Electric telescopic single or double-sided section ladder

Abstract

The application discloses an electric telescopic single / double-sided section ladder, and belongs to the technical field of ladders. The electric telescopic single / double-sided section ladder comprises an electric telescopic single-sided section ladder, a hand-pulled single-sided section ladder and a detachable hinge. The hand-pulled single-sided section ladder comprises a pair of ladder pipes, a connecting sleeve, a pedal and a locking structure. The connecting sleeve is provided with a square interface end and a round hole end. The pedal is fixedly connected with the square interface end of the connecting sleeve. The pair of ladder pipes are fixedly connected with the pair of connecting sleeves and are slidably connected with another pair of connecting sleeves. The locking structure is arranged in the connecting sleeve. The lower end of the electric telescopic single-sided section ladder is provided with a motor and a lead screw. The motor drives the rotation of the lead screw in the ladder pipe. The lead screw drives the telescopic function of each ladder pipe in sequence. The top of the electric telescopic single-sided section ladder and the top of the hand-pulled single-sided section ladder are respectively connected with the hinge to form an electric telescopic double-sided section ladder. When the double ladders are folded, the electric telescopic single-sided section ladder can drive the hand-pulled single-sided section ladder to synchronously and telescopically operate. The electric telescopic double-sided section ladder can be disassembled into an electric single-sided section ladder and a hand-pulled single-sided section ladder for separate use at any time by detaching the hinge.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ladders, and more particularly to an electric telescopic single / double-sided section ladder. BACKGROUND

[0002] Ladders are generally used for climbing operations, and most families have a backup ladder. The backup ladder in most families is usually an open A-frame ladder or a telescopic single ladder. The open A-frame ladder occupies a large space, cannot adjust the height, and cannot be deployed in a narrow area. The telescopic single ladder occupies a small space and is easy to move and store, but the existing telescopic ladder has poor stability, cannot overcome the influence of gravity on the ladder pipe, and has a small height adjustment area, which can only be used in a scene with a support surface. The electric telescopic single / double-sided section ladder occupies a small space, is easy to move and store, has a large height adjustment area, and can conveniently decompose the double-sided ladder into a single-sided ladder to meet the needs of different special working environments. The electric telescopic function can also greatly reduce the labor intensity of the operator. SUMMARY

[0003] The technical problem to be solved by the present application is to provide an electric telescopic single / double-sided section ladder which can reduce the labor intensity of the operator, is easy to move and store, and can conveniently decompose the double-sided ladder into a single-sided ladder to meet the needs of different special working environments.

[0004] The electric telescopic single / double-sided section ladder comprises an electric telescopic single-sided section ladder, a hand-pulled single-sided section ladder, and a hinge. The hand-pulled single-sided section ladder comprises a pair of ladder pipe frames, a plurality of connecting sleeves, and a plurality of steps. Each ladder pipe frame comprises a plurality of ladder pipes, the diameters of the plurality of ladder pipes gradually decrease from bottom to top, adjacent ladder pipes are coaxially nested and installed, the inner side of each ladder pipe is provided with an upper fixing hole and a lower fixing hole, when adjacent ladder pipes extend to the corresponding upper fixing hole position, a locking pin is inserted into the lower fixing hole of the ladder pipe, the self-locking of the second step of the ladder pipe is completed, the ladder pipe can complete two-stage sliding, and the working efficiency is improved. The plurality of connecting sleeves are provided with square interface ends and round hole ends, the two ends of the steps are fixedly connected with the square interface ends of a pair of connecting sleeves, the ladder pipes are provided with connecting sleeve positioning notches, the round hole ends of the connecting sleeves are respectively sleeved on a pair of ladder pipe frames, and a pair of ladder pipes are fixedly connected with one pair of connecting sleeves in the plurality of connecting sleeves through the connecting sleeve positioning notches and are slidably connected with the other pair of connecting sleeves. The two ends of the hinge are fixedly connected with the inner side of the top of the electric telescopic single-sided section ladder and the hand-pulled single-sided section ladder, respectively, to form a double ladder. The hinge is disconnected, and the electric telescopic single-sided section ladder and the hand-pulled single-sided section ladder can be independently used.

[0005] As a further improvement of the present application, the hinge comprises a first hinging piece, a second hinging piece and a plurality of sets of shaft pins, the shaft sleeves of the first hinging piece and the second hinging piece are matched with each other, one end of the shaft pin is provided with a thread, after hinging, a set of shaft pins are respectively inserted into the shaft sleeves at both ends of the first hinging piece and the second hinging piece and the threaded parts are tightened to complete the locking of the hinge, when the hinge needs to be separated, the shaft pins are pulled out after the threaded parts are loosened to complete the separation; the sum of the lengths of the set of shaft pins is equal to the length of the set of shaft sleeves after the first hinging piece and the second hinging piece are matched, the hinging stability is improved, and the safety hidden danger caused by the disconnection of the shaft sleeve is prevented.

[0006] As a further improvement of the present application, the electric telescopic single-side ladder further comprises a driving structure and a switch on the basis of the structure of the hand-pulled single-side ladder, the bottom of the ladder pipe frame is fixedly connected with the driving structure, and the switch is electrically connected with the driving structure.

[0007] As a further improvement of the present application, the round hole end of the connecting sleeve is provided with a locking groove, the inner side is provided with a circular through hole, the locking structure comprises a spring sleeve, a spring, a lock catch and a lock pin, the spring sleeve is fixedly connected in the connecting sleeve, one side of the spring sleeve is provided with a spring groove, the spring is arranged in the spring groove, one end of the spring elastically abuts against the bottom wall in the spring groove, the other end of the spring elastically abuts against the lock pin, the end of the lock pin away from the spring extends to the outside of the connecting sleeve through the circular through hole of the connecting sleeve, and the outer periphery of the lock pin near the circular through hole in the connecting sleeve is provided with a protrusion for preventing the lock pin from sliding as a whole, the middle end of the lock pin is provided with a clamping part, the connecting sleeve is provided with a groove matched with the lock catch, the middle part of the lock catch is rotationally connected with the connecting sleeve at the groove and forms a lever structure with the connecting sleeve, the displacement interval of the lock pin through the lever principle is greater than the extension length of the lock pin in the connecting sleeve, and the jamming caused by the too short displacement interval when the ladder pipe slides is prevented; when the adjacent ladder pipes are contracted, the lock catch is pressed by the pedal after the lock tongue is pressed, so that the lock pin exits the fixing hole, and the lock catch is clamped after being rotated, so that the locking is completed; after the adjacent ladder pipes are expanded, the lock catch is rotated when the lock pin is inserted into the fixing hole, the lock tongue is separated from the lock groove, and the locking is disconnected; the lock tongue is rotated after being pressed by the pedal, and the lock tongue can slide into the groove of the lock groove, so that the lock groove and the lock tongue do not need to be highly matched, the process requirement is reduced, and the production is facilitated.

[0008] As a further improvement of the present application, the sizes and shapes of the upper fixing hole and the lower fixing hole can be different, and are matched with the lock pins of the same specification, the size and shape difference of the upper fixing hole and the lower fixing hole satisfies that the lock pin inserted into the lower fixing hole does not interfere with the upper fixing hole when the ladder pipe is expanded, the lock pin is prevented from being inserted into the upper fixing hole in advance and incorrectly, the sequential sliding of the ladder pipe is ensured, and the steady operation of the one-section two-step scheme is facilitated.

[0009] As a further improvement of the present application, the driving structure comprises a motor and a screw rod, the motor is fixedly connected to the bottom of the ladder pipe of the electric telescopic single-section ladder, the motor is a driving motor with a built-in reducer, the screw rod comprises a light shaft part and a threaded part, the motor is directly connected to one end of the light shaft part of the screw rod, and the transmission structure is optimized, the detachable lithium battery for charging is arranged below the switch, the ladder pipe frame further comprises a plurality of nuts, the lower end of the ladder pipe is provided with nut positioning notches, the nuts are installed at the lower end of the ladder pipe through the nut positioning notches, the threaded part of the screw rod is in threaded connection with the nuts, and the threaded part of the screw rod can drive each ladder pipe to vertically and telescopically operate.

[0010] As a further improvement of the present application, the driving structure comprises a motor and a screw rod, the motor is fixedly connected to the bottom of the ladder pipe of the electric telescopic single-section ladder, the motor is a driving motor with a built-in reducer, the screw rod comprises a light shaft part and a threaded part, the motor is directly connected to one end of the light shaft part of the screw rod, and the transmission structure is optimized, the detachable lithium battery for charging is arranged below the switch, the ladder pipe frame further comprises a plurality of nuts, the lower end of the ladder pipe is provided with nut positioning notches, the nuts are installed at the lower end of the ladder pipe through the nut positioning notches, the threaded part of the screw rod is in threaded connection with the nuts, and the threaded part of the screw rod can drive each ladder pipe to vertically and telescopically operate.

[0011] Compared with the prior art, the present application has the beneficial effects that: one electric telescopic single-section ladder and one hand-pulled single-section ladder are connected through a hinge to form an electric telescopic single- and double-section ladder, which can be applied to different scenes with different requirements and improve the use efficiency of the functional ladder; the segmented self-locking structure is arranged, so that the defect that the ladder slides downward due to insufficient self-locking force of the motor when the functional ladder is not fully unfolded is solved; the self-locking state is released through the contact and extrusion of the lock tongue and the pedal, without the height matching of the lock slot and the lock tongue, so that the process requirement is reduced, and production is facilitated; the one-section two-step scheme is adopted, the composite part of the adjacent two pipes is reduced, the diameter of the pipe is reduced from one step to two steps, so that the maximum outer diameter of the pipe is one half of that of the one-step one-section pipe, the amount of pipe material is effectively reduced, the manufacturing difficulty is reduced, and the product cost is saved; the displacement interval of the lock pin through the lever principle is greater than the extension length of the lock pin in the connecting sleeve, so that the jamming caused by the too short displacement interval when the ladder pipe slides is prevented; the driving motor with a built-in reducer is directly connected to the screw rod, and the transmission structure is optimized; one fixing hole is arranged at each of the upper end and the lower end of the ladder pipe, so that the ladder pipe can complete two-stage sliding and improve the working efficiency; the size or shape of the fixing hole at the upper end of the ladder pipe is different from that of the fixing hole at the lower end, so that the ladder pipe is prevented from being inserted into the wrong fixing hole due to position grabbing when the ladder pipe is extended and operated, and the telescopic operation is abnormal; the electric telescopic single-section ladder can be replaced by the hand-pulled single-section ladder to form a hand-pulled single- and double-function ladder, which can be applied to a working environment where electric power cannot be used. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The structural diagram of the electric telescopic single- and double-section ladder of the present application is shown in the figure.

[0013] Figure 2 The structural diagram of the ladder pipe part of the electric telescopic single-section ladder of the present application is shown in the figure.

[0014] Figure 3 The schematic diagram of the hand-pulled single-section ladder of the present application is shown in the figure.

[0015] Figure 4 Fig. 1 is a schematic diagram of the locking structure of the present application;

[0016] Figure 5 Fig. 2 is a schematic diagram of the locked state of the present application;

[0017] Figure 6 Fig. 3 is a schematic diagram of the electric telescopic single-sided section ladder drive structure of the present application;

[0018] Figure 7 Fig. 4 is a schematic diagram of the hinge structure of the present application;

[0019] Figure 8 Fig. 5 is a schematic diagram of the hand-pulled single / double function ladder structure of the present application.

[0020] Fig. 1 is a schematic diagram of the locking structure of the present application;

[0021] Electric telescopic single-sided section ladder a; hand-pulled single-sided section ladder b; hinge c; first hinge c-1; second hinge c-2; shaft pin c-3; ladder pipe frame 1; ladder pipe 1-1; upper fixed hole 1-1-1; lower fixed hole 1-1-2; connecting sleeve positioning notch 1-1-3; nut positioning notch 1-1-4; nut 1-2; connecting sleeve 2; lock groove 2-1; pedal 3; drive structure 4; motor 4-1; lead screw 4-2; lithium battery 4-3; locking structure 5; spring sleeve 5-1; spring 5-2; lock catch 5-3; lock tongue 5-3-1; lock pin 5-4; stopper 6; switch 7; balance stop 8; displacement interval L; extension length l. DETAILED DESCRIPTION

[0022] Specific embodiment one: please refer to Figures 1-8The present application relates to a kind of electric telescopic single, double face ladder, including electric telescopic single face ladder a, hand-pulled single face ladder b and hinge c, hand-pulled single face ladder b includes a pair of ladder pipe frame 1, several connecting sleeves 2, several steps 3, locking structure 5, switch 7 and balance stop 8, several connecting sleeves 2 are equipped with square interface end and round hole end, the square interface end of the both ends of several connecting sleeves 2 is fixedly connected with a pair of connecting sleeves 2, the round hole end of a pair of connecting sleeves 2 is respectively sleeved on a pair of ladder pipe 1-1, and connecting sleeve positioning gap 1-1-3 is equipped on ladder pipe 1-1, a pair of ladder pipe 1-1 is fixedly connected with one of several connecting sleeves 2 by connecting sleeve positioning gap 1-1-3, and is slidably connected with another pair of connecting sleeves 2, locking structure 5 is arranged in connecting sleeve 2, and balance stop 8 is fixedly connected with the bottom of a pair of ladder pipe frame 1, on the basis of the structure of hand-pulled single face ladder b, the bottom of ladder pipe frame 1 is fixedly connected with driving structure 4, switch 7 is electrically connected with driving structure 4, and the lithium battery 4-3 of detachable charging is arranged below switch 7, to form electric telescopic single face ladder a, the inner side of the top of hinge c is fixedly connected with electric telescopic single face ladder a and hand-pulled single face ladder b respectively, to form electric telescopic double face ladder, disconnects hinge c, and electric telescopic double face ladder is decomposed into electric telescopic single face ladder a and hand-pulled single face ladder b that can be used independently.

[0023] In the above embodiment, as shown in Figure 2 Each ladder pipe frame 1 includes several ladder pipes 1-1, the diameter of each ladder pipe 1-1 constituting the ladder pipe frame 1 gradually decreases from bottom to top, and adjacent ladder pipes 1-1 are coaxially nested and slidably connected, and the inner side of each ladder pipe 1-1 is provided with upper fixing hole 1-1-1 and lower fixing hole 1-1-2, when the lower fixing holes 1-1-2 of any two adjacent ladder pipes 1-1 are operated to the hole positions of the locking pins 5-4 of each other, the locking pins 5-4 are ejected and lock the adjacent two ladder pipes 1-1, and the ladder pipe 1-1 can drive the next ladder pipe 1-1 to extend and operate; the size or shape of the upper fixing hole 1-1-1 at the upper end of the ladder pipe 1-1 and the lower fixing hole 1-1-2 at the lower end are different from each other and matched with the locking pin 5-4 of the same specification, and the size or shape difference between the upper fixing hole 1-1-1 and the lower fixing hole 1-1-2 satisfies that the locking pin 5-4 should be inserted into the lower fixing hole 1-1-2 when the ladder pipe 1-1 extends and operates, but cannot be inserted into the upper fixing hole 1-1-1 in advance, to ensure that the ladder pipe 1-1 operates in a one-step-two-step manner.

[0024] In the above embodiment, as shown in Figures 4-5As shown, the locking structure 5 includes a spring sleeve 5-1, a spring 5-2, a lock catch 5-3 and a lock pin 5-4, the round hole end of the connecting sleeve 2 is provided with a lock slot 2-1 and a circular through hole on the inner side, the spring sleeve 5-1 is fixedly connected with the connecting sleeve 2, the spring sleeve 5-1 is provided with a spring groove on one side, the spring 5-2 is arranged in the spring groove, one end of the spring 5-2 in contact with the bottom of the spring groove of the spring sleeve 5-1 is fixedly connected with the spring sleeve 5-1, one end of the lock pin 5-4 penetrates through the circular through hole of the connecting sleeve 2, and the other end compresses the spring 5-2 in the spring groove of the spring sleeve 5-1, the lock pin 5-4 is slidingly connected with the connecting sleeve 2, the middle end of the lock pin 5-4 is provided with a clamping portion, the lower end of the lock catch 5-3 is inserted into the two sides of the lock pin 5-4 and abuts against one side of the clamping portion of the lock pin 5-4 close to the circular through hole of the connecting sleeve 2, the connecting sleeve 2 is provided with a groove matching the lock catch 5-3, the middle part of the lock catch 5-3 is rotationally connected with the connecting sleeve 2 at the groove and forms a lever structure with the connecting sleeve 2, the rotating end of the lock catch 5-3 is provided with a lock tongue 5-3-1, and the lock tongue 5-3-1 is clamped with the lock slot 2-1; the displacement interval L of the lock pin 5-4 through the lever principle is greater than the extension length l of the lock pin 5-4 in the connecting sleeve 2, so that the ladder pipe 1-1 is prevented from being stuck due to too short displacement interval L when sliding.

[0025] As shown in the above embodiment, Figure 6 the driving structure 4 includes a motor 4-1 and a lead screw 4-2, the motor 4-1 is fixedly connected to the bottom of the ladder pipe frame 1 of the electric telescopic single-sided ladder, the motor 4-1 is a driving motor with a built-in reducer, the lead screw 4-2 includes a light shaft part and a threaded part, one end of the light shaft part of the lead screw 4-2 is directly connected to the motor 4-1, the transmission structure is optimized, the ladder pipe frame 1 further includes a plurality of nuts 1-2, the lower end of the ladder pipe 1-1 is provided with a nut positioning notch 1-1-4, and the nut 1-2 is installed at the lower end of the ladder pipe 1-1 through the nut positioning notch 1-1-4; the threaded part of the lead screw 4-2 is threadedly connected with the nut 1-2, and the threaded part of the lead screw 4-2 can drive each ladder pipe 1-1 to vertically extend and retract.

[0026] As shown in the above embodiment, Figure 2 the stopper 6 is further included, the stopper 6 is rotationally connected with the pedal 3, the initial height of the stopper 6 is not more than the height of the pedal 3, and the height of the stopper 6 after rotation is greater than the initial height, so that the ladder pipe 1-1 is prevented from sliding downward under gravity after the ladder is unfolded, which affects the use efficiency or causes safety hazards.

[0027] As shown in the above embodiment, Figure 7As shown, the hinge c includes a first hinge c-1, a second hinge c-2, and a plurality of sets of shaft pins c-3, the shaft sleeves of the first hinge c-1 and the second hinge c-2 match each other, one end of the shaft pin c-3 is provided with a thread, and after the hinge is matched, a set of shaft pins c-3 is inserted into the threaded part of the shaft sleeve at both ends of the first hinge c-1 and the second hinge c-2 respectively to complete the locking of the hinge c. When the hinge c needs to be separated, the threaded part of the shaft pin c-3 is loosened, and then the shaft pin c-3 is pulled out to complete the separation. The sum of the lengths of a set of shaft pins c-3 is equal to the length of a set of shaft sleeves after the first hinge c-1 and the second hinge c-2 are matched, which improves the stability of the hinge and prevents the hinge from being disconnected to cause safety hazards.

[0028] When the electric telescopic single / double-section ladder is used, the motor 4-1 drives the screw rod 4-2 to rotate, the screw nut 1-2 is rotated through the screw rod 4-2, thereby driving the ladder pipe 1-1 to extend or retract, when the ladder pipe 1-1 extends to the corresponding upper fixed hole 1-1-1, the locking pin 5-4 is compressed by the spring 5-2, the lock catch 5-3 is rotated through the lever principle, the lock tongue 5-3-1 is disconnected from the lock groove 2-1, and at the same time the spring 5-2 rebounds, the locking pin 5-4 is inserted into the upper fixed hole 1-1-1 of the ladder pipe 1-1, and the self-locking of the ladder pipe 1-1 is completed. Rotate the stopper 6 to the adjacent step 3 to prevent the ladder pipe 1-1 from sliding and causing the step 3 to fall and cause danger, and work; when the ladder pipe 1-1 is lowered, the lower end of the lock tongue 5-3-1 presses the surface of the step 3, the surface of the step 3 pushes the lock tongue 5-3-1 to generate a sliding force in the direction of the lock groove 2-1, the lock tongue 5-3-1 is clamped into the lock groove 2-1, at the same time the lock catch 5-3 rotates to drive the locking pin 5-4, the locking pin 5-4 is pushed out of the upper fixed hole 1-1-1 of the ladder pipe 1-1, the self-locking of the ladder pipe 1-1 is disconnected, the ladder pipe 1-1 slides downward, and the electric telescopic single / double-section ladder is retracted; when in a narrow or environment that needs to rely on the wall, the hinge c is disassembled to separate the electric telescopic single / double-section ladder into an electric telescopic single-section ladder a and a hand-pulled single-section ladder b, which are used independently to adapt to different needs and environments and improve the use efficiency.

[0029] Specific embodiment two: as shown in Figure 8 A single / double-function ladder, which comprises a pair of hand-pulled single-section ladders b and a hinge c, the two ends of the hinge c are respectively fixedly connected to the top inner sides of a pair of hand-pulled single-section ladders b, and the difference between the electric telescopic single / double-section ladder and the electric telescopic single / double-section ladder of embodiment one is that the electric telescopic single-section ladder a is replaced by the hand-pulled single-section ladder b, and the rest of the structure is the same as that of embodiment one.

[0030] When using, manually stretch one hand-pulled single-sided section ladder b, drive the other end hand-pulled single-sided section ladder b to stretch, after the ladder pipe 1-1 is self-locked, rotate the stopper 6 to prevent the pedal 3 from sliding down, and work, when folding, rotate the stopper 6 to the initial position, manually release the self-locking of the ladder pipe 1-1, and make the ladder pipe 1-1 slide down to complete folding, when needing to change the function ladder state, the double ladder can be divided into two hand-pulled single-sided section ladders b through disassembling the hinge c and used independently.

Claims

1. An electrically retractable single- or double-sided ladder, characterized in that: The ladder includes an electric telescopic single-sided ladder (a), a manual single-sided ladder (b), and a hinge (c). The manual single-sided ladder (b) includes a pair of ladder tube frames (1), several connecting sleeves (2), and several treads (3). Each ladder tube frame (1) includes several ladder tubes (1-1). The diameter of each ladder tube (1-1) gradually decreases from bottom to top. Adjacent ladder tubes (1-1) are coaxially nested and slidably connected. Each ladder tube (1-1) has an upper fixing hole (1-1-1) and a lower fixing hole (1-1-2) on its inner side. Several connecting sleeves (2) have square interface ends and round hole ends. The two ends of the treads (3) are fixedly connected to the square interface ends of a pair of connecting sleeves (2) respectively. The round hole ends of a pair of connecting sleeves (2) are respectively fitted onto a pair of ladder tubes (1-1). The ladder tube (1-1) is provided with a connecting sleeve positioning notch (1-1-3). A pair of ladder tubes (1-1) are fixedly connected to one pair of several connecting sleeves (2) through the connecting sleeve positioning notch (1-1-3) and slidably connected to another pair of connecting sleeves (2). The two ends of the hinge (c) are respectively connected to the inner top of the electric telescopic single-sided ladder (a) and the manual single-sided ladder (b) to form an electric telescopic double-sided ladder. When the hinge (c) is disconnected, the electric telescopic double-sided ladder is decomposed into an electric telescopic single-sided ladder (a) and a manual single-sided ladder (b) that can be used independently. The upper end of the round hole of the connecting sleeve (2) is provided with a locking groove (2-1) and the inner side is provided with a round through hole. The locking structure (5) includes a spring sleeve (5-1) and a spring (5-2). The lock (5-3) and the locking pin (5-4) are fixedly connected to the inner wall of the connecting sleeve (2) by the spring sleeve (5-1). The spring sleeve (5-1) has a spring groove inside, and the spring (5-2) is placed in the spring groove. One end of the spring (5-2) elastically abuts against the bottom wall of the spring groove, and the other end of the spring (5-2) elastically abuts against the locking pin (5-4). The end of the locking pin (5-4) away from the spring (5-2) extends through the circular through hole of the connecting sleeve (2) to the outside of the connecting sleeve (2). The locking pin (5-4) has a protrusion on its outer periphery near the circular through hole inside the connecting sleeve (2) to prevent the locking pin (5-4) from slipping off as a whole. The middle part of the locking pin (5-4) has a snap-fit ​​part. The lower end of the lock (5-3) is inserted into the snap-fit ​​part of the locking pin (5-4). The connecting sleeve (2) is provided with a groove for matching the locking buckle (5-3). The middle part of the locking buckle (5-3) is positioned and rotated with the connecting sleeve (2) at the groove and forms a lever structure with the connecting sleeve (2). The displacement range (L) of the locking pin (5-4) through the lever principle is greater than the extension length (l) of the locking pin (5-4) in the connecting sleeve (2). The upper fixing hole (1-1-1) and the lower fixing hole (1-1-2) are different in size and shape, and are matched with the locking pin (5-4) of the same specification. The difference in size and shape between the upper fixing hole (1-1-1) and the lower fixing hole (1-1-2) satisfies that the locking pin (5-4) inserted into the lower fixing hole (1-1-2) when the ladder tube (1-1) extends does not interfere with the upper fixing hole (1-1-1).

2. The electric telescopic single- or double-sided ladder according to claim 1, characterized in that: The hand-operated single-sided ladder (b) also includes a locking structure (5) and a balance stop (8). The locking structure (5) is located inside the connecting sleeve (2), and the balance stop (8) is fixedly connected to the bottom of a pair of ladder tube frames (1).

3. The electric telescopic single- or double-sided ladder according to claim 1, characterized in that: The electric telescopic single-sided ladder (a) is based on the structure of the hand-operated single-sided ladder (b), and also includes a drive structure (4) and a switch (7). The bottom of the ladder frame (1) is fixedly connected to the drive structure (4), and the switch (7) is electrically connected to the drive structure (4).

4. The electric telescopic single- or double-sided ladder according to claim 1, characterized in that: The hinge (c) includes a first hinge (c-1), a second hinge (c-2), and several sets of pins (c-3). One end of each pin (c-3) is threaded. The bushings of the first hinge (c-1) and the second hinge (c-2) are matched with each other. After the hinge is engaged, a set of pins (c-3) is inserted into the bushings at both ends of the first hinge (c-1) and the second hinge (c-2), respectively. The threaded part on the pin (c-3) is then tightened to lock the hinge (c). The threaded part of the pin (c-3) is loosened and the pin (c-3) is pulled out to separate the hinge (c). The sum of the lengths of a set of pins (c-3) is equal to the total length of the bushings after the first hinge (c-1) and the second hinge (c-2) are matched.

5. The electric telescopic single- or double-sided ladder according to claim 1, characterized in that: The locking bolt (5-3) has a locking tongue (5-3-1) at the rotating end. The locking tongue (5-3-1) rotates after pressing against the pedal (3). After rotating, the locking tongue (5-3-1) can slide into the groove of the locking groove (2-1).

6. The electrically retractable single- or double-sided ladder according to claim 3, characterized in that: The drive structure (4) includes a motor (4-1), a lead screw (4-2), and a lithium battery (4-3). The motor (4-1) is fixedly connected to the bottom of the ladder tube frame (1) of the electric telescopic single-sided ladder (a). The motor (4-1) is a drive motor (4-1) with a built-in reducer. The lead screw (4-2) includes a shaft part and a threaded part. The motor (4-1) is directly connected to one end of the shaft part of the lead screw (4-2). The ladder tube frame (1) also includes several nuts (1-2). The lower end of the ladder tube (1-1) is provided with a nut positioning notch (1-1-4). The nut (1-2) is installed at the lower end of the ladder tube (1-1) through the nut positioning notch (1-1-4). The threaded part of the lead screw (4-2) is threadedly connected to the nut (1-2). The threaded part of the lead screw (4-2) can drive each ladder tube (1-1) to extend and retract vertically. The detachable lithium battery (4-3) is installed below the switch (7).

7. The electric telescopic single- or double-sided ladder according to claim 1, characterized in that: The hand-operated single-sided ladder (b) also includes a stop (6), which is rotatably connected to the pedal (3). The initial height of the stop (6) does not exceed the height of the pedal (3), and the height after rotation is greater than the initial height.

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