Mechanism For Rigidifying A Collapsible Object

Abstract

A mechanism for rigidifying a collapsible object to be decorated to prevent the object from collapsing as a result of pressure being applied thereto in a hot stamping operation. Air is blown into the object for a period of time and released at the proper time to permit the object to be placed under pressure when a foil is pressed onto its surface.

Description

This invention relates to the surface decoration of hollow objects such as plastic bottles.

A machine for the surface decoration of hollow objects has been successfully developed and is depicted in my U.S. Pat. No. 3,309,256 entitled "APPARATUS FOR SURFACE DECORATING OF ARTICLES" issued on Mar. 14, 1967. This patent discloses a machine for hot stamping, via heat and pressure, a foil onto the surface of an object to be decorated. To accomplish this, an object is urged, under pressure, against the foil and a heated die. Generally, the object is rotated when it is circular in cross-section and a heated die presses the foil on the object, thereby transferring the decorative foil onto the surface of the object.

When a bottle is used which is non-circular in cross-section, the decorative foil cannot be placed on the surface of the bottle by rotating it. This occurs because it is essential that a uniform pressure be maintained between the die and the bottle and if the bottle is not circular, the higher and lower areas will be subjected to different pressures because the die is fixed.

To decorate a plastic bottle it must be made rigid or the pressure between the bottle and the die will collapse the bottle and this produces an unsatisfactory transfer of foil to the object.

To overcome the aforementioned disadvantage, the plastic bottle is inflated which serves to rigidify the bottle and prevents it from collapsing. There are a number of problems associated with rigidifying a plastic bottle. For example, it is essential that the air supply to the bottle be cut off before the bottle ruptures or is distended beyond its elastic limit and does not return to its original shape. It is also necessary that the air supply not be cut off too soon because the bottle can begin to collapse and the decorative foil will be distorted. Balanced against the latter, if the bottle is filled with air after it moves away from the die, the bottle can rupture because the die no longer acts as a counter balancing force. If the bottle is in contact with the die for too long a period of time then distortion will appear. Thus, it can be seen that timing is of the essence.

By utilizing a timer to control the injection of air into the bottle all of the aforementioned problems can be taken into consideration and eliminated. Thus, the timer signals an air valve which permits air under pressure to be supplied to a bottle. After the bottle is inflated, the timer maintains the air in the bottle at a fixed pressure and then the timer allows the air to be released from the bottle just a fraction of a second before it leaves the die.

It is therefore an object of the invention to provide a mechanism for rigidifying an article to be decorated and maintaining and releasing the rigidifying force at the proper time.

It is another object of the invention to provide a timer in conjunction with a rigidifying means to control the latter.

It is yet another object of the invention to provide a timer in conjunction with an air supply apparatus to control the supply and the shut off of the air.

It is still another object of the invention to provide a sealed system for pressurizing a bottle which is simple to fabricate, inexpensive and reliable in operation.

For a better understanding of the invention, reference may be had to the accompanying drawings in which:

FIG. 1 is a front view of a stamping machine incorporating the invention;

FIG. 2 is a side view thereof showing the details of the air supply actuating mechanism; and

FIG. 3 is a detail view of the components used to control the supply and shut off of the air to a bottle.

For the purpose of illustrating the present invention, a specific type of hot stamping machine is disclosed. It should be understood, however, that the aspects of the present invention are applicable to various types of stamping machine well known to those skilled in the art, and it is not intended to limit the present invention to the specific type of machine illustrated.

Referring now to the drawings, there is illustrated a hot stamping machine generally designated at 10. The housing 11 for the machine is preferably formed of a heavy guage metal, however, any known material can be used. The machine can be raised off the floor by means of legs 12 or the machine can rest flat on the floor. In either case the machine is firmly anchored to preclude lateral movement of the latter.

The work area 13 is an open area extending from front to rear of the machine and is defined by the side rails 14, a top rail 15 and a rigid horizontal bed 16. Securely fastened to the bed 16 is an air cylinder 17 which is supplied by an outside source (not shown) with air under pressure. The air cylinder 17 has a diaphragm therein (not shown) and air can be fed into the cylinder either above or below the diaphragm. Thus, as the diaphragm moves in an upward or downward direction, the shaft 18 moves correspondingly therewith.

The end of the shaft 18 is fixed to a platform 19 which is constrained to move in a vertical direction only corresponding to movement of the shaft 18. A pair of elevator guides 20 having longitudinal bores therein for the reception of a shaft 21 are provided to supply rigidity and stability to the platforms 19, 19a. The shafts 21 are free to move in their respective bores and are designed to have a close sliding fit. By utilizing these elevator guides, the platform 19 is firmly constrained to vertical movement without any lateral rocking of the platform. The platform 19 can include an upper part 19a rigidly held to the lower part 19 by posts 22 or it can be a unitary platform.

Mounted on top of and securely fastened thereto is a housing 23 which can have gears therein. An arm 24 which can be in the form of a mandrel is rotatably secured to the housing 23 whereby the arm is free to rotate or it can be positively driven through a gear arrangement within the housing 23. The object 25 to be decorated is placed on the mandrel 24 such that it can be either rotated or held stationary thereon.

A reel 26 is rotatably mounted on the housing 10 and a tape 27 is wound on the reel. The tape is preferably Mylar having a foil thereon which is to be transferred in the form of a decorative design to the object 25. The tape 27 is passed over a plurality of tape guides 28. Four guides are shown, however, the number used is a matter of choice. The guides 28 are preferably rollers having a low coefficient of friction and having flanged ends to prevent the tape from moving laterally from the roller. The tape 27 is threaded around the left set of guides 28 as illustrated in FIG. 1 and thence between the object 25 and a die 30 where it is subsequently passed over the right set of guides. The tape 27 is then fed between a pair of pull rollers 29. These rollers have a surface thereon having a relatively high coefficient of friction or any type of known surface which will grip the tape, for example, a knurled surface can be applied to the rollers. The rollers 29 are rotatably mounted on the housing 10 and can be driven by a motor (not shown) or they can be actuated by hand to advance the tape 28 after the foil carried by the tape has been transferred to the object 25. Thus, by rotating one or both of the rollers 29, a positive grip is exerted on the tape 27 and it is pulled to the right as shown in FIG. 1 so that a fresh portion of tape having foil thereon is placed between the object 25 and the die 30 for each new object placed on the mandrel 24.

The die 30 can have a design etched thereon or it can be plain according to the desires of the user and depending upon how he wishes to decorate the object 25. The die 30 is fixed to a carriage 31 having openings 32 bored therein for the reception of a pair of guide rails 33. The carriage 31 is freely slidable on the guide rails 33 under the influence of an air cylinder 34 or any other motor means. An arm 35 is fixed at one end thereof to the carriage 31 and at its opposite end to a rod 36. A piston in the air cylinder 34 is fixed to the rod 36 and under the influence of air pressure the rod 36 is moved to the right as shown in FIG. 5; thus, the die is moved therewith to contact the tape 27 and the object 25. The die 30 is preferably heated by electrical means (not shown) and by applying heat and pressure to the tape and the object, the foil on the tape can be transferred to the object.

Fixed to the elevator platform 19 is a finger 37 which can be any convenient configuration and is herein shown as an L-shaped member. When the platform 19 is raised, the finger 37 trips a switch 38 which can be a micro-switch. The micro-switch completes an electrical circuit to a conventional timer 39 having a dial 40 thereon which enables one to set desired time limits. The timer 39 is electrically connected to a solenoid air valve 41. The air valve includes a coil 42 which when energized attracts an armature 43. Fixed to one end of the armature 43 is a coil spring 44 which serves to return the armature to its rest position after it has been actuated and the field current is removed from the coil 42. The armature 43 is effectively a sliding valve having a passageway 45 bored therethrough. Another passageway 46 is bored through the block of the air valve 41 and air lines 47 are fixed to opposed ends of the passageway 46. When the armature coil 42 is energized by passing current therethrough, the armature is moved to the left as shown in FIG. 3 and the passageway 45 in the armature 43 aligns with the passageway 46 in the block 41. This permits air to flow through the air supply lines to a passageway 48 bored through the bottle support block 23. The block 23 can be formed to any convenient shape which will firmly cradle the bottle 25 therein. The block 23 has a seal 49 which can be rubber or neoprene pressed into a counterbore 50 at one end thereof. The inner diameter of the seal 49 is dimensioned to receive the neck of the bottle 25 firmly so as to prevent air from leaking out of the bottle 25. The air flows into the bottle through the passageway 48 and through the opening in the seal 49.

In actual operation, the operator presses an "on-off" switch (not shown) which actuates a pump to supply air to the air cylinder 17 thereby raising the platform 19. The finger 37 trips the micro-switch 38 thereby actuating the timer 39. The timer sends a signal to the solenoid 41 which opens an air valve permitting air under pressure to enter the bottle 25. The timer has a dial 40 which enables one to preset the amount of time that air can enter the bottle. The bottle is inflated and it contacts the heated die 30 whereby the decorative material on the tape 27 is transferred to the bottle 25. The timer 40, at the end of a pre-set time signals the solenoid 41 to release the air by actuating the armature 43. This signal occurs at approximately one-half a second before the timer 40 signals the air supply to the cylinder 17 to lower the platform 19 and thence the object 25 affixed thereto.

While there has been shown and described a particular embodiment of the present invention, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the invention in its broader aspects, and it is therefore, contemplated in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Claims

What is claimed is:

1. In a machine for decorating and inflating a bottle comprising,

a. a first base for supporting said machine,

b. a frame on said base defining an open work area,

c. a die mounted in said work area,

d. a platform mounted in said base for movement between proximate and distal positions with respect to said die,

e. means for selectively moving said platform between said proximate and distal positions,

f. said platform having a second base thereon having an air receiving opening therein and means to receive a bottle thereon whereby the neck of the bottle is contiguous with said opening,

g. a tape having decorative material removably secured thereto extending between said die and the bottle on said platform whereby the tape is impressed against the bottle and the die when the platform is in the proximate position with respect to the die,

h. an air line interconnecting an air supply to the air receiving opening in said second base,

i. selectively operable valve means in said air line for opening and closing said air line to selectively permit air to flow from said supply to said second base to inflate a bottle thereon,

j. an adjustable timer for selectively operating said valve means upon actuation of the timer to open said valve means for a selected predetermined period of time, which period of time after actuation of the timer, is independent of the position of said platform, thereby to pressurize said bottle for said predetermined period of time, and

k. means, responsive to movement of the platform, for actuating the timer.

2. The machine for decorating and inflating a bottle as defined in claim 1 wherein said predetermined period of time extends from the actuation of said timer to immediately prior to the movement of said platform from said proximate position to said distal position, whereby air pressure within said bottle is relieved prior to the release of the balancing pressure applied to the bottle by the die in said proximate position.

3. The machine for decorating and inflating a bottle as defined in claim 1 in which the means responsive to movement of the platform comprises a finger on the platform and a switch in the path of movement of said finger.

4. The machine for decorating and inflating a bottle as defined in claim 1 in which the valve means comprises a block having a first passageway bored therethrough and an armature having a second aperture bored therethrough reciprocally mounted in said block and electrical means adapted to reciprocate said armature such that in one position of the armature the first and second passageways are in alignment and in another position said passageways are not aligned.

5. The machine for decorating and inflating a bottle as defined in claim 4 in which said air line is attached to said first passageway at opposite ends thereof.

6. The machine for decorating and inflating a bottle as defined in claim 1 further comprising sealing means on said second base to seal the neck of the bottle thereon and to prevent the escape of air therefrom.

7. The method of rigidifying a bottle for decoration in a machine having a die and a platform mounted for movement between proximate and distal positions with respect to the die and having a base thereon having an air receiving opening and means to receive a bottle thereon whereby the neck of the bottle is contiguous to said opening, and a tape having decorative material removably secured thereto and extending between the die and the bottle on the platform, whereby the tape is impressed against the bottle and the die when the platform is in the proximate position with respect to the die, said method comprising the steps of

a. presetting a time interval into a timer

b. moving said platform to said proximate position with respect to said die,

c. actuating said timer as said platform approaches said proximate position,

d. opening an air valve upon actuation of said timer,

e. supplying air through said valve to said base opening and the bottle to inflate the bottle whereby the bottle is held rigidly against the die in the proximate position of said platform, and

f. releasing the air from said bottle after expiration of the preselected time interval in the timer independently of the position of the platform.

8. The method as defined in claim 7 wherein said step of presetting a time interval into the timer comprises the step of setting a time interval having a duration which will end prior to the movement of the platform from said proximate position to said distal position whereby the air in the bottle is released therefrom prior to movement of the bottle away from said die.