874,635. digging conveyers. GENERAL ELECTRIC CO. Ltd. Nov. 20, 1959 [Nov. 25, 1958], No. 37930/58. Class 78 (1). [Also in Group XXXII] A mechanical spring of the compression type for a vibratory linear conveyer comprises a helical coil spring 10 disposed between compression members 7, 13, whereby compressive forces are applied to the spring, the compression members being diametrically opposed with respect to the spring so that the compressive forces are applied at right angles to its axis. In the preferred embodiment the members 7 are secured to the undercarriage 8 of the trough 3 of the conveyer and arranged between a pair of springs 10 which may be adjusted by the members 13 and bolts 14 attached to side members 2 of the frame 1 for the conveyer, rods 16 being welded both to the plates and to the springs. Each spring 10 may consist of two or more helical coils of square cross-section in contact with one another, adjacent coils being of opposite hand. The trough of the conveyer is additionally supported by leaf springs 5, 6, from the side members 2 which may be floor-mounted or suspended by hooks 15 as described in Specification 796,161. The conveyer is provided with an electromagnetic vibrator 4. Specification 823,857 also is referred to.