US 6,981,372 B2
Hydraulic actuating device for a convertible top assembly of a vehicle
Laurentius Andreas Gerardus Mentink, Haaksbergen (Netherlands); and Johnny Antonius Jacobus Wiggemans, Oldenzaal (Netherlands)
Assigned to Actuant Corporation, Glendale, Wis. (US)
Filed on Aug. 22, 2002, as Appl. No. 10/227,261.
Application 10/227261 is a continuation of application No. PCT/NL01/00132, filed on Feb. 16, 2001.
Claims priority of application No. 1014476 (NL), filed on Feb. 23, 2000.
Prior Publication US 2003/0005692 A1, Jan. 09, 2003
Int. Cl. F16D 31/02 (2006.01)
U.S. Cl. 60—431 20 Claims
OG exemplary drawing
 
1. A hydraulic actuating device for a convertible top assembly of a motor vehicle, which actuating device comprises:
a hydraulic pump with an associated electric pump motor,
one or more hydraulic actuators, each for driving an associated moveable part of the convertible top assembly,
a control circuit for effecting a defined sequence of movements of the one or more hydraulic actuators,
which control circuit includes a feedback circuit for producing a feedback signal corresponding to a magnitude of current intensity in the pump motor and a control unit that receives the feedback signal from the feedback circuit, wherein the feedback signal provides an indication of the sequence of movements of an actuator back to the control unit, and wherein the control unit monitors the feedback signal to control the movements of the one or more hydraulic actuators to effect movement of the convertible top assembly, and wherein the control circuit further establishes within a predetermined time period starting after a predetermined time since activation of the actuator has elapsed weather a moving actuator has reached a limit position by determining whether the feedback signal conforms to at least one of a predefined value and an extent of change.