A lead screw mechanism 160, for example for a vehicle access ramp, comprising a support frame 110, a lead screw 150 and an internally-threaded mounting 160. The lead screw has an external thread and is rotatably mounted to the support frame. The mounting comprises a housing 161 and an internally-threaded insert 170 which is rotatably mounted in the housing and engages with the lead screw such that, when the lead screw rotates, the mounting travels along the lead screw. The mounting further comprises a lock 164 with a locked position in which the insert is rotatably fixed relative to the housing and a released position in which the insert is able to rotate in the housing. An electric, hydraulic or pneumatic motor may be used to rotate the lead screw. Therefore when the lock is in the released position the insert is free to rotate on the screw relative to the housing allowing for a manual actuation of the mechanism for instance in the event of a power failure.
Lead screw mechanism
2018-01-31
Patent
Elektronische Ressource
Englisch
IPC: | F16H Getriebe , GEARING / A61G TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS , Transport, persönliche Beförderungsmittel, oder Lagerung besonders ausgebildet für Kranke oder Behinderte / B60P Fahrzeuge zum Transport von Lasten oder zum Befördern, Tragen oder Aufnehmen besonderer Lasten oder Gegenstände , VEHICLES ADAPTED FOR LOAD TRANSPORTATION OR TO TRANSPORT, TO CARRY, OR TO COMPRISE SPECIAL LOADS OR OBJECTS / B61D Einzelheiten oder Arten des Wagenaufbaus von Eisenbahnfahrzeugen , BODY DETAILS OR KINDS OF RAILWAY VEHICLES |