Product conveying system for coating and treating surfaces

• US 5,651,820 A
• Filed: 04/03/1996
• Issued: 07/29/1997
• Est. Priority Date: 09/30/1993
• Status: Expired due to Fees

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Katayama, Shinji, Ogasawara, Toshifumi
• Primary Examiner(s): EDWARDS, LAURA ESTELLE
• Application Number:
  US08/627,252
• Time in Patent Office: 482 Days
• Field of Search: 118/58, 118/56, 118/61, 118/66, 118/320, 118/322, 118/326, 118/642, 198/378, 198/459.1-459.4, 198/465.1
• US Class Current: 118/66
• CPC Class Codes: B05B 13/0221 characterised by the means for moving or conveying the objects or other work, e.g. conveyor belts B05B13/0207 takes precedence; conveyors in general B65G
• CPC Class Codes: B05B 13/0452 the conveyed articles being vehicle bodies
• CPC Class Codes: B05B 16/20 Arrangements for spraying in combination with other operations, e.g. drying; Arrangements enabling a combination of spraying operations
• CPC Class Codes: B05D 1/002 the substrate being rotated
• CPC Class Codes: B05D 7/56 Three layers or more
• CPC Class Codes: F26B 2210/12 Vehicle bodies, e.g. after being painted

Abstract

A work is applied with a solvent-containing thermosetting coating composition to a thickness larger than a limit thickness over which the coating composition on a surface of the work extending in a vertical direction will normally run or sag in a coating zone. After applied with the coating composition, the work is rotated about a substantially horizontal axis to prevent the coating composition on the vertical surface of the work from running or sagging and is conveyed through a heat-hardening zone for hardening the coating composition applied to the work by heating by a conveyor line. The conveyor line includes a pair of conveyors which are separated from each other upstream of a position where the coating composition is applied to the work to a thickness larger than said limit thickness. The heat-hardening zone includes a pre-heat-hardening zone for half hardening the coating composition and a main heat-hardening zone for fully hardening the coating composition after the coating composition is half hardened. A pooling zone in which a predetermined number of works can be temporarily pooled is provided between the pre-heat-hardening zone and the main heat-hardening zone.

Claims

1. In a coating apparatus comprising

a coating station including a coating zone for applying a solvent-containing thermosetting coating composition to a work to a thickness larger than a limit thickness over which the coating composition on a surface of the work extending in a vertical direction will normally run or sag, a heat-hardening station including a heat-hardening zone for hardening the coating composition applied to the work by heating, a rotating means for rotating the work about a substantially horizontal axis after the coating in the coating zone to prevent the coating composition on the vertical surface of the work from running or sagging, and a conveyor means for passing the work through the coating zone and the heat-hardening zone in this order, the conveyor means including a pair of conveyors which form a conveyor line for conveying the work and are separated from each other upstream of a position where the coating composition is applied to the work to a thickness larger than said limit thickness, and said heat-hardening zone including a pre-heat-hardening zone for half hardening the coating composition and a main heat-hardening zone for fully hardening the coating composition after the coating composition is half hardened, wherein the improvement comprises that

the conveyor line for passing the work through the coating zone and the pre-heat-hardening zone in this order comprises a rotary conveyor which is formed in an endless fashion and conveys the work on a rotary truck which carries the work supporting it for rotation while the conveyor line for passing the work through the main heat-hardening zone comprises a non-rotary conveyor which conveys the work on a non-rotary truck which carries the work holding it stationary,

a first transfer means for transferring the work to the rotary truck on the rotary conveyor in a position upstream of the coating zone and a second transfer means for transferring the work on the rotary truck on the rotary conveyor to the non-rotary truck on the non-rotary conveyor in a position downstream of the pre-heat-hardening zone and upstream of the first transfer means are provided, and

a vacant truck changing station is provided on the rotary conveyor between the second transfer means and the first transfer means to transfer a vacant rotary truck from which the work has been removed by the second transfer means to a vacant truck maintenance station and to take out a vacant rotary truck which has been maintained from the vacant truck maintenance station.

2. A coating apparatus as defined in claim 1 in which said vacant truck maintenance station comprises a maintenance conveyor formed in an endless fashion.

3. A coating apparatus as defined in claim 2 in which said maintenance conveyor is disposed on a floor different from the floor on which the rotary conveyor is disposed.

4. A coating apparatus as defined in claim 3 in which said vacant truck maintenance station comprises a lifter which conveys up and down the vacant rotary truck between the rotary conveyor and the maintenance conveyor to transfer the vacant rotary truck from the former to the latter and from the latter to the former.

5. A coating apparatus as defined in claim 2 in which said maintenance conveyor is able to accommodate all rotary trucks on the rotary conveyor.