Patent GB-293975-A (GB)
Title: Improvements in methods of and apparatus for the measurement of feet, lasts and the like
IPC: A43D1/04
Filed: 1927-07-07
Abstract: 293,975. Bradley, H., and British Boot, Shoe, & Allied Trades Research Association. July 7, 1927. Boots, shoes, and lasts, measuring for.-Foot and last measuring apparatus comprises mechanical means adapted to indicate the data from which the focal ratio of the foot or last may be measured or calculated. Indicating means are also provided for giving a direct reading of the focal angle of the foot or last as well as its length and the slope of the instep. The focal angle is defined as the angle #, Fig. 1, between tangents DCF and ABF to the outer and inner edges of the foot. The focal ratio denoted P is the ratio of the lengths FB, FA, where CB and DA axe at right angles to FA. If a point G be marked on FD such as FG = #xl where x=FB and l = FA, then it is found that G coincides with the posterior end of the fifth metatarsal bone. FE is drawn bisecting the angle #. It is also stated that if the profile of the foot be placed in the quadrilateral CBAD, the line AP coincides with the slope of the instep, with the point P on the instep. GAB is called the angle # and a chart may be drawn up giving values of P for different values of # and #. Various forms of appartus may be designed to ascertain the three essential factors set out but one form of apparatus is as follows. A glass screen 3, Fig. 2, is used in a frame 4 and a member 7 slidable on a rod 5 is moved till it touches the heel of a foot or last placed to the right of it and against the frame 4. The length can be read off against a scale (not shown). For a left foot, a member 8 is pivoted about a left hand rod 10 and a wooden side plate 21 is rotated about the bearing 10 and also about its own links 19 so that it touches the side of the foot tangentially. The outline of the bar 8 is thrown on the glass screen and the angle is read off upon any suitably graduated scale, a flat plate 15 attached to the rod 8 shielding the part of the scale not required. A locating member 23 is moved along a rod 22 on the side plate 21 till it touches the projection at the posterior end of the fifth metatarsal bone of the foot. As the member 23 is moved, the relative rotation of the bar 25 causes a rotation of a right hand member 31 though a flat member 29 and notch 30. The connections of the rod 25 with the flat member 29 and the rods 18 with 16 are shown in side elevation in Fig. 4. The pivots 10 are also shown spring pressed to engage with the right or left end of the rod 8. While the foot is on the glass plate 3 an arm 33, Fig. 3, can be brought up so that a plate 34 lies along the instep and the angle of the instep can be read along a scale 35. When the right foot is to be measured then the catch at the left end is released and the bar 8 is pivoted at the right-hand end of the instrument. The apparatus may be used when the heel is supported at a height above the level of the flat of the foot. A source of illumination 36, Fig. 3, may 'be placed under the plate 3. There is rothing on a last corresponding to the fifth metatarsal bone of the foot but the value P AD can be determined from the ratio --. BC