| 摘要 |
1,183,723. Grinding blades. LITCHFIELD ENG. PTY. Ltd. 5 April, 1967 [6 April, 1966], No. 15622/67. Heading B3D. [Also in Division B4] A shear blade comprises a cutting face 14 and a back face 11 defining a cutting edge, the relief angle of the back face increasing towards the tip of the blade. The back face may be hollow ground and of helical form and the blade may be straight or curved. Grinding.-The shear blade is ground in apparatus comprising a main frame 27, a grinding wheel 21, a jig 35 for clamping the blade 10 and arranged to be pivoted about an axis substantially parallel to the axis of rotation of the grinding wheel, means 29 to move the jig back and forth across the grinding wheel, and cam means 41, 43 for rocking the jig about its pivoted axis as it moves across the grinding wheel. The blade 10 is clamped against a projection 46 on the jig by a member 49 moved by a wedge 48, and the jig is supported by pivots in bosses 31 on an oscillating frame 25 mounted by a universal joint 28 on a main slide 37 movable towards aid away from the grinding wheel along a guide 36. The frame is oscillated in a direction parallel to the axis of the grinding wheel by a fluid cylinder 29 to traverse the blade across the grinding wheel, the jig 35, during this movement being rocked about its pivotal axis to vary the angle of the back face 11 of the blade by engagement of a roller 43 with a cam 41 carried by a post 40 on the main slide 37. The back face thus formed may be helical. If the blade is curved, the frame 25 is rocked towards and away from the grinding wheel about the pivot 28 as it is moved past the grinding wheel by engagement of a cam 53 on the frame 25 with a roller 55 on the slide 37, a cylinder 56 retaining the cam and roller in engagement. A timing device limits the number of reciprocations, an automatic feed device indexes the blade forwardly after each reciprocation, and a device returns the blade to its initial position after grinding. Soluble oil is supplied to improve the grinding. |
