IL126398A - Conveyor system - Google Patents

Description

CONVEYOR SYSTEM ORBOTECH LTD.

C: 32336 32336or3.doc 27-Sep-98 CONVEYOR SYSTEM FIELD OF THE INVENTION The present invention relates generally to a system for continuous processing of successive workpieces along a production line, and particularly to a system for maintaining uninterrupted flow of workpieces which are registered with respect to a reference plane.

BACKGROUND OF THE INVENTION Systems for continuous processing of successive workpieces along a production line are well known. One example of such a system is described in applicant/assignee's European Patent Application EP 0 855 856, filed 28 January 1997 and published 29 July 1998. Other exemplary systems of this general type are described in EP 0 296 096 and US Patent 4, 274,529.

The system described in EP 0 855 856 includes a loader for loading workpieces, such as printed circuit boards, on to a main conveyor for conveying through a workstation, such as an optical inspection station, and an unloader for unloading the workpiece after processing. The loading and unloading are achieved without disturbing the main conveyor during operation of the workstation so as not to vibrate the workpiece during operation of the workstation.

SUMMARY OF THE INVENTION The present invention seeks to provide certain improvements to the system of EP 0 855 856. The system of the present invention maintains uninterrupted flow of workpieces which are registered with respect to a reference plane.

There is thus provided in accordance with a preferred embodiment of the present invention a conveyor system including a plurality of first conveyor belts arranged to convey a workpiece along a longitudinal axis, each of the first conveyor belts being separated from an adjacent first conveyor belt by a space along a lateral axis generally perpendicular to the longitudinal axis, a plurality of second conveyor belts arranged to convey the workpiece along the lateral axis, each of the second conveyor belts being disposed in the space between the adjacent first conveyor belts, a first actuator connected to the plurality of second conveyor belts for lifting each the second conveyor belt in a generally up and down direction in the space, the first actuator being capable of lifting the second conveyor belts above the first conveyor belts such that the workpiece is conveyed by the second conveyor belts along the lateral axis above the first conveyor belts, a plurality of third conveyor belts arranged to convey the workpiece along the longitudinal axis, the third conveyor belts being disposed in the spaces between the adjacent first conveyor belts, and a second actuator connected to the plurality of third conveyor belts for lifting the third conveyor belts in a generally up and down direction in the spaces, the second actuator being capable of lifting the third conveyor belts above the first and the second conveyor belts such that the workpiece is conveyed by the third conveyor belts along the longitudinal axis above the first and the second conveyor belts.

In accordance with a preferred embodiment of the present invention a feeder is provided for feeding the workpiece to the conveyor system.

Further in accordance with a preferred embodiment of the present invention a controller is in electrical communication with the first and second actuators and the feeder and controls operation of the first and second actuators and the feeder.

Additionally in accordance with a preferred embodiment of the present invention the controller controls operation of the first and second actuators and the feeder in accordance with an operating cycle wherein: a. the workpiece is received by the third conveyor belts from the feeder upstream of the first and second conveyor belts, b. the workpiece moves on the third conveyor belts in a downstream direction along the longitudinal axis above the first and second conveyor belts, c. the second actuator lowers the third conveyor belts below the first and second conveyor belts while the second conveyor belts are above the first conveyor belts, such that the workpiece falls off the third conveyor belts and moves on to the second conveyor belts which convey the workpiece along the lateral axis, d. the first actuator lowers the second conveyor belts below the first conveyor belts, such that the workpiece falls off the second conveyor belts and moves on to the first conveyor belts which convey the workpiece in the downstream direction along the longitudinal axis, and e. repeating steps (a)-(d) as required for successive workpieces.

In accordance with a preferred embodiment of the present invention a registration member is mounted along the lateral axis which defines a registration plane generally parallel to the longitudinal axis and which arrests movement of the workpiece along the lateral axis at the registration plane. Preferably in step (b) the workpiece falls off the third conveyor belts and moves on the second conveyor belts along the lateral axis and abuts against the registration plane.

Further in accordance with a preferred embodiment of the present invention a cleaner is provided which cleans the workpiece prior to feeding the workpiece to the conveyor system.

There is also provided in accordance with a preferred embodiment of the present invention a method for conveying workpieces including: a. feeding a workpiece to a conveyor system, b. moving the workpiece in a downstream direction a first predetermined distance along a longitudinal axis, c. moving the workpiece in a lateral direction a second predetermined distance along a lateral axis generally perpendicular to the longitudinal axis, d. resuming moving the workpiece in the downstream direction to an operating station for performing an operation on the workpiece. e. repeating steps (a)-(d) as required for successive workpieces.

In accordance with a preferred embodiment of the present invention, in step (c), the workpiece is constrained to abut against a registration plane defined along the longitudinal axis.

Further in accordance with a preferred embodiment of the present invention, in step (d), the workpiece is moved downstream in registration with the registration plane.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Figs. 1-6 are simplified pictorial illustrations and Figs. 7A-7D are simplified side-view illustrations of a conveyor system constructed and operative in accordance with a preferred embodiment of the present invention and of a method for conveying workpieces in accordance with a preferred embodiment of the present invention, wherein: Figs. 1 and 7A illustrate a feeder which feeds a workpiece onto the above-mentioned third conveyor belts; Figs. 2 and 7B illustrate the above-mentioned second actuator lifting the third conveyor belts above the first and second conveyor belts, and the workpiece moving on the third conveyor belts in a downstream direction along a longitudinal axis; Fig. 3 illustrates the workpiece moving to the position of the second conveyor belts; Figs. 4 and 7C illustrate the second actuator lowering the third conveyor belts below the first and second conveyor belts, wherein prior to or simultaneous with lowering the third conveyor belts, the first actuator lifts the second conveyor belts above the first conveyor belts, such that the workpiece falls off the third conveyor belts and moves on the second conveyor belts along a lateral axis; Fig. 5 illustrates the workpiece abutting against a registration member, thereby arresting its movement along the lateral axis; and Figs. 6 and 7D illustrate the first actuator lowering the second conveyor belts below the first conveyor belts, such that the workpiece falls off the second conveyor belts and moves on the first conveyor belts in the downstream direction along the longitudinal axis.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Fig. 1 which illustrates a conveyor system 10 constructed and operative in accordance with a preferred embodiment of the present invention.

Conveyor system 10 preferably includes a plurality of first conveyor belts 12 arranged to convey a workpiece 14 along a longitudinal axis 16. Each first conveyor belt 12 is separated from an adjacent first conveyor belt by a space 18 along a lateral axis 20 generally perpendicular to longitudinal axis 16. It is noted that the term "conveyor belts" throughout the specification encompasses any kind of conveying means such as belts, wires, strings, articulated pads, rollers, chains and the like.

A plurality of second conveyor belts 22 is preferably arranged to convey workpiece 14 along lateral axis 20. Each second conveyor belt 22 is preferably disposed in space 18 between the adjacent first conveyor belts 12. Referring additionally to Fig. 7 A, it is seen that a first actuator 24 is preferably connected to second conveyor belts 22 for lifting each belt 22 in a generally up and down direction in space 18, indicated by arrows 26 and 28 in Figs. 1 and 7A. As will be described further hereinbelow, first actuator 24 is capable of lifting second conveyor belts 22 above first conveyor belts 12 such that workpiece 14 is conveyed by second conveyor belts 22 along lateral axis 20 above first conveyor belts 12.

A plurality of third conveyor belts 30 is preferably arranged to convey workpiece 14 along longitudinal axis 16. Third conveyor belts 30 are preferably disposed in spaces 18. A second actuator 32 (Fig. 7 A) is preferably connected to third conveyor belts 30 for lifting third conveyor belts 30 in a generally up and down direction in spaces 18 (arrows 26 and 28). Second actuator 32 is capable of lifting third conveyor belts 30 above first and second conveyor belts 12 and 22, respectively, such that workpiece 14 is conveyed by third conveyor belts 30 along longitudinal axis 16 above first and second conveyor belts 12 and 22, respectively. Actuators 24 and 32 may be any kind of suitable actuator, such as a solenoid, linear actuator, servomotor, and the like.

A registration member 34, finite in length, is preferably mounted along lateral axis 20 which defines an infinite registration plane generally parallel to longitudinal axis 16. Registration member 34 arrests movement of workpiece 14 along lateral axis 20 at the registration plane, as described further hereinbelow.

A feeder 36 is preferably provided for feeding workpiece 14 to conveyor system 10. A controller 38 is preferably in electrical communication with actuators 24 and 32 and feeder 36. Controller 38 controls operation of actuators 24 and 32 and feeder 36, as described further hereinbelow.

A cleaner 40 is preferably provided which cleans workpiece 14 prior to feeding workpiece 14 to conveyor system 10. Cleaner 40 may include any kind of suitable cleaner such as an adhesive type of cleaner, in which workpiece 14 is passed between two rollers impregnated or coated with a tacky material. As the workpiece passes through the rollers, any foreign material, such as dust and the like, sticks to the tacky material. An example of such a cleaner is the MAGTAC SUBSTRATE CLEANER, commercially available from Western Magnum Corp., Calif., USA.

Reference is now made to Figs. 1-7D which illustrate a method for conveying workpieces in accordance with a preferred embodiment of the present invention.

As seen in Figs. 1 and 7A, feeder 36 preferably feeds workpiece 14 directly onto a drum 42 which drives third conveyor belts 30 and which is located upstream of the rest of conveyor system 10. At this initial point, the portion of third conveyor belts 30 downstream of drum 42 are positioned below first and second conveyor belts 12 and 22, respectively.

In Figs. 2 and 7B, second actuator 32 lifts third conveyor belts 30 above first and second conveyor belts 12 and 22, respectively, and drum 42 rotates to move workpiece 14 on to third conveyor belts 30 in a downstream direction along longitudinal axis 16 above first and second conveyor belts 12 and 22.

In Fig. 3, workpiece 14 has been moved to a position over second conveyor belts 22. In Figs. 4 and 7C, second actuator 32 lowers third conveyor belts 30 below first and second conveyor belts 12 and 22, respectively. Prior to or simultaneous with lowering third conveyor belts 30, first actuator 24 lifts second conveyor belts 22 above first conveyor belts 12, such that workpiece 14 falls off third conveyor belts 30 and moves on to second conveyor belts 22 which convey workpiece 14 along lateral axis 20 until workpiece 14 abuts against registration member 34 (Fig. 5), thereby arresting its movement along lateral axis 20. Sensors (not shown) may be provided in conjunction with controller 38 for sensing the abutment of workpiece 14 against registration member 34 so as to switch off a driver (not shown) of second conveyor belts 22.

In Figs. 6 and 7D, first actuator 24 lowers second conveyor belts 22 below first conveyor belts 12, such that workpiece 14 falls off second conveyor belts 22 and moves on to first conveyor belts 12 which convey workpiece 14 in registration with the registration plane in the downstream direction along longitudinal axis 16. The operation cycle is then repeated as required for successive workpieces.

Thus in accordance with the present invention, the flow of workpieces 14 in the downstream direction along longitudinal axis 16 plus their registration against registration member 34 is accomplished in an efficient and uninterrupted manner.

It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.

Claims (9)

126398/3 C L A I M S What is claimed is:

1. . A conveyor system comprising: a plurality of first conveyor belts arranged to convey a workpiece along a longitudinal axis, each of said first conveyor belts being separated from an adjacent first conveyor belt by a space along a lateral axis generally perpendicular to said longitudinal axis; a plurality of second conveyor belts arranged to convey said workpiece along said lateral axis, each of said second conveyor belts being disposed in said space between said adjacent first conveyor belts; a first actuator connected to said plurality of second conveyor belts for lifting each said second conveyor belt in a generally up and down direction in said space, said first actuator being capable of li ting said second conveyor belts above said first conveyor belts such that said workpiece is conveyed by said second conveyor belts along said lateral axis above said first conveyor belts; a plurality of third conveyor belts arranged to convey said workpiece along said longitudinal axis, said third conveyor belts being disposed in said spaces between said adjacent first conveyor belts; and a second actuator connected to said plurality of third conveyor belts for lifting said third conveyor belts in a generally up and down direction in said spaces, said second actuator being capable of lifting said third conveyor belts above said first and said second conveyor belts such that said workpiece is conveyed by said third conveyor belts along said longitudinal axis above said first and said second conveyor belts.

2. The conveyor system according to claim I and comprising a feeder for feeding said workpiece to said conveyor system.

3. The conveyor system according to claim 2 and comprising a controller in electrical communication with said first and second actuators and said feeder and which controls operation of said first and second actuators and said feeder.

4. The conveyor system according to claim 3 and wherein said controller controls operation of said first and second actuators and said feeder in accordance with an operating cycle wherein: a. said workpiece is received by said third conveyor belts from said feeder upstream of said first and second conveyor belts; 126398/3 b. said workpiece moves on said third conveyor belts in a downstream direction along said longitudinal axis above said first and second conveyor belts; c. said second actuator lowers said third conveyor belts below said first and second conveyor belts while said second conveyor belts are above said first conveyor belts, such that said workpiece falls off said third conveyor belts and moves on to said second conveyor belts which convey said workpiece along said lateral axis; d. said first actuator lowers said second conveyor belts below said first conveyor belts, such that said workpiece falls off said second conveyor belts and moves on to said first conveyor belts which convey said, workpiece in said downstream direction along said longitudinal axis; and e. repeating steps (a)-(d) as required for successive workpieces.

5. The conveyor system according to any of claims 1 -3 and comprising a registration member mounted along said lateral axis which defines a registration plane generally parallel to said longitudinal axis and which arrests movement of said workpiece along said lateral axis at said registration plane.

6. The conveyor system according to claim 4 and comprising a registration member mounted along said lateral axis which defines a registration, plane generally parallel to said longitudinal axis and which arrests movement of said workpiece along said lateral axis at said registration plane, and wherein in step (b) said workpiece falls off said third conveyor belts and moves on said second conveyor belts along said lateral axis and abuts against said registration plane.

7. The conveyor system according to any of claims 2-4 and comprising a cleaner which cleans said workpiece prior to feeding said workpiece to said conveyor system.

8. A conveyor system according to any of claims 1 -7 and substantially as described hereinabove.

9. A conveyor system according to any of claims 1.-7 and substantially as shown in anv of the drawings. For the Applicant, Sanford T. Colb & Co. Advocates & Patent Attorneys C:32336