High-torque ratchet wrench
11491613 ยท 2022-11-08
Assignee
Inventors
Cpc classification
B25B13/463
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A high-torque ratchet wrench including a wrench body having a driving aperture and a handle, and a drive member is disposed in the driving aperture and an axial position-limiting mechanism is disposed between the driving aperture and the drive member to limit the relative axial displacement. The external side wall of the drive member and the internal aperture side of the driving aperture form two cylindrical drive faces nested, wherein a first cylindrical drive face is provided with a pin recess, a pin is rotatably mounted in the pin recess, a relief is disposed on the side face of pin, the pin is connected with a resilient reset member, the pin is rotated with the resilience of a resilient reset member, and a relief is driven to stand out of the pin recess and contacts a second drive face.
Claims
1. A high-torque ratchet wrench comprising: a wrench body having a driving aperture (1) with a rounded through hole and a handle; a drive member (3) (a) disposed in the driving aperture (1) and (b) comprising an external side wall provided with a plurality of pin recesses (32) equally distributed along the external side wall of the drive member (3); an axial position-limiting mechanism disposed between the driving aperture and the drive member to prevent the drive member (3) from axially moving from the driving aperture (1) and further being released from the driving aperture (1), wherein the axial position-limiting mechanism is realized by adopting a snap spring (6) mounted in a snap spring recess (7); and a plurality of pins (4) each comprising (a) a relief (41) disposed on a side face of each of the plurality of pins (4), wherein the relief (41) has a direction of extension parallel to an axial direction of the driving aperture (1); (b) an arc surface (42) in a side and back of each of the pins (4) toward the relief (41), wherein the arc surface (42) fits an arc structure of the one pin recess (32) to reduce resistance encountered by each of the plurality of pins (4) during a process of rotation and to limit a rotation of each of the plurality of pins (4); (c) a stepped spring pressing portion (43) disposed at and projecting from an end of each of the plurality of pins (4) and (d) a flat bearing face (44) in plane parallel to an axial direction of each of the plurality of pins (4); wherein the external side wall of the drive member (3) and an internal aperture side of the driving aperture (1) form a first cylindrical drive face and a second cylindrical drive surface nested, each of the plurality of pins (4) is rotatably mounted in one of the plurality of pin recesses (32), each of the plurality of pins (4) is connected with a resilient reset member, each of the plurality of pins (4) is rotated with the resilience of the resilient reset member, the relief (4) is driven to stand out of the one of pin recesses (32) and contacts the second cylindrical drive face, and a distance between an outermost end point of the relief (41) and a central axis of each of the plurality of pins (4) is greater than a minimum distance between the second cylindrical drive face and the central axis of each of the plurality of pins (4), and the resilient reset member is a spring ring (5) that is arranged outside a circle surrounded by each of the plurality of pins (4), and the spring ring (5) is covered on the bearing face (44) of the spring pressing portion (43) of each of the plurality of pins (4) at the same time; the spring ring (5) contracts under the spring force, the spring ring j applies to the bearing face (44) of each of the plurality of pins (4) an elastic force which tends towards the central axis of the driving aperture (1), and under the decomposition of the bearing face (44), part of the elastic force is transformed to the force used for rotating each of the plurality of pins (4) clockwise so as to make the relief (41) of each of the plurality of pins (4) stand out of the one pin recess (32) gradually and contact the inner hole wall (11) of the driving aperture (1); namely, the diameter of an element formed by the drive member (3) and the pins (4) is gradually increased to expand and finally the external side face of this element is pressed against the inner hole wall (11) of the driving aperture (1); the external side face of the drive member (3) is provided with a fixed recess (33) used for limiting the axial movement of the spring ring (5), wherein the fixed recess (33) is intersected with the one pin recess (32) and the spring ring (5) is clamped in the fixed recess (33) to avoid axial movement; when the handle (2) rotates in a clockwise direction, a force of friction between an inner hole wall (11) of the driving aperture (1) and the relief (41) pushes the relief (41) in the clockwise direction, so that the pressure between the relief (41) of the pin (4) and the inner hole wall (11) of the driving aperture (1) is gradually increased and the force of friction presses the pin 4 against a side wall of the pin recess (32), and the pin (4) and the drive member (3) form a relatively stable structure under the pressure; the force of friction and the pressure push the drive member (3) to rotate by using the pin (4) to realize a torque transfer between the handle (2) via the driving aperture (1) and the drive member (3) and the fastener is engaged with the drive member (3); and when the handle (2) rotates in an anticlockwise direction, the force of friction between the inner hole wall (11) of the driving aperture (1) and the relief (41) drives the pin (4) to overcome an elastic force of the spring ring (5) and to rotate synchronously with the inner hole wall (11) of the driving aperture (1) in the anticlockwise direction, so that the spring ring (5) expands and gathers elastic potential energy under the force applied by the pin (4); due to the anticlockwise rotation of the pin (4), the relief (41) gradually moves in the direction of the pin recess (32) to increasingly reduce the pressure between the relief (41) and the inner hole wall (11) of the driving aperture (1) and also increasingly decrease the force of friction between the relief (1) and the inner hole wall (11) of the driving aperture (1), and finally, the relief (41) slides over the inner hole wall (11) of the driving aperture (1), so that the drive member (3) and the fastener engaged with the drive member (3) will not rotate synchronously with the handle (2) in the anticlockwise direction; and the handle (2) completes a disassembly of the fastener.
2. The high-torque ratchet wrench as claimed in claim 1, wherein the spring ring is covered on or pressed against the spring pressing portion, the spring ring is placed eccentrically from the central axis of the pin by using the force applied on the pin by a spring pressing portion, so that the pin rotates under a spring force of the resilient reset member.
3. The high-torque ratchet wrench as claimed in claim 2, wherein the fixed recess is disposed on the first cylindrical drive face and the second cylindrical drive face or the spring pressing portion to limit the axial movement of the spring ring.
4. The high-torque ratchet wrench as claimed in claim 3, wherein the pin side having the back toward the relief is an arc surface and the pin recess is provided with an arc structure adapting to the arc surface.
5. The high-torque ratchet wrench as claimed in claim 1, wherein ratchet teeth are evenly distributed on the second drive face, the direction of extension of the ratchet teeth is parallel to a central axis of the driving aperture, and the relief is pin teeth mated to the ratchet teeth.
6. The high-torque ratchet wrench as claimed in claim 5, wherein the two drive faces are provided with the snap spring recess at a corresponding location, and the snap spring is mounted in the snap spring recess.
7. The high-torque ratchet wrench as claimed in claim 6, further comprising a second driving aperture coupled with a second drive member, wherein the driving aperture is arranged on a first end of the handle, the second driving aperture is arranged on a second end of the handle opposite the first end, a mounting direction of each of the driving aperture and the second driving aperture is opposite to that of the drive member and the second drive member, respectively.
8. The high-torque ratchet wrench as claimed in claim 6, wherein a quincuncial through hole or a cylinder in the shape of a regular polyhedron standing out of a wrench surface is arranged in the center of the drive member.
9. The high-torque ratchet wrench as claimed in claim 6, wherein the resilient reset member is a ring-shaped spring.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16) Symbols of accompanying drawings: 1. driving aperture; 11. inner hole wall; 12. ratchet tooth 2. handle 3. drive member; 31. through-hole; 32. pin recess; 33. fixed recess; 34. cylinder; 4. pin; 41. relief; 42. arc surface; 43. spring pressing portion; 44. bearing face; 5. spring ring; 6. snap spring; 7. snap spring recess.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(17) The preferred embodiments, such as the shape and structure of each element involved, relative location and connection relationship between various parts, functions and operating principles of various parts, are described in detail by reference to the accompany drawings and the description of embodiments.
Embodiment 1
(18) As illustrated in
(19) As illustrated in
(20) To increase the force of friction between the relief 41 and the inner hole wall 11 of the driving aperture 1, the surface of the relief 41 and/or the inner hole wall 11 of the driving aperture 1 can be rough surface which has been polished, or knurled surface or striped surface, etc., and the basic principles of torque transfer are the same, so analysis will not be made in detail.
(21) The side of the pin 4 having the back toward the relief 41 is an arc surface 42 and the pin recess 32 is provided with an arc structure adapting to the arc surface 42, and the arc surface 42 fits the arc structure to reduce the resistance encountered by the pin 4 during the process of rotation and limit the rotation of the pin 4 properly.
(22) As illustrated in
(23) As illustrated in
(24) When the handle 2 rotates clockwise (as shown in the dotted arrow in
(25) As illustrated in
(26) It is understood that the relief 41 can be arranged at another ridge of the pin 4 and the direction of the bearing face 44 can be changed so as to change the direction of rotation of the drive member 3 in the driving aperture 1, and the engagement principle of the relief 41 with the inner hole wall 11 of the driving aperture 1 and the spring ring 5 is the same as that described above, so it will not be repeated.
(27) The limit of torque transfer of a conventional ratchet wrench is dependent on the strength of the engaging position of ratchet teeth, so in order to enhance the strength of the engaging position, the materials of ratchet teeth shall be improved (the costs shall be increased), or the engagement depth of the top of ratchet teeth shall be increased, but in this way, the idle stroke will be increased and the efficiency reduced when the wrench rotates in the opposite direction. In this embodiment, before the pin 4 is not mounted, the outer diameter of the drive member 3 is a and the inner diameter of the driving aperture 1 is a+b (a and b can be determined according to the specific machining requirements. b refers to the distance between the outermost end point of the pin relief and the first drive face after the pin is mounted), and in this case, the drive member 3 can flexibly rotate in the driving aperture 1; after the pin 4 and the spring ring 5 are disposed, one side of the relief 41 of the pin 4 will extend slightly upward to press against the inner hole wall 11 of the driving aperture 1 under the elastic force of the spring ring 5; namely, the motion distance of the relief 41 of the pin 4 is not more than b in the process of switching between normal rotation and reverse rotation of the wrench, so the pin 4 has an extremely small idle stroke when the wrench 2 stops rotating reversely and the reconnection and torque transfer between the drive member 3 and the driving aperture 1 can be realized after the wrench 2 stops rotating reversely, with the aim to improve the efficiency of the wrench.
(28) The single spring ring 5 is adopted in the above scheme to realize the resilient reset of all pins 4 at the same time, so that the structure can be greatly simplified, the parts and elements of the wrench can be conveniently assembled and the space usage can be reduced to realize a small, compact and easy-to-operate wrench structure. It is understood that the bearing face 44 should be an arc surface having the center of a circle based on the central axis of the driving aperture 1 in order to enhance the fit of the spring ring 5 and the spring pressing portion 43, and after the relief 41 is fitted with the inner hole wall 11 of the driving aperture 1, the arc surface can be perfectly fitted with the spring ring 5 so as to ensure the stability of the location of the relief 41, but the difficulty in the machining of this arc surface is relatively high and the corresponding functions still can be completed by using the planar bearing face 44, and the manufacturer can select and set the bearing face 44 as the plane or arc surface as needed. Spiral springs can be connected in an end-to-end manner to form the spring ring 5 and an elastic rubber ring can also be directly adopted, provided that the spring ring 5 are provided with the elastic force of contraction, and the torque transfer is not dependent on the size of elastic force of the spring ring 5; therefore, the requirements for elastic force of the spring ring 5 are not high and a common ring-shaped spring can be used, which will not be repeated herein.
(29) As illustrated in
(30) In this embodiment, the axial position-limiting mechanism adopts a snap spring 6 that is frequently used, the two drive faces are provided with a snap spring recess 7 at the corresponding location, and the snap spring 6 is mounted in the snap spring recess. The snap spring 6 is used to limit the axial movement of the drive member 3 in the driving aperture 1, having the advantages of small structure and easy mounting.
(31) Compared with the conventional wrenches with the ratchet meshing mode, the principle of torque transfer adopted by the wrench is entirely different, which relies on the pressing between the relief 41 and the inner hole wall 11 of the driving aperture 1; in this way, the upper limit of torque to be withstood by the wrench is dependent on the overall strength of the pin 4 and two drive faces, rather than the contact area and structural strength of rachet teeth, so the upper limit of torque transfer can be easily increased. When the wrench operates, the reliefs 41 of all pins 4 will contact the inner hole wall 11 of the driving aperture 1 so that the torque can be evenly distributed on all reliefs 41, and the manufacturer may increase the quantity of the pins 4 as needed and even arrange the pins 4 evenly on the external circumferential wall of the whole drive member 3 to obtain a greater limit of torque transfer.
(32) And because the pin 4 is disposed on the external circumferential wall of the drive member 3, its length can be slightly less than the width of the external circumferential wall of the drive member 3 and the whole side face of the relief 41 can contact the inner hole wall 11 of the driving aperture 1 to ensure sufficient force of friction between them, and the pressure between the relief 41 and the inner hole wall 11 of the driving aperture 1 is not concentrated on a point but distributed on the whole side face of the relief 41 to lower the requirement for the strength of the relief 41.
(33) In this embodiment, the driving aperture 1 is provided with a through-hole structure and both sides of the drive member 3 can be engaged with fasteners, so only the wrench is flipped over to realize the reverse torque transfer of the drive member 3 when a fastener is to be turned in the opposite direction.
Embodiment 2
(34) As illustrated in
(35) The principle of engagement of the ratchet teeth 12 with the relief 41 (i.e. snap teeth, the same below) is similar to that in Embodiment 1, as shown below:
(36) As illustrated in
(37) As illustrated in
(38) The mode of engagement of the ratchet teeth 12 with the relief 41 is adopted to lower the requirements for machining accuracy of the fit clearance between the relief 41 and the inner hole wall 11 of the driving aperture 1 and avoid the possible problem in Embodiment 1 that the reliefs 41 of some pins 4 fail to tightly press against the inner hole wall 11 of the driving aperture 1 due to insufficient accuracy of machining and further causing unevenly distributed stress between the drive member 3 and the driving aperture 1.
(39) It is understood that the relief 41 can also be arranged at another ridge of the pin 4 and the direction of tilt of the ratchet teeth 12 can be changed so as to change the direction of rotation of the drive member 3 in the driving aperture 1, and the engagement principle of the relief 41 with the ratchet teeth 12 and the spring ring 5 is the same as that described above, so it will not be repeated.
(40) Typically, the conventional ratchet wrench is provided with the mode of single-tooth or double-teeth meshing, and due to the limit on the strength of a single ratchet tooth, it is difficult to enhance the upper limit of torque transfer, and all pin teeth in this embodiment can mesh with the ratchet teeth 12, so that the torque can be evenly distributed on all pin teeth and the manufacturer may increase the quantity of pins 4 as needed, and in this embodiment, a plurality of pins 4 are evenly distributed on the external side face of the whole drive member 3 at regular intervals, so compared with the conventional ratchet wrench having the single-tooth or double-teeth meshing mode, a single ratchet tooth 12 or a pin tooth in this embodiment withstands less loads to lower the requirements for the material strength of the driving aperture 1, the ratchet teeth 12 and the pin teeth. And because the pin 4 and the ratchet tooth 11 are disposed on the drive face, its length can be close to the width of the drive face, and after the pin 4 and the ratchet tooth 12 mesh, the whole side face of the pin teeth can contact the whole side face of the ratchet teeth 12; therefore, the area of contract becomes larger and the requirements for the material strength of the driving aperture 1, the ratchet teeth 12 and the pin teeth are further lowered.
Embodiment 3
(41) As illustrated in
(42) It is understood that the spring ring 5 in Embodiments 1, 2 and 3 described above can also be arranged in a circle surrounded by all pins 4, and the spring ring 5 is pressed against the bearing face 44 of the spring pressing portion 43 of all pins 4 at the same time, and the elastic force that is produced by outward expansion of the spring ring 5 is employed to reset the pins 4.
(43) In addition,
(44) in the wrench as shown in
(45) In the wrench as shown in
INDUSTRIAL APPLICABILITY
(46) The high-torque ratchet wrench in the present invention has a significant influence on the fields of tightening and disassembly tools. Compared with the background art, the wrench in the present invention has a unique structure of torque transfer to greatly enhance the capability of torque transfer and simultaneously provide the whole wrench with a simple and compact structure, having very good utility.