A lifting stand for projector

Abstract

The present invention relates to the technical field of stage machinery, and in particular to a lifting frame for a projector, comprising a main frame body, a lifting rod, a lower mounting seat and a projector, wherein a spherical cavity is arranged inside the lower mounting seat, a ball head connecting piece is fixedly arranged on the upper end surface of the projector, the ball head connecting piece is movably arranged in the spherical cavity, a locking assembly is arranged inside the lower mounting seat, the lower mounting seat is connected to a side baffle, and a group of main baffles are arranged outside the side baffles for front and back shielding of the projector; an air bag is arranged on a side of each group of side baffles close to the projector; the present invention ensures that the projector can adaptively perform balance adjustment during the lifting process, keeps itself stable, reduces shaking and vibration, effectively avoids damage to mechanical parts caused by imbalance, and prolongs the service life of the equipment.

Description

Technical Field

[0001] The invention relates to the technical field of stage machinery, in particular to a lifting frame for a projector. Background Art

[0002] Projectors are widely used in modern conferences, education, and entertainment to project images, videos, and data. A projector lift is a device that allows the projector to be raised or lowered when needed, which can effectively save space and improve the convenience of using the projector.

[0003] At present, there are some products of projector lifting stand, which include a bracket, a lifting device and a control system. During installation, the bracket is fixed on the roof by a lifting screw, and the bracket is used to carry the projector. The lifting device generally uses a hydraulic cylinder or an electric push rod to realize the lifting of the bracket.

[0004] However, during actual lifting, a single electric push rod is used to maintain the lifting movement of the projector. On the one hand, it cannot provide sufficient support and stability, especially when carrying a heavy projector. This may cause shaking and instability during the lifting process, causing the projected image to tilt. On the other hand, it will also limit the angle adjustment range of the projector and cannot meet the needs of some special occasions. Summary of the invention

[0005] The object of the present invention is to provide a lifting stand for a projector to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a lifting frame for a projector, comprising a main frame, a lifting rod, a lower mounting seat and a projector, wherein the upper end of the lifting rod is fixedly connected to the main frame, the lower end of the lifting rod is fixedly connected to the lower mounting seat, a spherical cavity opening downward is provided inside the lower mounting seat, a ball head connector is fixedly provided on the upper end surface of the projector, the ball head connector is movably installed in the spherical cavity, and a locking assembly is provided inside the lower mounting seat for pressing and positioning the ball head connector;

[0007] A set of side baffles are fixedly connected to the left and right sides of the lower mounting seat, and a set of main baffles are arranged outside each set of side baffles. The two sets of main baffles are driven by a linkage assembly and perform 90° forward and reverse rotation on the lower mounting seat to block the projector from front to back;

[0008] An airbag is arranged on the side of each set of side baffles close to the projector, a through hole is opened at the lower end of the airbag, an access tube is inserted in the through hole, the end of the access tube away from the through hole is fixedly connected to the piston cylinder, the piston cylinder is arranged in the side baffle, a piston block is movably installed inside the piston cylinder, the upper end of the piston block is fixedly connected to the piston rod, the piston rod is driven by the pushing assembly to move up and down in a straight line, and the locking assembly, the pushing assembly and the linkage assembly are all powered by the main driving device.

[0009] Preferably, a placement cavity for accommodating the main drive device is opened inside the lower mounting seat, and the main drive device includes two groups of vertical push plates, an H-shaped push frame and a drive screw. The H-shaped push frame is limitedly slidably installed in the placement cavity, and the drive screw is horizontally placed in the placement cavity and driven to rotate by a motor.

[0010] Preferably, an internal threaded hole for accommodating a driving screw is opened in the middle of the H-shaped push frame, three toggle columns are fixedly connected to the left and right ends of the H-shaped push frame, one end of the vertical push plate is fixedly connected to the driving plate, and the other end of the vertical push plate extends into the side baffle and is fixedly connected to multiple vertical push rods.

[0011] Preferably, the driving plate is provided with three groups of linearly distributed inclined grooves, each group of inclined grooves is inserted with a toggle column, and a group of lateral pressure plates is provided under each group of driving plates, one end of the lateral pressure plate is fixedly connected to the vertical push plate, and the other end of the lateral pressure plate is in contact with the locking assembly, and one end of the vertical push plate close to the H-shaped push frame is fixedly connected to a driven rack, and the driven rack is connected to the linkage assembly.

[0012] Preferably, 3-5 vertical push rods are provided, each of which is connected to a group of pushing components, and the pushing components include a movable rack, a driving gear and a fixed rack. The fixed rack is fixedly arranged in the side baffle, and the movable rack is limitedly slidably installed in the side baffle, and the lower end of the movable rack is fixedly connected to the piston rod, and an articulated seat is rotatably installed outside the driving gear, and the articulated seat is fixedly connected to the vertical push rod, one end of the driving gear is meshedly connected to the fixed rack, and the other end of the driving gear is meshedly connected to the movable rack.

[0013] Preferably, the locking assembly includes a vertical push ring, a No. 1 spring, a driven push bar, a movable block, a No. 2 spring and a clamping block. Both sides of the upper end of the vertical push ring are in contact with a group of lateral pressure plates. Six groups of No. 1 springs are fixedly arranged on the lower end surface of the vertical push ring. The vertical push ring is limitedly slidably installed in the lower mounting seat.

[0014] Preferably, the moving blocks are arranged in four groups, and the four groups of moving blocks are distributed in a circular array about the ball head connector. One end of the moving block is fixedly connected to a No. 2 spring, and the other end of the moving block is fixedly connected to a clamping block, and the end of the clamping block close to the ball head connector is arranged to be an arc surface.

[0015] Preferably, a wedge-shaped cavity opening upward is provided inside the moving block, and a group of driven push bars are inserted into each group of wedge-shaped cavities, and one end of the driven push bars away from the moving block is fixedly connected to the vertical push ring.

[0016] Preferably, the linkage assembly includes a spur gear and a rotating shaft, the rotating shaft is mounted on a lower mounting seat for limited rotation, a spur gear is fixedly sleeved on the middle portion of the rotating shaft, and the spur gear is meshedly connected to a driven rack.

[0017] Preferably, the two ends of the rotating shaft extend outward from the lower mounting seat, the upper end of the main shield plate is fixedly sleeved on the rotating shaft, and the main shield plate is a door-shaped plate.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention provides a ball head connector as a movable connection between the projector and the lower mounting seat, replacing the existing rigid connection method, ensuring that the projector can adaptively adjust its balance during the lifting process, maintain its own stability, reduce shaking and vibration, and effectively avoid damage to mechanical parts caused by imbalance, extend the service life of the equipment and improve the projection effect.

[0020] 2. The structure of the present invention is ingenious. By arranging the driving plate, the inclined slot, the toggle column, the H-shaped push frame and the driving screw rod for use together, the single driving force of the motor can be simultaneously converted into the linear up and down motion of the two sets of vertical push plates; the vertical push plates can also synchronously convert their own linear motion into the driving force of the linkage assembly, the locking assembly and the pushing assembly through the driven rack, the lateral pressure plate and the vertical push rod, so that the multiple components can quickly make appropriate adjustment actions according to the use status of the projector, and the mechanical linkage is strong, ensuring the stability and safety of the projector.

[0021] 3. By setting up a movable rack, a driving gear and a fixed rack, the line spacing of the vertical push rod can be doubled and used to push the piston rod, so that the piston block can quickly fill the gas in the piston cylinder into the airbag. The inflated airbag can cover and press the outside of the projector, and provide an isolation buffer effect during the lifting process of the projector, further reducing the risk of shaking and vibration of the equipment.

[0022] 4. By setting up a vertical push ring, a No. 1 spring, a driven push bar and a wedge-shaped cavity for use, the linear driving force of the lateral pressure plate can be converted into synchronous radial movement of multiple groups of moving blocks, so that the pressing block can adaptively press or loosen the ball head connector, so that when the projector is raised or lowered, the ball head connector can move freely on the lower mounting seat, and when the projector is stationary, the ball head connector is limited and fixed on the lower mounting seat.

[0023] 5. By setting up two sets of main shields that can perform 90° flipping movements and working with side shields, they can be opened or closed appropriately according to the use status of the projector, so that while ensuring the normal operation of the projector, it can also be shielded and protected in time, further extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a three-dimensional schematic diagram of the structure of the present invention.

[0025] Figure 2 It is a schematic diagram of another viewing angle of the structure of the present invention.

[0026] Figure 3 This is a schematic diagram of the main shield of the present invention in an unfolded state.

[0027] Figure 4 It is a schematic cross-sectional view of the lower mounting seat in the present invention.

[0028] Figure 5 The figure is a connection diagram of the projector, the ball head connector and the airbag of the present invention.

[0029] Figure 6 It is a connection diagram of the projector, the ball head connector and the locking assembly in the present invention.

[0030] Figure 7 It is a schematic diagram of the airbag, main driving device and propulsion assembly in the present invention.

[0031] Figure 8 It is a schematic diagram of the main driving device in the present invention.

[0032] Fig. 9 It is a schematic diagram of the vertical push plate, airbag and push assembly in the present invention.

[0033] Fig.10 It is a schematic diagram of the connection between the airbag, the piston cylinder and the pushing assembly in the present invention.

[0034] In the figure: main frame 1, lifting rod 2, lower mounting seat 3, side baffle 4, main baffle 5, projector 6, ball head connector 7, airbag 8, access tube 9, piston cylinder 10, piston block 11, piston rod 12, movable rack 13, driving gear 14, vertical push rod 15, fixed rack 16, vertical push plate 17, driven rack 18, spur gear 19, rotating shaft 20, lateral pressure plate 21, drive plate 22, inclined groove 23, toggle column 24, H-shaped push frame 25, drive screw 26, vertical push ring 27, No. 1 spring 28, driven push strip 29, moving block 30, wedge-shaped cavity 31, No. 2 spring 32, clamping block 33. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figures 1 to 10 The present invention provides a technical solution: a lifting frame for a projector, comprising a main frame body 1, a lifting rod 2, a lower mounting seat 3 and a projector 6, wherein the upper end of the lifting rod 2 is fixedly connected to the main frame body 1, the lower end of the lifting rod 2 is fixedly connected to the lower mounting seat 3, a spherical cavity opening downward is provided inside the lower mounting seat 3, a ball head connector 7 is fixedly provided on the upper end surface of the projector 6, the ball head connector 7 is movably installed in the spherical cavity, and a locking assembly is provided inside the lower mounting seat 3 for pressing and positioning the ball head connector 7;

[0037] A set of side baffles 4 are fixedly connected to the left and right sides of the lower mounting seat 3, and a set of main baffles 5 are arranged outside each set of side baffles 4. The two sets of main baffles 5 are driven by a linkage assembly and perform 90° forward and reverse rotation on the lower mounting seat 3 to shield the projector 6 from the front and back.

[0038] An airbag 8 is provided on the side of each set of side baffles 4 close to the projector 6. A through hole is opened at the lower end of the airbag 8, and an access tube 9 is inserted in the through hole. The end of the access tube 9 away from the through hole is fixedly connected to a piston cylinder 10. The piston cylinder 10 is arranged in the side baffle 4. A piston block 11 is movably installed inside the piston cylinder 10. The upper end of the piston block 11 is fixedly connected to a piston rod 12. The piston rod 12 is driven by a pushing assembly to move up and down in a straight line. The locking assembly, the pushing assembly and the linkage assembly are all powered by the main driving device.

[0039] Furthermore, the present invention provides a ball head connector 7 as a movable connection between the projector 6 and the lower mounting seat 3, replacing the existing rigid connection method, ensuring that the projector 6 can adaptively adjust its balance during the lifting process, maintain its own stability, reduce shaking and vibration, thereby effectively avoiding damage to mechanical parts caused by imbalance, extending the service life of the equipment and improving the projection effect.

[0040] A placement cavity for accommodating the main drive device is provided inside the lower mounting seat 3. The main drive device includes two sets of vertical push plates 17, an H-shaped push frame 25 and a drive screw 26. The H-shaped push frame 25 is limitedly slidably installed in the placement cavity, and the drive screw 26 is horizontally placed in the placement cavity and driven to rotate by a motor.

[0041] An internal threaded hole for accommodating a driving screw 26 is provided in the middle of the H-shaped push frame 25. Three toggle columns 24 are fixedly connected to both left and right ends of the H-shaped push frame 25. One end of the vertical push plate 17 is fixedly connected to a driving plate 22. The other end of the vertical push plate 17 extends into the side baffle 4 and is fixedly connected to a plurality of vertical push rods 15.

[0042] Furthermore, by setting up a driving plate 22, an inclined groove 23, a toggle column 24, an H-shaped push frame 25 and a driving screw 26 for use in combination, the single driving force of the motor can be simultaneously converted into the linear up and down movement of two groups of vertical push plates 17; the vertical push plates 17, through the driven rack 18, the lateral pressure plate 21 and the vertical push rod 15, synchronously convert their own linear motion into the driving force of the linkage component, the locking component and the pushing component, so that the multiple components can quickly make appropriate adjustment actions according to the use status of the projector 6, with strong mechanical linkage, ensuring the stability and safety of the projector 6.

[0043] Three groups of linearly distributed inclined grooves 23 are provided on the driving plate 22, and a toggle column 24 is inserted in each group of inclined grooves 23. A group of lateral pressure plates 21 are arranged under each group of driving plates 22. One end of the lateral pressure plate 21 is fixedly connected to the vertical push plate 17, and the other end of the lateral pressure plate 21 is in contact with the locking assembly. One end of the vertical push plate 17 close to the H-shaped push frame 25 is fixedly connected to the driven rack 18, and the driven rack 18 is connected to the linkage assembly.

[0044] There are 3-5 vertical push rods 15, each of which is connected to a group of pushing components, which include a movable rack 13, a driving gear 14 and a fixed rack 16. The fixed rack 16 is fixedly arranged in the side baffle 4, and the movable rack 13 is limitedly slidably installed in the side baffle 4, and the lower end of the movable rack 13 is fixedly connected to the piston rod 12. The driving gear 14 is rotatably installed with an articulated seat on the outside, and the articulated seat is fixedly connected to the vertical push rod 15. One end of the driving gear 14 is meshedly connected to the fixed rack 16, and the other end of the driving gear 14 is meshedly connected to the movable rack 13.

[0045] Furthermore, by providing a movable rack 13, a driving gear 14 and a fixed rack 16, the line spacing of the vertical push rod 15 can be increased to twice and used to push the piston rod 12, so that the piston block 11 can quickly fill the gas in the piston cylinder 10 into the airbag 8, and the inflated airbag 8 can cover and press the outside of the projector 6, and provide an isolation and buffering effect during the lifting process of the projector 6, further reducing the risk of shaking and vibration of the equipment.

[0046] The locking assembly includes a vertical push ring 27, a No. 1 spring 28, a driven push bar 29, a moving block 30, a No. 2 spring 32 and a clamping block 33. Both sides of the upper end of the vertical push ring 27 are in contact with a group of lateral pressure plates 21. Six groups of No. 1 springs are fixedly arranged on the lower end surface of the vertical push ring 27. The vertical push ring 27 is limitedly slidably installed in the lower mounting seat 3.

[0047] There are four groups of moving blocks 30, which are distributed in a ring array about the ball head connector 7. One end of the moving block 30 is fixedly connected to a No. 2 spring 32, and the other end of the moving block 30 is fixedly connected to a clamping block 33. The end of the clamping block 33 close to the ball head connector 7 is set to an arc surface.

[0048] The moving block 30 is provided with a wedge-shaped cavity 31 opening upward inside, and a group of driven push bars 29 are inserted into each group of wedge-shaped cavities 31 . One end of the driven push bars 29 away from the moving block 30 is fixedly connected to the vertical push ring 27 .

[0049] Furthermore, by setting a vertical push ring 27, a No. 1 spring 28, and a driven push bar 29 for use in conjunction with the wedge-shaped cavity 31, the linear driving force of the lateral pressure plate 21 can be converted into synchronous radial movement of multiple groups of moving blocks 30, so that the clamping block 33 can adaptively clamp or loosen the ball head connector 7, so that when the projector 6 is raised or lowered, the ball head connector 7 can move freely on the lower mounting seat 3, and when the projector 6 is stationary, the ball head connector 7 is limited and fixed on the lower mounting seat 3.

[0050] The linkage assembly includes a spur gear 19 and a rotating shaft 20 . The rotating shaft 20 is mounted on the lower mounting seat 3 for limited rotation. The middle part of the rotating shaft 20 is fixedly sleeved with the spur gear 19 , and the spur gear 19 is meshedly connected to the driven rack 18 .

[0051] The two ends of the rotating shaft 20 extend outward from the lower mounting seat 3 , and the upper end of the main shield plate 5 is fixedly sleeved on the rotating shaft 20 , and the main shield plate 5 is a door-shaped plate.

[0052] Furthermore, by providing two groups of main shielding plates 5 that can perform a 90° flipping movement and are used in conjunction with the side shielding plates 4, they can be opened or closed appropriately according to the use status of the projector 6, so that while the normal operation of the projector 6 is ensured, it can also be shielded and protected in time, further extending the service life of the equipment.

[0053] When the present invention is actually used: the main frame 1 is fixed on the roof by four lifting screws, and then the lower mounting seat 3 is driven to move downward by opening the lifting rod 2. During this process, the ball head connector 7 moves freely in the ball cavity, and the inflated air bag 8 is close to the projector 6 for buffering, so that the projector 6 is not affected by the vibration or deviation of the lifting rod 2 and always keeps falling steadily; and after falling to the target position, the motor is turned on, thereby driving the driving screw 26 to rotate, and under the screwing action of the internal and external threads, the H-shaped push frame 25 is forced to drive the toggle columns 24 at both ends to move in the direction away from the motor, and the toggle columns 24 act on the inclined groove 23, so that the driving plate 22 is forced to drive the vertical push plate 17 to move upward; the driven rack 18, the vertical push rod 15 and the lateral pressure plate 21 on the vertical push plate 17 all move upward together;

[0054] In this process, the vertical push rod 15 that moves upward acts on the driving gear 14, and the driving gear 14 moves upward and rotates under the cooperation of the fixed rack 16, thereby pushing the moving rack 13 to drive the piston rod 12 to move upward with twice the line spacing of the vertical push rod 15, and the piston block 11 quickly moves to the upper end of the cylinder cavity of the piston cylinder 10, so that the internal gas of the airbag 8 enters the piston cylinder 10 through the access tube 9, and the airbag 8 returns to its original state and no longer covers and presses the projector 6. At this time, the projector 6 quickly adjusts to a balanced state under the action of its own gravity;

[0055] Next, the upward driven rack 18 acts on the spur gear 19, so that the rotating shaft 20 drives the main baffle 5 to flip upward 90°, thereby exposing the projector 6 and enabling it to start the projection effect normally; and the upward lateral pressure plate 21 releases the squeezing effect on the vertical push ring 27, so that the vertical push ring 27 drives the driven push strip 29 to move upward under the action of the No. 1 spring 28, and the upward driven push strip 29 releases the effect on the wedge-shaped cavity 31, so that the moving block 30 moves toward the direction of the ball head connector 7 under the elastic force of the No. 2 spring 32, so that the multiple sets of clamping blocks 33 quickly lock the ball head connector 7, so that the projector 6 can ensure the balance of its own body and can also be adjusted to an appropriate angle according to needs, thereby greatly improving the user experience and operating convenience, and has a high practical value.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lifting stand for a projector, comprising a main frame (1), a lifting rod (2), a lower mounting seat (3) and a projector (6), characterized in that: The upper end of the lifting rod (2) is fixedly connected to the main frame (1), and the lower end of the lifting rod (2) is fixedly connected to the lower mounting seat (3). The lower mounting seat (3) is provided with a spherical cavity opening downward. The upper end surface of the projector (6) is fixedly provided with a ball head connector (7). The ball head connector (7) is movably installed in the spherical cavity. A locking assembly is provided inside the lower mounting seat (3) for pressing and positioning the ball head connector (7). A set of side baffles (4) are fixedly connected to both left and right sides of the lower mounting seat (3); a set of main baffles (5) are arranged outside each set of side baffles (4); the two sets of main baffles (5) are driven by a linkage assembly and perform 90° forward and reverse rotation on the lower mounting seat (3) to shield the projector (6) from front and back; An air bag (8) is arranged on a side of each set of side baffles (4) close to the projector (6), a through hole is opened at the lower end of the air bag (8), an access tube (9) is inserted into the through hole, an end of the access tube (9) away from the through hole is fixedly connected to a piston cylinder (10), the piston cylinder (10) is arranged in the side baffle (4), a piston block (11) is movably installed inside the piston cylinder (10), the upper end of the piston block (11) is fixedly connected to a piston rod (12), and the piston rod (12) is driven by a pushing assembly to move up and down in a straight line The locking assembly, the pushing assembly and the linkage assembly are all powered by the main drive device; a placement cavity for accommodating the main drive device is provided inside the lower mounting seat (3); the main drive device comprises two sets of vertical push plates (17), an H-shaped push frame (25) and a driving screw (26); the H-shaped push frame (25) is limitedly slidably installed in the placement cavity; the driving screw (26) is horizontally placed in the placement cavity and driven to rotate by a motor; the linkage assembly comprises a spur gear (19) and a rotating shaft (20); the rotating shaft (20) is limitedly rotated The H-shaped push frame (25) is movably mounted on the lower mounting seat (3), the middle part of the rotating shaft (20) is fixedly sleeved with a spur gear (19), and the spur gear (19) is meshedly connected to the driven rack (18); the middle part of the H-shaped push frame (25) is provided with an internal threaded hole for accommodating a driving screw (26), and the left and right ends of the H-shaped push frame (25) are fixedly connected with three toggle columns (24), one end of the vertical push plate (17) is fixedly connected with a driving plate (22), and the other end of the vertical push plate (17) extends into the side baffle (4) and is fixedly connected with a plurality of vertical push rods (15) The driving plate (22) is provided with three groups of linearly distributed inclined grooves (23), each group of inclined grooves (23) is plugged with a toggle column (24), and a group of lateral pressure plates (21) are arranged below each group of driving plates (22), one end of the lateral pressure plate (21) is fixedly connected to the vertical push plate (17), and the other end of the lateral pressure plate (21) is in contact with the locking assembly, and one end of the vertical push plate (17) close to the H-shaped push frame (25) is fixedly connected to a driven rack (18), and the driven rack (18) is connected to the linkage assembly.

2. The lifting stand for a projector according to claim 1, characterized in that: The vertical push rods (15) are provided with 3 to 5 pieces, each of which is connected to a group of pushing components, the pushing components comprising a movable rack (13), a driving gear (14) and a fixed rack (16), the fixed rack (16) being fixedly arranged in the side baffle (4), the movable rack (13) being limitedly slidably installed in the side baffle (4), and the lower end of the movable rack (13) being fixedly connected to the piston rod (12), the driving gear (14) being rotatably installed with an articulated seat outside, the articulated seat being fixedly connected to the vertical push rod (15), one end of the driving gear (14) being meshedly connected to the fixed rack (16), and the other end of the driving gear (14) being meshedly connected to the movable rack (13).

3. The lifting stand for a projector according to claim 1, characterized in that: The locking assembly comprises a vertical push ring (27), a No. 1 spring (28), a driven push bar (29), a moving block (30), a No. 2 spring (32) and a pressing block (33); both sides of the upper end of the vertical push ring (27) are in contact with a group of lateral pressure plates (21); six groups of No. 1 springs are fixedly arranged on the lower end surface of the vertical push ring (27); and the vertical push ring (27) is limitedly slidably installed in the lower mounting seat (3).

4. The lifting stand for a projector according to claim 3, characterized in that: The moving blocks (30) are provided in four groups, and the four groups of moving blocks (30) are distributed in a ring array with respect to the ball head connecting piece (7). One end of the moving block (30) is fixedly connected to a No. 2 spring (32), and the other end of the moving block (30) is fixedly connected to a clamping block (33), and one end of the clamping block (33) close to the ball head connecting piece (7) is arranged to be an arc surface.

5. The lifting stand for a projector according to claim 4, characterized in that: The moving block (30) is provided with a wedge-shaped cavity (31) opening upward, and a group of driven push strips (29) are inserted into each group of wedge-shaped cavities (31). One end of the driven push strips (29) away from the moving block (30) is fixedly connected to the vertical push ring (27).

6. The lifting stand for a projector according to claim 1, characterized in that: The two ends of the rotating shaft (20) extend outward from the lower mounting seat (3), and the upper end of the main shielding plate (5) is fixedly sleeved on the rotating shaft (20), and the main shielding plate (5) is a door-shaped plate.

Images