Conveyors: power-driven – Conveyor section – Unit load conveying surface means moved about an endless or...
Reexamination Certificate
2001-09-19
2002-12-10
Ellis, Christopher P. (Department: 3651)
Conveyors: power-driven
Conveyor section
Unit load conveying surface means moved about an endless or...
C198S470100
Reexamination Certificate
active
06491155
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a device designed to hook pieces, in particular printed circuit boards, onto transport lines present in tunnel kilns or similar kilns.
The device in accordance with the invention can be classified among the equipment used to manufacture electronic cards or printed circuits, and in particular among the equipment used during the circuit firing stage in a kiln.
DESCRIPTION OF THE RELATED ART
The manufacture of printed circuits such as those of computer boards uses photographic processes to make the tracks or pattern of the circuit on a base plate, which consists of one or more layers of copper or other conductive material.
For this purpose a layer of material sensitive to ultraviolet light, for example, is spread on the plate; that layer is photographically exposed, and the plate is then introduced into baths that dissolve the unexposed layer and the underlying layer made of conductive material to produce the circuit tracks.
These known procedures comprise various stages; including the stage when the said sensitive layer is fired, during which the plates that constitute the circuit base are introduced into a kiln, usually the tunnel type, in which the coating layer is “fired”.
For the purpose of firing, each card is passed one or more times through a tunnel kiln together with other similar cards.
The existing conveyor equipment for the firing of rigid printed circuits allows the circuit boards to be introduced in succession into supports constituted by structural shapes arranged transversely on a conveyor belt situated in the lower part of the route, so that the boards maintain a vertical position as they advance through the kiln.
This type of equipment, which is used to handle basically rigid printed circuits, does not need to be fitted with restraint and gripping mechanisms, and is consequently unsuitable to support or move the more recent flexible circuits, as in this case the boards cannot maintain a vertically leaning position, and must therefore be hung from a transport line installed in the upper part of the tunnel and fitted with gripping jaws.
The main drawback encountered with the use of known systems for the transport of flexible printed circuits is that they use complex, bulky jaw assemblies, each of which is associated with pneumatic drive devices; this increases the cost of manufacture and also restricts the number of printed circuits that can be hung from the conveyor, due to the excessive bulk of these gripper activation devices.
SUMMARY OF THE INVENTION
The invention provides a new gripping system for the advance of flexible printed circuits through a tunnel kiln or the like, the main objective of which is to reduce the complexity of manufacture, thus limiting both production costs and overall dimensions, as the components of the hooking parts are simplified.
The immediate advantage of the proposed system is that the reduction in overall dimensions leads to a considerable increase in the carrying capacity of the conveyor line and in the number of circuits that can be treated simultaneously on the same line.
A further advantage of the innovation in question is that it features a new gripping system which eliminates components secured by screws or other screwing systems; such components, which are present in known hooking devices, can generate critical situations such as breakage or jamming of the gripping parts when they pass through the kiln at high temperature. These particular purposes, advantages and functions are all achieved, in accordance with this invention, by a device for hooking pieces, in particular printed circuits, to transport lines present in tunnel kilns and the like, in accordance with which shaped supports are fitted transversely to a conveyor belt, slat conveyor or the like, the said supports being constituted by roughly U-shaped guides fitted with elastic systems designed to maintain in the thrust position a pair of pins with sharp corners at the ends, which constitute the elements that grip the printed circuit.
The said elastic systems, subjected to the action of pistons which control their movement, enable the said pins to be maintained in the thrust position during the stages of gripping the circuit, and retracted for a certain distance during the loading and unloading stages.
REFERENCES:
patent: 1217030 (1917-02-01), Long
patent: 1976848 (1934-10-01), Ham
patent: 2776856 (1957-01-01), Ingram
patent: 2782067 (1957-02-01), Bonte et al.
patent: 3264030 (1966-08-01), Albert
patent: 3904027 (1975-09-01), Gilles et al.
patent: 4149623 (1979-04-01), Nelson
patent: 4172514 (1979-10-01), Shantz et al.
patent: 4174060 (1979-11-01), Porat
patent: 4183428 (1980-01-01), McGill et al.
patent: 4183571 (1980-01-01), Renfroe
patent: 4201286 (1980-05-01), Meier
patent: 4288313 (1981-09-01), Bormke et al.
patent: 4320894 (1982-03-01), Reist et al.
patent: 4369587 (1983-01-01), David
patent: 4408560 (1983-10-01), Caratsch
patent: 4425996 (1984-01-01), Hoffmann
patent: 4709910 (1987-12-01), Honegger
patent: 4727979 (1988-03-01), Wolfson et al.
patent: 4834232 (1989-05-01), Freermann
patent: 4903818 (1990-02-01), Loehr et al.
patent: 4915283 (1990-04-01), Buchko et al.
patent: 4921294 (1990-05-01), Klopfenstein
patent: 5071305 (1991-12-01), Curti
patent: 5244078 (1993-09-01), Silva et al.
patent: 5360101 (1994-11-01), Carlen
patent: 5419427 (1995-05-01), Wurgler
patent: 5542526 (1996-08-01), Wurgler
patent: 5575379 (1996-11-01), Schmetzer
patent: 5722530 (1998-03-01), Gunschera
patent: 5893595 (1999-04-01), Corbett
patent: 6116592 (2000-09-01), Gunschera
patent: 6193046 (2001-02-01), Segawa et al.
patent: 6213280 (2001-04-01), Abbadessa et al.
patent: 6213461 (2001-04-01), Ratz et al.
patent: 6227589 (2001-05-01), Brown et al.
patent: 6302172 (2001-10-01), De Villele
patent: 6315345 (2001-11-01), Garioni
patent: 6325592 (2001-12-01), Maier
Ellis Christopher P.
Sharma Rashmi
LandOfFree
Device for hooking pieces, in particular printed circuits,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for hooking pieces, in particular printed circuits,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for hooking pieces, in particular printed circuits,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2997603