HK1152367A1 - A tripod - Google Patents

Description

Tripod

Technical Field

The invention relates to a tripod for stabilizing photographic equipment or other instruments and equipment, in particular to a tripod with synchronously and quickly locked legs.

Background

To stabilize photographic equipment or other instruments for photography, or operations, a tripod is often used to support the photographic equipment or instruments. Such tripods typically include three telescoping legs and a stage on top of the legs to support photographic equipment or instruments. When the device is used, the three telescopic support legs are required to be stretched to the required length respectively and the length of each support leg is required to be locked respectively, then each support leg is unfolded to the required angle relative to the object stage, the bottom of each support leg is located on the ground, and finally the photographic equipment is fixed on the object stage to photograph or operate other instruments or equipment.

At present, the tripod on the market mainly focuses on reducing the weight of the tripod so as to achieve the purpose of convenient carrying. However, the operation of unfolding and folding these tripods is rather cumbersome and time consuming. Taking a three-section tripod with each supporting leg comprising three pipe fittings as an example, two joints are needed for connecting the three pipe fittings of each supporting leg, and six joints are needed for the whole tripod. In order to lock the length of each leg, two joints are operated to lock the upper and lower pipe members connected thereto relative to each other. Thus, the installation of one tripod requires the operation of six joints, which makes the work of installing these tripods rather cumbersome and requires relatively long installation times.

Although, for ease of installation, most tripod joints employ a "quick lock system". When each pipe fitting needs to be locked, only the lock catch of the quick locking system needs to be pulled, and two adjacent pipe fittings can be locked by one click. For three-section tripods, six times of 'snap' is needed to lock the length of each supporting leg, so that the tripod adopting the 'quick locking system' still cannot achieve the effect of quick installation. If the tripod is a four-section tripod comprising four tubes, the above-mentioned mounting operations are more cumbersome and time-consuming.

Thus, the above-mentioned drawbacks of these conventional tripods are more exposed when "snatching" in the face of an emergency.

When the shooting or operation is finished or the shooting or operation is continued by switching places, the tripod needs to be retracted by reversing the above operation, however, the reversing operation is also very troublesome and time-consuming.

In addition, a foot pin is connected to the bottom of each leg to seat the tripod on the ground. However, to accommodate the needs of different fields, a set of tripods typically includes both plastic and metal pins. When the tripod needs to be protected when the tripod is to be located on a wooden or marble floor, the plastic pins are required to be connected to the bottom of the tripod. When the tripod is to be located on outdoor snow or mud and the pins are required to be inserted into the ground, the metal pins are required to be connected to the bottom of the tripod. In such a case, the conventional tripod needs to be disassembled to replace the original foot pin with another type of foot pin. This adds even more to the complexity of tripod mounting.

Disclosure of Invention

In view of the above problems, the present invention provides a tripod comprising: a base; three support legs which are pivotally arranged on the periphery of the base, wherein each support leg comprises a first pipe fitting and a second pipe fitting, and the second pipe fitting is telescopically sleeved in the first pipe fitting; the first locking mechanism is arranged between the first pipe fitting and the second pipe fitting of each support leg, and locks the second pipe fitting relative to the first pipe fitting so as to prevent the second pipe fitting from moving relative to the first pipe fitting in a telescopic mode; the three groups of transmission chains extend into the support legs from the base respectively and are coupled with the corresponding first locking mechanisms so as to drive the corresponding first locking mechanisms to lock or unlock the second pipe fitting; and the actuating mechanism is arranged in the base and synchronously coupled with the three groups of transmission chains to actuate the three groups of transmission chains.

In addition, the tripod can further comprise three groups of supporting leg angle adjusting units which are respectively arranged between the base and each supporting leg connecting piece so as to selectively lock the corresponding supporting leg relative to the base and prevent the corresponding supporting leg from pivoting relative to the base; the three sets of leg angle adjustment units are coupled to the actuating assembly to unlock the respective legs relative to the base upon actuation of the actuating assembly.

The legs of the tripod according to the invention can be locked fast in synchronism and thus allow the tripod to be deployed fast.

Drawings

The above and/or other features and advantages of the present invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings, in which the components are shown by way of illustration and not in scale, and wherein:

FIG. 1 is a schematic view of the tripod of the present invention in a stowed condition;

FIG. 2 is a schematic view of the tripod of the present invention in a deployed state;

FIG. 3 is a top plan view of the tripod of FIG. 1;

FIG. 4 is a cross-sectional view of the tripod of the present invention taken along section A-A of FIG. 3;

FIG. 5 is a cross-sectional view of the tripod of the present invention taken along section B-B of FIG. 3;

FIG. 6 is an exploded schematic view of the base of the tripod of the present invention;

FIG. 7 is a cross-sectional view of the base of the tripod of the present invention taken along section C-C of FIG. 4;

FIG. 8 is a bottom plan view of the turntable of the tripod of the present invention;

FIG. 9 is a top plan view of the turntable of the tripod of the present invention;

figure 10 is a schematic view of the base of a tripod according to the present invention taken along section D-D in figure 4;

FIG. 11 is a schematic view showing the dust cover of the tripod of the present invention in a raised condition of the handle;

FIG. 12 is a schematic view of the base of a tripod according to the present invention taken along section E-E of FIG. 4 showing the dust side plate in a locked condition of the handle of the tripod according to the present invention;

FIG. 13 is a schematic view of the base of a tripod according to the present invention taken along section E-E of FIG. 4 showing the dust side plate in a relaxed state of the handle of the tripod according to the present invention;

FIG. 14 is a side elevational view, partially in section, of the tripod of the present invention in the stowed condition;

FIG. 15 is a side elevational view, partially in section, of the tripod of the present invention in a deployed condition;

figures 16 and 17 are schematic views showing the base and leg connection of the tripod of the present invention;

figure 18 is a cross-sectional view of the leg of the tripod of the present invention taken along section F-F of figure 14;

figure 19 is a cross-sectional view of the leg of the tripod of the present invention taken along section G-G of figure 14;

figure 20 is a cross-sectional view of the leg of the tripod of the present invention taken along section H-H of figure 14;

figure 21 is a cross-sectional view of a leg of a tripod according to the present invention taken along section I-I of figure 14;

figure 22 is a cross-sectional view of a leg of a tripod according to the present invention taken along section J-J of figure 14;

figure 23 is a cross-sectional view of a leg of a tripod according to the present invention taken along section K-K of figure 14;

figure 24 is a cross-sectional view of the leg of the tripod of the present invention taken along section L-L of figure 14;

figure 25 is a cross-sectional view of the leg of the tripod of the present invention taken along section M-M of figure 14;

figure 26 is a cross-sectional view of the leg of the tripod of the present invention taken along section N-N of figure 15;

FIG. 27 is a cross-sectional view of the leg of the tripod of the present invention taken along the O-O cross-section of FIG. 15;

figure 28 is a cross-sectional view of the leg of the tripod of the present invention taken along section P-P of figure 15;

figure 29 is a cross-sectional view of a leg of a tripod according to the present invention taken along section Q-Q in figure 15;

figure 30 is a cross-sectional view of the leg of the tripod of the present invention taken along section R-R in figure 15;

figure 31 is a cross-sectional view of the leg of the tripod of the present invention taken along section S-S of figure 15;

figure 32 is a cross-sectional view of the leg of the tripod of the present invention taken along section T-T of figure 15;

figure 33 is a cross-sectional view of the leg of the tripod of the present invention taken along the section U-U in figure 15;

figure 34 shows the positional relationship between the turntable and gears of a tripod according to the present invention with the handle locked;

figure 35 illustrates the relationship between the turntable and gears in a released condition of the tripod handle according to the present invention;

FIG. 36 is a schematic illustration of the tripod drive relationship of the present invention;

FIG. 37 is a perspective view of the initial state of the unlocking unit of the tripod leg of the present invention;

FIG. 38 is a schematic view of the initial state of the unlocking unit of the tripod leg of the present invention;

FIG. 39 is a perspective view of the operating condition of the unlocking unit of the tripod leg of the present invention;

FIG. 40 is a schematic view of the operating condition of the unlocking unit of the tripod leg of the present invention;

FIG. 41 is a cross-sectional view showing the connection of the leg pins to the legs of the tripod according to the present invention;

figure 42 is a cross-sectional view of the leg of the tripod of the present invention taken along section V-V of figure 41;

figure 43 is a cross-sectional view of a leg of a tripod according to the present invention taken along the section W-W in figure 41;

figure 44 is a cross-sectional view of the leg of the tripod of the present invention taken along section X-X of figure 41;

figure 45 is a cross-sectional view of a leg of a tripod according to the present invention taken along the Y-Y section of figure 41;

FIG. 46 is a schematic view showing the suction stroke of the tripod damping apparatus of the present invention;

FIG. 47 is a schematic view showing the exhaust stroke of the tripod damping apparatus of the present invention;

FIG. 48 is a cross-sectional view of a leg of a tripod according to the present invention taken along the Z-Z section of FIG. 41 showing a staple assembly positioning unit of the tripod according to the present invention;

FIG. 48A is a schematic view of a curvilinear slot in the staple assembly positioning unit of the tripod of the present invention;

FIG. 49 is a schematic view showing the spike assembly of the tripod of the present invention in an extended state; and

figure 50 is a schematic view showing the spike assembly of a tripod according to the present invention in a retracted state in which the spikes have been replaced with metal spikes.

Detailed Description

As shown in fig. 1 and 2, the tripod of the present invention mainly comprises: a base 1; three support legs 2 pivotally arranged on the base; a middle shaft 3 vertically penetrating the base and capable of moving up and down relative to the base, and a middle shaft locking device 4 sleeved on the middle shaft for locking the middle shaft relative to the base. Each leg 2 of the tripod according to the present invention comprises at least two tubes, but may also comprise three or more tubes. In the example shown in the figures, each foot 2 comprises four tubes 5, 6, 7, 8, respectively. Preferably, as shown in fig. 3, three legs 2 are arranged around the base 1 at even intervals from each other.

Referring to fig. 3-14, the base 1 includes a base body 11, a base inner cover 14 fastened to the base body 11, and a base outer cover 15 disposed on the base inner cover 14. A turntable 12 and an actuating assembly 13 coupled to the turntable 12 to actuate the same are rotatably disposed between the base main body 11 and the base inner cover 14. In addition, three sets of first gears 17 are provided on the side of the base body 11 spaced apart from each other between the base body 11 and the base inner cover 14 to contact the turntable 12. Three sets of second and third gears 18 and 19, which mesh with each other, are also provided at the side of the base main body 11 with a space.

The base main body 11 includes: a bottom tub 110 having a recess 111 formed on an upper surface thereof to receive the turntable 12; a pillar 112 extending upward from the center of the bottom tub 110, forming a center hole to receive the bottom bracket 3 and having an external thread 113 formed on an upper outer surface thereof; an annular detent 114 formed in recess 111 about post 112, a pair of opposed detent projections 1141 (see FIG. 7) formed in detent 114; three sets of brackets 115 (see fig. 6 and 14) spaced apart from each other and extending outwardly from the side wall of the base tub 110, each set of brackets including two spaced apart cantilevered arms for supporting the second and third gears 18, 19; a first opening 116 formed on the side wall of the base tub adjacent to each bracket 115 for the output shaft 20 connected to the first gear 17 to protrude out of the base body 11; a second opening 117 formed on the side of the bottom tub 110 in each bracket for the second gear 18 to contact with the turntable 12 in the recess 111; and a first protective cap 118 formed on the lower side of each first opening 116. To facilitate the discharge of water or impurities in the bottom tub 110, a plurality of guide holes 1142 penetrating the bottom tub 110 may be formed in the positioning groove 114.

The turntable 12 is generally truncated and conical in shape and defines a central opening 120 for fitting over the base body upright 112. The turntable 12 includes a pair of positioning blocks 121 formed on a bottom surface of the turntable opposite to each other such that the positioning blocks 121 are seated in the base body positioning grooves 114 when the turntable 12 is mounted in the base body 11. A spring 122 is disposed between each positioning block 121 and the corresponding stop tab 1141 in the positioning slot 114 of the base body, and tends to press the positioning block 121 against the other stop tab respectively (see fig. 7). An annular concave surface 123 is formed on the outer side of the lower surface of the turntable 12. Three spaced-apart racks 124 (see fig. 8) are formed on the concave surface 123 to selectively engage with the second gear 18, respectively. A plurality of teeth 125 (see fig. 9) are formed on the tapered side of the turntable 12 around the circumference of the turntable to mesh with the first gear 17. The upper surface of the rotary disk 12 is formed with a counterbore 126 about the central bore 120 to receive the actuating assembly 13. A semi-circular guide groove 127 is formed in the counterbore 126 around the central bore 120. To facilitate the discharge of water or foreign substances from the turntable 12, a plurality of guide holes 1271 may be formed through the turntable 12 in the guide groove 127.

The actuating assembly 13 comprises: a base plate 130 received in the carousel counterbore 126; the bottom plate 130 is centrally formed with a central hole 131 to be fitted over the base body column 112; a guide block 132 extending downwardly from the bottom surface of the base plate 130 seats in the turntable guide slot 127 when the actuating assembly 13 is installed in the turntable 12. A pair of springs 133 are disposed in the turntable guide slots 127, each spring bearing at its two ends against one end of the semi-circular guide slot 127 and the guide block 132, respectively, to tend to keep the actuating assembly 13 in an intermediate equilibrium position (see fig. 10). The actuating assembly 13 further includes a post 134 extending upward from the top surface of the base plate 130, and a handle 135 pivotally coupled to a top end of the post 134, wherein the post 134 is formed to have a height such that the top end thereof is positioned at an upper side of the base inner cover 14, and a distal end of the handle 135 extends out of the base outer cover 15.

The base inner cover 14 is formed with a central aperture 140 to fit over the base body post 112 and the actuating assembly post 134. The base inner cover 14 has a counterbore 141 formed in the bottom surface thereof corresponding to the rotary disk counterbore 126 and snap-fit into the actuator base plate 130 to cooperate with the rotary disk counterbore 126 to limit longitudinal displacement of the actuator assembly 13. The base inner cover 14 is provided with three concave receiving grooves 142 spaced apart from the bottom surface thereof to receive the first gear 17 therein such that the first gear 17 is engaged with the teeth 125 on the side of the turntable, respectively. A second protective cover 143 is formed on the side of the inner cover of the base at a position opposite to the first protective cover 118 of the base main body, and the first and second protective covers embrace the upper protective cover in a semi-cylindrical shape (see fig. 5). After the base inner cover 14 is snapped onto the base body 11, the two may be fastened together by a connector, such as a screw (see fig. 4), to limit the longitudinal displacement of the components received therebetween.

The base outer cover 15 defines a receiving cavity 150 for the inner ends of the post 134 and handle 135 of the actuator assembly 13 to rotate therein, and has a central opening 151 formed in the top center thereof to fit over the base body upright 112. An opening 152 is formed in the side wall of the base outer cover 15 for the outer end of the handle 135 to extend through the base outer cover. The opening 152 has a "T" shaped projection 153 (see fig. 1) formed therein. Thus, the handle 135 can be rotated from one side of the "T" shaped protrusion to the other side to achieve the two states of locking and unlocking, which will be described in detail below.

The base 1 may further include a fastening nut 16 screwed on the external thread 1131 of the upper portion of the pillar 112 to press the base outer cover 15 against the base inner cover 14, wherein the external thread 1131 is formed on the lower side of the external thread 113 and has an outer diameter larger than that of the external thread 113.

The middle shaft 3 is sleeved in the central hole of the base upright 112, and the upper end of the middle shaft is provided with an object stage 31. A threaded rod 32 is provided centrally on the top surface of the stage 31 for connection to photographic equipment or instruments (not shown). The bottom end of the central shaft 3 may be provided with a weight hook 33 for hanging a weight (not shown) to stabilize the tripod.

The bottom bracket lock 4 includes a lock body 41 and an annular wedge 42. The locker body 41 is formed with a central hole 410 and an internal thread 411 is formed on an inner wall of the central hole, wherein an upper end aperture of the central hole 410 is smaller than a lower end aperture. The internal threads 411 of the lock body engage the external threads 113 at the top end of the upright 112, while the annular wedge 42 is disposed between the upright 112 and the central shaft 3 within the central bore 410. When the position of the centre shaft 3 needs to be locked, the locking device body is screwed on the external thread 113 more tightly, so that the annular wedge 42 is pressed downwards and is wedged between the upright post and the centre shaft more tightly, and the purpose of locking the centre shaft is achieved. When it is desired to loosen the bottom bracket 3, the annular wedge 42 is loosened by unscrewing the lock body 41.

In addition, to reduce the possibility of dust getting into the base and blocking the moving parts therein, a dust cover 21 may be provided in the housing chamber 150 of the base cover 15. The dust cover 21 includes an opening 211 through which the pillar 112 passes and a pivot shaft 212 about which the dust cover 21 pivots (see fig. 12). The outer and inner covers are provided with upper and lower supporters 213 and 214, respectively, which are fastened to each other to support the pivot shaft 212. A support piece 215 extends from the pivot 212 in a direction away from the dust top cover 21, and a spring 216 is provided between it and the lower support 214. The spring 216 tends to push the support piece 215 upward to press the dust cap 21 against the handle 135 (see fig. 4). Thus, when the handle 135 is moved along the T-shaped projection 153, the dust cap 21 is moved while being closely attached to the handle 135 (see FIG. 11).

In addition, to prevent dust from entering the base 1 through the opening 152, a pair of arc-shaped dust-proof side plates 22 may be provided around the inner wall of the base outer cover 15. The dust side plates 22 are disposed on opposite sides of the handle 135 and slidably received in an annular recess 144 formed in the top surface of the inner base cover 14. The dust-proof side plates 22 are respectively pulled by springs 221, and both ends of each spring 221 are respectively fixed to the side of the dust-proof side plate 22 away from the handle 135 and the base cover 15, thereby tending to press the dust-proof side plate 22 against the handle 135 (see fig. 12 and 13). Thus, when the handle 135 is moved along the "T" shaped protrusion in the opening 152, the dust side plate 22 moves along against the handle 135.

Figures 14-40 show the leg 2 of a tripod according to the present invention and its connection to the base 1. The structure of each support leg of the present invention is the same, so only one support leg is taken as an example for description.

The foot 2 is joined to the base 1 by a foot connection 23. The leg connector 23 is fixedly attached to the top end of the leg first pipe member 5 and includes a pair of coupling pieces 231 extending vertically upward from the top surface thereof. The pair of connecting pieces 231 straddle the bracket 115 of the base and are pivotally connected to the bracket 115 by means of the support shaft 232 of the third gear 19. Between the third gear wheel 19 and the top surface of the foot link 23, a foot angle adjustment lever 24 is arranged, the end 241 thereof near the inside of the foot being pivotally connected to the foot link 23, while the end thereof near the outside of the foot being a free end. The adjusting lever 24 is formed with a plurality of teeth 243 toward the middle of the upper surface of the third gear 19 to be engaged with the third gear 19; while its lower surface directed towards the middle of the foot link 23 is supported by a spring 242 tending to push a tooth 243 in the middle of the adjustment lever 24 against the third gear wheel 19 (see figure 5).

A coupling protrusion 233 is formed at a position of the leg link 23 adjacent to the coupling piece 231, and a semi-cylindrical lower shield 25 is provided thereon to be fitted into the upper shield.

The output shaft 20 of each first gear 17 extends into a protective cavity formed by the respective upper and lower protective covers and has a first pawl 26 attached to its distal end. In engagement with the first pawl 26, a second pawl 27 is provided, which second pawl 27 is likewise located in the protective cavity and the output shaft 28 of which extends into the foot 2 and is pivotally connected to a first cylindrical drive shaft 281 in the foot 2. The first pawl 26 and the second pawl 27 may be six-pawl pawls. When the foot 2 is rotated relative to the base 1, the connecting piece 231 of the foot link 23 is rotated relative to the bracket 115 of the base, while the lower protective cover 25 is rotated within the upper protective cover until the lower protective cover and/or the coupling projection abuts against the lower edge of the upper protective cover. During this process, the first and second pawls 26, 27 remain engaged at all times (see fig. 16 and 17).

Referring to fig. 14 and 15, each leg 2 of the present invention includes four tube members, i.e., a first tube member 5, a second tube member 6, a third tube member 7, and a fourth tube member 8. The first pipe member 5 comprises a tubular housing 51, which housing 51 is open at its upper and lower ends and is connected at its upper end to the leg connector 23. Two sets of positioning holes 52 are formed in the inner wall of the housing 51 along the entire height of the housing 51. The two sets of positioning holes 52 are distributed angularly symmetrically with respect to the center of the housing 51 and each include a plurality of positioning holes 521 (see fig. 18 and 26) aligned up and down. A stopper 53 is formed at the bottom of the inner wall of the housing 51 to prevent the second pipe member 6 from being completely removed from the first pipe member 5, which will be described in detail later.

The second pipe 6 includes a tubular housing 61 fitted in the first pipe housing 51 movably up and down. A bracket 62 is secured to the upper end of the housing 61 and includes upper and lower support plates spaced apart from each other. The first cylindrical transmission shaft 281 penetrates the bracket 62 and can freely rotate relative to the bracket 62. The force-receiving gear 63 and the power gear 64 are sandwiched between upper and lower plates of the bracket 62 in an up-down stacked manner, and are fitted over the first cylindrical transmission shaft 281. The center hole of the force-receiving gear 63 is formed in a rectangular shape in cross section and is sized slightly larger than the cross section of the first cylindrical transmission shaft 281 so that when the force-receiving gear 63 is fitted thereon, it can slide in the length direction of the first cylindrical transmission shaft but cannot rotate relative to the first cylindrical transmission shaft (see fig. 19 and 28). However, the central bore of the work gear 64 is dimensioned to rotate freely relative to the first cylindrical drive shaft when it is fitted over the first cylindrical drive shaft (see fig. 20 and 28). The force receiving gear 63 and the power gear 64 are connected by a spring 65 having one end fixed to the force receiving gear 63 and the other end fixed to the power gear 64. Therefore, when the first cylindrical transmission shaft 281 rotates to rotate the force receiving gear 63, the force receiving gear 63 rotates the power gear 64 together with the spring 65.

A pin 2811 and a gasket 2812 are arranged at the lower end of the first cylindrical transmission shaft 281, wherein the gasket 2812 is arranged on the bracket 62. The inner bore of the washer 2812 is rectangular and has dimensions slightly larger than the cross-sectional dimensions of the cylindrical drive shaft 281. The washer 2812 thus prevents the pin 2811 from entering the central bore of the work gear 64.

The driven gear 66 is held between the upper and lower plates of the carrier 62 and is engaged with the force receiving gear 63. A second cylindrical transmission shaft 282 is fixedly coupled to the driven gear 66 and extends downward freely rotatably with respect to the bracket 62. For example, the driven gear 66 is formed with a central hole having a rectangular cross section (see fig. 19) and is sized slightly larger than the second cylindrical transmission shaft 282 so that it cannot rotate relative to the second cylindrical transmission shaft when the driven gear 66 is fitted over the second cylindrical transmission shaft.

In addition, a pin 2821 and a washer 2822 are provided at a position of the second cylindrical transmission shaft adjacent to the upper and lower plates of the bracket 62, wherein the washer 2822 is interposed between the pin 2821 and the upper and lower plates, thereby preventing the second cylindrical transmission shaft 282 from moving longitudinally relative to the driven gear 66 (see fig. 29). Meanwhile, since the spacer 2822 can disperse the longitudinal thrust of the second cylindrical transmission shaft 282 to the bracket 62, the two ends of the driven gear 66 can not bear excessive longitudinal thrust.

The leg second tube member 6 further includes a stopper unit 69 and a thrust spring 692 (see fig. 21 and 30) provided in the bracket 62. The stopper unit 69 is pivotally provided at one end in the bracket 62 and includes a stopper projection 691 extending outward of the bracket 62. The urging spring 692 has one end abutting on the bracket 62 and the other end abutting on the stopper unit to tend to push the stopper projection 691 out of the opening 611 through the side wall of the housing 61 and the bracket 62. Thus, when the upper end of the second pipe member 6 slides to the end of the first pipe member 5, the stop protrusion 691 of the stop unit 69 will contact and abut from above against the stop block 53 of the first pipe member, thereby preventing the second pipe member 6 from sliding out of the first pipe member 5.

In order to lock the second pipe member with respect to the first pipe member when the leg second pipe member is retracted, the second pipe member 6 further includes a locking unit 67 (see fig. 20 and 37) provided at one side of the power gear 64. The locking unit includes: a substrate 671; a rack gear 672 formed at an end of the base plate facing the work gear 64, the rack gear being engaged with the work gear; and a bifurcated end 673 formed at an end of the base plate 671 opposite to the end where the rack is formed. The bifurcated end 673 includes at least one alignment pin 6731 that mates with the alignment aperture 521 of the first tubular member 5. Meanwhile, openings 612 through which positioning pins 6731 pass are formed in the housing 61 and the bracket 62 of the second pipe 6. Thus, when the work gear 64 rotates clockwise (as viewed from the upper side), it drives the base plate 671 toward the opening 612 via the rack 672 so that the positioning pins 6731 of the bifurcated end 673 are inserted into the positioning holes 521 of the first pipe 5 through the bracket and the housing, thereby locking the first and second pipes without stretching the second pipe.

Preferably, in order to maintain balance, a further locking unit 68 may be provided for the second tube element 6, which locking unit 68 and locking unit 67 are angularly symmetrically distributed with respect to the work gear 64, so that the positioning pins of the diverging ends thereof can be selectively inserted into the positioning holes of the other set of positioning holes of the first tube element. Since the two locking units have basically similar structures, no further description is provided herein.

In order to make it possible to finely adjust the length of the second pipe element 6 extending beyond the first pipe element 5 with the entire leg positions locked, an unlocking unit 60 may be provided on the second pipe element 6, which includes: a drawing unit 601 provided at a lower portion of the second pipe housing 61; an actuator block 602 provided on a side surface of the lock unit substrate 671; an actuating wedge 603 disposed in the carriage 62 to be movable up and down adjacent to the actuating block 602; a thrust spring 604, the two ends of which bear against the bracket 62 and the actuating wedge 603, respectively, to tend to push the actuating wedge 603 away from the actuating block 602; and a traction cable 605, one end of which is fixed to the actuating wedge 603 and the other end of which is fixed to the traction unit 601 through the housing 61 of the second tube 6 (see fig. 27). The traction unit 601 includes a frame 6011 fixed to an outer surface of the casing; a swivel arm 6012 pivotably provided on the frame 6011; a pressing piece 6013 coupled to a free end of the rotating arm 6012. Preferably, the pressing piece 6013 is located in a recess 6014 formed at one side of the frame 6011. One end of the traction cable 605 fixed to the traction unit 601 is fixed to the pressing piece 6013 (see fig. 38).

Thus, when the pressing piece 6013 is pressed, the pulling rope 605 brings the actuating wedge 603 downward against the urging force of the urging spring 604, thereby pushing the locking unit 67 toward the inside of the bracket 62 by the actuating block 602, so that the positioning pin 6731 moves out of the positioning hole 521, so that the second pipe 6 can be unlocked with respect to the first pipe 5 and can move with respect to the latter.

In the case where the second pipe fitting 6 includes the locking unit 68, the rack gear 672 of the locking unit 67 urges the power gear 64 to rotate counterclockwise (as viewed from the upper side), thereby bringing the locking unit 68 while moving toward the inside of the bracket 62, so that the positioning pin of the locking unit 68 is also moved out of the positioning hole of the first pipe fitting to release the locking between the first and second pipe fittings (see fig. 39 and 40).

When the position of the second tubular element 6 with respect to the first tubular element 5 is adjusted and the pressing tab 6013 is released, the thrust spring 604 pushes the actuating wedge 603 away from the actuating block 602, so that under the return force of the spring 65, the work gear 64 rotates clockwise again, driving the two locking units to move outwards of the bracket 62, thus re-locking the second tubular element 6 with respect to the first tubular element 5.

Two positioning hole groups 613 are formed in the second pipe housing 61 at positions offset from the positioning hole groups 52 of the first pipe 5 along the entire height of the housing 61. The two positioning hole sets 613 respectively include a plurality of positioning holes 6131 aligned up and down (see fig. 36). In addition, a stopper hole 614 (see fig. 15) is formed at the bottom of the housing 61 of the second pipe 6 to prevent the third pipe 7 from being completely removed from the second pipe 6, which will be described in detail later.

A longitudinal through hole 721 is formed at a position of the bracket 72 of the third pipe 7 corresponding to the first cylindrical transmission shaft 281 for the first cylindrical transmission shaft 281 to pass through when the legs are retracted (see fig. 21, 22). When the upper end of the third pipe member 7 slides to the end of the second pipe member 6, the stopper protrusion 791 of the stopper unit 79 of the third pipe member 7 is engaged in the stopper hole 614 of the second pipe member 6, thereby preventing the third pipe member 7 from sliding out of the second pipe member 6. In addition, the locking units 77 and 78 of the third pipe member 7 form a staggered arrangement with the locking units 67 and 68 of the second pipe member 6. Thus, clockwise rotation (as viewed from the upper side) of the work gear 74 of the third tube member 7 may urge the locking units 77 and 78 to move inwardly toward the bracket 72. Except for the above differences, the third pipe 7 is similar to the second pipe 6 in structure, and therefore will not be described herein.

As shown in fig. 15 and fig. 32 to 33, a first longitudinal through hole 821 is formed at a position of the bracket 82 of the fourth pipe member 8 corresponding to the first cylindrical driving shaft 281 for passing through the first cylindrical driving shaft 281 when the legs are retracted; and a second longitudinal through-hole 822 is formed at a position thereof corresponding to the second cylindrical transmission shaft 282 to pass the second cylindrical transmission shaft 282 when the legs are retracted (see fig. 24 to 25 and 32). The locking units 87 and 88 of the fourth pipe member 8 are staggered from the locking units 77 and 78 of the third pipe member 7. Thus, counterclockwise rotation (as viewed from the upper side) of the work gear 84 of the fourth pipe member 8 can drive the locking units 87 and 88 to move inward toward the bracket 82. In addition, if the fourth pipe member 8 is an end pipe member of the leg, the pipe member may not include the driven gear and the columnar transmission shaft fixedly provided with respect to the driven gear. Except for the above differences, the structure of the fourth tube 8 is similar to that of the third tube 7, and therefore, the description thereof is omitted.

The operation of the tripod of the present invention will now be described in detail with reference to figures 34-36.

When the handle 135 of the actuating assembly 13 is in the locking position shown in fig. 34, i.e. in the position to the right of the "T" shaped projection shown in fig. 1, the guide block 132 of the actuating assembly 13 is in the rest position in the guide slot 127 of the rotary disk 12, so that the rotary disk 12 is in its initial position under the action of the spring 122. At this time, the second gear 18 is engaged with the rack 124 of the turntable, so that the second gear 18 cannot rotate freely. Since the second gear 18 is engaged with the third gear 19 (see fig. 5) and the third gear 19 is engaged with the teeth 243 of the leg angle adjusting lever 24, the third gear 19 cannot rotate and the leg angle adjusting lever 24 cannot rotate relative to the third gear 19, so that the leg angle adjusting lever 24 fixedly arranged at one end on the leg can prevent the leg from rotating and expanding outwards relative to the base 1.

At the same time, since the rotary disk 12 remains stationary, the first gear 17, which meshes with the teeth 125 of its side, also remains stationary, so that its output shaft 20 and the pawls 26 do not drive the first cylindrical transmission shaft 281 of the foot in rotation. Thus, the locking units of the second to fourth pipe members of the legs are in the initial positions projected out of the corresponding housings, and their respective positioning pins are also in the initial states inserted into the positioning holes of the previous pipe member, whereby the adjacent pipe members of the respective legs are in the locked states, respectively, and cannot be stretched.

When the handle 135 of the actuating assembly 13 is rotated to the release position shown in fig. 35, i.e., to the left of the "T" shaped projection shown in fig. 1, the guide block 132 of the actuating assembly 13 is rotated clockwise (as viewed from the upper side) in the guide groove 127 of the dial 12, and at the same time, the dial 12 is urged to rotate clockwise together by the spring 133. Due to the rotation of the turntable 12, the second gear 18 is disengaged from the rack 124 of the turntable, so that the second gear 18 can freely rotate in the annular concave surface 123 of the turntable 12. Since the second gear 18 is engaged with the third gear 19 (see fig. 5), and the third gear 19 is engaged with the teeth 243 of the leg angle adjusting lever 24, the third gear 19 can also rotate at this time, so that the leg angle adjusting lever 24 can drive the second gear 18 and the third gear 19 to rotate. Thus, when the foot is rotated relative to the base 1, the foot angle adjustment rod 24, which is fixedly arranged at one end on the foot, can drive the second gear 18 and the third gear 19 to rotate freely without any hindrance. This allows the legs 2 to be rotated and spread out at an angle relative to the base 1.

At the same time, as the turntable 12 rotates clockwise, the first gear 17, which is engaged with the teeth 125 on its side, rotates counterclockwise (as viewed from inside to outside the base), so that the output shaft 20 of the first gear drives the first cylindrical transmission shaft 281 of the foot 2 to rotate counterclockwise (as viewed from above) via the first pawls 26, the second pawls 27 and the second pawl output shaft 28. The first cylindrical transmission shaft 281 drives the force-receiving gear 63 to rotate counterclockwise, and the force-receiving gear 63 drives the power gear 64 to rotate counterclockwise via the spring 65, so that the power gear 64 drives the locking units 67 and 68 to move toward the bracket 62 by means of the rack, so that the locking pins of the locking units are moved out of the positioning holes in the first pipe 5, and the unlocking is performed between the first pipe 5 and the second pipe 6 of the leg.

At the same time, the force receiving gear 63 urges the driven gear 66 to rotate clockwise (as viewed from the upper side), and the driven gear 66 brings the second cylindrical transmission shaft 282 into rotation clockwise together. Similarly to the above operation, the second cylindrical transmission shaft 282 drives the force-receiving gear 73 of the third pipe member 7 to rotate clockwise, and the force-receiving gear 73 drives the work gear 74 to rotate clockwise via the spring 75, so that the work gear 74 drives the locking units 77 and 78 to move toward the bracket 72 by means of the racks of the locking units 77 and 78, so that the locking pins of the locking units of the third pipe member move out of the positioning holes in the second pipe member 6 to unlock between the second pipe member 6 and the third pipe member 7 of the leg.

By analogy, the unlocking between the third 7 and fourth 8 tube elements of the foot is also carried out. Thus, by the above-described transmission, the locking between the adjacent pipe members of each leg is released, so that each pipe member can be pulled out by a desired length from its one.

When the length of each leg and its angle of deployment relative to the base are adjusted, the legs can be locked by rotating the handle 135 back to the locked position, i.e., the right position of the "T" shaped protrusion shown in FIG. 1. When the handle 135 is turned back to the locking position, the turntable 12 is turned to the position shown in fig. 34 by the spring 122, whereby the second gear 18, the third gear 19 and the leg angle adjustment lever 24 of each leg are relocked, whereby the spreading angle of each leg with respect to the base is locked.

In addition, during the rotation of the rotary table 12 back to the position shown in fig. 34, the first gear 17 of each leg is driven to rotate clockwise (as viewed from the inside of the base to the outside), so that the cylindrical transmission shaft, the force-receiving gear, the power gear and the driven gear in each pipe rotate in the opposite direction to the unlocking operation, and the locking units of each pipe are driven to move toward the outside of the respective brackets, so that the locking pins of each locking unit are reinserted into the positioning holes in the positioning hole group of the previous pipe, respectively, to relock the adjacent pipes of each leg.

Thus, after the extension length and deployment angle of each leg are adjusted, the present invention can simultaneously lock all legs, including the angle at which each leg is deployed relative to the base and the length at which each leg is extended, by simply rotating the handle 135 back to the locked position, i.e., the right side position of the "T" shaped protrusion shown in FIG. 1.

In order to finely adjust the angle of spreading of the legs with respect to the base in the locked position of the handle, the free end of the leg angle adjustment lever 24 (see fig. 5) can be pressed against the spring force of the spring 242 to disengage the teeth 243 of the adjustment lever from the third gear wheel 19, so that the legs 2 can be freely rotated with respect to the base 1 without being restricted by the second and third gear wheels being unable to rotate.

Also, in a state where the handle is in the locked position, in order to finely adjust the protruding length of each pipe, the pressing piece of the unlocking unit thereof (see fig. 37 to 40) may be pressed, so that the traction cable drives the actuating wedge to move downward against the urging force of the urging spring, thereby pushing the locking unit toward the inside of the bracket by means of the actuating block, so that the positioning pin moves out of the positioning hole, so that the locking between the pipe and the pipe therebehind can be released.

The spike assemblies provided at the ends of the legs of a tripod according to the present invention will now be described with reference to figures 41-50.

The foot pin assembly 9 is disposed in the end tube of each leg, for example, the fourth tube 8 of the present example, and includes a support frame 91 disposed in the fourth tube of the leg to be movable up and down, a foot pin selection unit 92 disposed at a lower end portion of the support frame, a first foot pin 93 fixed to the foot pin selection unit, a second foot pin 94 fixed to the foot pin selection unit opposite to the first foot pin, a tension spring 95 having one end fixed to the support frame 91 and the other end fixed to the fourth tube, an air damping unit 96 disposed between the fourth tube and the support frame, and a foot pin assembly positioning unit 97.

The top end of the supporting frame 91 is open and is formed with a cavity 911 for inserting a cylindrical transmission shaft of a corresponding pipe fitting. In addition, channels 912 and 913 are formed inside the cavity 911, into which the first and second cylindrical transmission shafts 281 and 282 are inserted, respectively. The size of each channel is slightly larger than the size of the cross section of the corresponding cylindrical transmission shaft, so that the cylindrical transmission shaft can freely rotate and freely enter and exit in the channels. At the same time, since the dimensions of the channels are only slightly greater than the dimensions of the cross section of the cylindrical drive shaft, when the tripod is stowed and stored horizontally, the corresponding cylindrical drive shaft is inserted into the channels and supported by the side walls of the channels. Therefore, the bending of the transmission shaft caused by the suspension of the tail part of the columnar transmission shaft for a long time can be avoided.

The first and second pins 93 and 94 may be made of different materials to meet different field requirements. For example, the first foot nail 93 may be made of plastic to be suitable for indoor sites; and the second pins 94 may be made of metal to be suitable for use in outdoor venues.

As shown in fig. 49, the staple selecting unit 92 includes: a bearing platform 921 rotatably disposed at the lower end of the supporting frame 91, and the first pins 93 and the second pins 94 are respectively disposed at two opposite sides of the bearing platform 921; a selection plate 922 fixedly disposed at a central position of the bearing stage 921 with respect to the support frame 91 and symmetrically formed with two grooves 9221 and 9222 on a circumference thereof; and a selection spring 923 formed in a U-shape and having projections 9231 and 9232 formed at both end positions thereof toward the inside of the U-shape. The distance between the protrusions of the selection dome 923 is slightly smaller than the diameter of the selection plate 922. The middle portion of the selection spring 923 is fixed on the bearing stage 921, and its two protrusions 9231 and 9232 abut against the selection plate 922 along the diameter of the selection plate 922. Therefore, when the loading platform 921 is rotated to select the pins, the two protrusions of the selection spring 923 slide along the circumference of the selection tray 922 until the two protrusions slide into the grooves of the selection tray 922, so as to position the pins. When the pins need to be switched, the bearing table 921 is only required to be rotated by 180 degrees, so that the two protrusions of the selection spring plate 923 slide into the grooves of the opposite selection discs, and the pins are switched.

When the pins are required to be switched, the lower end of the supporting frame 91 is required to be pulled out of the fourth tube 8 of the supporting leg, and the bearing table 921 of the pin selection unit can be rotated to select the pins. When the pin conversion is completed, the tension of the tension spring 95 can pull the support frame 91 and the pin selection unit 92 carried thereon back into the fourth tube, so as to expose only the selected pin.

In order to prevent the tension spring 95 from suddenly pulling the support bracket 91 back into the fourth pipe 8 to cause injury to the user, an air damping unit 96 may be provided between the support bracket 91 and the fourth pipe 8. As shown in fig. 46 and 47, the air damping unit includes: a first cylinder 961 disposed vertically; a second cylinder 962 transversely fixed to the end of the first cylinder and communicating with the first cylinder; a piston 963 movably disposed within the first cylinder and a piston rod 964 coupled to the piston. An intake hole 9621 is formed in the second cylinder side wall; the diaphragm 9622 is disposed on the inner wall of the cylinder at a position corresponding to the intake hole 9621 to cover the intake hole. The diaphragm 9622 is fixed on the side away from the first cylinder, while the other edge is free. In addition, an outlet hole 9623 is formed in the cylinder wall of the second cylinder, and the size of the outlet hole 9623 is much smaller than that of the inlet hole 9621. Thus, when the piston 963 is drawn away from the second cylinder by the piston rod 964, air mainly enters the first and second cylinders through the intake holes 9621, so that the piston 963 can slide quickly. However, when the piston 963 is pushed by the piston rod 964 to approach the second cylinder, air in the first and second cylinders needs to be discharged, but the air to be discharged presses the diaphragm 9622 against the air inlet holes 9621, so that air cannot be discharged through the air inlet holes 9621 but can be discharged only through the air outlet holes 9623 having a small size. Thus, the piston 963 will experience a greater air resistance and will only slide slowly in its movement closer to the second cylinder.

The first cylinder and the second cylinder of the air damping unit are fixed on the fourth pipe fitting or the support frame of the foot nail component in the fourth pipe fitting, and the piston rods of the first cylinder and the second cylinder are oppositely fixed on the support frame or the fourth pipe fitting. Thus, due to the above-described working manner of the air damping unit, when the support frame is pulled out of the fourth pipe 8, the piston can be moved quickly, so that the support frame 91 can be pulled out quickly. However, when the tension spring 95 pulls the supporting frame 91 back into the fourth pipe 8, the piston is only slowly moved due to the air resistance, so that the supporting frame 91 is also only slowly moved into the fourth pipe 8, thereby performing the safety protection function.

In addition, when the staple selecting unit 92 is pulled out of the fourth pipe 8 to perform the staple conversion, in order to prevent the support frame 91 and the staple selecting unit 92 from being automatically pulled back into the fourth pipe 8 against the tensile force of the tension spring 95, a staple assembly positioning unit 97 may be provided in the fourth pipe 8. The staple module positioning unit 97 includes a positioning rod 971, a curved slot 972 formed on the supporting frame, and a spring 973 for pressing one end of the positioning rod 971 against the curved slot 972. One end of the positioning rod 971 is disposed on the fourth tube 8, and the other end is slidably engaged in the curved groove 972. This curved slot 972 is configured as a heart-shaped curved slot (see fig. 48A) comprising sequentially connected curved segments 9721, 9722, 9723 and 9724, wherein the depth of the slot at the intersection of each line segment is greater than the depth of each line segment itself, and the depth of the beginning of the latter curve segment is slightly greater than the depth of the end of the former curve segment, thereby ensuring that the end of the positioning rod 971 does not enter the wrong curve segment or slide back. Additionally, curved segment 9721 can be formed with a free end 9720 that does not intersect other curved segments. When the support bracket 91 and the staple selection unit 92 are in the fourth tube 8, the sliding end of the positioning rod 971 is at the free end 9720 of the curved section 9721. When the support bracket 91 is pulled out of the fourth tube 8, the sliding end of the positioning rod slides upward along the curved section 9721. When the support bracket 91 is fully pulled out, the sliding end slides to the first intersection between curved segments 9721 and 9722. When releasing the support 91, the support 91 is partially retracted into the fourth tube 8 of the foot due to the traction of the tension spring 95, so that the sliding end of the positioning rod 971 slides along the curved section 9722 to a second intersection between the curved section 9722 and the curved section 9723, and is in a stable state here, preventing the support 91 from being further retracted into the fourth tube 8. When the selection of the pins is completed and the support frame 91 and the pin selection unit 92 are required to be retracted into the fourth tube 8, the support frame 91 is pulled outward first, so that the sliding end of the positioning rod 971 leaves the second intersection, and reaches a third intersection between the curved segments 9723 and 9724 along the curved segment 9723, and crosses the third intersection into the curved segment 9724. At this time, the support frame 91 is released, and the entire support frame 91 and the nail selection unit 92 are retracted into the fourth pipe 8 under the traction of the tension spring 95. At the same time, the sliding end of the positioning rod 971 slides along the curved section 9724 and into the curved section 9721 and finally up to the free end 9720 of the curved section 9721, so that the support 91 and the foot nail selection unit 92 are stably retracted into the fourth tube 8.

Additionally, a bottom cap 98 may be provided at the end of the fourth tubular member 8 to close the area where the end of the fourth tubular member 8 is not closed by the staple assembly 9. The bottom cover 98 may have a channel 981 therein, which has the same structure and function as the channels 912 and 913, for receiving and carrying other cylindrical shafts, so as to prevent the shafts from bending due to the hanging of the tail portions of the cylindrical shafts for a long time. A guide hole 982 may be formed through the bottom cover 98 at the bottom of the bottom cover 98 to discharge water or foreign substances in each leg.

While various embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that further changes and modifications can be made. It is to be understood that such changes and modifications are within the spirit and scope of the present invention.

Claims (32)

1. A tripod, comprising:

a base;

three support legs which are pivotally arranged on the periphery of the base, wherein each support leg comprises a first pipe fitting and a second pipe fitting, and the second pipe fitting is telescopically sleeved in the first pipe fitting;

the first locking mechanism is arranged between the first pipe fitting and the second pipe fitting of each support leg, and locks the second pipe fitting relative to the first pipe fitting so as to prevent the second pipe fitting from moving relative to the first pipe fitting in a telescopic mode;

the three groups of transmission chains extend into the support legs from the base respectively and are coupled with the corresponding first locking mechanisms so as to drive the corresponding first locking mechanisms to lock or unlock the second pipe fitting;

the actuating mechanism is arranged in the base and synchronously coupled with the three groups of transmission chains to actuate the three groups of transmission chains, wherein the base comprises a base main body and a base outer cover buckled on the base main body; the base main body comprises a bottom basin with a concave formed on the upper surface, a vertical column extending upwards from the center of the bottom basin and three groups of brackets extending outwards from the side wall of the bottom basin at intervals; the outer cover of the base is provided with a central hole which is sleeved on the upright post;

wherein the tripod further comprises three sets of leg connectors, each leg connector being fixedly connected to the top end of the first tube of each leg and comprising a web extending vertically upwardly from an upper surface thereof, the web being pivotally connected to a respective support on the base, the actuating mechanism comprising:

a turntable formed with a central hole to be fitted over the pillar and rotatably received in the tub recess around the pillar, and formed with a plurality of teeth on a side surface of the turntable around a circumference thereof; and

an actuation assembly, comprising:

a base plate having a center hole formed therein, fitted over the column, and coupled to the turntable in such a manner as to actuate the turntable;

a pillar extending upward from the upper surface of the base plate; and

a handle pivotally connected to the top end of the support and having an outer end extending outside the outer cover of the base;

wherein, the base outer cover side wall is provided with an opening for extending the outer end of the handle and a T-shaped bulge, the handle can move from one side of the T-shaped bulge to the other side, and the first pipe fitting comprises a tubular shell with an open upper end and a open lower end; the second pipe fitting includes a tubular housing having open upper and lower ends and having the same cross-sectional shape as the first pipe fitting housing, and a bracket coupled to a top end of the second pipe fitting housing and including upper and lower support plates spaced apart from each other, the first locking mechanism includes:

the first positioning hole group is formed on the inner wall of the shell of the first pipe fitting along the length direction of the first pipe fitting and comprises a plurality of first positioning holes which are aligned up and down; and

a first locking unit orthogonally arranged in the second pipe bracket with respect to the first positioning hole group, the first locking unit including a first base plate, one end of the first base plate adjacent to the first positioning hole group being formed with at least one first positioning pin; wherein the second pipe fitting shell is provided with an opening corresponding to the position of the first positioning pin so as to allow the first positioning pin to extend out of or retract into the second pipe fitting bracket and to be inserted into or withdrawn from the first positioning hole, and each transmission chain comprises:

a first gear configured to mesh with teeth on a side of the turntable;

a first cylindrical transmission shaft coupled to an output shaft of the first gear, extending into the corresponding leg through the corresponding leg connector, and freely rotatably penetrating through the corresponding second pipe bracket; and

the first stressed gear and the first work gear are clamped between the upper supporting plate and the lower supporting plate of the corresponding second pipe fitting bracket in an up-down overlapping manner, a first traction spring is arranged between the first stressed gear and the lower supporting plate, one end of the first traction spring is fixed to the first stressed gear, and the other end of the first traction spring is fixed to the first work gear;

the first force-bearing gear is sleeved on the first cylindrical transmission shaft in a mode of being capable of longitudinally moving but not rotating relative to the first cylindrical transmission shaft, and the first work-doing gear is sleeved on the first cylindrical transmission shaft in a mode of being capable of longitudinally moving and rotating relative to the first cylindrical transmission shaft; and

wherein, the part of the first substrate of the first locking unit facing the first work gear is formed with a first rack engaged with the first work gear.

2. A tripod according to claim 1, wherein the first force-receiving gear is formed with a central aperture of rectangular cross-section and is dimensioned slightly larger than the cross-sectional dimension of the first cylindrical drive shaft.

3. A tripod according to claim 1, wherein the base tub further comprises an annular detent formed in the recess about the post, a pair of opposed stop lugs formed in the detent; the turntable comprises a pair of positioning blocks which are oppositely formed on the bottom surface of the turntable, and the positioning blocks are located in the positioning grooves; wherein a spring is provided between one of the pair of stop projections and one of the pair of positioning blocks to tend to urge the positioning block against the other of the pair of stop projections.

4. A tripod according to claim 3, wherein the upper surface of the turntable is formed with a counterbore to receive the base plate of the actuating assembly; the rotary disc also comprises a semicircular guide groove formed in the counter bore around the central hole of the rotary disc; the actuating assembly further comprises a guide block extending downwards from the bottom surface of the bottom plate, the guide block is located in the guide groove, a pair of springs are arranged in the guide groove, and two ends of each spring respectively abut against one end of the guide groove and the guide block so as to tend to enable the bottom plate of the actuating assembly to be in a middle balance position.

5. A tripod according to claim 1, wherein the base further comprises a base inner cover clamped between the base body and the base outer cover and snapped onto the base plate of the actuating assembly; the inner cover of the base is provided with a central hole which is sleeved on the upright post and the pillar; the base inner cover is formed with an annular receiving groove at its bottom periphery for receiving the first gear.

6. A tripod according to claim 5, wherein the tripod further comprises a dust cover disposed between the outer and inner base covers and pressed against the handle from above, the dust cover comprising an opening through which the upright passes and a pivot about which the dust cover pivots; the outer base cover and the inner base cover are respectively provided with an upper support member and a lower support member which are buckled with each other to support the pivot;

wherein, this dustproof upper cover still includes the backing sheet that extends from this pivot in the direction that deviates from this dustproof upper cover opening, is provided with the spring between this backing sheet and this lower support, and this spring tends to upwards push this backing sheet to this dustproof upper cover is pressed and is leaned on this handle.

7. A tripod according to claim 5, wherein said tripod further comprises a pair of arcuate dust-proof side plates disposed around the inner wall of said base outer cover, said dust-proof side plates being disposed on either side of said handle and slidably seated in an annular groove formed in the top surface of said base inner cover;

the dustproof side plates are respectively pulled by the springs, and two ends of each spring are respectively fixed on the side part, far away from the handle, of the corresponding dustproof side plate and the base outer cover, so that the dustproof side plates tend to be pressed against the handle from two sides of the handle respectively.

8. A tripod according to claim 5, wherein the output shaft of each first gear extends beyond the base and is engaged with the first cylindrical drive shaft by a pair of pawls.

9. A tripod according to claim 8, wherein the pair of pawls are six-pawl pawls.

10. A tripod according to claim 8, wherein a semi-cylindrical upper shield is formed at a position of the side portion of the base corresponding to the first gear output shaft, a semi-cylindrical lower shield fitted in the upper shield is provided at each leg connecting member, and the pair of pawls are located in the shield cavities formed by the upper and lower shields.

11. A tripod according to claim 1, wherein the first tube housing further comprises a stop formed at a bottom of an inner wall thereof; the second pipe fitting further comprises a first stop unit and a first thrust spring which are arranged in the second pipe fitting bracket; the first stop unit is pivotally arranged in the second pipe bracket at one end and comprises a first stop bulge which extends outwards towards the second pipe bracket and is aligned with the stop block; the first thrust spring has one end abutting against the second pipe bracket and the other end abutting against the first stopper unit so as to tend to push the first stopper projection out of the opening formed in the second pipe housing corresponding to the first stopper projection.

12. The tripod of claim 1, wherein each leg of the tripod further comprises a first unlocking unit for unlocking the second tube with respect to the first tube, the first unlocking unit comprising: a first traction unit arranged at the lower part of the second pipe fitting shell; a first actuating block disposed between the first rack and the first positioning pin on the first locking unit first base plate; a first actuating wedge disposed in the second tube carrier and movable up and down adjacent to the first actuating block; a first thrust spring, the two ends of which respectively abut against the second tube bracket and the first actuating wedge, so as to tend to push the first actuating wedge away from the first actuating block; and a first traction cable having one end fixed to the first actuating wedge and the other end fixed to the first traction unit through the second tube housing.

13. The tripod of claim 12, wherein the first traction unit comprises: a first frame secured to an outer surface of the second tubular housing; a first rotating arm pivotally arranged on the first frame; a first pressing piece combined with the free end of the first rotating arm; wherein the first traction rope is fixed on the first pressing sheet at the first traction unit.

14. A tripod according to claim 1, wherein the tripod further comprises:

the middle shaft vertically penetrates through the base and can move up and down relative to the base; and

the middle shaft locking device is sleeved on the middle shaft to lock the middle shaft relative to the base.

15. A tripod according to claim 14, wherein the pillar is formed with a central aperture; the middle shaft is sleeved in the central hole of the upright post, and the upper end of the middle shaft is provided with an object stage for bearing photographic equipment or other instruments.

16. A tripod according to claim 15, wherein the top surface of the object table is centrally provided with a threaded rod for attachment to the photographic equipment or other instrument, and the bottom end of the central shaft is provided with a weight hook for hanging a weight.

17. A tripod according to claim 15, wherein the bottom bracket lock comprises a lock body having a central bore with an internal thread formed on an inner wall thereof, wherein the central bore of the lock body has an upper end aperture smaller than a lower end aperture; the outer surface of the upper part of the upright post is provided with an external thread which is meshed with the internal thread; the annular wedge is disposed between the post and the bottom bracket within the central bore of the lock body.

18. A tripod according to claim 1, wherein each leg further comprises at least one third tube telescopically nested within one another and telescopically nested integrally within the second tube, each of said at least one third tubes comprising a tubular shell open at an upper and lower end and having the same cross-sectional shape as the second tube shell, and a bracket coupled to an upper end of said at least one third tube shell and including upper and lower support plates spaced from one another.

19. A tripod according to claim 18, wherein a second locking mechanism is provided between adjacent ones of the second and said at least a third tubular, which locks the inner one of said adjacent tubular with respect to the outer one thereof to prevent telescopic movement of the inner one with respect to the outer one; the second locking mechanism includes:

the second positioning hole group is formed on the inner wall of the shell of the external pipe fitting in the adjacent pipe fittings along the length direction of the support leg and comprises a plurality of second positioning holes which are aligned up and down, wherein two directly adjacent positioning hole groups in the first positioning hole group and the second positioning hole group are arranged in a staggered mode; and

a second locking unit which is arranged in the bracket of the pipe fitting in the inner part of the adjacent pipe fittings in an orthogonal way with the second positioning hole group and comprises a second base plate, and one end of the second base plate adjacent to the second positioning hole group is provided with at least one second positioning pin; and the outer shell of the external pipe fitting in the adjacent pipe fittings is provided with an opening corresponding to the position of the second positioning pin, so that the second positioning pin extends out of or retracts into the bracket where the second positioning pin is positioned and is inserted into or withdrawn from the second positioning hole.

20. A tripod according to claim 19, wherein each drive chain further comprises:

at least one group of second stressed gear and second work gear, wherein each group of second stressed gear and second work gear are respectively clamped between the upper and lower support plates of the bracket of the pipe fitting positioned inside the adjacent pipe fitting in an up-down overlapping manner, a second traction spring is arranged between the upper and lower support plates, one end of the second traction spring is fixed on the second stressed gear, and the other end of the second traction spring is fixed on the second work gear;

each driven gear is respectively clamped between the upper supporting plate and the lower supporting plate of the bracket of the external pipe fitting in the adjacent pipe fittings and is meshed with the corresponding first stressed gear or the second stressed gear;

the second cylindrical transmission shafts are respectively connected with a driven gear arranged in an outer pipe fitting in the adjacent pipe fitting and a second stressed gear and a second working gear arranged in an inner pipe fitting in the adjacent pipe fitting;

the driven gear is sleeved on the second cylindrical transmission shaft in a mode that the driven gear cannot move longitudinally relative to the corresponding second cylindrical transmission shaft and cannot rotate; the second stressed gear is sleeved on the second cylindrical transmission shaft in a mode of being capable of longitudinally moving but not rotating relative to the corresponding second cylindrical transmission shaft, and the work gear is sleeved on the first cylindrical transmission shaft in a mode of being capable of longitudinally moving and rotating relative to the corresponding second cylindrical transmission shaft;

wherein a portion of the second base plate of the second locking unit facing the corresponding second work gear is formed with a second rack engaged with the corresponding second work gear; and

and through holes aligned with the first cylindrical transmission shaft and the at least one second cylindrical transmission shaft are formed in the brackets of the inner pipe fittings of the adjacent pipe fittings so as to allow the first cylindrical transmission shaft and the at least one second cylindrical transmission shaft to be inserted.

21. A tripod according to claim 20, wherein the outer shell of an outer one of said adjacent tubes further comprises a stop hole formed in a bottom of a sidewall thereof; the inner one of the adjacent pipe fittings further comprises a second stop unit and a second thrust spring which are arranged in the bracket of the adjacent pipe fitting; the second stop unit is pivotally arranged at one end in the bracket of the inner one of the adjacent pipe fittings and comprises a second stop bulge which extends outwards towards the bracket of the inner one of the adjacent pipe fittings and is aligned with the stop hole; the second thrust spring has one end abutting against the bracket of the tube inside of the adjacent tubes and the other end abutting against the second stopper unit to tend to push the second stopper projection out of the opening formed in the housing of the tube inside of the adjacent tubes corresponding to the second stopper projection.

22. A tripod according to claim 20, wherein each leg of the tripod further comprises a second unlocking unit for unlocking an inner one of said adjacent tubes with respect to an outer one of said adjacent tubes, the second unlocking unit comprising: a second drawing unit disposed at a lower portion of the pipe housing at an inner portion among the adjacent pipes; a second actuating block disposed between the second rack and the second positioning pin on the second substrate of the second locking unit; a second actuating wedge disposed in the bracket of an inner one of the adjacent tubes and movable up and down adjacent to the second actuating block; a second thrust spring, the two ends of which respectively abut against the bracket of the inner one of the adjacent tubes and the second actuating wedge, so as to tend to push the second actuating wedge away from the second actuating block; and a second traction cable having one end fixed to the second actuating wedge and the other end fixed to the second traction unit through an inner one of the adjacent tubulars.

23. The tripod of claim 22, wherein the second traction unit comprises: a second frame secured to an outer surface of the pipe casing inwardly of the adjacent pipes; a second rotating arm pivotally arranged on the second frame; a second pressing piece combined with the free end of the second rotating arm; wherein the second traction rope is fixed on the second pressing sheet at the second traction unit.

24. A tripod according to any one of claims 1-23, wherein the tripod further comprises three sets of leg angle adjustment units respectively disposed between the base and each leg connector to selectively lock the respective leg relative to the base against pivoting relative to the base; the three sets of leg angle adjustment units are coupled to the actuating assembly to unlock the respective legs relative to the base upon actuation of the actuating assembly.

25. A tripod according to claim 24, wherein each set of brackets includes two spaced apart cantilevers; the side wall of the rotating disc is provided with an opening in the range limited by each bracket; an annular concave surface is formed on the outer side of the lower surface of the turntable, and three sections of racks which are spaced from each other are formed on the concave surface corresponding to the opening of the side wall of the turntable; wherein, each stabilizer blade angle adjusting unit includes:

the second gear is rotatably arranged between the cantilevers of the corresponding brackets and is meshed with the corresponding rack of the rotary disc through the opening on the side wall of the corresponding rotary disc;

a third gear rotatably disposed between the cantilevers of the bracket outside the second gear and engaged with the second gear; and

the support leg angle adjusting rod is pivotally connected to the corresponding support leg connecting piece at one end close to the inner side of the support leg, and the end close to the outer side of the support leg is a free end; a plurality of teeth are formed at the part facing the third gear to be meshed with the third gear; and its portion facing the corresponding leg joint is spring-supported so as to tend to push the teeth of the leg angle adjustment lever against the third gear.

26. A tripod according to claim 25, wherein the tripod further comprises a spike assembly provided at each end of each leg, each spike assembly comprising: a support frame; a foot nail selecting unit arranged at the lower end part of the supporting frame; a first pin and a second pin fixed to the pin selecting unit to face each other; a tension spring with one end fixed on the support frame and the other end fixed on the support leg; the air damping unit and the foot nail component positioning unit are arranged between the support frame and the support leg.

27. A tripod according to claim 26, wherein the first and second pins are each made of different materials.

28. A tripod according to claim 27, wherein the pin selection unit comprises:

the bearing table is rotatably arranged below the support frame and bears the first foot nail and the second foot nail at two opposite sides of the bearing table;

a selection disc which is fixedly arranged at the central position of the bearing table relative to the support frame and is symmetrically provided with two grooves on the circumference along the diameter of the selection disc; and

the selection elastic sheet is formed into a U shape, and protrusions facing the inside of the U shape are formed at the two tail ends of the selection elastic sheet, wherein the distance between the protrusions of the selection elastic sheet is slightly smaller than the diameter of the selection disc, the middle part of the selection elastic sheet is fixed on the bearing table, and the two protrusions of the selection elastic sheet abut against the circumference of the selection disc.

29. A tripod according to claim 28, wherein the air damping unit comprises:

the first air cylinder is arranged along the length direction of each support leg;

the second cylinder is transversely fixed at the tail end of the first cylinder and is communicated with the first cylinder, an air inlet hole and an air outlet hole are formed in the side wall of the second cylinder, and the size of the air outlet hole is far smaller than that of the air inlet hole;

a piston slidably disposed within the first cylinder;

a piston rod connected to the piston; and

the diaphragm covers the air inlet hole on the inner wall of the second cylinder, one side of the diaphragm, which is far away from the first cylinder, is fixed, and the other edges of the diaphragm are free;

wherein, the first cylinder is fixed on one of the support leg and the support frame, and the piston rod is connected on the other one of the support leg and the support frame.

30. A tripod according to claim 29, wherein the pin assembly positioning unit comprises a positioning rod, a curved slot formed on the supporting frame, and a spring for pressing one end of the positioning rod against the curved slot; one end of the positioning rod is arranged on the supporting frame, and the other end of the positioning rod is combined in the curve groove in a sliding way; the curve groove is a heart-shaped curve groove formed by a plurality of curve segments, the depth of the intersection of each adjacent curve segment is slightly larger than the depth of the curve segment, and the depth of the starting position of the next curve segment is slightly larger than the depth of the ending position of the previous curve segment.

31. A tripod according to claim 26, wherein the top end of the supporting frame is open and is formed with a cavity for the insertion of said first cylindrical driving shaft and/or said second cylindrical driving shaft, a plurality of first channels are formed in the cavity, the first channels are respectively used for the first cylindrical transmission shaft and/or the second cylindrical transmission shaft to be inserted, wherein the first channel is dimensioned to be slightly larger than the dimension of the cross section of the first cylindrical drive shaft and/or the second cylindrical drive shaft, namely, the first cylindrical transmission shaft and/or the second cylindrical transmission shaft can freely rotate and freely enter and exit in the corresponding first channel respectively, and when the tripod is folded up and stored horizontally, the first cylindrical transmission shaft and/or the second cylindrical transmission shaft are inserted into the corresponding first channel and supported by the side wall of the first channel.

32. A tripod according to claim 31, wherein a bottom cover is provided at the region of each leg distal end not closed by the foot pin assembly, a plurality of second channels being provided in the bottom cover, said second channels being respectively for the insertion of other ones of said first and/or second cylindrical drive shafts not inserted in said first channels, wherein said second channels are dimensioned to be slightly larger than the cross-sectional dimensions of said other cylindrical drive shafts in such a way that said other cylindrical drive shafts are respectively free to rotate and freely move in and out of the respective second channels, and said other cylindrical drive shafts are inserted in the respective second channels and are carried by the side walls of the second channels when the tripod is stowed for lying storage.