quick tire self-centering clamp

Abstract

The present disclosure relates to a quick tire self-centering clamp, including a clamp body assembly, a gear and rack transmission mechanism and a locking mechanism, where the clamp body assembly includes a seat body and three guide rails, each of the guide rails is provided with a sliding seat, and a gripping jaw for holding a tire tightly is fixed on the sliding seat; the gear and rack transmission mechanism includes three racks, one end of each of the racks is fixedly connected to the sliding seat and is parallel to the guide rail in opposite directions, a central shaft sleeve is mounted in the seat body, a gear is fixed on the central shaft sleeve; the locking mechanism includes a ratchet, a positioning pin rod and a positioning pin telescopic component. the gear and rack transmission mechanism can increase the adjustment stroke of the clamp.

What is claimed is: 
     
         1 . A quick tire self-centering clamp, comprising:
 a clamp body assembly, comprising a hollow cylindrical seat body and three guide rails arranged along the circumference of the seat body and extending outward, wherein each of the guide rails, is provided with a sliding seat, and a gripping jaw for holding a tire tightly is fixed on the sliding seat;   a gear and rack transmission mechanism, comprising three racks, wherein one end of each of the racks is fixedly connected to the sliding seat and is parallel to the guide rail in opposite directions, a central shaft sleeve is mounted in the seat body, a gear is fixed on the central shaft sleeve, the three racks respectively mesh with the gear for transmission, and an upper end of the central shaft sleeve is provided with a hand wheel for driving the central shaft sleeve to rotate;   a locking mechanism, comprising a ratchet, a positioning pin rod and a positioning pin telescopic component, wherein the ratchet is fixed on the central shaft sleeve and is adjacent to the gear, and the positioning pin telescopic component drives the positioning pin rod to be engaged with or separated from the ratchet; and   when the positioning pin rod is engaged with the ratchet, the hand wheel is rotated to drive the central shaft sleeve to implement unidirectional rotation, and the three racks rotate synchronously accordingly and drive the gripping jaw to clamp the tire; and when the positioning pin rod is separated from the ratchet, the hand wheel is rotated to drive the central shaft sleeve, the racks and the gripping jaw to rotate freely.   
     
     
         2 . The quick tire self-centering clamp according to  claim 1 , wherein one end of the seat body is closed, and the other end thereof is provided with an end cover, the center of the end cover is provided with a through center hole, and the central shaft sleeve passes through the center hole. 
     
     
         3 . The quick tire self-centering clamp according to  claim 2 , wherein the three guide rails are in a Y shape, the seat body is provided with a through wedge-shaped square hole below each of the guide rails, and the racks are each inserted in the wedge-shaped square hole in a direction opposite to the extending direction of the guide rail and fixed on the corresponding sliding seat. 
     
     
         4 . The quick tire self-centering clamp according to  claim 3 , wherein there is a height difference between the guide rails, and the thicknesses of the sliding seats on the guide rails are different to compensate for the height difference, so that all the gripping jaws are in the same horizontal plane. 
     
     
         5 . The quick tire self-centering clamp according to  claim 1 , wherein a guide portion protrudes from a side of the seat body and is provided with a guide hole allowing the positioning pin rod to pass through, and an annular clamping block protrudes from the front of the positioning pin rod and is disposed in the guide hole. 
     
     
         6 . The quick tire self-centering clamp according to  claim 1 , wherein a front end of the positioning, pin rod is provided with a clamping portion engaged with a tooth back of the ratchet, and the clamping portion is in a slope shape. 
     
     
         7 . The quick tire self-centering clamp according to  claim 1 , wherein the positioning pin telescopic component comprises a connecting plate fixedly connected to the seat body, a concave wheel, a cam, and a returning spring; the concave wheel, the cam and the returning spring penetrate the positioning pin rod; the concave wheel and the cam match each other, and the concave wheel is fixed to the connecting plate, and
 one end of the returning spring is pressed on, a lower plane of the concave wheel, the other end thereof is pressed on a limit pin of the positioning pin rod, and a nut is fixed to a rear end of the positioning pin rod.   
     
     
         8 . The quick tire self-centering clamp according to  claim 7 , wherein the concave wheel is provided with several concave inclined surfaces with rotation angles, and the cam is provided with convex inclined surfaces that match the concave inclined surfaces. 
     
     
         9 . The quick tire self-centering clamp according to  claim 7 , wherein the cam is provided with an operating handle, the connecting plate is provided with an inclined groove for the operating handle to be engaged in, and the operating handle is pulled to drive the convex inclined surfaces of the cam to rotate and rise or descend along the concave inclined surfaces of the concave wheel, to drive the positioning pin rod to be separated from or engaged with the ratchet. 
     
     
         10 . The quick tire self-centering clamp according to  claim 1 , wherein an upper end of one guide rail is provided with a handle. 
     
     
         11 . The quick tire self-centering clamp according to  claim 1 , wherein an outer end of the gripping jaw is a clamping portion, and friction protrusions are uniformly disposed on an outer side of the clamping portion in contact with the tire.