Extensible supporting leg

Abstract

The invention discloses an extensible supporting leg which comprises a front-section leg tube, a middle-section leg tube, a rear-section leg tube, a first clamping mechanism and a second clamping mechanism, wherein the front-section leg tube, the middle-section leg tube and the rear-section leg tube are axially telescopic; the first clamping mechanism is positioned between the front-section leg tube and the middle-section leg tube; the second clamping mechanism is positioned between the middle-section leg tube and the rear-section leg tube; the locking control mechanism comprises a locking ring connected to the upper end of the front-section leg tube in a sleeving manner and a transmission shaft which is in transmission connection with the locking ring, and one end of the transmission shaft extends into the front-section leg tube; when the locking ring rotates in the circumferential direction, the locking ring drives the transmission shaft to rotate in the axial direction of the transmission shaft. The drive shaft is operably connected to the first clamping mechanism to releasably prevent movement of the middle leg tube relative to the front leg tube, and the drive shaft is operably connected to the second clamping mechanism to releasably prevent movement of the rear leg tube relative to the middle leg tube. According to the supporting leg locking mode, the locking effect among the three leg pipes is good, pulling buckles arranged outside the leg pipes in a protruding mode are omitted, the phenomenon of mistaken touch is not likely to happen, and the supporting leg is convenient to store.

Description

Technical Field

[0001] The present invention relates to the technical field of photographic equipment, and particularly relates to an extendable support leg. Background Art

[0002] Camera support tripods include tripods and monopods. The support legs of tripods and monopods have three leg tubes with different diameters, and these leg tubes can slide relative to each other to change the length of the support leg. When the support leg is at the desired length, any two adjacent leg tubes are locked. Generally, the telescopic structure of the support leg requires gradually locking or loosening the locking mechanism between any two adjacent leg tubes, and the operation is relatively cumbersome.

[0003] In the prior art, although there are support legs that use a single buckle to achieve synchronous locking or unlocking of multiple leg tubes, the structure that uses only a buckle to achieve locking has a poor overall locking effect for the support leg, and it is prone to loosening when the support leg bears a large weight; moreover, the part of the buckle that protrudes outward relative to the main body of the support leg is relatively long, and it is easy to accidentally touch the buckle during use, resulting in unlocking of the multiple leg tubes. Therefore, it is necessary to design a support leg locking structure with better locking effect stability. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of poor locking effect and easy accidental unlocking of the buckle in the prior art, in which a single buckle is used to control the synchronous locking of multiple leg tubes of the support leg, so as to provide an extendable support leg.

[0005] To solve the above technical problem, the technical solution of the present invention is as follows:

[0006] An extendable support leg includes a front leg tube, a middle leg tube, and a rear leg tube that are sequentially arranged from outside to inside and can axially telescope. The support leg further includes a first clamping mechanism installed between the front leg tube and the middle leg tube, and a second clamping mechanism arranged between the middle leg tube and the rear leg tube;

[0007] A locking control mechanism includes a locking ring sleeved and connected to the upper end of the front leg tube and rotatably arranged circumferentially relative to the front leg tube, and a transmission shaft that is connected to the locking ring in a transmission manner and has one end extending into the front leg tube; when the locking ring rotates circumferentially relative to the front leg tube, the locking ring drives the transmission shaft to rotate around its own axis; the transmission shaft is operably connected to the first clamping mechanism to releasably prevent the movement of the middle leg tube relative to the front leg tube, and the transmission shaft is operably connected to the second clamping mechanism to releasably prevent the movement of the rear leg tube relative to the middle leg tube.

[0008] Further, the upper end of the front leg tube is fixedly connected with a lower base, and the transmission shaft is rotationally fixed relative to the circumference and fixedly connected to the lower base in the axial direction.

[0009] Further, the locking ring is rotationally fixed relative to the circumference and fixedly connected to the lower base in the axial direction.

[0010] Further, a stepped structure is provided on the outer periphery of the upper end of the lower base, and an inner convex structure that cooperates with the stepped structure is convexly provided on the inner wall of the locking ring.

[0011] Further, the locking ring and the transmission shaft are connected by gear meshing transmission.

[0012] Further, the locking ring is connected to the transmission shaft through a gear transmission assembly.

[0013] Further, an upper cover is fixedly connected above the lower base; the gear transmission assembly is a planetary gear assembly, and the planetary gear assembly includes a sun gear rotatably arranged on the central hole of the lower base, a plurality of planetary gears located between the upper cover and the lower base and meshing and transmitting on the outer periphery of the sun gear, and a ring gear located on the outer periphery of the plurality of planetary gears and meshing and transmitting with the plurality of planetary gears; the transmission shaft is fixedly connected to the gear shaft of the sun gear and is arranged coaxially with the gear shaft of the sun gear, and the locking ring is fixedly sleeved on the outer periphery of the ring gear.

[0014] Further, the ring gear is fixedly connected above the inner convex structure.

[0015] Further, an anti-slip sleeve is sleeved on the outer wall of the locking ring, and an anti-slip structure is provided on the outer periphery of the anti-slip sleeve.

[0016] Further, the first clamping assembly includes a transmission tube, an upper locking member, a locking main body, and a tensioning member; the transmission tube is connected to the outer periphery of the transmission shaft and remains rotationally fixed and axially slidable relative to the transmission shaft, the locking main body is fixedly connected to the middle leg tube and is threadedly connected to the outer periphery of the transmission tube, the upper locking member is fixedly connected to the outer periphery of the upper end of the transmission tube, and the tensioning member is axially fixed relative to the locking main body and is located on the outer periphery of the upper locking member; the tensioning member has a tightened state of expanding outwards to tighten the inner wall of the front leg tube and a loosened state of retracting inwards to separate from the inner wall of the front leg tube under the action of the upper locking member.

[0017] Further, the cross-sections of the transmission shaft and the transmission tube are the same and are both non-circular.

[0018] Further, the upper locking member includes a tapered section having an outer tapered inclined surface, the expansion member includes at least two mutually independent expansion blocks, the inner wall of the expansion block has an inner tapered inclined surface, and the outer tapered inclined surface cooperates with the inner tapered inclined surface.

[0019] Further, an elastic sleeve is sleeved on the outer periphery of at least two of the expansion blocks, and the elastic sleeve applies a force to at least two of the expansion blocks in the direction of inward convergence.

[0020] Further, an inner friction plate for abutting against the inner wall of the front leg tube is provided on the outer wall of the expansion member.

[0021] Further, the second clamping mechanism includes an inner tube that is axially fixedly connected to the transmission tube and is located inside the middle leg tube, a locking sleeve connected to the end of the inner tube away from the transmission tube and located inside the middle leg tube, and an elastic sleeve sleeved on the outer periphery of the rear leg tube and partially extending into the locking sleeve and axially fixedly connected to the middle leg tube relative to the middle leg tube; when the locking sleeve and the elastic sleeve move axially relative to each other, the elastic sleeve has a clamping state of inward convergence to clamp on the outer wall of the rear leg tube and a release state of separating from the locking sleeve to release the rear leg tube under the action of the locking sleeve.

[0022] Further, an inner inclined guide surface is provided on the inner wall of the locking sleeve, and an outer inclined guide surface is provided on the outer wall of the elastic sleeve, and the inner inclined guide surface cooperates with the outer inclined guide surface.

[0023] Further, a connecting sleeve is fixedly connected to the outer wall of the lower end of the middle leg tube, and an adjusting sleeve is threadedly connected to the outer periphery of the connecting sleeve; the elastic sleeve is axially fixedly connected to the adjusting sleeve.

[0024] Further, a notch is formed in the side wall of the elastic sleeve, and the notch extends from the middle of the side wall of the elastic sleeve to the end of the side wall.

[0025] Further, a first anti-slip structure for preventing the middle leg tube from sliding out of the front leg tube is provided between the front leg tube and the middle leg tube, and a second anti-slip structure for preventing the rear leg tube from sliding out of the inner tube is provided between the inner tube and the rear leg tube.

[0026] The technical solution of the present invention has the following advantages:

[0027] 1. The extendable support leg provided by the present invention is provided with a locking control mechanism composed of a locking ring and a transmission shaft at the upper end of the front leg tube. One end of the transmission shaft extends into the front leg tube and is in transmission connection with the first clamping mechanism and the second clamping mechanism. When adjusting the length of the support leg, rotate the locking ring in one direction, and the locking ring drives the transmission shaft to rotate positively around its own axis. The positive rotation of the transmission shaft is transmitted to the first clamping mechanism and the second clamping mechanism, so that the first clamping mechanism releases the movement of the middle leg tube relative to the front leg tube, and the second clamping mechanism releases the movement of the rear leg tube relative to the middle leg tube. When the length of the support leg is adjusted to the required length, rotate the locking ring in the opposite direction, and the locking ring drives the transmission shaft to rotate in the opposite direction. The reverse rotation of the transmission shaft is transmitted to the first clamping mechanism and the second clamping mechanism, so that the first clamping mechanism prevents the movement of the middle leg tube relative to the front leg tube, and the second clamping mechanism prevents the movement of the rear leg tube relative to the middle leg tube, thereby realizing the adjustment of the length of the support leg. Compared with the traditional method of adjusting the length of the support leg by using a buckle, the implementation method of driving the transmission shaft to rotate by the locking ring not only has a good locking effect between the three leg tubes of the support leg, but also eliminates the buckle protruding outside the leg tube, which is not easy to be accidentally touched, and is also convenient for the storage of the support leg. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a schematic structural diagram of a tripod in an embodiment of the present invention;

[0030] Figure 2 It is a schematic structural diagram of a single support leg in an embodiment of the present invention;

[0031] Figure 3 It is a schematic structural diagram of the locking control mechanism in an embodiment of the present invention;

[0032] Figure 4 It is a schematic structural diagram of the first clamping mechanism in an embodiment of the present invention;

[0033] Figure 5 It is a schematic structural diagram of the first anti-slip structure in an embodiment of the present invention;

[0034] Figure 6 It is a schematic structural diagram of the second clamping mechanism in an embodiment of the present invention;

[0035] Figure 7This is a schematic structural diagram of the second anti-slip structure in the embodiments of the present invention.

[0036] Explanation of reference numerals: 10, support leg; 20, head element; 1, front leg tube; 2, middle leg tube; 3, rear leg tube; 4, first clamping mechanism; 41, transmission tube; 42, upper locking member; 43, locking body; 44, expansion member; 45, elastic sleeve; 46, inner friction plate; 5, second clamping mechanism; 51, inner tube; 52, locking sleeve; 53, elastic sleeve; 531, notch; 54, connecting sleeve; 55, adjusting sleeve; 56, connecting member; 57, limiting turntable; 6, locking control mechanism; 61, locking ring; 611, inner convex structure; 62, transmission shaft; 631, sun gear; 632, planet gear; 64, lower base; 65, upper cover; 66, anti-slip sleeve; 7, first anti-slip structure; 8, second anti-slip structure; 9, head end assembly. Detailed implementation manners

[0037] The technical solutions of the present invention will be described clearly and completely below with reference to the accompanying drawings. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] The present invention discloses an extendable support leg, which can be the three legs of a tripod or the support leg of a monopod. Taking a camera tripod as an example, Figure 1A three-dimensional structure diagram of a camera tripod is shown. The tripod includes a head element 20 of the tripod located at the top of the tripod and three support legs 10. Each support leg 10 is pivotally connected to the head element 20, and these three support legs are the extendable support legs claimed in this application.

[0041] Figure 2 A three-dimensional structure diagram of the support leg 10 is shown. The support leg 10 includes a front leg tube 1, a middle leg tube 2, and a rear leg tube 3 that are sequentially arranged from outside to inside and can be axially telescoped. A locking control mechanism 6 is connected to the top end of the front leg tube 1. Inside the support leg 10, a first clamping mechanism ( Figure 2 not shown) is provided between the front leg tube 1 and the middle leg tube 2, and a second clamping mechanism ( Figure 2 not shown) is provided between the middle leg tube 2 and the rear leg tube 3.

[0042] Figure 3 A schematic internal structure diagram of the locking control mechanism 6 is shown. The locking control mechanism 6 includes a locking ring 61, a transmission shaft 62, a gear transmission assembly, a lower base 64, and an upper cover 65.

[0043] Among them, the lower base 64 is fixedly connected to the upper end of the front leg tube 1. The lower half of the lower base 64 is sleeved on the outer periphery of the upper end of the front leg tube 1, and the upper half of the lower base 64 blocks the end of the upper end of the front leg tube 1. A central hole is provided at the center of the upper half of the lower base 64. Both the locking ring 61 and the transmission shaft 62 are circumferentially rotatable and axially fixedly connected to the lower base 64. A stepped structure is provided on the outer periphery of the upper half of the lower base 64, and an inner convex structure 611 that cooperates with the stepped structure is convexly provided on the inner wall of the locking ring 61. The upper cover 65 is fixedly suspended above the lower base 64 by a plurality of bolts.

[0044] In some embodiments, the gear transmission assembly is specifically a planetary gear assembly located at an interval position between the lower base 64 and the upper cover 65; the head end assembly 9 of the support leg 10 for connecting to the head element 20 covers above the upper cover 65 and is fixedly connected to the upper cover 65. The planetary gear assembly includes a central sun gear 631, three planet gears 632 meshing and drivingly connected to the outer circumference of the sun gear 631, and a ring gear (not shown in the figure) located on the outer circumference of the three planet gears 632 and meshing and drivingly connected to the three planet gears 632. The gear shaft of the sun gear 631 penetrates through the central hole of the lower base 64 and is rotatably connected to the lower base 64 through a bearing. The gear shafts of the three planet gears 632 are connected between the lower base 64 and the upper cover 65, and the ring gear is located between the lower base 64 and the upper cover 65. A gasket is provided between the upper end of the ring gear and the lower end face of the upper cover 65 to reduce the friction when the two relatively rotate. In an alternative embodiment, the locking ring 61 is directly meshing and drivingly connected to the tooth profile structure on the outer circumference of the transmission shaft 62 through the tooth profile structure on the inner side wall, or a ring gear is fixedly connected to the inner side wall of the locking ring 61, and the ring gear is meshing and drivingly connected to the tooth profile structure on the outer circumference of the transmission shaft 62.

[0045] In this embodiment, the transmission shaft 62 is fixedly connected to the gear shaft of the sun gear 631 and is coaxially arranged with the gear shaft of the sun gear 631. One end of the transmission shaft 62 extends into the front leg tube 1. The locking ring 61 is fixedly sleeved on the outer circumference of the ring gear. The inner diameter of the locking ring 61 is larger than the outer diameter of the front leg tube 1. The lower half of the upper cover 65, the outside of the ring gear, and the outside of the lower base 64 are all covered inside the locking ring 61. When the locking ring 61 rotates circumferentially relative to the front leg tube 1, the locking ring 61 drives the transmission shaft 62 to rotate around its own axis through the planetary gear assembly; the transmission shaft 62 is operably connected to the first clamping mechanism 4 to releasably prevent the middle leg tube 2 from moving relative to the front leg tube 1, and the transmission shaft 62 is operably connected to the second clamping mechanism 5 to releasably prevent the rear leg tube 3 from moving relative to the middle leg tube 2.

[0046] In some embodiments, the lower end of the ring gear is fixed on the inner convex structure 611, so as to ensure that the locking ring 61 can drive the ring gear to rotate. A gasket is also provided between the lower end of the inner convex structure 611 and the lower base 64 to reduce the friction when the two relatively rotate.

[0047] In some embodiments, grooves are provided above and below the outer wall of the locking ring 61, and an anti-slip sleeve 66 is sleeved in the two grooves. An anti-slip structure is provided on the outer circumference of the anti-slip sleeve 66, and the anti-slip structure is specifically an anti-slip thread. By providing the anti-slip sleeve 66, it is convenient to operate the locking ring 61 by hand. Washers are provided at the contact positions between the inner wall of the upper end of the locking ring 61 and the outer wall of the upper cover 65 and between the inner wall of the lower end of the locking ring 61 and the outer wall of the lower base 64 to reduce the friction when relatively rotating.

[0048] In some embodiments, to reduce the overall weight of the support leg 10, the drive shaft 62 is a hollow tubular structure.

[0049] Figure 4 The structural schematic diagram of the first clamping assembly is shown. The first clamping assembly includes a drive tube 41, an upper locking member 42, a locking main body 43, and a tightening member 44; the cross-sections of the drive shaft 62 and the drive tube 41 are both non-circular. In this embodiment, the cross-sections of the drive shaft 62 and the drive tube 41 are both square. The inner diameter cross-sectional size of the drive tube 41 is the same as the outer diameter cross-sectional size of the drive shaft 62. The drive tube 41 is sleeved on the outer periphery of the drive shaft 62, and the drive tube 41 and the drive shaft 62 maintain relative circumferential fixation and relative axial sliding; an external thread structure is provided on the outer periphery of the middle part of the drive tube 41. The locking main body 43 is fixedly connected to the middle leg tube 2 and is threadedly connected to the outer periphery of the drive tube 41. The locking main body 43 includes a locking fixing sleeve fixedly connected to the end of the middle leg tube 2, and a locking sleeve fixedly arranged on the locking fixing sleeve and having an internal thread structure. The external thread structure of the drive tube 41 is in threaded cooperation with the internal thread structure of the locking sleeve. The upper locking member 42 is fixedly connected to the outer periphery of the upper end of the drive tube 41, and the lower end of the upper locking member 42 extends to the outside of the locking sleeve of the locking main body 43. The tightening member 44 is axially fixed relative to the locking main body 43 and is located on the outer periphery of the upper locking member 42. The upper locking member 42 includes a conical section with an external conical inclined surface. The tightening member 44 includes a plurality of independent tightening blocks, and the inner wall of the tightening block has an internal conical inclined surface, and the external conical inclined surface is matched with the internal conical inclined surface. When the locking ring 61 drives the drive shaft 62 to rotate forward, the drive shaft 62 drives the drive tube 41 to rotate. Due to the threaded cooperation between the drive tube 41 and the locking main body 43, the drive tube 41 moves downward, and the upper locking member 42 fixedly connected to the drive tube 41 also moves downward. When the upper locking member 42 moves downward, it squeezes the tightening member 44 through the action of the inclined surface. The tightening member 44 expands outward under the squeezing action of the upper locking member 42 to tightly support the inner wall of the front leg tube 1, thereby realizing the locking of the front leg tube 1 and the middle leg tube 2. On the contrary, when the locking ring 61 drives the drive shaft 62 to rotate reversely, the drive tube 41 moves upward, and the upper locking member 42 fixedly connected to the drive tube 41 also moves upward. When the upper locking member 42 moves upward, it releases the tightening member 44, the tightening member 44 retracts inward, and the front leg tube 1 and the middle leg tube 2 are separated, thereby realizing the unlocking of the front leg tube 1 and the middle leg tube 2.

[0050] In some embodiments, annular grooves are provided at the upper and lower ends of the outer periphery of the plurality of tightening blocks, and elastic kits 45 are sleeved in both annular grooves. The elastic kits 45 apply a force in the direction of inward retraction to the plurality of tightening blocks. The arrangement of the elastic kits 45 can prevent the loosening of the tightening blocks and provide an elastic movement space for the tightening blocks.

[0051] In some embodiments, the outer wall of the expansion block is provided with an inner friction plate 46 for contacting the inner wall of the front leg tube 1. The provision of the inner friction plate 46 can reduce rotational wear between the expansion block and the front leg tube 1. When the inner friction plate 46 is excessively worn, it can be replaced to maintain its original condition.

[0052] Figure 5 A structural schematic diagram of the first anti-slip structure 7 is shown. A first anti-slip structure 7 is provided between the front leg tube 1 and the middle leg tube 2 to prevent the middle leg tube 2 from sliding out of the front leg tube 1. The first anti-slip structure 7 is specifically an anti-slip plate located on the inner wall of the lower end of the front leg tube 1.

[0053] Figure 6 The second clamping mechanism 5 is shown as a schematic structural diagram. The second clamping mechanism 5 includes an inner tube 51, a locking sleeve 52 and an elastic sleeve 53. The inner tube 51 is located inside the middle leg tube 2. Figure 4 The lower end of the transmission tube 41 is fixedly connected to a pair of limit discs 57, and the outer circumference of the pair of limit discs 57 forms a limit groove. The upper end of the inner tube 51 is fixedly connected to a connector 56, and the upper end of the connector 56 is embedded in the limit groove, so that the connector 56 and the transmission tube 41 remain relatively fixed in the axial direction but can rotate relative to each other in the circumferential direction. The transmission tube 41 can drive the inner tube 51 to move up and down through the pair of limit discs 57 and the connector 56, and at the same time, the inner tube 51 can rotate relative to the transmission tube 41 in the circumferential direction. Figure 6 The locking sleeve 52 is fixedly connected to the lower end of the inner tube 51 away from the transmission tube 41. The elastic sleeve 53 is sleeved on the outer periphery of the rear leg tube 3 and partially extends into the inner side of the locking sleeve 52. The elastic sleeve 53 is relatively axially fixed to the middle leg tube 2. The inner wall of the locking sleeve 52 is provided with an inner inclined guide surface, and the outer wall of the elastic sleeve 53 is provided with an outer inclined guide surface. The inner inclined guide surface cooperates with the outer inclined guide surface. When the outer inclined guide surface of the outer wall of the elastic sleeve 53 is squeezed by the inner inclined guide surface of the locking sleeve 52, the elastic sleeve 53 is squeezed inwardly under the squeezing action of the locking sleeve 52 to clamp the outer wall of the rear leg tube 3, thereby achieving the locking of the middle leg tube 2 and the rear leg tube 3; when the squeezing force of the locking sleeve 52 on the elastic sleeve 53 disappears, the elastic sleeve 53 will return to its original state due to its own elasticity, and will be released from the outer wall of the rear leg tube 3, thereby achieving the unlocking of the middle leg tube 2 and the rear leg tube 3.

[0054] In some embodiments, a plurality of notches 531 are formed on the sidewall of the elastic sleeve 53, and the notches 531 extend from the middle of the sidewall to the end of the sidewall of the elastic sleeve 53. The provision of the notches 531 on the elastic sleeve 53 is conducive to improving the elastic deformation performance of the elastic sleeve 53.

[0055] In some embodiments, a connecting sleeve 54 is fixedly connected to the outer wall of the lower end of the middle leg tube 2, and an adjusting sleeve 55 is threadedly connected to the outer periphery of the connecting sleeve 54; an annular card slot is provided on the outer wall of the elastic sleeve 53, and a clamping block extending into the annular card slot is provided on the inner wall of the lower end of the adjusting sleeve 55. The clamping block cooperates with the side wall of the annular card slot to achieve relative axial fixation and relative circumferential rotation between the adjusting sleeve 55 and the elastic sleeve 53. By rotating the adjusting sleeve 55, the axial position of the elastic sleeve 53 relative to the middle leg tube 2 can be adjusted to better ensure that locking can be achieved between the elastic sleeve 53 and the locking sleeve 52.

[0056] Figure 7 The structural schematic diagram of the second anti-slip structure 8 is shown. A second anti-slip structure 8 for preventing the rear leg tube 3 from slipping out of the inner tube 51 is provided between the inner tube 51 and the rear leg tube 3. The second anti-slip structure 8 is specifically an anti-slip piece fixed to the outer wall of the upper end of the rear leg tube 3.

[0057] In summary, for the extendable support leg 10 provided by the present invention, a locking control mechanism 6 composed of a locking ring 61, a planetary gear assembly and a transmission shaft 62 is provided at the upper end of the front leg tube 1. One end of the transmission shaft 62 extends into the front leg tube 1 and is in transmission connection with the first clamping mechanism 4 and the second clamping mechanism 5; when adjusting the length of the support leg 10, the locking ring 61 is rotated in one direction, and the locking ring 61 drives the transmission shaft 62 to make a positive rotational movement around its own axis through the planetary gear assembly. The positive rotation of the transmission shaft 62 is transmitted to the first clamping mechanism 4 and the second clamping mechanism 5, so that the first clamping mechanism 4 releases the movement of the middle leg tube 2 relative to the front leg tube 1, and the second clamping mechanism 5 releases the movement of the rear leg tube 3 relative to the middle leg tube 2; when the length of the support leg 10 is adjusted to the required length, the locking ring 61 is rotated in the opposite direction, and the locking ring 61 drives the transmission shaft 62 to make a rotational movement in the opposite direction through the planetary gear assembly. The reverse rotation of the transmission shaft 62 is transmitted to the first clamping mechanism 4 and the second clamping mechanism 5, so that the first clamping mechanism 4 prevents the movement of the middle leg tube 2 relative to the front leg tube 1, and the second clamping mechanism 5 prevents the movement of the rear leg tube 3 relative to the middle leg tube 2, thereby realizing the adjustment of the length of the support leg 10. Compared with the traditional method of adjusting the length of the support leg 10 by using a buckle, the implementation method of driving the transmission shaft 62 to rotate by using the locking ring 61 and the planetary gear assembly not only has a good locking effect between the three leg tubes of the support leg 10, but also eliminates the buckle protruding outside the leg tube, is not prone to accidental touch, and is also convenient for the storage of the support leg 10.

[0058] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or alterations derived therefrom still fall within the protection scope of the present invention.

Claims

1. An extendable support leg, characterized in that, It includes a front leg tube (1), a middle leg tube (2), and a rear leg tube (3) that are sequentially arranged from outside to inside and can axially expand and contract. The support leg (10) further includes a first clamping mechanism (4) installed between the front leg tube (1) and the middle leg tube (2), and a second clamping mechanism (5) arranged between the middle leg tube (2) and the rear leg tube (3); A locking control mechanism (6), including a locking ring (61) sleeved and connected to the upper end of the front leg tube (1) and rotatably arranged circumferentially relative to the front leg tube (1), and a transmission shaft (62) drivingly connected to the locking ring (61) and having one end extending into the front leg tube (1); when the locking ring (61) rotates circumferentially relative to the front leg tube (1), the locking ring (61) drives the transmission shaft (62) to rotate around its own axis; the transmission shaft (62) is operably connected to the first clamping mechanism (4) to releasably prevent the movement of the middle leg tube (2) relative to the front leg tube (1), and the transmission shaft (62) is operably connected to the second clamping mechanism (5) to releasably prevent the movement of the rear leg tube (3) relative to the middle leg tube (2).

2. The extendable support leg according to claim 1, wherein The upper end of the front leg tube (1) is fixedly connected with a lower base (64), and the transmission shaft (62) is rotatably circumferentially and fixedly axially connected to the lower base (64).

3. The extendable support leg according to claim 2, wherein, The locking ring (61) is rotatably circumferentially and fixedly axially connected to the lower base (64).

4. The extensible support leg according to claim 2, wherein, A stepped structure is provided on the outer periphery of the upper end of the lower base (64), and an inner convex structure (611) matching the stepped structure is convexly provided on the inner wall of the locking ring (61).

5. The extendable support leg according to claim 4, characterized in that, The locking ring (61) and the transmission shaft (62) are drivingly connected through gear meshing.

6. The extensible support leg according to claim 5, characterized in that, The locking ring (61) is drivingly connected to the transmission shaft (62) through a gear transmission assembly.

7. The extendable support leg according to claim 6, wherein An upper cover (65) is fixedly connected above the lower base (64); the gear transmission assembly is a planetary gear assembly, and the planetary gear assembly includes a sun gear (631) rotatably arranged on the central hole of the lower base (64), a plurality of planet gears (632) located between the upper cover (65) and the lower base (64) and drivingly connected by gear meshing on the outer periphery of the sun gear (631), and a ring gear located on the outer periphery of the plurality of planet gears (632) and meshing and driving with the plurality of planet gears (632); the transmission shaft (62) is fixedly connected to the gear shaft of the sun gear (631) and is arranged coaxially with the gear shaft of the sun gear (631), and the locking ring (61) is fixedly sleeved on the outer periphery of the ring gear.

8. The extensible support leg according to claim 7, wherein, The ring gear is fixedly connected above the inner convex structure (611).

9. The extensible support leg according to claim 1, characterized in that, An anti-slip sleeve (66) is sleeved on the outer wall of the locking ring (61), and an anti-slip structure is provided on the outer periphery of the anti-slip sleeve (66).

10. The extendable support leg according to any one of claims 1-9, characterized in that, The first clamping assembly includes a transmission pipe (41), an upper locking member (42), a locking main body (43), and a tensioning member (44); the transmission pipe (41) is connected to the outer periphery of the transmission shaft (62) and is relatively fixed in the circumferential direction and relatively slidable in the axial direction with respect to the transmission shaft (62), the locking main body (43) is fixedly connected to the middle-section leg pipe (2) and is threadedly connected to the outer periphery of the transmission pipe (41), the upper locking member (42) is fixedly connected to the outer periphery of the transmission pipe (41), and the tensioning member (44) is axially fixed relative to the locking main body (43) and is located outside the upper locking member (42); the tensioning member (44) has a tightened state of expanding outwards to tighten the inner wall of the front-section leg pipe (1) and a loosened state of contracting inwards to separate from the inner wall of the front-section leg pipe (1) under the action of the upper locking member (42).

11. The extensible support leg according to claim 10, characterized in that, The cross-sections of the transmission shaft (62) and the transmission pipe (41) are the same and are both non-circular.

12. The extendable support leg according to claim 10, wherein The upper locking member (42) includes a conical section with an outer conical inclined surface, the tensioning member (44) includes at least two independent tensioning blocks, the inner wall of the tensioning block has an inner conical inclined surface, and the outer conical inclined surface cooperates with the inner conical inclined surface.

13. The extensible support leg according to claim 12, characterized in that, An elastic sleeve (45) is sleeved on the outer periphery of at least two of the tensioning blocks, and the elastic sleeve (45) applies a force in the direction of contracting inwards to at least two of the tensioning blocks.

14. The extensible support leg according to claim 12, wherein, The outer wall of the tensioning member (44) is provided with an inner friction plate (46) for abutting against the inner wall of the front-section leg pipe (1).

15. The extensible support leg according to claim 10, characterized in that, The second clamping mechanism (5) includes an inner pipe (51) that is relatively axially fixedly connected to the transmission pipe (41) and is located inside the middle-section leg pipe (2), a locking sleeve (52) connected to the end of the inner pipe (51) away from the transmission pipe (41) and located inside the middle-section leg pipe (2), and an elastic sleeve (53) sleeved on the outer periphery of the rear-section leg pipe (3) and partially extending into the locking sleeve (52) and being relatively axially fixed to the middle-section leg pipe (2); when the locking sleeve (52) and the elastic sleeve (53) move relatively axially, the elastic sleeve (53) has a clamping state of contracting inwards to clamp the outer wall of the rear-section leg pipe (3) and a loosening state of separating from the locking sleeve (52) to loosen the rear-section leg pipe (3) under the action of the locking sleeve (52).

16. The extendable support leg according to claim 15, wherein, The inner wall of the locking sleeve (52) is provided with an inner inclined guide surface, and the outer wall of the elastic sleeve (53) is provided with an outer inclined guide surface, and the inner inclined guide surface cooperates with the outer inclined guide surface.

17. The extendable support leg according to claim 15, wherein A connecting sleeve (54) is fixedly connected to the outer wall of the lower end of the middle-section leg pipe (2), and an adjusting sleeve (55) is threadedly connected to the outer periphery of the connecting sleeve (54); the elastic sleeve (53) is relatively axially fixedly connected to the adjusting sleeve (55).

18. The extensible support leg according to claim 15, wherein, A notch (531) is formed on the side wall of the elastic sleeve (53), and the notch (531) extends from the middle of the side wall of the elastic sleeve (53) to the end of the side wall.

19. The extensible support leg according to claim 15, characterized in that, A first anti-slip structure (7) for preventing the middle leg tube (2) from slipping out of the front leg tube (1) is provided between the front leg tube (1) and the middle leg tube (2), and a second anti-slip structure (8) for preventing the rear leg tube (3) from slipping out of the inner tube (51) is provided between the inner tube (51) and the rear leg tube (3).

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