US 5,499,892 AGranted

Apparatus for repairing cracks

AssigneeLock-N-Stitch International

InventorGary J. Reed

Life of this patent

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Abstract

A pin is provided for repairing cracks in a material such as iron casting materials. The pin includes threads with both upper surfaces and lower surfaces which angle upwards toward a head of the pin. A tapping bit is utilized in a hole of similar diameter to the pin, positioned with half of the hole on each side of a crack, the bit creating threads in the hole which are substantially complemental to the threads of the pin. The pin includes a shoulder which has a greater diameter than a diameter of the hole. A neck is located between the head of the pin and the shoulder of the pin having a lesser diameter than any other portion of the pin. When the pin is threaded into the hole, the shoulder abuts against a surface of the cracked material causing the pin to cease translation into the material. Upon further rotation of the pin, the upwardly angled threads draw opposite sides of the crack towards each other. Before a torsional load can be applied to the pin which would damage the threads, the head shears off at the neck. A threaded portion of the pin thus remains within the hole holding sides of crack tightly together.

Claims12

Dependent claims

A pin for location into a threaded hole for cold repair of a crack comprising, in combination:

a hole that straddles the crack in a material having a surface, the hole including a first curved wall on a first side of the crack and a second curved wall on a second side of the crack, said hole including hole threads therein with a major diameter and a minor diameter with a portion of each hole thread adjacent the major diameter closer to the surface than any other portion of the hole threads,
a head on said pin including a means to transfer torque to said pin,
a threaded shaft on said pin extending from said head along a central axis, and at least one of said shaft threads including a crest defining a major diameter of said threaded shaft, a root defining a minor diameter of said threaded shaft, and an upper surface extending from a bottom edge of said root to an upper edge of said crest, said upper surface having a portion thereof extending toward said crest at an angle greater than zero from a reference plane perpendicular to said central axis of said pin, and
means for opposing central axis translation of said pin disposed on said pin and positioned to contact the material near the crack;
said pin is threaded into said hole, said central axis translation opposition means coacts with said threads of said hole and said threads of said pin and causes further rotation of said pin to force the first side of the crack and the second side of the crack together.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/174,121Filed 17 Dec 1993 · continuation in part
Priority: 16 Jun 1993
Granted: 19 Mar 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

B23P 6/04
Restoring or reconditioning objects: repairing fractures or cracked metal parts or products, e.g. castings
B23G 5/06
Without means for adjustment: taps
F16B 33/02
Features common to bolt and nut: shape of thread; Special thread-forms
F16B 35/04
Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws: with specially-shaped head or shaft in order to fix the bolt on or in an object