JP4499305B2 - Telescopic ladder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a telescopic ladder.
[0002]
[Prior art]
Conventionally, as this type of telescopic ladder, a two-stage type that is slidably connected to each other, or a three-stage type that includes a lower ladder part, a middle ladder part, and an upper ladder part is generally used. Met.
[0003]
In particular, in the construction of overhead lines, it is necessary to extend the ladder to a considerably high place, and even in ordinary households, there are cases where climbing on the roof on the second floor or working at a high place such as three stories. Therefore, the demand for a three-stage or multi-stage telescopic ladder having more stages is also increasing.
[0004]
[Problems to be solved by the invention]
However, following the conventional telescopic ladder structure described above, for example, when trying to make a four-stage system, as shown in FIG. 10 (a), the ladder sections X1 to X4 of each stage can be nested, As shown in (b), the pillars Z1 to Z4 of the ladder portions Y1 to Y4 of each stage are superposed vertically.
[0005]
This increases the overall thickness D of the ladder when contracted, necessitating a large storage space and making handling inconvenient.
[0006]
Eventually, in ordinary homes and the like, the storage place was troubled and it was raining, and the ladder was often deteriorated.
[0007]
Moreover, when using for overhead wire construction, conveyance with a vehicle is also inconvenient.
[0008]
Furthermore, when the well-known technology using a rope and a pulley is used as it is to expand and contract a four-stage telescopic ladder, the pulling rope hangs down for each stage, not only getting in the way when raising and lowering the ladder, If it is caught, there is a risk of the ladder falling over, which is dangerous.
[0009]
An object of the present invention is to provide a telescopic ladder that can solve the above-described problems.
[0010]
[Means for Solving the Problems]
  In order to solve the above-mentioned problems, the present invention according to claim 1 includes a pair of left and right pedestals each provided with a step rail.A four-stage system consisting of a lowermost ladder, a lower ladder, a middle ladder, and an upper ladderThe ladder part of slidably connected up and downAs well asThe pedestal of the ladder at each stage is formed in a substantially U shape in cross-sectional view having a groove from the web and the flange, and the flanges of adjacent pedestals are combined in a superposed state and contracted to a length equivalent to approximately one stage. Possible configurationShiReduce the overall thickness of the ladder during contraction as much as possible.StretchLadderThe relative expansion and contraction of the lowermost ladder and the lower ladder is performed by engaging and releasing the stopper, and the expansion and contraction of the middle ladder and the upper ladder is performed by a flat belt or a rope. The first ladder is provided on the lower side of one side of the lower ladder part, and the second pulley is provided on the upper side of the lower ladder part. A pair of upper and lower third pulleys and a fourth pulley are provided at left and right symmetrical positions on the lower side of the fifth pulley, and a fifth pulley is provided at left and right symmetrical positions on the upper sides of the third and fourth pulleys. And a sixth pulley, and one end of a flat belt or rope for expanding and contracting the middle ladder portion is connected and fixed to a lower portion of a pedestal on one side of the lower ladder portion, and provided on the middle ladder portion. Extending horizontally through the upper side of the lower pulley of the third pulley, and After changing the direction downward through the upper part of the lower pulley of the fourth pulley, then changing the direction upward through the lower part of the first pulley of the lower ladder part, along the pedestal Extending substantially vertically, extending downwardly through the upper side of the second pulley, extending horizontally through the lower side of the upper pulley of the fourth pulley, and of the third pulley Flat belt E or rope for expanding and contracting the upper ladder part while being connected and fixed to the upper part of the pedestal on one side of the lower ladder part while being folded upward and extending through the lower part of the upper pulley The one end is connected and fixed in the vicinity of the upper end of the pedestal on one side of the lower ladder part, and directed downward through the upper part of the fifth pulley provided at the upper part of the pedestal of the middle ladder part. And extending upward through a belt sliding guide provided at the lower part of the left and right pedestals of the upper ladder part, In different directions on the lower side through the upper portion of the sixth sheaves of section ladder portion fixedly connected near the upper end of the lower ladder sectiondid.
[0011]
Further, in the present invention described in claim 2, the end portions of the crosspieces are arranged in a plurality of stages by alternately arranging the ladder portions attached to the webs of the respective pedestals and the ladder portions attached to the flanges.
[0012]
  Further, in the present invention described in claim 3,The lowermost ladder part and the lower ladder part are inward and outward, respectively, so that both groove parts face each other so that the flanges on one side are slidable in a superposed state, and the middle stage Ladder part pedestal groove is inward, and the upper ladder part pedestal having an outward groove part is slidably disposed in the groove part. Attach the guide holder that holds the ladderIt was.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a telescopic ladder in which a plurality of ladder sections each provided with a pair of left and right leg posts each provided with a step rail are slidably connected to each other, and the leg pillars of the ladder sections of each stage are connected to a web and a flange. It is formed in a substantially U-shape in cross-sectional view having a groove portion from each other, and the flanges of adjacent pedestals are combined in a superposed state so that it can be contracted to a length corresponding to approximately one step, and the thickness of the entire ladder at the time of contraction is reduced. It is as small as possible.
[0017]
In addition, a plurality of the above-mentioned step rails are provided at appropriate intervals between the pedestals of each ladder part, and both ends of the step pedestal are connected to the pedestal, but the thickness of the entire ladder when contracted In order to make this as small as possible, it is preferable that the end portion of the pedestal has a plurality of stages by alternately arranging a ladder portion attached to the web of each pedestal and a ladder portion attached to the flange.
[0018]
In consideration of the length and thickness during handling and storage, the telescopic ladder is preferably a four-stage system including a lowermost ladder part, a lower ladder part, a middle ladder part, and an upper ladder part.
[0019]
In this case, with the groove portions of the lowermost ladder portion and the lower ladder portion facing inward and outward, respectively, the two flange portions are combined so that the flanges on one side are slidable in a superposed state. The upper ladder part with the groove part of the upper ladder part having the outward groove part in the groove part is slidably disposed with the groove part of the leg pillar of the middle stage ladder part facing inward, and further on the upper position of the lower ladder part. It is desirable that a guide holder for holding the middle ladder portion is attached.
[0020]
Such a four-stage telescopic ladder can generally be used by freely extending it to the required height, and even when contracted, the thickness of the ladder is reduced and the storage capacity is made as small as possible. It is easy to store in a compact and easy to handle.
[0021]
  Further, the expansion and contraction operation of each ladder part is performed by arranging pulleys on the leg pillars of each ladder part, spanning a flat belt or rope between the leg pillars via the pulley, and pulling the flat belt or rope. The movable member can be slid back and forth.At this time, a first pulley is provided on the lower side of the pedestal on one side of the lower ladder part, a second pulley is provided on the upper side, and a pair of upper and lower parts is provided on the lower side of the left and right pedestal of the middle ladder part. The third pulley and the fourth pulley are provided at symmetrical positions on the left and right lines, and the fifth pulley and the sixth pulley are provided on the upper sides of the third pulley and the fourth pulley so as to be in the left-right symmetrical positions, One end of a flat belt or rope for expanding and contracting the middle ladder portion is connected and fixed to a lower side portion of a pedestal on one side of the lower ladder portion, and among the third pulleys provided on the middle ladder portion, After extending horizontally through the upper part of the lower pulley and further turning downward through the upper part of the lower pulley of the fourth pulley, the first pulley of the lower ladder part Turns upward through the lower part, extends substantially vertically along the pedestal, and downwards through the upper part of the second pulley Extended horizontally through the lower side of the upper pulley of the fourth pulley, folded upward and extended through the lower side of the upper pulley of the third pulley, One end of the flat belt E or rope for extending and contracting the upper ladder part is connected to and fixed to the upper part of the leg pillar on one side of the lower ladder part, and one end thereof is near the upper end part of the leg pillar on the one side of the lower ladder part And a belt slide provided at the lower part of the left and right leg pillars of the upper ladder part, changing the direction downward through the upper part of the fifth pulley provided at the upper part of the leg pillars of the middle ladder part. It can be extended and extended through a moving guide, and can be connected and fixed near the upper end of the lower ladder portion by changing the direction downward through the upper side of the sixth pulley of the middle ladder portion.
[0022]
In particular, in the case of a multi-stage expansion ladder such as a four-stage type, the relative expansion and contraction of the lowermost ladder section and the lower ladder section is performed by engaging and releasing the stopper, and the middle and upper ladder sections. Can be expanded and contracted by a flat belt or rope pulling operation.
[0023]
By adopting such a configuration, if the telescopic ladder is placed in a contracted state, and the lowermost ladder part is pulled out and used by releasing the stopper, it is a four-stage ladder, and the lowermost ladder part is not pulled out. It can be used as a ladder for a stage and can be easily selected according to the application.
[0024]
In addition, when expanding and contracting the middle ladder and the upper ladder, even in the state where the ladder is leaned, the leg pillars of both ladders can be easily expanded and contracted by belt operation or rope operation at hand, In particular, if a flat belt is used, it is easy to form a wide belt that is easy to grip, and operability is improved.
[0025]
Moreover, it can be set as the structure which an intermediate | middle stage ladder part and an upper stage ladder part operate | move to an expansion-contraction operation | movement by operation of one belt or a rope.
[0026]
That is, the upper ladder part is attached so that it can slide back and forth along the groove of the leg part of the middle ladder part, and the flat belt spans the leg parts of the lower ladder part, the middle ladder part, and the upper ladder part. Alternatively, the rope is spanned, and the leg pillars of the upper ladder part are configured to reciprocate and slide in conjunction with the reciprocal sliding of the leg parts of the middle ladder part.
[0027]
With such a configuration, even if the belt or rope is pulled, the pulled portion is absorbed by the upward movement of the upper ladder and can maintain the tension state, and the belt and the rope are slackened and remain below the ladder. Because there is nothing, there is no danger of getting in the way or getting people caught.
[0028]
Of course, the expansion and contraction of the lowermost ladder and the lower ladder may be performed by an operation using a belt or a rope.
[0029]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0030]
FIG. 1 (a) is a front view illustrating the stretched state of the telescopic ladder according to the present embodiment, FIG. 1 (b) is a side view, and FIG. 2 (a) is a partial contraction of the telescopic ladder. 2 (b) is an explanatory view showing the total contracted state, FIG. 3 is a cross-sectional explanatory view taken along the line II of FIG. 2 (a), and FIG. 4 is an I--section of FIG. 1 (a). FIG. 5 is a sectional explanatory view taken along the line II-II, FIG. 6 is a sectional explanatory view taken along the line III-III, and FIGS. 7A and 7B are the lowermost ladder portion and the lower ladder. 8A is a sectional view taken along the line aa 'in FIG. 7A, and FIG. 8B is a sectional view taken along the line BB' in FIG. 7B. 9 (a) and 9 (b) are explanatory views of the expansion / contraction mechanism of the middle ladder section and the upper ladder section.
[0031]
As shown in FIGS. 1 to 6, the telescopic ladder A according to the present embodiment is a four-stage system including a lowermost ladder part A1, a lower ladder part A2, a middle ladder part A3, and an upper ladder part A4. Yes, it is mainly composed of lightweight aluminum alloy material.
[0032]
Although the telescopic ladder A according to the present invention is not limited to a four-stage type, it is considered optimal for normal use from the length and thickness during handling and storage.
[0033]
Each ladder part A1 to A4 has a pair of opposed pedestals 1,1,2,2,3,3,4,4 and a plurality of traverses 5,6,7,8 constructed between them. Each pedestal 1,1,2,2,3,3,4,4 is connected to each other so as to be reciprocally slidable. In this embodiment, in the range of about 1.5m to 5.6m. It can be stretched. Therefore, it can be leaned to a sufficiently high place, and when stored, it can be contracted to a length of approximately one stage, so that it is compact and can be stored and transported easily.
[0034]
At the lower end of the lower ladder A1, the outrigger B, which is a well-known structure for increasing the stability when using the telescopic ladder A, is attached, and the top of the upper ladder A4 is leaned against the wall. For example, a safety hook F that is prevented from coming off when leaning against an overhead wire or the like is attached to the shaft so as to be rotatable around the axis and extendable in the axial direction. Therefore, a stable posture can be maintained and safe work at a high place can be performed. B1 is a left / right telescopic rod of the outrigger, B2 is a screw tube attached to the tip of the left / right telescopic rod B1 so as to be able to move up and down, and B3 is a leg seat having a non-slip function.
[0035]
In addition, as shown in FIG. 3, the respective pillars 1, 1, 2, 2, 3, 4, 4 of each of the ladder portions A1 to A4 are connected to the webs 11, 21, 31, 41, and 11 , 21, 31, 41 and flanges 12, 22, 32, 42 formed on both sides, and formed in a substantially U shape in cross section. 13, 23, 33, 43 are grooves formed by the webs 11, 21, 31, 41 and the flanges 12, 22, 32, 42.
[0036]
Each of the pillars 1, 1, 2, 2, 3, 3, 4, 4 is adjacent to each other, that is, as shown in FIG. 4, each flange 12 of the lowermost ladder portion A1 and the lower ladder portion A2. 5, between the flanges 22 and 32 of the lower ladder portion A2 and the middle ladder portion A3 as shown in FIG. 5, and between the flanges 32 and 42 of the middle ladder portion A3 and the upper ladder portion A4 as shown in FIG. In combination with the polymerization state, it is slidable, and as shown in FIG. 2, it can be shrunk to a length equivalent to one step when shrunk.
[0037]
Moreover, with the above configuration, as shown in FIG. 3, the thickness D of the entire telescopic ladder A at the time of contraction can be remarkably reduced, and storage and handling become extremely easy.
[0038]
Here, the configuration of each of the ladder portions A1 to A4 will be further described in detail.
[0039]
As shown in FIG. 3, the lowermost ladder portion A1 is formed with the flange 12 of the pedestal 1 in an approximately U-shape inwardly viewed in cross section, and both ends of the traverse 5 are flattened and substantially L-shaped. The web 11 and the flange 12 are overlapped from the outside and fixed with bolts or the like. Therefore, the step rail 5 is arranged on the surface side of the lowermost ladder portion A1. Further, a slide reinforcing plate 15 is attached to the upper position of the lowermost ladder portion A1 (see FIG. 1) so as to be wound around the pedestal 1.
[0040]
The lower ladder portion A2 is formed in a substantially U-shape with the web 21 of the pedestal 2 and the flange 22 facing outward in a cross-sectional view, and the both ends of the traverse 6 are fitted to the approximate center of the web 21 of the pedestal 2 It is fixed by caulking. Therefore, the step bar 6 and the step bar 5 have a slight gap in the thickness D direction so that they do not interfere with each other's sliding operation. Further, a slide reinforcing plate 25 is attached to a lower position of the lower ladder portion A2 (see FIG. 2).
[0041]
Further, a reinforcing material 26 formed in a channel shape opposite to the pedestal 2 is disposed in the groove 23 at the same position in the upper position of the lower ladder portion A2 (see FIGS. 1 and 5). Two guide holders H, H for slidably holding the middle ladder portion A3 are attached to the reinforcing member 26 at regular intervals (see FIGS. 1 to 5). H1 is a connecting bar that connects the left and right guide holders H at the back.
[0042]
And, the groove parts 13 and 23 of the lowermost ladder part A1 and the lower ladder part A2 face each other so that the flanges 12 and 22 on one side are slidable in a superposed state, and the flanges on both sides are First and second slide guide pieces 17 and 16 are attached between 12 and 22, respectively, to reduce the backlash as much as possible (FIGS. 3 and 4).
[0043]
Further, as shown in FIGS. 3 and 5, the middle ladder portion A3 is slidably disposed in the guide holders H, H, and the groove portion 33 provided in the pedestal 3 is replaced with a narrow groove portion. A partition 33a and a wide groove 33b are formed, and both the grooves 33a and 33b are arranged inward. 32a is a partition flange.
[0044]
Then, the cross rail 7 whose both ends are flattened is inserted into the narrow groove portion 33a and fixed with a bolt or the like. Since the step ladder 6 of the lower ladder portion A2 is disposed substantially at the center of the web 21 of the pedestal 2, a slight gap is formed between the step ladder 6 of the middle ladder portion A3. Further, the back sides of the left and right flanges 32 are connected by a reinforcing connecting bar 35.
[0045]
As shown in FIGS. 3 and 6, the upper ladder portion A4 is slidably disposed in the groove 33 of the leg pillar 3 of the middle ladder portion A3, and the leg pillar 4 of the upper ladder portion A4 is The web 41 and the flange 42 are formed in a substantially U-shape facing outward in a sectional view, and both end portions of the traverse 8 are fixed by being fitted and caulked in the approximate center of the web 41 of the pedestal 4. Therefore, the step rail 8 and the step rail 7 have a slight gap in the thickness D direction, and do not hinder each other's sliding operation.
[0046]
In this way, each ladder portion A1 to A4 is configured to be able to reduce the thickness D of the entire telescopic ladder A at the time of contraction as much as possible. Large storage space is not required and transportation is easy.
[0047]
The telescopic ladder A allows the lowermost ladder part A1 and the lower ladder part A2 to be slidable with each other via a stopper mechanism S.
[0048]
That is, as shown in FIGS. 1, 7, and 8, a knob S <b> 2 having a stopper pin S <b> 1 penetrating the pillar 2 is attached to the inner side surfaces of the left and right legs 2, 2 of the lower ladder A <b> 2. By operating the knob S2, the pin insertion hole 18 provided in the pedestal 1 of the lowermost ladder portion A1 can be engaged and disengaged. 7 and 8, S11 is a coil spring that urges the stopper pin S1 in the protruding direction, S12 has a tapered surface, and a guide body that allows the stopper pin S1 to be removed from the pin insertion hole 18 while turning the knob S2, S21 is It is a guide tube provided on the lower surface of the knob S2, and has an end surface with the same taper as the taper surface of the guide body S12.
[0049]
With this configuration, when the lowermost ladder portion A1 is used, the stopper mechanism S is operated to disengage the stopper pin S1 from the lowermost ladder A1, and the lowermost ladder portion A1 is manually moved downward. Can be pulled out by sliding.
[0050]
On the other hand, the middle ladder portion A3 and the upper ladder portion A4 can be slid back and forth with respect to the lower ladder portion A2 by belt operation.
[0051]
That is, the upper ladder portion A4 is reciprocally slidable in conjunction with the middle ladder portion A3. As shown in FIG. 9, the lower ladder portion A2, the middle ladder portion A3, and the upper ladder portion A4. The flat belt E is spanned across the pulley columns C across the pedestals 2, 3, and 4, and the limb 4 of the upper ladder A4 is linked to the reciprocating sliding of the limb 3 of the middle ladder A3. It is configured to reciprocate.
[0052]
In FIG. 9, C1 is the first pulley provided on the lower side of the pedestal 2 on one side of the lower ladder part A2, C2 is the second pulley provided on the upper side thereof, and C3 and C4 are the middle ladder part A3. A pair of upper and lower third and fourth pulleys C5 and C6 provided at left and right line symmetrical positions on the lower side of the left and right pedestal pillars 3 and 3 are arranged on the upper side of each pair so as to be in the same left and right symmetrical position. The fifth and sixth pulleys. Reference numeral 37 denotes a belt sliding guide provided on the lower side portions of the left and right leg columns 4, 4 of the upper ladder portion A4.
[0053]
One end of a flat belt E for extending and contracting the middle ladder portion A2 to the pulley group arranged as described above is connected and fixed to the lower side of the pillar 2 on one side of the lower ladder portion A2, It extended horizontally through the upper part of the lower pulley C3a of the third pulley C3 provided in the middle ladder part A3, and further turned downward through the upper part of the lower pulley C4a of the fourth pulley C4. Then, turn upward through the lower part of the first pulley C1 of the lower ladder part A2, extend substantially vertically along the pedestal 2 and extend downward through the upper part of the second pulley C2. Extend horizontally through the lower side of the upper pulley C4b of the fourth pulley C4, fold upward and extend through the lower side of the upper pulley C3b of the third pulley C3, and It is connected and fixed to the upper part of the side pedestal 2.
[0054]
On the other hand, the tuning flat belt E for expanding and contracting the upper ladder portion A4 has one end near the upper end of the leg 2 on one side of the lower ladder portion A2, that is, near the attachment end of the flat belt E for stretching operation. To the bottom of the left and right limbs 4 of the upper ladder A4. The upper ladder A5 is turned downward through the upper part of the fifth pulley C5 provided on the upper part of the pier 3 of the middle ladder A3. Extending upward through the belt sliding guides 37, 37, changing the direction downward through the upper part of the sixth pulley C6 of the middle ladder part A3, near the upper end of the lower ladder part A2, that is, of the second pulley C2. It is connected and fixed in the vicinity.
[0055]
With the above configuration, when the portion of the flat belt E for expansion / contraction operation that is located between the first pulley C1 and the second pulley C2 is pulled downward, the mounting end of the flat belt E serves as a support point, and the third and fourth The middle ladder portion A3 is pulled up via the pulleys C3 and C4. At this time, the lowered extra length portion of the flat belt E is pulled upward together with the third and fourth pulleys C3 and C4 that rise together with the middle ladder portion A3, and the tensioned state is maintained.
[0056]
When the middle ladder A3 slides upward, the tuning flat belt E connected and fixed to the pedestals 2 and 2 of the lower ladder A2 is pulled upward as the middle ladder A3 rises. As a result, the upper ladder portion A4 slides upward, and the entire telescopic ladder A is extended.
[0057]
The flat belt E to be used is a synthetic resin belt which is not stretchable and sufficiently strong.
[0058]
As described above, the telescopic ladder A according to the present embodiment can be used by extending freely to a necessary height in general, is easy to use, and when contracted, the thickness D of the ladder A , The storage volume can be made as small as possible, easy to store and easy to handle.
[0059]
In addition, when the middle ladder A3 and the upper ladder A4 are expanded and contracted, the legs 3 and 4 of the ladders A3 and A4 can be easily operated by the belt operation at hand even when the telescopic ladder A is leaned up. Moreover, since it is a flat belt, it can be easily formed in a wide width that is easy to grip, and the operability is improved.
[0060]
Even if the flat belt is pulled, the pulled portion is absorbed by the upward movement of the upper ladder portion A4 and can maintain a tension state, and the belt does not loosen below the telescopic ladder A. Therefore, there is no danger of getting in the way and people getting caught.
[0061]
In this embodiment, only the middle ladder portion A3 and the upper ladder portion A4 can be extended and contracted by a belt. However, as in the above configuration, the expansion and contraction operation is performed between the lowermost ladder portion A1 and the lower ladder portion A2. If a flat belt for synchronization is disposed between the lower ladder portion A2 and the middle ladder portion A3, the lower ladder portion A2 can be extended and contracted by operating the belt.
[0062]
In addition, a rope or the like can be used instead of the flat belt E.
[0063]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
[0064]
(1) A telescopic ladder in which a plurality of ladder sections each having a pair of left and right pedestals each provided with a step rail are connected to be freely slidable vertically, and the pedestals of each ladder section are connected to a web and a flange. It is formed in a substantially U-shape in cross section with a groove from the side, and the flanges of adjacent pedestals are combined in a superposed state so that it can be shrunk to a length equivalent to about one step, and the entire thickness of the ladder when shrunk is allowed. By making it as small as possible, compact storage can be performed and handling becomes easy.
[0065]
  In addition, the four-stage system including the lowermost ladder part, the lower ladder part, the middle ladder part, and the upper ladder part facilitates transportation and storage while ensuring a sufficient working height in normal use.
[0066]
  Furthermore, the relative expansion and contraction of the lowermost ladder and the lower ladder is performed by engaging and releasing the stopper, and the expansion and contraction of the middle ladder and the upper ladder is performed by pulling the flat belt or the rope. Therefore, it can be used as a three-stage ladder in the state where the lowermost ladder part is not pulled out, and can be selected according to the application. When extending or retracting the middle and upper ladder parts, The pedestals of both ladder sections can be easily expanded and contracted by operating the belt. In particular, if a flat belt is used, it is easy to grip and the operability is good.
[0067]
  Further, one end of a flat belt or rope for expanding and contracting the middle ladder portion is connected and fixed to a lower side portion of a pedestal on one side of the lower ladder portion, and the third pulley provided on the middle ladder portion is connected. After extending horizontally through the upper side of the lower pulley and further turning downward through the upper side of the lower pulley of the fourth pulley, the first of the lower ladder portion Turning upward through the lower part of the pulley, extending substantially vertically along the pedestal, extending downward through the upper part of the second pulley, and extending downwardly through the upper pulley of the fourth pulley. Extends horizontally through the lower side, extends upwardly through the lower side of the upper pulley of the third pulley, and extends to the upper side of the pedestal on one side of the lower ladder One end of the flat belt or rope for expanding and contracting the upper ladder portion is fixed to one side of the lower ladder portion. It is connected and fixed in the vicinity of the upper end of the pedestal, and turns downward through the upper part of the fifth pulley provided at the upper part of the pedestal of the middle ladder, and the left and right pedestals of the upper ladder are Since the belt is extended upward through a belt sliding guide provided at the lower part, the direction is changed downward through the upper part of the sixth pulley of the middle ladder part and connected and fixed in the vicinity of the upper end part of the lower ladder part. By operating two belts or ropes, the middle ladder section and the upper ladder section can be configured to expand and contract in conjunction with each other.
[0068]
  (2) In the present invention according to claim 2, the end portion of the traverse is made up of a plurality of steps by alternately arranging a ladder portion attached to the web of each pedestal and a ladder portion attached to the flange. The thickness of the entire ladder when shrinking can be reliably reducedThe
[0069]
  (3)Claim3In the present invention described, the flanges on the one side are slidable in a superposed state so that the groove portions of the lowermost ladder portion and the lower ladder portion are inward and outward, respectively, and both groove portions face each other. And the upper ladder portion having an outward groove portion in the groove portion is slidably disposed, and the lower ladder portion is further slidably disposed. By attaching a guide holder that holds the middle ladder portion to the upper position of the door, smooth expansion and contraction is achieved, and the thickness of the ladder is reduced during contraction, so that it can be stored compactly.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an extended state of a telescopic ladder according to the present embodiment.
FIG. 2 is an explanatory view showing a contracted state of the telescopic ladder.
FIG. 3 is a cross-sectional explanatory view taken along the line II in FIG. 2;
4 is an explanatory cross-sectional view taken along the line II of FIG. 1. FIG.
FIG. 5 is an explanatory sectional view taken along the line II-II.
FIG. 6 is an explanatory sectional view taken along line III-III.
FIG. 7 is an explanatory diagram of a stopper mechanism for expanding and contracting the lowermost ladder portion and the lower ladder portion.
FIG. 8 is an explanatory diagram of a stopper mechanism for expanding and contracting the lowermost ladder portion and the lower ladder portion.
FIG. 9 is an explanatory view of an expansion / contraction mechanism of a middle ladder portion and an upper ladder portion.
FIG. 10 is an explanatory view showing a thickness of a conventional telescopic ladder when contracted.
[Explanation of symbols]
A telescopic ladder
A1 Bottom ladder
A2 Lower ladder
A3 Middle ladder
A4 Upper ladder
E flat belt
D thickness
S Stopper mechanism
1-4 Pillar
5 to 8
11,21,31,41 Web
12,22,32,42 flange
13,23,33,43 Groove

Claims (3)

It includes a pair of left and right pedestal columns each provided with a traverse , and connects a four-stage ladder portion consisting of a lowermost ladder portion, a lower ladder portion, a middle ladder portion, and an upper ladder portion so as to be vertically slidable, The ladder pillars of each stage are formed in a substantially U-shape in cross section with a groove from the web and flange, and the flanges of adjacent leg pillars can be combined in a superposed state to shrink to a length equivalent to one stage. configured, the ladder overall thickness during shrinkage to a small the Shin contraction ladder as possible to,
Relative expansion and contraction between the lowermost ladder and the lower ladder is performed by engaging and releasing a stopper, and the expansion and contraction between the middle and upper ladders is performed by pulling a flat belt or rope. Configured as
In addition, a first pulley is provided on the lower side of the pedestal on one side of the lower ladder part, and a second pulley is provided on the upper side. The third pulley and the fourth pulley are provided in a left-right symmetric position, and the fifth pulley and the sixth pulley are provided in the left and right symmetrical positions on the upper sides of the third pulley and the fourth pulley,
One end of a flat belt or rope for expanding and contracting the middle ladder portion is connected and fixed to a lower side portion of a pedestal on one side of the lower ladder portion, and among the third pulleys provided on the middle ladder portion, After extending horizontally through the upper part of the lower pulley and further turning downward through the upper part of the lower pulley of the fourth pulley, the first pulley of the lower ladder part Turns upward through the lower part, extends substantially vertically along the pedestal, extends downward through the upper part of the second pulley, and under the upper pulley of the fourth pulley It extends horizontally through the part, and is folded upward and extended through the lower part of the upper pulley of the third pulley, and is connected and fixed to the upper part of the pedestal on one side of the lower ladder part. on the other hand,
One end of the flat belt E or rope for expanding and contracting the upper ladder portion is connected and fixed in the vicinity of the upper end portion of the leg column on one side of the lower ladder portion, and is provided on the upper portion of the leg column of the middle ladder portion. The direction of the fifth pulley is changed to the lower side through the upper part, and is extended upward through belt sliding guides provided at the lower portions of the left and right pedestals of the upper ladder part. A telescopic ladder characterized in that it is connected and fixed in the vicinity of the upper end of the lower ladder part by changing the direction downward through the upper part of the pulley . 2. The telescopic ladder according to claim 1, wherein an end portion of the step rail is alternately arranged with a ladder portion attached to a web of each pedestal and a ladder portion attached to a flange. The lowermost ladder part and the lower ladder part are inward and outward, respectively, so that both groove parts face each other so that the flanges on one side are slidable in a superposed state, and the middle stage Ladder part pedestal groove is inward, and the upper ladder part pedestal having an outward groove part is slidably disposed in the groove part. 3. The telescopic ladder according to claim 1, further comprising a guide holder for holding the ladder portion .

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