Pipe expander

Abstract

The present disclosure relates to a pipe expander comprising a housing, a chuck, and a transmission assembly. The transmission assembly comprises a conical needle, a reset mechanism, and an intermittent torque transmission mechanism. A driver drives the conical needle to feed along an axis of the pipe expander towards the chuck, such that the conical needle pushes jaws of the chuck to transition from a retracted state to an expanded state. The reset mechanism is configured to retract the conical needle along the axis of the pipe expander away from the chuck, such that the jaws of the chuck transition from the expanded state to the retracted state. The intermittent torque transmission mechanism is coupled to an output shaft of the driver and is configured to intermittently transmit a torque generated by the rotation of the output shaft of the driver to the chuck during a rotation of one revolution of the output shaft, thereby driving the chuck to rotate intermittently.

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 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., 30°–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 a housing, a chuck, and a drive assembly. The chuck includes a plurality of jaws movable between a contracted state and an expanded state. In the contracted state, the jaws are abutted against each other and collectively define a tapered end of the chuck; in the expanded state, the jaws expand radially outward. The drive assembly is configured to be coupled to an output shaft of a driver and to transmit power from the driver to the chuck to drive the jaws to expand and the chuck to rotate about an axis of the pipe expander. The drive assembly includes a tapered pin, a reset mechanism, and an intermittent torque transmission mechanism. The driver is configured to drive the tapered pin to feed toward the chuck along the axis of the pipe expander, such that the tapered pin pushes the jaws from the contracted state to the expanded state. The reset mechanism is configured to retract the tapered pin away from the chuck along the axis of the pipe expander, such that the jaws transition from the expanded state to the contracted state. The intermittent torque transmission mechanism is connected to the output shaft of the driver and is configured such that during one revolution of the output shaft of the driver, the intermittent torque transmission mechanism intermittently transmits the torque generated by the rotation of the output shaft to the chuck, thereby driving the chuck to rotate intermittently.

[0007] In some embodiments, the intermittent torque transmission mechanism includes a partial bevel gear disk and a bevel gear sleeve. The partial bevel gear disk is coupled to the output shaft and can rotate with the output shaft, and includes a partial bevel gear portion at a predetermined angle. The bevel gear sleeve is arranged along the axis of the pipe expander, and one end of the bevel gear sleeve is provided with a bevel gear portion extending around the axis of the pipe expander. The bevel gear portion of the bevel gear sleeve can mesh with the partial bevel gear portion of the partial bevel gear disk. When the partial bevel gear disk rotates to the point where the partial bevel gear portion meshes with the bevel gear portion of the bevel gear sleeve, the intermittent torque transmission mechanism transmits the torque of the output shaft to the chuck to drive the chuck to rotate.

[0008] In some embodiments, the intermittent torque transmission mechanism includes a dial and a Geneva wheel. The dial has an arcuate side surface and includes a pin projecting along the axial direction of the dial at its edge. The dial is coupled to an output shaft and is rotatable with the output shaft. The Geneva wheel includes a plurality of blades evenly distributed circumferentially. The side surface of each blade is configured to match the arcuate side surface of the dial. Between every two adjacent blades is a groove extending radially from the center of the Geneva wheel to its edge. These grooves receive and engage the pin of the dial. When the dial rotates such that the pin is received in one of the grooves of the Geneva wheel, the dial drives the Geneva wheel to rotate, and the intermittent torque transmission mechanism transmits the torque of the output shaft to the chuck to drive the chuck to rotate. When the pin of the dial is not engaged with the groove of the Geneva wheel, the rotation of the dial does not drive the Geneva wheel to rotate.

[0009] In some embodiments, the Geneva wheel includes a bevel gear portion extending around the axis of the Geneva wheel. The intermittent torque transmission mechanism also includes a bevel gear sleeve arranged along the axis of the pipe expander, one end of which is provided with a bevel gear portion extending around the axis of the pipe expander, the bevel gear portion of the bevel gear sleeve being capable of meshing with the bevel gear portion of the Geneva wheel to transmit torque to the chuck.

[0010] In some embodiments, the bevel gear sleeve is arranged to be fixed relative to the housing in the axial direction of the pipe expander.

[0011] In some embodiments, the transmission assembly further includes a push rod connected to or integrally formed with a tapered needle, and a bevel gear sleeve arranged around the push rod.

[0012] In some embodiments, the transmission assembly also includes an eccentric wheel coupled to the output shaft of the driver, which periodically pushes the push rod and the tapered needle toward the chuck along the axis of the pipe expander when the output shaft drives the eccentric wheel to rotate.

[0013] In some embodiments, the transmission assembly also includes a cam coupled to the output shaft of the driver, which periodically pushes the push rod and the tapered needle along the axis of the pipe expander toward the chuck when the output shaft drives the cam to rotate.

[0014] In some implementations, the end of the push rod away from the tapered needle is connected to a roller that can roll along the side surface of the cam.

[0015] In some embodiments, the reset mechanism includes a reset spring configured to bias the push rod away from the chuck along the axis of the pipe expander.

[0016] In some embodiments, the end of the push rod away from the conical needle includes a radially outwardly projecting annular protrusion, one end of the return spring abuts against the annular protrusion, and the other end of the return spring abuts against the bevel gear sleeve.

[0017] In some embodiments, the transmission assembly further includes a clutch ring and a rotating ring arranged around a tapered needle along the axis of the pipe expander. The clutch ring is coupled to a bevel gear sleeve, allowing torque to be transmitted between the clutch ring and the bevel gear sleeve. The rotating ring is coupled to a chuck, allowing torque to be transmitted between the rotating ring and the chuck. The clutch ring is configured to move along the axis of the pipe expander, thereby selectively engaging or disengaging with the rotating ring. When the clutch ring is engaged with the rotating ring, torque can be transmitted between the clutch ring and the rotating ring; when the clutch ring is disengaged from the rotating ring, torque cannot be transmitted between the clutch ring and the rotating ring.

[0018] In some embodiments, the clutch ring has end face teeth on its end facing the rotating ring, and the rotating ring also has end face teeth on its end facing the clutch ring. The end face teeth of the clutch ring and the rotating ring can mesh with each other to transmit torque between the clutch ring and the rotating ring. When the clutch ring rotates and the chuck and rotating ring are locked and cannot rotate, the end face teeth of the clutch ring and the rotating ring interact, causing the clutch ring to move away from the rotating ring and disengage from it.

[0019] In some embodiments, a spring is arranged between the clutch ring and the rotating ring, the spring being configured to bias the clutch ring toward the rotating ring along the axis of the pipe expander.

[0020] In some embodiments, the clutch ring has a plurality of protrusions extending along the axis of the pipe expander at its opposite end away from the rotating ring, and the bevel gear sleeve has a plurality of grooves at its opposite end to the end where the bevel gear portion is provided, and the plurality of protrusions of the clutch ring are received in the plurality of grooves of the bevel gear sleeve.

[0021] In some implementations, the opposite end of the rotating ring from the clutch ring is connected to the chuck via end face teeth.

[0022] In some embodiments, the intermittent torque transmission mechanism is configured to transmit torque to the chuck when the tapered pin is fed toward the chuck, and not to transmit torque to the chuck when the tapered pin is retracted away from the chuck.

[0023] In some implementations, the intermittent torque transmission mechanism is configured to drive the chuck to rotate an angle about the axis of the pipe expander before the tapered needle pushes multiple jaws from a contracted state to an expanded state.

[0024] In some implementations, the intermittent torque transmission mechanism is configured such that, during one revolution of the output shaft of the driver, the intermittent torque transmission mechanism transmits only the torque generated by the rotation of the output shaft at a predetermined angle to the chuck.

[0025] In some implementations, the intermittent torque transmission mechanism is configured to drive the chuck to rotate intermittently two or more times during one revolution of the output shaft of the driver.

[0026] On the one hand, the transmission assembly of the pipe expander according to this disclosure converts the rotational motion of the driver's output shaft into the reciprocating motion of a conical needle along the axis of the pipe expander. On the other hand, the transmission assembly of the pipe expander according to this disclosure also intermittently transmits the torque generated by the driver's output shaft to the chuck to drive the chuck to rotate. Based on these two aspects, this disclosure achieves the expansion and rotational motion of the chuck of 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

[0027] 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:

[0028] Figure 1 An exploded perspective view of a pipe expander according to a first embodiment of the present disclosure is shown;

[0029] Figure 2 It shows Figure 1 The diagram shows the assembled state of the pipe expander. For clarity, part of the pipe expander housing and chuck have been removed.

[0030] Figure 3 It shows Figure 1 A top view of the pipe expander with the chuck in the retracted position; for clarity, the upper housing of the pipe expander has been removed.

[0031] Figure 4 It shows along Figure 3 A longitudinal cross-sectional view taken from axis A of the pipe expander;

[0032] Figure 5 It shows Figure 1 A top view of the pipe expander with the chuck in the expanded position. For clarity, the upper housing of the pipe expander has been removed.

[0033] Figure 6 It shows along Figure 5 A longitudinal cross-sectional view taken from axis A of the pipe expander;

[0034] Figure 7 It shows Figure 1 A three-dimensional view of the bevel gear sleeve of a pipe expander;

[0035] Figure 8 It shows Figure 1 A three-dimensional view of a portion of the bevel gear disk of a pipe expander;

[0036] Figure 9 It shows Figure 1 A schematic diagram of the disengaged state of the clutch ring and the rotating ring of the pipe expander;

[0037] Figure 10 A top view of the pipe expander according to the second embodiment of the present disclosure is shown with the chuck in a retracted state. For clarity, the upper housing of the pipe expander has been removed.

[0038] Figure 11 It shows along Figure 10 A longitudinal cross-sectional view taken from the axis A' of the pipe expander;

[0039] Figure 12 It shows Figure 10 A top view of the pipe expander with the chuck in the expanded position. For clarity, the upper housing of the pipe expander has been removed.

[0040] Figure 13 It shows along Figure 12 A longitudinal cross-sectional view taken from the axis A' of the pipe expander;

[0041] Figure 14 It shows Figure 10 A top-view perspective view of the dial of a pipe expander;

[0042] Figure 15 It shows Figure 10 A bottom-view perspective of the grooved impeller of a pipe expander;

[0043] Figure 16 A perspective view of a pipe expander according to a third embodiment of the present disclosure is shown, with the upper housing of the pipe expander removed for clarity;

[0044] Figure 17 It shows Figure 16A top view of the pipe expander with the chuck in a partially expanded state; for clarity, the upper housing of the pipe expander has been removed.

[0045] Figure 18 It shows along Figure 17 The longitudinal cross-section of the pipe expander taken from axis A”. Detailed Implementation

[0046] 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.

[0047] 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.

[0048] First, combine Figures 1 to 9 The structure and working principle of the pipe expander 1 according to the first embodiment of this disclosure are explained.

[0049] Figure 1 An exploded perspective view of a pipe expander 1 according to a first embodiment of the present disclosure is shown. Figure 2 A three-dimensional view of the assembled state of the pipe expander 1 is shown. Figure 3 A top view of the pipe expander 1 with the chuck in the retracted state is shown. Figure 4 It shows along Figure 3 The longitudinal cross-section of the pipe expander 1 taken along axis A. Figure 5 A top view of the pipe expander 1 with the chuck in the expanded state is shown. Figure 6 It shows along Figure 5 The longitudinal cross-sectional view taken along axis A of the pipe expander 1. For clarity, Figure 2 Part of the housing and chuck of the central pipe expander 1 were removed. Figure 3 and Figure 5 The upper housing of the middle pipe expander 1 was removed.

[0050] like Figures 1 to 6As shown, the pipe expander 1 generally includes a housing 10, a chuck 20, and a transmission assembly 30. In this embodiment, the housing 10 includes an upper housing 11 and a lower housing 12. 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 plurality of jaws. The housing 10 may also include a support sleeve 13 disposed between the upper housing 11 and the lower housing 12 and supporting the mounting ring 21. Figures 1 to 4 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 4 As shown, in the retracted state, each of the claws 22 also collectively defines a conical hollow internal chamber 25. Each claw 22 can move radially outward relative to the mounting ring 21. Figure 5 and Figure 6 The expansion state is shown. In the expansion state, the individual jaws 22 are separated 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 rotatable about the axis A of the pipe expander 1. The transmission assembly 30 is configured to transmit the power of the actuator to the chuck 20 to drive the expansion of the jaws 22 and the rotation of the chuck 20.

[0051] like Figures 1 to 6 As shown, the transmission assembly 30 includes a tapered needle 31. The tapered needle 31 may include a conical section 311 and a cylindrical section 312. Figure 4 As shown, when the chuck 22 is in the retracted state, the conical section 311 of the conical needle 31 is housed within the hollow internal cavity 25 defined by the chuck 22. The conical needle 31 is movable along the axis A of the pipe expander 1. See also Figures 3 to 6 When the conical needle 31 feeds toward the chuck end 24, the conical section 311 of the conical needle 31 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.

[0052] In this embodiment, an eccentric wheel mechanism connected to the output shaft (not shown) of the driver periodically pushes the conical needle 31 along axis A to feed and drive the chuck 22 to expand. The driver can be, for example, an electric motor; alternatively, the driver may include a speed reducer. See also Figures 1 to 6The transmission assembly 30 includes an eccentric wheel 32, which comprises an integrally formed circular eccentric disk 321 and a shaft 322. The center of the eccentric disk 321 does not coincide with the rotation center of the shaft 322. The two ends of the shaft 322 are rotatably supported in the upper housing 11 and lower housing 12 by upper bearing 331 and lower bearing 332, respectively, and the shaft 322 is configured to connect to the output shaft of the driver. The cylindrical section 312 of the tapered needle 31 is hollow and has a pair of radially aligned pin holes 313. The transmission assembly 30 also includes a push rod 34, the front end 341 of which has a through pin hole 342. Figure 4 As shown, in the assembled state, the front end 341 of the push rod 34 is received in the hollow cylindrical section 312 of the conical needle 31. A pin 35 passes through a pin hole 313 on the cylindrical section 312 of the conical needle 31 and a pin hole 342 on the push rod 34 to connect the push rod 34 to the conical needle 31. The rear end 343 of the push rod 34 includes a radially outwardly projecting annular protrusion 344. The rear end 343 of the push rod 34 is capable of engaging with the side surface of the eccentric wheel 321. Figure 3 and Figure 4 In the contracted state shown, the concave point of the eccentric disk 321 engages with the rear end 343 of the push rod 34. As the eccentric disk 321 rotates from this state until its convex point engages with the rear end 343 of the push rod 34, the eccentric disk 321 pushes the push rod 34 and the conical needle 31 along axis A toward the chuck end 24, causing the chuck 22 to expand radially outward. Figure 5 and Figure 6 The expanded state is shown. In other embodiments, the push rod 34 and the conical needle 31 may also be formed as a single component.

[0053] like Figures 1 to 6 As shown, the transmission assembly 30 also includes a return spring 36. The return spring 36 is configured to bias the push rod 34 away from the chuck 20 along axis A, allowing the push rod 34 and the conical needle 31 connected to the push rod 34 to retract. In this embodiment, one end of the return spring 36 abuts against the annular protrusion 344 of the rear end 343 of the push rod 34, and the other end abuts against a structure fixed in the axial direction relative to the housing 10, to bias the push rod 34 and the conical needle 31 toward the eccentric wheel 32. In this embodiment, the transmission assembly 30 also includes a bevel gear sleeve 37. The bevel gear sleeve 37 is arranged around the push rod 34 along axis A of the pipe expander 1. Figure 1 and Figure 4As shown, an annular groove 371 is provided on the outer surface of the bevel gear sleeve 37. This annular groove 371 cooperates with the limiting block 111 provided on the housing 10, allowing the bevel gear sleeve 37 to rotate around axis A within the housing, but preventing it from shifting relative to the housing 10 along axis A. The two ends of the return spring 36 abut against the annular protrusion 344 of the rear end 343 of the push rod 34 and a part of the bevel gear sleeve 37, respectively, thereby forcing the rear end 343 of the push rod 34 to abut against the side surface of the eccentric wheel 321. In other embodiments, the return spring 36 may be configured to abut against a structure fixed in the axial direction other than the bevel gear sleeve 37, or other reset mechanisms (such as magnetic reset mechanisms) may be provided to retract the conical needle instead of the return spring 36.

[0054] In this embodiment, the rotation of the chuck 20 is driven intermittently by a bevel gear mechanism. For example... Figures 1 to 6 As shown, a portion of the bevel gear disk 38 for engaging with the bevel gear sleeve 37 is mounted on the shaft 322 of the eccentric wheel 32. Figure 7 A perspective view of the bevel gear sleeve 37 is shown. Figure 8 A perspective view of part of the bevel gear disk 38 is shown. Combined with... Figure 4 , Figure 6 and Figure 7 As shown, one end of the bevel gear sleeve 37 is provided with a bevel gear portion 372 extending around axis A, and the opposite end of the bevel gear sleeve 37 is provided with a plurality of grooves 373 arranged around the sleeve wall. Combined Figure 4 , Figure 6 and Figure 8 As shown, a partial bevel gear disk 38 is mounted to the shaft 322 of the eccentric wheel 32 through a hole 381 and can rotate with the shaft 322. A partial bevel gear portion 382 extending at a predetermined angle around the rotation axis B of the shaft 322 is provided on the lower surface of the partial bevel gear disk 38. The angle range, number of teeth, module, and other parameters of the partial bevel gear portion 382 extending around the rotation axis B can be set according to actual needs. In this embodiment, the angle range of the partial bevel gear portion 382 is approximately 30°. As the shaft 322 of the eccentric wheel 32 rotates, the partial bevel gear disk 38 can only drive the bevel gear sleeve 37 to rotate around the axis A when the partial bevel gear portion 382 of the partial bevel gear disk 38 meshes with the bevel gear portion 372 of the bevel gear sleeve 37. In this embodiment, the partial bevel gear disk 38 can be mounted such that one side edge of the partial bevel gear portion 382 in the direction of the axis B is approximately aligned with the most concave point of the eccentric wheel disk 321.

[0055] See Figure 1 , Figure 4 and Figure 6The transmission assembly also includes a clutch ring 39 and a rotating ring 41 for transmitting the rotational torque of the bevel gear sleeve 37 to the chuck 20. The clutch ring 39 and rotating ring 41 are arranged around the cylindrical section 312 of the conical needle 31 along the axis A of the pipe expander 1. A spring 42 may be arranged between the clutch ring 39 and the rotating ring 41, the spring 42 being configured to bias the clutch ring 39 toward the rotating ring 41 along the axis A. The end of the clutch ring 39 facing the bevel gear sleeve 37 has a plurality of protrusions 391 extending along the axis A. In the assembled state, the protrusions 391 of the clutch ring 39 are received in corresponding grooves 373 on the bevel gear sleeve 37, allowing the clutch ring 39 to rotate with the bevel gear sleeve 37. The clutch ring 39 has end face teeth 392 on its opposite end facing the rotating ring 41, and correspondingly, the rotating ring 41 has end face teeth 411 on its end facing the clutch ring 39. The end face teeth 392 of the clutch ring 39 and the end face teeth 411 of the rotating ring 41 can mesh with each other to transmit torque from the clutch ring 39 to the rotating ring 41 and drive the rotating ring 41 to rotate. The clutch ring 39 is configured to move slightly along axis A so that the end face teeth 392 of the clutch ring 39 and the end face teeth 411 of the rotating ring 41 can mesh or disengage, while the clutch ring 39 and the bevel gear sleeve 37 remain engaged at all times. Figure 1 As shown, the end of the swivel ring 41 facing the chuck 20 is provided with end face teeth 412. In the assembled state, the end face teeth 412 of the swivel ring 41 are always engaged with the end face teeth (not shown) on the jaws 22 of the chuck 20, so that the swivel ring 41 and the jaws 22 can rotate together.

[0056] During pipe expansion, if the clamp 22 becomes stuck in the pipe and cannot rotate, the clutch ring 39 can promptly disengage from the rotating ring 41, thus preventing continued forced rotation of the clamp 22 and potential damage to the clamp 22 or the pipe. Figure 4 and Figure 6 In the normal contracted and expanded states shown, spring 42 keeps clutch ring 39 engaged with rotating ring 41. At this time, torque can be transmitted between clutch ring 39 and rotating ring 41. Figure 9 A schematic diagram showing the clutch ring 39 and the rotating ring 41 in a disengaged state is illustrated. Figure 9As shown, when the frictional torque applied by the pipe to be expanded to the chuck 22 exceeds the maximum driving torque that the transmission assembly 30 can apply to the chuck 22, the chuck 22 is jammed by the pipe and cannot rotate, and the rotating ring 41 stops rotating accordingly. At this time, the end face teeth 392 of the continuously rotating clutch ring 39 and the end face teeth 411 of the fixed rotating ring 41 interact, causing the clutch ring 39 to overcome the tension of the spring 42 and retract along axis A away from the rotating ring 41, thereby disengaging the clutch ring 39 from the rotating ring 41. When the jammed state of the chuck 22 is released, the clutch ring 39 can re-engage with the rotating ring 41 under the tension of the spring 42. In other embodiments, other suitable clutch structures besides the end face teeth and spring can also be used to achieve selective engagement and disengagement of the clutch ring and the rotating ring.

[0057] Return to reference Figure 3 and Figure 4 In the initial position, the concave point of the eccentric wheel 321 engages with the rear end 343 of the push rod 34, the pawl 22 is in a retracted state, and the bevel gear portion 382 of the partial bevel gear disk 38 is arranged to engage with the bevel gear portion 372 of the bevel gear sleeve 37. As the eccentric wheel 32 and the partial bevel gear disk 38 rotate, the partial bevel gear portion 382 of the partial bevel gear disk 38 begins to engage with the bevel gear portion 372 of the bevel gear sleeve 37. The bevel gear sleeve 37 rotates and drives the chuck 20 to rotate by a predetermined angle through the clutch ring 39 and the rotating ring 41. At the same time, the engagement point between the eccentric wheel 321 and the push rod 34 gradually transitions from the concave point of the eccentric wheel 321 to the convex point of the eccentric wheel 321. The eccentric wheel 321 gradually pushes the push rod 34 and the conical needle 31 to overcome the elastic force of the return spring 36 and feed towards the chuck 20, and the pawl 22 begins to expand. Subsequently, the eccentric wheel 32 and part of the bevel gear disk 38 continue to rotate, and part of the bevel gear portion 382 of the bevel gear disk 38 disengages from the bevel gear portion 372 of the bevel gear sleeve 37. The bevel gear sleeve 37, clutch ring 39, rotating ring 41, and chuck 20 then stop rotating accordingly. See also... Figure 5 and Figure 6 The eccentric wheel 32 and part of the bevel gear disk 38 continue to rotate until the most convex point of the eccentric wheel disk 321 engages with the push rod 34. The push rod 34 and the conical needle 31 are fully ejected, causing the chuck 22 to expand radially outward to its expanded state. Next, the eccentric wheel 32 and part of the bevel gear disk 38 continue to rotate, causing the engagement point between the eccentric wheel disk 321 and the push rod 34 to transition from the most convex point of the eccentric wheel disk 321 to the most concave point of the eccentric wheel disk 321. Under the bias of the return spring 36, the push rod 34 and the conical needle 31 retract toward the eccentric wheel disk 321, and the chuck 22 gradually returns to its contracted state. During this reset process, the part of the bevel gear portion 382 of the part of the bevel gear disk 38 remains disengaged from the bevel gear portion 372 of the bevel gear sleeve 37, and the chuck 20 does not rotate.

[0058] Then, repeat the above process until the chuck 20 rotates 360° to uniformly enlarge the inner diameter of the pipe.

[0059] In the above embodiment, the cooperating bevel gear sleeve 37 and part of the bevel gear disk 38 constitute an intermittent torque transmission device that intermittently drives the chuck 20 to rotate. Preferably, in the above embodiment, the chuck 20 rotates when the conical needle 31 begins to feed along axis A, but does not rotate during the later stages of the axial feed of the conical needle 31 and when the conical needle 31 retracts. This allows the chuck 20 to rotate a predetermined angle first when the jaws 22 are essentially in a retracted state, and then expand. Rotating the jaws 22 when they are essentially in a retracted state advantageously avoids the friction of the pipe to be expanded hindering the rotation of the jaws 22.

[0060] This disclosure also includes further variations of the pipe expander 1 according to the aforementioned first embodiment.

[0061] Figures 10 to 15 A pipe expander 1' according to a second embodiment of the present disclosure is shown, wherein, Figure 10 A top view of the pipe expander 1' with the chuck in the retracted position is shown; Figure 11 It shows along Figure 10 A longitudinal cross-sectional view taken from the axis A' of the pipe expander 1'; Figure 12 A top view of the pipe expander 1' with the chuck in the expanded position is shown; Figure 13 It shows along Figure 12 A longitudinal cross-sectional view taken from the axis A' of the pipe expander 1'; Figure 14 A top perspective view of the dial 38' of the pipe expander 1' is shown; Figure 15 A bottom perspective view of the grooved wheel 43' of the pipe expander 1' is shown. For clarity, Figure 10 and Figure 12 The upper housing 11' of the middle pipe expander 1' was removed.

[0062] The main difference between the second embodiment and the first embodiment is that the pipe expander 1' replaces part of the bevel gear disk 38 of the pipe expander 1 with a combination of a dial 38' and a grooved wheel 43' to form an intermittent torque transmission device that intermittently drives the chuck 20' to rotate.

[0063] like Figure 11 , Figure 13 and Figure 14 As shown, the dial 38' is generally annular in shape. The dial 38' is mounted to the shaft 322' of the eccentric wheel 32' through a hole 381' and can rotate with the shaft 322'. Figure 14As shown, a pin 382' protruding along the axis B' of the dial 38' is provided at the edge of the dial 38', and the dial 38' includes an arc-shaped side surface 383'. Figure 10 , Figure 12 and Figure 15 As shown, the Geneva wheel 43' includes a plurality of blades evenly distributed in the circumferential direction. In this embodiment, the Geneva wheel 43' is clover-shaped and includes four blades 431a', 431b', 431c', and 431d' evenly distributed in the circumferential direction. The side surface of each blade is constructed to match the arcuate side surface 383' of the dial 38'. Between every two adjacent blades are grooves 432a', 432b', 432c', and 432d' extending radially from the center of the Geneva wheel 43' to the edge of the Geneva wheel 43', respectively. These grooves can receive and engage with the pin 382' of the dial 38'. When the pin 382' of the dial 38' is received in any of the grooves 432a', 432b', 432c', and 432d', the dial 38' can drive the Geneva wheel 43' to rotate together. The lower end of the grooved wheel 43' is provided with a bevel gear portion 433' that extends around the axis of the grooved wheel 43'. In the assembled state, the bevel gear portion 433' of the grooved wheel 43' meshes with the bevel gear portion 372' of the bevel gear sleeve 37'.

[0064] like Figure 10 and Figure 11 As shown, in the initial position, the concave point of the eccentric wheel 321' engages with the rear end 343' of the push rod 34', the pawl 22' is in a retracted state, the arcuate side surface of one blade 431a' of the Geneva wheel 43' engages with the arcuate side surface 383' of the dial 38', and the pin 382' of the dial 38' is about to enter a groove 432a' on the Geneva wheel 43'. As the eccentric wheel 32' and the dial 38' rotate, the pin 382' of the dial 38' begins to enter the groove 432a' on the Geneva wheel 43' and engage with the groove 432a', thereby driving the Geneva wheel 43' to rotate. Simultaneously, the engagement point between the eccentric wheel 321' and the push rod 34' gradually transitions from the most concave point of the eccentric wheel 321' to the most convex point. The eccentric wheel 321' gradually pushes the push rod 34' and the conical pin 31' to overcome the elastic force of the return spring 36' and feed towards the chuck 20', and the pawl 22' begins to expand. Subsequently, the eccentric wheel 32' continues to rotate. When the grooved wheel 43' rotates 90° so that the arcuate side surface of the adjacent blade 431b' engages with the arcuate side surface 383' of the dial 38', the pin 382' will leave the groove 432a' on the grooved wheel 43'. The rotating grooved wheel 43' drives the bevel gear sleeve 37' to rotate around axis A' through the meshing bevel gear parts 433' and 372', which in turn drives the chuck 20' to rotate by a predetermined angle through the clutch ring 39' and the rotating ring 41'. Next, as Figure 12 and Figure 13 As shown, since the pin 382' of the dial 38' leaves the groove 432a' on the Geneva wheel 43', the arcuate side surface of the blade 431b' of the Geneva wheel 43' engages with the arcuate side surface 383' of the dial 38'. Therefore, the rotation of the dial 38' no longer drives the Geneva wheel 43' to rotate together, and the chuck 20' correspondingly stops rotating. On the other hand, the eccentric wheel 32' continues to rotate until the most convex point of the eccentric wheel disk 321' engages with the push rod 34'. The push rod 34' and the conical pin 31' are completely pushed out, causing the pawl 22' to expand radially outward to the expanded state. Next, the eccentric wheel 32' and dial 38' continue to rotate, causing the engagement point between the eccentric wheel 321' and the push rod 34' to transition from the most convex point of the eccentric wheel 321' to the most concave point of the eccentric wheel 321'. Under the bias of the return spring 36', the push rod 34' and the conical needle 31' retract toward the eccentric wheel 321', and the pawl 22' gradually returns to its retracted state. During this reset process, the pin 382' on the dial 38' does not engage with any groove on the grooved wheel 43', therefore the chuck 20' does not rotate.

[0065] Subsequently, the next rotation of the dial 38' will cause the pin 382' to engage with the groove 432b' of the grooved wheel 43', and so on. The above process is repeated until the chuck 20' rotates 360° to uniformly enlarge the inner diameter of the pipe.

[0066] In similar embodiments, the grooved wheel 43' can be provided with different numbers of blades and grooves, and the angle between two adjacent grooves can be set according to actual needs.

[0067] Other aspects of the second embodiment may be the same as or similar to those of the first embodiment, and will not be described in detail here.

[0068] Figures 16 to 18 A pipe expander 1” according to a third embodiment of the present disclosure is shown, wherein, Figure 16 A perspective view of the pipe expander 1” is shown; Figure 17 A top view of the pipe expander 1” with the chuck in a partially expanded state is shown; Figure 18 It shows along Figure 17 The longitudinal cross-sectional view of the pipe expander 1” taken along axis A”. For clarity, Figure 16 and Figure 17 The upper housing 11” of the middle pipe expander 1” was removed.

[0069] The main difference between the third embodiment and the aforementioned second embodiment is that the pipe expander 1” uses a cam 32” connected to the output shaft of the driver instead of the eccentric wheel 321’ in the pipe expander 1” to periodically drive the axial feed motion of the tapered needle 31”.

[0070] like Figures 16 to 18 As shown, the rear end 343” of push rod 34” is connected to roller 45” via pin 44”, and roller 45” can rotate around pin 44”. Return spring 36” biases push rod 34” toward cam 32”, so that the side surface of roller 45” abuts against the side surface of cam 32”. As the driver drives cam 32” to rotate, roller 45” rolls along the side surface of cam 32”. As the engagement point between cam 32” and roller 45” gradually transitions from the concaveest point to the convexest point of cam 32”, cam 32” pushes push rod 34” and tapered pin 31” connected to push rod 34” to feed towards chuck 20” along axis A”, thereby pushing jaw 22” to expand. When cam 32” continues to rotate so that the engagement point between cam 32” and roller 45” gradually transitions from the convexest point to the concaveest point of cam 32”, return spring 36” forces push rod 34” and tapered pin 31” to retract towards cam 32” along axis A”, and jaw 22” returns to the retracted state.

[0071] Other aspects of the third embodiment may be the same as or similar to the first and second embodiments, and will not be described in detail here.

[0072] This disclosure provides a simple and compact pipe expander. On one hand, the pipe expander according to this disclosure converts the rotational motion of the driver's output shaft into the periodic axial reciprocating motion of a conical needle via a cam, eccentric wheel, or similar device, thereby achieving the expansion and contraction of the chuck. On the other hand, the pipe expander according to this disclosure intermittently transmits the continuous rotation of the driver's output shaft to the chuck via an intermittent torque transmission device. That is, during one revolution of the driver's output shaft, only the torque generated by a portion of the rotation angle can be transmitted to the chuck to drive its rotation. Based on these two aspects, the pipe expander according to this disclosure can simultaneously achieve the expansion and rotational motion of the chuck with a single driver and a simple and compact transmission assembly.

[0073] Preferably, the intermittent torque transmission device can be configured to transmit torque to the chuck only when the conical needle is feeding forward, so that the chuck rotates first when the jaws are basically in the retracted state and then expands. This effectively avoids the friction between the pipe and the chuck end hindering the chuck rotation and facilitates uniform expansion of the pipe. However, this disclosure is not limited to this. For example, the timing of the chuck rotation can be adjusted as needed by adjusting the relative angle between the cam or eccentric wheel and the intermittent torque transmission device.

[0074] The intermittent torque transmission devices described in the various embodiments of this disclosure include fully bevel gear sections and partially bevel gear sections that cooperate with each other, or dials and grooved wheels that cooperate with each other, but this disclosure is not limited thereto, and other intermittent torque transmission devices based on similar principles are also conceivable.

[0075] Furthermore, while the above-described embodiments of this disclosure describe driving the chuck to rotate only once during one revolution of the driver's output shaft, it should be understood that the intermittent torque transmission device according to this disclosure can also be configured to drive the chuck to rotate intermittently two or more times during one revolution of the driver's output shaft. For example, the partial bevel gear disk 38 in the first embodiment described above may be provided with two or more circumferentially spaced partial bevel gear portions 382, ​​or the dial 38' in the second embodiment described above may be provided with two or more circumferentially spaced pins 382'. Thus, the pipe expander can be configured to rotate the chuck by a small angle during the process of the conical needle pushing the chuck to expand the pipe, and to further rotate the chuck by a certain angle when the chuck is not expanding the pipe. In other words, the rotation angle of the chuck during the pipe expansion phase can be reduced, and the rotation angle of the chuck can be compensated during the non-pipe expansion phase to achieve the expected chuck rotation angle after each pipe expansion. This advantageously prevents the friction of the pipe from hindering the rotation of the chuck while ensuring that the chuck rotates to the expected angle, thereby reducing the power consumption of the driver and preventing or mitigating wear on the chuck and the pipe.

[0076] 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: case; 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 be coupled to the output shaft of a driver and to transmit power from the driver 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 tapered needle, the actuator being configured to feed the tapered needle toward the chuck along the axis of the pipe expander, such that the tapered needle pushes the plurality of jaws from the contracted state to the expanded state; A reset mechanism, configured to retract the conical needle along the axis of the pipe expander away from the chuck, thereby transitioning the plurality of jaws from the expanded state to the contracted state; and An intermittent torque transmission mechanism is connected to the output shaft of the driver and configured such that, during one revolution of the output shaft of the driver, the intermittent torque transmission mechanism intermittently transmits the torque generated by the rotation of the output shaft to the chuck, thereby driving the chuck to rotate intermittently. The intermittent torque transmission mechanism is configured to transmit torque to the chuck when the tapered needle is fed toward the chuck, and not to transmit torque to the chuck when the tapered needle is retracted away from the chuck.

2. The pipe expander according to claim 1, characterized in that, The intermittent torque transmission mechanism includes a portion of a bevel gear disk and a bevel gear sleeve. The partial bevel gear disk is connected to the output shaft and can rotate with the output shaft. The partial bevel gear disk includes a partial bevel gear portion at a predetermined angle. The bevel gear sleeve is arranged along the axis of the pipe expander, and one end of the bevel gear sleeve is provided with a bevel gear portion extending around the axis of the pipe expander. The bevel gear portion of the bevel gear sleeve can mesh with the bevel gear portion of the partial bevel gear disk. When the partial bevel gear disk rotates to the point where the partial bevel gear part meshes with the bevel gear part of the bevel gear sleeve, the intermittent torque transmission mechanism transmits the torque of the output shaft to the chuck to drive the chuck to rotate.

3. The pipe expander according to claim 1, characterized in that, The intermittent torque transmission mechanism includes a dial and a grooved wheel. The dial has an arc-shaped side surface and includes a pin at the edge of the dial that protrudes along the axial direction of the dial. The dial is connected to the output shaft and is capable of rotating with the output shaft. The grooved wheel includes a plurality of blades evenly distributed in the circumferential direction. The side surface of each blade is configured to be an arc shape that matches the arc-shaped side surface of the dial. A groove is defined between every two adjacent blades, extending radially from the center of the grooved wheel to the edge of the grooved wheel. The groove is capable of receiving and engaging the pin of the dial. When the dial rotates such that the pin is received in one of the slots of the Geneva wheel, the dial drives the Geneva wheel to rotate, and the intermittent torque transmission mechanism transmits the torque of the output shaft to the chuck to drive the chuck to rotate; when the pin of the dial is not engaged with the slot of the Geneva wheel, the rotation of the dial does not drive the Geneva wheel to rotate.

4. The pipe expander according to claim 3, characterized in that, The grooved wheel includes a bevel gear portion extending around the axis of the grooved wheel; The intermittent torque transmission mechanism further includes a bevel gear sleeve arranged along the axis of the pipe expander. One end of the bevel gear sleeve is provided with a bevel gear portion extending around the axis of the pipe expander. The bevel gear portion of the bevel gear sleeve can mesh with the bevel gear portion of the grooved wheel to transmit torque to the chuck.

5. The pipe expander according to claim 2 or 4, characterized in that, The bevel gear sleeve is arranged to be fixed relative to the housing in the axial direction of the pipe expander.

6. The pipe expander according to claim 5, characterized in that, The transmission assembly also includes a push rod, which is connected to or integrally formed with the conical needle, and the bevel gear sleeve is arranged around the push rod.

7. The pipe expander according to claim 6, characterized in that, The transmission assembly also includes an eccentric wheel connected to the output shaft of the driver. When the output shaft drives the eccentric wheel to rotate, the eccentric wheel periodically pushes the push rod and the conical needle to feed towards the chuck along the axis of the pipe expander.

8. The pipe expander according to claim 6, characterized in that, The transmission assembly also includes a cam connected to the output shaft of the driver, which periodically pushes the push rod and the tapered needle toward the chuck along the axis of the pipe expander when the output shaft drives the cam to rotate.

9. The pipe expander according to claim 8, characterized in that, The end of the push rod away from the conical needle is connected to a roller, which is capable of rolling along the side surface of the cam.

10. The pipe expander according to any one of claims 6 to 9, characterized in that, The reset mechanism includes a reset spring configured to bias the push rod away from the chuck along the axis of the pipe expander.

11. The pipe expander according to claim 10, characterized in that, The end of the push rod away from the conical needle includes a radially outwardly projecting annular protrusion, one end of the return spring abuts against the annular protrusion, and the other end of the return spring abuts against the bevel gear sleeve.

12. The pipe expander according to claim 5, characterized in that, The transmission assembly further includes a clutch ring and a rotating ring, which are arranged around the tapered needle along the axis of the pipe expander. The clutch ring is connected to the bevel gear sleeve, so that torque can be transmitted between the clutch ring and the bevel gear sleeve; The rotating ring is connected to the chuck, so that torque can be transmitted between the rotating ring and the chuck; The clutch ring is configured to move along the axis of the pipe expander, thereby selectively engaging or disengaging with the rotating ring. When the clutch ring is engaged with the rotating ring, torque can be transmitted between the clutch ring and the rotating ring; when the clutch ring is disengaged from the rotating ring, torque cannot be transmitted between the clutch ring and the rotating ring.

13. The pipe expander according to claim 12, characterized in that, The clutch ring has end face teeth on the end facing the rotating ring, and the rotating ring also has end face teeth on the end facing the clutch ring. The end face teeth of the clutch ring and the end face teeth of the rotating ring can mesh with each other to transmit torque between the clutch ring and the rotating ring. When the clutch ring rotates and the chuck and the rotating ring are jammed and cannot rotate, the end face teeth of the clutch ring and the end face teeth of the rotating ring interact with each other, causing the clutch ring to move away from the rotating ring and disengage from the rotating ring.

14. The pipe expander according to claim 13, characterized in that, A spring is arranged between the clutch ring and the rotating ring, the spring being configured to bias the clutch ring toward the rotating ring along the axis of the pipe expander.

15. The pipe expander according to claim 13, characterized in that, The clutch ring has a plurality of protrusions extending along the axis of the pipe expander at its opposite end away from the rotating ring, and the bevel gear sleeve has a plurality of grooves at its opposite end to the end where the bevel gear portion is located, and the plurality of protrusions of the clutch ring are received in the plurality of grooves of the bevel gear sleeve.

16. The pipe expander according to claim 13, characterized in that, The opposite end of the rotating ring, away from the clutch ring, is connected to the chuck via end face teeth.

17. The pipe expander according to any one of claims 1 to 4, characterized in that, The intermittent torque transmission mechanism is configured to drive the chuck to rotate an angle about the axis of the pipe expander before the tapered needle pushes the plurality of jaws from the contracted state to the expanded state.

18. The pipe expander according to any one of claims 1 to 4, characterized in that, The intermittent torque transmission mechanism is configured such that, during one revolution of the output shaft of the driver, the intermittent torque transmission mechanism transmits only the torque generated by the rotation of the output shaft at a predetermined angle to the chuck.

19. The pipe expander according to any one of claims 1 to 4, characterized in that, The intermittent torque transmission mechanism is configured to drive the chuck to rotate intermittently two or more times during one revolution of the output shaft of the drive.

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