| 摘要 |
976, 682. Photo-electric inspection apparatus. P. NASH. April 29, 1963 [June 22, 1962], No. 16701/63. Heading G1A. The invention relates to a self aligning light gate member which is a modification of that described in Specification 899,856 in which the light gate is used for example in the detection of wrinkles in a moving web of paper. In the embodiment shown the gate member 6 having a contact line 15 with the moving material 1 is resiliently secured by a screw 13 and a spring 14 to a fixed member 4, vertical movement being about pivots 12 secured near its edge. In a further embodiment (Figs. 5-7 not shown) the light gate is loosely held by screws to the member, without springs and has a single pivot and is held in contact with the moving material by weights secured to its edge, the friction between the light gate and the moving material serving to pull the light gate into alignment, by the fixing screws contacting the edges of the holes in the light gate through which they pass. In another embodiment (Figs. 8 and 9 not shown) that part of the light gate contacting the moving material, is in the form of a number of cylindrical metal rollers secured in a housing and held in contact with the material and lubricated by an air stream fed to the housing. Specification 899,855 also is referred to. |
