Patent GB-1348166-A (GB)
Title: Long-arm grinding machine
IPC: B24B27/04
Filed: 1971-06-30
Abstract: 1348166 Grinding E EVERTZ 30 June 1971 [12 Aug 1970 23 Dec 1970] 30602/71 Heading B3D [Also in Division F2] A long-arm machine for grinding a surface 1 comprises an elongated shaft 6 which, at one end, has a grinding wheel 4 and, at the other end, a motor 5, the shaft being pivotally mounted for movement about an axis transverse to the shaft by a bearing 6 on the machine frame to move the grinding wheel over the width of the surface and movable longitudinally to move the grinding wheel over the length of the surface, the bearing being pivotally moved by a drive 14 for effecting the pivotal movement of the shaft and connected by a linkage 21, 21<SP>1</SP> and pawl- and-ratchet mechanism 17, 20 for effecting the longitudinal movement of the shaft. The bearing 6 is mounted on a disc 7 rotatable on a plate 8 having rollers engaging rails 10 on the machine frame. An arm 11 extends from the disc and is formed with a slot 12 engaged by a block 13 adjustably mounted on a crank arm 14 whereby the disc is oscillated at a variable amplitude. A link 21 is adjustably connected to the disc and to a further link 21<SP>1</SP> connected to a support 19 for pawls 20, the support being rotatable on a shaft 18 mounted on the plate 8. The pawls 20 engage a ratchet wheel 17 in mesh with a rack 16 on the machine frame. The pawls are spring loaded to rotate the ratchet wheel in one direction or the other, the direction being changed upon abutment with stops 33, 34. The pawls 20<SP>1</SP>, 20<SP>11</SP>, Figs. 2 and 3, are carried by a lever rockable to one side or the other of a central position about a pivot 21 by a spring 23. The pivot is carried by support 19 which, together with an abutment lever 27 are pivoted on the shaft 18, the lever 27 and a control lever 26 is journalled on a shoulder 25 on the shaft 18 and a spring 30 urges the levers 27, 26 to one side or other of a central position so that abutments thereon engage a bolt 28 or a bolt 29 the lever 26 has surfaces 35, 36 for abutting a pin 22 extending from the pawls 20<SP>1</SP>, 20<SP>11</SP> and acted upon by the spring 23. Upon abutment with stops 33 or 34 the levers 26, 27 are moved from engagement with one of the bolts 28, 29 across their central position to engage the other bolt so that the surface 35 or 36 rock the pawls through their central positions so that the other of the pawls engages the ratchet wheel to reverse the direction of movement of the plate 8. In another embodiment, the disc 103, Fig. 4, carrying the shaft 104 for the grinding wheel 105 is connected by a universal coupling 102 to a rod 100 having its other one connected by a universal coupling 8 to a disc 9. A pedestal 114 carries bearings 111, 112 for a shaft 110 driven by a motor 113 and carrying the disc 9. The pedestal is mounted for pivotal adjustment about an axis 117 in bearings 115, 116. In the position shown in Fig. 4, rotation of the disc 9 causes no movement of the coupling 102 and the disc 103 remains stationary. Movement of the pedestal through 90 degrees from the position shown causes maximum oscillation of the disc 103. In a modification of the embodiment shown in Fig. 1, the block 13, Fig. 6, is mounted on a pin 51 on a slide 52 reciprocable along guides 53 by a cam 56 which is rotated by a motor and engages a follower 55 on the slide. In a modification of the embodiment shown in Fig. 4, the coupling 61, Fig. 8, for the coupling rod 62 connected to the disc (103) is mounted on a slide reciprocated by a cam 39 and follower 60, the arrangement being mounted for adjustment about the axis of a bearing 45 to vary the amplitude of oscillation of the disc (103).