US2698969A - Manufacture of candles and like articles - Google Patents

Description

Jan. 11,1955 D. J. KEOGH 2,698,969

MANUFACTURE OF CANDLES AND LIKE ARTICLES Filed May; 12, 1951 3 Sh eetS Sheet l FIG. I

INVENTOR DANIEL JAMES KEOGH Y fifiJ HIS ATTORNEY Jan. 11, 1955 D. J. KEOGH 2,698,969

MANUFACTURE OF CANDLES AND LIKE ARTICLES Filed May 12, 1951 3 Sheets-Sheet 2 n g; 8 (5" 'l as M L .4

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C0 o1 INVENTOR DANIEL JAMES KEOGH HIS ATTORNEY Jan. 11, 1955 D. J. KEOGH 2,693,969

MANUFACTURE OF CANDLES AND LIKE ARTICLES Filed May 12, 1951 :s Shets-Sheet s INVENTOR:

DANIEL JAMES KEOGH HI ATTORNEY United States Patent M MANUFACTURE OF CANDLES AND LIKE ARTICLES Daniel James Keogh, Saltdean, England, assignor to Prices Patent Candle Company Limited, London, England, a British company Application May 12, 1951, Serial No. 226,009

Claims priority, application Great Britain May 18, 1950 3 Claims. (Cl. 1859) The art of manufacturing candles and like articles has for very many years proceeded on lines which have not suffered major change.

As regards candles the practice which is probably more Widespread than any other involves moulding the articles say in batches of 50 or more. In such practice a plurality of water-jacketed moulds through the centre of each of which a wick is disposed, received molten wax and when this has solidified by cooling, means are provided for sliding the moulded candles out of the moulds so as to leave the latter, still containing a wick disposed along the centre axis, free to receive a further batch of molten material. In the manufacture of tapers or wax wire as used n certain types of foundry work another practice which is often followed involves dipping in a bath of molten wax a long continuous length of wick disposed on and between two large-diameter rotatable drums. The wick pulled through the bath by rotation of the large drums picks up on each successive traverse through the bath a certain amount of wax which solidifies wholly or in part on exposure to the atmosphere, and this build-up is allowed to continue until a sufficient deposit of wax is secured.

In both these procedures the wick is impregnated by the molten wax, and indeed such a result has long been deemed essential, or at least highly desirable, by most workers skilled in this industry.

From time to time proposals have been advanced to make the process of forming candles and like articles continuous. To this end arrangements have been sug gested to extrude wax, cooled in the extrusion apparatus from the liquid to a semi-solid or plastic state, continuously through orifices around a wick fed continuously to the centres of these orifices, the wax-covered wick being thereupon subjected to water cooling in order to harden and solidify the wax. In practice however, such proposals have encountered serious difiiculties which have prevented their commercial adoption. Thus the solidification of the extruded product proceeds in such a manner that a lengthy tempering process is needed in order to produce a satisfactory product. Moreover, variations in temperature with consequential variations in plasticity of the wax have led to mechanical instability of the extruded product which has proved most difficult to handle and process to satisfactory finished candles.

The present invention is concerned with a continuous process of making finished candles and like articles and is based on considerable experimental work which has led to the surprising discovery that cold solid wax can be extruded by pressure through an orifice to give a continuous rod of wax which, with no cooling of the extruded product other than that occasioned by contact with the atmosphere, is firm enough to handle and process without distortion; and to the further surprising discovery that this pressure extrusion of cold solid wax can be efiected through an orifice which is simultaneously fed with a continuous length of wick so as to give a continuous rod of wax-covered wick which is likewise sufiiciently firm to handle and process without distortion to produce finished articles such as candles of a quality satisfying commercial requirements. Candles produced by such technique have a wick which has not suffered impregnation by the wax because the latter does not approach the degree of plasticity necessary to secure impregnation of the wick. Nevertheless the surrounding wax 2,698,969 Patented Jan. 11, 1955 adheres firmly to the central wick and the finished candle or like article burns efficiently under normal conditions of use.

According to the present invention therefore a continuous rod of wax-covered wick is formed by extruding solid wax through an orifice around a wick which is guided towards the centre of the orifice and is free to be drawn forward by the extruded wax, the extrusion being carried out at a temperature and speed such that, with no cooling of the extruded product other than that occasioned by contact with the atmosphere, the said product is a continuous rod of wax-covered wick which is non-brittle and is sufficiently firm to be handled without distortion. If desired, this continuous extruded rod of wax-covered wick is continuously processed to finished candles and like articles by causing relative movement towards each other of the successive free ends of the rod and a rotating cutter adapted to uncover a short length of wick at the said end of the rod, and then cutting off in succession the desired lengths of rod to form candles.

A preferred form of the invention is illustrated by way of example by the accompanying drawings, which show a machine for extruding a rod of wax-covered wick according to the invention and converting this rod into candles by successively uncovering a short length of wick at the forward end of the rod to form a tip, and then cutting off the desired length of rod. In the drawings,

Figure 1 is a perspective view of the extruding apparatus,

Figures 2A and 2B are sectional and exploded perspective views respectively of the extrusion nozzle,

Figure 3 is a side elevation of the tipping and cutting apparatus, and

Figure 4 is an end view of the apparatus shown'in Figure 3, taken on the line IVIV of that figure.

The extruding apparatus shown in Figure 1 is mounted in a framework comprising girders 1, 2, 3 and 4, standards 5, 6 and 7, plates 8, 9 and 10 bolted together by bolts such as 11 and 12. and a cross beam 19. The extrusion is effected by hydraulic pressure, a supply of hydraulic oil being contained in a tank 13 and subjected to pressure by a pump 14 driven by a motor 15. The hydraulic cylinder 16 is mounted between the plates 8 and 9, and the extrusion cylinder 20 is held by the plate 8 and a strap 17 welded to the beam 19. Contained in cylinder 16 is the hydraulic piston whose piston rod passes through a gland in plate 9 and carries on its exposed end the extrusion ram 18. The hydraulic piston is operated by a conventional hydraulic system comprising the tank 13, pump 14 and valve 22.

The extrusion nozzle shown in section in Figures 2A and 2B comprises a base plate 28 bolted to the plate 7, a nozzle plate 29 hinged to the base plate 28 at 30, and a die plate 31 bolted to the nozzle plate 29 and having an extrusion orifice 32. The nozzle assembly can be clamped in position for extrusion, as shown in Figure 2A, by means of a lever 33 pivoted to the base plate 28, the plate 29 being centered by means of a boss 37 on the plate 28 which has a conical surface co-operating with a like surface in the plate 29. The rear face of the plate 29 is provided with a slot 39 in which is fixed by means of screws not shown in the drawing the rectangular shank 34 of a wick tube. The tip of the wick tube is bent at 35 so that a wick threaded through the tube issues on the axis of the orifice 32. A length of wick is carried on a spool 36 (Figure l) which is mounted on the plate 8 so as to be capable of free rotation. When the nozzle plate assembly is brought into the extrusion position, the shank 34 of the wick tube is accommodated by a slot 38 in the boss 37. A stripper cone 42 is secured to plates 40a and 40b which are themselves fixed to the die plate 31 by bolts 43, a clearance between the plate 40a and die plate 31 being maintained by washers 41. The rear or smaller edge of the cone 42 is sharpened for the purpose of stripping the extruded wax rod, as described below.

In order to charge the machine with wax, the nozzle plate assembly is released by operation of the lever 33 and a rod of solid wax is pushed into the extrusion cylinder 20 through the hole 44 in the base plate 28, this hole being of the same diameter as the extrusion cylinder. The wax rod may be produced by casting and is as nearly as possible equal in diameter to the extrusion cylinder, so that the rod makes a sliding or push fit in the cylinder. When the wax rod has been inserted, the nozzle plate assembly, after ensuring that a length of wick protrudes through the orifice 32, is closed and clamped in position by the lever 33. The valve 22 is then operated to supply the rear of the cylinder 16 with the pressure fluid, so that the ram 18 begins to extrude the wax through the orifice 32. The extruded rod is formed round the wick protruding from the wick tube, the wick being drawn forward by the wax as the latter advances through the extrusion nozzle.

The temperature of the wax, which was inserted into the machine at room temperature, is raised by the extrusion process to an extent depending on the speed of extrusion. This speed must not be sufiiciently great to heat the wax to a temperature such that cooling (other than any cooling which is necessarily occasioned by contact of the rod with the atmosphere) is necessary in order to render the rod firm enough to be handled without distortion. This maximum permissible speed depends partly on the composition of the wax and partly on the ambient temperature. If desired, in hot climates, the extrusion cylinder and/ or nozzle assembly may be provided with water cooling in order to increase the speed at which the extrusion can be carried out. By governing the extrusion process in such a manner that cooling of the extruded product is unnecessary, not only is the necessity of providing extensive cooling baths avoided, but a superior product which is less liable to distortion or breakage is obtained.

As an example of a speed which has been found satisfactory for producing small candles such as are used for decorating cakes, it proved to be possible to produce 300 such candles a minute at a room temperature of about 65 to 70 F., without any artificial cooling. In this instance a wax of the following composition: parafiin wax of melting point l35140 F., 89.5 per cent., stcarin 7.5 per cent, beeswax 3 per cent, was extruded under a pressure of the order of 2000 pounds per square inch in a hydraulic cylinder of 6 inch diameter from an extrusion cylinder of 1%; inch diameter through an orifice of inch diameter. The extruded rod was cut into candles, as described below, each having a length of about 2 inches.

In order to ensure that there is no inclusion of air pockets in the Wax, the rod of wax is, as stated above,

made to fit closely in the extrusion cylinder. Inclusion of air would lead to the formation of blow holes or, in extreme cases, to disintegration of the product. It is further desirable that the difference in pressure between the wax in the interior of the extrusion cylinder and as it leaves the extrusion orifice shall not be too great, since too great a pressure difierential in some cases reduces the c herence or tenacity of the product.

Whi e the extrusion orifice 32 is shown as being circular in shape, orifices of other shapes may be used, denendinq on the section required for the extruded rod. Like ise the orifice may be provided with a helical groove for r d cing decorative candles having a helical exterior.

On emerging from the extrusion orifice 32, the rod n ss s through the hole formed by the small edge of the stripper c ne 42. This hole is of slightly less diameter th n the orifice 32 and serves to strip a thin outer layer from the extruded rod. the wax thus removed escaping throuwh the clearance between plate 4% and die plate 31. The ob ect of this strioning process is to remove any s i ht surface irregularities which may have been caused by the extrusion, so that the rod after stripping has a smooth polished surface which is not inferior to that which can be obtained by moulding the wax. If the rod is to be used for a purpose for which surface finish is of no importance. for example, as wax wire, the strioner cone may be omitted.

After passing throu h the stripper cone, the rod is led to the tipping and cutting machine shown in Figures 3 and 4, for conversion into candles. In order to permit the tinning and cutting machine to work continuously in spite of interruptions in the operation of the extrusion machine to enable a fresh rod of wax to be inserted in the extrusion cylinder, the extruded rod may, where its diameter is sufficiently small to make the procedure practicable, be passed through a loop-forming device as shown in Figure l. The device shown comprises a pulley 50 mounted in a frame 51 which is capable of running on inclined rails 52. The extruded rod 53, after issuing from the stripper cone 42, passes over the pulley 50 and then over a pulley 54 rotatably mounted on an axle fixed in a frame 55 which also supports the rails 52 at one end thereof. When the extruding machine is working, it extrudes the rod at a slightly greater rate than the average rate at which the latter is fed to the tipping and cutting machine. The loop formed round the pulley 5) thus increases in length, the frame 51 taking up the slack by running down the rails 52. When the extrusion machine is stopped for recharging, the loop of wax rod shortens and the pulley 50 runs up the rails 52. Thus the supply of rod to the tipping and cutting machine remains steady. The device shown is suitable, for example, for use with wax rod which is to be made into small candles such as are used for decorating cakes.

The machine shown in Figures 3 and 4 comprises a set of four pairs of feed rollers 69 which grip the rod 53 and advance it intermittently towards a tipping cutter head 61 which is fixed on the shaft of sn all electric motor 62 and continuously rotated thereby. When the rollers, which are driven by a mechanism indicated generally at 63, have advanced the rod through nearly the length of one candle, the motor 62 and tippmg cutter head 61 are moved to the left (as seen in Figure 3) by a cam 64 and arm 65 so as to meet the advanc' g rod 53 and cut a conical tip on the rod, leaving a short I t wick exposed for lighting the candle. After cu conical tip, the tipping cutter head 61 is moved a the right. As the tipping operation is cor rollers 69 hold the rod 53 stationary and a k blade 66 carried by a rotor 67 parts the rod so as to produce a finished candle. As each candle is parted an arm 68 pushes it transversely into a chute 69.

it may be convenient to arrange several extrusion cylinders on a single bed and actuate the several ran .cm a common source of hydraulic fluid. Alternan sly a. single extrusion cylinder may be provided with a on 1 of die plates and extrusion orifices. Thus, for er the feed rollers 60, tipping cutter head 61 and shown in Figures 3 and 4 may conveniently be d'. and this duplicate machine could be fed by truded by the same hydraulic apparatus or c cylinder.

The apparatus suitable for carrying out this method is further described and claimed in copending application Serial No. 226,010. filed May 12, ll, now Patent No. 2,657,425.

I claim:

1. A method of making a continuous rod of waxcovered wick for the manufacture of wax candles, tapers, wax wire and the like which comprises introducing a coherent mass of solid wax into an extrusion cylinder, extruding a continuous rod of wax-covered wick by forcing solid wax consisting predominantly of parar'fin wax from the extrusion cylinder into a wick-receiving chamber, said wick being guided toward the center of said chamber and supplied freely to said chamber, whereby said wick is drawn forward by the wax, forcing the wax-covered wick through an extrusion orifice of substantially smaller crosssectional area than that of the wick receiving chamber, and continuously passing the extruded rod through a stripper orifice having an orifice similar to but of slightly smaller size than the extrusion orifice, and continuously stripping off and removing from the surface of the rod and from the entry edge of the orifice in solid form any wax surface irregularities which may have been formed thereon by the extrusion, said process being carried out without externally applied change in temperature of the wax other than that occasioned by contact with the atmosphere, and at a temperature and at a speed such that the extruded, continuous rod is non-brittle and sufificiently firm to be handled without distortion.

2. A method of making tipped waxed candles, tapers and the like which comprises introducing a coherent mass of solid wax into an extrusion cylinder. extruding a continuous rod of wax-covered wick by forcing solid wax consisting predominantly of paraffin wax from the extrusion cylinder through an extrusion orifice around a continuous length of wick, said wick being guided toward the center of the orifice and supplied freely to said orifice, whereby said wick is drawn forward by the extruded wax,

i the to the i said extrusion being carried out without cooling of the extruded product other than by contact with the atmosphere and at a temperat re and at a speed such that the extruded, continuous rod is non-brittle and sufliciently firm to be handled without distortion, advancing the extruded rod of Wax-covered wick to a variable length takeup device at a rate determined by the said speed of the extrusion, withdrawing the rod from said device at a periodically variable rate, and successively tipping the outer end of the rod by cutting wax peripherally to uncover a short length of the wick at said end, and cutting off a length of the tipped rod to form a candle, said periodically variable rate of withdrawal being determined by and synchronized with said tipping and cutting operations independently of said extrusion.

3. A method of making tipped waxed candles, tapers and the like which comprises introducing a coherent mass of solid wax into an extrusion cylinder, extruding a continuous rod of a wax-covered wick by forcing solid wax consisting predominantly of paraffin wax from the extrusion cylinder through an extrusion orifice around a continuous length of wick, said wick being guided toward the center of the orifice and supplied freely to said orifice, whereby said wick is drawn forward by the extruded wax, said extrusion being carried out without cooling of the extruded product other than by contact with the atmosphere and at a temperature and at a speed such that the extruded, continuous rod is non-brittle and suificiently firm to be handled without distortion, continuously passing the extruded rod of wax-covered wick through a stripper orifice having an orifice similar to, but of slightly smaller size than the extrusion orifice, and stripping off from the surface of the rod in solid form any surface irregularities which may have been formed thereon by the extrusion, advancing the extruded rod of wax-covered Wick to a variable length takeup device at a rate determined by the said speed of the extrusion, withdrawing the rod from said device at a periodically variable rate, and successively tipping the outer end of the rod by cutting wax peripherally to uncover a short length of the wick at said end, and cutting off a length of the tipped rod to form a candle, said periodically variable rate of withdrawal being determined by and synchronized with said tipping and cutting operations independently of said extrusion.

References Cited in the file of this patent UNITED STATES PATENTS 4,389 Drummond Feb. 20, 1846 1,294,008 Will Feb. 11, 1919 1,482,000 Engman Ian. 29, 1924 1,483,555 Sevigne Feb. 12, 1924 1,571,589 Kerr Feb. 2, 1926 FOREIGN PATENTS 360,995 Great Britain Nov. 19, 1931

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