Shape restoration metal rolling tool and method
A metal shaping tool assembly, e.g., for auto body repair, includes shaper having a roller mounted between opposite legs in a yoke member. The central member has a recess for receiving an end of a manipulator, which is used as a handle. The manipulator may comprise a tool such as a tire iron. In a method, shaper is operated so that the roller engages the surface being worked to shape to restore the metal to a desired.
1. Field of the Invention
The present subject matter relates generally to a tool for restoring the shape of a deformed metal surface, such as a hand tool which may be used, for example, for auto body work, and a method for employing the tool.
2. Related Art
One form of metal shaping comprises working a deformed metal surface to restore a shape such as a continuous contour. One important example of this form of metal shaping is auto body repair work. Techniques for shaping metal surfaces are used to repair dents in auto bodies, for example, in auto fenders. A dent in a fender usually comprises a depression or a protuberance in a continuous contour of a fender. In order to repair the dent, the dent must be worked so that it is returned to a previous state as part of the continuous contour. A standard (as opposed to sub-standard) repair will take advantage of “memory” in the metal's crystalline structure in order to restore a fender to its prior contour.
A prevalent method of repairing dents is the hammer-and-dolly method of metal repair. A dolly is a hand tool usually comprising a shaped block of steel. It may be used as a hammer or an anvil. In the hammer-and-dolly method, a technician beats on a metal fender, for example, until the fender is restored to its proper shape. In the simplest form of this technique, the technician holds a dolly behind a surface to be worked. The technician hits the fender with the hammer, and the dolly acts as an anvil. The weight of the hammer, the shape of the hammerhead, and the shape of the dolly are all carefully selected to fit the desired shape of a repaired fender. A dolly with a pronounced radius is desirable for a rounded fender. A flatter dolly or the flatter side of a dolly is preferred for a flat quarter-panel or doorskin. The technician uses the hammer to flatten the metal against the dolly.
This technique gives the appearance of being simple and straightforward. However, a technician must accumulate years of experience in order to perform the technique properly. Inexperienced technicians using hammers and dollys inflict a great deal of damage on automobile bodies. The hammer generally causes tool marks. A common form of tool mark is an arcuate indentation left by an edge of a circular hammer head. A significant percentage of the repair time is often required simply in removing marks. Additionally, and significantly, repeated hard hitting of the sheet metal in a fender generally causes the undesirable effects of stretching, deforming, and warping the metal.
These undesirable effects are due to a phenomenon called work hardening. Work hardening is a permanent distortion of crystal structure caused by repeated plastic deformation of the metal. Working of the metal between a hammer and dolly constitutes plastic, rather than elastic, deformation. In addition to the effects already described, the metal loses its memory of a contour.
When this work hardening causes stretching, warping, and other deformation, additional work is necessary to complete an acceptable repair. A preferred process for helping the metal regain its original shape is heat shrinking. The metal is heated in order to allow steel molecules to move back into their original contour. A body hammer is often used to “fine tune” the shaping of a contour. Cooling the heated area shrinks the metal close to its original thickness.
Even this remedial work is ineffective in many cases. The metal cannot regain its original shape. Integrity of the metal structure may be destroyed, which can lead to eventual cracking within the affected area. Options at this point of the repair process are to accept a substandard repair, use Bondo® to give the appearance of a standard repair, or to replace the dented body component.
The extra operations required to complete the repair increase costs. Insurance companies do not wish to pay for additional work that could have been avoided, car owners do not want to have uninsured costs, and body shop owners do not want to see their profit margins decreased.
Undesired effects can be reduced by use of a technique in which a dolly is used to shape the area including a dent. Shaping is completed by hammering the surface “off-dolly,” i.e., without using the dolly as an anvil. However, successful employment of this technique requires a highly experienced technician. Even then, work hardening results.
In recent years, the difficulties described above have been compounded by advances in the construction of automobile bodies. For example, ten years ago, many cars had fenders that were made of steel ⅛″ thick. Today, some car models have body sections made of alloys other than steel. Body sections may be as thin as 1 mm. The different alloys utilized to make such sections strong demand precise repair methods. Distorted alloy panels have a low level of repairability compared to thicker steel panels. Also, today's body technicians must spend a significant portion of their time fixing the tool marks made from pushing a dent down or pulling a dent out. There is a need for a tool that will overcome the disadvantages of the prior art.
SUMMARY OF THE PRESENT SUBJECT MATTERA tool assembly metal shaping, e.g., for auto body repair, includes a shaper and a tool manipulator which functions as a handle. The shaper, which is a subcombination of the assembly, comprises a roller on a transversely disposed axle. The shaper includes a roller which is mounted between opposite legs in a yoke member.
In a plane intersecting the axis, the roller has a curved surface with a central portion having a reduced curvature, and increased curvature between the central portion and lateral sides of the roller. Dimensions of the legs and the roller are selected such that the legs will not contact the metal when the curved surface of the roller is in contact with the metal surface being worked. Additionally, transverse ends of the roller are shaped so that a technician will feel a change in force reaction before the shaper pivots about a corner of the roller.
At one end, the shaper comprises means for securing the shaper to the tool manipulator. The shaper may be releasably secured to or unitary with the tool manipulator. In one form, the shaper receives a tapered end of a tool, for example, as a tire iron. The shaper is operated so that the roller engages the work surface to restore the metal to a desired contour.
A method for a roller constructed as described above is utilized in the context of, for example, auto body repair. For example the metal may be heated. Then the roller is applied against an area displaced from a surface contour. The roller is moved reciprocally, and force is applied against the dent to restore the metal to an original contour. The number of reciprocal motions required is generally a function of the depth of the dent.
Embodiments of the invention are more particularly described with reference to the following drawings taken in connection with the following description.
Embodiments according to the present subject matter will help minimize creation of damage during the repair process and, in selected situations, allow previously unrepairable damaged panels to be repaired. Relatively inexperienced technicians have an increased chance of executing successful, efficient repairs.
One form of tool manipulator 10 may comprise a pry bar such as a tire iron. In this case; the grip 15 may not be formed on the handle 14. The shaper 12 may be designed to fit securely onto distal ends of most commonly used pry bars. A tool manipulator 10 having a selected length may be used for determining the linear displacement in a longitudinal direction of the shaper 12 from a proximal end 13 of the handle 14. Many tool manipulators 10 can fit into one shaper 12, irrespective of their lengths. This allows a technician to, in effect, have a whole set of tool assemblies 1 while needing only one shaper 12. A longer shaft 16 will allow a technician to gain greater leverage than with a shorter shaft. The handle 14 comprises a fulcrum. The fulcrum is operated by one hand of a technician (not shown) closer to the proximal end 13. The shaft 16 may pivot with respect to an other hand of the technician closer to the distal end 19. However, the other hand of the technician will generally not comprise a fixed pivot point.
The shaper 12 is further described with respect to
In the present illustration, the shaper 12 comprises a yoke 26. The yoke 26 has a proximal end 20 and a distal end 22. For the purpose of spatial reference, the degree of freedom in the direction from the proximal end 20 to the distal end 22 is called the longitudinal direction. A direction normal to the longitudinal direction is a transverse direction. A direction normal to the both the longitudinal direction and the transverse direction is a lateral direction.
The yoke 26 comprises a central body 28, which may have a proximal end comprising the proximal end 20. A first arm 32 and a second arm 34 each extend in a longitudinal direction from first and second longitudinal sides 36 and 38 of the central body 28.
The first arm 32 and the second arm 34 need not be displaced by the same longitudinal distance as the first and second longitudinal sides 36 and 38. In the present illustration, longitudinally inward portions of the first and second arms 32 and 34 are separated by a width W in the transverse direction. An inner surface 40 intermediate the first and second arms 32 and 34 is a distance H in the longitudinal direction from the distal end 22 of the yoke 26. The transversely inward sides of the first and second arms 32 and 34 and the inner surface 40 define a recess 42.
A shaft 50, having an axis 52, is mounted in the transverse direction. The shaft 50 is supported at opposite transverse sides thereof by the first and second arms 32 and 34. The opposite ends of the shaft 50 may be press fit, welded, or otherwise secured to the first and second arms 32 and 34 respectively. A roller 54 is mounted for rotation about the shaft 50. The roller 54 may be unitary with the shaft 50 if desired. The roller 54 has first and second lateral sides 55 and 56 for positioning adjacent the first and second arms 32 and 34 respectively. A shaping surface 58 is defined by an intersection of the roller 54 and a plane 60 intersecting the axis 52.
It is generally desirable to form a radius at corners 62 and 64 defined by the intersection of the shaping surface 58 with the lateral sides 55 and 56 respectively. In this manner, the corners 62 and 64 will not comprise sharp edges which may leave undesired lines in a surface being worked. Alternatively, the corners 62 and 64 may be chamfered. In some applications, it may be desirable to provide a roller 54 comprising a right circular cylinder.
One material out of which to make the roller 54 is of stainless steel. Stainless steel does not pick up metal shavings and does not contaminate aluminum panels. The roller 54 may be either polished or unpolished. For use on steel, the roller 54 may be unpolished. It is preferable but not essential that the roller 54 be highly polished for use on aluminum. This construction will meet auto makers' requirements for avoiding galvanic corrosion caused by the contact of dissimilar metals such as steel and aluminum.
The shaper 12 may be releasably secured to the manipulator 10 (
In an alternative form, illustrated in
In an alternative embodiment illustrated in
In one preferred form, a nominal transverse width for a roller 54 may be 1½″ or 40 mm. This width is an optimization for a nominal car fender repair. The width is wide enough to work a piece of metal and narrow enough to afford a technician a high degree of control. Additionally, the force applied by a technician is spread across the width of the roller 54. Therefore, it is desirable to provide a concentration of force at the shaping surface 58 which is adequate to work a dent but which will not easily cause undesired deformation. It is desirable to have a shaping surface 58 wherein curvature increases toward outer transverse ends. If curvature is too extreme, the roller 54 will produce undesired deformation.
A circle 170 is illustrated in
The shaping surface 58 may be resolved into a central section 182 and first and second outer sections 184 and 186. The central section 182 has a high point 183, which is at a maximum radial distance from the axis 50. The outer sections 184 and 186 extend between the central section 182 and the first and second, opposite transverse ends 55 and 56 of the roller 54 respectively. The sections 182, 184, and 186 may be substantially equally wide. However, this is not necessary. Curvature increases from the high point 183 to the ends of the roller 54.
The central section 182 may comprise a section with substantially constant curvature. A transition segment 188 connects one lateral end of the central section 182 (
In one form, the work area is heated to approximately 250° to 300° F., as with a torch 338. The shaper 12 is may be applied to a heated fender. This system minimizes or eliminates creation of tool marks in the metal during a repair. The common disadvantage of prior art methods is that they require expenditures of time and effort to remove tool marks placed in the metal during repairs. Since the present subject matter utilizes a roller, creation of tools marks is minimized.
Prior to use of the tool 12, the operation of
Prior to use of the shaper 12, the dent 310 may be heated to approximately 250° to 300° F. The technician 240 (
Shaping of the dent 310 back into the original contour 302 is aided by the molecular structure of the metal within the quarter panel 300 which provides a degree of shape memory. Because the dent 310 is not subjected to plastic deformation, the memory characteristic is not lost.
The present subject matter will also provide a convenience for technicians. Technicians will often want to grab the nearest tool in order to accomplish a certain task. When a commonly utilized tool is employed as the tool manipulator 10, the tool assembly 1 can be used for common tasks. These tools may be used for frequently performed functions such as patching tires, applying tape seam sealer, repairing bumpers, gluing upholstery, and even for use in rolling into place auto mats or even kitchen tiles. Embodiments of the present subject matter have been utilized successfully in virtually all categories of auto body repair.
The previous description of some aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the spirit or scope of the invention. For example, one or more elements can be rearranged and/or combined, or additional elements may be added. Thus, the present invention is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A shape restoration metal rolling tool comprising:
- a shaper comprising first and second legs displaced in a transverse dimension in a longitudinal dimension;
- a roller having a transverse axis and mounted to said first and second legs and comprising a body having a cylindrical envelope and having an axis extending in a transverse direction, the body having a surface contour in a plane intersecting the axis;
- the surface having a central section, the central section comprising a curve having a lesser curvature than that of a circle having a reference origin which is circle is tangent to the central section;
- first and second outer sections of the surface located between the central section of the surface and first and second transverse ends of the roller, the curvature of first and second other ends being greater than the curvature of the central section; and
- the dimensions of said roller and said legs being proportioned such that when a portion of the surface contour is tangent to a preselected contour, the legs are displaced from the plane.
2. A shape restoration metal rolling tool according to claim 1 comprising a yoke having a distal end in a longitudinal direction and comprising said first and second legs, and adding a proximal end for securing to a tool manipulator.
3. A shape restoration metal rolling tool according to claim 2 wherein said tool manipulator is unitary with said yoke.
4. A shape restoration metal rolling tool according to claim 2 wherein said shaper comprises a lateral surface at a proximal end thereof and wherein a longitudinally extending recess is formed, the recess intersecting the lateral surface to define an aperture, the recess being proportioned for receiving an end of a tool manipulator.
5. A shape restoration metal rolling tool according to claim 4 wherein said yoke comprises releasable securing means for securing said yoke to a tool manipulator.
6. A shape restoration metal rolling tool according to claim 4 wherein a recess is tapered and shaped to receive an end of a tool manipulator, said recess further being shaped to facilitate a press fit between said yoke and the end of the tool manipulator.
7. A shape restoration metal rolling tool according to claim 6 further comprising the tool manipulator.
8. A shape restoration metal rolling tool according to claim 7 wherein the tool manipulator comprises a tire iron.
9. A roller for mounting in a shape restoration metal rolling tool comprising:
- a body having an outer surface defining a cylindrical envelope and having an axis extending in a transverse direction, the body having a surface contour in a plane intersecting the axis;
- the surface having a central section, the central section comprising a curve having a lesser curvature than a circle tangent to a transverse center of the surface contour;
- first and second outer sections of the surface located between the central section of the surface and first and second transverse ends of the roller, the curvature of first and second other ends being greater than the curvature of the central section.
10. A roller according to claim 9 wherein the body comprises a solid of rotation.
11. A roller according to claim 10 wherein each opposite transverse side of the body has a radially extending surface intersecting surface contour.
12. A method for shape restoration of a metal panel having a preselected contour and having a dent therein, said dent comprising at least one deformation wherein an area is displaced from the contour, comprising:
- heating the metal to a repair temperature that is a function of the metal's composition;
- applying to the metal a roller comprising a body having an outer surface defining a cylindrical envelope and having an axis extending in a transverse direction, the body having a surface contour in a plane intersecting the axis;
- the surface having a central section, the central section comprising a curve having a lesser curvature than a circle tangent to a transverse center of the surface contour;
- first and second outer sections of the surface located between the central section of the surface and first and second transverse ends of the roller, the curvature of first and second other ends being greater than the curvature of the central section of the surface contour;
- working the metal with said roller to reduce displacement of selected portions of the area from contour by applying force from the roller to the dent as the roller is moved to rotate about the axis.
13. The method of claim 12 further comprising, prior to applying the roller to the dent, reducing the deformation by impacting the area with hammer strokes utilizing an instrument with a padded cover.
14. The method of claim 12 wherein the dent comprises a peak and a crown on opposite sides of the contour respectively further comprising working the peak and the chrome separately.
Type: Application
Filed: Sep 15, 2009
Publication Date: Feb 2, 2012
Inventor: Ronald P. Starr (El Cajon, CA)
Application Number: 12/584,995
International Classification: B21B 1/08 (20060101);