GB2091133A - Dual orbit sprayer assembly - Google Patents

Abstract

A dual orbit sprayer assembly particularly for use in continuous coaters includes a pair of rods 20 rotatable about a central shaft 16, thereby defining a primary orbit. At the end of each rod 20 is a pair of arms 30 rotatable about their own individual shafts 26, such arms having spray nozzles 36 at the ends thereof. Rotation of the arms 30 causes the nozzles to pass about secondary orbits having their centers maintained upon the primary orbit. Rotation of the shafts 16,26 is achieved in one embodiment by a motor driving the central shaft with a sprocket and chain interconnection being provided among the shafts. In another embodiment, Figure 2 (not shown) the central shaft consists of inner and outer concentric shafts (74,84), each driven by a uniquely associated DC motor. The inner shaft controls the rotational movement of the rods, while the outer shaft is interconnected with the remaining shafts to independently control rotation of the arms. <IMAGE>

Description

SPECIFICATION Dual orbit sprayer assembly The invention herein resides in the art of coating equipment and is particularly adapted for utilization with continuous coaters. More particularly, the invention relates to a sprayer assembly for such coaters in which spray nozzles are caused to rotate about secondary or sub-orbits while passing about a primary orbit.

Continuous coaters have become well known for a number of years. Such coaters typically include a cabinet through which a part is passed by means of a conveyor or the like. Sprayers are maintained within the cabinet to direct the coating such as paint, varnish, asphaltums, vinyls, or the like onto such part to achieve a uniform and complete coating of the same. The cabinet and associated vestibules confine and contain oversprayfrom reaching surrounding equipment while providing means for recapturing such overspray for future use.

In known continuous coaters, the spray nozzle is either fixedly secured to the interior of the cabinet or is adapted with a reciprocator for linear movement upon a track therewithin. In either case, the fan of spray emittered by the nozzle is particularly adapted for coating planar surfaces. Particular difficulty has been experienced using such systems for the coating of structural steel fabrications wherein brackets, sub-plates, and the like cause the part to be of a three-dimensional nature. With a relatively fixed spray angle, prior art continuous coaters find difficulty in completely and totally covering such threedimensional parts. Such systems often require a manual touch-up following the coating operation to assure that all areas of the part have been coated.

Due in large part to the fixed spray angle of presently known continuous coaters, multiple passes at parts within the coater were often necessary to achieve the desired coating, such passes resulting in an excess of coating on certain areas of the part. The major difficulties experienced with prior art continuous coaters have been a result of the immobility of the spray nozzle. While some known sprayers provide for a linear movement of such nozzle, with the spray angle being changed at the path limits for return travel, the fan of the spray is still unidirectional, adapted particularly for planar coating.

In light of the foregoing, it is an object of a first aspect of the invention to provide a dual orbit sprayer assembly having an expanded spray field to accommodate three-dimensional as well as planar objects.

An object of another aspect of the invention is to provide a dual orbit sprayer assembly having a spray angle which is constantly changing.

A further object of an additional aspect of the invention is to provide a dual orbit sprayer assembly eliminating the possiblity of overspraying or excess coating of the workpiece.

Still a further object of an aspect of the invention is to provide a dual orbit sprayer assembly which may be utilized to achieve the simultaneous coating of two sides of a part during a single operation.

Another object of an aspect of the invention is to provide a dual orbit sprayer assembly which provides a spray fan achieving uniform coating of complex surfaces and which is adaptable for implementation with any of numerous types of sprayers and spray nozzles available in the art.

Yet an additional object of another aspect of the invention is to provide a dual orbit sprayer assembly which is durable and reliable in operation and which may be readily constructed with state-of-the-art components for implementation with state-of-the-art components for implementation with state-of-the-art continuous coaters.

The foregoing and other objects of the invention which will become apparent as the detailed description proceeds are achieved by a dual orbit sprayer assembly for continuous coaters, comprising: a first rotatable shaft; a pair of coaxial rods normally extending from said first rotatable shaft and being rotatable therewith; a second rotatable shaft connected to an end of each said rod, each said second rotatable shaft having a pair of coaxial arms extending therefrom, and an end of each said arm having a coating spray nozzle attached thereto; and rotational drive means connected to each of said second rotatable shafts for effectuating relative rotational movement therebetween.

For a complete understanding of the objects, techniques, and structure of the invention, reference should be had to the following detailed description and accompanying drawings wherein: Figure 1 is a front elevational view illustrating a first embodiment of the invention; Figure 2 is a front elevational view, showing a partial cross-section, of a second embodiment of the invention; and Figure 3 is a top plan view of the apparatus of Figure 2.

Referring now to the drawings and more particularly Figure 1, it can be seen that a first embodiment of the dual orbit sprayer assembly of the invention is designated generally by the numeral 10. The assembly 10 includes a collar or other suitable casing 12 attached to the cabinet wall 14 of a continuous coater. The collar 12 has extended therethrough a shaft 16 driven by a motor (not shown). The motor is preferably of a reversible DC nature to be regulatable as to both speed and rotational direction. Preferably, the shaft 16 has a central bore or passage therethrough to provide a conduit for the coating to be sprayed.

A bracket 18 is affixed to the top end of the shaft 16 and has extending therefrom a pair of coaxial rods 20. As will be appreciated by those skilled in the art, there could be any number of such rods, the same preferably being uniformly spaced about the shaft 16 and in normal interconnection with respect to the axis thereof. Attached at the ends of each of the rods 20 are rotary head assemblies 22, each being interconnected by a fluid hose 24 to the inner conduit of the shaft 16. Such interconnection may readily be achieved by those skilled in the art, as, for example, by means of a rotary union or connector.

It will be appreciated that Figure 1 illustrates only one complete assemblage at the end of the one of the rods 20, but the invention contemplates that the end of the other rod 20 wouid also be so characterized. With attention now to the complete assemblage illustrated, it will be noted that a shaft 26 is received within the rotary head 22 and has connected at an end thereof a bracket 28. This bracket has a pair of coaxial arms or rods 30 extending therefrom in preferably normal relationship to the axis of the shaft 26. Of course, the pair of rods 30 could comprise a single rod passing through the bracket 28. The end of the shaft 26 is provided with a fluid coupling 32 communicating through fluid hoses 34 to nozzle heads 36 maintained at the end of each of the rods 30.With the conduit of the shaft 16 being in communication with a pressurized source of coating, communication may be had from such source through the shaft 16, the hose 24, the shaft 26, and thence through the hoses 34 to the nozzles 36.

As noted, a primary driven sprocket 38 is con nectedto and rotatable with the shaft 26. A main drive sprocket 40 is fixedly secured to the collar 12, the sprockets 38,40 being interconnected by a roller chain 42 or other appropriate means. A secondary driven sprocket 44 is interconnected by means of a chain 46 to the sprocket 48 maintained upon the shaft of the other sprayer assemblage as shown.

In operation, the DC motor is used to rotationally drive the shaft 16, causing the sprayer assemblages 22-36 to rotate about a primary orbit. Rotation of the shaft 16 causes the fixed main drive sprocket 40 to effectuate rotation of the shafts 26 via the sprockets 38,44, 48. This rotation causes the spray nozzle heads 36 to rotate about sub-orbits, the locus of the center points of such sub-orbits lying upon the primary orbit. This movement, akin to planetary orbital movement, achieves a nutation of the paths of the spray nozzles 36 such that the angle of incidence to the part being coated is constantly changing, guaranteeing that all areas of even complex parts are coated. It will also be appreciated that the gear ratios between the various sprockets will control the relative rotational speeds between the primary and sub-orbits.The direction and speed of the rotation of the DC motor controlling the shaft 16 will, of course, provide the initial input parameters for such orbits. With the sprockets being effectively interconnected with a single DC motor source, the relative rotational speeds of the orbits are fixed for any given sprocket ratio.

With reference now to Figure 2, a second embodiment of the dual orbit sprayer assembly can be seen as designated generally by the numeral 50. Here, a plate 52 is adapted for attachment to a spray cabinet in standard fashion. The DC motors 54, 56 are provided in standard fashion with associated gear boxes 58, 60. the motors 54, 56 are reversible and of regulatable speed. Brackets 62 receive the motor and gear box assemblies and are secured to the plate 52 by means of bolts 64 and slots 66 to achieve desired positional adjustment.

The gear box 58 is operative for driving a sprocket 68 which, through a chain 70, drives a sprocket 72.

This latter sprocket is attached to a rotatable center shaft 74 as shown. A rotary union 76 is connected to the end of the center shaft 74to pass coating material from a pressurized source to the spray nozzles in a manner to be discussed hereafter. It is to be understood that the center shaft 74 is characterized by a bore to provide a conduit for such coating.

A sprocket 78 is provided in similar interconnection with the gear box 60. A sprocket 82 is connected to an outer rotary shaft 84 which is driven by interconnection of the sprockets 78,82 by the chain 80. It will now be appreciated that the center and outer shafts 74,84 comprise a concentric rotational shaft for the assembly 50. Of course, appropriate bearings, mounts, and seals 86,88,90,92 are provided in standard fashion to achieve secure rotation of the concentric shafts.

As illustrated, a collar 94 is attached to the center shaft 74 and is rotatable therewith. A cap or plug 96 is provided at the end of the shaft 74 to seal the conduit thereof and to provide means for transferring the coating media to the nozzles as will be described. Extending from the collars 94 are coaxial rods or arms 98, preferably interconnected with such collar normal to the axis of the concentric shaft.

Spinner mounts 100 are provided at each end of the rods 98, each having a spinner shaft rotatable in bearing mounts therewithin as shown. A rotary union 104 interconnects the bottom of each shaft 102 and communicates the coating media thereto by means of an associated hose 106 interconnected with the cap 96. It will be appreciated that the spinner shafts 102 are also characterized by bores or conduits passing axially therethrough. A sprocket 108 is connected to one of the spinner shafts 102 as shown, and is driven via a roller chain 110 by a sprocket 112 connected to the outer shaft 84.

In similar fashion, a sprocket 114 is connected to the shaft 102 at the right most end of the rod 98 as illustrated in Figure 2. Again, the actual nozzle assemblage is not shown for the reason that the same duplicates that shown on the left most end of the rod 98 of Figure 2. In any event, the sprocket 114 is interconnected by means of a chain 116 to the sprocket 118 as illustrated. This lattersprocket, similar to the sprocket 112 is also connected to and rotatable with the outer shaft 84.

With reference now to Figures 2 and 3, it will be noted that a cap 120, similar to the cap 96, is provided at the end of each of the shafts 102. It will also be noted that axially aligned rods or arms 122 are fixed to and rotatale with the spinner mount 100 as illustrated. At the end of each of the arms 122 is a spray nozzle 124. The spray nozzles communicate with the source of coating by means of hoses 126 interconnected with the cap 120. Those skilled in the art will recognize that the coating media passes from a pressurized source through the rotary union 76, center shaft 74, cap 96, hoses 106, rotary union 104, spinner shaft 102, cap 120, and thence through the hoses 126 to the nozzles 124.

The operation of the embodiment of Figures 2 and 3 is similar in nature to that of Figure 1. However, in this embodiment, the rotational speed and direction of the primary orbit is determined by the drive of the center shaft 74 by means of the motor and gear box 58. The rotational speed and direction of the nozzles themselves, in their sub-orbits, are determined by the interconnection of the outer shaft and its interconnection with the motor and gear box 56, 60.

Accordingly, various combinations of spray arrangements may be obtained.

Thus it can be seen that the objects of the invention have been satisfied by the structure presented hereinabove. The concept of the invention is a planetary-type orbiting arrangement wherein the nozzles themselves rotate within a sub-orbit while rotating about a primary orbit. Such rotation achieves a spray fan which can effectively coat the most geometrically complex surfaces. It will be appreciated that the invention may be utilized in a variety of coater systems. The specifics of the nozzles and other elements of the invention presented hereinabove will be readily perceived by those skilled in the art as determined by the nature of the coating media, the type of part to be treated, and the air movement patterns within the coating booth.

Additionally, certain structural changes may readily be perceived such as the use of air motors for the DC motors presented herein. Suffice it to say that numerous variations on the basic theme of this invention may now be perceived by those skilled in the art.

While in accordance with the patent statutes only the embodiments of the invention as now best contemplated by the inventors have been presented and described in detail, it will be understood that the invention is not limited thereto or thereby. Accordingly, for an appreciation of the true scope and breadth of the invention, reference should be had to the following claims.

Claims (19)

1. A dual orbit spray assembly, comprising: a first member rotatable about a first axis; a second member connected at an end of said first member, said second member being rotatable about a second axis, such rotation causing said second axis to define a first orbit about said first axis; and a coating spray nozzle means connected to and carried by said second member, rotation of said second member causing said nozzle means to define a second orbit about said second axis.

2. The spray assembly accordng to claim 1 wherein said first member comprises a first shaft having a first rod extending therefrom normal to said first axis.

3. The spray assembly according to claim 2 wherein said second member comprises a second shaft rotatable about said second axis at an end of said first rod, and a first arm connected to and extending from said second shaft normal to said second axis, said nozzle means being connected at an end of said first arm.

4. The spray assembly according to claim 3 wherein said second member further includes a second arm, coaxial with said first arm, and extending from said second shaft, said nozzle means further being connected at an end of said second arm.

5. The spray assembly according to claim 4 wherein said first member further includes a second rod, coaxial with said first rod and extending from said first shaft, said second rod having a third shaft rotatable about a third axis at an end thereof and further including third and fourth coaxial arms extending normally from said third shaft, said third and fourth arms having additional nozzle means connected at ends thereof.

6. The spray assembly according to claim 3 which further includes drive means interconnected between said first and second shafts for achieving rotational movement of said shafts.

7. The spray nozzle according to claim 6 wherein said drive means comprises: a motor connected to and rotatably driving said shaft; a drive sprocket fixedly maintained about said first shaft; a driven sprocket connected to and maintained about said second shaft; and a chain interconnecting said drive and driven sprockets.

8. The spray nozzle according to claim 6 wherein said first shaft comprises inner and outer concentric shafts, each having a sprocket connected thereto in driven interconnection with a separate motor.

9. The spray nozzle according to claim 8 wherein said outer shaft has an additional sprocket connected thereto, said additional sprocket being in driven interconnection with a sprocket attached to said second shaft.

10. The spray nozzle according to claim 9 wherein said inner and second shafts provide conduits for passing a coating from a pressurized source to said nozzle means.

11. A dual orbit spray assembly for continuous coaters, comprising: a first rotatable shaft; a pair of coaxial rods normally extending from said first rotatable shaft and being rotatable therewith; a second rotatable shaft connected to an end of each said rod, each said second rotatable shaft having a pair of coaxial arms extending therefrom, an end of each said arm having a coating spray nozzle attached thereto; and rotational drive means connected to each of said first and second rotatable shafts for effectuating relative rotational movementtherebetween.

12. The spray assembly as recited in claim 11 wherein each of said first and second rotatable shafts comprise conduits passing coating to said spray nozzles.

13. The spray assembly as recited in claim 11 wherein said drive means comprises: a stationary drive sprocket coaxially maintained about said first rotatable shaft; primary and secondary driven sprockets, each connected to and rotatable with one of said second rotatable shafts, said drive sprocket and primary drive sprocket being interconnected; and a drive sprocket connected to the other of said second rotatable shafts and interconnected with said secondary drive sprocket.

14. The spary assembly as recited in claim 11 wherein said first rotatable shaft comprises inner and outer concentric shafts, and wherein said drive means comprise first and second motors connected to said inner and outer shafts.

15. The spray assembly as recited in claim 14 wherein said outer shaft is interconnected with each of said second rotatable shafts.

16. The spray assembly as recited in claim 15 wherein said inner shaft is interconnected with said pair of coaxial rods.

17. The spray assembly as recited in claim 16 wherein said motors are reversible, variable speed, DC motors.

18. The spray assembly as recited in claim 17 wherein said motors are driven independently of each other.

19. A dual orbit spray assembly substantially as herein described with reference to Figure 1 or Figures 2 and 3 of the accompanying drawings.