Wednesday, February 12, 2014

Windsor Industries Vac Pac Shoulder Harness Redesign

Improved Windsor Vac Pac Harness Design
While at Windsor Industries I worked on a redesign of the harness system for their backpack vacuum. It is simply a vacuum cleaner worn on the back. This product is used in commercial cleaning to clean office cubicles. You may have seen it if you work late in an office setting.The idea is that the operator is less fatigued wearing the vacuum then pushing a heavy upright vacuum back and forth several hundred times an evening. The original harness was a stripped down version of a competitors that offered minimal comfort as can be seen in the photo below- no back padding, poor should straps and a small padded belt.

Prior Vacuum Harness Design

This project was spurred on by customer complaints about comfort, dropping sales and more competitors entering the market. After initial research into user issues,ergonomics and related product designs, like backpacks, a number of concept were developed to address the project demands. These sketches show some of my first thoughts.

One Piece Harness Concept Sketch
Back of Harness with Tool Holder

To address the comfort issues a number of improvements were made. Applying ergonomics to the concepts the range of people that the harness would fit was expanded greatly to include about 90% of the general population. This included changes to the size of the waist belt and shoulder straps. Padding in each of these were improved because users often carried the Vac Pac by its straps because they hurt so much.  When the vacuum is full it can weigh up to 35 pounds and the straps can cut into the shoulders sharply. Straps were also contoured to fit over the shoulders and curve in under the arms and fitted with a sternum strap to keep the shoulder straps in the right place.  Padding was also added to the back panel to protect back muscles and spine. Working with an outside contractor, we started to develop some physical  prototypes. Below is the base concept showing these improvements.

Base Back Vacuum Concept
Graphic Representation of the Concept

While straps were lengthened to fit a broader range of people it was difficult working with the current frame design to provide a better weight management and fit for taller people. The next concept looked into how the shoulder strap system could slide up the frame more to address these challenges.You can see the height adjustment strap attached at the base of the padded back pad down to the hip belt which achieved this goal in the concept below.
Base Concept with Adjustable Height
Adjustable Height Strap Added

While the changes to the second concept were a step in the right direction it did not satisfy the need of the user. One of the project's boundaries was to use the current frame in the new design.  There was also the push to make the new design reto-fit to older machines so the new harness design could be sold as a replacement or upgrade too. To keep these parameters, an additional sub-frame piece was developed to fit the existing frame.

Design with added Sub-Frame
Vac Pac with Extended Height Adjustment

While the parameters of using the same frame for the redesign sounded good at the beginning it was realized that this requirement was interfering with the main  goal of the project. The added sub-frame along with an extra lumbar pad on the waist belt was running up the cost quickly. It was also felt the design was not substantial enough for the rigors of commercial cleaning. Taking a look at the opportunity to develop a new frame allowed us to get the height we needed to fit people much better. It also enabled us to incorporate a lumbar support right into the frame which allowed us to remove the cost of the padded lumbar pad on the waist belt.

One Piece Frame Design with Carry Handle
New Frame Design

In the end, the final design used a new longer length frame with a lumbar support curve molded right in. Bearing straps, running from the top of the shoulder strap to the top of the frame, were eliminated because the frame was not designed to handle the forces that would be put through them.

The redesign was met with good success. Sales increased. Orders came in for replacing the harness on vacuums with the old design and user comfort was improved with minimal cost increase to the product.

If you are interested in design services for your product or product idea, please click this link to go to my website, Bullseye Design Worx. To see more examples of sketching click here, and to see more examples of prototyping click here.