Method Of And Apparatus For Applying Caps To Containers

Abstract

In the application of caps in interconnected strip form to cup-like containers, the containers and the caps are fed along respective feedpaths to a position at which the caps are applied to the containers in succession, the spacing of the caps being slightly greater (by about 0.3 percent) than the spacing of the containers, and the rate of feed being such as to ensure registration between each successive container and a respective cap at said position. The successive containers with applied caps are advanced from the capping position to a discharge point at which the applied caps are severed from the strip and the edges of the caps are crimped onto the rims of the containers.

Description

This invention relates to a method of, and apparatus for, applying caps to containers. The invention is more particularly applicable to the capping of containers known as "individual portion caps", which are cup-like containers usually of frusto-conical shape.

In the capping of such containers it is usual to feed the containers to a capping station at a predetermined speed, the caps being fed to the capping station in interconnected strip form also at said predetermined speed so that each successive cap is brought into register with a respective container prior to its being applied to the container. Typically the caps are in the form of a die-cut strip having a layer of foil on one side which is coated with hot melt adhesive, the caps being heat-sealed to the rims of the containers and the edges of the caps subsequently being crimped onto the containers. It is obviously important to ensure accurate registration between the caps and the containers at the time they are to be sealed; this requires that the feed rates of the caps should be very accurately controlled in relation to one another and, when filling and capping are carried out in the same apparatus, in relation to the speed of operation of the filling mechanism. Such control becomes very difficult in apparatus designed to operate at high speeds. Automatic control systems based on the use of position sensors and motor speed control devices are available for synchronizing the feed rates, but such systems are complicated and expensive, and require careful servicing.

The present invention solves the problem of ensuring registration between the caps and containers in high speed capping operations in an unexpectedly simple manner. This is achieved by advancing the caps at a slightly higher speed so that the containers, after application of the caps at the capping station, are advanced at said higher speed and thereby advanced in relation to the means by which they were fed to the capping station.

Thus, according to the invention, the containers and the caps in interconnected strip form are fed along respective feedpaths to a position at which the caps are applied to the containers in succession, the spacing of the caps being slightly greater than the spacing of the containers and the respective rates of feed being such as to ensure registration between each successive container and a respective cap at said position; thereafter the successive containers with applied caps are advanced from the capping position to a position at which the caps are severed from the strip.

A preferred apparatus for carrying out the method of the invention comprises:

AN ENDLESS BELT CONVEYOR HAVING A HORIZONTAL FORWARD RUN, SAID FORWARD RUN DEFINING A FIRST FEEDPATH;

THE CONVEYOR PROVIDING A SERIES OF EQUALLY SPACED POCKETS ADAPTED TO RECEIVE AND SUPPORT THE CONTAINERS;

CONTAINER DISPENSING MEANS MOUNTED ABOVE SAID FORWARD RUN FOR DISPENSING CONTAINERS INTO SAID POCKETS;

DRIVE MEANS CONNECTED TO THE ENDLESS BELT CONVEYOR FOR DRIVING THE CONVEYOR AT A FIRST RATE OF FEED WHEREBY TO ADVANCE THE CONTAINERS ALONG SAID FEEDPATH;

MEANS FOR ADVANCING A SUCCESSION OF CAPS IN INTERCONNECTED STRIP FORM ALONG A SECOND FEEDPATH HAVING A POINT OF REGISTER WITH THE FIRST;

CAPPING MEANS LOCATED AT SAID POINT OF REGISTER FOR APPLYING EACH SUCCESSIVE CAP TO A RESPECTIVE CONTAINER FED THERETO;

A HORIZONTAL RAMP MOUNTED BENEATH SAID FORWARD RUN, THE RAMP BEING ENGAGEABLE WITH THE BOTTOMS OF THE CONTAINERS IN ADVANCE OF THE POINT OF REGISTER FOR RAISING THE CONTAINERS WITHIN SAID POCKETS;

FEED MEANS LOCATED AFTER THE POINT OF REGISTER AND ENGAGEABLE WITH THE CONTAINERS AND APPLIED CAPS FOR ADVANCING SAME ALONG A HORIZONTAL FEEDPATH AT A SECOND RATE OF FEED GREATER THAN THE FIRST, AND

SEVERING MEANS SYNCHRONIZED WITH SAID FEED MEANS FOR SEVERING THE APPLIED CAPS FROM THE STRIP.

In order that the invention may be readily understood, one preferred embodiment thereof will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a general elevational view of the apparatus, the figure showing the manner in which the containers are dispensed, advanced, filled, capped and eventually discharged from the apparatus;

FIG. 2 is a section on line 2--2 in FIG. 1;

FIG. 3 is a section on line 3--3 in FIG. 1;

FIG. 4 illustrates a detail of one control mechanism by which a liquid dispensing mechanism for filling the containers may be controlled; and

FIG. 5 shows in section one of the filling nozzles of the liquid dispensing mechanism.

In the present example the containers to be filled and capped are individual portion cups 10 of frusto-conical shape, the cups 10 being dispensed four at a time from a cup dispenser 11 and filled from a liquid dispenser 12 as they are advanced. The apparatus comprises a frame structure 13 on which is mounted an endless belt conveyor 14 having a horizontal forward run. The conveyor 14 provides a series of equally spaced circular pockets 15 (FIG. 2) of such a size as to receive and support the cups. The conveyor 14 is supported at its ends by a drive sprocket 16 and an idler drum 17, respectively, the drive sprocket 16 being driven from an electric motor 27. The cup dispenser 11 and liquid dispenser 12 are reciprocated in the longitudinal direction of the conveyor 14, in synchronism with the conveyor drive. When the dispensers are at the rear extremity of their stroke, shown in chain-dotted lines in FIG. 1, four cups are released simultaneously from the cup dispenser 11 into the pockets 15. These cups are therefore advanced at the conveyor speed, the dispensers also being advanced at the same speed until they reach the forward extremity of their stroke, shown in full lines in FIG. 1. In this position the dispensing of liquid from the liquid dispenser 12 into the preceding cups has ceased; the dispensers 11 and 12 are returned to their rear position in which the cup dispenser is aligned with the next four empty pockets of the conveyor 14, and in which the four nozzles 18 of the liquid dispenser 12 are aligned with the cups that were dispensed in the previous cycle. As these cups are advanced the liquid dispenser 12 operates to fill them, being returned to the initial position once again at the end of the forward stroke. In this way the cups are dispensed and filled four at a time as the conveyor advances continuously without interruption.

A horizontal ramp 19, supported from the frame structure 13, is mounted beneath the forward run of the conveyor 14, the ramp having a downturned forward edge 20. The ramp 19 is so positioned as to be engageable with the bottoms of the cups 10 thereby to raise the latter within the pockets 15. It will be observed that when the cups are so raised there is a small clearance between each cup and the edge of the respective pocket, the raised cups therefore being pushed along the ramp 19 by the conveyor 14, rather than being carried and supported by the conveyor.

Up to the position at which the caps are applied to the cups, the cups 10 are advanced continuously at a first rate of feed, i.e. the rate of advance of the conveyor 14, the latter defining a first feedpath and the capping position representing a terminal location of the first feedpath as will now be described.

The caps to be applied to the cups are fed successively in interconnected strip form, the strip having been die-cut. The strip of interconnected caps is shown at 21 in FIG. 1. The strip 21 may be of the conventional form, having a thin layer of foil on one side and being pre-coated on that side with a hot-melt adhesive. The strip of interconnected caps is dispensed from a roll 22, passing over a drive sprocket 23, an idler 24, and under a heating means 25 by which each successive cap is applied and sealed to a respective one of the cups 10. As the cups 10 leave the ramp 19 they are supported in the raised position by means of an endless conveyor 26, the upper run of which is backed by a series of spring-loaded plates 28 so that the cups are urged into firm engagement with the caps. To ensure registration between the successive cups and caps at the capping position, that is, at the position of the heat-sealing means 25, without interfering with the continuous advance of the conveyor 14, the cups are in effect disengaged from the conveyor 14 at the capping position. This is achieved in the following way.

The spacing of the caps is slightly greater than the spacing of the pockets 15, the former spacing being typically 2 inches and the latter spacing being typically 1.994 inches. However, the drive sprocket 23, is geared to the motor 27 so as to be driven at a correspondingly higher speed, than the conveyor drive sprocket 16. Thus, in the case in which the cap spacing is 2 inches and the spacing of the pockets 15 is 1.994 inches, the strip 21 is advanced at a speed which is 0.3 percent higher than the speed of advance of the conveyor 14. In this way registration between the caps and the cups can be ensured. However, as soon as a cap is applied to a cup, the latter is advanced at the slightly higher speed, thus being displaced within the pocket 15 in which it is contained and so becoming disengaged from the conveyor.

A cooler 29 is positioned immediately after the heating means 25. After the capping position the advance of the cups with applied caps is controlled by means of an endless belt 30 which engages the top surface of the strip of caps, the cups being firmly held between this conveyor and the endless belt conveyor 26. The conveyor 26 and endless belt 30 are driven at the same speed from a common drive motor 32, the speed being such as to maintain the strip under slight tension. It is important that the tension in the strip should not be so great as to break the strip, and to prevent this from happening the driving torque from the motor 32 is applied through a slipping clutch 33, the clutch being preset so as to determine the tension in the strip.

Finally the applied caps are severed from the strip and are crimped onto the cups. In the present example this is achieved by a rotary multi-bladed knife 34 having a series of crimping pockets 35 and blades 36 between the pockets. The rotary knife is, of course, driven at the same speed as the drive sprocket 23. The separated cups are discharged from the conveyor 14 via a chute 37.

FIG. 4 illustrates diagrammatically one method by which the cup dispensing and liquid dispensing operations are controlled. In this example the dispensers 11 and 12 are reciprocated by a pneumatic motor 38 (FIG. 2) mounted on the frame structure 13, the operation of which is controlled by a pilot valve 39. The piston 40 of the valve 39 is connected to a crank lever 41, the latter engaging a rotary cam 42 which is driven from the motor 27. Thus the reciprocatory movement of the dispensers is determined by the speed of the conveyor 14. A control valve 43 for the liquid dispensing operation is also operated from the lever 41, the liquid being supplied from a reservoir (not shown) via ball valves 44, 45 to the dispensing nozzle 18. The motor 38 is governed so that on each forward movement the dispensers are advanced at the same speed as the cups which are being conveyed, and on each return movement are returned to the positions corresponding respectively to the next four pockets to receive cups and the next four cups to be filled.

FIG. 5 illustrates the form of a dispensing nozzle 18. This comprises a body 46 providing an upper chamber 47 connected to the main manifold of the liquid dispenser 12 by a pipe 48. The nozzle is controlled by a ball valve 49 which is biassed to the closed position by a spring 50, the purpose of this arrangement being to ensure a sharp cut off of liquid at the end of a dispensing operation.

In operation of the apparatus the cups 10 are fed in succession in equally spaced relation along a first feedpath, defined by the upper run of the conveyor 14, and at a first rate of feed corresponding to the conveyor speed. At the same time the interconnected strip of caps 21 is fed along a second feedpath at a second rate of feed, the strip being dispensed from the roll 22 and passing over the sprocket 23 and idler 24. As previously mentioned, the spacing of the caps is slightly larger than the spacing of the cups, and the rates of feed are such as to ensure registration between each successive cup and a respective cap at the capping position, which defines a terminal location of the first feedpath. The caps are applied successively, and thereafter the cups with the caps applied are advanced at the second rate of feed, thereby being disengaged from the conveyor 14, and the caps are severed from the interconnected strip as the cups are so advanced. At the same time the cup dispenser 11 and liquid dispenser 12 are reciprocated along said first feedpath, and at the commencement of each forward movement four cups are dispensed to the conveyor 14. During the forward movement a measured quantity of liquid is dispensed into each of the four cups that were dispensed at the commencement of the preceding cycle. Finally the dispensers are returned to the initial position for a repetition of the cycle, the dispenser 11 being brought into register with four empty pockets 15 and the dispenser 12 being brought into register with the next four cups to be filled.

Claims

What I claim as my invention is:

1. A method of capping containers which comprises

feeding a succession of containers in equally spaced relation along a first feedpath,

feeding a succession of caps in interconnected strip form in equally spaced relation along a second feedpath,

the spacing of the caps being slightly greater than the spacing of the containers and the respective rates of feed being such as to ensure registration between each successive container and a respective cap at a terminal location of the first feedpath,

applying the caps successively to the containers at said terminal location,

advancing the successive containers with applied caps at a uniform speed from said terminal location, and

while so advancing the containers, severing the caps from the strip.

2. A method of capping containers which comprises

feeding a succession of containers in equally spaced relation along a first feedpath at a first rate of feed,

feeding a succession of caps in interconnected strip form in equally spaced relation along a second feedpath at a second rate of feed,

the spacing of the caps being slightly greater than the spacing of the containers and the respective rates of feed being such as to ensure registration between each successive container and a respective cap at a terminal location of the first feedpath,

applying the caps successively to the containers at said terminal location,

advancing the successive containers with applied caps at said second rate of feed from said terminal location, and

while so advancing the containers, severing the caps from the strip.

3. A method according to claim 2, wherein the strip of interconnected caps is pre-coated on one side with hot-melt adhesive, said one side being brought into engagement with the containers and being heat-sealed thereto at said terminal location.

4. A method according to claim 2, which includes the addition steps of:

reciprocating a liquid dispensing means along said first feedpath,

dispensing a measured quantity of liquid from said means simultaneously into a plurality of containers during each forward motion of the dispensing means,

and returning the dispensing means at the end of each forward motion to a start position in register with a plurality of succeeding containers to be filled.

5. Apparatus for capping containers, comprising:

first conveyor means for feeding a succession of containers in equally spaced relation along a first feedpath at a first rate of feed,

means for advancing a succession of caps in interconnected strip form along a second feedpath having a point of register with the first,

means for applying each successive cap to a respective container at said point of register,

second conveyor means positioned adjacent to the point of register and engageable with said containers with applied caps, said second conveyor means being operable to disengage the containers from the first conveyor means and to advance the containers at a second rate of feed greater than the first,

and severing means synchronized with the second conveyor means for severing the applied caps from the strip.

6. Apparatus for capping cup-like containers of frusto-conical shape, comprising:

an endless belt conveyor having a horizontal forward run, said forward run defining a first feedpath,

the conveyor providing a series of equally spaced pockets adapted to receive and support the containers,

container dispensing means mounted above said forward run for dispensing containers into said pockets,

drive means connected to the endless belt conveyor for driving the conveyor at a first rate of feed whereby to advance the containers along said feedpath,

means for advancing a succession of caps in interconnected strip form along a second feedpath having a point of register with the first,

capping means located at said point of register for applying each successive cap to a respective container fed thereto,

a horizontal ramp mounted beneath said forward run, the ramp being engageable with the bottoms of the containers in advance of the point of register for raising the containers within said pockets,

feed means located after the point of register and engageable with the containers and applied caps for advancing same along a horizontal feedpath at a second rate of feed greater than the first, and

severing means synchronized with said feed means for severing the applied caps from the strip.

7. Apparatus according to claim 6, wherein said feed means comprises a lower belt conveyor having a forward run aligned with said ramp and engageable with the raised containers for supporting the containers in the raised position, an upper belt conveyor having a forward run aligned with said second feedpath, said lower and upper conveyors being spaced so that the containers with applied caps are engaged frictionally between their forward runs, and drive means connected to the upper conveyor for driving the latter at said second rate of feed.

8. Apparatus according to claim 7, including a liquid dispensing device having a plurality of dispensing nozzles aligned along said first feed path, means for reciprocating said device along said first feedpath, said reciprocating means being synchronized with said endless belt conveyor for moving the device at said first rate of feed on each forward and return motion, and means for dispensing a measured quantity of liquid from said device simultaneously into each of a plurality of containers on each forward motion of the device.

9. Apparatus according to claim 7, wherein said means for advancing a succession of caps comprises a pay out reel for dispensing the caps in interconnected strip form, a driven sprocket engageable with the interconnected caps as they are dispensed, and guide means for guiding the strip to the capping means at said point of register.

10. Apparatus according to claim 9, wherein said severing means comprises a rotary multi-bladed knife combined with a crimper for crimping the edges of the caps onto the containers.