A collet assembly for a jigsaw

Abstract

The application provides a chuck assembly of a jigsaw, and relates to the technical field of jigsaws, which comprises a chuck body, a rotating sleeve, an elastic clamping sleeve and a plurality of steel balls. The inner periphery of the rotating sleeve is provided with a plurality of eccentric grooves in the circumferential direction, the plurality of eccentric grooves are arranged in one-to-one correspondence with the plurality of steel balls, and each eccentric groove is in communication with a saw blade mounting position. The plurality of eccentric grooves comprise a first eccentric groove group located on both sides of the saw blade in the width direction and a second eccentric groove group located on both sides of the saw blade in the thickness direction. When the rotating sleeve rotates from the release position to the locking position, the steel balls located in the first eccentric groove group move radially inward and press the elastic clamping sleeve tightly, so that the elastic clamping sleeve deforms towards the saw blade to clamp the saw blade in the width direction. The steel balls located in the second eccentric groove group move radially inward and press both sides of the saw blade in the thickness direction to clamp the saw blade in the thickness direction. The eccentric grooves drive the steel balls to apply radial force in different regions to clamp the saw blade in the width and thickness directions simultaneously.

Description

Technical Field

[0001] This invention relates to the field of jigsaw technology, and more specifically, to a jigsaw chuck assembly. Background Technology

[0002] A jigsaw is a common handheld power tool mainly used for cutting curved surfaces of wood, metal, and plastic. During operation, the saw blade reciprocates at high speed driven by a reciprocating lever; therefore, the reliability of the connection between the saw blade and the chuck directly affects cutting accuracy and operational safety.

[0003] The saw blade chucks in the relevant technologies have many shortcomings in actual use. After the saw blade is clamped, the force position is relatively singular. When the equipment works at high frequency for a long time, the saw blade is prone to deviation and shaking. This will not only cause uneven cutting surfaces, but also accelerate saw blade wear and shorten the saw blade's service life. Summary of the Invention

[0004] The problem this invention addresses is: how to solve the problem that existing single-point clamping chucks easily lead to saw blade wobbling and displacement, poor cutting accuracy, and rapid wear.

[0005] To address the above problems, the present invention provides a chuck assembly for a jigsaw, comprising:

[0006] The chuck body has a saw blade mounting position for accommodating the saw blade;

[0007] A rotating sleeve is rotatably fitted around the outer periphery of the chuck body and has a locked position and a released position;

[0008] An elastic clamping sleeve is disposed within the chuck body;

[0009] Multiple steel balls;

[0010] The inner circumference of the rotating sleeve is provided with a plurality of eccentric grooves, each of which corresponds to a plurality of steel balls, and each of the eccentric grooves is connected to the saw blade mounting position; the plurality of eccentric grooves include a first eccentric groove group located on both sides of the saw blade width direction and a second eccentric groove group located on both sides of the saw blade thickness direction.

[0011] When the rotating sleeve rotates from the release position to the locking position, the steel balls located in the first eccentric groove group move radially inward and press against the elastic clamping sleeve, causing the elastic clamping sleeve to deform toward the saw blade to clamp the saw blade in the width direction; the steel balls located in the second eccentric groove group move radially inward and press against both sides of the saw blade in the thickness direction to clamp the saw blade in the thickness direction.

[0012] Optionally, it also includes an elastic element disposed between the chuck body and the rotating sleeve, the elastic element having a preload force for driving the rotating sleeve to rotate toward the locking position.

[0013] Optionally, the peripheral wall of the chuck body is provided with a plurality of clamping holes, the plurality of clamping holes being provided in a one-to-one correspondence with the plurality of eccentric grooves, and each of the clamping holes being connected to the corresponding eccentric groove and the saw blade mounting position.

[0014] Optionally, the top inner periphery of the chuck body is provided with an inwardly protruding placement platform, and the top outer periphery of the elastic clamping sleeve is provided with an outwardly protruding overlapping portion, which overlaps on the placement platform.

[0015] The elastic clamping sleeve is provided with a clamping block on each side of the saw blade width direction. The clamping block extends from the top of the elastic clamping sleeve toward the insertion direction of the saw blade mounting position, and the outer side of the clamping block is provided with a clamping surface for contacting the steel ball.

[0016] Optionally, the steel ball and the clamping block interact within the clamping surface, and the clamping block and the saw blade interact at least partially within the clamping surface.

[0017] Optionally, the clamping surface is formed by the clamping block protruding toward the clamping hole.

[0018] Optionally, the bottom of the clamping block extends at an angle away from the saw blade mounting position, so as to form a guide opening between the two clamping blocks, the guide opening being aligned with the insertion port of the saw blade mounting position.

[0019] Optionally, the top inner peripheral wall of the chuck body is provided with at least one positioning groove, and the overlapping part of the elastic clamping sleeve is provided with at least one outwardly protruding positioning block. The positioning blocks are arranged in a one-to-one correspondence with the positioning grooves, and each positioning block is accommodated in the corresponding positioning groove.

[0020] Optionally, the upper end of the chuck body is provided with a first limiting block that protrudes outward in the circumferential direction, and the lower end of the first limiting block is provided with a first pad.

[0021] The lower outer periphery of the chuck body is provided with a circumferentially extending groove, a retaining ring is engaged in the groove, and a second washer is provided at the upper end of the retaining ring.

[0022] The axial limit of the rotating sleeve is located between the first gasket and the second gasket.

[0023] Optionally, the upper inner peripheral wall of the rotating sleeve is provided with a clearance groove, and the elastic element is at least partially accommodated in the clearance groove.

[0024] The beneficial effects of the chuck assembly of the jigsaw of the present invention are as follows: by rotating the rotating sleeve, the steel balls in the first eccentric groove group located on both sides of the saw blade width direction are driven to move radially inward using the multiple eccentric grooves arranged circumferentially on its inner circumference. This first presses the elastic clamping sleeve to cause it to deform toward the saw blade, thereby clamping the saw blade width direction. At the same time, the steel balls in the second eccentric groove group located on both sides of the saw blade thickness direction also move radially inward, directly pressing the two sides of the saw blade thickness direction. Thus, during the process of the rotating sleeve switching from the release position to the locking position, multi-dimensional synchronous clamping of the saw blade width and thickness directions is achieved.

[0025] The chuck assembly of the present invention can apply clamping force to the saw blade simultaneously from the width and thickness directions, effectively solving the problems of single force and easy shaking of the saw blade in the prior art. It significantly suppresses the deviation of the saw blade in high-frequency reciprocating motion, thereby greatly improving the flatness and cutting accuracy of the cutting surface, while reducing abnormal wear of the saw blade, extending the service life of the saw blade, and improving the operational safety and clamping reliability of the equipment during long-term operation. Attached Figure Description

[0026] Figure 1 This is an exploded view of a chuck assembly according to one embodiment of the present invention;

[0027] Figure 2 This is a three-dimensional structural diagram of the chuck body according to one embodiment of the present invention;

[0028] Figure 3 This is a three-dimensional structural diagram of a rotating sleeve according to one embodiment of the present invention;

[0029] Figure 4 This is a three-dimensional structural diagram of an elastic clamping sleeve according to one embodiment of the present invention;

[0030] Figure 5 A cross-sectional view of the chuck assembly in an unclamped state according to one embodiment of the present invention;

[0031] Figure 6 for Figure 5 A sectional view along the CC direction.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Chuck body; 11. Saw blade mounting position; 12. Clamping hole; 13. Placement platform; 14. Positioning groove; 15. First limiting block; 16. Slot; 17. Snap ring; 2. Rotating sleeve; 21. Eccentric groove; 22. Clearance groove; 3. Elastic clamping sleeve; 31. Overlapping part; 32. Clamping block; 33. Clamping surface; 34. Guide opening; 35. Positioning block; 4. Steel ball; 5. Elastic element; 6. First washer; 7. Second washer; 8. Saw blade; 9. Reciprocating rod. Detailed Implementation

[0034] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0035] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0036] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0037] like Figure 1 , Figure 2 , Figure 3 As shown, an embodiment of the present invention provides a chuck assembly for a jigsaw, comprising:

[0038] The chuck body 1 is provided with a saw blade mounting position 11 for accommodating the saw blade 8;

[0039] The rotating sleeve 2 is rotatably fitted around the outer periphery of the chuck body 1 and has a locked position and a released position;

[0040] The elastic clamping sleeve 3 is disposed inside the chuck body 1;

[0041] Multiple steel balls 4;

[0042] The inner circumference of the rotating sleeve 2 is provided with a plurality of eccentric grooves 21, and the plurality of eccentric grooves 21 are arranged in a one-to-one correspondence with the plurality of steel balls 4, and each eccentric groove 21 is connected to the saw blade mounting position 11; the plurality of eccentric grooves 21 include a first eccentric groove group located on both sides of the saw blade width direction and a second eccentric groove group located on both sides of the saw blade thickness direction.

[0043] When the rotating sleeve 2 rotates from the release position to the locking position, the steel ball 4 located in the first eccentric groove group moves radially inward and presses the elastic clamping sleeve 3, causing the elastic clamping sleeve 3 to deform toward the saw blade 8, so as to clamp the saw blade 8 in the width direction; the steel ball 4 located in the second eccentric groove group moves radially inward and presses the two sides of the saw blade 8 in the thickness direction, so as to clamp the saw blade 8 in the thickness direction.

[0044] Specifically, the top of the chuck body 1 is connected to the reciprocating rod 9 to form an integral structure. When the jigsaw is working, the reciprocating rod 9 drives the chuck body 1 and the saw blade 8 to perform reciprocating linear motion.

[0045] When the chuck assembly is in operation, the saw blade 8 is first inserted into the saw blade mounting position 11 of the chuck body 1. At this time, the rotating sleeve 2 is in the released position, the elastic clamping sleeve 3 is in the natural state, and the saw blade 8 can be freely inserted.

[0046] Then rotate the rotating sleeve 2 from the released position to the locked position, as follows: Figure 5 , Figure 6 As shown, multiple eccentric grooves 21 distributed circumferentially on the inner circumference of the rotating sleeve 2 rotate synchronously. As the distance from the bottom of the eccentric groove 21 to the rotation center gradually decreases with the change of rotation angle, each steel ball 4 is gradually pushed radially inward in the groove and reaches the working position through the connecting path between the eccentric groove 21 and the saw blade mounting position 11. Among them, the steel balls 4 in the first eccentric groove group located on both sides of the width direction of the saw blade 8 move radially inward and press against the inner wall of the elastic clamping sleeve 3, forcing the elastic clamping sleeve 3 to produce elastic deformation towards the center of the saw blade 8, reducing the inner diameter of the elastic clamping sleeve 3 and uniformly wrapping the two sides of the saw blade 8 in the width direction from both sides, providing frictional clamping force in a surface contact manner; at the same time, the steel balls 4 in the second eccentric groove group located on both sides of the thickness direction of the saw blade 8 move radially inward and directly press against the upper and lower surfaces in the thickness direction of the saw blade 8, restricting the movement of the saw blade 8 in the thickness direction in a point contact manner.

[0047] When the rotating sleeve 2 reaches the locking position, the elastic clamping sleeve 3 deforms to its maximum, and the saw blade 8 is firmly clamped in both the width and thickness directions, thus completing the clamping and locking.

[0048] When the saw blade 8 needs to be replaced, simply rotate the rotating sleeve 2 back to the release position. The steel ball 4 will be gradually pushed radially outward in the groove, and the elastic clamping sleeve 3 will spring back and release, making it easy to remove the saw blade 8.

[0049] In this embodiment, the steel balls 4 located on both sides of the saw blade 8 in the width direction move radially inward under the pushing force of the eccentric groove 21. They do not directly contact the saw blade 8, but instead press against the elastic clamping sleeve 3, forcing the elastic clamping sleeve 3 to deform towards the width side of the saw blade 8. The deformation of the elastic clamping sleeve 3 causes it to tightly wrap around or abut against both sides of the saw blade 8 in the width direction, thereby achieving stable surface contact clamping of the saw blade 8. Furthermore, the elastic deformation of the elastic clamping sleeve 3 can automatically adapt to slight differences in the width of the saw blade 8, ensuring reliable clamping every time.

[0050] By setting multiple eccentric grooves 21, divided into a first eccentric groove group and a second eccentric groove group, along the inner circumference of the rotating sleeve 2, and cooperating with multiple steel balls 4, bidirectional synchronous clamping of the saw blade 8 in both the width and thickness directions is achieved: in the width direction, the elastic clamping sleeve 3 is compressed by the steel balls 4 and undergoes elastic deformation to uniformly wrap around the saw blade 8, providing a large area of ​​frictional clamping force to effectively resist the horizontal deviation of the saw blade 8; in the thickness direction, the steel balls 4 directly press on the upper and lower surfaces of the saw blade 8, precisely limiting the vertical jump of the saw blade 8. The synergistic effect of the two changes the saw blade 8 from the traditional single-point force to multi-point and multi-surface force, with uniform clamping force distribution and effective constraint in both orthogonal directions, fundamentally eliminating the deviation and shaking of the saw blade 8 in high-frequency reciprocating motion, thereby significantly improving the flatness of the cutting surface and the cutting accuracy. At the same time, the uniform force distribution and the elastic buffering effect of the elastic clamping sleeve 3 effectively reduce the abnormal wear of the saw blade 8 and extend the service life of the saw blade 8.

[0051] In addition, the operation of the rotating sleeve 2 allows for quick clamping and disassembly with one hand, and the geometric self-locking characteristics of the eccentric groove 21 ensure the stability and reliability of the clamping state during operation. The overall structure is simple, easy to operate, safe and efficient.

[0052] Optionally, such as Figure 5 As shown, it also includes an elastic element 5, which is disposed between the chuck body 1 and the rotating sleeve 2. The elastic element 5 has a preload force, which is used to drive the rotating sleeve 2 to rotate toward the locking position.

[0053] Specifically, the elastic element 5 (such as a torsion spring or coil spring) is installed between the chuck body 1 and the rotating sleeve 2, and is pre-compressed or twisted at a certain angle to store elastic potential energy (i.e., preload). Under the continuous action of this preload, the rotating sleeve 2 always bears a torque or thrust pointing towards the locking position. Therefore, when there is no manual operation, the rotating sleeve 2 will automatically rotate and stay in the locking position, the steel ball 4 is pushed to the innermost radial side by the eccentric groove 21, and the saw blade 8 is firmly clamped.

[0054] When the user needs to insert or replace the saw blade 8, they need to overcome the preload of the elastic element 5 and actively rotate the rotating sleeve 2 in the opposite direction (from the locked position to the released position). At this time, the elastic element 5 is further compressed or twisted, storing more energy. When the rotating sleeve 2 reaches the released position, the saw blade 8 can be freely inserted or pulled out.

[0055] After the user releases the rotating sleeve 2, the external force disappears. The preload stored in the elastic element 5 immediately drives the rotating sleeve 2 to automatically rotate from the released position back to the locked position, causing the steel ball 4 to press against the saw blade 8 again (indirectly pressing in the width direction through the elastic clamping sleeve 3, and directly pressing in the thickness direction). The entire process does not require the user to perform any additional "locking" action.

[0056] The preload of the elastic element 5 ensures that the rotating sleeve 2 is always subjected to a continuous thrust toward the locking position during operation. Even under the condition of high-frequency reciprocating vibration of the jigsaw, it can effectively resist the risk of the rotating sleeve 2 accidentally rotating and loosening due to vibration. It upgrades from passive locking to active self-locking, which greatly improves the reliability and safety of the saw blade 8 clamping.

[0057] In this optional embodiment, the preload of the elastic element 5 ensures that the rotating sleeve 2 is always subjected to a torque toward the locked position. Even if the equipment experiences severe vibrations due to prolonged high-frequency reciprocating operation, the rotating sleeve 2 will not rotate in the opposite direction to the release position; even if the user forgets to rotate it fully to the locked position, the elastic element 5 will automatically pull it back, thus significantly reducing the risk of accidental loosening of the chuck and the saw blade 8 flying out and causing injury. Furthermore, the user only needs to rotate the rotating sleeve 2 with one hand (overcoming the elastic force) to insert the saw blade 8, and the chuck automatically locks after releasing the hand, without the need for secondary manual tightening or confirmation. In scenarios where the saw blade 8 is frequently changed (e.g., alternating between cutting wood and metal in a single job), this "automatic reset" feature greatly improves operational convenience.

[0058] Optionally, such as Figure 2 , Figure 5 , Figure 6 As shown, the chuck body 1 has multiple clamping holes 12 on its peripheral wall. The multiple clamping holes 12 are arranged in a one-to-one correspondence with multiple eccentric grooves 21. Each clamping hole 12 is connected to the corresponding eccentric groove 21 and the saw blade mounting position 11.

[0059] Specifically, when the rotating sleeve 2 rotates from the released position to the locked position, the gradually curved surface of the eccentric groove 21 pushes the steel ball 4 radially inward. The steel ball 4 does not roll freely, but is confined within the clamping hole 12. The inner wall of the clamping hole 12 forms a sliding or rolling fit with the steel ball 4, forcing the steel ball 4 to move only along the centerline direction of the hole (i.e., the strict radial direction).

[0060] The steel ball 4 corresponding to the first eccentric groove group moves radially inward under the guidance of the clamping hole 12, and its inner end face accurately presses against the outer wall of the elastic clamping sleeve 3. The steel ball 4 corresponding to the second eccentric groove group moves radially inward under the guidance of the clamping hole 12, and its inner end face directly passes through the wall thickness of the chuck body 1, accurately pressing against both sides in the thickness direction of the saw blade 8.

[0061] In the locked state, even if subjected to vibration or impact, the inner wall of the clamping hole 12 restricts the radial position of the steel ball 4, preventing it from accidentally rolling from the shallow to the deep position of the eccentric groove 21, thus playing an auxiliary locking role.

[0062] In this optional embodiment, the clamping hole 12 provides a unique and precise radial movement track for the steel ball 4. Without the clamping hole 12, multiple steel balls 4 may move circumferentially, collide with each other, or deviate from the predetermined force application direction, causing some steel balls 4 to fail to effectively clamp the elastic clamping sleeve 3 or saw blade 8, resulting in dispersed clamping force or even failure. The clamping hole 12 ensures that the force of each steel ball 4 is strictly applied radially to the correct position, thereby achieving uniform and repeatable clamping.

[0063] When the saw blade 8 is not inserted or during assembly / disassembly, the clamping holes 12 retain the steel balls 4 within their respective holes, preventing them from falling out due to gravity or the rotation of the rotating sleeve 2, thus avoiding part loss. Furthermore, the steel balls 4 are confined within their respective clamping holes 12, preventing them from shifting into other eccentric grooves 21, ensuring that each eccentric groove 21 corresponds to the correct force application object (width or thickness direction), and avoiding assembly errors. When the user rotates the rotating sleeve 2, the steel balls 4 roll or slide stably within the clamping holes 12, without any stiffness caused by friction or jamming between the steel balls 4, improving the operating feel.

[0064] Because the movement of the steel ball 4 is strictly constrained, the rotational torque of the rotating sleeve 2 can be efficiently converted into radial clamping force. It will not lose energy due to the skewness or lateral movement of the steel ball 4, so that the clamping force actually applied to the saw blade 8 is larger and more stable under the same rotation angle and spring preload.

[0065] Furthermore, by directly machining the clamping hole 12 on the circumferential wall of the chuck body, the steel ball 4, the eccentric groove 21, and the elastic clamping sleeve 3 can be integrated into a very small radial space. Compared with other complex linkage or lever-type guide structures, the clamping hole 12 solution has a simple structure and occupies little space, making it particularly suitable for the limited working head space of handheld jigsaws.

[0066] Optionally, such as Figure 2 , Figure 4 As shown, the top inner periphery of the chuck body 1 is provided with an inwardly protruding placement platform 13, and the top outer periphery of the elastic clamping sleeve 3 is provided with an outwardly protruding overlapping part 31, which overlaps on the placement platform 13.

[0067] The elastic clamping sleeve 3 is provided with a clamping block 32 on each side of the saw blade width direction. The clamping block 32 extends from the top of the elastic clamping sleeve 3 toward the insertion direction of the saw blade mounting position 11, and the outer side of the clamping block 32 is provided with a clamping surface 33 for contacting the steel ball 4.

[0068] Specifically, the inner circumference of the top end of the chuck body 1 is provided with an inwardly protruding placement platform 13, forming an annular or intermittent support surface. The outer circumference of the top of the elastic clamping sleeve 3 is provided with an outwardly protruding overlapping portion 31, the outer diameter of which is larger than the inner diameter of the placement platform 13. In this embodiment, the elastic clamping sleeve 3 is manufactured using a metal powder injection molding process.

[0069] During assembly, the elastic clamping sleeve 3 is inserted into the chuck body 1 from above, and its overlapping part 31 naturally falls on the placement table 13, forming an axial suspension, so that the elastic clamping sleeve 3 will not fall downward under gravity and working vibration, while providing a stable reference position for its lower deformable part.

[0070] The elastic clamping sleeve 3 is located on both sides of the saw blade 8 in the width direction, and each side has a clamping block 32. The two clamping blocks 32 extend downwards from the top of the elastic clamping sleeve 3, forming two opposing "cantilever" or "jaw" structures. Each clamping block 32 has a clamping surface 33 on its outer side, which corresponds to the position of the clamping hole 12 and is used for direct contact with the steel ball 4 (e.g., ...). Figure 5 (As shown).

[0071] When the rotating sleeve 2 rotates to the locking position, the steel ball 4 located in the first eccentric groove 21 group moves radially inward under the guidance of the clamping hole 12. The steel ball 4 first contacts and presses against the clamping surface 33 on the outside of the clamping block 32. Under the pressure of the steel ball 4, the two clamping blocks 32 (which are elastic) on the left and right sides undergo elastic deformation in the width direction of the saw blade 8, and their inner surfaces tightly abut against both sides of the saw blade 8 in the width direction, thus achieving clamping.

[0072] In this optional embodiment, the cooperation between the placement platform 13 and the overlapping part 31 ensures that the elastic clamping sleeve 3 is precisely limited in the axial direction, preventing it from moving axially or falling off during high-frequency reciprocating operation. At the same time, the support of the placement platform 13 on the overlapping part 31 ensures that the top of the elastic clamping sleeve 3 always has a stable force reference when it is deformed by radial force, preventing the elastic clamping sleeve 3 from tilting or swaying due to uneven force, and ensuring the symmetrical and uniform clamping force.

[0073] The clamping block 32 and the clamping surface 33 concentrate the force exerted by the steel ball 4 on the elastic clamping sleeve 3 in specific areas on both sides of the width direction, rather than dispersing it across the entire inner wall of the elastic clamping sleeve 3. This makes the deformation of the elastic clamping sleeve 3 more controllable and the clamping force more concentrated. Compared to the uniform pressure on the entire elastic clamping sleeve 3, the local deformation response of the clamping block 32 is faster, and the locking can be completed by rotating the rotating sleeve 2 at a very small angle.

[0074] The clamping surface 33 serves as a dedicated contact surface between the steel ball 4 and the elastic clamping sleeve 3. This not only increases the contact area between the steel ball 4 and the elastic clamping sleeve 3 to reduce local stress and wear, but also ensures that the radial thrust can be efficiently converted into the radial contraction deformation of the elastic clamping sleeve 3, thus avoiding force dispersion and energy loss.

[0075] Optionally, such as Figure 6 As shown, the steel ball 4 and the clamping block 32 are located within the clamping surface 33, and the clamping block 32 and the saw blade 8 are located at least partially within the clamping surface 33.

[0076] Specifically, when the steel ball 4 moves radially inward within the clamping hole 12, its contact point with the clamping block 32 is strictly limited to the range of the clamping surface 33. That is, the steel ball 4 always rolls or slides on the clamping surface 33 and will not cross the boundary of the clamping surface 33 to contact other non-designed areas of the clamping block 32. At the same time, when the clamping block 32 deforms radially with the elastic clamping sleeve 3, at least a portion of its contact area with the side of the saw blade 8 in the width direction falls within the geometric range defined by the clamping surface 33. That is, the point of action of the clamping block 32 applying clamping force to the saw blade 8 and the point of action of the steel ball 4 applying driving force to the clamping block 32 are highly coincident in space. The two share the common action area of ​​the clamping surface 33, thus achieving precise constraint of the force transmission path.

[0077] In this optional embodiment, the clamping block 32 and the saw blade 8 are at least partially located within the clamping surface 33. This means that the input point of the driving force (the contact point between the steel ball 4 and the clamping surface 33) and the output point (the contact point between the clamping block 32 and the saw blade 8) are highly overlapping in space. The force transmission path is the shortest and the lever arm is the smallest. The radial thrust of the steel ball 4 is converted into the clamping force of the clamping block 32 on the saw blade 8 with almost no loss. This avoids torque deflection and energy waste caused by misalignment of the application point, optimizes the force path, and improves the clamping stability of the saw blade 8.

[0078] Since the force transmission path is precisely constrained within the clamping surface 33, the deformation mode of the elastic clamping sleeve 3 during the clamping process is completely controllable and predictable. The clamping force on both sides of the saw blade 8 in the width direction is consistent in magnitude and symmetrical in direction, which fundamentally eliminates the slight deflection of the saw blade 8 caused by uneven clamping force, and further ensures the trajectory accuracy and cut surface quality in the high-frequency reciprocating cutting process.

[0079] Optionally, such as Figure 4 As shown, the clamping surface 33 is formed by the clamping block 32 protruding towards the clamping hole 12.

[0080] Specifically, on the outer side of the clamping block 32 of the elastic clamping sleeve 3, a structure protruding towards the clamping hole 12 is processed or formed. The protrusion can be dot-shaped, line-shaped (rib-shaped) or surface-shaped (boss-shaped). The radial outer surface of the protrusion is the clamping surface 33.

[0081] When the clamping block 32 is not under pressure, the protruding clamping surface 33 is the part on the outer surface of the clamping block 32 closest to the clamping hole 12 (i.e., the outermost radially). The steel ball 4 is located inside the clamping hole 12. When the rotating sleeve 2 rotates to the locking position, the steel ball 4 moves radially inward. The first part that the steel ball 4 contacts is necessarily the protruding clamping surface 33 on the clamping block 32, rather than other parts of the clamping block 32 (such as the root above the protrusion or the tip below the protrusion).

[0082] Because the contact between the steel ball 4 and the clamping block 32 is forcibly concentrated on the raised clamping surface 33, the pressure applied by the steel ball 4 is no longer dispersed across the entire outer surface of the clamping block 32, but is highly concentrated in the raised area. This protrusion effectively transmits the point contact or small-area contact pressure of the steel ball 4 to the body of the clamping block 32, thereby driving the clamping block 32 to produce elastic deformation toward the saw blade 8.

[0083] In this optional embodiment, the protruding structure serves as a stress concentration point, allowing even a small displacement of the steel ball 4 to generate significant local pressure on the clamping block 32. This enables the rotating sleeve 2 to rotate only a small angle, allowing the steel ball 4 to quickly drive the clamping block 32 to deform via the protrusion, achieving rapid locking and improving the response speed of the chuck assembly.

[0084] The clamping surface 33 protrudes towards the clamping hole 12, which is equivalent to actively setting a receiving surface on the movement path of the steel ball 4. When the steel ball 4 moves radially inward, it does not need to find a contact point, but directly and naturally fits with the protruding clamping surface 33. This avoids the problem of slippage or unstable point contact caused by insufficient contact surface of the steel ball 4, and ensures that the steel ball 4 and the clamping surface 33 always maintain reliable surface contact or line contact.

[0085] Optionally, such as Figure 4 , Figure 5 As shown, the bottom of the clamping block 32 extends at an angle away from the saw blade mounting position 11, so that a guide opening 34 is formed between the two clamping blocks 32, and the guide opening 34 is aligned with the insertion opening of the saw blade mounting position 11.

[0086] Specifically, the bottom of the clamping block 32 is tilted outward (i.e. away from the center of the saw blade 8), thereby forming a "trumpet-shaped" guide opening 34 at the bottom between the two clamping blocks 32 located on both sides of the width direction of the saw blade 8. The position of the guide opening 34 is precisely aligned with the insertion port of the saw blade mounting position 11 on the chuck body 1.

[0087] During the saw blade 8 clamping process, when the user inserts the saw blade 8 into the insertion port of the saw blade mounting position 11, the two sides of the saw blade 8 in the width direction first contact the inner wall of the guide opening 34 formed by the outward tilt of the bottom of the two clamping blocks 32. Since the guide opening 34 is a wide opening that is narrow at the top and wide at the bottom, even if there is a slight lateral offset or tilt during the insertion process, the two sides of the saw blade 8 will be naturally guided by the tilted surface of the guide opening 34 and slide along the tilted surface to the center position of the saw blade mounting position 11, and finally slide smoothly into the mounting position. When the saw blade 8 is fully inserted, the tilted surface of the guide opening 34 still provides effective support for the bottom edge of the saw blade 8, preventing the saw blade 8 from slipping out in the axial direction. At the same time, the two sides of the saw blade 8 in the width direction are precisely aligned at this time, forming a precise matching relationship with the clamping surface 33 above and the elastic clamping sleeve 3.

[0088] In this optional embodiment, the trumpet-shaped structure of the guide port 34 provides a clear geometric guide path for the saw blade 8. The two sides of the saw blade 8 always slide in along the inclined surface during the insertion process. Even if there is a lateral offset or angular tilt when the saw blade 8 is initially inserted, the inclined surface of the guide port 34 will automatically correct the offset, so that the saw blade 8 slides in smoothly without getting stuck or scraped with the clamping block 32 or the chuck body 1. This greatly reduces the difficulty of clamping and realizes fast and smooth insertion of the saw blade 8.

[0089] Optionally, such as Figure 2 , Figure 4 As shown, the top inner peripheral wall of the chuck body 1 is provided with at least one positioning groove 14, and the overlapping part 31 of the elastic clamping sleeve 3 is provided with at least one outwardly protruding positioning block 35. The positioning block 35 is provided in correspondence with the positioning groove 14, and each positioning block 35 is accommodated in the corresponding positioning groove 14.

[0090] Specifically, when the elastic clamping sleeve 3 is inserted into the chuck body 1, the overlapping part 31 is first placed on the placement platform 13 to achieve initial positioning. Then, the circumferential rotation of the elastic clamping sleeve 3 relative to the chuck body 1 is constrained by the cooperation of the positioning block 35 and the positioning groove 14. The positioning block 35 is precisely embedded in the positioning groove 14, and the elastic clamping sleeve 3 can no longer rotate circumferentially relative to the chuck body 1, thereby achieving precise circumferential angle positioning.

[0091] During operation, when the rotating sleeve 2 drives the steel ball 4 to reach the clamping surface 33 through the clamping hole 12, the elastic clamping sleeve 3 is locked in a unique circumferential position by the positioning block 35 and the positioning groove 14. The docking relationship between each steel ball 4 and the clamping surface 33 on the corresponding clamping block 32 remains unchanged, ensuring that the steel ball 4 can accurately act on the preset clamping surface 33 position each time it is locked.

[0092] In this optional embodiment, the cooperation between the positioning block 35 and the positioning groove 14 eliminates the circumferential degree of freedom of the elastic clamping sleeve 3 relative to the chuck body 1, so that the elastic clamping sleeve 3 is always at the same circumferential angle after each clamping, ensuring that the clamping surface 33 on each clamping block 32 is always precisely aligned with the movement path of the corresponding steel ball 4, avoiding the steel ball 4 acting on the non-designed area outside the clamping surface 33 due to the circumferential offset of the elastic clamping sleeve 3, thereby ensuring that the magnitude and direction of the clamping force are completely consistent each time.

[0093] The placement platform 13 and the overlapping part 31 provide axial limiting, and the positioning groove 14 and the positioning block 35 provide circumferential limiting. The two work together to form a complete constraint on the elastic clamping sleeve 3 from both axial and circumferential dimensions, so that the elastic clamping sleeve 3 will not move axially or rotate circumferentially in the high-frequency reciprocating vibration environment, fundamentally eliminating the possibility of displacement or deflection of the elastic clamping sleeve 3 during operation.

[0094] Optionally, such as Figure 2 , Figure 5 As shown, the upper end of the chuck body 1 is provided with a first limiting block 15 that protrudes outward in the circumferential direction, and the lower end of the first limiting block 15 is provided with a first gasket 6.

[0095] The lower outer periphery of the chuck body 1 is provided with a circumferentially extending groove 16, and a retaining ring 17 is engaged in the groove 16. The upper end of the retaining ring 17 is provided with a second washer 7.

[0096] The axial limit of the rotating sleeve 2 is located between the first gasket 6 and the second gasket 7.

[0097] Specifically, regarding axial limiting, a first limiting block 15 protrudes circumferentially from the upper end of the chuck body 1. The first limiting block 15 acts as an annular stop at the upper end of the rotating sleeve 2. A first gasket 6 is fitted at its lower end. The first gasket 6 is an annular thin sheet structure, fitted onto the outer periphery of the upper end of the rotating sleeve 2 and sandwiched between the first limiting block 15 and the rotating sleeve 2. A groove 16 is formed circumferentially on the outer periphery of the lower end of the chuck body 1. A retaining ring 17 is engaged in the groove 16. The retaining ring 17 is an annular buckle that closes circumferentially. A second gasket 7 is fitted at its upper end. The second gasket 7 is also an annular thin sheet structure, fitted onto the outer periphery of the lower end of the rotating sleeve 2 and sandwiched between the retaining ring 17 and the rotating sleeve 2. The axial length of the rotating sleeve 2 is precisely limited between the first gasket 6 and the second gasket 7. Both ends are limited by the first gasket 6 and the second gasket 7, respectively, preventing it from moving upward beyond the first limiting block 15 or downward out of the constraint range of the retaining ring 17.

[0098] During operation, the rotating sleeve 2 rotates smoothly on the low-friction sliding surface provided by the first washer 6 and the second washer 7. The first washer 6 and the second washer 7 bear the axial pressure of the rotating sleeve 2 and minimize the sliding friction, so that the preload of the elastic element 5 can be efficiently converted into the rotational driving force of the rotating sleeve 2.

[0099] When vibration attempts to cause the rotating sleeve 2 to move axially, the first limiting block 15 and the retaining ring 17 form rigid stops from both ends, and the rotating sleeve 2 is firmly locked between the two gaskets. The relative relationship between the eccentric groove 21 and the steel ball 4 will not be disrupted by axial displacement, making the automatic locking function of the chuck assembly more stable, durable and reliable.

[0100] In this optional embodiment, the first limiting block 15 forms a bidirectional axial constraint on the rotating sleeve 2 from the upper end and the retaining ring 17 from the lower end, so that the rotating sleeve 2 will not undergo axial displacement due to the repeated pre-tightening and release of the elastic element 5 under high-frequency reciprocating vibration conditions, ensuring that the relative position of the eccentric groove 21 and the steel ball 4 remains stable, and ensuring the continuous and reliable clamping force.

[0101] The first gasket 6 and the second gasket 7 are respectively disposed between the rotating sleeve 2 and the first limiting block 15 and the retaining ring 17, providing a sliding interface with a low coefficient of friction for the rotation of the rotating sleeve 2, making the rotating sleeve 2 rotate more smoothly and with less resistance when driven by the elastic element 5, and making it easier for the user to operate. At the same time, the gaskets can also effectively absorb the axial impact force when the rotating sleeve 2 rotates, reducing noise and wear.

[0102] Optionally, such as Figure 3 , Figure 5 As shown, the upper inner circumferential wall of the rotating sleeve 2 is provided with a relief groove 22, and the elastic member 5 is at least partially accommodated in the relief groove 22.

[0103] Specifically, when the elastic element 5 is disposed between the chuck body 1 and the rotating sleeve 2 and has a pre-tightening force, one end of the elastic element 5 abuts against the chuck body 1 and the other end abuts against the rotating sleeve 2, and the part of the rotating sleeve 2 that contacts the elastic element 5 falls into the relief groove 22. The elastic element 5 is "received" in the relief groove 22 and will not protrude beyond the outline of the upper inner peripheral wall of the rotating sleeve 2 in the axial direction.

[0104] In this optional embodiment, after the elastic element 5 is accommodated in the relief groove 22, the elastic element 5 no longer adds extra contour dimensions to the rotating sleeve 2 in the axial direction, so that the upper end of the rotating sleeve 2 can fit more tightly with the first gasket 6, and the overall axial dimension is more compact, which is conducive to the miniaturization design of the chuck assembly, and at the same time makes the axial constraint of the first limiting block 15 on the rotating sleeve 2 fit more closely.

[0105] Furthermore, the clearance groove 22 provides circumferential and radial constraints to the elastic element 5, preventing the elastic element 5 from axially shifting or circumferentially deviating due to vibration during operation. The preload of the elastic element 5 is always stably output along the design direction and will not be affected by changes in the position of the elastic element 5, thus ensuring the long-term stability and reliability of the elastic element's preload.

[0106] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A collet assembly for a jigsaw, characterized by, include: The chuck body (1) is provided with a saw blade mounting position (11) for accommodating the saw blade; The rotating sleeve (2) is rotatably fitted around the outer periphery of the chuck body (1) and has a locked position and a released position; An elastic clamping sleeve (3) is disposed inside the chuck body (1); Multiple steel balls (4); The inner circumference of the rotating sleeve (2) is provided with a plurality of eccentric grooves (21), and the plurality of eccentric grooves (21) are arranged in a one-to-one correspondence with the plurality of steel balls (4), and each of the eccentric grooves (21) is connected to the saw blade mounting position (11); the plurality of eccentric grooves (21) includes a first eccentric groove group located on both sides of the saw blade width direction and a second eccentric groove group located on both sides of the saw blade thickness direction; When the rotating sleeve (2) rotates from the release position to the locking position, the steel ball (4) located in the first eccentric groove group moves radially inward and presses against the elastic clamping sleeve (3), causing the elastic clamping sleeve (3) to deform toward the saw blade to clamp the saw blade in the width direction; the steel ball (4) located in the second eccentric groove group moves radially inward and presses against both sides of the saw blade in the thickness direction to clamp the saw blade in the thickness direction; The chuck body (1) has a plurality of clamping holes (12) on its peripheral wall. The plurality of clamping holes (12) are provided in a one-to-one correspondence with the plurality of eccentric grooves (21). Each clamping hole (12) is connected to the corresponding eccentric groove (21) and the saw blade mounting position (11). The top inner circumference of the clamp body (1) is provided with an inwardly protruding placement platform (13), and the top outer circumference of the elastic clamping sleeve (3) is provided with an outwardly protruding overlapping part (31), which overlaps on the placement platform (13). The elastic clamping sleeve (3) is provided with a clamping block (32) on each side of the saw blade width direction. The clamping block (32) extends from the top of the elastic clamping sleeve (3) toward the insertion direction of the saw blade mounting position (11), and the outer side of the clamping block (32) is provided with a clamping surface (33) for contacting the steel ball (4).

2. A clamp head assembly for a curve saw according to claim 1, wherein, It also includes an elastic element (5), which is disposed between the chuck body (1) and the rotating sleeve (2). The elastic element (5) has a preload force, which is used to drive the rotating sleeve (2) to rotate toward the locking position.

3. The chuck assembly of the jigsaw according to claim 1, characterized in that, The steel ball (4) and the clamping block (32) are positioned within the clamping surface (33), and the clamping block (32) and the saw blade are positioned at least partially within the clamping surface (33).

4. The chuck assembly of the jigsaw according to claim 3, characterized in that, The clamping surface (33) is formed by the clamping block (32) protruding toward the clamping hole (12).

5. The chuck assembly of the jigsaw according to claim 3, characterized in that, The bottom of the clamping block (32) extends at an angle away from the saw blade mounting position (11) so that a guide opening (34) is formed between the two clamping blocks (32), and the guide opening (34) is aligned with the insertion port of the saw blade mounting position (11).

6. The chuck assembly of the jigsaw according to claim 1, characterized in that, The top inner peripheral wall of the clamp body (1) is provided with at least one positioning groove (14), and the overlapping part (31) of the elastic clamping sleeve (3) is provided with at least one outwardly protruding positioning block (35). The positioning block (35) is provided in correspondence with the positioning groove (14), and each positioning block (35) is accommodated in the corresponding positioning groove (14).

7. The chuck assembly of the jigsaw according to claim 2, characterized in that, The upper end of the clamp body (1) is provided with a first limiting block (15) that protrudes outward in the circumferential direction, and the lower end of the first limiting block (15) is provided with a first gasket (6). The lower outer periphery of the clamp body (1) is provided with a circumferentially extending slot (16), and a retaining ring (17) is engaged in the slot (16). The upper end of the retaining ring (17) is provided with a second gasket (7). The rotating sleeve (2) is axially confined between the first gasket (6) and the second gasket (7).

8. The chuck assembly of the jigsaw according to claim 7, characterized in that, The upper inner circumferential wall of the rotating sleeve (2) is provided with a relief groove (22), and the elastic element (5) is at least partially accommodated in the relief groove (22).

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