Apparatus for cooling preformed articles and method of cooling preformed articles

An apparatus for cooling preformed articles, which is capable of very effectively cooling the preformed articles and is, further, capable of sufficiently suppressing or preventing the preformed articles from being locally damaged as a result of coming in contact with each other as they are conveyed neighboring one another in a state of not yet fully cooled. A spray is blown onto the preformed articles 34 conveyed passing through a predetermined conveyer passage 42, a cooling liquid is blown next thereto, and a gas stream is further blown thereto.

TECHNICAL FIELD

The present invention relates to an apparatus for cooling preformed articles which will be formed into containers through blow forming in a subsequent step.

BACKGROUND ART

Plastic containers have now been widely put into practical use as containers for beverages. As is widely known among people skilled in the art, the plastic containers are obtained by forming preformed articles (also, usually, called “preforms”) by compression-forming or injection-forming a suitable synthetic resin and, thereafter, blow-forming the preformed articles. The preformed article, usually, has a cylindrical mouth-and-neck portion and a blow-formed portion of the shape of a cylinder with bottom or of a circular truncated cone with bottom continuous to the mouth-and-neck portion and, further, has a ring-like flange formed at the lower end of the mouth-and-neck portion.

The preformed article of a considerably high temperature (a [glass transition temperature] of a synthetic resin which is a material of the preformed article up to the [glass transition temperature]+0.22×{[melting temperature]−[glass transition temperature] thereof}, in polyethylene terephthalate e.g., about 80° C. to about 120° C., usually, about 100° C.) is often taken out from the mold after compression-formed or injection-formed. In this case, the temperature, usually, must be cooled down to 60° C. or lower to prevent the formed articles from being melt-adhered together or from being damaged upon coming in contact with one another. JP-A-7-171888 and JP-A-8-103948 disclose apparatuses for cooling preformed articles by blowing the air stream to the preformed articles while the preformed articles taken out from the mold are being conveyed through a predetermined carrier passage.

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

The conventional apparatuses for cooling the preformed articles by blowing the air stream to the preformed articles, however, involve a problem in that they are not capable of sufficiently and effectively cooling the preformed articles and require a time of 1.5 to 2 minutes for cooling the formed articles from about 100° C. down to about 60° C. When an extended time is required for cooling, the length the preformed articles are conveyed for being cooled inevitably increases accompanied by a problem of an increase in the size of the cooling apparatus.

The conventional apparatuses further involve a problem in that the preformed articles which are conveyed neighboring one another in a state of not yet fully cooled may come in contact with each other and may be locally damaged.

The present invention was accomplished in view of the above-mentioned facts, and its first technical problem is to provide a novel and improved apparatus for cooling preformed articles, which is capable of cooling the preformed articles very effectively.

A second technical problem is to provide a novel and improved apparatus for cooling preformed articles, which is capable of sufficiently suppressing or preventing the preformed articles from being locally damaged as a result of coming in contact with each other as they are conveyed neighboring one another in a state of not yet fully cooled. When an extended period of time is required for the cooling, there occurs such a problem that the synthetic resin is crystallized causing the formed articles to become whitened.

Means for Solving the Problems

The present invention is concerned with an apparatus for cooling preformed articles, wherein the preformed article as formed by a forming machine but before being subjected to a blow-forming includes a mouth-and-neck portion and a blow-formed portion, the mouth-and-neck portion being of a cylindrical shape and having a ring-like flange formed at the lower end thereof, and the blow-formed portion being of the shape of a cylinder with bottom continuous to the lower end of the mouth-and-neck portion, the apparatus for cooling preformed articles, comprising:

conveyer means for conveying the preformed articles through a conveyer passage inclusive of a cooling zone;

holding means for holding the preformed articles in at least the cooling zone; and

cooling means for cooling the preformed articles by the cooling water in the cooling zone.

In the apparatus for cooling preformed articles, the cooling means comprises cooling nozzles arranged along the conveyer passage, and a spray of water is blown onto the preformed articles from the cooling nozzles.

In the apparatus for cooling preformed articles, the cooling means comprises cooling nozzles arranged along the conveyer passage, and the cooling water is blown onto the preformed articles from the cooling nozzles.

In the apparatus for cooling preformed articles, the cooling means comprises a water tank storing the cooling water, and the preformed articles are cooled by immersing the blow-formed portions of the preformed articles in the cooling water in the water tank.

In the apparatus for cooling preformed articles, the cooling means comprises a water tank storing the cooling water, and the preformed articles are cooled by being submerged in the cooling water in the water tank.

In the apparatus for cooling preformed articles, the conveyer means may comprise conveyers of endless chains including at least either a straight conveyer passage or a curved conveyer passage.

In the apparatus for cooling preformed articles, the conveyer means may be a rotary conveyer passage which rotates with the axis of rotation as a center.

In the apparatus for cooling preformed articles, the holding means comprises upper surfaces of conveyer running portions of conveyers constituted by endless chains arranged in parallel on the right and left maintaining a distance, and ring-like flanges of the preformed articles are suspended between the conveyer running portions.

In the apparatus for cooling preformed articles, the holding means comprises gap portions formed maintaining a gap up and down in the conveyer running portions of conveyers constituted by endless chains arranged in parallel on the right and left maintaining a distance, and ring-like flanges of the preformed articles are held in the gap portions.

In the apparatus for cooling preformed articles, the conveyers comprising the endless chains provided in parallel on the right and left maintaining a distance, travel at speeds different relative to each other at the time of conveying the preformed articles.

In the apparatus for cooling preformed articles, the holding means comprises grippers arranged on the rotary conveyer passage for holding the preformed articles maintaining a distance to the surroundings of the blow-formed portions of the preformed articles, and the ring-like flanges of the preformed articles are placed on the upper surfaces of the grippers.

In the apparatus for cooling preformed articles, the cooling means includes a circulating pump for supplying the cooling water, water-purifying means for removing fouling matter from the cooling water, sterilizing means for sterilizing the cooling water, and temperature-maintaining means for adjusting the temperature of the cooling water.

In the apparatus for cooling preformed articles, gas ejection means is provided on the downstream of the cooling apparatus for removing the cooling water adhering on or staying in the preformed articles.

In the apparatus for cooling preformed articles, the gas ejection means injects a gas onto the outer surfaces of the preformed articles from the transverse direction, and the position where the gas ejection means blows the gas onto the outer surfaces of the preformed articles becomes low from the upstream side toward the downstream side in the direction in which the preformed articles are conveyed.

In the apparatus for cooling preformed articles, the gas ejection means injects a gas into the inner surface side of the preformed articles though the openings thereof, and the positions where the gas ejection means blows the gas into the inner surfaces of the preformed articles are deviated from the centers of the openings of the preformed articles.

The preformed articles of the blow-formed containers formed by the compression forming and taken out at a high temperature, can be cooled by using the water.

EFFECT OF THE INVENTION

In the apparatus for cooling preformed articles provided by the present invention, a cooling liquid is blown onto the preformed articles conveyed through the cooling zone and, therefore, the preformed articles are effectively cooled.

In the apparatus for cooling preformed articles provided by the present invention, a spray is blown onto the preformed articles prior to cooling the preformed articles in order to sufficiently suppress or prevent the preformed articles from being locally damaged as a result of coming in contact with each other as they are conveyed neighboring one another in a state of not yet fully cooled though the reason thereof has not yet been clarified.

In the apparatus for cooling preformed articles provided by the present invention, the holding means comprises grippers for holding the preformed articles arranged on the rotary conveyer passage maintaining a distance to the surroundings of the blow-formed portions of the preformed articles, and the ring-like flanges of the preformed articles are placed on the upper surfaces of the grippers, or the mouth-and-neck portions thereof are held thereby, so that the preformed articles are reliably held one by one while being conveyed at an increased speed.

The apparatus for cooling preformed articles provided by the present invention comprises conveyer means for conveying the preformed articles through a conveyer passage inclusive of a cooling zone, holding means for holding the preformed articles in at least the cooling zone, and a water tank for cooling the blow-formed portions of the preformed articles conveyed through the cooling zone in the cooling water. Therefore, the preformed articles can be effectively cooled. By shortening the conveying length necessary for cooling the preformed articles, the apparatus for cooling preformed articles can be realized in a small size. In particular, when the conveyer means is a rotary conveyer passage that rotates with the axis of rotation as a center, it is allowed to further decrease the size of the conveyer line in the apparatus for cooling preformed articles.

In the invention, the holding means for holding the preformed articles in the cooling zone comprises gap portions formed maintaining a gap up and down in the pair of right and left endless chains, and ring-like flanges of the preformed articles are held in the gap portions. Namely, flanges of the preformed articles can be held in the gap portions. When submerged in the cooling water in the water tank, the upper surfaces of the gap portions support the preformed articles utilizing the buoyancy. Out of the cooling water, the lower surfaces of the gap portions support the preformed articles utilizing the gravitational action.

In the invention, the traveling speed is differed relative to each other between the right and left conveyers constituted by a pair of right and left endless chains that form conveyer means. This makes it possible to turn the preformed articles, to blow the cooling solution onto the preformed articles or to immerse them in the cooling solution.

The apparatus for cooling preformed articles provided by the present invention comprises a water tank for cooling the formed articles in the cooling water, means for conveying the preformed articles through the water tank and for conveying them out of the water tank, means for correcting the preformed articles conveyed out of the water tank so as to assume the same attitude, and means for removing the cooling water from the preformed articles. Therefore, the preformed articles can be efficiently cooled.

According to the invention, means for removing the cooling water from the preformed articles is air injection means, and the positions of nozzles of the air injection means may be arranged at the centers of openings of the mouth-and-neck portions when the air is to be injected but are arranged deviated from the centers thereof to efficiently remove the cooling water staying in the preformed articles. The nozzles may be inserted in the preformed articles when the air is to be injected.

The above inventions include a circulation pump for supplying the cooling water to the water tank, water-purifying means for removing fouling matter from the cooling water, sterilizing means for sterilizing the cooling water, and temperature-maintaining means for adjusting the temperature of the cooling water. Therefore, the cooling temperature is maintained in the water tank and, besides, the cooling water is purified and is sterilized to save the cooling water.

In the above inventions, the preformed articles are formed by compression-forming a synthetic resin. By using an extrusion-forming machine which makes possible to shorten the residence time of the plasticized resin as compared to that of the injection-forming machine, therefore, formation of acetaldehyde can be decreased, and there can be provided preformed articles of containers having excellent favor property.

According to the method of cooling preformed articles provided by the present invention, the preformed articles as formed by the compression forming, taken out at a high temperature but before being subjected to the blow forming, are cooled by the water. Therefore, the preformed articles can be cooled in a shorter period of time than when the preformed articles are cooled by the air.

BEST MODE FOR CARRYING OUT THE INVENTION

A first embodiment of the apparatus for cooling preformed articles constituted according to the present invention will be described below in further detail with reference to the accompanying drawings.

Referring toFIGS. 1 to 3, the apparatus for cooling preformed articles constituted according to the present invention includes conveyer means2which is constituted by a pair of conveyers4aand4barranged maintaining a distance in the transverse direction (up-and-down direction inFIG. 1or right-and-left direction inFIG. 3). The pair of conveyers4aand4binclude drive wheels6aand6bas well as driven wheels8aand8barranged spaced apart in the direction of conveyance (right-and-left direction inFIGS. 1 and 2or in a direction perpendicular to the surface of paper inFIG. 3). The drive wheels6aand6bas well as the driven wheels8aand8bare fitted to rotate about the center axes that extend substantially vertically (direction perpendicular to the surface of paper inFIG. 1or up-and-down direction inFIG. 3), while the drive wheels6aand6bare drivingly coupled to electric motors10aand10b. Endless chains12aand12bare wrapped round the drive wheels6aand6band round the driven wheels8aand8b. The endless chains12aand12bare arranged in a direction in which they run and are each constituted by a number of chain members14aand14b(FIG. 3) rotatably coupled to each other. Referring toFIG. 3, pairs of stationary members16aand16bare fixed between the drive wheels6a,6band the driven wheels8a,8b, the pairs of stationary members16aand16bextending in parallel in the direction of conveyance. Upper guide members18a,18band lower guide members20a,20bare fixed to the pairs of stationary members16aand16b. Guide rail portions22aand22bare formed protruding downward at both side edges of the upper guide members18aand18bthat are protruding sideways beyond the pairs of stationary member16aand16b. Guide rail portions24aand24bare formed protruding upward at both side edges of the lower guide members20aand20bthat are protruding sideways beyond the pairs of stationary members16aand16b. The chain members14aand14bhave to-be-guided portions26aand26band suspension portions28aand28b, respectively. The to-be-guided portions26aand26bhave upper to-be-guided grooves30aand30bformed so as to engage with the guide rail portions22aand22bof the upper guide members16aand16b, as well as lower to-be-guided grooves32aand32bformed so as to engage with the guide rail portions24aand24bof the lower guide members20aand20b. The suspension portions28aand28bextend downward from the lower ends of inner side edges of the to-be-guided portions26aand26band, further, extend sideways toward the insides.

FIG. 3also illustrates a preformed article34that is to be cooled. The preformed article34that can be formed by compression-forming or injection-forming a suitable synthetic resin such as polyethylene terephthalate, has a mouth-and-neck portion36and a blow-formed portion38with bottom continuous to the lower end of the mouth-and-neck portion36. The mouth-and-neck portion36of the preformed article34that is shown is of a cylindrical shape and has a flange40of a ring-like shape formed at the lower end thereof. The main portion of the blow-formed portion38is of the shape of an inverse circular truncated cone of which the outer diameter slightly decreases downward.

If further described with reference toFIGS. 1 to 3, when the electric motors10aand10bare energized, the endless chains12aand12bare rotated and driven in the directions indicated by arrows40aand40binFIG. 1. The transverse inner running portions of the endless chains12aand12bwork as conveyer running portions, and the transverse outer running portions are the return running portions. As clearly shown inFIG. 3, the preformed article34has its ring-like flange40suspended by the conveyer running portions of the endless chains12aand12band, if described in further detail, suspended on the suspension portions28aand28bof the chain members14aand14b, and is conveyed in the directions indicated by arrows40aand40baccompanying the motion of the endless chains12aand12b. In the embodiment as will be clearly understood fromFIG. 1, the conveyer4aand the conveyer4bconstituting the conveyer means2are slightly displaced in the direction of conveyance; i.e., the upstream end of the conveyer4adoes not cooperate with the conveyer4band the downstream end of the conveyer4bdoes not cooperate with the conveyer means4a. As simply illustrated by two-dot chain lines inFIG. 1, the upstream end of the conveyer4acooperates with the downstream end of one of the pair of conveyers of the conveying means arranged on the upstream side, and the downstream end of the conveyer4bcooperates with the upstream end of one of the pair of conveyers of the conveyer means arranged on the downstream side. Thus, the preformed articles34to be cooled are conveyed onto the conveying means2from the conveying means arranged on the upstream side, are conveyed by the conveyer means2, and are delivered to the conveyer means arranged on the downstream side. As will be clearly understood from the description appearing later, the preformed articles34are effectively cooled while being conveyed by the cooling means2.

As will be clearly understood fromFIG. 1, a conveyer passage42for the preformed articles34is defined between the pair of conveyers4aand4b. In the illustrated embodiment, the conveyer passage42for the preformed articles34includes a spray zone44, a cooling zone46and a drying zone48successively arranged in the direction of conveyance. Spray blow means50is arranged in the spray zone44, cooling liquid blow means52is arranged in the cooling zone46, and gas stream blow means54is arranged in the drying zone48.

As shown inFIGS. 1,2and4, the spray blow means50is constituted by a plurality of, or in the illustrated embodiment, five spray blow nozzles56arranged on one side of the conveyer passage42for the preformed articles34. As will be clearly understood fromFIG. 1, the spray blow nozzles56are arranged facing the conveyer passage42and are slightly tilted toward the upstream side. A water supply (not shown) which may be the city water is connected to the spray blow nozzles56which work to spray the water. The spray is injected from a single injection hole58formed at an end of each of them, and is blown to the blow-formed portions38of the preformed articles34conveyed through the conveyer passage42. It is desired that the particles constituting the spray have a diameter of 1 to 5 μm and, particularly, 1 to 3 μm to avoid the particles adhered on the blow-formed portions38from gathering together to form droplets and, further, to avoid the blow-formed portions38of the preformed articles34from being cooled by dot regions, so that the surfaces will not become spotted or rugged.

In the embodiment as will be clearly understood with reference toFIGS. 1 to 3andFIG. 5, the cooling liquid blow means52is constituted by a plurality of, or in the illustrated embodiment, twenty-four cooling liquid blow nozzles60arranged on each side of the conveyer passage42for the preformed articles34. As will be understood fromFIG. 1, the cooling liquid blow nozzles60, too, are arranged facing the conveyer passage42and are slightly tilted toward the upstream side. As clearly shown inFIG. 5, each cooling liquid blow nozzle60has a plurality of injection holes62arranged in the direction of conveyance. A cooling liquid source (not shown) is connected to the cooling liquid blow nozzles60which inject the supplied cooling liquid as a cooling liquid stream from the plurality of injection holes62so as to be blown onto the blow-formed portions38of the preformed articles34conveyed through the conveyer passage42. The cooling liquid may be the city water of about 25° C. The position of blowing the cooling liquid is desirably the upper ends of the blow-formed portions38of the preformed articles34.

If further described with reference toFIGS. 1 to 3andFIG. 6, the gas stream blow means54in the embodiment is constituted by a plurality of, or in the illustrated embodiment, four air stream blow nozzles64arranged on each side of the conveyer passage42for the preformed articles34. As will be understood fromFIG. 1, the gas stream blow nozzle members, too, are arranged facing the conveyer passage42and are slightly tilted toward the upstream side. As will be understood with reference toFIG. 2, the height for arranging the gas stream blow nozzles64gradually decreases toward the downstream side in view of the fact that the cooling liquid adhered on the blow-formed portions38of the preformed articles34flows downward. If described in further detail, the most upstream gas stream blow nozzle64is disposed facing the upper end of the blow-formed portion38of the preformed article34, the gas stream blow nozzle64positioned on the downstream side thereof is disposed facing a portion slightly higher than the intermediate portion in the up-and-down direction of the blow-formed portion38of the preformed article34, the gas stream blow nozzle64positioned on the downstream thereof is disposed facing a portion slightly lower than the intermediate portion in the up-and-down direction of the blow-formed portion38of the preformed article34, and the most downstream gas stream blow nozzle64is disposed facing the lower end of the blow-formed portion38of the preformed article34. As will be clearly understood fromFIG. 6, each gas stream blow nozzle64has an injection hole66slenderly extending in the direction of conveyance. A gas source (not shown) is connected to the gas stream blow nozzles64which inject the supplied gas as an air stream from the injection holes66thereof so as to be blown onto the blow-formed portions38of the preformed articles34conveyed through the conveyer passage42. The gas may be an inert gas or the air of normal temperature.

The actions of the above-mentioned apparatus for cooling preformed articles will be summarized below.

While the preformed articles34are conveyed by the pair of conveyers4aand4b, the spray is blown to the blow-formed portions38of the preformed articles34by the spray blow means50in the spray zone44. The present inventors have learned through their experience that blowing the spray onto the blow-formed portions38of the preformed articles34effectively works to suppress or prevent damage to the blow-formed portions38of the neighboring preformed articles34caused by the contact among them despite the distance is set to be relatively small to the preformed articles34that are subsequently conveyed and, besides, despite the preformed articles34are conveyed at a relatively high speed. Though the reason has not been clarified yet, the present inventors presume that the spray covering the blow-formed portions38suppress the blow-formed portions38of the neighboring preformed articles34from coming into contact to an excess degree.

While the preformed articles34are conveyed through the cooling zone46, the cooling liquid is blown to the upper ends of the blow-formed portions38of the preformed articles34by the cooling liquid blow means52. The cooling liquid flows down on the blow-formed portions38, and the preformed articles34are cooled very effectively. Next, while the preformed articles34are conveyed passing through the drying zone48, the gas stream is blown to the upper ends gradually down to the lower ends of the blow-formed portions38of the preformed articles34by the gas stream blow means54. The cooling liquid adhered on the blow-formed portions38is effectively blown away, and the blow-formed portions38are dried.

FIGS. 7 to 10illustrate a second embodiment of the apparatus for cooling preformed articles constituted according to the present invention. As shown inFIGS. 7 and 8, this modified embodiment, too, is provided with conveyer means89constituted by a pair of conveyers90aand90b. The conveyer means89may be substantially the same as the conveyer means2shown inFIGS. 1 and 2, and a conveyer passage92for the preformed articles34is defined between the pair of conveyers90aand90b. The conveyer passage92includes a cooling zone93and a drying zone94arranged downstream of the cooling zone93, but does not include any spray zone (therefore, no spray blow means is disposed in the embodiment shown inFIGS. 7 to 10). Cooling liquid blow means95is disposed in the cooling zone93and gas stream blow means96is disposed in the drying zone94.

As will be clearly understood with reference toFIGS. 7 to 9, the cooling liquid blow means95is constituted by a plurality of, or in the illustrated embodiment, four cooling liquid blow nozzles97on each side of the conveyer passage92for the preformed articles34. Each cooling liquid blow nozzle97has a front surface that extends in parallel with the conveyer passage92, and a slenderly extending injection hole97ais formed in the front surface along the conveyer passage92. A cooling liquid source (not shown) is connected to the cooling liquid blow nozzles97which inject the supplied cooling liquid as a cooling liquid stream from a plurality of injection holes97aso as to be blown onto the blow-formed portions38of the preformed articles34conveyed through the conveyer passage92. The cooling liquid may be the city water of about 25° C. The position of blowing the cooling liquid is desirably the upper ends of the blow-formed portions of the preformed articles34.

If further described with reference toFIGS. 7,8andFIG. 10, the gas stream blow means96is constituted by a plurality of, or in the illustrated embodiment, six air stream blow nozzles98ato98farranged on each side of the conveyer passage92for the preformed articles34. The gas stream blow nozzles98a,98b,98dand98eare arranged substantially horizontally. The gas stream blow nozzles98cand98f, on the other hand, are extending relatively long in the direction of conveyance and are tilted downward toward the downstream in the direction of conveyance. If described in further detail, as will be clearly understood with reference toFIG. 10, the gas stream blow nozzle98cis neighboring the gas stream blow nozzle98band is extending being tilted from an upstream end thereof positioned substantially at the same height as the air stream blow nozzle98bdown to the downstream end positioned under the gas stream blow nozzle98din the direction of conveyance. The gas stream blow nozzle98fis neighboring the gas stream blow nozzle98eand is extending being tilted from an upstream end thereof positioned substantially at the same height as the air stream blow nozzle98edown to the downstream side in the direction of conveyance. Each of the gas stream blow nozzles98ato98fhas a front surface extending in parallel with the conveyer passage92, and an injection hole99slenderly extending and is formed in the front surface along the conveyer passage92. The injection holes99of the gas stream blow nozzles98a,98b,98dand98eare arranged facing the upstream ends of the blow-formed portions of the preformed articles34, and the injection holes99of the gas stream blow nozzles98cand98fare tilted from the upstream ends corresponding to the upper ends of the blow-forming portions of the preformed articles34down to the downstream ends corresponding to the lower ends of the blow-formed portions of the preformed articles34in the direction of conveyance. A gas source (not shown) is connected to the gas stream blow nozzles98ato98fwhich inject the supplied gas as an air stream from the injection holes99thereof so as to be blown onto the blow-formed portions of the preformed articles34conveyed through the conveyer passage92. The gas may be the air of normal temperature.

In the apparatus for cooling preformed articles shown inFIGS. 7 to 10, the preformed articles34are conveyed by the conveyer running portions constituted by the pair of belt conveyers90aand90bin a direction indicated by arrows40aand40b. While the preformed articles34are conveyed through the cooling zone93, the cooling liquid is blown to the upper ends of the blow-formed portions of the preformed articles34by the cooling liquid blow means95. The cooling liquid flows down on the blow-formed portions, and the preformed articles34are cooled very effectively. Next, while the preformed articles34are conveyed passing through the drying zone94, the gas stream is blown to the upper ends gradually down to the lower ends of the blow-formed portions of the preformed articles34by the gas stream blow means96. The cooling liquid adhered on the blow-formed portions is effectively blown away, and the blow-formed portions are dried.

The apparatus for cooling preformed articles according to a third embodiment of the invention will be described below with reference to the drawings.

FIG. 11is a view illustrating the whole apparatus for cooling preformed articles according to the invention,FIG. 12is a plan view of a conveyer line in a water tank for the preformed articles, andFIG. 13is a front view thereof.

Referring toFIG. 11, the apparatus1for cooling the preformed articles includes a conveyer2and a water tank3. The conveyer2is constituted by a pair of endless chains14aand14barranged in the direction of conveyance maintaining a distance in the transverse direction. The endless chains14aand14bare provided with drive wheels6a,6band driven wheels8a,8barranged being spaced apart in the direction of conveyance.

The drive wheels6a,6band the driven wheels8a,8bare mounted to rotate about center axes that extend substantially vertically (in a direction perpendicular to the surface of paper inFIG. 12), the drive wheels6aand6bbeing drivingly coupled to electric motors10aand10bshown inFIG. 13. Endless chains14aand14bare wrapped round the drive wheel6aand the driven wheel8aand round the drive wheel6band the driven wheel8b. The endless chains14aand14bare each constituted by many float-preventing chains13a,13b(FIG. 14) arranged in the running direction and coupled to each other so as to be folded up and down and to be turned right and left.

Referring toFIG. 14, a pair of stationary members16aare fixed between the drive wheel6aand the driven wheel8aso as to extend in parallel in the direction of conveyance. Similarly, another pair of stationary members16bare fixed between the drive wheel6band the driven wheel8bso as to extent in parallel in the direction of conveyance. Upper guide members18a,18band lower guide members20a,20bare fixed to the stationary members16aand16b.

The upper guide member18aand the lower guide member20aof the one side protrude sideways beyond the pair of stationary members16a, and guide rail portions22aare formed along both side edges of the upper guide member18aso as to protrude downward. Further, guide rail portions24aare formed along both side edges of the lower guide member20aso as to protrude upward.

Each of the float-preventing chains13ahas a to-be-guided portion26aand a suspension portion28a. The to-be-guided portion26ahas an upper to-be-guided groove30aformed therein to engage with the guide rail portion22aof the upper guide member16aand a lower to-be-guided groove32aformed therein to engage with the guide rail portion24aof the lower guide member20a. The suspension portion28aextends downward from the lower end of the inner edge of the to-be-guided portion26aand, further, extends sideways toward the inside like a flange. Further, a float-preventing plate29aextends sideways toward the inside over the suspension portion28amaintaining a gap31arelative thereto.

The upper guide member18band the lower guide member20bof the other side protrude sideways beyond the pair of stationary members16b, and guide rail portions22bare formed along both side edges of the upper guide member18bso as to protrude downward. Further, guide rail portions24bare formed along both side edges of the lower guide member20bso as to protrude upward.

Each of the float-preventing chains13bhas a to-be-guided portion26band a suspension portion28b. The to-be-guided portion26bhas an upper to-be-guided groove30bformed therein to engage with the guide rail portion22bof the upper guide member16band a lower to-be-guided groove32bformed therein to engage with the guide rail portion24bof the lower guide member20b. The suspension portion28bextends downward from the lower end of the inner edge of the to-be-guided portion26band, further, extends sideways toward the inside like a flange. Further, a float-preventing plate29bextends sideways toward the inside over the suspension portion28bmaintaining a gap31brelative thereto.

The preformed article34shown inFIG. 14can be formed by compression-forming or injection-forming a suitable synthetic resin such as polyethylene terephthalate. When a polyester resin is formed by using an injection-forming machine, however, the resin is subjected to the steps of melting, kneading and injection at the time of forming the preformed articles from the polyester resin pellets. Namely, the polyester resin is thermally decomposed forming an acetaldehyde which is a decomposition product and causes bad flavor property. Formation of acetaldehyde can be suppressed by various special means. One of them is to form the preformed articles by the compression forming which features a short residence time of the resin suppressing the formation of acetaldehyde.

The preformed article34has a shape that includes the mouth-and-neck portion36with an opening on the upper side and the blow-formed portion38with bottom continuous to the lower end of the mouth-and-neck portion36. The mouth-and-neck portion36of the preformed article34is of a cylindrical shape. The flange40of a ring-like shape is formed at the lower end of the mouth-and-neck portion36. The flange40is arranged between the suspension portion28aand the float-preventing plate29a, and between the suspension portion28band the float-preventing plate29b. The blow-formed portion38with bottom is of the shape of an inverse circular truncated cone with its outer diameter slightly decreasing downward.

When the electric motors10aand10bshown inFIG. 13are driven, the endless chains14aand14bare rotated and driven in the direction indicated by arrows40aand40binFIG. 12. The transverse inner running portions of the endless chains14aand14bwork as conveyer running portions, and the transverse outer running portions are the return running portions.

As shown inFIG. 14, the preformed article34has its ring-like flange40suspended by the conveyer running portions of the endless chains14aand14band, if described in further detail, suspended on the suspension portions28aand28bof the float-preventing chains13aand13bby utilizing the gravitational action, and is conveyed in the directions indicated by arrows40aand40b(arrows of the transverse inner running portions or leftward on the surface of the paper inFIG. 12) accompanying the motion of the endless chains14aand14b.

Referring toFIG. 14, the water tank3is filled with the cooling water under the conveyer2, and the surface of the water is close to the flange40of the preformed article34. As shown inFIG. 15, the water vessel3is equipped with a cooling water circulation facility141. The cooling water circulation facility141is connected to a circulating pump143through a pipe142astarting from the water tank3. The circulating pump143pumps the cooling water in the cooling water circulation facility141with pressure so as to be circulated. The circulating pump143is connected to a water purifying unit144through a pipe142b. The water purifying unit144has a 6 μm-mesh filter provided in the passage of the cooling water. The water purifying unit144is connected to a sterilizing vessel145through a pipe142c, and a UV lamp for sterilization is arranged in the interior of the sterilizing vessel145. The sterilizing vessel145is connected to a temperature-maintaining unit146through a pipe142d. A heat exchanger is disposed in the temperature-maintaining unit146which is connected to the water tank3through a pipe142e. Thus, the cooling water circulates through water tank3, circulating pump143, water purifying unit144, sterilizing vessel145and temperature-maintaining unit146, and returns back to the water tank3. The cooling water circulation facility141is arranged in the above first embodiment as well as in the above second embodiment, is provided under the conveyer passage, and circulates the cooling water recovered from the water tank3which plays the role of a recovery tray through pumping, purification, sterilization and temperature control.

Referring toFIG. 11, a descending portion147is provided on the upstream of the conveyer2and terminates at a connection portion a, and a spray conveyer portion151is provided neighboring thereto on the upstream of the descending portion147. Spray blow nozzles56are arranged in the spray conveyer portion151.

As shown inFIG. 4, a plurality of spray blow nozzles56are provided on one side of the spray conveyer portion151. A water supply (not shown) which is the city water is connected to the spray blow nozzles56which work to spray the water. The spray is injected from a single injection hole58formed at an end of each of them, and is blown to the blow-formed portions38of the preformed articles34conveyed through the spray conveyer portion151.

A conveyer149is arranged on the upstream of the spray conveyer portion151to convey the preformed articles34formed by using a compression-forming machine or an injection-forming machine (not shown) into the water tank3. An ascending portion148of which the end side is upwardly directed is provided on the downstream of the conveyer2, and a drain conveyer portion150is connected to the downstream of the ascending portion148. The descending portion147and the ascending portion148are constituted by guiding the stationary members16aand16bin the form of, for example, a dish as viewing from the front as shown inFIG. 11. Further, the endless chains14aand14bcan be folded up and down to smoothly convey the preformed articles34. Here, as shown inFIG. 12, dead plates182are arranged at a connection portion between the conveyer149and the spray blow conveyer portion151and at a connection portion between the drain conveyer portion150and a conveyer line181of the next step, so as to work as guide members.

A plurality of air nozzles64are arranged in the drain conveyer portion150as shown inFIG. 6. Each air nozzle64has an injection port66slenderly formed in the direction of conveyance, the end of the injection port66facing the outer peripheral surface of the preformed articles34. A gas source (not shown) is connected to the air nozzles64. The gas may be an inert gas in addition to the air.

Next, described below is the action of the apparatus for cooling preformed articles of the embodiment.

Referring toFIG. 11, the preformed articles34formed by using a compression-forming machine or the like machine but before being blow-formed are conveyed by the conveyer149up to the water tank3. The preformed articles34are conveyed by the conveyer149at a high speed and, therefore, pass through the connection portion between the conveyer149and the spray conveyer portion151due to the force of inertia thereof. In the spray conveyer portion151, the distance among the preformed articles34being conveyed is shortened since the speed therein is slower than the speed of the conveyer149. In the spray conveyer portion151, further, the spray is blown to the outer peripheral surfaces of the blow-formed portions38of the preformed articles34from the spray blow nozzles56(seeFIG. 4) while the preformed articles34are being conveyed. A blow of the spray onto the blow-formed portions38of the preformed articles34effectively works to suppress or prevent damage to the blow-formed portions38of the neighboring preformed articles34caused by the contact among them despite the distance is set to be relatively small to the preformed articles34that are subsequently conveyed and, besides, despite the preformed articles34are conveyed at a relatively high speed. It is desired that the particles constituting the spray have a diameter of 1 to 5 μm and, particularly, 1 to 3 μm to avoid the particles adhered on the blow-formed portions38from gathering together to form droplets and, further, to avoid the blow-formed portions38of the preformed articles34from being cooled by dot regions, so that the surfaces will not become spotted or rugged.

In the descending portion147as shown inFIG. 14, the flange40of the preformed article34is arranged between the suspension portion28aand the float-preventing plate29aof one float-preventing chain13aand between the suspension portion28band the float-preventing plate29bof the other float-preventing chain14b. In the descending portion47, the flange40is supported on the upper surfaces of suspension portions28a,28bof the float-preventing chains13a,13b. Through the descending portion147, the preformed articles34are conveyed to a water-immersion portion180(seeFIG. 11). The preformed articles34are conveyed close to the surface of the cooling water and approaches the connection point a; i.e., the preformed articles34approaches the surface of water in the water tank3.

The bottom of the blow-formed portion38with bottom of the preformed article34of the form of a container comes in contact with the surface of the water; i.e., the preformed article34is forced to be submerged in the water. Due to the buoyancy, the preformed article34is lifted up (seeFIG. 16). Namely, due to the buoyancy, the preformed article comes in contact with the float-preventing plates29a,29bpositioned over the flange40, and is limited from floating up any more. The blow-formed portion38with bottom of the preformed article34is gradually submerged. In the water-immersion portion180arranged in the horizontal direction, the blow-formed portion38is maintained submerged up to the lower part of the flange40and is maintained at the same height.

While being conveyed in the water-immersion portion180, the flange portion40of the preformed article34is limited by the float-preventing plates29aand29bfrom moving upward. Therefore, the preformed article34maintains a stable upright attitude due to buoyancy, is conveyed toward the downstream side in this state, and is cooled by the cooling water.

After cooled in the water tank3, the preformed article34is handed over to the ascending portion148at a boundary point which is a connection portion b (seeFIG. 11) between the water-immersion portion180and the ascending portion148. In the ascending portion48, the preformed article34is conveyed upward and goes over the surface of the water where no buoyancy works. Therefore, the flange40is supported in a state of being placed on the suspension portions28aand28b(seeFIG. 14).

In the drain conveyer portion150, the cooling water adhered to the preformed articles34is blown away by the air nozzles64shown inFIG. 6. Referring toFIG. 12, the preformed articles34are conveyed from the drain conveyer portion150to the conveyer181of the next step. At the connection portion, however, the drive rollers6aand6bare offset back and forth. Despite of being conveyed at a low speed, therefore, the preformed article34engages with the endless chain14aor with a conveyer belt181bprotruding rearward from the conveyer181of the next step, and is transferred onto the conveyer181. Thus, the preformed articles34are cooled in a short period of time, and are collected and stored in the next step, or are heated again so as to be blow-formed.

It is desired that the cooling water in the water tank3flows from the upstream to the downstream to adjust the speed of conveying the preformed articles, so that the cooling water will not become a resistance against conveying the preformed articles.

In the above first to third embodiments, the right and left traveling speeds are differed between the pair of right and left conveyers4aand4b, belt conveyers90aand90aand in the conveyer2, enabling the preformed articles to be conveyed while being rotated so as to be uniformly cooled in the cooling zone. In the first and second embodiments in which the cooling liquid is allowed to be blown to the preformed articles from the transverse direction only, the above constitution is more preferred. By setting the same constitution in the spray zone44, too, the spray can be blown to the whole periphery of the preformed articles, which is desirable.

Next, a fourth embodiment of the invention will be described with reference to the drawings.

An apparatus161for cooling preformed articles shown inFIG. 17(imaginary lines shown double-dash chain line as viewed from an arrow therein are drawing a plan view of a conveyer belt) includes a water tank162, a conveyer163, an aligning conveyer line164and a drain line165. The conveyer163has one end thereof (upstream side) provided on the bottom of the water tank162and has the other end thereof (downstream side) arranged outside the water tank162. The conveyer163is provided with a plurality of rollers166ato166d, and the circumference thereof is wrapped with a conveyer belt168. Belt guides163aand163bare provided at the folding portions of the conveyer belt. A plurality of partitioning plates169are arranged along the circumference of the conveyer belt168maintaining a distance in the circumferential direction of the conveyer belt168, the partitioning plates169being erected at right angles with the conveyer surface of the conveyer belt168and are extending over the whole width of the conveyer surface. The height of the partitioning plates169is such that the preformed articles34can be conveyed.

The water tank162includes the cooling water circulation facility comprising the circulating pump143, water purifying unit144, sterilizing vessel145and temperature-maintaining unit employed by the third embodiment shown inFIG. 15, and is capable of adjusting the temperature and sterilizing the cooling water.

An aligning conveyer line164is provided just under the downstream end of the conveyer163. The aligning conveyer line164is such that the two guide shafts170and171that are becoming slightly narrow toward the ends170a,171athereof (seeFIG. 18) are so arranged that the gap therebetween becomes slightly broad toward the downstream, the gap being greater than the diameter of the blow-formed portion38of the preformed article but smaller than the outer diameter of the ring-like flange40(gap of a width through which the flange40cannot pass through). The guide shafts170and171are arranged being so tilted that the downstream side thereof becomes low in the direction of conveyance. The guide shafts170and171are forming a mild screw shape on the outer peripheral surfaces thereof, and are rotated in the opposite directions as shown (seeFIGS. 18 and 19).

The preformed article34is heavier on the side of the blow-formed portion38than on the side of the mouth-and-neck portion36with the flange40as a reference. When the preformed article34is being conveyed, therefore, the blow-formed portion38only passes through the gap. As the blow-formed portion38passes through the gap, the preformed article34assumes an upright attitude, whereby the bottom of the blow-formed portion38is directed downward and the flange40is supported by the peripheral surfaces on the upper side of the guide shafts170and171. The guide shafts170,171are arranged in parallel in at least one or more pairs.

On the drain line165, the preformed articles34are conveyed in an erected attitude, and an injection device172is arranged on the drain line165(FIGS. 17 and 20). The injection device172is arranged in a direction in which the preformed articles34are conveyed, and an injection slit173is formed in a lower portion thereof along the direction in which the preformed articles34are conveyed. The injection slit173is arranged facing the openings of the mouth-and-neck portions36of the preformed articles34and, in a preferred embodiment, is arranged at upper positions of the openings deviated outwards from the centers thereof.

A conveyer174is arranged on the upstream of the conveyer163to convey the preformed articles34formed by the compression-forming machine or the injection-forming machine (not shown) into the water tank162. An end174aof the conveyer174is protruding inward beyond the end of the water tank162in the direction in which the preformed articles34are conveyed. The preformed articles34must fall on the conveyer163in the water vessel162from the conveyer174. Therefore, a guide member (net, plate member, etc.) is desirably provided in the water tank162so that the preformed articles34reliably falls on the conveyer163.

The action of the fourth embodiment of the invention will be described next.

The preformed articles34conveyed onto the conveyer174fall on the water tank162from the end174aof the conveyer174. Then, the longitudinally elongated preformed articles34float lying on the surface of the cooling water in the water tank162. As the cooling water enters through the openings of the mouth-and-neck portions36, however, the preformed articles34submerge under the surface of the water successively. The conveyer163is arranged under the surface of the water, and the preformed articles34are fed onto the conveyer belt168which is provided with partitioning plates169. Being guided by the partitioning plates169, therefore, the preformed articles34ascend on the conveyer163while being cooled by the cooling water. By taking the temperature of the cooling water and the time for cooling the preformed articles34by the cooling water into consideration, the conveying speed of the conveyer163is so set that the temperature of the preformed articles34is, for example, 60° C. at an end (above near the roller166d) of the conveyer163. After having emerged out of the cooling water, the preformed articles34arrive at the end of the conveyer163and are successively fed onto the aligning conveyer line164. On the aligning conveyer line164, the preformed articles34are nearly lying down and are arranged between the guide shafts170and171due to the gravitational action. Here, with the flanges40as fulcrums, the blow-formed portions38with bottom which are heavy and are becoming narrow toward the end enter into the gap between the guide shafts170and171and, thereafter, assume the upright attitude. The cooling water that has entered into the preformed articles34while being cooled in the water tank162is mostly drained in a state when they fell sideways on the aligning conveyer line164.

Next, the preformed articles34that have acquired the upright attitude on the aligning conveyer line164are conveyed just under the injection device172, and the air is injected from the upper injection slit173into the lower blow-formed portions38with bottom. Since the injection slit173is offset from the centers of the preformed articles34as shown inFIG. 20, the air is inverted along a curved surface formed in the bottom of the blow-formed portions38with bottom, and flows out while coming in contact with the inner peripheral walls. Therefore, the cooling water staying in the bottoms of the blow-formed portions38with bottom is injected out of the preformed articles34together with the air to accomplish the drying.

Next, a fifth embodiment of the invention will be described with reference to the drawings.

FIG. 21illustrates part of a preformed article compression-forming machine201, hand-over units202and203for the preformed articles on the upstream side and on the downstream side, a preformed article cooling/drying unit204, and a conveyer205.

The compression-forming machine201rotates so that a plurality of metal molds206successively moves along a circular orbit. The formed article hand-over unit202on the upstream side comprises a plurality of (six) rotary arms208that can be rotated about an axis of rotation maintaining a distance being driven by a motor that is not shown. Grip units209are attached to the ends of the rotary arm208.

The grip unit209is illustrated on the left side inFIG. 22. The grip unit209has a swing shaft210disposed on the side of the proximal end (arm) thereof with its axis heading in the up-and-down direction permitting the grip unit209to swing with respect to the rotary arm208as shown inFIG. 21. The swing shaft210is provided with a swing arm212which has a slide block214that extends in the radial direction of the swing turn of a grip218. The slide block214is allowed to slide enabling the grip218to move forward or back in the radial direction thereof.

Next, a slide mechanism of the slide block214will be described.

The swing arm212is provided with a rotary shaft215that penetrates through the swing arm212in a horizontal direction, and a fan-shaped pinion gear216is attached to the rotary shaft215. The pinion gear216meshes with a rack217that is fixed to the slide block214. The rack217is so disposed as to move in a horizontal direction and in a radial direction of the swing turn of the grip218. Here, the rotary shaft215is connected to a torsion spring that is not shown, or is linked to an air cylinder or a spring via a pinion-rack structure (not shown) arranged on the back surface side of the grip unit209shown inFIG. 22. The rotary shaft215is so urged that the grip unit209is headed toward the front end thereof. Referring toFIG. 26, at the time of handing over the preformed article34from the compression-forming machine201, a guide block244provided under the slide block214is limited by being contacted to the compression-forming metal mold206, so that the slide block214retreats (see an orbit X inFIG. 23) and that the grip unit209is positioned.

Referring toFIGS. 27 and 28, at the time of handing the preformed article34over to the cooling/drying unit204, the guide block244provided under the slide block214is limited by being contacted to an extension-limiting block245that is provided on the cooling/drying unit204and that rotates together with the grip unit209, so that the slide block214retreats and is positioned.

The slide block214may be moved forward and back by being controlled by drive means such as a servo motor or the like instead of using the guide block244and the extension-limiting block245, to determine the position of the grip unit209.

Handing over the preformed articles34between the downstream hand-over unit203and the cooling/drying unit204is the same as handing over the preformed articles34between the upstream hand-over unit202and the cooling/drying unit204.

Over the slide block214, a slide plate221is mounted to move forward and back in the radial direction of the rotary arm208on the guide plate219that is provided on the upper surface of the slide block214. Between an end surface of the guide plate219on the proximal end side thereof and a protuberance222formed on the upper surface of the slide block214, a rod223is provided penetrating through the protuberance222and with its axis extending in the radial direction of swing turn of the grip218. The rod223is surrounded by a spring224which is so disposed as to urge the slide plate221toward the end side.

Referring to the right side inFIG. 22, a grip support member226and a grip218are attached to an end of the slide plate221. The grip218is so constituted as to be opened when the grip support member226moves back and to be closed when the grip support member226moves forward. When the grip218is closed, the ring-like flange40of the preformed article34is supported on the grip groove220nearly in concentric therewith.

Referring toFIG. 22, a cam follower228of a circular shape in cross section is attached to the lower part of the swing arm212. Referring toFIG. 21, a cam groove229is fixed to the hand-over unit202, and the grip unit209turns and moves along the shape of the cam groove229as the cam follower228is fitted to the cam groove229. On the side of the compression-forming machine201and the cooling/drying unit204, the cam groove229is formed describing a deformed arcuate orbit so as to meet a circular orbit of the metal molds206of the compression-forming machine201and to meet a circular orbit of the cooling/drying unit204.

A grip opening/closing cam follower241is attached to an upper part of the slide plate221in the grip unit209. Referring toFIG. 23, the hand-over unit202is provided with a deformed arcuate cam242. As the grip opening/closing cam follower241comes into contact with the deformed arcuate cam242, the slide plate221moves backward, whereby the grip218opens, and the ring-like flange is placed on the grip groove220so as to hold the blow-formed portion of the preformed article34. The grip218closes as the grip opening/closing cam follower241passes over the deformed arcuate cam242.

In the cooling/drying unit shown inFIG. 21, a plurality of rotary arms231supporting the grip units209aon the side of the cooling/drying unit are arranged maintaining an equal distance, and the grip units209aattached to the support members232arranged at the ends of the rotary arms231rotate so as to move on a circular orbit with the axis of rotation as a center.

Referring toFIG. 22, the support member232is provided with a slide plate221awhich moves the guide plate219aprovided on the lower surface of the support member232forward and backward in the radial direction of the rotary arms231. Between an end surface of the guide plate219aon the proximal end side thereof and a protuberance222aformed on the lower surface of the support member232, a rod223ais provided penetrating through the protuberance222aand with its axis extending in the radial direction of swing turn of the grip218a. The rod223ais surrounded by a spring224awhich is so disposed as to urge the slide plate221atoward the end side.

Referring toFIG. 24, a grip support member226aand a grip218aare attached to an end of the slide plate221a. The grip218ais so constituted as to be opened when the grip support member226amoves back and to be closed when the grip support member226amoves forward. When a pair of grips218aare closed, the mouth-and-neck portion36of the preformed article34is held. An upright portion232aextending upward in the vertical direction is provided at an end of the support member232, and a lift slide233is disposed on the outer surface of the upright portion232a. A lift cam234is attached to the outer surface side of the lift slide233, is disposed along a direction in which the grip unit209arotates, and moves up and down being guided by a cam plate235having a curved line in the up-and-down direction. A passage236for the cooling air or for the cooling liquid and for the drying air, is formed inside the lift slide233, and a nozzle237is attached to the lower part of the lift slide233. Referring toFIG. 24, a connection port238is provided at an upper end of the lift slide233, and is connected to a compressed air supply portion and to a cooling liquid supply portion through an air/cooling liquid change-over valve239.

The change-over valve39may be omitted when the interior of the preformed article34is to be cooled by the air only.

InFIG. 21, cooling liquid blow nozzles60(same as those shown inFIG. 5or those shown inFIG. 9but that are curved) are arranged as shown inFIG. 24along the conveyer passage upstream of the cooling/drying unit204with the ends of nozzles thereof being directed to the blow-formed portions of the preformed articles34. The cooling liquid blow nozzles60may be the spray blow nozzles56shown inFIG. 4. InFIG. 21, further, gas stream blow nozzles64(same as those shown inFIG. 6) are arranged as shown inFIG. 25along the conveyer passage downstream of the cooling/drying unit with the ends of nozzles thereof being directed to the blow-formed portions of the preformed articles34. A circular cooling liquid recovery tray240is arranged under the orbit of the grip units209aof the cooling/drying unit204. It is desired that the cooling liquid recovered by the recovery tray240is repetitively used being circulated again to the cooling liquid blow nozzles60through the circulating pump143, purifying unit144, sterilizing vessel145and temperature-maintaining unit146in the water conduit system shown inFIG. 15.

Based on the above-mentioned constitution as shown inFIG. 21, the preformed article formed by the compression-forming machine201approaches the circular orbit of the grips218of the preformed article hand-over unit202on the upstream side. When the preformed article34arrives at a region of a section L shown inFIG. 21, the grip218also arrives at the region of the section L and is controlled for its orbit so as to follow the circular orbit of the metal mold206. The orbit is controlled by moving the slide block214forward and back while permitting the grip unit209to swing. In the region of the section L, the transfer (circumferential) speeds are brought into agreement between the grip218and the metal mold206. Referring next toFIG. 23, the grip218is opened by the deformed arcuate cam242, and is caused to advance toward the blow-formed portion of the preformed article34so as to hold the preformed article34. Thereafter, the grip218is closed after having passed over the deformed arcuate cam242, and the ring-like flange of the preformed article34is supported by the grip218.

Upon turning about one-half, the grip unit209comes in contact with the orbit of the cooling/drying unit204. At the position of handing over the preformed articles34to the hand-over unit203from the cooling/drying unit204, as shown inFIG. 22, the grip218aholds the lower side of the mouth-and-neck portion36(upper side of the ring-like flange40). The grip218ais opened and closed by the same mechanism as the one for the grip218shown inFIG. 23.

At a moment when the preformed article34is handed over to the cooling/drying unit204from the hand-over unit202, as shown inFIG. 22, the lift slide233is at an upper position, and the nozzle237is just over the preformed article34. Next, as shown inFIG. 24, the lift slide233descends being guided by the cam plate235, and the nozzle237is inserted in the preformed article34. When the grip unit209aturns to a place where the cooling liquid blow nozzle60is disposed, the cooling liquid blow nozzle60injects the cooling water onto the blow-formed portion38of the preformed article34. The preformed article34is thus cooled. At the same time, the compressed air is fed to the nozzle237through the change-over valve239, and the interior of the preformed article is cooled by the air. The interior of the preformed article may be cooled by the cooling water instead of using the air.

After cooled by the cooling liquid, the preformed article34is conveyed to the downstream side of the conveyer line of the cooling/drying unit204. The gas stream blow nozzles64are arranged along the downstream conveyer line as shown inFIG. 25to blow away the droplets of cooling water adhered on the outer peripheral surfaces of the preformed articles34. When the interior of the preformed article34is cooled by the cooling water or when the cooling water has entered into the interior, the residual cooling water is blown away by the injection nozzle237to dry the preformed article34.

On the most downstream side of the cooling/drying unit204, the nozzle237is taken out from the interior of the preformed article34due to the action of the lift cam234and the cam plate235, and the preformed article34is handed over to the hand-over unit203on the downstream side. Thereafter, the preformed article34is transferred from the hand-over unit203to the conveyer205, and is conveyed to the working step on the downstream side. The structure of the hand-over unit203on the downstream side is the same as the structure of the hand-over unit202on the upstream side.

Use of the rotary type cooling/drying unit makes it possible to further decrease the space for working.

The compression-forming machine201successively forms preformed articles34maintaining an equal distance, and the hand-over unit202successively hands the preformed articles34over to the cooling/drying unit204, so that the preformed articles34are cooled by the cooling water under the same cooling condition. As a result, the preformed articles34are uniformly cooled.

When the preformed articles34are formed by the compression-forming machine201, the compression-forming machine201conveys the preformed articles34to the cooling means on the downstream side maintaining an equal distance and successively in the above-mentioned first to fourth embodiments, too, that use no rotary conveyer means. Therefore, the preformed articles34are cooled by the cooling water under the same condition and are, therefore, uniformly cooled.

Though the invention was described above by way of embodiments, it should be noted that the invention can be further modified or changed in a variety of other ways, as a matter of course, without departing from the technical spirit of the invention.

Further, the preformed article is not limited to the one of the shape of an inverse circular truncated cone but may be the one of the shape of a preformed article usually used for the blow-forming, such as the one of an ordinary cylindrical shape with bottom of a semispherical shape.

The mouth-and-neck portion36may have a screw formed on the outer peripheral surface thereof when a sealing member for sealing the opening is a cap.

Like the cooling liquid blow nozzles60and the gas stream blow nozzles64, the spray blow nozzles56work to evenly blow the spray if the spray is brown from both sides. Like the spray blow nozzles56, further, the cooling liquid blow nozzles60and the gas stream blow nozzles64may effect the blow from one side only. By effecting the blow from both sides as in this embodiment, however, the cooling and drying by blow are evenly effected from both sides, which is desirable.

The guide shafts170and171of the aligning conveyer line164may have smooth conical surfaces without forming screws on the outer surfaces thereof.

Further, the guide shafts170and171may comprise two ordinary cylinders arranged in parallel with the axes of rotation being tilted and the lower side thereof working as an aligning outlet. Or, the two ordinary cylinders may be horizontally arranged out of parallel so that the broader side works as an aligning outlet.