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Technical information about products
Load case I: horizontal suction pads, vertical force
F
TH
= theoretical holding force [N]
m = mass [kg]
g = acceleration due to gravity [9,81 m/s
2
]
a = system acceleration [m/s
2
]
(remember to include the “emergency off” situation!)
S = safety factor
(minimum value 1,5;
for critical inhomogeneous or porous
materials or rough surfaces 2,0 or higher)
The suction pads are placed on a horizontal workpiece
which is to be moved sideways.
Example: F
TH
= 61,33 x (9,81 +5) x 1,5
F
TH
= 1363 N
Comparison:
A comparison of the figures for load cases I and II results, in this example, in a maximum value for FTH =1822 N in load case II,
and this value is therefore used for further design calculations.
Load case II: horizontal suction pads, horizontal force
F
TH
= theoretical holding force [N]
Fa = acceleration = m • a
m = mass [kg]
g
= acceleration due to gravity [9,81 m/s
2
]
a
= system acceleration [m/s
2
]
(remember to include the “emergency off” situation!)
µ
= coeff. of friction* = 0,1 for oily surfaces
= 0,2 ...0,3 for wet surfaces
= 0,5 for wood, metal, glass, stones,...
= 0,6 for rough surfaces
S = safety factor (minimum value 1,5;
for critical inhomogeneous or porous
materials or rough surfaces 2,0 or higher)
The suction pads are placed on a horizontal workpiece
which is to be moved sideways.
F
TH
= m x (g +a/µ) x S
Load case III: vertical suction pads, vertical force
F
TH
= (m/µ) x (g +a) x S
* Attention! The coefficients of friction shown above
are average values.
The actual values for the workpiece to be handled
must be determined by testing.
For the example used for this description,
load case III can be ignored, since the workpieces
are to be handled only in a horizontal orientation.
F
TH
= theoretical holding force [N]
m = mass [kg]
g
= acceleration due to gravity [9,81 m/s
2
]
a
= system acceleration [m/s
2
]
(remember to include the “emergency off” situation!)
µ
= coeff. of friction = 0,1 for oily surfaces
= 0,2 ...0,3 for wet surfaces
= 0,5 for wood, metal, glass, stones, ...
= 0,6 for rough surfaces
S = safety factor (minimum value 2;
higher for critical, inhomogeneous or porous
materials or rough surfaces)
The suction pads are placed on a vertical or horizontal workpiece
which is to be moved vertically or turned to the other orientation.
Example: F
TH
= 61,33 x (9,81 +5/0,5) x 1,5
F
TH
= 1822 N
Example: F
TH
= 61,33 x (9,81 +5/0,5) x 1,5
F
TH
= 1822 N
a
APPENDIX
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