# How do I determine ‘closed angle’ and ‘open angle’ of a cover?

Filling in the Cover angle ‘closed angle’ and ‘open angle’ (Start angle and End angle)

The following agreements – in accordance with the hour hand of the clock – apply here:

• 12 hours on the clock =  90 degrees …. cover stands right up
• 3 hours on the clock  =     0 degrees ….. cover lies horizontally ……………..’Lying’ Cover
• 6 hours on the clock  = – 90 degrees …. cover hangs down vertically ….. ‘Hanging’ Cover

Left part of the page: Cover positions such as those which could occur with a ‘Lying’ Cover:

• Roof hatch (skylight)
• Attic hatch
• Toy box
• Basement hatch
• Garden box
• Hatch cover
• etc.

Right part of the page: Cover positions such as those which could occur with a ‘Hanging’ Cover:

• Sales vehicle hatch
• Takeaway counter hatch
• Safety screen
• Awning on horse trailer/handyman bus
• etc.

* Cover rotates from Start angle to End angle (length of gas spring is then at a maximum)

The intermediate Cover angles can be determined, for example, with an inclinometer or by means of a smart phone (with an inclinometer app).

Important!

Do not just accept the inclinometer or smartphone reading as the actual cover angle.

But first, determine the difference between Cover position and horizontal or between Cover position and vertical and then calculate the actual Cover angle from those according to the aforementioned statement.

Cover angles can also be determined by measuring and calculating.

In what ways can such a measurement be carried out and how the calculation is then done, is illustrated in the following examples:

A = inclination of the Cover measured from horizontal (or measured from vertical in another example)

S = Hinge side of the Cover

L = Length of the Cover

Calculating a Cover angle: