| 摘要 |
An indicator (5,10) on the tongs (1-3) rides along a scale as a function of the spreading movement, the scale in turn calibrated to the degree of anal opening obtained by the tongs. The indicator travels a straight or curved scale and consists of a cursor (5) fitted to one or other tong arm (1,2) so as to move at an angle along the scale in proportion to the relative tong arm movement. Thus the cursor is preferably fixed to the scale-fitted arm and hinged to the other arm by means of a rigid connector (7) which is pivoted on arm (2) to engage the cursor joint (8). The indicator (12) moves along rod (11) which is hinged to one or other arm (1,2) and carries the scale and the two arms (1,2) can be arrested at pre-set spread by arrester (10). |
