Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
  • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
  • B21C37/30—Finishing tubes, e.g. sizing, burnishing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
  • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
  • B21C37/15—Making tubes of special shape; Making tube fittings
  • B21C37/155—Making tubes with non circular section
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
  • B21D5/14—Bending sheet metal along straight lines, e.g. to form simple curves by passing between rollers

Definitions

• the present invention relates to an apparatus and a method for reshaping tubes, in particular helically-wound lock-seam tubes for ventilation ductwork.
• WO-A-99/51371 discloses an apparatus, referred to as ovaliser, for forming round ductwork to oval, that is an apparatus for altering the cross-section of a tube from round to oval.
• the tube is a spiral duct, also referred to as helically-wound tubing by the skilled person.
• the apparatus has an elongate, horizontal duct forming assembly with two duct forming members vertically spaced from each other.
• the two duct forming members are connected to each other by power means configured to move the duct forming members to and from each other vertically.
• a round tube to be reshaped is placed on the duct forming assembly and the power means (several hydraulic cylinders) is activated. As the distance between the duct forming members is increased, they press against the inner surface of the tube in two opposite locations and the tube is reshaped to an oval cross-section. Each duct forming member has a semi-circular head which presses against the inner surface of the tube.
• the tube wall is deformed and the material is stretched. This stretching may lead to ruptures and other defects in the tube wall.
• the pressing action may lead to slippage or sliding in the lock seam, which in turn may pro- cute tubes with different dimensions at each end. This makes it difficult to connect the tubes in a ventilation duct system.
• the semi-circular heads of the duct forming members have to be replaced for each diameter of the tube.
• the replacement operation is time-consuming, and several duct forming heads have to be kept in stock. This adds costs.
• the known apparatus has low flexibility since it can only be used for reshaping from round to oval .
• a bending machine has a roller assembly to which a plate or sheet of metal is fed and formed to the desired shape, for instance to round cross-section. In a final step, the tube is closed by a longitudinal weld along the tube wall.
• these bending machines cannot be used for reshaping of a tube from, for instance, round to oval since the starting material always is a flat plate or sheet.
• An object of the present invention is to provide a new and improved technique for reshaping of tubes, in particular helically-wound lock-seam tubes for ventila- tion ductwork, thereby avoiding or at least making the disadvantages discussed above less severe.
• the shaping rollers are configured to apply the bending forces in points of action which are spaced with respect to the periphery of the wall.
• the shaping rollers are configured to apply the bending forces along generatrices of the tube, which further enhances the reshaping operation.
• the rotation means comprises a roller nip which has two opposite rollers configured to engage the tube wall in a nip and drivingly rotate the tube along its longitudinal axis. Such a roller nip pro- vides for a secure and smooth rotational operation.
• the shaping rollers and the nip rollers are parallel in order to provide for simple control of the reshaping operation.
• the structure of the apparatus is very compact by this arrangement.
• the apparatus comprises a frame with two opposite, spaced frame members between which the tube is disposed in operation.
• Each frame mem- ber has guiding means to which end portions of the shaping rollers are connected and which are configured to provide said movement of the shaping rollers.
• These guiding means in the frame members provide for a very distinct control of the reshaping movement of the shaping rollers. No disadvantageous inertia is involved.
• the guiding means are grooves provided in the respective frame members.
• actuator means such as hydraulic cylinders, are mounted between the end portions of the shaping rollers and the frame members. Consequently, a distinct movement of the shaping rollers is achieved.
• a roller unit for reshaping a tube having a cross-section and a longitudinal axis comprising: a first roller assembly configured to rotate the tube about the longitudinal axis, a second roller assembly configured to apply bending forces to the tube directed towards or away from the tube, thereby altering the cross-section of the tube.
• Fig. 1 is a perspective view of an apparatus according to a first embodiment of the invention.
• Figs 2-4 are side views of a reshaping mechanism of the apparatus shown in Fig. 1.
• Fig. 5 shows various positions of rollers included in the reshaping mechanism.
• Figs 6-8 are side views of an alternative reshaping mechanism with an additional roller.
• Fig. 9 is a perspective view of an apparatus according to a second embodiment of the invention.
• Fig. 10 is a side view of a reshaping mechanism of the apparatus shown in Fig . 9.
• an apparatus comprises a frame 1 with two opposite, spaced frame members 2 and 3.
• a roller arrangement comprises two rotatable nip rollers 10, 11 and two rotat- able shaping rollers 12, 13.
• the nip rollers 10, 11 provide means for drivingly rotating the tube 4 about its longitudinal axis C, and the shaping rollers 12, 13 pro- vide for reshaping of the tube 4. This will be further described below.
• the tube 4 shown in this example is a helically- wound lock-seam tube of sheet metal, suitable for ventilation ductwork. All rollers 10-13 are parallel with each other and with the longitudinal axis C of the tube 4.
• the nip rollers 10, 11 are rotated by a motor M mounted in the frame 1 (schematically shown in Fig. 1) .
• a mounting assembly connecting the ends of the rollers 10-13 to the respective frame members. Only one mounting assembly is shown in Fig. 1.
• This assembly comprises two arms 14, 15 which are pivotally mounted on the frame member 3 (at 14a, 15a, respectively, see Figs 2-4) .
• the arm 14 is connected to an end shaft portion 12a of the shaping roller 12 inside the tube 4, and the arm 15 is connected to an end shaft portion 13a of the shaping roller 13 out- side the tube 4.
• the pivotal movements of the arms 14, 15 are operated by actuator means, here shown as hydraulic cylinders 16, 17 mounted on the frame member 3.
• the upper nip roller 10 inside the tube 4 is rotat- ably connected to the frame members 2 , 3 at its two end shaft portions 10a.
• this nip roller 10 is "stationary" in the sense that it cannot be moved from its position in the frame 1.
• the lower nip roller 11, how- ever, is vertically moveable with the aid of actuator means, here a hydraulic cylinder 18, mounted on the frame member 3.
• FIGs 2-5 The principles of the operation of the tube reshaping apparatus are illustrated in Figs 2-5.
• a tube 4 of circular cross-section is arranged in the apparatus and rotated clockwise by the nip rollers 10, 11 clamping the tube wall 5 in the nip.
• the inner or upper shaping roller 12 engages the inner surface 8 of the tube 4
• the outer or lower shaping roller 13 engages the outer sur- face of the tube 4.
• the shaping rollers 12, 13 are applied to the tube wall 5 along generatrices G of the tube 4.
• the shaping rollers 12, 13 apply bending forces to the tube wall 5 in points of action 19, 21 which are spaced with respect to the periphery 6 of the tube 4.
• the shaping rollers 12, 13 are moved in relation to each other and in relation to the nip rollers 10, 11.
• the tube 4 can be formed to the intermediate cross- sectional shape shown in Fig. 3 and finally to the aimed- at oval cross-sectional shape shown in Fig. 4.
• the movements of the shaping rollers 12, 13 are precisely controlled by a computer (not shown) .
• the mutual cooperative action between the two shaping rollers 12, 13 applying said bending forces to the tube wall 5 provides for smooth reshaping of the tube 4.
• the first shaping roller 13 serves to decrease the radius R of curvature of the tube 4 whereas the second shaping roller 12 serves to increase the radius of curvature of the tube 4.
• the outer shaping roller 13 applies bending forces substantially directed to the centre of the tube 4 whereas the inner shaping roller 12 applies bending forces directed away from the center of the tube 4.
• the two shaping rollers 12, 13 cooperate for providing the appropriate bending action.
• the arms 14, 15 are pivotable in a plane P which is perpendicular to the longitudinal axis C of the tube 4.
• the end positions of the shaping rollers 12 and 13, respectively, are shown by dotted lines in Fig. 5. Indeed, the end positions may vary depending on the aimed-at final shape of the tube 4.
• a round tube 4 is reshaped to an oval tube, that is altering the radius R of curvature of the tube.
• the apparatus can also be used for reshaping an oval tube to a round, etc. There are no specific limitations on the reshaping as to the initial or final cross-section of the tube.
• the frame member 3 is pivotably mounted at 21 so that this part of the frame 1 can be "opened” for feeding tubes into the apparatus, and removing reshaped tubes from the same.
• the inner rollers 10, 12 have to be disconnected from their mountings when a tube is to be fed into or removed from the apparatus .
• the number of rollers are not crucial to the reshaping.
• an alternative embodiment is shown in Figs 6-8.
• the rollers 10-13 are the same as in the embodiment described above, but an additional outer shaping roller 22 has been added. Since this additional shap- ing roller 22 and the outer shaping roller 13 are disposed on either side of the outer nip roller 10, a very smooth and effective reshaping operation is achieved. By raising and lowering these two shaping rollers 13 and 21 in a well defined sequence (controlled by a computer) , a very favourable reshaping is accomplished.
• FIG. 9-10 A second embodiment of the apparatus is shown in Figs 9-10.
• the main difference between this embodiment and the first embodiment concerns the means for mounting and moving the rollers 10-13.
• the apparatus of Figs 9-10 has two sets of mounting means, one at each end. In the following, only one set will be described.
• grooves 23, 24 constitute means for guiding the movement of the associated rollers 11 and 13 by actuator means, here (as in the first embodiment) hydraulic cylinders 18 and 17.
• actuator means here (as in the first embodiment) hydraulic cylinders 18 and 17.
• the design of the grooves 23, 24 has to be calculated with respect to the desired movement and reshaping operation. Normally, the grooves 23, 24 are linear, but they could have a slight curvature as well (not shown) .
• the outer or lower nip roller 11 is vertically moveable, whereas the inner or upper nip roller 10 is "stationary" (but of course rotat- able) .
• the inner and outer shaping rollers 12 and 13, respectively, are moveable in directions which form an angle with the vertical movement of the lower nip roller 11. It is seen in Fig. 9 that the two grooves 23 and 24 form an angle .
• a slightly modified hydraulic cylinder 16' is connected to the end shaft portion 12a of the inner shaping roller 12. The difference with respect to the cylinder 16 shown in Fig. 1 is that the modified cylinder 16' is detachably connected to the end shaft portion 12a by means of a gripping member or claw 25.
• the cylinder 16' can be detached from the shaping roller 12 and swung to a vertical position about a pivot 26, allowing a change of tube.
• the nip roller 11 is lowered by means of the cylinder 18, the gripping member 25 is detached from the end shaft portion 12a and the cylinder 16' is swung to its vertical position.
• the frame member 3 is pivotable at 21 so that this part of the frame can be "opened” .
• the cylinders 16', 17 and 18 are disposed substantially in a common plane which is perpendicular to the longitudinal axis C of the tube 4. This results in a very compact and reliable structure.
• the first shaping roller 13 decreases the radius of curvature whereas the second shaping roller 12 increases the same.
• the inner shaping roller 12 is shown in its highest position above the nip rollers 10, 11, but the shaping roller 12 can be lowered in the direction of the cylinder 16 ' to a position in which it applies bending forces to the tube wall 5 in cooperation with the outer shaping roller 13. Then the cylinder 16' is pivoted about the pivot 26.
• rollers can also be used.
• the cylinder 18 moving the roller 11 can be replaced by a unit (not shown) comprising an axially actuated cylinder which moves the roller 11 up and down by means of a wedge assembly.
• the device 16', 25 moving the roller 12 can be replaced by a gear ring unit (not shown) coupled to the roller 12 or its end shaft portion 12a.
• the gear ring is actuated by suitable means, preferably electrically driven.
• this gear ring unit the roller 12 can be swung between two end positions, for instance along a semi-circle.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shaping Of Tube Ends By Bending Or Straightening (AREA)
• Bending Of Plates, Rods, And Pipes (AREA)
• Rolls And Other Rotary Bodies (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

Family

ID=20284178

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (7)

Citations (5)

• 2001
  • 2001-05-18 SE SE0101775A patent/SE521361C2/sv unknown
• 2002
  • 2002-05-17 CZ CZ20033401A patent/CZ20033401A3/cs unknown
  • 2002-05-17 PL PL02367747A patent/PL367747A1/xx not_active Application Discontinuation
  • 2002-05-17 WO PCT/SE2002/000942 patent/WO2002094467A2/en active Application Filing
  • 2002-05-17 EP EP02733700A patent/EP1387726A2/en not_active Withdrawn
  • 2002-05-17 CN CNA028101480A patent/CN1509215A/zh active Pending
  • 2002-05-17 JP JP2002591172A patent/JP2004525773A/ja active Pending
  • 2002-05-17 AU AU2002305982A patent/AU2002305982A1/en not_active Abandoned

Patent Citations (5)

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