members (6) on the left and right locking mechanisms (7) are placed on the back of the first upper step (4C), which is the third step from the bottom of the front ladder (2F). The upper operation member (8) for releasing the lock is provided so as to be able to perform a predetermined operation, and the upper operation member (8) and each locking member (72) are interlocked with each other. Two transmission members (9) on the left and right are provided along each column (3). Then, by operating the upper operation member (8) to perform a predetermined operation, each locking member (72) is switched to the unlocked position via each transmission member (9).
In consideration of the size of a normal ladder body, the first step rail (4C) with the upper operation member (8) on the back side is considered to be appropriate. Depending on the size and usage of the body, it may be a stepped pedestal at the second step from the bottom or a stepped pedestal at the fourth step from the bottom.

The upper operation members are attached to the backs of the substantially left half and substantially right half of the first upper crosspiece (4C) so as to be swingable about the axis extending in the left-right direction and arranged close to each other. It consists of two flap-shaped upper control levers (8). By swinging these upper operation levers (8) in the unlocking operation direction (counterclockwise direction in FIGS. 10 (a) and 10 (b)) approaching the back of the first upper step bar (4C), the transmission member The locking member (71) can be switched to the unlocked position via (9).
Each upper operation lever (8) has a lever body (81) made of a metal shape such as an aluminum alloy shape. The lever main body (81) has a flat hollow shape, and has an inclined wall portion (811) extending upward and obliquely upward at an upper edge portion thereof. A hinge-forming fitting ridge (811a) curved rearward is formed at the tip edge of the inclined wall portion (811).
On the other hand, a hinge-forming fitting groove (41) extending in the left-right direction is formed on the upper edge of the back surface of the first upper step (4C). The fitting groove (41) for forming the hinge has a cross section extending obliquely upward and forward from the upper edge of the back surface of the first upper step rail (4C), and its inner part curves backward. It has been made.
Then, the hinge-forming fitting ridge (811a) of the lever body (81) is inserted into the hinge-forming fitting groove (41) of the first upper step rail (4C) from its opening so as to be rotatable. Thus, the lever main body (81) is attached to the back side of the first upper step rail (4C) so as to be swingable about the fitting protrusion (811a).

A first end cap (82) is fitted over the outer end of the lever body (81) in the left-right direction, which is the side closer to the support post (3). The first end cap (81) is made of a synthetic resin molded product, and passes through the end cap (81) with a tapping screw (not shown) screwed into a tapping screw hole (812) at the bottom of the lever body (81). It is fixed to the lever body (81).
The first end cap (82) is integrally provided with an arm portion (821) extending forward from the lower portion so as to protrude into the lower space of the first upper step rail (4C).
A cam shaft (821a) extending into the opening of each column (3) is integrally formed at an intermediate position (or tip position) of the length of the arm portion (821).
In addition, a swing stopper (84) that can swing around an axis extending in the left-right direction is provided at the base end portion of the arm portion (821). As shown in FIG. 10, the swing stopper (84) is substantially bell-shaped when viewed from the side, and has a half-shaped insertion formed so as to protrude outward in the left-right direction from one end thereof. The portion (841) is loosely inserted into a hole formed in the vertical wall portion of the arm portion (82), so that the portion (841) can swing around the insertion portion (841). As shown in FIGS. 10 (a) and 10 (b), the swing stopper (84) swings in the clockwise direction in FIG. 10 when the ladder and stepladder (1) is used as a stepladder. The arm portion (82) is tilted sideways so as to come into contact with the horizontal lower wall portion so as not to interfere with the first upper step rail when the upper operation lever is swung. On the other hand, as shown in FIG. 10 (c), when one ladder body (for example, the front ladder (2F)) is turned upside down in order to use the ladder and stepladder (1) as a ladder, the same ladder body is used. The rocking stopper (84) is swung counterclockwise in FIG. 10 (c) by its own weight and is brought into contact with the lever body (81), and the lever body (81) of the upper operating lever (8) It is located so that it may be pinched | interposed between the back surfaces of a 1st upper step crosspiece (4C). Therefore, when the ladder body is turned upside down as shown in the figure, the upper operation lever (8) is swung in the unlocking operation direction (counterclockwise direction in FIG. 10 (c)) by the swing stopper (84). For example, even if the upper operating lever (8) is pushed when going up and down the ladder, the locking mechanism (7) may cause the locking of the telescopic leg member (6) by mistake. And can be used safely.

A second end cap (83) is fitted over the inner end of the lever body (81) in the left-right direction, which is the side closer to the center of the length of the first upper step (4C). The second end cap (83) is made of a synthetic resin molded product, and the insertion part (832) having a substantially cross-shaped cross section formed so as to protrude from one side thereof is provided in the inner end of the lever body (81) in the left-right direction. Is fixed to the same end.
The second end cap (83) is integrally formed with a lever return leaf spring (lever return biasing member) (831). The leaf spring portion (831) has a substantially tongue-like shape when viewed from the front and extends in a curved shape obliquely forward from the second end cap (83) toward the left and right in the left-right direction. ) And the back surface of the first upper step rail (4C), and the upper operation lever (8) is biased away from the back surface of the first upper step rail (4C) by its spring elasticity. .

Each transmission member (9) has a gap (S between the left and right struts (3) and the left and right ends of the bottom stepped foot (4A) and the second upper stepped foot (4B) located at the second step from the bottom. ) And an elevating bar (91) that is slidable along the length direction of each column (3). The elevating bar (91) has a substantially strip-like shape in which front and rear edges are bent outward in the left-right direction. The length of the lifting bar (91) is slightly shorter than the length from the lower surface of the first upper step (4C) to the upper surface of the lowermost step (4A) at the inner side in the left-right direction of the column (3). Has been made. The width of the elevating bar (91) is slightly smaller than the width of the inner side in the left-right direction of the column (3).
A vertically long strip-shaped communication window (911) is formed at the lower end of the lift bar (91). This communication window (911) is used when the retaining cap (62) is fitted and fixed to the upper end of the telescopic leg member (6) inserted into the support column (3). The retaining cap (62) has a retaining portion (621) that protrudes inward in the left-right direction, and the retaining portion (621) contacts the upper edge of the cover member (103) to expand and contract. The leg member (6) is prevented from falling off the support (3). By providing a communication window (911) in the lifting bar (91), the retaining cap (62) is fitted and fixed to the upper end of the telescopic leg member (6) in the final step of assembling the front ladder body (2F). As a result, assembly work is simplified.

A slider (92) is slidably accommodated through the opening of the column (3) in the lower part of the first upper step (4C) in the column (3). The slider (92) is connected to the upper end of the lift bar (91).
The slider (92) is made of a synthetic resin molded product having a substantially square block shape, and the upper end of the elevating bar (91) is connected and fixed to the lower part of the inner side surface in the left-right direction by a rivet or the like.
On the upper surface of the slider (92), a cam surface (921) having an upwardly inclined shape is formed. The cam shaft (821a) is slid on the cam surface (921) as the upper operation lever (8) swings. These cam surfaces (921) and cam shafts (821a) provide a cam mechanism (upper interlocking mechanism) that converts the swinging motion of the upper control lever (8) into the vertical motion of the slider (92) and the lifting bar (91). It is composed. That is, when the upper operating lever (8) is swung in the unlocking operation direction (counterclockwise direction in FIGS. 10 (a) and 10 (b)), the cam shaft (821a) moves over the cam surface (921) with its lower end. The slider (92) is pushed down by sliding from the portion toward the upper end portion, and as a result, the lift bar (91) is slid downward.
The slider (92) is provided with a lock state holding stopper (922) so as to be positioned above the lower end of the cam surface. The stopper portion (922) is a substantially horizontal rod-like shape provided on the outer wall portion that rises from the lateral outer edge of the cam surface (921) of the slider (92) so as to protrude toward the cam surface (921). The upper operation lever (8) is positioned above the cam shaft (821a) when the upper operation lever (8) is swung in a direction away from the back surface of the first upper step rail (4C). Therefore, even when an unintended downward external force is applied to the lifting / lowering bar (91) by touching the lifting / lowering bar (91), for example, the stopper portion (922) is provided on the camshaft (821a) from above. This prevents the slider (92) and the lift bar (91) from sliding downward and unlocking the telescopic leg member (6).

A pressing member (93) is attached to the lower end of the elevating bar (91). The pressing member (93) has a substantially vertically long plate shape, and is made of, for example, a synthetic resin molded product. The pressing member (93) has a step portion (932) that receives the lower end surface of the elevating bar (91) at a height intermediate position on the back surface thereof, and is connected and fixed to the lower end portion of the elevating bar (91) by a rivet, for example. Has been.
The lower end portion of the pressing member (93) is narrower than the upper portion, and the lower end portion is close to or abuts on the upper surface of the locking portion (721) of the locking member (72). The pressing portion (931) is positioned.

Next, an operation procedure for unlocking the telescopic leg member (6) by the lock mechanism (7) using the remote operation mechanism will be described.
That is, when the upper control lever (8) is held with one hand together with the first upper step bar (4C) and swung in the unlocking operation direction, the cam shaft (821a) is directed forward on the cam surface (921). Thus, the slider (92), the elevating bar (91) and the pressing member (93) are slid downward. Then, the pressing portion (931) of the pressing member (93) presses the upper surface of the locking portion (721) of the locking member (72), and the locking member (72) is rotated in the unlocking direction, and the rack The engagement (engagement) between the teeth (711) of (71) and the teeth (721a) of the locking portion (721) is released. As a result, the telescopic leg member (6) is slidable with respect to the column (3), so that the telescopic leg member (6) can be expanded and contracted by a required length.
When the hand is released from the upper operating lever (8), the locking member (72) is rotated in the locking direction by the spring elastic force of the spring (73), and the teeth (721a) of the locking portion (721) are moved to the rack ( 71) and the telescopic leg member (6) is locked again. Further, by the above rotation of the locking member (72), the locking portion (721) presses the pressing portion (931) of the pressing member (93) upward. Along with this, the slider (92), the lifting bar (91) and the pressing member (93) are slid upward, and the cam shaft (821a) is slid rearward on the cam surface (921). Thereby, the upper operation lever (8) is swung in a direction away from the back surface of the first upper step bar (4C). Since the spring elastic force of the lever return leaf spring portion (831) also acts on the swinging of the upper operation lever (8) in the above direction, the upper operation lever (8) can be quickly moved to the standby position when not operated. It will definitely return.
As described above, according to the telescopic leg device (5) of this embodiment, the unlocking operation of the telescopic leg member (6) is performed at the first upper position located at the third level from the bottom of the ladder bodies (2F) (2R). Since it is performed by the upper operation lever (8) provided on the back surface of the step rail (4C), it can be easily performed in an easy posture while standing.
The unlocking operation is performed separately for the left and right telescopic leg members (6), and if the left and right upper control levers (8) are held together with the first upper step (4C) with one hand at the same time, The telescopic leg member (6) can be unlocked at the same time, which is convenient.
Furthermore, according to the telescopic leg device (5) of this embodiment, even when the ladder-supporting stepladder (1) is used as a ladder by inverting one of the ladder bodies (2F), the upper operation lever (8) is provided. Since it does not appear on the front or upper surface (tread) of the first upper step rail (4C), there is no risk of hindering the use of the ladder.

  In the above embodiment, the example of applying the extendable leg device of the ladder body according to the present invention to the ladder-supporting stepladder has been shown, but the present invention is another structure for working at a high altitude equipped with a ladder body, that is, The same applies to ladders, dedicated stepladders, scaffolding platforms, and the like.

  The present invention is preferably used as a telescopic leg device provided at a lower portion of a support of a ladder body in a structure for working at a high place such as a ladder provided with a ladder body, a dedicated stepladder, a ladder-supporting stepladder, and a scaffolding platform. is there.

(1): Ladder stepladder
(2F): Front ladder body
(2R): Rear ladder body
(3): Prop
(4A): Bottom pedestal
(4B): 2nd upper pedestal (second level pedestal counting from the bottom)
(4C): No. 1 upper tram (third level tram from the bottom)
(41): Fitting groove for hinge formation
(5): Telescopic leg device
(6): Telescopic leg member
(61): Grounding part
(7): Lock mechanism
(71): Rack (locked part)
(711): (rack) teeth
(72): Locking member
(721): Locking part
(73): Spring (biasing member)
(8): Upper operation lever (upper operation member)
(81): Lever body
(811a): Mating ridge for hinge formation
(82): First end cap
(821): Arm
(821a): Cam shaft (cam mechanism, upper interlocking mechanism)
(83): Second end cap
(831): Lever return leaf spring (lever return biasing member)
(84): Swing stopper
(9): Transmission member
(91): Lift bar
(92): Slider
(921): Cam surface (cam mechanism, upper interlocking mechanism)
(922): Stopper for holding locked state
(10) (11): Bracket
(S): The left and right ends of the lowermost step rail and the gaps between the left and right ends of the second upper step rail and each column

Claims (9)

In a ladder body in which a plurality of step bars are stepped between two left and right hollow struts, each ladder is slidably inserted from the lower end into each strut, and a grounding portion at the end on the non-insertion side 2 left and right telescopic leg members, and two left and right locking mechanisms that can lock each telescopic leg member to the ladder body at an arbitrary slide position. And a locked position that engages with a locked portion of each telescopic leg member that is provided near the lower end of each column in the ladder body. A ladder body telescopic leg device having a locking member that is switchable between unlocking positions where the engagement with the part is released,
An upper operation member for releasing the lock of each telescopic leg member by each lock mechanism is provided on the back surface of the first upper stepped bar located at the required multiple steps from the bottom so as to perform a predetermined operation. In addition, two left and right transmission members for interlocking the upper operation member and each locking member are provided along each column, and the upper operation member is operated to perform a predetermined operation. A ladder body telescopic leg device in which each locking member is switched to the unlocked position via each transmission member.   Upper and lower operation members are provided on the rear surfaces of the left and right sides of the first upper crosspiece, respectively, and can be used to switch the locking member of each lock mechanism to the unlocked position via each transmission member by a predetermined operation. The ladder leg extendable leg device according to claim 1, comprising an upper operation member.   Two left and right upper operation members are attached to the back of each of the substantially left half and substantially right half of the first upper step rail so as to be swingable around a shaft extending in the left-right direction and close to each other. It consists of two left and right flap-shaped upper operation levers, and each locking member is unlocked via each transmission member by swinging each upper operation lever in the unlocking operation direction approaching the back of the first upper step rail. The expansion / contraction leg device for a ladder body according to claim 2, wherein the expansion / contraction device is adapted to be switched to a position. Each strut is positioned between the bottom and first upper pedestals when the left and right ends of the lowermost pedestal and the first upper pedestal are 3rd or higher from the bottom. The left and right ends of the second upper step rail are attached via brackets so that the necessary gaps are formed between the columns.
Each transmission member has an elevating bar that is passed through the gap and is slidable along the length direction of each column.
An upper interlocking mechanism is provided at the upper end of each lifting bar and each upper operating lever, which allows each lifting bar to slide downward as each upper operating lever is swung in the unlocking operation direction.
Each locking member is attached to the vicinity of the lower end portion of each column in the ladder body so as to be rotatable about an axis extending in the front-rear direction, and when the locking member is rotated in a required locking direction, It has a locking part to be engaged and is biased in the locking direction by the biasing member so that the engaged state between the locked part and the locking part is maintained.
When the upper / lower bar is slid downward as the upper operating lever swings in the unlocking operation direction, the required position of each locking member is pressed to the lower end of each lifting / lowering bar. The expansion / contraction leg device for a ladder body according to claim 3, wherein a pressing member that rotates in a direction in which the engagement between the portion and the locking portion is released is attached. Each strut has a substantially U-shaped cross section that opens inward in the left-right direction,
A slider is slidably received through the opening in a lower portion of the first upper step in each column, and the slider is connected to the upper end of each lifting bar,
An arm portion extending in the front-rear direction is provided at the outer end in the left-right direction of each upper operation lever so as to protrude into the lower space of the first upper step rail,
The upper interlocking mechanism has a cam surface inclined in the front-rear direction on the slider, moves from the arm part into the opening of each support column, and moves on the cam surface as each upper operation lever swings. The extendable leg device for a ladder body according to claim 4, which is a cam mechanism comprising a cam shaft.   Each upper operation lever has a lever body made of a metal shape, the first upper step bar is made of a metal shape, the upper edge of the lever body of each upper operation lever, and the back surface of the first upper step bar One of the upper edge portions is formed with a hinge-forming fitting groove extending in the left-right direction, and the other is inserted into the hinge-forming fitting groove from its opening and freely rotatable. The extension / contraction leg apparatus of the ladder body as described in any one of Claims 3-5 in which the fitting convex line for hinge formation fitted in is formed.   The slider is provided so as to be positioned above the camshaft when each upper operation lever is swung away from the back surface of the first upper step rail to prevent the slider and the lifting bar from sliding downward. The ladder body extendable / contracting leg device according to claim 5 or 6, further comprising a locking state holding stopper portion.   Each upper control lever arm is provided with a swing stopper that can swing around an axis extending in the left-right direction. The swing stopper is moved in a predetermined direction by its own weight when the ladder body is turned upside down. The upper control lever can be prevented from swinging in the unlocking operation direction by swinging and being positioned between each upper operation lever and the back surface of the first upper step rail. The expansion-contraction leg apparatus of the ladder body as described in any one of -7. The lever return urging member for urging each upper operation lever in a direction away from the back surface of the first upper step bar is interposed between each upper operation lever and the back surface of the first upper step bar. The ladder leg expansion / contraction device according to any one of 3 to 8.

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