desigining a Touchscreen display for use on oil derricks 

The Challenge

Display maker, Planar Custom Products Group, wanted to build a touch screen control interface for industrial equipment on oil derricks. Lacking the full internal team for the project, they came to Sherpa for industrial design and mechanical engineering on the project.

Our job was to take the display and electrical boards, package them and provide detailed final design model for manufacturing.

Requirements

The Planar Touchscreen had a challenging requirements list. Sitting in the hot sun in a marine environment (salt water, air, rain, sun, stormy winds), the touch screen will be used all hours of the day.

It needed to be protected from the elements including the input-output ports. It had to dissipate heat from the internal electrical components. It also needed a sun shield so that the display screen was visible in the middle of the day in the full sun. It needed to have a standard mounting bolt pattern on the back of it and be able to mount on the deck of rig, oil derrick, and other industrial environments. The unit had to be watertight and have condensation factors for the internal components. The display had to be sealed, and the entire back case turned into a giant heatsink to dissipate heat. 

Our Approach

We started by collecting all the components, arranging them and then developing some industrial design concepts.  We researched materials and appropriate finishes for the environment.  You can see some of our concepts below along with the questions they generated.

Prior to having our own industrial designers, we partnered with Dennis Veatch at CreatID for this project. Once the cosmetic looks of the product were approved by the end customer, we went into the detailed mechanical design phase incorporating seals, fasteners and design for assembly manufacturability. 

Special consideration was given to surface finish process because the case was made of diecast aluminum and sealing cast aluminum surface finishes is inherently challenging.

In addition to sealed input-output connectors, a portion of the case was designed to protect the external cable connections.

The sealing solution, the dual-purpose sun shield and screen protector, and general packageability of the product were unique design elements.

Sealed Enclosure Solution

The device had to be sealed so no external cooling air could be introduced.  In order to dissipate the heat produced from the electrical components, thermal pathways had to ensure heat was transferred to main enclosure.

To tackle this challenge, we used cooling fins, gap pads, and sealed one-way vents to balance the outside air pressure. A CFD study was conducted to confirm that the temperatures would remain inline to specs.

Dual Purpose Cover

We needed to protect the screen with a removable shield/cover, but wanted to avoid a completely removable part that could potentially get lost.  We decided to utilize this cover feature to also solve the “viewing in direct sunlight” challenge.  By utilizing two integrated spring plungers in machined pockets the cover can be held open at various positions in combination with detents in the hinge bracket.  That in combination with friction washers provided adequate adjustment and holding power.

Packageability

The entire unit featured a die cast front and rear bezel with injection-molded front cover.  The entire chassis weight was under 10 lbs. We used injection- molded glass-filled ABS or Nylon for the front cover with an integrated gasket to reduce vibration when closed.

Planar wanted to improve the handle design, allowing a technician to be able to hold it with one hand, keeping installation and uninstallation in mind. We used a 3/4” aluminum tube handle with 10-32 ‘tube nut.’

We needed to protect the cables coming into the bottom from getting damaged in service. We made sure they were inset and reviewed leg length and proper strain relief accommodation. We made sure the cover engaged at the bottom edge of the bezel for greater fit assertion when closed. We increased the width of the cover to accommodate load transfer to case sides to enable unit stacking.

Conclusion

Upon approval of the finished design, prototypes were made and tested successfully in a real-world environment. The final product was sent for manufacturing and is used today in various marine environments –like the Electronic Drilling Recorder shown here as Rig Display 19.