Patent Number: 050139452
Section: claims

1. A linearly operating motor for stepwise advance of a driven member (11), such as a shaft, comprising an elongated body (10) with length variable properties, and means for changing the length of said body (10), said driven member (11) being provided with at least a first pivotally mounted locking means (12) and having a through-hole to drive said driven member (11), said first locking means (12), upon length increase of said body (10), being adapted to first swing so that a grip is obtained between said driven member (11) and hole and adapted to move said locking means (12) and the driven member (11) in the advance direction thereof. 2. A linearly operating motor for stepwise advance of a driven member (11), such as a shaft, comprising an elongated body (10) with length variable properties, and means for changing the length of said body (10), said driven member (11) being provided with at least a first locking means (12), said first locking means (12), upon length increase of said body (10), being adapted to be brought into engagement with said driven member (11) by means of said length increase and said body (10) being adapted to act upon the first locking means (12) in such a manner that said locking means and thereby also said driven member (11) are displaced at length increase of the body (10), said locking means comprising a ring (30) having a through-hole for the driven member (11) and a wedge (31) with a wedge surface adapted to rest against the ring (30), whereby at length increase of the elongated body, the wedge (31) is adapted to first press the ring (30) against the driven member (11) and then to displace the driven member (11) in the advance direction thereof. 3. A linearly operating motor for stepwise advance of a driven member (11), such as a shaft, comprising an elongated body (10) with length variable properties, and means for changing the length of said body (10), said driven member (11) being provided with at least a first locking means (12), said first locking means (12), upon length increase of said body (10), being adapted to be brought into engagement with said driven member (11) by means of said length increase and said body (10) being adapted to act upon the first locking means (12) in such a manner that said locking means and thereby also said driven member (11) are displaced at length increase of the body (10), said locking means comprising a first pivotally arranged element (24) and a friction element (25) connected thereto and intended for engagement with the driven member (11), whereby the elongated body (10) at its length increase is arranged to swing the first element (24) in a direction towards said driven member (11) by first forcing the friction element (25) to abutment against the driven member (11) and then advancing the driven member (11). 4. A motor as claimed in claim 1, wherein the locking means 12 is displaced against the action of a resilient element (22), which is adapted to apply a pretensioning force upon the elongated body (10).