CA1161611A - Process and apparatus for production of bottle caps with tear strips - Google Patents
Process and apparatus for production of bottle caps with tear stripsInfo
- Publication number
- CA1161611A CA1161611A CA000399618A CA399618A CA1161611A CA 1161611 A CA1161611 A CA 1161611A CA 000399618 A CA000399618 A CA 000399618A CA 399618 A CA399618 A CA 399618A CA 1161611 A CA1161611 A CA 1161611A
- Authority
- CA
- Canada
- Prior art keywords
- cap
- caps
- station
- spindle
- tear strip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
- B26D3/00—Cutting work characterised by the nature of the cut made; Apparatus therefor
- B26D3/08—Making a superficial cut in the surface of the work without removal of material, e.g. scoring, incising
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
- B26F3/00—Severing by means other than cutting; Apparatus therefor
- B26F3/06—Severing by using heat
- B26F3/08—Severing by using heat with heated members
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
- B26F2210/00—Perforating, punching, cutting-out, stamping-out, severing by means other than cutting of specific products
- B26F2210/04—Making plastic pilferproof screw caps by cutting a tamper ring
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Forests & Forestry (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Closures For Containers (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process and apparatus is described for the production of caps or so-called overcaps particularly for wine bottles, of the type having a tear strip for separating an end portion of the cap from the skirt. In accordance with the invention, caps are first injection molded, and are then passed to a multi-spindle machine which receives the caps on rotatable spindles, and which successively pierces the end of each cap to form perforations, prints the skirt portion of the cap, and then cuts the tear strip in the cylindrical wall of the cap. The tear strip is cut by a special knife having cutting edges which are spaced apart by an amount equivalent to the tear strip width, the cutting edges having a part circular sickle shape so as to contact the cylindrical wall of a cap and to form parallel lines of weakness therein while the cap moves between two stations of the rotary head machine. The major portions of the cutting edges are serrated, hut adjacent ends of the knife edges have a connecting portion which is unserrated and is arranged to cut through the cylindrical walls to form an outer end of the tear strip.
A process and apparatus is described for the production of caps or so-called overcaps particularly for wine bottles, of the type having a tear strip for separating an end portion of the cap from the skirt. In accordance with the invention, caps are first injection molded, and are then passed to a multi-spindle machine which receives the caps on rotatable spindles, and which successively pierces the end of each cap to form perforations, prints the skirt portion of the cap, and then cuts the tear strip in the cylindrical wall of the cap. The tear strip is cut by a special knife having cutting edges which are spaced apart by an amount equivalent to the tear strip width, the cutting edges having a part circular sickle shape so as to contact the cylindrical wall of a cap and to form parallel lines of weakness therein while the cap moves between two stations of the rotary head machine. The major portions of the cutting edges are serrated, hut adjacent ends of the knife edges have a connecting portion which is unserrated and is arranged to cut through the cylindrical walls to form an outer end of the tear strip.
Description
L6~
The present lnvention relates to the production of tamper-proof caps for containers and more particularly to so-called over-caps for wine bottles which eover the end of the neck portion of the bottle and prevent tampering with the cork while also keeping the cork area clean.
A eap of this kind usually has an end portion or top connected to a flange or skirt by a tear strip which surrounds the cap, and which allows the end portion to be removed when the tear strip is torn away. The end portion is preferably perforated to ensure that the cork can breathe.
While in the past such caps were usually made of metal, nowadays such caps may be formed of synthetic plastics material, by injection molding. Canadian Patent No. ~15,366, whieh issued ~ 17, 1969 to Marcel, shows an injection mold for molding a plastic eap with a tear strip. However, even if the tear strip is formed while the cap is being molded, it is still likely to be necessary to perform additional operations on the cap, such as printing the cap with a design.
Furthermore, it is considered unsatisfactory to perforate the end portlon of the cap simultaneously with the injection molding step because pins forming such perforations may interfere with plastic flow, and because possible flash formation around the perforations may make it impossible for the cork to breathe.
In accordance with one aspect of the invention, in a process for making an injection molded plastic cap of the type described, the operation of forming the tear strip is performed in a machine which is separate from the injection molding machine and which mav also be used for piercing the end portion of the Cap and/or for printing of the cap.
~ore specifically in accordance with the invention, a process for making a plastic eap of the type described comprises the steps of injeetion molding a cap having an 6:~
imperforate end portion and a skirt (but wi-thout a tear strip), conveying the injection molded caps to a machine having a rotary head carrying a series of rotatable spindles which are sized to recei~e the caps, and loading each cap onto a spindle of the machine while that spindle is at a loading station. Each cap is then indexed from the loading station to a piercing station where the end portion is pierced to provide the required perforations. The cap is then further indexed from the piercing station, past a printing station if required, and towards an unloading station, and while the cap passes in orbital manner towards the unloading station it is cut with a heated, double-edged knife so arranged as to form parallel lines of weakness deEining a tear strip~
In accordance with another aspect of the invention, a machine for use in the production of plastic caps of the type described has a rotary indexing head carrying a series of rotatable spindles sized to receive the caps, the machine having a loading station with means for loading caps onto a spindle at the loading station, and an unloading station with means for removing the caps from spindles at the unloading station, and one or more intermediate stations suitable for example for piercing or printing between said loading and unloading stations. A double-edged knife is situated so as to contact the cylindrical surfaces of caps passing between the loading and unloading stations, the knife having two cutting edges which are spaced apart along the axis of the cap to form lines of weakness defining the tear strip, the cutting edges having a part circular sickle shape and being of suitable length to maintain contact with the cylindrical surface of the cap while causing the cap to rotate through substantially one revolution. Adjacent ends of said cutting edges have a connecting portion which is arranged to cut through the thickness of the cap material and thus to form an outer cut end of the tear strip.
The knife is preferably heated by a thermostatically controlled electrical resistance heater.
The invention will be described in more detail with reference to the accompanying drawings, in which:-Figure 1 is a view, partially sectioned, of the cap which is produced in accordance with this invention;
Figure 2 is a diagrammatic elevation of the rotary head of the machine with associated conveyors, printing mechanism, and knife;
Figure 3 is a diagrammatic plan view of the main components of the machine, with the printing mechanism removed for clarity;
Figure 4~ which with Figures 5 to 7 appears on the same drawing sheet as Fig. 1, is a partly sectioned view oE
the piercer device;
Figure 5 is a front elevational view of the knife which forms the tear strip;
Figure 6 is a sectional view on lines 5-5 of Figure 4; and Figure 7 is a view on lines 7-7 of the lower end of the knife.
As seen in Figure 1, the cap comprises an end portion 1 connected to a skirt by a tear strip 3. The majority of the length of the tear strip is defined by two parallel rows of short narrow slits which penetrate through the majority but not necessarlly the whole thickness oE the sidewall, and form lines which can easily be torn. The end portion 3a of the tear strip which extends perhaps 1 centimeter is formed by cuts which do penetrate completely through the wall of the cap, and due to the resiliency of the material there is a tendency for the outer end of portion 3a to flex Itwardly sli~htl~ from the surface of the cap so that this can easily be grasped. The cap additionally has a band 5 of enlarged diameter which is adjacent the ~ear strip, and the main section of the skirt adjacent the ban~ 5 has wedge shaped projections 6 designed so that the cap can be pushed onto the neck of a wine bottle and the projections ~ will snap past a bead at the end of the neck and hold the cap onto the neck. The cap is preferably printed with a design such as that indicated at 8, and which may identify the wineO
The cap also has perforations la formed in the end portion 1, which allows the cork to breathe.
The cap is formed with all the items shown excep-t the perforations la, the tear strip 3, and the printed design 8, in an injection molding machine which is not part of the present invention. The caps are taken from the injection molding machine and loaded onto a feed conveyor 10 shown in Figures 2 and 3. This conveyor has two sprocket chains which hold between them a series ofrollers 11 in pairs, each spaced pa.ir of rollers rotatably supporting one of the caps as indicated in Figures 2 and 3. While moving along the conveyor, the caps are heated by a gas flame heating device 12 which heats the caps by a gas flame while simultaneously rotating the caps to ensure evennessof heating.
Rotation is achieved by pushing the caps by means of a rotatable pusher against a rotating disk aligned with the conveyor, while the conveyor is stationary for a short time interval. The gas heater is similar to heating devices existing on other machines and is not a part of the present invention.
The conveyor 10 feeds the caps step by step towards the loading station A of a multi-spindle turret machine, which is basically a printing machine of the type S ~
.~ sold under the trade mark orqso and identiied as ~&~0 Automatic Screen Printing Machine Model.R5-30H.
The mach.ine has a rotary head lS
a~ --carrying six spindles 16 which project parallel to the rotational axis of the head, and the head has an indexing mechanism of well known type which rotates it in steps of 60 to move the spindles between successive stations A, s, C, D, E, and F. Of these stations:-A is the loading station;
B is the piercing station for forming perforations la;
C is the printing or paint applying station forapplying the patt~rn 8;
E is the unloading station. While no operation is performed at station D, between stations D and E the tear strip 3 is cut by a knife to be described. At station F the spindle is empty~
The spindles 16 each include a stem 16a projecting out of the head 15, and a freely rotatable sleeve 16b which is of slightly larger diameter than the stem and which is a snug fit within the ski.rt 2 of the cap. At the outer end of the spindle there is a gap between the rotatable sleeve and the stem to accommodate piercing pins which will be described with reference to Figure 4.
The loading station A, as indicated, includes an end of the conveyor 10 which brings a cap into alignmenk with a spindle 16. The station also includes a pusher bar which is not shown but which is a metal cylinder carried by the piston rod of air cyl.inder 1~ shown in Figure 3. Air cylinder 18 is operated automatically to push the cap onto the spindle : at station A.
- Station B includes the piercer shown in detail in Figure 4, and which is aligned with the cap when in station B. The piercer includes a bushing 20 slidable on a co--axial rod 22 ~7hich forms the piston rod of an air cylinder 24, cylinder 24 being mounted above cylinder 18 by an upper bracket 26. Fixed to the piston rod 22 is a collar 28, and a compression spring 30 acts hetween the collar 28 and the bushing 20. The bushing 20 has socket 32 which is dimellsioned to contact the outer corners of the cap, and this leads to a recess 33 in which is movable a plate 34 fixed to the outer end of rod 22. At its periphery, the plate 34 carries four piercing pins 36 which are arranged so that they can move in between the space between the stem 16a and sleeve 16b of a spindle, piercing the end portion of a cap to provide the perforations la., The spring loaded bushing holds the cap firmly on the spindle while the piercing is performed and e-specially while the piercing pins are withdrawn from the cap.
In the next station C the cap is printed with the pattern 8 by printing means of known form, being for example similar to printing means for cans. The printing '~ means includes a paint tray 40 carried by a carriage 42 which is reciprocable on shafts 44 so as to move horizontally in contact with the cap as this rotates on the spindle. Also indicated in Figure 2 are a paint applicator 46 which serves ; to push paint through the screen in the bottom of paint tray 40 as the tray moves across the cap, and a screen cleaner 48 which acts to clean the screen while the paint tray moves in the opposite direction.
,' While in station C, and also in station D, the cap is held on the spindle by means of a curved retaining bar 50 held by a bracket 52.
Between the stations D and E the tear strip 3 is cut by knife 60 which is part of knife fixture 62 which is the central feature of this invention.
The knife fixture includes a support member 64 fixed to the face plate of the machine and having a machined under-6-~
side surface. Held against this undersurface is an adjustable support 66 which has a machined surface 67 parallel to the face plate of the machine. The fore and aft position of the adjustable support 66 can be adjusted by knob 68 which rotates a threaded rod to move lug 69, fixed to support 66, relative to the fixed support 64. Against surface 67 is held a knife assembly 70, which is similarly adjustable along this surface by knob 72. The position of the knife radially and axially relative to the spindle moving in between stations D and E can be adjusted by knobs 68 and 72.
The knife assembly 70 is shown in Figures 5 and 6.
This includes a solid metal back plate 74 having a recess for the knife 60, and an electrical heater bar 76 which is firmly clamped onto the front surEace of the knife by screws 78. Bar 76 includes a thermostatically controlled electrical resistant heater which maintains the knife between 160 and 180F.
The knife 60 is a solid piece of tool steel having ~1 sickle shaped blade cut to a circular arc corresponding to the radius of the outermost surface of the main skirt - portions of caps held by the spindles, relative to the center of rotary head 15. As seen in Figure 6 and 7 the knife is formed with two cutting edges 60a, 60b by having a groove cut in its curved edge, the groove extending along the majority of the length of the curved edge but termina-ting in a curved end just short of the lower end of the knife. The cutting edges are formed by grinding the outer lands of the groove so that they form sharp edges with the straight inner sides oE the grooves. Additionally/ the main length of the cutting edges are serrated so that these are interrupted at intervals of about 1/10 of an inch. An unserrated, ~J-shaped connecting portion 60' connects the lower ends of the serrated cutting edges; portion 60' is designed to cut completely through the cap wall.
~ ~3L6~
The knife is shaped and arranged so that the upper ends of the two cutting edges contact the cylindrical surface of the cap adjacent the end portion 1, just as this leaves the station D. The cap is then rolled in contact with the cutting edges which maintain the position of the cap on the spindle so that the retainer bar 50 is not needed to hold the cap once the knife has made contact. The main part of the knife makes a series of elongated slits in the plastic, through a large portion at least of the thickness of the plastic, these slits being connected by uncut portions to provide parallel lines of weakness. The length of the knife blade is slightly greater than the circumference of the cap so that there is some overlap between the cuts formed by the upper end of the blade, and the end portion 3a which is completely severed from the cap by the U-shaped portion 60a of the blade.
" Upon reaching station E the cap is removed from the spindle by an unloader indicated at 80 in Figure 3, and which includes a cylinder 82 mounted on the piston rod 83 of an air cylinder 84 and which has at its outer end a - suetion cup 86 connected via a central bore in the piston rod to a source of vaeuum which is connected to an end 83a of the piston rod projecti~ng from the rear end of cylinder 84. This unloader arrangement, which is known per se, applies vaeuum to the suction cup 86 when this is pressed against the end of the cap, and the cylinder 84 is operated to pull ~- the cap from the spindle, at which point suction is released and the cap drops into a cup 90 of an unload conveyor 91.
The unload conveyor 91 which again is known per se, comprises two sprocket chains 92 connected by bars 94 carrying the cups 90, the sprocketchains being moved in timed relation to the machine movements so that each cup recei~es one finishecL cap.
All of the operations of the machine are sequenced automatically. Thus, the feed conveyor 10 and the off-load conveyor 91 move in timed relation to the indexed movement of the rotary head 15. Also, the movementsof the loader, the piercer, the printing device, and the unloader ~0 are all timed in relation to movements of the rotary head, so that these operations take place while the rotary head is stationary.
It will be seen that the invention provides a simple way of cutting a tear strip in a plastic cap when the cap is required to undergo operations on a multi-spindle type machine, and the nature of the other operations being performed can of course be varied.
It will be understood that the nature of the lines of weakness produced by the knife may he varied; for example these may be formed by a series of indentations or cuts (slits), or may be an uninterrupted score line. Only at the end portion 3a are complete through-cuts desirable.
The present lnvention relates to the production of tamper-proof caps for containers and more particularly to so-called over-caps for wine bottles which eover the end of the neck portion of the bottle and prevent tampering with the cork while also keeping the cork area clean.
A eap of this kind usually has an end portion or top connected to a flange or skirt by a tear strip which surrounds the cap, and which allows the end portion to be removed when the tear strip is torn away. The end portion is preferably perforated to ensure that the cork can breathe.
While in the past such caps were usually made of metal, nowadays such caps may be formed of synthetic plastics material, by injection molding. Canadian Patent No. ~15,366, whieh issued ~ 17, 1969 to Marcel, shows an injection mold for molding a plastic eap with a tear strip. However, even if the tear strip is formed while the cap is being molded, it is still likely to be necessary to perform additional operations on the cap, such as printing the cap with a design.
Furthermore, it is considered unsatisfactory to perforate the end portlon of the cap simultaneously with the injection molding step because pins forming such perforations may interfere with plastic flow, and because possible flash formation around the perforations may make it impossible for the cork to breathe.
In accordance with one aspect of the invention, in a process for making an injection molded plastic cap of the type described, the operation of forming the tear strip is performed in a machine which is separate from the injection molding machine and which mav also be used for piercing the end portion of the Cap and/or for printing of the cap.
~ore specifically in accordance with the invention, a process for making a plastic eap of the type described comprises the steps of injeetion molding a cap having an 6:~
imperforate end portion and a skirt (but wi-thout a tear strip), conveying the injection molded caps to a machine having a rotary head carrying a series of rotatable spindles which are sized to recei~e the caps, and loading each cap onto a spindle of the machine while that spindle is at a loading station. Each cap is then indexed from the loading station to a piercing station where the end portion is pierced to provide the required perforations. The cap is then further indexed from the piercing station, past a printing station if required, and towards an unloading station, and while the cap passes in orbital manner towards the unloading station it is cut with a heated, double-edged knife so arranged as to form parallel lines of weakness deEining a tear strip~
In accordance with another aspect of the invention, a machine for use in the production of plastic caps of the type described has a rotary indexing head carrying a series of rotatable spindles sized to receive the caps, the machine having a loading station with means for loading caps onto a spindle at the loading station, and an unloading station with means for removing the caps from spindles at the unloading station, and one or more intermediate stations suitable for example for piercing or printing between said loading and unloading stations. A double-edged knife is situated so as to contact the cylindrical surfaces of caps passing between the loading and unloading stations, the knife having two cutting edges which are spaced apart along the axis of the cap to form lines of weakness defining the tear strip, the cutting edges having a part circular sickle shape and being of suitable length to maintain contact with the cylindrical surface of the cap while causing the cap to rotate through substantially one revolution. Adjacent ends of said cutting edges have a connecting portion which is arranged to cut through the thickness of the cap material and thus to form an outer cut end of the tear strip.
The knife is preferably heated by a thermostatically controlled electrical resistance heater.
The invention will be described in more detail with reference to the accompanying drawings, in which:-Figure 1 is a view, partially sectioned, of the cap which is produced in accordance with this invention;
Figure 2 is a diagrammatic elevation of the rotary head of the machine with associated conveyors, printing mechanism, and knife;
Figure 3 is a diagrammatic plan view of the main components of the machine, with the printing mechanism removed for clarity;
Figure 4~ which with Figures 5 to 7 appears on the same drawing sheet as Fig. 1, is a partly sectioned view oE
the piercer device;
Figure 5 is a front elevational view of the knife which forms the tear strip;
Figure 6 is a sectional view on lines 5-5 of Figure 4; and Figure 7 is a view on lines 7-7 of the lower end of the knife.
As seen in Figure 1, the cap comprises an end portion 1 connected to a skirt by a tear strip 3. The majority of the length of the tear strip is defined by two parallel rows of short narrow slits which penetrate through the majority but not necessarlly the whole thickness oE the sidewall, and form lines which can easily be torn. The end portion 3a of the tear strip which extends perhaps 1 centimeter is formed by cuts which do penetrate completely through the wall of the cap, and due to the resiliency of the material there is a tendency for the outer end of portion 3a to flex Itwardly sli~htl~ from the surface of the cap so that this can easily be grasped. The cap additionally has a band 5 of enlarged diameter which is adjacent the ~ear strip, and the main section of the skirt adjacent the ban~ 5 has wedge shaped projections 6 designed so that the cap can be pushed onto the neck of a wine bottle and the projections ~ will snap past a bead at the end of the neck and hold the cap onto the neck. The cap is preferably printed with a design such as that indicated at 8, and which may identify the wineO
The cap also has perforations la formed in the end portion 1, which allows the cork to breathe.
The cap is formed with all the items shown excep-t the perforations la, the tear strip 3, and the printed design 8, in an injection molding machine which is not part of the present invention. The caps are taken from the injection molding machine and loaded onto a feed conveyor 10 shown in Figures 2 and 3. This conveyor has two sprocket chains which hold between them a series ofrollers 11 in pairs, each spaced pa.ir of rollers rotatably supporting one of the caps as indicated in Figures 2 and 3. While moving along the conveyor, the caps are heated by a gas flame heating device 12 which heats the caps by a gas flame while simultaneously rotating the caps to ensure evennessof heating.
Rotation is achieved by pushing the caps by means of a rotatable pusher against a rotating disk aligned with the conveyor, while the conveyor is stationary for a short time interval. The gas heater is similar to heating devices existing on other machines and is not a part of the present invention.
The conveyor 10 feeds the caps step by step towards the loading station A of a multi-spindle turret machine, which is basically a printing machine of the type S ~
.~ sold under the trade mark orqso and identiied as ~&~0 Automatic Screen Printing Machine Model.R5-30H.
The mach.ine has a rotary head lS
a~ --carrying six spindles 16 which project parallel to the rotational axis of the head, and the head has an indexing mechanism of well known type which rotates it in steps of 60 to move the spindles between successive stations A, s, C, D, E, and F. Of these stations:-A is the loading station;
B is the piercing station for forming perforations la;
C is the printing or paint applying station forapplying the patt~rn 8;
E is the unloading station. While no operation is performed at station D, between stations D and E the tear strip 3 is cut by a knife to be described. At station F the spindle is empty~
The spindles 16 each include a stem 16a projecting out of the head 15, and a freely rotatable sleeve 16b which is of slightly larger diameter than the stem and which is a snug fit within the ski.rt 2 of the cap. At the outer end of the spindle there is a gap between the rotatable sleeve and the stem to accommodate piercing pins which will be described with reference to Figure 4.
The loading station A, as indicated, includes an end of the conveyor 10 which brings a cap into alignmenk with a spindle 16. The station also includes a pusher bar which is not shown but which is a metal cylinder carried by the piston rod of air cyl.inder 1~ shown in Figure 3. Air cylinder 18 is operated automatically to push the cap onto the spindle : at station A.
- Station B includes the piercer shown in detail in Figure 4, and which is aligned with the cap when in station B. The piercer includes a bushing 20 slidable on a co--axial rod 22 ~7hich forms the piston rod of an air cylinder 24, cylinder 24 being mounted above cylinder 18 by an upper bracket 26. Fixed to the piston rod 22 is a collar 28, and a compression spring 30 acts hetween the collar 28 and the bushing 20. The bushing 20 has socket 32 which is dimellsioned to contact the outer corners of the cap, and this leads to a recess 33 in which is movable a plate 34 fixed to the outer end of rod 22. At its periphery, the plate 34 carries four piercing pins 36 which are arranged so that they can move in between the space between the stem 16a and sleeve 16b of a spindle, piercing the end portion of a cap to provide the perforations la., The spring loaded bushing holds the cap firmly on the spindle while the piercing is performed and e-specially while the piercing pins are withdrawn from the cap.
In the next station C the cap is printed with the pattern 8 by printing means of known form, being for example similar to printing means for cans. The printing '~ means includes a paint tray 40 carried by a carriage 42 which is reciprocable on shafts 44 so as to move horizontally in contact with the cap as this rotates on the spindle. Also indicated in Figure 2 are a paint applicator 46 which serves ; to push paint through the screen in the bottom of paint tray 40 as the tray moves across the cap, and a screen cleaner 48 which acts to clean the screen while the paint tray moves in the opposite direction.
,' While in station C, and also in station D, the cap is held on the spindle by means of a curved retaining bar 50 held by a bracket 52.
Between the stations D and E the tear strip 3 is cut by knife 60 which is part of knife fixture 62 which is the central feature of this invention.
The knife fixture includes a support member 64 fixed to the face plate of the machine and having a machined under-6-~
side surface. Held against this undersurface is an adjustable support 66 which has a machined surface 67 parallel to the face plate of the machine. The fore and aft position of the adjustable support 66 can be adjusted by knob 68 which rotates a threaded rod to move lug 69, fixed to support 66, relative to the fixed support 64. Against surface 67 is held a knife assembly 70, which is similarly adjustable along this surface by knob 72. The position of the knife radially and axially relative to the spindle moving in between stations D and E can be adjusted by knobs 68 and 72.
The knife assembly 70 is shown in Figures 5 and 6.
This includes a solid metal back plate 74 having a recess for the knife 60, and an electrical heater bar 76 which is firmly clamped onto the front surEace of the knife by screws 78. Bar 76 includes a thermostatically controlled electrical resistant heater which maintains the knife between 160 and 180F.
The knife 60 is a solid piece of tool steel having ~1 sickle shaped blade cut to a circular arc corresponding to the radius of the outermost surface of the main skirt - portions of caps held by the spindles, relative to the center of rotary head 15. As seen in Figure 6 and 7 the knife is formed with two cutting edges 60a, 60b by having a groove cut in its curved edge, the groove extending along the majority of the length of the curved edge but termina-ting in a curved end just short of the lower end of the knife. The cutting edges are formed by grinding the outer lands of the groove so that they form sharp edges with the straight inner sides oE the grooves. Additionally/ the main length of the cutting edges are serrated so that these are interrupted at intervals of about 1/10 of an inch. An unserrated, ~J-shaped connecting portion 60' connects the lower ends of the serrated cutting edges; portion 60' is designed to cut completely through the cap wall.
~ ~3L6~
The knife is shaped and arranged so that the upper ends of the two cutting edges contact the cylindrical surface of the cap adjacent the end portion 1, just as this leaves the station D. The cap is then rolled in contact with the cutting edges which maintain the position of the cap on the spindle so that the retainer bar 50 is not needed to hold the cap once the knife has made contact. The main part of the knife makes a series of elongated slits in the plastic, through a large portion at least of the thickness of the plastic, these slits being connected by uncut portions to provide parallel lines of weakness. The length of the knife blade is slightly greater than the circumference of the cap so that there is some overlap between the cuts formed by the upper end of the blade, and the end portion 3a which is completely severed from the cap by the U-shaped portion 60a of the blade.
" Upon reaching station E the cap is removed from the spindle by an unloader indicated at 80 in Figure 3, and which includes a cylinder 82 mounted on the piston rod 83 of an air cylinder 84 and which has at its outer end a - suetion cup 86 connected via a central bore in the piston rod to a source of vaeuum which is connected to an end 83a of the piston rod projecti~ng from the rear end of cylinder 84. This unloader arrangement, which is known per se, applies vaeuum to the suction cup 86 when this is pressed against the end of the cap, and the cylinder 84 is operated to pull ~- the cap from the spindle, at which point suction is released and the cap drops into a cup 90 of an unload conveyor 91.
The unload conveyor 91 which again is known per se, comprises two sprocket chains 92 connected by bars 94 carrying the cups 90, the sprocketchains being moved in timed relation to the machine movements so that each cup recei~es one finishecL cap.
All of the operations of the machine are sequenced automatically. Thus, the feed conveyor 10 and the off-load conveyor 91 move in timed relation to the indexed movement of the rotary head 15. Also, the movementsof the loader, the piercer, the printing device, and the unloader ~0 are all timed in relation to movements of the rotary head, so that these operations take place while the rotary head is stationary.
It will be seen that the invention provides a simple way of cutting a tear strip in a plastic cap when the cap is required to undergo operations on a multi-spindle type machine, and the nature of the other operations being performed can of course be varied.
It will be understood that the nature of the lines of weakness produced by the knife may he varied; for example these may be formed by a series of indentations or cuts (slits), or may be an uninterrupted score line. Only at the end portion 3a are complete through-cuts desirable.
Claims (10)
1. A machine for use in the production of plastic caps for bottles of the type having a tear strip for separating an end portion of the cap from the skirt, said machine having a rotary indexing head carrying a series of parallel rotatable spindles sized to receive said caps, said machine having a loading station with means for loading caps onto a spindle at said loading station, an unloading station with means for removing the caps from a spindle at the unloading station, and one or more intermediate stations between the loading and unloading stations wherein operations are performed on the caps, and wherein there is provided a knife situated to contact cylindrical surfaces of caps passing between the loading and unloading stations, said knife having two cutting edges which are spaced apart along the axis of the caps so as to cut opposite sides of the tear strip, the cutting edges having a part circular sickle shape so as to contact cylindrical parts of a cap and to form parallel lines of weakness therein while the cap is orbited by the rotary head and while the cap rotates on the spindle through about one revolution, adjacent ends of said cutting edges being connected by a connecting portion arranged to cut completely through the said cylindrical part of the cap to form an outer end of the tear strip.
2. A machine according to Claim 1, wherein the knife is formed from a single piece of steel having a groove cut between the two cutting edges, one end of the groove defining an edge of the blade at the said connecting portion.
3. A machine according to Claim 1 or 2, wherein the major part of the cutting edges are serrated so that the knife forms a series of indentations or cuts in the cap walls, the indentations or cuts being separated by uncut portions.
4. A machine according to Claims 1 or 2, wherein the knife is heated by a thermostatically controlled resistance heater.
5. A machine according to Claim 1, wherein said intermediate stations include a piercing station wherein perforations are formed in an end wall of the cap.
6. A machine according to Claim 5, wherein said means for forming said perforations include a piercing head having a bushing with a socket which receives the end of a cap, and a piercing element movable within the socket so as to pierce the cap and so as to withdraw while the bushing holds the cap on the spindle.
7. A machine according to Claim 1, wherein one of said intermediate stations is a printing station where a pattern is imprinted on the caps by printing means which reciprocate in contact with the skirt portion of a cap held by a spindle at the printing station.
8. A process for making a-plastic cap for bottles of the type having a perforated end portion and a tear strip for separating the end portion from the skirt, said process comprising the steps of:-a) injection molding a cap having an unperforated end portion and a skirt, b) conveying the injection molded caps to a machine having a rotary head carrying a series of rotatable spindles sized to receive said caps, and loading each cap onto a spindle of the machine while the spindle is in a loading station, c) indexing each cap on the spindle from the loading station to a piercing station and there piercing the end portion of the cap to form perforations therein, d) indexing each cap in orbital manner from the piercing station towards an unloading station, and while the cap is so moving, contacting a cylindrical wall of the cap with a heated, double-edged knife of sickle shape so arranged so as to form parallel lines of weakness defining a tear strip in the cylindrical wall of the cap, and e) unloading the caps from the spindle at an unloading station.
9. A process according to Claim 8, wherein each cap is printed at a printing station by printing means which moves relative to a spindle so as to rotate a cap held by said spindle and apply a pattern to the skirt of the cap.
10. A process according to Claim B, wherein the caps are heated by a flame heater while being conveyed to the rotary head machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000399618A CA1161611A (en) | 1982-03-29 | 1982-03-29 | Process and apparatus for production of bottle caps with tear strips |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000399618A CA1161611A (en) | 1982-03-29 | 1982-03-29 | Process and apparatus for production of bottle caps with tear strips |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1161611A true CA1161611A (en) | 1984-02-07 |
Family
ID=4122431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000399618A Expired CA1161611A (en) | 1982-03-29 | 1982-03-29 | Process and apparatus for production of bottle caps with tear strips |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1161611A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0657256A2 (en) * | 1993-10-14 | 1995-06-14 | Owens-Illinois Closure Inc. | Method and apparatus for scoring plastic tamper indicating closures |
| EP3103603A1 (en) * | 2015-06-08 | 2016-12-14 | Bortolin Kemo S.P.A. | Bottle cap cutting machine |
| IT201700049100A1 (en) * | 2017-05-05 | 2018-11-05 | Telerobot S P A | CUTTING DEVICE FOR PLASTIC OBJECTS |
| IT202000024511A1 (en) * | 2020-10-16 | 2022-04-16 | Sacmi | CAPSULE ENGRAVING KNIFE |
-
1982
- 1982-03-29 CA CA000399618A patent/CA1161611A/en not_active Expired
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0657256A2 (en) * | 1993-10-14 | 1995-06-14 | Owens-Illinois Closure Inc. | Method and apparatus for scoring plastic tamper indicating closures |
| EP0657256A3 (en) * | 1993-10-14 | 1995-09-06 | Owens Illinois Closure Inc | Method and apparatus for scoring plastic tamper indicating closures. |
| EP0960700A1 (en) | 1993-10-14 | 1999-12-01 | Owens-Illinois Closure Inc. | Apparatus for forming a circumferential score in a plastic closure |
| EP3103603A1 (en) * | 2015-06-08 | 2016-12-14 | Bortolin Kemo S.P.A. | Bottle cap cutting machine |
| US10052782B2 (en) | 2015-06-08 | 2018-08-21 | Bortolin Kemo S.P.A. | Cap cutting machine |
| IT201700049100A1 (en) * | 2017-05-05 | 2018-11-05 | Telerobot S P A | CUTTING DEVICE FOR PLASTIC OBJECTS |
| WO2018203159A1 (en) * | 2017-05-05 | 2018-11-08 | Telerobot S.P.A. | A cutting device for cutting plastic objects |
| IT202000024511A1 (en) * | 2020-10-16 | 2022-04-16 | Sacmi | CAPSULE ENGRAVING KNIFE |
| EP3988264A1 (en) * | 2020-10-16 | 2022-04-27 | Sacmi Cooperativa Meccanici Imola Societa' Cooperativa | Knife for cutting caps |
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| MKEX | Expiry | ||
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Effective date: 20010207 |