Abstract:
An orthodontic self-locking bracket includes a bracket body having an arch wire bracket slot and a bracket cover matched with the bracket body. Two sides of the arch wire bracket slot are provided with work wings. A bracket opening is arranged at the intersection of the arch wire bracket slot on the bracket body, and the bracket cover is inserted into the bracket opening and is in sliding fit with the bracket body. Left side of the arch wire bracket slot is provided with a pin shaft penetrating through the bracket opening, and the pin shaft is in clamping fit with the lower part of the bracket cover, so that the arch wire bracket slot can be closed and opened by the bracket cover. The bracket is locked and unlocked only by sliding rather than overturning the bracket cover. Complex operation for ligaturing the steel wire is eliminated.

Description:
[0001]    The present application claims the priorities of Chinese Patent Application No. 201410013451.9 filed Jan. 3, 2014, Chinese Patent Application No. 201420017518.1 filed Jan. 3, 2014, Chinese Patent Application No. 201410121284.X filed Mar. 24, 2014, Chinese Patent Application No. 201410121283.5 filed Mar. 24, 2014, Chinese Patent Application No. 201410344506.4 filed Jul. 10, 2014, and Chinese Patent Application No. 201410670875.2 filed Nov. 10, 2014, under 35 U.S.C. §119, which are hereby incorporated by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to the technical field of dental orthodontics, in particular to an orthodontic self-locking bracket. 
       BACKGROUND OF THE INVENTION 
       [0003]    In the prior art, during the orthodontics, an orthodontic bracket is fixedly arranged on the dental face, an arch wire penetrates through an arch wire slot (a square wire slot) on the bracket, the arch wire is directly ligatured into the arch wire slot of the bracket by a ligature rubber ring or a ligature steel wire, and the orthodontic force of the arch wire transfers to the tooth through the bracket, so that the tooth can move prospectively, and the aim of the orthodontics can be achieved. 
         [0004]    The ligature rubber ring or the ligature steel wire in the prior art is ligatured onto a ligature wing of the bracket, the force is directly applied onto the arch wire, the higher pressure is applied onto the arch wire, and the normal movement of the arch wire is baffled, so that the orthodontic effect of the tooth can be influenced. At present, there are various self-locking brackets on the market, having two major series such as the active type and the passive type, however, the self-locking brackets are complex in structure, difficult to manufacture, high in cost, expensive in price, and hard to operate. 
       SUMMARY OF THE INVENTION 
       [0005]    Aiming at the defects in the prior art, the present invention provides an orthodontic self-locking bracket which is convenient to manufacture, simple to operate, stable and reliable. 
         [0006]    The technical solution of the present invention is realized as follows: 
         [0007]    An orthodontic self-locking bracket, comprising a bracket body having an arch wire bracket slot and a bracket cover matched with the bracket body, wherein two sides of the arch wire bracket slot are provided with work wings, a bracket opening is arranged at the intersection of the arch wire bracket slot on the bracket body, and the bracket cover is inserted into the bracket opening and is in sliding fit with the bracket body; the left side of the arch wire bracket slot is provided with a pin shaft penetrating through the bracket opening, and the pin shaft is in clamping fit with the lower part of the bracket cover, so that the arch wire bracket slot can be closed and opened by the bracket cover. 
         [0008]    Preferably, two sides of the bracket opening are symmetrically provided with the sliding chute respectively, and the bracket cover is arranged within the sliding chutes. 
         [0009]    Preferably, the sliding chutes arranged at two sides of the bracket opening are integrated into a dovetail groove, the longitudinal section of the bracket cover has the shape of swallow tail, and two sides of the bracket cover are clamped into the sliding chutes and slide along therewith. The sliding chutes are designed into the dovetail groove, and the shape and the size of the bracket cover are matched with those of the sliding chutes, so that the sliding chutes are simpler to manufacture and more smooth to slide. 
         [0010]    Preferably, the sliding chutes arranged at two sides of the bracket opening are square chutes, two ends of the bracket cover are symmetrically provided with sliding blocks of which the shapes and the sizes are matched with the those of the square chutes, and the sliding blocks are clamped into the sliding chutes and slide along therewith. The square or rectangular sliding rails are convenient to machine and smooth in sliding fit. 
         [0011]    Preferably, the upper part of the bracket cover covers on the work wing at the left side of the arch wire bracket slot, and a sliding rail face matched with the bracket cover is formed on the upper end of the work wing at the left side of the arch wire bracket slot. The space can be saved due to the structure design, so that the whole height of the bracket can be reduced. Meanwhile, the upper part of the bracket cover directly covers on the arch wire bracket slot and the work wing at the left side of the arch wire bracket slot, the upper surface of the bracket is integrated, a fractal line of the sliding chutes is unavailable, and the upper surface of the work wing at the right side of the arch wire bracket slot is level, so that the bracket is more clean and attractive in appearance integrally. 
         [0012]    Preferably, the bracket cover has the shape of “I” integrally, two sides of the bracket cover are symmetrically provided with the concave sliding chutes, the bracket opening is narrow in the upper part and wide in the lower part, two sides of the upper part of the bracket opening are symmetrically provided with two sliding rails, after the bracket cover is inserted into the bracket opening, the sliding rails are in sliding fit with the sliding chutes, and the upper part of the bracket cover covers on the arch wire bracket slot and the work wing at the left side of the arch wire bracket slot. 
         [0013]    Preferably, the bracket opening is a swallow-tail sliding chute integrally, the bracket cover comprises a bracket cover body and sliding blocks arranged under the bracket cover body to be matched with the swallow-tail sliding chute, after the bracket cover is inserted into the bracket opening, the sliding blocks are in sliding fit with the swallow-tail sliding chute, and the bracket cover body covers on the arch wire bracket slot and the work wing at the left side of the arch wire bracket slot. 
         [0014]    Preferably, the bracket cover is provided with an elastic element which is deformable after being stressed, and a clamping slot which is in clamping fit with the pin shaft is arranged on the elastic element; the pin shaft makes the elastic element to be deformed and to be in clamping fit with the different positions of the clamping slot when the bracket cover slides, and the right end of the bracket cover covers or departs from the arch wire bracket slot. The pin shaft penetrates into the shaft hole always, the pin shaft is immovable relative to the bracket body, and the bracket cover slides within the sliding chute and is further in clamping fit with the pin shaft through the elastic element provided with the clamping slot, so that the bracket cover can be in clamping fit with the pin shaft at the different positions, and the bracket cover can be opened and locked. 
         [0015]    The structure form of the elastic element has two solutions: 
         [0016]    The first solution of the elastic element is as follows, preferably, the elastic element is a hook which is deformable after being stressed at one end of the bracket cover in a bending way, the hook is inserted into the bracket opening, and the hook is internally provided with the clamping slot; the bracket cover slides left and right, so that the right end of the bracket cover covers or departs from the arch wire bracket slot, and the hook is matched with the pin shaft, so that the bracket cover can be opened and closed. The clamping slot can be named as a hook slot of the hook, and the pin shaft is placed within the hook and matched with the hook. 
         [0017]    Preferably, the clamping slot of the hook is an arc slot, the free end of the hook tilts to form into a lug boss which is in clamping fit with the pin shaft, the pin shaft is clamped into the clamping slot of the hook and is limited by the lug boss when the bracket cover is closed, the lug boss passes through the pin shaft and makes the hook to be deformed when the bracket cover is opened. 
         [0018]    Preferably, the shape and the size of the clamping slot of the hook are matched with those of the cross section of the pin shaft; and the free end of the hook titles to form into the lug boss which is in clamping fit with the pin shaft. 
         [0019]    Preferably, the hook is formed by the means that one end of the bracket cover is bent towards the bottom surface of the bracket cover at 180 degrees, the length of the hook is lengthened, so that the pin shaft can not slide out of the clamping slot, the clamping slot of the hook comprises an internal clamping slot which departs from the free end of the hook and an external clamping slot which is near to the free end of the hook, the shape and the size of the internal clamping slot are matched with those of the cross section of the pin shaft, and the height of the external clamping slot is less than the diameter of the pin shaft; the pin shaft is clamped into the internal clamping slot when the bracket cover is closed, and the pin shaft is arranged within the external clamping slot and makes the hook to be deformed when the bracket cover is opened. The height of the external clamping slot is the distance between the inner side face of the hook and the bottom surface of the bracket cover, and due to the technical solution, the length of the hook is properly lengthened, so that after the pin shaft departs from the internal clamping slot of the hook and enters into the external clamping slot, the pin shaft can be still arranged within the hook, therefore, when the bracket cover is closed, the resistance can be reduced, and the ideal object that the force is large to apply when the bracket cover is opened and the force is small to apply when the bracket cover is closed can be realized. 
         [0020]    Preferably, the hook is slantwise arranged towards the bottom surface of the bracket cover, and the size of the clamping slot of the hook is gradually reduced from inside to outside; the pin shaft is clamped into the maximum space of the clamping slot when the bracket cover is closed, and the pin shaft is arranged at the place which is near to the free end of the hook and makes the hook to be deformed when the bracket cover is opened. Therefore, the pin shaft makes the bracket cover to be locked due to the elastic force of the bracket cover, and the bracket cover is easy to reset from being opened to being closed. 
         [0021]    Preferably, an arc lug boss is arranged in the middle of the clamping slot of the hook, and the clamping slot is divided into a left clamping slot and a right slot, which can be in clamping fit with the pin shaft respectively, by the arc lug boss; 
         [0022]    when the bracket cover is rightwards pushed, the pin shaft is clamped into the left clamping slot of the hook, the hook is positioned with the pin shaft through the arc lug boss in a clamping way, the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0023]    when the bracket cover is leftwards pushed, the pin shaft is clamped into the right clamping slot of the hook, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0024]    Preferably, the clamping slot is divided into two sections, the left section is an arc slot, the right section is a straight slot, and the lowest point at the lower end of the pin shaft and the bottom of the arc slot are lower than the bottom of the straight slot; 
         [0025]    When the bracket cover is rightwards pushed, the pin shaft is clamped into the arc slot, the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0026]    When the bracket cover is leftwards pushed, the pin shaft departs from the arc slot, enters into the straight slot, and makes the hook to be deformed, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0027]    Preferably, a stop block used for stopping the pin shaft to prevent the bracket cover from sliding out of the bracket body is arranged on the bottom surface of the bracket cover, and the stop block is arranged within the bracket opening. Therefore, the bracket cover can not slide out of the bracket body when the bracket cover is opened. 
         [0028]    Preferably, the part of the right end of the bracket cover, which is used for covering the arch wire bracket slot, is configured into a thin and flat cover body. Therefore, in the case that the arc wire placing space is guaranteed, the height of the bracket body can be reduced. 
         [0029]    In order to make the whole bracket to be more attractive in appearance, based on the solution that the upper part of the bracket cover covers on the work wing at the left side of the arc wire bracket slot, preferably, the upper surface of the work wing at the left side of the arch wire bracket slot is lower than the upper surface of the work wing at the right side of the arch wire bracket slot, and when the upper part of the bracket cover covers on the work wing at the left side of the arch wire bracket slot, the upper surface of the bracket cover is in parallel with the upper surface of the work wing at the right side of the arch wire bracket slot. 
         [0030]    The second solution of the elastic element is as follows: 
         [0031]    Preferably, the clamping slot is concavely arranged on the bottom surface of the bracket cover, the elastic element is the shrapnel which is deformable after being stressed above the clamping slot, and the upper end of the pin shaft is arranged within the clamping slot and is in contacting fit with the shrapnel. 
         [0032]    Preferably, the clamping slot is divided into two sections, the left section is the arc slot of which the bottom is arc, the right section is the straight slot of which the bottom is horizontal, the highest point of the arc slot is higher than the plane where the bottom of the straight slot is placed, and the height of the plane where the bottom of the straight slot is placed is lower than the highest point of the pin shaft; the bracket cover is internally provided with a gap, the start point of the gap is placed at the right end of the clamping slot, the end point of the gap is placed above the arc slot, and the shrapnel is formed at the part surrounded by the gap and the clamping slot; 
         [0033]    When the bracket cover is rightwards pushed, the upper end of the pin shaft is clamped into the arc slot of the bracket cover, the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0034]    When the bracket cover is leftwards pushed, the arc slot of the bracket cover departs from the pin shaft, the pin shaft makes the shrapnel to be deformed and clamped into the straight slot of the bracket cover, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0035]    Preferably, the clamping slot is an arc slot integrally, a flange downwards extends out of the middle of the arc slot, the lower end of the flange is higher than the bottom surface of the bracket cover, and the arc slot is divided into a left arc slot and a right arc slot, which can be in clamping fit with the pin shaft respectively, by the flange; the bracket cover is internally provided with a gap, the start end of the gap is placed at the right end of the clamping slot, the end point of the gap is placed above the left arc slot, and a shrapnel is formed at the part surrounded by the gap and the clamping slot; the lower end of the flange is higher than the bottom surface of the bracket cover, i.e. the lower end of the flange can not exceed the bottom surface of the bracket cover; 
         [0036]    When the bracket cover is rightwards pushed, the upper end of the pin shaft is clamped into the left arc slot of the bracket cover, the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0037]    When the bracket cover is leftwards pushed, the arc slot of the bracket cover departs from the pin shaft, the pin shaft makes the shrapnel to be deformed and clamped into the right arc slot of the bracket cover, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0038]    Preferably, from right to left, the gap is arranged upwards and slantwise. 
         [0039]    Preferably, the bottom of the straight slot is arranged horizontally or slantwise. 
         [0040]    Preferably, the clamping slot is divided into two sections, the left section is the arc slot of which the bottom is arc, the right section is the straight slot of which the bottom is horizontal, the highest point of the arc slot is higher than the plane where the bottom of the straight slot is placed, and the height of the plane where the bottom of the straight slot is placed is lower than the highest point of the pin shaft; the bracket cover is internally provided with a gap, the start point of the gap is placed on the right side face of the bracket cover, the end point of the gap is placed above the arc slot, and the shrapnel is formed between the gap and the clamping slot; 
         [0041]    When the bracket cover is rightwards pushed, the upper end of the pin shaft is clamped into the arc slot of the bracket cover, the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0042]    When the bracket cover is leftwards pushed, the arc slot of the bracket cover departs from the pin shaft, the pin shaft makes the shrapnel to be deformed and clamped into the straight slot of the bracket cover, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0043]    Preferably, the clamping slot is an arc slot integrally, a flange downwards extends out of the middle of the arc slot, the lower end of the flange is higher than the bottom surface of the bracket cover, and the arc slot is divided into a left arc slot and a right arc slot, which can be in clamping fit with the pin shaft respectively, by the flange; the bracket cover is internally provided with a gap, the start end of the gap is placed on the right side face of the bracket cover, the end point of the gap is placed above the arc slot, and a shrapnel is formed between the gap and the clamping slot; 
         [0044]    When the bracket cover is rightwards pushed, the upper end of the pin shaft is clamped into the left arc slot of the bracket cover, the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0045]    When the bracket cover is leftwards pushed, the left arc slot of the bracket cover departs from the pin shaft, the pin shaft makes the shrapnel to be deformed and clamped into the right arc slot, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0046]    In order to make the bracket cover to be smoother to slide, preferably, the flange is arc. 
         [0047]    Preferably, the gap is linear, and the gap is in parallel with the bottom surface of the bracket cover basically. 
         [0048]    Preferably, the clamping slot is an arc slot integrally, a flange downwards extends out of the middle of the arc slot, the lower end of the flange is higher than the bottom surface of the bracket cover, and the arc slot is divided into a left arc slot and a right arc slot, which can be in clamping fit with the pin shaft respectively, by the flange; the bracket cover is internally provided with a kidney hole, the kidney hole is arranged above the clamping slot, and a shrapnel is formed between the kidney hole and the clamping slot; 
         [0049]    When the bracket cover is rightwards pushed, the upper end of the pin shaft is clamped into the left arc slot of the bracket cover, the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0050]    When the bracket cover is leftwards pushed, the left arc slot of the bracket cover departs from the pin shaft, the pin shaft makes the shrapnel to be deformed and clamped into the right arc slot, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0051]    In order to make the shrapnel deformation to be more easily controlled, preferably, the shape of the kidney hole is matched with that of the bottom of the clamping slot. 
         [0052]    Preferably, the lower part of the bracket cover is provided with a convex block, the convex block is inserted into a bracket opening, the bracket is arranged on the bottom surface of the convex block, and the shrapnel is arranged within the convex block. Therefore, the machining of the shrapnel is wider in machining range, the slide of the bracket cover and the deformation of the shrapnel can not be influenced with each other, and the height of the bracket body can be reduced. 
         [0053]    Preferably, the part of the right end of the bracket cover, which is used for covering the arch wire bracket slot, is configured into a thin and flat cover body. Therefore, in the case that the arc wire placing space is guaranteed, the height of the bracket body can be reduced. 
         [0054]    In order to make the whole bracket to be more attractive in appearance, preferably, a cover plate used for covering the bracket opening extends towards the middle of the bracket opening on the work wing at the right side of the arch wire bracket slot. 
         [0055]    Preferably, the work wing at the right side of the arc wire bracket slot is provided with an auxiliary correcting hole through which an auxiliary arc wire can penetrate, and the auxiliary correcting hole is in parallel with the arc wire bracket slot. Therefore, the double arc wires can be formed, so that the bracket is better in correcting effect. 
         [0056]    Preferably, the highest point of the pin shaft or the shaft hole is lower than the plane where the bottom of the sliding chute is placed. Therefore, the bracket can be installed more conveniently only by the means that the bracket cover is clamped into the sliding chutes, and the pin shaft is assembled. 
         [0057]    The installing mode of the pin shaft is as follows: preferably, the work wing at the left side of the arch wire bracket slot is provided with a shaft hole, the shaft hole is intercrossed with the bracket opening and penetrates through the bracket body, and the pin shaft penetrates into the shaft hole and penetrates through the bracket opening. 
       Industrial Applicability and Advantageous Effects 
       [0058]    The present invention adopts the structure of a sliding lock plate, the bracket cover is inserted into the bracket opening and is in sliding fit with the bracket body, the work wing at the left side of the arc wire bracket slot is provided with the pin shaft, the pin shaft penetrates into the shaft hole always, the pin shaft is immovable relative to the bracket body, and the bracket cover slides within the sliding chute and is further in clamping fit with the pin shaft through the elastic element provided with the clamping slot, so that the bracket cover can be closed or opened. 
         [0059]    Specifically, aiming at the match between the bracket cover and the bracket opening, the present invention provides two different structure forms, wherein one structure form is that two sides of the bracket opening are provided with the sliding chutes; and the other structure form is that the bracket cover covers on the upper surface of the work wing at the left side of the arc wire bracket slot, and the sliding chutes are arranged on the bracket cover. 
         [0060]    Furthermore, aiming at the elastic element, the present invention further provides two different structure forms, one structure form is the hook form, the inner side face of the hook is provided with a clamping slot or a hook slot, and the bracket cover can be closed or opened due to the match between the hook and the pin under different conditions; when the bracket cover slides left and right, the pin shaft can be matched with the different positions of the hook within the clamping slot of the hook, or the pin shaft is clamped into or departs from the clamping slot of the hook, and the right end of the bracket can depart from or cover the arc wire bracket slot, so that the bracket cover is closed or opened; the other structure form is that the bottom of the bracket cover is cut with a shrapnel, and the clamping slot is placed on the bottom surface of the shrapnel, so that along with the slide of the bracket cover, the pin shaft makes the shrapnel to be deformed and clamped into the different positions of the clamping slot, and the right end of the bracket can cover or depart from the arc wire bracket slot, therefore, the bracket cover is closed or opened. 
         [0061]    Generally, the bracket body and the bracket cover are easy to manufacture and can be formed at one time by means of linear cutting, so that the bracket is convenient to operate. Meanwhile, the bracket cover is placed within the bracket body, so that the bracket is less in volume. The bracket can be locked and unlocked only by sliding the bracket cover rather than overturning the bracket cover; in the clinical application, not only can the complex operation for ligaturing the steel wire be eliminated, but also the bracket can be conveniently operated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0062]      FIG. 1  is the structure schematic diagram of the bracket body in embodiment 1; 
           [0063]      FIG. 2  is the auxiliary view A of  FIG. 1 ; 
           [0064]      FIG. 3  is the top plan structure schematic diagram of  FIG. 1 ; 
           [0065]      FIG. 4  is the structure schematic diagram of the bracket cover in embodiment 1; 
           [0066]      FIG. 5  is the side view of  FIG. 4 ; 
           [0067]      FIG. 6  is the top plan structure schematic diagram of  FIG. 4 ; 
           [0068]      FIG. 7  is the schematic diagram of the close status of the bracket cover in embodiment 1; 
           [0069]      FIG. 8  is the schematic diagram of the sliding fit status between the bracket cover and the sliding chutes in embodiment 1; 
           [0070]      FIG. 9  is the schematic diagram of the open status of the bracket cover in embodiment 1; 
           [0071]      FIG. 10  is the structure schematic diagram of the deformation 1 of the bracket cover in embodiment 1; 
           [0072]      FIG. 11  is the schematic diagram of the open status of the deformation 1 of the bracket cover in embodiment 1; 
           [0073]      FIG. 12  is the structure schematic diagram of the deformation 2 of the bracket cover in embodiment 1; 
           [0074]      FIG. 13  is the schematic diagram of the open status of the deformation 2 of the bracket cover in embodiment 1; 
           [0075]      FIG. 14  is the structure schematic diagram of the deformation 3 of the bracket cover in embodiment 1; 
           [0076]      FIG. 15  is the schematic diagram of the open status of the deformation 3 of the bracket cover in embodiment 1; 
           [0077]      FIG. 16  is the structure schematic diagram of the deformation 4 of the bracket cover in embodiment 1; 
           [0078]      FIG. 17  is the schematic diagram of the match between the deformation 4 of the bracket cover and the pin shaft under the status that the bracket cover is closed in embodiment 1; 
           [0079]      FIG. 18  is the schematic diagram of the match between the deformation 4 of the bracket cover and the pin shaft under the status that the bracket cover is opened in embodiment 1; 
           [0080]      FIG. 19  is the structure schematic diagram of the deformation 5 of the bracket cover in embodiment 1; 
           [0081]      FIG. 20  is the schematic diagram of the match between the deformation 5 of the bracket cover and the pin shaft under the status that the bracket cover is closed in embodiment 1; 
           [0082]      FIG. 21  is the schematic diagram of the match between the deformation 5 of the bracket cover and the pin shaft under the status that the bracket cover is opened in embodiment 1; 
           [0083]      FIG. 22  is the structure schematic diagram of the bracket body in embodiment 2; 
           [0084]      FIG. 23  is the auxiliary view A of  FIG. 22 ; 
           [0085]      FIG. 24  is the top plan structure schematic diagram of  FIG. 22 ; 
           [0086]      FIG. 25  is the structure schematic diagram of the bracket cover in embodiment 2; 
           [0087]      FIG. 26  is the side view of  FIG. 25 ; 
           [0088]      FIG. 27  is the structure schematic diagram of the vertical status of  FIG. 25 ; 
           [0089]      FIG. 28  is the schematic diagram of the sliding fit status between the bracket cover and the sliding chutes in embodiment 2; 
           [0090]      FIG. 29  is the structure schematic diagram of the bracket body in embodiment 3; 
           [0091]      FIG. 30  is the A-A section view of  FIG. 29 ; 
           [0092]      FIG. 31  is the top plan structure schematic diagram of  FIG. 29 ; 
           [0093]      FIG. 32  is the structure schematic diagram of the bracket cover in embodiment 3; 
           [0094]      FIG. 33  is the auxiliary view A of  FIG. 32 ; 
           [0095]      FIG. 34  is the structure schematic diagram of the vertical status of  FIG. 32 ; 
           [0096]      FIG. 35  is the schematic diagram of the close status of the bracket cover in embodiment 3; 
           [0097]      FIG. 36  is the auxiliary view A of  FIG. 35 ; 
           [0098]      FIG. 37  is the structure schematic diagram of the bracket body in embodiment 4; 
           [0099]      FIG. 38  is the A-A section view of  FIG. 37 ; 
           [0100]      FIG. 39  is the structure schematic diagram of the bracket cover in embodiment 4; 
           [0101]      FIG. 40  is the auxiliary view A of  FIG. 39 ; 
           [0102]      FIG. 41  is the schematic diagram of the close status of the bracket cover in embodiment 4; 
           [0103]      FIG. 42  is the auxiliary view A of  FIG. 41 ; 
           [0104]      FIG. 43  is the structure schematic diagram of the bracket body in embodiment 5; 
           [0105]      FIG. 44  is the auxiliary view A of  FIG. 43 ; 
           [0106]      FIG. 45  is the top plan structure schematic diagram of  FIG. 43 ; 
           [0107]      FIG. 46  is the structure schematic diagram of the bracket cover in embodiment 5; 
           [0108]      FIG. 47  is the side view of  FIG. 46 ; 
           [0109]      FIG. 48  is the structure schematic diagram of the vertical status of  FIG. 46 ; 
           [0110]      FIG. 49  is the schematic diagram of the close status of the bracket cover in embodiment 5; 
           [0111]      FIG. 50  is the schematic diagram of the sliding fit status between the bracket cover and the sliding chutes in embodiment 5; 
           [0112]      FIG. 51  is the schematic diagram of the open status of the bracket cover in embodiment 5; 
           [0113]      FIG. 52  is the structure schematic diagram of the deformation 1 of the bracket cover in embodiment 5; 
           [0114]      FIG. 53  is the schematic diagram of the match between the deformation 1 of the bracket cover and the pin shaft under the status that the bracket cover is closed in embodiment 5; 
           [0115]      FIG. 54  is the schematic diagram of the match between the deformation 1 of the bracket cover and the pin shaft under the status that the bracket cover is opened in embodiment 5; 
           [0116]      FIG. 55  is the structure schematic diagram of the deformation 2 of the bracket cover in embodiment 5; 
           [0117]      FIG. 56  is the schematic diagram of the match between the deformation 2 of the bracket cover and the pin shaft under the status that the bracket cover is closed in embodiment 5; 
           [0118]      FIG. 57  is the schematic diagram of the match between the deformation 2 of the bracket cover and the pin shaft under the status that the bracket cover is opened in embodiment 5; 
           [0119]      FIG. 58  is the structure schematic diagram of the deformation 3 of the bracket cover in embodiment 5; 
           [0120]      FIG. 59  is the schematic diagram of the match between the deformation 3 of the bracket cover and the pin shaft under the status that the bracket cover is closed in embodiment 5; 
           [0121]      FIG. 60  is the schematic diagram of the match between the deformation 3 of the bracket cover and the pin shaft under the status that the bracket cover is opened in embodiment 5; 
           [0122]      FIG. 61  is the structure schematic diagram of the deformation 4 of the bracket cover in embodiment 5; 
           [0123]      FIG. 62  is the schematic diagram of the match between the deformation 4 of the bracket cover and the pin shaft under the status that the bracket cover is closed in embodiment 5; 
           [0124]      FIG. 63  is the schematic diagram of the match between the deformation 4 of the bracket cover and the pin shaft under the status that the bracket cover is opened in embodiment 5; 
           [0125]      FIG. 64  is the structure schematic diagram of the side face of the bracket cover in embodiment 6; 
           [0126]      FIG. 65  is the structure schematic diagram of the sliding chutes of the bracket body in embodiment 6; 
           [0127]      FIG. 66  is the schematic diagram of the sliding fit between the bracket cover and the sliding chutes in embodiment 6; 
           [0128]      FIG. 67  is the structure schematic diagram of the bracket body in embodiment 7; 
           [0129]      FIG. 68  is the A-A section view of  FIG. 67 ; 
           [0130]      FIG. 69  is the structure schematic diagram of the side face of the bracket cover in embodiment 7; 
           [0131]      FIG. 70  is the schematic diagram of the sliding fit between the bracket cover and the sliding chutes in embodiment 7; 
           [0132]      FIG. 71  is the schematic diagram of the lock status of the bracket cover within the bracket body in embodiment 7; 
           [0133]      FIG. 72  is the structure schematic diagram of the bracket body in embodiment 8; 
           [0134]      FIG. 73  is the A-A section view of  FIG. 72 ; 
           [0135]      FIG. 74  is the structure schematic diagram of the side face of the bracket cover in embodiment 8; 
           [0136]      FIG. 75  is the schematic diagram of the sliding fit between the bracket cover and the sliding chutes in embodiment 8; 
           [0137]      FIG. 76  is the schematic diagram of the lock status of the bracket cover within the bracket body in embodiment 8. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0138]    The specific embodiments of the present invention are as follows: 
       Embodiment 1 
       [0139]    An orthodontic self-locking bracket, as shown in  FIG. 1-FIG .  9 , comprising a bracket body  2  having an arch wire bracket slot  1  and a bracket cover  3  matched with the bracket body  2 , wherein two sides of the arch wire bracket slot  1  are respectively provided with work wings  4  and  5 , a bracket opening  6  is arranged at the intersection of the arch wire bracket slot  1  on the bracket body  2 , two sides of the bracket opening  6  are symmetrically provided with a sliding chute  7  respectively formed by means of linear cutting, the bracket cover  3  is put into the sliding chutes  7  and slides along with the sliding chutes  7 , the work wing  4  at the left side of the arch wire bracket slot  1  is provided with a shaft hole  8 , the shaft hole  8  is intercrossed with the bracket opening  6  and penetrates through the bracket body  2 , the shaft hole  8  is internally provided with a pin shaft  9  which penetrates through the bracket opening  6 , and the upper end of the shaft hole  8  is not higher than the bottom surfaces  70  of the sliding chutes  7 . 
         [0140]    As shown in  FIG. 2  and  FIG. 8 , the sliding chutes  7  at two sides of the bracket opening are the square chutes, two ends of the bracket cover  3  are symmetrically provided with sliding blocks  16  of which the shapes and the sizes are matched with the those of the square chutes, and the sliding blocks  16  are clamped into the sliding chutes  7  and slide along with the sliding chutes  7 . 
         [0141]    As shown in  FIG. 4 ,  FIG. 5  and  FIG. 6 , the bracket cover  3  is provided with an elastic element which is in clamping fit with the pin shaft  9 , the elastic element is a hook  10  which is deformable after being stressed at one end of the bracket cover  3  in a bending way, the hook  10  is inserted into the bracket opening  6 , the hook  10  is internally provided with the clamping slot  11 , the clamping slot  11  can be named as a hook slot as well, the clamping slot  11  is an arc slot matched with the pin shaft  9 , the preferable mode is as follows: the shape and the size of the clamping slot  11  are matched with those of the cross section of the pin shaft  9 ; and a free end  12  of the hook  10  is provided with a lug boss  15  which is in clamping fit with the pin shaft  9 . 
         [0142]    Under the structure form of the embodiment, a stop block  14  used for stopping the pin shaft to prevent the bracket cover from sliding out of the bracket body is arranged in the middle of the bottom surface  300  of the bracket cover  3 , and the stop block  14  is arranged within the bracket opening  6 . 
         [0143]    As shown in  FIG. 7  and  FIG. 8 , when the bracket cover is rightwards pushed, the pin shaft  9  is clamped into the clamping slot  11 , the hook is in positioned with the pin shaft  9  by the lug boss  15  in a clamping way, the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way. 
         [0144]    As shown in  FIG. 9 , when the bracket cover is leftwards pushed, the pin shaft  9  departs from the clamping slot  11 , the lug boss  15  is stressed to make the hook  10  to be elastically deformed when passing through the pin shaft  9 , the pin shaft  9  departs from the clamping slot  11  finally, meanwhile, the stop block  14  arranged at the bottom surface of the bracket cover  3  is stopped by the upper end of the pin shaft  9 , and the right end of the bracket cover  3  departs from the arch wire bracket slot  1  as well, so that the arch wire bracket slot  1  can be exposed, the arch wire  13  can be taken in or out, and the bracket cover  3  is opened. 
         [0145]    The part of the right end of the bracket cover  3 , which is used for covering the arch wire bracket slot  1 , is configured into a thin and flat cover body  301 , so that the arc wire placing space can enlarged, and the height of the bracket body can be reduced. 
         [0146]    The deformation 1 of the bracket cover in embodiment 1: as the improvement of the bracket cover in embodiment 1, the hook  10  is lengthened to prevent the pin shaft  9  from departing from the hook  10  at the beginning design time; as shown in  FIG. 10  and  FIG. 11 , the deformation 1 of the bracket cover is that an extension section  17  extends out of the free end  12  of the hook  10  outwards and horizontally, the width of the extension section  17  can be less than that of the hook  10 , and the inner side face of the extension section  17 , i.e. the side facing to the bottom surface  300  of the bracket cover, is in parallel with the upper end face of the lug boss  15 , so that after the pin shaft  9  departs from the clamping slot  11  of the hook  10 , the pin shaft  9  can be still placed within the hook  10 , therefore, when the bracket cover  3  is closed again, the resistance can be reduced, and the ideal object that the force is large to apply when the bracket cover is opened and the force is small to apply when the bracket cover is closed can be realized. 
         [0147]    The deformation 2 of embodiment 1: being similar to the deformation 1: as shown in  FIG. 12  and  FIG. 13 , the hook  10  is formed by the means that one end of the bracket cover is bent towards the bottom surface of the bracket cover at 180 degrees, the length of the hook  10  is lengthened, so that the pin shaft  9  can not slide out of the clamping slot, the free end  12  of the hook  10  is placed at the end of the hook, the clamping slot  11  of the hook comprises an internal clamping slot  121  which departs from the free end  12  of the hook and an external clamping slot  122  which is near to the free end  12  of the hook, the shape and the size of the internal clamping slot  121  are matched with those of the cross section of the pin shaft  9 , and the height of the external clamping slot  122 , i.e. the distance between the lower end face  1220  of the external clamping slot and the bottom surface  300  of the bracket cover, is less than the diameter of the pin shaft  9  or the lower end face  1220  of the external clamping slot  122  is higher than the lower end of the pin shaft  9 ; the pin shaft is clamped into the internal clamping slot when the bracket cover is closed, and the pin shaft is arranged within the external clamping slot and makes the hook to be deformed when the bracket cover is opened. 
         [0148]    The deformation 3 of the bracket cover in embodiment 1, as shown in  FIG. 14  and  FIG. 15 , the hook  10  is slantwise arranged towards the bottom surface  300  of the bracket cover  3 , and the size of the clamping slot  11  of the hook is gradually reduced from inside to outside; the pin shaft  9  is clamped into the maximum place of the clamping slot  11  when the bracket cover is closed, and as shown in  FIG. 15 , the pin shaft  9  is arranged at the place which is near to the free end  12  of the hook and makes the hook  10  to be deformed when the bracket cover  3  is opened. After the structure is adopted, the hook can be made to be thin, i.e. a thin elastic reed, and the bottom of the clamping slot of the hook is always contacted with the pin shaft whatever the bracket cover slides, so that the bracket cover is convenient to lock. The structure has the benefit effect that the size error of the clamping slot in the bracket cover can be amplified, so that the bracket is more convenient to manufacture. 
         [0149]    The deformation 4 of the bracket cover in embodiment 1: similarly, the hook  10  is lengthened to prevent the pin shaft  9  from departing from the hook  10  at the beginning design time, as shown in  FIG. 16 , an arc lug boss  101  is arranged in the middle of the clamping slot  11  of the hook  10 , and the clamping slot  11  is divided into a left clamping slot  111  and a right slot  112 , which can be in clamping fit with the pin shaft respectively, by the arc lug boss  101 . 
         [0150]    When the bracket cover  3  is rightwards pushed, as shown in  FIG. 17 , the pin shaft  9  is clamped into the left clamping slot  111  of the hook  10 , the hook  10  is positioned with the pin shaft  9  through the arc lug boss  101  in a clamping way, the right end of the bracket cover  3  covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0151]    when the bracket cover  3  is leftwards pushed, as shown in  FIG. 18 , the pin shaft is clamped into the right clamping slot  112  of the hook  10 , and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0152]    The deformation 5 of the bracket cover in embodiment 1: the difference between the deformation 5 and the deformation 4 is as follows, as shown in  FIG. 19  and  FIG. 20 , the clamping slot  11  is divided into two sections, the left section is an arc slot  113 , the right section is a straight slot  114 , and the lowest point at the lower end of the pin shaft  9  and the bottom of the arc slot  113  are lower than the bottom of the straight slot  114 ; the free end  12  of the hook is provided with the stop block  123  for preventing the pin shaft  9  from departing from the hook. 
         [0153]    When the bracket cover is rightwards pushed, as shown in  FIG. 20 , the pin shaft  9  is clamped into the arc slot  113 , the right end of the bracket cover covers the arch wire bracket slot, and the bracket cover is locked in a closing way; 
         [0154]    when the bracket cover is leftwards pushed, as shown in  FIG. 21 , the pin shaft  9  departs from the arc slot  113 , enters into the straight slot  114 , and makes the hook  10  to be deformed, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
       Embodiment 2 
       [0155]    the embodiment focuses on the deformation of the sliding fit mode between the bracket cover and the bracket body, being different from the structure that the sliding chutes are the square chutes in embodiment 1, as shown in  FIG. 22-FIG .  28 , the sliding chutes  7  arranged at two sides of the bracket opening  7  are integrated into a dovetail groove, two sides of the bracket cover  3  are provided with the swallow-tail sliding blocks  33  of which the shapes and the sizes are matched with those of the dovetail groove, and two sides of the bracket cover  3  are clamped into the sliding chutes  7  and slide along with the sliding chutes  7 . In the present invention, the highest point of the shaft hole  8  is lower than the plane where the bottoms  70  of the sliding chutes are placed. 
       Embodiment 3 
       [0156]    as shown in  FIG. 29-FIG .  36 , as the other deformation of the sliding fit mode between the bracket cover and the bracket body, as shown in  FIG. 32-FIG .  33 , the bracket cover  3  has the shape of “I” integrally, two sides of the bracket cover  3  are symmetrically provided with the concave sliding chutes  7 . As shown in  FIG. 30 , the bracket opening  6  is narrow in the upper part and wide in the lower part, two sides of the upper part of the bracket opening  6  are symmetrically provided with two sliding rails  41  which extend towards the middle of the bracket opening  6 , after the bracket cover  3  is inserted into the bracket opening  6 , the sliding rails  41  are clamped into the sliding chutes  7 , the sliding rails  41  are in sliding fit with the sliding chutes  7 , and the upper part  31  of the bracket cover covers on the arch wire bracket slot  1  and the work wing  4  at the left side of the arch wire bracket slot. 
         [0157]    The upper surface  42  of the work wing  4  at the left side of the arch wire bracket slot is lower than the upper surface  52  of the work wing  5  at the right side of the arch wire bracket slot, and when the upper part  31  of the bracket cover covers on the work wing  4  at the left side of the arch wire bracket slot, as shown in  FIG. 35 , the upper surface  32  of the bracket cover  3  is in parallel with the upper surface  52  of the work wing  5  at the right side of the arch wire bracket slot. 
       Embodiment 4 
       [0158]    being different from embodiment 3, as shown in  FIG. 37-FIG .  42 , the bracket opening  6  is a swallow-tail sliding chute  7  integrally, similarly, the bracket opening  6  is narrow in the upper part and wide in the lower part, the bracket cover  3  comprises a bracket cover body  34  and sliding blocks  16  arranged under the bracket cover body  34  to be matched with the swallow-tail sliding chute  7 , after the bracket cover  3  is inserted into the bracket opening  6 , the sliding blocks  16  are in sliding fit with the swallow-tail sliding chute  7 , and the bracket cover body  34  covers on the arch wire bracket slot  1  and the work wing  4  at the left side of the arch wire bracket slot  1 . 
         [0159]    The upper end of the bracket cover covers on the work wing at the left side of the arc wire bracket slot in embodiment 3 and embodiment 4, and the structure design has the greatest advantage: in the case that the height of the bracket is not heightened, the upper end of the bracket cover is configured to completely cover the arc wire bracket slot and the bracket body at the left side of the arc wire bracket slot, and the upper end of the bracket body at the right side of the arc wire bracket slot is sealed and is in parallel with the upper surface of the bracket cover, so that the whole upper surface of the bracket is integrated and covers all the slots, therefore, the cleanliness and the aesthetics of the bracket can be greatly improved. 
       Embodiment 5 
       [0160]    the embodiment focuses on the difference between the structure form of the elastic element in embodiment 5 and that in embodiment 1, an orthodontic self-locking bracket of the embodiment 5, as shown in  FIG. 43-FIG .  51 , comprising a bracket body  2  having an arch wire bracket slot  1  and a bracket cover  3  matched with the bracket body  2 , wherein two sides of the arch wire bracket slot  1  are respectively provided with work wings  4  and  5 , a bracket opening  6  is arranged at the intersection of the arch wire bracket slot  1  on the bracket body  2 , two sides of the bracket opening  6  are symmetrically provided with a sliding chute  7  respectively formed by means of linear cutting, the bracket cover  3  is arranged within the sliding chutes  7  in a sliding way, the work wing  4  at the left side of the arch wire bracket slot  1  is provided with a shaft hole  8 , the shaft hole  8  is intercrossed with the bracket opening  6  and penetrates through the bracket body  2 , the shaft hole  8  is internally provided with a pin shaft  9  which penetrates through the bracket opening  6 , and the upper end of the shaft hole  8  is not higher than the bottom surfaces  70  of the sliding chutes  7 . 
         [0161]    As shown in  FIG. 44  and  FIG. 50 , the sliding chutes  7  at two sides of the bracket opening are the square chutes, two ends of the bracket cover  3  are symmetrically provided with sliding blocks  16  of which the shapes and the sizes are matched with the those of the square chutes, and the sliding blocks  16  are clamped into the sliding chutes  7  and slide along with the sliding chutes  7 . 
         [0162]    As shown in  FIG. 47-FIG .  48 , the bracket cover  3  is provided with an elastic element which is in clamping fit with the pin shaft  9 , specifically, the lower part of the bracket cover  3  is provided with a convex block  35 , the convex block  35  is arranged in the middle at the bottom surface of the bracket cover  3 , the convex block  35  is inserted into the bracket opening  6 , the bottom surface  300  of the convex block  35  or the bracket cover  3  are concavely provided with a clamping slot  11  matched with the pin shaft  9 , the elastic element is a shrapnel  36  which is deformable after being stressed above the clamping slot  11 , the shrapnel  36  is arranged within the convex block  35 , and the upper end of the pin shaft  9  is arranged within the clamping slot  11  and is in contacting fit with the shrapnel  36 . 
         [0163]    It should be noted that, the part of the right end of the bracket cover  3 , which is used for covering the arch wire bracket slot  1 , is configured into a thin and flat cover body  301 , therefore, the arc wire placing space can be enlarged, and the height of the bracket body can be reduced. 
         [0164]    As shown in  FIG. 46 , the clamping slot  11  is an arc slot integrally, a flange  29  downwards extends out of the middle of the arc slot, and the lower end of the flange  29  is higher than the bottom surface  300  of the bracket cover, i.e. the lower end of the flange  29  can not exceed the bottom surface  300  of the bracket cover; the flange  29  is arc integrally, the arc slot is divided into a left arc slot  117  and a right arc slot  118 , which can be in clamping fit with the pin shaft respectively, by the flange  29 . 
         [0165]    As shown in  FIG. 49 , when the bracket cover  3  is rightwards pushed, the upper end of the pin shaft  9  is clamped into the left arc slot  117  of the bracket cover, and the bracket cover is locked in a closing way. 
         [0166]    As shown in  FIG. 51 , when the bracket cover  3  is leftwards pushed, the arc slot  117  of the bracket cover departs from the pin shaft  9 , the pin shaft  9  makes the shrapnel  33  to be deformed and clamped into the right arc slot  118  when passing through the flange  29 , the right end of the bracket cover departs from the arch wire bracket slot  1  as well, and the bracket cover is opened. 
         [0167]    The deformation 1 of embodiment 5: as the improvement of the bracket cover or the clamping slot in embodiment 5, as shown in  FIG. 52 , the clamping slot  11  is divided into two section, the left section is the arc slot  115  of which the bottom is arc, the right section is the straight slot  116  of which the bottom is horizontal, the highest point of the arc slot  115  is higher than the plane where the bottom of the straight slot  116  is placed, and the height of the plane where the bottom of the straight slot  116  is placed is lower than the highest point of the pin shaft  9  or the shaft hole  8 ; specifically, the shrapnel  36  is formed as follows, the bracket cover  3  is internally provided with a gap  24 , the start point of the gap  24  is placed at the right end of the clamping slot  11 , i.e. the right-most end of the straight slot  116 , the end point of the gap  24  is placed above the arc slot  115 , and the shrapnel  36  is formed at the part surrounded by the gap  24  and the clamping slot  11 ; from right to left, the gap  24  is arranged slantwise and upwards. 
         [0168]    As shown in  FIG. 53 , the pin shaft  9  is immovable, when the bracket cover  3  is rightwards pushed, the pin shaft  9  is clamped into the arc slot  115  of the bracket cover  3 , the right end of the bracket cover covers the arc wire bracket slot  1 , and the bracket cover  3  is locked in a closing way. 
         [0169]    As shown in  FIG. 54 , the pin shaft  9  is immovable, when the bracket cover  3  is leftwards pushed, the arc slot  115  of the bracket  3  departs from the pin shaft  9 , the pin shaft  9  makes the shrapnel  36  to be deformed and clamped into the straight slot  116  of the bracket cover, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0170]    The deformation 2 of the bracket cover in embodiment 5: as shown in  FIG. 55 , the clamping slot  11  is divided into two section, the left section is the arc slot  115  of which the bottom is arc, the right section is the straight slot  116  of which the bottom is horizontal, the highest point of the arc slot  115  is higher than the plane where the bottom of the straight slot  116  is placed, and the height of the plane where the bottom of the straight slot  116  is placed is lower than the highest point of the pin shaft; the bracket cover  3  is internally provided with a gap  24 , the start point of the gap  24  is placed on the right side face  302  of the bracket cover  3 , the end point of the gap  24  is placed above the arc slot  115 , and the shrapnel  36  is formed between the gap  24  and the clamping slot  11 ; 
         [0171]    As shown in  FIG. 56 , the pin shaft  9  is immovable, when the bracket cover  3  is rightwards pushed, the upper end of the pin shaft  9  is clamped into the arc slot  115  of the bracket cover, the right end of the bracket cover covers the arc wire bracket slot, and the bracket cover is locked in a closing way; 
         [0172]    As shown in  FIG. 57 , the pin shaft  9  is immovable, when the bracket cover is leftwards pushed, the arc slot  115  of the bracket departs from the pin shaft  9 , the pin shaft  9  makes the shrapnel  36  to be deformed and clamped into the straight slot of the bracket cover, and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0173]    The deformation 3 of the bracket cover in embodiment 5: as shown in  FIG. 58 , the clamping slot  11  is an arc slot integrally, a flange  29  downwards extends out of the middle of the arc slot, the lower end of the flange  29  is higher than the bottom surface  300  of the bracket cover, and the arc slot is divided into a left arc slot  117  and a right arc slot  118 , which can be in clamping fit with the pin shaft respectively, by the flange  29 ; the bracket cover is internally provided with a gap  24 , the start point of the gap  24  is placed on the right side face  302  of the bracket cover  3 , the end point of the gap is placed above the left arc slot  117 , and the shrapnel  36  is formed between the gap and the clamping slot; the gap  24  is linear, and the gap is in parallel with the bottom surface of the bracket cover basically. 
         [0174]    As shown in  FIG. 59 , the pin shaft  9  is immovable, when the bracket cover is rightwards pushed, the upper end of the pin shaft  9  is clamped into the left arc slot  117  of the bracket cover, the right end of the bracket cover covers the arc wire bracket slot, and the bracket cover is locked in a closing way; 
         [0175]    As shown in  FIG. 60 , when the bracket cover is leftwards pushed, the arc slot  117  of the bracket cover departs from the pin shaft  9 , the pin shaft  9  makes the shrapnel  36  to be deformed and clamped into the right arc slot  118 , and the right end of the bracket cover departs from the arch wire bracket slot as well, so that the arch wire bracket slot can be exposed, the arch wire can be taken in or out, and the bracket cover is opened. 
         [0176]    The deformation 4 of the bracket cover in embodiment 5: as shown in  FIG. 61 , the clamping slot  11  is an arc slot integrally, a flange  29  downwards extends out of the middle of the arc slot, the lower end of the flange  29  is higher than the bottom surface of the bracket cover  3 , and the arc slot is divided into a left arc slot  117  and a right arc slot  118 , which can be in clamping fit with the pin shaft respectively, by the flange  29 ; the bracket cover  3  is internally provided with a kidney hole  43  cast by the powder metallurgic method, certainly, the kidney hole  43  can be further made by the other methods, the kidney hole  43  is placed right above the clamping slot  11 , the shape of the kidney hole  43  is matched with that of the bottom of the clamping slot  11 , and the shrapnel  33  is formed between the kidney hole  43  and the clamping slot  32 . 
         [0177]    As shown in  FIG. 62  and  FIG. 63 , the bracket cover  3  is leftwards or rightwards pushed, and the pin shaft can make the shrapnel  36  to be deformed when passing through the flange  29 , so that the pin shaft can be clamped into the left arc slot  117  or the right arc slot  118 . 
       Embodiment 6 
       [0178]    the embodiment focuses on the deformation of the sliding fit mode between the bracket cover and the bracket body, the form mode of the elastic element and the lock mode of the bracket cover in embodiment 6 are as the same as those in embodiment 5, but the structure that the sliding chutes are the square chutes in embodiment 6 is different from that in embodiment 5, as shown in  FIG. 64-FIG .  66 , the sliding chutes  7  arranged at two sides of the bracket opening  6  are integrated into a dovetail groove, two sides of the bracket cover  3  are provided with swallow-tail sliding blocks  33  of which the shapes and the sizes are matched with those of the dovetail groove, a convex block  35  is arranged under the swallow-tail sliding blocks  33 , and two sides of the bracket cover  3  are clamped into the sliding chutes  7  and slide along with the sliding chutes  7 . In the present invention, the highest point of the shaft hole  8  is lower than the plane where the bottoms  70  of the sliding chutes  7  are placed. 
       Embodiment 7 
       [0179]    the embodiment focuses on the deformation of the sliding fit mode between the bracket cover and the bracket body, the form mode of the elastic element and the lock mode of the bracket cover in embodiment 7 are as the same as those in embodiment 5, and the structure that the sliding chutes are the square chutes in embodiment 7 is different from that in embodiment 5, as shown in  FIG. 67-FIG .  71 , as the other deformation of the sliding fit mode between the bracket cover and the bracket body, as shown in  FIG. 69-FIG .  70 , the bracket cover  3  has the shape of “I” integrally, two sides of the bracket cover  3  are symmetrically provided with the concave sliding chutes  7 . As shown in  FIG. 68 , the bracket opening  6  is narrow in the upper part and wide in the lower part, two sides of the upper part of the bracket opening  6  are symmetrically provided with two sliding rails  41  which extend towards the middle of the bracket opening  6 , after the bracket cover  3  is inserted into the bracket opening  6 , the sliding rails  41  are clamped into the sliding chutes  7 , the sliding rails  41  are in sliding fit with the sliding chutes  7 , and the upper part  31  of the bracket cover covers on the arch wire bracket slot  1  and the work wing  4  at the left side of the arch wire bracket slot. 
         [0180]    The upper surface  42  of the work wing  4  at the left side of the arch wire bracket slot is lower than the upper surface  52  of the work wing  5  at the right side of the arch wire bracket slot, and when the upper part  31  of the bracket cover covers on the work wing  4  at the left side of the arch wire bracket slot, as shown in  FIG. 71 , the upper surface  32  of the bracket cover  3  is in parallel with the upper surface  52  of the work wing  5  at the right side of the arch wire bracket slot. 
       Embodiment 8 
       [0181]    being similar to but being different from embodiment 7, as shown in  FIG. 72-FIG .  76 , the bracket opening  6  is integrated into a swallow-tail sliding chute  7 , similarly, the bracket opening  6  is narrow in the upper part and wide in the lower part, the bracket cover  3  comprises a bracket cover body  34  and sliding blocks  16  arranged under the bracket cover body  34  to be matched with the swallow-tail sliding chute  7 , the convex block  35  is arranged under the sliding blocks  16 , after the bracket cover  3  is inserted into the bracket opening  6 , the sliding blocks  16  are in sliding fit with the swallow-tail sliding chute  7 , and the bracket cover body  34  covers on the arch wire bracket slot  1  and the work wing  4  at the left side of the arch wire bracket slot  1 . 
         [0182]    The upper end of the bracket cover covers on the work wing at the left side of the arc wire bracket slot in embodiment 7 and embodiment 8, and the structure design has the greatest advantage: in the case that the height of the bracket is not heightened, the upper end of the bracket cover is configured to completely cover the arc wire bracket slot and the bracket body at the left side of the arc wire bracket slot, and the upper end of the bracket body at the right side of the arc wire bracket slot is sealed and is in parallel with the upper surface of the bracket cover, so that the whole upper surface of the bracket is integrated and covers all the slots, therefore, the cleanliness and the aesthetics of the bracket can be greatly improved.