A type of force-saving pliers

Abstract

This invention discloses a force-saving pliers, comprising a first handle, a second handle, a first jaw, and a second jaw. A positioning pin is provided on the first handle, and the first jaw is fixed to the upper end of the first handle. The second jaw is hinged to the first jaw via a pin, and its lower end has a clamping drive post and an opening drive post, forming a limiting part between them. A positioning hole is provided at the upper end of the second handle to engage with the positioning pin, and the second handle passes through the limiting part and can rotate around the positioning pin. The driving part of the second handle has a first driving surface and a second driving surface, which engage bidirectionally with the clamping drive post and the opening drive post, respectively. The clamping drive post can be equipped with absorbent cotton for automatic lubrication or fitted with a rotating cylinder. The lower part of the handle has an arc-shaped section adapted to the palm and fingers. When the jaws are closed, the distance between the pin and the positioning pin is greater than the distance between the positioning pin and the clamping drive post, and the ratio of the latter to the length of the free end of the handle is 10% to 15%. This invention utilizes a compound lever force-multiplying principle, resulting in effortless cutting, comfortable operation, and a compact structure.

Description

Technical Field

[0001] This invention relates to the field of hardware tools technology, specifically to a force-saving pliers. Background Technology

[0002] Pliers are a type of hand tool widely used in mechanical assembly, electrical repair, and household applications. Existing conventional pliers have a relatively simple structure, mainly consisting of two pliers bodies. Hinged through holes are located at the center of the connection point between the two bodies. A connecting pin passes through these two through holes to hinge the two pliers bodies together, thus forming a pliers structure that can rotate relative to each other.

[0003] However, this traditional type of pliers has significant technical drawbacks in use. Because the connecting pin passes through the center of the hinge joint between the two pliers, meaning the hinge fulcrum is located in the middle of the pliers, the ratio of the resistance arm (vertical distance from the fulcrum to the cutting point of the jaws) to the effort arm (vertical distance from the fulcrum to the end of the handle) is relatively large according to the lever principle. When using this type of pliers to cut steel wire or electrical wire, the operator needs to apply considerable gripping force to complete the cut, which is quite strenuous. For users with less hand strength, it is often difficult to cut the object smoothly, and sometimes the object cannot be cut at all. Furthermore, operators who engage in high-frequency cutting operations for extended periods are prone to hand fatigue due to excessive force, affecting work efficiency. Therefore, existing ordinary pliers have significant shortcomings in terms of labor-saving performance, causing considerable inconvenience in use. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of existing ordinary pliers, which require a lot of force to cut and high strength from the user because the hinge fulcrum is located in the middle of the pliers body, and to provide a force-saving pliers that can significantly reduce the gripping force required for cutting.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A force-saving pliers includes a first handle, a second handle, a first pliers head, and a second pliers head.

[0006] A positioning pin is provided on the first handle, and the first jaw is fixedly mounted on the upper end of the first handle. The first jaw has a first mounting hole. A second jaw has a second mounting hole. A pin passes through both the first and second mounting holes, hinged together, allowing the first and second jaws to rotate relative to each other around the pin. At the lower end of the second jaw, away from the jaws, a clamping drive post and an opening drive post are provided, with a gap between them forming a limiting part. A positioning hole is provided at the upper end of the second handle, which engages with the positioning pin on the first handle. The positioning pin moves through the positioning hole, allowing the second handle to rotate around it. The upper end of the second handle passes through the limiting part between the clamping and opening drive posts. When the second handle rotates around the positioning pin, the limiting part can slide relative to the second handle along its length.

[0007] The above structure forms a compound lever transmission system. The first and second handles form the first-stage rotational fulcrum through a positioning pin, while the clamping drive pin at the lower end of the second jaw forms the second-stage action point with the second handle. When the operator grips the first and second handles, the second handle rotates around the positioning pin, pushing the clamping drive pin and causing the second jaw to rotate around the pin, closing the jaws. This allows for the application of a smaller force while generating a larger shearing force at the jaws, achieving a labor-saving effect.

[0008] As a preferred technical solution, the upper part of the second handle has a driving part for cooperating with the limiting part. One side of the driving part forms a first driving surface. When the first handle and the second handle are subjected to a force that brings them closer together (i.e., a gripping action), the first driving surface abuts against the outer peripheral surface of the clamping driving post and generates compression, pushing the second jaw head to rotate and close the jaws. The other side of the driving part is provided with a second driving surface. When the first handle and the second handle are subjected to a force that moves them away from each other (i.e., a releasing action), the second driving surface abuts against the outer peripheral surface of the opening driving post and generates compression, pushing the second jaw head to rotate in the opposite direction and open the jaws.

[0009] As a further preferred technical solution, a receiving groove is formed along the axial direction in the clamping drive column, and the receiving groove is filled with oil-absorbing cotton, which absorbs a sufficient amount of lubricating oil. An oil guiding hole is formed along the radial direction on the clamping drive column, and the position of the oil guiding hole corresponds to the first drive surface. When the first drive surface repeatedly rubs against the outer peripheral surface of the clamping drive column, the lubricating oil absorbed in the oil-absorbing cotton can slowly seep out through the oil guiding hole and transfer to the first drive surface, automatically lubricating the contact surface, reducing frictional resistance and wear, and extending service life.

[0010] As a further preferred technical solution, the bottom of the receiving groove is a closed structure, and the top is an open structure to facilitate the insertion of oil-absorbing cotton. A sealing cap is provided at the top of the receiving groove to close the opening of the receiving groove, preventing lubricating oil from evaporating or overflowing, and at the same time preventing external dust from entering and contaminating the oil-absorbing cotton.

[0011] As another preferred technical solution, a freely rotatable drum is fitted onto the clamping drive post. The outer circumferential surface of the drum forms a rolling contact with the first drive surface, rather than a sliding contact. The drum transforms sliding friction into rolling friction, further reducing the frictional resistance between the first drive surface and the clamping drive post, making the operation smoother and less strenuous.

[0012] As a preferred technical solution, the lower part of the second handle has a first arc-shaped segment that curves towards the first handle. This first arc-shaped segment ensures that the minimum distance between the first and second handles occurs in the middle region of the first arc-shaped segment. This design not only reduces the distance between the first and second handles, facilitating grip, but also conforms to the natural curvature of the fingers when gripping, improving grip comfort. The lower part of the first handle has a second arc-shaped segment that curves towards the gripping direction. The outer contour of the second arc-shaped segment is designed to conform to the natural curvature of the palm. Thus, when the operator grips the pliers, the second arc-shaped segment fits snugly against the palm, distributing grip pressure and avoiding concentrated pressure on the palm from a straight handle, further improving ergonomics and reducing fatigue during prolonged use.

[0013] As a preferred technical solution, the lower parts of the first and second jaws together form a receiving space. The upper end of the second handle is located within this receiving space. This arrangement ensures that the upper end of the second handle is covered by the lower parts of the first and second jaws, protecting the internal transmission components from external debris and making the overall structure more compact and aesthetically pleasing.

[0014] As a preferred technical solution, the positioning pin is positioned on the first handle away from the pin and above the clamping drive post. When the first and second jaws are fully closed, the distance between the axis of the pin and the axis of the positioning pin is greater than the distance between the axis of the positioning pin and the axis of the clamping drive post, and the former is two to three times the latter. When the first and second jaws are fully open, the distance between the axis of the pin and the axis of the positioning pin is greater than the distance between the axis of the positioning pin and the axis of the clamping drive post, and the former is 1.1 to 1.5 times the latter.

[0015] As a further preferred technical solution, the distance between the axis of the positioning pin and the axis of the clamping drive post is defined as the first distance. The distance between the axis of the positioning pin and the free end of the second handle, i.e., the end of the handle, is defined as the second distance. The first distance is set to 10% to 15% of the second distance. When the ratio of the first distance to the second distance is within this range, the best labor-saving effect can be obtained while ensuring sufficient jaw opening stroke and shearing stroke, without affecting the feel during shearing.

[0016] As a further preferred technical solution, the distance between the axis of the clamping drive column and the axis of the pin is 1.5 to 2 times the distance between the axis of the pin and the shearing point.

[0017] The beneficial effects of this invention are: 1. This invention employs a structure where the first handle is fixed and the second handle can swing around a positioning bolt. It utilizes the cooperation between the clamping drive post on the second pliers head and the drive part of the second handle to form a force-amplifying lever system. Compared to traditional pliers, the required gripping force is significantly reduced when cutting steel wire of the same hardness, resulting in a remarkable labor-saving effect and catering to the needs of users with varying strengths.

[0018] 2. The first driving surface and the second driving surface of the drive unit cooperate with the clamping drive post and the opening drive post respectively, realizing bidirectional drive for clamping and opening. The structure is compact, the operation is reliable, and no additional reset element is required.

[0019] 3. Oil-absorbing cotton and oil-guiding holes are installed inside the clamping drive column, enabling automatic micro-lubrication of the friction pair, extending service life, and maintaining smooth operation. The rotating drum transforms sliding friction into rolling friction, further reducing operating resistance and providing multiple optimization solutions.

[0020] 4. The first and second handles are respectively designed with arc-shaped sections that conform to the natural curvature of the palm and fingers, which improves grip comfort, conforms to ergonomic principles, and reduces fatigue during long-term use.

[0021] 5. The containment space enclosed at the lower part of the first and second jaws protects the internal transmission components, prevents foreign objects from entering, and improves reliability and durability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure (closed state) of the force-saving pliers provided in the embodiment of the present invention.

[0023] Figure 2 This is an exploded view of the force-saving pliers provided in an embodiment of the present invention.

[0024] Figure 3 This is an exploded view of the force-saving pliers provided in an embodiment of the present invention from another angle.

[0025] Figure 4 This is a schematic diagram of the structure of the second handle in an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the structure of the second clamp head in an embodiment of the present invention (showing the oil-absorbing cotton and the oil-guiding through hole).

[0027] Figure 6 This is a schematic diagram of the structure of the second clamp head in an embodiment of the present invention (showing the rotating drum).

[0028] Figure 7 This is a schematic diagram of the force-saving clamp provided in the embodiment of the present invention in the open state.

[0029] The names corresponding to each mark in the diagram: 1-First handle; 11-Positioning bolt; 12-Second arc segment; 2-Second handle; 21-Positioning hole; 22-Drive unit; 221-First drive surface; 222-Second drive surface; 23-First arc-shaped segment; 24-Free end; 3-First clamp head; 31-First mounting hole; 4-Second clamping head; 41-Second mounting hole; 42-Clamping drive post; 421-Receiving groove; 422-Oil-absorbing cotton; 423-Oil guide hole; 424-Sealing cap; 425-Rotating drum; 43-Opening drive post; 44-Limiting part; 5-Pin. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "upper end," "lower end," "upper part," "lower part," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only to distinguish different components and should not be construed as indicating or implying relative importance or quantity.

[0032] This specific embodiment will describe in detail a force-saving clamp that achieves a significant force-saving effect during cutting through a unique hinge and drive structure design.

[0033] like Figure 1 , Figure 2 and Figure 3 As shown, in one or more embodiments, the force-saving pliers provided by the present invention include a first handle 1, a second handle 2, a first pliers head 3, a second pliers head 4, and a pin 5.

[0034] The first handle 1 is the gripping part of the pliers, formed from a metal material such as high-carbon steel or chrome vanadium steel through forging or stamping processes. At the upper end of the first handle 1, i.e. Figure 2 A first clamp head 3 is fixedly mounted on the left end of the first handle 1. The first clamp head 3 and the first handle 1 can be integrally forged to ensure sufficient strength and rigidity, or they can be separately welded or riveted. A first mounting hole 31 is provided on the first clamp head 3 for the pin 5 to pass through. Figure 3 As shown, the first handle 1 is provided with a positioning pin 11 for hinged connection with the second handle 2. The positioning pin 11 is a cylindrical pin, which is fixedly installed on the side of the first handle 1 and can pass through the thickness direction of the first handle 1.

[0035] like Figure 1 and Figure 2 As shown, in one or more embodiments, the lower part of the first handle 1 is provided with a second arc-shaped segment 12, which curves away from the second handle 2. The outer contour of the second arc-shaped segment 12 is designed as a smooth arc surface, the curvature of which matches the curvature of the palm in a natural fist-clenched state. When the operator grips the pliers, the second arc-shaped segment 12 of the first handle 1 conforms to the thenar eminence of the palm, evenly distributing the gripping pressure across the entire palm contact surface, avoiding concentrated pressure on a small area of ​​the palm as with a straight handle. This can significantly reduce hand fatigue and pain for operators who need to perform cutting operations for extended periods.

[0036] In one or more embodiments, the second jaw 4 has a second mounting hole 41. The axis of the pin 5 is parallel to the axis of the positioning bolt 11. The pin 5 passes through both the first mounting hole 31 and the second mounting hole 41, allowing the first jaw 3 and the second jaw 4 to be hinged and rotate relative to each other around the pin 5. One end of the pin 5 may have a shoulder, and the other end may have a cotter pin or a retaining ring to prevent the pin 5 from axially dislodging. The front ends of the first jaw 3 and the second jaw 4, i.e. Figure 1 The upper end, as shown, has shearing blades on opposite sides. These blades are heat-treated and quenched to achieve high hardness and wear resistance, and are used for cutting steel wires, electrical wires, and other objects. The first clamp head 3 and the second clamp head 4 are hinged together by the pin 5 to form a scissor-type opening and closing structure.

[0037] like Figure 3 and Figure 4 As shown, in one or more embodiments, a positioning hole 21 is provided at the upper end of the second handle 2. The inner diameter of the positioning hole 21 is slightly larger than the outer diameter of the positioning bolt 11, forming a clearance fit. The positioning bolt 11 is movably inserted into the positioning hole 21, allowing the second handle 2 to rotate freely around the positioning bolt 11. The positioning bolt 11 acts as a connector between the first handle 1 and the second handle 2, and also serves as a fulcrum for the rotation of the second handle 2.

[0038] In one or more embodiments, the lower end of the second handle 2, i.e. Figure 4 The right end of the second handle 2 is a free end 24. The area between the free end 24 and the drive unit 22 has a first arc-shaped segment 23 that curves towards the first handle 1. That is, the lower part of the second handle 2 is curved inward, towards the first handle 1, into an arch or arc shape. The maximum curvature point of the first arc-shaped segment 23, that is, the point closest to the first handle 1, is located in the middle area of ​​the first arc-shaped segment 23. When the operator grips the handle, four fingers naturally bend and wrap around the second handle 2. The shape of the first arc-shaped segment 23 conforms to the contour of the bent fingers, while providing the narrowest gap in the middle area, allowing the fingers to apply force firmly. This design avoids the pressure on the fingers caused by a straight handle, and also reduces the distance between the first handle 1 and the second handle 2, improving the stability and comfort of the grip. The combined use of the first arc-shaped segment 23 and the second arc-shaped segment 12 allows the entire force-saving clamp to naturally adapt to the geometry of the hand when gripped, allowing the operator to apply force in the most relaxed posture, further improving the user experience.

[0039] like Figure 2 and Figure 5 As shown, in one or more embodiments, at the lower end of the second clamp 4, i.e. Figure 2 On the right side of the jaws, there are clamping drive post 42 and opening drive post 43. Both clamping drive post 42 and opening drive post 43 are cylindrical protrusions extending from the body of the second jaw 4, and they can be integrally forged or welded to the second jaw 4. A gap is left between the clamping drive post 42 and the opening drive post 43, which forms a limiting part 44. The upper end of the second handle 2 passes through this limiting part 44, that is, the upper part of the second handle 2 is located between the clamping drive post 42 and the opening drive post 43.

[0040] like Figure 1 , Figure 3 and Figure 5As shown, in one or more embodiments, the upper part of the second handle 2 has a driving part 22, which is located at the section where the second handle 2 passes through the limiting part 44. One side of the driving part 22, that is, the side near the clamping driving post 42, forms a plane, which is called the first driving surface 221. The other side of the driving part 22, that is, the side near the opening driving post 43, also forms a plane, which is called the second driving surface 222.

[0041] When the operator grips the first handle 1 and the second handle 2 tightly, bringing them close together, as... Figure 7 As shown, the second handle 2 rotates clockwise around the positioning pin 11, and its driving part 22 moves accordingly. At this time, the first driving surface 221 will contact the outer peripheral surface of the clamping driving post 42 and generate pressure. As the gripping force increases, the first driving surface 221 pushes the clamping driving post 42, causing the second jaw 4 to rotate clockwise around the pin 5, thereby gradually closing the cutting edges at the front ends of the first jaw 3 and the second jaw 4, realizing the shearing of the object. This process is called clamping drive.

[0042] When the operator releases the handle and applies a force that moves the first handle 1 and the second handle 2 away from each other, such as Figure 7 As shown, the second handle 2 rotates counterclockwise around the positioning pin 11. At this time, the second driving surface 222 will contact the outer peripheral surface of the opening driving post 43 and generate pressure, pushing the second jaw 4 to rotate counterclockwise around the pin 5, thereby opening the jaws to prepare for the next cutting. This process is called opening drive.

[0043] It should be noted that the above rotation direction is based on Figure 7 This is for illustrative purposes only, and not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0044] With this bidirectional drive design, whether gripping or releasing, the second handle 2 can interact effectively with the two drive posts at the lower end of the second jaw 4 through the drive unit 22, thereby achieving precise control over the opening and closing of the jaws.

[0045] In this invention, the axis of the positioning bolt 11 forms the fulcrum for the rotation of the second handle 2, and this fulcrum is marked as point O. The contact point between the clamping drive post 42 and the first drive surface 221 forms the force transmission point, and this point is marked as point B. The shearing point at the jaws forms the actual resistance point, and this point is marked as point A. The first arc-shaped segment 23 where the operator's hand grips the second handle 2 forms the power application point, and this point is marked as point C.

[0046] In this embodiment, when the first and second jaws are closed, the point on the cutting edge that comes into contact first is the shearing point.

[0047] According to the lever principle, the torque balance equation is: F1 × L1 = F2 × L2, Where L1 is the distance from fulcrum O to the point of application of the force C, i.e., the power arm OC, and F1 is the force applied by the operator at point C perpendicular to the power arm OC; L2 is the distance from fulcrum O to the force transmission point B, i.e., the resistance arm OB, and F2 is the force applied by the first driving surface 221 to the clamping driving column 42 perpendicular to the resistance arm OB. It should be noted that the above descriptions of F1, F2, L1, and L2 are only for the purpose of understanding the force-saving effect of this scheme and should not be construed as limitations on this scheme. In actual use, the force applied to the first arc segment 23 does not necessarily have to be perpendicular to the power arm OC.

[0048] Because the positioning pin 11 is positioned on the first handle 1 away from the pin shaft and close to the clamping drive post 42, with the positioning pin 11 above the clamping drive post 42 and the clamping drive post 42 located at the lower end of the second clamp head 4, the distance OB is significantly smaller than the distance OC. Therefore, L1 is much larger than L2, and according to the lever principle, F1 can be much smaller than F2. In other words, the operator can generate a large driving force at point B by applying a small force at point C.

[0049] Furthermore, a second-stage lever consisting of pin 5 separates points B and A. The second clamp head 4 rotates around pin 5. The distance from point B to pin 5 corresponds to the effort arm of the second-stage lever, while the distance from point A to pin 5 corresponds to the resistance arm. In this embodiment, the distance from point B to pin 5 is greater than the distance from point A to pin 5, thus further amplifying the force. Therefore, after being amplified by two stages of levers, a sufficiently large shearing force can be obtained at the shearing point A. Compared to traditional clamps (which have only one fulcrum located in the middle of the two clamp bodies), this invention achieves a significant force-saving effect through a composite lever system.

[0050] The distance between the axis of the positioning bolt 11 and the axis of the clamping drive post 42 is defined as the first distance, or OB distance. The distance between the axis of the positioning bolt 11 and the free end of the second handle 2 is defined as the second distance, or OC distance.

[0051] In this embodiment, the ratio of the first distance to the second distance is in the range of 10% to 15%, that is, the clamping drive post 42 is located near the positioning bolt 11 and away from the free end of the second handle 2. This allows the driving force to achieve a large jaw opening angle with a small stroke change, improving the sensitivity of operation, and at the same time making the first-stage magnification reach 6.7 to 10 times.

[0052] Meanwhile, in this embodiment, the distance between the axis of the clamping drive column and the axis of the pin is 1.5 to 2 times the distance between the axis of the pin and the shearing point, so that the second-stage lever produces a force amplification effect of 1.5 to 2 times.

[0053] Since the distance from the fulcrum O to the force transmission point is significantly smaller than the distance to the power application point, according to the lever transmission principle, the gripping force applied by the operator in the first arc segment 23 can be efficiently transmitted to the clamping drive column 42 after being amplified by the first-stage lever. Then, through the rotation of the second jaw 4 around the pin shaft 5, it is further amplified to the jaw shearing edge, achieving two-stage composite force saving.

[0054] When the first jaw 3 and the second jaw 4 are in a fully closed state, such as Figure 1 In the indicated state, the distance between the axis of pin 5 and the axis of positioning bolt 11 is greater than the distance between the axis of positioning bolt 11 and the axis of clamping drive post 42. Furthermore, the distance between the axis of pin 5 and the axis of positioning bolt 11 is two to three times the distance between the axis of positioning bolt 11 and the axis of clamping drive post 42. This proportional relationship ensures that when the jaws are fully closed, the distance between the point of application of the driving force and the fulcrum is moderate, guaranteeing sufficient driving torque while avoiding an excessively large structure.

[0055] When the first jaw 3 and the second jaw 4 are in the fully open state, such as Figure 7 In the indicated state, the distance between the axis of pin 5 and the axis of positioning bolt 11 is greater than the distance between the axis of positioning bolt 11 and the axis of clamping drive post 42. Furthermore, the distance between the axis of pin 5 and the axis of positioning bolt 11 is 1.1 to 1.5 times the distance between the axis of positioning bolt 11 and the axis of clamping drive post 42. This proportional relationship ensures that no interference occurs between the components when the jaws are fully open, while maintaining reasonable force transmission efficiency.

[0056] To reduce the frictional resistance between the first driving surface 221 and the clamping driving post 42 and make the operation smoother, the present invention provides two preferred solutions.

[0057] Option 1: Automatic lubrication structure like Figure 5 As shown, in one or more embodiments, in the clamping drive post 42, along its axial direction, i.e. perpendicular to... Figure 5 A receiving groove 421 is made in the direction of the paper. The bottom of the receiving groove 421 is closed and the top is open, forming a blind hole. An oil-absorbing cotton 422 is filled into the receiving groove 421. The oil-absorbing cotton 422 can be a sponge, felt, or highly oil-absorbing fiber material, and its interior absorbs a sufficient amount of lubricating oil, such as machine oil or grease.

[0058] One or more oil guide holes 423 are formed radially on the circumferential wall of the clamping drive column 42. The positions of the oil guide holes 423 correspond to the contact areas of the first drive surface 221. The diameter of the oil guide holes 423 is small, typically between 0.5 mm and 1.5 mm, to ensure that the lubricating oil can slowly seep out through capillary action without gushing out in large quantities.

[0059] A sealing cap 424 is installed at the top opening of the receiving groove 421. The sealing cap 424 can be connected to the inner wall of the receiving groove 421 by means of threads, interference fit, or snap-fit. The function of the sealing cap 424 is to seal the receiving groove, prevent lubricating oil from evaporating and external dust from entering, and at the same time prevent the oil-absorbing cotton 422 from falling out.

[0060] During repeated gripping and releasing, the first driving surface 221 rubs against the outer peripheral surface of the clamping driving column 42, causing a slight temperature increase and vibration in the clamping driving column 42. Lubricating oil in the absorbent cotton 422, driven by capillary action and pressure difference, slowly seeps out through the oil guide hole 423, evenly coating the contact interface between the first driving surface 221 and the clamping driving column 42, forming an extremely thin oil film. This oil film significantly reduces the coefficient of friction, decreases wear, makes operation smoother, and extends the service life of both the clamping driving column 42 and the driving part 22.

[0061] It should be noted that the above-mentioned structure for reducing the frictional resistance between the first driving surface 221 and the clamping driving post 42 is not necessary. Those skilled in the art can choose the structure for reducing the frictional resistance between the first driving surface 221 and the clamping driving post 42 based on the specific application scenario.

[0062] Option 2: Rolling contact structure like Figure 6 As shown, in one or more embodiments, a freely rotatable rotating cylinder 425 is fitted around the outer periphery of the clamping drive post 42. The rotating cylinder 425 is a cylindrical part with an inner diameter slightly larger than the outer diameter of the clamping drive post 42, forming a clearance fit between the two. The rotating cylinder 425 can rotate flexibly around the clamping drive post 42, and the outer peripheral surface of the rotating cylinder 425 forms a rolling contact with the first driving surface 221.

[0063] When the first driving surface 221 pushes the clamping driving column 42, the rotating drum 425 rotates accordingly, converting sliding friction into rolling friction. The coefficient of rolling friction is usually an order of magnitude smaller than that of sliding friction, thus greatly reducing frictional resistance. The rotating drum 425 can be made of wear-resistant materials, such as bearing steel, high-carbon steel, or engineering plastics such as polyoxymethylene (POM), or a bearing can be used directly. To further reduce friction, grease can be applied between the clamping driving column 42 and the rotating drum 425.

[0064] It should be noted that for the fit between the opening drive post 43 and the second drive surface 222, since the force experienced during the opening action is much smaller than the shear force during the clamping action, additional friction optimization structures are usually not required. However, in some embodiments with special requirements, the same rotary drum or lubrication design can be used for the opening drive post 43.

[0065] like Figure 2 and Figure 3 As shown, in one or more embodiments, the lower parts of the first jaw 3 and the second jaw 4 together form a receiving space. Specifically, the lower part of the first jaw 3 extends rearward to form an arc-shaped guard arm, and the lower part of the second jaw 4 also extends rearward to form another arc-shaped guard arm. These two guard arms intersect each other and rotate around the pin 5. The gap between them and the space enclosed between them and the upper end of the first handle 1 constitute the receiving space. Figure 2 As shown, the upper end of the second handle 2, including the area where the drive part 22 and the positioning hole 21 are located, is situated within this receiving space.

[0066] This design, which conceals the moving parts, offers several advantages: First, it makes the overall appearance more concise and aesthetically pleasing, with no exposed connecting rods or joints; second, it effectively prevents external debris such as wires, chips, and dust from falling into the transmission mechanism, causing jamming or accelerated wear, thus improving reliability in harsh environments; third, during handling and storage, the concealed moving parts are less likely to snag or collide with other tools, protecting the precision-fitted parts at the upper end of the second handle 2.

[0067] The operation process of the force-saving pliers of the present invention is described in detail below: In the initial state, the jaws may be closed. The operator applies slight force to move the first handle 1 and the second handle 2 away from each other. The second drive surface 222 pushes the opening drive post 43, causing the second jaw 4 to rotate around the pin 5, and the jaws open to a sufficient width. Then place the wire or cable to be cut between the blades of the first pliers head 3 and the second pliers head 4, ensuring that the object to be cut is within the effective area of ​​the cutting blades; The operator holds the second arc-shaped segment 12 of the first handle 1 with their palm, ensuring the palm is in contact with it; simultaneously, the fingers grip the first arc-shaped segment 23 of the second handle 2, with the curvature of the fingers matching that of the first arc-shaped segment 23. Then, the operator grips firmly. At this point, the first handle 1 remains essentially stationary, while the second handle 2 rotates around the positioning pin 11. The first driving surface 221 presses against the clamping driving post 42, pushing the second jaw 4 to rotate relative to the first jaw 3, gradually closing the cutting edge and cutting the object. Due to the amplifying effect of the compound lever, the required gripping force is much less than that of traditional pliers.

[0068] The operator releases their grip and moves the first handle 1 and the second handle 2 away from each other. The second drive surface 222 pushes the opening drive post 43, causing the jaws to open to the initial opening width. At this point, the cut object automatically falls off or is taken away by the operator.

[0069] Repeat steps one through four above to perform the cutting operation continuously.

[0070] The various components of the force-saving pliers of this invention can be made of appropriate materials according to specific performance requirements. The first handle 1, second handle 2, first jaw 3, and second jaw 4 are preferably made of high-strength alloy steel such as chromium-vanadium steel (Cr-V) or chromium-molybdenum steel (Cr-Mo), formed by die forging to ensure the density of the internal structure and mechanical properties. The pin 5 and the positioning bolt 11 are made of bearing steel or No. 45 steel, and are subjected to quenching and tempering treatment and surface hardening to improve wear resistance. The rotating drum 425 can be made of bearing steel or bronze. The oil-absorbing cotton 422 is made of oil-resistant sponge or felt.

[0071] The cutting edges of the first jaw 3 and the second jaw 4 need to be subjected to high-frequency quenching or laser quenching, and the hardness should reach HRC55-60. The first driving surface 221 and the second driving surface 222 can be ground and surface nitrided to improve surface hardness and reduce friction. All metal parts are subjected to rust prevention treatment, such as chrome plating, nickel plating, or black anodizing.

[0072] Based on the above detailed description, the present invention provides a novel, labor-saving, comfortable, and reliable pair of pliers, which effectively solves the technical problem of laborious cutting with traditional pliers and has high industrial practical value and market promotion prospects.

Claims

1. A type of force-saving pliers, characterized in that: Includes a first handle, a second handle, a first clamp head, and a second clamp head; The first handle is equipped with a positioning bolt; The first pliers head is fixedly disposed at the upper end of the first handle, and the first pliers head is provided with a first mounting hole; The second clamp head is provided with a second mounting hole, and a pin is passed through the first mounting hole and the second mounting hole to hinge the first clamp head and the second clamp head. The lower end of the second clamp head is provided with a clamping drive post and an opening drive post, and a limiting part is provided between the clamping drive post and the opening drive post. The upper end of the second handle is provided with a positioning hole that cooperates with the positioning bolt. The positioning bolt is movably disposed in the positioning hole. The second handle passes through the limiting part. The second handle is configured such that when it rotates around the positioning bolt, the limiting part slides along the second handle.

2. The force-saving pliers according to claim 1, characterized in that: The upper part of the second handle has a driving part that cooperates with the limiting part. One side of the driving part forms a first driving surface, which is used to abut against the outer peripheral surface of the clamping driving post when the first handle and the second handle are subjected to a force that brings them closer together. The other side of the driving part is provided with a second driving surface, which is used to abut against the outer peripheral surface of the opening driving post when the first handle and the second handle are subjected to a force that moves them away from each other.

3. The force-saving pliers according to claim 2, characterized in that: The clamping drive column has an axially oriented receiving groove, which contains oil-absorbing cotton that absorbs lubricating oil. The clamping drive column also has a radially oriented oil guide hole, which is positioned to supply oil to the contact area when the first driving surface abuts against the outer circumferential surface of the clamping drive column.

4. The force-saving pliers according to claim 3, characterized in that: The bottom of the receiving groove is closed and the top is open, and the top of the receiving groove is provided with a sealing cover.

5. The force-saving pliers according to claim 2, characterized in that: A freely rotatable rotating cylinder is fitted onto the clamping drive column, and the outer circumferential surface of the rotating cylinder is in rolling contact with the first drive surface.

6. The force-saving pliers according to claim 1, characterized in that: The lower part of the second handle has a first arc-shaped segment that bends toward the first handle, such that the minimum distance between the first handle and the second handle is located in the middle region of the first arc-shaped segment; the lower part of the first handle is provided with a second arc-shaped segment that bends toward the gripping direction, and the outer contour of the second arc-shaped segment is adapted to the natural curvature of the palm.

7. The force-saving pliers according to claim 1, characterized in that: The lower parts of the first and second pliers form a receiving space, and the upper end of the second handle is located in the receiving space.

8. The force-saving pliers according to claim 1, characterized in that: The positioning pin is positioned on the first handle away from the pin and above the clamping drive post. When the first and second jaws are fully closed, the distance between the axis of the pin and the axis of the positioning pin is greater than the distance between the axis of the positioning pin and the axis of the clamping drive post, and the former is two to three times the latter. When the first and second jaws are fully open, the distance between the axis of the pin and the axis of the positioning pin is greater than the distance between the axis of the positioning pin and the axis of the clamping drive post, and the former is 1.1 to 1.5 times the latter.

9. The force-saving pliers according to claim 1, characterized in that: The distance between the axis of the positioning bolt and the axis of the clamping drive post is a first distance, and the distance between the axis of the positioning bolt and the free end of the second handle is a second distance. The first distance is 10% to 15% of the second distance.

10. The force-saving pliers according to claim 1, characterized in that: The distance between the axis of the clamping drive column and the axis of the pin is 1.5 to 2 times the distance between the axis of the pin and the shearing point.

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