Patent GB-1234714-A (GB)
Title: Apparatus for selecting parts for assembly
IPC: B23P19/00
Filed: 1969-09-04
Abstract: 1,234,714. Computer-control of parts assembly. INTERNATIONAL BUSINESS MACHINES CORP. 4 Sept., 1969 [30 Sept., 1968], No 43761/69. Heading G4A. Apparatus for selecting for assembly pairs of parts having correlated values of co-operating parameters, the two parts of each pair coming from two respective classes of parts having parameter values within respective tolerance ranges, classifies parts of each class into subclasses having narrower tolerance ranges than the respective classes and selects a subclass of one or each class such that two parts, each from a different one of the classes, will have parameter values correlated within a tolerance range narrower than either of the class tolerance ranges. As described, a batch of pistons is manufactured and the diameter of each automatically measured and compared with subclass limits by a computer. If the diameter is not between the limits of any of the subclasses (which divide up the acceptable range of diameters for the pistons), the piston is diverted to a reject bin, but otherwise it is stored in the first free location of a piston store, determined by scanning a location address table, which has an entry for each piston storage location, to find the first zero entry, this entry then being replaced by an identification of the subclass. Similar arrangements, from the measurement onwards are provided for cylinders (into which the pistons are intended to fit). Periodically, control means for the piston manufacturing by means of a counter which can specify the piston subclasses in turn, requests the computer, which controls the system, to compute a figure of merit for the subclasses specified by the counter. If the sign of the figure of merit is positive, the control means orders a batch of pistons in that subclass (nominally) to be manufactured (for measurement &c. as above). If the sign is negative the counter is incremented to specify the next subclass and the computer requested to calculate its figure of merit. The figure of merit, which is designed to minimize the number of parts in storage, specifies the demand for pistons in the subclass and depends on the numbers of pistons and cylinders of the various subclasses stored and various statistical quantities, this information being obtained from stored tables (core or thin film matrices, or shift registers) which are continually updated. An assembler informs the computer it is ready for a pair of parts and the computer, using the location address tables, disburses a piston and a cylinder of matching subclasses from their stores to the assembler which assembles them and informs the computer it is ready for another pair, and so on. If the piston store becomes full, a piston of the subclass least in demand (calculated by the computer) is transferred to surplus piston storage. The computer executes four fixed routines for: classifying cylinders into subclasses, classifying pistons into subclasses, disbursing a piston-cylinder pair, and computing the figure of merit respectively, with the associated updating and calculating, a priority network giving priority to requests for the above routines in the above order (priority decreasing) but after routines of the last two types are executed single-shots impose delays before they can be selected again so that re-run requests for these two types are ignored in favour of requests for the other two types. A modification lacks storage of cylinders. Instead of being dimensions, the parameters may represent variables such as resistance or capacitance, and the two parameters may represent different variables.