Geometrical instruments – Distance measuring – Opposed contacts
Reexamination Certificate
1998-08-19
2001-02-13
Hirshfeld, Andrew H. (Department: 2859)
Geometrical instruments
Distance measuring
Opposed contacts
C033S711000, C033S747000
Reexamination Certificate
active
06185832
ABSTRACT:
FIELD OF THE INVENTION
This invention relates in general to manufacturing magazines and similar publications, and relates in particular to a calipering apparatus and method for determining the completeness of each magazine by measuring the thickness of each signature group.
BACKGROUND OF THE INVENTION
Magazines and similar publications are manufactured by assembling individual page sets, known as signatures, into a group of signatures known as a book. This assembly takes place on a chain conveyor having a number of pockets that move in turn past signature feeders, each containing a different signature for the book being assembled. Signatures are fed to each chain station from some or all signature feeders, depending on the composition of a particular magazine. The resulting book, or group of signatures, then is trimmed and stapled to complete the magazine. Individual signature feeders may be selectively actuated as each chain station passes that feeder, so as to customize the contents of each assembled magazine according to subscriber information or other data known to the printer. The foregoing and related details of magazine production are known to those skilled in the art.
It is important that each assembled book contain the proper number and selection of signatures. If a particular magazine contains more than the intended number of signatures, that magazine wastes the resources of the printer or publisher and also may appear defective to readers. If a magazine contains fewer signatures than desired, readers likely will detect the missing pages and any advertisers on those pages are entitled to compensation from the printer or publisher of the defective magazine. In either case, printers usually measure the thickness of each book assembled pocket of the chain conveyor, to determine whether that book contains the appropriate number of pages. Books that are thicker or thinner than appropriate are diverted from the remaining steps of the assembly operation.
Books of signature groups usually are calipered while moving along the chain by passing each book between a pair of rollers. The rollers compress the pages making up one side of the book, so that the spacing between the rollers is determined by the thickness of the book, that is, by the number of signatures in that book.
Such books are known to have an amount of resilience or elasticity, depending on variable factors such as the number of signatures in the group, the weight of the various signatures making up that group, atmospheric conditions (which may change during a printing run) in the printing plant, and other factors. This resiliency causes the caliper rollers to undergo a degree of bounce relative to each other, as the leading edge of each book enters the nip between the rollers. To avoid an erroneous thickness indication by the caliper, it has been customary to delay measuring the spacing between caliper rollers for a time sufficient to allow this resilient bounce to settle out. Because the amount of dwell time between the caliper rollers for each book is inversely related to the linear travel speed of the chain conveyor carrying the books, the maximum becomes limited as the dwell time diminishes to the minimum time required for the moveable caliper roller to settle out from the bounce induced by the arrival of each book and the elasticity inherent in that book. This limitation on the chain speed limits the throughput, and thus the efficiency, of manufacturing magazines or the like.
SUMMARY OF THE PRESENT INVENTION
Accordingly, it is an object of the present invention to provide an improved method and apparatus for calipering books of signature groups.
It is another object of the present invention to caliper such books without regard to the amount of bounce induced by the resilience of the book.
It is a further object of this invention to provide an apparatus and method for calipering such books without requiring any dwell time for settling the bounce of a movable caliper element.
It is still another object of the present invention to provide a more efficient technique for calipering books.
Other objects and advantages of the present invention will become apparent from the following description.
Stated in general terms, a book is calipered according to the present invention by maintaining the caliper elements mutually spaced apart while the book first moves between those elements. At least one caliper element then moves toward the other caliper element so as to compress the book between the caliper elements. The resilient force applied to close the caliper elements causes an initial maximum compression of the book between the caliper elements, followed by a rebound from that maximum compression in response to the resilience of the book. However, instead of waiting for the rebounding movement to settle out as in the prior art, the minimum distance between the caliper elements is sensed. That minimum spacing occurs as the caliper elements initially reach maximum compression of the book, before resiliently bouncing from that minimum spacing. This minimum spacing is a function of the thickness of the book between the caliper elements. Any subsequent rebound or bounce of the caliper elements from that initial maximum compression of the book is disregarded in sensing the minimum spacing between the caliper elements.
Stated in somewhat more detail, the caliper elements comprise a pair of mutually-opposed rollers mounted on opposite sides of the path traveled by the books. The axis of one roller is selectively moveable relative to the axis of the other roller so as to selectively separate the caliper rollers. As a book approaches the caliper rollers, the moveable roller is separated from the fixed roller to allow the book to enter the space between the rollers. Once the book arrives in that space, the moveable roller is urged to close toward the other roller, thereby engaging and initially compressing the moving book between the caliper roller to a maximum extent determined by the thickness of that book. This closing movement of the one roller displaces a measuring element in proportion to the closing movement of the roller during that initial compression. However, the bounce or rebound movement of the roller from that initial compression is decoupled from the measuring element, which remains at a state indicating the maximum closing travel of the measuring roller during initial compression of the book. A sensor associated with the measuring element is responsive to that state, producing a signal for comparison with a reference signal corresponding to the nominal or desired thickness for that particular book.
Stated in further detail, the moveable caliper roller is selectively urged toward the fixed roller by a resilient force, but the actual closing movement of the moveable roller preferably is initially restrained and then released. Upon that release, the roller undergoes a sudden closing movement with sufficient force to produce the desired maximum compression of the book, and the resilient nature of that force permits the movable roller to rebound from that maximum compression. A lost-motion link couples the closing movement of the moveable roller to the measuring element, and that element preferably is restrained from undergoing return displacement when the moveable roller undergoes resilient bounce. After the maximum displacement of the measurable element is sensed, that element and the moveable roller are restored to their initial positions to await arrival of the next book between the caliper rollers.
REFERENCES:
patent: 2848816 (1958-08-01), O'Neill
patent: 3191925 (1965-06-01), McCain
patent: 3528002 (1970-09-01), Dunlavey
patent: 3581402 (1971-06-01), London et al.
patent: 3622147 (1971-11-01), Mebus
patent: 3627303 (1971-12-01), Zeewy
patent: 4121716 (1978-10-01), Luperti et al.
patent: 4121818 (1978-10-01), Riley
patent: 4136454 (1979-01-01), Jenkins et al.
patent: 4621757 (1986-11-01), Osako
patent: 4741109 (1988-05-01), McCurdy et al.
patent: 2-168107 (1990-06-01), None
Hirshfeld Andrew H.
Stockton Kilpatrick
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