| 摘要 |
A variable-length crutch 1 has a main body 2, a foot 5 extensible and retractable with respect to the main body 2, and an actuator, which actuator involves a motor 6, a rotary output shaft 9, an irreversible worm transmission converting rotation of the motor shaft 9 into linear movement of the foot 5 with respect to the main body 2, a sensor 10 for extending the foot 5 with respect to the main body 2, and a programmable module 8 connected to the motor 6 to control extension and/or retraction of the crutch to a preprogrammed length and to stop the motor 6 when the length is reached. |
| 主权项 |
1. A variable-length crutch (1) comprising
a) a main body (2), b) a foot (5) extensible an retractable with respect to the main body (2), and c) an actuator including
i) a motor (6) with a rotary output shaft (9) andii) a worm transmission for converting rotation of the motor shaft into linear movement of the foot with respect to the main body and comprising a threaded rod (12) coupled to the motor shaft (9) and a nut (14) engaged on the threaded rod (12), the nut (14) being coupled to the foot (5) through a first hollow tube (15) mounted telescopically with respect to a second tube (16) fixed to the main body (2), wherein the first tube (15) comprises a longitudinal groove engaged with a screw (17) fixed radially to the second tube (16), so as to form a linear guide preventing rotation of the nut (14), the first tube (15), and the foot (5) with respect to the main body (2) when the threaded rod (12) turn, and d) an electric programmable control module (8) for controlling the motor (6), the module (8) being connected to the motor (6) in order to control the extension and/or retraction of the crutch (1) to one or more lengths preprogrammed into, and under the control of, the module and to stop the motor (6) when the length is reached and being operable for providing progressive acceleration of the speed of the motor (6) at the start of each movement in order to avoid starting shocks. |
