JP2010024653A - Lock mechanism of extensible/contractible object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lock mechanism capable of inserting an insertion body into a cylindrical body in a freely extensible and contractible manner to fix the insertion body at an extending or contracting position and maintaining a locked state by use of a locking member by a locking member itself. <P>SOLUTION: In this lock mechanism for fixing the insertion body 16 inserted into the cylindrical body 15 in a freely extensible or contractible manner at the extending or contracting position, an engaging hole 20 is formed in the insertion body 16, the locking member 27 is pivotally supported on a supporting frame 25 fixed on the cylindrical body 15 to swing freely, and an engaging part 45 entering the engaging hole 20 in the insertion body 16 and engaging with it from an inner side is formed on the locking member 27. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lock mechanism for a telescopic body that can be suitably used for a support such as a scaffold, a ladder, or a stepladder.

There is a stepladder disclosed in Patent Document 1 as an apparatus including an expansion body and a lock mechanism that locks expansion and contraction of the expansion body.
The pair of left and right columns (extensible bodies) of the stepladder are telescopic, and each column has a cylindrical column main body and a leg column inserted into the column main body. The pedestal is fixed so as not to move with respect to the column main body by a lock mechanism.
The lock mechanism includes a lock member that is swingably supported by a foot member that connects the left and right support columns, and that engages with the leg column by swinging, and a handle that swings the lock member away from the leg column. The engagement of the lock member with the pedestal is released by placing the hand on the handle and swinging the lock member in the disengagement direction.

Further, the handle is supported so as to be movable in a direction perpendicular to the swinging direction with respect to the support frame, and the lock member is moved by the movement of the handle when the lock member locks the insertion body between the support frame and the handle. There is provided a latching means for preventing the swaying movement.
In other words, after the operation of swinging the handle to swing the lock member and the operation of moving the handle in the axial direction and hooking, the telescopic extension of the column is locked or the locked state is changed. It was configured to be released.
JP 2006-52581 A

In a conventional locking mechanism for a telescopic body, the lock state of the lock member is maintained by stopping the swinging of the handle, and two operations, an operation of swinging the handle and an operation of moving the handle in the axial direction and hooking it. Was necessary.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lock mechanism for a telescopic body that can maintain the locked state by the lock member with the lock member itself.

In order to achieve the above object, the present invention has taken the following measures.
In other words, the lock mechanism 12 of the stretchable body 10 according to the present invention is a lock mechanism that fixes the insert 16 that is inserted into the cylinder 15 so as to be stretchable and retracted. The lock member 27 is pivotally supported on the support frame 25 fixed to the cylindrical body 15 so as to be swingable. The lock member 27 enters the engagement hole 20 of the insert 16 and engages from the inside. A portion 45 is formed.
According to this, the state which locks the insertion body 16 by the lock member 27 can be maintained by the lock member 27 itself.

According to another technical means for solving the problems in the present invention, the engaging portion 45 of the lock member 27 abuts against the upper edge 20a of the engaging hole 20 to prevent it from coming out of the insert 16. A working surface 48 is provided.
According to this, when the engagement portion 45 of the lock member 27 is engaged with the engagement hole 20 of the insert 16 and is in the locked state, the lock member 27 is extended when the cylinder 15 and the insert 16 are extended. The action surface 48 prevents the insertion body 16 from coming off.
According to another technical means for solving the problems in the present invention, the action surface 48 of the lock member 27 is formed as an arc surface having a concave surface along the swinging direction of the lock member 27. The curvature center line R is arranged so as to pass through the rocking fulcrum P of the lock member 27 or the lower part P1 thereof.

Thus, when the working surface 48 of the lock member 27 is a concave arcuate surface, the lock member 27 can be more reliably prevented from coming off, and when the lock member 27 is swung, the working surface 48 and the engagement hole 20 are separated. The contact with the hole upper edge 20a is hardly increased.
Another technical means for solving the problems in the present invention is that the working surface 48 of the lock member 27 is obliquely upward from the point of contact with the upper edge 20a of the engagement hole 20 toward the inside of the insert 16. The perpendicular S to the flat surface is arranged so as to pass through the swing fulcrum P of the lock member 27 or the lower side P1 thereof.

In this way, even if the working surface 48 of the lock member 27 is flat, the lock member 27 can be more reliably prevented from being pulled out, and when the lock member 27 is swung, the hole between the working surface 48 and the engagement hole 20 can be obtained. There is almost no increase in contact with the upper edge 20a.
The “tubular body 15” and the “insert 16” include a strip material having a hollow cross-section and a groove-shaped strip material having a U-shaped cross section.

  In the lock mechanism of the stretchable body according to the present invention, the lock state by the lock member can be maintained by the lock member itself.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIGS. 1 to 4 show a locking mechanism of the telescopic body 10 according to the present invention, and FIGS. 5 to 7 show an example of a scaffolding base 1 equipped with this locking mechanism.
As shown in FIG. 5 to FIG. 7, the scaffold base 1 is formed by connecting the upper portions of a pair of ladders 2 arranged at a predetermined interval with a base plate 3, and a bracket 4 fixed to each ladder 2. It is mainly configured by pivotally supporting a bracket 5 fixed to the base plate 3 with a pin 6. The brackets 4 and 5 can be fixed to each other by changing the rotation angle of the lock lever 7 by selectively engaging the lock lever 7 with the positioning holes 8a and 8b. The platform 1 can be changed between a use state in which both ladders 2 are placed on the ground surface and a folded state in which both ladders 2 are folded so as to be folded on the base plate 3.

The ladder 2 includes a pair of telescopic struts 10 (hereinafter referred to as “expandable bodies 10”) arranged at a predetermined interval from each other, and a plurality of traverse members 11 (steps) that connect the both stretchable bodies 10 to each other. And have. In all the stretchable bodies 10, a lock mechanism 12 (lock device) is provided at a connecting portion between the lowermost stepped-piece member 11 and the stretchable body 10.
In the following description, for convenience of explanation, as shown in FIG. 5, the longitudinal direction of the base plate 3 (the left-right direction in FIG. 5 and the through direction in FIG. 6) is referred to as the front-rear direction, and as shown in FIG. The longitudinal direction of the crosspiece member 11 (the left and right direction in FIG. 6 and the through direction in FIG. 5) is referred to as the left and right direction.

Each stretchable body 10 includes a column main body 15 (hereinafter referred to as “cylinder 15”) and a pedestal 16 (hereinafter referred to as “insert 16”) inserted into the cylinder 15; The stretchable body 10 can be stretched by sliding the insert 16 in the axial direction (vertical direction), and the insert 16 is moved in the axial direction at a predetermined position stretched by operating the lock mechanism 12. Can be fixed to impossible.
The cylinder 15 is a strip formed of a metal material such as aluminum in a rectangular tube shape. In this embodiment, a groove-shaped strip material having a U-shaped cross section is employed, and the side surface corresponding to the bottom of the groove is outward in the left-right direction, and the opening generated in the longitudinal direction of the groove is inward in the left-right direction. Are arranged as follows. Further, both end portions in the longitudinal direction of the cylindrical body 15 are open ends.

The insert 16 is a strip formed of a metal material such as aluminum in a rectangular tube shape. In the present embodiment, a rectangular tube material that fits in the groove without rattling is adopted for the groove-shaped material used for the tube body 15, and the groove opening in the tube body 15 is set when this fitting state is established. A plurality of engagement holes 20 are formed at predetermined intervals on the side surface to be closed. In this embodiment, the engagement hole 20 is a horizontally long square hole. A grounding member 21 is attached to the lower end portion of the insert 16 so that the ladder 2 is grounded to the grounding surface in a stable state.
The crosspiece member 11 is formed as a hollow trapezoidal square tube, and is laid between the left and right cylinders 15 and 15 via a connecting plate 23 that is fixed so as to sandwich the cylinder 15. On the upper surface of the crosspiece member 11, a non-slip unevenness is formed in the longitudinal direction.

The locking mechanism 12 has a support frame 25 fixed to the cylindrical body 15 and a pivot 26 provided in the front-rear direction (the paper surface penetrating direction in FIG. 1) near the upper portion of the support frame 25. A lock member 27 pivotally supported in a direction (direction a in FIG. 1) and a handle 28 for swinging the lock member 27 are provided.
The support frame 25 is mounted so as to embrace the corner portion where the cylinder 15 and the crosspiece member 11 are connected from the front and rear, and is formed by bending a metal plate such as aluminum into a box shape. The support frame 25 is fixed by a fixing tool 30 such as a rivet in a state where the front and rear peripheral wall portions are in contact with the front and rear walls of the cylindrical body 15 and the front and rear walls of the tread member 11, respectively. That is, the support frame 25 also functions as a bracket for connecting the lowermost stepped-piece member 11 to the cylindrical body 15, which leads to a reduction in the number of connection plates 23 used.

A notch-shaped restriction port 33 (see FIG. 2) along the longitudinal direction of the traverse member 11 is formed on the upper surface of the traverse member 11 at a portion where the support frame 25 is covered. A restriction piece 34 that fits into the restriction port 33 is formed so as to extend downward. The restricting piece 34 swings in the restricting port 33 without rattling as the lock member 27 swings.
The handle 28 is connected to the pivot 26 so as to be rotatable together. The handle 28 is provided with a swing guide 35 that passes through the support frame 25 in the front-rear direction so that the pivot 26 and the axis are parallel to each other below the pivot 26. Accordingly, when the handle 28 is swung, the swing guide 35 swings (circular movement) together with the pivot 26 as a fulcrum. As shown in FIG. 6, the handle 28 has a display indicating the operation direction at a position where the scaffold 1 can be easily seen in the appearance (in the example shown, the lower end of the handle 28 is shaped like an arrow and “ 3) is displayed in 3D.

On the other hand, the support frame 25 is formed with guide holes 36 through which both end portions of the swing guide 35 are passed. These guide holes 36 are formed as long holes having an arc shape centered on the pivot 26 so as to allow the swing (arc movement) when the swing guide 35 swings together with the handle 28. ing.
The lock member 27 is provided with a guide receiving portion 37 that is fitted to the swing guide 35 from above. The guide receiving portion 37 in the illustrated example is formed in a semicircular groove shape with the opening facing downward. That is, the lock member 27 is in a state in which the pivot 26 passes through the upper part, and is fitted to the swing guide 35 by the guide receiving portion 37 provided on the lower side, so that the handle 28 supports the pivot 26 as a fulcrum. As a result, the handle 28 (the swing guide 35) swings integrally (the lock member 27).

A protrusion 38 is formed at the tip of the pivot 26 (the end opposite to the handle 28), and escape from the rear wall of the support frame 25 is prevented. The member 27 and the handle 28 are not detached from the support frame 25.
The pivot 26 is fitted with an engagement biasing tool 40 that biases the swing guide 35 toward the insertion body 16. In the present embodiment, a coil spring is employed as the engagement biasing device 40. Protruding legs 41 that are in contact with the inner inner surface of the support frame 25 are provided at both ends of the coil spring, and swinging is provided at the center of the coil spring. A U-shaped bent leg 42 that engages with the guide 35 is provided.

That is, between the projecting leg 41 and the bent leg 42, a spring force repelling this is generated as a restoring force when the coil spring is twisted in the winding direction. By utilizing this, the inner back surface of the support frame 25 and the swing guide 35 are separated from each other. As a result, the lock member 27 and the handle 28 are subjected to a swinging biasing action around the pivot 26 via the swinging guide 35 by the engagement biasing tool 40, so that the lock member 27 is pressed against the insert 16. Become.
The lock member 27 is provided with an engagement portion 45 that can be inserted into and removed from the engagement hole 20 of the insertion body 16 by swinging, and that is inserted into and engaged with or disengaged from the engagement hole 20. Yes. As shown in FIG. 7, the engagement holes 20 are a plurality of square holes formed in the insert 16 along the longitudinal direction, and the engagement portions 45 have a square shape in plan view so that they can be inserted into and removed from the square holes. What is formed as a protrusion to be exhibited is shown.

As shown in FIGS. 3 and 4, the engaging portion 45 is provided with a claw portion 46 that protrudes upward inside the cylindrical body 15 and the insertion body 16 while being engaged with the engaging hole 20. The upper edge surface of the claw portion 46 forms a working surface 48 that performs a cam action. The action surface 48 is formed in a circular arc surface having a concave surface along the rocking direction of the lock member 27, and is arranged so that the curvature center line R of the arc surface passes through the rocking fulcrum P of the lock member 27. Has been.
In the present embodiment, the working surface 48 with respect to the mutual distance L between the contact point Q at which the working surface 48 of the engaging portion 45 contacts the hole upper edge 20a of the engaging hole 20 and the rocking fulcrum P of the lock member 27. The case where the curvature center line R of (arc surface) is the same length (L = R) is shown. Therefore, when the lock member 27 is swung, the contact point Q moves on the working surface 48 while maintaining a certain distance from the rocking fulcrum P, and slides against the rocking of the lock member 27. There is no increase in dynamic resistance.

With such a configuration, the cylindrical body 15 and the insertion body 16 are extended in the stretchable body 10 in a state where the engagement portion 45 is engaged with the engagement hole 20 (in short, a locked state by the lock member 27). Even so, the contact point Q does not move with respect to the working surface 48. Therefore, no rotational moment is generated with respect to the lock member 27 so as to swing the engaging portion 45 in the direction away from the engaging hole 20, and the lock member 27 does not swing.
As described above, the operation of extending the cylindrical body 15 and the insertion body 16 does not lead to the detachment swinging of the lock member 27, so that the engagement between the engagement portion 45 and the engagement hole 20 is not released. Rather, a cam action that strengthens the contact of the engagement hole 20 with the upper edge 20a of the engagement hole 20 occurs on the action surface 48, and this locks the lock state by the lock member 27 more reliably. The insert 16 does not extend.

Therefore, unless the handle 28 is swung, the lock member 27 cannot be detached and swung (the engagement portion 45 can be disengaged from the engagement hole 20). On the other hand, the handle 28 is locked. Therefore, it is only necessary to swing once. As a result, the operation of the handle 28 is simplified.
As shown in FIG. 4, when the external force acting on the contact point Q when the cylindrical body 15 and the insertion body 16 are extended is F, at the contact point Q, the acting surface 48 (assuming the tangential direction of the arc surface) ) To generate a component force F1 perpendicular to. In order to prevent the component force F <b> 1 from becoming a rotational moment that detaches and swings the lock member 27, the working surface 48 is formed as a concave arc surface, or the curvature center line R of the arc surface is defined as the lock member 27. Are arranged so as to pass through or below.

Next, in the scaffold base 1 provided with the locking mechanism 12 of the expansion / contraction body 10 according to the present invention, the usage situation will be briefly described. When the handle 28 is in a locked state, the engagement portion 45 of the lock member 27 and the engagement hole 20 of the insert 16 are engaged, and the action surface 48 of the engagement portion 45 and the engagement hole 20 are above the hole. The edge 20a is in contact. When in the locked state, the engagement between the engagement portion 45 and the engagement hole 20 is disengaged as described above even if the cylinder 15 and the insertion body 16 are extended in the telescopic body 10. There is no. Therefore, the locked state is reliably maintained.
On the other hand, when it is necessary to extend the cylinder 15 and the insert 16 in the telescopic body 10, the handle 28 is swung only once in the unlocking direction. The swinging of the handle 28 is performed against the spring force of the engaging biasing device 40, and the lock member 27 is also swung together via the swinging guide 35 as the handle 28 swings. Will move. Thus, when the lock member 27 is swung by receiving the operation force from the handle 28, the operation of the engagement portion 45 to be disengaged from the engagement hole 20 becomes possible for the first time.

While the engagement portion 45 is detached from the engagement hole 20, the cylinder 15 and the insertion body 16 are extended or contracted in the telescopic body 10, and then the operating force to the handle 28 is loosened. Then, the handle 28 is returned to the state before the swinging operation by the spring force of the engagement biasing tool 40.
Accordingly, the lock member 27 is also returned to the state before the swinging together with the handle 28, and the engagement portion 45 of the lock member 27 and the engagement hole 20 of the insert 16 are engaged, It returns to the locked state where the action surface 48 of the engaging portion 45 and the hole upper edge 20a of the engaging hole 20 abut. As described above, in this locked state, even if the cylinder 15 and the insert 16 are extended in the stretchable body 10, the locked state is reliably maintained. There is no need to perform an operation to ensure the locked state.

8 and 9 show another embodiment of the lock member 27. The working surface 48 formed on the lock member 27 of this embodiment is formed in a circular arc surface that is concave so as to follow the swinging direction of the lock member 27, and the curvature center line R of this arc surface is the lock member 27. It is arranged so as to pass below (P1) from the swing support point P of 27. That is, the angle θ formed between Q-P1 and the straight line QP connecting the contact point Q and the swing fulcrum P is 0 <θ.
In the present embodiment, the working surface 48 with respect to the mutual distance L between the contact point Q at which the working surface 48 of the engaging portion 45 contacts the hole upper edge 20a of the engaging hole 20 and the rocking fulcrum P of the lock member 27. The case where the curvature center line R of (arc surface) is short (L> R) is shown. Note that L = R may be set. Further, R <L and θ = 0 may be set.

With such a configuration, when the engagement portion 45 is engaged with the engagement hole 20 (in short, locked by the lock member 27), the cylindrical body 15 and the insertion body 16 are extended in the stretchable body 10. When doing so, a cam action that enhances the contact of the engagement hole 20 with the upper edge 20a of the engagement hole 20 occurs on the action surface 48.
10 and 11 show still another embodiment of the lock member 27. The working surface 48 formed on the lock member 27 of this embodiment starts from a point (abutment point Q) that abuts on the hole upper edge 20a of the engagement hole 20 when the engagement portion 45 engages with the engagement hole 20. It is formed in the flat surface which inclines diagonally upward toward the inside of the cylinder 15 or the insertion body 16, and the perpendicular line S with respect to this flat surface passes below the rocking | fluctuation fulcrum P of the lock member 27 (P1). Is arranged. That is, 0 <θ.

According to this, since the action surface of the lock member can be formed as a flat surface, there is an advantage that the structure can be simplified and the cost can be reduced.
In addition, the perpendicular line S with respect to the flat surface of the working surface 48 may be disposed so as to pass through the swing fulcrum P of the lock member 27.
The present invention is not limited to the embodiments described above. For example, the lock mechanism 12 of the stretchable body 10 according to the present invention may be applied not only to the scaffold base 1 having the extendable support column but also to a ladder or a stepladder having the extendable support column.

In addition, the stretchable body 10 is not limited to a support composed of a support body and a pedestal, and the stretchable body 10 may be a member that expands and contracts as a whole when an insert is inserted into a cylindrical member. The cylindrical body 15 only needs to be able to insert the insertion body 16, and the cylindrical body 15 includes, for example, a U-shaped channel material or a solid material.
The engaging portion 45 of the lock member 27 has an L-shaped hook-shaped tip, and the hook-shaped tip is inserted from the engaging hole 20 of the insert 16 to abut the inner surface of the insert 16. Accordingly, the engaging portion 45 may be engaged with the engaging hole 20 from the inside of the insertion body 16 so as to prevent it from coming off. In this case, the cam action for pulling the engaging portion 45 into the insert 16 at the tip of the engaging portion 45 is not successful.

Although the restriction port 33 is provided on the upper surface of the traverse member 11, and the lock member 27 is provided with the restriction piece 34 that fits into the restriction port 33, these may be omitted.
The engagement hole 20 may have an opening shape other than the square hole. Similarly, the shape of the engagement portion 45 can be changed as appropriate in accordance with the opening shape of the engagement hole 20.

The principal part of embodiment of this invention is shown and it is the DD sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG. It is the side view which showed the locking member of the locking mechanism. It is the X section enlarged view of FIG. It is a side view of a stepladder. It is a front view equivalent to the AA line arrow enlarged view of FIG. It is a BB line arrow line view of FIG. It is the side view which showed another embodiment of the locking member. It is the Y section enlarged view of FIG. It is the side view which showed another embodiment of the locking member. It is the Z section enlarged view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Locking mechanism 15 Cylindrical body 16 Insert body 20 Engagement hole 25 Support frame 27 Lock member 28 Handle 45 Engagement part 48 Working surface

Claims (4)

A locking mechanism for fixing the insertion body (16) inserted into the cylinder (15) in a telescopic position at the telescopic position;
An engagement hole (20) is formed in the insert (16), and a lock member (27) is pivotally supported on a support frame (25) fixed to the cylinder (15). 27) A locking mechanism for a telescopic body, characterized in that an engaging portion (45) that engages from the inside by entering the engaging hole (20) of the insert (16) is formed in 27).   The engaging portion (45) of the locking member (27) is in contact with the upper edge (20a) of the engaging hole (20) to prevent the locking member (27) from coming out of the insert (16). The locking mechanism for the stretchable body according to claim 1, wherein   The action surface (48) of the lock member (27) is formed as a concave arc surface along the swinging direction of the lock member (27), and the curvature center line (R) of the arc surface is locked. The lock mechanism of the telescopic body according to claim 2, wherein the lock mechanism is arranged so as to pass through the swing fulcrum (P) of the member (27) or below (P1).   The working surface (48) of the locking member (27) is a flat surface that is inclined obliquely upward from the point in contact with the upper edge (20a) of the engagement hole (20) toward the inside of the insert (16). The vertical line (S) with respect to the flat plane is disposed so as to pass through the swing fulcrum (P) of the lock member (27) or below (P1) thereof. The lock mechanism of the elastic body as described.

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