| 摘要 |
<p>1. A self-centring steady rest (10) comprising:
- a first and a second pivoting lever (11, 12) that are arranged in symmetry relative a plane A - A passing through a centring point B, wherein each lever (11, 12) is divided by a pivot point (5) into a forward portion (13) for contacting a work piece and a rear portion (14) comprising a cam (15) having a cam surface (19)
- a slide (13) that is linearly displaceable in the plane A - A relative the centring point B, wherein said slide (13) has a forward portion (17) for contacting a work piece and a rear portion (16) comprising cam followers (18);
- wherein said cams (15) and said cam followers (18) couples the displacement of the slide (13) to the pivotal movement of the pivot levers (11, 12) between a maximum open working position C and a minimum open working position D so that, the support means on the first and second levers (11, 12) and the slide (13) always are at the same radial distance from the centring point B. According to the invention said at least one lever (10, 60) comprises a first guide groove (40) wherein said at least one lever is coupled to the slide (30) by a connection means (50) which comprises a guide pin (53) that is guided in the guide groove (40), wherein said connection means (50) and said guide grove (40) are designed such that said at least one lever (10, 60) is pivoted from the maximum working position C to a further open release position F when the slide (30) is moved from a rear working position G to a rearmost release position H and such that said at least one lever (10, 60) is pivoted from said further open release position F to said maximum open working position C when said slide (30) is moved from the rearmost release position H to said rear working position G.</p> |
