The white goods maker was only able
to make high-current load connections on “drops” or bottom contacts, but it wanted to have the
option of creating these loads on the top or bottom—to have more
flexibility with design. It also wanted to be able to deliver additional
features such as a timer capable of rotating both forward and backward,
making it easier for users to select cycle settings.
Invensys,
a longtime supplier to Whirlpool, knew of its customer’s
wishes because there had been previous discussions about this topic.
Therefore, the Carol Stream, IL, U.S.-based controls and sensors manufacturer
decided to propose to Whirlpool that it would create a new timer to meet
its needs. Whirlpool readily agreed, and the companies began working
together to create a new, customized component—the HD (high-definition)
Timer. While the initial startup began in 2001, the timer did not go
into high-volume production until last year.
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The
HD Timer from Invensys enabled
Whirlpool to add more functionality to its washing
machine. The constant-drive device has a 360-degree
layout that works with switches on a flat disc
and single axis. |
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“It started back a while ago because we previously used their old 168
and 184 series timers,” Jim Miller, manager of washer platform
integrity, Whirlpool, tells APPLIANCE. “We [at Whirlpool] always
just said, ‘Hey, if we do a new timer, this is what we would do
with it.’ Not having one was limiting the ability of us to do the
higher-end machines. In fact, we used to put relays in the machines to
make up for the shortcomings of what the old timer could not do.”
The old timer was a round disc with switches on the outside, explains
Gary LaGesse, vice president/Whirlpool global key account manager at
Invensys. Because of the 360-degree layout of the timer, only so much
switching could be done because this timer was a pulsing mechanism that
used an impulse drive. During the specified interval, the timer could
move a certain number of degrees. In contrast, the HD Timer is a constant-drive
timer and bi-directional. The timer provides more switching in the same
360-degree dial rotation. “Since it is moving all of the time,
it allows for difficult switching without the need for a secondary mechanism,” notes
Mr. LaGesse. Indentation points were also put on the timer so that a
user can actually feel the spot on the dial he or she wants. There is
no longer the need to do a complete 360-degree turn to reach that “detent” again.
“
This allows more to be done in the 360 degrees and for it to be able
to move at a slower, more precise rate as it is turned, which is much
easier and convenient for the consumer,” Mr. LaGesse explains.
The HD Timer is a flat disc with all of the switches on one axis, which
enables more complex switching. “Having a disc instead of a round
drum eliminates tolerance stackups, which allows it to be more accurate,” Mr.
LaGesse adds. “The switches sit in a neutral position—they
are not open or closed. When the mechanism—a follower plate—is
actuated, the switches fall onto the disc. As the disc rotates, it either
opens or closes the switches, depending on the program designed into
it.”
Once the timer was launched, Whirlpool quickly implemented it into its
washing machines, immediately using it in its high-volume models. Within
about 8 months of the timer’s original launch, Whirlpool started
using the timer in its Catalyst model, the company’s premium top-loading,
agitator-based washing machine. The difference, Mr. Miller observes,
has been significant.
“
It has improved our ability to go from concept to production—to
reduce the amount of time in this,” Mr. Miller explains. Previously,
complicated harnessing was used for sub-interval switches to control
dispensers, making the design more complex and less flexible. “It
limited us. We were forced to use the same sub-interval pattern that
we had for a hand-wash cycle also for the dispense cycle,” Mr.
Miller notes. “It limited maximum performance of the washer. There
was also a high amount of assembly labor involved in the old timers.
With the extra parts, just their sheer number drove the opportunity for
something to go wrong.”
One advantage of the HD Timer is that connections can be made on both
the top and the bottom. “It just throws a tremendous amount of
flexibility into the circuit,” Mr. Miller explains. Additionally,
the overall number of components in the new timer is nearly half of the
old one. This alone increases the reliability of the Whirlpool washers,
Mr. Miller explains. “As you reduce the number of components, you
are improving the reliability of the system,” he says. “Also,
there are fewer needs for jumpers and jumper wires, which also improve
reliability. We improved our overall Service Instance Rate (SIR) because
of the new timer.”
During the development of the HD Timer, both Invensys and Whirlpool played
a major part in its conception. Both companies regularly met to determine
what was needed and what actions they could both take to successfully
develop the timer. Once a prototype was developed, they also both took
part in testing the new timer. “The testing and development of
the timer were done together,” Mr. Miller points out. “The
testing was split halfway. The joint test plan we had was trying to maximize
the best thing everybody could bring to the table.” Invensys performed
all of the accelerated contact life testing, while Whirlpool executed
the end application tests in an actual machine at its facility.
The close relationship between the two companies proved particularly
important when Whirlpool added new features, which meant the timer’s
design had to be altered. “The requirement was always evolving,” he
tells APPLIANCE. “This product was designed with flexibility in
mind. For the period when close cooperation was required during the design
phases, this initial design concept proved to be invaluable. What otherwise
could have been an extremely lengthy redesign only promoted a more constructive
exchange of ideas between Whirlpool and Invensys.”
Ultimately, all of the features Whirlpool wanted were provided, including
the forward and backward motion of the timer and the ability to implement
this feature in both its high-end and value products. “Invensys
did a good job of developing the timer and developing it to our needs,” Mr.
Miller notes. “As we went along, there were obstacles. In every
case, they came back to us with very good solutions to our problems.
It kept us on track.”
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