MXPA00000908A - Powder feed system - Google Patents

Abstract

The present invention is directed to a vibratory powder feeding and metering apparatus that achieves the above-mentioned requirements. Generally, the apparatus of the present invention includes a housing (12) defining a powder reservoir (18), a powder storage hopper (14) having an outlet disposed to deliver powdered resin to the reservoir, a powder distribution block (16) having one or more generally vertical fill tubes, a plurality of discharge ports extending from the reservoir (18) to the fill tubes in the distribution block, and a vibration device to which the housing is mounted. Typically, the fill tubes are in communication with individual spray nozzles for transmission of the powdered resin. The housing also carries an adjustable barrier (34) which serves as a dam to control or meter the flow of powdered resin into the discharge ports.

Description

POWDER FEED SYSTEM FIELD OF THE INVENTION The present invention relates generally to powder conveyor systems. More particularly, the present invention is directed to a powder metering and feeding apparatus for use in supplying resin powder to a powder resin rolling nozzle. The invention finds particularly advantageous application in processes for applying resin powder to fasteners. BACKGROUND OF THE INVENTION [0002] A variety of vibratory systems have been known in the art for the use of powders. Such feeding systems, dating back to the 1950's and 1960's, have included both rotationally vibrated balls and linearly vibrated channels or channels. In the field of threaded fasteners, there is a need for useful feeding systems for the application of powder resins on the fasteners. These resins, once applied, can serve for any of several functions, including closure, sealing, lubrication or protection. Frequently, the same feeding apparatus will therefore be used with different resin powders, each having its own distribution of particle size, specific gravity, coefficient of friction and perhaps other properties that affect its flow characteristics. In addition, the same feeding apparatus can be used with many different sizes of fasteners thus requiring substantially different powder flow rates. Still, the apparatus can be used with different spraying installations, using one, two, three or even four spray nozzles. As a result there is a need for a simple, efficient, vibratory feeder apparatus that offers greater versatility while still dosing and accurately feeds the powdered resin, for its spray application to threaded fasteners. SUMMARY OF THE INVENTION The present invention is directed to a vibratory apparatus for feeding and dosing powder, which achieves the above-mentioned requirements. Generally, the apparatus of the present invention includes a housing defining a powder container, a powder storage hopper having an outlet positioned to deliver the powder resin to the reservoir, a powder distribution block having one or more tubes generally vertical filling, a plurality of discharge ports extending from the reservoir to the filling tubes in the distribution block and a vibrating device to which the housing is installed. Typically, the filling tubes are in communication with individual spray nozzles for the transmission of the powder resin. The housing also carries an adjustable barrier that serves as a dam to control or dose the flow of the resin powder to the discharge ports. BRIEF DESCRIPTION OF THE DRAWINGS The novel aspects that are characteristic of the invention are set forth in the appended claims. However, the invention by itself, together with the objects and accompanying advantages thereof, will be better understood by reference to the following description taken in relation to the accompanying drawings, in which: Figure 1 is a side view of the feeding apparatus and powder dosing of the present invention, the supply of the powdered resin to a typical powder rolling nozzle is also schematically illustrated; Figure 2 is a front view of the apparatus of Figure 1 having a powder distribution block used with a four nozzle application; and Figures 3 and 4 are each front views showing distribution blocks used, respectively, with one or two nozzle applications. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As illustrated in the drawings, the powder feeding and dosing apparatus of the present invention is generally designated 10 and includes a housing 12, a supply or storage hopper and a distribution block 16. The housing 12 defines a powder resin reservoir 18 having in the middle a horizontally oriented bottom 20 and walls 22 and 24.

Extending through the end wall 24 is a plurality of generally oriented unloading ports 26, each having an inner end 30 in communication with the reservoir 18 and an outer end 32. The housing 12 also supports a barrier generally vertical and adjustable 34, which together with the bottom 20 of the housing defines a metering orifice, through which the powder resin flows. Alternatively, the barrier 34 may be placed in direct contact with the bottom 20 and may have one or more dosage openings for dosing the flow powder. Still other barriers with differently sized dosing slots or slots can be used to vary the flow rate of the powder. The supply hopper 14 has an outlet 15 positioned to supply resin powder to the reservoir 18. This form of powder supply is conventionally known as an "inflow filling" technique and has been used in the powder transfer apparatus for many years. . As is well known in the art, the level of dust in the tank 18 will remain at the level of the lower part of the outlet 15. The powder distribution block 16 is installed in the housing 12. The block 16 includes a common passage 42 and one or more powder filling tubes 44, each in communication with the passageway 42. The upper dust receiving end 45 of each filling tube is supplied with powder resin leaving the outer ends 32 of the discharge ports. 26. The lower powder distribution end 46 of the fill tube is in communication with the powder supply port of a conventional powder roll nozzle to supply powder for application to a fastener. The distribution block is configured for a particular number of filling tubes and can be interchanged with other distribution blocks, such as blocks 17 and 19, having different numbers of filling tubes as illustrated in Figures 3 and 4. Of this In this manner, the apparatus of the present invention can be adapted to be used with one, two, three, four or even more rolling nozzles. The distribution block 40 also includes one or more suction ports 48, which communicate with the common passage 42. Many conventional roll nozzles currently in use utilize a high pressure air supply to transport the powder. These nozzles are known to create a negative pressure in the powder supply. In other words, the nozzle tends to suck dust from the powder feed system. Port 48 ensures that any suction effect caused by the nozzle will not act to increase the flow velocity of the powder leaving the discharge ports. The housing 12 is installed to any conventional linear vibration device 49 well known to those skilled in the art. Typically, such vibrators include frequency and / or amplitude controls that allow adjustment of the vibratory action. Since accurate dosing of the resin powder for separate nozzles may be important in some applications, it is desirable to level the bottom 20 of the housing and the interior openings of the discharge ports 26 so that the flow of powder to each port 26 be approximately the same. For this purpose, a visual level indicator 50 is installed on the end wall 24 to facilitate leveling adjustments. For an alternative embodiment, a horizontal platform 52 can be installed to the barrier 34. This platform directs first the flow of powder towards the wall 22, then below the bottom 20 and then along the bottom 20 under the barrier 34 towards the ports of discharge 26. This installation has been found desirable for low volume flow rates. In accordance with the present invention, a wide range of powder resin materials and flow rates can be adapted. By adjusting the vibration level, the height of the powder in the tank and the dosing opening of the barrier, the flow rate, can be effectively controlled. Flow rates from about 0.15 grams per hour to as high as about 22.5 grams per hour can be achieved. Of course, it should be understood that various changes and modifications to the preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without diminishing their accompanying advantages. Therefore, it is intended that such changes and modifications be protected by the following claims.

Claims (8)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore the property described in the following claims is claimed as property. An apparatus for feeding and dosing resin powder to a powder roll nozzle to thereby apply the resin to a fastener, comprising: a housing defining a dust deposit, said housing being mounted to a linear vibration device and having a fund generally oriented horizontally; a powder storage hopper having an outlet positioned to supply the resin powder to the tank; a powder distribution block installed in the housing and having at least one generally vertical filling tube with an upper dust receiving end and a lower powder distribution end; a plurality of generally oriented horizontally discharging ports extending through a wall of the housing, each port having an inner end in communication with the reservoir and an outer end located to deposit the powdered resin at the receiving end of the reservoir. a powder filling tube; and the dispensing end of the powder filling tube being in communication with the powder supply to the nozzle. The apparatus according to claim 1, characterized in that it further comprises a barrier installed to said housing, the barrier and the lower wall of the housing acting together to control the flow of powder to the discharge ports. 3. The apparatus according to claim 2, characterized in that the barrier is installed in an adjustable manner to the housing. The apparatus according to claim 1, characterized in that the distribution block is installed in an adjustable manner to the housing. The apparatus according to claim 1, characterized in that the distribution block has at least one suction port associated with each powder filling tube. The apparatus according to claim 1, characterized in that each discharge port is placed adjacent to the bottom of the tank. The apparatus according to claim 1, characterized in that it further comprises a plurality of distribution blocks, each being mounted interchangeably to the housing and having a number of filling tubes different from that of other distribution blocks. The apparatus according to claim 1, characterized in that it also comprises a visual indicator of the horizontal level of the discharge ports in relation to one another.