Patent GB-1140804-A (GB)
Title: Apparatus for coating surfaces of automobile bodies
Inventor: LEGEZA THOMAS BODNAR
IPC: B05B13/04
Filed: 1966-10-25
Abstract: 1,140,804. Coating apparatus. DEVILBISS CO. 10 Nov., 1967 [25 Oct., 1966], No. 47821/66. Heading B2L. Coating apparatus comprises a conveyor for irregular objects to be coated, such as automobile bodies, spray heads mounted on a frame for reciprocation laterally of the direction of movement of the conveyor, means for raising and lowering the frame, and means for regulating the height of the frame to maintain a substantially constant distance between the spray heads and a body being coated, the regulating means comprising a series of driving cams each contoured to provide such constant distance for a particular body type, and means for selectively engaging each of the driving cams. A conveyor moves automobile bodies beneath a frame 14 which carries transverselymovable spray heads and which is rigid with a pivoted arm 18 for movement towards and away from the conveyor. Arm 18 is moved by a hydraulic motor 16 so controlled that frame 18 is e.g. initially lowered for coating the bonnet, then raised for coating the roof, and finally lowered for coating the boot. Oil is drawn by a pump 32 from a reservoir 33 and is delivered via a conduit 34 to a valve 35 connected by conduits 30, 31 to the upper and lower ends respectively of motor 16, and by a conduit 37 to reservoir 33. An outwardly spring biassed plunger of value 35 engages a pivoted bar 36 so spring biased that said plunger is normally held retracted, when conduits 34, 31 and 30, 37 are respectively interconnected for raising frame 14. Moving bar 36 away from valve 35 allows said plunger to advance, whereby conduits 34, 30 and 31, 37 are respectively interconnected for lowering frame 14. The position of bar 36 is determined by cam discs 61, 62, 63 which engage respective followers on bar 36, and which are journalled on and may be selectively coupled to a shaft 64 driven in synchronism with said conveyor. The apparatus is started by manually actuating an air valve 40 to close switches 41, 42, 103. A programmer 50 then detects both the presence of and the characteristics of a body to be coated and accordingly operates an appropriate one of relays 51, 52, 53. As shown, relay 51 operates to energise a solenoid 51<SP>1</SP> to actuate a valve 55 for momentarily admitting compressed air from a line 56 to a motor 57 to -raise the piston thereof. A detent 58 is thereby withdrawn from a notch 67 in a disc 66, and a valve 59 is actuated to admit air to a clutch 60 for coupling cam 61 to shaft 64. On de-energisation of solenoid 51<SP>1</SP>, detent 58 rides on the periphery of disc 66 and reengages notch 67 on completion of a single revolution of cam 61 to actuate valve 59 for uncoupling cam 61 from shaft 64. The contour of cam 61 ensures the appropriate positioning of frame 14 during said revolution corresponding to the complete coating of the subject sensed. On operation of pump 32, a switch 102 is closed to energise a solenoid 76<SP>1</SP> for actuating a -valve 76, whereby air passes via a manually-operated valve 75 to actuate a valve 78 for disconnecting a bypass between the conduits 30, 31. A valve 80 is also actuated for connecting a source 82 of low pressure air to the lower end of a motor 100 connected to arm 18 to act thereby as a counterpoise thereto. In the event of failure of either hydraulic pressure, air pressure or electrical potential, the associated switch 102, 103<SP>1</SP> or 104 is opened to de-energise solenoid 76<SP>1</SP>. Valve 76 is thereby actuated to de-pressurise valves 78 and 80, whereby the bypass connection between conduits 30, 31 is established for immobilising motor 16, and motor 100 is connected to a source 81 of high pressure air for raising frame 14.