LOCKING DEVICE

Abstract

Locking device, comprising: a cuff body (10) with two surfaces facing opposite directions, an inner circumference, a mounting opening (11) which is defined in one of the two surfaces of the cuff body (10), an insertion opening (12) which is defined in the other of the two surfaces of the cuff body (10) and is aligned coaxially with the mounting opening (11), a chamber (13) which is formed inside the cuff body (10) and is connected to the mounting opening (11) and the insertion opening (12), several first concave depressions (14) formed in the inner circumference of the cuff body (10) and causing the mounting opening (11) to have a corrugated contour, and several first arc-shaped grooves, which are arranged in a ring shape and separated from each other around the insertion opening (12) and are connected to the chamber (13), a roller cage (20) which is installed in the chamber (13) and has several slots (21) which are each aligned according to the several first concave recesses (14), wherein each of the multiple slots (21) has a groove which is arranged in the direction of the mounting opening (11), and several rollers (22), each rotatably mounted in the several slots (21) and correspondingly bearing against the several first concave recesses (14), a clamping group (30) which is installed in the chamber (13) and inside the roller cage (20), wherein the terminal group (30) has several clamping blocks (31) arranged in a ring shape inside the roller cage (20), wherein each of the multiple terminal blocks (31) is curved and has an outer circumferential surface that faces the inner circumference of the cuff body (10), and wherein several second concave depressions (311) are formed in the outer circumferential surface, wherein the several second concave recesses (311) of the several clamping blocks (31) bear against the several rollers (22) and make each of the several rollers (22) rotatable along a corresponding of the several first concave recesses (14) and a corresponding of the several second concave recesses (311), wherein each of the multiple clamping blocks (31) also has multiple radial grooves (313) which each extend along the radial directions of the clamping block (31), wherein the clamping group (30) further comprises several first balls which are rotatably received in the several first arcuate grooves and the several radial grooves (313) of the several clamping blocks (31), wherein the several clamping blocks (31) are rotatable around the insertion opening (12) by the several first balls which are rotatably received in the several first arcuate grooves and the several radial grooves (313) of the several clamping blocks (31), and a locking plate (40) which is attached to the cuff body (10) to retain the roller cage (20), the multiple rollers (22) and the clamping assembly (30) inside the cuff body (10), wherein the locking plate (40) has a surface which rests against the cuff body (10), the roller cage (20), the multiple rollers (22) and the multiple clamping blocks (31).

Description

1. Field of the invention

[0001] The present invention relates to a locking device and in particular to a locking device suitable for firmly clamping objects. 2. Description of the state of the art

[0002] A locking device is used to tighten or loosen a fastener attached to an object and is applied to holding devices such as a toolholder tightener or a wrench. A conventional locking device employs a keyway to engage the object or clamps the object by abutting against it. The conventional locking device, mounted on a toolholder fixture, includes a frame, a collar body, a needle roller cage, a plurality of needle rollers, and a lock plate. The collar body is mounted to the frame and has an inner peripheral surface in which a plurality of concave recesses are defined. The needle roller cage has a plurality of slots.The plurality of needle rollers are retained in the plurality of slots and are respectively arranged in correspondence with the plurality of concave recesses. The locking plate is fixed to the sleeve body to retain the needle roller cage and the plurality of needle rollers inside the sleeve body.

[0003] When a tool holder is inserted into the sleeve body, the multiple needle rollers rest against the tool holder and are pressed toward the multiple concave recesses. The multiple needle rollers then rest against the multiple concave recesses, are clamped between the sleeve body and the tool holder, and are unable to rotate.

[0004] Devices of the type mentioned are known from the prior art.

[0005] For example, the documents US 1 412 688 A, US 2010 / 0 270 756 A1 and DE 36 44 442 C1 each show devices of the type mentioned, wherein roller-shaped elements clamp and lock a picked-up object by sliding along an inner contour.

[0006] Conventional locking devices lock the tool holder in place using multiple needle rollers, which are unable to rotate. However, each of the multiple needle rollers contacts the tool holder in a linear manner with a limited contact area. Therefore, the tool holder is very likely to wobble within the sleeve body and cannot be held securely by conventional locking devices.

[0007] The document NL 1013470 C2 shows a locking device with movable clamping jaws which, in the locked state, form a flat contact with the object to be picked up, although no grooves are formed in the cuff body of this device.

[0008] In order to eliminate the deficiencies of the conventional locking devices, the present invention provides a locking device that can reduce or avoid the aforementioned problems.

[0009] The main object of the present invention is to provide a locking device which can stably hold and tighten an object.

[0010] The locking device includes a sleeve body, a roller cage, a plurality of rollers, and a clamp assembly. The sleeve body has a chamber formed inside the sleeve body and a plurality of concave recesses formed in an inner periphery of the sleeve body. The roller cage is mounted in the chamber. The clamp assembly has a plurality of clamp blocks arranged annularly inside the roller cage. Each of the plurality of clamp blocks is curved and has a plurality of second concave recesses formed in an outer peripheral surface of the clamp block. The plurality of rollers are rotatably mounted on the roller cage and are received in the plurality of first concave recesses and the plurality of second concave recesses, respectively.Each of the plurality of rollers is rotatable along a corresponding one of the plurality of first concave recesses and a corresponding one of the plurality of second concave recesses.

[0011] Further objects, advantages and novel features of the invention will become more apparent from the following detailed description with reference to the accompanying drawings. In the drawings: Fig. 1 is a perspective view of a locking device according to the present invention, Fig. 2A is an exploded perspective view of the locking device of Fig. 1, Fig. 2B is a partially enlarged perspective view of a roller cage of the locking device of Fig. 2A, Fig. 3 is another perspective view of the locking device of Fig. 1, Fig. 4 is a side view of the locking device of Fig. 1 in partial section, Fig. 5 is a top view of the locking device of Fig. 1 in cross section, Fig. 6 is a schematic top view of the locking device of Fig. 1 in cross section, Fig. Figure 7 is a schematic perspective view of the locking device of Fig. 1, which shows the locking device when assembled with a frame of a tool holder tightening device, and Fig. Figure 8 is another schematic perspective view of the locking device of Fig. 1, which shows the locking device when connected to a handle.

[0012] Referring to Fig. 1 to 4, a locking device according to the present invention comprises a sleeve body 10, a roller cage 20, a plurality of rollers 22, a clamping group 30 and a locking plate 40.

[0013] The cuff body 10 is a circular bracket and has two surfaces, an inner circumference, a mounting hole 11, an insertion hole 12, a chamber 13, a plurality of first concave recesses 14, and a plurality of guide grooves 15. The two surfaces of the cuff body 10 face opposite directions. The mounting hole 11 is formed in one of the two surfaces of the cuff body 10. The insertion hole 12 is formed in the other of the two surfaces of the cuff body 10. The insertion hole 12 and the mounting hole 11 are coaxially aligned with each other. The chamber 13 is formed inside the cuff body 10. The chamber 13 is connected to the mounting hole 11 and the insertion hole 12. The plurality of first concave recesses 14 are formed in the inner circumference of the cuff body 10. The plurality of first concave recesses 14 ensure that the mounting opening 11 has a wavy contour.

[0014] The plurality of guide grooves 15 are a plurality of first arcuate grooves and a plurality of second arcuate grooves. The plurality of first arcuate grooves are arranged annularly and separately from each other around the insertion opening 12. The plurality of first arcuate grooves communicate with the chamber 13. The plurality of second arcuate grooves are also arranged annularly and separately from each other around the insertion opening 12. The plurality of second arcuate grooves surround the plurality of first arcuate grooves, are arranged adjacent to the plurality of first arcuate grooves, and are located between the first arcuate grooves and the inner periphery of the sleeve body 10. A plurality of threaded holes 16 are formed in one of the two surfaces of the sleeve body 10 and are arranged around the mounting opening 11.

[0015] The roller cage 20 is mounted in the chamber 13 via the mounting hole 11. The roller cage 20 is circular and has an axial direction and a plurality of slots 21, each aligned with the plurality of first concave recesses 14. Each of the plurality of slots 21 has a groove arranged toward the mounting hole 11 and two inner bulges extending along the axial direction of the roller cage 20 and facing each other. The plurality of rollers 22 are rotatably mounted in the plurality of slots 21, respectively, and abut against the plurality of first concave recesses 14, respectively. Each of the plurality of rollers 22 is retained by the two inner bulges of a corresponding one of the plurality of slots 21.

[0016] The clamping assembly 30 is mounted in the chamber 13 and within the roller cage 20. The clamping assembly 30 includes a plurality of clamping blocks 31, a plurality of balls 32, and an O-ring 33. The plurality of clamping blocks 31 are arranged in a ring shape within the roller cage 20. Each of the plurality of clamping blocks 31 is curved and has a plurality of radial directions, an outer peripheral surface, an inner peripheral surface, an inner flange, a plurality of second concave recesses 311, a receiving groove 312, and a plurality of radial grooves 313. The outer peripheral surface and the inner peripheral surface of each of the plurality of clamping blocks 31 face in opposite directions to each other. The plurality of outer peripheral surfaces of the plurality of clamping blocks 31 face the inner periphery of the sleeve body 10. The inner flange of each of the plurality of terminal blocks 31 protrudes inward from the inner peripheral surface of the terminal block 31 and is arranged adjacent to the insertion opening 12.The receiving groove 312 of each of the plurality of clamp blocks 31 is formed in the inner flange of the clamp block 31, is curved, and faces the mounting opening 11. The plurality of receiving grooves 312 of the plurality of clamp blocks 31 are arranged in a ring shape. The plurality of radial grooves 313 of each of the plurality of clamp blocks 31 extend along the plurality of radial directions of the clamp block 31, respectively. The plurality of balls 32 are a plurality of first balls and a plurality of second balls. The plurality of first balls are rotatable and are respectively received in the plurality of first arcuate grooves and the plurality of radial grooves 313 of the plurality of clamp blocks 31. The plurality of second balls are rotatable and are respectively received in the plurality of second arcuate grooves and the plurality of radial grooves 313 of the plurality of clamp blocks 31. The O-ring 33 is received in the plurality of receiving grooves 312 of the plurality of clamp blocks 31.

[0017] The locking plate 40 is annular and is attached to the sleeve body 10 to retain the roller cage 20, the plurality of rollers 22, and the clamp assembly 30 inside the sleeve body 10. The locking plate 40 has a plurality of through holes 41 formed through the locking plate 40. A plurality of screws 42 pass through the plurality of through holes 41, respectively, and are screwed into the plurality of threaded holes 16, respectively, to connect the locking plate 40 and the sleeve body 10.

[0018] Referring to Fig. 5 and Fig. 6, an object such as a tool holder is mounted through the locking plate 40, the mounting hole 11, the chamber 13, and the plurality of clamp blocks 31, and then goes out through the insertion hole 12. The object abuts against the plurality of clamp blocks 31. Since each of the plurality of clamp blocks 31 is a curved block, a contact area between the object and each of the plurality of clamp blocks 31 is increased, and friction between the object and each of the plurality of clamp blocks 31 increases accordingly. The plurality of clamp blocks 31 against which the object abuts are pressed toward the plurality of first concave recesses 14, and the plurality of rollers 22 are clamped by the plurality of first concave recesses 14 and the plurality of second concave recesses 311, respectively.The plurality of clamp blocks 31 are movable toward or away from the plurality of first concave recesses 14 by the plurality of first balls and the plurality of second balls received in the plurality of radial grooves 313.

[0019] When the object is tightened by a fastener, the object rotates relative to the cuff body 10, and the plurality of clamp blocks 31 rotate with the object. The plurality of clamp blocks 31 rotate around the insertion opening 12 through the plurality of first balls received in the plurality of first arcuate grooves and the plurality of second balls received in the plurality of second arcuate grooves.

[0020] Each of the plurality of rollers 22 rotates and moves between a corresponding one of the plurality of first concave recesses 14 and a corresponding one of the plurality of second concave recesses 311 of the plurality of clamping blocks 31. Eventually, each roller 22 becomes stuck between the corresponding first concave recess 14 and the corresponding second concave recess 311 and is unable to rotate and move. As a result, the object and the plurality of clamping blocks 31 are unable to rotate relative to the cuff body 10, and the object is stably held by the locking device according to the present invention.

[0021] Compared with the conventional locking device that engages the object through a plurality of needle rollers, the locking device according to the present invention engages the object through the plurality of clamp blocks 31, thereby increasing the contact area and friction between the object and each of the plurality of clamp blocks 31. Moreover, each of the plurality of rollers 22 is stuck between a corresponding one of the plurality of first concave recesses 14 and a corresponding one of the plurality of second concave recesses 311 of the plurality of clamp blocks 31. In the manner described above, the locking device according to the present invention can stably hold the object when the fastener attached to the object is tightened. The locking device according to the present invention ensures that a tool is firmly attached to the object and improves machining quality.

[0022] The plurality of first balls received in the plurality of first arcuate grooves and the plurality of second balls received in the plurality of second arcuate grooves guide the plurality of clamp blocks 31 and facilitate the plurality of clamp blocks 31 to rotate smoothly around the insertion opening 12.

[0023] Referring to Fig. 7, the locking device according to the present invention can be mounted on a frame 50 of a tool holder tightening device. The frame 50 has a base 51, two support arms 52, and a pivot seat 53. The two support arms 52 are mounted upright on the base 51. The pivot seat 53 is arranged between the two support arms 52 and is pivotally connected to the two support arms 52. The locking device according to the present invention is connected to the pivot seat 53 to form the tool holder tightening device. Referring to Fig. 8, the locking device according to the present invention can be assembled with a handle 60. The handle 60 is connected to an outer peripheral surface of the sleeve body 10 to form a holder for tightening or loosening fasteners, such as nuts or bolts.

Claims

[1] Locking device comprising: a cuff body (10) with two surfaces facing opposite directions, an inner circumference, a mounting opening (11) defined in one of the two surfaces of the sleeve body (10), an insertion opening (12) defined in the other of the two surfaces of the sleeve body (10) and coaxially aligned with the mounting opening (11), a chamber (13) formed inside the sleeve body (10) and communicating with the mounting opening (11) and the insertion opening (12), a plurality of first concave recesses (14) formed in the inner circumference of the sleeve body (10) and causing the mounting opening (11) to have a corrugated contour, and a plurality of first arcuate grooves arranged in a ring shape and separated from one another around the insertion opening (12) and communicating with the chamber (13), a roller cage (20) mounted in the chamber (13) and having a plurality of slots (21) each aligned with the plurality of first concave recesses (14), wherein each of the plurality of slots (21) has a groove arranged in the direction of the mounting opening (11), and a plurality of rollers (22) each rotatably mounted in the plurality of slots (21) and correspondingly abutting the plurality of first concave recesses (14), a clamping group (30) mounted in the chamber (13) and inside the roller cage (20), wherein the clamping group (30) has a plurality of clamping blocks (31) arranged in a ring shape within the roller cage (20), wherein each of the plurality of clamping blocks (31) is curved and has an outer peripheral surface facing the inner circumference of the sleeve body (10), and wherein a plurality of second concave recesses (311) are formed in the outer peripheral surface, wherein the plurality of second concave recesses (311) of the plurality of clamping blocks (31) respectively abut the plurality of rollers (22) and make each of the plurality of rollers (22) rotatable along a corresponding one of the plurality of first concave recesses (14) and a corresponding one of the plurality of second concave recesses (311), wherein each of the plurality of clamping blocks (31) further comprises a plurality of radial grooves (313) each extending along the radial directions of the clamping block (31), wherein the clamping group (30) further comprises a plurality of first balls which are rotatably received in the plurality of first arcuate grooves and the plurality of radial grooves (313) of the plurality of clamping blocks (31), respectively, wherein the plurality of clamping blocks (31) are rotatable around the insertion opening (12) by the plurality of first balls which are rotatably received in the plurality of first arcuate grooves and the plurality of radial grooves (313) of the plurality of clamping blocks (31), respectively, and a locking plate (40) attached to the sleeve body (10) to retain the roller cage (20), the plurality of rollers (22) and the clamping group (30) inside the sleeve body (10), wherein the locking plate (40) has a surface that abuts the sleeve body (10), the roller cage (20), the plurality of rollers (22) and the plurality of clamping blocks (31). [2] Locking device according to claim 1, in which the sleeve body (10) further comprises a plurality of second arcuate grooves arranged annularly and separately from each other around the insertion opening (12), arranged adjacent to the plurality of first arcuate grooves and communicating with the chamber (13), and the clamping group (30) further comprises a plurality of second balls rotatably received in the plurality of second arcuate grooves and the plurality of radial grooves of the plurality of clamping blocks (31), respectively. [3] Locking device according to one of claims 1 or 2, in which each of the several terminal blocks (31) has an inner peripheral surface facing in a direction opposite to the outer peripheral surface of the clamping block (31), wherein an inner flange projects inwardly from the inner peripheral surface of the terminal block (31) and is arranged adjacent to the insertion opening (12), and wherein a receiving groove (312) is formed in the inner flange of the clamping block (31) and faces the mounting opening (11), and the plurality of receiving grooves (312) of the plurality of clamping blocks (31) are arranged in a ring shape and serve to receive an O-ring in order to hold the plurality of clamping blocks (31) in their positions. [4] Locking device according to claim 3, wherein the sleeve body (10) has a plurality of threaded bores (16) formed in one of the two surfaces of the sleeve body (10) and arranged around the mounting opening (11), and several screws (42) are passed through the locking plate (40), are screwed accordingly to the several threaded holes (16) and connect the locking plate (40) to the sleeve body (10). [5] A locking device according to claim 4, wherein each of the plurality of slots (21) has two inner bulges extending along an axial direction of the roller cage (20), facing each other, and having a concave shape corresponding to a peripheral surface of each of the plurality of rollers (22) to retain a corresponding one of the plurality of rollers (22). [6] A locking device according to claim 5, wherein the locking device is suitable for mounting on a frame (50) to form a tool holder tightening device. [7] A locking device according to claim 5, wherein an outer peripheral surface of the sleeve body (10) is connected to a handle (60) to form a holder for tightening or loosening fasteners. [8] Locking device according to one of claims 1 or 2, wherein the locking device is suitable for mounting on a frame (50) to form a tool holder tightening device. [9] A locking device according to any one of claims 1 or 2, wherein an outer peripheral surface of the sleeve body (10) is connected to a handle (60) to form a holder for tightening or loosening fasteners.

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