Patent Application
20200198105
The present invention relates to a ratchet wrench, and more particularly, to a ratchet wrench having two kinds of driving modes with torque sensing function.
The conventional ratchet wrench known to applicant is disclosed in U.S. Pat. No. 6,457,386 and comprises a main body, a drive shaft, a handle, a first annular gear, a second annular gear, a drive member, a pair of first pawls, a pair of second pawls, a rotating wheel, a control member, a plurality of balls, a plurality of compression springs, and a coiled spring. The main body has a through hole to receive the drive shaft, a pair of pivot holes, a groove to receive the drive member, and a plurality of inner teeth. The through hole communicates with the groove. The drive member has a through aperture and a chamber. The handle has a blind hole to receive the drive shaft. The first annular gear has a plurality of inner periphery serrations and a plurality of one-sided serrations. The second annular gear has a plurality of inner periphery teeth and a plurality of one-sided teeth. Each of the first pawls has a plurality of positioning recesses and a plurality of outer teeth. Each of the second pawls has a plurality of periphery serrations and a plurality of one-sided serrations. The rotating wheel has an oblong center hole. The control member has a pillar and a press disk disposed on the pillar. The pillar has a plurality of circular holes, and each of the circular holes of the pillar receives the corresponding compression spring and the corresponding ball. A pair of studs pass through the pivot holes of the main body and an annular recess of the drive shaft. The chamber of the drive member receives the first pawls and the second pawls. The first annular gear encloses one of the first pawls and one of the second pawls. The second annular gear encloses the other of the first pawls and the other of the second pawls. The pillar is inserted through the coiled spring, the oblong center hole of the rotating wheel, and the through aperture of the drive member. The coiled spring is disposed between the press disk and the rotating wheel, and each of the balls engages with one of the first pawls and the second pawls.
However, the two second annular gears are not adjustable relative to the driving member so that the engagement between the beveled teeth of the drive shaft and the two second annular gears may not be perfect as expected. Each of the driving member, the second annular gears and the drive shaft has its own tolerance, if the tolerance is too big, the engagement between the beveled teeth of the drive shaft and the two second annular gears is affected. The maximum diameter of the driving member has to be matched with the inner teeth of the inner teeth so that the driving member is supported by the inner teeth. The main body and the driving member are pivotably connected to the inner teeth, the pivotable connection between the main body and the driving member will be affected. The driving member is made as a one piece and this requires higher manufacturing cost.
Another ratchet wrench is disclosed in U.S. Pat. No. 9,038,505 has similar shortcomings as those in U.S. Pat. No. 6,457,386.
Another ratchet wrench is disclosed in U.S. Pat. No. 9,868,191 which is previous invention of the present inventor and has no torque sensing function.
The present invention intends to provide a ratchet wrench to eliminate the shortcomings mentioned above.
The present invention relates to a ratchet wrench and comprises an annular head, a driving unit, a control unit, a rotary member, a forcing unit and at least one torque sensor. The annular head receives the driving unit therein and a shaft extends from the annular head. The driving unit has a top part and a bottom part, a first toothed ring, a first pawl and at least one second pawl. The rotary member is rotatably inserted into an axial hole of the shaft and has one end mechanically engaged with the driving unit. The forcing unit includes a tubular handle and a display unit. The torque sensor is mounted on an outer periphery of the shaft. The shaft inserts into an axial chamber of the handle, so that the torque sensor is positioned between an inner wall of the axial chamber and the outer periphery of the shaft. When a user drives the handle to actuate the driving unit to drive a workpiece, the shaft is bended by the handle to produce a deformation. The torque sensor senses the deformation of the shaft to generate a torque sensing signal and transmits the torque sensing signal to the display unit, and the display unit converts the torque sensing signal to a torque value and displays the torque value.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
Referring to
The annular head 10 has a shaft 100 extending therefrom. Multiple ratchet teeth 11 are defined in the middle portion of the inner periphery of the annular head 10. A first space 12 and a second space 13 are respectively defined in the top and the bottom of the inner periphery of the annular head 10, wherein the first and second spaces 12, 13 have the same diameter which is larger than the diameter enclosed by the ratchet teeth 11. A first groove 14 is defined in the inner periphery of the first space 12, and a second groove 15 is defined in the inner periphery of the second space 13. A first shoulder 141 is formed between the first groove 14 and the first space 12, and a second shoulder 151 is formed between the second groove 15 and the second space 13. An axial hole 16 is defined axially in the shaft 100. A communication hole 17 is defined in the inner end of the axial hole 16 and communicates with the first and second spaces 12, 13. The communication hole 17 does not communicate the ratchet teeth 11. A receiving hole 18 is defined in one side of the shaft 100 and communicates with the axial hole 16.
The driving unit 20 is located in the annular head 10 and has a bottom part 21, a first toothed ring 23, a first pawl 24, two second pawls 25, a third pawl 26, a second toothed ring 27, a top part 28 and four locking members 29. The bottom plate 21 is a round disk and its periphery is engaged with the second groove 15. The bottom part 21 has a first disk 212 which contacts the second shoulder 151. The first disk 212 has four locking holes 217, a base 213 and two columns 214. Each column 214 has a first end face 216. The height of the two columns 214 from the first disk 212 is higher than that of the base 213. The base 213 and the two columns 214 each have a circular hole 215 defined therethrough, and each circular hole 215 communicates with the locking hole 217 corresponding thereto. A receiving room 218 is formed between the base 213 and the columns 214, and each of the columns 214 is a rectangular column. Three of the locking holes 217 respectively extend through the base 213 and the first end faces 216 of the columns 214.
The bottom part 21 has a driving end 219 extending from the first disk 212. The driving end 219 is a rectangular end for being connected to a rectangular recess of a workpiece (such as a socket, a connection rod or an adapter). The first toothed ring 23 is located on the first disk 212 and mounted to the base 213 and rotatably received in the second space 13. The first toothed ring 23 having first teeth 231 and first inner teeth 232. The first inner teeth 232 have the same number teeth and inner diameter as the ratchet teeth 11. The first pawl 24 is pivotably connected to the first disk 212 and located on one side of the two columns 214 and located away from the base 213. A first toothed portion is formed on each of two ends of the first pawl 24 and engaged with the first inner teeth 232. The first pawl 24 has a first hole 241 which is located in alignment with one of the locking holes 217. One of the two second pawls 25 is mounted to the base 213, and the other second pawl 25 is located above the first pawl 24. The two second pawls 25 are located symmetrically to each other relative to the columns 214. A second toothed portion is formed on each of two ends of each of the second pawls 25 so as to be engaged with the ratchet teeth 11. Each of the two second pawls 25 has a second hole 251. The second hole 251 of one of the second pawls 25 that is located above the base 213 is located in alignment with the circular hole 215 and the locking hole 217 corresponding thereto. The second hole 251 of the other one of the second pawls 25 that is located above the first pawl 24 is located in alignment with the first hole 241 and the locking hole 217 corresponding thereto. The third pawl 26 is pivotably connected to the top of the second pawl 25 on the base 213. A third toothed portion is formed on each of two ends of the third pawl 26. A third hole 261 is defined through the third pawl 26 and which is located in alignment with the second hole 251, the circular hole 215 and one of the locking holes 217 corresponding thereto. The second toothed ring 27 is rotatably received in the first space 12 and has second teeth 271 which face the first teeth 231 at a distance. The second toothed ring 27 has second inner teeth 272 which are engaged with the third toothed portions of the third pawl 26. The second toothed ring 27 is identical to the first toothed ring 23.
The top part 28 is a round disk and faces the bottom part 21 at a distance. The periphery 281 of the top part 28 is rotatably received in the first groove 14. The top part 28 has a second disk 282 which contacts the first shoulder 141. A block 283 extends from the second disk 282. The second toothed ring 27 is mounted to the block 283. The top part 28 has four connection holes 284 which are located in alignment with the circular holes 215 and the locking holes 217. The block 283 has a second end face 285 which is located close to the first end faces 216 of the columns 214. The second pawl 25 located above the first pawl 24 has a top face which is located close to the second end face 285. There are three connection holes 284 defined in the block 283. The top part 28 has a fourth hole 286 defined centrally therethrough, the fourth hole 286 is located in alignment with the receiving room 218.
The four locking members 29 respectively extend through the connection holes 284, the first hole 241, the second holes 251, the third hole 261 and the circular holes 215, and are locked to the locking holes 217 to pivotably connect the first pawl 24, the second pawls 25 and the third pawl 26 to the locking members 29. The locking members 29 each are a cylindrical member and has threads at one end thereof. Two of the locking members 29 extend through the connection holes 284 of the top part 28 and the circular holes 215 of the bottom part 21 and are locked to the locking holes 217 corresponding thereto. One of the four locking members 29 extends through the connection hole 284 of the top part 28, the second hole 251, the first hole 251 and the first hole 241 and is locked to the locking hole 217 corresponding thereto. Another one of the locking members 29 extends through the connection hole 284 of the top part 28, the third hole 261, the second hole 251 and the circular hole 215 and is locked to the locking hole 217 corresponding thereto.
The control unit 30 is connected to the driving unit 20 and has an operation disk 31, a shaft 32, a first controller 33, two second controllers 34 and a third controller 35. The operation disk 31 is pivotably connected to the top part 28 and protrudes beyond the annular head 10 such that the user can rotates the operation disk 31. The shaft 32 extends from the center of the operation disk 31 and is pivotably extends through the fourth hole 286 and inserted into the receiving room 218 of the bottom part 21. The first controller 33 is a semi-circular member and protrudes radially from the shaft 32 and is located in alignment with the inside of the first pawl 24 so as to control the direction of rotation of the first pawl 24. The two second controllers 34 each are a semi-circular member and symmetrically extend from the outside of the shaft 32 and are located in alignment with two respective insides of the second pawls 25 so as to control the direction of rotation of the two second pawls 25. The third controller 35 protrudes radially from the shaft 32 and is located in alignment with the inside of the third pawl 25 so as to control the direction of rotation of the third pawl 25.
The rotary member 40 is pivotably located in the axial hole 16 and has third teeth 41 at the front end thereof. The front end of the rotary member 40 is for inserting into the inner periphery of the annular head 10 and for mechanically connecting with the driving unit 20. The third teeth 41 are engaged with the first and second teeth 231, 271 at the communication hole 17. A rectangular recess 42 is defined in the rear end of the rotary member 40. An engaging groove 43 is defined in the outside of the rotary member 40 and located in alignment with the receiving hole 18. The driving unit 20 will be actuated to drive the workpiece when the rotary member 40 is rotated in the axial hole 16.
The forcing unit 50 includes a tubular handle 51, a display unit 53, a battery seat 54 and at least one battery 55. The handle 51 has an axial chamber 511 which is communicated with the axial hole 16. A receiving inner portion 515 is defined in a front portion 512 of the axial chamber 511. The receiving inner portion 515 is mounted with the shaft 100 of the annular head 10. An outer periphery of the handle 51 is defined a lateral recess 514 therefrom. The lateral recess 514 is in communication with the axial chamber 511. A driving part 520 is received in the axial chamber 511. The driving part 520 is sleeved with the rectangular recess 42 of the rear end of the rotary member 40. When the driving part 520 rotates to rotate the rotary member 40, the driving unit 20 is actuated by the rotary member 40 so that the driving end 219 drives the workpiece. The display unit 53 is received in the lateral recess 514. The battery seat 54 is disposed in a rear portion of the axial chamber 511, and the battery seat 54 has a receiving chamber 541 for accommodating the at least one battery 55. The at least one battery 55 provides electric power for the display unit 53. The forcing unit 50 includes an electric motor 52. The at least one battery 56 provides electric power for the electric motor 52. The electric motor 52 is received and fixed in the chamber 511. The driving part 520 has a connecting port 521 and is fixedly mounted on an output end of the electric motor 52. The connecting port 521 is connected with the rear end of the rotary member 40. When the electric motor 52 starts to rotate the driving part 520, the driving part 520 rotates the rotary member 40, so that the rotary member 40 actuates the driving unit 20 to drive the workpiece. The display unit 53 includes a starting switch 530. The starting switch 530 is for controlling the electric motor 52 on and off. A wall of the axial chamber 511 is defined two penetrating holes 516 therethrough, an outer periphery of the electric motor 52 is defined two locking holes 522 therefrom, and two locking pins 57 respectively mount in the corresponding penetrating hole 516 and locking hole 522 so as to fix the electric motor 52 in the axial chamber 511. A cover 56 is mounted to an opening 513 of a rear end portion of the axial chamber 511 for limiting the battery seat 54 in the axial chamber 511 and limiting the at least one battery 55 in the battery seat 54. The driving part 520 of the forcing unit 50 is provided a rotating force by a pneumatic power source, an electric power source or a manual power source. The display unit 53 includes a wireless transmitting module 532, the wireless transmitting module 532 transmits the torque value to a mobile phone 80 or a computer 81 (referring to
The bead 60 is located in the receiving hole 18 and engaged with the engaging groove 43 so that the rotary member 40 is restricted by the bead 60 and does not drop from the axial hole 16. When the rotary member 40 is rotated by the forcing unit 50, the bead 60 rolls in the engaging groove 43 to reduce wearing. The end piece 61 is securely engaged with the receiving hole 18 and restricts the bead 60 from dropping out from the receiving hole 18. The end piece 61 has outer threads which are threadedly connected to the receiving hole 18. The end piece 61 limits the bead 60 in the receiving hole 18.
The at least one torque sensor 70 is mounted on an outer periphery of the shaft 100, received in the axial chamber 511 and electrically connected with the display unit 53. When a user drives the handle 51 to actuate the driving unit 20 to drive the workpiece, the shaft 100 is bended by the handle 51 to produce a deformation. The at least one torque sensor 70 senses the deformation of the shaft 100 to generate a torque sensing signal and transmits the torque sensing signal to the display unit 53, and the display unit 53 converts the torque sensing signal to a torque value and displays the torque value. In one embodiment, the at least one torque sensor 70 is two torque sensors 70 (referring to
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While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
