Electro-magnetic dent puller
US 3126046 A
Description (OCR text may contain errors)
March 24, 1964 w. H. RICHEY ELECTRO-MAGNETIC DENT PULLER Filed July 18, 1961 ///e//z BY @.2
United States Patent O 3,126,046 ELEC'IRQ-MAGNETHQ DENT FULLER William H. Richey, London, Ohio (446 E. Church St, Marion, Ohio) Filed July 18, 1961, Ser. No. 124,833 1 Claim. (ill. 1533-2) This invention relates to automobile body repair tools, and more particularly to an electro-magnetic apparatus for removing dents from automobile bodies or fenders, or from other articles constructed of similar magnetic sheet material.
A main object of the invention is to provide a novel and improved electro-magnetic tool for use in straightening dented vehicle fenders, door panels, or other sheet metal areas of a vehicle body, or any other object.
A further object of the invention is to provide an improved electro-magnetic tool for straightening dents in sheet metal surfaces, said tool being relatively simple in construction, being easy to operate, and enabling vehicle fenders, door panels, or other body portions to be straigh ened without the necessity of drilling holes therein or of using hooks, pry bars, or other auxiliary tools.
Further objects and advantages of the invention will become apparent from the following description and claim, and from the accompanying drawings, wherein:
FIGURE 1 is a longitudinal vertical cross sectional view taken through an improved electro-magnetic dent puller constructed in accordance with the present invention, shown positioned in operative relationship with respect to a body panel area to be straightened.
FIGURE 2 is a transverse vertical cross sectional view taken substantially on the line 22 of FIGURE 1.
FIGURE 3 is a perspective view of the tool shown in FIGURES 1 and 2.
Referring to the drawings, the improved electro-magnetic dent pulling tool is designated generally at 11 and comprises a generally cylindrical elongated main body portion 12 which is integrally formed at one end thereof with a transversely extending hollow handle 13 which extends on opposite sides of the end of the sleeve-like main body 12 so as to provide a grip for both hands of the operator using the implement. To improve the grip on the laterally projecting portions of the hollow handle 13, the inside surfaces of said laterally projecting portions are sinuously curved, as shown at 14.
The outer side of the handle 13 is integrally formed at its center portion with a supporting eye member 15 which may be employed to support the implement from a suitable hook, or the like, when not in use.
Designated at 17 is an end cap which is threadedly en gaged on the end of the main sleeve-like housing 12 opposite the handle 13, said cap 17 being provided with a knurled outer surface 18 to facilitate the manual securement of the cap on the end of the member 12. Rigidly secured in the end portion of the sleeve-like housing 12 is a transverse wall 19, and secured thereto in side-byside relationship are a pair of electro-magnets 2t), 2t) said electro-magnets having hollow cores 21 through which extend the respective axial securing bolts 22. The securing bolts 22 have beveled heads which engage in suitable countersunk central openings in the front core flanges 23 of the electro-magnets, the bolts extending through the fixed wall 19 and being fastened thereto by suitable nuts 24, as shown in FIGURE 1. Integrally formed with the wall 19 is a spacer plate 26 which extends between the side-by-side electro-magnets 2t), 26 and which merges with the diametrically opposite peripheral portions of the cap 17, as is clearly shown in FIGURE 3.
The electro-magnets 2h, are connected together in series and are so arranged that a north pole is produced at the face 23 of one of the electro-magnets while a south pole is produced at the face 23 of the other when the magnets are energized. The terminal wires of the seriesconnected magnets extend through and are insulated from the partition wall 19, said wires being shown at 27 and 28. The wires 27 and 28 are connected respectively to the terminals of the secondary winding of a step-down transformer 29 which is mounted in the sleeve-like main housing 12, as shown in FIGURE 1.
A supply cord Si) is provided, said cord extending through a flexible supporting sleeve 31 secured in the ends of one of the laterally projecting arms of the handle 13, the wires of the supply cord being connected respectively to the terminals of the primary winding of the transformer 29 through a control switch 32. Thus, one of the supply wires, shown at 33, is connected directly to a terminal of the primary winding of transformer 29, and the other supply wire, shown at 34, is connected to one of the terminals of the control switch 32, the opposite terminal of the control switch being connected by a wire 35 to the remaining terminal of the primary winding of the transformer 29. The control switch 32 is mounted in the end portion of the sleeve-like housing 12, as shown in FIGURE 1, and is provided with an operating trigger member 36 which projects externally and which extends into the space defined within a trigger guard 38 provided between one of the laterally projecting arms of the handle 13 and the adjacent end portion of the sleeve-like main housing 12.
As will be readily apparent, by employing the stepdown transformer 29, a high current may be provided in the secondary circuit including the electro-magnets 20, 20 at low voltage, so that the primary current in the supply wires 33 and 34 is held to a reasonable value.
In using the tool, a back-up block 40 is employed behind the sheet metal portion 41 to be straightened, the block 463 being of magnetic material so as to cooperate with the sheet metal portion 41 to provide a region where high fiux concentration can be obtained. With the switch 32 closed, the electro-magnets 26, 2% are energized so that the flux developed thereby flows through the sheet metal portion 41 and the back-up block 4h, providing strong adhesion of the implement to the sheet metal portion 41. The sheet metal portion may then be pulled outwardly by exerting outward force on the laterally projecting arms of the handle 13, enabling the portion 41 to be accurately and efiiciently straightened, without the necessity of exerting hammer blows on the inside of the sheet metal portion 41, or of drilling holes for the insertion of pry bars, hooks or other implements.
It will be understood that in using the implement, the normal technique required in dent straightening must be employed. Thus, the electro-magnetic head portion of the tool must first be applied to the outer edge of the dent and the outer edge portion of the dent must then be pulled out by the physical force of the workman. The remaining portions of the dented area may then be straightened by following the usual procedure.
In using the device on large dented areas, the tool may be employed to provide an electro-magnetic connection to a central area of the panel portion to be straightened, so that outward force may be applied to said central area by pulling outwardly on the tool with one hand, and a suitable tool, such as a slapping spoon may be employed to apply impact to the outer edges or ridge of the dent. In such a procedure, in many cases, the central portion of the dent will pop out to its proper shape within a very short time after starting the straightening operation.
An auxiliary mechanical pulling or leverage device may be employed with the tool, whenever required, by connecting same to the supporting ring 15. Thus, the
outward pull may be applied to the tool by the auxiliary pulling or leverage device by means of its fastening to the ring 15, while the user merely holds the switch 32 closed to maintain the electro-rnagnetic attachment of the tool to the portion of the panel to be straightened.
While a specific embodiment of an improved dent pulling tool has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claim.
What is claimed is:
An electro-magnetic dent puller comprising an elongated main housing having a transverse hollow handle at one end, a transverse partition wall in the main housing adjacent to and spaced inwardly from its other end, a longitudinal partition wall in said main housing secured to said transverse partition wall and extending to said other end defining a pair of side-hy-side compartments at said other end of the main housing, respective electromagnets disposed in said compartments and having hollow longitudinally extending cores, respective bolts in said cores extending axially therethrough and through said transverse partition wall and securing the electromagnets thereto, said bolts having heads exposed at said other end of the main housing and flush with the end faces of the electro-rnagnets at said other end, means connecting said electro-magnets in series and so that the end faces of the electro-magnets adjacent the bolt heads will have opposite magnetic polarity when the electro-magnets are energized, a step-down transformer mounted in the housing, means connecting the secondary of the transformer to the series-connected electro-magnets, a control switch mounted in the housing and having an externally projecting operating element located adjacent the handle, and a line cord extending through the handle and connected to the primary of the transformer through said control switch.
Sanchez Aug. 5, 1952 Crowder Dec. 7, 1954