DUAL MONITOR ARM
2015
Retractable monitor system for up to 4 monitors per chair
Responsible for:
-
Industrial design
-
Mechanical design
-
Patent strategy
-
Prototyping and testing
Monitors are a central part of many operator chairs, and often the user must change between working based on monitor feedback and based on viewing whats in front. Monitors, however, have important ergonomic guidelines to them. When working in front of a monitor for more than a few seconds, any viewing angle outside the 60-90° forward cone induces discomfort in both neck, back and eyes. Therefore, a good way to change the positions of one or two monitors is an advantage for the user.
RETRACTABLE MONITOR MOUNT
NOV RISE: Retractable monitors as mounted on the NOV RISE sit/stand chair. The touch monitors are always kept within proper reaching distance for touch functions, and maintains view angle towards the user's head at all points during the movement.
Mechanical aesthetics: The arm structures are stiff and strong while allowing large movements of monitors and cable chains. This is accomplished by creating overlaying channeled structures from thin sheetmetal spot welded together. Using the natural curvatures of sheetmetal bends can create a modern technical aesthetic when used right.
A tight spot
The ergonomic situation in an operator chair is quite complex. Not only must the monitors be tilted to adjust away any glare based on the users height of vision, but must also adapt to the variable scenarios related to vision. If important information used in the work is displayed on screen, it must lie within a certain angle of vision. Intermittent messages can lie at the edges of these angles, but anything outside the ±60° angle is at risk of not being sensed.
When working with viewing whats in front of the chair, through the cabin window, any monitor inside the proper viewing angle now becomes a hindrance, and should be moved outside the center part of the view. But usually the display is used at short intervals to check levels, cameras etc., so the screen should be angled properly to avoid forward glare. And some systems require more that one screen on each side, which requires the rear monitor to move first in order to make room for the front one.
Finally, the monitor setup has to allow the user to enter and exit the chair in a quick fashion, and not block the side passage in small cabins when doing so.
Elliptical path: The retraction path follows a quarter of an ellipse, which maintains the users head as the center. Notice the monitor normals at various points during the movement.
The solution
In addition to the monitor movements, the mounting system has to provide mechanical stiffness and strength to handle the shocks and vibrations in maritime environments, plus management of the cabling going up to the monitors. Introducing such large movements to a cabled setup requires strict adherence to bending radius and cable friction guidelines.
The retractable monitor mount solves this nicely by having a cable carrier chain follow the outer edges of the arms, which bends in a minimal fashion by curling the chain around the joints
3-point strength
The solution uses the principle of spreading the anchoring at 3 or more points with a large X / Y directional distance between the points.
The problem of existing solutions has been that all force and momentum travels through 1 point, which sets high mechanical requirements to both the single joint and the structure it is bound to.
This 1-point solution also introduces a problem in small cabins, where moving the front monitor to exit requires the user to move the monitor back towards the chair again in order to fit the passage between the chair side and the cabin wall.
By anchoring the mechanism at 2 or 3 points, the local structure around each anchor can be much more simple. Therefore it is more suited for ordinary casted aluminium or sheetmetal walls without any additional struts or strengthening behind.