CN108937263B

CN108937263B - Drawing board centre gripping and slewing mechanism

Info

Publication number: CN108937263B
Application number: CN201810892786.0A
Authority: CN
Inventors: 王逸妍
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-08-07
Filing date: 2018-08-07
Publication date: 2020-05-22
Anticipated expiration: 2038-08-07
Also published as: CN108937263A

Abstract

The invention discloses a drawing board clamping and rotating mechanism which comprises a first supporting rod, an upper clamping plate, a central rod, a second supporting rod, a first cross rod, a third supporting rod, a second cross rod and a lower clamping plate. The upper plate comprises a first upper plate, a first roller, a first connecting rod, a second upper plate, a fixing rod, a limiting shaft, a second roller and a second connecting rod. The lower plate comprises a first lower plate, a second lower plate, a third roller, a limiting opening, a locking device and a third connecting rod, wherein the locking device comprises a button, a limiting block, a first sliding claw, a compression block, a second sliding claw, a guide rail, a first spring, a shell and an expansion rod. The mechanism is simple in structure, capable of widely adjusting the size of the clamped drawing board and widely adjusting the angle of the clamped drawing board, high in stability and small in occupied area.

Description

Drawing board centre gripping and slewing mechanism

Technical Field

The invention relates to the field of art accessories, in particular to a drawing board clamping and rotating mechanism.

Background

The art painting refers to that a static visual image is created in a two-dimensional space by using art languages such as lines, colors, shapes and the like through art means such as modeling, colors, composition and the like so as to express an art form of aesthetic feeling of an author. And the drawing board is an indispensable article for an author to create art painting. Drawing board on the market is smaller to the size control range of the drawing board of centre gripping, and the control range of the angle of centre gripping drawing board is also smaller, lacks certain stability relatively, and area is still big.

Disclosure of Invention

The invention aims to provide a drawing board clamping and rotating mechanism to solve the problems in the prior art.

In order to achieve the purpose, the invention provides the following technical scheme:

a drawing board clamping and rotating mechanism comprises a first supporting rod, an upper clamping plate, a central rod, a second supporting rod, a first cross rod, a third supporting rod, a second cross rod and a lower clamping plate; the first supporting rod, the second supporting rod are parallel to each other, the first cross rod and the second cross rod are parallel to each other, two ends of the first cross rod are respectively connected with the first supporting rod and the second supporting rod, two ends of the second cross rod are respectively connected with the first supporting rod and the second supporting rod, the central rod is connected with the first cross rod and the second cross rod and is parallel to the first supporting rod, the upper clamping plate is arranged on the central rod and is parallel to the first cross rod, the position of the upper clamping plate is higher than that of the first cross rod and the second cross rod, the upper clamping plate comprises a first upper clamping plate, a first roller, a first connecting rod, a second upper clamping plate, a fixing rod, a limiting shaft, a second roller and a second connecting rod, the second upper clamping plate is provided with the first connecting rod and the second connecting rod, the first connecting rod is parallel to the second connecting rod and slides in the first upper clamping plate through the first roller and the second roller respectively, and the fixing rod with fixed length is, the first connecting rod and the second connecting rod are connected by the fixing rod, a limiting shaft is arranged on the first upper clamping plate, the first upper clamping plate is fixed on the central rod through the limiting shaft, and a groove with the same size as the limiting shaft is arranged on the second upper clamping plate; the lower clamping plate is arranged on the second supporting plate and comprises a first lower clamping plate, a second lower clamping plate, a third roller, a limiting port, a locking device and a third connecting rod, the third connecting rod is arranged on the second lower clamping plate and slides in the first lower clamping plate through the third roller, a groove is formed in the third connecting rod, the first lower clamping plate is provided with the limiting port, and the locking device can penetrate through the limiting port to enter the groove of the third connecting port; the locking device comprises a button, a limiting block, a first sliding claw, a compression block, a second sliding claw, a guide rail, a first spring, a shell and an expansion rod, wherein the button and the limiting block are sequentially connected with the shell; the third supporting rod is connected with the central rod.

As preferred scheme, be provided with the pivot casing on well core rod, first pivot has been inlayed to the pivot casing, be provided with the connecting axle in the first pivot, be provided with the screw thread on the connecting axle, the third bracing piece includes the gasket, lower support bar and last bracing piece, go up bracing piece and connecting axle threaded connection, it is provided with the aperture to go up the same distance of every on the bracing piece, lower support bar and last bracing piece sliding connection, be provided with on the lower support bar and press the buckle, the number of pressing the buckle is the same with the aperture number on last bracing piece, the interval distance of pressing the buckle is unanimous with the aperture interval distance on last bracing piece, the gasket is connected with the lower bracing piece, the sectional area of gasket is.

As the preferred scheme, the first cross rod is movably connected with the first supporting rod and the second supporting rod, the first cross rod is provided with a second rotating shaft, a locking buckle is arranged on the second rotating shaft, the second rotating shaft penetrates through the first supporting rod, a locking ring is arranged on the first supporting rod, a plurality of grooves are formed in the locking ring, and the shape of each groove is consistent with that of a locking opening.

As the preferred scheme, be provided with the telescopic link on the second horizontal pole, the second horizontal pole passes through the telescopic link and is connected with well core rod.

Preferably, the expansion rod is connected with the compression block through a rectangular gasket, a small rod of the expansion rod is movably connected with one corner of the rectangular gasket, the compression block is movably connected with the other corner of the rectangular gasket, and the two corners are in a diagonal relationship.

As preferred scheme, punch holder and lower plate all are provided with the leather parcel, are provided with the sponge between punch holder and lower plate and the leather.

As preferred scheme, be provided with the slide rail on the well core rod, spacing axle can slide on well core rod.

Compared with the prior art, the invention has the beneficial effects that: the invention clamps the drawing board through the upper clamping plate and the lower clamping plate, the upper clamping plate and the lower clamping plate are both provided with leather packages, sponge is arranged between the upper clamping plate and the leather, the leather has certain softness and hardness, the softness can protect drawing paper on the drawing board from being pressed and prevent indentation, the hardness can prevent the drawing board from generating slight displacement, and the effect during drawing is influenced, the sponge is arranged between the upper clamping plate and the leather, the sponge has the buffer function, when the leather is used for a long time, the leather is broken by the clamping plates and comprises a first upper clamping plate and a second upper clamping plate, the second upper clamping plate is connected with the first upper clamping plate through a first connecting rod and a second connecting rod, the first connecting rod and the second connecting rod are parallel, and respectively slide in the first upper clamping plate through a first roller and a second roller, when the width of the drawing board is larger, can pull open first punch holder and second punch holder to both ends, make the centre gripping to the drawing board like this more stable, prevent the drawing board landing. Be provided with the dead lever of fixed length in the first punch holder, the dead lever couples together head rod and second connecting rod, sets up the dead lever in order to prevent to pull open first punch holder and second punch holder to both sides when, and too hard leads to head rod and second connecting rod to take place rupture, collision. Set up the spacing axle of punch holder, on the one hand be in order to can be with the punch holder setting on well core rod, on the other hand is in order to remove in the slide rail on well core rod to the height of the drawing board that the regulation can the centre gripping. Be provided with on the second punch holder with spacing axle recess that is the same with size, be for first punch holder can be when carrying out centre gripping drawing board width adjustment with the second punch holder, can hold the width of nai centre gripping drawing board littleer to make the drawing board more stable. The lower plate comprises a first lower plate and a second lower plate, the second lower plate slides in the first lower plate through a third connecting rod and a third roller, and therefore the width of the lower plate can be adjusted conveniently, and the stability of the drawing board clamping is improved. The third connecting rod is provided with a groove, the first lower clamping plate is provided with a limiting opening, and the locking device can penetrate through the limiting opening to enter the groove of the third connecting opening to lock the third connecting rod and the first lower clamping plate, so that the third connecting rod is prevented from moving relative to the first lower clamping plate. When the locking device is locked, the button is firstly pressed to push the limiting block to push the first sliding claw, the first sliding claw is provided with sawteeth matched with the second sliding claw, the first sliding claw pushes the second sliding claw and simultaneously drives the second sliding claw to rotate, the second sliding claw rotates to enter the chute of the guide rail, the chute of the guide rail is used for fixing the position of the second sliding claw, the guide rail is fixed, the second sliding claw pushes the compression block, the compression block pushes the expansion rod out of the shell while extruding the first spring, when the expansion rod is in the shell, due to the limiting effect of the shell, the two small rods are tightly leaned together to extrude the second spring, when the expansion rod pushes the shell, due to the effect of the second spring, the two small rods of the expansion rod expand outwards, the width is increased, and the expansion rod is clamped in the groove of the third connecting rod. The expansion rod is connected with the compression block through the rectangular gasket, the small rod of the expansion rod is movably connected with one corner of the rectangular gasket, the compression block is movably connected with the other corner of the rectangular gasket, the two corners are in a diagonal relationship, and the expansion rod can be fixed in the shell and can be expanded outside the shell due to the connection relationship. The third bracing piece is connected through the connecting axle on screw thread and the well core rod, is as supporting on the one hand, and on the other hand when this mechanism does not use, can dismantle, reduces to take up an area of the space. Be provided with the pivot casing on the well core rod, first pivot has been inlayed to the pivot casing, is provided with the connecting axle in the first pivot, and first pivot can drive the connecting axle and rotate and then drive the third bracing piece and rotate. The third bracing piece is provided with lower support bar and last bracing piece, it is provided with the aperture to go up every the same distance on the bracing piece, lower support bar and last bracing piece sliding connection, be provided with on the lower support bar and press the buckle, the number of pressing the buckle is the same with the aperture number on the last bracing piece, the spacing distance of pressing the buckle is unanimous with the aperture spacing distance on the last bracing piece, such setting makes the height of third bracing piece can adjust and fix. The gasket is connected with the lower support rod, and the sectional area of gasket is greater than the cross-sectional area of lower support rod, can make the third bracing piece more stable on the one hand, on the other hand. Thereby well core rod is connected with first horizontal pole and second horizontal pole, is provided with the telescopic link on the second horizontal pole, and the second horizontal pole passes through the telescopic link to be connected with well core rod, and first horizontal pole is swing joint with being connected of first bracing piece and second bracing piece, and first horizontal pole is provided with the second pivot, thereby the second pivot drives first horizontal pole and rotates and drive well core rod and rotate, thereby the angle scope of centre gripping drawing board can be adjusted to well. Be provided with the locking in the second pivot and detain, the second pivot passes first bracing piece, is provided with the locking collar on the first bracing piece, is provided with a plurality of recesses on the locking collar, and the shape of recess is unanimous with the locking mouth, and when the second pivot drove well core rod and rotated the certain position, the recess on the locking collar can be got into to the locking mouth, fixes the pivoted angle. The mechanism is simple in structure, capable of adjusting the size of the clamped drawing board widely, capable of adjusting the angle of the clamped drawing board widely, high in stability and small in occupied area.

Drawings

FIG. 1 is a schematic structural diagram of a drawing board clamping and rotating mechanism according to the present invention;

FIG. 2 is a schematic view of an upper clamping plate structure of a drawing board clamping and rotating mechanism according to the present invention;

FIG. 3 is a schematic view of a lower plate structure of a clamping and rotating mechanism for a drawing board according to the present invention;

FIG. 4 is a schematic structural diagram of a drawing board clamping and rotating mechanism according to the present invention when the locking device is unlocked;

FIG. 5 is a schematic structural diagram of a locking device of a clamping and rotating mechanism for a drawing board according to the present invention;

FIG. 6 is a schematic view of the connection structure of the expansion rod and the compression block of the drawing board clamping and rotating mechanism according to the present invention;

fig. 7 is a schematic position diagram of a telescopic rod and a central rod of the drawing board clamping and rotating mechanism according to the invention;

fig. 8 is a schematic view of a connection structure of a center rod and a third support rod of the drawing board clamping and rotating mechanism according to the present invention;

fig. 9 is a schematic view of a connection structure of a first cross bar and a first support bar of the drawing board clamping and rotating mechanism according to the present invention;

in the figure: 1-first supporting rod, 11-locking ring, 2-upper clamping plate, 21-first upper clamping plate, 22-first roller, 23-first connecting rod, 24-second upper clamping plate, 25-fixing rod, 26-limiting shaft, 27-second roller, 28-second connecting rod, 3-central rod, 31-connecting shaft, 32-rotating shaft shell, 33-first rotating shaft, 4-second supporting rod, 5-first cross rod, 51-second rotating shaft, 52-locking buckle, 6-third supporting rod, 61-gasket, 62-lower supporting rod, 63-pressing buckle, 64-upper supporting rod, 7-second cross rod, 71-telescopic rod, 8-lower clamping plate, 81-first lower clamping plate, 82-second lower clamping plate, 83-third roller, 84-limiting opening, 85-locking device, 851-button, 852-limiting block, 853-first sliding claw, 854-compression block, 855-second sliding claw, 856-guide rail, 857-first spring, 858-shell, 859-expansion rod, 86-third connecting rod, 8 a-second spring and 8 b-rotary buckle.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 9, in an embodiment of the present invention, a palette clamping and rotating mechanism includes a first supporting rod 1, an upper clamp 2, a central rod 3, a second supporting rod 4, a first cross rod 5, a third supporting rod 6, a second cross rod 7, and a lower clamp 8; the first support rod 1, the second support rod 4 are parallel to each other, the first cross rod 5 and the second cross rod 7 are parallel to each other, two ends of the first cross rod 5 are respectively connected with the first support rod 1 and the second support rod 4, two ends of the second cross rod 7 are respectively connected with the first support rod 1 and the second support rod 4, the central rod 3 is connected with the first cross rod 5 and the second cross rod 7 and is parallel to the first support rod 1, the upper clamp plate 2 is arranged on the central rod and is parallel to the first cross rod 5, the position of the upper clamp plate is higher than that of the first cross rod 5 and the second cross rod 7, the upper clamp plate 2 comprises a first upper clamp plate 21, a first roller 22, a first connecting rod 23, a second upper clamp plate 24, a fixing rod 25, a limiting shaft 26, a second roller 27 and a second connecting rod 28, the second upper clamp plate 24 is provided with the first connecting rod 23 and the second connecting rod 28, the first connecting rod 23 is parallel to the second connecting rod, the first upper clamping plate 21 slides in the first upper clamping plate 21 through a first roller 22 and a second roller 27 respectively, a fixed rod 25 with a fixed length is arranged in the first upper clamping plate 21, the fixed rod 25 connects a first connecting rod 23 and a second connecting rod 28, a limiting shaft 26 is arranged on the first upper clamping plate 21, the first upper clamping plate 21 is fixed on the central rod 3 through the limiting shaft 26, and a groove with the same size as the limiting shaft 26 is arranged on the second upper clamping plate 24; the lower clamp plate 8 is arranged on the second support rod 4 and comprises a first lower clamp plate 81, a second lower clamp plate 82, a third roller 83, a limiting opening 84, a locking device 85 and a third connecting rod 86, the second lower clamp plate 82 is provided with the third connecting rod 86, the third connecting rod 86 slides in the first lower clamp plate 81 through the third roller 83, the third connecting rod 86 is provided with a groove, the first lower clamp plate 81 is provided with the limiting opening 84, and the locking device 85 can penetrate through the limiting opening 84 and enter the groove of the third connecting rod 86; the locking device 85 comprises a button 851, a limiting block 852, a first sliding claw 853, a compression block 854, a second sliding claw 855, a guide rail 856, a first spring 857, a housing 858 and an expansion rod 859, wherein the button 851 and the limiting block 852 are sequentially connected with the housing 858, the first sliding claw 853, the second sliding claw 855, the guide rail 856, the compression block 854 and the expansion rod 859 are sequentially connected in the housing 858, the housing 858 is provided with a small hole for the expansion rod 859 to go in and out, the first sliding claw 853 and the second sliding claw 855 are provided with sawteeth matched with each other, the guide rail 856 is externally provided with a sliding groove, the interior of the guide rail 856 is hollow, the compression block 854 penetrates through the guide rail 856 to be connected with the second sliding claw, the expansion rod 859 comprises two small rods and a second spring 8a, and the second spring 8a is arranged between the two small rods 855; the third support bar 6 is connected with the central bar 3.

Be provided with pivot casing 32 on well core rod 3, pivot casing 32 has inlayed first pivot 33, be provided with connecting axle 31 on the first pivot 33, be provided with the screw thread on the connecting axle 31, third bracing piece 6 includes gasket 61, lower support rod 62 and last bracing piece 64, it is connected with connecting axle 31 threaded connection to go up bracing piece 64, it is provided with the aperture to go up the same distance of every turn on the bracing piece 64, lower support rod 62 and last bracing piece 64 sliding connection, 62 is provided with on the lower support rod and presses buckle 63, the number of pressing buckle 63 is the same with the aperture number on last bracing piece 64, the spacing distance of pressing buckle 63 is unanimous with the aperture spacing distance on last bracing piece 64, gasket 61 is connected with lower support rod 62, the sectional area of gasket 61 is greater than the sectional area of lower support.

The first cross rod 5 is movably connected with the first supporting rod 1 and the second supporting rod 4, the first cross rod 5 is provided with a second rotating shaft 51, a locking buckle 52 is arranged on the second rotating shaft 51, the second rotating shaft 51 penetrates through the first supporting rod 1, a locking ring 11 is arranged on the first supporting rod 1, a plurality of grooves are formed in the locking ring 11, and the shapes of the grooves are consistent with those of the locking buckle 52.

The second cross rod 7 is provided with an expansion link 71, and the second cross rod 7 is connected with the central rod 3 through the expansion link 71.

The expansion rod 859 is connected with the compression block 854 through a rectangular gasket 8b, the small rod of the expansion rod 859 is movably connected with one corner of the rectangular gasket 8b, the compression block 854 is movably connected with the other corner of the rectangular gasket 8b, and the two corners are in a diagonal relationship.

The upper splint 1 and the lower splint 8 are both provided with leather packages, and sponges are arranged between the upper splint 1 and the lower splint 8 and the leather.

The central rod 3 is provided with a slide rail, and the limiting shaft 26 can slide on the central rod 3.

The working principle of the invention is as follows: the invention clamps the drawing board through the upper clamping plate and the lower clamping plate, the upper clamping plate 2 and the lower clamping plate 8 are both provided with leather packages, and the sponge is arranged between the upper clamping plate 2 and the leather and between the lower clamping plate 8 and the leather, because the leather has certain softness and hardness, the softness can protect drawing paper on the drawing board from being pressed and prevent indentation, the hardness can prevent the drawing board from slightly displacing and influencing the effect during drawing, and the sponge is arranged between the upper clamping plate 2 and the leather and between the lower clamping plate 8 and the leather to protect the leather, has a buffering effect and prevents the leather from being broken by the clamping plates during long-term use. The punch holder 2 includes first punch holder 21 and second punch holder 24, second punch holder 24 is connected with first punch holder 21 through first connecting rod 23 and second connecting rod 28, first connecting rod 23 is parallel with second connecting rod 28, and slide in first punch holder 21 through first gyro wheel 22 and second gyro wheel 27 respectively, when the width ratio of drawing board is great, can pull open first punch holder 21 and second punch holder 24 to both ends, make the centre gripping to the drawing board more stable like this, prevent the drawing board landing. The fixing rod 25 with fixed length is arranged in the first upper clamping plate 21, the fixing rod 25 connects the first connecting rod 23 and the second connecting rod 28, and the fixing rod 25 is arranged to prevent the first connecting rod 23 and the second connecting rod 28 from being broken and collided due to the fact that force is too strong when the first upper clamping plate 21 and the second upper clamping plate 24 are pulled away towards two sides. The limiting shaft 26 of the upper clamping plate 2 is arranged on one hand to enable the upper clamping plate 2 to be arranged on the central rod 3, and on the other hand to be capable of moving in a sliding rail on the central rod 3, so that the height of the drawing board capable of being clamped can be adjusted. The second upper clamp 24 is provided with a groove with the same size as the limiting shaft 26, so that the width of the clamping-resistant drawing board can be smaller when the first upper clamp 21 and the second upper clamp 24 are used for clamping the drawing board for width adjustment, and the drawing board is more stable. The lower clamp plate 8 comprises a first lower clamp plate 81 and a second lower clamp plate 82, and the second lower clamp plate 82 slides in the first lower clamp plate 81 through a third connecting rod 86 and a third roller 83, so that the width of the lower clamp plate 8 can be conveniently adjusted, and the stability of clamping the drawing board is improved. The third connecting rod 86 is provided with a groove, the first lower clamping plate 81 is provided with a limiting opening 84, and the locking device 85 can penetrate through the limiting opening 84 to enter the groove of the third connecting rod 86, so that the third connecting rod 86 and the first lower clamping plate 81 are locked, and the third connecting rod 86 is prevented from moving relative to the first lower clamping plate 81. When the locking device 85 is locked, firstly, the button 851 is pressed to push the limiting block 852 to push the first sliding claw 853, the first sliding claw 853 is provided with saw teeth matched with the second sliding claw 855, the first sliding claw 853 pushes the second sliding claw 855 while driving the second sliding claw 855 to rotate, the second sliding claw 855 rotates to enter a chute of the guide rail 856, the chute of the guide rail 856 is used for fixing the position of the second sliding claw 855, the guide rail 856 is fixed, the second sliding claw 855 pushes the compression block 854, the compression block 854 pushes the first spring 857 and simultaneously pushes the expansion rod 859 out of the housing 858, when the expansion rod 859 is in the housing 858, due to the restraining action of the housing 858, the two small rods are brought close together, compressing the second spring 8a, as the spreader bar 859 is pushed out of the housing 858, due to the second spring 8a, the two small rods of the expansion rod 859 expand outward, and the width thereof becomes large, thereby being caught in the groove of the third connecting rod 86. The expansion rod 859 is connected with the compression block 854 through a rectangular gasket, a small rod of the expansion rod 859 is movably connected with one corner of the rectangular gasket, the compression block 854 is movably connected with the other corner of the rectangular gasket, the two corners are in a diagonal relationship, and the expansion rod 859 can be fixed in the shell 858 and can be expanded outside the shell 858 due to the connection relationship. The third support rod 6 is connected with the connecting shaft 31 on the central rod 3 through threads, on one hand, the third support rod serves as a support, and on the other hand, when the mechanism is not used, the third support rod can be detached, so that the occupied space is reduced. Be provided with pivot casing 858 on well core rod 3, pivot casing 858 has inlayed first pivot 33, is provided with connecting axle 31 on the first pivot 33, and first pivot 33 can drive connecting axle 31 and rotate and then drive third bracing piece 6 and rotate. The third bracing piece 6 is provided with lower support bar 62 and last bracing piece 64, it is provided with the aperture to go up every the same distance on bracing piece 64, lower support bar 62 and last bracing piece 64 sliding connection, be provided with on the lower support bar 62 and press buckle 63, the number of pressing buckle 63 is the same with the aperture number on last bracing piece 64, the interval distance of pressing buckle 63 is unanimous with the aperture interval distance on last bracing piece 64, such setting up makes the height of third bracing piece 6 can adjust and fix. The gasket 61 is connected with the lower support rod 62, and the sectional area of the gasket 61 is larger than that of the lower support rod 62, so that the third support rod 6 is more stable on one hand, and on the other hand. Well core rod 3 is connected with first horizontal pole 5 and second horizontal pole 7, be provided with telescopic link 71 on the second horizontal pole 7, second horizontal pole 7 passes through telescopic link 71 and is connected with well core rod 3, first horizontal pole 5 is swing joint with being connected of first bracing piece 1 and second bracing piece 4, first horizontal pole 5 is provided with second pivot 51, thereby second pivot 51 drives first horizontal pole 5 and rotates and drive well core rod 3 and rotate, be provided with locking button 52 in the second pivot 51, second pivot 51 passes first bracing piece 1, be provided with locking ring 11 on the first bracing piece 1, be provided with a plurality of recesses on the locking ring 11, the shape of recess is unanimous with locking button 52, when second pivot 51 drives well core rod 3 and rotates a certain position, locking button 52 can get into the recess on locking ring 11, fix the pivoted angle.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. The utility model provides a drawing board centre gripping and slewing mechanism which characterized in that: the mechanism comprises a first supporting rod (1), an upper clamping plate (2), a central rod (3), a second supporting rod (4), a first cross rod (5), a third supporting rod (6), a second cross rod (7) and a lower clamping plate (8); the supporting device comprises a first supporting rod (1), a second supporting rod (4) and a first cross rod (5) and a second cross rod (7), wherein the first supporting rod (1) and the second supporting rod (4) are parallel to each other, two ends of the first cross rod (5) are respectively connected with the first supporting rod (1) and the second supporting rod (4), two ends of the second cross rod (7) are respectively connected with the first supporting rod (1) and the second supporting rod (4), a central rod (3) is connected with the first cross rod (5) and the second cross rod (7) and is parallel to the first supporting rod (1), an upper clamping plate (2) is arranged on the central rod and is parallel to the first cross rod (5), the position of the upper clamping plate is higher than that of the first cross rod (5) and the second cross rod (7), and the upper clamping plate (2) comprises a first upper clamping plate (21), a first rolling wheel (22), a first connecting rod (23), a second upper clamping plate (24), a fixing rod (25), The clamping device comprises a limiting shaft (26), a second roller (27) and a second connecting rod (28), wherein the second upper clamping plate (24) is provided with a first connecting rod (23) and a second connecting rod (28), the first connecting rod (23) is parallel to the second connecting rod (28) and slides in the first upper clamping plate (21) through a first roller (22) and the second roller (27), a fixing rod (25) with fixed length is arranged in the first upper clamping plate (21), the fixing rod (25) connects the first connecting rod (23) with the second connecting rod (28), the first upper clamping plate (21) is provided with the limiting shaft (26), the first upper clamping plate (21) is fixed on the central rod (3) through the limiting shaft (26), and the second upper clamping plate (24) is provided with a groove a with the same size as the limiting shaft (26); the lower clamping plate (8) is arranged on the second supporting rod (4) and comprises a first lower clamping plate (81), a second lower clamping plate (82), a third roller (83), a limiting opening (84), a locking device (85) and a third connecting rod (86), the third connecting rod (86) is arranged on the second lower clamping plate (82), the third connecting rod (86) slides in the first lower clamping plate (81) through the third roller (83), a groove b is formed in the third connecting rod (86), the first lower clamping plate (81) is provided with the limiting opening (84), and the locking device (85) can penetrate through the limiting opening (84) to enter the groove b of the third connecting rod (86); the locking device (85) comprises a button (851), a limiting block (852), a first sliding claw (853), a compression block (854), a second sliding claw (855), a guide rail (856), a first spring (857), a shell (858) and an expansion rod (859), wherein the button (851), the limiting block (852) and the shell (858) are sequentially connected, the first sliding claw (853), the second sliding claw (855), the guide rail (856), the compression block (854) and the expansion rod (859) are sequentially connected in the shell (858), a small hole a for the expansion rod (859) to go in and out is arranged on the shell (858), sawteeth which are matched with each other are arranged on the first sliding claw (853) and the second sliding claw (855), a sliding groove is arranged outside the guide rail (856), the interior of the guide rail (856) is hollow, the compression block (854) penetrates through the guide rail (856) to be connected with the second sliding claw (855), and the expansion rod (859) comprises two small rods and the second spring (8 a), the second spring (8 a) is arranged between the two small rods; the third supporting rod (6) is connected with the central rod (3);

the improved structure is characterized in that a rotating shaft shell (32) is arranged on the central rod (3), a first rotating shaft (33) is embedded in the rotating shaft shell (32), a connecting shaft (31) is arranged on the first rotating shaft (33), threads are arranged on the connecting shaft (31), the third supporting rod (6) comprises a gasket (61), a lower supporting rod (62) and an upper supporting rod (64), the upper supporting rod (64) is in threaded connection with the connecting shaft (31), small holes b are arranged on the upper supporting rod (64) at the same interval, the lower supporting rod (62) is in sliding connection with the upper supporting rod (64), pressing buckles (63) are arranged on the lower supporting rod (62), the number of the pressing buckles (63) is the same as that of the small holes b on the upper supporting rod (64), and the interval distance of the pressing buckles (63) is the same as that of the small holes b on the upper supporting rod (64), the gasket (61) is connected with the lower support rod (62), and the sectional area of the gasket (61) is larger than that of the lower support rod (62);

the first cross bar (5) is movably connected with the first supporting rod (1) and the second supporting rod (4), the first cross bar (5) is provided with a second rotating shaft (51), the second rotating shaft (51) is provided with a locking buckle (52), the second rotating shaft (51) penetrates through the first supporting rod (1), the first supporting rod (1) is provided with a locking ring (11), the locking ring (11) is provided with a plurality of grooves c, and the shapes of the grooves c are consistent with those of the locking buckle (52);

the second cross rod (7) is provided with a telescopic rod (71), and the second cross rod (7) is connected with the central rod (3) through the telescopic rod (71);

the expansion rod (859) is connected with the compression block (854) through a rectangular gasket (8 b), a small rod of the expansion rod (859) is movably connected with one corner of the rectangular gasket (8 b), the compression block (854) is movably connected with the other corner of the rectangular gasket (8 b), and the two corners are in a diagonal relationship;

the upper clamping plate (2) and the lower clamping plate (8) are both provided with leather packages, and sponge is arranged between the upper clamping plate (2) and the leather packages and between the lower clamping plate (8) and the leather packages;

the central rod (3) is provided with a slide rail, and the limiting shaft (26) can slide on the central rod (3).