GB1000934A - Trailing blade coater - Google Patents

Abstract

1,000,934. Web coating apparatus. RICE BARTON CORPORATION. May 23, 1963 [May 28, 1962], No. 20680/63. Heading D1L. A trailing blade type coater having a backing roll 10 over which a travelling web 16 to be coated is drawn in a downward direction and a pond and doctor blade assembly including a pond enclosure having an open face closed by the web, and a doctor blade forming a bottom closure against the web, is characterised by movable supports on which the pond enclosure is movable for adjustment toward and away from the travelling web and a system of relatively shiftable overlapping main and auxiliary dyke members forming a liquid light expandable and collapsible closure between the rear face of the pond enclosure and the web, at each end of the pond. As shown the doctor black and pond assembly comprises a tubular support member 17, a bar 18 bolted thereto and shaped to provide a pond for the coating material, a lower movable jaw 22 which supports doctor blade 23 and a dykes assembly 24, 25 at each end. Each dyke assembly consists of a dyke 24 fitted to and in fixed relation to the internal face of the pond to be movable adjusted therewith and an auxiliary dyke 25 which is held in a relatively stationary position adjacent the backing roll and web the two dyke parts having sealing means there between and being capable of relative movement. The tubular member 17 has, secured to each end, end plate members 26 which are pivotally mounted on elements 28 at 32, the pivot 32 being substantially in alignment with the edge of the doctor blade so that the entire assembly can be rocked about this edge. The elements 28 are pivotally supported by pins 38 on normally stationary brackets 42 pivotally mounted on shaft 12 of roll 10 such that movement of links 28 about pins 38 will have the effect of moving the pond and doctor blade assembly in an in and out direction with relation to the backing roll 10 and web 16. Rotational movement of brackets 42 has the effect of raising or lowering and thereby adjusting vertically, the position of the pond and doctor blade assembly. The position of brackets 42 is determined by links 48, 52 and rock shaft 56 operated by a motor and brake unit 58. Rocking of the assembly about centers 32 is controlled by a pair of pneumatic cylinders 60 and associated pistons 62 and the in and out adjustment is controlled by a pair of pneumatic cylinders 68 and associated pistons 72. The dyke assemblies for closing the end of the pond have air pressure sealing means at their peripheries and the two positions 24 and 25 are in sliding contact with each other by means of bolt and elongated slot connections. Further the dyke assemblies are adjustable in position by telescoping connections 100, 102; 86, 88. The doctor blade 23 is mounted in a holder 110 which in turn is mounted in the slotted upper surface of slide bar 112 which is supported for backward and forward sliding movement between upper jaw 20 and lower jaw 22. Towards its outer edge blade 23 is supported by edge plate 114 there being a loose fit between the jaw 20 and plate 114 so that the blade 23 can bend downwardly under the pressure of fluid in the pond. The lowe jaw 22 is mounted on a series of yokes 116 which are pivotally mounted on shaft 118 and has rearward extensions 120 which engage an inflated tube 122 resting against the underside of tubular member 17 so that the weight of the lower jaw is carried directly by the member 17 and thus does not tend to strain or warp the blade 23. Forward and backward adjustment of the blade 23 can be effected by means of screw threaded rods 124, sleeves 126 and nuts 128. A fine adjustment may be effected by knobs 134. In a second embodiment the entire dyke assembly is mounted on a bracket which is supported for adjustment longitudinally on a guide bar secured to the bar 18, and comprises two spaced parallel plate members with a movable auxiliary member there between.