Pipe receiving assembly for pipe grooving device

Abstract

A pipe grooving device includes an assembly adapted to receive a pipe end. The assembly includes a cup that stops around the tube end. The cup and tube end stops are mounted on a fixed pinion about which the carrier rotates. The carrier carries a toothed cam that engages and rotates synchronously with the pinion gear when the carrier rotates relative to the pinion gear. The cam engages a tube element received by the cup and forms a circumferential groove in the tube element. The cup and the tube end stop move axially along the pinion shaft independently of each other to actuate rotation of the carrier. The cup may accommodate tube diameter dimensional tolerances and reduce tube flaring and maintain tube roundness during the grooving process.

Description

[0001] Cross-reference to related applications This application is a continuation to U.S. Patent Application No. 16 / 998,385, filed August 20, 2020, which claims the benefit of U.S. Provisional Application No. 62 / 889,671, filed August 21, 2019, both of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a machine for cold-working tubular components using a cam. Background Technology

[0003] Cold working of tubular components (e.g., imprinting circumferential grooves in the tubular component to receive mechanical tubular connectors) is advantageously accomplished using a roller grooving machine having an inner roller that engages the inner surface of the tubular component and an outer roller opposite the inner roller that simultaneously engages the outer surface of the tubular component. As the tubular component typically rotates about its longitudinal axis by driving the inner roller, the outer roller is gradually pushed toward the inner roller. The roller has a surface profile that is imprinted onto the circumference of the tubular component as it rotates, thereby forming circumferential grooves.

[0004] This technology faces various challenges in cold-working tubular components to the required precision within the desired tolerances. The most pressing is the difficulty associated with producing a groove with the desired radius (measured from the center of the tubular component's bore to the bottom of the groove) within the expected tolerance range. Furthermore, imprinting circumferential grooves near the ends of tubular components often results in the end region of the component being enlarged in diameter, a phenomenon known as "flaring." Flaring and tubular component tolerances must be considered in the design of mechanical couplings and seals, complicating their design and manufacture. These considerations have led to complex prior art devices, which, for example, require actuators to force rollers to engage with the tubular component and require an operator to adjust the roller stroke to achieve the desired groove radius. Additionally, prior art roller grooving machines apply significant torque to the tubular component and have low productivity, typically requiring the component to rotate many times to obtain the finished circumferential groove. Clearly, there is a need for a device that, for example, uses cams to accurately cold-work tubular components, a device that is simple yet produces faster results and requires less operator intervention. Summary of the Invention

[0005] This invention relates to an apparatus for forming a circumferential groove in a tubular element. In an exemplary embodiment, the apparatus includes a pinion fixed to prevent rotation about a pinion axis arranged coaxially with the pinion. A bracket surrounds the pinion. The bracket is rotatable about the pinion axis and defines an opening coaxially with the pinion axis for receiving the tubular element. A cup is positioned near the pinion. The cup has sidewalls arranged coaxially with the pinion axis and defining an interior. The sidewalls have an inner surface. The inner surface has a first diameter located away from the pinion and a second diameter located near the pinion. The first diameter is larger than the second diameter. In a specific exemplary embodiment, the sidewall may have a tapered inner surface. In an exemplary embodiment, the tapered inner surface may define an included angle from 11° to 16°.

[0006] The interior faces the opening for receiving the tube element. The cup is movable toward and away from the pinion along the pinion axis. A tube end stop is positioned inside between the first and second diameters. The tube end stop is movable relative to the cup along the pinion axis toward and away from the pinion. A cup spring can act between the cup and the pinion to bias the cup away from the pinion. A stop spring can act on the tube end stop and bias the tube end stop away from the pinion. A plurality of gears are mounted on a bracket. Each gear is rotatable relative to the bracket about a corresponding gear axis. At least one of the gears directly engages the pinion. In an example embodiment, each gear directly engages the pinion. A plurality of cam bodies are mounted on a corresponding one of the gears. A plurality of first cam surfaces extend around a corresponding one of the cam bodies and are engageable with the tube element received within the opening. Each of the first cam surfaces includes a region with an increasing radius. Each of the first cam surfaces includes a first discontinuity of the first cam surface.

[0007] The exemplary device according to the invention may further include a pinion shaft. The pinion is fixedly mounted on the pinion shaft. A bracket is rotatably mounted on the pinion shaft. In an exemplary embodiment, the pinion shaft defines a hole coaxially aligned with the pinion axis. A cup shaft can be positioned within the hole. The cup shaft is movable within the hole along the pinion axis. A first end of the cup shaft extends from the hole. A cup is mounted near the first end of the cup shaft. In an exemplary embodiment, the cup includes a hub coaxially receiving the cup shaft. A rear wall extends outwardly from the hub. Side walls are attached to the rear wall.

[0008] In an example device according to the invention, the tube end stop includes a sleeve fixedly mounted on a cup shaft. A plate mounted on the sleeve extends outward from the sleeve. The plate defines a tube engagement surface facing the opening. For example, the plate may also include a reverse tapered surface positioned within the tube engagement surface.

[0009] In another example, the cup may include a hub that coaxially receives a sleeve. A rear wall extends outward from the hub. Side walls are attached to the rear wall. An example device may also include a base and a post mounted on the base. A pinion shaft may be fixedly mounted on the post. In an example embodiment, the cup spring includes a conical spring.

[0010] Additionally, as an example, each gear has the same pitch circle diameter. Also as an example, each of the first cam surfaces may include a region with a constant radius located near a corresponding one of the first discontinuities. In a specific example embodiment, each of the second cam surfaces includes a region with a constant radius located near a corresponding one of the second discontinuities. Furthermore, as an example, each of the second cam surfaces may have a constant radius.

[0011] In an example embodiment, at least one traction surface extends around a portion of a cam body. The at least one traction surface has a gap therein. This gap is axially aligned with a first discontinuity of a first cam surface surrounding a cam body. In a specific example embodiment, at least one traction surface includes a plurality of protrusions extending outward therefrom. As another example, at least one traction surface is positioned close to a first cam surface surrounding a cam body.

[0012] In one example embodiment, the pinion has a pitch circle diameter equal to the outer diameter of the tube element. In another example embodiment, at least one traction surface has a pitch circle diameter equal to the pitch circle diameter of one of the gears.

[0013] The exemplary device according to the invention may further include a plurality of traction surfaces. Each of the traction surfaces extends around a corresponding one of the cam bodies. Each of the traction surfaces has a gap therein. Each gap is axially aligned with a corresponding discontinuity of a first cam surface on each of the cam bodies. Each of the traction surfaces has a pitch circle diameter equal to the pitch circle diameter of the gear. In an exemplary embodiment, at least one traction surface extends around one of the cam bodies. The at least one traction surface has a gap therein. The gap is axially aligned with a first discontinuity of a first cam surface surrounding a cam body. The exemplary embodiment may have a first cam surface positioned between at least one traction surface and a second cam surface surrounding a cam body. Furthermore, as an example, the first and second cam surfaces may be positioned between at least one traction surface and a gear on which a cam body is mounted.

[0014] Example embodiments may further include multiple traction surfaces. Each of the traction surfaces extends around a corresponding one in the cam body. Each of the traction surfaces has a gap therein. Each gap is axially aligned with a corresponding one of the discontinuities in the first cam surface on each of the cam bodies. Each of the traction surfaces may have a pitch circle diameter equal to the pitch circle diameter of the gear. Furthermore, as an example, each of the first cam surfaces may be positioned between a corresponding one of the traction surfaces and a corresponding one of the second cam surfaces on each cam body. In another example embodiment, each of the first and second cam surfaces may be positioned between a corresponding one of the traction surfaces and a corresponding one of the gears on each cam body. In a specific example, each of the first cam surfaces is positioned close to a corresponding one of the traction surfaces on each cam body. Example embodiments of the device according to the invention may include at least three gears or at least five gears. Attached Figure Description

[0015] Figure 1 This is a longitudinal cross-sectional view of an example device for forming circumferential grooves in a tubular element; Figure 1A yes Figure 1 A magnified longitudinal cross-sectional view of a portion of the device shown. Figure 2 It involves forming circumferential grooves in the tubular component. Figure 1 Longitudinal cross-sectional view of the device shown; Figure 2A yes Figure 2 A magnified longitudinal cross-sectional view of a portion of the device shown. Figure 3 and Figure 3A yes Figure 1 Exploded isometric view of selected components of the device shown; Figure 4 Is Figure 1 An isometric view of the example cam used in the device shown. Figure 5 Is Figure 1 A magnified end view of the example cam used in the device shown. Figure 6 Is Figure 1 A magnified side view of the example cam used in the device shown. Figure 7 Is Figure 1 An isometric view of the gear reduction assembly used in the device shown. Figure 8 Is Figure 1 End view of selected components used in the illustrated device; Figure 9This is a longitudinal cross-sectional view of an example device for forming circumferential grooves in a tubular element; Figure 9A yes Figure 9 A magnified longitudinal cross-sectional view of a portion of the device shown. Figure 10 It involves forming circumferential grooves in the tubular component. Figure 9 Longitudinal cross-sectional view of the device shown; Figure 10A yes Figure 10 A magnified longitudinal cross-sectional view of a portion of the device shown. Figure 11 yes Figure 9 Exploded isometric view of selected components of the device shown; Figure 12 Is Figure 9 A magnified side view of the example cam used in the device shown. Figure 13 Is Figure 9 A magnified end view of the example cam used in the device shown. Figure 14 Is Figure 9 End view of selected components used in the illustrated device; Figure 15 This is an exploded isometric view of another exemplary embodiment of a device according to the invention for forming a circumferential groove in a tube element, having an example tube receiving assembly; Figure 16 yes Figure 15 A cross-sectional side view of the tube receiving assembly shown; Figures 17 to 19 yes Figure 15 The cross-sectional side view of the tube receiving assembly shown illustrates the operation of the assembly; and Figure 20 yes Figure 15 The front cross-sectional view of the device and tube receiving assembly shown. Detailed Implementation

[0016] Figure 1 and Figure 1A An example device 10 for forming circumferential grooves in a tube element is shown. Device 10 is advantageous for slotting tube elements with a nominal diameter of 1.25 inches or greater. Device 10 includes a pinion 12 mounted on an intermediate shaft 14 (see also...). Figure 3The pinion 12 and intermediate shaft 14 are fixedly mounted to prevent rotation about a pinion axis 16 arranged coaxially with the pinion and shaft. Rotational fixation of the pinion 12 is achieved by a key 18 between the pinion and intermediate shaft 14 and by engaging a portion 14a of the intermediate shaft 14 with a mounting bracket 20. The mounting bracket 20 is fixedly mounted on a base 22. The portion 14a of the intermediate shaft 14 has a polygonal cross-section that extends through an opening 24 in the mounting bracket 20. The shape of the opening 24 matches the shape of the portion 14a of the intermediate shaft 14, and thus prevents rotation of the shaft about the pinion axis 16, but allows axial movement of the shaft. In this example embodiment, the portion 14a has a square cross-section, and the opening 24 has a substantially matching square shape.

[0017] A bracket 26 surrounds the pinion 12. The bracket 26 is mounted on the flange 28 of the outer shaft 30. The outer shaft 30 is hollow, surrounds and is coaxial with the intermediate shaft 14. A bearing 32 positioned between the outer shaft 30 and the intermediate shaft 14 allows the outer shaft and thus the bracket 26 attached to the outer shaft to rotate relative to the intermediate shaft 14 about the pinion axis 16. The bracket 26 defines an opening 34 for receiving a tubular element, in which a groove will be formed. The opening 34 is arranged coaxially with the pinion axis 16. A stop plate 36 is mounted on the intermediate shaft 14 via the pinion 12. The stop plate 36 is axially movable along the pinion axis 16 together with the intermediate shaft 14 and the pinion 12. The stop plate 36, the intermediate shaft 14, and the pinion 12 are biased toward the opening 34 via the shaft flange 28 by a spring 38 acting between the pinion and the outer shaft 30. Because the intermediate shaft 14 is rotatably fixed relative to the base 22, a thrust bearing 40 can be used between the pinion 12 and the spring 40 to protect the spring 38, which rotates together with the flange 28 and the outer shaft 30, and to reduce friction between the pinion 12 and the flange 28. A stop plate 36 mates with the pinion 12 and the thrust bearing 40 to provide a form-locking stop, which positions the tube element to ensure proper positioning of the groove.

[0018] Multiple gears 42 are mounted on bracket 26. Figure 1 , Figure 2 and Figure 3 In the example embodiment shown, the bracket has four gears spaced 90° apart from each other. Each gear 42 is rotatable about a corresponding gear axis 44. In a practical embodiment, each gear is mounted on a gear shaft 46, which is fixed between a front plate 48 and a rear plate 50 constituting the bracket 26. Bearings 52 positioned between each gear 42 and its corresponding shaft 46 provide low-friction rotation of the gear within the bracket 26. Each gear 42 engages with a pinion 12.

[0019] like Figure 4As shown, a cam body 54 is mounted on each gear 42. A first cam surface 56 extends around each cam body 54. The first cam surface 56 can engage with a tubular element received through an opening 34. Figure 5 As shown, the first cam surface 56 includes a region 58 with an increasing radius and a discontinuity 60 on the cam surface. The discontinuity 60 is a location on the cam body 54 where the cam surface 56 does not contact the tube element. It is further advantageous to include a region 62 of a constant radius positioned near the discontinuity 60 as part of each first cam surface 56. At least one traction surface 64 may extend around one of the cam bodies 54. Figure 3 In the example shown, the corresponding traction surface 64 extends around each cam body 54. The traction surface 64 may also engage with a tubular element received within the bracket 26, but each traction surface has a gap 66 axially (i.e., in the direction along the gear axis 44) aligned with a discontinuity 60 in the first cam surface 56 on each cam body 54. Figure 4 As shown, the traction surface 64 may include a plurality of protrusions 68 extending outwardly therefrom. The protrusions provide gripping between the tubular element and the traction surface 64 during device operation and may be formed, for example, by embossing the traction surface. The traction surface has a pitch circle diameter 128. When the protrusions 68 are present on the traction surface 64, the pitch circle diameter 128 of the traction surface will be determined by the interaction between the protrusions 68 and the tubular element 79 (including the imprinting made by the protrusions 68 on the tubular element 79). If the protrusions 68 are not present, the pitch circle diameter 127 of the traction surface 64 will be equal to the pitch circle diameter of the traction surface. Figure 4 As further shown, the first cam surface 56 is positioned between the gear 42 and the traction surface 64, spaced apart from the traction surface, but closer to the traction surface than the gear.

[0020] like Figure 1 and Figure 4 As shown, the second cam surface 70 is also positioned on and extends around the cam body 54. The second cam surface 70 is a controlled flaring surface. Flaring is the radial expansion of the end of a tubular element, which tends to occur when a circumferential groove is formed near that end. The second cam surface 70 (the controlled flaring surface) is positioned near the gear 42 such that it contacts the tubular element near its end, where the flaring will be most pronounced due to the groove formation. Figure 4 and Figure 6As shown, apart from its discontinuity 70a, the second cam surface 70 has a constant radius 72, which is designed to engage with the tube element to control flaring and, for example, to hold its end at the original nominal diameter of the tube element during and after groove formation. The discontinuity 70a is aligned with the discontinuity 60 in the first cam surface 56 and is the position on the cam body 54 of the tube element where the cam surface 70 does not contact the tube element. In an alternative embodiment, the second cam surface 70 may have an area with an increased radius and a finishing area with a constant radius, or the second cam surface 70 may have an increased radius over its entire arc length.

[0021] like Figure 1 , Figure 3 and Figure 3A As shown, the device 10 also includes an expansion mold 74 positioned adjacent to the pinion 12. In this example, the mold 74 includes four sections 76 radially slidably mounted on the pinion 12 and coupled to an actuator. In this example, the actuator includes a pull rod 78 extending through a hollow bore 80 of the intermediate shaft 14. The pull rod 78 has a tapered, faceted end 82 that engages a mating faceted surface 84 on each mold section 76. The pull rod 78 is axially movable relative to the intermediate shaft 14 within the bore 80, and the mold sections 76 are radially movable relative to the pinion 12 toward and away from the pinion axis 16. The radial movement of the mold sections 76 is achieved by the axial movement of the pull rod 78. Figure 1 and Figure 1A The diagram illustrates the pull rod 78 in the retracted position and the mold section 76, and... Figure 2 and Figure 2A The diagram illustrates the tie rod and mold section in the expanded position. When the tie rod 78 extends toward the opening 34 of the bracket 26 ( Figure 1 , Figure 1A The mold section 76 is positioned on the smaller portion of the tapered end 82 of the tie rod 78, and the mold section is in its retracted position. The mold 74 also includes a circular spring 86 (see...). Figure 3 a) It surrounds the mold section 76 and biases it to the retracted position. When the pull rod 78 is pulled away from the opening 34 of the bracket 26 ( Figure 2 , Figure 2A The mold section 76, axially fixed to the pinion 12, is radially pushed outward by the interaction between the faceted surface 84 on each section 76 and the tapered faceted end 82 of the pull rod 78. As the pull rod 78 returns toward the opening 34 of the bracket 26, the mold section 76 travels radially inward under the influence of the circular spring 86 and returns to the retracted position.

[0022] like Figure 1A and Figure 3AAs further shown, each mold section 76 has a mold surface 88 that is radially opposed to the pinion axis 16 to engage the inner surface of the tubular element received within the bracket 26. The mold surface 88 has a profile shape that conforms to the shape of the first cam surface 56 on the cam body 54. As described below, the first cam surface 56 and the mold surface 88 mate to form a circumferential groove of the desired shape in the tubular element (see [link to documentation]). Figure 2 , Figure 2A For tubular components with a nominal diameter of 1.25 inches or greater, it may be advantageous to use the die 74 in conjunction with the first cam surface 56 to more precisely control the final groove shape and size of the tubular component. Using the die 74 is expected to produce a better-defined circumferential groove compared to using the cam surface alone. Note that the die surface 88 has a tapered surface 88a. Figure 1A , Figure 2A and Figure 3A When the tube element is larger than its nominal diameter, the tapered surface 88a provides free space for the second (controlled flaring) cam surface 70 to form the end of the tube element. Surface 88a is also useful when the controlled flaring surface 70 is used to reduce the outer diameter of the tube element.

[0023] like Figure 1 and Figure 2 As shown, the actuator that axially moves the pull rod 78 to expand and retract the mold 74 also includes a cylinder and a piston 90. In this example embodiment, the cylinder and piston 90 include a double-acting pneumatic cylinder 92 having a piston 94 coupled to the pull rod 78. The pneumatic cylinder 92 is mounted on a frame 96, which is attached to an intermediate shaft 14 and is movable relative to the base 22. Thus, the pneumatic cylinder 92 moves axially with the intermediate shaft 14, but its piston 94 can move the pull rod 78 relative to the intermediate shaft 14. A position sensor 98 is used to detect the position of the assembly including the pull rod 78, the mold 74, the pinion 12, the intermediate shaft 14, and the pneumatic cylinder 92 and its frame 96. The position sensor 98 may include, for example, a proximity sensor or a microswitch. A pressure sensor 100 is used to detect the pressure state of the pneumatic cylinder 92. Both the position sensor 98 and the pressure sensor 100 communicate with a controller 102, which may include, for example, a programmable logic controller or other microprocessor. The controller 102 uses information from the position sensor 98 and the pressure sensor 100 to control the operation of the device 10, as described below.

[0024] like Figure 1 and Figure 7As shown, the reduction gear train 104 is used to rotate the outer shaft 30 about the pinion axis 16. In this example embodiment, the reduction gear train 104 includes a worm gear 106 driven by a servo motor (not shown) controlled by a controller 102. The servo motor acts as an indexing drive and has an encoder that provides precise information about the position of the motor shaft, thereby allowing precise control of the rotation of the worm gear 106.

[0025] The worm 106 meshes with the worm wheel 108. For example... Figure 1 and Figure 7 As shown, the worm gear 108 is mounted on the output shaft 110, which is supported on a bearing 112 between the output shaft 110 and the gearbox 114 to rotate about the pinion axis 16. The gearbox 114 is fixed to the base 22. The output shaft 110 is connected to the outer shaft 30 by a key 116, thus ensuring the rotation of the outer shaft 30 when the output shaft 110 is rotated by the worm 106 and the worm gear 108.

[0026] The operation of device 10 begins as follows Figure 8 The cam bodies 54, as shown, have discontinuities 60 and 70a in their respective first cam surfaces 56 and second cam surfaces 70 (not visible) facing the pinion axis 16, and gaps 66 in their respective traction surfaces 64 (if present) also facing the pinion axis 16. This orientation of the cam bodies 54 is established when the gear 42 and pinion 12 are assembled in the bracket 26, and is controlled by the controller 102. Figure 1 The servo motor (not shown), acting via the worm gear 106 and worm wheel 108, is set to the starting position. The mold section 76 is in its retracted position. Figure 1A ).

[0027] like Figure 1 and Figure 1AAs shown, with the cam body 54 in the initial position and the die section 76 retracted, the tube element 118 to be slotted is inserted through the opening 34 in the bracket 26 and abuts against the stop plate 36. The alignment of the gap 66 in the traction surface 64 (when present) with the corresponding discontinuities 60, 70a in the first cam surface 56 and the second cam surface 70, and the retracted position of the die section 76, provides clearance for tube insertion. The tube element 118 further presses against the stop plate 36, compressing the spring 38 and causing the assembly including the die 74, pinion 12, tie rod 78, thrust bearing 40, and pneumatic cylinder 92 to move axially relative to the base 22 and the fixed mounting 20 attached to the base 22, thereby achieving a form-locked stop state when the thrust bearing 40 abuts against the flange 28. The position of the assembly is sensed by the position sensor 98, which sends a signal indicating the position of the assembly to the controller 102. Upon receiving a position signal, controller 102 commands pneumatic cylinder 92 to pull rod 78 away from opening 34 of bracket 26. This causes mold section 76 to move radially outward to the expansion position. Figure 2 , Figure 2A This causes the mold surface 88 to engage with the inner surface 120 of the tube element 118. The expanded position of the mold section 76 will vary depending on the inner diameter of the tube element. The pneumatic cylinder 92 maintains the force on the pull rod 78, thereby locking the mold 76 against the inner surface of the tube element. When the pressure sensor 100 senses a lower threshold pressure on the retracted side of the pneumatic cylinder 92, which indicates that the pull rod 78 has been pulled, it sends a signal to the controller 102 indicating that the mold section 76 is in the expanded state. Upon receiving the mold status signal from the pressure sensor 100, the controller 102 commands the servo motor to rotate the worm gear 106, which in turn rotates the worm wheel 108. In this example, the rotation of the worm wheel 108 causes the output shaft 110 to rotate counterclockwise (when in...). Figure 8 (During observation) rotation, which causes its keyway (key 116, see...) Figure 2A The outer shaft 30 rotates. The rotation of the outer shaft 30 causes the bracket 26 to rotate counterclockwise about the pinion axis 16. (The direction of rotation of the bracket 26 is predetermined by the arrangement of the first cam surface 56 on the cam body 54.) This causes the gear 42 and its associated cam body 54 to rotate about the pinion axis 16. However, the pinion 12 is fixed to prevent rotation because the intermediate shaft 14 is locked to the mounting bracket 20 by the interaction between the intermediate shaft portion 14a and the opening 24 of the mounting bracket. Because the gear 42 engages (fixes) the pinion 12, the relative rotation of the bracket 26 about the pinion axis 16 causes the gear 42 and its associated cam body 54 to rotate about their respective gear axes 44 (see...). Figure 2 , Figure 2A and Figure 8Rotation of the cam body 54 brings the traction surface 64 and the first cam surface 56 into contact with the outer surface 124 of the tube element 118. As the radius-increasing region 58 and the constant radius region 62 of each first cam surface 56 traverse the tube element 118, the traction surface 64 clamps the tube element, while the first cam surfaces 56 imprint grooves into the outer surface 124 of the tube element. The die section 76 engages and supports the inner surface 120 of the tube element 118, and the die surface 88 mates with the first cam surface 56 to form a circumferential groove.

[0028] The positions of the first cam surface 56 and the second (controlled flaring) cam surface 70 on the cam body 54 are coordinated with the position of the tubular element 118 received within the bracket 26, such that a groove is formed at a desired distance from the end of the tubular element 118, and the flaring at the end of the tubular element is controlled, i.e., limited or reduced to approximately its nominal diameter or smaller. The controller 102 rotates the bracket 26 through the necessary number of revolutions (depending on the gear ratio between gear 42 and pinion 12) to form a circumferential groove with a substantially constant depth for a tubular element with uniform wall thickness. In this example embodiment, only one revolution of the bracket is required to form a complete circumferential groove of constant depth. Upon completion of groove formation, the controller 102, through the action of the servo motor and gear train 104, returns the bracket 26 to a position where the gap 66 in the traction surface 64 and the discontinuity 60 in the first cam surface 56 and the discontinuity 70a in the second cam surface 70 again face the pinion axis 16. Figure 8 Then, controller 102 commands pneumatic cylinder 92 to move pull rod 78 toward opening 34, and allows mold sections 76 to move radially inward under the biasing force of circular spring 86 to their retracted position and disengage from tube element 118. Figure 1 and Figure 3A The position of the cam body 54 and the mold 74 allows the tube element 118 to be withdrawn from the bracket 26. When the tube element 118 is withdrawn, the spring 38 pushes the assembly including the pull rod 78, pinion 12, thrust bearing 40, intermediate shaft 14, pneumatic cylinder 92 and mold 74 back to its initial position, and the device 10 is once again ready to slot another tube element.

[0029] Significant advantages are achieved using device 10 because it applies minimal torque to the tube element during the grooving process while simultaneously forming the groove to a fixed diameter. For example... Figure 8 and Figure 5 As shown, this condition is met under the following conditions: 1) The pitch circle diameter 126 of the pinion 12 is substantially equal to the outer diameter of the tube element ( Figure 8 ); and 2) the pitch circle diameter 128 of the traction surface 64 is substantially equal to the pitch circle diameter 130 of the gear 42. Figure 5When these two conditions are met, the traction surface 64 is restricted to traversing the outer surface of the tube element, resulting in little or no tendency for the tube to rotate, and thus applying only minimal torque to the tube element. The terms "equal" and "substantially equal," used herein to refer to the relationship between the pitch circle diameters of the pinion, gear, and traction surface and the outer diameter of the tube element, mean that the pitch circle diameter of the pinion is sufficiently close to the outer diameter of the tube element, and the pitch circle diameter of the traction surface is sufficiently close to the pitch circle diameter of the gear, such that minimal torque is applied to the tube element. For practical purposes, if the difference between these values ​​is on the order of a hundredth of an inch, the pitch circle diameter of the pinion can be considered "equal" or "substantially equal" to the outer diameter of the tube element. Because actual tubes have significant diameter tolerances relative to nominal values, the relationship between the pitch circle diameter of the traction surface and the outer diameter of the tube element is expected to be affected by tube diameter deviations, such that torque will be applied to the tube element, making the use of an external clamp advantageous in these cases. In device 10, the mold 74 can act as a clamp when mounted on the rotating fixed pinion 12.

[0030] In a practical example design, the device 10, suitable for slotting tube elements with a nominal tube size of 2.5 inches, uses four gears 42 and a cam body 54, as shown. The outer diameter of the 2.5-inch nominal tube is 2.875 inches. The pinion 12, with 36 teeth and a pitch circle diameter of 72 mm (2.835 inches), is sufficiently close (with a difference of 0.040 inches) to apply minimal torque when the pitch circle diameter of the gear and the pitch circle diameter of the traction surface are also substantially equal to each other. This example embodiment uses a gear 42 with 36 teeth and a pitch circle diameter of 72 mm (2.835 inches). When embossed or otherwise prepared, the traction surface 64, although not a gear, has a substantially equivalent pitch circle diameter (i.e., the diameter of a cylinder providing the same motion as an actual gear), which is imprinted into the tube as the tube is passed through the traction surface. The difference of one-hundredth of an inch between the pitch circle diameter of the traction surface and the gear pitch circle diameter satisfies the constraint of "equal" or "equivalent" in practical applications. Given that the gear ratio between pinion 12 and gear 42 is equal in this example, it is clear that bracket 26 will rotate one revolution to form a complete circumferential groove around the tubular element.

[0031] In another example design suitable for a 4-inch nominal size tube with a 4.5-inch outer diameter, a pinion with 72 teeth and a pitch circle diameter of 4.5 inches is feasible. This design uses four pinions, each with 72 teeth and a 4.5-inch pitch circle diameter. The 1:1 ratio between the pinion and gears indicates that a single turn of the carrier is required to form a complete groove. Other ratios between the pinion and gears will result in multiple or partial turns of the carrier to form a complete groove.

[0032] The device 10 is designed such that the bracket 26 and its associated gear 42, cam body 54, pinion 12, outer shaft 30, intermediate shaft 14, and mold 74, together with other related components, form an assembly 132 interchangeable with the gear train 104, allowing the device to be easily adapted to slot a series of tubes with different diameters and wall thicknesses. Interchangeability is provided by using a removable clip 134 to secure the outer shaft 30 to the gearbox 114 and a key 116 between the outer shaft 30 and the output shaft 110 of the worm gear 108, attaching the intermediate shaft 92 to the frame by engaging the frame 96 of the pneumatic cylinder 92 with a slot 136 in the intermediate shaft 14, and attaching the piston 94 to the pull rod 78 using interlocking slots and shoulders 138. Component 132 can be removed by lifting the pneumatic cylinder 92, disengaging the frame 96 from the intermediate shaft 14 and the piston 94 from the pull rod 78, and then removing the retaining clip 34 (which allows the outer shaft 30 to disengage from the worm gear 108) and sliding the component along the pinion axis 16. Different bracket assemblies suitable for slotting different tubular elements can then be replaced.

[0033] The device 10 according to the invention is expected to improve the efficiency of pipe grooving operations because it will operate quickly and accurately across a wide range of pipe element sizes and schedules without requiring supports to hold the pipe elements in place and accommodate their rotation and ensure alignment. The device 10 will also allow grooving of curved pipe elements and pipe assemblies with bends without involving the rotational movement of the lateral pipe elements.

[0034] Figure 9 Another device 11 for forming circumferential grooves in a tubular element is shown. Device 11 includes a pinion 13, which is fixedly mounted to prevent rotation about a pinion axis 15 arranged coaxially with the pinion. Rotational fixation of the pinion 13 is achieved by mounting it on one end 17 of a pinion shaft 19, the opposite end 21 of which is secured to a post 23 by a key 25. The post is mounted on a base 27.

[0035] A bracket 29 surrounds the pinion 13. The bracket 29 is mounted on the flange 31 of the drive shaft 33. The drive shaft 33 is hollow, surrounds the pinion shaft 19, and is coaxial with the pinion shaft 19. A bearing 35 positioned between the drive shaft 33 and the pinion shaft 19 allows the drive shaft and thus the bracket 29 attached to the drive shaft to rotate about the pinion axis 15. The bracket 29 defines an opening 37 for receiving a tubular element, in which a recess will be formed. The opening 37 is arranged coaxially with the pinion axis 15. Figure 9 and Figure 11As shown, cup 39 is mounted coaxially with pinion 13. A tubular element abuts against cup 39 and, in this example, is mounted on cup shaft 41, which extends coaxially through a hole 43 in the hollow pinion shaft 19. Cup shaft 41 is axially movable along pinion axis 15 and biased toward opening 37 by a spring 45 acting between pinion shaft 19 and cup 39. The end 47 of cup shaft 41 opposite cup 39 is used in conjunction with a switch 49 mounted near post 23 to activate the device, as described below. In this example embodiment, the switch includes a proximity sensor, but it could also be a contact switch such as a microswitch.

[0036] Multiple gears 51 are mounted on bracket 29. Figure 9 and Figure 11 In the example embodiment shown, the bracket has three gears 51 spaced 120° apart from each other. Each gear 51 is rotatable about a corresponding gear axis 53. In a practical embodiment, each gear is mounted on a gear shaft 55, which is fixed between the front plate 57 and the rear plate 59 constituting the bracket 29. Bearings 61 positioned between each gear 51 and its corresponding shaft 55 provide low-friction rotation of the gear within the bracket 29. Each gear 51 engages with a pinion 13.

[0037] like Figure 12 As shown, a corresponding cam body 63 is mounted on each gear 51. A corresponding cam surface 65 extends around each cam body 63. The cam surface 65 can engage with a tubular element that receives and abuts against a cup 39 through an opening 37. Figure 13 As shown, each cam surface 65 includes a region 67 with an increased radius of the cam surface and a discontinuity 69. The discontinuity 69 is a location on the cam body 63 where the cam surface 65 does not contact the tube element. It is further advantageous to include a region 71 of a constant radius positioned near the discontinuity 69 as part of each cam surface 65. Traction surface 73 (see...) Figure 12 () extends around at least one of the cam bodies 63. Figure 11 In the example shown, the corresponding traction surface 73 extends around each cam body 63. The traction surface 73 may also engage with a tubular element received within the bracket 29, but each traction surface has a gap 75 that axially (i.e., in the direction along the gear axis 53) aligns with a discontinuity 69 in the cam surface 65 on each cam body 63. Figure 12As shown, the traction surface 73 may include a plurality of protrusions 77 extending outward therefrom. The protrusions provide additional gripping between the tubular element and the traction surface 73 during device operation and may be formed, for example, by embossing the traction surface. The traction surface has a pitch circle diameter 87. When the protrusions 68 are present on the traction surface 64, the pitch circle diameter 87 of the traction surface will be determined by the interaction of the protrusions 87 with the tubular element 79 (including the imprinting made by the protrusions 87 on the tubular element 79). If the protrusions 68 are not present, the pitch circle diameter 87 of the traction surface 64 will be equal to the pitch circle diameter of the traction surface. Figure 12 As further shown, the cam surface 65 is positioned between the gear 51 and the traction surface 73, spaced apart from the traction surface, but closer to the traction surface than the gear.

[0038] like Figure 9 and Figure 7 As shown, the reduction gear train 104 is used to rotate the drive shaft 33 about the pinion axis 15. In this example embodiment, the reduction gear train 104 includes a worm gear 106 driven by a servo motor (not shown), which is controlled by a microprocessor such as a programmable logic controller (not shown). The servo motor acts as an indexing drive and has an encoder that provides precise information about the position of the motor shaft, thereby allowing precise control of the rotation of the worm gear 106.

[0039] The worm 106 meshes with the worm wheel 108. The worm wheel 108 is mounted on a hollow output shaft 110, which is supported on a bearing 112 between the output shaft 110 and the gearbox 114 to rotate about the pinion axis 15. The output shaft 110 is connected to the drive shaft 33 by a key 95, thus ensuring the rotation of the drive shaft 33 when the output shaft 110 is rotated by the worm 106 and the worm wheel 108.

[0040] The operation of device 11 begins as follows Figure 14 The cam bodies 63 shown are positioned such that the discontinuities 69 in their respective cam surfaces 65 face the pinion axis 15, and the gaps 75 in their respective traction surfaces 73 (see...) Figure 11 It also faces the pinion axis 15. This orientation of the cam body 63 is established when the gear 51 and the pinion 13 are assembled in the bracket 29, and is set to the starting position by the control system and a servo motor (not shown) acting through the worm 106 and the worm wheel 108.

[0041] When the cam body 63 is in Figure 14 In the starting position shown, the slotted tube element 79 is inserted through the opening 37 in the bracket 29 and abuts against the cup 39 (see...). Figure 9 The gap 75 in the traction surface 73 is aligned with the discontinuity 69 in the cam surface 63 (see...). Figure 11 This provides a clearance for tube insertion. The tube element further presses against the cup 39, compressing the spring 45 and causing the cup 39 to move against the locking stop (in this example, the face of the pinion shaft 19), so that the end 47 of the cup shaft 41 interacts with the switch 49 (in this example, a proximity switch). Closing the switch 49 sends a signal to the control system, which commands the servo motor to rotate the worm 106, which in turn rotates the worm wheel 108. In this example, the rotation of the worm wheel 108 causes the output shaft 110 to rotate counterclockwise (when...). Figure 14 When observed, the cam 51 rotates, which causes the drive shaft 33, which is keyed (key 95), to rotate. The rotation of the drive shaft 33 causes the bracket 29 to rotate counterclockwise about the pinion axis 15. (The direction of rotation of the bracket 29 is determined by the arrangement of the cam surfaces 65 on the cam body 63.) This causes the gear 51 and its associated cam body 63 to rotate about the pinion axis 15. However, because the pinion shaft 19 is keyed to the post 23 via key 25, the pinion 13 is fixed to prevent rotation. Because the gear 51 engages the pinion 13, the relative rotation of the bracket 29 about the pinion axis 15 causes the gear 51 and its associated cam body 63 to rotate about their respective gear axes 53. The rotation of the cam body 63 causes the traction surface 73 and the cam surface 65 to contact the outer surface 83 of the tube element 79. As the radius-increasing region 67 and the constant radius region 71 of each cam surface 65 traverse the tube element, the traction surface 73 clamps the tube element 79, while the cam surface 65 imprints grooves into its outer surface 83. When the tube element is inserted to a position sufficient to reach the locking stop and the switch 49 is triggered, the position of the cam surface 65 on the cam body 63 is aligned with the position of the tube element, such that a groove is formed at a desired distance from the end of the tube element. The controller rotates the bracket 29 through the necessary number of revolutions (depending on the gear ratio between gear 51 and pinion 13) to form a circumferential groove with a substantially constant depth in the tube element. When the groove formation is complete, the controller returns the bracket 29 to a position where the gap 75 in the traction surface 73 and the discontinuity 69 in the cam surface 65 again face the pinion axis 15 (see [reference]). Figure 14 This position of the cam body 63 allows the tube element 79 to be removed from the bracket 29, and the device 11 is ready to slot another tube element.

[0042] Significant advantages are achieved using device 11 because it applies minimal torque to the tubular element during the grooving process while simultaneously forming the groove to a fixed diameter. This is achieved when: 1) the pitch circle diameter of the pinion 13 is 85 ( Figure 11 ) equals the outer diameter of tube element 79; and 2) the pitch circle diameter 87 of traction surface 73 equals the pitch circle diameter 89 of gear 51. Figure 12When these two conditions are met, the traction surface 73 is restricted to traversing the outer surface of the tube element, and the tendency to cause the tube to rotate is small or nonexistent, and therefore only a minimum torque is applied to the tube element. The term "equal," as used herein to refer to the relationship between the pitch circle diameter of the pinion and the outer diameter of the tube, means that the pitch circle diameter is close enough to the outer diameter that a minimum torque is applied to the tube element. A difference on the order of a hundredth of an inch between the pitch circle diameter and the outer diameter of the tube element satisfies this constraint of "equal" in practical applications. Because actual tube elements have significant diameter tolerances relative to nominal values, the relationship between the pitch circle diameter of the traction surface and the outer diameter of the tube element is expected to be affected by tube diameter deviations, such that torque will be applied to the tube element, making the use of an external clamp 99 advantageous in these cases (see [link to relevant documentation]). Figure 9 ).

[0043] In a practical example design, the device 11 suitable for slotting a 1-inch nominal diameter tube uses three gears 51 and a cam body 63 as shown. The outer diameter of the 1-inch nominal tube is 1.315 inches. The pinion 13, with 21 teeth and a pitch circle diameter of 1 5 / 16 inches (1.3125 inches), is sufficiently close (with a difference of 0.0025 inches) to apply minimal torque when the pitch circle diameters of the gear and the traction surface are also equal to each other. This example embodiment uses a gear 51 with 42 teeth and a pitch circle diameter of 2 5 / 8 inches. When embossed or otherwise prepared, the traction surface 73, although not a gear, has an equivalent pitch circle diameter (i.e., the diameter of a cylinder providing the same motion as an actual gear), which is imprinted into the tube as the traction surface passes through it. The difference of one-hundredth of an inch between the pitch circle diameter of the traction surface and the gear pitch circle diameter satisfies the constraint of "equal" or "equivalent" in practical applications. Considering the gear ratio between pinion 13 and gear 51 in this example, it is clear that bracket 29 will rotate two revolutions to form a complete circumferential groove around the tube element.

[0044] In another example design suitable for a 2-inch nominal tube with an outer diameter of 2 3 / 8 inches (2.375 inches), a pinion with 30 teeth and a pitch circle diameter of 2.362 inches is feasible (with a difference of 0.013 inches). This design uses 5 pinions, each with 30 teeth and a pitch circle diameter of 2.362 inches. The 1:1 ratio between the pinion and the gears indicates that a single turn of the bracket is required to form a complete groove. When tube elements with thin walls or larger diameters are being grooved, a design with more than three pinions is advantageous because such a tube tends to elastically bulge in the area between the cams when compressed between three cam surfaces spaced 120° apart. This elastic behavior causes the tube element to spring back to a larger nominal shape and inhibits groove formation. However, more pinions mean more cams applying force at more points around the tube element to better support it, thus significantly reducing elastic bulging by half a turn. The tighter spacing and greater constraint around the tube element forces deformation largely into the plastic zone, where springback is reduced and compensated for.

[0045] Another example design uses four gears and cams for tubular elements with nominal diameters of 1.25 and 1.5 inches. Gear-to-pinion ratios of 1.5:1 and 1:1 are also feasible for this design.

[0046] The device 11 is designed such that the bracket 29 and its associated gear 51, cam body 63, pinion 13, cup shaft 41, cup 39, spring 45, drive shaft 33, and pinion shaft 19 constitute an assembly 91 interchangeable with the gear train 104, allowing the device to be easily adapted to slot a series of tubes with different diameters and wall thicknesses. Interchangeability is achieved by using a key 25 between the pinion shaft 19 and the post 23, and a key 95 between the drive shaft 33 and the output shaft 110, engaging with a retaining nut 97 threadedly connected to the drive shaft 33 and acting against the output shaft 110. When the retaining nut 97 disengages from the threaded engagement with the drive shaft 33, the assembly 91 can be removed by sliding it along the pinion axis 15. Different bracket assemblies suitable for slotting different tube elements can then be replaced.

[0047] The device 11 according to the invention is expected to improve the efficiency of pipe grooving operations because it will allow for quick, accurate, and safe operation across a wide range of pipe element sizes and schedules without requiring supports to accommodate pipe elements and ensure alignment during rotation. The device 11 will also allow grooving of pipe assemblies with bends without involving rotational movement of the lateral pipe elements.

[0048] Figures 15 to 20 Another example embodiment of the slotting device 140 according to the present invention is illustrated. Similar to the device 11 described above, the device 140 includes a plurality of gears 51. Figure 15 The illustrated embodiment 140 has five gears. As... Figure 12 and Figure 13 As shown, each gear 51 includes a cam body 63, which supports a cam surface 65 and an optional traction surface 73. Various features of the gear, cam surface, and traction surface have been described above. Figure 15 As shown, gear 51 is rotatably mounted on bracket 29, which itself rotates about pinion axis 15, similar to device 11. As described above, bracket 29 includes a front plate 57 and a rear plate 59, the front plate 57 defining an opening 37 for receiving a tubular element to be slotted. Figure 16 As shown, at least one of the gears 51 meshes (directly engages) with the pinion 13, which is coaxially mounted on the pinion shaft 19. (In the example embodiment shown, all gears directly engage with the pinion 13.) Both the pinion 13 and the pinion shaft 19 are arranged coaxially with respect to the pinion axis 15 (see [reference]). Figure 16 Both are rotatably fixed relative to bracket 29. For the operation of the grooving device 140, bracket 29 can replace device 11 and be mounted on... Figure 9 On the drive shaft 33 shown, and as described above for device 11, when the bracket rotates about the pinion axis 15, the gear 51 rotates about its corresponding gear axis 53, and the cam surface 65 forms a circumferential groove in the tube element.

[0049] like Figure 16 As shown, device 140 differs from device 11 because it has a flared cup 142 positioned adjacent to the pinion 13 and surrounding a tube end stop 144. The tube end stop 144 includes a plate 146 defining a tube engagement surface 148. The plate 146 is mounted on and extends outward from a sleeve 150, which is fixedly mounted on a cup shaft 152. The cup shaft 152 is received within a bore 154 of a pinion shaft 19 coaxially aligned with the pinion axis 15. A first end 159 of the cup shaft 152 protrudes from the bore 154, and both the cup 142 and the tube end stop 144 are mounted close to the protruding first end 159 of the cup shaft 152. The cup shaft 152 is movable relative to the pinion shaft 19 in a direction along the pinion axis 15 and is biased toward the cam surface 65 of the cam body 63 by a stop spring 156, which in this example is a helical spring arranged coaxially about the pinion axis 15 and acting between the pinion shaft 19 and the shoulder 158 of the sleeve 150. The cup shaft 152 is held within the pinion shaft bore 154 against the biasing force of the spring 156 by engagement between the enlarged second end 160 of the cup shaft and the undercut 162 in the pinion shaft bore 154. In this example, a threaded nut 164 engages the first end 159 of the cup shaft 152 to hold the tube end stop 144 to the cup shaft.

[0050] Cup 142 includes a sidewall 166 arranged coaxially with the pinion axis 15. Sidewall 166 defines an interior 167 and surrounds a plate 146 of tube end stop 144. A radially extending rear wall 168 connects sidewall 166 to an axially extending hub 170. Hub 170 receives cup shaft 152 via a sleeve 150 engaging tube end stop 144 and is movable relative to cup shaft 152 along pinion axis 15. Cup spring 172 can act between cup 142 and pinion 13 to bias cup 142 away from pinion 13. In this example, spring 172 is a conical spring that is compressed more flat than a straight-compression helical spring might be used, allowing for a greater range of axial movement to cup 142. Therefore, cup 142 “floats” (moves independently) relative to tube end stop 144. Sidewall 166 defines an inner surface 174 that engages the tube element, as described below. The inner surface 174 has a first diameter 174a located away from the pinion 13 and a second diameter 174b located near the pinion. The first diameter 174a is larger than the second diameter 174b, creating a flared cup 142. A tube end stop 144 is positioned within an interior 167 between the first diameter 174a and the second diameter 174b. In one example embodiment, the inner surface 174 is advantageously tapered. In practical designs, the inner surface 174 defines an included angle 176, which can range from about 11° (for a 1.25-inch diameter tube) to about 12° (for a 1.5-inch diameter tube) and up to about 16° (for a 2-inch diameter tube). The taper of the tapered surface 174 is designed such that the cup 142 engages the tube element before the tube end stop 144, as described below.

[0051] Reference Figures 17 to 19 The operation of the flared cup 142 and the tube end stop 144 is described. For example... Figure 17 As shown, with the cam surface 65 and the traction surface 73 oriented towards the pinion axis 15 with their respective discontinuities 69 and gaps 75, the tube element 178 is inserted into the bracket 29 and received within the cup 142. Upon insertion, the outer circumference of the end of the tube element 178 first engages the inner surface 174 (note the gap 180 between the tube engagement surfaces 148 of the tube element and the tube end stop 144). The taper of the inner surface 174 is designed to accommodate dimensional tolerances on the diameter of the tube element, such that the gap 180 is initially present, regardless of the actual diameter of the particular tube element. Figure 17 In the example shown, the tube element 178 is at the smaller end of the diameter tolerance range, and the tube element is relatively deeply engaged into the cup interior 167. Figure 18As shown, the tube element 178 is further inserted into the bracket 29. In response, the cup 142 moves axially along the sleeve 150 relative to the tube end stop 144 and the cup shaft 152, compressing the cup spring 172 between the pinion 13 and the cup 142. The axial movement of the cup 142 continues independently of the tube end stop 144 until the gap 180 closes and the tube engagement surface 148 of the end engagement plate 146 of the tube element 178 is reached. Figure 19 As shown, continued insertion of the tube element 178 causes the tube end stop 144 to move relative to the pinion 13, thereby compressing both the spring 172 and the coil spring 156. The axial movement of the tube element 178, the cup 142, and the tube end stop 144 ceases when the sleeve 150 of the tube end stop engages the inner shoulder 181 within the hole 154 of the pinion shaft 19 (compare). Figure 18 and Figure 19 The sleeve 150 and inner shoulder 181 are sized to achieve two effects: 1) positioning the tube element 178 relative to the cam surface 65 such that the circumferential groove formed in the tube element when the bracket 29 rotates will be at a desired distance from the end of the tube element; and 2) positioning the enlarged end 160 of the cup shaft 152 to trigger the switch of the actuation device 140, which rotates the bracket 29 to form the circumferential groove when the tube element 178 is in the correct position. Similar to device 11, the switch could be a proximity sensor 49, such as... Figure 10 As shown. Figure 16 As shown, a threaded screw 182 can be positioned in the enlarged end 160 of the cup shaft 152 to provide adjustability to the apparent length of the cup shaft 152 for fine-tuning the switch throw. Figure 16 and Figure 20 As shown, in some cases, the use of a reverse tapered surface 184 on the tube engagement surface 148 of plate 146 can provide increased accuracy in the positioning of the circumferential groove on tube element 178. The reverse tapered surface 184 has an increased slope when measured in a direction extending radially from the sleeve 150. This feature is advantageous when tube elements cut by a roller cutter are being slotted. Roller cutters do not operate by removing material (cutting), but rather by separating material at the cutting plane using wedge-shaped blades. Therefore, the cut end of the tube element will have a tapered outer surface. The reverse tapered surface 184 is designed to accommodate this tapered outer surface and ensure that the circumferential groove is positioned at a desired distance from the end of tube element 178, measured from the point where the tube element is at its full outer diameter, rather than at the end of the tapered surface. In practical designs of the reverse tapered surface 184, a reverse tapered angle of up to approximately 5° can be used.

[0052] Using the floating cup 142 according to the invention provides the following advantages: 1) the cup accommodates dimensional tolerances of the outer diameter of the tube element; 2) the cup restricts radial expansion of the ends of the tube element during grooving, and thus reduces flaring (permanent radial deformation); and 3) the cup restricts local outward bulging of the tube element in the region between the cam surfaces 65 of the plurality of cam bodies 63, and thus helps to prevent the ends of the tube element from being "out of round". It is anticipated that the exemplary device 140 according to the invention will be able to groove tube elements faster and more accurately than grooving devices according to the prior art.

Claims

1. An assembly adapted to receive an end of a pipe element, the assembly comprising: axis; a cup comprising: a hub disposed coaxially with the axis; a rear wall extending outwardly from the hub transverse to the axis; a side wall attached to the rear wall and disposed coaxially with the axis, the rear wall and the side wall defining an interior, the side wall having an interior surface, the interior surface having a first diameter located distally from the rear wall and a second diameter located proximate to the rear wall, the first diameter being greater than the second diameter, the interior being adapted to receive the tubular element; A tube end stop positioned within the interior between the first and second diameters, the tube end stop comprising: a sleeve coaxially received within the interior; a plate mounted on the sleeve and extending outwardly from the sleeve transversely to the axis, the plate defining a tube engaging surface facing away from the rear wall; wherein the tube end stop is capable of moving along the axis toward and away from the rear wall of the cup.

2. The assembly according to claim 1, wherein The side wall has a tapered inner surface.

3. The assembly according to claim 2, wherein: The tapered inner surface defines an included angle from 11° to 16°.

4. The assembly according to claim 1, further comprising: a pinion shaft defining a bore coaxially aligned with the axis and on which the cup is mounted; a retaining spring acting between the pinion shaft and the sleeve for biasing the plate of the end stop away from the rear wall of the cup; A cup spring acts between the cup and the pinion shaft for biasing the rear wall of the cup away from the plate of the end stop.

5. The assembly of claim 4 further comprising a back plate mounted on the pinion shaft, the pinion shaft and the back plate being rotatable relative to each other about the axis.

6. The assembly according to claim 5, further comprising: a plurality of gears mounted on the rear plate, each of the gears being rotatable relative to the rear plate about a corresponding gear axis; a plurality of cam bodies, each of the cam bodies being mounted on a corresponding one of the gears; A plurality of first cam surfaces, each of the first cam surfaces extending around a respective one of the cam bodies and engageable with the tube element received within the cup, each of the first cam surfaces including an area of ​​increased radius, each of the first cam surfaces including a first discontinuity in the first cam surface.

7. The assembly of claim 6 further comprising a pinion fixedly mounted on said pinion shaft between said cup spring and said back plate.

8. The assembly according to claim 7, wherein: At least one of the gears is directly engaged with the pinion.

9. The assembly according to claim 7, wherein: Each of the gears is directly engaged with the pinion.

10. The assembly according to claim 7, wherein: The pinion shaft defines a bore coaxially aligned with the axis.

11. The assembly of claim 10, further comprising a cup shaft positioned within the bore, the cup shaft being movable within the bore along the axis, a first end of the cup shaft extending from the bore, the cup being mounted proximate the first end of the cup shaft.

12. The assembly of claim 1, wherein: The plate of the tube end stop also includes a reverse tapered surface positioned within the tube engaging surface, the reverse tapered surface having an increasing slope when measured in a direction extending radially from the sleeve.

13. The assembly of claim 4, further comprising: base; A column is mounted on the base, and the pinion shaft is fixedly mounted on the column.

14. The assembly of claim 4, wherein: The cup spring includes a conical spring.

15. The assembly of claim 6, wherein: Each of the gears has the same pitch diameter.

16. The assembly of claim 6, wherein: Each of the first cam surfaces includes a region having a constant radius positioned adjacent a respective one of the first discontinuities.

17. The assembly of claim 6 further comprising at least one traction surface extending about one of said cam bodies, said at least one traction surface having a gap therein axially aligned with said first discontinuity of said first cam surface about said one cam body.

18. The assembly of claim 17, wherein: The at least one traction surface includes a plurality of protrusions extending outwardly therefrom.

19. The assembly of claim 17, wherein: The at least one traction surface is positioned proximate to the first cam surface surrounding the one cam body.

20. The assembly of claim 17, wherein: The pinion gear has a pitch diameter equal to the outer diameter of the tube element.

21. The assembly of claim 17, wherein: The at least one traction surface has a pitch diameter equal to the pitch diameter of one of the gears.

22. The assembly of claim 6 further comprising a plurality of said traction surfaces, each of said traction surfaces extending around a respective one of said cam bodies, each of said traction surfaces having a gap therein, each of said gaps being axially aligned with a respective one of said discontinuities of said first cam surface on each of said cam bodies, each of said traction surfaces having a pitch diameter equal to said pitch diameter of said gear.

23. The assembly of claim 6 comprising at least three of said gears.

24. The assembly of claim 6 including at least five of said gears.

Images