Method And Apparatus For Manufacturing Sparklers

Abstract

A method and machine for producing sparklers in solid rod form enwrapped in a paper or other combustible material casing from powdered pyrotechnic material which is dispensed onto an arcuated paper web which is drawn through a heated tubing and thence onto a wet belt of fabric, the paper web and contents being drawn by said belt through a garniture wherein the belt wraps around the paper web and contained material to form a rod shape after which the belt is stripped therefrom and the rod is severed into desired lengths.

Description

The invention relates to apparatus and method for the manufacture of sparklers molded into a rigid rod form and more particularly to a continuous rod making machine and method for producing a pyrotechnic sparkler from particulate material.

In our co-pending application Ser. No. 146,366 filed May 24, 1971, now abandoned entitled "Sparkler Composition," a novel sparkler is described which is a molded rigid rod of pyrotechnic material enclosed within a thin paper or other combustible material outer covering which incorporates all of the beauty of the previously known sparklers when ignited but eliminates the hazards of the resulting hot wires onto which the pyrotechnic composition is applied. The new sparklers which can be made on the apparatus described herein eliminate the necessity for the wire support, since the resulting sparklers are self-supporting rods.

It is an object of the present invention to provide a machine and a method for producing a continuous rod from normally powered ingredients with means for severing the formed rod into units of predetermined length.

It is another object of the present invention to provide a machine and a method adapted to produce a continuous rod having a paper casing.

Other objects and the nature and advantages of the present invention will be apparent from the following description when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a machine in accordance with the present invention;

FIG. 2 is a cross sectional view taken along the line 2--2 of FIG. 1;

FIG. 3 is an enlarged side elevational view partly in cross section showing a portion of the machine;

FIG. 4 is a cross sectional view taken along the line 4--4 of FIG. 3;

FIG. 5 is a cross sectional view taken along the line 5--5 of FIG. 3;

FIG. 6 is a cross-sectional view taken along the line 6--6 of FIG. 3;

FIG. 7 is a diagrammatic illustration of four phases of the operation of the portion of the machine shown in FIG. 3; and

FIG. 8 is a diagrammatic showing of the use of a transfer roller for wetting the belt.

The accompanying drawings illustrate the preferred embodiment of the present invention. The machine as illustrated comprises an elongated table or bed 10, the right hand or rear end being the feed end. A drum or wheel 12 is provided for a supply roll 14 of a paper web 16 which is led about vertically aligned guide rollers 18, 20 mounted on the table 10, and thence in a forward direction over a drive roll 22 mounted for rotation upon the table 10. The paper or other combustible material web 16 has a width corresponding to the circumference of the sparkler to be produced. From the drive roll 22 the web is led forwardly and then rearwardly between guide rolls 24, 26 for training about a roll 28 for directing the paper web forwardly and longitudinally of table 10. Provided for cooperation with drive roll 22 is a rubber covered pinch roll 30 having a follower arm 32 which rides upon the paper web 16. The pinch roll 30 is so mounted that when slack develops in the paper web, the follower arm 32 will swing downwardly effecting a pinching of the paper against drive roll 22 for automatically controlling the tension.

From roller 28, the paper web is received within an elongated support channel 34 disposed upon the table 10 and having an upwardly opening, semi-circular recess 36 as best shown in FIG. 2 which extends throughout its length for causing the paper web received therein to conform to this configuration as it is moved slidingly therealong, to present a receptacle for powdered material as indicated at 38, discharged from a hopper 40. The hopper 40 is mounted on a frame 42 for vibratory movement as by means of a conventional vibrator 44 which effects vibration of a feeder 46 located at the lower end of hopper 40 and having a tapered, downwardly extending discharge chute 48 at its end remote from the hopper 40. The hopper is mounted near the feed end of the machine. The powdered material 38 is contained in the hopper 40 and is discharged through the chute 48 which is located immediately above recess 36 of support channel 34 for reception upon the now upwardly concave paper web 16 (FIG. 2). Electrically operated control means (not shown) are provided for energization of vibrator 44 to vibrate hopper 40 and feeder 46 to assure a continuous uniform delivery of material 38 dispensed from the hopper 40.

It is obvious that the specific powdered material which might be dispensed from the hopper may be of any type. By way of example, only the hopper may be charged with the various, dry powdered ingredients adapted for the formation of a sparkler in accordance with the disclosure of pending patent application Ser. No. 146,366 referred to above. Thus, the hopper charge may consist of iron or steel powder, an oxidizer including ammonium perchlorate to which may be mixed barium nitrate and other oxidizers, a fuel supporting agent, accelerators, a binder, colorant and combustion rate modifiers. The binder is preferably starch, dextrin, acrylic powder, methyl methacrylate, ethyl methacrylate and butyl methacrylate polymers and copolymers, cellulose acetate, ethyl cellulose, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, vegetable glues, animal glues, shellac, red gum and synthetic adhesives.

The binders serve the function of binding together the remaining ingredients into a solid rod that will withstand handling, and the binders are usually activated by a combination of moisture and heat.

The vibratory action of hopper 40 reliably causes the mixture of powdered ingredients to be discharged onto the paper web 16 in desired proportionality so that the resultant rod will be of a homogeneous character having a uniform composition throughout its entire extent so that each section cut off from the continuous rod will be of like characteristics and properties. It will be recognized that the discharging action of hopper 40 and feeder 46 is continuous, being correlated or synchronized with the rate of travel of paper web 16.

An endless fabric web or belt 50 is provided immediately beyond the hopper 40, the belt being directed from an enlarged drive wheel 51 about a guide roller 53 into a vat 52 containing a liquid 54 by meas of guide rollers 56, 58 and 60. The rollers 58 and 60 being located beyond the liquid level so that the belt 50 is conducted into the liquid. The web belt emerges vertically from the vat 52 about a guide roller 62 and then reverses direction around a guide roller 64. The guide roller 64 is mounted with its upper edge at about the same level as the support channel 34 so that as the semi-cylindrically formed paper web loaded with powder material, as shown in FIG. 2, leaves the support channel 34 it engages the wet belt 50 and is supported thereon as shown at I in FIG. 7. The belt 50 is preferably a tight woven fabric designed for resistance to heat and having a width substantially the same as that of the paper web 16. The belt may be cotton or the equivalent which can readily be saturated with a liquid by dipping therein.

The vat 52 is merely an example of a means for wetting the belt. It is contemplated that other means could be utilized such as a transfer roller, 53 as shown in FIG. 8. The belt 50 passes between the wetted transfer roller 53 and a presser roller 55 whereby the belt is wetted by the liquid in the vat.

Paper web drive wheel 22 and belt drive wheel 51 are operated by means of a prime mover M which is connected through suitable motion transmitting means indicated generally at 55 to a clutch and gear transmission (not shown) connected to the drive wheels. In accordance with customary practice the cutter, not shown, is properly synchronized so as to sever the formed rod into units of desired length.

A guide tube 66 with an outwardly tapered receiving end 68 is provided to receive the wet belt as well as the semi-circular formed paper web and its powdered contents. Due to the cross-sectional shape of the tube 66, the wet belt is formed also into a semi-cylindrical form conforming to and encircling the paper web as best shown at II in FIG. 7. An electrical heater 70 is shown surrounding the tube 66 so as to heat the tube and its contents. The heat acts to vaporize the liquid carried in the web belt through the paper web to the powdered material 38 carried by the paper web conveyor, for saturation of this material in order to activate the binder so as to promote adhesion between the binder, the other components of the mixture and the paper web. The vapor from the liquid readily and uniformly penetrates the powdered material and permits use of a minimum amount of the liquid which must, at a later juncture, be driven off. Thus, the heater which may be of the electrical high resistance type, causes the mixture of materials to be maintained in a plastic, readily moldable mass. Upon emission from the forward end of the tube 66, the arcuated paper web 16 with its now plastic mixture, all supported on the arcuated belt 50 is conveyed to and through a garniture or forming thimble 72 which is axially aligned with the tube 66 and spaced therefrom a short distance.

The garniture or forming thimble 72 comprises an enclosed tubular passage 74 which longitudinally tapers forwardly and inwardly, with its widest portion or mouth at its rearward end so that material moving therethrough is gradually compressed into conformity with the reduced or narrow portion, as indicated at 76, of garniture 72, the portion 76 being circular in cross section and of constant diameter. Garniture 72 is designed and dimensioned so that passage 74 and portion 76 thereof may receive belt 50, together with the embraced paper web 16 and mixture 38 supported thereby in order to cause the latter to be formed into rod shape with the paper web 16 being wrapped thereabout. Belt 50 is thus, in turn, wrapped tightly about the thus formed rod 78 during travel through garniture portion 76 as best shown at III in FIG. 7. It will be seen that such close gripping of belt 50, the now formed rod 78, together with its paper casing will be pullingly advanced through garniture 72, the rod being subjected to desired pressure for effecting cohesion of the rod ingredients, with the belt simultaneously assuring of proper heat retention. Surrounding the garniture 72 is a heater 80 which also may be of the electrical high resistance type for presenting a thermal environment conductive to the rod formation while preventing any inadvertent premature hardening or setting.

Upon emission from the forward end of garniture 72, belt 50 will be liberated from the confining effects thereof for returning to its normal flat character (see IV in FIG. 7) and thus withdrawing from wrapped disposition about the paper covered rod 78 and being directed about drive wheel 51 for return travel and rewetting in the vat 52. The formed rod 78 with the paper web 16 wrapped thereabout is received within an upwardly opening arched conduit 82 for supporting during cooling, and for delivery to an automatic cutter 84 (not shown) by introduction into a cutter housing wherein the rod 78 is severed into units 86 of predetermined length; such units 86 which constitute fully operable sparklers when dried are discharged from housing 84 into a suitable collecting device (not shown).

The liquid contained in vat 42 or applied by transfer roller may be water, however, preferably it further contains a detergent or wetting agent. The liquid is preferably heated so that it is quite warm at the time of application. A methyl alcohol solution containing a wetting agent can also be used for best results. Preferably a 5 percent methyl alcohol solution is used although other percentages are satisfactory and other alcohols or solvents are used such as other aliphatic alcohols, e.g. ethyl, propyl, butyl, etc., acetone, methyl ethyl ketone and ketones, esters and the like.

It should be noted that if the binder is heat sensitive, such as a thermosetting or thermoplastic resin, good solidification can be obtained without the liquid utilizing heat alone. For certain other binders which are liquid sensitive, the liquid alone can be used without the necessity for the heat.

Control means are provided to insure that the temperature in the heated garniture 72 is greater than that in the heated tube 66 so as to insure the complete activation of the binder.

It should be observed that in the formation of the sparkler units 86 the provision of the encasing paper web provides physical strength for the sparkler. As shown above, the paper web 16 serves as a conveyor for receiving the powdered discharge from hopper 40 and for retaining same during travel through the machine including providing a proper base for the vapor action. Further, during burning of the sparkler the paper wrapper tends to decrease sparks thrown to the rear. The wrapping of endless belt 50 about the paper web brings about a unique physical engagement of the two conveyors whereby the belt 50 serves to pull the powdered charged paper web 16 through the machine to effect the requisite force for pushing the formed rod to the cutter, and for bringing the liquid into the tube 66.

In view of the foregoing it will be noted that the machine of the present invention is adapted for high volume, rapid operation, being automatic in all phases of its operation so as to obviate the necessity of the services of skilled personnel.

Although this machine is especially suited for the manufacture of sparklers, it may also be used for the production of a re-ignitable match and for myriad other uses.

When the term "paper web" is used herein it should be understood that this may be any suitable combustible material including plastic materials.

It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification.

Claims

What is claimed is:

1. A method of producing sparklers in solid rod units from a powdered pyrotechnic composition including a binder therein which comprises feeding a combustible material web whose width is approximately the same as the circumference of the rod to be formed, shaping the web to semi-cylindrical form, feeding said powdered pyrotechnic composition onto said semi-cylindrically formed web, wetting a fabric belt having a width similar to that of said web with a volatilizable liquid, bringing said wetted belt into contact with said loaded web, shaping said belt to conform to the shape of said loaded web to form an assembly of the pyrotechnic composition surrounded by the combustible material web and the wetted fabric belt, heating said assembly to vaporize said liquid in said belt to penetrate through said powdered material to activate said binder therein, feeding said assembly through a garniture to form the assembly in said garniture, removing said assembly from said garniture, removing said fabric belt from about the formed solid rod and cutting said solid rod into desired lengths.

2. A method according to claim 1 wherein said web is made of paper.

3. Apparatus for producing a solid rod from a powdered material which includes a binder therein comprising:

means for feeding a web of combustible material,

means for transversely arcuating said web to define an upwardly opening trough,

means located upwardly of said arcuating means for dispensing powdered filler material onto said transversely arcuated web,

an endless fabric belt in underlying relationship to said arcuated web,

drive means for said endless belt,

means for wetting said belt with a liquid,

guide means for directing said belt from said wetting means and thence into underlying contact with said web,

means for shaping said wet belt into an upwardly concave configuration conforming to the shape of said arcuated web,

heated tubular means for receiving said arcuated web and belt and to vaporize the liquid contained in said belt into contact with said powered material to render it plastic,

garniture means downstream from said heated tubular means for receiving said arcuated web and belt containing the plasticized material therein for directing said belt and said web into enclosing relationship about said plasticized contents,

and means for disengaging said belt from wrapped disposition about said web.

4. Apparatus according to claim 3 wherein heat producing means are provided in immediate proximity to said garniture means.

5. Apparatus according to claim 3 wherein said wetting means comprises a vat containing said liquid with means for guiding said belt beneath the surface of said liquid.

6. Apparatus according to claim 3 wherein said wetting means comprises a transfer roller.

7. Apparatus according to claim 3 further comprising means for severing said web and contents into units of predetermined length.

8. Apparatus according to claim 3 further comprising guide means for directing said disengaged belt to said wetting means.