The present invention relates sheet metal roll forming and more particularly to a method and apparatus for forming shaped members from a strip of malleable material with commonly powered sections having two different pass lines.
In roll forming apparatus, a flat sheet of malleable material, such as sheet metal, enters the apparatus at the entry end, is formed by a plurality of rollers, and exits the apparatus as a shaped member at the discharge end. A portion of the material passes through the apparatus without any forming. For example, in apparatus for forming a rain gutter with a trough having a flat bottom, generally the trough bottom at any point along the length of the apparatus is parallel to the flat sheet at the entry end and passes through the apparatus without being formed. The path along which the material passes without being formed is a surface called the pass line.
The pass line is defined by the forming rollers. The pass line extends longitudinally in the direction that material travels through the roll forming apparatus and laterally parallel to the axis of the rollers. The pass line may be a planar or may be a curved surface. U.S. Pat. No. 3,529,461 to Knudson discloses a pass line that follows a parabolic section along the length of the roll forming apparatus.
In prior known roll forming applications, powered drive rollers and powered forming rollers apply power at the material pass line. Powered forming rollers have contours to form or shape material with diameters that vary from the nominal pass line diameter. Generally, the nominal throughput speed of the roll forming apparatus is a function of drive roller rotational speed and diameter at the pass line. The actual linear speeds of the rollers vary where they contact the material due to changes in diameter away from pass line.
Forming that takes place above or below the pass line is often accomplished using idled forming rollers rather than powered forming rollers to avoid the speed variations that occur in powered forming rollers as diameters vary away from nominal pass line. However, forming away from the pass line without power also induces a great deal of drag on the profile. This drag typically leads to profile distortion and unbalanced residual forces in the finished profile.
In other prior known roll forming apparatus the forming of complex shapes is performed at or near the pass line. U.S. Pat. No. 4,899,566 to Knudson discloses apparatus to form ogee type rain gutter. The multiple variations from the pass line of each set of rollers for such apparatus must be accounted for in the roller design to prevent distortion and residual stress and the design is therefore complex.
Errors in the design of such complex rollers can create residual stress in the product, leading to warped output from the roll forming apparatus. Often such errors can only be corrected by fabricating and installing new rollers.
Apparatus for roll forming shaped members includes a roll forming primary powered section with a primary pass line and a roll forming secondary powered section with a secondary pass line separate from the primary pass line. The secondary powered section is coupled to the primary powered section by a gear based transmission that provides consistent gear mesh while allowing adjustment of the secondary pass line relative to the primary pass line in two directions and about two rotational axis. The method includes roll forming a first shape with a primary powered section having a primary pass line and then roll forming a second shape with a secondary powered section having a secondary pass line. The secondary powered section eliminates the drag, profile distortion and unbalanced residual forces created by idled forming rollers out of the primary pass line. Forming shaped members in multiple sections reduces the complexity and cost of the design and fabrication of the forming rollers. The adjustability of the secondary powered section allows warp and residual stress to be eliminated in the final shaped member.
Details of this invention are described in connection with the accompanying drawings which like parts bear similar reference numerals in which:
Referring now to
Describing the specific embodiments herein chosen for illustrating the invention, certain terminology is used which will be recognized as being employed for convenience and having no limiting significance. For example, the terms “vertical”, “horizontal, “lateral”, “longitudinal”, “upper” and “lower” refer to the illustrated embodiment in its normal position of use. Further, all of the terminology above-defined includes derivatives of the word specifically mentioned and words of similar import.
The frame 11 has laterally spaced, opposed, generally vertical first and second sides 23 and 24, each having a generally rectangular shape and extending longitudinally from the entry end 19 to the discharge end 21. Each of the first and second sides 23 and 24 has a lower member 25, an upper member 26 spaced in a parallel relationship above the lower member 25, and a plurality of spaced upright members 27 rigidly connected between the lower member 25 and the upper member 26. A plurality of spaced lower cross members 28 rigidly connect between the lower members 25 of the first and second sides 23 and 24. A plurality of spaced upper cross members 29 rigidly connect between the upper members 26 of the first and second sides 23 and 24. In the illustrated embodiment, the lower members 25, upright members 27, lower cross members 28 and upper cross members are made from square steel box tubing and the upper members 26 are steel angle iron.
The primary powered section and secondary powered section 14 and 15 are spaced consecutively along the longitudinal extent of the frame 11, with the primary powered section 14 nearer the entry end 19. Referring to
A plurality of longitudinally spaced, horizontal primary cross plates 42 extend between the upper members 26 of the first and second sides. Longitudinally extending, vertical, spaced first and second primary hanging plates 43 and 44 depend downward from the primary cross plates 42, parallel to and intermediate the first and second sides 23 and 24. Spaced upper primary shaft bearings 45 are mounted in the first and second primary hanging plates 43 and 44 with upper primary shafts 46 rotably mounted in the upper primary shaft bearings 45 and the upper primary rollers 33 mounted on the upper primary shafts 46 over the lower primary rollers 34. Upper drive shaft 47 is rotably mounted in the first and second primary hanging plates 43 and 44 between two of the upper primary shafts 46.
As shown in
Referring again to
The primary pass line PL1 is defined by the upper and lower primary rollers 33 and 34. The primary pass line PL1 is a generally horizontal surface that extends the length of apparatus 10 and laterally parallel to and intermediate the lower and upper primary shafts 39 and 46. In the illustrated embodiment, in which a rain gutter having a trough with a flat bottom is formed, the trough is formed by the primary powered section 14 and the trough bottom passes unformed along the primary pass line PL1. The powered drive rollers 50 drive the material 18 along the primary pass line PL1.
As shown in
Referring to
The primary gear 74 has a beveled primary gear head 84 with a plurality of primary gear teeth 85, and an elongated, hollow, cylindrical primary gear sleeve 86 extending through the primary gear head 84. The primary gear sleeve 86 is sized to receive a lower primary shaft 39, and is pressed into the primary gear bearing 81 to rotably mount the primary gear 74 in the first body plate 77. The secondary gear 75 has a beveled secondary gear head 88 with a plurality of secondary gear teeth 89, and a hollow, cylindrical secondary gear sleeve 90 extending through the primary gear head 88. The secondary gear sleeve 90 is sized to receive a secondary shaft 70, and is pressed into the secondary gear bearing 82 to rotably mount the secondary gear 75, in meshed relationship to the primary gear 74, in the second body plate 78.
In the illustrated embodiment, the primary gear sleeve 86 is located on the lower primary shaft 39 having a drive roller 50 that is nearest to the entry end 19 and the secondary gear sleeve 90 is located on the secondary shaft 70 that is nearest to the entry end 19. A pin 93 is fixed in the lower primary shaft 39 and extends into a slotted primary gear aperture 92 in the primary gear sleeve 90, so that the primary gear 74 rotates with the lower primary shaft 39 and the primary gear 74 can move laterally on the lower primary shaft 39. A secondary gear keyway 95 extends along the secondary gear sleeve 90 and a key 96 fixed in the secondary shaft 70 engages the secondary gear keyway 95 such that the secondary gear 75 powers the secondary shaft 70 while allowing the secondary shaft 70 to move up and down relative to the secondary gear 75.
As shown in
Spaced first and second adjustment plates 101 and 102 are rigidly mounted vertically on third side plate 48, at opposite ends of the lower plate 64 of the subframe 58. Adjustment bolts 99 extend through the first and second adjustment plates 101 to the lower plate 64, to provide adjustment of the subframe 58 laterally, and angular adjustment relative to the direction of travel of material 18 through apparatus 10.
The first and second secondary rollers 68 and 69 provide powered forming along a secondary pass line PL2. In the illustrated embodiment, the secondary pass line PL2 is a generally vertical surface that extends in the direction that the material 18 moves through apparatus 10, and up and down parallel to and intermediate the first and second secondary rollers 68 and 69. The transmission 60 allows adjustment in translation of the secondary powered section and thereby the secondary pass line PL2, relative to the to the primary pass line PL1, in two directions and rotational adjustment of the secondary powered section and thereby the secondary pass line PL2, relative to the to the primary pass line PL1, in two directions. Moving the primary gear 74 along the lower primary shaft 39 translates the secondary pass line PL2 laterally. Moving the subframe 58 up and down relative to the transmission 60, with the secondary shaft 70 sliding up and down in the secondary gear 75, translates the secondary pass line PL2 up and down. The axis of the lower primary shaft 39 forms a first axis A1 of rotation and rotating the transmission 60 and subframe 58 about the lower primary shaft 39 rotates the secondary pass line PL2 in a vertical plane. The axis of the secondary shaft 70 forms a second axis A2 of rotation and rotating the subframe 58 about the secondary shaft 70 rotates the secondary pass line PL2 in a horizontal plane.
The angle between the first and second body plates 77 and 78, and the angles of the primary and secondary gears 74 and 75, define the angle between the primary and secondary pass lines PL1 and PL2. In the illustrated embodiment, the angle between the primary and secondary pass lines PL1 and PL2 is 90 degrees. Any angle can be provided between the primary and secondary pass lines PL1 and PL2 by appropriate selection of the angle between the first and second body plates 77 and 78, and the angles of the primary and secondary gears 74 and 75. The primary gear 74 can be mounted on and driven by either a lower or an upper primary shaft 39 or 46.
Referring to
The method of the present invention generally includes roll forming shaped members from an elongated strip of malleable sheet material with powered sections each having a separate pass line. Specifically, the method includes a first step of providing the roll forming primary powered section 14 having the primary pass line PL1. The next step is forming the material 18 at the primary pass line PL1 with the primary powered section 14. The next step is providing the roll forming secondary powered section 15, coupled to and powered by the primary powered section 14, and having a secondary pass line PL2, separate from the primary pass line Pl1. The next step is forming the material 18 at the secondary pass line PL2 with the secondary powered section 15. The secondary pass line PL2 is adjustable in two directions in translation and two directions in rotation relative to the primary pass line PL1.
By providing the secondary powered section 15 with the secondary pass line PL2, the drag created by idled off pass line forming is reduced. The design of the forming rollers is simplified since the majority of the forming does not need to be at the primary pass line. Forming rollers can be designed to form in logical sections. Simpler rollers mean reduced fabrication costs. The adjustability of the secondary pass line PL2 relative to the primary pass line PL1 allows elimination of warp and residual stresses in the form members that can be caused by variations in operating conditions, input material and roller fabrication.
Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.
Number | Name | Date | Kind |
---|---|---|---|
1184947 | Gossett | May 1916 | A |
2150731 | Smith | Mar 1939 | A |
2248088 | Kane | Jul 1941 | A |
2561634 | Picton | Jul 1951 | A |
3529461 | Knudson | Sep 1970 | A |
3777531 | McClain | Dec 1973 | A |
4724695 | Stoehr | Feb 1988 | A |
4787233 | Beymer | Nov 1988 | A |
4899566 | Knudson | Feb 1990 | A |
5187964 | Levy | Feb 1993 | A |
Number | Date | Country | |
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20040000181 A1 | Jan 2004 | US |