JP2013057244A - Stopper device for stepladder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stopper device for a stepladder which is configured to eliminate the risk for a worker to be injured by catching a finger between legs when opening/closing the legs.SOLUTION: A stopper device (6) is provided in which a pair of legs (4a, 4b) are connected to be freely opened/closed and are held not to be opened from a predetermined leg opening state. First arm means (7) is configured by providing a pair of right and left arm members (7R, 7L) pivotally connected at a lower side of a stepping bar (3a) of the first leg (4a), and second arm means (8) is configured by providing a pair of right and left arm members (8R, 8L) pivotally connected at a lower side of a stepping bar (3b) of the second leg (4b). Distal end portions of the mutually confronted arm members of both the arm means (7, 8) are pivotally connected by pivot means (10). Distal end portions of the mutually confronted arm members (7R, 8L) (7L, 8R) of the first arm means (7) and the second arm means (8) are separated (S1) from side to side via spacer means (15) coaxially with the pivot means (10).

Description

The present invention relates to a device for preventing an opening in a stepladder having a pair of legs that can be freely opened and closed.

Conventionally, a stepladder has a ladder-like first leg and second leg each having a pedestal installed between the left and right columns, and a pivot that pivots the upper ends of both legs so that both legs can be opened and closed. Means are provided so that the operator can work at a high place by getting on the stepped pedestal in an open leg state. In view of this, the stepladder is provided with an anti-opening device that connects both legs so as to be freely opened and closed, and holds the leg from a predetermined open state in an inability to open the leg.

JP 2011-84869 A Special opening / closing 9-41855 Registered Utility Model No. 3024614

As shown in the above-mentioned Patent Document 1, a device for preventing an opening by connecting the outer side surfaces of a pair of legs with a link-like arm is used to open and close the legs by the operator holding the poles by hand. When doing this, there is a risk of injury by clogging your fingertips between the support and the arm.

Therefore, it is preferable to provide an arm on the inner surface of the support as in Patent Documents 2 and 3. However, even in such a case, since the distal ends of the arms extending from both legs and pivoted to each other overlap, there is a risk of injury due to the operator's fingertips being stuffed into the overlapping parts of the arms that are bent and extended when the legs are opened and closed. Is not resolved. In addition, when an opening stop device is provided in the vicinity of the step rail, an operator who works on the step rail will step on the opening stop device as well as the step rail in order to stabilize the working posture. Therefore, there is a problem that the opening prevention device is damaged.

For this reason, the opening prevention device is safe without danger such as finger-filling when opening and closing the leg, is easy and easy to open and close, and prevents damage caused by the operator's stepping, and is suitable for the intended function. There is a problem to be solved in these points.

The present invention provides an anti- opening device for a stepladder that solves the above-mentioned problems. As a means for the device, the first leg body and the second leg body, each of which is constructed by installing a step rail between columns arranged in the left-right direction , respectively. In a stepladder provided with an anti-opening device that pivotally connects the upper ends of both legs so that the legs can be opened and closed in an opening and closing direction, and connects both legs so that they can be opened and closed, and keeps the legs from opening in a predetermined open state. In the above-described anti-opening device, the base end portions of the pair of arm members arranged on the left and right sides are pivotally connected to the lower side of the first leg under a step rail via a bracket fitting between the opposite steps of both legs. A first arm means, and a second arm means in which a base end portion of a pair of arm members arranged on the left and right is pivotally connected to a lower side of a foot of the second leg via a bracket fitting, The left and right of the second arm means The distal end portion of the arm member facing is pivotally connected by pivot means extending in the left-right direction, and the pivot means is a cylindrical center shaft and a pair of heads inserted into both end openings of the center shaft. A center pin with a handle, and a handle pipe and a pair of spacer means which are externally inserted to the center shaft, respectively, and the handle pipe is interposed between a pair of arm members located on the inner side in the left-right direction, The first arm means and the second arm means are refracted by lifting the center shaft together with the handle pipe, and the spacer means includes a pair of opposing left and right sides of the first arm means and the second arm means, respectively. The pair of arm members are interposed between the arm members, and the thickness of the finger of the operator is determined via the spacer means. The center pin with the head is arranged between the pair of spaced arm members in a state in which the shaft portion of the pin is inserted into both end openings of the center shaft. The shaft end of the center shaft is caulked and fixed to the shaft .

In a preferred embodiment of the present invention, a recess is formed in the shaft portion of the center pin, and the shaft end portion of the center shaft is caulked and fixed to the recess .

Preferably, the shaft portion of the center pin is inserted into the cylindrical center shaft so as to reach the inner region of the handle pipe beyond the spacer means .

According to the first aspect of the present invention, the anti-opening device 6 includes the first leg 4a and the first leg 4a as the base ends of the pair of left and right arm members constituting the first arm means 7 and the second arm means 8, respectively. Since it is pivotally connected to the lower side of the foot of the bipedal body 4b via the bracket metal fitting 9, when the operator M gets on the step rail in the state of use with both legs open, When performing, it is made difficult for the foot tip MF to reach the detent device 6, and it is prevented from being damaged by receiving a load due to the weight of the operator .

According to the present invention, the pivot means 10 that pivotally connects the distal ends of the first arm means 7 and the second arm means 8 is provided with a single cylindrical center shaft 16 and openings at both ends of the center shaft 16. A pair of center pins 18 and 18 with heads to be inserted, and a handle pipe 17 and a pair of spacer means 15 and 15 which are externally inserted into the center shaft 16, respectively. Since it is interposed between a pair of arm members located on the inside, the operator can easily open and close both legs 4a and 4b by grasping the handle pipe 17 and moving the pivot means 10 up and down. It can be done easily .

In addition, by interposing the spacer means 15 between the pair of arm members facing each other on the left and right sides of the first arm means 7 and the second arm means 8, the pair of arm members can be attached to the operator. Since it is spaced apart S1 in the left-right direction X with a dimension larger than the thickness of the finger, there is no risk of injury due to the operator's fingers being packed between the bending and extending arm members during the opening / closing operation .

Then, the pivot means 10 has the shaft end portion 16a of the center shaft 16 between the pair of arm members spaced apart S1 in a state in which the shaft portion 18b of the centered center pin 18 is inserted into both end openings of the center shaft 16. Is fixed to the shaft portion 18b, so that the center pin 18 can be prevented from being removed by a simple and easy crimping operation .

At this time, as described in claim 2, if the shaft end portion 16 a of the center shaft 16 is caulked and fixed to the recess portion 18 c formed in the shaft portion 18 b of the center pin 18, The fixed insertion state becomes strong .

According to the third aspect of the present invention, the shaft portion 18 b of the center pin 18 is inserted into the center shaft 16 so as to reach the inner region of the handle pipe 17 beyond the spacer means 15. Therefore, it is possible to firmly support the cylindrical center shaft 16 together with the lifted handle pipe 17 by the shaft portion 18b .

It is a perspective view which shows the leg open state of the stepladder which concerns on one Embodiment of this invention. It is a side view which illustrates the work posture in case a worker performs work at a high place using a stepladder. It is a perspective view showing one embodiment of a stopper device. It is a perspective view which shows one Embodiment of an opening stopper in an exploded state. 1 shows one embodiment of the pivot means, (A) is a cross-sectional view showing a state before inserting a center pin, (B) is a cross-sectional view showing a state where the center pin is inserted and the center shaft is fixed by caulking. is there. An example of the crimping method is shown, (A) is a sectional view showing a state before crimping, and (B) is a sectional view showing a state after crimping. It is a side view which shows the relationship between the operator's foot boarded on the foot cross and the opening prevention device. The relationship between each part of the locking device which concerns on 1 embodiment, and the support | pillar of a leg is shown, (A) is explanatory drawing which shows a front, (B) is explanatory drawing which shows a plane. The leg closing action of the leg is shown, (A) is a side view showing a state where the leg is being closed, and (B) is a side view showing the state where the leg is completed. It is a front view which shows the relationship between each part of the stopper device in the completion state of a closed leg, and the support | pillar of a leg.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, each of the stepladders is a ladder in which a top plate 2 and a footrail 3 are installed between columns 1 and 1 arranged on the left and right in the illustrated arrow X direction (hereinafter referred to as “left-right direction X”). The first leg body 4a and the second leg body 4b are provided, and the upper end portions of both leg bodies 4a and 4b are pivoted to each other by the pivoting means 5 so as to be in the direction indicated by the arrow Y (hereinafter referred to as "opening and closing direction Y"). )) Is configured to be openable and closable and is provided with a locking device 6. For convenience of explanation, in the drawings, the support of the first leg 4a, the top plate, and the crosspiece are indicated by reference numerals 1a, 2a, and 3a, respectively, and the support, the top plate, and the crosspiece of the second leg 4b are indicated by reference numerals 1b, 2b, respectively. 3b.

In the drawings, the structure of the stepladder excluding the stopper device 6 is a conventionally known structure, and therefore, the technical structure of the known part is not limited by the structure of the illustrated example. Further, the “stepladder” of the present invention broadly includes an aerial work platform having ladder-like legs 4a and 4b that are pivotably coupled by the pivot means 5, and has the same configuration and function. For example, it should be understood that it is intended to be included in the present invention regardless of its size or name.

As shown in FIG. 1 to FIG. 4, the opening stop device 6 is provided between the opposite crossing legs 3 a and 3 b of both legs 4 a and 4 b, in the illustrated example, a stepping bar 3 a positioned immediately below the pivot means 5. Between the 3b, the link-like 1st arm means 7 and the 2nd arm means 8 which are mutually connected are comprised. The first arm means 7 is composed of a pair of right arm member 7R and left arm member 7L located on the left and right when the first leg 4a is viewed from the outside in the Y direction, and the second arm means 8 includes When the leg 4b is viewed from the outside in the Y direction, the leg 4b is composed of a pair of right arm member 8R and left arm member 8L located on the left and right.

The left and right arm members 7R, 7L constituting the first arm means 7 are arranged in parallel with a predetermined distance L7, and a bracket metal fitting 9 is pivotally connected to the base end portion on the tail end side.

The left and right arm members 8R, 8L constituting the second arm means 8 are arranged in parallel with a predetermined distance L8 (in the example shown in the figure , equal to the predetermined distance L7, and therefore L8 = L7), and are arranged on the tail end side. A bracket fitting 9 is pivotally connected to the base end.

Accordingly, the first arm means 7 constituted by the left and right arm members 7R and 7L and the second arm means 8 constituted by the left and right arm members 8R and 8L are point-symmetric, that is, around the vertical axis in the illustrated example. The right arm member 7R of the first arm means 7 and the left arm member 8L of the second arm means 8 are opposed to each other, and the left arm member 7L and the second arm of the first arm means 7 are configured to be symmetrical. The right arm members 8R of the means 8 are opposed to each other, and the tip portions of these arm members are pivoted by pivot means 10 extending in the left-right direction X.

In the case of the illustrated example, the left and right arm members 7R and 7L of the first arm means 7 and the left and right arm members 8R and 8L of the second arm means 8 are constituted by common parts, and the bracket metal fittings are formed by press molding of a metal plate or the like. 9 includes an L-shaped portion 11 extending downward from 9 and an extension portion 12 extending from the L-shaped portion 11 toward the pivot means 10, and a reinforcing rib 13 is formed on the extension portion 12.

The bracket 9 that is pivotally connected to the base end portion of the L-shaped portion 11 in each of the arm members 7R, 7L, 8R, and 8L is constituted by a common part, and the side surface of the L-shaped portion 11 is formed by press molding of a metal plate or the like. A vertical piece 9a pivoted by a support shaft 14 such as a rivet and the like, and a horizontal piece 9b bent in the horizontal direction from the upper end edge of the vertical piece 9a. It is fixed to the lower surfaces of the step bars 3a and 3b with screws or the like.

The left and right arm members 7R and 7L of the first arm means 7 and the left and right arm members 8R and 8L of the second arm means 8 are opposed to each other, that is, the right arm of the first arm means 7 facing each other. The tip of the left arm member 8L of the member 7R and the left arm member 8L of the second arm means 8 and the tip of the left arm member 7L of the first arm means 7 and the right arm member 8R of the second arm means 8 facing each other are the pivot means. It is held in a state of being spaced apart in the left-right direction X so as to have an interval S1 (see FIG. 8) via spacer means 15 provided on the same axis. In the case of the illustrated embodiment, a metal collar is employed as the spacer means 15 and will be described below as the collar 15, but is not limited thereto. The spacing S1 secured by the spacer means 15 is formed to have a dimension sufficiently larger than the average thickness dimension of the operator's finger.

As shown in FIGS. 4 to 6, the pivot means 10 includes a single cylindrical center shaft 16 made of metal, a pair of collars 15 and 15 constituting the spacer means, and a cylindrical handle pipe 17. And a pair of metal center pins 18, 18.

The pivot means 10 including the center shaft 16 includes the right arm member 7R of the first arm means 7 and the distal end portion of the left arm member 8L of the second arm means 8, the left arm member 7L of the first arm means 7 and the second arm member 7L. The end of the right arm member 8 </ b> R of the arm means 8 is passed through and pivotally supported, and the collars 15 and 15 and the handle pipe 17 are extrapolated to the center shaft 16 .

As described above, the collars 15 and 15 are interposed between the tip portions of the arm members 7R and 8L facing each other and between the tip portions of the arm members 7L and 8R, respectively. Extrapolated.

The handle pipe 17 is interposed between the arm members 7R and 8R facing and facing each other in the left-right direction X, and is rotatably inserted on the center shaft 16.

The center pins 18, 18 are center pins with a head having a head portion 18a and a shaft portion 18b. The shaft portions 18b are inserted from the openings at both ends of the center shaft 16, and the head portion 18a is connected to the outer arm member 7L, The shaft 18b is inserted and attached so as to reach the inner region of the handle pipe 17 beyond the collar 15 while locking to the outer surface of 8L.

In the case of the embodiment shown in FIG. 4, the collar 15 is positioned in the diameter direction of the peripheral wall between the pair of ribs 15 a and 15 a that are positioned in the diameter direction of the outer peripheral surface and extend in the axial direction, and the ribs 15 a and 15 a. A pair of window portions 15b, 15b opened in this manner is provided, and the shaft portion 18b of the center pin 18 forms a concave portion 18c composed of a circumferential groove provided at a position corresponding to the window portion 15b.

Therefore, as shown in FIG. 5, in the first arm means 7 and the second arm means 8, the tip portions of the arm members 7R and 8L facing each other (and the tip portions of the arm members 7L and 8R) are pivoted. When pivoting with the arm 10, the collar 15 is interposed between the end portions of both arm members 7R and 8L, and the handle pipe is in a state where the shaft supporting holes 7a and 8a of both arms are aligned with the shaft center. The shaft end 16a of the center shaft 16 protruding from 17 is inserted, the shaft portion 18b of the center pin 18 is inserted into the center shaft 16 through the opening 16b of the shaft end 16a, and the head 18a is inserted into the arm member 8L. Lock to the outside surface. In this state, the shaft end portion 16a facing the window portion 15b is caulked and fixed to the recess portion 18c, thereby fixing the center pin 18 in a retaining shape. The shaft portion 18b of the center pin 18 and the center shaft 16 together with the handle shaft 17 is supported.

In the case of the illustrated configuration , the caulking work is performed by positioning the ribs 15a and 15a of the collar 15 by mounting them on the positioning base 19, as shown in FIG. 6A, and then in the windows 15b and 15b. This can be done easily and easily by crushing the shaft end 16a of the center shaft 16 toward the recess 18c by the crimping jigs 20 and 20 facing each other.

As shown in FIG. 2, the stepladder configured as described above is placed on the step rail 3a or 3b with the first leg 4a and the second leg 4b open, Work at a certain place. At this time, the worker M usually takes a forward leaning posture in which the body is deposited on the top plate 2a or 2b in order to obtain a stable working posture, so that the foot MF protrudes downward from the step rail 3a or 3b. become. In this regard, according to the configuration of the above-described embodiment , as shown in FIG. 7, as shown in FIG. 7, all the arm members of both the arm means 7, 8 have the crosspieces 3 a, 3 b Since the pivot means 10 is disposed at a sufficiently lower position as shown by the distance L1 from the sole placement line F defined by the upper surfaces of the step bars 3a and 3b, The foot tip MF does not reach the arm member extension 12 or the pivot means 10 and is therefore not stepped on. The distance L1 is configured to be larger than the upper and lower thickness dimension T of the step rails 3a and 3b, that is, L1> T, and it is preferable to configure the distance L1 as large as possible.

In the case of the illustrated embodiment, as shown in FIG. 9 (B), the distance L1 is such that the first leg 4a and the second leg 4b are closed until the legs 4a and 4b are parallel to each other. The extension portions 12 of all the arm members are overlapped with each other so as to be parallel to the legs 4a and 4b. Therefore, in the case of the distance L1 shown in the figure, as shown in FIG. 7, it becomes possible for the worker to reach the pivot means 10 by forcibly pointing the foot MF downward. If the posture is continued, it may become unstable on the crosswalks 3a and 3b and fall from the stepladder, and the worker will not continue such an unreasonable posture, so at least L1> T. If comprised in this way, the arm member and the pivot means 10 will not receive damage by receiving the load by a worker's weight.

As shown in FIG. 8, when the bracket device 9 is fixed to the lower surfaces of the step ladders 3a and 3b of the stepladder, the opening stop device 6 has a base end portion (see FIG. 8) of each arm member 7R, 7L, 8R, 8L . The brackets 9 facing the L-shaped portion 11) in the configuration of the example are attached in a state of being spaced apart from the inner surfaces of the pillars 3a, 3b of the legs 4a, 4b facing the brackets 9 so as to have spacings S2, S3. In the case of the illustrated embodiment, there is a distance S2 between the left arm member 7L of the first leg 4a and the column 3a it faces, and between the left arm member 8L of the second leg 4b and the column 3b it faces. Is formed. Further, a space S3 is formed between the right arm member 7R of the first leg 4a and the column 3a facing it, and between the right arm member 8R of the second leg 4b and the column 3b facing it. . In the illustrated embodiment, the intervals S2 and S3 are formed such that S2 <S3. However, any interval is formed to have a dimension sufficiently larger than the average thickness dimension of the operator's finger. .

The opening and closing of the first leg body 4a and the second leg body 4b of the stepladder can be easily and easily performed by the operator holding the handle pipe 17 and moving the pivot means 10 up and down. As shown in FIG. 9 (A), when the pivot means 10 is lifted upward U, the first arm means 7 and the second arm means 8 are refracted to close both legs 4a and 4b. When 10 is pushed downward D, the first arm means 7 and the second arm means 8 extend to open the legs 4a and 4b.

In such an opening / closing operation, the arm members 7R, 8L and the arm members 7L, 8R facing each other as described above are separated by the collar 15 provided in the pivot means 10 via the interval S1, so that the handle The finger of the operator who grips the pipe 17 is packed between the arm members and is not injured.

As shown in FIGS. 9B and 10, when the first leg 4a and the second leg 4b are completely closed, the extensions 12 of all the arm members overlap between the legs 4a and 4b. The legs 4a and 4b are folded in parallel. At this time, the spacing S2 as described above is formed between the struts 2a and 2b and the arm members 7L and 8L disposed closest to the support columns 2a and 2b. As shown in FIG. In the state of the posture, a space S4 is formed between both ends of the pivot means 10 and the inner surface of the support column 2, and the space S4 is larger than the average thickness dimension of the operator's finger. It is formed in a sufficiently large dimension. Therefore, even when the operator grips the handle pipe 17 with one hand and grips the column 2 with the other hand during the opening / closing operation, the finger of the hand holding the column is placed between the arm member and the column 2. You won't be injured.

2 strut 2a first leg strut 2b second leg strut 3a first leg tread 3b second leg tread 4a first leg 4b second leg 5 pivoting means 6 locking device 7 first arm means 7R right arm member 7L left arm member 8 second arm means 8R right arm member 8L left arm member 9 bracket metal piece 9a vertical piece 9b horizontal piece 10 pivot means 11 L-shaped part 12 extension part 13 reinforcing rib 14 support Shaft 15 Spacer means (color)
16 Center shaft 16a Shaft end 17 Handle pipe 18 Center pin 18a Head 18b Shaft 18c Recess

Claims (3)

The upper ends of both legs so that the first leg (4a) and the second leg (4b) can be opened and closed in the opening and closing direction (Y). In a stepladder provided with an anti-opening device (6) for connecting both legs so that they can be opened and closed and holding the legs in an unopenable state from a predetermined open state,
The opening stop device (6) has a base end portion of a pair of arm members (7R, 7L) arranged on the left and right sides between the opposite crosspieces (3a, 3b) of both legs (4a, 4b) as a first. The first arm means (7) pivotally connected to the lower side of the step (3a) of the leg (4a) via the bracket fitting (9) and the base of the pair of arm members (8R, 8L) arranged on the left and right Second arm means (8) having an end pivoted via bracket bracket (9) on the lower side of the foot (3b) of the second leg (4b) is provided. Two arm means (8) are pivotally connected by pivot means (10) extending in the left-right direction (X) at the left and right ends of the arm members facing each other,
The pivot means (10) includes a single cylindrical center shaft (16), a pair of center pins with heads (18) and (18) inserted into both end openings of the center shaft (16), Consists of a handle pipe (17) and a pair of spacer means (15) (15) to be extrapolated to the center shaft (16),
The handle pipe (17) is interposed between a pair of arm members located on the inner side in the left-right direction (X), and the first arm means (by lifting the center shaft (16) together with the handle pipe (17)). 7) and second arm means (8) are configured to refract,
The spacer means (15) (15) is interposed between a pair of arm members facing each other on the left and right of the first arm means (7) and the second arm means (8), and the spacer means (15 ) Through the left and right direction (X) with a dimension larger than the thickness of the operator's finger via the pair of arm members (S1),
The headed center pins (18) and (18) are arranged between the pair of arm members separated (S1) in a state in which the shaft portions (18b) of the pins are inserted into both end openings of the center shaft (16). And a shaft end portion (16a) of the center shaft (16) is caulked and fixed to the shaft portion (18b). A recess (18c) is formed in the shaft portion (18b) of the center pin (18), and the shaft end portion (16a) of the center shaft (16) is caulked and fixed to the recess (18c). The stop device for a stepladder according to claim 1, characterized in that: The shaft portion (18b) of the center pin (18) is inserted into the cylindrical center shaft (16) so as to reach the inner region of the handle pipe (17) beyond the spacer means (15). The stop device for a stepladder according to claim 1 or 2, characterized in that:

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