Lock Washer

• US 20110027039A1
• Filed: 07/28/2009
• Published: 02/03/2011
• Est. Priority Date: 07/28/2009
• Status: Active Grant

• Current Assignee: Saint Technologies, Inc.
• Original Assignee: Saint Technologies, Inc.
• Inventors: Blair, James F.L.
• Granted Patent: US 8,186,919 B2
• Time in Patent Office: Days
• US Class Current: 411/149
• CPC Class Codes: B21D 53/20 washers, e.g. for sealing
• CPC Class Codes: F16B 39/108 with a locking washer under the nut or bolt head having at least one tongue or lug folded against the nut or bolt head, or against the object itself F16B39/103 takes precedence

Abstract

A lock washer includes a planar washer body formed of a sheet of resilient metal having a selected thickness no less than the pitch thread of the bolt with which it is to be used. First and second lock tabs integral with the body extend radially outward of the central aperture, wherein each of the tabs has a radially inward facing, straight, free edge transverse to a radius of the body, and each of the tabs is displaced by a spring bend to one side of the plane of the body. The washer body is etched to a selected lesser thickness in the area of the spring bend to provide a selected spring force when the tab is pushed down to the plane of the body.

Claims

1. A lock washer for use with a nut and bolt, wherein the bolt has a threaded shank with a pitch thread, said lock washer comprising;

a planar washer body formed of a sheet of resilient metal having a selected thickness no less than the bolt pitch thread, said body having a central aperture and adapted to receive the shank of the bolt to which the nut is to be attached and locked;

first and second lock tabs integral with said body radially outward of said central aperture, wherein

each of said tabs has a radially inward facing, straight, free edge transverse to a radius of said body,

each of said tabs is displaced by a spring bend to one side of the plane of said body, said washer body being etched to a selected lesser thickness in the area of the spring bend to provide a selected spring force when the tab is pushed down to the plane of said body.

2. The lock washer of claim 1, wherein:

the nut has N flats where N is an integer equal to one of 4, 5 and 6, and

said lock tabs are angularly spaced by more than 90° and

less 180°

whereby when the free edge of one lock tab is engaging the flat of the nut, the free edge of the other lock tab underlies a point of the nut between two adjacent flats.

3. The lock washer of claim 1, wherein said lock tabs and free edge are defined by notches.

4. The lock washer of claim 1, wherein the nut has N flats, and the number of said lock tabs is in an integer of two or greater and less than N.

5. The lock washer of claim 1, further comprising a wing on the end of each lock tab, each wing projecting generally radially outwardly from the end of the lock tab.

6. The lock washer of claim 5, wherein said etching does not extend to said wings whereby said wings have said selected thickness.

7. The lock washer of claim 6, wherein said etched area is on said one side of the plane of said body.

8. The lock washer of claim 1, wherein said etched area is on said one side of the plane of said body.

9. A method of forming a lock washer for use with a nut and bolt, wherein the bolt has a threaded shank with a pitch thread, comprising the steps of:

forming a planar washer body from a sheet of resilient metal having a selected thickness no less than the bolt pitch thread, said body having a central aperture adapted to receive the shank of the bolt to which the nut is to be attached and locked;

cutting notches in said body radially outward of said central aperture to define first and second lock tabs, each of said notches extending substantially transverse to a radius of said body to define a radially inward facing, straight, free edge also transverse to a radius of said body;

etching said washer body outward of said central aperture to a selected lesser thickness in an area wherein the lock tabs are integral with the washer body;

forming a spring bend in the lesser thickness area of each lock tab to displace the associated tabs to one side of the plane of said body whereby the spring bend provides a selected spring force when the tab is pushed down from its displaced position to the plane of said body.

10. The method of claim 9, wherein said lock tabs each include a wing extending in a generally radial direction from their end, wherein said etching is not performed on said wings whereby said wings have said selected thickness.

11. The method of claim 10, wherein said etching is performed on said one side of said plane of said washer body.

12. The method of claim 9, wherein said etching is performed on said one side of said plane of said washer body.