Patent Grant
11794233
Benders disclosed herein may be used in the convenient, accurate, and precise bending of tubing. Benders disclosed herein include a variety of features that allow for bending operations that enhance many bend characteristics including the accuracy and precision of bend angles, bend plane angles, and bend positioning along the tubing.
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As that term is used herein “tubing” includes hollow generally cylindrical structures having an outer diameter less than 0.7 inches capable of conveying fluids over a distance.
As that phrase is used herein “bend radius” designates a property of the bender including the mandrel. Typically, a bender-mandrel combination has a specified tubing outside diameter and bend radius for which the bender-mandrel combination is designed to work. In that case, the bend radius designates the nominal bend radius for the bender-mandrel combination. Absent a nominal bend radius, the bend radius designates the bend radius created by bending the largest tubing that fits in the mandrel. Bend radius is also used herein as a unit of measure. For example, 1.5 bend radii designates 1.5 times the bend radius.
As that phrase is used herein “bend plane” indicates the plane in which a section of a bent piece of tubing or other similar material lies. When a piece of tubing is in a bender, the bend plane designates the plane in which bending is to occur.
As that phrase is used herein “active bend” designates the bend to be made by the bender or being made by the bender.
As that phrase is used herein “distal bend” designates a bend separated from the active bend by a section of tubing that is generally straight.
As that phrase is used herein “active bend plane” designates the plane in which bending by the bender occurs.
As that phrase is used herein “distal bend plane” designates the bend plane of a distal bend on the same piece of tubing that is separated from the active bend plane by a length of tubing that is generally straight.
As that phrase is used herein “bend plane angle” indicates the degree to which a distal bend plane is rotated out of alignment with the active bend plane. The axis from which bend plane angle is judged is the axis of the tubing between the active bend and the distal bend. The bend plane angle, as used herein, is directional and is measured by looking down the tubing from the active bend to the distal bend to judge the degree of clockwise separation of the distal bend from the active bend. Thus, two 90° bends having a bend plane angle of 0° would create a shape resembling a “U.” Similarly two 90° bends having a bend plane angle of 180° would create a shape resembling a zigzag. Although the two described bend pairs occur in the same plane, they have distinct bend plane angles.
As that phrase is used herein “stationary side” designates the side of the tubing that remain stationary during bending.
As that phrase is used herein “free side” designates the side of the tubing that moves during the bending process.
As that phrase is used herein “bend plane angle support” is a support that holds some portion of a distal bend in place either at the initiation of bending by the bender or during bending by the bender.
As that phrase is used herein a “multiple bend plane angle support” is a bend plane angle support that may be used to support multiple bend plane angles.
As that phrase is used herein a “rotating bend plane angle support” is a bend plane angle support that may be rotated to support multiple bend plane angles.
As that phrase is used herein a “infinite rotating bend plane angle support” is a bend plane angle support that may be rotated to support an infinite number of bend plane angles.
As that phrase is used herein “bend plane angle double support” is a bend plane angle support having multiple surfaces that act collectively to restrain tubing from rotating in either direction.
As that phrase is used herein “incremental angle lock” designates the various types of mechanical devices capable of locking one component to another component in multiple precise, repeatable angular relationships to one another based on pre-determined angle spacing. Examples include Hirth joints, various types of pin locks, and precision machined pairs of components meeting that criterion. Infinitely adjustable angle locks would not be incremental angle locks as that phrase is used herein.
As that phrase is used herein “mechanical stop” is limited to components that physically limit the bending range of motion thereby preventing both damage and overbending of the tubing. U.S. Pat. No. 6,834,527 to Hopwood discloses a bender with an “adjustable mechanical stop.” However, the type of stop described would not be considered a mechanical stop as that phrase is used herein because it allows for bending beyond the stop and because it allows for tubing damage from overbending. Either characteristic would disqualify a stop from being a mechanical stop as that phrase is used herein. According to the present disclosure, the type of mechanical relationship described by the Hopwood patent is a potentially destructive bend angle indicator not a mechanical stop.
Tubing, conduit, and other similar materials may be bent with the bending apparatus described herein and the bending methods described herein. The invention may have particular utility when making precise bends and may have particular utility when used on nominal ½ inch diameter tubing and smaller tubing sizes. Features described herein may allow bend angles to be achieved with both accuracy and precision. Mechanical stops, repeatable settings, a stable work environment, and precise fine adjustments may each contribute to reliable and repeatable bending operations that may be difficult or impossible to achieve with traditional manually operated benders.
Oftentimes to make the desired bends, a conventional manual tubing bender with a fixed or rotatable mandrel about which the tubing is bent is employed, and these mandrels typically include a plurality of radially inscribed lines on the mandrel corresponding to the bend angle that personnel use to determine when the bend is complete. Personnel using conventional manual tubing benders may experience challenges including closely spaced angle markings on the mandrel that have large increments such as 15° increments. This may result in personnel estimating bend angles and inaccurately executing bend angles due to the scale resolution.
Certain embodiments described herein have a scale located at least 1.2 bend radii from the mandrel axis of symmetry, with some scales located at least 1.6 bend radii from the mandrel axis of symmetry, with a fraction of those scales located at least 2.5 bend radii from the mandrel axis of symmetry, and certain scales located at least 4.0 bend radii from the mandrel axis of symmetry.
Various backstops and bend angle supports described herein aid in achieving accurate and repeatable start-of-bend locations.
The bender described herein is a bi-directional bender which may more easily accommodate sufficient clearance to bend tubing of certain geometries with long tangents and multiple bends. The bender is also alignable with and attachable to tables allowing for large tubing support surfaces. Benders having a single bend direction are also contemplated and may have many combinations of the remaining features disclosed herein.
The bi-directional bending configurations described herein may have further operational benefits. When the angle between the active bend plane and the distal bend plane is greater than 180°, but less than zero degrees, bending the active bend in the counterclockwise direction enables the user to potentially use the backstop to align the distal bend plane provided that the backstop is designed for the bend angle of the distal bend and the backstop includes a groove machined at an angle that corresponds to the desired bend plane angle. This may have extra utility beyond what is achievable with the bend plane plate when the distance between the distal bend and the active bend exceeds that which the bend plane plate can accommodate. The length of tubing the bend plane plate can accommodate is limited by the length of the extension shaft and the effects of long cantilevers on the extension shaft. Furthermore, even if the extension shaft is long enough to accommodate a distal bend, if the tangent on the free side of the active bend is relatively short, and the tangent on the stationary side of the active bend is relatively long, it will be much easier to manipulate the tubing into the proper position in the bender as well as execute the bend if the longer portion of the tubing is the stationary side rather than the free side.
The depicted bender may include a mandrel around which tubing may be bent. The mandrel may be fixed to the housing such that the mandrel does not rotate. The roller carriage may rotate around the mandrel pressing the tubing against the mandrel to bend the tubing. The mandrel may be a replaceable mandrel. Replaceable mandrels allows for the same bender to be reconfigured to bend different diameter tubing and reconfigured to bend the same diameter tubing to a different bend radius.
During the bending, catches may hold the stationary side of the tubing in place. The lever handle may act as a lever to urge the roller carriage around the mandrel for the bending. In the depicted embodiment, the lever handle may be secured to the roller carriage in a variety of orientations to enable bending tubing in the clockwise direction as well as the counterclockwise direction without having to replace any of the bender's components
The bend angle Hirth joint connects the stop ring to the bend angle fine adjustment arm. The bend angle Hirth joint may for example have 24 teeth allowing the stop ring to orient itself in increments of 15° relative to the bend angle fine adjustment arm. The bend angle Hirth joint may have a variety of tooth configurations including those that create increments of 10° and 5°. The annular post may be secured within the stop ring such that they operate as a single component. The Hirth joint lock bolt which runs through the annular post may fasten to the bend angle arm Hirth joint plate and when tightened the Hirth joint lock bolt locks the bend angle arm Hirth joint plate and the bend angle fine adjustment arm in place relative to the annular post and the stop ring mechanical stop. The stop ring may have two stop ring mechanical stops when the bender is configured for bending in both directions. In such cases, the operation of the other stop ring mechanical stop is essentially the same as the first stop ring mechanical stop. The bend angle arm Hirth joint plate is situated within a circular recess in housing upper plate. Coarse adjustments may be locked in place using the bend angle Hirth joint which may be characterized as an incremental angle lock.
The bender link arm freely rotates around the annular post with the assistance of the needle bearing. In some embodiments a bushing or other suitable bearing may be used in place of the needle bearing. The bender link arm and the roller carriage begin at the initial 0° bend position because the housing limits further rotation of the roller carriage around the housing to help ensure correct starting position for the bend.
When the bend angle fine adjustment arm points at 0° on the bend angle fine adjustment scale, the relationship in the bend angle Hirth joint controls the maximum tubing bend allowed by the bender giving possible maximum bend angles of 15°, 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, 150°, 165°, and 180° at which point the bender link arm contacts the stop ring mechanical stop completing the bend. Separate fine adjustment scales and coarse adjustment scales may be used based on the direction of bending. That is, different scales may be used for clockwise bending and counterclockwise bending. In each of those cases, repeatable bending may be accomplished by bending until reaching the mechanical stop. A precise replica of the bend angle may be repeated by inserting another piece of tubing and bending again to the mechanical stop.
Springback of tubing during the bending process and a desire to achieve angles between the increments allowed by the bend angle Hirth joint may both be accounted for by adjustment of the bend angle fine adjustment arm. Adjustment of the bend angle fine adjustment arm may be accomplished by loosening the fine angle lock bolt and moving the bend angle fine adjustment arm such that the bend angle fine adjustment arm points to the desired location bend angle fine adjustment scale and then locking the bend angle fine adjustment arm in place with the fine angle lock bolt. The fine angle lock bolt slot allows the bend angle fine adjustment arm to move freely relative to the housing upper plate and to lock securely to the housing upper plate in any desired position. The combination of incremental adjustments using the bend angle Hirth joint and by positioning the bend angle fine adjustment arm allows for the coarse and fine adjustment of the position of the stop ring mechanical stop at any angle within the range of motion of the bender. The position of the bend angle fine adjustment scale allows for manual adjustments of bend angle having a high degree of accuracy. The precisely repeatable positions into which the bend angle Hirth joint may lock prevents the loss of the benefit of the high accuracy adjustments on the bend angle fine adjustment scale by preventing the introduction of small coarse adjustment angle setting errors. The bend angle fine adjustment scale may be in 1° increments or in 0.5° increments.
The mandrel and various other components of the bender may be configured such that they allow for bending in both directions around the mandrel. In such cases the stop ring would have an additional stop ring mechanical stop on the opposite side of the stop ring. The operation of the additional stop ring mechanical stop would be similar and interact with the bender link arm in a similar way that creates a similar control of bend angle. Indication of bend angle by indicators such as the counterclockwise bend coarse indicator operate on the depicted clockwise coarse bend scale and the depicted counterclockwise coarse bend scale. When setting the coarse range of motion of the bender the range of motion may be confirmed by observing the range of motion on the indicators on these coarse scales. The utility of the bender may be enhanced by having a scale that has at least one marking for every 5° on the scale, with further enhanced utility in cases where the scale has at least one marking for every 1° on the scale, still further enhanced utility in cases where the scale has at least one marking for every 0.5° on the scale, and still further enhanced utility in cases where the scale has at least one marking for every 0.2° on the scale.
The extension shaft may be configured to be slidably held by the extension shaft support bushing and the vice lug-extension shaft support bushing to support the bend plane angle plate. The bend angle plate may be connected to the extension shaft by the bend plane plate support arm and the associated bend plane Hirth joint. The extension shaft support bushing and the vice lug-extension shaft support bushing may be attached to the housing lower plate so that the extension shaft support bushing and the vice lug-extension shaft support bushing may be used for connection to a table, vice or other equipment. The bend plane Hirth joint may be configured with 24 teeth like the bend angle Hirth joint allowing easily setting of a range of typical bend plane angles. When setting up for bending, the tubing to be bent may rest on the bend plane angle plate with the bend plane angle plate configured such that the distal bend is supported at the desired bend plane angle. Once the appropriate bend plane angle is established, the bend plane angle plate may be removed or may remain in place depending on the degree to which it would interfere with the bend to be made.
The housing cover may be positioned to support the tubing during and before bending. The housing cover may also include a T-slot for aligning and securing the axial position of a backstop. The T-slot in the housing cover may align with a table T-slot such that the backstop may be positionable in a wide range of locations situated various distances from the start-of-bend location. The bender may be table mountable such that the stationary side of the tubing rests flat on the table prior to bending. The backstop may be repositionable along a tubing axis of the stationary side of the tubing to be bent such that the backstop is in alignment with that axis. The variable position backstop allows for precise and measured control of the location of bends in the tubing. Backstops such as the block backstop and the half-cylinder backstop may contain a 0° slot for holding 90° distal bends at a bend plane angle of either 0° or 180°. Those backstops may contain a 45° slot for holding 90° distal bends at a bend plane angle of 45°. A 90° slot and a 135° slot may hold corresponding bend plane angles. The backstops may be configured to support a distal bend having a bend plane angle of −90°. Achieving a bend plane angle of −90° may be accomplished in a similar manner to creating a bend plane angle of 90°, but the tubing and bender would be set up for a counterclockwise bend rather than a clockwise bend. Other bend plane angles such as −45° would be accomplished using similar techniques. The block backstop may contain similar slots aligned with the other side of the mandrel so that equivalent restraint of bend plane angles may be accomplished during both clockwise and counterclockwise bending when the backstop is securely held in a T-slot. The distal non-90°-angle bend slot may be used to hold distal bends that are non-90° bends. However, the distal non-90°-angle bend slot is primarily useful when the bend plane angle is 0° or 180°. Support bar openings may be used to hold a support bar situated in one of support bar openings which may be used along with support bar tabs to further restrain the position of tubing held in the distal non-90°-angle bend slot. These bend slot configurations provide readily accessible multi surface support for the tubing to be bent. The backstop may be flipped to alternate between usage of the distal non-90°-angle bend slot and the other slots. In certain embodiments, the backstop may be configured to support bend plane angles of −135°, −90°, −45°, 0°, 45°, 90°, 135°, and 180°. A variety of similar backstops may be utilized including those having slots ranging from 0°-180° in 15° increments and backstops that accommodate distal bend angles that are other than 90° including backstops that would for example accommodate distal bend angles of 45° such as the partially conical backstop. The partially conical backstop accommodates 45° distal bend angles and has a generally conical form with slots in the outer surfaces of the generally conical form. The partially conical backstop is depicted as accommodating 45° distal bend angles, but a wide variety of alternate angles could be produced.
A tabletop T-track may be used with an existing table such that a tabletop T-slot within the tabletop T-track accommodates components to secure distal bends. The tabletop T-track may be secured to a table by Tabletop T-track bolts. Pin holes in the tabletop T-track may be arranged along the tabletop T-slot such that a pin secured tube support disk is positioned to abut the piece of tubing being bent. Similarly, a T-slot boltable tube support disk may be used to contact and stabilize the piece of tubing being bent. These support discs may take many forms including locks, cylinders, etc. and may be configured to provide only horizontal support or they may be configured to have a lip, recess, or other feature restraining the tubing from vertical movement. Such support discs are useful in conjunction with backstops that accommodate distal bends less than 90°, such as the partially conical backstop, 530, because they can limit the tendency of such backstops to act as a wedge elevating the tubing off the supporting table. Support discs and other components arranged for intermittent attachment to the tabletop T-track or the table may alternatively be attached by magnet or by weighting those components such that they operate as stable supports.
Backstops such as the half-cylinder backstop and the partially conical backstop may be configured with offset backstop bolt holes allowing the slots on the backstops to align with tubing on either side of the T-slot that allows a both ends of a single backstop to be used for both clockwise and counterclockwise bends. These backstops may be configured with T-slot fasteners that fix the backstop in alignment with the T-slot on either side of the T-slot. This configuration allows the slots on this type of backstop to have a first set of slots on one side incremented for bend plane angles such as 30°, 60°, 90°, etc. and another set of slots on the other side incremented for bend plane angles such as 15°, 45°, 75°, etc. The selection of slot angles may be chosen based on common needs or specialty considerations.
Tubing benders described herein may include adjustable mechanical stops. Those stops may be configured such that the maximum bend angle may be set. The manner of setting may be such that a coarse adjustment may be set followed by a fine adjustment. When setting the bend angle, the user may add some number of degrees to the final desired tubing bend angle to account for springback of the tubing. Because the amount of springback is dependent on the bend angle as well as the strength of the material being bent, the setting of the bend angle may be determined by experimentation, tables, formulas, or other equivalent methods. The determination of the correct bend angle setting on the bender and the mechanical stops that allow reproduction of that precise bend angle allows for precise and accurate repetition of identical bends in the tubing or for production according to specifications.
The bend angle fine adjustment arm extends well beyond the bend radius of the mandrel, so the user is much better able to perceive small changes in the bend angle. For example, the bend angle fine adjustment arm may be long enough to allow users, without using optical magnification, to make adjustments on a scale incremented at 0.2°. The stops may be manually set relying on hand adjustment while observing the physical position of the bend angle fine adjustment arm. In the depicted embodiment, the bend angle Hirth joint may be engaged and disengaged to set coarse adjustments which may for example be in 15° increments. The bend angle Hirth joint, may be locked and unlocked by rotating the Hirth joint lock bolt such that the bend angle Hirth joint may reoriented to the desired coarse adjustment angle then screwed in to lock in the desired coarse adjustment angle.
The way the bend angle fine adjustment arm and the bend angle Hirth joint combine to control adjustment of the mechanical stop allow for high accuracy bending from a device having limited dimensions.
The bend plane angle plate may be used to accurately and efficiently establish the target bend plane angle. The bend plane angle plate may be connected to the bender via a bend plane Hirth joint with 24 teeth to facilitate adjusting it to the more commonly used angles. Hirth joints with other numbers of teeth or connections that otherwise limit the number of angle options may also be used. Also, the connection may be one that doesn't limit the orientations to common angles. The bend plane Hirth joint may for example be configured such that it is capable of locking into place with an infinite number of orientations such as by including a washer between the teeth of the bend plane Hirth joint before locking the bend plane Hirth joint in place.
The backstop may be used to establish the start-of-bend location accurately and efficiently for each bend. The backstop may be adjusted by loosening a bolt that runs through the backstop into a threaded fastening plate in the T-slot, sliding the backstop to the new desired location, and re-tightening the bolt running through the backstop.
The bender may be capable of executing clockwise as well as counterclockwise bends. This capability may resolve users need for large clearance areas on all sides of the bender as may be needed with unidirectional benders.
Operation of the bender may proceed by loosening the Hirth joint lock bolt and rotating the annular post until the appropriate range of motion for the coarse adjustment is established then retightening the Hirth joint lock bolt. The fine angle lock bolt then may be loosened for adjustment of the position of the bend angle fine adjustment arm relative to the bend angle fine adjustment scale followed by tightening the fine angle lock bolt. The catch may be opened to slide tubing between the mandrel and the roller carriage positioning and securing the tubing optionally with the assistance of either the backstop or the bend plane angle plate. Once the tubing is properly positioned bending may occur by pulling the lever handle until the mechanical stop is reached.
The roller carriage may be configured symmetrically with four rollers such that the roller carriage can use two rollers for clockwise bending then reorient to use the opposite two rollers for counterclockwise bending. Doing so may be accomplished by simply rotating the lever handle and roller carriage into the starting bending position for the opposite direction bend and setting the new bend angle. This may be accomplished without replacing bender components. This process may optionally include reorienting the lever handle relative to the roller carriage.
Most of the features described herein may be executed as a rotary draw bender.
Similar mechanical stops, bend angle mechanical Hirth joint, bend angle fine adjustment arm, backstops, and other components would be executed in a similar way with application of those changes necessary to alter the manner of bending to match the form of a rotary draw bender.
Benders described herein may, for example comprise a mandrel configured to bend tubing having an outer diameter that is less than 0.7 inches; an axis of symmetry of the mandrel; a first adjustable mechanical stop arranged and configured to limit the bending of tubing around the mandrel in a first direction; a securing mechanism arranged and configured to releasably fix the first adjustable mechanical stop in a position relative to the mandrel; a tubing contact component arranged and configured to rotate around the mandrel; a lever arranged and configured for manual operation of the tubing contact component; and a scale arranged and configured to correspond to a tubing bend angle; such that the scale is located at least 1.2 bend radii from the axis of symmetry of the mandrel. In a related example, the bender may have a multiple bend plane angle support arranged and configured to lock in place at various distances from the mandrel. In a related example, the bender may have a scale has at least one marking for every 5° on the scale. In a related example, the scale may have at least one marking for every 1° on the scale. In a related example, the bender may have a multiple bend plane angle support lockable at multiple distances from the mandrel. In a related example, the bender may have a second adjustable mechanical stop arranged and configured to limit the bending of tubing around the mandrel in a second direction.
Benders described herein may, for example comprise a mandrel configured to bend tubing having an outer diameter that is less than 0.7 inches; an axis of symmetry of the mandrel; an adjustable mechanical stop arranged and configured to limit the bending of tubing around the mandrel; a first securing mechanism arranged and configured to releasably fix the adjustable mechanical stop in a position relative to the mandrel; a tubing contact component arranged and configured to rotate around the mandrel; an indicator corresponding to a position of the mechanical stop; and a scale arranged and configured to correspond to a bend angle; such that the indicator is adjacent to the scale and a position of the indicator relative to the scale corresponds to a position of the adjustable mechanical stop; and the scale is located at least 3.0 bend radii from the axis of symmetry of the mandrel. In a related example, the first securing mechanism may include a Hirth joint. In a related example, the bender may have a second securing mechanism arranged and configured to releasably fix the adjustable mechanical stop in a position relative to the mandrel. In a related example, the bender may have a multiple bend plane angle support arranged and configured to lock in place at various distances from the mandrel. In a related example, the scale may have at least one marking for every 5° on the scale. In a related example, the scale may have at least one marking for every 1° on the scale. In a related example, the bender may have a multiple bend plane angle support lockable at multiple distances from the mandrel. In a related example, the bender may have a rotating bend plane angle support lockable at multiple distances from the mandrel.
Benders described herein may, for example comprise a mandrel configured to bend tubing having an outer diameter that is less than 0.7 inches; an axis of symmetry of the mandrel; a tubing contact component arranged and configured to rotate around the mandrel; a coarse adjustment scale; a coarse adjustment indicator; a fine adjustment scale; a fine adjustment indicator; an incremental angle lock; such that the incremental angle lock sets a relationship between the coarse adjustment scale and the fine adjustment scale; a tubing bend angle may be determined by reference to the coarse adjustment scale, the coarse adjustment indicator, the fine adjustment scale, and the fine adjustment indicator; and the fine adjustment scale is located at least 2.5 bend radii from the axis of symmetry of the mandrel. In a related example, the bender may have a multiple bend plane angle support arranged and configured to lock in place at various distances from the mandrel. In a related example, the coarse adjustment scale may have at least one marking for every 30° on the coarse adjustment scale. In a related example, the fine adjustment scale may have at least one marking for every 1° on the fine adjustment scale. In a related example, the bender may have a multiple bend plane angle support lockable at multiple distances from the mandrel. In a related example, the bender may have a rotating bend plane angle support lockable at multiple distances from the mandrel.
The above-described embodiments have a number of independently useful individual features that have particular utility when used in combination with one another including combinations of features from embodiments described separately. There are, of course, other alternate embodiments which are obvious from the foregoing descriptions, which are intended to be included within the scope of the present application.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3236082 | Beck | Feb 1966 | A |
| 3433042 | Crihfield | Mar 1969 | A |
| 4403496 | Kowal | Sep 1983 | A |
| 6834527 | Hopwood | Dec 2004 | B2 |
| 8713984 | Wilson | May 2014 | B2 |
| 20090193864 | Bulle | Aug 2009 | A1 |
| Entry |
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| Hand Tube Bender, ⅜ in. Tube OD, 15/16 in. Bend Radius, https://products.swagelok.com/en/c/hand-tube-bender/p/MS-HTB-6T captured Oct. 26, 2022. |
| Declaration Regarding Prototype Testing of Tubing Bender, Tom Hamner & Tom DePierri Jan. 27, 2023, Robert DePierri Jan. 28, 2023. |
