US3844455A

US3844455A - Captive cap for dispensers

Info

Publication number: US3844455A
Application number: US00308237A
Authority: US
Inventors: M Stull
Original assignee: STULL ENGRAVING CO
Current assignee: STULL ENGRAVING CO
Priority date: 1969-10-17
Filing date: 1972-11-20
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29

Abstract

A captive cap for dispensers comprising a threaded tubular body or spout and a screw cap both of molded plastic composition. The spout and cap have cooperable stop lugs one of which has a camming surface. When the cap is applied at the factory, it is screwed clockwise to the full-on, sealing position. Part way through the screwing on, the lugs become engaged, and are forced past each other by a camming action which temporarily cams radially outward the lug on the screw cap and also causes a localized stretching of the adjoining wall of the cap. Thereafter the lugs constitute stops to halt the screw cap in the full-on sealing position, or in the partially unscrewed, dispensing position. The screw cap is thus held captive on the body, being turnable to various dispensing positions and to the full-on sealing position, even though it was initially applied by a turning or screwing-on movement.

Description

United States Patent .[191

Stull @ct. 29, 1974 CAPIIVE CAP FOR DISPENSERS [76] Inventor: Morton B. Stull, c/o Stull Engraving Primary Emmljlerstanley Tonberg CQ 221 223 Banta Ave" Garfield Assistant Examiner-Norman L. Stack, Jr. 07026 Attorney, Agent, or Firm-H. Gibner Lehmann; K.

Gibner Lehmann [22] Filed: Nov. 20, 1972 [21] Appl. No: 308,237 [57] ABSTRACT Related US. Application Data A captive cap for dispensers comprising a threaded [63] Continuation-impart of Ser. No. 867,199, Oct. 17, tubular y P and a Screw p both of molded 19 9, abandon plastic composition. The spout and cap have cooperable stop lugs one of which has a camming surface. 52 us. c1. 222/525 When the p is pp at the flattery, it is Serewed [51] Int. Cl B67d 3/28 clockwise to the full-0n, Sealing po o Part y [58] Field of Search 222/499, 520, 521, 525; o g e screwing the g become e g g 215/40 and are forced past each other by a camming action which temporarily cams radially outward the lug on [56] Referen Cit d the screw cap and also causes a localized stretching of UNITED STATES PATENTS the adjoining wall of the cap. Thereafter the lugs constitute stops to halt the screw cap in the full-on sealing g g position, or in the partially unscrewed, dispensing po- 3I351I249 11/1967 StulliIIiIiIII 1:: 222 520 Sition- The Screw cap is thus held captive the body, 3,370,764 2/1968 Stull 222 499 being tumable to various dispensing Positions and to 3 40 ,379 10 19 3 5 222/520 X the full-on sealing position, even though it was initially 3,406,880 10/1968 Stull 222/521 applied by a turning or screwing-on movement.

3,407,967 10/1968 Stull 222/521 X 0 3,598,285 8/1971 Stull 222/521 x 7 Chums 11 Drawing Flgures Pmmcunme is 3.844.455

SHEH 1 M 3 YNVENTOR. -Mov on B. StuLL Pmcmmm 29 m4 3. 844.455

SHEU 2 0f 3 INVENTOR. Mqr'to n E). 5131M,

CAPTIVE CAP FOR DISPENSERS The present application is a continuation-in-part of my copending application, Ser. No. 867,199 filed Oct. 17, 1969 and having the same title; this copending application has been abandoned for lack of prosecution.

CROSS REFERENCES TO RELATED APPLICATIONS AND PATENTS 1. US. Pat. No. 3,319,843 dated /16/67 2. US. Pat. No. 3,339,773 dated 9/5/67 3. U.S. Pat. No. 3,351,249 dated 11/7/67 4. U.S. Pat. No. 3,407,967 dated /29/68 5. US. Pat. No. 3,406,880 dated 10/22/68 6. US. Pat. No. 3,370,764 dated 2/27/68 7. Copending application of Morton B. Stull, Ser. No. 855,971 filed 9/8/69, entitled Captive Dispensing Cap Construction", and having common ownership with the present application.

BACKGROUND This invention relates to screw caps or closures for dispensers, and more particularly to closures of this type wherein the screw cap proper is held captive on the spout or body portion. The present invention is another species of the generic invention described and claimed in my above-identified copending application.

Heretofore, dispensing caps of the captive type involved either a construction where the cap was initially applied to the body part by mainly an axial movement involving stripping of the threads past each other, or a construction wherein annular detent beads were initially forced past each other and thereafter constituted the stop means. These prior caps performed satisfactorily in many circumstances but could not be assembled by conventional rotary-type capping equipment.

SUMMARY The above disadvantage of prior captive screw caps is obviated by the present invention, one object being the provision of an improved captive screw cap wherein the initial applying of the cap proper is done by the usual clockwise turning or screwing-on movement, and wherein there are positive stops not only to limit the screwing-on of the cap but also to prevent the complete unscrewing and removal of the cap. This is accomplished by a cap construction comprising a threaded tubular body or spout and a screw cap both of molded plastic composition. The spout and cap have cooperable stop lugs one of which has a camming surface. When the cap is applied at the factory, it is screwed clockwise to the full-on, sealing position. Part way through the screwing-on, the lugs become engaged, and are forced past each other by a camming action which temporarily cams radially outward the lug on the screw cap and also causes a localized stretching of the adjoining wall of the cap. Thereafter the lugs constitute stops to halt the screw cap in the full-on sealing position, or in the partially unscrewed, dispensing position. The stop lugs normally have abutting engagement whereby the stop action is of a positive nature.

Other objects and features of the invention reside in the provision of an improved captive screw cap as above set forth, which is especially effective and reliable in its operation, simple construction, involves few parts, and is inexpensive to produce.

Still other feature and advantages will hereinafter appear. 1n the drawings:

FIG. 1 is a side elevational view of the cap body part of the construction, with the screw cap part shown in axial section.

FIG. 2 is a top plan view of the body part.

FIG. 3 is a bottom plan view of the body part.

FIG. 4 is a side elevational view of the screw cap part of the construction.

FIG. 5 is a top plan view of the screw cap part.

FIG. 6 is an axial section of the screw cap part, taken on line 66 of FIG. 5.

FIG. 7 is a side elevatioal view of the cap construction with a portion of the cap part broken away. This view illustrates the interference and camming action between the stop lugs during assembly of the cap part to the body part.

FIG. 8 is a transverse section taken on line 8-8 of FIG. 7.

FIG. 9 is a section similar to that of FIG. 8 but illustrating a modification of the invention.

FIG. 10 is an axial section similar to FIG. 6, of a screw cap part as used in the modification of FIG. 9.

FIG. 111 is a side elevational view of the cap construction, constituting another embodiment of the invention. The upper portion of the screw cap is shown in axial section.

As seen in FIGS. l-8, the improved dispensing cap construction of the invention comprises a cap body or spout part designated generally by the numeral 10, and a screw cap part designated generally by the numeral 12. The spout or cap body part 10 is of tubular configuration, being adapted for attachment to a container (not shown) as by means of internal screw threads 14 disposed in a lower portion 16. It will be understood that the portion 16 of the body part may be screwed onto the threaded neck of the container. Containers having spouts which are integral with the container walls are well known, and the body part l0, 18 could be constituted as such.

The body part 10 has a discharge spout portion 18 terminating at its upper or outer end in a stopper pin 20 which is supported by three webs 22 defining triangular openings 24 through which the product from the container can pass after traversing the spout portion. The screw cap part 12 has a central opening 26 in its tip to accommodate the topper pin 20 when the cap is screwed down to its full-on position as shown in FIG. I. A seal is thus effected by the pin 20, preventing leakage of the product from the cap construction. The screw cap part 12 also has an annular sealing surface 28 arranged for tight engagement with a shoulder portion 30 of the spout 18 to effect a seal below the triangular openings 24 of the spout.

The body part 10 and screw cap part 12 have a pair of mutually engageable portions comprising cooperable screw thread means 32, 34 respectively on said parts for moving the cap part axially as it is turned. The screw thread means comprises a helical thread element 32 of the buttress type, said thread element having working surfaces characterized by a relatively small slope or angle with respect to the axis of the cap construction. In place of the buttress type thread, a usual rounded bead-like thread can be employed. The non sloping shoulders of the buttress thread element prevent a one-way stripping, that is, prevent the cap part from being forcibly applied to the body part by purely axial movement In accordance with the present invention at least one of the parts of the cap construction, and preferably both said parts are constituted of resilient, yieldable plastic substance such as polyethylene or other suitable well-known formulation whereby advantage is taken of the yieldability to effect a captive or stop action which prevents complete unscrewing and removal of the cap part 12. The cap part is normally held captive on the body part after it has been screwed on the latter to the full-on position or at least past an intermediate position representing the full-open or unstopped condition of the cap.

The

helical thread elements

32, 34 function to effect downward (as viewed in FIGS. 1 and 7) axial movement of the cap part 12 as the latter is turned in a clockwise direction (as viewed from the top) and applied to the body part 10. However, if during such screwing-on operation the cap part 12 should encounter some momentary or yieldable obstruction to its axial movement, as by cooperable lugs shortly to be described, one or both of the closure parts can yield radially and become temporarily oval or out-of-round in cross section as the cap part overcomes the obstruction. This is shown in FIG. 8. When the temporary obstruction to turning and axial movement of the cap part ceases, the parts will spring back and be restored to their initial, normal or non-yielding, non-deformed condition. The lug structure which provides the temporary obstruction is described further below.

The body part has a second or additional thread element, comprising a cam track 36 provided around the base of the spout portion 18, said cam track being cooperative with an interior stop lug 38 provided within the bottom rim 40 of the cap part 12. The lug 38 rides on the cam track 36 and imparts a positive outward axial movement to the cap part as the latter is turned in unscrewing direction.

In accordance with the invention the cap and body parts have a second pair of mutually engageable portions. comprising cooperable stop lugs, one of which is constituted as the lug 38, said lugs providing the abovementioned temporary obstruction. The second lug, disposed on the spout portion 18 of the body part, is designated 42 and is disposed at the high end of the cam track 36. The stop lug 42 has opposite surfaces 44, 46 which are respectively engageable with

opposite surfaces

48, 50 of the stop lug 38. Aslo, in accordance with the invention, the lug 42 has a camming portion 52 constituting a face which slopes with respect to the direction of movement to be engaged by the stop lug 38 of the cap part 12 as the latter is screwed onto the body part 10, such engagement being illustrated in FIGS. 7 and 8. The engagement with the sloping face 52 constitutes a momentary obstruction or impediment to the downward turning or screwing-on movement of the cap part 12 and as such movement is forcibly continued the

parts

10 and 12 will yield and the lug 38 will ride past the outside of the lug 42 as effected by the sloped face 52. This action will cause a deformation of the wall of the cap 12 and more particularly of the rim 40 thereof, so that said rim assumes somewhat of an egg shape. Also, the rim 40 adjacent the lug 38 will experience a localized temporary stretching of the plastic material, until the lug 38 becomes disengaged from the lug 42. Referring again to FIGS. 7 and 8, as the clockwise turning movement of the cap part 12 is continued, the stop lug 38 thereof will be forced completely past the lug 42 of the body part 10 and upon reaching the surface 44 of the lug 42 it will snap radially inward so as to engage the high portion of the cam track 36. This snapping inward of the lug 38 and adjoining wall of the cap part 12 is due to the tendency for the deformed parts to resume the non-yielding or unsprung condition.

Upon the lug 38 of the cap part being cammed past the lug 42 of the body part, the screwing-on movement of the cap part can be continued until it reaches the full-on position of FIG. I.

It will now be understood that as the consumer unscrews the cap part 12 to avail himself of the product, the lug 38 can be brought into engagement with the stop surface 44 of the lug 42, whereby further unscrewing of the cap part 12 will be prevented. For the full-on position of the cap part, the surface 48 of the lug 38 is engaged with the surface 46 of the lug 42, whereupon there exist positive stops defining not only the full-on position of the screw cap but also the full-open position of the same.

For different intermediate positions of the cap part 12, the extent of closing of the discharge opening 26 by the sealing pin 20 can be varied, thereby providing a degree of control of flow of the liquid product from the container.

A modification of the invention is illustrated in FIGS. 9 and 10. In these figures the spout or cap body part 10a has a lug 42a which is not provided with the sloping face; instead the lug 380 on the cap part 120 has the sloping face 52a at its lower portion. During the screwing on of the cap part 12a, the sloping face 52a of the lug 38a will engage the lug 42a of the spout part, and this will cause the lug 38a to ride outside of the lug 42a as shown in FIG. 9. After the lug 38a has been forced past the lug 42a, the opposite surfaces 48a and 50a of the lug 30a will be cooperable with the corresponding surfaces 440 and 46a of the lug 42a to prevent removal of the cap part and to limit the screwing-on movement of the same in the manner already described above in connection with the cap part 12.

As seen in FIG. 10, the cap part 12a has an orifice opening 26a, screw threads 34a and a bottom rim 40a similar to the corresponding portions of the cap part 12.

As with the embodiment of FIGS. I-8, the cap and body parts 12a, are preferably molded of resilient plastic substance, and both parts yield so as to become slightly egg-shaped or out-of-round as shown in FIG. 9, in order to permit the lug 38a to bypass the lug 42a during the screwing-on operation of the cap part.

In FIG. 8 it will be noted that the

surfaces

44, 52 of the lug 42 lie in planes which are substantially parallel to the axis of the body part 10. Also, surfaces of the lug 38 which are cooperable with the

surfaces

44, 52 lie in plane which are substantially parallel to the axis of the body part 10.

In FIG. 9 the

surfaces

44a and 46a of the lug 42a lie in planes which are substantially parallel to the axis of the body part 10a. Further, the surfaces of the lug 38a which cooperate with the surfaces 440 and 46a lie in planes which are substantially parallel to the axis of the body part 10a. By such disposition of the cooperable surfaces of the cap-captivating lugs a unique and surprisingly new mode of operation occurs when assmebling the cap part to the body part, since the yieldable wall of either one of said parts which is resilient and which moves radially outward or inward constitutes a circumferentially localized wall portion, with the result that the entire circumference of the wall is not required to either simultaneously expand or contract in order to permit bypassing of the lugs. This constitutes an important feature of the invention, since it makes for a softer and more yieldable screw-on action.

It is to be noted from FIGS. 8 and 9 that the extent of engagement of the lugs 38, 42 (38a, 42a) corresponds to a small fractional part of the arcuate extent of the circumference. That is to say, the lugs engage one nother along an arc of substantially less that 90 during the bypass thereof.

Another embodiment of the invention is illustrated in FIG. 11, wherein there is shown a tubular body part 18b having a double helical'thread 32b of rounded or convex cross-configuration. The screw cap part 12b has a cooperable double thread formation 34b mating with the threads 32b. By this arrangement a faster lead is had, in response to turning movement of the cap 12b. The tubular body 18b includes a lug 42b, 44b with a sloping surface 52b. The screw cap 12b has a cooperable lug 38b which is shown in dotted outline in H0. ll.

The connstruction of FIG. 11 has the advantage that a more secure screwing action is provided by the rounded nature of the screw threads and by the fact that a double thread is provided, resulting in a more uniform distribution of the axial forces as the cap 12b is screwed down. This insures a positive by-passing of the lug 42b, 44b by the cap lug 38b.

It will now be understood from the foregoing that l have provided a novel and improved captive dispensing cap construction wherein the cap part is threaded onto the body part by a conventional screwing-on movement, and wherein after the cap part reaches its full-on position, it will be prevented and held from complete removal by a positive stop. The unscrewed or dispensing position of the cap part 12 and also the full-on or sealing position of the part are determined by positiveaction stop lugs, and the cap part is held captive on the body part once it has been applied thereto and screwed past the full-open dispensing position.

Variations of the structures shown are possible without departing from the spirit of the invention.

I claim:

I. A captive dispensing cap construction comprising, in combination:

a. a tubular body part adapted to be carried by a container and having a discharge spout,

b. a screw cap part carried by said body part and surrounding said discharge spout.

c. said cap and body parts having two pairs of mutually engageable portions,

d. one pair of mutually engageable portions comprising cooperable screw thread means respectively on said parts, for moving the cap part axially on the body part as the cap part is turned,

e. the other pair of mutually engageable portions comprising cooperable stop lugs disposed respectively on the body and cap parts only at circumferentially localized points, said lugs having a plurality of sets of mutually engage-able surfaces which are disposed in planes substantially parallel to the axis of the tubular body.

f. one set of said mutually-engageable surfaces of the lugs becoming engaged and acting in a manner to halt the turning of the cap part as the latter is screwed toward its full-on position on the body part,

g. another set of surfaces of the said lugs becoming engaged and halting the opposite turning of the cap part as the latter is unscrewed through part of a revolution from said full-on position,

b. one of the mutually-engageable surfaces of said stop lugs having a sloping camming face with respect to the other stop lug, to cam one lug radially outwardly and facilitate bypass of the lugs as the cap part is screwed. onto the body part,

. at least one of said parts having lug-carrying wall portion which is resilient and yieldable in a radial direction and capable of localized stretching to enable the stop lug on the cap part to be forced past the outside of the stop lug on the body part as the cap part is applied to the body part and screwed toward its full-on position,

j. said lugs engaging one another along an arc of substantially less than during said bypass of the lugs.

2. A cap construction as in claim 1, wherein:

a. the lug-carrying wall portion which is resilient and capable of localized stretching is on the cap body part.

3. A cap construction as in claim 1, wherein:

a. the lug-carrying wall portion which is resilient and capable of localized stretching is on the cap part.

4. A cap construction as in claim 1, wherein:

a. both the cap part and the cap body part have lugcarrying wall portions which are resilient and yieldable and capable of localized strtching.

5. A cap construction as in claim 1, wherein:

a. the stop lug on the body part has the sloping face.

6. A cap construction as in claim 1, wherein: a. the stop lug on the cap part has the sloping face.

7. A cap construction as in claim 1, wherein:

a. the cooperable screw means on said parts comprise a double thread on the body part and a double thread on the cap part, and

b. said double threads being of rounded cross-

Claims

1. A captive dispensing cap construction comprising, in combination: a. a tubular body part adapted to be carried by a container and having a discharge spout, b. a screw cap part carried by said body part and surrounding said discharge spout, c. said cap and body parts having two pairs of mutually engageable portions, d. one pair of mutually engageable portions comprising cooperable screw thread means respectively on said parts, for moving the cap part axially on the body part as the cap part is turned, e. the other pair of mutually engageable portions comprising cooperable stop lugs disposed respectively on the body and cap parts only at circumferentially localized points, said lugs having a plurality of sets of mutually engageable surfaces which are disposed in planes substantially parallel to the axis of the tubular body. f. one set of said mutually-engageable surfaces of the lugs becoming engaged and acting in a manner to halt the turning of the cap part as the latter is screwed toward its full-on position on the body part, g. another set of surfaces of the said lugs becoming engaged and halting the opposite turning of the cap part as the latter is unscrewed through part of a revolution from said full-on position, h. one of the mutually-engageable surfaces of said stop lugs having a sloping camming with respect to the other stop lug, to cam one lug radially outwardly and facilitate bypass of the lugs as the cap part is screwed onto the body part, i. at least one of said parts having lug-carrying wall portion which is resilient and yieldable in a radial direction and capable of localized stretching to enable the stop lug on the cap part to be forced past the outside of the stop lug on the body part as the cap part is applied to the body part and screwed toward its full-on position. j. said lugs engaging one another along an arc of substantially less than 9* during said bypass of the lugs.

2. A cap construction as in claim 1, wherein: a. the lug-carrying wall portion which is resilient and capable of localized stretching is on the cap body part.

3. A cap construction as in claim 1, wherein: a. the lug-carrying wall portion wHich is resilient and capable of localized stretching is on the cap part.

4. A cap construction as in claim 1, wherein: a. both the cap part and the cap body part have lug-carrying wall portions which are resilient and yieldable and capable of localized strtching.

5. A cap construction as in claim 1, wherein: a. the stop lug on the body part has the sloping face.

7. A cap construction as in claim 1, wherein: a. the cooperable screw means on said parts comprise a double thread on the body part and a double thread on the cap part, and b. said double threads being of rounded cross-sectional configuration.