POTS WITH UNDERCUTS, OPENING MOLDS, FORMING MACHINES, AND PRODUCTION LINES FOR POTS WITH UNDERCUTS
20180148211 ยท 2018-05-31
Inventors
- Fabien Jego (Asnieres sur Seine, FR)
- Christian JACQUEMIN (CONFLANS SAINTE HONORINE, FR)
- Jean Albert LARMARAUD (VERNEUIL SUR SEINE, FR)
- Guy CHAUVET (MAISON LAFFITTE, FR)
Cpc classification
A47J41/00
HUMAN NECESSITIES
B29K2105/256
PERFORMING OPERATIONS; TRANSPORTING
B65D1/26
PERFORMING OPERATIONS; TRANSPORTING
B65D81/3813
PERFORMING OPERATIONS; TRANSPORTING
B65D77/2024
PERFORMING OPERATIONS; TRANSPORTING
B29L2031/7136
PERFORMING OPERATIONS; TRANSPORTING
B29C51/38
PERFORMING OPERATIONS; TRANSPORTING
B29C51/266
PERFORMING OPERATIONS; TRANSPORTING
B29C51/20
PERFORMING OPERATIONS; TRANSPORTING
International classification
B29C51/38
PERFORMING OPERATIONS; TRANSPORTING
A47J41/00
HUMAN NECESSITIES
Abstract
Pot with an undercut that includes a bottom wall (5), a side wall (6) that is closed on itself and connected to the bottom wall (5), with an opening providing access to the interior of the pot. The outside surface of the side wall of the pot has a non-symmetrical undercut shape for rotation around the vertical direction (Z). The outside surface has at least one vertical demolding plane (P) such that an undercut value of the pot with respective side ends of the pot, with a maximum side spacing of the outside surface in relation to the vertical demolding plane (P), is less than a maximum undercut value of the pot on the circumference of the outside surface of the pot.
Claims
1. Pot with an undercut (1) that comprises a bottom wall (2) as well as a side wall (3) that is closed on itself and connected to the bottom wall (2), with the side wall and the bottom wall comprising an inside surface (4) that defines a pot's interior as well as an outside surface (5) that is opposite to the inside surface, with the pot also comprising an opening (6) that provides access to the pot's interior, said opening (6) being able to be covered by a top closure (7) to insulate the pot's interior, with the opening extending along a horizontal plane (H) and defining a vertical direction (Z), perpendicular to the horizontal plane (H), passing through a barycenter of the opening and oriented from the bottom wall to the opening, with the pot being wherein the outside surface (5) of the side wall (3) of the pot has a non-symmetrical undercut shape for rotation around the vertical direction (Z), said outside surface (5) having at least one vertical demolding plane (P) such that an undercut value of the pot with respective side ends of the pot, with a maximum side spacing of the outside surface in relation to the vertical demolding plane (P), is less than a maximum undercut value of the pot (1) on the circumference of the outside surface (5) of the pot.
2. Pot according to claim 1, wherein the vertical demolding plane (P) is defined by the vertical direction (Z) and a demolding direction (D) of the horizontal plane (H), and is such that a side spacing E(t,z)=R(t,z)sin((t,z)) of the outside surface (5) in relation to the demolding direction (D) is a convex function for t varying from 0 to 1, with a maximum side spacing value of DM1(t1,z)=max.sub.t[0,1]E(tz) at a position t1(z) of the first mold opening section, and a concave function for t varying from 1 to 2, with a maximum side spacing value of DM2(t2,z)=max.sub.t[1,2](E(t,z)) at a position t2(z) of the second mold opening section, where z is a distance to the bottom wall from a point of the outside surface of the side wall, in the vertical direction (Z), t[0,2] is a circumferential position from a point of the outside surface (5) such that t=0 at an intersection between the outside surface (5) and the demolding direction (D), t=1 at an intersection between the outside surface and the direction that is opposite to the demolding direction (D), and t varies from 0 to 2 by passing through a complete circumference of the outside surface around the vertical direction (Z), (t,z) is an angle that is oriented in the horizontal plane (H) in relation to the demolding direction (D) from a point of the outside surface to the position t and the height z, and R(t,z) is a distance in the vertical direction (Z), in the horizontal plane (H), from a point of the outside surface (5) to the position t and the height z, and the outside surface of the side wall has: A height z1=argmax.sub.z(DM1(t1(z),z)) with maximum spacing of the first undercut at the location of the first mold opening section, A height z1=argmin.sub.z>z1(DM1(t1(z),z)) with minimum spacing of the first undercut at the location of the first mold opening section, A height z2=argmax,(DM2(t2(z),z)) with maximum spacing of the second undercut at the location of the second mold opening section, A height z2=argmin.sub.z>z2(DM2(t2(z),z)) with minimum spacing of the second undercut at the location of the second mold opening section.
3. Pot according to claim 2, wherein An overhang of the first undercut at the location of the first mold opening section D1(t1)=R(t1(z1),z1)R(t1(z1),z1) is smaller than a maximum overhang of the first undercut D1.sub.max=max.sub.t(R(t,z1))min.sub.t(R(t,z1)) on the circumference of the outside surface of the pot, and An overhang of the second undercut at the location of the second mold opening section D2(t2)=R(t2(z1),z2)R(t2(z2),z2) is smaller than a maximum overhang of the second undercut D2.sub.max=max.sub.t(R(t,z2))min.sub.t(R(t,z2)) on the circumference of the outside surface of the pot.
4. Pot according to claim 2, wherein the outside surface (5) of the side wall (3) of the pot is such that A longitudinal distance from the first undercut on a first half of the pot D1.sub.long(t)=F(c1(t),z1)F(t,z1) for t[0,t1(z1)] has a local minimum at the location of the first mold opening section t=t1(z1), A longitudinal distance from the first undercut on a second half of the pot D1.sub.long(t)=F(c2(t),z1)F(t,z1) for t[t1(z1),1] has a local minimum at the location of the first mold opening section t=t1(z1), A longitudinal distance from the second undercut on a second half of the pot D2.sub.long(t)=F(c3(t),z2)F(t,z2) for t[1,t2(z2)] has a local minimum at the location of the second mold opening section t=t2(z2), A longitudinal distance from the second undercut on a first half of the pot D2.sub.long(t)=F(c4(t),z2)F(t,z2) for t[t2(z2),2] has a local minimum at the location of the second mold opening section t=t2(z2), where F(t,z)=R(t,z)cos((t,z)) is a longitudinal spacing of the outside surface (5) of said side wall in the demolding direction (D), c1(t) is a longitudinal conversion of the position of the first undercut on a first half of the pot such that sin((c1(t),z1)) R(c1(t),z1)=sin((t,z1)) R(t,z1) for t[0,t1(z1)], c2(t) is a longitudinal conversion of the position of the first undercut on a second half of the pot such that sin((c2(t),z1)) R(c2(t),z1)=sin((t,z1)) R(t,z1) for t[t1(z1),1], c3(t) is a longitudinal conversion of the position of the second undercut on a second half of the pot such that sin((c3(t),z2)) R(c4(t),z2)=sin((t,z2)) R(t,z2) for t[1,t2(z2)], and c4(t) is a longitudinal conversion of the position of a second undercut on a first half of the pot such that sin((c4(t),z2)) R(c3(t),z2)=sin((t,z2)) R(t,z2) for t[t2(z2),2].
5. Pot according to claim 2, wherein A lateral distance from the first undercut D1.sub.lat(t)=E(d(t),z1)E(t,z1) has a local minimum at the location of the first mold opening section t=t1(z1), and A lateral distance from the second undercut D2.sub.lat(t)=E(d(t),z2)E(t,z2) has a local minimum at the location of the second mold opening section t=t2(z2), where d1(t) is a lateral conversion of the position of the first undercut such that d1(t)=argmax.sub.t((t,z1)=(t,z1)), and d2(t) is a lateral conversion of the position of the second undercut such that d2(t)=argmax.sub.t(t,z2))).
6. Pot according to claim 1, wherein the distance from the first undercut at the location of the first mold opening section D1(t1) and the distance from the second undercut at the location of the second mold opening section D2(t2) are respectively smaller than one-fourth of the maximum spacing of the first undercut at the location of the first mold opening section DM1(t1,z1) and one-fourth of the maximum spacing of the second undercut at the location of the second mold opening section DM2(t2,z2), preferably respectively less than one-tenth of the maximum spacing of the first undercut at the location of the first mold opening section DM1(t1,z1) and one-fourth of the maximum spacing of the second undercut at the location of the second mold opening section DM2(t2,z2).
7. Pot according to claim 1, wherein the first mold opening section and the second mold opening section are essentially opposite to one another in relation to the longitudinal axis (Z).
8. Pot according to claim 1, wherein the first mold opening section and the second mold opening section are at right angles in relation to the demolding direction (D) in the vertical direction (Z), in such a way that (t1(z),z)=/2 and (t2(z),z)=/2 over the entire height z of the pot.
9. Pot according to claim 1, wherein the opening (6) is surrounded by a flat collar (8) that extends into the horizontal plane (H), suitable for making possible the attachment of a top closure (7) on the pot in such a way as to close the pot (1) in an airtight manner.
10. Pot according to claim 1, wherein the pot (1) is made of plastic material.
11. Pot according to claim 1, wherein the opening (6) of the pot is sealed by a top closure (7).
12. Opening mold (100) that is specially designed to be used in a forming machine (200) to shape at least one pot (1) according to claim 1, comprising a first sub-mold (110) and a second sub-mold (120), with said sub-molds being adapted to be moved in a demolding direction (D) between a closed position in which the first sub-mold and the second sub-mold are in mutual contact and an open position in which said sub-molds are separated from one another, with said first sub-mold and second sub-mold forming at least one inside cavity (130) in the closed position of the mold, said at least one cavity being defined by an inside surface of the cavity (131) comprising an inside surface of the first sub-mold (111) and an inside surface of the second sub-mold (121), with the cavity being open at the location of an upper surface (101) of the opening mold, by an upper opening (140) that extends along a horizontal plane (H) comprising the demolding direction (D), the upper opening defining a vertical direction of the cavity (Z), perpendicular to the horizontal plane (H), passing through a barycenter of said upper opening and oriented from a cavity bottom toward the upper opening, with the opening mold being wherein the inside surface of the cavity (131) in the closed position has a non-symmetrical undercut shape for rotation around the vertical direction (Z), with said inside surface having a vertical demolding plane (P) comprising the vertical direction (Z) as well as the demolding direction (D) and being such that an undercut value of the mold at the respective side ends of the inside cavity of the mold, with maximum side spacing of the inside surface in relation to the vertical demolding plane (P), is less than a maximum undercut value of the mold on the circumference of the inside surface of the inside cavity.
13. Opening mold according to claim 12, wherein the vertical demolding plane (P) is such that a side spacing E(t,z)=R(t,z)sin((t,z)) of the inside surface of the cavity (131) of the opening mold in the closed position in relation to the demolding direction (D) is a convex function for t varying from 0 to 1, with a maximum value of side spacing DM1(t1,z)=max.sub.t[0,1]E(t,z) at a position t1(z) of the first mold opening section corresponding to a location for contact between respective first opening surfaces of the first sub-mold and the second sub-mold, and a concave function for t varying from 1 to 2, with a maximum value of side spacing DM2(t2,z)=max.sub.t[1,2](E(t,z)) at a position t2(z) of the second mold opening section corresponding to a location for contact between the respective second opening surfaces of the first sub-mold and the second sub-mold, where z is a distance to the cavity bottom from a point of the inside surface of the cavity, in the vertical direction (Z), t[0,2] is a circumferential position from a point of the inside surface such that t=0 at an intersection between the inside surface and the demolding direction (D), t=1 at an intersection between the inside surface and the direction that is opposite to the demolding direction (D), and t varies from 0 to 2 by passing through a complete circumference of the inside surface around the vertical direction (Z), (t,z) is an angle that is oriented in the horizontal plane (H) in relation to the demolding direction (D) from a point of the inside surface to the position t and the height z, and R(t,z) is a distance in the vertical direction (Z), in the horizontal plane (H), from a point of the inside surface to the position t and the height z, and the inside surface of the cavity has: A height z1=argmax.sub.z(DM1(t1(z),z)) of maximum spacing of the first undercut at the location of the first mold opening section, A height z1=argmin.sub.z>z1(DM1(t1(z),z)) of minimum spacing of the first undercut at the location of the first mold opening section, A height z2=argmax.sub.z(DM2(t2(z),z)) of maximum spacing of the second undercut at the location of the second mold opening section, A height z2=argmin.sub.z>z2(DM2(t2(z),z)) of minimum spacing of the second undercut at the location of the second mold opening section.
14. Opening mold according to claim 13, wherein An overhang of the first undercut at the location of the first mold opening section D1(t1)=R(t1(z1),z1)R(t1(z1),z1) is smaller than a maximum overhang of the first undercut D1.sub.max=max.sub.t(R(t,z1))min.sub.t(R(t,z1)) on the circumference of the inside surface of the cavity, and An overhang of the second undercut at the location of the second mold opening section D2(t2)=R(t2(z1),z2)R(t2(z2),z2) is smaller than a maximum overhang of the second undercut D2.sub.max=max.sub.t(R(t,z2))min.sub.t(R(t,z2)) on the circumference of the inside surface of the cavity.
15. Opening mold according to claim 13, wherein the inside surface of the cavity (131) is such that A longitudinal distance from the first undercut on a first cavity half D.sub.long(t)=F(c1(t),z1)F(t,z1) for t[0,t1(z1)] has a local minimum at the location of the first mold opening section t=t1(z1), A longitudinal distance from the first undercut on a second cavity half D1.sub.long(t)=F(c2(t),z1)F(t,z1) for t[t1(z1),1] has a local minimum at the location of the first mold opening section t=t1(z1), A longitudinal distance from the second undercut on a second cavity half D2.sub.long(t)=F(c3(t),z2)F(t,z2) for t[1,t2(z2)] has a local minimum at the location of the second mold opening section t=t2(z2), A longitudinal distance from the second undercut on a first cavity half D2.sub.long(t)=F(c4(t),z2)F(t,z2) for t[t2(z),2] has a local minimum at the location of the second mold opening section t=t2(z2), where F(t,z)=R(t,z)cos((t,z)) is a longitudinal spacing of the inside surface of the cavity in the demolding direction (D), c1(t) is a longitudinal conversion of the position of the first undercut on a first cavity half such that sin((c1(t),z1)) R(c1(t),z1)=sin((t,z1) R(t,z1) for t[0,t1(z1)], c2(t) is a longitudinal conversion of the position of the first undercut on a second cavity half such that sin((c2(t),z1)) R(c2(t),z1)=sin((t,z1) R(t,z1) for t[t1(z),1], c3(t) is a longitudinal conversion of the position of the second undercut on a second cavity half such that sin((c3(t),z2)) R(c4(t),z2)=sin((t,z2)) R(t,z2) for t[1,t2(z2)], and c4(t) is a longitudinal conversion of the position of the second undercut on a first cavity half such that sin((c4(t),z2)) R(c3(t),z2)=sin((t,z2)) R(t,z2) f or t[t2(z2),2].
16. Opening mold according to claim 13, wherein A lateral distance from the first undercut D1.sub.lat(t)=E(d(t),z1)E(t,z1) has a local minimum at the location of the first mold opening section t=t1(z1), and A lateral distance from the second undercut D2.sub.lat(t)=E(d(t),z2)E(t,z2) has a local minimum at the location of the second mold opening section t=t2(z2), where d1(t) is a lateral conversion of the position of the first undercut such that d1(t)=argmax.sub.t(t,z1)=(t,z1), and d2(t) is a lateral conversion of the position of the second undercut such that d2(t)=argmax.sub.t(t,z2)=(t,z2)).
17. Opening mold according to claim 12, wherein said first sub-mold (110) and second sub-mold (120) form, in the closed position of the mold, a number of inside cavities (130) that are aligned in a longitudinal direction (X).
18. Opening mold according to claim 12, wherein in the open position, the first sub-mold (110) and the second sub-mold (120) are separated from one another, in the demolding direction (D), by a distance from the opening O of between one and three times a sum between a maximum distance from the undercut of the side wall in the demolding direction (D) and a maximum distance from the undercut of the side wall in the direction that is opposite to the demolding direction (D).
19. Forming machine (200) that comprises at least one opening mold (100) according to claim 12.
20. Forming machine according to claim 19, comprising a number of opening molds (100) that are aligned for forming at least two rows of molds (210) that each extend in a longitudinal direction (X) that is perpendicular to the demolding direction (D) of said opening molds, each row of molds (210) comprising one or more opening molds that are juxtaposed in the longitudinal direction (X), with said rows of molds being arranged with a spatial period p in the demolding direction (D), in which said spatial period p is less than one and one-half times a maximum dimension of the inside cavity (131) of an opening mold (100) in the demolding direction (D).
21. Forming machine according to claim 19, also comprising at least one locking device (240) for separating opening molds that are put under pressure, with said locking device (240) for separating comprising a first cam (241) and a second cam (242), said first and second cams respectively coming into contact with the first sub-mold (110) and the second sub-mold (120) of an opening mold in the closed position in such a way as to prevent a relative movement of said sub-molds in the demolding direction (D), with said first and second cams (241, 242) coming into contact with said first and second sub-molds by a side that is opposite to the upper surface (101) of said opening mold (100) in the vertical direction (Z) in such a way as not to exceed the upper surface of said opening mold in the vertical direction (Z).
22. Line for producing pots by forming, comprising a forming machine (200) according to claim 19 as well as intake means of a sheet of material for forming (310) starting from at least one feed roll (311), with the intake means of said sheet of material for forming being suitable for bringing a portion of the sheet of material (312) into contact with the upper face (101) of the opening molds (100), with said portion of the sheet of material being connected in a continuous manner to the feed roll (311).
23. Line for producing pots by forming according to claim 22, wherein said portion of the sheet of material (312) in contact with the upper face (101) of the opening molds (100) covers at least at least [sic] two rows (210) of opening molds of the forming machine.
24. Line for producing pots by forming according to claim 22, also comprising intake means of a capping sheet (320) starting from at least one feed roll (321), with said intake means of a capping sheet being adapted to bring a portion of the capping sheet (322) opposite to the opening (6) of rows of pots (1) that are shaped by the pot-forming machine (200), said pots having, if necessary, their collars (8) connected to one another by the portion of the sheet of materials, said portion of the capping sheet being connected in a continuous manner to the feed roll, with the line also comprising a device for sealing pots (330) that is suitable for bringing into contact and sealing said portion of the capping sheet with the collars of the pots.
25. Method for manufacturing pots by forming, wherein: A line (300) for manufacturing pots by forming is arranged according to claim 22, Starting from the feed roll (311), a portion of the sheet of material (312) is brought into contact with the upper face (101) of a number of opening molds (100) that are aligned for forming at least two rows of molds (210) that each extend in a longitudinal direction (X) that is perpendicular to the demolding direction (D) of said opening molds, said portion of the sheet of material being connected in a continuous manner to the feed roll, The pots (1) are formed in said opening molds.
Description
[0102] The figures of the drawings will now be briefly described.
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[0116] Below, a detailed report on several embodiments of the invention coupled with examples and a reference to the drawings.
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[0118] As can be seen in
[0119] The opening 6 extends along a horizontal plane H and further defines a vertical direction Z, perpendicular to the horizontal plane H and passing through a barycenter of the opening 6. The vertical direction Z is oriented from the bottom wall 2 to the opening 6.
[0120] In particular, the opening 6 can be surrounded by a flat collar 8 that extends into the horizontal plane H. The collar 8 can be adapted for making possible the attachment of the top closure 7 to the pot 1 in such a way as to close the pot 1 in an airtight manner.
[0121] The pot is made of, for example, plastic material, and can in particular be made by heat-forming a plastic sheet as presented in detail below.
[0122] As can be seen in
[0123] In the closed position of the opening mold 100, the first sub-mold 110 and the second sub-mold 120 together form at least one inside cavity 130 of the opening mold.
[0124] The inside cavity 130 is defined by an inside surface of the cavity 131 that comprises an inside surface of the first sub-mold 111 and an inside surface of the second sub-mold 121. The cavity 130 is open at the location of an upper surface 101 of the opening mold 100, by an upper opening 140.
[0125] The upper opening 140 extends along a horizontal plane H that comprises the demolding direction D of the mold. The upper opening 140 also defines a vertical direction of the cavity Z, perpendicular to the horizontal plane H and passing through a barycenter of the upper opening 140. The vertical direction Z is oriented from a cavity bottom 132 to the upper opening 140 of the opening mold 100.
[0126] In the closed position, the first sub-mold 110 and the second sub-mold 120 are in mutual contact, on the one hand, at the location of the respective first opening surfaces 111, 121, and, on the other hand, at the location of the respective second opening surfaces 112, 122. The first opening surfaces 111, 121 and the second opening surfaces 112, 122 are placed on either side of the upper opening 140 of the opening mold 100.
[0127] In the open position, the first sub-mold 110 and the second sub-mold 120 are separated from one another by a distance from the opening O that is sufficient to make it possible to extract the formed pot from the mold by relatively moving the mold in relation to the pot in the vertical direction Z.
[0128] The pot that is illustrated in
[0129] As can be seen in
[0130] Thus, when the maximum radius of the pot, Rmax, becomes large with respect to the radius of the neck of the pot, Rmin, the distance from the opening O tends toward a value that is close to the maximum diameter of the pot, Rmax. Actually, as can be seen in
[0131] One of the objectives of this invention is to provide a pot that makes it possible to reduce the distance from the opening O between the sub-molds of the opening mold in the open position and therefore the spacing E between the rows of opening molds.
[0132] For this purpose,
[0133] The shape of the outside surface 5 of the side wall 3 of the pot 1 according to the invention is, however, different from the shape of the outside surface 5 of the side wall 3 of the pot 1 of
[0134] More specifically, the outside surface 5 of the side wall 3 of the pot 1 according to the invention has a non-symmetrical undercut shape for rotation around the vertical direction Z. The outside surface 5 thus has at least one vertical demolding plane P, illustrated in
[0135] In a general manner, an undercut value is defined as a difference between a bulkiness of the pot in the area of the neck of the pot and a bulkiness of the pot in the area of the stomach of the pot.
[0136] This particular form of the outside surface 5 of the pot 1 makes it possible to simplify the demolding of the pot and to reduce the distance from the opening of the opening mold O, while preserving a significant undercut offering the expected advantages of a pot with an undercut, in particular from the standpoint of the outside appearance of said pot.
[0137] This will now be explained in more detail with reference to
[0138] A side spacing E(t,z) of the outside surface 5 in relation to the demolding plane P can then be defined as E(t,z)=R(t,z)sin((t,z)) where [0139] z is a distance to the bottom wall 2, for example to the outside surface of the bottom wall, from a point of the outside surface 5 of the side wall, in the vertical direction (Z), and [0140] t[0,2] is a circumferential position from a point of the outside surface 5 such that
[0141] t=0 at an intersection between the outside surface 5 and the demolding direction D,
[0142] t=1 at an intersection between the outside surface 5 and the direction that is opposite to the demolding direction D, and
[0143] t varies from 0 to 2 in passing through a complete circumference of the outside surface 5 around the vertical direction Z.
[0144] It is also possible to define cylindrical coordinates ((t,z),z),z) of the outside surface points 5 in the reference point formed by the vertical direction Z and the demolding direction D where
[0145] (t,z) is an angle that is oriented in the horizontal plane H in relation to the demolding direction D from a point of the outside surface to the position t and the height z, and
[0146] R(t,z) is a distance to the vertical direction Z, in the horizontal plane H, from a point of the outside surface to the position t and the height z.
[0147] The side spacing E(t,z) based on t for a fixed height z is illustrated in
[0148] convex for t varying from 0 to 1, with a maximum side spacing value DM1(t1,z)=max.sub.t[0,1]E(t,z) at a position t1(z) of the first mold opening section, and
[0149] concave for t varying from 1 to 2, with a maximum side spacing value DM2 (t2,z)=max.sub.t[1, 2](E(t,z)) at a position t2(z) of the second mold opening section.
[0150] In this manner, it is possible to demold the pot with an opening mold 100 as illustrated in
[0151] the first respective opening surfaces 151, 152 of the sub-molds are in contact with the outside surface 5 of the pot at the location of the positions t1(z) of the first mold opening section for every height z, and
[0152] the second respective opening surfaces 161, 162 of the sub-molds are in contact with the outside surface 5 of the pot at the location of the positions t2(z) of the second mold opening section for every height z.
[0153] In a particular embodiment of the invention, the first mold opening section and the second mold opening section can be essentially opposite in relation to the longitudinal axis Z.
[0154] The first mold opening section and the second mold opening section can also be arranged at right angles in relation to the demolding direction D in the vertical direction Z, i.e., (t1(z),z)=/2 and (t2(z),z)=/2.
[0155] There are also defined on the outside surface of the side wall: [0156] A height z1=argmax.sub.z(DM1(t1(z),z)) of maximum spacing of the first undercut at the location of the first mold opening section, [0157] A height z1=argmin.sub.z>z1(DM1(t1(z),z)) of minimum spacing of the first undercut at the location of the first mold opening section, [0158] A height z2=argmax.sub.z(DM2(t2(z),z)) of maximum spacing of the second undercut at the location of the second mold opening section, [0159] A height z2=argmin.sub.z>z2(DM2(t2(z),z)) of minimum spacing of the second undercut at the location of the second mold opening section. [0160] zi=argmax.sub.z(f(z)) for a function f(z) is defined as the value zi of z for which f(z) reaches its highest value. If the function f(z) reaches its maximum for a set of multiple values {zj, zk, zl} of z, it will then be assumed that zi is the highest value in said set, or zi=max(argmax.sub.z(f(z))). For the sake of brevity, simply zi=argmax.sub.z(f(z)) will be used in this description.
[0161] In a similar way, zi=argmin.sub.z>zj(f(z)) for a function f(z) is defined as the value zi of z for which f(z) reaches its lowest value above zj. Here also, if the function f(z) reaches its minimum for a set of multiple values {zj, zk, zl} of z, it will then be assumed that zi is the highest value in said set, or zi=max(argmin.sub.z>zj(f(z))). For the sake of brevity, simply zi=argmin.sub.z>zj(f(z)) will be used in this description.
[0162] The heights z1 and z2 thus correspond to the height of the stomach of the pot 1, respectively in the area of the first mold opening section and the second mold opening section.
[0163] The heights z1 and z2 correspond to the height of the neck of the pot 1, respectively in the area of the first mold opening section and the second mold opening section.
[0164] As can be understood by examining
[0165]
[0166] Thus, the pot according to the invention can be such that an overhang of the first undercut at the location of the first mold opening section D1(t1)=R(t1(z1),z1)R(t1(z1),z1) is smaller than a maximum overhang of the first undercut D1.sub.max=max.sub.t(R(t,z1))min.sub.t(R(t,z1)) on the circumference of the outside surface of the pot.
[0167] In a similar manner, an overhang of the second undercut at the location of the second mold opening section D2(t2)=R(t2(z1),z2)R(t2(z2),z2) may be smaller than a maximum overhang of the second undercut D2.sub.max=max.sub.t(R(t,z2))min.sub.t(R(t,z2)) on the circumference of the outside surface of the pot.
[0168] In particular, the distance from the first undercut at the location of the first mold opening section D1(t1) may be less than one-fourth of the maximum spacing of the first undercut at the location of the first mold opening section DM1(t1,z1). Likewise, the distance from the second undercut at the location of the second mold opening section D2(t2) may also be less than one-fourth of the maximum spacing of the second undercut at the location of the second mold opening section DM2(t2,z2).
[0169] In a particular embodiment, said distances from the first undercut to the location of the first mold opening section D1(t1) and the distance from the second undercut to the location of the second mold opening section D2(t2) may be respectively less than one-tenth of the maximum spacing from the first undercut to the location of the first mold opening section DM1(t1,z1) and one-fourth of the maximum spacing from the second undercut to the location of the second mold opening section DM2(t2,z2).
[0170] In particular, it can be seen in
[0171] The curve in dotted form of
[0172] Thanks to this geometry, the distance from the opening O is thus also reduced between the first and second sub-molds of an opening mold that forms the pot 1.
[0173] An alternative way of loosening said constraints on the distance from the opening O between the first and second sub-molds is illustrated in
[0174] More specifically, the longitudinal spacing of the outside surface 5 of the side wall 3 of the pot 1 in the demolding direction D, which is provided by F(t,z)=R(t,z)cos((t,z)), is considered here.
[0175] In this embodiment of the invention, the outside surface 5 of the side wall 2 of the pot is stressed on the first half of the pot as well as on the second half of the pot, respectively corresponding to the portion of the pot received by a first sub-mold and a second sub-mold of an opening mold that forms the pot, and in particular stressed in the area of the first and second mold opening sections.
[0176] Thus, a longitudinal distance from the first undercut to a first half of the pot D1.sub.long(t)=F(c1(t),z1)F(t,z1) for t[0,t1(z1)] has a local minimum at the location of the first mold opening section t=t1(z1), where c1(t) is a longitudinal conversion of the position of the first undercut on a first half of the pot such that sin((c1(t),z1)) R(c1(t),z1)=sin((t,z1)) R(t,z1) for t[0,t1(z1)].
[0177] Because of the convex shape of the lateral spacing E(t,z) for t varying from 0 to t1(z) and for every fixed height z, the longitudinal conversion of the position of the first undercut is well defined for every t[0,t1(z1)].
[0178] Likewise, a longitudinal distance from the first undercut on a second half of the pot D1.sub.long(t)=F(c2(t),z1)F(t,z1) for t[t1(Z1),1] has a local minimum at the location of the first mold opening section t=t1(z1) where c2(t) is a longitudinal conversion of the position of the first undercut on a second half of the pot such that sin((c2(t),z1)) R(c2(t),z1)=sin((t,z1)) R(t,z1) for t[t1(Z1),1].
[0179] Here also, because of the convex shape of the side spacing E(t,z) for t varying from t1(z) to 1 and for every fixed height z, the longitudinal conversion of the position of the first undercut is well defined for every t[t1(z1),1].
[0180] A longitudinal distance from the second undercut on a second half of the pot D2.sub.long(t)=F(c3(t),z2)F(t,z2) for t[1,t2(z2)] has a local minimum at the location of the second mold opening section t=t2(z2) where c4(t) is a longitudinal conversion of the position of the second undercut on a second half of the pot such that sin((c3(t),z2)) R(c4(t),z2)=sin((t,z2)) R(t,z2) for t[1,t2(z2)].
[0181] Because of the concave shape of the side spacing E(t,z) for t varying from to 1 t2(z) and for every fixed height z, the longitudinal conversion of the position of the second undercut is well defined for every t[1,t2(z2)].
[0182] Finally, a longitudinal distance from the second undercut on a first half of the pot D2.sub.long(t)=F(c4(t),z2)F(t,z2) for t[t2(z2),2] also has a local minimum at the location of the second mold opening section t=t2(z2) where c4(t) is a longitudinal conversion of the position of the second undercut on a first half of the pot such that sin((c3(t),z2)) R(c3(t),z2)=sin((t,z2)) R(t,z2) for t[t2(z2),2].
[0183] Here also, because of the concave shape of the side spacing E(t,z) for t varying from t2(z) to 2 and for every fixed height z, the longitudinal conversion of the position of the second undercut is well defined for every t[t2(z2), 2].
[0184]
[0185] As can be seen in
[0186] Also, another way of loosening said constraints on the distance from the opening 0 between the first and second sub-molds is illustrated in
[0187] This time, the side spacing of the outside surface 5 of the side wall 3 of the pot 1 is considered again in the demolding direction D, which is provided by E(t,z)=R(t,z)sin((t,z)).
[0188] In this embodiment of the invention, the outside surface 5 of the side wall 2 of the pot is stressed in the area of the first and second mold opening sections in the following manner.
[0189] A lateral distance from the first undercut D1.sub.lat(t)=E(d1(t),z1)E(t,z1) has a local minimum at the location of the first mold opening section t=t1(z1) where d1(t) is a lateral conversion of the position of the first undercut such that d1(t) is a higher value of [0,1] such that (d1(t),z1)=(t,z1). In contrast to the preceding embodiment that is defined by the longitudinal distance, it is possible to obtain multiple values t such that (t,z1)=(t,z1)); d1(t) is therefore the highest value of the interval [0,1] that verifies this equality.
[0190] In addition, a lateral distance from the second undercut D2.sub.lat(t)=E(d1(t),z2)E(t,z2) has a local minimum at the location of the second mold opening section t=t2(z2) or d2(t) is a lateral conversion of the position of the second undercut such that d2(t) is a higher value of [1,2] such that (d2(t), z2)=(t,z2). Here, also, it is possible to obtain multiple values t such that (t,z2)=(t,z2)); d2(t) is thus the highest value of the interval [1,2] that verifies this equality.
[0191] This is shown in particular in
[0192] The embodiments of the pots that are described above make it possible in particular to reduce the distance from the opening between the sub-molds of an opening mold used for forming said pot.
[0193] Thus, in at least some of these embodiments, it is possible to form the pot with an opening mold such that, in the open position, the first sub-mold and the second sub-mold are separated from one another, in the demolding direction D, by a distance from the opening O of between one and three times a total spacing of the undercut.
[0194] Total spacing of the undercut is defined as a sum between a maximum distance from the undercut of the side wall in the demolding direction D and a maximum distance from the undercut of the side wall in the direction that is opposite to the demolding direction D.
[0195]
[0196] The invention also has as its object an opening mold 100 that is specially designed to be used in a forming machine for shaping at least one pot as described above.
[0197] The opening mold 100 comprises a first and second sub-molds 110, 120 as described above, such that, in the closed position of the opening mold 100, the first sub-mold 110 and the second sub-mold 120 together form at least one inside cavity 130 that is defined by an inside surface of the cavity 131 and that is open at the location of an upper surface 101 of the opening mold 100, by an upper opening 140 that extends along a horizontal plane H. The demolding direction D of the mold and the vertical direction of the cavity are defined and oriented as indicated above and illustrated in, for example,
[0198] The opening mold according to the invention is in particular such that the inside surface of the cavity 131 of the opening mold in the closed position has a non-symmetrical undercut shape for rotation around the vertical direction Z of the opening mold.
[0199] More specifically, the inside surface has a vertical demolding plane P that comprises the vertical direction Z of the mold as well as the demolding direction of the mold D and is such that an undercut value of the opening mold at the respective side ends of the inside cavity of the mold, with the maximum side spacing of the inside surface in relation to the vertical demolding plane P, is less than a maximum undercut value of the opening mold on the circumference of the inside surface of the inside cavity of the opening mold.
[0200] With the opening mold being specially designed to form the pot 1 that was just described, the inside surface 131 of the inside cavity 130 has a geometric shape that is similar to the one that was just described for the outside surface 5 of the side wall 3 of the pot 1.
[0201] The elements that are presented in detail above, relative to the outside surface of the side wall of the pot, are therefore also applicable to the mold, by replacing the outside surface of the side wall of the pot by the inside surface of the cavity of the opening mold in the closed position.
[0202] Reference is therefore made to the geometric characteristics that are presented in detail above and that will not be repeated here.
[0203] Furthermore, relative to the shape of the inside surface of the opening mold in the closed position, it will be noted that the first mold opening section corresponds in the case of the mold to a location for contact between the first respective opening surfaces 151, 152 of the first sub-mold and the second sub-mold.
[0204] Likewise, the second mold opening section corresponds, in the case of the mold, to a location for contact between the second respective opening surfaces 161, 162 of the first sub-mold and the second sub-mold.
[0205] In addition, the first half of the pot and the second half of the pot, in the case of the outside surface, correspond respectively, in the case of the mold, to a first half of the inside cavity and to a second half of the inside cavity.
[0206] In this manner, the opening mold is such that, in the open position, the first sub-mold and the second sub-mold are separated from one another, in the demolding direction D, by a distance from the opening O that is between one and three times a total spacing of the undercut.
[0207] Total spacing of the undercut is defined as a sum between a maximum distance from the undercut of the side wall in the demolding direction D and a maximum distance from the undercut of the side wall in the direction that is opposite to the demolding direction D.
[0208] The opening mold 100 is designed to be used in a forming machine 200 for shaping one or more pot(s) 1 as described above.
[0209] Thus, the first and second sub-molds 110, 120 can in particular form, in the closed position of the mold 100, a number of n inside cavities 130a, 130b, . . . 130n, aligned in a longitudinal direction X. The longitudinal direction X can in particular be perpendicular to the demolding direction D of the opening molds.
[0210] In this manner, it is possible to manufacture in a single operation a complete row of pots 1 with a single opening mold 100.
[0211] Multiple such rows of pots 1 can be manufactured by a forming machine 200 as will now be described.
[0212] A forming machine 200 according to the invention is illustrated in, for example,
[0213] Advantageously, this forming machine 200 comprises a number of opening molds 100a, 100b, . . . , 100m.
[0214] The opening and closing of the m opening molds 100 is controlled in a synchronous manner by a forming control device 220. The mold forming machine 200 further comprises counter-molds and punches 230 for shaping the pots 1 in the opening molds 100, with said counter-molds and punches 230 being advantageously also controlled in a synchronous manner with the opening and closing of the m opening molds 100 by the forming control device 220.
[0215] Such synchronization can be done in a mechanical manner by connecting rods or cams connecting the opening molds 100 to the counter-molds and punches 230, or it can be done in an electronic manner by control motors that are separate from the opening molds 100 and counter-molds and punches 230 as well as sensors and an electronic synchronization unit.
[0216] It is thus possible, in a forming step, to shape n*m pots using n*m inside cavities of the opening molds 100.
[0217] The opening molds 100a, 100b, . . . , 100m are advantageously arranged in such a way that their demolding directions D are parallel to one another and thus define a longitudinal direction X of the forming machine 200, perpendicular to said demolding directions D. The opening molds 100a, 100b, . . . , 100m are arranged to form at least two rows of molds 210 that each extend in the longitudinal direction X of the forming machine. Each row of molds 210 comprises one or more opening molds 100 that are juxtaposed and aligned in the longitudinal direction X.
[0218] As can be seen in
[0219] Actually, because of the limited distance from the opening O of the opening molds 100, it is possible to position the rows of molds 210 with a relative distance in the demolding direction D, i.e., a spatial period p, reduced in relation to the prior art.
[0220] In this manner, it is possible to use a single and continuous sheet of forming material, covering all of the n*m inside cavities of the opening molds 100, for forming n*m pots in a forming step.
[0221] The use of accompanying devices for precutting the sheet of forming materials is thus avoided.
[0222] As is illustrated in
[0223] The locking device 240 for separating can comprise, for example, a first cam 241 and a second cam 242, respectively coming into contact with the first sub-mold 110 and the second sub-mold 120 when the opening mold is in the closed position.
[0224] The first cam 241 and the second cam 242 are suitable for, when they are in contact with said sub-molds 110, 120, preventing a relative movement of said sub-molds 110, 120 in the demolding direction D.
[0225] As can be seen in
[0226] The forming machine 200 that is described above may also be integrated into a line 300 for producing pots by forming according to the invention, for example as illustrated in
[0227] Such a production line comprises a forming machine 200 as well as intake means 310 of a sheet of forming material starting from at least one feed roll 311.
[0228] The intake means 310 of the sheet of forming material are suitable for bringing a portion of the sheet of material 312 into contact with the upper face 101 of the opening molds 100 in such a way that the portion of the sheet of material 312 is connected in a continuous manner to the feed roll 311.
[0229] Thus, in particular, the intake means 310 of the sheet of forming material in the opening molds 100 of the forming machine 200 do not cut said sheet of forming material.
[0230] Furthermore, as illustrated in
[0231] As indicated above, because of the limited distance from the opening O of the opening molds 100, the rows of molds 210 are close to one another in the demolding direction D, and it is possible to use a single and continuous sheet of forming material for forming n*m pots in a forming step without resorting to accompanying devices for precutting the sheet of forming material.
[0232] A heating device 213 can be placed upstream from the forming machine 200 for preheating the sheet of forming material for the forming operation.
[0233] The line 300 for producing pots can also comprise intake means 320 of a capping sheet starting from at least one feed roll 321 of the capping sheet.
[0234] In a manner that is similar to what was described relative to the sheet of forming material, the intake means 320 of the capping sheet are suitable for bringing a portion of the capping sheet 322 opposite to the openings 3 of pots 1 that are shaped by the pot-forming machine of the production line.
[0235] The production line then advantageously comprises a device for sealing pots 330 that is suitable for putting into contact and sealing said portion of the capping sheet 322 with the collar 6 of the pots 1.
[0236] As can be seen in
[0237] Finally, the production line can also comprise, as is known, a device for metering contents 350 as well as a device for cutting out pots 340, illustrated in