Lockbolt for forming a mechanically secured and sealant sealed connection between components

#This application is based on and claims the priority under 35 U.S.C. §119 of German Patent Application 101 07 952.4, filed on Feb. 20, 2001, the entire disclosure of which is incorporated herein by reference.

#1. Field of the Invention

#The invention relates to a lockbolt with a locking collar such as a swageable collar for mechanically securing two or more components, i.e. workpieces, through a hole that has been sealed with a sealant.

#In order that the invention may be clearly understood, it will now be described in connection with example embodiments, with reference to the accompanying drawings, wherein:

#FIG. 1 is a side view of a first embodiment of a lockbolt according to the invention;

#FIG. 2 is a side view of the lockbolt of FIG. 1, installed in two sectionally illustrated plate-shaped workpieces that are to be joined, and a sectionally illustrated locking collar arranged on the bolt, at a stage before the locking or joining process;

#As shown in FIG. 1, a lockbolt 1 includes a flat countersunk head 3 mechanically rigidly connected to one end of a generally cylindrical shaft 20. Instead of the countersunk head 3, the lockbolt may have any other conventionally known head configuration, such as a cylindrical head, a pan head, a round head, or the like. Adjoining the bolt head 3, the shaft 20 includes a cylindrical shank 2, which transitions through a preferably conically tapering portion 4 into a profiled or surface-patterned locking portion 5. The surface profiling of this locking portion 5 comprises a knurling 6 therearound, made up of knurling peaks 7B bounded by knurling flanks 7, between respective adjacent knurling grooves 7A. In this embodiment, the knurling peaks 7B are essentially diamond-shaped, i.e. having a pyramid shape with a four-sided diamond-shaped base, and the knurling grooves 7A include two sets of grooves respectively extending in opposite spiral directions helically around the surface of the bolt shaft and intersecting one another.

#The locking portion 5 of the bolt shaft 20 is connected through a predetermined breaking point or frangible neck 8 to a break-away portion 10 of the bolt shaft 20 that is adapted to have an installation tool (not shown) engaged thereon. In this embodiment, the predetermined breaking point or frangible neck 8 is formed by a circumferentially extending groove 9. For securely engaging the installation tool onto the break-away portion 10 of the lockbolt 1, at least a part of the break-away portion 10 is provided with grooves 11, particularly such as the illustrated parallel circumferentially extending grooves 11.

#FIG. 2 shows the arrangement of the lockbolt 1 during the installation process. The lockbolt 1 will cooperate with a cylindrical (i.e. circumferentially continuous) sleeve-shaped locking collar 16 (which may alternatively have an axially shorter ring configuration) to form a mechanically secure connection of two workpieces 12 and 13 with each other. The joint and the lockbolt will additionally be sealed by a sealant 18. In this example, the workpieces 12 and 13 are substantially plate-shaped workpieces. These two workpieces 12 and 13 are arranged overlapping and surfacially contacting each other with respective individual facing surfaces thereof, and are respectively provided with mutually aligned fitting bore holes 14 and 15, through which the shank 2 of the lockbolt 1 extends.