Patent Application
20180311797
The present invention relates to a ratchet wrench, and more particularly, to a ratchet wrench having a simple structure and easily maintained.
U.S. Pat. No. 8,042,433 discloses a ratchet wrench and includes a parts replacement structure that ensures effort-saved and smooth operation and prevents parts from getting lost. The wrench has a handle having an end forming a head portion that rotatably receives therein a driving collar. A lid plate is fixed to the head portion to retain a pawl member that engages and controls the rotation of the driving collar. The pawl member includes a pusher pad positioned on and movable along a top of the lid plate. A retention block is set at the side of the pawl member opposite to the driving collar to apply a biasing force to the pawl member through a push bar. In this arrangement, the push bar will not get lost when the pawl member disengages from and thus releases the driving collar for replacement.
However, there are too many parts involved in this structure and includes the pawl member, the linking bar, the pusher pad, the retention block, the push bar and the resilient biasing element. These parts require a lot of time to be assembled. The ratcheting teeth have to be drilled a passage for receiving the linking bar to extend, the passage weakens the ratcheting teeth.
The pusher pad and the linking bar are adhered together, and the adherent gradually fails so that the pusher pad may drop. If the pusher pad and the linking bar are connected by way of threading, the pusher pad and the linking bar have to be drilled a threaded hole which also increases manufacturing cost.
When the ratcheting teeth are moved backward, the pusher pad is moved backward with the ratcheting teeth, and the pusher pad vibrates when rotating the wrench.
When the driving collar is removed, the resilient biasing element pushes the ratcheting teeth, the pusher pad, the retention block and the push bar to be removed from the collar chamber. The ratcheting teeth, the pusher pad, the retention block and the push bar are difficult to be assembled correctly by the users.
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 a ratchet wheel and a pawl received in the head thereof. Two control members are movably connected to the top and bottom of the head and retain the pawl. Each control member includes a restriction hole and the protrusion on the pawl is movably received in the restriction hole. When the pawl is not engaged with the ratchet wheel, the protrusions move in the two respective restriction holes, and the ratchet wheel is still located in the through hole of the head. When the control members move outward, the protrusions and the pawl are moved outward, so that the pawl is separated from the ratchet wheel, and the top face and bottom face of the pawl are separated from the lip of the ratchet wheel and ring. The ratchet wheel can be removed from the through hole.
The present invention will become more apparent 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
A ratchet wheel 20 is rotatably received in the through hole 11 and has a toothed portion 21 defined in the outer periphery thereof. A polygonal mounting hole 22 is defined through the ratchet wheel 20. A lip 24 extends radially from the top of the ratchet wheel 20, and an annular groove 23 is defined in the outer periphery of the bottom end of the ratchet wheel 20. A ring 30 is connected to the annular groove 23 of the ratchet wheel 20. The ring 30 includes an engaging groove 31. The top surface 32 of the ring 30 is located to face the lip 24. A resilient C-shaped clip 40 is engaged between the annular groove 23 and the engaging groove 31 to retain the ratchet wheel 20 in the through hole 11.
A pawl 50 is movably received in the first and third recesses 12, 13, and the pawl 50 has an engaging portion 51 defined in the front end thereof. The engaging portion 51 is engaged with the toothed portion 21 of the ratchet wheel 20. The engaging portion 51 of the pawl 50 includes a top face 511 and a bottom face 512, wherein the top face 511 contacts the lip 24, and the bottom face 512 contacts the ring 30. The ratchet wheel 20 is retained by the pawl 50. A curved face 52 is formed on one end of the rear end of the pawl 50, and contacts the inner periphery of the first recess 12. A cylindrical connection portion 54 formed on the other end of the rear end of the pawl 50. Two protrusions 53 respectively extend from the top and the bottom of the pawl 50. A resilient member 60 has one end connected to the connection portion 54, and the other end of the resilient member 60 is biased in third recess 13 to engage the engaging portion 51 with the toothed portion 21.
Two control members 70 are respectively and linearly movably received in the second recesses 14 and the two guide recesses 15, and contact two respective inner bottoms 16 of the guide recesses 15. Each control member 70 has a curved contact end 71 which contacts the stop wall 161 so that the two control members 70 are not separated from the two guide recesses 15. The stop wall 161 and the contact end 71 are complementary in shape. A restriction hole 72 is defined in each control member 70 and the protrusion 53 movably extends through the restriction hole 72 corresponding thereto. The inner diameter of each of the restriction holes 72 is larger than the outer diameter of each of the protrusions 53. When the pawl 50 is not engaged with the ratchet wheel 20, the protrusions 30 move in the restriction holes 72, and the top face 511 and the bottom face 512 are respectively in contact the lip 24 and the top surface 32 of the ring 30. so that the ratchet wheel 20 is still in the through hole 11.
Each restriction hole 72 has an inside 73 to contact the protrusion 53 to restrict the pawl 50 from being disengaged from the first recess 12. When each of the control members 70 moves outward the guide recesses 15, the inside 73 pushes the protrusion 53 and the pawl 50 to move outward to disengage the engaging portion 51 from the toothed portion 21. The top face 511 and the bottom face 512 are respectively separated from the lip 24 and the ring 30, so that the ratchet wheel 20 is able to be removed from the through hole 11. Each of the two control members 70 has a tubular portion 74 extending from a facing side 78/79 thereof which is in contact with the guide recess 151/152 corresponding thereto. Each tubular portion 74 has a passage 75 defined therein. One of the two tubular portions 74 has a tongue 77, and the other one of the two tubular portions 74 has a notch 76 in which the tongue 77 is inserted. A fastening member 80 extends through the two respective passages 75 and is connected with a clip 81 so that the two control members 70 are co-movable.
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The lip 24 and the ratchet wheel 20 can be two individual parts as shown in
In another embodiment, the ring 30 and the ratchet wheel 20 are threadedly connected to each other or force-fitted to each other.
In yet another embodiment, the ring 30 is force-fitted to the through hole 11, and the clip 40 is a ring-shaped clip, so that when the ratchet wheel 20 is removed from the head 100, the ring 30 and the clip 40 are not separated from the head 100. The advantages of the present invention are that: 1) the pawl 50 does not have a recess so as to have better strength; 2) When the pawl 50 is disengaged from the ratchet wheel 20, because the protrusions 53 are located in the restriction holes 72, the control members 70 do not shift; 3) The contact end 71 of each control member 70 is stopped by the stop wall 161 so as to restrict the control member 70 from being disengaged from the guide recess 15, and the pawl 50 is not disengaged from the first recess 12 by the inside 73; 4) When the pawl 50 is not engaged with the ratchet wheel 20, the protrusions 53 move in the restriction holes 72, and the top face 511 and the bottom face 512 are respectively in contact the lip 24 and the top surface 32 of the ring 30, so that the ratchet wheel 20 is still in the through hole 11; 5) When each of the control members 70 moves outward the guide recesses 15, the inside 73 pushes the protrusion 53 and the pawl 50 to move outward to disengage the engaging portion 51 from the toothed portion 21. The ratchet wheel 20 is able to be removed from the through hole 11; 6) When the pawl 50 is disengaged from the ratchet wheel 20, the two control members 70 do not shift. When the control members 70 shift in the guide recesses 15, the pawl 50 is driven in the first recess 12; and 7) The ratchet wheel 20 can be removed from the top or bottom of the head from the through hole 11 when the two control members 70 and the pawl 50 are shifted.
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.
