Gripper

Abstract

To provide a gripper which achieves downsizing with a simple structure.SOLUTION: A gripper includes: at least three idler pulleys installed on the same circumference; a belt wound around the idler pulleys; tension pulleys as many as the idler pulleys, the tension pulleys installed on a center side of the circumference on which the idler pulleys are installed to give tension to the belt, and deforming the belt into a radial shape projecting from the center of the circumference on which the idler pulleys are installed to an idler pulley side; and a moving member installed in a portion between the idler pulleys and the tension pulleys of the belt. The belt is deformed by the tension pulleys so that an interval between portions folded by the idler pulleys is smaller than a diameter of the idler pulley on the center side of the circumference on which the idler pulleys are installed. The moving member is oriented so as to move in a radial direction of the circumference on which the idler pulleys are installed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a gripper, and more particularly to a gripper that is designed to have a simple structure and be compact. [Background technology]

[0002] For example, Patent Document 1 discloses a configuration of a gripper. The workpiece gripping device described in Patent Document 1 has a driving spur gear in the center that is rotated by a drive motor, and three driven spur gears are installed around the driving spur gear. A timing belt is wound around the driving spur gear and the driven spur gear. Six regulating rollers are installed near the driving spur gear to mesh the timing belt with the driving spur gear. With this configuration, the timing belt extends radially in three directions toward the driven spur gear. A gripping claw is attached to each of the three radial portions of the timing belt via a connecting member. When the drive spur gear is rotated in one direction, the gripping jaws are moved toward each other and the workpiece is held by the gripping jaws, and when the drive spur gear is rotated in the other direction, the gripping jaws are moved away from each other and the gripping jaws release the gripping jaws from holding the workpiece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2641571 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above conventional configuration has the following problems. In other words, a driving spur gear is installed in the center, and the timing belt is pressed against the driving spur gear by regulating rollers, resulting in a shape that extends radially in three directions in which the driven spur gears are arranged.As a result, at least two regulating rollers are required for each driven spur gear, which increases the number of parts and makes the holding device larger.

[0005] The present invention has been made based on the above points, and an object of the present invention is to provide a gripper that has a simple structure and can be made compact. [Means for solving the problem]

[0006] In order to solve the above problem, the gripper according to claim 1 of the present invention comprises at least three idler pulleys arranged on the same circumference, a belt wound around the idler pulleys, tension pulleys arranged in the same number as the idler pulleys on the central side of the circumference on which the idler pulleys are arranged to apply tension to the belt and deform the belt into a radial shape protruding from the center of the circumference on which the idler pulleys are arranged toward the idler pulleys, and a moving member arranged in a portion of the belt between the idler pulleys and the tension pulleys, wherein the belt is deformed by the tension pulleys so that the distance between the portions folded back by the idler pulleys on the central side of the circumference on which the idler pulleys are arranged is smaller than the diameter of the idler pulleys, and the moving member is oriented so as to move in the radial direction of the circumference on which the idler pulleys are arranged. A gripper according to claim 2 is characterized in that in the gripper according to claim 1, the idler pulleys are arranged at equal intervals in the circumferential direction. Furthermore, the gripper according to claim 3 is characterized in that, in the gripper described in claim 1, the belt is a timing belt and the tension pulley is a timing pulley, the tension pulley is wound around the toothed surface of the timing belt, and the back side of the toothed surface of the timing belt is wound around the idler pulley. Furthermore, the gripper according to claim 4 is characterized in that, in the gripper described in claim 1, a tension adjustment pulley whose fixed position can be changed so as to adjust the tension of the belt is installed between the idler pulley and the tension pulley. Further, a gripper according to claim 5 is the gripper according to claim 1, characterized in that a finger is connected to the moving member, and the finger is guided by a guide mechanism so as to move linearly. A gripper according to claim 6 is characterized in that in the gripper according to claim 5, the guide mechanism is a rolling member. Moreover, a gripper according to claim 7 is characterized in that in the gripper according to claim 5, the guide mechanism is a sliding member. Furthermore, a gripper according to claim 8 is characterized in that in the gripper described in any one of claims 1 to 7, one of the tension pulleys is a drive pulley that drives the belt. Moreover, a gripper according to claim 9 is characterized in that in the gripper according to claim 8, the driving pulley is connected to a driving motor via a reduction mechanism. A gripper according to claim 10 is characterized in that in the gripper according to claim 9, the reduction mechanism includes a hypoid gear. Furthermore, the gripper according to claim 11 is a gripper according to any one of claims 1 to 7, characterized in that a screw shaft is installed, one of the moving members is provided with a nut that is screwed onto the screw shaft, and by rotating the screw shaft, one of the moving members is moved, thereby driving the belt and moving the other of the moving members. Effect of the Invention

[0007] As described above, the gripper described in claim 1 of the present invention comprises at least three idler pulleys arranged on the same circumference, a belt wound around the idler pulleys, tension pulleys arranged in the same number as the idler pulleys on the center side of the circumference on which the idler pulleys are arranged to apply tension to the belt and deform the belt into a radial shape protruding from the center of the circumference on which the idler pulleys are arranged toward the idler pulley side, and a moving member arranged in a portion of the belt between the idler pulley and the tension pulley, and the belt is deformed by the tension pulley so that the distance between the portions folded back by the idler pulley on the center side of the circumference on which the idler pulleys are arranged is smaller than the diameter of the idler pulley, and the moving member is oriented so as to move in the radial direction of the circumference on which the idler pulleys are arranged, thereby making it possible to simplify the configuration and make the gripper compact. According to the gripper of claim 2, in the gripper of claim 1, the idler pulleys are arranged at equal intervals in the circumferential direction, so that the object can be gripped effectively and without bias. Furthermore, according to the gripper of claim 3, in the gripper of claim 1, the belt is a timing belt and the tension pulley is a timing pulley, the tension pulley is wound around the toothed surface of the timing belt and the back side of the toothed surface of the timing belt is wound around the idler pulley, so that the belt can be driven reliably while providing appropriate tension to the belt. In addition, according to the gripper described in claim 4, in the gripper described in claim 1, a tension adjustment pulley whose fixed position can be changed so as to adjust the tension of the belt is installed between the idler pulley and the tension pulley, so that the tension of the belt can be easily changed. Furthermore, according to the gripper described in claim 5, in the gripper described in claim 1, fingers are connected to the moving member, and the fingers are guided by a guide mechanism to move in a straight line, so that the object can be securely grasped by the fingers. According to a sixth aspect of the present invention, in the gripper according to the fifth aspect, the guide mechanism is a rolling member, so that the fingers can be reliably guided with a simple structure. According to the gripper recited in claim 7, since the guide mechanism in the gripper recited in claim 5 is a sliding member, the fingers can be reliably guided with a simpler configuration. Furthermore, according to the gripper described in claim 8, in the gripper described in any one of claims 1 to 7, one of the tension pulleys is a driving pulley that drives the belt, so that the belt can be driven with a simple configuration. According to a ninth aspect of the present invention, in the gripper according to the eighth aspect, the driving pulley is connected to the driving motor via a reduction mechanism, so that an object can be gripped effectively. Furthermore, according to the gripper of claim 10, in the gripper of claim 9, the reduction mechanism includes a hypoid gear, so that the drive motor can be arranged in a direction perpendicular to the output shaft of the reduction mechanism, thereby further reducing the size of the gripper. Furthermore, according to the gripper described in claim 11, in the gripper described in any one of claims 1 to 7, a screw shaft is installed, and one of the moving members is provided with a nut that is screwed onto the screw shaft, and by rotating the screw shaft, one of the moving members is moved, thereby driving the belt and also moving the other of the moving members, so that the moving member can be driven directly without driving the tension pulley or the idler pulley. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a first embodiment of the present invention, and is a perspective view of a gripper. [Diagram 2] FIG. 1 is an exploded perspective view of a gripper according to a first embodiment of the present invention. [Diagram 3] 3A and 3B are diagrams showing a first embodiment of the present invention, in which FIG. 3A is a plan view of a finger drive unit of a gripper, and FIG. 3B is a plan view of the finger drive unit of the gripper with a moving member removed. [Figure 4] FIG. 1 is an exploded perspective view of one of the moving members of a finger drive unit separated from a belt, showing the first embodiment of the present invention. [Diagram 5] 5A is a perspective view of a finger guide portion and a cross-sectional view taken along line Vb-Vb of FIG. 5A, showing the first embodiment of the present invention. FIG. [Figure 6] 6A and 6B are diagrams showing a first embodiment of the present invention, in which FIG. 6(a) is a plan view of the gripper with its fingers open, and FIG. 6(b) is a plan view of the gripper with its fingers open, with the finger guide section and finger drive section housing removed. [Figure 7] 7A and 7B are diagrams showing a first embodiment of the present invention, in which FIG. 7(a) is a plan view of a gripper with its fingers closed, and FIG. 7(b) is a plan view of the gripper with its fingers closed, with the finger guide section and finger drive section housing removed. [Figure 8]FIG. 11 is a diagram showing a second embodiment of the present invention, and is a plan view of the gripper with the fingers open, with the finger guide portion and the finger drive unit housing removed. [Figure 9] 9A and 9B are diagrams showing a third embodiment of the present invention, and FIG. 9A is a plan view of a gripper with a finger guide portion and a finger drive unit housing removed, and FIG. 9B is a cross-sectional view taken along line IXb-IXb of FIG. 9A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A first embodiment of the present invention will be described below with reference to Figures 1 to 7. As shown in Figure 1, a gripper 1 includes a motor housing 3, a finger drive unit housing 5, and a finger guide unit .

[0010] As shown in FIG. 2, the motor housing 3 is a cylindrical member that opens in the vertical direction in FIG. 2. The motor 11 and the reducer 15 are installed in the motor housing 3. A motor side pulley 19 is fixed to the output shaft 17 of the motor 11, and a reducer side pulley 23 is also fixed to the input shaft 21 of the reducer 15. A belt 25 is wound around the motor side pulley 19 and the reducer side pulley 23, so that the rotation of the output shaft 17 of the motor 11 is reduced by the reducer 15, and the output shaft 27 of the reducer 15 is rotated. The rotation of the motor side pulley 19 is also reduced when it is transmitted from the motor side pulley 19 to the reducer side pulley 23, and a reduction mechanism 26 is configured by the motor side pulley 19, the belt 25, the reducer side pulley 23, and the reducer 15. The reducer 15 uses a hypoid gear (not shown), and the input shaft 21 and the output shaft 27 are oriented perpendicular to each other. The opening of the motor housing 3 on the lower side in FIG.

[0011] A finger drive unit 31 is installed on the upper side of the motor housing 3 in FIG. 2. The finger drive unit 31 has a finger drive unit base 33 installed on the opening side of the upper side of the motor housing 3 in FIG. 2. As shown in FIG. 3, three idler pulleys 35, 37, 39 are installed rotatably on the same circumference at equal intervals in the circumferential direction on the outer periphery of the finger drive unit base 33. A timing belt 41 is wound around the idler pulleys 35, 37, 39 as a belt for driving the finger drive unit 31. The idler pulleys 35, 37, 39 are pulleys without teeth, and a toothed surface 43 of the timing belt 41 faces outward, and the idler pulleys 35, 37, 39 are in contact with a toothless surface 45 of the timing belt 41. A tension pulley 47 and tension pulleys 49 and 51 are rotatably installed on the inner peripheral side of the idler pulleys 35, 37, and 39 of the finger drive unit base 33. The tension pulley 47 and tension pulleys 49 and 51 are timing pulleys, and are engaged with the toothed surface 43 of the timing belt 41.

[0012] In addition, tension is applied to the timing belt 41 by the tension pulleys 47, 49, and 51, and the timing belt 41 is deformed radially in three directions from the center of the finger drive unit base 33 toward the idler pulleys 35, 37, and 39. In addition, the tension pulleys 47, 49, 51 make the following smaller than the diameter φ of the idler pulleys 35, 37, 39 on the central side: a distance a between the portion 53 between the idler pulley 35 and the tension pulley 47 of the timing belt 41 and a distance 55 between the idler pulley 35 and the tension pulley 49 of the timing belt 41, a distance b between the portion 57 between the idler pulley 37 and the tension pulley 49 of the timing belt 41 and a distance 59 between the idler pulley 37 and the tension pulley 51 of the timing belt 41, and a distance c between the portion 61 between the idler pulley 39 and the tension pulley 51 of the timing belt 41 and a distance 63 between the idler pulley 39 and the tension pulley 47 of the timing belt 41.

[0013] Further, the tension pulley 47 is a drive pulley that drives the timing belt 41, and is connected to the output shaft 27 of the reduction gear 15. When the tension pulley 47 is rotated by the motor 11, the timing belt 41 is driven.

[0014] In addition, a movable member 71 is provided in a portion 53 of the timing belt 41 between the idler pulley 35 and the tension pulley 47, a movable member 73 is provided in a portion 57 of the timing belt 41 between the idler pulley 37 and the tension pulley 49, and a movable member 75 is provided in a portion 61 of the timing belt 41 between the idler pulley 39 and the tension pulley 51.

[0015] As shown in FIG. 4, the movable member 71 is composed of a movable member main body 77 arranged on the upper side of the timing belt 41 in FIG. 4, and a fixed portion 79 formed by protruding from the movable member main body 77 on the lower side in FIG. 4. The movable member 71 is fixed by positioning the fixed portion 79 on the inside of the timing belt 41, interposing the timing belt 41 between the fixed portion 79 and a pressure belt 81 arranged on the outside of the timing belt 41, and further positioning a pressure plate 83 on the side of the pressure belt 81 opposite the movable member 71 (upper left side in Figure 4), and passing a bolt 85 through the pressure plate 83, the pressure belt 81, and the timing belt 41 and screwing it into the fixed portion 79. The moving members 73 and 75 are fixed to the timing belt 41 in the same manner as the moving member 71 .

[0016] As shown in FIG. 3( a), depending on the positions of the tension pulleys 47, 49, 51 relative to the idler pulleys 35, 37, 39, the timing belt 41 is deformed so that the moving members 71, 73, 75 move along a linear trajectory from the positions of the idler pulleys 35, 37, 39 toward the center of the finger drive unit base 33.

[0017] The finger drive unit housing 5 is interposed between the motor housing 3 and the finger guide unit 7, and the finger drive unit 31 is accommodated inside the finger drive unit housing 5.

[0018] As shown in FIG. 5(a), the finger guide section 7 is composed of three finger guide mechanisms 91, 93, 95 and a central member 97. The finger guide mechanism 91 has a finger guide section base 99 in a substantially sector shape obtained by dividing a substantially circular plate-like member into three equal parts in the circumferential direction. The finger guide section base 99 has a finger accommodating recess 101 extending from the outer periphery of the sector shape toward the center. As shown in FIG. 5(b), guide rail recesses 103, 103 are formed on both sides of the finger accommodating recess 101 in the width direction (left and right direction in FIG. 5(b)), and guide rails 105, 105 are engaged with and installed in the guide rail recesses 103, 103. The guide rail 105 has a guide recess 107 formed therein.

[0019] In the finger accommodating recess 101, a finger 111 is installed so as to be movable along the finger accommodating recess 101 in a direction from the outer periphery side of the approximately sector shape of the finger guide portion base 99 toward the center. The finger 111 has a finger body 113 that is arranged in the finger accommodating recess 101 with a part of it protruding toward the upper side of the finger guide portion base 99 in FIG. 5(b). Guide rails 115, 115 are installed on both sides of the finger body 113 in the width direction (left and right direction in FIG. 5(b)). A guide recess 117 is also formed in the guide rail 115, and the guide recess 107 of the adjacent guide rail 105 and the guide recess 117 of the guide rail 115 are arranged to face each other, and a plurality of steel balls 119 are installed as rolling members between the guide recess 107 and the guide recess 117 that face each other. End plates 121, 121 are installed on both sides of the finger 111 in the front-to-rear direction (from the lower left to the upper right in Figure 5(a)), and the steel ball 119 is held on both sides of the finger 111 in the width direction (the left-to-right direction in Figure 5(b)) and is adapted to move in conjunction with the finger 111.

[0020] The central member 97 is a low triangular prism-shaped member having an equilateral triangular cross section. A flat contact portion 123 that contacts the side surface of the central member 97 is provided on the center side of the approximately sector shape of the finger guide portion base 99. A through hole 125 which is an elongated hole aligned along the finger accommodating recess 101 is formed in the bottom of the finger accommodating recess 101 of the finger guide portion base 99 (the lower side in FIG. 5(b)).

[0021] The finger guide mechanisms 93 and 95 are configured in a similar manner to the finger guide mechanism 91, and a finger 127 having a similar configuration to the finger 111 is movably mounted on the finger guide mechanism 93, and a finger 129 having a similar configuration to the finger 111 is movably mounted on the finger guide mechanism 95. The abutment portions 123 of the finger guide portion bases 99 of the three finger guide mechanisms 91 , 93 , 95 abut against each side surface of the central member 97 . The upper portion of the moving member 71 is positioned within the through hole 125 of the finger guide mechanism 91, the upper portion of the moving member 73 is positioned within the through hole 125 of the finger guide mechanism 93, and the upper portion of the moving member 75 is positioned within the through hole 125 of the finger guide mechanism 95. The finger 111 is fixed by passing a bolt 131 through the finger 111 and screwing it to the moving member 71. The finger 127 is fixed to the moving member 73 by passing a bolt 133 through the finger 127 and screwing it to the moving member 73, and the finger 129 is fixed to the moving member 75 by passing a bolt 135 through the finger 129 and screwing it to the moving member 75.

[0022] Next, the operation of the first embodiment will be described. The rotation of the output shaft 17 of the motor 11 is reduced by the reducer 15 which is a part of the reduction mechanism 26, and the output shaft 27 of the reducer 15 is rotated. Further, the tension pulley 47 is connected to the output shaft 27 of the reducer 15, and the tension pulley 47 is rotated by the motor 11, thereby driving the timing belt 41.

[0023] As shown in Fig. 6, when the tension pulley 47 is rotated counterclockwise in Fig. 6(b) and the timing belt 41 is driven clockwise in Fig. 6(b), the moving members 71, 73, and 75 are moved outward. At this time, the fingers 111, 127, and 129 are also moved outward. 7, when the tension pulley 47 is rotated in the clockwise direction in Fig. 7(b) and the timing belt 41 is driven in the counterclockwise direction in Fig. 7(b), the moving members 71, 73, and 75 are moved inward. At this time, the fingers 111, 127, and 129 are also moved inward.

[0024] As shown in Fig. 7, when the fingers 111, 127, and 129 are moved inward, an object (not shown) placed at the center is gripped by the fingers 111, 127, and 129. From this state, when the fingers 111, 127, and 129 are moved outward as shown in Fig. 6, the grip of the object (not shown) is released. The finger 111 is guided by a finger guide mechanism 91, the finger 127 is guided by a finger guide mechanism 93, and the finger 129 is guided by a finger guide mechanism 95, so that they move linearly.

[0025] In addition, the tension pulleys 47, 49, 51 are arranged so that the distance a between the portion 53 between the idler pulley 35 and the tension pulley 47 of the timing belt 41 and the portion 55 between the idler pulley 35 and the tension pulley 49 of the timing belt 41, the distance b between the portion 57 between the idler pulley 37 and the tension pulley 49 of the timing belt 41 and the portion 59 between the idler pulley 37 and the tension pulley 51 of the timing belt 41, and the distance c between the portion 61 between the idler pulley 39 and the tension pulley 51 of the timing belt 41 and the portion 63 between the idler pulley 39 and the tension pulley 47 of the timing belt 41 are smaller than the diameter φ of the idler pulleys 35, 37, 39 on the central side.

[0026] Next, the effects of the first embodiment will be described. A timing belt 41 is wound around three idler pulleys 35, 37, 39 arranged on the same circumference, tension pulleys 47, 49, 51 are arranged on the inner circumferential side of the idler pulleys 35, 37, 39, and the timing belt 41 is deformed radially in three directions from the center of the finger drive unit base 33 toward the idler pulleys 35, 37, 39. A moving member 71 is arranged in a portion 53 of the timing belt 41 between the idler pulley 35 and the tension pulley 47, a moving member 73 is arranged in a portion 57 of the timing belt 41 between the idler pulley 37 and the tension pulley 49, and a moving member 75 is arranged in a portion 61 of the timing belt 41 between the idler pulley 39 and the tension pulley 51. Therefore, there is no configuration that may obstruct the center where the moving members 71, 73, 75 move when the gripper 1 grips an object (not shown), and the gripper 1 can be made small in size by a simple configuration.

[0027] In addition, the tension pulleys 47, 49, 51 adjust the distance a between a portion 53 between the idler pulley 35 and the tension pulley 47 of the timing belt 41 and a portion 55 between the idler pulley 35 and the tension pulley 49 of the timing belt 41, the distance b between a portion 57 between the idler pulley 37 and the tension pulley 49 of the timing belt 41 and a portion 59 between the idler pulley 37 and the tension pulley 51 of the timing belt 41, and the distance b between the idler pulleys 37 and the tension pulley 49 of the timing belt 41 and a portion 59 between the idler pulley 37 and the tension pulley 51 of the timing belt 41. The distance c between the portion 61 between the idler pulley 39 and the tension pulley 51 and the portion 63 between the idler pulley 39 and the tension pulley 47 of the timing belt 41 is smaller than the diameter φ of the idler pulleys 35, 37, 39 at the center side, so that the dead space at the center side can be reduced, the movable range of the moving members 71, 73, 75, and ultimately the fingers 111, 127, 129 can be increased, and the fingers can be deformed radially in three directions toward the idler pulleys 35, 37, 39.

[0028] Furthermore, since the idler pulleys 35, 37, and 39 are installed at equal intervals in the circumferential direction on the same circumference, the movable members 71, 73, and 75, and therefore the fingers 111, 127, and 129, can be evenly arranged in the circumferential direction, and the object can be effectively gripped without bias.

[0029] Furthermore, of the tension pulleys 47, 49, and 51, the tension pulley 47 is connected to the motor 11 via the reduction gear 15, so that the timing belt 41 can be driven with a simple configuration. In addition, the toothed surface 43 of the timing belt 41 faces outward, the idler pulleys 35, 37, 39 are in contact with the toothless surface 45 of the timing belt 41, and the tension pulley 47 and tension pulleys 49, 51 are timing pulleys that are meshed with the toothed surface 43 of the timing belt 41, so that the idler pulleys 35, 37, 39 apply appropriate tension to the timing belt 41, while the tension pulleys 47, 49, 51 can reliably drive the timing belt 41.

[0030] Furthermore, since the tension pulley 47 is connected to the motor 11 via the reducer 15, the timing belt 41 can be driven effectively, and the object can be gripped effectively by the fingers 111, 127, 129. In addition, a hypoid gear (not shown) is used in the reducer 15, and the input shaft 21 and the output shaft 27 are oriented perpendicular to each other. Therefore, the motor 11 can be arranged in a direction perpendicular to the output shaft 27 of the reducer 15, and the gripper 1 can be further made smaller.

[0031] In addition, the finger 111 is guided by finger guide mechanism 91, the finger 127 is guided by finger guide mechanism 93, and the finger 129 is guided by finger guide mechanism 95, and thus they are moved in a straight line, so that an object (not shown) can be grasped more reliably. In addition, a plurality of steel balls 119 are rollably installed between the guide recesses 117 of the guide rails 115 of the fingers 111, 127, 129 and the guide recesses 107 of the guide rails 105 of the finger guide portion base 99, thereby enabling the fingers 111, 127, 129 to be guided with a simple configuration.

[0032] Next, a second embodiment of the present invention will be described with reference to FIG. The gripper 201 in the second embodiment has a configuration substantially similar to that of the gripper 1 in the first embodiment described above, but includes an additional tension adjustment pulley 203. The tension adjustment pulley 203 is not a timing pulley, but is in contact with the toothless surface 45 of the timing belt 41.

[0033] The base 33 for the finger drive unit is provided with an attachment hole for the tension adjustment pulley 203 (not shown), so that the attachment position of the tension adjustment pulley 203 can be finely adjusted, and the tension of the timing belt 41 can be adjusted by the tension adjustment pulley 203. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0034] In the case of the second embodiment, the same actions and effects as those of the first embodiment are achieved. In addition, the tension of the timing belt 41 can be easily adjusted by the tension adjusting pulley 203, and the winding angle of the timing belt 41 around the tension pulley 47 serving as a drive pulley can be increased, thereby increasing the number of meshing teeth between the tension pulley 47 and the toothed surface 43.

[0035] Next, a third embodiment of the present invention will be described with reference to FIG. The gripper 301 in this third embodiment has a configuration substantially similar to that of the gripper 1 in the first embodiment described above, but has a screw shaft 303 on the underside of the base 33 for the finger drive unit, and a nut 305 screwed onto the screw shaft 303.

[0036] The fixed portion 79 of the moving member 73 is extended downward in FIG. 9( b ) and is provided with a nut connecting portion 307 , and the moving member 73 and the nut 305 are connected via the nut connecting portion 307 . Support members 309 and 311 for the screw shaft are provided on the rear side (lower side in FIG. 9(b)) of the base 33 for the finger drive unit, and both ends of the screw shaft 303 are rotatably supported by bearings (not shown) installed on the support members 309 and 311 for the screw shaft. Further, the finger drive unit base 33 is formed with a through hole 313 through which the nut connection portion 307 of the moving member 73 passes. The screw shaft 303 is rotated and driven by a motor (not shown). The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0037] In the case of the third embodiment, when the screw shaft 303 is rotated, the nut 305 and therefore the moving member 73 are moved. When the moving member 73 is moved, the timing belt 41 is also driven, and the other moving members 71 and 75 are also moved. In the case of the third embodiment, the same actions and effects as in the case of the first embodiment described above are achieved.

[0038] The present invention is not limited to the first to third embodiments. First of all, there are various possible numbers of idler pulleys and tension pulleys. Also, a separate gripping member may be attached to the finger, and the object may be gripped via the gripping member. The finger guide may also be a sliding member. Also, the toothed surface and the toothless surface of the timing belt may be interchanged to drive the idler pulley side. Also, belts other than timing belts and pulleys other than timing pulleys may be used. In addition, the reduction mechanism may take various forms, such as a reduction mechanism using a worm gear and a worm wheel, a spiral bevel gear, or a spur gear, in addition to a reduction mechanism using a pulley and a belt or a hypoid gear. Additionally, the configurations shown in the drawings are merely examples. [Industrial Applicability]

[0039] The present invention relates to a gripper, and in particular to a gripper that is designed to have a simple configuration and be miniaturized, and is suitable for use in industrial robots, for example. [Explanation of symbols]

[0040] 1 Gripper 7 Finger guide section (guide mechanism) 11 Motor (drive motor) 15 Reducer 17 Output shaft 19 Motor side pulley 21 Input shaft 23 Reducer side pulley 25 Belt 26 Reduction mechanism 27 Output shaft 35 Idler pulley 37 Idler pulley 39 Idler pulley 41 Timing belt (belt) 43 Tooth surface 45 toothless surface (back side of toothed surface 43 of timing belt 41) 47 Tension pulley (drive pulley) 49 Tension pulley 51 Tension pulley 53 The portion between the idler pulley 35 and the tension pulley 47 55 Part between idler pulley 35 and tension pulley 49 57 Part between idler pulley 37 and tension pulley 49 59 Part between idler pulley 37 and tension pulley 51 61: A portion between the idler pulley 39 and the tension pulley 51 63 Between the idler pulley 39 and the tension pulley 47 71 Moving parts 73 Moving parts 75 Moving parts 111 Finger 119 Steel balls (rolling components) 127 Finger 129 Finger 201 Gripper 203 Tension adjustment pulley 301 Gripper 303 Screw shaft 305 Nut a Interval b Interval c Interval φ Diameter of idler pulleys 35, 37, 39

Claims

1. At least three idler pulleys arranged on the same circumference; A belt wound around the idler pulley; tension pulleys, which are installed in the same number as the idler pulleys on the center side of the circumference on which the idler pulleys are installed, and which apply tension to the belt and deform the belt into a radial shape protruding from the center of the circumference on which the idler pulleys are installed toward the idler pulleys; a moving member disposed in a portion of the belt between the idler pulley and the tension pulley, The belt is deformed by the tension pulley so that the distance between the portions folded back by the idler pulley on the central side of the circumference on which the idler pulley is installed is smaller than the diameter of the idler pulley, A gripper characterized in that the moving member is oriented so as to be moved in a radial direction of a circumference on which the idler pulley is installed.

2. 2. The gripper according to claim 1, A gripper characterized in that the idler pulleys are arranged at equal intervals in the circumferential direction.

3. 2. The gripper according to claim 1, A gripper characterized in that the belt is a timing belt and the tension pulley is a timing pulley, the tension pulley is wound around the toothed surface of the timing belt, and the back side of the toothed surface of the timing belt is wound around the idler pulley.

4. 2. The gripper according to claim 1, A gripper characterized in that a tension adjustment pulley whose fixed position can be changed to adjust the tension of the belt is installed between the idler pulley and the tension pulley.

5. 2. The gripper according to claim 1, A gripper, characterized in that a finger is connected to the moving member, and the finger is guided so as to move linearly by a guide mechanism.

6. 6. The gripper according to claim 5, A gripper characterized in that the guide mechanism is a rolling member.

7. 6. The gripper according to claim 5, A gripper characterized in that the guide mechanism is a sliding member.

8. The gripper according to any one of claims 1 to 7, A gripper characterized in that one of the tension pulleys is a drive pulley that drives the belt.

9. 9. The gripper according to claim 8, A gripper characterized in that the driving pulley is connected to a driving motor via a reduction mechanism.

10. 10. The gripper of claim 9, A gripper characterized in that the reduction mechanism includes a hypoid gear.

11. The gripper according to any one of claims 1 to 7, The screw shaft is installed, One of the moving members is provided with a nut that is screwed onto the screw shaft, A gripper characterized in that one of the moving members is moved by rotating the screw shaft, thereby driving the belt and moving the other of the moving members.

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