CA2388521A1 - Straightening machine for straightening elongated bodies - Google Patents

Abstract

The invention relates to a straightening machine for straightening an elongated body, especially a pipe, a compound pipe or a rod. The inventive machine comprises a machine frame (2, 3) and, disposed therein, a number of radially adjustable straightening rolls (32-35) that are mounted alongside a straightening channel (20) and alternately on supports (24-27) in the direction of the longitudinal axis (10) and in a peripheral direction. The inventive machine allows an adjustment to different diameters or outer contours of the elongated bodies. To this end, the supports (24-27) are guided in at least one displacement plate (8, 9) that can be rotated about the longitudinal axis (10) of the straightening channel (20). Said displacement plate (8, 9) comprises first adjustment elements (36-39) which engage with second adjustment elements (40, 41) of the supports (24-27). The radial distance of the straightening rolls (32-35) relative to the longitudinal axis (10) is changed by turning the displacement plate (8, 9).

Description

Straightening Machine for Straightening Elongated Bodies The invention relates to a bending machine for straightening elongated bodies, especially pipes, plastic composite pipes, rods, or profiles according to the features stated in the preamble of Claim 1.
Such a bending machine is known from German Patent Application A1-197 50 616 that is designed to straighten rolled profiles. Said bending machine comprises a number of straightening rollers that form a straightening channel and act on the surface of the rolled profile or elongated body that is led into the straightening channel. In addition, an adjustment element is provided that has an adjustable runout roller to guide the straightened rolled profile, and that is adjustable by means of a sensor and an adjustment regulator.
The bending machine is a complex, stationary piece of equipment used in rolling mills, and is not suited particularly for mobile applications at work sites, machine shops, or workshops.
Furthermore, a bending machine for pipes, profiles, and the like is known from German Patent C2-35 34 42$ that has a design based on a linear, straight alignment and having bends and curves with small bending radii. Said bending machine comprises on the one hand feed rollers between which the pipe or similar body is led in a specified first direction, and on the other hand bending rollers on which slides are arranged that can be moved at right angles to said first direction.
Although the bending machine constitutes a compact, portable unit, the pipes, profiles, and similar bodies that are prepared in a curved or bent state cannot be straightened without further processing. The feed rollers are diametrically arranged in pairs to accommodate the diameter or outer contour of the elongated body, so that for other diameters or outer contours, said rollers must be replaced by other rollers of appropriate design. This is extremely time-intensive, and unsuitable for the austere operating conditions at the work site. Moreover, sets of various rollers must be kept on hand.
A further significant disadvantage is that the rollers are externally accessible, resulting in potential safety hazards.
In the current art, elongated bodies such as pipes, rods, or profiles are often processed on rollers whose diameters typically range from 1 to 2 m, corresponding to the flexibility of the elongated body. After the elongated body is rolled out, it has a corresponding bend radius such that said body generally cannot be laid out perfectly straight. Evan slight curvatures are undesirable, particularly for installation techniques such as laying water pipes, especially surface installations, but also for subsurface installations as wall. Similar problems arise in the laying or installation of rods or profiles, such as for cable ducts, sheathing, scaffolding, and the like.
The object of the invention is to provide a bending machine of the aforementioned type, having low construction costs, which allows adjustments to be easily made for different diameters or outer contours of the elongated body, and which avoids the need for special modifications. It is further proposed that the bending machine allow for easy handling and have low material and production costs.
This object is achieved according to the features stated in Claim 1.

The bending machine according to the invention is characterized by a simple construction that allows adjustments to be easily made for different diameters or outer contours of the elongated body to be straightened. A number of straightening rollers are mounted along a straightening channel on radially displaceable supports, which together may be adjusted by a displacement plate. It is advantageous for the supports to be diametrically opposed in pairs, said supports having at least two diametrically opposed straightening rollers. In a special embodiment, four supports are offset by at least approximately 90- to one another in relation to the straightening channel or the longitudinal axis, whereby each respective pair of diametrically opposed supports has at least one pair of diametrically arranged rollers. In a special embodiment, said supports are mounted in the machine frame so as to be radially displaceable, so that by means of the displacement plate the radial position of the supports, and thus of the respective straightening rollers, can be specified with respect to the longitudinal axis by rotating the displacement plate. Alternatively, the supports may be pivotably mounted about a fixed pivot bearing, or may also be mounted by means of the free bearing formed by the displacement plate so as to be radially adjustable in the required manner.
The displacement plate and the respective supports have mutually corresponding guide elements which in particular are designed as a shaft and a corresponding guide groove, whereby the shaft is associated with the support and the guide groove is associated with the displacement plate, or vice versa. Said displacement plate is rotatably mounted in the machine frame about the longitudinal axis of the straightening channel, whereby the radial adjustment of the supports, and thus of the straightening rollers adjoining the straightening channel, is specified corresponding to the rotational position of the displacement plate. The bending machine is a compact, preferably portable unit having a total weight of a few kilograms, and can be easily carried by one parson to the desired location of use.
It is advantageous to mount two displacement plates, one on each axial end of the supports, to assure a secure mounting of the supports along with the straightening rollers in the machine frame. An adjustment handle is advantageously connected to the one or two displacement plates, thereby facilitating synchronous rotation of the displacement plates) about the longitudinal axis. Furthermore, adjustment marks are assigned to at least one plate in such a way that the position at the time, and ultimately the adjusted distance of the straightening rollers relative to the longitudinal axis and thus to the adjusted pipe diameter, may be easily determined by an operator.
The machine frame, which advantageously has a guide plate on each end. has an opening at each end for inserting and withdrawing the elongated body, With the straightening channel and the straightening rollers being situated between said openings. The straightening rollers are preferably mounted radially inside each support, thus protecting against undesired access and eliminating safety hazards for the operator.
In a particular development of the invention, the banding machine has a cutting device for cutting the elongated body to a desired length. In this manner primarily pipes. especially plastic composite pipes, may be cut to the required length for further processing. By integrating the cutting device according to the invention into the bending machine, said bending machine has a double function, thus allowing elongated bodies to be straightened and cut within a short time.

Special embodiments and developments of the invention are stated in the subclaims.
The invention is explained in more detail with reference to an exemplary embodiment represented in the drawings, without thus limiting the invention. The drawings show the following:
Figure 1 A perspective view of the bending machine according to the invention, Figure 2 A longitudinal section through the bending machine in the sectional plane II according to Figure 1, Figure 3 A partial view in the viewing direction III
according to Figure 2, Figure 4 A perspective view in the sectional plane II
according to Figure l, and Figure 5 A view of a straightening roller.
Figure 1 shows in perspective view the bending machine, comprising a machine frame having two guide plates 2, 3 that are connected to one another by rods 4. Corresponding to rod 4 on the right in the drawing, an additional rod is present in the region of the lower ends 6 of the guide plates 2, 3. Two displacement plates 8, 9 are mounted on the mutually facing inner surfaces of the guide plates 2, 3 so as to be rotatable about the longitudinal axis 10. An adjustment handle 12, provided for rotation of the displacement plates 8, 9, is affixed to radially outwardly projecting cams 14, 15 on the displacement plates 8, 9. The guide plate 2 has an adjustment mark 16 which is coordinated with markings on the outer surface of the displacement plate 8. The markings 18 relate to different diameters of a straightening channel 20 which is coaxial to the longitudinal axis 10 and which can be preset by means of straightening rollers, to be described hereinafter.
Corresponding to the straightening channel, whose diameter is adjusted by rotating the displacement plates 8, 9 about the longitudinal axis 10, elongated bodies, especially pipes or plastic composite pipes, of different diameters can be straightened using the bending machine. The marking 18 corresponding to the respective diameter is aligned with the adjustment mark 16 by rotating the displacement plates 8, 9 in the direction of the arrow 22.
Four supports are mounted between the displacement plates 8, 9 essentially parallel to the longitudinal axis 10. The two supports 24, 25 visible in the drawing are mounted so as to offset one another by 90- in relation to the longitudinal axis 10. A third support is mounted diametrically opposing and below the upper support 24 as shown in the drawing, and a fourth support is mounted diametrically opposing the support 25. Supports 24, 25, and correspondingly the other two supports, have bearing blocks 28, 29 for the aforementioned straightening rollers, with only the one straightening roller 32 of the rear support diametrically opposed to the front support 25 being visible in the drawing.
The displacement plates 8, 9 comprise first adjustment elements which correspond to second adjustment elements of the respective support 24, 25. According to the drawing, the first adjustment element 36 is constructed as a groove that is spiral-shaped with respect to the longitudinal axis 10, within which groove the second adjustment element of support 24 in the form of a shaft, not visible here, engages. Said adjustment elements, the spiral-shaped groove 36, and the shaft engaging in said groove are designed in such a way that rotation of the displacement plates 8, 9 corresponding to the arrow 22 radially displaces the support 24 outwardly in the direction of the arrow 23. It is understood that rotation in the direction opposite to the arrow 22 radially displaces the support 24 inwardly. In addition, it is noted that the adjustment elements are designed to correspond to the other axial end of the support 24 and the displacement plate 8 mounted there. Furthermore, the three other supports are radially adjustable in an analogous fashion by means of adjustment elements. It is essential that all supports be synchronously radially displaced outwardly or radially displaced inwardly by rotation of the two displacement plates 8, 9 that are connected by the adjustment handle 12, so that the straightening rollers of all the supports have matching radial distances relative to the longitudinal axis 10, corresponding to the rotational position of the displacement plates 8, 9. The guide plate 2 has an opening 42, the diameter of which is equal to or greater than the outer diameter of the body or pipe, rod, or the like to be straightened by the bending machine. The guide plate 3 on the opposite end also has a corresponding opening that is coaxial to the longitudinal axis 10. The diameters-or for profiles or rods with different outer contours, the widths-of said openings are significantly larger than the maximum diameters or the maximum widths of the outer contours, thus reliably avoiding safety hazards for the operator when inserting a body or pipe into the opening. The fact that the straightening rollers are shielded by the radially outwardly mounted supports also avoids hazards for the operator.
The guide plate 2 on its inner side facing toward supports 24, 25 has four radial guide grooves 46 through 49 in which shafts of the respective support engage. Each support advantageously has two radially spaced shafts, whereby the width of the guide grooves 46 through 49 is substantially equal to the diameter of said shafts. The radial length of the guide grooves 46 through 49 is matched to the radial displacement path of the supports, taking the shaft diameters into account. Functionally reliable mounting and radial guiding of the supports in the machine frame are thus assured.
Instead of the two essentially cylindrical shafts provided for each support, each support may have an elongated guide body, similar to a feather key, which engages with the associated guide groove, the radial length of which is specified in accordance with the radial displacement path of the support.
It should be noted that not only the front guide plate 2 according to the drawing, but also the other guide plate 3 likewise has corresponding guide grooves. Alternatively, the radial guide elements according to the invention can be designed in such a way that shafts are mounted on the guide plates 2, 3 and the supports have corresponding radial guide grooves. In addition, the guide plate 3 has an axial adjustment pin 58 which will be further explained hereinafter.
Although the arrangement of four supports, mounted so as to be offset from one another by 90- relative to the longitudinal axis, has proven to be particularly advantageous, a different number of supports may be provided within the scope of the invention. It is preferable to mount at least three supports.
According to the invention, the supports are symmetrically mounted about the longitudinal axis so as to offset one another, each by the same angle.
Figure 2 shows a section through the bending machine in an axial sectional plane, with the two axially spaced, outer guide plates 2, 3 and the rear connecting rod 5 of the machine frame. According to the invention, the guide plates 2, 3 have support or guide surfaces, coaxial to the longitudinal axis 10, for the associated displacement plates 8, 9. In the region of the mutually facing inner surfaces of the guide plates 2, 3 are preferably provided axial projections 44, 45, having outer surfaces coaxial to the longitudinal axis 10, upon which the two displacement plates 8, 9 are rotatably mounted. The aforementioned second adjustment elements, in the form of the aforementioned axially aligned shafts 40, 41 of the respective upper or lower support 24 or 26 shown in the drawing, engage with the first adjustment elements 36, 38 of the displacement plates 8, 9, said adjustment elements being designed as spiral grooves. The displacement plates 2, 3 also contain the radial guide grooves 46, 47 in which the second adjustment elements or shafts 40, 41 likewise engage. The shafts 40, 41 are components of rods 50, 51, whose respective axial lengths are greater than the axial lengths of the supports 24, 26. The respective supports 24, 26 and correspondingly, the supports situated behind or in front of the plane of projection, are axially penetrated by two of said rods 50, 51. The radial guide grooves 46, 48 act to radially guide and prevent rotation of the respective supports during rotation of the displacement plates 8,9 to adjust the straightening rollers 32, 34, 35 of the respective support. It can be seen that said supports each have four axially spaced straightening rollers.
The different straightening rollers of the individual supports are axially offset from one another. For each support, the respective straightening rollers are arranged equidistantly.
The support 27 situated behind the plane of projection has two bearing blocks 30, 31 for rotatably mounting the straightening roller 35 situated between said bearing blocks 30, 31. It is understood that the straightening rollers for the three other supports are arranged and mounted in a corresponding fashion.
The bending machine further comprises a cutting device 52 having cutting rollers 54, 55. The cutting rollers may be adjusted in the radial direction by the cutting device 52, so that the distance between said cutting rollers may be reduced, if needed, to cut off the body or pipe present in the bending machine. For this purpose the cutting device 52 has a spindle, indicated by a dotted line 56, which is mounted outside the straightening channel and by which the cutting rollers 54, 55 may be radially adjusted as desired. Both of the cutting rollers 54, 55 are adjusted during the straightening process so as not to contact the outer surface of the body or pipe.
Cutting is performed by adjusting the cutting rollers 54, 55 to the outer surface of the body or pipe, successively readjusting to reduce the radial distance from the cutting rollers 54, 55, and rotating the body or pipe about the longitudinal axis 10.

Figure 3 shows the banding machine in a partial axial view, namely, in the sectional plane III according to Figure 2. The displacement plate 9 rotatably mounted on the axial projection 45 has four spiral-shaped grooves 36 through 39 in or through which the radially spaced shafts 40, 41 of the respective supports 24 through 27 engage. The straightening rollers 32 through 35 enclosing the straightening channel 20 may be easily identified here. The guide plate situated in front of the plane of projection has at least one adjustment pin 58 which extends into the region of the displacement plate 9. The displacement plate 9 has an adjustment groove 60 running in the circumferential direction which has locking positions 62 designed as indentations. Rotating the displacement plate 9 in the direction of the arrow 22 causes the adjustment pin 58 to move into the adjustment groove 60.
The adjustment groove 60 and its locking positions 62 are preferably designed in such a way that during rotation of the displacement plate 9, specified adjustment positions of the displacement plate are occupied corresponding to specified pipe diameters. The adjustment grooves and locking positions are formed and constructed, for example, so that during rotation of the displacement plate 9 the supports 24 through 27 are radially displaced in a specified adjustment range in preset increments, for example, by 16 to 32 mm for pipe diameters, and are sat in a fixed manner. It is advantageous to provide four such adjustment pins 58 with corresponding adjustment grooves, distributed over the circumference. For simplicity, only one adjustment groove 60 is shown here.
Additionally or alternatively, at least one of the spiral-shaped grooves 36 through 39 may have, in the region of its lateral surfaces, corresponding notches 64, 65 as locking positions in order to specify defined rotational angle positions of the displacement plate 9, and thus the defined adjustments of the straightening rollers 32 through 35, whereby the shafts 40, 41 engage in the angle positions of the displacement plate 9 which are thus specified.

Figure 4 shows in an axial sectional plane a perspective view of the bending machine comprising two guide plates 2, 3 having radial guide grooves 46, 48 for the shafts 40, 41 for the two supports 24, 26, shown here in a diametrically opposed arrangement. The four equidistant straightening rollers 35 of the support 37 Isic: 27] and the associated bearing blocks 30, 31 for the respective straightening roller 35 may be easily identified here. The rods 50, 51 engage at their ends, which are formed by said shafts 40, 41, in the radial guide grooves 46. The supports 24, 26 are represented in the radially adjustable position that is nearest to the longitudinal axis.
Corresponding to the free section of the guide groove 46 situated radially above the rod 50 or the shaft 40 thereof, the support 24 and correspondingly the other supports as well may be displaced outwardly or inwardly in the radial direction as indicated by the arrow 23, by rotating the displacement plates 8, 9.
Figure 5 shows a view of the straightening roller 32, the outer surface 70 of which has a specified curvature that allows use for different diameters of the pipes to be straightened. To this and, the outer surface 70 is adapted, in the canter 72 of the straightening roller 32, to the radius of the smallest pipe diameter. At the axial and regions of the roller 32, the roller diameter is increased out to the edge region 74 to accommodate the largest possible pipe diameter.
The following procedure is performed to straighten a body or pipe. First, the bending machine is adjusted to the desired diameter by rotating the displacement plates 8, 9 by means of the adjustment handle 12 until the marking 18 associated with the desired diameter matches up with the adjustment mark 16, as shown in Figure 1. In addition, the adjusting pin 58 engages in the associated locking position 62, and/or the shafts) 40, 41 engage with the respective notches 64, 65 of the spiral-shaped groove 36, as described above with reference to Figure 3. The pipe which is unrolled or otherwise bent by a roller is pushed through the opening 42 into the straightening channel and is than manually pushed out until it exits through the other opening 43 in a straightened state.

Reference Numbers 2, 3 Guide plate 4, 5 Rod 6 Lower end 8, 9 Displacement plate 10 10 Longitudinal axis 12 Adjustment handle 14, 15 Cam 16 Adjustment mark 18 Marking 20 Straightening channel 22, 23 Arrow 24-27 Support 28-31 Bearing block 32-35 Straightening roller 36-39 First adjustment element/spiral-shaped groove 40, 41 Second adjustment element/shaft 42, 43 Opening 44, 45 Projection from 2, 3 46-49 Radial guide groove 50, 51 Rod 52 Cutting device 54, 55 Cutting roller 56 Dotted line/spindle 58 Adjustment pin 60 Adjustment groove 62 Locking position 64, 65 Notch/locking position in 36 66 Section of 46

Claims (10)

Claims

1. Bending machine for straightening an elongated body, especially a pipe, a composite pipe, or a rod, comprising a machine frame (2, 3) and, disposed therein, a number of radially adjustable straightening rollers (32-35) that are mounted along a straightening channel (20) in the direction of the longitudinal axis (10) and offset on supports (24-27) in the circumferential direction, with the body being moved through the straightening channel (20), characterized in that the supports (24-27) are guided in at least one displacement plate (8, 9) that can be rotated about the longitudinal axis (10) of the straightening channel (20), and that the displacement plate (8, 9) comprises first adjustment elements (36-39) which engage with second adjustment elements (40, 41) of the supports (24-27), and that the radial distance of the straightening rollers (32-35) relative to the longitudinal axis (10) is changed by rotating the displacement plate (8, 9).

2. Bending machine according to Claim 1, characterized in that the first adjustment elements (36-39) are designed as spiral-shaped grooves and that the second adjustment elements (40, 41) are designed as shafts that engage with the spiral-shaped grooves, or vice versa.

3. Bending machine according to Claim 1 or 2, characterized in that the machine frame has two guide plates (2, 3) arranged at an axial distance from one another, and/or that the machine frame or the guide plates (2, 3) have openings (42, 43) for leading the straightened body through.

4. Bending machine according to one of Claims 1 through 3, characterized in that the supports (24-27) are axially mounted between the two axially spaced displacement plates (8, 9), and/or that the displacement plates (8, 9) are axially mounted between the guide plates (2, 3) arranged at a distance from one another on the machine frame.

5. Bending machine according to one of Claims 1 through 4, characterized in that the displacement plates (8, 9) are connected to one another by an adjustment handle (12).

6. Bending machine, especially according to one of Claims 1 through 5, characterized in that the machine frame and/or the guide plates (2, 3) have at least one axial projection (44, 45) upon whose outer surface the displacement plate (8, 9) is rotatably mounted, and/or that the machine frame and/or the guide plates (2, 3) have guide or support surfaces, coaxial to the longitudinal axis (10), for the displacement plate 8, 9.

7. Bending machine according to one of Claims 1 through 6, characterized in that the machine frame and/or the guide plates (2, 3) have essentially radially aligned guide grooves (46-49) for radially guiding the supports (24-27), and/or that guide bodies (40, 41) of the respective support (24) engage with the guide grooves (46-49), and/or that said guide bodies are designed as essentially axially aligned shafts (40, 41).

8. Bending machine according to one of Claims 1 through 7, characterized in that the supports (24-27) are respectively axially penetrated by at least one rod (50, 51), and/or that the free ends of the rods (50, 51) projecting from the supports (24-27) form said shafts (40, 41), and/or that the free ends of the rods (50, 51) engage with the spiral-shaped groove (36-39) and furthermore preferably engage with the radial guide groove (46) of the guide plate (2, 3) associated with the respective support (24-27).

9. Bending machine according to one of Claims 1 through 8, characterized in that a cutting device (52) having at least two cutting rollers (54, 55) is provided, and/or that the cutting device (52) along with the cutting rollers (54, 55) is mounted on two of the diametrically opposed supports (24-27).

10. Bending machine according to one of Claims 1 through 9, characterized in that the straightening rollers (32-34) are respectively arranged between two bearing blocks (28-31) of the associated support (24-27) and rotatably mounted.