Patent GB-613002-A (GB)
Title: Method and apparatus for forming the heat-exchanging ribs or the cylinders of engines, frigorific apparatus and the like
IPC: B24B5/16
Filed: 1941-09-08
Abstract: 613,002. Grinding and polishing. FOUQUET, E. Sept. 8, 1941, No. 11462. Convention date, Aug. 2, 1939. [Class 60] A method for forming by grinding the annular heatexchanging ribs on bodies such as the cylinders of engines and frigorific apparatus and the like is characterised in that the cylinder is rotated while the grinding is effected by a composite grinder formed of a number of coaxial grinding discs alternating with spacers and forming simultaneously the ribs on the cylinder wall by grinding grooves therein. The work 427, such as an aircooled aviation engine cylinder, is mounted on a mandrel 404 carried by a fixed headstock and a movable headstock 424, the whole being mounted, together with the motor 403 for rotating the work, on a slide 402 movable towards the grinding unit by a rack and pinion, a stop 454 limiting the approach. The grinding unit 431 comprises a number of grinding wheels 431a separated by spacers 432 and rotated by motor 439. A trueing roller 444 and motor 441 for rotating it, are carried by a slide 440 movable towards and away from the grinding unit by screw 450 and nut 449 mechanism; a bush freely rotatable on the screw shaft has a worm-wheel 456 meshing with a worm 460 rotatable by hand wheel 461; the bush also has a pinion 451 meshing with a pinion 452 on a screw 453 engaging a nut in the stop 454 to adjust the latter. The bush can be clutched to the shaft 450 by hand wheel 459, whereupon feed of the trueing roller into the grinding unit simultaneously effects a corresponding adjustment of the stop 454 towards the grinding unit. Before retracting the trueing device the bush is uncoupled, so that the stop adjustment remains unaltered. Trueing may be continuously effected. The Specification as open to inspection under Sect. 91 describes also an automatic machine in which the work 15 is rotatably mounted on a carriage 3 traversed, through two - speed gear, by an electric motor 68. The work is rotated by a motor 14. A primary grinder 21 for forming the ribs is driven alternatively by a high-speed motor 35 and a low-speed motor 41, the arrangement including a free-wheel; the grinder 21 is mounted on a carriage 50. A primary trueing wheel 52<SP>1</SP> is mounted on a carriage 52 which is traversed on the carriage 50 alternatively by a high-speed motor 59 and a lowspeed motor 60. A secondary grinder 126 for forming the tips of the ribs is rotated alternatively by high-speed and low-speed motors 130, 131; the grinder 126 is mounted on a carriage 92 traversed on carriage 3 by a motor 106. A secondary trueing wheel 112 is mounted on a carriage 108 which is traversed on the carriage 92 by a motor 121. In operation, the primary grinder 21 is rotated at high speed and the work carriage 3 is traversed slowly to feed the work to the grinder; a gauge finger 140 is maintained inoperative until the work is nearly to size; when the work is to size, movement of the gauge finger 140 causes the motor 68 for traversing the work carriage 3 to be reversed and the two-speed gear to be operated, whereby the work is withdrawn at high speed from the grinder. The primary trueing wheel 52<SP>1</SP> is moved up to the primary grinder 21, first rapidly and then slowly, the grinder 21 being rotated slowly during trueing. The motor 106 is actuated to feed the secondary grinder 126 up to the work. A second gauge finger 141 becomes operative when this operation is nearing completion. Wear of the grinders 21, 126 is automatically compensated for in that stops which limit the movement of the trueing wheels 521, 112 up to the grinders are automatically adjusted in accordance with the feed of the work into the primary grinder 21 and the feed of the secondary grinder 126 into the work. A servo-device may be provided for power tightening of the nuts for securing the work on its mandrel and for securing the multiple grinding discs on their spindle. This subjectmatter does not appear in the Specification as accepted.