I have some university work to do based on a real world application with five or six bar mechanism, but I am unable to find such a device. Are there real applications of such mechanisms? I've considered some, such as the trigger of a gun and a locking plier, but they are all four bar mechanisms.
Six bar linkages are pretty easy to find. Six bar is the go to guy when a four bar does not offer enough movement flexibility. Bigger European style hidden hinges are nearly all six bar mechanisms, essentially they are two four bar mechanisms that share part of the structure. These are common in many uses but the sixbar hinge you can probably find at home with no special effort usually in kitchen/other cabinets. Sixbar linkages are nearly as common as fourbar linkages.
Five bar linkages are a bit problematic. They have a freedom of 2. And they can not be connected in multi loop configurations as the only config possible is one loop. Since two degrees of freedom is A bit bad design they tend to be avoided. Sometimes you see these with a cam/Gear connection serving as link 5. I have seen powershears that have this property, they are easily mistaken as fourbars as the fifth bar is of limited movement. Sometimes also you see these in robotics setups where corner connected fourbar would not fit.
PS: I'm not at home so I don't have my catalogue with me. So no pictures and details.
To find a ready-made device that utilizes a six-bar mechanism, you can dig through some of the classical resources below. Instead of pointing out a few devices, I think it would be better to point you to these databases.
- 507 Mechanical Movements: Mechanisms & Devices. (amazon link). This book is also available for free as an animated database.
- Mechanisms and Mechanical Devices Sourcebook. (amazon link)
I have used most of them frequently while attending a course on mechanisms design and found all of them equally useful.