BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an automatic height adjusting manifold, and in particular to a manifold that is adjustable to be located adjacent to a workpiece.

2. Description of the Related Art

Parts washers have incorporated conveyors for many years, wherein parts or workpieces are placed on a conveyor and moved through a parts washing machine. The machine can have several zones, such as wash, rinse, blowoff and dry. There may be multiple numbers and combinations of zones in a particular machine. An air manifold, or knife, can be used in the blowoff zone to distribute air or another gas for removing moisture from parts.

The effectiveness of the blowoff and blowoff is affected by the distance between the air manifold and the parts. Fixed position manifolds need to be placed within the machine at a height that allows the largest possible parts to pass through the machine. In this regard, the effectiveness of the machine to dry small parts can be greatly compromised.

Knowing this relationship, engineers and designers have developed manually adjustable air manifolds. Yet, there can be considerable downtime associated with making manual adjustments.

Thus, there exists a need for an automatic height adjusting manifold that solves these and other problems.

SUMMARY OF THE INVENTION

The present invention relates to an automatic height adjusting manifold, and in particular to a manifold that is adjustable to be located adjacent to a workpiece. A conveyor can have an overhead structure that supports a concealer such as a canopy or removable doors. A sizing device measures the height of a workpiece. The sizing device is outside of the work areas of the machine. A height safety is provided to make sure that no workpieces taller than the measured piece enter the machine. There are liquid bays and blowoff bays within the machine. The blowoff bay has an air knife or other manifold device. A height system is provided and is adjustable to correlate with the measured height at the sizing device. A string potentiometer can be used for an air knife position feedback to the programmable logic controller (PLC).

According to one advantage of the present invention, a sizing device has a sensor to measure the height of an object passing through the sizing device. The sensor can sense a height either on a batch basis or on an every piece basis. The same sensor, or an additional sensor can be used to sense the lateral dimensions of the workpiece so that the nozzles can be adjusted in accordance with workpiece width.

According to another advantage of the present invention, the sizing device can be a light curtain. A light curtain, or light array, is accurate and is located on an external portion of the machine that is outside of the liquid and blowoff bays. The insides of machines typically have challenging environments (heated wash for example) that can be tough on sensitive measuring equipment. The optics of the light array, by being removed from this environment, are less prone to sensor damage or obfuscation.

According to another advantage of the present invention, a blowoff assembly is adjustably provided within the machine. The blowoff assembly is adjustable in correlation to a height sensed by the sizing device. This is advantageous as no machine disassembly or human intervention is needed for adjustment of the air knife. Automatic adjustment is quicker resulting in reduced machine downtime. Also, without the need to remove a canopy or door, there is a reduced chance of canopy or door damage therefore extending the useful life of the canopy or door.

According to another advantage of the present invention, the sensed height can be correlated to a voltage. The voltage, in turn, can be communicated to a PLC used in connection with the blowoff assembly to position the air knife. The string potentiometer is robust and accurate. The string or cable is unwound or wound until the length is equal to the communicated voltage.

According to a further advantage of the present invention, the height of the spray nozzles can also be adjusted for increased cleaning spray impingement.

According to a further advantage of the present invention, a height safety is provided. The height safety is adjusted in unison with the blowoff assembly and is positioned to the slightly lower height than the blowoff assembly. The height safety can have a plate that is hinged. A proximity switch can sense when the plate is pivotally moved. The conveyor is automatically stopped when the proximity switch senses hinged movement of the plate preventing damage to the machine and/or parts being processed. In this regard, no workpiece can enter the machine that will contact the air knifes causing damage to the machine and/or parts.

According to another advantage of the present invention, in a batch system, a PLC can determine when to take a new measurement based on conveyor speed and last part being measured. In another embodiment, the sizing device can measure every workpiece and adjust the blowoff assembly accordingly by the time the workpiece reaches the blowoff assembly.

Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings.

