Dispense for applying an adhesive to remote surfaces

Abstract

A dispense for dispensing an adhesive onto a remote surface, such as a case mouth and primer ammunition. The dispense includes a reservoir containing an adhesive; a positive displacement pump; and a nozzle having a tapered tip. The positive displacement pump delivers a predetermined amount of the adhesive, preferably an anaerobic adhesive, from the reservoir to the nozzle at predetermined intervals. The nozzle discharges the predetermined amount of adhesive through the air and at least 1/16-inch onto the remote surface.

Claims

1. A method for dispensing an adhesive onto a surface, steps of which comprise: providing a reservoir containing an adhesive; providing a positive displacement pump to deliver a predetermined amount of adhesive dispensed from the reservoir at predetermined intervals; providing a nozzle having a tapered tip to receive the adhesive and discharge it onto the surface; a first conduit for directly connecting the reservoir and the positive displacement pump such that the adhesive is supplied directly from the reservoir to the positive displacement pump; and a second conduit for directly connecting the positive displacement pump and the nozzle such that the adhesive is supplied directly from the positive displacement pump to the nozzle.

2. The method according to claim 1, wherein the adhesive in the reservoir is an anaerobic adhesive.

3. The dispenser method according to claim 1, wherein the adhesive in the reservoir is light curable.

4. The method according to claim 1, wherein the adhesive has a viscosity of 30-45 cps.

5. The method according to claim 1, wherein the surface is a case mouth and primer ammunition round.

6. The method according to claim 1, wherein the tapered tip is 1/16 or more from the surface while the adhesive is being discharged.

7. The method according to claim 1, wherein the nozzle having a tapered tip is configured to receive the adhesive and discharge it onto the surface without the tapered tip of the nozzle contacting the surface.

8. The method according to claim 1, wherein the nozzle having a tapered tip is configured to discharge the adhesive onto the surface by shooting the adhesive at least 1/16 from the nozzle onto the surface at greater than 200 rounds per minute.

9. A method for dispensing an adhesive onto a remote surface, steps of which comprise: providing a dispenser comprising: a reservoir containing a liquid adhesive, a positive displacement pump, and a nozzle having a tapered tip; delivering a predetermined amount of the liquid adhesive from the reservoir to the nozzle at predetermined intervals; discharging the predetermined amount of adhesive through the air onto the remote surface; a first conduit for directly connecting the reservoir and the positive displacement pump such that the adhesive is supplied directly from the reservoir to the positive displacement pump; and a second conduit for directly connecting the positive displacement pump and the nozzle such that the adhesive is supplied directly from the positive displacement pump to the nozzle.

10. The method according to claim 9, wherein the adhesive has a viscosity of 30-45 cps.

11. The method according to claim 9, wherein the remote surface is a case mouth and primer ammunition round.

12. The method according to claim 9, wherein the tapered tip is 1/16 or more from the remote surface while the adhesive is being discharged.

13. The method according to claim 9, wherein the discharging of the predetermined amount of adhesive through the air onto the remote surface is performed without the tapered tip of the nozzle contacting the remote surface.

14. The method according to claim 9, wherein the discharging of the predetermined amount of adhesive through the air onto the remote surface is performed by shooting the adhesive at least 1/16 from the nozzle onto the remote surface at greater than 200 rounds per minute.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The preferred embodiments of the dispense of the present invention, as well as other objects, features and advantages of this invention, will be apparent from the accompanying drawings wherein:

(2) FIG. 1 is a side view of the dispense being used to seal a case mouth and primer ammunition round.

(3) FIG. 2 is a sectional view A-A of the dispense shown in FIG. 1.

(4) FIG. 3 is a side view of a preferred nozzle for discharging the adhesive with a tapered tip needle, which is used with the dispense shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(5) The present invention is a dispense (also interchangeably referred to herein as the dispense or the dispense system) used for dispensing of adhesives, preferably light curing anaerobic adhesives having viscosities of 30-45 cps, onto remote surfaces. As used herein, the term remote surfaces refers to any surface not in contact with the dispense that can be bonded to another surface by an adhesive, wherein the surface can include metal, plastic, wood and synthetic and composite materials. The dispense system preferably dispenses an anaerobic sealant or adhesive (e.g., Loctite 190700 CMS) onto a remote surface. In preferred embodiments, the anaerobic sealant is dispensed onto the surface of a case mouth and primer ammunition round. Anaerobic adhesives begin to cure when they come in contact with a metal and the absence of air. The dispense shoots adhesive approximately 1/16 from the discharge port in the nozzle tip to the remote surface without the nozzle tip contacting the remote surface, preferably the case mouth and the primer of the bullet. This dispense uses a rapid fire through the air technique that overcomes the problems encountered by touch transfer dispenses, wherein the tip contacts the surface. By shooting the adhesive through the air, the dispense system eliminate the potential to contaminate the dispense tip by eliminating contact of the tip with active metals on the surface.

(6) The dispense system includes an adhesive, a first conduit for supplying the adhesive to a pump and a second conduit connecting the pump discharge to a nozzle through which the adhesive is dispensed. The adhesive can be stored in a reservoir or a cartridge and delivered to the pump using well known methods, such as pressurizing the reservoir/cartridge to force the adhesive to flow to the pump or using a plunger/rod assembly to push the adhesive out of the reservoir/cartridge. The pump delivers a predetermined amount of adhesive to the nozzle with sufficient pressure so that, when the adhesive exits the nozzle, it travels through the air and onto the bullet. The nozzle preferably has a tapered needle tip that provides back pressure and helps to direct the adhesive. The discharge port of the tapered needle tip has a diameter of 25 gauge or larger, preferably about 27 gauge. The tapered tip needle has been found to provide more accurate and reliable dispensing.

(7) The pump is preferably a positive displacement pump that can be adjusted to discharge specific volumes of adhesive according to the user's application. Positive displacement pumps are well known to those skilled in the art and they deliver a definite volume of liquid for each cycle of pump operation. This volume is constant regardless of the resistance to flow offered by downstream components in the system up to the rated capacity of the pump. A positive displacement pump cyclically delivers liquid in separate volumes with no delivery in between. This allows the cycles to correspond to the bullets that are sequentially placed in front of the nozzle. As the pump shaft rotates, a notched portion of the pump head displaces the fluid from one side of the pump to the other. This motion is what shoots the adhesive through the air and onto the bullet.

(8) The positive displacement pump operates at speeds of from 0 to 1,500 rpm, preferably 1,200-1,500 rpm and most preferably between 1,400 and 1,500 rpm. The most preferred positive displacement pumps for the dispense system are rotary positive displacement pumps. The dispense system of the present invention can increase throughput from about 200 rounds per minute for prior art methods to about 400 rounds per minute using a single dispense.

(9) The dispense system deposits an anaerobic adhesive onto a bullet without the dispense tip contacting the remote surface. This eliminates the problems in the touch transfer method caused when the adhesive began to cure upon contacting a metal surface, such as the surface of an ammunition round. Instead, the dispense tip is positioned a distance from the surface and shoots adhesive through the air (about 1/16 or more) from the tip to the bullet case mouth and primer. This eliminates the need for a mechanism that slides in and out and provides increased throughput potential. When dispensed onto an ammunition round, the anaerobic adhesive travels through the air and contacts either the case mouth or primer and wicks around the surfaces. Because the tip of the dispense nozzle does not contact the bullet, the adhesive does not begin to cure and clog the dispense tip due to contact with active metals. This allows the dispense system to operate at high speeds of up to 400 parts per minute.

(10) Referring now to the figures, FIG. 1 shows a side view of the dispense system 10, which includes a positive displacement pump 12, a nozzle 14, a pressurized reservoir containing the adhesive 16, and connecting tubing 18, 20. The adhesive flows from the reservoir 16 under pressure to the rotary pump 12, which delivers the adhesive to the nozzle 14 at predetermined intervals in predetermined amounts. The adhesive is discharged from the nozzle 14 through the air and onto a bullet 90. FIG. 2 is a sectional view A-A of the dispense system 10 shown in FIG. 1 and it shows the pump shaft linkage 22 that connects to a motor. FIG. 3 is a side view of a preferred nozzle 14 with a tapered tip needle used with the dispense shown in FIG. 1. The nozzle 14 has a tapered tip 24 with a discharge port 26, which provides a back pressure and improves the accuracy of the adhesive deposited on the bullet 90.

EXAMPLES

(11) The examples set forth below serve to provide further appreciation of the invention but are not meant in any way to restrict the scope of the invention.

Example 1

(12) An ammunition customer would like to dispense anaerobic onto ammunition case mouth and primer at a rate of 400 bullets per minute with few dispensing points as possible. Touch transfer simply is not fast enough. The dispense system is used to dispense adhesive through the air (i.e., shooting) onto the bullet, which allows the customer to gain the required process speed. The dispenser is capable of dispensing at a rate of 400 bullets per minute using 1 dispense point.

Example 2

(13) A customer wishes to positively dispense anaerobic adhesive onto the case mouth or primer of a round. Current methods for dispensing onto ammo rounds are based on pressure timed system dispense, which is rate limiting and accuracy limiting. The dispense system uses a positive displacement pump to dispense a predetermined amount of adhesive onto the case mouth and satisfy the customers requirements.

Example 3

(14) The dispense system eliminates touch transfer from the dispense method and reduces the potential for the dispense tip to clog/cure over time as the adhesive contacts the metal of the bullet.

(15) Thus, while there have been described the preferred embodiments of the present invention, those skilled in the art will realize that other embodiments can be made without departing from the spirit of the invention, and it is intended to include all such further modifications and changes as come within the true scope of the claims set forth herein.