GB268628A - Machine for making grinding bodies for grinding mills - Google Patents

Abstract

268,628. Jorgensen, E. T. Aug. 17, 1926. Crushing and pulverizing apparatus. - In a machine for making grinding-members used in coffee or other mills a shaping-tool or milling- cutter is reciprocated over the work which is rotated during the cutting strokes and held stationary during the return strokes, thus producing a series of helicoidal cuts on the work. The shaping ram 4 carries a head 6 which is pivoted to the ram by a stud 7 and is provided with a bevel segment 8 coacting with a bevel segment 10 mounted on a pin 9 connected by links 11, 13 with a fixed pin 14. The tool 18 has its cutting edge in the axis of the stud and is mounted on a rotatable holder 16 provided with an arm 21 engaging a pin 22 secured to a bracket 23 on the ram. During the reciprocation of the ram the head is oscillated by the links 11, 13 and bevel segments and thus the tool is oscillated' about the axis of the stud 7. At the same time the tool is oscillated about a transverse axis by the engagement of the arm 21 with the pin 22. The blank 30 comprising a hollow truncated cone is secured over a conical member 28 on a hollow shaft 27 by means of a clamping-disc 33 on a spindle 31 which may be rotated from a handle 34. The shaft 27 is connected through bevel gearing 29 with a shaft 35 carrying a ratchet wheel operated by a pawl 39. The latter is actuated by a rod 40 secured to the ram and the blank is thus rotated on the cutting stroke of the tool. During the return stroke the blank remains stationary. The blank spindle is journaled in a frame 26 which is pivoted at 25 to the machine table 24 which carries a shaft 42 on which are secured lever arms 43, 44. The arm 43 is pivoted to a link 45 connected at 46 with the frame 26. The lever system is actuated by stops 48, 49 on a rod 47 which reciprocates in unison with the ram. During the cutting stroke the parts are in the position shown in Fig. 1, with the arm 43 engaging the fixed stop 50. At the end of the stroke the stop 48 engages the arm 44 and causes the frame 26 to swing downwards about the pivot 25 to hold the work clear of the tool on the return stroke. If desired, the rotation of the tool-holder 16 may be dispensed with by disengaging the arm 21 from the pin 22. In a modification, the relieving movement may be applied to the tool instead of to the work. The tool may be replaced by a milling-cutter journaled in the holder 16 and driven by a flexible shaft.