Bolt and nut thread friction locking device with opposite hand threads with a captured spring or spring lock washer

• US 5,855,463 A
• Filed: 09/15/1997
• Issued: 01/05/1999
• Est. Priority Date: 09/15/1997
• Status: Expired due to Fees

• Current Assignee: John C. Newby
• Original Assignee: John C. Newby
• Inventors: Newby, John C.
• Primary Examiner(s): Meyers, Steven
• Assistant Examiner(s): ESTREMSKY, GARY WAYNE
• Application Number:
  US08/929,684
• Time in Patent Office: 477 Days
• Field of Search: 411/222, 411/223, 411/229, 411/231, 411/243, 411/244, 411/262, 411/263, 411/289, 411/312, 411/318, 411/432, 411/910, 411/929.1, 411/931, 411/932
• US Class Current: 411/244
• CPC Class Codes: F16B 39/18 in which the locknut grips with screw-thread in the nuts as well as on the bolt
• CPC Class Codes: F16B 39/38 with a second part of the screw-thread which may be resiliently mounted F16B39/30 takes precedence
• CPC Class Codes: Y10S 411/932 Oppositely threaded

Abstract

A friction thread locking device assembly consisting of several components, which are so constructed and assemble to resist the rotational effects of vibration forces. The resistance is achieved by the use and placement of opposing threads (right and left hand threads) with differing threads per inch and the containment of a compressed spring force and the use of the clearance between matching female and male threads. This bolt and nut assembly by unique construction, combines and improves the aspects of the standard bolt and nut with a spring lock washer. The outer nut and inner nut matching threads are axially aligned and the two are threaded together in opposite directions to compresses the captured spring(s) or lock washer(s). This preloaded, three part assembly with matching inner female threads on both the outer nut and inner nut are axially aligned with each other is then rotated onto the threaded rod with matching male threads. Once in place the outer nut and inner nut are rotated in the opposite direction from each other, which transfers the preload to the male threaded shaft threads. This is due to the clearance between the two sets of male and female threads and to the threads per inch difference between the two sets. The inner nut and outer nut of the assembly can only be rotated in an opposite direction until they meet the resisting force of the opposite hand thread interaction. The assembly is now in a load condition whereas to loosen itself from the rod threads it must tighten itself against and overcome the spring force of the spring lock washer(s) or spring(s).

Claims

1. A locking nut assembly comprising:

a first nut having an opening therethrough, the opening having first female threads therein adapted for threading engagement with a male threaded member, the first nut having a first outer portion of a given diameter and a second outer portion of reduced diameter relative to the first diameter portion of the first nut, the reduced diameter portion having first male threads thereon, the first male threads being substantially concentric with the first female threads and opposite-handed relative to the first female threads, and;

a second nut having an opening therethrough, the opening having a first inner portion of a given diameter, the first inner portion having first female threads therein also adapted for threading engagement with the male threaded member such that the first female threads of the second nut are of similar diameter and the same-handedness as the first female threads of the first nut, the second nut having a second inner portion of a larger diameter relative to the first inner portion, the second inner portion having second female threads of similar diameter and same-handedness as the first male threads of the first nut such that the first male threads of the first nut can be threadedly engaged and assembled with the second female threads of the second nut, the first and second female threads of the second nut being substantially concentric with each other, and;

a spring means for insertion between the first and second nuts prior to their assembly such that the spring is compressed between the nuts when assembled for biasing the nuts in a relative unthreading direction, wherein the assembled first nut, second nut, and spring means can be removably threaded onto the male threaded member in a vibration-resistant connection.

2. A locking nut assembly comprising:

a male threaded member, and;

a first nut having an opening therethrough, the opening having first female threads therein for threading engagement with the male threaded member, the first nut having a first outer portion of a given diameter, and a second outer portion of reduced diameter relative to the first diameter portion of the first nut, the reduced diameter portion having first male threads thereon, the first male threads being substantially concentric with the first female threads and opposite-handed relative to the first female threads and;

a second nut having an opening therethrough, the opening having a first inner portion of a given diameter, the first inner portion having first female threads for threading engagement with the male threaded member such that the first female threads of the second nut are of similar diameter and the same-handedness as the first female threads of the first nut, the second nut having a second inner portion of a larger diameter relative to the first inner portion, the second inner portion having second female threads of similar diameter and same-handedness as the first male threads of the first nut such that the first male threads of the first nut can be threadedly engaged and assembled with the second female threads of the second nut, the first and second female threads of the second nut being substantially concentric with each other, and;

a spring means for insertion between the first and second nuts prior to their assembly such that the spring is compressed between the nuts when assembled for biasing the nuts in a relative unthreading direction, wherein the assembled first nut, second nut, and spring means can be removably threaded onto the male threaded member in a vibration-resistant connection.

3. The locking nut assembly of claim 2 wherein the male threaded member has a concentric opening therethrough defining a pipe such that the locking nut assembly can be used as a bulkhead fitting.

4. The locking nut assembly of claim 2, wherein the second nut has a mounting flange portion of larger dimension than the first and second diameter portions for mounting the assembly.