US20030234195A1

US20030234195A1 - Container having adjusting compartments

Info

Publication number: US20030234195A1
Application number: US10/178,609
Authority: US
Inventors: Milan Earl; Brian Earl
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-06-24
Filing date: 2002-06-24
Publication date: 2003-12-25

Abstract

A closeable container for storing and protecting materials having internal partitions extending radially and longitudinally creating at least two independent adjustable internal chambers within which stored materials are kept separated and are individually accessed for adding and dispensing purposes. In a substantially cylindrical embodiment of the instant device, separators forming the internal compartments are rotatable, thereby allowing adjustment of the volume of the internal compartments to accommodate dimensionally or quantitatively differing material. The compartments of the container automatically adjust volume as materials are added or dispensed. A variety of access means are presented which preclude commingling of materials between compartments during access. Transparent sides facilitate identification of stored materials within the chambers. The device is simple in design and inexpensive to produce and is envisioned to have a wide variety of uses for convenient and efficient storage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

This invention relates to storage containers, specifically to such containers that store various small articles

Organizing and storing small items has always been a problem for people like homeowners, handymen, carpenters, machinists, chefs and many others. They are frequently wasting time searching for particular items necessary to finish a task. Items at home are many times mixed and misplaced in junk drawers or in containers such as jars, cans, bags, and boxes. Countless hours are also wasted in organizing and storing items for future use.

Transporting such items also presents problems, since open containers may not be overturned without spillage. In addition, common storage methods are inefficient with regard to space utilized, and many unnecessary containers are usually required for carrying materials.

Since common storage containers are fixed in volume, unrelated materials are often combined within them in order to utilize the space available more efficiently. Screws, buttons, nails, brackets etc. will end up in the same jar, and must be identified and separated when wanted. A jar with a few screws in it wastes space, but adding nails creates its own set of problems.

Many products are currently available which organize, store and provide accessibility to small items. Such things as tool cabinets and medicine chests are designed to separate and differentiate their contents for storage. While these products have had some degree of success, they all lack certain qualities that are essential to people who need secure, compact, segregated, and convenient storage that affords easy identification of their stored items; e.g. carpenters who must organize types of screws, nails, bolts, etc.

The instant invention provides several advantages to its user. The contents are visible, so time is not wasted in finding items. The organizer has segmented compartments that can store and divide a variety of articles and keep them securely divided when the container is in any orientation. The device provides for the efficient use of storage capacity, with minimal empty space. Additionally, the contents of the organizer are easily dispensed, with no commingling of articles from adjacent compartments.

The instant containing device utilizes longitudinal dividers which create separate chambers accessible from the top or sides. Many embodiments are presented herein to describe different aspects of its novel feature. These embodiments have all the advantages described previously, allowing efficient use of space, organization, easy identification, portability, simple dispensing and secure containment.

A preferred embodiment of the container is a transparent closeable cylinder having separating vanes rotatably communicated around a central longitudinal axis of the cylinder, creating a number of wedge-shaped compartments which are independent of each other and are radially adjustable as to size. The vanes are contoured to match the contour of the container walls to prevent mixing of the items between adjacent chambers. Since all of the compartments are completely enclosed, the container may be turned in any orientation without spilling or commingling of the contents from chamber to chamber. The size-adjustable compartment principle of this embodiment is novel and unique and is not taught in any prior art.

The proposed container may be constructed with simple materials, such as plastics, for inexpensive production and efficient use.

Because the vanes, or separators, are radially adjustable, materials requiring smaller volume are automatically stored in a smaller wedge because chambers holding materials requiring more space will widen to accommodate those materials. In this manner, the device is very efficient in the use of space, while keeping the contents separated according to category.

This embodiment has a further advantage in that it allows the contents to be readily viewed through the transparent sidewalls. By rotating the device around the central axis, all the contents are instantly visible in a sequential compartment after compartment manner. Presently used storage methods, such as small utility cabinets having transparent plastic drawers, require bending and provide poor visibility of the drawer contents, which are usually only viewable from the front. Cabinets are typically large, and hold very little. In addition, these holders are not easily moved, since the enclosed materials spill when the cabinet is tilted or inverted. The instant invention stores materials more securely and does not waste space.

Although specifically designed molded holders, such as closeable drill bit cases with sized cavities for each bit, meet many needs previously discussed, they are necessarily large and limited in their storage capacity. These molded cases typically leave no options for storing other related materials, only those materials for which the case is expressly designed. The instant device can provide a number of highly visible compartments of variable volume and are thereby more practical, especially for adding related materials.

None of the prior art presented herein teaches variable volume for storage.

Prior art such as U.S. Pat. Nos. 3,498,471, 3,441,033, 6,364,125 and 6,378,533 do not afford easy identification of the articles that they organize. It is necessary for users to label or memorize the contents. Furthermore, in some cases, removal of stored articles is complicated and time consuming. The cosmetic jar of U.S. Pat. No. 6,378,533 shows a horizontally compartmentalized container. The advantages described herein, such as visibility, security, accessibility, and simplicity of the present invention are obvious over this prior art, U.S. Pat. Nos. 3,498,471, 3,441,033, and 6,378,533 also teach lateral storage of materials and need pivoted movement to access those materials.

U.S. Pat. Nos. 5,626,266, 6,318,602 and 522,693 do not permit an assortment of items to be stored and are limited in their design because they must remove the entire contents of their container at one time.

U.S. Pat. No. 5,797,491 describes a tool carrier which is not fully enclosed, therefore contents will spill when tipped or overturned. Although providing segmented compartments, they are made of fabric and cannot visually display the contents of the carrier. Furthermore, this carrier is quite cumbersome, and not convenient for transport.

U.S. Pat. Nos. 5,277,329, 5,344,024 and 5,027,972 have the same shortcomings and are somewhat complicated in their general structure. The case of U.S. Pat. No. 5,344,024 does not teach a separate access to cells which lie within. The entire lid must be raised to add or remove articles. Secure enclosure of the other compartments therefore falls very short of the instant device, which provides access to individual compartments within the container from the exterior, without disturbing the integrity of the remaining compartments.

Further embodiments of the present invention are described herein since it may be designed for a variety of uses. Fixed longitudinal separators are described, with compartments that may be permanently sized according to expected use of enclosed materials, with secure enclosure and access from the top or sides. None of the prior art provides all of these elements of the instant device: complete secure enclosure, portability, simple access, readily visible identification, and variable volume of chambers.

Although presently used containers exist having separate internal chambers with independent access means, such as weekly pill dispensers, these devices lack the shape and storage capacity provided by a device as presented herein. The embodiments of the instant invention have large storage capacity relative to the access cavity, they are more easily viewable, and they represent a structure which is generally more easily handled and durable than such existing devices. These valuable features are not obvious, evidenced by the lack of such devices for storage of articles today. Embodiments of the present device produce unforeseen advantages for storage of materials.

None of the prior art teaches a secure longitudinal compartmental container which offers individual accessibility from the exterior which maintains the integrity of the remaining compartments.

In short, the prior art or commonly used containers in use today do not anticipate the individual or combined advantages described in the present device. Some of these advantages are:

Easy and quick dispensing of contents

Portability and rugged security of contents

Efficient use of storage space

Simplicity of manufacture

Practical mass production of inexpensive construction material

Storage for a variety of items and materials

Design can be altered to accommodate both small and large storage volumes

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention a storage container comprises a top, a base and a substantially cylindrical body with at least one enclosed radially distributed rotatable separator and an access means that facilitates the storage of small items. The advantages of the instant invention are visibility of stored items, accessibility, easy transport, and variable volume storage. This invention is intended to provide a secure, efficient, and useful storage device.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

In the drawings, closely related figures have the same number but different alphabetic suffixes. [0033]
FIG. 1 illustrates a preferred embodiment of the container. [0034]
FIG. 2 illustrates the top view of the lid with rotatable disk. [0035]
FIG. 3 illustrates an independent unit of pivotable separators with rotating means. [0036]
FIGS. 4 and 5 illustrate differing views of the lid with divided access door entry. [0037]
FIG. 6 illustrates a view of the lid with flexible restraining bar access system for divided access doors. [0038]
FIG. 7 illustrates an adjustable access entry using upper and lower slotted access disks. [0039]
FIGS. 8 and 8[0040] a illustrate an embodiment of the invention with a sidewall aperture.
FIGS. 9[0041] a and 9b illustrate differing views of a primary rotatable separator which is centrally notched to accommodate secondary rotatable separator.
FIG. 9[0042] c illustrates a hinged embodiment of primary and secondary separators.
FIGS. 9[0043] d and 9e illustrate top views of the primary and secondary separators.
FIG. 10 illustrates a doublet embodiment of storage containers. [0044]
FIG. 11 illustrates a doublet embodiment of storage containers having both fixed and adjustable separators.[0045]

DETAILED DESCRIPTION OF INVENTION

FIG. 1 illustrates a preferred embodiment of the device. [0046] Top 10, tubular cylindrical body 20 and base 30 form a secure container.
[0047] Top 10 is comprised of a threaded retaining rim 40 having threads 50 matching those threads on cylindrical body 20 so it may be screwed on in a manner similar to a common jar. Holding lip 60 allows movement of rotatable disk 70 when retaining rim 40 is loosened, similar to the design of common mason jars. Flap 80 covers access hole 90 which rotates to a desired position when rotatable disk 70 is turned. Sidewalls 100 of tubular cylindrical body 20 are optionally transparent and may be constructed from a variety of materials, including plastic or glass.
Internally, [0048] pivotable separators 110 having hinges 120 are rotatably communicated with axle 130, which longitudinally extends from base 30 to top 10 along a central longitudinal axis. Axle 130 is optionally affixed to base 30 at a central point 140 thereby facilitating the free rotation of separator 110. Separators 110 are substantially rigid and flat and extend radially from axle 130 to sidewalls 100 and longitudinally from base 30 to top 10. Edges of separators 110 are shaped to closely conform to the interior contour of base 30, sidewalls 100 and top 10 so that they may be rotated easily yet prohibit stored material from transferring around the edges of these partitions.
Any number of [0049] separators 110 may be used, depending upon the intended use of the device. As can be seen, two adjacent separators 110, base 30, top 10 and sidewall 100 create a wedge-shaped compartment 150 within the container which confines materials to that compartment 150. Since separators 110 are pivotable in this embodiment, an angular movement of separator 110 changes the volume of compartment 150. This feature permits storage of differing quantities and sizes of materials within compartments 150.
Since [0050] cylindrical body 20 of the device is transparent, items stored within are easily identified from the exterior as the container is rotated. Because of gravitational principles, separators tend to flip as the container is rotated while in a horizontal orientation, further facilitating identification of stored materials.
A closer view of the top [0051] 10 of the embodiment is shown in FIG. 2. Finger catch 160 protrudes from rotatable disk 70 simplifying rotation by providing a location where lateral force may be effectively applied.
To access a [0052] particular compartment 150 within the container, rotatable disk 70 is turned to a position whereby access hole 90 is aligned with compartment 150. Flap 80 is frictionally closed over access hole 90 during storage and snapped open when addition or dispensing of materials is required. Flap 80 rotates around pivot pin 170 so that rear element 180 extends downward as the forward portion of flap 80 is deployed upward. Rear element 180 is sized and shaped to extend sufficiently downward and laterally to prevent the two pivotable separators 110 forming the compartment 150 from moving into the access hole 90 opening. In this manner, only one compartment 150 is accessible at a time and materials will not mix with other compartments when the container access hole 90 is open. Since rear element 180 extends downward into compartment 150 when flap 80 is deployed, the top edge of a pivotable separator 110 will prevent flap 80 from deploying if pivotable separator 110 is beneath flap 80. In this way, access may only occur when separators 110 are spaced sufficiently wide and are properly aligned.
A particular compartment may be widened if the device is horizontally oriented and the desired compartment is faced upward. Gravity forces the materials within the compartments to compress downward, thereby widening the [0053] uppermost compartment 150. Once this compartment 150 is of sufficient width, flap 80 may be raised and rear element 180 thereafter restrains adjacent separators 110, allowing access. This secured access to one compartment is maintained, regardless of orientation of the device, while flap 80 is deployed.
This embodiment, therefore, provides visibility, security, adjustable volume and access to compartmentalized materials. It is also envisioned that the internal structure of this invention is marketable as an independent device. As shown in FIG. 3, [0054] pivotable separators 110, and pivoting means 190 form an independent unit which may be inserted into an existing appropriate container in order to longitudinally compartmentalize that container. The unit may be designed to have dimensions which allow insertion and conformation to standardized containers such as jars and coffee cans, thereby forming longitudinally compartmentalized containers having many of the benefits presented in the instant described embodiments. Other embodiments of the interior structure of the present device are presented hereafter, all of which may also obviously be designed to be marketed independently.
It is obvious that form and structure changes may be made to the embodiment, such as having a sliding flap on the top, having a one piece top, having separators which hang over a central tube as rotating means, or curving the sidewalls of the tubular body while keeping it equidistant from the central axis for aesthetic purposes, without changing the basic concept presented herein. [0055]
Another embodiment of a top-located access to the interior chambers is illustrated in FIGS. 4 and 5 which show the lid in open and closed positions from different angles. Divided [0056] access doors 200 are of a size and shape to snugly cover pie-shaped access hole 90 and have finger tabs 210 which protrude slightly and communicate with top 10 by frictionally snap-fitting into snap depressions 220 when divided access doors 200 are closed. Top 10 rotates freely when divided access doors 200 are closed but remains in loose contact with the top of pivotable separators 110, so that materials do not intermingle when the device is inverted during use.
Divided [0057] access doors 200 have springable access hinges 230 that allow pivoting around access hole sides 240 when divided access doors 200 are forced downward or finger tabs 210 are lifted. Access to an internal compartment is possible only when two adjacent separators 110 are positioned wider than the dimensions of the access hole 90, since separators 110 will prevent downward movement of divided access doors 200 otherwise. Once the access hole 90 is rotated to the correct position, divided access doors 200 are forced downward or finger tabs 210 are lifted to provide access to a desired compartment. Divided access doors 200 restrain the two separators forming the compartment while material is added or removed from that compartment. This feature insures that material in all other compartments remains separate and secure when the desired compartment is accessed and the device is turned in any orientation. Closure occurs when finger tabs 210 are depressed and thereafter snapped. Finger tabs 210 also provide grip for easy rotation of top 10.
It may be noted herein that it is difficult to overfill a compartment when loading through [0058] access hole 90, since any material that interferes with closure of divided access doors 200 must first be removed. This insures that enough space is available for divided access doors 200 to pivot freely at a later time.
Rather than gaining access through divided [0059] access doors 200 as previously described, FIG. 6 illustrates a flexible restraining bar 250 which forces divided access doors 200 apart when depressed. Flexible restraining bar 250 bends over fulcrum 260 when depressed and is firmly attached at end point 270 to top 10. While flexible restraining bar 250 is held down, separators 110 are held apart by divided access doors 200. When released, flexible restraining bar 250 returns to a neutral position and divided access doors 200 are forced to a closed position by flexure of springs 275.
A further embodiment of adjustable access to an internal chamber of a container is illustrated in FIG. 7 wherein lower slotted [0060] access disks 280 and upper slotted access disk 290 are stacked and have pie-shaped notches 300 which provide access to a particular chamber within the device when pie-shaped notches 300 are aligned by rotation. Lower slotted access disk 280 is overlapped by upper slotted access disk 290 having retaining lip 310 which is rotatably pressure fit over cylindrical body 20 having wide rim 320. In this embodiment upper slotted access disk 290 necessarily has a larger diameter than lower slotted access disk 280 in order to fit around retaining rim 320 and hold lower slotted access disk 280 in place. It may be noted that upper slotted access disk 290 has characteristics similar to those of presently used safety medicine bottle tops, which design is obviously envisioned for use in the present device but not presented herein.
An embodiment of a sidewall aperture for dispensing enclosed material is illustrated in FIGS. 8 and 8[0061] a. Turning ring 330 is rotatably mounted on grooves 340 on cylindrical body 20 and has a slidable cover 350 over sidewall aperture 360. Turning ring 330 is shaped and wide enough to be flush with the interior surface of sidewall 100. In this manner, mixing of enclosed materials is prevented and structural integrity of the container is maintained. This embodiment illustrates that sidewall access to the longitudinal chambers within the container is feasible and embodiments having this feature are envisioned.
FIGS. 9[0062] a and 9 b illustrate an embodiment of the present invention having primary rotatable separator 370 which is centrally notched to accommodate communication with a secondary rotatable separator 380. This design is direct in nature, in that there are few moving parts, the rotatable separators simply fit together as illustrated. The means for pivoting is the notched communication between these separators. Interior chambers formed by this embodiment are more limited, since those chambers laterally opposite of each other are affected by rotational movement of the separator. By hinging at least one of the separators, as shown in FIG. 9c, chambers produced are somewhat independent of movements of other separators. Vanes 390 are hinged around pin 400 but still form a primary notch 410 which accepts secondary notch 420 of rigid divider 430. FIG. 9d illustrates an overhead view of this embodiment with dashed arrows showing possible movements of vanes 390. It may be seen that chamber volume is variable up to one half of the total volume in this embodiment.
A slotted embodiment of the device is not limited to four compartments. As can be seen in FIG. 9[0063] e, additional dividers may be structured to accommodate a variety of positions and sizes of chambers. Straight divider 440 is appropriately notched to accept two angled dividers 450. It is obvious that a multitude of notched embodiments are possible.
Since the present invention is longitudinally compartmentalized, an embodiment, as illustrated in FIG. 10, may be created to afford additional storage space and provide a unitary container which is easy to carry. This doublet embodiment simply connects two of the previously described embodiments in a base to base relationship wherein tops [0064] 10 are at opposing ends and afford access to interior compartments. It is possible to construct this embodiment with either pivotable or immovable separators or a combination of both. In this illustration, upper pivotable separators 460 move independently of lower pivotable separators 470.
The bases may either be permanently affixed or designed to be disconnected and reconnected as necessary by common snapping or threading means. It is envisioned that standardized dimensions of containers will allow combinations of different items to be transported and stored. For instance, one day a handyman may need metal screws and a certain assortment of brackets, another day he may need metal screws and nails. By disconnecting the container holding the brackets and connecting the container holding nails, he creates a single, transportable container for his needs on each day. By storing items in a number of single containers which are compatible for combining in a base-to-base manner, the user may transport the items he/she needs in fewer carrying units. It may be noted that such an embodiment is envisioned to have bases which are attachable and detachable, so that two devices holding materials may be mated temporarily to form a unit for transporting purposes and may thereafter be detached or attached to other devices. It is obvious that a similar arrangement is designable for compatibly connecting tops and bases to form connected stacks of the device. [0065]
FIG. 11 illustrates another doublet embodiment having both fixed [0066] separators 505 and pivotable separators. Some of the compartments extend from top to opposing top-such as long compartment 480, halfway-such as half compartment 490, or somewhere in between-such as short compartment 500. Long compartment 480 is shown to be fixed, while the others are adjustable. Arrows indicate the possible adjustable movement of pivoting partitions 510, allowing variations in volume of those affected compartments.
An example of a use for such a design is a common ratchet set. Bits may be stored in smaller chambers, but the ratchet driver itself is long and would be stored in a long fixed chamber. [0067]
The present invention has many obvious advantages over prior art. It represents a novel approach to storage of a variety of materials and its novelty is evidenced by the absence of any similar carrying and storage methods in use today. [0068]
Not only does the instant device have specific novel aspects, the combined effect of these novel features present an unobvious invention which is not anticipated in the prior art or in present usage. [0069]

It has advantages over other storage methods such as in this partial listing:



	compact storage	durability
	visible storage	lightweight
	not spillable	holds a variety of materials
	simple and variable design	inexpensive and simple to manufacture
	categorized materials kept	accessibility to stored materials
	separated
	may be sized to meet needs

The device is envisioned for use in containing the following partial list of materials;



	miscellaneous	change
	tools	samples
	fasteners	sewing needs
	craft supplies	drill bits, other bits
	art supplies	collectibles
	teaching supplies- chalk, tacks etc.	snacks
	desk supplies	candy
	keys	pills
	training supplies- band aids, tape etc.

It has been shown that the referenced prior art does not anticipate this device and that this device has advantages over presently existing storage methods. Since similar embodiments of the present device are not available in the present environment and the instant device represents a useful item having many advantages, it follows that it is novel in nature and unobvious. [0072]
Although the descriptions herein contain many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of the invention, thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. [0073]

Reference Numerals in

Drawings



10	top	20	tubular cylindrical body
30	base	40	retaining rim
50	threads	60	holding lip
70	rotatable disk	80	flap
90	access hole	100	sidewall
110	pivotable separators	120	hinges
130	axle	140	central point
150	compartment	160	finger catch
170	pivot pin	180	rear element
190	pivoting means	200	divided access doors
210	finger tabs	220	snap depressions
230	access hinges	240	access hole sides
250	flexible restraining bar	260	fulcrum
270	end point	275	springs
280	lower slotted access disk	290	upper slotted access disk
300	pie-shaped notches	310	retaining lip
320	wide rim	330	turning ring
340	grooves	350	slidable cover
360	sidewall aperture	370	primary rotatable separator
380	secondary rotatable separator	390	vane
400	pin	410	primary notch
420	secondary notch	430	rigid divider
440	straight divider	450	angled dividers
460	upper pivotable separator	470	lower pivotable separator
480	long compartment	490	half compartment
500	short compartment	510	pivoting partitions

Claims

We claim:

1. A container for holding items comprising:

(a) a top,

(b) a base,

(c) a substantially tubular sidewall,

(d) at least one substantially planar separator,

(e) at least one access means,

(f) a pivoting means,

whereby said tubular sidewall communicates distally with said base and proximally with said top forming a substantially cylindrical enclosed volume and said at least one substantially planar separator is in longitudinal rotatable communication with said pivoting means and edges of said at least one planar separator internally and substantially continuously communicate with said base, said top, and said sidewall forming at least two enclosed internal compartments whereby rotation of said at least one substantially planar separator with respect to said pivoting means volumetrically alters at least one of said at least two enclosed compartments and said items may be inserted into and dispensed from said at least two enclosed internal compartments through an access opening created by said at least one access means.

2. The container of claim 1 having connecting means whereby said connecting means communicates with a said connecting means of at least one other of said containers forming a combination of said containers whereby said combination increases total storage capacity and facilitates transport and manipulation of said containers.

3. The container of claim 1 wherein longitudinal dimension of said substantially tubular sidewall is greater than any dimension of said top and said base whereby said container is elongate and therefore easily transportable and manipulable.

4. The container of claim 1 wherein said at least one substantially planar separator and said pivoting means are components independent of said top, said base, and said substantially tubular sidewall whereby said at least one substantially planar separator and said pivoting means are insertable and removable from said enclosed volume.

5. The container of claim 1 wherein said at least one access means is moveably communicated with said container whereby said at least one access means is alignable to provide access to at least one of said at least two enclosed internal compartments.

6. The container of claim 1 whereby said at least one access means incorporates a restraining means whereby said restraining means prevents rotation of a said at least one planar separator into said access opening formed by said access means thereby precluding simultaneous access to more than one of said at least two enclosed compartments.

7. The container of claim 1 wherein at least one of said at least one substantially planar separators is in fixed communication with said pivoting means, said top, said base and said substantially tubular sidewall.

8. A substantially cylindrical enclosed hollow storage device for storing materials having at least one longitudinal internal partition and at least one external access means whereby at least one of said at least one longitudinal internal partition is moveable and communicates with internal surfaces of said substantially cylindrical enclosed hollow storage device thereby forming at least one enclosed interior chamber within said substantially cylindrical enclosed hollow storage device which is variable in volume and said materials are insertable and removeable from said at least one enclosed interior chamber through said at least one external access means.

9. The substantially cylindrical enclosed hollow storage device of claim 8 whereby said at least one external access means is moveable and alignable with said at least one enclosed interior chamber.

10. The substantially cylindrical enclosed hollow storage device of claim 8 wherein said at least one external access means has a separating means whereby said separating means forcibly restrains at least two of said at least one longitudinal internal partitions thereby providing external access to only one of said at least one enclosed interior chambers.