A wrench

Abstract

This invention provides a wrench, including a handle, a drive assembly, and an elastic element. The handle has a mounting portion for mounting a screwdriver. The drive assembly, which drives the screwdriver to rotate, is slidably and rotatably mounted on the handle. The sliding direction of the drive assembly relative to the handle is consistent with the extension / retraction direction of the elastic element. The drive assembly has several force-applying surfaces for finger pressing, which are parallel to the rotation axis of the drive assembly. Along the length of the force-applying surface, each surface includes a proximal point closest to the rotation axis. The angle between the plane passing through the proximal point and the rotation axis and the force-applying surface is θ, where 0 < θ < 90°. The length of the force-applying surface is perpendicular to the rotation axis. The two ends of the elastic element along the extension / retraction direction respectively abut against the drive assembly and the handle. The force exerted by the elastic element on the drive assembly is directed towards the side where the mounting portion is located. This design prevents excessive torque output from the wrench during use.

Description

Technical Field

[0001] This invention relates to screw installation tools, specifically to a wrench. Background Technology

[0002] In clinical practice, hand-held or machine-operated screwdrivers are commonly used to remove implant cover screws and abutment center screws. During use, the screwdriver is connected to a ratchet wrench, and the screwdriver tip is attached to the screw on the implant to be tightened or loosened. The screw is tightened or loosened by moving the ratchet wrench back and forth. However, when using a ratchet wrench to tighten screws, excessive torque can easily cause damage to the screw, wrench, implant, or even bone. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems mentioned in the background art above, and to provide a wrench that can prevent excessive torque during use.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A wrench includes a handle, a drive assembly, and an elastic element. The handle has a mounting portion for mounting a screwdriver. The drive assembly is used to drive the screwdriver to rotate and is slidably and rotatably mounted on the handle. The sliding direction of the drive assembly relative to the handle is consistent with the extension and retraction direction of the elastic element. The drive assembly has a plurality of force-applying surfaces for finger pressing, and the force-applying surfaces are parallel to the rotation axis of the drive assembly. Along the length direction of the force-applying surface, the force-applying surface includes a proximal point closest to the rotation axis, wherein the angle between the plane passing through the proximal point and the rotation axis and the force-applying surface is θ, 0 < θ < 90°. The length direction of the force-applying surface is perpendicular to the rotation axis. The two ends of the elastic element along the extension and retraction direction respectively abut against the drive assembly and the handle, and the force exerted by the elastic element on the drive assembly is directed towards the side where the mounting portion is located.

[0006] Furthermore, the drive assembly includes a drive wheel and a turn wheel coaxially arranged. The drive wheel is slidably and rotatably mounted on the handle and is used for transmission connection with the screwdriver. The turn wheel is synchronously rotatably connected to the drive wheel. The force-applying surface is disposed on the turn wheel. One end of the elastic member elastically abuts against the drive wheel.

[0007] Furthermore, the outer peripheral wall of the actuating wheel is provided with a plurality of actuating protrusions spaced apart along the circumference, and each actuating protrusion has a force-applying surface on its side facing away from the center of the actuating wheel.

[0008] Furthermore, the drive wheel includes an axle and a disc rotatably fitted onto the axle. Both ends of the axle are slidably connected to the handle. The disc is used for conveying a screwdriver. One end of the elastic element elastically abuts against the axle. The actuating wheel is fitted onto the axle.

[0009] Furthermore, the actuating wheel is detachably mounted on the axle.

[0010] Furthermore, the cross-section of the axle is non-circular, and the center of the actuating wheel is provided with a insertion groove. The cross-section of the insertion groove is non-circular and matches the cross-section of the axle. The axle is inserted into the insertion groove.

[0011] Furthermore, the sliding direction of the drive wheel is parallel to the length direction of the handle.

[0012] Furthermore, the mounting part is a mounting hole provided at one end of the handle, and the mounting part is used for inserting a screwdriver.

[0013] Furthermore, the handle is provided with an installation space, which is connected to the mounting part. The drive wheel is located in the installation space, and the elastic element is housed within the installation space. The actuating wheel is located outside the installation space.

[0014] Furthermore, a groove is recessed on the inner wall of the mounting part; a fixing groove is provided on the outer peripheral wall of the screwdriver, and a retaining ring is provided in the fixing groove, the retaining ring engaging with the groove.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects:

[0016] The aforementioned wrench has a force-applying surface on its drive assembly. The structure of the force-applying surface allows it to determine the direction of the external force. When the external force is greater than a preset value, the external force in that direction can compress the elastic element, causing the drive assembly to slide away from the mounting part and separate from the screwdriver, thereby disconnecting the power transmission. This limits the torque output of the wrench during use and prevents excessive torque. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of a wrench according to a preferred embodiment of the present invention;

[0018] Figure 2 for Figure 1 A schematic diagram of the main structure of the wrench shown;

[0019] Figure 3 for Figure 1 A top view of the wrench shown.

[0020] Figure 4 for Figure 3 A schematic cross-sectional view of the wrench along line AA;

[0021] Figure 5 for Figure 4 A magnified view of the wrench at point I;

[0022] Figure 6 This is a three-dimensional structural diagram of a screwdriver in a preferred embodiment of the present invention;

[0023] Figure 7 for Figure 6 The diagram shows a cross-sectional view of the screwdriver in the longitudinal section.

[0024] Figure 8 A schematic diagram illustrating the force analysis of the lever in use according to a preferred embodiment of the present invention;

[0025] Figure 9 This is an exploded view of a wrench according to a preferred embodiment of the present invention;

[0026] Figure 10 for Figure 3 The diagram shows the installation of the wrench after the actuation wheel has been flipped.

[0027] Explanation of main component symbols

[0028] 10. Wrench; 11. Handle; 112. Mounting part; 114. Slot; 116. Mounting space; 117. Sliding groove; 118. Sliding hole; 119. Guide rod; 12. Drive assembly; 13. Drive wheel; 131. Axle; 132. Wheel disc; 134. Guide rod; 15. Elastic element; 17. Actuating wheel; 171. Actuating protrusion; 172. Force application surface; 174. Insertion groove; 30. Screwdriver; 31. Base; 311. Fixing groove; 33. Drive shaft; 34. Driven wheel; 35. Screwdriver tip; 36. Limiting flange; 37. Retaining ring. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] Please see Figure 1 A preferred embodiment of the present invention provides a wrench for driving a screwdriver 30 to rotate for operation. The wrench 10 includes a handle 11, a drive assembly 12, and an elastic element 15. The drive assembly 12 is slidably and rotatably disposed on the handle 11, and the two ends of the elastic element 15 along the extension and retraction direction respectively abut against the drive assembly 12 and the handle 11.

[0033] The handle 11 is for the user to grip. In this embodiment, the handle 11 is generally elongated cylindrical in shape, and its length direction is parallel to the first direction X. One end of the handle 11 is provided with a mounting portion 112 for mounting a screwdriver 30. Please refer to [reference needed]. Figure 4 and Figure 5 In this embodiment, the mounting portion 112 is a mounting hole provided at one end of the handle 11, and the mounting portion 112 is used for inserting a screwdriver 30. Specifically, the mounting portion 112 passes through the opposite sides of the handle 11 along the second direction Z, which is perpendicular to the first direction X, to form a through-hole structure. In this embodiment, the bottom end of the inner wall of the mounting portion 112 is also recessed with a slot 114. The handle 11 is also provided with a mounting space 116 for mounting the drive wheel 13 and the elastic element 15. The mounting space 116 communicates with the mounting portion 112. In this embodiment, the mounting space 116 is located between the mounting portion 112 and the end of the handle 11 opposite to the mounting portion 112, and the mounting space 116 is set close to the mounting portion 112. The mounting space 116 also passes through the opposite sides of the handle 11 along the third direction Y to facilitate the installation of the drive wheel 13 and the elastic element 15. The third direction Y is perpendicular to both the first direction X and the second direction Z.

[0034] The drive assembly 12 is used to drive the screwdriver 30 to rotate. The drive assembly 12 is slidably and rotatably mounted on the handle 11, and the sliding direction of the drive assembly 12 relative to the handle 11 is consistent with the extension and retraction direction of the elastic member 15. Please refer to [further details omitted]. Figure 3 and Figure 8 The drive assembly 12 is provided with a plurality of force-applying surfaces 172 for finger pressing. The force-applying surfaces 172 are parallel to the rotation axis of the drive assembly 12. Along the length direction of the force-applying surface 172, the force-applying surface 172 includes a proximal point closest to the rotation axis. The angle between the plane α passing through the proximal point and the rotation axis of the drive assembly 12 and the force-applying surface 172 is θ, where 0 < θ < 90°. The length direction of the force-applying surface 172 is perpendicular to the rotation axis of the drive assembly 12.

[0035] Please see also Figure 2 , Figure 5 and Figure 9 The drive assembly 12 includes a drive wheel 13 and a turn wheel 17 coaxially arranged. The drive wheel 13 is slidably and rotatably mounted on the handle 11 and is used for transmission connection with the screwdriver 30. In this embodiment, the drive wheel 13 is slidably mounted in the mounting space 116 and can rotate relative to the handle 11. Specifically, the drive wheel 13 includes an axle 131 and a disc 132 rotatably mounted on the axle 131. The disc 132 rotates around the central axis of the axle 131 under force, and the central axis of the axle 131 constitutes the axis of rotation. Both ends of the axle 131 are slidably connected to the handle 11. In this embodiment, one end of the axle 131 also slidably extends outside the mounting space 116. Specifically, the mounting space 116 has a sliding groove 117 and a sliding hole 118 on its bore wall. The sliding groove 117 and the sliding hole 118 are respectively provided on the bore walls on opposite sides of the mounting space 116 and are parallel to the length direction of the handle 11. The axle 131 is perpendicular to the handle 11, and one end of the axle 131 is slidably connected to the sliding groove 117. The other end of the axle 131 slidably extends outside the mounting space 116 through the sliding hole 118. In this embodiment, the length directions of the sliding groove 117 and the sliding hole 118 are both parallel to the first direction X, and the sliding direction of the drive wheel 13 is also parallel to the length direction of the handle 11, that is, the first direction X; the wheel 132 is a gear, and the wheel 132 is located in the installation space 116.

[0036] The actuating wheel 17 is sleeved on the axle 131 to be synchronously connected with the drive wheel 13. In this embodiment, the actuating wheel 17 is detachably sleeved on the axle 131. Specifically, the actuating wheel 17 is located outside the mounting space 116 and is detachably connected to the end of the axle 131 located outside the mounting space 116. For example, in one embodiment, the cross-section of the axle 131 can be a non-circular structure such as a quadrilateral. The center of the actuating wheel 17 is provided with a insertion groove 174. Specifically, the center positions of the opposite two end faces of the actuating wheel 17 are respectively recessed with an insertion groove 174. The cross-section of the insertion groove 174 is a non-circular structure that matches the cross-section of the axle 131. The axle 131 is inserted into the insertion groove 174, thereby detachably connecting the axle 131 of the drive wheel 13 and enabling the actuating wheel 17 and the drive wheel 13 to rotate synchronously. It is understood that the detachable connection between the actuating wheel 17 and the drive wheel 13 is not limited to the above embodiments. For example, in another embodiment, the axle 131 and the actuating wheel 17 can be connected by a spline. Specifically, an internal spline is provided at the center of each of the opposite end faces of the actuating wheel 17, and an external spline can be provided on the end of the axle 131 facing the actuating wheel 17, with the external spline connected to the internal spline. Please refer again. Figure 3 and Figure 8 The outer peripheral wall of the actuating wheel 17 is provided with a plurality of actuating protrusions 171 at intervals along the circumference, and each actuating protrusion 171 has the force-applying surface 172 on its side facing away from the center of the actuating wheel 17.

[0037] The two ends of the elastic element 12 along the extension direction abut against the axle 131 of the drive wheel 13 and the handle 11, respectively. The force exerted by the elastic element 12 on the drive assembly 12 is directed towards the side where the mounting portion 112 is located. In this embodiment, the elastic element 15 is a spring. The elastic element 15 is housed within the mounting space 116 and its opposite ends elastically abut against the axle 131 of the drive wheel 13 and the handle 11, respectively. Specifically, please refer again... Figure 5 A guide rod 134 protrudes from the side of the axle 131 facing away from the mounting portion 112. A guide rod 119 protrudes from the hole wall in the mounting space 116 opposite to the guide rod 134. An elastic element 15 is parallel to the length direction of the handle 11, and its opposite ends along the extension direction are respectively sleeved on the guide rod 134 and the guide rod 119, and elastically abut against the axle 131 and the hole wall of the mounting space 116. The spring is preferably made of stainless steel 304, stainless steel 316, Ni-Ti, etc. More specifically, the spring's Hooke's coefficient is preferably k = 50 N / mm to achieve the best effect of controlling the torque. It is understood that the material and Hooke's coefficient of the spring are not limited to this embodiment, and other materials or other values ​​of Hooke's coefficient can be used as needed.

[0038] Please see again Figure 8The force-applying surface 172 receives pressure from fingers to provide the external force F required for the rotation of the actuating wheel 17 and the switching of different elastic states of the elastic element 15: when the external force is not greater than a preset value, the driving wheel 17 is driven to connect with the screwdriver 30 under the action of the elastic element 15, thereby driving the screwdriver 30 to rotate; when the external force is greater than the preset value, the external force compresses the elastic element 15, causing the driving wheel 13 to slide away from the mounting part 112 and separate from the screwdriver 30. The force-applying surface 172 determines the direction of the external force F, so that the direction of the external force F is toward the center of the actuating wheel 17 and deviates from the center of the actuating wheel 17, so that the external force F has a rotational component F1 in the tangential direction of the actuating wheel 17 to drive the actuating wheel 17 to rotate and a radial component F2 in the radial direction of the actuating wheel 17, and the radial component F2 has a sliding component F3 parallel to the sliding direction of the driving wheel 13. When the external force is greater than the preset value, the sliding component F3 of the radial component F2 causes the actuating wheel 17 and the drive wheel 13 coaxially connected to the actuating wheel 17 to move away from the mounting part 112 and compress the elastic member 15. The angle between the plane α passing through the near point on the force application surface 172 and the rotation axis of the drive assembly 12 and the force application surface 172 is θ, and 0 < θ < 90°. This is because if the angle θ = 0°, that is, the force application surface 172 is parallel to the plane α, then the external force F is perpendicular to the radial direction of the actuating wheel 17. It only has a rotational force in the tangential direction of the actuating wheel 17 to drive the actuating wheel 17 to rotate, and cannot provide a sliding component force F3 parallel to the sliding direction of the drive wheel 13. Therefore, it cannot compress the elastic element 15, and thus cannot control the magnitude of the torque. If the angle θ = 90°, that is, the force application surface 172 is perpendicular to the plane α, then the external force F is parallel to the radial direction of the actuating wheel 17. In this state, it cannot provide a rotational force in the tangential direction of the actuating wheel 17 to drive the actuating wheel 17 to rotate, resulting in the inability to drive the actuating wheel 17 and the drive wheel 13 to rotate, thus making it difficult to drive the screwdriver 30 to work.

[0039] The screwdriver 30 is rotatably inserted into the mounting part 112 at one end of the handle 11. Please refer to [other locations]. Figure 6 and Figure 7In this embodiment, the screwdriver 30 includes a base 31, a drive shaft 33 fixedly connected to the base 31 at one end, and a driven wheel 34 fixed to the end of the base 31 facing away from the drive shaft 33. In this embodiment, the end of the base 31 with the driven wheel 34 is rotatably inserted into the mounting portion 112. A limiting flange 36 is also protruding from the outer peripheral wall of the base 31. The limiting flange 36 is located outside the handle 11 and abuts against the side of the handle 11 facing the screwdriver head 35. When the screwdriver 30 is tightening a screw, the limiting flange 36 can prevent the screwdriver 30 from moving away from the screw relative to the handle 11 under the pressure of the screw. The screwdriver 30 has a fixing groove 311 on the outer peripheral wall of its base 31. The fixing groove 311 is located on the side of the limiting flange 36 facing away from the screwdriver head 35. A retaining ring 37 is installed in the fixing groove 311. The retaining ring 37 engages with the retaining groove 114 in the mounting part 112 to position the screwdriver 30 and prevent it from accidentally falling off the handle 11. In this embodiment, the retaining ring 37 is preferably an O-ring or a wire retaining ring, which has a certain elasticity and can ensure that the retaining ring 37 is securely held in the retaining groove 114 and facilitates the removal of the screwdriver 30 from the handle 11. The free end of the drive shaft 33 is provided with a screw head 35 that is connected to a screw (not shown).

[0040] Driven wheel 34 is housed within mounting portion 112 and meshes with the disc 132 of drive wheel 13 to achieve transmission. Specifically, when the external force is not greater than the preset value, drive wheel 13 is connected to driven wheel 34 under the action of elastic member 15, thereby driving screwdriver 30 to rotate; when the external force is greater than the preset value, the external force compresses elastic member 15, causing drive wheel 13 to slide away from driven wheel 34 and thus separate from driven wheel 34. In this embodiment, driven wheel 34 is a gear meshing with drive wheel 13, and driven wheel 34 is integrally formed with seat 31. Compared with other transmission methods, gear transmission has the advantages of high transmission efficiency, large transmission ratio, and large transmitted torque. It is understood that driven wheel 34 and seat 31 can also be fixedly connected by welding or other methods in the prior art.

[0041] During implant restoration surgery, the dentist attaches a screwdriver 30 to a wrench 10, with the screwdriver tip 35 matching the countersunk shape of the screw to be tightened. When installing the screwdriver 30, the end with the driven wheel 34 is inserted into the mounting portion 112 of the handle 11 of the wrench 10 until the limiting flange 36 abuts against the side of the handle 11 facing the screwdriver tip 35. At this point, the retaining ring 37 on the screwdriver 30 engages with the retaining groove 114 in the handle 11, positioning the screwdriver 30 through the engagement of the retaining ring 37 and the retaining groove 114. Because the screwdriver 30 used in surgery is small, there is a risk of it falling into the patient's airway. The engagement of the retaining ring 37 and the retaining groove 114 effectively secures the screwdriver 30, preventing it from falling into the patient's airway and causing danger.

[0042] When it is necessary to tighten the implant cover screw or the abutment center screw, insert the screwdriver 30 tip 35 into the countersunk of the screw to be tightened (not shown), press the force application surface 172 of the actuating wheel 17 near the screwdriver 30, and determine the direction of the force applied to the actuating wheel 17 through the force application surface 172, so that the user can only apply an external force toward the center of the actuating wheel 17 and deviating from the center of the actuating wheel 17. This external force has a rotational component F1 in the tangential direction of the actuating wheel 17 to drive the actuating wheel 17 to rotate and a radial component F2 in the radial direction of the actuating wheel 17. When the external force is not greater than a preset value, the sliding component F3 of the radial component F2 is less than the elastic force of the elastic element 15. The elastic force of the elastic element 15 makes the driven wheel 34 mesh with the driving wheel 13, and the rotational component F1 can drive the driving wheel 13 to rotate in the first rotation direction R1. Figure 3 The rotating drive wheel 13 drives the driven wheel 34, which meshes with it, to rotate, thereby causing the screwdriver 30 to rotate to tighten the screw. When the external force is greater than the preset value, the sliding component force F3 causes the actuating wheel 17 and the drive wheel 13, which is coaxially connected to the actuating wheel 17, to move away from the mounting part 112 and compress the elastic element 15, thereby separating the drive wheel 13 from the driven wheel 34 to disconnect the power transmission between the drive wheel 13 and the driven wheel 34. At this time, the screwdriver 30 stops working, thereby preventing damage to the implant or bone due to excessive torque.

[0043] When it is necessary to remove the implant cover screw or the abutment center screw, first, move the actuating wheel 17 axially along the axle 131 until the actuating wheel 17 separates from the drive wheel 13. Then, flip the actuating wheel 17 and insert the insertion slot 174 on the flipped actuating wheel 17 facing the drive wheel 13 onto the axle 131 of the drive wheel 13. Figure 10 As shown, at this time, the inclination direction of the force-applying surface 172 of the flipped actuating wheel 17 is opposite to the inclination direction of the force-applying surface 172 of the flipped actuating wheel 17. Therefore, when the force-applying surface 172 is pressed, the direction of the rotational component force determined by the force-applying surface 172 of the flipped actuating wheel 17 is opposite to the direction of the rotational component force determined by the force-applying surface 172 of the flipped actuating wheel 17. This rotational component force can cause the drive wheel 13 to rotate in the second rotational direction R2, which is opposite to the first rotational direction R1, thereby loosening the screw to realize the operation of removing the implant cover screw or the central screw of the abutment.

[0044] The aforementioned wrench, through the force-applying surface 172 provided on the drive assembly 12, the structure of the force-applying surface 172 enables it to determine the direction of the external force. Thus, when the external force is greater than the preset torque, the external force in that direction can compress the elastic element 15, causing the drive assembly 12 to slide away from the mounting part 112 and separate from the screwdriver 30, thereby disconnecting the transmission of power. This limits the torque output of the wrench during use and prevents excessive torque.

[0045] Existing force-limiting wrenches, such as the one disclosed in Chinese Utility Model Patent CN2917963Y, include a rotating shaft, a gear sleeve, an upper clutch plate, and a lower clutch plate. The upper and lower clutch plates have corresponding meshing protrusions and grooves with slopes. A spring is located between the lower clutch plate and the gear sleeve. Rotating the upper clutch plate causes the lower clutch plate to rotate simultaneously, generating downward pressure on the lower clutch plate. When the rotational force reaches a certain level, the lower clutch plate overcomes the spring force and moves downward until the upper and lower clutch plates disengage. At this point, the upper clutch plate simply spins freely, thus achieving the force-limiting effect. This makes it safe, convenient, and labor-saving to use. During operation, the power for rotating the shaft is transmitted through the meshing of the sloped protrusions and grooves on the lower surface of the upper clutch plate and the upper surface of the lower clutch plate, while the lower clutch plate generates downward pressure to overcome the spring force and achieve disengagement. Because the toothed structure of its protrusions and grooves needs to simultaneously satisfy the requirements of transmitting the power to rotate the shaft and forcing the lower clutch plate to generate downward pressure, the upper and lower clutch plates require high manufacturing and assembly precision, increasing production costs. Furthermore, the engagement and disengagement of the upper and lower clutch plates involve significant impact; repeated engagement and disengagement over a long period can damage the protrusions and grooves of the upper and lower clutch plates. When the torque applied to the wrench reaches a certain level, the lower clutch plate may be unable to overcome the spring force and slide away from the upper clutch plate, leading to a decrease in torque control accuracy.

[0046] In this embodiment, the wrench engages and disengages via the force-applying surface 172 on the actuating wheel 17. Compared to the method in Chinese Utility Model Patent CN2917963Y, which uses the toothed structure of protrusions and grooves between the upper and lower clutch plates to simultaneously transmit the power to rotate the shaft and force the lower clutch plate to generate downward pressure, the actuating wheel 17 in this wrench does not need to transmit power through meshing or other transmission methods with other parts. Its manufacturing and assembly precision is reduced, which helps to reduce production costs. Furthermore, during the engagement and disengagement of the drive wheel 13 and the driven wheel 34, the force-applying surface 172 of the actuating wheel 17 will not be damaged by the impact generated during the engagement and disengagement of the drive wheel 13 and the driven wheel 34, thus not affecting the control precision of the wrench torque.

[0047] The aforementioned wrench achieves clutch engagement and disengagement through a drive wheel 13 that slides along the length of the handle 11. When used in dentistry, compared to the method in Chinese utility model patent CN2917963Y where the lower clutch plate moves up and down along the height of the shaft, it can further reduce the requirements on the size of the patient's mouth opening.

[0048] The aforementioned wrench uses the force application surface 172 on the actuating wheel 17 to determine the direction of force application and achieve engagement and disengagement. When using it, the operator only needs to apply force to the force application surface 172 with their fingers, making it easy to learn.

[0049] The aforementioned wrench has a detachable connection between its actuating wheel 17 and drive wheel 13. By flipping the actuating wheel 17, the tilt direction of the force-applying surface 172 can be changed. This, in turn, causes the drive wheel 13, driven wheel 34, and screwdriver 30 to rotate in two directions via the different tilt directions of the force-applying surface 172, enabling it to not only tighten but also loosen screws. Furthermore, the screwdriver 30 is detachably connected to the handle 11. During use, by replacing the screwdriver 30 with different shaped blades 35, it can be used not only for tightening or loosening different types of screws but also for inserting and removing implants.

[0050] The aforementioned wrench drives the screwdriver 30 to rotate through the cooperation of the drive wheel 13 and the driven wheel 34. When in use, the screwdriver 30 can be rotated by turning the turn wheel 17 with the finger, without the need for the doctor to put their hand completely into the mouth. It saves effort and operating space, making it suitable for use in situations with limited operating space, such as in the oral cavity.

[0051] It is understandable that this wrench can be used not only in the dental field, but also in other scenarios where screws need to be tightened or loosened.

[0052] It is understood that the drive wheel 13 and the driven wheel 34 are not limited to the gear transmission method of this embodiment. For example, they can also adopt transmission methods such as friction wheel transmission.

[0053] It is understood that the elastic element 15 is not limited to the spring in this embodiment, and may also be other components with elastic restoring force in the prior art.

[0054] It is understood that the connection method between the screwdriver 30 and the handle 11 is not limited to this embodiment. For example, in other embodiments, the screwdriver 30 can be rotatably connected to the handle 11 through a bearing.

[0055] It is understood that the structure of the handle 11 is not limited to this embodiment. For example, in other embodiments, the installation space 116 can be omitted. In this case, the drive wheel 13 can be disposed outside the handle 11 and slidably connected to the handle 11.

[0056] It is understood that the sliding direction of the drive wheel 13 is not limited to being parallel to the length direction of the handle 11 in this embodiment, but it can also be at a preset angle to the length direction of the handle 11.

[0057] It is understood that the shape of the handle 11 is not limited to this embodiment, and it can be designed into other shapes as needed.

[0058] It is understood that the mounting part 112 is not limited to the through hole structure of this embodiment. It can also adopt a countersunk groove or a protruding post. When the mounting part 112 is a protruding post, the screwdriver 30 can be provided with a socket hole, and the screwdriver 30 is rotatably mounted on the protruding post through the socket hole.

[0059] It is understood that in other embodiments, when the actuating wheel 17 rotates in the first rotation direction R1, the screw is loosened, and when the actuating wheel 17 rotates in the first rotation direction R2, the screw is tightened.

[0060] It is understood that the number of insertion slots 174 is not limited to two in this embodiment. In another embodiment, the number of insertion slots 174 can be one, and the insertion slots 174 pass through the opposite end faces of the actuating wheel 17. In this case, a support frame or support plate can be provided on the axle 131 and / or the handle 11 to support the bottom of the actuating wheel 17 and prevent the actuating wheel 17 from contacting the driven wheel 34.

[0061] It is understood that in other embodiments, the wrench may also include a protective cover (not shown). The protective cover is movably connected to the handle 11 by means of hinge, detachable connection, etc. The protective cover covers the actuating wheel 17 to protect the actuating wheel 17, and the side of the protective cover facing the screwdriver 30 also has an opening to expose the force-applying surface 172 of the actuating wheel 17. This opening allows the force-applying surface 172 of the actuating wheel 17 near the screwdriver 30 to be exposed outside the protective cover, so as to facilitate the user to press, and to ensure that the user only presses the force-applying surface 172 of the actuating wheel 17 near the screwdriver 30, so as to ensure that the drive wheel 13 can be smoothly separated from the driven wheel 34 when the torque is too large. When it is necessary to flip the actuating wheel 17, the entire actuating wheel 17 can be exposed by rotating or removing the protective cover from the handle 11.

[0062] It is understood that the preset value of the external force can be set according to actual needs, but for the sake of brevity, it will not be elaborated here.

[0063] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A wrench, characterized in that, The device includes a handle, a drive assembly, and an elastic element. The handle has a mounting portion for mounting a screwdriver. The drive assembly is used to drive the screwdriver to rotate and is slidably and rotatably mounted on the handle. The sliding direction of the drive assembly relative to the handle is consistent with the extension and retraction direction of the elastic element. The drive assembly has several force-applying surfaces for finger pressing, and the force-applying surfaces are parallel to the rotation axis of the drive assembly. Along the length direction of the force-applying surface, the force-applying surface includes a proximal point closest to the rotation axis, wherein the angle between the plane passing through the proximal point and the rotation axis and the force-applying surface is θ, where 0° < θ < 90°. The length direction of the force-applying surface is perpendicular to the rotation axis. The two ends of the elastic element along the extension and retraction direction respectively abut against the drive assembly and the handle, and the force exerted by the elastic element on the drive assembly is directed towards the side where the mounting portion is located.

2. The wrench according to claim 1, characterized in that, The drive assembly includes a drive wheel and a turn wheel coaxially arranged. The drive wheel is slidably and rotatably mounted on the handle and is used for transmission connection with the screwdriver. The turn wheel is synchronously rotatably connected to the drive wheel. The force-applying surface is disposed on the turn wheel. One end of the elastic member elastically abuts against the drive wheel.

3. The wrench according to claim 2, characterized in that, The outer peripheral wall of the actuating wheel is provided with a plurality of actuating protrusions at intervals along the circumference, and each actuating protrusion has a force-applying surface on its side facing away from the center of the actuating wheel.

4. The wrench as described in claim 2, characterized in that, The drive wheel includes an axle and a disc rotatably fitted onto the axle. Both ends of the axle are slidably connected to the handle. The disc is used for conveying a screwdriver. One end of the elastic element elastically abuts against the axle. The actuating wheel is fitted onto the axle.

5. The wrench as described in claim 4, characterized in that, The actuating wheel is detachably mounted on the axle.

6. The wrench as described in claim 5, characterized in that, The cross-section of the axle is non-circular, and the center of the actuating wheel is provided with a insertion groove. The cross-section of the insertion groove is non-circular and matches the cross-section of the axle. The axle is inserted into the insertion groove.

7. The wrench as described in claim 2, characterized in that, The sliding direction of the drive wheel is parallel to the length direction of the handle.

8. The wrench as described in claim 2, characterized in that, The mounting part is a mounting hole located at one end of the handle, and the mounting part is used for inserting a screwdriver.

9. The wrench as described in claim 8, characterized in that, The handle also has an installation space, which is connected to the mounting part. The drive wheel is located in the installation space, and the elastic element is housed within the installation space. The actuating wheel is located outside the installation space.

10. The wrench as described in claim 8, characterized in that, The inner wall of the mounting part is recessed with a slot; the outer peripheral wall of the screwdriver is provided with a fixing groove, and a retaining ring is provided in the fixing groove, the retaining ring engaging with the slot.

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