JP4861350B2 - stepladder - Google Patents

Description

  The present invention relates to a stepladder capable of opening and closing a leg, and more particularly to a stepladder having an improved mechanism for preventing the leg from opening and closing.

Conventionally, the upper ends of a pair of ladder-like legs are pivotably connected to open and close the legs, and the base ends of the connecting links are rotatably attached to the vertical intermediate positions on both sides of each leg, One end of each pair of connecting links facing each other in the leg opening / closing direction is overlapped with each other and connected to each other by a connecting pin so as to be relatively rotatable. A long hole through which the operation shaft passes is formed, and each long hole is formed in an arc shape around the coupling pin and the leg so that the operation shaft moves relative to each other when the leg is opened from the closed state. There is known a stepladder composed of a hanging engagement portion that hangs downward from an end of an arc-shaped portion where an operation shaft is located when the angle is opened by a predetermined angle (see Patent Document 1).
Japanese Patent Laid-Open No. 9-41855

  In the stepladder of Patent Document 1, a long hole is provided in the overlapping portion of each connection link tip, and a long operating shaft is installed in the long hole in a penetrating state. It can be closed, and when the leg is opened, when the predetermined angle is reached, the leg is fixed by locking the operating shaft to the drooping engagement part at the end of the long hole. It is intended to prevent the opening and the closing without permission. However, in this configuration, since one long operation shaft is used, not only the number of parts and the number of assembling steps are increased, but also when the leg is closed, a foreign object is formed between the connecting link and the leg. May be caught or pinched, and the legs may not be completely closed or the connecting link may be damaged.

  An object of the present invention is to provide a stepladder that can prevent a foreign matter from being caught or pinched between a connecting link and a leg, and that can also avoid an increase in the number of parts and the number of assembling steps.

In order to achieve the above object, the present invention provides a pair of ladder-like legs that are pivotably connected to each other at the upper end portion and can be opened and closed, and bends and stretches when the legs are opened and closed. in order to stop holding the leg in the open leg angle intervals upward is narrowed, the proximal end portion in the vertical direction middle of each leg is connected by the connecting arranged and connecting pin tip to each other via a support shaft A stepladder with a pair of connected links,
One of the middle portion of the base end side or the leg of the connecting link, an acute angle formed by being sandwiched s between the coupling link base end side and the leg middle section by the open leg state of the leg In order to close the space, there is provided a cover piece that protrudes in a mountain shape reaching the other and overlaps with the other when the leg is closed.
According to this configuration, when the leg is rotated from the open leg state to the close leg direction, foreign matter enters a space (acute angle space) in which the leg and the connecting link are relatively close to each other and narrowed. Can be prevented by the cover piece.

The cover piece may be integrally formed with the connection link, or may be formed separately from the connection link and attached to the connection link.
It is preferable that the cover piece protrudes in a mountain shape upward from the connection link in a leg open state .

  According to the present invention, it is possible to prevent a foreign object from being caught or pinched between the connecting link and the leg body when the stepladder is stored or transported after use, and the number of parts and assembly man-hours are also increased. It can be avoided.

Hereinafter, a stepladder according to a first embodiment of the present invention will be described with reference to FIGS.
1 to 2, the stepladder 1 is composed of a pair of ladder-like legs 2 and 2. Each leg 2 has a pair of struts 3 and 3 arranged at an appropriate interval so that the interval is narrowed upward, and an upper end portion between these struts 3 and 3 and at an appropriate interval below the upper end. It comprises a plurality of traversing bars 4 arranged.
The step rail 4 at the upper end portion integrally forms the top plate 5 of the stepladder 1 inside. The support column 3 is made of a hollow mold material having a square cross section, and the crosspiece 4 is made of a hollow mold material having a substantially triangular cross section, both of which are made of an aluminum alloy. The step rail 4 at the upper end includes the same cross-sectional shape portion as the other step rails 4 and is a hollow mold member made of an aluminum alloy integrally formed with a top plate 5 portion having a substantially triangular cross section extending further inward from this portion. It is made up of. In addition, the support | pillar 3, the footrail 4, and the top plate 5 may be comprised with another material or another shape. Each step bar 4 and the top plate 5 are disposed between a pair of support columns 3 and 3, and both ends thereof are screwed or riveted to the support column 3 to constitute a ladder-like leg body 2.

  As shown in FIGS. 3 and 4, the pair of legs 2, 2 are connected to each other by hinge portions 6, 6 integrally formed inside the top plates 5, 5 at the upper end. The hinge portions 6 and 6 are formed with an arc-shaped concave portion having a cutout portion on one top plate 5 and an arc-shaped convex portion formed on the other top plate 5, which are fitted to each other to be rotatable. The screws 7 are attached to both ends to prevent the screws from coming off. In addition, the hinge parts 6 and 6 are provided with stopper pieces 6a so that the top plates 5 and 5 on both sides are horizontal when the legs 2 and 2 are in the open leg state and do not rotate any more. Further, an end member 8 such as a non-slip leg rubber is fitted and fixed to the lower end portion of each column 3.

  In the middle of the pair of legs 2 and 2 in the vertical direction, in the illustrated example, connecting links 9 and 9 are connected and arranged at a substantially intermediate position between the first and second step rails 4 and 4 from the top. The connecting links 9, 9 have base end portions 9 a that are rotatably attached to the support pillars 3 of the leg bodies 2 by the support shafts 10, 10, and the distal end portions 9 b that are connected by the connecting pins 11, thereby allowing the leg bodies 2 to be connected. , 2 is operated to bend and extend, and when the legs are opened, the legs 2, 2 are stopped and held at a predetermined opening angle. The connecting links 9 and 9 are bent and extended around the support shafts 10 and 10 with respect to the support columns 3 and 3 when the legs 2 and 2 are opened and closed. When the angle is reached, it is stretched and held in a straight line. At this time, in the present embodiment, the connecting pin 11 of the distal end portion 9b is stopped and held at a position slightly beyond the position where the connecting pins 11 and 10 of the proximal end portion 9a are aligned on the same straight line. In addition, a stopper projection 9c and a receiving portion 9d are provided at the distal end portion 9b of the connecting links 9 and 9 so as not to rotate in the leg opening direction. However, the present invention is not limited to this configuration, and other configurations, for example, in a state where the connecting links 9 and 9 are extended in a straight line state in an open leg state, the connecting pin 11 is viewed from a straight line connecting the support shafts 10 and 10. It may be shifted upward or may be arranged on the same straight line. As shown in FIG. 5, the connecting links 9, 9 exemplify the case where they are attached to the inner side of the ladder-like columns 3, 3 constituting the legs 2, 2. 3 may be attached to the outside.

In the stepladder 1 having the above-described configuration, the present invention covers a cover for closing an acute angle space S formed between the legs 2 and 2 and the connecting links 9 and 9 in the range of opening and closing of the legs 2 and 2. The piece 12 is provided on the connecting links 9 and 9. The acute angle space S is a space formed between the upper surfaces of the connecting links 9 and 9 and the inner surfaces of the legs 2 and 2 when the cover piece 12 is not provided.
In the range from the open leg state of the leg bodies 2 and 2 shown in FIG. 1 and FIG. 3 to the closed leg state of the leg bodies 2 and 2 shown in FIG. 2 and FIG. It is provided for the purpose of closing so as to prevent foreign matter from entering and biting into the acute angle space S formed between the connecting links 9 and 9. The larger the rising angle α of the front surface 12a of the cover piece 12 with respect to the upper surface 9e, the better. Further, the angle between the legs 2 and 2 and the connecting links 9 and 9 changes as the legs 2 and 2 approach the closed leg from the open leg state, and the front surface 12a of the cover piece 12 and the leg 2 and 2 change. Similarly, the angle between 2 and 2 also changes slightly, so that it is necessary to prevent foreign objects from being caught or caught in the closed leg state of the legs 2 and 2 where the angle is minimized. That is, when the legs 2 and 2 are closed, it is necessary to set a large angle between the front surface 12a of the cover piece 12 and the legs 2 and 2, that is, the minimum angle β. Although β depends on the size of the foreign matter, it may be appropriately set in the range of 40 ° to 90 °. In order to satisfy these conditions, in the first embodiment of the present invention, β is set to about 60 °, and the cover piece 12 is ridged from the upper surface in the longitudinal direction of the connecting links 9 and 9 toward the base end portion 9a. The case where it is made to project in the shape is illustrated. In this way, by forming the cover piece 12 in a mountain shape, the protrusion 12b on the rear side (the base end portion 9a side of the connecting link 9) on the rear side of the peak shape 12b is eliminated, and the material is saved. Yes. In addition, the shape of the rear surface 12c of the cover piece 12 may be connected with a straight line from the mountain-shaped apex 12b toward the base end portion 9a of the connecting links 9, 9, or may be connected with a concave curve or a convex curve. Good.

In the first embodiment of the present invention shown in FIGS. 1 to 6, the case where the cover piece 12 is integrally provided on the upper surface 9 e of the connecting links 9, 9 is illustrated.
The cover piece 12 may be separated from the connecting links 9 and 9 and may be formed by forming an attachment portion 13 to the connecting links 9 and 9 and fixing them with fixing members 14 such as rivets and screws (FIG. 7). 8 (see the second embodiment shown in FIG. 8), or a fitting groove 15 (see FIG. 11) may be formed and fitted to the connecting links 9, 9 (third embodiment shown in FIGS. 9 and 10). See form). In the latter case, the connecting links 9 and 9 fitted in the fitting groove 15 and the cover pieces 12 and 12 may be fixed with screws.

The stepladder 1 of the first to third embodiments shows a case where the present invention is applied to a type in which the top plate 5 (the first step rail 4) is wide. In this case, since the lengths of the connecting links 9 and 9 are long, the cover piece 12 has a mountain peak upward from the middle of the connecting links 9 and 9 in the longitudinal direction (near the substantially intermediate position) toward the base end 9a. It is formed to protrude into the shape.
However, as shown in FIGS. 12 and 13 as the fourth embodiment, the present invention can also be applied to a stepladder 1 of a type in which the width of the top plate 5 (the first step rail 4) is narrow. In this case, since the length of the connecting links 9 and 9 is shorter than that of the above-described embodiment, the cover piece 12 has a peak on the upper surface in the range (substantially full length) from the proximal end portion to the distal end portion of the connecting links 9 and 9. It is integrally formed by projecting into a shape. Also in this type, the cover piece 12 may be configured separately from the connection links 9 and 9 and attached to the connection links 9 and 9 by the same means as in the second embodiment or the third embodiment. . Moreover, the top plate 5 in this embodiment is provided with hinge brackets 6b and 6b inside the other step rails 4, and these are connected to each other by hinge pins 7a so as to be opened and closed.

The stepladder 1 according to the first to fourth embodiments of the present invention having the above-described configuration includes the leg bodies 2, 2 and the connecting links 9, 9 when the legs 2, 2 are rotated from the open state to the closed leg direction. The acute angle space S formed by being relatively close to each other and narrowed between them is narrowed, but the cover piece 12 that closes the acute angle space S is provided, so that foreign matter enters the acute angle space S. Thus, the occurrence of biting and pinching is prevented.
In carrying out the present invention, when the cover piece 12 is provided integrally with the connecting links 9, 9, the connecting links 9, 9 and the cover piece 12 can be integrally manufactured as one part by press molding or the like. There is an advantage that the strength of the connecting links 9 and 9 can be increased, and when the connecting links 9 and 9 are separated, they can be retrofitted to an existing stepladder, or made of a material different from that of the connecting links 9 and 9, such as resin There are advantages such as being able to use.

  The present invention includes the above embodiment, but is not limited to this embodiment. For example, you may install the cover piece 12 in the support | pillars 3 and 3 side of the leg bodies 2 and 2 instead of installing in the connection links 9 and 9 side. The shape of the cover piece 12 prevents foreign matter from entering and biting into the acute angle space S formed between the legs 2 and 2 and the connecting links 9 and 9. As long as it can be closed as much as possible, it may have a shape other than the illustrated example.

It is a side view of the whole leg stand state of the stepladder according to the first embodiment of the present invention. It is a side view of the whole stepladder state of the stepladder of 1st Embodiment of this invention. It is a principal part enlarged side view of FIG. It is a principal part enlarged side view of FIG. FIG. 4 is an enlarged front view of FIG. 3. It is an enlarged side view of the connection link simple substance of a 1st embodiment. It is a top side view of the leg state of the stepladder of a 2nd embodiment of the present invention. It is an upper side view of the stepladder state of the stepladder of a 2nd embodiment of the present invention. It is a top side view of the leg stand state of a stepladder of a 3rd embodiment of the present invention. It is an upper side view of a stepladder state of a stepladder of a 3rd embodiment of the present invention. It is an expanded sectional view of the cover piece of 3rd Embodiment of this invention. It is a side view of the whole stepladder state of the stepladder of 4th Embodiment of this invention. It is a side view of the whole stepladder state of the stepladder of 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stepladder 2 Leg 3 Post 4 Standing bar 5 Top plate 6 Hinge part 6a Stopper piece 6b Hinge bracket 7 Screw 7a Hinge pin 8 End member 9 Connection link 9a Base end part 9b Tip part 9c Stopper projection 9d Receiving part 9e Upper surface 10 Support shaft DESCRIPTION OF SYMBOLS 11 Connecting pin 12 Cover piece 12a Front surface 12b Vertex 12c Rear surface 13 Attaching part 14 Adhering member 15 Fitting groove S Sharp angle space α Rising angle of cover piece β Minimum angle between leg and cover piece

Claims (3)

A pair of ladder-like legs that are pivotably connected to each other at the upper end and can be opened and closed, and the legs are bent and stretched when the legs are opened and closed, and the legs are narrowed upward when the legs are opened. In order to stop and hold at an open leg angle, a stepladder having a pair of connecting links in which the base end portion is connected via a support shaft in the middle of each leg in the vertical direction and the tip ends are connected to each other by a connecting pin. In
One of the middle portion of the base end side or the leg of the connecting link, an acute angle formed by being sandwiched s between the coupling link base end side and the leg middle section by the open leg state of the leg A stepladder comprising a cover piece that protrudes in a mountain shape reaching the other to close the space and overlaps with the other when the leg is closed.   The stepladder according to claim 1, wherein the cover piece is formed integrally with the connection link, or is formed separately from the connection link and attached to the connection link. The stepladder according to claim 2, wherein the cover piece protrudes in a mountain shape upward from the connection link in a leg open state .

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