Pipe expander
By using a tapered needle with inclined or spiral guide grooves and a one-way torque transmission mechanism in the pipe expander, the problems of complex structure and heavy weight in the prior art are solved, and a simple and efficient pipe expansion and rotational motion is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- EMERSON PROFESSIONAL TOOLS SHANGHAI
- Filing Date
- 2023-01-12
- Publication Date
- 2026-06-05
AI Technical Summary
Existing pipe expanders have complex mechanical structures, resulting in large size and weight, and their expansion and rotation movements are not simple or efficient.
The chuck expands and rotates by using a tapered needle with inclined or spiral guide grooves and a unidirectional torque transmission mechanism. The axial movement and rotation of the tapered needle enable the chuck to expand and rotate, while the unidirectional torque transmission mechanism transmits torque in only one direction.
The pipe expander has a simple and compact structure, reducing the number of parts and weight, while achieving uniform expansion and rotation of the chuck and avoiding the resistance of pipe friction to rotation.
Smart Images
Figure CN116117011B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to tools for use in the field of piping, and more particularly to a pipe expander. Background Technology
[0002] The content in this section provides only background information related to this disclosure and may not constitute prior art.
[0003] When connecting one pipe to another or other equipment, pipe expanders are often used to increase the pipe's inner diameter. A common pipe expander includes a chuck consisting of several jaws. The jaws, in their contracted state, collectively define a tapered (e.g., truncated conical) end of the chuck, which can then be inserted into the pipe to be expanded. The individual jaws of the chuck can then expand radially outward, thereby increasing the pipe's inner diameter. To ensure uniform expansion, after each expansion, the chuck is typically contracted and rotated by a predetermined angle (e.g., 60°) before expanding again, until the chuck has rotated 360°. The mechanical structures used to achieve the expansion and rotation of the chuck in existing pipe expanders of this type are often quite complex. Summary of the Invention
[0004] One object of this disclosure is to provide a pipe expander with a simple and compact structure, reducing the size and weight of the pipe expander.
[0005] Another objective of this disclosure is to realize the expansion and rotational movement of the chuck of a pipe expander using a simple mechanical structure.
[0006] One aspect of this disclosure provides a pipe expander. The pipe expander includes: an actuator; a chuck including a plurality of jaws movable between a contracted state and an expanded state, wherein in the contracted state the jaws are abutted against each other and collectively define a tapered end of the chuck; and in the expanded state the jaws expand radially outward; and a transmission assembly configured to transmit power from the actuator to the chuck to drive the jaws to expand and the chuck to rotate about an axis of the pipe expander. The transmission assembly includes: a tapered needle comprising a conical section and a cylindrical section, the cylindrical section having a guide groove including an inclined section extending obliquely relative to an axis; a driver configured to drive the tapered needle to feed along the axis toward the chuck, such that the conical section pushes multiple jaws from a retracted state to an expanded state; a reset mechanism configured to retract the tapered needle away from the chuck along the axis, such that the multiple jaws change from an expanded state to a retracted state; a pin and a pin mounting seat, the pin being disposed in the pin mounting seat and at least a portion of the pin being received in the guide groove, the pin being able to engage with the inclined section of the guide groove, such that the tapered needle can rotate about the axis while moving along the axis; and a one-way torque transmission mechanism configured to transmit torque generated by the rotation of the tapered needle in one direction to the chuck, but not to transmit torque generated by the rotation of the tapered needle in the opposite direction to the chuck.
[0007] In some embodiments, the one-way torque transmission mechanism may include a one-way bearing, the inner ring of which is arranged to rotate with the tapered needle around the cylindrical section of the needle, and the outer ring of which is connected to a chuck. The one-way bearing is configured such that when the inner ring rotates in one direction, the inner and outer rings are locked together to transmit torque to the outer ring; and when the inner ring rotates in the opposite direction, the inner ring rotates freely relative to the outer ring without transmitting torque to the outer ring.
[0008] In some embodiments, the transmission assembly may include a chuck drive sleeve arranged about the outer ring of a one-way bearing and rotating with it. The chuck drive sleeve includes end face teeth that mesh with end face teeth on the chuck to transmit torque to the chuck.
[0009] In some embodiments, the unidirectional torque transmission mechanism may include a ratchet disc arranged to rotate with the conical needle around the cylindrical section of the conical needle. The ratchet disc is connected to the chuck via end face ratchet teeth. When the ratchet disc rotates in one direction, the ratchet disc transmits torque to the chuck via the end face ratchet teeth. When the ratchet disc rotates in the opposite direction, the end face ratchet teeth slip, preventing the torque from being transmitted to the chuck.
[0010] In some embodiments, the transmission assembly may include a chuck drive sleeve, one side of which is provided with end face ratchet teeth for engaging with end face ratchet teeth on the ratchet disc, and the opposite side of the chuck drive sleeve includes end face teeth, the end face teeth of the chuck drive sleeve engaging with end face teeth on the chuck to transmit torque to the chuck.
[0011] In some implementations, the transmission assembly may include a cam or eccentric wheel connected to the output shaft of the driver, which periodically pushes a tapered needle along the axis toward the chuck as it rotates.
[0012] In some implementations, the reset mechanism may include a spring configured to bias the tapered needle toward a cam or eccentric wheel.
[0013] In some implementations, the guide groove may extend through the cylindrical section of the conical needle.
[0014] In some embodiments, the pin mounting base may be configured as a sleeve surrounding a cylindrical section of a conical pin, the sleeve having a pair of radially aligned pin holes on its wall, through which the pin passes and through a guide groove for fixation.
[0015] In some embodiments, the guide groove may further include a straight section extending along an axis, the straight section being connected to an inclined section, and the inclined section being disposed on one side near the conical section of the conical needle.
[0016] In some implementations, the guide groove may be configured as a spiral shape relative to the axis.
[0017] In some embodiments, the unidirectional torque transmission mechanism may be configured to transmit the torque generated by the rotation of the tapered needle as it feeds toward the chuck to the chuck, rather than the torque generated by the reverse rotation of the tapered needle as it retracts away from the chuck.
[0018] On the one hand, the tapered needle in the pipe expander according to this disclosure is provided with an inclined or spiral guide groove. By engaging a fixed pin with the guide groove, the tapered needle can be constrained to rotate along its axis while performing axial reciprocating motion. On the other hand, the pipe expander according to this disclosure is provided with a unidirectional torque transmission mechanism, thereby transmitting the torque generated only when the tapered needle rotates in one direction (e.g., when the tapered needle rotates during feeding) to the chuck and driving the chuck to rotate accordingly. Based on these two aspects, this disclosure achieves the expansion and rotational movement of the chuck in the pipe expander with a simple mechanical structure, which is beneficial for reducing the size, weight, and number of parts of the pipe expander. Attached Figure Description
[0019] Embodiments of this disclosure will now be described by way of example only with reference to the accompanying drawings. In the drawings, the same features or components are indicated by the same reference numerals, and the drawings are not necessarily drawn to scale. In the drawings:
[0020] Figure 1 A perspective view of a pipe expander according to a first embodiment of the present disclosure is shown;
[0021] Figure 2 It shows along Figure 1 A longitudinal cross-sectional view of the pipe expander taken along axis A in the diagram;
[0022] Figure 3 and Figure 4 Showing views from different angles Figure 1 Exploded view of the pipe expander in the image;
[0023] Figure 5 It shows Figure 1 A three-dimensional view of the conical needle of the pipe expander in the image;
[0024] Figure 6 It shows Figure 1 An exemplary perspective view of a one-way bearing in a pipe expander;
[0025] Figure 7 It shows Figure 6 A cross-sectional view of the central section of a one-way bearing in a machine;
[0026] Figure 8 A perspective view of a pipe expander according to a second embodiment of the present disclosure is shown;
[0027] Figure 9 It shows along Figure 8 A longitudinal cross-sectional view of the pipe expander taken from axis A' in the diagram;
[0028] Figure 10 and Figure 11 Showing views from different angles Figure 8 Exploded view of the pipe expander in the image;
[0029] Figure 12 A top view of a pipe expander according to a third embodiment of the present disclosure is shown. Detailed Implementation
[0030] The following description is exemplary in nature and is not intended to limit the scope, application, or use of this disclosure. It should be understood that in all these figures, similar reference numerals indicate the same or similar parts and features. The figures are merely schematic representations of the concept and principles of embodiments of this disclosure and do not necessarily show the specific dimensions and scale of the various embodiments of this disclosure. Certain details or structures of embodiments of this disclosure may be exaggerated in specific portions of particular figures.
[0031] In the description of the embodiments of this disclosure, the directional terms related to "upper" and "lower" are used to describe the upper and lower positions of the views shown in the accompanying drawings. In practical applications, the positional relationships of "upper" and "lower" used herein can be defined according to actual circumstances, and these relationships can be reversed.
[0032] First, combine Figures 1 to 7 The structure and working principle of a pipe expander 1 according to one embodiment of the present disclosure are explained.
[0033] Figure 1 A perspective view of a pipe expander 1 according to a first embodiment of the present disclosure is shown; Figure 2 It shows along Figure 1 The longitudinal cross-sectional view of the pipe expander 1 taken from axis A in the diagram. Figure 3 and Figure 4 An exploded view of the pipe expander 1 as viewed from different angles is shown.
[0034] like Figure 1 and Figure 2 As shown, the pipe expander 1 generally includes a driver 10, a chuck 20, and a transmission assembly 30. In this embodiment, the driver 10 is a motor. The chuck 20 may include a mounting ring 21 and a plurality of jaws 22 (six jaws 22 in this embodiment) connected to the mounting ring 21 along the inner circumferential surface of the mounting ring 21, each jaw having the same shape. In other embodiments, a different structure than that of the mounting ring 21 may be used to connect the multiple jaws. Figure 1 and Figure 2 The diagram shows the retracted state of the jaws 22, in which the jaws 22 are adjacent to each other, thereby collectively defining the cylindrical section 23 and the tapered chuck end 24. (See diagram for reference.) Figure 2As shown, in the retracted state, each jaw 22 also collectively defines a conical hollow internal chamber 25. Each jaw 22 is capable of radially outward movement relative to the mounting ring 21 to an expanded state (not shown). In the expanded state, the jaws 22 separate from each other, causing the cylindrical section 23 and the chuck end 24 to expand radially outward. Furthermore, the chuck 20 as a whole is capable of rotating about axis A. The transmission assembly 30 is configured to transmit power from the actuator 10 to the chuck 20 to drive the expansion of the jaws 22 and the rotation of the chuck 20.
[0035] like Figures 2 to 4 As shown, the transmission assembly 30 includes a tapered needle 31. Figure 5 A perspective view of a conical needle 31 is shown. The conical needle 31 has a conical section 311 and a cylindrical section 312. Figure 2 As shown, when the jaws 22 are in the retracted state, the conical section 311 of the conical needle 31 is housed within the hollow internal cavity 25 defined by the jaws 22. The conical needle 31 can move along axis A. When the conical needle 31 feeds toward the chuck end 24, the conical section 311 of the conical needle 31 uniformly pushes each jaw 22 radially outward relative to the mounting ring 21; when the conical needle 31 retracts away from the chuck end 24, each jaw 22 can return to the retracted state. Figure 2 As shown, in this embodiment, a portion of the cylindrical segment 312 is hollow, thereby reducing the material and weight of the conical needle 31. In this embodiment, the conical segment 311 and the cylindrical segment 312 of the conical needle 31 are integrally formed, but this disclosure is not limited thereto; in other embodiments, the conical needle may also be a separate component.
[0036] like Figure 5 As shown, the cylindrical section 312 of the conical needle 31 is provided with a guide groove 313 penetrating the cylindrical section 312. In this embodiment, the guide groove 313 includes a straight section 313a extending in the axial direction and an inclined section 313b extending obliquely from the straight section 313a relative to the axial direction, wherein the inclined section 313b is provided on one side near the conical section 311 of the conical needle 31. Figure 2 and Figure 3 As shown, the transmission assembly 30 may further include a pin 32 and a pin mounting seat 33. In this embodiment, the pin mounting seat 33 is constructed as a sleeve arranged around a cylindrical section 312 of the conical pin 31, and its cylindrical wall is provided with a pair of pin holes 331, 332 aligned in the radial direction. Figure 2It can be clearly seen that the pin 32 is fixed by passing through the guide groove 313 of the tapered needle 31 and the pin holes 331 and 332 of the pin mounting seat 33, so as to connect the tapered needle 31 to the pin mounting seat 33. When the tapered needle 31 moves along axis A, the pin 32 and the pin mounting seat 33 remain fixed, and the guide groove 313 of the tapered needle 31 cooperates with the pin 32 to constrain the movement of the tapered needle 31. When the inclined section 313b of the guide groove 313 of the tapered needle 31 engages with the pin 32, as the tapered needle 31 moves along axis A, the tapered needle 31 will simultaneously rotate along axis A, and the rotation direction of the tapered needle 31 when feeding toward the chuck 20 is opposite to the rotation direction of the tapered needle 31 when retracting. In other embodiments, guide grooves of different shapes can also be envisioned. For example, the straight section of the guide groove can be omitted, or a spiral guide groove can be provided. Furthermore, the guide groove does not need to penetrate the cylindrical section of the conical needle. For example, it is conceivable to provide a non-through guide groove on one side or opposite sides of the cylindrical section of the conical needle, as long as at least a portion of the pin is received in the guide groove, the pin and the guide groove can cooperate to constrain the movement of the conical needle. In other embodiments, pin mounting seats of different shapes can also be provided, and the pin and the pin mounting seat can be integrally formed.
[0037] like Figure 5 As shown, a keyway 314 extending along the axis A is also provided on the cylindrical section 312 of the conical needle 31. Figures 2 to 4 As shown, the transmission assembly 30 may further include a bushing 34 for mounting on the cylindrical section 312 of the tapered needle 31. See also Figure 4 A radially inwardly protruding key 341 is provided on the inner circumferential surface of the bushing 34. The key 341 is used to fit into the keyway 314 on the cylindrical section 312 of the tapered needle 31 so that the bushing 34 rotates together with the tapered needle 31. In other embodiments, the bushing 34 may be omitted.
[0038] like Figures 2 to 4 As shown, the transmission assembly 30 may further include a one-way bearing 35 and a chuck drive sleeve 36. For example... Figure 3 and Figure 4 As shown, the chuck drive sleeve 36 has end face teeth 361 on its end face facing the chuck end 24, and each jaw 22 of the chuck 20 has end face teeth 221 on its end face facing the chuck drive sleeve 36. The end face teeth 361 of the chuck drive sleeve 36 mesh with the end face teeth 221 of the jaws 22 of the chuck 20 to transmit torque from the chuck drive sleeve 36 to the chuck 20. In other embodiments, the chuck drive sleeve 36 may be omitted or integrally formed with the chuck 20. Figure 2As shown, a one-way bearing 35 is arranged between the bushing 34 and the chuck drive sleeve 36. Specifically, the inner ring of the one-way bearing 35 is arranged around the tapered pin 31 and the bushing 34, while the chuck drive sleeve 36 is arranged around the outer ring of the one-way bearing 35. The inner ring of the one-way bearing 35 can rotate together with the tapered pin 31 and the bushing 34, and the outer ring of the one-way bearing 35 can rotate together with the chuck drive sleeve 36. The one-way bearing 35 can only transmit torque in one direction from the inner ring to the outer ring. When the inner ring of the one-way bearing 35 rotates in one direction, the inner and outer rings are locked together, allowing torque to be transmitted from the inner ring to the outer ring, and the outer ring can rotate with the inner ring. When the inner ring of the one-way bearing 35 rotates in the opposite direction, the inner ring can rotate freely relative to the outer ring, thus preventing torque from being transmitted from the inner ring to the outer ring. Therefore, the one-way bearing 35 allows the chuck drive sleeve 36 to rotate only when the tapered needle 31 and bushing 34 rotate in one direction, thereby driving the chuck 20 to rotate. In this embodiment, the one-way bearing 35 is preferably installed to drive the chuck drive sleeve 36 and the chuck 20 to rotate only when the tapered needle 31 is fed toward and rotates toward the chuck 20. In other embodiments, the one-way bearing 35 can also be installed in the reverse direction, i.e., driving the chuck drive sleeve 36 and the chuck 20 to rotate when the tapered needle 31 retracts and rotates.
[0039] In this embodiment, the one-way bearing 35 is a one-way needle roller bearing. Figure 6 An exemplary perspective view of a one-way bearing 35 is shown. Figure 7 A central cross-sectional view of the one-way bearing 35 is shown. (As shown) Figure 6 and Figure 7 As shown, a plurality of needle rollers 353, springs 354, and wedge blocks 355 are evenly arranged between the inner ring 351 and the outer ring 352 of the one-way bearing 35. Each needle roller 353 and the spring 354 located on one side of the needle roller 353 are sandwiched between two adjacent wedge blocks 355, and the spring 354 biases the needle roller 353 toward the wedge block 355. In the illustrated embodiment, each spring 354 is arranged on the clockwise side of each needle roller 353. When the inner ring 351 of the one-way bearing 35 is relative to the outer ring 352 in the direction that compresses the spring 354 (in... Figure 7 When the inner ring 351 rotates in the clockwise direction (within the center), it can rotate freely relative to the outer ring 352, and the inner ring 351 will not transmit torque to the outer ring. When the inner ring 351 of the one-way bearing 35 rotates in the opposite direction (within the center), the inner ring 351 can rotate freely relative to the outer ring 352, and the inner ring 351 will not transmit torque to the outer ring. Figure 7 When the bearing rotates counterclockwise (in the middle direction), the spring 354 locks the needle roller 353 against the wedge block 355, thereby locking the inner ring 351, outer ring 352, and needle roller 353 of the one-way bearing 35 into one unit. At this time, the inner ring 351 can transmit torque to the outer ring 352. In other embodiments, any other suitable type of one-way bearing may be used.
[0040] like Figures 2 to 4As shown, a support sleeve 37 or other support components or connectors may also be provided between the chuck drive sleeve 36 and the mounting ring 21 of the chuck 20 as needed.
[0041] In this embodiment, the driver 10 periodically drives the tapered needle 31 axially via a cam mechanism. For example... Figures 1 to 4 As shown, the transmission assembly 30 may further include a cam 38, a roller 39 cooperating with the cam 38, a roller shaft 41, a roller shaft mounting base 42, a housing 43, and a spring 44. The cam 38 is connected to the output shaft 11 of the driver 10 through a mounting hole 381 thereon, thereby enabling it to rotate with the output shaft 11. Figure 3 As shown, the roller shaft mounting base 42 includes a plate-shaped body 421, with a pair of opposing lugs 422 on one side of the body 421, each lug 422 having a hole 423. The roller shaft 41 passes through the hole 423 and the roller 39 to connect the roller 39 between the two lugs 422. Figure 4 As shown, a cylindrical portion 424 is provided on the opposite side of the body 421 of the roller shaft mounting base 42. The cylindrical portion 424 is configured to receive the end of the cylindrical section 312 of the conical needle 31. A pair of opposing holes 425 are provided on the cylindrical wall of the cylindrical portion 424. Accordingly, see... Figures 2 to 5 An annular groove 315 is provided near the end of the cylindrical section 312 of the conical needle 31. The pin 45 can pass through the hole 425 on the cylindrical section 424 and extend into the annular groove 315, thereby connecting the conical needle 31 to the roller shaft mounting base 42 and allowing the conical needle 31 to rotate relative to the roller shaft mounting base 42.
[0042] See Figure 3 and Figure 4 The housing 43 is generally cylindrical and defines two guide grooves 431 extending along axis A. These two guide grooves 431 are used to receive and guide the two ends of the roller shaft 41, respectively. Figure 2 As shown, in the assembled state, the roller 39, roller shaft 41, roller shaft mounting seat 42, and a portion of the tapered pin 31 are received in the housing 43. The housing 43 is fixed against the pin mounting seat 33, and a spring 44 is arranged in the housing 43 between the roller shaft mounting seat 42 and the pin mounting seat 33. The spring 44 presses the roller shaft mounting seat 42 and the connected roller 39 against the cam 38.
[0043] like Figure 1 and Figure 2 As shown, in the initial position, the roller 39 is in contact with the concave point of the cam 38, the pin 32 is located at the front end of the inclined section 313b of the guide groove 313 of the tapered needle 31, and the jaws 22 of the chuck 20 are in a retracted state. At this time, the tapered end 24 of the chuck can be inserted into the pipe to be expanded.
[0044] As the driver 10 drives the cam 38 to rotate, the contact point between the cam 38 and the roller 39 gradually transitions from the concave point to the convex point of the cam. Under the constraint of the guide groove 431 of the housing 43 on the roller shaft 41, the cam 38 pushes the roller 39 and the roller shaft mounting seat 42 to move towards the chuck 20 along the axis A. Furthermore, the roller shaft mounting seat 42 overcomes the elastic force of the spring 44 and pushes the tapered needle 31 to move towards the chuck 20 along the axis A. Due to the constraint of the inclined section 313b of the guide groove 313 of the tapered needle 31 and the pin 32 passing through the guide groove 313, the tapered needle 31 rotates around the axis A and drives the bushing 34 to rotate when it begins to feed axially towards the chuck 20. The one-way bearing 35 transmits the torque of the bushing 34 to the chuck drive sleeve 36 and then to the chuck 20, thereby causing the chuck 20 to rotate by a predetermined angle. Subsequently, the conical needle 31 continues to advance forward. When the straight section 313a of the guide groove 313 of the conical needle 31 begins to engage with the pin 32, the conical needle 31 only feeds axially without rotating. The conical section 311 of the conical needle 31 pushes the jaws 22 of the chuck 20 to expand radially outward relative to the mounting ring 21, thereby expanding the pipe fitted on the end 24 of the chuck.
[0045] Subsequently, the driver 10 continues to drive the cam 38 to rotate, and the contact point between the cam 38 and the roller 39 rapidly changes from the most convex point of the cam to the most concave point of the cam. The spring 44 biases the roller shaft mounting seat 42 and the connected conical needle 31 back to their initial positions toward the cam 38. The conical needle 31 rotates in the opposite direction during retraction, but the one-way bearing 35 does not transmit this reverse rotation to the chuck 20. That is, in this embodiment, the chuck 20 rotates a predetermined angle only in the initial stage of the axial feed of the conical needle 31 (i.e., when the inclined section 313b of the guide groove 313 of the conical needle 31 engages with the pin 32); the chuck 20 does not rotate in the later stage of the axial feed of the conical needle 31 (i.e., when the straight section 313a of the guide groove 313 of the conical needle 31 engages with the pin 32) and during the axial retraction of the conical needle 31. Thus, the chuck 20 can rotate a predetermined angle first when the jaw 22 is basically in the retracted state, and then expand. Rotating the chuck 22 while it is essentially in a contracted state can advantageously prevent the friction of the pipe to be expanded from hindering the rotation of the chuck 22.
[0046] Then, repeat the above process until the chuck 20 rotates 360° to uniformly enlarge the inner diameter of the pipe.
[0047] This disclosure also includes further variations of the pipe expander 1 according to the aforementioned first embodiment.
[0048] Figures 8 to 11 A pipe expander 1' according to a second embodiment of the present disclosure is shown, wherein Figure 8A perspective view of the pipe expander 1' is shown. Figure 9 It shows along Figure 8 The longitudinal cross-sectional view of the pipe expander 1' taken from axis A' in the diagram. Figure 10 and Figure 11 An exploded view of the pipe expander 1' as viewed from different angles is shown.
[0049] The main difference between this embodiment and the first embodiment is that in the first embodiment, a one-way bearing 35 is used to realize the one-way torque transmission between the tapered needle and the chuck, while in this embodiment, a ratchet disc 35' is used to replace the one-way bearing 35 as the one-way torque transmission mechanism between the tapered needle and the chuck.
[0050] like Figures 9 to 11 As shown, the ratchet disc 35' is generally annular and is disposed between the pin mounting seat 33' and the chuck drive sleeve 36'. The ratchet disc 35' abuts against the chuck drive sleeve 36' under the pressure of the spring 46'. The ratchet disc 35' is arranged around the cylindrical section 312' of the conical needle 31' and is connected to the cylindrical section 312' of the conical needle 31', for example, via a keyway fit structure, so that it can rotate with the conical needle 31'. Similar to the aforementioned embodiments, as... Figure 10 and Figure 11 As shown, end face teeth 361' and 221' are respectively provided on the opposite end faces of the chuck drive sleeve 36' and the chuck 20'. The end face teeth 361' and 221' mesh with each other to transmit torque from the chuck drive sleeve 36' to the chuck 20'. Furthermore, as... Figure 10 As shown, the ratchet disc 35' has an end face ratchet 351' on the side facing the chuck drive sleeve 36'. Correspondingly, as... Figure 11As shown, the side of the chuck drive sleeve 36' facing the ratchet disc 35' is provided with end face ratchet 362'. When the ratchet disc 35' rotates relative to the chuck drive sleeve 36' in one direction (e.g., when the conical needle 31' is axially fed and rotates), the end face ratchet 351' of the ratchet disc 35' and the end face ratchet 362' of the chuck drive sleeve 36' mesh with each other, so that torque can be transmitted from the ratchet disc 35' to the chuck drive sleeve 36', thereby driving the chuck 20' to rotate; when the ratchet disc 35' rotates relative to the chuck drive sleeve 36' in the opposite direction (e.g., when the conical needle 31' is axially retracted and rotates), the end face ratchet 351' of the ratchet disc 35' and the end face ratchet 362' of the chuck drive sleeve 36' slip with each other, so that torque cannot be transmitted from the ratchet disc 35' to the chuck drive sleeve 36', and the chuck 20' does not rotate. In other embodiments, the chuck drive sleeve 36' can be omitted, allowing the ratchet disc 35' to directly engage with the end face ratchet provided on the chuck. Other aspects of this embodiment may be the same as or similar to the first embodiment, and will not be described in detail here. In other embodiments, other alternative unidirectional torque transmission mechanisms can also be used to achieve unidirectional torque transmission between the tapered needle and the chuck.
[0051] Figure 12 A top view of the pipe expander 1” according to the third embodiment of this disclosure is shown for clarity. Figure 12 Components similar to the housing 43 and pin mounting base 33 in the first embodiment are not shown. The main difference between this embodiment and the first embodiment is that an eccentric wheel 38” is used instead of the cam 38 in the first embodiment to periodically push the tapered needle axially. In this embodiment, a plate-like member 316” is provided at the end of the cylindrical section 312” of the tapered needle 31”, and a spring 44” is disposed between the plate-like member 316” and the pin mounting base (not shown). The driver 10” drives the eccentric wheel 38” to rotate. As the contact point between the eccentric wheel 38” and the plate 316” gradually transitions from the proximal periphery of the eccentric wheel 38” to the distal periphery of the eccentric wheel 38”, the eccentric wheel 38” pushes the tapered needle 31” axially forward through the plate 316”. As the eccentric wheel 38” rotates further, the contact point between the eccentric wheel 38” and the plate 316” gradually transitions from the distal periphery of the eccentric wheel 38” to the proximal periphery of the eccentric wheel 38”, and the spring 44” biases the plate 316” toward the eccentric wheel 38”, thereby causing the tapered needle 31” to retract. Other aspects of this embodiment may be the same as or similar to the foregoing embodiment, and will not be described again here.
[0052] Furthermore, while a spring is used as the retraction mechanism for the conical needle in the foregoing embodiments, this disclosure is not limited to this. Any other suitable type of retraction mechanism can be provided in other embodiments. For example, a T-slot can be provided around the periphery of the cam or eccentric wheel, and the cam or eccentric wheel and the conical needle can be directly connected by a pin whose end is engaged in the T-slot and can slide freely within the T-slot. A magnetic retraction mechanism can also be used, for example.
[0053] This disclosure provides a simple and compact pipe expander, which includes a conical needle with inclined or spiral guide grooves and a one-way torque transmission device. This achieves the expansion and rotational movement of the pipe expander's chuck through a simple mechanical structure. Preferably, the one-way torque transmission device is configured to transmit the rotation of the conical needle only during forward feeding to the chuck, allowing the chuck to rotate first when the jaws are essentially in a contracted state before expanding. This effectively avoids friction between the pipe and the chuck end, preventing it from hindering rotation and facilitating uniform expansion of the pipe.
[0054] Exemplary embodiments of the pipe expander according to this disclosure have been described in detail herein; however, it should be understood that this disclosure is not limited to the specific embodiments described and shown above. Various modifications and variations can be made to this disclosure by those skilled in the art without departing from its spirit and scope. All such modifications and variations fall within the scope of this disclosure. Furthermore, all components described herein can be replaced by other technically equivalent components.
Claims
1. A pipe expander, comprising: drive; A chuck, the chuck including a plurality of jaws movable between a retracted state and an expanded state, wherein in the retracted state the plurality of jaws are adjacent to each other and together define a tapered end of the chuck; and in the expanded state the plurality of jaws expand radially outward. A transmission assembly configured to transmit power from the actuator to the chuck to drive the plurality of jaws to expand and the chuck to rotate about the axis of the pipe expander. The transmission assembly is characterized in that it comprises: A conical needle, comprising a conical section and a cylindrical section, wherein the cylindrical section is provided with a guide groove, the guide groove including an inclined section extending obliquely relative to the axis, and the driver is configured to drive the conical needle to feed toward the chuck along the axis, such that the conical section pushes the plurality of jaws from the retracted state to the expanded state; A reset mechanism is configured to retract the conical needle away from the chuck along the axis, thereby causing the plurality of jaws to transition from the expanded state to the contracted state. A pin and a pin mounting base, the pin being disposed in the pin mounting base and at least a portion of the pin being received in the guide groove, the pin being capable of engaging with the inclined section of the guide groove, such that the tapered needle can rotate about the axis while moving along the axis; and A unidirectional torque transmission mechanism is configured to transmit the torque generated by the rotation of the conical needle in one direction to the chuck, but not to transmit the torque generated by the rotation of the conical needle in the opposite direction to the chuck. The unidirectional torque transmission mechanism is configured to transmit the torque generated by the rotation of the tapered needle as it feeds toward the chuck to the chuck, but not the torque generated by the reverse rotation of the tapered needle as it retracts away from the chuck to the chuck.
2. The pipe expander according to claim 1, characterized in that, The one-way torque transmission mechanism includes a one-way bearing, the inner ring of which is arranged around the cylindrical section of the tapered needle to rotate together with the tapered needle, and the outer ring of which is connected to the chuck. The one-way bearing is configured such that when the inner ring rotates in one direction, the inner ring and the outer ring are locked together to transmit torque to the outer ring; and when the inner ring rotates in the opposite direction, the inner ring rotates freely relative to the outer ring without transmitting torque to the outer ring.
3. The pipe expander according to claim 2, characterized in that, The transmission assembly includes a chuck drive sleeve arranged around the outer ring of the one-way bearing to rotate together with the outer ring. The chuck drive sleeve includes end face teeth that mesh with end face teeth on the chuck to transmit torque to the chuck.
4. The pipe expander according to claim 1, characterized in that, The unidirectional torque transmission mechanism includes a ratchet disc arranged around the cylindrical section of the conical needle to rotate together with the conical needle. The ratchet disc is connected to the chuck via end face ratchet teeth. When the ratchet disc rotates in one direction, it transmits torque to the chuck via the end face ratchet teeth. When the ratchet disc rotates in the opposite direction, the end face ratchet teeth slip, preventing torque from being transmitted to the chuck.
5. The pipe expander according to claim 4, characterized in that, The transmission assembly includes a chuck drive sleeve. One side of the chuck drive sleeve is provided with end face ratchet teeth for engaging with the end face ratchet teeth of the ratchet disc. The opposite side of the chuck drive sleeve includes end face teeth. The end face teeth of the chuck drive sleeve mesh with the end face teeth on the chuck to transmit torque to the chuck.
6. The pipe expander according to claim 1, characterized in that, The transmission assembly includes a cam or eccentric wheel connected to the output shaft of the driver. When the cam or eccentric wheel rotates, it periodically pushes the tapered needle along the axis toward the chuck.
7. The pipe expander according to claim 6, characterized in that, The reset mechanism includes a spring configured to bias the tapered needle toward the cam or eccentric wheel.
8. The pipe expander according to claim 1, characterized in that, The guide groove extends through the cylindrical section of the conical needle.
9. The pipe expander according to claim 8, characterized in that, The pin mounting base is constructed as a sleeve surrounding the cylindrical section of the conical pin. The sleeve has a pair of pin holes aligned radially on its wall. The pin passes through the pair of pin holes and the guide groove to be fixed.
10. The pipe expander according to claim 1, characterized in that, The guide groove also includes a straight section extending along the axis, the straight section being connected to the inclined section, and the inclined section being disposed on one side of the conical section near the conical needle.
11. The pipe expander according to claim 1, characterized in that, The guide groove is spiral-shaped relative to the axis.