Patent GB-416863-A (GB)
Title: Improvements in or relating to shoe stiffeners
IPC: A43B23/08
Filed: 1933-03-23
Abstract: 416,863. Shoe stiffeners; endless conveyers. BRITISH UNITED SHOE MACHINERY CO., Ltd., Belgrave Road, Leicester.-(United Shoe Machinery Co., Soc. Anon. Espanola; 5, Calle de Fortuny, Barcelona, Spain.) March 23, 1933, No. 8750. [Classes 17 (i) and 17 (ii).] Shoe stiffeners comprising porous absorbent blanks impregnated with a solution of cellulosic stiffening material receive the necessary strength by employing a solution which contains more than 20 per cent by weight of the stiffening substance, a viscosity reducing agent, such as 1 per cent by weight of the celluloid of potassium acetate, being added to the stiffening substance to ensure permeation of the stiffener blanks. The rear or other marginal part of the stiffener blank may be compressed before impregnation so as to take up less of the impregnating solution per unit volume and to be softer at that locality. Apparatus for impregnating died-out blanks with stiffening material comprises a pair of presses 9, Fig. 1, arranged side by side under the control of a single operator and similar in construction to presses employed for heating thermoplastic toe stiffeners and pressing them into shoe uppers before lasting. The lower dies 11 are locked against movement and the upper dies 13 are under treadle control to apply pressure for a predetermined period, say 5 secs. and then rise. A conveyer 17, consisting of a plurality of cables carries the blanks, which are placed thereon in two rows in staggered relation by the operator, to an enclosed impregnating apparatus, shown in Fig. 2. The blanks are delivered at regular intervals by a roll 23 to a conveyer 29, similar in construction to the conveyer 17 with the cables of one conveyer running between the cables of the other, and are carried thereby to the impregnating roll 31 which rotates slowly with its lower portion in stiffening solution contained in a tank 43 and maintained at a temperature of about 40‹ C. by a water bath heated by an electric unit 85. The roll 23 makes three revolutions to every two revolutions of the roll 31 so that the blanks are delivered to a coated part of the roller 31. Stripper rolls 73 and felt presses 75 remove impregnating solution from the conveyer 17. The blanks are carried between the cable conveyer 29 and a similarly constructed conveyer 55, arranged as shown, through the solution to a roll 33 and are progressively squeezed, as they pass to the roll 33, between the rolls 31, 33. The blanks, as they expand after the squeezing, absorb more solution from the roll 33. Similar progressive squeezing occurs between the rolls 33, 35 where the blanks are calendared and surplus solution is removed between rolls 35, 37. A pulley 38 aided by a stripper 61 delivers the impregnated blanks from the conveyer 29 to a receptacle 39, which rests on a vertically movable support the upper end of which is held up against a felt sealing washer 69. An alternative form of impregnating apparatus is shown in Fig. 5, the blanks being fed by a conveyer 17, as before, to a roll 101 from which they are taken by strippers 103 and fed between rolls 105, 107. The amount of solution on the roll 107 is controlled by a stripper 109. The blanks adhere to the smoother of the two rolls 105, 107 and the roll 105 is for this reason scored more deeply than the roll 107, which is grooved for feed fingers 111 by which the blanks are removed from the roll 107. After passing through the solution, the blanks are squeezed progressively between rolls 107, 115, the distance between the axes of which is adjustable. The blanks pass from the roll 115 to calendaring rolls 115, 117, strippers 127 preventing the blanks from travelling upward on the roll 117. Roughened strips of steel on the roll 115 prevent bending over of the blanks as they pass to the roll 115 from the rolls 107, 115. Fine wire spring conveyers 133 under tension and passing over a series of fine toothed wheels 129, 131, the former of which remove the blanks from the roll 115, convey the blanks to a receptacle.