WO1998025836A1

WO1998025836A1 - Container closure with slide lock

Info

Publication number: WO1998025836A1
Application number: PCT/US1997/022312
Authority: WO
Inventors: Ray Pritchett; Paul Andrews; Harry Fletcher; Merrel J. Locke; John Bitner; Mark W. Dressel
Original assignee: Lawson Mardon Wheaton Inc.
Priority date: 1996-12-11
Filing date: 1997-12-08
Publication date: 1998-06-18

Abstract

A closure for a container is provided. The container has a neck (51) and a flange (52) on the neck. The flange has an opening (54). The closure comprises a cap having a top surface and a cylindrical wall. The cylindrical wall has a top end proximate to the top surface, a bottom end, and an arcuate opening (22) at the bottom end. An arcuate slide (30) is slidably mounted to the cap for axial movement. The slide is sized to cover the opening in the cylindrical wall. The slide has a retracted position and an extended position, such that the slide extends beyond the bottom end of the cylindrical wall when the slide is in the extended position. The slide is manually actuable to the retracted position. A biasing mechanism is provided for moving the slide towards the extended position, so that the slide extends into the opening in the flange when the cap is screwed onto the container. This limits rotation of the cap relative to the container.

Description

CONTAINER CLOSURE WITH SLIDE LOCK

FIELD OF THE INVENTION

The present invention relates to closures for containers generally, and in particular to locking closures.

BACKGROUND OF THE INVENTION A variety of locking (child resistant) closures for containers have been developed. These closures reduce the risk of harmful substances being handled or consumed by children or other persons lacking the ability to understand the danger posed by the substances in the containers. Some child resistant closures also have the desirable feature of automatically locking when the cap is placed on the container. Unfortunately, the same features that make the child resistant closure difficult for a child to open may make the closure difficult for an adult to open.

Many child resistant closures of the prior art present a problem for individuals who have the knowledge and maturity to handle or use the substances properly but do not have the muscular strength or dexterity needed to open and/or close the containers.

For example, some common child resistant closures are described in U.S. Patent 2,847,139 to B.G. Christiansson et al and U.S. Patent 2,964,207 to E. J. Townes. The Townes and Christiansson et al. patents describe two-piece caps in which the inner portion is threaded for engaging the threads of the container. The outer portion has a raised position in which it rotates freely relative to the inner portion, and a lowered position in which the outer portion engages the inner portion. The outer portion is biased upward, to the raised position. The outer portion must be pushed down manually for engagement between the outer portion and the inner portion. If the outer portion of the cap is not pressed downward, when the outer cap is rotated, it simply spins without affecting the inner portion. To open the container, the user must push the outer portion of the cap down at the same time the cap is twisted to loosen the cap. This may be difficult for users with limited muscle strength, especially if the cap is screwed on tightly. U.S. Patent 4,989,739 to Falcone describes a child-resistant container and closure combination. The closure and container are threaded. The container includes a flange on the neck portion of the container, located below the threads. The flange includes a hole. The cap portion includes a pin slidably mounted in the cap. When the cap is screwed on and positioned correctly, the pin can be pushed downwards through the hole in the flange, thus locking the cap in place. The pin is engaged in the cap in a friction fit. The pin is not biased downward to engage the hole in the flange. The pin must be inserted into the flange manually. The cap does not lock automatically, which is a disadvantage in that an adult may forget to lock the cap, making the contents of the container accessible to children.

U.S. Patent 5,325,980 to Grimm et al. describes a locking cap closure combination. The closure includes a satellite ring which extends from one side of the circular closure. The container also includes a satellite ring. When the closure and container are threaded together, the satellite rings align, and a pin may be manually inserted through the rings. The pin is designed such that, once inserted, it is not removable. The pin must be cut off, and is not reusable. The pin thus locks the container and also acts as a tamper indicator. Furthermore, the container and closure do not lock automatically. The pin must be inserted manually once the closure is attached to the container. Again, manual locking allows a user to leave the container unprotected. U.S. Patent 3,526,332 to Adelberger also shows a threaded cap and closure assembly including a locking pin. Adelberger' s pin does not interact with a flange on the neck of the bottle. Rather, the threads on the container are discontinuous in one area. When the cap is threaded onto the container, and the pin is aligned with the thread-free neck portion, the pin can be pushed downward and fits snugly against the thread-free portion of the neck of the container. This way, the cap cannot be unscrewed without raising the pin, because the pin cannot pass over the threaded area. The security is not automatic; the pin must be manually pushed into the locking position.

A locking, child-resistant closure is desired that is difficult for a child to open, but easy for an adult to open. Preferably, the child resistant closure may be opened and closed by individuals with limited strength and/or dexterity. Additionally, the child resistant closure should automatically lock when it is screwed on to the container.

SUMMARY OF THE INVENTION

The present invention is a closure for a container having a neck and a flange on the neck. The flange has an opening.

The closure comprises a cap having a top surface and an outer wall. The outer wall has a top end proximate the top surface, a bottom end, and an opening at the bottom end.

A slide is slidably mounted in the cap for axial movement. The slide is sized to cover the opening in the outer wall. The slide has a retracted position and an extended position, such that the slide extends beyond the bottom end of the outer wall when the slide is in the extended position. The slide is manually actuable to the retracted position.

A biasing mechanism is provided for moving the slide to the extended position, so that the slide extends into the opening in the flange when the cap is screwed on to the container. This limits rotation of the cap relative to the container.

According to another aspect of the invention, a closure for a container comprises a cap and an arcuate slide. The container has a neck and a flange on the neck. The flange has an opening. The cap has a top surface. The cap has outer and inner cylindrical walls.

The outer cylindrical wall has a top end proximate the top surface, a bottom end, and an arcuate opening at the bottom end. The inner cylindrical wall is concentric with and smaller in diameter than the outer cylindrical wall. The cap has a pair of side walls connecting the outer and inner cylindrical walls to form a channel. The cap also has a pair of retaining members positioned at the bottom end of the outer cylindrical wall, on opposite sides of the opening in the outer cylindrical wall.

The arcuate slide is slidably mounted to the cap for axial movement within the channel and is retained by the retaining members. The slide is sized to cover the opening in the outer cylindrical wall. The slide has a retracted position, to which the slide is manually actuable, and an extended position, in which the slide extends beyond the bottom end of the cylindrical wall. The slide has a top end facing the top surface of the cap, and at least one projection formed of a flexible material attached to the top end of the slide for biasing the slide towards the extended position. The slide extends into the opening in the flange when the cap is screwed on to the container, thereby limiting rotation of the cap relative to the container.

These and other aspects of the invention are described with reference to the Figures and the exemplary embodiments.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is an exploded front isometric view of an exemplary container and closure in accordance with the invention.

FIG. 2 is a front isometric view of the container and closure of FIG. 1, with the closure screwed onto the container.

FIG. 3 is a side isometric view of the container and closure of FIG. 2, with the closure partially unscrewed.

FIG. 4A is a front elevation view of the cap of FIG. 1.

FIG. 4B is a bottom plan view of the cap of FIG. 4A.

FIG. 4C is a cross sectional view of the cap of FIG. 4B, taken along section line 4C-4C. FIG. 4D is an enlarged view of the retaining member shown in FIG. 4A.

FIG. 5 A is a front elevation view of the slide shown in FIG. 1.

FIG. 5B is a cross sectional view of the slide shown in FIG. 5A, taken along section line 5B-5B.

FIG. 5C is a top plan view of the slide shown in FIG. 5A. FIG. 5D is a bottom plan view of the slide shown in FIG. 5A.

FIG. 6A is an exploded isometric view of a second exemplary container and closure according to the invention. FIG. 6B is a bottom plan view of the second exemplary cap shown in FIG. 6A.

FIG. 7A is a front elevation view of a second exemplary slide suitable for use in the caps shown in FIGs. 1 and 9. FIG. 7B is a cross sectional view of the slide shown in FIG. 7A, taken along section 7B-7B.

FIG. 8A is a front elevation view of a further exemplary slide suitable for use in the caps shown in FIGs. 1 and 9A.

FIG. 8B is a cross sectional view of the slide shown in FIG. 8A, taken along section 8B-8B.

FIG. 9A is an exploded front isometric view of another exemplary locking container and closure in accordance with the invention.

FIG. 9B is a front isometric view of the container and closure of FIG. 9A, with the closure screwed onto the container. FIG. 9C is a plan view of a variation of the container shown in FIGS. 9 A and 9B.

FIGS. 10A-10C are front elevation, cross sectional and plan views of another further exemplary slide suitable for use in the caps shown in FIGs. 1 and 9A.

DETAILED DESCRIPTION FIG. 1 is an exploded front elevation view of an exemplary locking container assembly 100 according to the invention.

The assembly includes a container 50 having a neck 51 and an annular flange 52 on the neck 51. The flange 52 has an opening 54. In the exemplary container 50, the flange 52 ends on either side of opening 54; the opening is generally a complete interruption of the flange. Optionally, the opening may also be a portion (not shown) of the flange which does not protrude as far from neck 51 as do surrounding portions of the flange 52. A cap 10 has a top surface 12 and an outer cylindrical wall 14. The outer cylindrical wall 14 has a top end 14a proximate the top surface 12, a bottom end 14b, and an arcuate opening 22 at the bottom end 14b.

An arcuate slide 30 is slidably mounted to the cap 10 for axial movement. The slide 30 is sized to cover the opening 22 in the outer cylindrical wall 14. The slide

30 has a retracted position (shown in FIG. 3) and an extended position (shown in FIG. 1). The slide 30 extends beyond the bottom end 14b of the outer cylindrical wall 14 when the slide 30 is in the extended position. The slide 30 is manually actuable from the extended position (FIG. 1) to the retracted position (FIG. 3). Biasing means are included for biasing the slide 30 towards the extended position. In the exemplary embodiment, the biasing means include flexible projections 32 (described below with reference to FIGS. 5A-5C). The biasing means 32 cause the slide 30 to extend into the opening 54 in the flange 52 when the cap 10 is screwed on to the container 50, thereby limiting rotation of the cap 10 relative to the container 50. FIG. 2 is a front isometric view of the container and closure of FIG. 1, with the closure screwed onto the container. When the cap 10 is screwed onto the neck 51 of the container 50, the biasing means 32 push the slide 30 away from the top surface 12 of the cap 10, towards the container 50. Once the cap 10 is advanced sufficiently, the slide 30 extends down into the opening 54 in the flange 52. This substantially limits the rotation of the cap, so that the cap cannot be removed without actuating the slide to the retracted position, making it difficult for a child to open the container.

FIG. 3 is a side isometric view of the container and closure of FIG. 2, with the closure partially unscrewed. The container is rotated 90 degrees from the view of FIG. 2, with the opening 54 on the left. (Side 58 on the right of FIG. 2 is rotated to the left side of FIG. 3). To remove the cap 10, the user manually actuates the slide 30 against the biasing means to the retracted position, allowing the user to freely twist the cap 10 off the container 50. This may be accomplished by, for example, actuating the slide 30 with the thumb while twisting the cap 10 relative to the container 50.

The container and closure are in the same configuration shown in FIG. 3 while the cap 10 is being screwed onto the container 50, before the slide 30 is aligned with the opening 54 in the flange 52 of the container 50. While placing the cap 10 onto the container 50, the biasing means 32 push the slide 30 down against the flange 52. When the slide 30 is advanced sufficiently onto the bottle and rotated to a position in which the slide 30 is aligned with the opening 54 in the flange 52, the biasing means 32 automatically moves the slide 30 into the extended position to prevent rotation of the cap

10 relative to the container 50.

Because the cap 10 cannot rotate while the slide 30 is protruding into the opening 54 of the flange 52, the twisting torque for rotating the cap 10 to the position in which the slide 30 and the opening 54 are aligned is fixed. One of ordinary skill in the art can readily select the configuration of the cap, the flange and the threads so that any desired twisting torque is achieved. In particular, the cap 10 may be designed so that the slide 30 and the opening 54 are aligned (and rotation of the cap is prevented) without screwing the cap tightly onto the container. Thus, the slide extends into the opening in the flange to lock the cap while the cap is screwed onto the container with a torque less than a maximum desired torque. This makes the invention particularly advantageous for individuals with low muscle strength or dexterity.

FIGS. 4A-4D show the exemplary cap 10 of FIG. 1. As best seen in FIGS. 4B and 4C, the exemplary cap 10 has a two wall construction. Cap 10 also has an inner cylindrical wall 16 which is concentric with, and smaller in diameter than, the outer cylindrical wall 14. A channel 24 is formed between the outer cylindrical wall 14 and the inner cylindrical wall 16, for guiding the slide 30 between the retracted and extended positions.

The cap 10 may include at least one side wall 18 connecting the outer cylindrical wall 14 and the inner cylindrical wall 16, for guiding a side edge 30d of the slide 30 between the retracted and extended positions. In the exemplary embodiment, there are two radial side walls 18, one on each side of the channel 24. The channel 24 subtends an angle β.

According to another aspect of the invention, the cap 10 includes means for retaining the slide in the cap. In the exemplary embodiment, as best seen in FIG. 4D, the retaining means includes a pair of retaining members 20 positioned at the bottom end 14b of the outer cylindrical wall 14. The retaining members 20 are positioned on opposite sides of the opening 22 in the outer cylindrical wall 14. The retaining members 20 are of sufficient size to prevent the slide 30 from falling out or from becoming separated from the cap 10 inadvertently. The retaining members 20 are sufficiently small so that is easy to (intentionally) force the slide 30 past the retaining members 20 when assembling the cap 10 and the slide 30.

In the exemplary embodiment, the cap 10 is formed of polypropylene. Other materials known in the art may also be used, including (but not limited to): polyamides, polyethylene, polystyrene, ABS, polyesters, or any other appropriate material.

FIGS. 5A-5D show the slide 30 of FIG. 1. Slide 30 has an arcuate section 30c which may be in the form of a sector of a cylinder subtending an arc β of about 55 degrees. The radius of the outer cylindrical wall of arcuate section 30c is substantially the same as the radius of cap 10, so that the outer wall of section 30c is substantially flush with the outer wall of cap 10. The width γ of section 30c is slightly smaller than the width δ of opening 22 (shown in FIG. 4A) of the outer cylindrical wall 14 of cap 10. The width γ of section 30c is slightly greater than the distance between the two retaining members 20, to prevent the slide 30 from falling out. Optionally, the top corners of section 30c may be bevelled or rounded (not shown) to make it easier to insert the slide 30 past the retaining members 20 during assembly.

Exemplary slide 30 has two side rails 30d which are slidably received in the channel 24 of cap 10. Thus, slide 30 is free to move in only one direction (up and down). The side rails 30d subtend an angle which is substantially the same as the angle subtended by channel 24 (as shown in FIG. 4B); the tolerances on these angles are small. In the exemplary embodiment, both the channel and side rails 30d subtend an angle of about 70 degrees. Thus, the exact position of slide 30 (in the tangential direction) is determined by the close fit between the channel 24 of cap 10 and the side rails 30d of slide 30. A gap is maintained between the arcuate section 30c and the width of opening 22 of the outer cylindrical wall of cap 10; it is not necessary to maintain a tight tolerance on the difference between the width of arcuate section 30c and the width of opening 22. ( Alternatively, a small gap having a tight tolerance could be maintained between arcuate section 30c and opening 22; and a slightly greater gap with a looser tolerance would be present between side rails 30d and the channel 24).

Slide 30 also has an upper cylindrical section 30b. In the exemplary embodiment, section 30b covers the top of the opening 22 in outer cylindrical wall 14 when the slide 30 is in the extended position.

The top end 30a of the slide 30 faces the top surface 12 of the cap 10. As noted above, in the exemplary embodiment, the biasing means includes two projections 32 attached to the top end 30a of the slide 30. The exemplary projections 32 are arcuate members, formed of a flexible material. In the exemplary embodiment, the projections 32 are integrally formed as a part of the slide 30, and the entire slide is formed of polypropylene.

As noted above, section 30c of the exemplary slide 30 subtends an angle β of approximately 55 degrees. The opening 54 in the flange 52 of the exemplary container 50 subtends an angle α of approximately 90 degrees. By having an opening 54 that subtends a substantially larger angle α than the slide 30, a large tolerance is provided in the alignment between the slide 30 and the opening 54. This makes the alignment easy for an individual lacking manual dexterity, but still allows automatic, positive locking to make the container-closure combination 100 child resistant.

Variations of the invention are contemplated in which the angles α and β are varied. The angle β may vary within a range of, for example, approximately 40-70 degrees; the angle α may vary within a corresponding range of approximately 70-110 degrees, depending on the size of the slide 30.

VARIATIONS OF THE EXEMPLARY EMBODIMENT In addition to the exemplary embodiment, the invention may be practiced with a variety of variations.

FIG. 6A is an exploded isometric view of a second exemplary assembly 200 according to the invention, including a container 150 and cap 110. The cap 110 has two slides 30, which may be the same as the slide of FIGS. 5A-5D. Alternatively, these slides may subtend a smaller angle.

The cylindrical wall 114 of the cap 110 includes first and second arcuate openings 122 at the bottom end 114b of the cylindrical wall 114. In the exemplary embodiment of FIG. 6A, each opening 122 is the same as opening 22 of FIGS. 4A to 4D, and the two openings 122 are positioned at opposite sides of the cap 110, 180 degrees apart. Of course, if the slides subtend a smaller angle as set forth above, the openings should also subtend smaller angles.

The flange of the container 150 is divided into two annular portions 152a and 152b. First and second openings 154a and 154b separate the two portions 152a and 152b.

Operation of the assembly 200 shown in FIG. 6A is similar to the operation of the assembly 100 shown in FIG. 1 , except that for assembly 200, both slides 30 must be simultaneously placed in the retracted position (shown in FIG. 3) to allow rotation of the cap 110 relative to the container. The embodiment of FIG. 6 A may be more difficult for a child to open because of the need to manipulate two slides.

FIG. 6B is a bottom plan view of a possible configuration of the second exemplary cap shown in FIG. 6A. In FIG. 6B, the side walls 118 of the channels 124 are not radial, but are parallel to the axis of symmetry 128 of the cap 110. If a channel 124 as shown in FIG. 6B is used, the side rails 30d of slide 30 are shaped so as to be accommodated by channels 124. One skilled in the art would recognize that the walls 118 of cap 110 may also be oriented in the radial direction, like wall 18 of FIG. 4B.

One skilled in the art would recognize that variations in the exemplary slide 30 are also contemplated within the scope of the invention. These contemplated embodiments include, for example, variations of the biasing means of the slide 30. FIG.

7 A shows one such variation of slide 30.

FIG. 7A shows slide 130 having a slide spring 72 in place of the projections 32 (shown in FIG. 5A). As in the exemplary embodiment of FIG. 5 A, the thumb slide spring 72 is integrally formed as a part of slide 130. Such a configuration allows an individual to operate the slide in the same manner as that described above with reference to FIG. 5A, wherein the projections 32 are shown.

One skilled in the art could readily construct further variations of the biasing means, such as that shown in FIG. 8A, which includes two slide springs 82 on slide 230. The slide springs 82 may also be formed separately from the main section 30c of the slide, and inserted. The slide springs may also be formed as part of the cap (not shown). Alternatively, conventional springs (not shown) or their equivalent may be attached to the top end of the slide 230 or the underside of the cap for biasing the slide 230. FIG. 9A is an exploded front isometric view of a further exemplary container in accordance with the invention. FIG. 9 A shows an exemplary locking container assembly 300, including a platform 90 on the neck 51. The arcuate slide 30 contacts platform 90 when the cap 10 is secured onto the container 50. The addition of the platform 90 prevents the insertion of a finger or object under the slide which could otherwise actuate the slide upward. Such a platform makes it more difficult for a child to open the container because it requires the user to push upward on the front face of the slide. FIG. 9B shows the container 50 and cap 10 with the cap 10 screwed onto the container 50.

FIG. 9A also shows a notch 92 on flange 52. The notch 92 is formed with a reverse taper. Notch 92 pulls slide 30 inward and prevents the slide from bowing outward or moving in the radial direction when the cap 10 is turned without actuating the slide upward towards its retracted position. The notch 92 locks the slide 30 in when actuating or removing the cap 10 from container 50. Notch 92 prevents accidental circumvention of the locking mechanism which could otherwise occur if the slide 30 bows outward or moves in the radial direction.

FIG. 9C shows a variation of the container shown in FIGS. 9A and 9B. In the exemplary embodiment of FIG. 9C, the opening 354, notch 392 and platform 390 face one of the flat sides 356 of the container 350, instead of facing one of the corners (as shown in FIGS. 9A and 9B). The inventors have discovered that it is easier for some individuals to actuate the locking slide mechanism if the opening 354 and the slide 30 are aligned with a flat face 356. With the container of FIG. 9C, the user can place one thumb on the flat face 354 and the other thumb on the slide 30 while actuating the slide. One of ordinary skill in the art readily understands that the containers shown in FIGS. 1-3 and 6A may also be modified to have the opening 54 facing a flat face of the containers 50 or 150, respectively, for the same reason.

One skilled in the art could readily construct further variations of the biasing means, such as that shown in FIG. 10, which includes two lemon-shaped slide springs 1035 on slide 1030. The front surface 1031 may also have a plurality of ribs 1032, 1034, to provide a more positive grip on the slide face. The larger rib 1032 has a bottom surface 1032a which the user can push up directly. Other variations of the front surface 1031 may be used, such as a knurled front surface.

ADDITIONAL VARIATIONS

Although the exemplary container shown in the drawings has a round cap, other cap shapes may be used. For example, the top surface of the cap may be any polygon, for example, a square or octagon. In that case, the side outer wall of the cap would comprise a plurality of rectangles.

In particular, if the container is square shaped (i.e., a horizontal cross section of the container is square), a square cap may be preferable. The outer (side) wall of the square cap consists of four rectangular sides. At least one of the sides includes an opening at its bottom end, which may be a flat rectangular opening. A flat slide, which may be substantially rectangular, is slidably mounted for longitudinal up-and-down movement in the opening. The slide is sized to cover the opening in the outer wall. The slide has a retracted position and an extended position, such that the slide extends beyond the bottom end of the outer wall when the slide is in the extended position, the slide being manually actuable to the retracted position. The biasing means for a square cap may be the same as for the circular cap, and may operate the same way. The container flange for use with the square cap may either be round or square. In either case, the flange has an opening of sufficient size and appropriate shape to receive at least a portion of the slide.

Many other variations not shown in the drawings are also contemplated within the scope of the present invention. For example, in a further variation of the assembly in FIG. 1, the flange of the container may have a radius greater than the radius of the slide and may extend 360 degrees around the circumference of the container; the opening in the flange would be in the form of a slot or cut-out (not shown) in the flange, the slot having a radius approximately equal to the radius of the slide 30, and subtending a sufficient angle to receive the slide 30.

Although the invention has been described with reference to exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed to include other variants and embodiments of the invention which may be made by those skilled in the art without departing from the true spirit and scope of the present invention.

Claims

What is Claimed: 1. A closure for a container having a neck and a flange on the neck, the flange having an opening, the closure comprising: a cap having a top surface and an outer wall, the outer wall having a top end proximate the top surface, a bottom end, and an opening at the bottom end; a slide, slidably mounted to the cap for movement in a longitudinal direction, the slide being sized to cover the opening in the outer wall, the slide having a retracted position and an extended position, such that the slide extends beyond the bottom end of the outer wall when the slide is in the extended position, the slide being manually actuable to the retracted position; and biasing means for moving the slide towards the extended position, so that the slide extends into the opening in the flange when the cap is screwed on to the container, thereby limiting rotation of the cap relative to the container.

2. A closure according to claim 1, wherein the outer wall is an outer cylindrical wall, the opening in the outer cylindrical wall is arcuate, and the slide is arcuate.

3. A closure according to claim 2, wherein the cap has an inner cylindrical wall concentric with and smaller in diameter than the outer cylindrical wall, and a channel is formed between the outer cylindrical wall and the inner cylindrical wall for guiding the slide between the retracted and extended positions.

4. A closure according to claim 3, further comprising at least one side wall connecting the outer cylindrical wall and the inner cylindrical wall, for guiding a side edge of the slide between the retracted and extended positions.

5. A closure according to claim 2, wherein the outer cylindrical wall of the cap includes a second arcuate opening at the bottom end of the outer cylindrical wall, and the flange of the container includes a second opening, the closure further comprising: a second slide, slidably mounted to the cap for axial movement, the second slide being sized to cover the second opening in the outer cylindrical wall, the second slide having a retracted position and an extended position, such that the second slide extends beyond the bottom end of the outer cylindrical wall when the second slide is in its extended position, the second slide being manually actuable to its retracted position; and further biasing means for moving the second slide towards its extended position, so that the second slide extends into the second opening in the flange when the cap is screwed on to the container.

6. A closure according to claim 1, wherein the slide extends into the opening in the flange to lock the cap while the cap is screwed onto the container with a torque less than a maximum desired torque.

7. A closure according to claim 1, wherein the slide subtends an angle of approximately 55 degrees, and the opening in the flange subtends an angle of approximately 90 degrees.

8. A closure according to claim 1, wherein the cap includes means for retaining the slide in the cap.

9. A closure according to claim 8, wherein the retaining means includes a pair of members positioned at the bottom end of the outer wall on opposite sides of the opening in the outer wall.

10. A closure according to claim 1, wherein the biasing means include at least one projection attached to a top end of the slide, the top end of the slide facing the top surface of the cap, the projection being formed of a flexible material.

11. A closure according to claim 10, wherein the projection is an arcuate member.

12. A closure according to claim 10, wherein the projection includes a loop at an end thereof.

13. A closure for a container having a neck and a flange on the neck, the flange having an opening, the closure comprising:

(a) a cap having: (1) a top surface, (2) outer and inner cylindrical walls, the outer cylindrical wall having a top end proximate the top surface, a bottom end, and an arcuate opening at the bottom end, the inner cylindrical wall being concentric with and smaller in diameter than the outer cylindrical wall, (3) a pair of side walls connecting the outer and inner cylindrical walls to form a channel, and (4) a pair of retaining members positioned at the bottom end of the outer cylindrical wall on opposite sides of the opening in the outer cylindrical wall; and (b) an arcuate slide, slidably mounted to said cap for axial movement within the channel and retained by the retaining members, (1) said slide being sized to cover the opening in the outer cylindrical wall, (2) said slide having a retracted position to which said slide is manually actuable and an extended position, in which said slide extends beyond the bottom end of the outer cylindrical wall,

(3) said slide having a top end facing the top surface of said cap, and at least one projection formed of a flexible material attached to the top end of said slide for biasing said slide towards the extended position, wherein said slide extends into the opening in the flange when said cap is screwed on to the container, thereby limiting rotation of said cap relative to the container.

14. A locking container assembly comprising:

a container having a neck and a flange on the neck, the flange having an opening; a cap having a top surface and an outer wall, the outer wall having a top end proximate the top surface, a bottom end, and an opening at the bottom end; a slide, slidably mounted to the cap for movement in a longitudinal direction, the slide being sized to cover the opening in the outer wall, the slide having a retracted position and an extended position, such that the slide extends beyond the bottom end of the outer wall when the slide is in the extended position, the slide being manually actuable to the retracted position; and biasing means for moving the slide towards the extended position, so that the slide extends into the opening in the flange when the cap is screwed on to the container, thereby limiting rotation of the cap relative to the container.

15. A locking container assembly according to claim 14, wherein the flange has a notch facing the opening, the notch preventing radial movement of the slide if the cap is turned without actuating the slide to the retracted position.

16. A locking container assembly according to claim 14, wherein the neck has a platform located below the opening of the flange.

17. A locking container assembly comprising: a container having a neck and a flange on the neck, the flange having an opening; a cap having a top surface and an outer cylindrical wall, the outer cylindrical wall having a top end proximate the top surface, a bottom end, and an arcuate opening at the bottom end; an arcuate slide, slidably mounted to the cap for axial movement, the slide being sized to cover the opening in the outer cylindrical wall, the slide having a retracted position and an extended position, such that the slide extends beyond the bottom end of the outer cylindrical wall when the slide is in the extended position, the slide being manually actuable to the retracted position; and biasing means for moving the slide towards the extended position, so that the slide extends into the opening in the flange when the cap is screwed on to the container, thereby limiting rotation of the cap relative to the container.

18. A locking container assembly according to claim 17, wherein the flange has a notch facing the opening, the notch preventing radial movement of the slide if the cap is turned without actuating the slide to the retracted position.

19. A locking container assembly according to claim 17, wherein the neck has a platform located below the opening of the flange.

20. A locking container assembly according to claim 17, wherein the cap has an inner cylindrical wall concentric with and smaller in diameter than the outer cylindrical wall, and a channel is formed between the outer cylindrical wall and the inner cylindrical wall for guiding the slide between the retracted and extended positions.

21. A locking container assembly according to claim 20, further comprising at least one side wall connecting the outer cylindrical wall and the inner cylindrical wall, for guiding a side edge of the slide between the retracted and extended positions.

22. A locking container assembly according to claim 17, wherein the slide extends into the opening in the flange to lock the cap while the cap is screwed onto the container with a torque less than a maximum desired torque.

23. A locking container assembly according to claim 17, wherein the slide subtends an angle of approximately 55 degrees, and the opening in the flange subtends an angle of approximately 90 degrees.

24. A locking container assembly according to claim 17, wherein the cap includes means for retaining the slide in the cap.

25. A locking container assembly according to claim 24, wherein the retaining means includes a pair of members positioned at the bottom end of the outer cylindrical wall on opposite sides of the opening in the cylindrical wall.

26. A locking container assembly according to claim 17, wherein the biasing means include at least one projection attached to a top end of the slide, the top end of the slide facing the top surface of the cap, the projection being formed of a flexible material.

27. A locking container assembly according to claim 26, wherein the projection is an arcuate member.

28. A locking container assembly according to claim 17, wherein the outer cylindrical wall of the cap includes a second arcuate opening at the bottom end of the cylindrical wall, and the flange of the container includes a second opening, the locking container assembly further comprising: a second slide, slidably mounted to the cap for axial movement, the second slide being sized to cover the second opening in the outer cylindrical wall, the second slide having a retracted position and an extended position, such that the second slide extends beyond the bottom end of the outer cylindrical wall when the second slide is in its extended position, the second slide being manually actuable to its retracted position; and further biasing means for moving the second slide towards its extended position, so that the second slide extends into the second opening in the flange when the cap is screwed on to the container.

29. A locking container assembly according to claim 17, wherein: said container has a flat face, and said opening and said flat face of said container are aligned in a common direction.

30. A locking container assembly according to claim 14, wherein: said container has a flat face, and said opening and said flat face of said container are aligned in a common direction.