Bolt Hole Aligner And Inserting Tool

Abstract

An elongated generally cylindrical body having one end portion tapering to a point and its opposite end having an internally threaded axial recess defining a flat transverse inner end wall surface for abutting engagement with the threaded end of a bolt, for aligning misaligned holes in work pieces to be bolted together and to guiding the bolt through the holes when hammer blows are applied to the head end of the bolt.

Description

BACKGROUND OF THE INVENTION

Drift pins for enlarging holes in sheet metal or for aligning misaligned holes are known, as are elongated points for attachment to rivets, bolts and the like. These are exemplified in U.S. Pat. Nos. 41,170; 375,373; 1,109,094; 1,115,307; 1,394,608; and 1,640,970; French Patent 1,338,898; and German Patent No. 169,471. Most of these are adapted for light duty and are used in connection with leather, fabrics or easily moved work pieces wherein the holes may be formed or aligned by hand pressure or light taps with a hammer. The tool disclosed in German Patent No. 169,471 is of this type. Examples of the heavy duty variety are found in U.S. Pat. No. 1,394,608, all of which are adapted for use with bolts having special forms.

SUMMARY OF THE INVENTION

Tools for aligning bolt holes and piloting conventional or standard bolts through the aligned holes, must of necessity have very thin bolt encompassing walls to pass through most clearance holes for the bolts. When the bolts do not bottom in the recesses of the pilot or inserting tools, hammer blows on the pilot equipped bolts being driven place extreme shear loads on the threads of the piloting tool. In addition, the shock loads on the thin wall portion of the tool causes the wall portion to bulge outwardly or fracture, and the tool quickly becomes useless.

In view of the above, an important object of this invention is a bolt hole aligner and inserting or pilot tool which, when hammer blows are struck on the head of a bolt to be inserted, the shock loads of the blows are applied directly against the solid portion of the tool toward the pointed end thereof, and a minimum of such shock loads are applied to the thin screw threaded wall of the tool. To this end, I provide an elongated generally cylindrical body having one end portion tapering to a point and an axial recess in its other end. The recess is defined by a thin internally threaded cylindrical wall, the maximum diameter of the thread extending axially to a transverse wall surface portion defining the bottom of the recess, so that a standard bolt can be threaded into abutting engagement with the transverse wall surface. Thus, when the head of the bolt is struck with a hammer or like tool, the shock load is transferred directly to the transverse wall surface and from thence axially to the point. Very little, if any, of the shock load is applied against the thread and thin side wall of the recess, so that no outward bulging of this wall occurs.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view partly in plan and partly in section, illustrating the use of this invention in aligning a pair of misaligned holes in work pieces to be bolted together;

FIG. 2 is a view corresponding to FIG. 1, but showing a different position of some of the parts;

FIG. 3 is an enlarged fragmentary view partly in elevation and partly in section, taken substantially on the line 3--3 of FIG. 1, some parts being removed; and

FIG. 4 is a view in plan of a modified form of the tool of this invention.

DETAILED DESCRIPTION

In FIGS. 1 and 2, a pair of work pieces in the nature of flat metal plates are shown fragmentarily and indicated at 1 and 2, these having respective bolt receiving openings 3 and 4 extending transversely therethrough. When in substantial alignment, the openings 3 and 4 are intended to receive a standard bolt or machine screw, indicated at 5, the bolt 5 having a threaded shank portion 6 and an enlarged head 7 in the usual manner.

The form of the tool of this invention, illustrated in FIGS. 1-3, comprises an elongated generally cylindrical body 8 having an end portion 9 formed with an elongated curved taper terminating at a point 10. The opposite end of the body 8 is drilled and tapped to define an axially outwardly opening recess 11 having internal threads 12 encompassed by a thin cylindrical wall 13. Preferably, the outer diameter of the wall portion 13 is only slightly greater than the diameter of the shank of the screw or bolt 5, the outer diameter being preferably only slightly less than that of a normal free fit clearance hole for the bolt 5.

Preferably, the recess 11 is formed at its inner end with a flat surface. Inwardly of the inner end of the recess 11, the body is formed with an axial bore 14, the flat inner end surface of the recess providing an annular shoulder 15 around the adjacent end of the bore 14. An inner body section, indicated generally at 16, comprises a cylindrical stem 17 of a size to snugly fit in the bore 14, and a diametrically enlarged head 18 having a flat outer end 19. The under surface of the head 18 is adapted to seat on the annular shoulder 15.

Preferably, the internal threads 12 are formed with a commercial tapping tool having a tapered outer end. When using such a tool, the maximum diameter of the thread decreases on a taper at the inner end of the recess. In the absence of a body section 16, or the head 18 thereof, the bolt 5 would not bottom in the recess 11. Hence, the axial dimension of the enlarged head 18 is such that the maximum diameter of the thread 12 extends at least to the outer surface 19 of the head 18, so that the adjacent end of the screw or bolt 5 has abutting engagement with the head 18, as shown in FIG. 3. It is realized that a so-called bottoming tap may be used to form the threads 12 at substantially maximum outer diameter to the bottom of the recess 11. However, this involves an additional machining operation without assurance that the maximum diameter extends all the way to the bottom of the recess.

When the main body 8 is screw threaded onto the threaded shank 6 of the bolt 5, with the inner end of the shank 6 tightly against the transverse wall surface formed by the outer flat end 19 of the head 18, and the tool inserted into the openings 3 and 4 of the work pieces 1 and 2, as shown in FIG. 1, hammer blows on the bolt head 7 will cause the tapered portion 9 to move the work pieces 1 and 2 relative to each other to bring the openings 3 and 4 into alignment so that the tool and bolt shank may pass through the openings 3 and 4, as shown in FIG. 2. The impact or shock loads, imparted to the bolt 5 when a hammer is struck against the outer end of the bolt head 7, are primarily borne by the head 18 and transferred axially toward the point 10 of the tool 8 through the annular shoulder 15. By having the bolt end tight against the surface 19, little if any of the shock load is applied to the thread 12 and thin wall 13. Thus, the thread 12 does not become damaged under heavy treatment, nor does bulging of the thin wall 13 occur. As soon as the bolt 5 is disposed in the openings 3 and 4, as shown in FIG. 2, the tool is merely unscrewed from the bolt 5 and applied to another bolt if alignment of holes in other work pieces is necessary.

The form of the tool shown in FIG. 4, comprises a cylindrical main body 20 having a cylindrical end portion 21 and a tapered end portion 22. The tapered end portion 22 defines a plurality of flat faces 23 that converge to a point 24. Internally, the tool of FIG. 4 is identical to that of FIGS. 1-3, the internal portions being shown by dotted lines and indicated by like numerals with the exponent a added.

Preferably, the tools are provided in sets, each set having a plurality of different sized tools to accommodate screws or bolts of different diameters and thread dimensions. Preferably, the tools are made from metal, such as steel, and case hardened or otherwise treated to give long wear.

While I have shown and described a commercial embodiment of bolt hole aligning and bolt inserting tool, and a single modification thereof, it will be understood that the same is capable of further modification without departure from the spirit and scope of the invention, as defined in the claims.

Claims

I claim:

1. A bolt hole aligner and bolt inserting tool comprising a body including an elongated generally cylindrical outer body section having one end portion tapering to a point and an opposite end defining an axial recess, said recess having a thin cylindrical wall the inner surface of which defines a screw thread, said outer body section defining an axial bore extending from said recess toward said pointed end, and an annular shoulder; and an inner body section including a generally cylindrical head engaging said annular shoulder, and a reduced diameter stem received in said bore, said head having a transverse surface for engagement with the end of a bolt threaded in said recess; said screw thread having a uniform maximum diameter axially inwardly from said opposite end of the outer body section to said transverse surface; whereby said transverse wall surface receives shock loads imparted to a bolt in said recess axially in the direction of the pointed end of said outer body section.