RU2011486C1 - Tap wrench - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: body 1 has square-shaped hole 3 housing oppositely located two pairs of clamping cams 8-11 which form square-shaped seat. Cam 8 has through threaded hole receiving adjusting screw 16. One of the pairs of cams, for example 8 and 9, is mounted in hole 3 so that amount of maximum dimensions along diagonal of square of seat is less than dimension of square-shaped hole 3 of body 1 along the same diagonal. Difference of dimensions between amount of maximum dimensions of cams and dimensions of square-shaped hole 3 of body 1 is equal to 0.2-0.3 mm. In another case adjoining surface 15 of one of the cams 9, 10, 11 relative to wall 13 of square-shaped hole 3 may be radial. To adjust desired dimension of seat 12 screw 16 is to be rotated to provide movement of cam 8 along wall of square-shaped hole 3 and its pressing against beveled face of cam 9 to move it to the left. Cam 9 in its turn lowers cam 10 and cam 10 displaces cam 11 to the right. Thus the seat is formed to receive shank of working tool. The shank is clamped by rotation of screw. EFFECT: enhanced operating reliability. 3 cl, 4 dwg

Description

 The invention relates to mechanical engineering, namely to hand tools, in particular locksmith doors, and can be used to clamp and rotate a working tool, such as a tap, when manually cutting internal threads.

 Known for the fastening of the tool holder, equipped with a fixed cam fastened to the housing, and a movable cam, moved by means of an adjusting screw, combined with one of the handles. Cams have angled depressions on the working surfaces for clamping the working tool [1].

 Such a design and installation of the cams does not allow for a uniform fit of their working surfaces to the faces of the shank of the working tool when clamping and does not allow a wide selection of tool sizes to be used without changing the cams.

 There is also a knob, in the square hole of the body of which, with the possibility of reciprocating movement, two pairs of opposed clamping jaws are installed, forming a square socket under the tool shank, one of the cams connected to an adjusting screw located in the housing [2].

 However, this collar, due to the fact that it is practically impossible to ensure the shape and size of the socket that exactly corresponds to the shank of each specific working tool (which, in turn, cannot be perfectly accurate), does not ensure that all cam working surfaces are fully adhered to the corresponding the edges of the shank of the working tool. Only point contact can be achieved, most often at three points, which during prolonged operation due to uneven load distribution causes the edges of the working tool shank and cam working surfaces to crumple.

 The basis of the invention is the task of creating a locksmith with such a socket for the tool, which could copy the size and shape of the surfaces of the faces of the shank of the working tool, while ensuring uniform load distribution.

 The problem is solved in that in a winch, in a square hole of the body of which, with the possibility of reciprocating movement, two pairs of opposed clamping jaws are installed, forming a square socket under the tool shank, one of the cams connected to an adjustment screw located in the housing, in one of pairs of cams, the sum of the maximum dimensions along the diagonal of the square of the socket is smaller than the dimensions of the square hole of the housing along the same diagonal.

 This condition can be ensured by the fact that the size difference between the sum of the maximum dimensions of the cams and the dimensions of the square opening of the housing is 0.2-3.0 mm; or the contact surface of the square hole of one of the cams of the pair is made along the radius.

 This installation of the cams allows the clamping tool to achieve full fit of all working surfaces of the cams to the corresponding faces of the shank of the working tool, thereby ensuring uniform distribution of the load.

 In FIG. 1 shows the proposed knob with the initial position of the cams, plan (top cover removed); in FIG. 2 - the same side view; in FIG. 3 - the same plan in the position of the job tool with the installation of the cams with a gap; in FIG. 4 - the same, with the implementation of the contact surface of the square hole of one of the cams along the radius.

 The gate consists of a housing 1 with handles 2 and a square hole 3, closed by covers 4, 5 with holes 6, 7 (see. Fig. 1,2). Inside the square hole 3, two pairs of clamping cams 8-11 are opposite, forming a square socket 12 for the tool shank. One of the cams 8 (leading) has a through hole with a screw thread into which an adjusting screw 16 is screwed, passing along one of the walls of the square hole 3 of the housing 1.

 Leading 8 and driven 9-11 cams are in terms of quadrangles with two straight (one of them central) corners. In the side faces of the cams 9 and 11, cylindrical grooves are made (not shown in the drawing). One of the pairs of cams, for example 8 and 9, is installed in such a way that the sum of the maximum dimensions along the diagonal of the square of the socket is less than the size of the square hole 3 of the housing 1 along the same diagonal. The size difference between the sum of the maximum dimensions of the cams and the dimensions of the square hole 3 of the housing 1 (clearance 14) is 0.2-3.0 mm. Similarly, either of the cam pairs or both can be set.

 In another case, the contact surface 15 (see Fig. 4) of one of the driven cams, for example 10, to the wall 13 of the square hole 3 can be made in radius. With a similar shape of the contact surface, any of the driven cams 9-11 or all at the same time can be made.

 Vorotok works as follows.

 In the initial position, the leading 8 and driven 9, 10, 11 cams are summarized by the vertices to the center of the square hole 3 (see Fig. 1). To set the required size of the socket 12, turn the adjusting screw 16, while the leading cam 8 moves along the wall of the square hole 3 and presses on the beveled face of the driven cam 9, shifting it to the left. The cam 9, in turn, lowers the cam 10, and that cam biases the cam 11 to the right. Thus, in the center of the square hole 3, a square socket 12 is formed (see Fig. 3).

 A shank of a working tool (not shown) is inserted into the formed socket 12 and, turning the adjusting screw 16 in the opposite direction, clamp the shank. In this case, after reaching the first point contacts of the working surfaces of the cams with the corresponding faces of the shank of the working tool due to the gap 14, one or several cams 9, 10, 11 are distorted until their working surfaces completely adhere to the corresponding faces of the tool shank. The size of the gap 14 may be 02, -3.0 mm If the specified gap value is less than 0.2 mm, then the skewness of the cams 9, 10, 11 may not be sufficient to ensure full fit of their working surfaces to the edges of the shank of the working tool. In the case of installing at least one of the driven cams 9, 10, 11 with a gap of 14, the value of which is more than 3.0 mm, it becomes impossible to clamp the working tool with a small size of the shank, since during operation it may turn in the socket 12.

 If the surface 15 of the abutment of one of the driven cams, for example 10, to the wall 13 of the square hole 3 in radius, when the shank of the working tool is clamped, the driven cams are also distorted until their working surfaces completely adhere to the corresponding faces of the shank.

 Thus, the proposed design of the handle ensures that, when clamped, the full contact of all working surfaces of the cams adheres to the corresponding faces of the tool shank, thereby achieving uniform load distribution when working across the entire surface of the faces of the tool shank.

Claims (3)

 1. A WRIST, in a square hole of the body of which, with the possibility of reciprocating movement, two pairs of opposed clamping jaws are installed, forming a square socket under the tool shank, one of the cams connected to an adjusting screw located in the housing, characterized in that in one of pairs of cams the sum of the maximum dimensions along the diagonal of the square of the socket is smaller than the size of the square hole of the housing along the same diagonal.  2. Vorotok under item 1, characterized in that the difference in the size of the sum of the maximum dimensions of the cams and the size of the square hole of the housing is 0.2 - 3.0 mm  3. Vorotok under item 1, characterized in that the contact surface of the square hole of one of the cams of the pair is made along the radius.

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