Single-Thread Screw Thread Variator Device

Abstract

A screw thread variator device, provided in an opening (3) of a package, and a cap 26, provided with a plurality of protruding cutting elements (30) on the internal face 29 of the cap element 27 thereof. Said screw thread variator device is provided with a plurality of downward grooves 2c which connect to upward grooves 2f, within which internal screw thread segments (19) can pass.

Claims

1. A single-groove screw thread variator device 1 provided with an outer thread 2 applied to the outer surface of an elongate cylindrical body 3 which is attached to the upper face 9s of a base element 9 and provided with a lower face 9i, said outer thread 2 comprising: a plurality of first downward upper ridges 2a, each provided with an upper face 10 and a lower flank 12; a plurality of first downward lower ridges 2b, each provided with an upper flank 11 and a lower flank 13; a plurality of downward grooves 2c formed between the lower flanks 12 of each first downward upper thread 2a and the upper flanks 11 of each first downward lower thread 2b, with each downward groove 2c provided with an entry 4a; a plurality of second upward upper ridges 2d, each provided with an upper flank 14 and a lower flank 16; a plurality of second upward lower ridges 2e, each provided with an upper flank 15 and a lower flank 17; a plurality of downward end-stop 18, each downward end-stop 18 provided with a lower flank 18a; the lower flanks 12 of each first downward upper thread 2a meet the lower flanks 16 of each second upward upper thread 2d at a first junction point 6, wherein one flank is a continuity of the other and forms a concave angle between them; the upper flanks 11 of each first downward lower thread 2b meet the top flanks 15 of each second upward lower thread 2e at a second junction point 7, wherein one flank is a continuity of the other and forms a convex angle between them; the upper end of said lower flank 18a of each upward end-stop 18 meets the lower flank 16 of each second upward upper thread 2d at a third junction point 32, wherein one flank is a continuity of the other and forms a convex angle there between; the lower end of said lower flank 18a of each upward end-stop 18 meets the upper flank 15 of each second upward lower thread 2e at a fourth junction point 33, wherein one flank is a continuity of the other and forms a convex angle there between; and a plurality of upward grooves 2f, adjacent to the said downward grooves 2c, and formed between the lower flank 16 of each upward upper thread 2d, the upper flank 15 of each upward lower thread 2e, and the lower flank 18a of each upward marker 18, with the upward grooves 2f having a thread angle of opposite orientation to the thread angle of the adjacent downward grooves 2c.

2. Cap 26 for a single-groove screw thread variator device, comprising: a disc-like top element 27, provided with an inner face 29; an elongate side wall 28 which completely surrounds the inner face 29 of the top element 27 and extends vertically in the shape of a cylinder trunk; a plurality of inner thread segments 19, provided on the inner face of the elongate side wall 28, equidistant from each other and from the inner face 29 of the top element 27, and each inner thread segment 19 provided with an front end 20 and an rear end 21; and at least one protruding cutting member 30, extending vertically from the inner face 29 of the top element 27, said element having at least one protruding cutting member 30 provided with a sharp end 30a.

3. A method for installing a cap 26 according to claim 2 in a container provided with a single-groove screw thread variator device 1 according to claim 1, comprising the following steps: initiate a screwing movement of the cap 26 on the thread 2 of the spout 3 of said container, so that the front ends 20 of each inner thread segment 19 pass through the entries 4a of the thread 2 and engage the downward grooves 2c; proceed with the screwing movement of the cap 26 on the thread 2 of the spout 3 until the rear ends 21 of each inner thread segment 19 pass by the first junction point 6 and the front ends 20 of the inner thread segments 19 reach the second junction point (7); continue the screwing movement of the cap 26 on the thread 2 of the spout 3 so that the inner thread segments 19 leave the downward groove 2c and are directed to the upward groove 2f, causing the front ends 20 of the inner thread segments 19 to be forced against the upper flanks 15 of the second lower ridges 2e, and the cap 26 begins an upward axial movement; proceed with the screwing movement of the cap 26 on the thread 2 of the spout 3 until the front ends of the inner thread segments 19 reach the lower face 18i of the end-stops 18 and front ends 20 of the inner thread segments 19 reach the fourth junction points 33, to stop the upward axial screwing movement of the cap 26 on the thread 2 of the spout 3; and affix the assembly formed by the cap 26 screwed fully onto the spout 3 to the container, in the region where it will be opportunely opened.

4. A method for opening a container provided with a single-groove screw thread variator device 1 according to claim 1 which has been previously screwed to a cap 26 according to claim 2, according to the method described in claim 3; the method to open said container comprising the following steps: start an unscrewing movement of the cap 26 in relation to the thread 2 of the spout 3, so that the rear ends 21 of the inner thread segments 19 begin an unscrewing movement within the enlarged grooves 4f and impinge the lower flanks 16 of the second upward upper ridges 2d, whereby the cap 26 performs a downward axial movement; proceed with the unscrewing of the cap 26 in relation to the thread 2 of the spout 3, causing the ends of the inlet 20 of the inner thread segments 19 to pass through the upper flanks 15 of the second upward lower ridges 2e, continuing the axial downward movement of the cap 26, so that the rear ends 21 of the inner thread segments 19 pass completely beyond the first junction point 6 and the front ends 21 of the internally threaded segments 19 reach the second junction point (7) so that the execution of this initial unscrewing and downward axial movement of the cap 26 forces each of the downward cutting elements 30 of the cap 26 to penetrate and rupture the material of the container; proceed with the unscrewing movement of the cap 26 in relation to the thread 2 of the spout 3, so that the inner thread segments 19 begin to be inserted in the lower regions of the downward grooves 2c wherein the axial movement of the cap 26 becomes an ascending movement to enable it to be unscrewed from the spout 3.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The features of the present invention will be better appreciated from the detailed description which follow, by way of example, associated with the attached drawings referenced below which are an integral part of this specification.

[0065] FIG. 1 is a front view of an outer thread provided with a spout which is part of the single-groove screw thread variator device, object of the present invention.

[0066] FIG. 2 is a bottom perspective view of a cap provided with inner thread segments forming part of the single-groove screw thread variator device of the present invention.

[0067] FIG. 3 is a front cross-sectional view showing the time when the inner thread segments of the cap begin to be inserted into the inner thread of the spout.

[0068] FIG. 4 is a front cross-sectional view showing the moment when the inner threads of the cap are in a first position, partially inserted in the grooves of the inner thread of the spout.

[0069] FIG. 5 is a front cross-sectional view showing the moment when the inner threads of the cap are in a second position, partially inserted in the grooves of the inner thread of the spout.

[0070] FIG. 6 is a front cross-sectional view showing the moment when the inner threads of the cap are fully inserted into the grooves of the inner thread of the spout in their final mounting position.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0071] FIGS. 1 to 6 depict a spout device provided with a cap on which is employed a container opening mechanism which uses the screw thread variator device, object of the present invention, with the purpose of obtaining the longitudinal movements with advance and retreat to effect the opening of the container.

[0072] In FIG. 1, according to the present embodiment, a screw thread variator device 1, object of the present invention, is used in an elongate cylindrical body 3. An outer screw thread 2, or simply a thread 2, is provided on the outer surface of an elongated cylindrical body 3, which in the present case is a three-entries thread.

[0073] The elongated cylindrical body 3 may, for example, be a spout of a container to which a cap, not shown in the Figure, may be screwed onto the upper face 9s of a base element 9, whose lower face 9i shall be affixed to a container, as shown in FIGS. 1 to 6.

[0074] Hereafter, the term spout and the terms elongate cylindrical body will be used interchangeably, i.e., to indicate the same component.

[0075] Each ridge of the outer thread 2 comprises a first downward upper thread 2a, provided with an upper flank 10 and a lower flank 12, and a first downward lower thread 2b, provided with an upper flank 11 and a lower flank 13.

[0076] A downward groove 2c is formed between the first downward upper thread 2a and the first downward lower thread 2b, and is provided with an inlet (4a).

[0077] The outer thread 2 also comprises a second upward upper thread 2d, adjacent to the first downward upper thread 2a, a second upward lower thread 2e, adjacent to the first downward thread 2b, and an end-stop 18.

[0078] The second upward upper thread 2d is provided with an upper flank 14 and a lower flank 16, and the second upward lower thread 2e is provided with an upper flank 15 and a lower flank 17. The end-stop 18 is provided with a lower flank 18a.

[0079] An upward groove 2f is formed between the second upward upper thread 2d, the second upward lower thread 2e and the end-stop 18.

[0080] At a first junction point 6, there is a connection between each first descending upper thread 2a and each second upward upper thread 2d, so that the transition from the lower flank 12 of the first downward upper thread 2a to the lower flank 16 of the second upward upper thread 2d is such that one flank is a continuity of the other and forms a concave angle there between.

[0081] At the first junction point 6 a transition occurs from the right-handed thread configuration of the first downward upper thread 2a to a left-handed thread configuration of the second upward upper thread 2d.

[0082] Thus, the angle of inclination of the first downward upper thread 2a relative to the thread generatrix and the inclination angle of the second upward upper thread 2d relative to the thread generatrix is chosen to conform to a right-handed thread and a left-handed-thread, respectively.

[0083] At a second junction point 7 a union occurs between each first downward lower thread 2b and each second upward lower thread 2e, so that the transition from the upper flank 11 of the first downward lower thread 2b to the upper flank 15 of the second upward lower thread 2e is such that one flank is as an extension of the other and forms a convex angle between them.

[0084] At the second junction point 7 the transition occurs from a right-handed thread configuration of the first downward lower thread 2b to a left-handed thread configuration for the second upward lower thread 2e.

[0085] Thus, the inclination angle of the first downward lower thread 2b in relation to the thread generatrix and the inclination angle of the second upward lower thread 2e in relation to the thread generatrix are both chosen to conform to a right-handed thread and a left-handed thread, respectively.

[0086] The angle of inclination of the left-handed thread from the second upward lower thread 2e is substantially equal to the angle of inclination of the left-handed thread of the second upward upper thread 2d.

[0087] The second upward upper thread 2d is attached to the end-stop 18 at a third junction point 32. The end-stop 18 has a right-handed thread configuration, in this embodiment having an angle of inclination substantially identical to the angle of the first downward upper thread 2a and the first downward lower thread 2b.

[0088] As the second upward lower thread 2e is a left-handed thread, consequently the end-stop 18 will join the second upward lower thread 2e at a fourth junction point 33. The upward groove 2f is formed between the second upward upper thread 2d, the second upward lower thread 2e and the end-stop 18, as can be seen in FIG. 1.

[0089] The cap 26, shown in FIG. 2, basically comprises a disc-shaped cap element 27 having an inner face 29 and an elongate side wall 28 in the shape of a straight cylinder trunk. Inner thread segments 19 are provided inside the elongated side wall 28. In the present case, three segments are provided equidistant from each other in a sequence.

[0090] The inner thread segments 19 are provided with a front end 20 and a rear end 21.

[0091] In the present embodiment the inner thread segments 19 are, in fact, segments of an internal six-entries thread, which has the same characteristics as the thread 2 applied to the spout 3, wherein only three inner thread segments 19 were manufactured instead the six inner thread segments 19 that could have been manufactured. In other words, segments were manufactured in an alternate manner.

[0092] It should be mentioned that the provision in the present embodiment of only three inner thread segments 19 is only a design option, and can in no way be considered a limitation of the invention. There would be no impediment for the cap 26 to be provided with all possible inner thread segments 19. In the case of the present embodiment there would be six inner thread segments 19.

[0093] As can be seen in FIG. 2, the inner face 29 of the top element 27 is provided with multiple protruding cutting elements 30, distributed circumferentially and provided with sharp ends 30a, which in this embodiment form a rotating cutting element, intended to make the package cut, as will be seen later.

[0094] When the cap 26 is screwed for the first time on the thread 2 of the spout 3, a factory-made operation, the front ends 20 of the inner thread segments 19 will pass through the entries 4a of the thread 2, and will engage the downward groove s 2c, as can be seen in FIG. 3.

[0095] As the inner thread segments 19 are screwed onto the outer thread 2, they will effect a concomitant downward axial movement, and consequently, the same will occur with the cap 26. In other words, in addition to the rotational twisting movement, there will also occur a downward axial movement.

[0096] With the continuity of the rotational screwing movement of the inner thread segments 19 on the downward groove s 2c of the thread 2 of the spout 3, the front ends 20 of internally threaded segments 19 will advance along the inside of the downward groove s 2c, as shown in FIG. 4.

[0097] At a determined moment, the rear ends 21 of each inner thread segment 19 will pass by the first junction point 6 and the front ends 20 of the inner thread segments 19 will reach the second junction point 7 at the lower end of the first downward lower thread 2b, as shown in FIG. 5.

[0098] Thereafter, the inner thread segments 19 will leave the downward groove 2c and will be directed to the upward groove 2f, and the front ends 20 of the inner thread segments 19 will be forced against the upper flanks 15 of the second upward lower threads 2e.

[0099] Upon continuation of the screwing movement, the front ends 20 of the inner thread segments 19 will slide through the upper flanks 15 of the second upward lower threads 2e.

[0100] As the second upward lower threads 2e have a left-handed upward thread configuration, this will cause the inner thread segments 19 to undergo a reversal of direction in their axial movement, which will then be an upward axial movement, as the inner thread segments 19 are traversing the extension of the upper flanks 15 of the second upward lower threads 2e within the upward groove 2f.

[0101] Consequently, the cap 26 will cause an upward axial movement, which ends at the instant the entry ends 20 of the inner thread segments 19 reach the lower flank 18i of the end-stops 18.

[0102] At this instant, the closure movement of the cap 26 on the spout 3 then ends.

[0103] It is important to mention that the inner thread segments 19 are dimensioned in such a way as to perfectly fit within the upward groove s 2f, so that no problems occur during the closing operation of the cap 26, and in particular at the moment the inner thread segments 19 undergo a change of direction in their axial movement to start their entry into the upward grooves 2f.

[0104] When it is necessary to remove the cap 26 from its engagement to the spout 3 for the first time, a rotational movement of unscrewing of the cap 26 relative to the outer thread 2 of the spout 3 should be effected.

[0105] At the start of this unscrewing movement, the rear ends 21 of the inner thread segments 19 will touch the lower flanks 16 of the second upward upper threads 2d, which will cause the inner thread segments 19, in addition to effectuating an unscrewing rotating movement, to also start a downward axial movement as a result of the second upward upper threads 2d having a left-handed upward thread configuration.

[0106] Concomitantly, the front ends 20 of the inner thread segments 19 will run through the upper flanks 15 of the second upward lower threads 2e as the unscrewing movement of the cover 26 is effected.

[0107] This downward axial movement of the inner thread segments 19 ends when the rear ends 21 of the inner thread segments 19 fully passes by the first junction point 6 and the front ends 20 of the inner thread segments 19 reach the second junction point 7.

[0108] At this moment the inner thread segments 19 will start their entry into the lower regions of the downward groove s 2c passing between the first downward upper threads 2a and the first downward lower threads 2b.

[0109] From this moment on, and with the continued unscrewing movement of the cap 26, the inner thread segments 19 will travel the downward groove s 2c towards the entries 4a. After the inner thread segments 19 have passed entirely through the entries 4a the cap 26 is then completely unscrewed from the spout 3.

[0110] The combination of the initial circular unscrewing movement of the cap 26 and the consequent downward axial movement described above when the inner thread segments 19 pass through the upward groove 2f will cause the sharp ends 30a of the protruding cutting elements 30 to project onto the container from their initial mounting position, thereby effecting the cut and the consequent opening of the container on which the cap 26 is mounted.

[0111] The magnitude of the downward axial movement of the cap 26 will be dependent on the angles of inclination of the second upward upper thread 2d and the second upward lower thread 2e with respect to their generatrixes, which are substantially the same.

[0112] Although the rotating cutting element shown in FIG. 2 has protruding cutter elements 30 nearly the entire perimeter thereof, to ensure that the package is cut by their sharp ends 30a when the cap is opened the first time, a lesser number of protruding cutter elements 30 may be provided to save material, as long as they are provided in sufficient number to ensure the cutting of the package during the initial downward unscrewing of the cap.

[0113] For reasons of safety and hygiene, the cap 26 may be provided with an unscrewing prevention mechanism, not shown in the Figures. One of the functions of these cap screw unscrewing mechanisms is to provide the end user with a guarantee that the cap 26 has remained in the position in which it was assembled at the factory until the time when it will be unscrewed for removal of the contents from the container.

[0114] It is known in the art various types of tamper evident device to prevent unauthorised unscrewing of the cap, which, for this reason, are not described herein. In addition, they are not part of the present invention, and there is no impediment to them being used in conjunction therewith.

[0115] Thus, as has been shown, the screw thread variator device 1 object of the present invention provides an effective means of simple manufacture and use by providing components which cause a change in the direction of axial movement of the cap 26 at the initial moment when it is unscrewed from the spout 3.

[0116] Further, the present invention obviates the use of additional components, requires less material and less manufacturing time, and simplifies the entire assembly operation in the factory thereby reducing manufacturing costs and offers significant economic advantages.

[0117] While the present invention has been described with its application in threaded container spouts and applied to mechanisms driven by the unscrewing movement of caps or closures coupled to these spouts, it should be mentioned that the screw thread variator device of the present invention may be employed in any case in which it is necessary to use a cap provided with a rotating cutting element which serves to cut the material located immediately below the cap when the cap starts to be unscrewed from the spout to which it is threaded.

[0118] Thus, the present invention is not limited to the applications described in this specification and is only limited to the content of the claims that follow.