Model 16: Stepdwell motion of a strip for punching and extrusion
Kinematic scheme:
Dimensions:

Dimensions [m] 
a 
0.0240 
b 
0.0480 
d 
0.0635 
k 
1.016823 rad 
r 
0.4074 
e 
0.0306 
f 
0.0125 
g 
0.045 
h 
0.063 
m 
0.374 
n 
0.063 
u 
0.138 
v 
0.329 
p 
0.198 
q 
0.008 
a_{2} 
0.007 
a_{3} 
0.018 
c_{2} 
0.158 
c_{3} 
0.160 
a_{0} 
0.1 rad 
b_{0} 
0.5 rad 
Explanation:
The fourbar linkage performs a symmetrical coupler curve with equal
curve radius r at the symmetry points K^{1} and
During dwell the punching of the metal strip can take place. A disk is
punched out and in the same motion cycle it is deformed by the second punch
until a cuplike product. Both punches are withdrawn sufficiently when the
transport of the metal strip starts, see the picture with the transfer
functions.
Literature: VDIRichtlinie 2728I. Loesung von Bewegungsaufgaben mit
symmetrischen Koppelkurven – Uebertragungsaufgaben.
Remarks:
The motion analysis has been performed with the program Runmec. The
values of angle k and radius r
have been precalculated acc. (lit) for given (measured) values of a, b and d.
The values of m, n and f are calculated also based on them. All other values
are as measured from the model.
The start positions of both cranks are such that their phase angle
differs from the one appearing in the model. The toothed belt at the backside
of the model, connecting both cranks, is mounted such that the phase angle is apparently
not correct.
In the real machine one of the pulleys has a permanent brake to
guarantee the required decelleration of the strip.