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(11) | EP 1 179 394 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Over-center power clamp toggle mechanism |
| (57) A rotary clamp (10) having a linkage assembly (17) that provides an over-center condition
for providing high actuation and clamping forces without excessively wearing the components
of the linkage assembly. The linkage assembly (17) is connected to a linear actuator
(12) for converting linear actuator motion into rotary clamp motion between a clamped
position and an unclamped position. The linkage assembly provides a first link (64)
having an aperture (68) for receiving a pin (72) and a roller (70) wherein the roller
is coaxially connected o the pin. A second link (76) is pivotally connected to the
first link, and a third link (82) is pivotally connected to the second link. The roller
of the first link rollably engages a surface (104) on the third link when moving in
and out of the clamped position. A beam-like structure (26) connected to the housing
(18) provides a wear surface wherein the pin (72) engages the wear surface in response
to the roller engaging the third link to prohibit the first link from reaching an
over-center position. A spring detent (118, Fig. 4A; 106, Fig. 4B) is provided in
the third link to engage the roller in the clamped position and resist movement of
the roller from moving toward the end clamped position when power is lost to the rotary
clamp. |