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Preventive Mechanism of Set Screw Loosening

IP.com Disclosure Number: IPCOM000121528D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Kaneko, Y: AUTHOR [+4]

Abstract

Described is a mechanism for preventing set screw loosening by depositing sintered hard alloy over the point and screw thread of a set screw with the use of discharge arc-welding equipment.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 85% of the total text.

Preventive Mechanism of Set Screw Loosening

      Described is a mechanism for preventing set screw
loosening by depositing sintered hard alloy over the point and screw
thread of a set screw with the use of discharge arc-welding
equipment.

      Set screws may be loosened on account of vibration or shocks
from collision.  However, there are few set screws with the
preventive mechanism against loosening.

      The set screw fixes an object mainly with its own screw point,
as shown in Fig. 1.  The causes of set screw loosening are:
   - The pressing force of a set screw to an object decreases due to
the collapse of the point of the set screw at the time of fixing or
exhaustion caused by machine vibration.
   - The pressing force to an object decreases because the set screw
rotates back.

      In order to increase the hardness of the set screws, to prevent
the set screws from rotating back, and to modify the set screws
available on the market at a low price and without any difficulty, we
developed a method to coat the points and screw threads of set screws
with sintered hard alloy by using discharge arc welding equipment.

      The sintered hard alloy coating on the surface of set screws
increases their hardness, and therefore prevents the collapse and the
exhaustion of their points.  It also prevents loosening because it
increases the frictional resistance between the external thread and
the internal thread (Fig. 2).

      Moreover, any kin...