GB687344A - Improved digging machines - Google Patents

Abstract

687,344. Digging-machines. LEIGH, A. D. Jan. 9,1950 [Feb. 4, 1949], No. 3211/49. Class 68(i) [Also in Group I] In a machine for digging fields, trenches, or for mixing materials, the spade or spades are forced vertically downwards, tilted about a pivot into a horizontal position, then raised and returned to the original position, and during this last motion the spade is rotated and returned through 90‹ so that the excavated soil is dislodged from the spade. On one side of a wheeled carriage is a linkage system comprising a pivotally mounted anchor rod 9 to which is pivoted a beam 12, 13 that is pivotally secured to a cross-head 31 that slides on a guide rod 28 pivotally attached to the carriage. The spade shaft 33 is rotatably mounted in the cross-head 32 and on rotation of the crank 7 which is connected to the beam 12, 13 by rods 17, 18, the desired motion is given to the spade by suitable adjustment of stops 39, 40, 22 and 50. As the spade returns from the horizontal to the raised vertical position, a roller 54 mounted on the shaft 33 engages a cam 57 on the beam 13 so that the shaft is rotated against the action of a coiled spring connecting the shaft and cross-head. For each spade there is provided a separate linkage mechanism. Operation of the linkage is used to propel the carriage by a pawl and ratchet mechanism. In conjunction with each spade coulters may be secured to the carriage, whilst for trenchdigging similarly operating side-cutting spades are used.