GB562338A - New straight line motion linkage - Google Patents

Abstract

562,338. Straight-line motions; conveying circular motion. BUTLER, F. G. J., and KITE, E. A. Dec. 22, 1942. No. 18165. [Class 80 (iii)] A straight-line linkage comprises a link CB pivoted to a fixed point C at the intersection of lines X-X<1>, Y-Y<1>, this link being pivoted to a lever BA, a point D in which is connected by a long link DE to a pivot E fixed on the line X-X<1>. To obtain the position of E, a point K is taken about one-quarter of the length of the link BC from B and with centre C an arc is struck cutting X-X<1> at F. The point D is taken at one quarter of the length of lever AB from B. The arc or line joining the points D, F is bisected at right-angles by a line H-H<1> which, produced downwards intersects X-X<1> at E. With the linkage described, the point A moves along the line Y-Y<1> over a considerable range. In a modification, motion may also be obtained along the line X-X<1> by extending the lever AB. In a further modification, Fig. 7, two points of support are provided for the element to be moved by prolonging the link DE to a point T and connecting T with A by two links TL, LA similar to TD, DA but oppositely disposed. In a still further modification, Fig. 9, a shaft M with crank-pin A is to drive a shaft C at half speed. The shaft C carries a disc P in which, previously, there has been a groove along Y-Y<1> to accommodate a roller on crank-pin A. According to the invention, instead of the groove, linkwork is employed, the crank-pin A being the equivalent of the point A, Fig. 1, and the pivot E is on a line X-X<1> on the disc P. Hence A moves along Y-Y<1>. The throw of the crank is equal to the eccentricity of the shafts.