JP5865046B2 - Stop device for stepladder - Google Patents

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 a state where the leg cannot be opened.

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, and is configured as means for the first leg body and the second leg body, each of which has a step rail installed between left and right columns. In a stepladder provided with a pivoting means for pivotally connecting the upper ends of both legs so that both legs can be opened and closed, the both legs are connected in an openable and closable manner and are prevented from opening from a predetermined open state. A first arm means composed of a pair of left and right arm members whose base ends are pivotally connected to the first leg between the opposite struts of both legs. Second arm means comprising a pair of left and right arm members whose ends are pivoted to the second leg body is provided, and the distal end portions of the arm members facing each other of the first arm means and the second arm means are arranged on both legs. Pivots via pivot means extending in the left-right direction between And is, the base end portion of the pair of left and right arm members in the first arm means is pivotally connected to the underside of踏桟the first leg, the proximal end of the pair of arm members in said second arm means The portion is pivotally connected to the lower side of the second leg, and in a state where both legs are opened, each arm member extends downward from the lower side of the footpiece to which the arm member is pivoted. An L-shaped portion, and an extending portion extending from the L-shaped portion toward the pivot means, wherein the pivot means is disposed at a position lower than a foot placement line defined by the upper surface of the step rail. It is in.

Also, the left and right arm members of the first arm means and the left and right arm members of the second arm means are spaced inward from the inner surfaces of the legs of the legs facing each other.

The pivot means includes a cylindrical center shaft that is pivotally supported through the distal ends of the left and right arm members of the first arm means and the left and right arm members of the second arm means, and the distal ends of the arm members facing each other. Spacer means formed of a collar that is interposed between the arm member and the center shaft, and a handle pipe that is interposed between the arm members positioned inside each other and rotatably inserted into the center shaft. Preferably, the center shaft includes a center pin that is inserted from both ends of the center shaft so as to reach the inner region of the handle pipe beyond the collar.

At this time, a window portion is provided on the peripheral wall of the collar, a concave portion is provided on the peripheral surface of the center pin corresponding to the window portion, and the peripheral wall of the center shaft facing the window portion is caulked and fixed to the concave portion. Is possible.

According to the first aspect of the present invention, the base end portions of the pair of left and right arm members 7R and 7L in the first arm means 7 are pivotally connected to the lower side of the step rail 3a of the first leg 4a, and the second Since the base ends of the pair of left and right arm members 8R, 8L in the arm means 8 are pivoted to the lower side of the step 3b of the second leg 4b, the first leg 4a and the second leg 4b are opened. In the legged state of use, all of the constituent members of the locking device 6 are arranged below the step bars 3a, 3b, and in particular, the arm members 7R, 7L, 8R, 8L are below the step bars 3a, 3b. And an extension portion 12 extending from the L-shaped portion 11 toward the pivot means 10, and the pivot means 10 is defined by the sole placement line F defined by the upper surfaces of the step bars 3 a and 3 b. Since the operator M gets on the stepping rail 3a or 3b, Even when the foot MF protrudes downward from the step rail 3a or 3b by taking a forward leaning posture in which the body is entrusted to the top plate 2a or 2b when working at a high place, the foot MF is prevented from opening. It is difficult to reach the device 6, and at least the anti-opening device 6 is not damaged by receiving a load due to the weight of the operator.

According to the second aspect of the present invention, the legs 4a and 4b that face the base ends of 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, respectively. Since the arms 1a and 1b are spaced apart from each other so as to have an interval S2 and S3, the operator's fingers are packed between the adjacent arm members and the columns when the legs 4a and 4b are opened and closed. There is no risk of injury.

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. FIGS. 4A and 4B show a method of crimping, wherein FIG. 4A is a sectional view showing a state before crimping, and FIG. 4B 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 a locking device 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, the stepladder includes a ladder-like first leg 4 a and a second leg, each of which has a top plate 2 and a traverse 3 installed between columns 1 and 1 arranged on the left and right in the direction of the arrow X shown in the drawing. A leg 4b is provided, and the upper ends of both legs 4a and 4b are pivotally connected to each other by a pivoting means 5 so as to be openable and closable in the direction of the arrow Y shown in the figure. 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 interval L8 (equal to the predetermined interval L7, and therefore L8 = L7), and a bracket is attached to the proximal end portion on the tail end side. The metal fitting 9 is pivoted.

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, symmetrical about the vertical axis. 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 of the first arm means 7 and the right arm of the second arm means 8 are configured. The members 8R are opposed to each other, and the distal end portions of these arm members are pivoted by pivot means 10 extending in the left-right direction.

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 extend downward from the bracket metal fitting 9 by press molding of a metal plate or the like. An L-shaped portion 11 and an extending portion 12 extending from the L-shaped portion 11 toward the pivot means 10 are provided, and a reinforcing rib 13 is formed on the extending 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. Ten spacers 15 provided on the same axis are held in a state of being separated in the left-right direction so as to have an interval S1 (see FIG. 8). 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 metal cylindrical center shaft 16, a pair of collars 15 and 15 constituting the spacer means, and a metal cylindrical handle pipe 17. And a pair of metal center pins 18, 18.

The center shaft 16 has a right arm member 7R of the first arm means 7 and a distal end portion of the left arm member 8L of the second arm means 8 and a left arm member 7L and a second arm of the first arm means 7 at both ends. The tip end portion of the right arm member 8R of the means 8 is pivotally supported.

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 each other on the inner side, and is rotatably inserted on the center shaft 16.

The center pins 18 and 18 have 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 placed on the outer surface of the outer arm members 7L and 8L. The shaft 18b is inserted so as to reach the inner region of the handle pipe 17 beyond the collar 15 while being locked.

As shown in FIG. 4, the collar 15 is located in the diameter direction of the peripheral wall between the ribs 15a and 15a and a pair of ribs 15a and 15a extending in the axial direction and positioned in the diameter direction of the outer peripheral surface. A pair of window portions 15b, 15b 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.

As shown in FIG. 6A, the caulking operation is performed by positioning the ribs 15a and 15a of the collar 15 on the positioning table 19, and then facing the windows 15b and 15b so as to face each other. This can be done easily and easily by crushing the shaft end 16a of the center shaft 16 toward the recess 18c with the jigs 20 and 20.

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 above-described configuration, as shown in FIG. Since it is provided at a lower position and the pivot means 10 is disposed sufficiently downwardly as shown by the distance L1 from the sole placement line F defined by the upper surfaces of the steps 3a and 3b, the foot MF Does not reach the extension 12 of the arm member 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 (L of each arm member 7R, 7L, 8R, 8L as shown in FIG. It is 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 facing each of the shape parts 11). 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)
15a rib 15b window portion 16 center shaft 17 handle pipe 18 center pin 18a head portion 18b shaft portion 18c recess 19 positioning table 20 caulking jig

Claims (2)

The first leg (4a) and the second leg (4b), each of which has a pedestal installed between the left and right columns, and a pivoting means that pivots the upper ends of both legs so that both legs can be opened and closed ( In the stepladder with 5), there is provided an anti-opening device (6) for connecting both legs so as to be openable and closable and preventing the leg from being opened from a predetermined open state,
The anti-opening device (6) includes a pair of left and right arms whose base ends are pivotally connected to the first leg (4a) between the opposing crosspieces (3a, 3b) of both legs (4a, 4b). First arm means (7) composed of members (7R, 7L), and second arm means (8R, 8L) composed of a pair of left and right arm members (8R, 8L) whose base ends are pivotally connected to second legs (4b). 8), and the distal ends of the arm members (7R, 8L) (7L, 8R) facing each other of the first arm means (7) and the second arm means (8) in the left-right direction between the legs. Pivoted via a pivot means (10) that extends,
A base end portion of the pair of left and right arm members (7R, 7L) in the first arm means (7) is pivotally connected to the lower side of the step rail (3a) of the first leg (4a), and the second arm The base ends of the pair of left and right arm members (8R, 8L) in the means (8) are pivotally connected to the lower side of the step (3b) of the second leg (4b),
In a state in which both legs (4a, 4b) are opened, each arm member (7R, 7L, 8R, 8L) extends downward from the lower side of the footrail (3a, 3b) that pivotally connects the arm members. A shape portion (11) and an extension portion (12) extending from the L-shape portion toward the pivot means (10), and the pivot means (10) is defined by the upper surface of the step rail (3a, 3b) An anti-opening device for a stepladder, wherein the device is disposed at a position lower than the sole mounting line (F) . Leg struts (1a, 1b) facing the base ends of the left and right arm members (7R, 7L) of the first arm means (7) and the left and right arm members (8R, 8L) of the second arm means (8), respectively. 2. The opening prevention device for a stepladder according to claim 1 , wherein the device is separated from the inner surface (S <b> 2, S <b> 3 ) to the inside of the stepladder.

Images