Sleeve anti-falling device for impact tool

Abstract

The present invention provides a sleeve anti-drop device for an impact tool, the impact tool including a housing in which an anvil is provided in a protruding manner in front of the housing and a sleeve is removably mounted on the anvil; the sleeve anti-disengagement device comprises at least one connecting member for connecting the sleeve to a non-rotating portion of the impact tool by means of axial form-fitting fixation to prevent disengagement of the sleeve. By using the sleeve anti-falling device according to the invention, the sleeve is directly and fixedly connected to the non-rotating part of the impact tool in the axial direction by means of the connecting member instead of being connected to the anvil, so that the strength of the anvil will not be affected. Besides, the normal operation of the sleeve is not hindered by the axial fixed connection realized by the conformal matching, and the fixed connection between the sleeve and the impact tool along the axial direction is ensured, so that the sleeve is effectively prevented from being separated from the anvil block of the impact tool.

Description

Technical Field

[0001] The invention relates to an impact tool, in particular to a sleeve anti-dropping device for the impact tool. Background Art

[0002] Impact tools, especially impact wrenches, generally include a motor as a driving source, a gear transmission mechanism and a spindle that rotate as the motor performs a driving action, a hammer, and an anvil as an output shaft. The spindle and the hammer are driven by the motor, and the rotation of the spindle can be converted into an intermittent rotational impact force (impact) of the hammer to act on the anvil, so as to provide rotation and impact to the anvil, thereby intermittently transmitting the rotational impact driving force to the top tool (such as a sleeve connected to the anvil) to perform the tightening / removal of the screw / bolt / nut. Herein, the central rotation axis of the anvil is the axial direction, which generally extends in the front-to-back direction of the anvil.

[0003] Typically, the front end of the anvil forms an interface (such as an outer square) for mounting and connecting the sleeve. The sleeve for the impact tool is a common and standard component. The sleeve is generally cylindrical and includes: a rearward portion, which is provided with a hexagonal hole and the head of a hexagonal bolt or the like can be inserted into the hole; and a forward portion, which is coaxially connected to the rearward portion and is formed with a square hole, and the anvil head is inserted into the square hole. A circumferential groove is formed on the forward portion, and a through hole orthogonal to the axis of the forward portion is formed at the position of the groove in a penetrating manner.

[0004] In the current state of the art, mounting the sleeve on the square interface of the anvil is mainly based on two principles: conformal fit or friction. In the case of a conformal fit, the square interface of the anvil provides a through hole or a stop pin. In the case of a through hole, the conformal fit between the anvil and the sleeve is achieved by a pin that passes through the aligned through holes in the anvil and the sleeve. If a stop pin is used, the spring and the stop pin are integrated in a blind hole in the square interface of the anvil; under the action of the spring, the stop pin can be buckled or squeezed out of the through hole of the sleeve, thus producing a conformal fit. However, both methods will weaken the structure of the square interface of the anvil, and this may shorten the life of the anvil of a high-power impact tool.

[0005] In the case of a friction-based connection between anvil and sleeve, a friction ring is usually used. This is a radially compressible annular element which is located in a circumferential groove at the front part of the square interface of the anvil and will therefore not adversely affect the structure of the square interface. However, the friction force of the friction ring is limited and decreases with ageing and wear of compression-type annular elements. In the case of heavy sleeves, the axial fixing force may not be sufficient to meet the safety requirements.

[0006] The socket of an impact wrench used for demanding applications may weigh more than 1.2 kg. If the socket accidentally falls off the anvil of the impact tool, thereby interrupting the work, it may damage things or even seriously injure people. Therefore, a device is needed to prevent the socket from being disengaged from the anvil of the impact tool. Summary of the invention

[0007] An object of the present invention is to provide a socket anti-falling device which can effectively prevent a socket from falling off from an anvil of an impact tool.

[0008] A sleeve anti-dropping device for an impact tool, the impact tool comprising a shell, wherein an anvil is arranged in a protruding manner in front of the shell, and a sleeve is removably mounted on the anvil; the sleeve anti-dropping device comprises at least one connecting member, which is used to fixedly connect the sleeve to a non-rotating part of the impact tool in an axial direction by conformal fit to prevent the sleeve from falling off.

[0009] By means of the sleeve anti-dropping device according to the present invention, the sleeve is directly fixedly connected to the non-rotating part of the impact tool in the axial direction by means of the connecting member instead of being connected to the anvil, so the strength of the square interface of the anvil will not be affected. In addition, the axial fixed connection achieved by conformal fit will not hinder the normal circumferential rotation operation of the sleeve, and ensure that the sleeve and the impact tool are axially fixed relative to each other, so that the sleeve can be effectively prevented from being disengaged from the anvil of the impact tool.

[0010] According to an embodiment of the present invention, the connecting member includes a first end fixedly connected to the non-rotating part in the axial direction, and a second end fixedly connected to the sleeve in the axial direction, the first end is connected to the second end by means of an axially extending connecting portion, and the connecting member rotates synchronously with the sleeve. Therefore, the sleeve is fixedly connected to the impact tool in the axial direction by means of the connecting member, and the sleeve can still rotate under the driving action of the anvil, wherein the connecting member rotates synchronously with the sleeve.

[0011] The front part of the housing of the impact tool is provided with a shaft support part for rotatably supporting the anvil, and a bushing is provided inside the shaft support part, the bushing protrudes from the front end of the shaft support part and forms a circumferentially arranged annular channel, which forms a non-rotating component. By using the annular channel of the bushing protruding from the shaft support part as a non-rotating component, a convenient and reliable non-rotating connection part is provided for directly connecting the sleeve to the impact tool, thereby making the axial connection of the sleeve to the impact tool simple and easy.

[0012] The sleeve is provided with a through hole substantially perpendicular to the central axis of the sleeve, the first end portion includes a pair of arc clips, which are partially engaged in the annular channel to fixedly connect the connecting member to the non-rotating component in the axial direction, and the second end portion includes a protrusion extending substantially perpendicular to the connecting portion, which can be inserted into the through hole to fixedly connect the connecting member to the sleeve in the axial direction. The arc clip of the first end portion of the connecting member is engaged in the non-rotating annular channel, and the arc clip is in a clearance fit with the annular channel, that is, the arc clip can rotate in the annular channel. Since the protrusion of the connecting member is inserted into the through hole in the sleeve, the connecting member and the sleeve are fixed relative to each other in the axial direction, and therefore the connecting member can rotate synchronously with the sleeve.

[0013] The outer peripheral surface of the sleeve is further provided with a circumferential groove, and the second end further comprises a pair of elastic arms, which are partially engaged in the groove, mainly for holding the connecting member in place against the centrifugal force. Therefore, when the elastic arms of the second end of the connecting member are engaged in the circumferential groove of the sleeve, the elastic arms are tightly pressed against the groove on the outer peripheral surface of the sleeve to a certain extent in the radial direction, so that the sleeve is fixed relative to the connecting member in the axial direction.

[0014] Preferably, the free end of the protrusion comprises an elastic side bend, which engages with the peripheral surface of the sleeve. The friction between the peripheral surface of the sleeve and the elastic side bend ensures a fixed connection between the connecting member and the sleeve against centrifugal forces; the connecting member and the sleeve rotate synchronously in the circumferential direction while remaining stationary relative to each other in the axial direction.

[0015] According to another embodiment of the present invention, the connecting member includes a first end fixedly connected to the non-rotating part in the axial direction, and a second end fixedly connected to the sleeve in the axial direction, the first end being connected to the second end by means of an axially extending connecting part, and the sleeve can rotate circumferentially relative to the connecting member. Therefore, the connecting member fixes the sleeve to the impact tool in the axial direction, and may or may not rotate synchronously with the sleeve, depending on the friction conditions between the connecting member and the non-rotating part or (respectively) between the connecting member and the sleeve. That is, the relative positions of the non-rotating part, the connecting part and the sleeve in the axial direction are fixed, and at the same time they can rotate relative to each other; therefore, the function of preventing the sleeve from disengaging is achieved, while ensuring the greatest possible degree of freedom in installation.

[0016] The peripheral surface of the sleeve is provided with a circumferential groove, and a fixed stop is provided on the peripheral surface of the shaft support part of the impact tool, which fixed stop forms the non-rotating part. The protruding fixed stop is mounted as a non-rotating part on the peripheral surface of the shaft support part of the impact tool; the shaft support part is part of the housing and is therefore static and non-rotating. Mounting the fixed stop on the outside of the shaft support part is a simple and convenient solution for forming an additional non-rotating part on the impact wrench.

[0017] The first end portion includes a long hole provided at one end of the connecting portion, the long hole being fitted on the fixing stopper to fixedly connect the connecting member to the non-rotating portion in the axial direction, and the second end portion includes a pair of elastic arms engageable in the groove, which are rotatable along the circumference of the groove. Due to the shape fit between the long hole and the fixing stopper, the connecting member is fixedly connected to the non-rotating portion of the impact tool in the axial direction. The elastic arm of the second end portion performs the function of fixedly connecting the connecting member to the sleeve in the axial direction, while rotation between the groove and the elastic arm is possible.

[0018] The second end further includes a push rod for disengaging the long hole from the fixed stop. When the push rod is pressed down, the connecting portion transmits a torque to the first end, thereby causing the first end to move upward; the long hole is disengaged from the fixed stop, thereby destroying the connection between the connecting member and the impact tool.

[0019] According to another embodiment of the present invention, the outer peripheral surface of the sleeve is provided with a circumferential groove, a pair of connecting holes are provided on the outer peripheral surface of the shaft supporting portion of the impact tool, the first end of the connecting member includes two pins respectively engageable in these connecting holes, the second end includes an arcuate ring at least partially engaged in the groove, and the rotation of the pin in the connecting hole drives the second end to engage in the groove or release from the groove. When the arcuate ring is engaged in the groove, the sleeve is fixedly connected to the impact tool in the axial direction; at the same time, the arcuate ring can rotate circumferentially in the groove, the connecting member and the impact tool are stationary relative to each other, and the sleeve can rotate relative to the connecting member and the impact tool.

[0020] Alternatively, the outer peripheral surface of the sleeve is provided with a circumferential groove, a fastening portion having at least one pair of connecting holes is provided on the outer peripheral surface of the shaft supporting portion of the impact tool, the fastening portion forms a non-rotating portion, the first end of the connecting member includes two pins respectively insertable into the connecting holes, the second end includes an arcuate ring at least partially engaged in the groove, and the rotation of the pin in the connecting hole drives the second end to engage in the groove or release from the groove. Therefore, it is not necessary to make a hole directly in the housing; instead, the pin is connected by forming a connecting hole as a non-rotating portion in the fastening portion attached to the front end of the housing, so that processing and assembly are simpler.

[0021] Preferably, the pair of holes are offset from each other in the axial direction to enable two rest positions of the connecting member.

[0022] According to another embodiment of the invention, the connection member is a ball interlocking chuck, the steel balls of which engage in circumferential grooves of the sleeve.

[0023] According to another embodiment of the present invention, the first end portion includes a pair of arc-shaped clips partially engaged in the annular channel, the second end portion includes a pair of elastic arms that can be engaged in the groove, and the connecting portion is an axially extending beam connecting the first end portion to the second end portion. The sleeve can be fixedly connected to the impact tool in the axial direction simply by engaging the arc-shaped clips of the first end portion and the elastic arms of the second end portion in the annular channel of the impact tool and the circumferential groove of the sleeve, respectively. Preferably, a reinforcement structure or material is selected for the beam used as the connecting portion to ensure the reliability of the axial fixed connection.

[0024] According to a preferred embodiment of the present invention, the connecting portion is formed as a circumferentially openable or closable annular sleeve, the first end and the second end are respectively provided at both ends of the annular sleeve, the first end comprises an annular flange at least partially engaged in the annular channel, and the second end comprises a rib at least partially engaged in the groove. The fact that the connecting portion is a circumferentially openable / closable sleeve greatly increases the strength of the connecting portion to better achieve the effect of fixing the sleeve to the non-rotating portion of the impact tool in the axial direction.

[0025] Preferably, the sleeve is formed by coupling two half rings together, each half ring having a joint structure, which is a snap joint or hinge respectively arranged on at least one side edge of the two half rings. The joint structure is configured to realize the function of opening / closing the sleeve. Such a sleeve can fixedly connect the sleeve to the impact tool in the axial direction without the need for additional fastening components.

[0026] Alternatively, the sleeve is formed by joining two half rings together, each half ring having a joint structure, and at least one elastic band for retaining the sleeve is arranged on the outside of the sleeve, the elastic band being fitted around the outer peripheral surface of the sleeve, close to the joint structure. Thus, the joint structure here will keep the two half rings axially aligned with each other. The elastic band helps to keep the sleeve in a closed state during operation.

[0027] The engagement structure is a recess provided at the end of one half ring and a protrusion provided at the end of the other half ring, when the protrusion is received in the recess, the two half rings are locked together to form a sleeve.

[0028] Alternatively, the engagement structure is a hook portion and a groove portion respectively arranged at the ends of the two half rings, the hook portion is engaged in the groove portion, and the two half rings are locked together to form a sleeve. The engagement structure forms a hinge between the two half rings to achieve the function of opening / closing the sleeve. When the sleeve is opened, the annular channels of the sleeve and the impact tool are respectively engaged with the ribs and flanges inside the sleeve, and then the engagement structure is closed via the locking mechanism of the engagement structure (such as a recess / protrusion or a hook / groove locking mechanism), and in this way, the sleeve is fixedly connected to the impact tool in the axial direction.

[0029] Preferably, the engagement structure (30) is positioned near the annular channel of the impact tool. This creates a lever condition which causes a closing force when trying to pull out the sleeve, thereby preventing the sleeve from being released (self-locking principle). To release the sleeve, the half rings can be opened by pressing on their lateral push rods.

[0030] The impact tool is an impact wrench. Considering that the universal socket for impact tools currently on the market is not suitable for other impact tools (such as impact drivers), for example, impact drivers often use a tool chuck connected to the anvil head to clamp a tool (such as a drill bit) to perform construction work, and there is no risk of the socket being detached from the anvil. Therefore, the socket anti-drop device of the present invention is particularly suitable for impact wrenches. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] A better understanding of the embodiments described herein can be obtained from the following detailed description with reference to the accompanying drawings. It should be emphasized that the various components are not necessarily drawn to scale. In fact, the dimensions may be arbitrarily enlarged or reduced for the purpose of clear discussion. In the accompanying drawings, the same reference numerals refer to the same elements.

[0032] Figure 1 is a schematic diagram of an impact tool and a socket in an exemplary embodiment of the present invention.

[0033] Figure 2 is a perspective view of an anti-falling device in an exemplary embodiment of the present invention.

[0034] Figure 2a to Figure 2b It shows the installation Figure 2 Schematic diagram of the process of the sleeve anti-falling device shown in .

[0035] Figure 3 Schematic diagram of a sleeve anti-dropping device for an impact tool according to another embodiment of the present invention.

[0036] Figure 3a to Figure 3b It shows the installation Figure 3 Schematic diagram of the process of the sleeve anti-falling device shown in .

[0037] Figure 4 2 is a schematic diagram of a sleeve anti-dropping device for an impact tool according to a third embodiment of the present invention.

[0038] Figure 4a to Figure 4b It shows the installation Figure 4 Schematic diagram of the process of the sleeve anti-falling device shown in .

[0039] Figure 5 4 is a schematic diagram of a sleeve anti-dropping device for an impact tool according to a fourth embodiment of the present invention.

[0040] Figure 5a to Figure 5b It shows the installation Figure 5 Schematic diagram of the process of the sleeve anti-falling device shown in .

[0041] Figure 6 4 is a schematic diagram of a sleeve anti-dropping device for an impact tool according to a fifth embodiment of the present invention.

[0042] Figure 6a to Figure 6b It shows the installation Figure 6 Schematic diagram of the process of the sleeve anti-falling device shown in .

[0043] Figure 7 4 is a schematic diagram of a sleeve anti-dropping device for an impact tool according to a sixth embodiment of the present invention.

[0044] Figure 7a to Figure 7b It shows the installation Figure 7 Schematic diagram of the process of the sleeve anti-falling device shown in .

[0045] Figure 8 2 is a schematic diagram of a sleeve anti-dropping device for an impact tool according to a seventh embodiment of the present invention.

[0046] Figures 8a to 8c It shows the installation Figure 8 Schematic diagram of the process of the sleeve anti-falling device shown in .

[0047] Fig. 9 4 is a schematic diagram of a sleeve anti-dropping device for an impact tool according to an eighth embodiment of the present invention.

[0048] Figures 9a to 9c It shows the installation Fig. 9 Schematic diagram of the process of the sleeve anti-falling device shown in .

[0049] Fig.10 4 is a schematic diagram of a sleeve anti-dropping device for an impact tool according to a ninth embodiment of the present invention. DETAILED DESCRIPTION

[0050] References below Figures 1 to 10A socket anti-drop device for an impact tool is described.

[0051] refer to Figure 1 and Figure 2 The impact wrench 1 is exemplarily shown as an impact tool. The impact wrench of the present invention comprises: a main housing 2 for accommodating a motor, the main housing 2 being generally formed by assembling a left half housing and a right half housing together; and a gear box housing 3 made of metal, the gear box housing 3 being assembled in front of the main housing 2 ( Figure 1 The left side in the figure). As the front housing, the gear box housing accommodates the gear transmission mechanism, the main shaft, the impact mechanism, and the anvil 4 used as the output shaft. The gear transmission mechanism and the impact mechanism are well known in the industry. The gear transmission mechanism converts the high-speed rotation of the motor shaft into the rotation of the main shaft by speed reduction, the torque is transmitted to the impact mechanism, and the hammer body repeatedly engages and disengages with the anvil 4, thereby generating impact in the rotation direction.

[0052] The gearbox housing 3 is a tubular body, the rear portion of which is inserted into the main housing 2. The front portion of the gearbox housing 3 exposed to the outside of the main housing 2 has a tapered form that is narrower at the front, and is covered by a shield made of synthetic resin. The anvil 4 is axially supported by an axial support portion 5 formed at the front end of the gearbox housing 3, and protrudes toward the front. The sleeve 6 is removably mounted on the front end of the anvil 4, which protrudes from the axial support portion 5. A bushing 7 for rotatably supporting the anvil is further provided inside the axial support portion 5 at the front end of the gearbox housing.

[0053] In the present invention, the socket for the impact wrench is a universal standard component. The socket 6 removably mounted on the head of the anvil 4 is cylindrical and includes: a rearward portion 61, which is provided with a hexagonal hole 62, into which the head of a hexagonal bolt or the like can be inserted; and a forward portion 63, which is coaxially coupled to the rearward portion 61 and is formed with a square hole, into which the anvil head is inserted. A circumferential groove 65 is formed on the forward portion 63, and a through hole 66 orthogonal to the axis of the forward portion 63 is formed at the position of the groove 65 in a penetrating manner.

[0054] The present invention provides a sleeve anti-dropping device 8 to directly and fixedly connect the sleeve 6 to an impact tool, particularly an impact wrench 1, in an axial direction. The impact wrench 1 includes a non-rotating portion 10, and the sleeve anti-dropping device 8 includes a connecting member, which is respectively and fixedly connected to the non-rotating portion 10 and the sleeve 6 in the axial direction, while not affecting the movement of the sleeve in the rotation direction driven by the anvil head. That is, the sleeve anti-dropping device 8 can not only rotate synchronously with the sleeve, but also remain stationary relative to the non-rotating portion 10, and can also rotate relative to the sleeve and / or the non-rotating portion 10, as long as the sleeve anti-dropping device 8 is fixedly connected to the non-rotating portion 10 and the sleeve 6 in the axial direction, wherein the fixed connection is achieved by conformal fit; therefore, the sleeve is fixed to the impact tool in an axial direction in a simple and reliable manner, and the sleeve 6 will not be accidentally detached from the anvil 4.

[0055] The sleeve anti-dropping device of the present invention is particularly suitable for impact tools with high application requirements, especially impact wrenches. Such applications often require heavy sleeves, and the torque load transmitted by the anvil is very high, so the strength of the square interface part of the anvil needs to be guaranteed. Therefore, the sleeve anti-dropping device of the present invention is particularly suitable for impact wrenches with high torque requirements, which is due to the fact that it directly and fixedly connects the sleeve to the non-rotating part of the impact wrench in the axial direction instead of connecting it to the anvil.

[0056] Figure 2 as well as Figure 2a to Figure 2b The present invention shows a sleeve anti-dropping device according to an embodiment of the present invention. Figure 2 As shown in the figure, a bushing 7 for rotatably supporting the anvil is provided inside the shaft support portion 5 located at the front end portion of the gearbox housing 3 of the impact wrench 1. In this embodiment, the bushing 7 for axially supporting the anvil 4 protrudes from the front end portion of the housing and forms a circumferential annular channel 11. The bushing 7 is generally formed integrally with the shaft support portion 5 and is engaged with at least the interior of the shaft support portion 5. Both the bushing 7 and the shaft support portion 5 can be considered as part of the gearbox housing 3. Therefore, both the shaft support portion 5 and the bushing 7 are relatively stationary components, that is, when the impact wrench 1 is working, neither the shaft support portion 5 nor the bushing 7 rotates, but the anvil 4 used as an output shaft rotates around the central axis in the hole formed by the shaft support portion 5 and the bushing 7.

[0057] The sleeve anti-drop device 8 of the present invention is a connecting member 20; the connecting member 20 includes a first end 21 connected to the annular channel 11, and a second end 22 connected to the sleeve 6, and the first end 21 is connected to the second end 22 by an axially extending connecting portion 23. The first end 21 includes a pair of arc clips, which are at least partially engaged in the annular channel 11; here, the annular channel 11 is used as a non-rotating part of the present invention. The arc clip is in a clearance fit with the annular channel 11; the arc clip can rotate in the annular channel 11, and the annular channel 11 limits the axial movement of the arc clip. The second end 22 includes a protrusion 24 extending substantially perpendicular to the connecting portion. The protrusion 24 can be inserted into the through hole 66, and the elasticity of the protrusion 24 enables the protrusion 24 to be firmly supported in the through hole 66, so that the connecting member and the sleeve are fixed relative to each other in the axial direction. Thus, the first end 21 fixes the connecting member 20 to the non-rotating part 10 in the axial direction, the second end 22 fixes the connecting member 20 to the sleeve 6 in the axial direction, and the axially extending connecting portion 13 ensures that the positions of the first end and the second end do not change in the axial direction. Thus, the connecting member fixedly connects the sleeve 6 to the impact wrench 1 in the axial direction, and the sleeve 6 will not move axially relative to the non-rotating part.

[0058] Preferably, the protrusion 24 forms a spring-elastic "press fit" toward the through hole 66 to ensure that the connecting member 20 is not disengaged due to centrifugal force. For example, the protrusion 24 further includes an elastic side bend, which may be slightly larger than the through hole to some extent and generate friction / clamping force. This can ensure that the protrusion 24 is not disengaged due to centrifugal force.

[0059] According to a preferred solution of the present invention, the second end 22 further includes a pair of elastic arms 25, which are partially engaged in the groove to achieve the purpose of axially retaining the sleeve. The protrusion 24 is located on the center line of the second end, and the elastic arms 25 extend from the center of the second end to both sides in an arc shape, and the curvature of the elastic arms 25 is substantially the same as or slightly smaller than the curvature of the groove 65 of the sleeve. Therefore, when the elastic arms 25 are engaged in the circumferential groove 65 of the sleeve, the elastic arms 25 are tightly pressed against the groove on the peripheral surface of the sleeve in the radial direction, thereby ensuring that the connecting member is free from disengagement due to centrifugal force. Therefore, the sleeve 6 is fixed relative to the connecting member in the axial direction.

[0060] In this embodiment, the arc clamp of the first end 21 of the connecting member can rotate along the non-rotating annular channel 11, and the protrusion 24 of the second end 22 of the connecting member is inserted into the through hole 66 in the sleeve, so that a fixed connection is formed between the connecting member and the sleeve, so that the connecting member 20 can rotate synchronously with the sleeve 6.

[0061] Figure 2a to Figure 2b It shows the installation Figure 2 The schematic diagram of the process of the sleeve anti-dropping device shown in FIG. First, as Figure 2a As shown in , the sleeve 6 is mounted on the head of the anvil 4; the through hole 66 of the sleeve is aligned with the through hole of the head of the anvil 4, and then the two arc clips at the first end of the connecting member are engaged in the arc channel, and the protrusion 24 at the second end is inserted into the through hole 66, and the elastic arm 25 is engaged in the groove 65 of the sleeve. In this way, the connecting member simply and conveniently connects the sleeve fixedly in the axial direction.

[0062] Figure 3 as well as Figure 3a to Figure 3b A socket anti-dropping device 10 according to another embodiment of the present invention is shown. Here, the impact wrench and the socket are Figure 2 The impact wrench and socket in the embodiment shown in are identical, but the non-rotating portion 10 of the impact tool is different. Figure 2 In the embodiment shown in FIG. 1 , the bushing 7 protrudes from the front end of the shaft support portion 5 and forms an annular channel 11 which serves as a non-rotating portion. Figure 3 In the embodiment shown in , the bushing 7 does not need to protrude from the shaft support portion 5 and the annular channel 11 does not need to be formed. It will be understood that in this embodiment, the bushing 7 can also have the same structure as that in the previous embodiment, except that the bushing 7 no longer serves as a non-rotating portion for connecting to the sleeve anti-dropping device. In this embodiment, a fixed stopper 12 is provided on the peripheral surface of the shaft support portion 5, and the fixed stopper 12 serves as a non-rotating portion 10 for connecting to the sleeve anti-dropping device of this embodiment. Installing the protruding fixed stopper as a non-rotating portion at the front end of the impact wrench housing is a simple and convenient solution for forming an additional non-rotating portion on the impact wrench.

[0063] The sleeve 6 in this embodiment may have the structure of a standard sleeve as shown in the previous embodiment; a circumferential groove 65 is formed on the forward portion 63 of the sleeve 6, and a through hole 66 orthogonal to the axis of the forward portion 63 is formed in a penetrating manner at the position of the groove 65. It is also possible not to provide the through hole 66, that is, only the circumferential groove 65 is formed on the forward portion, because the connecting member in this embodiment does not need to be connected to the through hole, but is instead connected only to the circumferential groove 65.

[0064] In this embodiment, the first end 21 of the connecting member 20 is a long hole 26 provided at the front of the connecting portion 23, the long hole 26 is fitted on the fixing stopper 12 to axially fix the connecting member, and the second end 22 includes a pair of elastic arms 25 that can be engaged in the groove 65, and these elastic arms 25 can rotate circumferentially along the groove 65. Due to the shape fit between the long hole and the fixing stopper, the connecting member is fixedly connected to the non-rotating part of the impact tool in the axial direction. The elastic arm 25 of the second end plays the function of fixedly connecting the connecting member 20 to the sleeve 6 in the axial direction, while the rotation between the groove 65 and the elastic arm 25 is possible.

[0065] Preferably, if Figure 3b and Figure 3b As shown in , the second end further includes a push rod 27, which is used to disengage the long hole from the fixed stop. The push rod 27 is a lever, which is arranged at one side of the connecting portion 23 close to the second end and extends upward to form a pressing portion. When the push rod 27 is pressed down, the connecting portion transmits a torque to the first end 21, thereby causing the first end 21 to move upward; the long hole 26 is disengaged from the fixed stop 12, thereby destroying the connection between the connecting member 20 and the impact tool, and then the sleeve 6 can be removed from the anvil.

[0066] Figure 4 as well as Figure 4a to Figure 4b A sleeve anti-dropping device 10 according to another embodiment of the present invention is shown. Figure 2 The impact tool is the same as the one in the embodiment shown in FIG. 1 , that is, a bushing 7 for axially supporting the anvil 4 protrudes from the front end of the housing and forms a circumferentially arranged annular channel 11, and a sleeve 6 is connected to the anvil 4. Figure 3 The sleeve in the embodiment shown in FIG. 1 is the same, that is, a circumferential groove 65 is formed on the forward portion 63 of the sleeve 6, and a through hole 66 orthogonal to the axis of the forward portion 63 is formed in a penetrating manner at the position of the groove 65, but the through hole 66 may not be provided.

[0067] In this embodiment, the connecting member 20 is a sleeve that can be opened / closed in the circumferential direction, that is, the connecting portion 23 generally has the shape of a sleeve. The first end 21 and the second end 22 are two end faces of the sleeve, respectively, and the sleeve is continuous in both the axial direction and the circumferential direction. Therefore, the strength of the connecting portion 23 is greatly increased to better achieve the effect of fixing the sleeve in the axial direction to the non-rotating part of the impact tool. Herein, plastic is the preferred material for forming the sleeve, but other materials (such as sheet metal with an integrated hinge) may also be conceivable.

[0068] The first end portion 21 comprises an annular flange 28 which is at least partially engaged in the annular channel 11. Figure 6aAs shown in , the annular flange 28 has a structure and size that matches the annular channel 11. Once the annular flange 28 has been engaged in the annular channel 11, the first end 21 of the connecting member is fixed in the axial direction relative to the annular channel serving as a non-rotating portion, that is, the annular flange 28 cannot move in the annular channel 11 in the axial direction, but the annular flange 28 can rotate relative to the annular channel 11 in the circumferential direction.

[0069] The second end 22 includes a rib 29 that is at least partially engaged in the groove 65. The rib 29 is a rib that is arranged inside the sleeve and protrudes radially inward, and is configured to engage in the circumferential groove 65 of the sleeve. The rib 29 can be continuous, or it can be two, three, four or more discrete ribs uniformly distributed in the circumferential direction around the inner side of the second end of the sleeve, so that the rib is uniformly pressed against the bottom of the groove in the circumferential direction; the rib 29 cannot move axially in the groove, and thus achieves axial fixation of the connecting member 20 and the sleeve 6. However, the rib 29 does not limit the relative circumferential movement between the connecting member and the sleeve. The sleeve 6 rotates under the driving action of the anvil, and the sleeve may or may not rotate synchronously with the sleeve, and may even remain stationary without rotating with the sleeve, depending on the matching mode between the rib and the groove.

[0070] Preferably, the sleeve is formed by connecting two half rings together, each half ring having a joint structure 30, which is a snap joint or hinge respectively arranged on at least one side edge of the two half rings. The joint structure 30 is configured to realize the function of opening / closing the sleeve. Such a sleeve can fixedly connect the sleeve to the impact tool in the axial direction without the need for additional fastening components. In this embodiment, the joint structure 30 is a hook and a hole respectively arranged in the center position on the side edges of the two half rings; the side edges at the other side of the two half rings can be hinged, and then the hook on one half ring is engaged in the hole on the other half ring, so that the two half rings are locked together to form a single sleeve surrounding the non-rotating annular channel of the impact tool and the circumferential groove of the sleeve. Therefore, as Figure 4b As shown in FIG. 1 , when the sleeve 6 is connected to the anvil 4 , the connecting member 20 in the form of a sleeve fixedly connects the sleeve 6 to the impact wrench 1 in the axial direction, and the sleeve 6 will not be disengaged from the anvil 4 under the action of the connecting member 20 .

[0071] Figure 5 as well as Figure 5a to Figure 5b The fourth embodiment of the present invention is a sleeve anti-drop device for an impact tool. In this embodiment, the structures of the impact tool and the sleeve are both the same as Figure 4 The structure of the embodiment shown in FIG. 1 is substantially the same, and the structure of the connecting member 20 is similar to that of the embodiment shown in FIG. Figure 4The structure of the embodiment shown in is similar, with the difference that the engagement member 30 is arranged at the first end 21 of the connecting member. This creates a lever condition, which causes a closing force when trying to pull out the sleeve, thereby preventing the sleeve from being released (self-locking principle). In order to release the sleeve, the half rings can be opened by pressing the lateral push rods (27) of the half rings, which are also arranged on the annular sleeve. For example, refer to Figure 5a and Figure 5b , the engagement structure is a recess provided at the first end of one half ring and a protrusion provided at the first end of the other half ring; when the protrusion is received in the recess, the two half rings are locked together to form a sleeve. A pair of lateral push rods 27 are provided on the first ends of the two half rings of the sleeve. The lateral push rods 27 are preferably provided in the center of the half rings. Therefore, the engagement structure 20 can be easily disengaged by pressing the lateral push rods 27.

[0072] Preferably, at least one elastic band 31 is provided on the outside of the sleeve to retain the sleeve. Providing the engagement structure 30 at the first end helps to facilitate insertion into the sleeve during installation so that the rib 29 can easily engage in the circumferential groove 65. Figure 5a As shown in FIG. 1 , first, the annular flange of the first end of the connecting member is engaged in the annular channel of the bushing 7, and then Figure 5b As shown in , the engagement structures 30 are coupled together and an elastic band 31 is fitted thereon. In this embodiment, the elastic band 31 is fitted around the peripheral surface of the sleeve, close to the engagement structure, to help keep the sleeve in a closed state during operation. Preferably, a receiving channel is formed on the peripheral surface to receive the elastic band 31. Ideally, the sleeve 6 is inserted into the sleeve so that the ribs 29 inside the sleeve engage in the circumferential grooves of the sleeve, thereby firmly and fixedly connecting the sleeve 6 to the non-rotating part of the impact tool in the axial direction.

[0073] Figure 6 as well as Figure 6a to Figure 6b The fifth embodiment of the present invention is a sleeve anti-dropping device for an impact tool. Figure 5 The difference of the embodiment shown in is that the engagement structure 30 in this embodiment is arranged at the second end 22 of the connecting member 20. For example, Figure 6a As shown in , the engagement structure is a hook portion and a groove portion respectively provided at the ends of the two half rings, the hook portion is engaged in the groove portion, and the two half rings are locked together to form a sleeve. Similarly, at least one elastic strip 31 is provided outside the sleeve to retain the sleeve; preferably, the elastic strip 31 is close to the engagement structure to more effectively keep the sleeve in a closed state. Figure 6bThe advantage of arranging the engagement structure at the second end is that the sleeve can be inserted into the sleeve before closing the sleeve, and once the rib has engaged in the groove, the hook and groove parts of the two half rings are connected together and the elastic strip is moved close to the engagement structure. Therefore, the installation process of fixedly connecting the impact tool to the sleeve in the axial direction by means of the connecting member is relatively simple and convenient, and the strength of the axial fixed connection achieved by the connecting member is relatively high.

[0074] Figure 7 as well as Figure 7a to Figure 7b The sixth embodiment of the present invention is a sleeve anti-drop device for an impact tool. In this embodiment, both the impact tool and the sleeve are connected to Figure 4 The impact tool and the socket are both identical in the embodiment shown in FIG. 1 , but a structurally simpler connecting member 20 is provided in this embodiment. Figure 7 In this embodiment, the first end 21 of the connecting member includes a pair of arc-shaped clips that are partially engaged in the annular channel, the second end 22 includes a pair of elastic arms that can be engaged in the groove, the elastic arms can rotate along the circumference of the groove, and the connecting portion is an axially extending beam connecting the first end to the second end. Figure 7a and Figure 7b As shown in , the sleeve can be fixedly connected to the impact tool in the axial direction simply by engaging the arc-shaped clip at the first end and the elastic arm at the second end in the annular channel of the impact tool and the circumferential groove of the sleeve, respectively. Preferably, a reinforcement structure or material is selected for the beam used as the connecting part to ensure the reliability of the axial fixed connection.

[0075] refer to Figure 8 as well as Figures 8a to 8c , these figures show a sleeve anti-dropping device for an impact tool according to a seventh embodiment of the present invention. In this embodiment, the bushing 7 of the impact tool does not need to protrude from the front end of the shaft support part 5, and the front end of the bushing 7 does not need to form an annular channel. In this embodiment, the non-rotating portion is no longer the annular channel in the previous embodiment, but is instead the shaft support part 5. Preferably, a pair of connecting holes 13 are provided on the peripheral surface of the shaft support part 5. The first end of the connecting member includes two pins 32 that can be inserted into the connecting holes respectively, and the second end 22 includes an arcuate ring 33 that is at least partially engaged in the groove; the pin 32 rotates in the connecting hole 13, thereby enabling the arcuate ring 33 to be released from the groove 65. When the arcuate ring is engaged in the groove, the sleeve is fixedly connected to the impact tool in the axial direction; at the same time, relative circumferential rotation between the arcuate ring and the groove is possible, the connecting member and the impact tool are stationary relative to each other, and the sleeve can rotate relative to the connecting member and the impact tool. Fig. 9 as well as Figures 9a to 9cDemonstrates the ability to connect an impact tool to Figure 8 Another method of the sleeve anti-drop device shown in Figure 8 Unlike the embodiment shown in (in which a pair of connecting holes are formed directly on the peripheral surface of the shaft supporting portion), the shaft supporting portion of the impact tool is provided with a fastening portion 14 having a connecting hole 13, which forms a non-rotating portion. The first end of the connecting member includes two pins that can be inserted into the connecting holes respectively, the second end includes an arcuate ring that is at least partially engaged in the groove, and the pin rotates in the connecting hole so that the second end can be released from the groove. Therefore, it is not necessary to make a hole directly in the housing; instead, the pin is connected by forming a connecting hole as a non-rotating portion in the fastening portion attached to the front end of the housing, so that processing and assembly are simpler.

[0076] Preferably, the pair of connecting holes 13 described above are not in line with each other, but are arranged to be slightly axially offset from each other in such a way that the spring elastic connecting member 20 is elastically deformed and preloaded, so that it has two rest positions: engaged with the circumferential groove 11 of the sleeve 6 and not engaged.

[0077] refer to Fig.10 , the sleeve anti-dropping device can be a tool chuck. Typically, the tool chuck is a ball interlocking chuck. Such ball interlocking chucks have been widely used on impact drivers to fix screw bits. Ordinary ball interlocking chucks use springs to push interlocking balls into circumferential grooves of sleeves or tools to lock the chuck. The tool chuck in this embodiment has a similar structure, except that the tool chuck of the present invention combines a ball interlocking piece (such as in a screw bit chuck of an impact driver) with an external square anvil of an impact wrench to ensure that the sleeve is not disengaged.

[0078] Finally, it must be explained that the sleeve anti-dropping device of the present invention directly connects the sleeve to the impact tool in an axial direction, so that an axial fixed connection between the sleeve and the anvil is not required, and the sleeve will not be detached from the anvil. At the same time, the sleeve anti-dropping device of the present invention does not exclude the conventional fit between the sleeve and the anvil. Therefore, the sleeve can still be connected to the anvil by means of a friction ring or a fixed stop, in which case the sleeve anti-dropping device of the present invention can further ensure that the sleeve will not be detached from the anvil.

[0079] As mentioned above, although exemplary embodiments of the present invention have been explained herein with reference to the accompanying drawings, the present invention is not limited to the above specific embodiments and may have many other embodiments. The scope of the present invention should be defined by the claims and their equivalents.

Claims

1. A sleeve anti-dropping device (8) for an impact tool, the impact tool comprising a housing (2), wherein an anvil (4) is arranged in a protruding manner in front of the housing, and a sleeve (6) is removably mounted on the anvil (4), It is characterized in that The sleeve anti-dropping device (8) comprises at least one connecting member (20) for fixedly connecting the sleeve (6) to the non-rotating part of the impact tool in the axial direction by conformal fit to prevent the sleeve (6) from falling off.

2. The sleeve anti-dropping device (8) for an impact tool according to claim 1, It is characterized in that The connecting member (20) includes a first end (21) fixedly connected to the non-rotating portion along the axial direction, and a second end (22) fixedly connected to the sleeve (6) along the axial direction, the first end (21) being connected to the second end (22) by means of an axially extending connecting portion (23), and the connecting member (20) rotates synchronously with the sleeve (6).

3. The sleeve anti-dropping device (8) for an impact tool according to claim 2, It is characterized in that The front portion of the housing of the impact tool is provided with an axis support portion (5) for rotatably supporting the anvil, and a bushing (7) is arranged inside the axis support portion (5), the bushing (7) protruding from the front end portion of the axis support portion (5) and forming a circumferentially arranged annular channel (11), which forms the non-rotating portion.

4. The sleeve anti-dropping device (8) for an impact tool according to claim 3, It is characterized in that The sleeve (6) is provided with a through hole (66) substantially perpendicular to the central axis of the sleeve (6), the first end (21) includes a pair of arc clips, which are partially engaged in the annular channel (11) to fixedly connect the connecting member (20) to the non-rotating part along the axial direction, and the second end (22) includes a protrusion (24) extending substantially perpendicular to the connecting part (23), and the protrusion (24) can be inserted into the through hole (66) to fixedly connect the connecting member (20) to the sleeve (6) along the axial direction.

5. The sleeve anti-dropping device (8) for an impact tool according to claim 4, It is characterized in that The outer peripheral surface of the sleeve (6) is further provided with a circumferential groove (65), and the second end of the connecting member (20) further includes a pair of elastic arms (25), which are partially engaged in the groove (65) for retaining the sleeve (6) along the axial direction.

6. The sleeve anti-dropping device (8) for an impact tool according to claim 4, It is characterized in that The protrusion (24) forms a spring-elastic press fit toward the through hole (66) to ensure that the connecting member (20) is prevented from being disengaged due to centrifugal force.

7. The sleeve anti-dropping device (8) for an impact tool according to claim 1, It is characterized in that The connecting member (20) includes a first end (21) fixedly connected to the non-rotating portion in the axial direction, and a second end (22) fixedly connected to the sleeve (6) in the axial direction, the first end (21) being connected to the second end (22) by means of an axially extending connecting portion (23), and the sleeve (6) being rotatable in the circumferential direction relative to the connecting member (20).

8. The sleeve anti-dropping device (8) for an impact tool according to claim 7, It is characterized in that The outer peripheral surface of the sleeve (6) is provided with a circumferential groove (65), and a fixed stopper (12) is provided on the outer peripheral surface of the shaft supporting part (5) of the impact tool, and the fixed stopper (12) forms the non-rotating part.

9. The sleeve anti-dropping device (8) for an impact tool according to claim 8, It is characterized in that The first end portion (21) includes a long hole (26) provided at one end portion of the connecting portion (23), the long hole (26) being mounted on the fixed stopper (12) to fixedly connect the connecting member (20) to the non-rotating portion along the axial direction, and the second end portion (22) includes a pair of elastic arms (25) capable of engaging in the groove (65), and the elastic arms (25) are capable of rotating circumferentially along the groove (65).

10. The sleeve anti-dropping device (8) for an impact tool according to claim 9, It is characterized in that The second end portion (22) further comprises a push rod (27) for disengaging the elongated hole (26) from the fixed stop (12).

11. The sleeve anti-dropping device (8) for an impact tool according to claim 7, It is characterized in that The outer surface of the sleeve (6) is provided with a circumferential groove (65), at least one pair of connecting holes (13) is provided on the outer surface of the shaft support part (5) of the impact tool, the first end (21) of the connecting member (20) includes two pins (32) respectively capable of engaging in these connecting holes (13), the second end (22) includes an arcuate ring (33) at least partially engaged in the groove (65), and the rotation of these pins (32) in these connecting holes drives the second end (22) to engage in the groove (65) or release from the groove (65).

12. The sleeve anti-dropping device (8) for an impact tool according to claim 7, It is characterized in that The outer surface of the sleeve (6) is provided with a circumferential groove (65), a fastening portion (14) having at least one pair of connecting holes (13) is provided on the outer surface of the shaft supporting portion of the impact tool, the fastening portion (14) forms the non-rotating portion, the first end portion (21) of the connecting member (20) includes two pins (32) that can be inserted into the connecting holes (13) respectively, the second end portion (22) includes an arcuate ring (33) that is at least partially engaged in the groove (65), and the rotation of these pins (32) in the connecting hole (13) drives the second end portion (22) to engage in the groove (65) or release from the groove (65).

13. The sleeve anti-dropping device (8) for an impact tool according to claim 11 or 12, It is characterized in that The pair of holes are axially offset from each other.

14. The sleeve anti-dropping device (8) for an impact tool according to claim 7, It is characterized in that The outer surface of the sleeve (6) is provided with a circumferential groove (65), the front part of the shell of the impact tool is provided with an axial support part (5) for rotatably supporting the anvil (4), and a bushing (7) is arranged inside the axial support part (5), and the bushing (7) protrudes from the front end of the shell and forms a circumferentially arranged annular channel (11), and the annular channel (11) forms the non-rotating part.

15. The sleeve anti-dropping device (8) for an impact tool according to claim 14, It is characterized in that The connection member (20) is a ball interlocking chuck, wherein the balls of the chuck engage into a circumferential groove (65) of the sleeve (6).

16. The sleeve anti-dropping device (8) for an impact tool according to claim 14, It is characterized in that The first end (21) includes a pair of arcuate clips partially engaged in the annular channel (11), the second end (22) includes a pair of resilient arms (25) capable of engaging in the groove (65), and the connecting portion (23) is an axially extending beam connecting the first end (21) to the second end (22).

17. The sleeve anti-dropping device (8) for an impact tool according to claim 14, It is characterized in that The connecting portion (23) is formed as an annular sleeve that can be opened or closed in a circumferential direction, the first end (21) and the second end (22) are respectively arranged at the two ends of the sleeve, the first end (21) includes an annular flange (28) at least partially engaged in the annular channel (11), and the second end (22) includes a rib (29) at least partially engaged in the groove (65).

18. The sleeve anti-dropping device (8) for an impact tool according to claim 16, It is characterized in that The sleeve is formed by joining two half rings together, each half ring having a joint structure (30) which is a snap joint or hinge respectively arranged on at least one side edge of the two half rings.

19. The sleeve anti-dropping device (8) for an impact tool according to claim 16, It is characterized in that The sleeve is formed by connecting two half rings together, each half ring has a joint structure (30), and the outer peripheral surface of the sleeve is provided with at least one elastic band (31) for retaining the sleeve, and the elastic band (31) is assembled around the outer peripheral surface of the sleeve and close to the joint structure (30).

20. The sleeve anti-dropping device (8) for an impact tool according to claim 18, It is characterized in that The engagement structure (30) is a recess provided at the end of one half ring and a protrusion provided at the end of the other half ring, when the protrusion is received in the recess, the two half rings are locked together to form the sleeve.

21. The sleeve anti-dropping device (8) for an impact tool according to claim 18, It is characterized in that The engaging structure (30) is a hook portion and a groove portion respectively arranged at the ends of the two half rings, the hook portion is engaged in the groove portion, and the two half rings are locked together to form the sleeve.

22. The sleeve anti-dropping device (8) for an impact tool according to any one of claims 18 to 21, It is characterized in that The engagement structure (30) is positioned near the annular channel (11) of the impact tool. This creates a lever condition which causes a closing force when trying to pull out the sleeve, thereby preventing the sleeve from being released (self-locking principle). To release the sleeve, the half rings can be opened by pressing the lateral push rods (27) of the half rings.

23. The sleeve anti-dropping device (8) for an impact tool according to any one of claims 1 to 20, characterized in that: The impact tool is an impact wrench.

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