JP5360077B2 - Extension attachment of ladder and stepladder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extension attachment which allows a ladder or a straight ladder converted from a stepladder to be extended with an easy operation and enables the ladder to be stabilized. <P>SOLUTION: A hook body 5 is fixed to the lower end of a base substance 1, and an engaging rod 8 having a V-shape with an opening facing the rear side on a projected plane perpendicular to a vertical rod of the base substance is fixed to the uppermost part, separately. The base substance engaged with the rear side of a ladder or a stepladder comes in contact with the rear face of the ladder or the stepladder through the hook body, a pressing body is then rotated through a control lever 19 of a fixing mechanism which is projecting from the front face and is pressure-contacted with the underside of a step bar of the ladder or the stepladder, so that the hook body and the pressing body are connected. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an extension attachment of a ladder and a stepladder (hereinafter simply referred to as an attachment), and can extend the ladder or a stepped ladder (hereinafter simply referred to as a ladder) by a simple operation and stabilize the ladder. It relates to possible attachments.

  Since the structure and intended use of the ladder and stepladder have been well known for a long time, further detailed explanation is omitted here.

Japanese Patent Application No. 2010-273711 JP 08-042272 A JP 09-235972

  When using a stepladder with a ladder and legs expanded as a ladder by leaning on a utility pole or tree, the step bar at the top of the ladder and the utility pole are in point contact, so in places where the scaffolding is bad It is very dangerous to slip or slip if the center of gravity changes.

  Therefore, the applicant previously provided a horizontal engaging rod at the uppermost end of the stepladder having a three-stage structure, which becomes a ladder when unfolded, according to the invention described in Patent Document 1 above. Proposed a stepladder that doubles as a ladder with a shallow V-shaped notch on the back side of the utility pole.

  However, the stepladder that also serves as a ladder, however, has the inconvenience that the position of the engaging rod becomes constant and the position of the engaging rod cannot be changed according to the mounting position of the tree or the utility pole.

  Further, if the engagement rod is to be mounted on a ladder or a stepladder so that the mounting position thereof can be adjusted, an attachment mechanism as described in Patent Documents 2 and 3 is required, but these structures are complicated and heavy. However, there is still room for improvement such as troublesome handling.

  Accordingly, an object of the present invention is to provide an attachment that can extend a ladder or a ladder of a stepladder that has been expanded into a ladder shape by a simple operation and can stabilize the ladder.

  In order to achieve the above object, the invention described in claim 1 is integrally coupled to a ladder-like base body in which a pair of vertical rods are connected by a plurality of horizontal step bars, and a step bar at the lowest stage of the base body. An L-shaped member having a cross-section, which is mounted on the top of the base at a position parallel to the step bar, and is attached to the top of the base at a position parallel to the step bar. A V-shaped engagement rod whose projection shape on a plane perpendicular to the rod is open on the back side, and a base body with a hooking body engaged with any step bar of the ladder or stepladder from the back side can be removed to the ladder or stepladder The fixing mechanism is connected to the vertical shaft above the hook body, or perpendicular to the base body rotatably supported in the vicinity of the vertical shaft above the hook body in the horizontal direction. Spindle and end on the surface side of this spindle An arm parallel to the mounted base, a screw rod parallel to a support shaft fixed to the free end of the arm, a pressing body made of an elastic body screwed coaxially with the screw rod, and the screw rod And an operation lever parallel to the arm attached to the end of the front side of the base, and the base engaged with the back side of the ladder or stepladder is brought into contact with the back side of the ladder or stepladder through the hooking body. After that, the pressing body is rotated through the operation lever that has penetrated to the surface side, and this is pressed against the lower surface of the step bar of the ladder or stepladder so that the hooking body and the pressing body are expanded in the vertical direction. It is characterized by that.

  The attachment according to the present invention configured as described above is configured such that the hook is hooked on a step bar of an arbitrary height from the back side of the ladder, and then the base is brought close to the back side of the ladder and penetrates to the front side of the rear ladder. Since it can be attached to the ladder by operating the fixing mechanism, attachment is very easy to install.

  In addition, since a V-shaped engagement rod whose projection shape with respect to a plane perpendicular to the vertical rod is open on the back side is attached to the uppermost portion of the base, the V-shape of the engagement rod is engaged with a utility pole, a tree, or the like. This makes the ladder much more stable and improves usability.

  Furthermore, under normal use conditions, the static load applied to the fixing mechanism is zero, and the load in the length direction of the ladder applied to the attachment is carried by the hooking body.

  The hook body carrying the load is strong because of its simple structure, and therefore the attachment has various effects such as maintaining its function for a long period of time.

The front view of the attachment by one Example of this invention. The expanded partial sectional view by the II-II line of FIG. The expanded partial sectional view by the III-III line of FIG. The partial cross section top view by the IV-IV line of FIG. The expanded side view by the VV line | wire of FIG. The side view of an attachment. The enlarged front view of a fixing mechanism. The partial cross section enlarged side view of a fixing mechanism. The partial cross-section enlarged plan view of the support shaft portion of the fixing mechanism. The front view of an arm. The side view which shows the use condition of a ladder.

  A hook is attached to the lower end of the base, and a V-shaped engagement hook having a projected shape with respect to a plane perpendicular to the vertical hook of the base is opened on the back side, and a ladder or a stepladder is placed via the hook. After the base engaged with the back side of the ladder is brought into contact with the back side of the ladder or stepladder, the pressing body is rotated via the operation lever of the fixing mechanism that has penetrated to the front side, and this is moved to the step bar of the ladder or stepladder. Since the hook body and the pressing body are expanded in the vertical direction by being pressed against the lower surface of the door, not only can the attachment be easily and easily mounted on the ladder, but the engagement rod can be attached to a power pole, etc. By engaging, the ladder can be stood stably on the utility pole and the like, and the usability of the ladder is greatly improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes an entire attachment base, which is a ladder-like structure in which a pair of vertical rods 2, 2 are connected by a plurality of horizontal (three in the illustrated embodiment) step bars 3, 3. It is molded into.

  As shown in FIG. 2, the vertical rod 2 in the illustrated embodiment is an aluminum shape having a U-shaped cross section, for example. As shown in FIGS. 2 and 3, the step bar has a trapezoidal shape with a narrow cross section. The step bar 3 is fixed by, for example, fixing the rivet 4 so that both ends of 3 are inserted inside the U-shape of the vertical rod 2.

  As shown in FIGS. 1 and 3, the step bar 3 is fixed to the vertical rod 2 at a relative position in which the thin side faces the front side.

  On the other hand, as shown in FIGS. 1 and 4, at least one (two in FIG. 1) hooks 5 and 5 are integrally coupled to the lowermost step bar 3 of the base body.

  As shown in FIG. 5, the hooking body 5 has a front hanging portion 6 that is parallel to the base body protruding from the surface side, and is fixed to the step bar 3 by screws 7, for example.

  On the other hand, as shown in FIGS. 1 and 6, an engagement rod 8 is integrally attached to the uppermost portion of the base 1 at a position parallel to the step bar 3.

  As shown in FIG. 6, the engagement rod 8 has a V shape in which a projection shape with respect to a plane perpendicular to the vertical rod 1 of the base is opened on the back side (upward in FIG. 6).

  Therefore, when the V-shape of the engagement rod 8 is leaned against a utility pole or standing tree, the engagement rod 8 holds the utility pole and the like, so the upper end of the attachment does not move and the ladder is stabilized.

  For the reasons described above, it is desirable to rubberize the V-shaped rear surface (the upper surface in FIG. 6) of the engagement rod 8.

  Further, as shown in FIG. 1, above the hook body 5, there is fixedly attached to the ladder or stepladder so that the base body in which the hook body is engaged with an arbitrary step bar of the ladder or stepladder from the back side. A mechanism 9 is provided.

  As shown in FIG. 8, the fixing mechanism 9 is rotatably supported in the vicinity of the vertical hook 2 (see FIG. 1) above the hook 5 or in the horizontal direction of the vertical hook 2 above the hook. A support shaft 11 (see FIGS. 8 and 9) perpendicular to the base body 1 is provided.

  As shown in FIGS. 8 and 9, the support shaft 11 in the illustrated embodiment is usually made of a hard material such as iron or stainless steel nested inside an aluminum vertical rod 2 and has a cross-sectional shape. The U-shaped support shaft support 12 is rotatably supported and guided so as to penetrate both side plates.

  In order to prevent the support shaft 11 from moving to the left and right in FIGS. 8 and 9, for example, a stopper such as an E-ring is provided at the portion of the support shaft 11 where the side plate of the support shaft support 12 is located. It is fitted.

  As shown in FIG. 8, a pair of upper and lower vertically elongated holes 14 and 14 are opened on the back surface of the support shaft support body 12. These elongated holes and bolt holes on the back surface of the vertical shaft (not shown) are provided. The vertical position of the support shaft support 12 can be adjusted by loosening the penetrating bolt and nut, and the position can be fixed by tightening the nut.

  The significance of adjusting the position of the support shaft 11 in this way is to secure the function of the fixing mechanism corresponding to the change in the interval of the stepladder and ladder because the step bar interval differs slightly depending on the manufacturer. It is.

  An arm 15 parallel to the base is attached to the end of the support shaft 11 on the surface side of the base.

  As shown in FIG. 10, the arm 15 is a plate-like body having an oval shape as a whole, and an odd-shaped odd hole is opened on the right side of the arm 15. The arm 15 is mounted on the support shaft by fitting the deformed section of the same shape formed in the above into the deformed hole of the arm and caulking the fitting section.

  On the other hand, as shown in FIG. 10, a female screw hole 16 is opened at the free end of the arm 15, and a screw parallel to the support shaft 11 with one end (right end in FIG. 8) screwed into the female screw hole 16. By welding the base of the flange 17 (ie, the screwed portion with the arm), the free end of the arm of the screw rod 17 is firmly fixed.

  As shown in FIG. 8, a thick disc-shaped pressing body 18 made of an elastic body such as rubber or soft plastic is screwed on the screw rod 17 coaxially with the screw rod 17.

  In order to screw and attach the pressing body 18 to the screw rod, an elastic disk may be bonded around a nut-like cylinder that is screwed to the male thread portion of the screw rod, When a disk made of an elastic material formed around a small-diameter hole from the male screw portion is forcibly inserted into the screw rod and turned, the screw moves along the screw rod while creating a female screw hole on the inner surface of the small-diameter hole.

  The significance of enabling the pressing body 18 to be moved along the length direction of the screw rod is that the lower surface of the step bar of the ladder is usually inclined, so that by changing the position of the pressing body 18, The pressing force can be adjusted.

  On the other hand, an operating lever 19 parallel to the arm 15 is attached to the end of the screw rod 17 on the front surface side (left end portion in FIG. 8) so as to be L-shaped with the screw rod 17.

  In order to fix the operation lever 19 to the screw rod 17, for example, if the operation lever 19 is operated to the left end portion in FIG. 8, a female screw hole (not shown) formed at the lower end portion of the screw rod 17 is screwed. After the relative angle position with respect to the arm 15 (the relative angle in FIG. 7 is 0 degree) is appropriately set, the operation lever 19 and the threaded portion of the screw rod 17 are welded.

  Actually, after a series of members from the support shaft 11 to the operation lever 19 are connected to each other, the support shaft 11 is long in the vertical direction opened from the surface side of the attachment base to the side surface of the vertical rod 2. Insert through the non-numbered oblong hole and the spindle support body 12 and fix them with retaining rings 13 and 13.

  As shown in FIG. 11, the attachment according to the embodiment of the present invention configured as described above has a base body in which the hook body 5 is engaged with an arbitrary step bar of the ladder from the back side. Then, the operation lever 19 is rotated to fix the attachment to the ladder 21.

  That is, in FIG. 7 and FIG. 8, the operation lever 19 is at the 12 o'clock angle position in terms of the clock face. For example, the left operation lever is at the 10 o'clock position and the right operation lever is at the 2 o'clock angle position. Then, the levers 19 and 19 are rotated clockwise in the left direction and counterclockwise in the right direction.

  Then, the left and right pressing bodies 18 are rotated around the support shaft 11 and approach the lower surface of the step bar 3 of the ladder from below, and come into contact with the lower surface and are elastically deformed as shown in FIGS. It reaches the top position.

  Actually, the left pressing body 18 is further slightly rotated clockwise from the state shown in FIG. 7 (the right one is counterclockwise). The reason is as described in the following paragraph [0045].

  Therefore, as shown in FIG. 7, the pin-like stopper 22 provided on the vertical shaft of the attachment is brought into contact with the right end surface of the fan-shaped guide notch 23 formed on the lower end edge of the arm 15. .

  Then, the arm 15 is blocked by the stopper 22 if it tries to rotate clockwise, and if it tries to rotate counterclockwise, the pressing body 18 has to push up the step bar of the ladder. The state slightly lower than the position is stable.

  Returning to the original state, rotating the operation lever and pushing up the ladder step bar 3 by the pressing body 18 means that the attachment pushes the hook body 5 and the pressing body 18 between the ladder step bars. Therefore, the attachment is fixed to the ladder through the frictional engagement of the pressing body 18.

  Even if the ladder to which the attachment is connected is brought to the site and leaned against a standing tree or the like as shown in FIG. 11, the attachment and the ladder can be removed even if the operation lever is turned to remove the pressing body 18 from the ladder step bar. There is no separation.

  The reason is that a moment acts so that the attachment is pressed against the back surface of the ladder, and both are pressed.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Vertical rod 3 Step bar 4 Rivet 5 Hook 6 Front drooping portion 7 Screw 8 Engaging rod 9 Fixing mechanism 11 Support shaft 12 Support shaft support body 13 Retaining ring 14 Long hole 15 Arm 16 Female screw hole 17 Screw rod 18 Press Body 19 Operation lever 21 Ladder 22 Stopper 23 Notch

Claims (1)

A ladder-shaped base body in which a pair of vertical rods are connected by a plurality of horizontal step bars, and an L-shaped member integrally joined to the lowermost step bar of the base body. At least one hook projecting to the side, and a V-shaped projection mounted on the top surface of the base at a position parallel to the step bar and projected onto the plane perpendicular to the vertical plane of the base. An engagement rod, and a fixing mechanism that removably connects the base body, which is hooked to an arbitrary step bar of the ladder or stepladder from the back side, to the ladder or stepladder. A vertical shaft above the vertical shaft, or a support shaft perpendicular to the base that is pivotally supported in the vicinity of the vertical shaft in the horizontal direction, and an arm parallel to the base mounted on the end of the surface side of the support shaft, The support shaft fixed to the free end of this arm And an operating lever parallel to the arm mounted on the end of the surface of the screw rod. After the base engaged with the back side of the ladder or stepladder is brought into contact with the back side of the ladder or stepladder, the pressing body is rotated through the operation lever that has penetrated to the front side, and this is moved to the ladder or stepladder. An extended attachment of a ladder and a stepladder, wherein the hook and the pressing body are expanded in the vertical direction by being brought into pressure contact with the lower surface of the step bar.

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