Tool holder and hammer drill

Abstract

The present application relates to a tool holder and an electric hammer, in addition to a first spring for providing pressure to lock a tool head and a second spring for providing pressure to lock the tool holder on the electric hammer, a third spring is additionally arranged between the second sleeve and a support ring, the support ring has no axial movement relative to the holder base, so that the third spring can provide a stable support force to the first sleeve in any position, preventing the first sleeve from falling towards the second sleeve due to the loss of support of the first spring and the third spring when the slide is pushed by the drill bit during the process of inserting the electric hammer into the drill bit, causing the first locking element to jam, resulting in the drill bit being unable to be inserted or being blocked.

Description

[Technical Field]

[0001] This invention relates to the field of power tools, and in particular to an electric hammer for impacting or rotating concrete, masonry and other structures, and a tool holder for such an electric hammer. [Background Technology]

[0002] Tool clamps are typically attached to a hammer drill to hold the drill bit. The tool clamp includes a sleeve, which allows the drill bit to be inserted and removed. When inserting the drill bit, the sleeve must always be kept at the front end to prevent the sleeve from getting stuck with the steel balls inside the tool clamp, which would make it difficult to insert the drill bit.

[0003] Normally, the sleeve is kept at the front due to the interference fit with the front rubber dust cap. However, when the interference fit between the two is insufficient due to wear or other reasons, the sleeve will move downward due to gravity when the drill bit is inserted vertically and slowly, causing the drill bit to be unable to be inserted or to be blocked from insertion.

[0004] Therefore, it is indeed necessary to provide an improved tool holder and an electric hammer equipped with the tool holder to overcome the defects of the prior art. [Summary of the Invention]

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a compact tool clamp and an electric hammer equipped with the tool clamp.

[0006] The technical solution adopted by the present invention to solve the problem of the prior art is: a tool clamp for an electric hammer, characterized in that: the tool clamp includes:

[0007] A clamp base, the clamp base including a first cylindrical portion, a second cylindrical portion and a stepped portion located between the first cylindrical portion and the second cylindrical portion, the first cylindrical portion being provided with a first through hole and the second cylindrical portion being provided with a second through hole;

[0008] The first locking mechanism includes: a first sleeve, a sliding member, a first spring, and a first locking element;

[0009] The first end of the first spring abuts against the stepped portion, and the second end of the first spring biases the slider against the first sleeve, so that the first sleeve limits the first locking element to the locking position radially along the first through hole;

[0010] The second locking mechanism includes: a second sleeve, a second spring, a support ring, and a second locking element;

[0011] The support ring is at least partially located in front of the stepped portion and has no axial movement relative to the clamp base. The first end of the second spring biases the second sleeve, and the second end of the second spring biases the support ring, causing the second sleeve to hold the second locking element along the second...

[0012] The through-hole radial limit is in the locked position;

[0013] The first locking mechanism further includes: a third spring, the first end of which biases the support ring, and the second end of which biases the first sleeve.

[0014] A further improvement is that the third spring can provide support force to the first sleeve in each position.

[0015] A further improvement is that, along the axial direction of the clamp base, the first spring and the second spring at least partially overlap.

[0016] A further improvement is that, along the axial direction of the clamp base, the support ring and the sliding member at least partially overlap, and the sliding member is relatively movably disposed on the inner ring of the support ring.

[0017] A further improvement is as follows: a stop ring is also fitted on the clamp base. The stop ring is located in front of the support ring and is connected to the clamp base without axial movement. The end of the support ring away from the first spring has multiple axially extending support claws. The inside of the first sleeve includes multiple axially extending through grooves. The support claws pass through the through grooves and abut against the stop ring.

[0018] A further improvement is that the third spring is at least partially sleeved on the outer periphery of the support claw.

[0019] A further improvement is as follows: the first sleeve includes multiple axially forward-extending extensions, the outer periphery of the stop ring includes multiple outward-extending lugs, the lugs are located between every two of the extensions, and the support claw passes through the through groove and abuts against the lugs.

[0020] A further improvement is as follows: the tool fixture further includes a dust cover disposed at the front end of the first sleeve, the interior of the dust cover includes a protrusion that engages with the fixture base, a gap is formed between the protrusion and the outer ring of the dust cover, and the extension extends into the gap.

[0021] A further improvement is as follows: the second sleeve has a locking ring fixed inside it, the locking ring surrounds the second locking element, the support ring is provided with a receiving groove facing the locking ring, and the second spring is supported between the receiving groove and the locking ring;

[0022] The locking ring, under the biasing force of the second spring, pushes the second locking element radially inward through the second through hole, so that the second locking element is in the locked position.

[0023] A further improvement is that the end of the second sleeve furthest from the first sleeve has a notch that allows the second locking element to move radially outward;

[0024] By sliding the second sleeve, the locking ring moves against the force of the second spring toward the first sleeve to a position separated from the second locking element, and the second locking element can be moved radially into the notch to put the second locking element in the released position.

[0025] A further improvement is as follows: the first sleeve has a pressure ring fixed inside it, and the pressure ring has a pressure surface facing the first locking element;

[0026] The sliding member is held inside the pressure ring by the bias force of the first spring, and the pressure surface presses the first locking element through the first through hole to put the first locking element in the locked position.

[0027] A further improvement is as follows: the end of the pressing surface away from the sliding member has a guide slope, and the inner wall of the first sleeve facing the clamp base, together with the guide slope and the stop ring, forms a receiving space;

[0028] Slide the first sleeve, and the first sleeve moves toward the second sleeve against the force of the first spring through the slider. The first locking element is disengaged from the radial limit of the pressing surface and can move into the receiving space so that the first locking element is in the released position.

[0029] A further improvement is that the elastic coefficient of the third spring is less than that of the first spring, and the elastic coefficient of the first spring is less than that of the second spring.

[0030] A further improvement is: an electric hammer, the electric hammer including a housing, a motor housed in the housing, a rotating shaft driven by the motor, and a tool clamp connected to the rotating shaft.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] In addition to the first spring for providing pressure to lock the tool head and the second spring for providing pressure to lock the tool clamp onto the hammer drill, the tool clamp of the present invention also provides a third spring between the second sleeve and the support ring. The support ring has no axial movement relative to the clamp base. Therefore, the third spring can provide stable support force to the first sleeve in any position, preventing the first sleeve from falling towards the second sleeve due to the loss of support from the first and third springs when the sliding member is pushed by the drill bit and moves towards the second sleeve against the force of the first spring during the process of inserting the hammer drill into the drill bit. This would cause the first locking element to jam, resulting in the drill bit being unable to be inserted or being obstructed during insertion. [Image Description]

[0033] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings:

[0034] Figure 1 This is a perspective view of the tool clamp mounted on the electric hammer according to a preferred embodiment of the present invention;

[0035] Figure 2 yes Figure 1 The tool fixture and electric hammer shown are partially sectional.

[0036] Figure 3 yes Figure 1 A three-dimensional view of the tool fixture shown;

[0037] Figure 4 yes Figure 3 The tool fixture shown is a half-sectional view taken from the first locking element;

[0038] Figure 5 yes Figure 3 Exploded view of the tool fixture;

[0039] Figure 6 yes Figure 3 A partial sectional view of the tool fixture shown;

[0040] Figures 7 to 9 Is Figure 3 A half-section view of the process of inserting a drill bit into the tool fixture shown; Figure 10 This is a half-sectional view of a second possible implementation where the support ring has no axial movement relative to the clamp base;

[0041] Figure 11 yes Figure 10 Exploded view of the slider, support ring and clamp base in the embodiment shown;

[0042] Figure 12 This is a half-sectional view of a third possible implementation where the support ring has no axial movement relative to the clamp base;

[0043] Figure 13 yes Figure 12 Exploded view of the slider, support ring and clamp base in the embodiment shown;

[0044] Figure 14 This is a three-dimensional view of a round shank drill bit;

[0045] Figure 15 This is a three-dimensional view of a square shank drill bit;

[0046] Figure 16 yes Figure 3 The tool holder shown is in the round shank position, and is cut from the torque transmission element.

[0047] Figure 17 yes Figure 6 The cross-sectional view of the tool fixture AA shown;

[0048] Figure 18 yes Figure 3 The tool fixture shown is in the square shank position, and is cut from the torque transmission element.

[0049] Figure 19 yes Figure 8 The cross-sectional view of the tool fixture at BB is shown;

[0050] Figure 20 This is a three-dimensional view of the torque transmission element;

[0051] Figure 21 This is a three-dimensional view of the second sleeve;

[0052] Figure 22 These are exploded views of the first and second sleeves;

[0053] Meaning of the reference numerals in the diagram:

[0054] Electric hammer 100, casing 10

[0055] Rotating shaft 11, receiving groove 111

[0056] Motor 20, Motor Shaft 21

[0057] Tool fixture 30; Fixture bases 31, 31', 31″

[0058] Second cylindrical section 311, 311′, 311″; Second through hole 312, 312′, 312″ First through holes 313, 313′, 313″; stepped portions 314, 314′, 314″ First cylindrical section 315, third through hole 316

[0059] Protrusion 3111′ Connecting channel 3112″

[0060] Second locking elements 32, 32', 32″; First locking elements 33, 33', 33″

[0061] Second sleeve 34, 34′, 34″, locking ring 341

[0062] Notch 342 Locking block 343

[0063] Indicator arrow 344 First sleeve 35, 35′, 35″

[0064] Through groove 351, pressure ring 352

[0065] Guide slope 3521, pressing surface 3522

[0066] Containment space 3523 Recess 3524

[0067] Inner peripheral wall 3525 Extension 353

[0068] Locking slot 354 Connecting slot 355

[0069] Gear position marking 356, square handle gear position 3561

[0070] Round handle stop 3562 Second spring 36, 36′, 36″

[0071] First springs 37, 37′, 37″; support rings 38, 38′, 38″.

[0072] Support claw 381 Receiving slot 382

[0073] Abutment part 383′ L-shaped groove 3831′

[0074] Support part 384′, stop groove 385′, 385″

[0075] Support arm 386″, hook 3861″

[0076] Stop ring 39, lug 391

[0077] Slider 310, 310', 310″; Protrusion 3101', 3101″

[0078] Third spring 320, dust cover 330

[0079] Bump 3301, Gap 3302

[0080] Receiving cavity 340 Torque transmission element 350

[0081] Guide surface 3501 First end face 3502

[0082] Second end face 3503 O-ring 360

[0083] Transmission mechanism 40 First gear 41

[0084] Eccentric wheel 42, eccentric pin 43

[0085] Second gear 44, small bevel gear 45

[0086] Impact mechanism 50, large bevel gear 51

[0087] Impact rod 52, hammer 53

[0088] Piston 54, connecting rod 55

[0089] Drill bit 200, 200′ Shank 201, 201′

[0090] Groove 2011, 2011′; Guide groove 2012 [Detailed Implementation]

[0091] The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as "front" and "rear" used below to indicate orientation or positional relationship are based solely on the orientation or positional relationship shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device / 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.

[0092] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0093] Please see Figures 1 to 9 The diagram illustrates a preferred embodiment of the present invention, including a tool holder 30 and an electric hammer 100 for drilling or chiseling on walls, concrete floors, and other surfaces. The output direction of the electric hammer 100 is defined as forward. The electric hammer 100 includes a housing 10, a motor 20, a transmission mechanism 40, an impact mechanism 50, a tool holder 30 detachably connected to the front end of the housing 10, and a tool head 200 detachably mounted in the tool holder 30. In this embodiment, the tool head 200 can be a drill bit or a chisel, etc. After the electric hammer 100 is started, the motor 20 drives the tool head 200 within the tool holder 30 to rotate and output power via the transmission mechanism 40; simultaneously, the motor 20 drives the impact mechanism 50 to input impact power via the transmission mechanism 40, and the impact mechanism 50 drives the tool head 200 within the tool holder 30 to output impact power.

[0094] Please see Figures 1 to 2As shown, the motor 20 includes a motor shaft 21 extending perpendicular to the output direction. The transmission mechanism 40 includes a first gear 41, an eccentric wheel 42, an eccentric pin 43, a second gear 44, and a small bevel gear 45. The impact mechanism 50 includes a rotating shaft 11, a large bevel gear 51 sleeved on the rotating shaft 11, and an impact rod 52, a hammer 53, a piston 54, and a connecting rod 55 arranged sequentially from front to back within the rotating shaft 11. The tool clamp 30 is connected to the rotating shaft 11. The second gear 44 meshes with the first gear 41 on the left and right sides of the motor shaft 21, respectively. The second gear 44 is connected to the small bevel gear 45. The motor shaft 21 drives the small bevel gear 45 to rotate through the second gear 44. The small bevel gear 45 meshes with the large bevel gear 51 to drive the rotating shaft 11 to rotate. The rotating shaft 11 drives the tool head 200 in the tool holder 30 to rotate. The eccentric wheel 42 is connected to the first gear 41. The motor shaft 21 drives the eccentric wheel 42 to rotate through the first gear 41. The eccentric pin 43 is integrally set with the eccentric wheel 42. The rear end of the connecting rod 55 is sleeved on the eccentric pin 43, and the front end is pivotally connected to the piston 54. The eccentric wheel 42 drives the piston 54 to reciprocate through the connecting rod 55. When the piston 54 reciprocates, the compressed air drives the hammer 53 to strike the impact rod 52. After being impacted, the impact rod 52 strikes the tool head 200 in the output direction.

[0095] Please see Figures 4 to 6 As shown, the tool clamp 30 includes a clamp base 31, a first locking mechanism, and a second locking mechanism. The clamp base 31 has a receiving cavity 340 for receiving the tool head 200. The clamp base 31 includes a first cylindrical portion 315, a second cylindrical portion 311, and a stepped portion 314 located between the first cylindrical portion 315 and the second cylindrical portion 311. The first cylindrical portion 315 has a first through hole 313 and a third through hole 316 that extend from the outside to its inner wall in the radial direction. The second cylindrical portion 311 has a second through hole 312 that extends from the outside to its inner wall in the radial direction.

[0096] The first locking mechanism includes a first sleeve 35, a slider 310, a first spring 37, a first locking element 33, and a torque transmission element 350. The first locking element 33 is located in the first through hole 313 and is used to hold the handle 201 of the tool head 200 to prevent the tool head 200 from disengaging from the tool holder 30 in the longitudinal direction. The torque transmission element 350 is located in the third through hole 316 and is used to transmit torque. The first end of the first spring 37 abuts against the stepped portion 314, and the second end of the first spring 37 biases the slider 310 against the first sleeve 35 so that the first sleeve 35 radially limits the first locking element 33 to the locked position along the first through hole 313.

[0097] The second locking mechanism includes a second sleeve 34, a second spring 36, a support ring 38, and a second locking element 32. The second locking element 32 is located in the second through hole 312 and is used to engage the tool clamp 30 with the electric hammer 100. The support ring 38 is at least partially located in front of the step portion 314 and has no axial movement relative to the clamp base 31. In this embodiment, a stop ring 39 is also sleeved on the clamp base 31. The stop ring 39 is located in front of the support ring 38 and has no axial movement relative to the clamp base 31. The first sleeve 35 includes a plurality of axially extending through grooves 351 and a plurality of axially forward extending extension portions 353 inside. The stop ring 39 includes a plurality of outwardly extending lugs 391 on its outer periphery. The lugs 391 are located between every two extension portions 353. The end of the support ring 38 away from the first spring 36 has a plurality of axially extending support claws 381. The support claws 381 pass through the through grooves 351 and abut against the lugs 391. Specifically, a slot is provided at the front end of the clamp base 31. The slot is located at the front end of the stop ring 39 and a retaining spring is provided in the slot. The second spring 36 biases forward on the support ring 38, so that the support claw 381 of the support ring 38 abuts against the stop ring 39. The stop ring 39 cannot move forward due to the limitation of the front retaining spring, so that the support ring 38 has no axial movement relative to the clamp base 21.

[0098] The first end of the second spring 36 biases the second sleeve 34, and the second end of the second spring 36 biases the support ring 38, so that the second sleeve 34 radially limits the second locking element 32 to the locked position along the second through hole 312.

[0099] Along the axial direction of the clamp base 31, the first spring 37 and the second spring 36 at least partially overlap, which shortens the overall length of the tool clamp 30. Therefore, when the tool clamp 30 is mounted on the electric hammer 100, it is beneficial to the miniaturization of the whole machine.

[0100] In one possible implementation, the first sleeve 35 has a pressing ring 352 fixed inside it, the pressing ring 352 having a pressing surface 3522 facing the first locking element 33. The sliding member 310 is held inside the pressing ring 352 by the biasing force of the first spring 37. The pressing surface 3522 presses the first locking element 33 through the first through hole 313, so that the first locking element 33 is in the locked position; specifically, please refer to Figures 7 to 9The diagram illustrates the process of inserting a tool head 200 into the tool clamp 30. When the tool head 200 is inserted, the end of the tool head 200 pushes the first locking element 33 backward and presses against the sliding member 310, thereby compressing the first spring 37. When the first locking element 33 disengages from the radial limit of the pressing ring 352, the first locking element 33 can move radially outward, and the tool head 200 can continue to be inserted backward. When the first locking element 33 passes the end of the tool head 200 and falls into the groove 2011 on the handle 201 of the tool head 200, the elastic force of the first spring 37 pushes the sliding member 310, thereby further pushing the first locking element 33 forward into the pressing ring 352, ensuring that the first locking element 33 is in the locked position, that is, the tool clamp 30 holds the tool head 200.

[0101] The end of the pressing surface 3522 away from the sliding member 310 has a guide slope 3521. The inner wall of the first sleeve 35 facing the clamp base 31, together with the guide slope 3521 and the stop ring 39, forms a receiving space 3523. When the tool head 200 needs to be removed, the first sleeve 35 is slid backward. The first sleeve 35 moves towards the second sleeve 34 against the force of the first spring 37 through the sliding member 310. The first locking element 33 disengages from the radial limit of the pressing surface 3522 and can move into the receiving space. In space 3523, the first locking element 33 is in the released position, that is, the tool chuck 30 can release the tool head 200; the support ring 38 is not pushed to move axially during the entire travel of the first sleeve 35, that is, when the first locking mechanism is driven to unlock the tool head 200, the second spring 36 maintains its original pressure state. This avoids the need to overcome the forces of the first spring 37 and the second spring 36 when pulling the first sleeve 35 during the release of the tool head 200, which would affect the operator's operating comfort.

[0102] Please refer again. Figures 4 to 5 As shown, the second sleeve 34 has a locking ring 341 fixed inside it, which surrounds the second locking element 32. The support ring 38 is provided with a receiving groove 381 facing the locking ring 341. The second spring 36 is supported between the receiving groove 382 and the locking ring 341. The locking ring 341 is subjected to the biasing force of the second spring 36, which pushes the second locking element 32 radially inward through the second through hole 312, so that the second locking element 32 is in the locked position. The end of the second sleeve 34 away from the first sleeve 35 has a notch 342 for the second locking element 32 to move radially outward. By sliding the second sleeve 35, the locking ring 341 moves against the force of the second spring 36 toward the first sleeve 35 to a position separated from the second locking element 32. The second locking element 32 can move radially into the notch 342, so that the second locking element 32 is in the released position.

[0103] An O-ring 360 is also fitted on the fixture base 31. The O-ring 360 is located at the rear end of the recess 342 and partially covers the opening at the rear end of the recess 342 to prevent the second locking element 32 from falling out of the opening at the rear end of the recess 342 after it moves into the recess 342.

[0104] Please refer to the following: Figure 4 , Figure 5 As shown, the first locking mechanism also includes a third spring 320. The first end of the third spring 320 biases against the support ring 38 and is at least partially sleeved on the outer periphery of the support claw 381 of the support ring 38. The second end of the third spring 320 biases against the first sleeve 35. During the insertion of the tool head 200, the third spring 320 can always provide support force to the first sleeve 35, keeping the first sleeve 35 at the front. This prevents the first sleeve 35 from falling towards the second sleeve 34 due to the loss of support from the first spring 37 when the electric hammer 100 is inserted into the tool head 200 while it is placed vertically. This would cause the first locking element 33 to jam, resulting in the tool head 200 being unable to be inserted or being obstructed during insertion.

[0105] Along the axial direction of the clamp base 31, the support ring 38 and the slider 310 at least partially overlap, and the slider 310 is relatively movable in the inner ring of the support ring 38. This is conducive to compact space and can prevent the distance between the slider 310 and the first sleeve 35 from shortening when the support ring 38 and the slider 310 are not overlapping. During the operation of removing the tool head 200, when the first sleeve 35 is moved backward, the third spring 320 may be completely compressed. The first sleeve 35 continues to press against the support ring 38 to the right through the fully compressed third spring 320. At this time, the operator will clearly feel that the first sleeve 35 cannot be pushed forward, which makes it difficult to remove the tool head 200.

[0106] In one embodiment, the elastic coefficient of the first spring 37 is less than that of the second spring 36, meaning that the force pushing the first sleeve 35 backward is less than the force pushing the second sleeve 34 forward. This results in a greater locking force when the tool clamp 30 is connected to the rotating shaft 11 of the electric hammer 100, ensuring high reliability of the connection when the electric hammer 100 is working. At the same time, it provides a suitable force for clamping the tool head 200, ensuring high ease of operation and comfort during the high-frequency operation of changing the tool head 200. The elastic coefficient of the third spring 320 is less than that of the first spring 37, ensuring that the third spring 320 generates almost no additional resistance during the insertion and removal of the tool head 200, thus affecting the comfort of inserting and removing the tool head.

[0107] In one possible implementation, the spring constant of the first spring 37 is 1.44 N / mm, the spring constant of the second spring 36 is 2.5 N / mm, and the spring constant of the third spring 320 is 0.5-1 N / mm.

[0108] Please see Figures 10 to 11 The diagram shows a second possible implementation where the support ring 38′ has no axial movement relative to the clamp base 31′. The support ring 38′ has a radially outwardly extending abutment portion 383′ and a support portion 384′ extending toward the stepped portion 314′. The outer periphery of the support portion 384′ has several L-shaped grooves 3831′. The outer periphery of the second cylindrical portion 311′ near the stepped portion 314′ has several radially outwardly extending protrusions 3111′. These protrusions 3111′ can pass through the axial portion of the L-shaped grooves 3831′ and then be rotated into the radial portion of the L-shaped grooves 3831′, thus stopping the support ring 38′ axially relative to the clamp base 31′; simultaneously, it abuts against the first locking element. The outer periphery of the slider 310' of 33' has at least one protrusion 3101' formed radially outward. The support ring 38' also includes at least one stop groove 385', which extends from the front end face of the support ring 38' toward the stepped portion 314' and communicates with the radial portion of at least one L-shaped groove 3831'. The protrusion 3101' can move axially within the stop groove 385', which allows the slider 310' to move axially relative to the clamp base 31'. Since the slider 310' cannot rotate relative to the clamp base 31', the protrusion 3101' extending into the stop groove 385' makes the support ring 38' unable to rotate relative to the clamp base 31'. Specifically, in this embodiment, four L-shaped grooves 3831′ are evenly arranged along the outer periphery of the support portion 384′, and four corresponding protrusions 3111′ are also provided; two stop grooves 385′ are provided, which are connected to any two oppositely arranged L-shaped grooves 3831′, and two corresponding protrusions 3101′ are also provided.

[0109] The second spring 36' is at least partially sleeved on the outer periphery of the support portion 384', with one end abutting against the abutting portion 383' of the support ring 38', and the other end biasing against the second sleeve 34' so that the second sleeve 34' radially limits the second locking element 32' to a locked position along the second through hole 312'; one end of the first spring 37' abuts against the stepped portion 314', and the other end biases against the sliding member 310' against the first sleeve 35', so that the first sleeve 35' is radially limited to a locked position relative to the first locking element 33' along the first through hole 313'; along the axial direction of the clamp base 31', the second spring 36' and the first spring 37' at least partially overlap. Simultaneously, this embodiment also includes a third spring, which is located on the other side of the abutting portion 383' of the support ring 38' relative to the second spring 36', with one end abutting against the abutting portion 383', and the other end biasing against the first sleeve 35', which also provides support force to the first sleeve 35' in each position.

[0110] Please see Figures 12 to 13 The diagram shows a third possible implementation where the support ring 38″ has no axial movement relative to the clamp base 31″. The support ring 38″ has several support arms 386″ extending toward the stepped portion 314″. At least one support arm 386″ has an inwardly bent end forming a hook portion 3861″. A generally L-shaped connecting channel 3112″ is formed on the outer surface of the second cylindrical portion 311″. The hook portion 3861″ can pass through the axial portion of the connecting channel 3112″ and then be rotated to engage with the radial portion of the connecting channel 3112″, thereby fixing the support ring 38″ axially relative to the clamp base 31″; it also serves to abut against the first lock. At least one protrusion 3101" is formed on the outer periphery of the sliding member 310" of the fixed element 33" and at least one stop groove 385" is formed on the support arm 386". The stop groove 385" extends from the front end face of the support ring 38" toward the step portion 314" and the protrusion 3101" can move axially in the stop groove 385". This allows the sliding member 310" to move axially relative to the clamp base 31". Since the sliding member 310" cannot rotate relative to the clamp base 31", the protrusion 3101" extending into the stop groove 385" makes the support ring 38" unable to rotate relative to the clamp base 31. Specifically, in this embodiment, there are four support arms 386″, wherein any two support arms 386″ arranged opposite each other have hooks 3861″ formed at their ends, and there are two L-shaped connecting channels 3112″ corresponding to the hooks 3861″; there is one stop groove 385″, and there is one protrusion 3101″ corresponding to it.

[0111] The second spring 36″ is at least partially sleeved on the outer periphery of the support arm 386″, with one end biased against the support ring 38″ and the other end biased against the second sleeve 34″, so that the second sleeve 34″ radially limits the second locking element 32″ to the locked position along the second through hole 312″; one end of the first spring 37″ abuts against the stepped portion 314″ and the other end biases against the sliding member 310″ against the first sleeve 35″, so that the first sleeve 35″ is radially limited to the locked position relative to the first locking element 33″ along the first through hole 313″; along the axial direction of the clamp base 31″, the second spring 36″ and the first spring 37″ at least partially overlap; at the same time, this embodiment also has a third spring, which is located on the other side of the abutment portion 383″ of the support ring 38″ relative to the second spring 36″, with one end abutting against the abutment portion 383″ and the other end biased against the first sleeve 35″, which can also provide support force to the first sleeve 35″ in each position. Please refer to Figure 4 As shown, the tool clamp 30 also includes a dust cover 330 disposed at the front end of the first sleeve 35. The dust cover 330 has an integrally formed protrusion 3301 inside. One end of the protrusion 3301 engages with the clamp base 31, and the other end forms a gap 3302 between it and the outer ring of the dust cover 330. The extension 353 extends into the gap 3302. If the dust cover 330 needs to be removed, the protrusion 3301 needs to move towards the gap 3302. At this time, the extension 353 can play a certain role in blocking the movement of the protrusion 3301. A large force is required to compress and deform the protrusion 3301 before the dust cover 330 can be removed. Therefore, the extension 353 extending into the gap 3302 plays a role in preventing the dust cover 330 from accidentally falling off.

[0112] Please see Figure 14 As shown, the tool head 200 is a round-shank tool head. The shank 201 of the tool head 200 has a generally cylindrical outer surface, and two radially opposing grooves 2011 are formed on the outer surface. Please refer to [further details omitted]. Figure 4 , Figure 6 and Figure 7 As shown, during the insertion of the tool head 200 into the tool holder 30, the shank 201 presses against the first locking element 33 to compress the first spring 37 by the sliding member 310. When the shank 201 is fully inserted, the first locking element 33 is biased by the first spring 37 and enters the groove 2011 of the shank 201 to hold the tool head 200. In addition, with a circumferential phase rotation of approximately 90 degrees relative to the two grooves 2011, two radially opposite longitudinal guide grooves 2012 are formed on the outer surface of the shank 201. These two guide grooves 2012 extend directly to the free end of the shank 201. After the tool head 200 is inserted into the tool holder 30, the guide grooves 2012 engage with the torque transmission element 350 inside the tool holder 30 to drive the tool head 200 to rotate.

[0113] Please see Figure 15 As shown, the tool head 200' is a square-shank tool head. Unlike the round-shank tool heads described above, the shank 201' of the tool head 200' has a generally square outer surface, and a groove 2011' is formed in each of the four flat surfaces of the outer surface. Please refer to [further details omitted]. Figure 4 , Figure 7 and Figure 8 As shown, after the tool head 200' is inserted, the first locking element 33 engages with any two radially opposite grooves 2011' to hold the tool head 200' in place; the tool holder 30 for mounting the square shank tool head, the inner wall of its holder base 31 is also usually square. After the tool head 200' is inserted into the tool holder 30, because the square outer surface can make complementary contact with the inner wall shape of the tool holder 30, the torque can be transmitted between the two to drive the tool head 200' to rotate.

[0114] Please refer to 16 to 17. Figure 20 The image shows a tool holder 30 that is compatible with both types of tool heads mentioned above.

[0115] The inner wall of the first cylindrical portion 315 has a shape that allows torque to be transmitted from the clamp base 31 to the handle 201 of the tool head 200. In this embodiment, the inner wall of the first cylindrical portion 315 is square. The clamp base 31 also includes a torque transmission element 350, which can selectively engage with the handle 201 inserted into the receiving cavity 340 to transmit torque from the clamp base 31 to the handle 201 independently of the inner wall of the first cylindrical portion 315. The clamp base 31 includes a conversion mechanism that allows the torque transmission element 350 and the handle 201 to be in different engagement states, so as to select that torque is transmitted by either the inner wall of the first cylindrical portion 315 or the torque transmission element 350.

[0116] Specifically, the pressure ring 352 is configured as a conversion mechanism. The pressure ring 352 is sleeved on the outside of the torque transmission element 350 and the first locking element 33. The first sleeve 35 drives the pressure ring 352 to move back and forth and rotate. The inner peripheral wall 3525 of the pressure ring 352 has at least one recess 3524. The recess 3524 can be selectively aligned with the torque transmission element 350.

[0117] Please see Figure 14 , Figure 16 ,、 Figure 17 and Figure 21As shown, when the tool head 200 to be inserted is a round-shank tool head, and the recess 3524 is not aligned with the torque transmission element 350, the torque transmission element 350 is pressed into the receiving cavity 340 by the inner peripheral wall 3525 of the pressing ring 352. Before inserting the tool head 200, first ensure that the guide groove 2012 of the tool head 200 is aligned with the torque transmission element 350 extending into the receiving cavity 340. In this way, the torque transmission element 350 can smoothly slide into the guide groove 2021 during the insertion of the tool head 200. At this time, the torque of the clamp base 31 is transmitted to the shank 201 by the torque transmission element 350. Of course, the first locking element 33 will also transmit a small part of the torque, but this is not enough to constitute substantial torque transmission in this embodiment. In this embodiment, there are two torque transmission elements 350 and two second locking elements 33, which are spaced apart from each other in the circumferential direction of the clamp base 31.

[0118] Please see Figure 15 , Figure 18 , Figure 19 and Figure 21 As shown, when the tool head 200' to be inserted is a square shank tool head, and the recess 3524 is aligned with the torque transmission element 350, the recess 3524 provides radially movable space for the torque transmission element 350, allowing the torque transmission element 350 to move radially into the recess 3534; please refer to Figure 20 As shown, the torque transmission element 350 includes a first end face 3502 and a second end face 3503 disposed opposite each other in the radial direction of the clamp base 31. The first end face 3502 abuts against the inner peripheral wall 3525 of the pressure ring, and the second end face 3503 selectively abuts against the shank 201'. The front end of the second end face 3503 has an inclined guide surface 3501, which can be used to guide the insertion of the shank 201'. When the tool head 200' is inserted, the shank 201' pushes against the guide surface 3501, smoothly pushing the torque transmission element 350 radially outward into the receiving cavity 340, so that the tool head 200' can be smoothly inserted. When the tool head is inserted into the clamp base 31, since the inner wall of the tool base 31 is a square surface that complements the outer surface of the square shank tool head, the torque of the clamp base 31 is transmitted to the shank 201' through the inner wall of the receiving cavity 340. Of course, the first locking element 33 will also transmit a small portion of the torque, and the torque transmission element 350 will also transmit a small portion of the torque, but these do not constitute substantial torque transmission in this embodiment. During the insertion of the tool head 200', the torque transmission element 350 may still touch the shank 201', but the torque transmission in this embodiment refers to the force sufficient to drive the tool head through the shank.

[0119] As the tool fixture 30 is used for an extended period, the torque transmission element 350 will wear out before other parts and fail. Traditionally, the torque transmission element 350 is integrated with the fixture base 31, requiring the entire fixture base 31 to be replaced during maintenance, resulting in high maintenance difficulty and cost. In this embodiment, since the torque transmission element 350 is a movable individual component, it can be repaired and replaced separately when wear occurs, reducing maintenance difficulty and cost.

[0120] Please see Figure 21 As shown, the first sleeve 35 has a first rotational position and a second rotational position relative to the second sleeve 34. The first sleeve 35 can selectively move back and forth relative to the second sleeve. After the first sleeve 35 moves a certain distance toward the second sleeve 34, the first sleeve 35 is unlocked and rotates relative to the second sleeve 34 to switch between the first rotational position and the second rotational position. Specifically, the second sleeve 34 is provided with a locking block 343 protruding from its surface. The second sleeve 34 is provided with a U-shaped groove on its inner circumferential surface. When the locking block 343 selectively reaches the bottom of the U-shaped groove along either side, the first sleeve 35 is unlocked and rotates relative to the second sleeve 34.

[0121] At least two locking grooves 354 and a connecting groove 355 connecting the two locking grooves 354 are provided on the inner circumferential surface of the first sleeve 35. The locking grooves 354 and the connecting groove 355 together form a U-shaped groove.

[0122] Please see Figure 3 As shown, in this embodiment, a gear position mark 356 is also provided on the outer surface of the first sleeve 35. The gear position mark 356 includes a square-shaped square handle gear position 3561 and a round handle gear position 3562. An indicator arrow 344 is provided on the outer surface of the first sleeve 34. When the indicator arrow 344 is opposite to the square handle gear position 3561, the locking block 343 engages with the locking groove 354 corresponding to the square handle gear position 3561. At this time, the large diameter portion 3524 of the pressure ring 352 abuts against the torque transmission element 350. When the indicator arrow 344 is opposite to the round handle gear position 3562, the locking block 343 engages with the locking groove 354 corresponding to the round handle gear position 3562, and the small diameter portion 3525 of the pressure ring 352 abuts against the torque transmission element 350.

[0123] Specifically, when the tool clamp 30 needs to be switched from the square shank position 3561 to the round shank position 3562, the first sleeve 35 can be slid toward the second sleeve 34 and the first spring 37 can be compressed. The locking block 343 can be moved from the current locking groove 354 to the connecting groove 355. At this time, there is no relative rotation between the second sleeve 34 and the clamp base 31. By rotating the first sleeve 35, the locking block 343 can pass through the connecting groove 355 and enter the locking groove 354 of the round shank position 3562.

[0124] In this embodiment, in addition to the first spring 37 for providing pressure to lock the tool head 200 and the second spring 36 for providing pressure to lock the tool clamp 30 onto the electric hammer 100, the tool clamp 30 also has a third spring 320 between the second sleeve 34 and the support ring 38. The support ring 38 has no axial movement relative to the clamp base 31. Therefore, the third spring 320 can provide stable support force to the first sleeve 35 in any position, preventing the first sleeve 35 from falling towards the second sleeve 34 due to the loss of support from the first spring 37 and the third spring 320 when the electric hammer 100 is inserted into the drill bit 200, and the sliding member 310 is pushed by the drill bit 200 and moves towards the second sleeve 34 against the force of the first spring 37. This would cause the first locking element 33 to jam, resulting in the drill bit 200 being unable to be inserted or being blocked from insertion.

[0125] This invention is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many alternative solutions exist for the tool clamp and electric hammer of this invention without departing from the principles and scope of the invention. The scope of protection of this invention is defined by the claims.

Claims

1. A tool clamp for selectively mounting a tool head on an electric hammer, characterized in that: The tool fixture includes: A clamp base, the clamp base including a first cylindrical portion, a second cylindrical portion and a stepped portion located between the first cylindrical portion and the second cylindrical portion, the first cylindrical portion being provided with a first through hole and the second cylindrical portion being provided with a second through hole; The first locking mechanism includes: a first sleeve, a sliding member, a first spring, and a first locking element; The first end of the first spring abuts against the stepped portion, and the second end of the first spring biases the slider against the first sleeve, so that the first sleeve limits the first locking element to the locking position radially along the first through hole; The second locking mechanism includes: a second sleeve, a second spring, a support ring, and a second locking element; The support ring is at least partially located in front of the stepped portion and has no axial movement relative to the clamp base. The first end of the second spring biases the second sleeve, and the second end of the second spring biases the support ring, so that the second sleeve limits the second locking element to the locking position radially along the second through hole. The first locking mechanism further includes: a third spring, the first end of which biases the support ring, and the second end of which biases the first sleeve.

2. The tool fixture according to claim 1, characterized in that: The third spring provides support to the first sleeve in each position.

3. The tool fixture according to claim 1, characterized in that: Along the axial direction of the clamp base, the first spring and the second spring at least partially overlap.

4. The tool fixture according to claim 1, characterized in that: Along the axial direction of the clamp base, the support ring and the slider at least partially overlap, and the slider is relatively movably disposed on the inner ring of the support ring.

5. The tool fixture according to claim 1, characterized in that: A stop ring is also fitted on the clamp base. The stop ring is located in front of the support ring and is connected to the clamp base without axial movement. The end of the support ring away from the first spring has a plurality of axially extending support claws. The inside of the first sleeve includes a plurality of axially extending through grooves. The support claws pass through the through grooves and abut against the stop ring.

6. The tool fixture according to claim 5, characterized in that: The third spring is at least partially sleeved on the outer periphery of the support claw.

7. The tool fixture according to claim 5, characterized in that: The first sleeve includes a plurality of axially forward-extending extensions, and the outer periphery of the stop ring includes a plurality of outwardly extending lugs, the lugs being located between every two of the extensions, and the support claw passing through the through groove abutting against the lugs.

8. The tool fixture according to claim 7, characterized in that: The tool fixture also includes a dust cover disposed at the front end of the first sleeve. The interior of the dust cover includes a protrusion that engages with the fixture base. A gap is formed between the protrusion and the outer ring of the dust cover, and the extension extends into the gap.

9. The tool fixture according to claim 1, characterized in that: The second sleeve has a locking ring fixed inside it, the locking ring surrounding the second locking element, and the support ring having a receiving groove facing the locking ring, with the second spring supported between the receiving groove and the locking ring; The locking ring, under the biasing force of the second spring, pushes the second locking element radially inward through the second through hole, so that the second locking element is in the locked position.

10. The tool fixture according to claim 9, characterized in that: The end of the second sleeve away from the first sleeve has a notch that allows the second locking element to move radially outward; By sliding the second sleeve, the locking ring moves against the force of the second spring toward the first sleeve to a position separated from the second locking element, and the second locking element can be moved radially into the notch to put the second locking element in the released position.

11. The tool fixture according to claim 1, characterized in that: The first sleeve has a pressure ring fixed inside it, the pressure ring having a pressure surface facing the first locking element; The sliding member is held inside the pressure ring by the bias force of the first spring, and the pressure surface presses the first locking element through the first through hole to put the first locking element in the locked position.

12. The tool fixture according to claim 11, characterized in that: The end of the pressing surface away from the sliding member has a guide slope, and the inner wall of the first sleeve facing the clamp base, together with the guide slope and the stop ring, forms a receiving space. Slide the first sleeve, and the first sleeve moves toward the second sleeve against the force of the first spring through the slider. The first locking element is disengaged from the radial limit of the pressing surface and can move into the receiving space so that the first locking element is in the released position.

13. The tool fixture according to claim 1, characterized in that: The elastic coefficient of the third spring is less than that of the first spring, and the elastic coefficient of the first spring is less than that of the second spring.

14. An electric hammer, the electric hammer comprising a housing, a motor housed within the housing, a rotating shaft driven by the motor, and a tool holder as claimed in any one of claims 1-13 connected to the rotating shaft.

Images