Product category:
Springs, dampers, latches, locks and small components
News Release from: Abssac | Subject: Machined springs
Edited by the Engineeringtalk Editorial
Team on 06 July 2005
Machined springs solve battlefield noise
problems
For those engineers familiar with the traditional wound spring format, Abssac is offering a new way of looking at reliability, performance and attachment by use of a machined spring.
During the Gulf War a TV battlefield crew was conducting an interview with a battle tank in the background The interview was stopped due to abnormal audible noise emanating from the tank
The source was found to be a night vision system externally mounted on the side of the tank.
Within the system, an armature suspended by two wound compression springs made up the dynamically moving parts.
These parts are then altered from their state of rest by a linear motor, which supports the infra-red optical scanner.
The resonance of the linear motor was then being audibly amplified by the wound springs, which naturally had serious issues with a battlefield arena.
The noise was also obviously consuming some of the potential efficiency of the linear motor.
The manufacturer of the equipment needed a solution - and fast.
After serious review and analysis a machined spring design was developed.
A double start coil configuration, which incorporated the head and foot attachment plates into the single piece design was developed.
By nature, the end coil of a machined spring does not contact or wind into adjoining coils.
The end result is no contact, no noise, more efficiency and greater spring performance within the system.
For those engineers familiar with the traditional wound spring format, Abssac is offering a new way of looking at reliability, performance and attachment by use of a machined spring.
Although we all agree that traditional wire wound springs have numerous bona fide applications, the very nature of how they are manufactured can limit their reliability and performance in the more demanding or high duty cycle spring applications.
Machined springs, as many existing Abssac customers have found, are more useful than you may first think.
As with its wire wound brother, all types of spring format such as, compression, extension, torsion, lateral translation and lateral bending springs are available in the machined format.
However, from this point the similarities between wound and machined springs stop.
Machined springs can provide very precise, linear deflection rates because virtually all residual stresses are eliminated.
As a result, there are no internal stresses to overcome before deflection occurs, which can be the case in the wire wound spring.
In addition to this we can offer multiple start spring coil configurations.
The most common configuration is the single start spring, which consists of a single continuous coil element, which starts at one end and terminates at the other end, much like its wire wound counterpart.
A double start spring has two intertwined continuous coil elements.
In effect, this puts two independent helixes in the same cylindrical plane.
Multiple start flexures, such as triple start etc, are similar extensions of this concept.
The advantages of multiple start spring elements are beneficial because they not only provide redundant elastic elements should a failure occur, but a failed element (coil) will be physically trapped by the remaining one and in many cases will allow the albeit reduced function of the spring design to still operate.
Another multistart benefit applies to compression and tension springs, as when compressed (or extended), single start springs provide a reaction force plus a moment.
On multiple start flexures, all internal moments are resolved within the spring itself which translates into excellent compression or extension parallelism.
There is no tendency for the spring to squirm when deflected, and no restraint is necessary to resolve the free moment.
Double and triple start variants make the loading points irrelevant on the radius of the spring but increase the accuracy of parallelism.
With the machined spring, perpendicularity, parallelism, lateral bending, axial and torsional rates can be guaranteed.
The next time you require a spring in a critical or high duty cycle environment, a machined spring from Abssac may be the answer to the design problems. Request a free brochure from Abssac ...
• Abssac: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
Search the Pro-Talk network of sites
