Bourns Sensors & Controls Product Line -
Model 6639 Product Enhancements

In line with their commitment to product excellence and
continuous improvement, Bourns Sensors & Controls Product Line
is pleased to introduce design enhancements to our Model 6639
Single-Turn Precision Potentiometer. The design enhancements
include the addition of a C-ring to help prevent damage that may
be induced by excessive axial force applied to the shaft when
installing gears or other mechanical devices, and the addition
of an internal shoulder to the shaft to better resist shaft pull
out from the body if excessive shaft pull force is applied.

Bourns first advised of this change in May, 2012 but the
implementation of the design enhancements listed above was
delayed as we are also including a process enhancement change to
the attachment of the contact spring to the rotor. The current
process for attachment of the contact spring to the rotor is a
three-point heat stake design. This process will change to a
five-point heat stake design for more accurate positioning of
the contact spring.

Externally, the design enhancements will be recognized by the
C-ring that is visible in front of the bushing. The noted
enhancements to this product family will have no effect on form
or function. Both the new internal shoulder and five-point heat
stake of the contact spring will help increase the robustness
and reliability of the part. These design enhancements allow the
potentiometer to withstand higher axial loads typically
encountered on installation or removal of mechanical devices
from the shaft . All performance specifications listed on the
current data sheet will remain unchanged.

Revised implementation dates are as follows:

Last time buy date: February 24, 2013
First date code using the above changes: 1314M
Deliveries of modified product will begin: April, 2013

Please contact a Mouser Technical Sales Representative for
further assistance.

5-0113-48