Connecting rod stabilizing structure for herringbone ladder

Abstract

The invention discloses a connecting rod stabilizing structure for a herringbone ladder. The connecting rod stabilizing structure comprises a transverse pipe and two connecting rod structures, the connecting rod structure comprises a first connecting rod and a second connecting rod. And one end of the first connecting rod is fixedly sleeved with a connecting sleeve. A bolt rod is slidably connected into the connecting sleeve. And an insertion hole is formed in the second connecting rod. The transverse pipe is connected between the two connecting sleeves and communicated with the two connecting sleeves. And a driving structure for driving the two bolt rods to retract into the connecting sleeves at the same time and forming rebound force on the bolt rods is arranged in the transverse pipe and the two connecting sleeves. After the herringbone ladder is installed on the herringbone ladder, when the herringbone ladder is completely unfolded, the first connecting rod and the second connecting rod can be automatically fixed, so that the connecting rod structures are locked, when a user does not stand on the herringbone ladder, the connecting rod structures can also play a role in improving the stability of the herringbone ladder, and the two connecting rod structures can be unlocked at the same time through one key; the unlocking process of the connecting rod structure is quick and convenient, and the efficiency of folding the herringbone ladder is not influenced.

Description

Technical Field

[0001] The invention relates to the technical field of ladders, in particular to a connecting rod stabilizing structure for a stepladder. Background Art

[0002] A stepladder is a device that supports construction workers to work in the air. The stepladder in the prior art is generally composed of two ladder bodies hinged at the top. When idle, the two ladder bodies are rotated and folded to facilitate the storage of the stepladder. When in use, the two ladder bodies are rotated and unfolded to form a certain angle between the two ladder bodies, and the bottom ends of the two ladder bodies are in contact with the ground. When in use, it does not require special support or other objects to support itself.

[0003] However, since the angle between the two ladder bodies is not restricted, the ladder rod will slide when a certain vibration occurs, the angle between the two ladder bodies will increase, and the telescopic ladder body will shake to a certain extent, which is quite dangerous.

[0004] Therefore, in the prior art, two symmetrically arranged stable structures are usually connected between the two ladder bodies, and the stable structures are generally composed of two connecting rods, and the ends of the two connecting rods that are separated from each other are respectively hinged to the two ladder bodies, and the opposite sides of the two connecting rods are hinged to each other. For example, the folding household safety ladder model A11, the household ladder model A0113-104, and the fiberglass insulated ladder model 33-4, etc.

[0005] The stable structure will be folded and unfolded synchronously with the ladder. On the one hand, the stable structure is used to limit the unfolding angle of the ladder to prevent the ladder from being unstable when the user stands on it due to the ladder being unfolded too much; on the other hand, it is used to improve the stability of the ladder when the user stands on it. However, when the ladder is unfolded and the user is not standing on the ladder, the stability of the ladder itself is not strong because the two connecting rods are not fixed. Once the bottom part of the ladder is accidentally touched, the ladder is at risk of tipping over. For example, after the user unfolds the ladder and is about to climb up the ladder, he accidentally falls and falls on the bottom part of the ladder. At this time, the ladder will rotate and fold to a certain angle, and the ladder cannot be stably placed on the ground, causing the ladder to tip over or even fall on the user.

[0006] In summary, the stabilizing structure of the prior art can only stabilize the ladder under the action of the user's gravity when the user stands on the ladder. When the user does not stand on the ladder, the stabilizing structure only limits the unfolding angle of the ladder, but does not enhance the stability of the ladder.

[0007] Therefore, the present invention proposes a technical solution to solve the above-mentioned problem that when the stepladder is unfolded and the user is not standing on the stepladder, the stepladder itself is not very stable. Summary of the invention

[0008] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a connecting rod stabilizing structure for a stepladder, so that when the stepladder is fully unfolded, the first connecting rod and the second connecting rod can be automatically fixed, thereby locking the connecting rod structure; when the user is not standing on the stepladder, the connecting rod structure can also play a role in improving the stability of the stepladder, and the two connecting rod structures can be unlocked at the same time with one button. The unlocking process of the connecting rod structure is quick and convenient, and does not affect the efficiency when folding the stepladder.

[0009] The two levers are connected along the longitudinal axis of the ladder and the two levers are connected along the longitudinal axis of the ladder to the cam, wherein the levers are connected along the longitudinal axis of the ladder to the cam, wherein the levers are connected along the longitudinal axis of the ladder to the cam.

[0010] By adopting the above technical solution, as the two ladder bodies in the stepladder rotate relative to each other, the first connecting rod and the second connecting rod in the connecting rod structure will also rotate relative to each other. When the stepladder is unfolded, the connecting rod structure is also unfolded, and the angle between the first connecting rod and the second connecting rod gradually increases until the angle between the first connecting rod and the second connecting rod is 180°. During the process of rotating and unfolding the connecting rod structure, the second connecting rod will press on the end of the latch rod that passes through the connecting sleeve. Since its cross section is set to an arc shape, under the pressure of the second connecting rod, the latch rod retracts into the connecting sleeve, and the latch rod drives the driving structure to operate, and the driving structure forms a rebound force on the latch rod. When the angle between the first connecting rod and the second connecting rod is 180°, the latch rod corresponds to the socket. Under the action of the rebound force, the latch rod moves and resets, and the end of the latch rod that passes through the connecting sleeve is inserted into the socket, thereby completing the fixation between the first connecting rod and the second connecting rod. The connecting rod structure is automatically locked after the stepladder is unfolded. Similarly, when the stepladder needs to be folded, the two latch rods are first driven by the driving structure to retract into the connecting sleeve at the same time, so that the connecting rod structure can be unlocked. When the stepladder is folded, the connecting rod structure is automatically folded. After the present invention is installed on the stepladder, when the stepladder is fully unfolded, the first connecting rod and the second connecting rod can be automatically fixed, thereby locking the connecting rod structure. When the user is not standing on the stepladder, the connecting rod structure can also play a role in improving the stability of the stepladder, and the two connecting rod structures can be unlocked at the same time with one key. The unlocking process of the connecting rod structure is quick and convenient, and does not affect the efficiency of folding the stepladder.

[0011] A further configuration of the present invention is that a positioning plate for positioning the second connecting rod is integrally formed on the outer side wall of the connecting sleeve.

[0012] By adopting the above technical solution, when the second connecting rod contacts the positioning plate, the first connecting rod and the second connecting rod cannot continue to rotate and unfold. At this time, the angle between the first connecting rod and the second connecting rod is exactly 180°, and the latch rod also corresponds to the socket. The setting of the positioning plate can ensure that the latch rod is accurately aligned with the socket.

[0013] The present invention is further configured as follows: the driving structure comprises a first button, a push rod and two first driving components, the two first driving components are respectively located in two connecting sleeves and are symmetrically arranged front and back, the first driving component comprises a push block, a fixed sleeve and a moving block, the fixed sleeve is fixed in the connecting sleeve, one end of the latch rod is inserted into the fixed sleeve in a sliding connection manner and is fixedly connected to the inner bottom wall of the fixed sleeve with a first spring, the moving block is located in the connecting sleeve, and the fixed sleeve is arranged on the outside of the latch rod, a first inclined surface is arranged on the moving block, the pushing block is located in the connecting sleeve, a first sliding groove extending horizontally left and right is opened on the pushing block, and a second inclined surface matching the first inclined surface is arranged, the pushing block moves left and right along the inner side wall of the connecting sleeve, and is slidably sleeved on the outside of the latch rod through the first sliding groove, the pushing rod moves left and right along the inner side wall of the cross tube, the front and rear ends of the pushing rod are respectively inserted into the two connecting sleeves and are fixedly connected to the two pushing blocks respectively, one end of the first button is fixedly connected to the push rod, and the other end of the first button passes through the cross tube in a sliding connection manner.

[0014] By adopting the above technical solution, when it is necessary to drive the two latch rods to retract into the connecting sleeve at the same time through the driving structure, press the first button. The first button drives the push rod to move along the inner wall of the cross tube. The push rod drives the two push blocks to move simultaneously. The push blocks move along the inner wall of the connecting sleeve and move along the latch rod through the first slide groove. The second inclined surface is pressed on the first inclined surface. The force applied to the first inclined surface can be decomposed into a force that moves it toward the fixed sleeve. Under the action of this force, the moving block drives the latch rod to move into the fixed sleeve. Thereby, the latch rod is pulled out of the socket and retracted into the connecting sleeve. At the same time, the first spring is pressed to form a rebound force.

[0015] A further configuration of the present invention is that first auxiliary springs are fixedly connected between both ends of the push rod and the inner side walls of the two connecting sleeves.

[0016] By adopting the above technical solution, when the push rod moves along the inner wall of the transverse tube, the first auxiliary spring is pressed to form a rebound force. The first auxiliary spring cooperates with the first spring to ensure that the drive structure and the latch rod can be reset after the first button is released.

[0017] The present invention is further configured as follows: the driving structure includes a second button, a fixing sleeve, a mounting block and two second driving components, the fixing sleeve being arranged in the middle position of the outer side of the transverse tube, a first opening communicating with the interior of the fixing sleeve is provided on the outer side wall of the fixing sleeve, a second opening communicating with the interior of the fixing sleeve and corresponding to the first opening is provided on the transverse tube, the mounting block is fixed to the interior of the transverse tube, two front-to-back symmetrical mounting grooves are provided on one side of the mounting block close to the second opening, second sliding grooves are provided on the groove walls on the opposite sides of the two mounting grooves, one end of the second button is located outside the fixing sleeve, and the other end of the second button is inserted into the fixing sleeve through the first opening in a sliding connection manner, the two second driving components correspond to the two mounting grooves respectively, and are symmetrically arranged front-to-back, the second driving component includes a pressing rod, a rotating block and a sliding rod, one end of the pressing rod is fixedly connected to the second button, and the other end of the pressing rod is hinged to the rotating block The cam is connected with the second end of the rotating shaft by the rotating shaft, and the cam is connected with the second end of the rotating shaft by the rotating shaft, and the cam is connected with the second end of the rotating shaft by the rotating shaft.

[0018] By adopting the above technical solution, when it is necessary to drive the two latch rods to retract into the connecting sleeve at the same time through the driving structure, press the second button. The second button drives the pressing rod to move. The pressing rod drives the rotating block to rotate. The rotating block drives the rotating plate to rotate. The rotating plate drives the circular plate to rotate. The circular plate presses on the sliding rod. The sliding rod penetrates into the second sliding groove, and the second spring is pressed to form a rebound force. The sliding rod drives the moving rod to retract into the cross tube through the transition rod. The moving rod drives the latch rod to be pulled out of the socket and retracted into the connecting sleeve.

[0019] A further configuration of the present invention is as follows: a second auxiliary spring located between the two mounting grooves is fixed on one side of the mounting block close to the second opening, and the other end of the second auxiliary spring is fixedly connected to the second button.

[0020] By adopting the above technical solution, when the second button is pressed, the second auxiliary spring is pressed to form a rebound force. The second auxiliary spring cooperates with the second spring to ensure that the drive structure and the latch rod can be reset after the second button is released.

[0021] Further arrangement of the present invention: the driving structure is composed of two third driving components symmetrically arranged front and back, the third driving component includes an installation sleeve, a slider, a third slide groove and a pulling rod, the installation sleeve is fixed in the transverse tube, one end of the pulling rod is inserted into the installation sleeve in a sliding connection manner, and a third spring is fixedly connected to the inner bottom wall of the installation sleeve, the other end of the pulling rod passes through the installation sleeve and is fixedly connected to the latch rod, the third slide groove is opened on the outer side wall of the transverse tube, the third slide groove extends horizontally front and back and is communicated with the interior of the transverse tube, the slider slides back and forth along the third slide groove, the bottom end of the slider is fixedly connected to the pulling rod, and the top end of the slider passes through the transverse tube through the third slide groove.

[0022] By adopting the above technical solution, when it is necessary to drive the two latch rods to retract into the connecting sleeve at the same time through the driving structure, the two sliders are moved toward each other. The slider slides along the third slide groove. The slider drives the pull rod to move into the installation sleeve. The pull rod drives the latch rod to retract into the connecting sleeve. At the same time, the third spring is pressed to form a rebound force.

[0023] A further configuration of the present invention is that a slide plate for shielding the third slide groove is integrally formed at the top of the sliding block, and a vertical plate is integrally formed at the top of the slide plate.

[0024] By adopting the above technical solution, the vertical plate is arranged to facilitate the movement of the slide plate, and the slide plate can cover the third slide groove, thereby preventing dust, rain and other impurities from entering the horizontal pipe.

[0025] Compared with the prior art, the present invention has the following beneficial effects: A connecting rod stabilizing structure for a stepladder. After the present invention is installed on the stepladder, when the stepladder is fully unfolded, a first connecting rod and a second connecting rod can be automatically fixed, thereby locking the connecting rod structure. When a user is not standing on the stepladder, the connecting rod structure can also play a role in improving the stability of the stepladder, and the two connecting rod structures can be unlocked simultaneously with one button. The unlocking process of the connecting rod structure is quick and convenient, and does not affect the efficiency when the stepladder is folded. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the first embodiment when it is installed on a stepladder; Figure 2 It is a structural schematic diagram of embodiment 1; Figure 3 It is a partial cross-sectional view of the first embodiment in the top view direction; Figure 4 for Figure 3 The enlarged view of point A in the middle; Figure 5It is a partial structural schematic diagram of the first connecting rod, the second connecting rod, the latch rod, the push rod and the first driving assembly in the first embodiment; Figure 6 It is a structural schematic diagram of Embodiment 2; Figure 7 It is a partial cross-sectional view of the second embodiment in the top view direction; Figure 8 for Figure 7 The enlarged view of point B in the middle; Fig. 9 for Figure 7 Enlarged view of point C in the middle; Fig.10 It is a partial structural diagram of the second button and the second driving assembly in the second embodiment; Fig.11 This is a schematic diagram of the structure of Embodiment 3; Fig.12 It is a partial cross-sectional view of the side view of the third embodiment; Fig.13 for Fig.12 The enlarged view of point D in the middle; Fig.14 for Fig.12 Enlarged view of point E in the middle.

[0027] Figure numerals: 1, stepladder; 2, horizontal tube; 3, mounting plate; 4, first connecting rod; 5, second connecting rod; 6, connecting sleeve; 7, latch rod; 8, socket; 9, first button; 10, push rod; 11, push block; 12, fixed sleeve; 13, moving block; 14, first spring; 15, first inclined surface; 16, first slide groove; 17, second inclined surface; 18, first auxiliary spring; 19, positioning plate; 20, second button; 21, fixed sleeve Tube; 22, mounting block; 23, first opening; 24, second opening; 25, mounting slot; 26, second slide slot; 27, pressing rod; 28, rotating block; 29, sliding rod; 30, rotating plate; 31, circular plate; 32, second spring; 33, transition rod; 34, moving rod; 35, second auxiliary spring; 36, mounting sleeve; 37, sliding block; 38, third slide slot; 39, pulling rod; 40, third spring; 41, sliding plate; 42, vertical plate. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0029] A connecting rod stabilizing structure for a stepladder, such as Figure 1-Figure 5 As shown, it includes a cross tube 2 and two connecting rod structures. Both connecting rod structures are hinged between the two ladder bodies of the ladder and are symmetrically arranged front and back. The connecting rod structure includes a first connecting rod 4 and a second connecting rod 5. The ends of the first connecting rod 4 and the second connecting rod 5 that are separated from each other are respectively hinged with the two ladder bodies of the ladder. The other end of the first connecting rod 4 is fixedly sleeved with a connecting sleeve 6. A latch rod 7 is slidably connected in the connecting sleeve 6. One end of the latch rod 7 passes through the first connecting rod 4 and passes through the connecting sleeve 6 in a sliding connection manner, and its cross section is set to be arc-shaped. The other end of the second connecting rod 5 is rotatably connected to the connecting sleeve 6 and the first connecting rod 4 through a pin shaft. The second connecting rod 5 is provided with a socket 8 for inserting one end of the latch rod 7 that passes through the connecting sleeve 6. The cross tube 2 is connected between the two connecting sleeves 6 and is in communication with the two connecting sleeves 6. A driving structure for driving the two latch rods 7 to retract into the connecting sleeve 6 at the same time and forming a rebound force on the latch rod 7 is arranged in the cross tube 2 and the two connecting sleeves 6.

[0030] The driving structure includes a first button 9, a push rod 10 and two first driving components. The two first driving components are respectively located in two connecting sleeves 6 and are symmetrically arranged front and back. The first driving component includes a push block 11, a fixed sleeve 12 and a moving block 13. The fixed sleeve 12 is fixed in the connecting sleeve 6. One end of the latch rod 7 is inserted into the fixed sleeve 12 in a sliding connection manner and a first spring 14 is fixedly connected to the inner bottom wall of the fixed sleeve 12. The moving block 13 is located in the connecting sleeve 6, and the fixed sleeve is arranged on the outside of the latch rod 7. A first inclined surface 15 is arranged on the moving block 13. The pushing block 11 is located in the connecting sleeve 6. A first sliding groove 16 extending horizontally to the left and right is opened on the pushing block 11, and a second inclined surface 17 matching the first inclined surface 15 is arranged. The pushing block 11 moves left and right along the inner side wall of the connecting sleeve 6, and is slidably sleeved on the outside of the latch rod 7 through the first sliding groove 16. The push rod 10 moves left and right along the inner wall of the cross tube 2, and the front and rear ends of the push rod 10 are respectively inserted into the two connecting sleeves 6 and are respectively fixedly connected to the two push blocks 11. One end of the first button 9 is fixedly connected to the push rod 10, and the other end of the first button 9 passes through the cross tube 2 in a sliding connection. The first auxiliary spring 18 is fixedly connected between the two ends of the push rod 10 and the inner walls of the two connecting sleeves 6.

[0031] Additionally, a positioning plate 19 for positioning the second connecting rod 5 is integrally formed on the outer wall of the connecting sleeve 6. When the second connecting rod 5 contacts the positioning plate 19, the first connecting rod 4 and the second connecting rod 5 cannot continue to rotate and unfold. At this time, the angle between the first connecting rod 4 and the second connecting rod 5 is exactly 180°, and the latch rod 7 also corresponds to the socket 8. The setting of the positioning plate 19 can ensure that the latch rod 7 is accurately aligned with the socket 8.

[0032] It is worth noting that in the present embodiment, the first connecting rod 4 and the second connecting rod 5 can be hinged to the ladder body of the stepladder by directly hingedly connecting the first connecting rod 4 and the second connecting rod 5 to the pedal or ladder tube of the stepladder or to the plastic part between two adjacent ladder tubes; or two mounting plates 3 can be provided, and the two mounting plates 3 are respectively hinged between the left and right ends of the two connecting rod structures, and then the mounting plates 3 are fixed to the pedals of the stepladder by bolts.

[0033] Working principle: As the two ladder bodies in the herringbone ladder 1 rotate relative to each other, the first connecting rod 4 and the second connecting rod 5 in the connecting rod structure also rotate relative to each other.

[0034] When the stepladder 1 needs to be folded, the first button 9 is pressed first. The first button 9 drives the push rod 10 to move along the inner wall of the cross tube 2. The first auxiliary spring 18 is pressed to form a rebound force. The push rod 10 drives the two push blocks 11 to move simultaneously. The push block 11 moves along the inner wall of the connecting sleeve 6 and moves along the latch rod 7 through the first slide groove 16. The second inclined surface 17 presses on the first inclined surface 15. The force on the first inclined surface 15 can be decomposed into a force that moves it toward the fixed sleeve 12. Under the action of this force, the moving block 13 drives the latch rod 7 to move into the fixed sleeve 12. As a result, the latch rod 7 is pulled out of the socket 8 and retracted into the connecting sleeve 6. At the same time, the first spring 14 is pressed to form a rebound force. The connecting rod structure can be unlocked, and when the stepladder 1 is folded, the connecting rod structure automatically folds. After releasing the first button 9, with the cooperation of the first auxiliary spring 18 and the first spring 14, it is ensured that the driving structure and the latch rod 7 can be reset.

[0035] Similarly, when the stepladder 1 is unfolded, the connecting rod structure is also unfolded, and the angle between the first connecting rod 4 and the second connecting rod 5 gradually increases until the angle between the first connecting rod 4 and the second connecting rod 5 is 180°. During the process of rotating and unfolding the connecting rod structure, the second connecting rod 5 will press on the end of the latch rod 7 that passes through the connecting sleeve 6. Since its cross section is set to an arc shape, under the pressure of the second connecting rod 5, the latch rod 7 retracts into the connecting sleeve 6, and the first spring 14 forms a rebound force. When the angle between the first connecting rod 4 and the second connecting rod 5 is 180°, the latch rod 7 corresponds to the socket 8. Under the action of the rebound force of the first spring 14, the latch rod 7 moves and resets, and the end of the latch rod 7 that passes through the connecting sleeve 6 is inserted into the socket 8, thereby completing the fixation between the first connecting rod 4 and the second connecting rod 5. The connecting rod structure is automatically locked after the stepladder 1 is unfolded.

[0036] After the present invention is installed on the stepladder 1, when the stepladder 1 is fully unfolded, the first connecting rod 4 and the second connecting rod 5 can be automatically fixed, thereby locking the connecting rod structure. When the user is not standing on the stepladder 1, the connecting rod structure can also play a role in improving the stability of the stepladder 1, and the two connecting rod structures can be unlocked at the same time with one button. The unlocking process of the connecting rod structure is quick and convenient, and does not affect the efficiency when the stepladder 1 is folded. Example 2

[0037] The difference from the first embodiment is that the driving structure no longer includes the first button 9, the push rod 10 and the two first driving components. Figure 6-Figure 10 As shown, it includes a second button 20, a fixed sleeve 21, a mounting block 22 and two second drive components. The fixed sleeve 21 is fixedly sleeved in the middle position of the outside of the transverse tube 2. A first opening 23 communicating with the interior of the fixed sleeve 21 is provided on the outer wall of the fixed sleeve 21. A second opening 24 communicating with the interior of the transverse tube 2 and corresponding to the first opening 23 is provided on the transverse tube 2. The mounting block 22 is fixed to the interior of the transverse tube 2. Two front-to-back symmetrical mounting grooves 25 are provided on one side of the mounting block 22 close to the second opening 24. Second slide grooves 26 are provided on the groove walls on the opposite sides of the two mounting grooves 25. One end of the second button 20 is located outside the fixed sleeve 21. The other end of the second button 20 penetrates into the fixed sleeve 21 through the first opening 23 in a sliding connection. The two second drive components correspond to the two mounting grooves 25 respectively and are symmetrically arranged front-to-back. The second drive component includes a pressing rod 27, a rotating block 28 and a sliding rod 29. One end of the pressing rod 27 is fixedly connected to the second button 20. The other end of the pressing rod 27 is hinged to the rotating block 28. The other end of the rotating block 28 is rotatably connected between the upper and lower groove walls of the mounting groove 25 through a rotating shaft, and two rotating plates 30 arranged at intervals are integrally formed. A circular plate 31 is integrally formed on the ends of the two rotating plates 30 that are away from the rotating block 28. One end of the sliding rod 29 penetrates into the second sliding groove 26 in a sliding connection manner, and a second spring 32 is fixedly connected to the groove bottom of the second sliding groove 26. The other end of the sliding rod 29 penetrates the second sliding groove 26 and is fixed with a transition rod 33. The other end of the transition rod 33 is fixed with a moving rod 34. The sliding rod 29, the transition rod 33 and the moving rod 34 are all concentrically and coaxially arranged, and the cross-sectional areas of the sliding rod 29 and the moving rod 34 are larger than the transition rod 33. The transition rod 33 passes through the gap between the two circular plates 31 in a matching connection manner. The opposite sides of the sliding rod 29 and the moving rod 34 are both in contact with the outer side wall of the circular plate 31. The two moving rods 34 correspond to the two latch rods 7 respectively. One end of the moving rod 34 that is away from the transition rod 33 passes through the mounting block 22 in a sliding connection manner, and passes into the connecting sleeve 6 and is fixedly connected to the latch rod 7. A second auxiliary spring 35 located between the two mounting grooves 25 is fixed on one side of the mounting block 22 near the second opening 24. The other end of the second auxiliary spring 35 is fixedly connected to the second button 20.

[0038] When the stepladder 1 needs to be folded, the second button 20 is pressed. The second auxiliary spring 35 is pressed to form a rebound force. The second button 20 drives the pressing rod 27 to move. The pressing rod 27 drives the rotating block 28 to rotate. The rotating block 28 drives the rotating plate 30 to rotate. The rotating plate 30 drives the circular plate 31 to rotate. The circular plate 31 is pressed on the sliding rod 29. The sliding rod 29 penetrates into the second sliding groove 26, and the second spring 32 is pressed to form a rebound force. The sliding rod 29 drives the moving rod 34 to retract into the cross tube 2 through the transition rod 33. The moving rod 34 drives the latch rod 7 to be pulled out of the socket 8 and retracted into the connecting sleeve 6. The connecting rod structure can be disengaged, and when the stepladder 1 is folded, the connecting rod structure automatically folds. After releasing the second button 20, with the cooperation of the second auxiliary spring 35 and the second spring 32, it is ensured that the driving structure and the latch rod 7 can be reset.

[0039] Similarly, when the stepladder 1 is unfolded, the connecting rod structure is also unfolded, and the angle between the first connecting rod 4 and the second connecting rod 5 gradually increases until the angle between the first connecting rod 4 and the second connecting rod 5 is 180°. During the process of the connecting rod structure rotating and unfolding, the second connecting rod 5 will press on the end of the latch rod 7 that passes through the connecting sleeve 6. Since its cross section is set to an arc shape, under the pressure of the second connecting rod 5, the latch rod 7 retracts into the connecting sleeve 6, and the latch rod 7 drives the moving rod 34 to retract into the cross tube 2. The moving rod 34 drives the sliding rod 29 to penetrate into the second sliding groove 26 through the transition rod 33, and the second spring 32 is pressed to form a rebound force. When the angle between the first connecting rod 4 and the second connecting rod 5 is 180°, the latch rod 7 corresponds to the socket 8. Under the action of the rebound force of the second spring 32, the latch rod 7 and the driving structure move to reset, and one end of the latch rod 7 that passes through the connecting sleeve 6 is inserted into the socket 8, thereby completing the fixation between the first connecting rod 4 and the second connecting rod 5. The connecting rod structure is automatically locked after the stepladder 1 is unfolded. Example 3

[0040] The difference from the first embodiment is that the driving structure no longer includes the first button 9, the push rod 10 and the two first driving components. Figure 11-Figure 14As shown, the driving structure is composed of two third driving components symmetrically arranged front and back. The third driving component includes a mounting sleeve 36, a slider 37, a third slide 38 and a pull rod 39. The mounting sleeve 36 is fixed in the transverse tube 2. One end of the pull rod 39 penetrates into the mounting sleeve 36 in a sliding connection manner, and a third spring 40 is fixedly connected to the inner bottom wall of the mounting sleeve 36. The other end of the pull rod 39 passes through the mounting sleeve 36 and is fixedly connected to the latch rod 7. The third slide 38 is provided on the outer wall of the transverse tube 2. The third slide 38 extends horizontally front and back and communicates with the interior of the transverse tube 2. The slider 37 slides forward and backward along the third slide 38. The bottom end of the slider 37 is fixedly connected to the pull rod 39, and the top end of the slider 37 passes through the transverse tube 2 through the third slide 38 and is integrally formed with a slide plate 41 for shielding the third slide 38. The top end of the slide plate 41 is integrally formed with a vertical plate 42.

[0041] When the stepladder 1 needs to be folded, the user pinches the two vertical plates 42 with his fingers to move the two vertical plates 42 toward each other. The two sliders 37 are then moved toward each other through the slide plate 41. The slider 37 slides along the third slide groove 38. The slider 37 drives the pull rod 39 to move into the installation sleeve 36. The pull rod 39 drives the latch rod 7 to retract into the connecting sleeve 6. At the same time, the third spring 40 is pressed to form a rebound force. The connecting rod structure can be disengaged, and when the stepladder 1 is folded, the connecting rod structure automatically folds. After the vertical plates 42 are released, the driving structure and the latch rod 7 can be reset under the rebound force of the third spring 40.

[0042] Similarly, when the stepladder 1 is unfolded, the connecting rod structure is also unfolded, and the angle between the first connecting rod 4 and the second connecting rod 5 gradually increases until the angle between the first connecting rod 4 and the second connecting rod 5 is 180°. During the process of rotating and unfolding the connecting rod structure, the second connecting rod 5 will press on the end of the latch rod 7 that passes through the connecting sleeve 6. Since its cross section is set to an arc shape, under the pressure of the second connecting rod 5, the latch rod 7 retracts into the connecting sleeve 6, and the latch rod 7 drives the pulling rod 39 to move into the installation sleeve 36. The third spring 40 is pressed to form a rebound force. When the angle between the first connecting rod 4 and the second connecting rod 5 is 180°, the latch rod 7 corresponds to the socket 8. Under the action of the rebound force of the third spring 40, the latch rod 7 and the driving structure move and reset, and the end of the latch rod 7 that passes through the connecting sleeve 6 is inserted into the socket 8, thereby completing the fixation between the first connecting rod 4 and the second connecting rod 5. That is, the connecting rod structure is automatically locked after the stepladder 1 is unfolded.

[0043] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0046] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A connecting rod stabilizing structure for a herringbone ladder, characterized in that: The invention comprises a transverse tube (2) and two connecting rod structures, wherein the two connecting rod structures are hinged between two ladder bodies of the stepladder and are symmetrically arranged front and back, wherein the connecting rod structure comprises a first connecting rod (4) and a second connecting rod (5), wherein the ends of the first connecting rod (4) and the second connecting rod (5) which are separated from each other are respectively hinged to the two ladder bodies of the stepladder, wherein the other end of the first connecting rod (4) is fixedly sleeved with a connecting sleeve (6), wherein a latch rod (7) is slidably connected in the connecting sleeve (6), wherein one end of the latch rod (7) passes through the first connecting rod (4) in a sliding connection manner and passes through the connecting sleeve ( 6) and its cross section is arranged in an arc shape, the other end of the second connecting rod (5) is rotatably connected to the connecting sleeve (6) and the first connecting rod (4) through a pin shaft, the second connecting rod (5) is provided with a socket (8) for inserting one end of the latch rod (7) passing through the connecting sleeve (6), the transverse tube (2) is connected between the two connecting sleeves (6) and is in communication with the two connecting sleeves (6), and a driving structure is arranged in the transverse tube (2) and the two connecting sleeves (6) for driving the two latch rods (7) to retract into the connecting sleeves (6) at the same time and forming a rebound force on the latch rods (7).

2. A connecting rod stabilizing structure for a stepladder according to claim 1, characterized in that: A positioning plate (19) for positioning the second connecting rod (5) is integrally formed on the outer side wall of the connecting sleeve (6).

3. The connecting rod stabilizing structure for a stepladder according to claim 2, characterized in that: The driving structure comprises a first button (9), a pushing rod (10) and two first driving components, the two first driving components are respectively located in two connecting sleeves (6) and are symmetrically arranged front and back, the first driving component comprises a pushing block (11), a fixed sleeve (12) and a moving block (13), the fixed sleeve (12) is fixed in the connecting sleeve (6), one end of the latch rod (7) is inserted into the fixed sleeve (12) in a sliding connection manner and a first spring (14) is fixedly connected to the inner bottom wall of the fixed sleeve (12), the moving block (13) is located in the connecting sleeve (6), and the fixed sleeve is arranged on the outside of the latch rod (7), the moving block (13) is provided with a first inclined surface (15), the pushing block (11) is fixed to the outside of the latch rod (7), and the moving block (13) is provided with a first inclined surface (15). 1) is located in the connecting sleeve (6), the pushing block (11) is provided with a first sliding groove (16) extending horizontally to the left and right, and is provided with a second inclined surface (17) matching the first inclined surface (15), the pushing block (11) moves left and right along the inner wall of the connecting sleeve (6), and is slidably sleeved on the outside of the latch rod (7) through the first sliding groove (16), the pushing rod (10) moves left and right along the inner wall of the cross tube (2), the front and rear ends of the pushing rod (10) are respectively inserted into the two connecting sleeves (6), and are respectively fixedly connected to the two pushing blocks (11), one end of the first button (9) is fixedly connected to the pushing rod (10), and the other end of the first button (9) passes through the cross tube (2) in a sliding connection manner.

4. The connecting rod stabilizing structure for a stepladder according to claim 3, characterized in that: A first auxiliary spring (18) is fixedly connected between the two ends of the push rod (10) and the inner side walls of the two connecting sleeves (6).

5. The connecting rod stabilizing structure for a stepladder according to claim 2, characterized in that: The driving structure comprises a second button (20), a fixed sleeve (21), a mounting block (22) and two second driving components. The fixed sleeve (21) is fixedly sleeved at the middle position outside the transverse tube (2). The outer wall of the fixed sleeve (21) is provided with a first opening (23) communicating with the interior thereof. The transverse tube (2) is provided with a second opening (24) communicating with the interior thereof and corresponding to the first opening (23). The mounting block (22) is fixed inside the transverse tube (2). Two front-to-rear symmetrical mounting grooves (25) are provided on one side of the mounting block (22) close to the second opening (24). The two mounting grooves (25) are provided with a plurality of mounting grooves (26) disposed on the mounting block (22). 5), a second slide groove (26) is provided on the groove wall on the opposite side, one end of the second button (20) is located outside the fixed sleeve (21), and the other end of the second button (20) is inserted into the fixed sleeve (21) through the first opening (23) in a sliding connection manner, and the two second drive components correspond to the two installation grooves (25) respectively, and are symmetrically arranged front and back, and the second drive component includes a pressing rod (27), a rotating block (28) and a sliding rod (29), one end of the pressing rod (27) is fixedly connected to the second button (20), the other end of the pressing rod (27) is hinged to the rotating block (28), and the rotating block (2 The other end of the sliding rod (29) is rotatably connected to the upper and lower groove walls of the installation groove (25) through a rotating shaft, and two rotating plates (30) are integrally formed with each other. The ends of the two rotating plates (30) that are away from the rotating block (28) are integrally formed with a circular plate (31). One end of the sliding rod (29) penetrates into the second sliding groove (26) in a sliding connection manner, and a second spring (32) is fixedly connected to the groove bottom of the second sliding groove (26). The other end of the sliding rod (29) penetrates out of the second sliding groove (26) and is fixed with a transition rod (33). The other end of the transition rod (33) is fixed with a moving rod (34). The sliding rod (29) ), the transition rod (33) and the moving rod (34) are all coaxially arranged, and the cross-sectional areas of the sliding rod (29) and the moving rod (34) are larger than those of the transition rod (33). The transition rod (33) passes through the gap between the two circular plates (31) in a matching connection manner. The opposite sides of the sliding rod (29) and the moving rod (34) are both in contact with the outer side wall of the circular plate (31). The two moving rods (34) correspond to two latch rods (7) respectively. One end of the moving rod (34) that is away from the transition rod (33) passes through the mounting block (22) in a sliding connection manner, and passes into the connecting sleeve (6) and is fixedly connected to the latch rod (7).

6. The connecting rod stabilizing structure for a stepladder according to claim 5, characterized in that: A second auxiliary spring (35) located between the two mounting grooves (25) is fixed on one side of the mounting block (22) close to the second opening (24), and the other end of the second auxiliary spring (35) is fixedly connected to the second button (20).

7. The connecting rod stabilizing structure for a stepladder according to claim 2, characterized in that: The driving structure is composed of two third driving components symmetrically arranged front and back, and the third driving component includes a mounting sleeve (36), a slider (37), a third slide groove (38) and a pulling rod (39). The mounting sleeve (36) is fixed in the transverse tube (2), one end of the pulling rod (39) is inserted into the mounting sleeve (36) in a sliding connection manner, and a third spring (40) is fixedly connected to the inner bottom wall of the mounting sleeve (36), the other end of the pulling rod (39) passes through the mounting sleeve (36) and is fixedly connected to the latch rod (7), the third slide groove (38) is opened on the outer wall of the transverse tube (2), the third slide groove (38) extends horizontally front and back and communicates with the interior of the transverse tube (2), the slider (37) slides front and back along the third slide groove (38), the bottom end of the slider (37) is fixedly connected to the pulling rod (39), and the top end of the slider (37) passes through the transverse tube (2) through the third slide groove (38).

8. The connecting rod stabilizing structure for a stepladder according to claim 7, characterized in that: A slide plate (41) for covering the third slide groove (38) is integrally formed at the top of the sliding block (37), and a vertical plate (42) is integrally formed at the top of the sliding block (41).

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