JP2008528834A - Folding combination ladder - Google Patents

Abstract

  A folding stepladder 1 having two ladder legs 2 and 3, and the ladder legs 2 and 3 are hinged to each other at one end. Each of the ladder legs 2, 3 comprises several ladder sections 4a-4d, each section comprising two ladder bars 6, 7 arranged parallel to each other, and two ladder bars 6, 7 Are interconnected at one end by a crosspiece 8 to form a U-shaped ladder section. The ladder section is telescopically inserted into the lower ladder section 4e to form a folding ladder with at least three ladder sections. One of the ladder legs 3 includes a support portion 12 at one end. The support part 12 can be telescopically extended from the ladder leg 3 to form an extension ladder of the ladder leg, and the support part 12 protrudes upward from the hinge 5 between the two ladder legs 2 and 3.

Description

  The present invention relates to a folding stepladder with ladder sections which are inserted in a mutually nested manner.

  Foldable telescopic stepladders are known in the art. Examples of prior art stepladders are described below.

  WO-A1-99 / 51848 discloses a nested folding stepladder comprising two legs hinged to each other. Each leg is comprised of a telescopic collapsible section having a latching mechanism on each of the crosspieces, the latching mechanism for automatically locking the sections together when the legs are extended. The latch mechanism of each crosspiece is designed to release the upper section as soon as the crosspiece is folded towards the lower crosspiece. When the stepladder is extended, the distance between the horizontal bars of one leg is larger than the distance between the horizontal bars of the other leg. The problem with the stepladder of WO-A1-99 / 51848 is that the collapsible sections of the two legs have different heights. This is why this stepladder never passes the type test. Furthermore, the stepladder cannot be converted to a straight ladder because the two legs are folded adjacent to each other, resulting in a ladder with many small steps due to the different heights of the collapsible sections.

  U.S. Pat. No. 4,498,692 discloses a ladder that includes two hinge portions that can be inverted V-shaped for use as a stepladder or linear for use as a linear ladder. Each section of the ladder includes a number of U-shaped support units, each of which forms a crossbar and two downwardly extending side rails. Since the side rails of different U-shaped units have a stepped cross-sectional dimension, the units can be contracted together by sliding the side rails that align to nest together. The problem with the ladder of US-A-4996992 is that the two sections of the ladder cannot be used without external support. That is, the user needs to balance during work, which is undesirable from the viewpoint of work safety. This is due to the lack of support provided to the ladder when using the upper section of the ladder. Another problem with this ladder is that when the ladder is converted to a straight ladder, the two legs are folded and secured to each other by the swing tie bar 26 so that the ladder is somewhat unstable. Such a fixed structure is not very solid and is not very stable and will not pass the type test.

  Another stepladder is disclosed in GB-A-2110286, said second stepladder comprising a first set of rigid nesting elements and a second set of parts each comprising a support surface constituting a stage of a ladder. Including. Each part is connected laterally to one element or group of rigid elements of the first set. The set of stopper studs and locking means between the various rigid elements of the first set at least guarantees the stability of the two extreme positions of the ladder: the position when the ladder is folded and the position when extended. It is configured as follows. The ladder of GB-A-2110286 not only has the same problems as US-A-44989692, but also has a poor locking or fixing configuration in the conversion form.

  The object of the present invention is to overcome the disadvantages and problems of prior art stepladders and provide a stepladder that is easy to handle and safe and that can be converted to a linear ladder without lowering the standards of safety and ease of handling. That is.

  A stepladder according to the features of claim 1 solves the above problem.

  The features of the dependent claims define further aspects and preferred embodiments of the claimed invention.

  Next, the present invention will be described with reference to the accompanying drawings.

  A folding stepladder 1 according to the invention is shown in the drawing. FIG. 1 shows a folding stepladder 1 comprising a first ladder leg 2, which is connected to a first and second ladder legs 2, 3 by a first hinge connection 5. Is hinged to the second ladder leg 3 at the upper end of. Each of the ladder legs 2, 3 comprises several ladder sections 4a-4d, each ladder section 4a-4d comprising two ladder bars 6, 7 arranged parallel to each other, said two Ladder bars 6, 7 are interconnected at one end by a crosspiece 8 to form U-shaped ladder sections 4a-4d. Ladder sections 4a-4d are telescopically inserted into the lower ladder section to form foldable ladder legs 2,3. The ladder legs 2, 3 further comprise a lower ladder section 4e, the lower ladder section 4e comprising two ladder bars 6, 7, which are parallel to each other. Arranged and interconnected by a horizontal rail 9 at the upper end, by a ladder base 10 at the lower end and between the horizontal rail 9 and the ladder base 10 by another horizontal rail 11. Ladder sections 4a-4d are telescopically inserted into ladder section 4e.

  Although the ladder legs 2, 3 must comprise at least three ladder sections 4a-4e, in the preferred embodiment, four collapsible ladder sections 4a-4d are arranged with the lower ladder section 4e. The number of ladder sections is limited by the stability of the stepladder and the requirements for passing the type test.

  Each crosspiece 8, 9 includes a locking mechanism for automatically locking the ladder sections together when the ladder legs 2, 3 are extended. The securing mechanism may be of any type known in the art, for example, any of the securing mechanisms shown in EP-B1-0527766 or EP-A1-1402143.

  The second ladder leg 3 includes a support portion 12 at one end. The support 12 is extendable telescopically from the second ladder leg 3 to form a ladder extension 12 of the second ladder leg 3, the support 12 being a hinge between the two ladder legs 2, 3. It protrudes above the connection part 5. The support part 12 comprises at least one support section 12a-12b, each support section comprising two ladder bars 6, 7 arranged parallel to each other, the two ladder bars 6, 7 being at least One end is interconnected by a crosspiece 16 to form one U-shaped support section 12a-12b. Support sections 12 a-12 b are telescopically inserted into the ladder legs 3 to form a collapsible support 12. The support part 12 also comprises an upper support section 12c, which is arranged in parallel with each other to form a U-shaped support section 12c and interconnected at one end by a crosspiece 13 Ladder rods 6 and 7 are included. Support section 12c is telescopically inserted into lower support sections 12a-12b.

  In FIG. 2, a ladder is shown in which both ladder legs 2, 3 and the support or extension 12 are fully extended. The support 12 allows the user to stand on the upper ladder sections 4a-4b while making the stepladder user feel safe. In FIG. 2, the support 12 comprises two collapsible ladder sections 12a and 12c. A holding device for holding a tool or an object such as a tray, a table, a shelf, a box / case, or a basket can be arranged on the upper horizontal rail 13 of the support portion 12. The device is arranged in a clamping, clamping, hanging, hooking or other manner suitable for being placed on the upper crosspiece 13. Receiving means such as a hole, a chamfer, a recess or the like for better receiving the holding device can be provided on the crosspiece 13.

  Also shown in FIG. 2 is a strap 14 disposed between the ladder legs 2 and 3 to increase the stability of the ladder and prevent the ladder legs from spreading in the extended and folded modes. The strap 14 is attached at one end to the rear surface of the cross beam 8 of the ladder leg 2 and at the other end to the rear surface of the horizontal beam 8 of the ladder leg 3 by suitable fastening means such as pop rivets or the like. . The strap is preferably attached to the horizontal beam 8 arranged in the ladder section 4e of the ladder legs 2 and 3, respectively, but the strap 14 is attached to the horizontal beam connected to the ladder section at the upper stage or the lower stage from the ladder section 4e. It is also possible. The strap 14 is also shown in FIGS. 3 and 5, but is omitted from FIGS. 1 and 4 for clarity of explanation. The strap 14 can be made of a nylon woven nylon material.

  In FIG. 3 it is shown how the hinge connection 5 creates a platform between the tops of the ladder legs 2, 3, which platform is used to place or stand a tool box or the like it can.

  4 and 5, the ladder section 4d of the ladder leg 2 is folded. The stepladder 1 is converted into a linear ladder and is arranged to lean against the wall. The support 12 allows the stepladder to lean against the wall without the ladder leg 2 obstructing or destabilizing the ladder in the leaning position. Since the ladder section 4d of the ladder leg 2 is folded, when the ladder is converted into a straight ladder, the ladder leg 2 hangs down and does not get in the way. Any or some of the collapsible ladder sections 4a-4d can be folded. In order to prevent the folded ladder section from extending due to its own weight, the holding means 15 holds together the folded ladder section and the ladder section located adjacent to the lower side of the folded ladder section. .

  In FIG. 4, the holding means is a nylon strap 15, but it may be a hook attached to a cross rail of one ladder section, and the hook portion surrounds the cross rail of the adjacent ladder section. It can be rotated like this. It is also possible to use a U-shaped clamp of plastic material that holds together the folded ladder section and the ladder section located adjacent below the folded ladder section. The advantage of the clamp is that any of the ladder sections 4a-4d can be folded and held in the clamp, whereas the position of the hook or strap is which of the folding ladder sections 4a-4d is folded. Determines whether it should be held together with the ladder section located adjacent to it. According to yet another alternative embodiment, the folding mechanism, more specifically the locking pin of the locking mechanism, is used to place the collapsible ladder sections 4a-4d underneath the folded ladder sections 4a-4d. Can be held or locked against the ladder section.

  4 and 5, the ladder section 4d is folded and the strap 15 or holding means surrounds the folded ladder section 4d and the ladder section 4e of the ladder leg 2. The strap 15 is preferably attached to either the side rail 8 or the side rail 9 and is connected to the side rail of the folded ladder section and the side rail of the ladder section located adjacent to the lower side of the folded ladder section. It is long enough to surround it. In the embodiment shown in FIGS. 4 and 5, the strap 15 is attached to the crosspiece 9 by pop rivets or other suitable fastening means. The strap 15 is fastened at the center of the strap 15 so that the strap extends substantially equally in both directions from the fastening position. The end of the strap 15 is provided with a Velco® fastener or similar fastening means that interacts when the strap end surrounds the crosspiece.

  The ladder sections 4b-4e of the ladder leg 3 are provided with deeper transverse bars 8, 9, 11 (see FIGS. 3 and 5) to provide additional foot support compared to the ladders of the ladder section of the ladder leg 2. Designed properly. The crosspieces are suitably made of extruded aluminum profiles.

  In the above embodiment where the ladder is used as a converted ladder or a linear ladder, the at least one collapsible ladder section 4a-4d of the first ladder leg 2 allows the ladder to be used as a linear ladder. To be folded. However, it is also possible to fold the ladder leg 2 so that all the ladder sections 4a to 4d of the first ladder leg 2 are extended and are adjacent to and parallel to the second ladder leg 3. In this case, the holding means 15 can be used to maintain the two ladder legs 2, 3 in adjacent parallel positions. In this case, the lower ladder section 4e of the second ladder leg 3 is made longer than the lower ladder section 4e of the first ladder leg 2 so that both lower ends of the two ladder legs 2 and 3 are simultaneously supported by the ground. be able to.

  A foldable stepladder with fewer foldable ladder sections, as shown in FIGS. The locking device 20 includes a first part 21 and a second part 22. The first part 21 is pivotally connected at one end to the crosspiece 8 of the first ladder leg 2, preferably to the crosspiece 8 of the ladder section located immediately below the hinge connection 5. The second part 22 is likewise pivotably connected at one end to the corresponding crosspiece of the second ladder leg 3, preferably to the crosspiece 8 of the ladder section located directly below the hinge connection 5. Is done. The other ends of the first and second parts 21, 22 are connected to each other in a lockable and foldable manner. In the connection between the first part 21 and the second part 22, a locking part 23 having a handle portion 24 extending upward is also arranged.

  The locking device 20 helps to ensure that the legs 2, 3 of the stepladder 1 are not accidentally folded during use of the stepladder 1. When the collapsible ladder section of the stepladder 1 is extended and the fully extended ladder legs 2, 3 are unfolded for use, the first part 21 and the second part 22 of the locking device 20 are It is spread out so as to form a substantially straight horizontal portion between the crosspieces 8 of the corresponding ladder section. By pulling up the lock part 23 with the handle 24, the first part 21 and the second part 22 of the lock device 20 are locked to each other by the lock part 23, and the ladder legs 2, The person using the stepladder 1 by folding 3 will not be in a dangerous situation. In FIG. 6, the locking device 20 is in the locked position.

  In order to release the locking device 20, the handle 24 is pushed down, thereby moving the ends of the first part 21 and the second part 22 of the locking device 20 downward so that the ladder legs 2, 3 are folded. The ladder legs 2 and 3 can be folded.

  Since the entire locking device 20 is arranged inside the ladder bars 6, 7, the locking device 20 is protected from any external force during handling of the stepladder 1. Further, since the first part 21 and the second part 22 of the locking device 20 are arranged in a small protrusion at the short end of the crosspiece 8, the locking device 20 is folded without disturbing the telescopic folding function of the stepladder 1. Although, the locking device 20 moves downward with the ladder section when the ladder section is folded. 7 and 8 show the space in which the locking device 20 is formed by the ladder legs 2, 3, more specifically the space formed by the ladder bars 6 or 7 of the ladder legs 2, 3 and the crosspiece 8 of the ladder section. It clearly shows that it is placed inside.

  The invention is not limited to the embodiments described above and shown in the figures, but can be supplemented and modified in any way within the scope of the invention as defined by the claims.

FIG. 4 is a perspective view of a stepped up stepladder according to the present invention. FIG. 4 is a perspective view of a stepladder according to the present invention with all ladder sections fully extended. FIG. 2 is a side view of a stepladder according to the present invention with all ladder sections fully extended. FIG. 2 is a perspective view of a ladder according to the invention in a transformed form of a linear ladder with one ladder section folded. FIG. 4 is a side view of a ladder according to the present invention in a converted form as a linear ladder with one ladder section convoluted. FIG. 2 is a side view of a stepladder according to the invention with a locking device, with all ladder sections fully extended. FIG. 4 is a side view of a stepladder according to the invention with a locking device, with all ladder sections fully folded; FIG. 4 is a side view of a stepladder according to the invention with a locking device, with all ladder sections fully folded;

Claims (14)

A foldable stepladder (1) comprising first and second ladder legs (2, 3), wherein the ladder legs (2, 3) are hinged to each other at one end, and the ladder legs (2 3) each comprises several ladder sections (4a-4e), each ladder section (4a-4d) comprising two ladder bars (6, 7) arranged parallel to each other, The two ladder bars (6, 7) are interconnected at one end by a cross rail (8) to form a U-shaped ladder section, and each ladder section (4a-4d) is connected to the lower ladder section. Inserted telescopically into a foldable ladder having at least three ladder sections, the second ladder leg (3) is provided with a support (12) at one end, the support being Enter from the ladder leg (3) to form an extension ladder of the ladder leg (3) And can extend into telescopic, the support (12) protrudes above the hinge (5) interconnecting the two ladder legs (2, 3), the folding stepladder (1),
Folding stepladder (1), wherein the folding stepladder (1) is configured to be converted into a linear ladder.   Folding according to claim 1, wherein said first ladder leg (2) comprises holding means (15) for maintaining one or several collapsible sections (4a-4d) in a collapsed position. Formula stepladder (1).   The holding means (15) is adapted to hold the folded ladder section (4a-4d) together with a ladder section located adjacent to the lower side of the folded ladder section (4a-4d). The folding stepladder (1) according to claim 2, which is a strap or hook attached to one of the ladder sections (4a-4e) of the first ladder leg (2).   The holding means (15) is arranged on the side rail of the folded ladder section (4a-4d) and the side of the ladder section located adjacent to the lower side of the folded ladder section (4a-4d). Folding stepladder (1) according to claim 2, which is a U-shaped clamp configured to hold the crosspieces (8, 9) together.   The folding stepladder (1) according to claim 1, wherein the ladder leg (1) is fully extended, and is configured to be converted into a linear ladder using the hinged ladder legs (2, 3). Folding stepladder (1) that allows (2, 3) to be placed in parallel.   The folding stepladder (1) according to claim 5, wherein the lower ladder section (4e) of the second ladder leg (3) is longer than the lower ladder section (4e) of the first ladder leg (2).   Folding stepladder (1) according to any one of the preceding claims, wherein the support (12) comprises at least one collapsible ladder section (12a, 12b, 12c).   Folding stepladder (1) according to any one of the preceding claims, wherein the support (12) comprises means for holding a tool, paint or other working member.   The two ladder legs (2, 3) are located between corresponding ladder sections (4b-4d) of the ladder legs in order to prevent the ladder legs (2, 3) of the stepladder from spreading during use. Folding stepladder (1) according to any one of the preceding claims, connected by a flexible link (14) deployed on the heel.   The two ladder legs (2, 3) are connected to corresponding ladder sections (4b-4d) of the ladder legs in order to prevent the ladder legs (2, 3) of the stepladder from moving towards each other during use. Folding stepladder (1) according to any one of the preceding claims, connected by a locking device (20) deployed between.   The locking device (20) is configured such that one end of the first and second parts can be pivoted to one side of the corresponding cross rail of the corresponding ladder section (4b-4d) of the two ladder legs (2, 3). 11. A folding stepladder (1) according to claim 10, wherein the folding stepladder (1) is configured to be attached and the first and second parts are connected to each other at the other end in a lockable and foldable manner.   12. The locking device (20) according to claim 10 or 11, wherein the locking device (20) in a folding mode is configured to be housed and folded in a space between the ladder legs (2, 3). Folding stepladder (1).   Folding stepladder (1) according to any one of the preceding claims, wherein at least one of the ladder legs (2, 3) of the stepladder comprises means (10) for improving lateral stability. .   The stabilizing means includes a ladder base (10) attached to a lower end of a ladder bar (6, 7) of a lowermost ladder section (4e) of the ladder leg, and the ladder base extends between the ladder bars. The folding stepladder according to claim 13, which is (10).

Images