US3020691A

US3020691A - Carton-closing machines

Info

Publication number: US3020691A
Application number: US27436A
Authority: US
Inventors: Oxborrow Bernard Hewlett
Original assignee: Metal Box PLC
Current assignee: Crown Packaging UK Ltd
Priority date: 1959-08-07
Filing date: 1960-05-06
Publication date: 1962-02-13
Anticipated expiration: 1979-02-13

Description

Feb. 13, 1962 Filed May 6, 1960 B. H. OXBORROW 3,020,691

CARTON-CLOSING MACHINES 5 Sheets-Sheet 1 Inventor BERNARD H. OXBDRROW Feb. 13, 1962 B. H. OXBORROW 3,020,691

CARTON-CLOSING MACHINES Filed May 6, 1960 5 Sheets-Sheet 2 ln v entor BER NARD H- OXB RROV BW M Attorneys Feb. 13, 19 B. H. OXBORROW 3,020,691

CARTON-CLOSING MACHINES Filed May 6, 1960 s Sheets-Sheet s Inventor BERNARD 'H. OXBO RR OW A ttorney Feb. 13, 1962 B. H. oxBoRRow 3,020,691

CARTON-CLOSING MACHINES Filed May 6, 1960 5 Sheets-Sheet 4 Invenlor I BERNARD H. axsoRRoW A ttorn e 53 Feb. 13, 1962 B. H. OXBORROW 3,020,691

CARTON-CLOSING MACHINES Filed May 6, 1960 5 Sheets-Sheet 5 Inventor BERNARD H. 0X BoRRow A ttorneys Stats This invention relates to carton-closing machines and in particular to a machine for closing a carton having a lid hinged to the back of the carton body and side and front lid flaps to be engaged with the sides and front of the body and secured thereto by heat-sealing,

It is a main object of the present invention to provide a machine for closing cartons of the kind mentioned above the machine being so constructed as to ensure that the carton remains in the machine for an interval of time which ensures adherence of the parts of the carton which are to be secured in the machine while providing a machine of relatively small compass and which is capable of effecting closing of cartons at a relatively high rate.

According to the invention there is provided for closing a carton having a lid hinged to the back of the carton body and side and front lid flaps to be engaged. with the sides and front of the body and secured thereto by heat-sealing, said machine comprising first conveyor means arranged to move cartons in succession along a horizontal path while folder means cause the lids of the cartons to overlie the bodies thereof, and second conveyor means arranged to receive cartons from the first conveyor means and to move them in succession in a vertical path to a discharge position and through sealing means arranged to effect engagement of the side and front lid flaps with the carton bodies, to apply heat to the lid flaps, and to effect cooling of the cartons before they reach the discharge position.

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

FIG. 1 illustrates a carton to be closed by the machine according to the invention,

FIGS. 2A and 23 together are a side elevation of a machine according to the invention,

FIG. 3 illustrates to an enlarged scale a part of the machine shown in FIG. 2B,

FIGS. 4A and 43 together are a section on line IV-IV, FIG. 2A,

FIG. 5 illustrates to an enlarged scale a part of a first conveyor means,

PEG. 6 is a section on line VIVI, FIG. 2A, and

FIG. 7 is a section on line VIIVII, FIG. 2A. Referring to FIG. 1, the carton therein disclosed is made from a cardboard blank the opposite sides of which are gloss-waxed by the application to the whole area of the blank of a coating of low viscosity parafiin wax. The carton comprises a body portion having a rectangular four-sided bottom 1, side walls 2, 3, a front wall 4, and a rear wall 5. To the rear wall 5 there is hinged a lid 6 having side lid flaps '7, 8 and a front lid flap 9. The inner surfaces of the flaps 7, 6 and 9 are coated with a thermoplastic adhesive composition indicated by the reference It), this composition being applied to the flaps beneath the paraffin wax mentioned above. The thermoplastic adhesive composition is a composition which is incompatible with the Wax, is non-tacky at normal temperatures and is softened at a temperature higher than the melting temperature of the wax. The softening temperature of the adhesive composition is preferably appreciably above the melting temperature of the wax, the difierence being, for example of the order of 20 C.

One suitable form of thermoplastic adhesive composition is a polyvinyl acetate resin having incorporated therein plasticizers which render it heat-scalable but non-tacky at normal temperatures when applied to a blank as illustrated in the drawings.

It is to be understood that although the invention is being described with particular reference to a carton coated with wax as just described a machine according to the invention can be employed with other forms of heat-sealed cartons, for example with a carton one side of which is coated with a thermoplastic coating such as polythene.

Following insertion of the contents thereinto, the cartons are received by a first conveyor means arranged to move them in succession along a horizontal path while folding means cause the lids of the cartons to overlie the bodies thereof. The first conveyor means comprises endless chains 11, FIGS. 2A and 5, driven from an electric motor 12, FIG. 2A, through chains 13 and 14 and an intermediate shaft 15. The chains 11 are provided with a plurality of equi-spaced pusher elements 16, FIG. 5, which are pivoted at 17 to the chains. Bars 18 are secured to and extend between the chains 11 and a spring 19 is anchored beneath the pusher element and to a bracket Zil secured to a bar 13, the spring acting to urge the pusher element to the carton-engaging position thereof shown in FIG. 5.

The cartons received by the first conveyor means are moved thereby between side guides 21, FIGS. 4A and 4B, which extend lengthwise of the path of the conveyor means and a stationary plough folder 22, FIG, 4A of known construction causes the lids of the cartons to overlie the bodies thereof. The cartons in this condition are moved by the first conveyor means against a stop 23, FIG. 4B, by which they are located in the path of second conveyor means arranged to receive the cartons and to move them in succession in a vertical path to a discharge position and through sealing means arranged to eiiect engagement of the side and front lid flaps 7, 8, 9, with the sides 2, 3 and front 4 of the body, to apply heat to the lid flaps, and to effect cooling of the cartons before they reach the discharge position.

The second conveyor means comprises an endless chain 24 driven from the shaft 15 through

bevel gears

25, 26, FIG. 4B, and a plurality of equi-spaced carton-engaging elements 27 which are arranged in pairs and attached to the chain 24 to engage the bottoms of cartons while moving them through the sealing means. The cartonengaging elements extend outwards from plates 28 which are pivoted at 29 to the chain 24 and are urged by springs 36 FIG. 3, to the positions thereof at which the elements 27 engage the bottom of a carton during movement thereof through the sealing means.

Just after a carton is engaged by the second conveyor means, it is moved vertically upwards thereby into engagement with the folding means which cause the lid flaps to be engaged with the sides and front of the body and in the embodiment of the invention shown in the drawings these folder means are comprised by guide elements consisting of rounded lower ends R, FIG. 2A, of the sides of the heating chamber. The heating chamber is a vertically disposed chamber having three

sides

32, 33, 34, FIG. 6, of which

sides

32 and 34 engage the lid flaps 7, 8 and the side 33 engages the lip flap 9. Heating of the

walls

32, 33, 34 may be effected in any suitable manner, but in the preferred embodiment of the invention, the heated sides of the heating chamber embody electric resistance heater elements 35 adapted in any suitable manner for connection with a source of electric potential. The length of the heating chamber is determined by the extent of the heating afforded thereby and the time necessary to effect adherence between the lid flaps and the sides and front of the body by softening of the thermoplastic adhesive, for example if 150 cartons per minute are being moved through the heating chamber the length of the heating chamber is of the order of 40 inches, each carton remaining in the heating chamber for approximately four seconds.

As the second conveyor means moves the carton out of the heating chamber it moves the carton immediately into a cooling chamber having three

walls

36, 37, 38, FIG. 7, which are provided with

conduits

39, 40, 41 to permit cooling of the walls by a cooling fluid. The cooling fluid is preferably cold water passed through the cooling chamber walls from a main supply. Water is admitted to the conduits by inflow pipes 42 and flows out of the conduits through outflow pipes 43. The length of the cooling chamber is also determined by the time required to effect eflicient cooling of the cartons and if the heating chamber is constructed according to the example given above, to accommodate the closing of cartons at the rate of about 150 per minute, the length of the cooling chamber is of the order of 20 inches so that each carton remains in the cooling chamber for approximately two seconds.

As the cartons are moved out of the cooling chamber by the second conveyor means they are delivered to the discharge position at which they are moved laterally from the second conveyor means in any desired manner. In the machine illustrated in the drawings the cartons are moved laterally from the carton-engaging elements by rocking of the carton-engaging elements 27 about their pivots 29 so that the cartons are discharged by gravity laterally into a chute 44, FIGS. 2A, 2B, and 3, down which the cartons slide by gravity to be received by a discharge conveyor 45, FIG. 2B, so located relative to the lower end of the chute that the cartons delivered from the chute pass over a guide 46 and on to the conveyor 45 which moves then away from the chute.

Rocking of the carton-engaging elements 27 about their pivots 29 is efiected by a stationary cam 47 which engages a projection on a plate 28 to effect rocking thereof as illustrated in FIG. 3. The carton-engaging elements 27 are constrained against rocking movement about their pivots 29 while they are moving cartons through the heating and cooling chambers due to the plates 28 then being engaged by vertical guides 48. The chute 44 is supported relative to the vertical heating and cooling chambers by bracing elements 49, FIG. 2B.

I claim:

1. A machine for closing a carton having a lid hinged to the back of the carton body and side and front lid flaps to be engaged with the sides and front of the body and secured thereto by a thermoplastic adhesive, comprising first conveyor means to move the cartons in succession along a horizontal path, folder means operable to cause the lids of the cartons to overlie the bodies thereof while the cartons are moved by the first conveyor means, second conveyor means arranged to receive cartons from the first conveyor means to move them in succession in a vertical path to a discharge position, and sealing means disposed along said vertical path and operable to effect engagement of the side and front lid flaps with the carton bodies, to apply heat to the lid flaps, and means to effect cooling of the cartons before they reach the discharge position.

2. A machine for closing a carton having a lid hinged to the back of the carton body and side and front lid flaps to be engaged with the sides and front of the body and secured thereto by a thermoplastic adhesive, comprising first conveyor means arranged to move cartons in succession along a horizontal path, folder means operable to cause the lids of the cartons to overlie the bodies thereof while the cartons are moved by the first conveyor means, second conveyor means arranged to receive cartons from the first conveyor means and to move them in succession in a vertical path to a discharge position, said first conveyor means including an endless chain conveyor and a plurality of equi-spaced pusher elements pivotally connected to the chain conveyor and spring-urged to carton-engaging positions, and each being rockable about the pivot for disengagement from a carton moved thereby into the path of the second conveyor means, and sealing means disposed along said vertical path and operable to effect engagement of the side and front lid flaps with the carton bodies and to apply heat to the lid flaps, and means to effect cooling of the cartons before they reach the discharge position.

3. A machine for closing a carton having a lid hinged to the back of the carton body and side and front lid flaps to be engaged with the sides and front of the body and secured thereto by a thermoplastic adhesive, comprising first conveyor means to move cartons in succession along a horizontal path, folder means operable to cause the lids of the cartons to overlie the bodies thereof while the cartons are moved by the first conveyor means, second conveyor means arranged to receive cartons from the first conveyor means to move them in succession in a vertical path to a discharge position, a vertically disposed heating chamber, a vertically disposed cooling chamber aligned with the heating chamber and including cooled walls to engage the side and front lid flaps of a carton after movement thereof through the heating chamber, and guide elements interposed in the path of a carton being moved by the second conveyor means and operable to move the side and front lid flaps of the carton into engagement with the sides and front of the carton body and to retain said engagement until the engaged flaps are moved by the second conveyor means into contact with heated sides of the heating chamber.

4. A machine according to claim 3, wherein the guide elements are integral with the heated sides of the heating chamber.

5. A machine according to claim 3, wherein the heated sides of the heating chamber embody electric resistance heater elements.

6. A machine according to claim 3, wherein the cooled walls of the cooling chamber are cooled by a cooling fluid.

7. A machine according to claim 6, wherein the cooled walls are provided with conduits connectable with inflow and outflow pipes to permit the flow of cold water therethrough.

8. A machine according to claim 3, wherein the second conveyor means comprises an endless chain having a plurality of equi-spaced carton-engaging elements at tached thereto to engage the bottoms of cartons While moving them through the sealing means.

9. A machine according to claim 8, including discharge means operable to effect lateral movement of a carton from a carton-engaging element at the discharge position.

10. A machine for closing a carton having a lid hinged to the back of the carton body and side and front lid ifiaps to be engaged with the sides and front of the body and secured thereto by a thermoplastic adhesive, comprising first conveyor means to move cartons in succession along a horizontal path, folder means operable to cause the the lids of the carton to overlie the bodies thereof while the cartons are moved by the first conveyor means, second conveyor means arranged to receive cartons from the first conveyor means and to move them in succession in a vertical path to a discharge position, said second conveyor means including an endless chain, a plurality of equi-spaced carton-engaging elements pivoted to said chain each to engage the bottom of a carton while moving in said vertical path, and for each said element a spring operating to urge the element to the carton-engaging position thereof, a vertically disposed heating chamber, a vertically disposed cooling chamber aligned with the heating chamber and including cooled walls to engage the side and front lid flaps of a carton after movement thereof through the heating chamber, and guide elements interposed in the path of a carton being moved by the second conveyor means and operable to move the side and front lid flaps of the carton into engagement with the sides and front of the carton body and to retain said engagement until the engaged flaps are moved by the second conveyor means into contact with heated sides of the heating chamber.

11. A machine according to claim 10, including a cam located at said discharge position and engageable with each carton-engaging element to effect rocking thereof about the pivot therefor against the action of its spring to a position at which a carton resting on said element slides laterally therefrom.

12. A machine according to claim 11, including a chute to receive cartons discharged from the carton-engaging elements.

13. A machine according to claim 12, including a discharge conveyor so located relative to the lower end of the chute as to receive cartons therefrom and to convey them away from the chute.

14. A machine for closing a carton having a lid hinged to the back of the carton body and side and front lid flaps to be engaged with the sides and front of the body and secured thereto by a thermo-plastic adhesive, com prising a first endless chain conveyor, movable in a horizontal plane, a plurality of equispaced pusher elements pivotally connected to the chain conveyor and spring-urged to the carton-engaging positions thereof, folder means operable to cause the lid of a carton to overlie the body thereof while the carton is moved by one of the pusher elements, a second endless chain conveyor movable in a vertical path, a plurality of equispaced carton-engaging elements pivoted to said second 6 W endless chain conveyor each to engage the bottom of a carton delivered thereto by one of said pusher elements, a spring for each carton-engaging element operating to urge the element to a carton engaging position thereof, a heating chamber having heated walls and a cooling chamber having cooled walls located in succession about the vertical path of the second endless chain conveyor, and guide elements interposed in the path of a carton resting on a carton-engaging element and operable to move the side and front lid flaps of the carton into engagement with the sides and front of the carton body and to retain said engagement until the engaged flaps are moved by the carton-engaging element into contact with the heated sides of the heating chamber.

15. A machine according to claim 14, including a cam located on the outlet side of the cooling chamber and engageable with each carton-engaging element to effect rocking thereof about the pivot therefor against the action of its spring to a position at which a carton resting on said element slides laterally therefrom.

r16. A machine according to claim 15, including a chute to receive cartons discharged from the cartonengaging elements.

'17. A machine according to claim 16, including a discharge conveyor so located relative to the lower end of the chute as to receive cartons therefrom and to convey them away from the chute.

References Cited in the file of this patent UNITED STATES PATENTS 1,924,045 Molins et a1 Aug. 22, 1933 2,420,763 Wells May 20, 1947 2,904,941 Midnight Sept. 22, 1949