Automobile body dent repair tool

Abstract

A set of tools for the process generally known as “paintless dent repair” for removing a class of dents in automobile body panels is modified to have interchangeable handles with a range of positions relative to the working end of the tool. Thus, permitting the modified set of tools to be comprised of many fewer individual tools than is the current practice in the art.

Description

RELATED APPLICATIONS

None

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to an improved tool for repairing dents in automobile body panels by working the back of the dent in the process generally known as “paintless dent repair”.

2. Description of the Prior Art

Removing dents in automobile panels historically has been a crude application of hammer blows using various shaped anvils and intermediary impact-transfer shapes known as “spoons” and/or drilling through the dent and attaching a puller or slide hammer. Failing to achieve complete success with these techniques, the dent was finished by filling with lead or epoxy-like plastics. The resulting work left a damaged or unpainted surface required repainting of the panel and all the attendant problems of matching colors, surface characteristics, etc., followed over time, by differential fading and weathering.

More recently, especially with the use of the thinner materials in automobile body panel construction, a process of gently tapping and pushing from the back side has been developed. Because the straightening process itself does not damage the exterior surface, it is generally known as “paintless dent repair”

Paintless dent repair is a highly skilled art and requires a large variety of tool tips at the working end of the tool. In addition to a variety of tips, a variety of end curves, shaft lengths, and shaft diameters and/or shapes are needed. In most cases the dent is coaxed out without disassembly of the auto body, thus, the tools are generally long and thin to reach the dent through whatever openings are available or can be made without noticeable damage. The long slim design of most of the tools predicates the use of very high quality tempered steel. Which is not only costly, the tools cannot be bent to suit the immediate task. Because a dent can occur in so many diverse locations, the artisan requires a large set of tools, some differing only by the orientation of the handle relative to the working tip.

The space within a door panel, a common place where suitably denting often occurs, is especially crowded with window glass, window raising mechanisms, locks, motors, structural bracing, etc., and the crowding is getting worse as more gadgetry and structural integrity (for crash protection) is added with each successive model of automobiles.

Furthermore, occasionally dents to be repaired may be better repaired with tools not in the conventional set. The present invention more easily accommodates the construction of special tools.

Most of the tools in the sets available to the trade have handles formed by bending the shank stock into loops or other shapes for handling. Such handles are light weight and somewhat flexible, conditions not always optimum for the work to be performed. Furthermore, a formed handle usually requires 20 inches of steel rod. This may be 30 to 40% of the steel used in a typical set of 300 tools. It is apparent that using shank stock for handles is an inefficient use of the high quality steel required in the rest of the tool.

Paintless dent repair tools were first used in Germany by the Daimler-Benz company. Two current suppliers of the tools in the United States are U.S. Denttools, of Olathe, Kans. and Dentcraft Tools of Oklahoma City, Okla.

In recognition of some of the limitations of the conventional tool set, Mike Cmelik has been awarded U.S. Pat. No. 6,543,270. Mr. Cmelik discloses a tool with interchangeable tips and a means for forming custom temporary end shapes. The movable joint system and need for a tip coupler makes Mr. Cmelik's tool necessarily thicker than the standard “fencing foil” design. Further, Mr. Cmelik did not anticipate the desirability of having a variety of handle shapes and/or orientation.

The present invention utilizes a set of separate handle assemblies designed specifically for gripping and applying pushing, pulling and twisting forces. Each handle has a disconnectable joining means between the handle and tool shank. The joining coupling has a square shank so that the handle may be rotated to any of 4 positions about the axis of the tool shank. A workman can assemble a large number of customized tools from a significantly smaller number of interchangeable components. Thereby significantly reducing the number of individual tool parts required to be a complete working set.

Fenders and fender repair have some unique characteristics. A special fender tool is desirable.

Prior art methods for fender repair comprise the steps of elevating the automobile, removing the tire and wheel, and perhaps the brake drum, then to use various jacks, hammers, pry bars and other crude methods of applying force to straighten out the crumpled fender. Then the fender surface has to be finished smoothly and repainted. Finally, the wheel has to be reinstalled. The method using the tool described herein is a much simpler and less labor intensive process of fender dent repair and dent repair in general.

OBJECTS OF THE PRESENT INVENTION

It is an object of the present invention to have a set of tools for paintless dent repair having significantly fewer individual tool components than is the current practice

It is another object of the present invention to provide a variety of handle shapes orientable in different positions in relative to the working tip of the tool

It is another object of the present invention to provide a tool set that has the same, similar, or improved operational feel and performance as are the tool sets of the current practice.

It is another object of the present invention to provide attachment means for attaching non-conventional, special purpose handles to a conventional style dent tool shaft.

It is another object of the present invention to make provisions for attaching extension shafts between the handle and working tool shaft.

It is another object of the present invention to provide handles of various weights or to be able to be weighted with lead or iron slugs inside a tubular outer form.

It is another object of the present invention to provide handles that can be adapted to tools other than dent repair tools.

The invention described herein fulfills all these objects and others not enumerated.

SUMMARY OF THE INVENTION

Most of the paintless dent repair tools that are the subjects of this improvement in the art of automobile body repair and similar applications have a long thin rapier like shape with a tip on the distal end adapted for urging or forcing a dent from the back side. On the proximal end of the shaft is a fitting adapted to cooperate with a complementary fitting on a handle piece, thereby permitting a handle to be removably attached to the shaft. Said handles are designed for manipulation of the distal end in tight places, and since the handle piece may be in interference with another portion of the automobile body, there must be a variety of offsets available in either or both the handle shape and the attachment to the shaft.

To provide for a stable, yet orientable, attachment of the handle to the shank, the joining means has a square tang that fits into a square socket as part of the handle subassembly and accidental disassembly is prevented by a set screw, a pin, or other retention means. The square tang and socket will connect in any of four radial orientations.

The new handles may emulate the handles found in the art or be specifically constructed to better fit the craftsman's hand. Various shapes, in particular a serpentine form and an L form are preferred. The serpentine or S shaped handle has operating characteristics similar to a T handle.

The new fender dent repair tool is a heavy duty puller which uniquely has a second handle near the working tip. The second handle permits the use of two hands to apply force and to control the placement and stability of the working tip on the dent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is prior art showing a typical tool from a set of available paintless dent repairing tools.

FIG. 2 is an overall view of a typical tool from a set of the present invention.

FIG. 3 is a cross section detail of the joining means between a handle and shank of a tool from the present invention tool set.

FIG. 4 shows the cooperating elements of the joining means of the present invention.

FIG. 5 shows a variety of handles from the present invention tool set.

FIG. 6 shows a 3-section handle with thumb rest.

FIG. 7 is a specialized tool for repairing dents along the edge of a wheel fender.

FIG. 8 shows a handle socket detail showing a holding means for an Allen wrench.

FIG. 9 is a forward handle with clamping means.

INDEX OF COMPONENT IDENTIFIERS

• 1. Prior art tool, overall
• 2. Tool working tip
• 3. Shank
• 4. Handle
• 5. Offset portion
• 6. The present invention, overall
• 7. Joining assembly
• 8. Handle, typical
• 9. ½ of joining assembly
• 10. ½ of joining assembly
• 11. Tang (a.k.a. pin, post, shaft, rod) element of coupling assembly
• 12. Receiving hole for tang of joining assembly
• 13. Setscrew
• 14. Weld
• 15. Detente cooperating with a setscrew
• 16. Generals angle between the axis of coupling and the gripping portion of the handle.
• 17. A general offset angle between the axis of the joiner and the handle
• 18. Thumb rest section of handle
• 19. Thumb rest button
• 20. Allen wrench receiving slot
• 21. Allen wrench receiving hole
• 22. Fender tool shank
• 23. Fender tool shank offset segment
• 24. Fender tool hook
• 25 Fender tool working tip
• 26. Fender tool forward handle
• 27. Angle for thumb rest segment
• 28a. Lower clamp plate
• 28b. Upper clamp plate
• 29. Shank retention groove
• 30. Clamp assembly screws
• 31. Handle piece

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 is representative of a typical paintless dent repair tool (1) in the prior art It is comprised of three essential parts, a working tip 2 at the distal end, a long thin shank 3, and a handle 4 at the proximal end. Typically, the handle is a length of the shank stock formed into a loop or L then covered with a vinyl or similar protective coating for providing both gripping friction and avoiding metal contact with the auto body under repair. As can be seen, the whole assembly is fixed. The handle is a light structure and is in a fixed orientation with the working tip. A set of tools usually contains several tools with the distal end bent into either a radially projecting segment 5 or a hook. A hook if used, is often an arc of approximately 180 degrees for working the far side of a dent.

A full set of paintless dent repair tools may be as many as 300 individual tools. If each has a handle made from 20 inches of high quality steel, approximately 40% of the steel used in the prior art is used in handles. One can see that the present invention results in large savings of quality material, plastic handle covering, and fabrication steps.

Dent removal is a pragmatic art and when necessary, tools are fabricated for special circumstances. This is a situation usually avoided as it is labor intensive and the most readily available source of materials is a tool in the set on hand. Because the present invention has a variety of interchangeable components, the occasions where custom fabrication are minimized. Furthermore, since there is less length in the shank portion, common material from around the shop may suffice for one-time use.

The present invention (6) as shown in FIG. 2 utilizes industry recognizable shanks 2 and tip assemblies, but the shanks are fitted with joiner part 7 for receiving a handle 8.

FIGS. 3 and 4 illustrate the details of the preferred embodiment of the handle to shank joining means.

The shank 3 is fastened to a first portion of the joiner 9, and the handle terminus comprises a structure as a second cooperating portion 10 of the joiner assembly (7). One portion of the joining means further comprises a tang structure 11, shown in FIGS. 3 and 4 as a square rod, which fits within a matching square hole 12 in the other portion. To avoid unintentional disengagement, a retention means is employed. The illustrations show a set screw 13 in the handle and a cooperating detente 15 in a square tang. Other retention means are anticipated and may be freely substituted. Among them, bolts, bolts with knobs or wings, through pins such as cotter pins or roll pins, ball and spring assemblies, etc.

The tang must be long enough and have sufficient cross section to withstand bending and torsional forces encountered while using the tool. A steel tang having dimensions of ⅜ inch square with a length of 1 inch has been found sufficient. Shorter tangs put additional stress on the coupling socket which unless made a larger diameter, may result in the square socket hole being distorted or broken out. Longer tangs reduce the stress and permit use of a smaller diameter joiner body. Small tools may use ¼ inch square tangs, although their inclusion increases the number of handle pieces in a set. A diameter of ⅝ to ¾ inch has been found satisfactory for the joining body which is usually carried into the handle portion at the same diameter.

The gripping portion of the handle may also be fitted with an elastic grip such as a piece of tubing, a bicycle handle grip, or similar.

Shank 3 is shown attached to the associated joining member by welding 14. “Welding” should be interpreted broadly to include similar processes such as soldering, brazing, and glueing. Other attachment methods are anticipated, such as casting, forging, swaging, and various interference press fits including upsets such as knurling and splines. Also anticipated are threaded tangs and chuck-type assemblies. Also included is having the proximal end of shank 3 squared and secured with a setscrew, or threaded. A squared or threaded shank may be attached to either a transition joining assembly as described or directly into the handle socket. Thus, eliminating ½ of the joining means altogether. All these methods of joining the handle and shank have the common characteristic of that the shank is firmly and non-rotatably attached to the handle.

It should be obvious that the two joiner halves can be interchanged, that is, the half with the tang can be on the handle half and the hole in the shank half without diminishing the utility, way, mode, or function of the handle to shank joining device. Similarly, should be obvious that the tang may be a third and separate component with both joiner halves having cooperating holes and retention means.

FIG. 5 shows a representative set of the most common handle shapes. Shown are a serpentine or S shape, an L shape, and a T handle. Not shown, but intended to be included in the mix are ring grips, D grips, grips coaxial with the shank, and grips emulating the prior art. The joiner socket detailed in FIG. 6 is applicable to all the variants illustrated in FIG. 5 and other compatible handle designs.

The angle 16 between the shank axis and the gripping portion may be varied to suit any anticipated applications. The angle of offset 17 away from the axis of the shank may be any varied to suit any anticipated applications. Generally angle 16 will be 90 degrees for T and S handles and approximately 100 degrees for L handles, but a range of 45 to 135 degrees will cover most applications. Generally, the offset angle 17 will be 0 degrees, but a range of zero to 90 degrees will be satisfactory for most applications.

FIG. 6 is a preferred variation on the L handle shown in FIG. 5. FIG. 6 includes three details not shown in the other figures. First, the square socket (or a tang) 12 is located on each end of those handle embodiments where it is practical to use either end. This effectively doubles the options of usage. The second socket may be offset 45 degrees, effectively providing eight positions of rotation as well as a different configuration of handles. Second, instead of an arc joining the two segments of the L handle there is a short approximately straight segment 18. This portion serves as a thumb rest which is more comfortable than a circular arc as illustrated in FIG. 5. Third, a special thumb rest area 19 for receiving the thumb is provided. The general cylindrical curvature of the handle stock localizes the pressure on the thumb. The thumb rest spreads out that load. The thumb rest depicted is a dip ground or forged into segment 18. A thumb rest may be a separate piece of plastic or metal attached to the handle.

The handles of the present invention have larger diameter gripping surfaces than the prior art.

They also may be constructed of heavier material to provide more inertia to use the tool as a hammer to apply taps or blows to very precise places on the backside of the dent being repaired. The handles may be filled with heavy material such as lead or even temporary weighting such as lead shot or slugs, or sand, and the like to provide weight as needed.

In the case of the T, S, D, and some other handle shapes, a portion of the handle is in line with the axis of the shank thus pushing, tapping, or jigging on the handle sends force down the shaft to the tip. This is not possible with the prior art tool depicted in FIG. 1.

Another very positive attribute of the present invention over the prior art is that the removable shank portion is essentially straight, thus, they may be stored compactly in an elongated tool box, a golf club bag, or similar.

Experience with the new tool bears out the design goal that because the handle can be rotated relative to the working tip, it is more comfortable, easier to apply and control the working forces, and is not restricted by interference with the automobile body being repaired. Part of the success of the invention is credited to the larger diameter and rigidity of the handle element. In contrast, the prior art tool handle portion is thin and flexible. The thinness of the prior art handle produces much higher pressures on the palm of the hand for the same working forces at the tool tip. The flexibility of the prior art interferes with the “feel” of sensing pressures, especially in twisting actions.

FIG. 8 details an embodiment of the socket end further comprising a holder for the Allen wrench used to tighten setscrew 13. A hole 21 receives the long end of a standard Allen wrench, and slot 20 permits the short end to be below the end surface of the square socket 12. To keep the Allen wrench from dropping out, a piece of resilient material may be inserted in hole 21 or another small piece of resilient material such as a nylon screw may be inserted through a hole drilled radially from the handle surface into hole 21.

Alternatively, the Allen wrench may be bent slightly and will grip the sides of the receiving hole 21.

FIG. 7 depicts a new specialized tool for repairing dents in the edges of a fender. A typical fender has a rolled bead or inwardly directed stiffening rib on the edge near the tire to add strength and form a smooth, rounded edge. These add significant stiffening to the fender and subsequent dent repair will require much larger forces and more finesse in the application of those forces than is usual for mid-panel dent repair.

The tool shown in FIG. 7 is made of heavier stock and has a unique forward handle 26 for two-handed application of increased force and better control of the working tip. In addition, the handle can act as a fulcrum point by placing a block of wood or similar between the handle and the tire, thereby permitting the repair forces to be applied through leverage actions.

Referring to FIG. 7, handle 8 is one of the embodiments previously described. Shank 22 is a rod approximately 12 to 20 inches long and of sufficient strength to support the necessary loads of the repair operation. Offset 23 is optional. Hook 24 is approximately 4 inches in diameter, but may be more or less. Its purpose is to align tip 25 to enable the tip to transfer force perpendicular to the dent. The diameter of the hook is not critical, and smaller diameters are for working more closely to the fender edge. Larger diameters can reach further into the wheel well. The hook can also reach and grab any internal bracing that may have been crumpled. Most of the paintless dent removal tools are used within auto body cavities and there is no room for forward handles. However, the fender area is open and a forward handle 26 is of considerable assistance to the dent repair artisan. Furthermore, some other dents are near enough to an edge or entrance or are on more open panels such as engine compartment hoods, trunk lids, and roofs. For repairing dents like these, a removable, adjustable forward handle may prove useful in controlling the forces and in the placing of the working tip. Also, with a forward handle, a tool that is longer than optimum may be used, thereby reducing the number of various shank lengths needed in a repair tool set. A forward handle may be either fixedly attached to the shank, or it may be clamped to the shank.

Clamping permits variable axial and radial placement of the handle.

FIG. 9 shows a typical forward handle comprising handle piece and clamp assembly. The clamp comprising fixed 28a and movable parts 28b with a shank retention groove 29 is attached to a handle piece 31. Screws 30 provide the closing and clamping forces. The clamp can be applied to any portion of the shank and turned to any radial angle before tightening the screws.

How to Use the Invention

Paintless dent repair is an art requiring much practice to apply efficiently, therefore, much of how to use the tools cannot be described, but in general, for the current invention, the shank with the most appropriate shape is selected, a handle is selected and attached to the shank in a position where it will be both comfortable to use and not bump into the automobile under repair. The dent is removed by applying pressure at an artfully selected series of spots on the back of the dent by pushing, pulling, twisting, or some combination of those efforts on the tool.

Alternate Embodiments

The figures show the tang being square being a square rod. Obviously, other shapes will provide the same or enhanced functional ability. In particular, hexagonal and octagonal shapes are easy to manufacture and offer a larger number of optional rotational positions than a square rod. Another embodiment of the tang is to replace the polygonal shaped rod with a round rod (ie. pin or cylinder) having an annular ring cut around the surface for engaging the setscrew point. Alternatively, in place of an annular ring, a series of detentes in the same track would provide better resistance against rotation. Another embodiment is to replace the tang with a threaded rod. Flat and wavy (spring) washers or a thin lock nut between the two halves of the joiner would be used to adjust rotational position of the handle relative to the shank's working tip.

The various embodiments of the tang described may be implemented as a separate threaded or polygonal rod sliding into matching holes in both of the joiner elements attached to the handle and shank. It is also obvious that such a pin element may have differently shaped ends as long as the whole joining assembly rigidly connects the handle to the shank.

Another embodiment for the tang structure is to swage, forge, or grind the proximal end of the shank into the tang shape, thereby eliminating the extra pieces and steps pertaining to the shank end joiner mechanism without diminishing the operation and function of the tool with the improved handle.

Another embodiment for the tang function is to have a plurality of pins or rods and cooperating holes arrayed evenly spaced around a circular locus. Only one pin and hole pair needs to have a retention means. One or more pins may protrude through part of the joint assembly and be threaded and secured with a nut or equivalent.

An extender comprising a shaft with each half of the described connector assembly on each end may be part of the tool set. The extender would be installed between the handle and the tool shank.

The ball handle shown in FIG. 5 may have alternate shape such as ovoid, “foot ball” shape, or simply large diameter cylinders. The disk handle shown also includes various non-circular shapes and shapes comprising grip enhancing fluting or projections.

Although the present invention has been described in considerable detail and with reference to certain preferred versions, other versions are possible. For example, while a considerable number of component dimensions have been given, they are illustrative only of the preferred embodiment, and some alterations could be resorted to, while still in keeping within the teachings of the invention. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred and alternative versions disclosed.

The invention has been described in language more or less specific as to methodical features. The invention is not, however, limited to the specific features described, since the means herein disclosed comprise the preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.

Claims

1. An automobile body dent repair tool comprising in combination:

a. an elongated shank having distal and proximal ends, and

b. at least one handle, and

c. a joining means for releasably attaching a handle to said proximal end of said shank, and

d. said joining means further comprising at least one rod and a like number of holes adapted to receive said rods, and

e. said joining means further comprising a securing means for preventing disengagement, and

f. when joined, said shank and handle are rigidly joined and comprise a tool having a handle at proximal end and a working tip at the distal end.

2. The dent repair tool of claim one where said joining means having first and second parts, the first part having an axially extending tang having a polygonal cross section and the second part having an axial hole adapted to receive said polygonal tang in a sliding engagement, said first part attached to said shank, and said second part attached to said handle, whereby when said two parts are joined, said handle and said shank are securely connected.

3. The dent repair tool of claim 1 where said joining means having first and second parts, the first part having an axially extending threaded tang, and the second part having a threaded axial hole adapted to receive said tang in a threaded engagement, whereby when said two parts are joined, said handle and said shank are securely connected.

4. The joining means of the dent repair tool of claim 1 further comprising a rod and where said joining means having first and second parts each having an axially located hole adapted to receive said rod, whereby said rod engaging said holes joins said handle and shank in a securely connected alignment.

5. The dent repair tool of claim 1 further comprising a plurality of interchangeable handles and a plurality of interchangeable shanks, and each handle and shank having cooperating joining means to removably attach said handles to said shanks in a securely connected alignment, thereby comprising a dent repair tool.

6. The dent repair tool of claim 1 further comprising a second handle attached near the distal end of the shank.

7. The second handle of the dent repair tool of claim 6 is fixedly attached to the shank.

8. The second handle of the dent repair tool of claim 6 is removably attached to the shank.

9. The dent removal tool of claim 1 further comprising an extension means comprising a shaft having joining means adapted to couple with cooperating portions of said joining means of claim 1, whereby said extension means is in a securely connected alignment between said handle and said shank, thereby forming an extended dent repair tool

10. The handle at the proximal end of said shank of the dent repair tool of claim 1 further having a thumb rest.

11. An automobile body dent repair tool comprising in combination:

a. an elongated shank having distal and proximal ends, and

b. at least one handle, and

c. a joining means for releasably attaching a handle to said proximal end of said shank, and

d. said joining means further comprising a rod and cooperating hole adapted to receive said rod, and

e. said cooperating rod and hole further comprising anti-rotation means to prevent axial rotation between said rod and hole, and

f. said joining means further comprising a securing means for preventing disengagement, and

g. when attached, said shank and handle are rigidly joined and comprise a tool having a handle at proximal end and a working tip at the distal end.

12. The dent repair tool of claim 11 further comprising:

said rod and hole having a polygonal cross sectional shape.

13. The dent repair tool of claim 11 further comprising:

said rod and hole having threaded engagement means.