The annexed engravings are views of an improvement in Boot Trees, invented by David Sadlier, of McWilliamstown, Pa., and for which a patent was granted on the 23rd of last November, (1852.) Figure 1 is an inner face view of the hind part of the boot-tree; and figure 2 is a vertical section showing the levers partly depressed, and the tree extended. The same letters refer to like parts. The nature of the invention consists in forming cavities in the hind part of the boot tree, and inserting therein a series of levers and friction rollers, which being operated by a screw are made to expand the tree whilst in the boot, by bearing against the shin piece. A is the boot ; is the shin, and C the back part forming the tree, all of which are of the ordinary external form. In the inner side of the hack part is the cavity, ; the vertical groove, b, crosses the cavities and admits the screw, c, levers, d, and friction rollers, e, all folding within the hind part, C. These levers have their fulcra in the lower end of he two cavities at J\ two levers in each, one on either side of the screw, c. The upper ends of the levers are attached to said screw by swivel collars, g, with a gudgeon on either side which serve as connections for the levers and axes for the friction rollers, e. Said swivels are secured at any desired point on the screw by set nut, , above and below each, which, when set, are keyed on the screw to prevent them from turning across the upper end of the back part, C. The groove in the back part is covered with a plate,;', and there is a slide, A, fitted in a groove on the top of the tree. This slide has a graduated edge, and a left-handed nut on its inner end, through which the screw, e, works. The shin part, B, has a metal plate fitted on its inner side, for the friction rollers, e, to work against, also a metal shield, m, from the top to bottom on each side, to give a bearing to the leather between the shin and back when extended by the levers. The foot, A, is connected with the shin, B, in the usual manner. The several parts of this boot-tree being placed in their respective position, the tree is held in the left h&jt! on tins top of the parts, and C, the thumb tightly bearing against the oater end of the slide, k. The screw, c, is then turned down by the lever, !, on its upper end, which extends the levers, rf, their friction wheels bearing against the shin part, force it and the hinder part asunder and thus stretch the leg of the boot to any desired size. If it is desired to stretch the lower part of the leg more than the upper part, it can be done by moving the upper nut, n, higher on screw, e, and keying it in that position, which makes the levers, d', act against the shin part sooner than the upper levers are run up on the screw ; this makes the upper levers, d, press against the shin part first. By this arrangement the centre wedge in the common boot trees is dispensed with, and the leg can be stretched at the upper and lower parts as desired, which cannot be done with the wedge without danger of bursting. The leather of the leg is also prevented from wrinkling down, as is commonly the case with pressing the wedge ; it is also a tree to suit the largest and smallest sized boots, by the greater or less extension of the levers, d d. More information may be obtained by letter addressed to the inventor.
This article was originally published with the title "Improvement in Boot Trees" in Scientific American 8, 24, 185 (February 1853)