Patent Publication Number: US-8540104-B2

Title: Optical lens case

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of and claims priority to the subject matter in common with copending Nonprovisional patent application, Ser. No. 12/614,306, filed on Dec. 15, 2010, the complete disclosure of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The resent invention generally relates to the field of containers for carrying cameras, optical lenses, and other photographic equipment. More particularly, the present invention relates to embodiments of an interchangeable lens canister that affords protection against high impacts, high static force loads, extreme environmental temperatures, and water penetration. 
     BACKGROUND 
     Photographic cameras that support interchangeable lenses are the most common used among professional and semi-professional photographers. The ability to change the optical lens mounted to the camera body simply and quickly is the key to the utility of the interchangeable lens/camera system. Because a particular photographic task may require a particular photographic lens design, the user (photographer) can easily change the optical lens of the camera unit to best satisfy the optical requirement for the particular photographic task. Effectively, the interchangeable lens camera system allows the photographer to be able to meet a wide array of photographic tasks with a single camera body (and the correct interchangeable lens unit) as opposed to multiple cameras with fixed lens designs. 
     Due to the high utility provided by interchangeable lens camera systems, most photographers carry a single camera body and multiple interchangeable lens units to meet a wide array of photographic tasks. It is typical for the advanced photographer to have more money invested in interchangeable lenses than in the individual camera body, since typically camera bodies are replaced or upgraded while optical lenses are kept to meet future photographic needs. 
     Many camera case designs exist to carry and protect the camera unit and its mounted camera lens. Cases designed to carry individual (unmounted) camera lenses also exist. Most lens cases are either a) rectangular in shape, and/or b) composed of soft or semi-rigid material. Very few lens cases offer protection against high impacts, high static force loads, extreme environmental temperatures, and/or water penetration. 
     Typically, photographers carry their complete photo kit (camera body, multiple lenses, electronic accessories, etc.) in one large dedicated protective bag or hard case. This system works well in protecting all equipment simultaneously and equally. The downsides to this method for transporting equipment are a) the case or bag makes compromises in protecting each individual piece of equipment, b) it is difficult to make large “photographic” style bags subtle and low-key, c) carrying a large photographic bag prevents the user from carrying other required gear, d) photographic bags may not be adequate for transporting other equipment since they are specialized for a single purpose. 
     There are many photographers who must be able to carry other equipment into the field. This type of user may include outdoor, adventure, travel, and/or journalistic photographers to name a few. For these users, carrying a large, single-function camera bag is not an option. While on assignment, these users must be able to carry and protect a few pieces of photo equipment (mainly a camera body and spare lenses) and other ion-Photo related equipment in a single bag (backpack, luggage, or similar) designed for multiple purposes, not uniquely designed to transport and protect photographic equipment. These types of photographers do not have the luxury of needing to carry only photo equipment, and thus must accommodate professional and personal gear in their personal luggage. 
     Lens cases relevant to this disclosure are discussed in the following U.S. Patents, which are hereby incorporated by reference: U.S. Pat. Nos. 4,172,485; 4,177,894; 4,383,565; 5,49,589; 5,199,563; and 5,372,980. 
     SUMMARY 
     A dedicated rigid interchangeable lens case allows the photographer to carry a spare interchangeable lens in a single small well-protected package. With a dedicated spare interchangeable lens case, the photographer can have the choice to carry as few or as many interchangeable lenses as they desire. This, in turn, allows the photographer to carry any necessary amount of luggage, rather than a single large photo bag. 
     Depending on the size of each lens and the size of the interchangeable lens case, either multiple lenses can be stored in a single interchangeable lens case or each lens can be transported in individual smaller interchangeable lens cases. The rigid interchangeable lens case (with lens) can then be stored in personal baggage that does not have to be designed or dedicated to protecting and transporting photographic equipment, thus allowing the user to have more flexibility in baggage and equipment selection. With this dedicated lens case approach the photographer can carry only the protective case(s) he or she needs in a non-dedicated photo bag, yet not compromise on protection of the interchangeable lens unit(s). 
     Embodiments of an apparatus for receiving and protecting interchangeable camera lenses include a cylindrical body shell, having an outer rigid casing with inner and outer diameters, and having an inner soft-lined receptacle within the inner diameter of the body shell for receiving the camera lens; a base end cap; a ringed shaped mouth member having inner and outer diameters; a lid cap assembly; a first visco-elastic material bonded to the lid cap assembly; a second visco-elastic material bonded to the base end cap; and, the first and second visco-elastic materials conform to the shape of the lens when the lid cap assembly is engaged with the mouth member. 
     Some embodiments include a lid cap or lid cap assembly that is adapted to be removably engageable in a two-stage rotational interference fit with a mouth member, in which the lid cap is retained thereto. In a first stage of such a rotational interference fit, the lid cap is translatable along the axis of the body shell, with respect to the mouth member, between a non fluid-tight position and a fluid-tight position; and in a second stage of the rotational interference fit, the lid cap is retained in a fluid-tight position. 
     A set of components suitable for use with embodiments of the lens case apparatus described herein, for example to allow a user to create one or more customized cushioning rings for a lens or other item to be carried within a lens case, may include at least one shock-absorbing stabilizing disk having an outer diameter of a dimension adapted to engage the interior surface of the body shell in a friction fit; and a guide member having concentric circle indicia of different diameters thereon and adapted to be concentrically aligned with the stabilizing disk by means of the circle indicia, the circle indicia including indicia indicating the diameter of the interior surface of the body shell. 
     The concepts, features, methods, and embodiment configurations briefly described above are clarified with reference to the accompanying drawings and detailed description below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an exploded, perspective front view of the lens case constructed according to the teachings of the present invention. 
         FIG. 2  is a perspective front view of the lens case shown in  FIG. 1 . 
         FIG. 3  is a top plan view of the lens case shown in  FIG. 1 . 
         FIG. 4  is a bottom plan view of the lens case shown in  FIG. 1 , 
         FIG. 5  is a side plan, cross-sectional view of the lens case shown in  FIG. 1 , 
         FIG. 6  is a side plan, cross-sectional view of a non-limiting embodiment of the lens case. 
         FIG. 7  is a perspective front view of a lens case constructed according to the teachings of the present invention, and featuring an illustrative example of an alternate closure arrangement between the mouth member and the lid cap to that shown in  FIG. 1 , with a portion of the lid cap cut away to reveal internal structure. 
         FIG. 8  is a top plan view of the cylindrical body shell of the lens case of  FIG. 7 . 
         FIG. 9  is a bottom plan view of the lid cap of the lens case of  FIG. 7 . 
         FIG. 10  is a partial elevation view of the side of the mouth member, and the upper part of the cylindrical body shell, of the lens case of  FIG. 7 , and also shows various positions of one of the ridges of the engagement thread arrangement of the lid cap (which is not itself shown) relative to one of the ridges of the engagement thread arrangement of the mouth member. 
         FIG. 11  is a side plan, partial cross-sectional view of the mouth member and lid cap of the lens case of  FIG. 7  engaged in a first stage of a two-stage rotational interference fit, taken along the line  11 - 11  of  FIG. 7 . 
         FIG. 12  is a side plan, partial cross-sectional view of the mouth member and lid cap of the lens case of  FIG. 7  engaged in a second stage of a two-stage rotational interference fit, taken along the line  12 - 12  of  FIG. 7   
         FIG. 13  is a perspective front view of two stabilizing disks and two guide members which feature an illustrative example of additional components that a user may selectively employ to securely store a camera lens within a lens case. 
     
    
    
     DETAILED DESCRIPTION 
     Non limiting embodiments of the present invention utilize a lens case that is especially suited to transport and protect optical photographic lenses of various sizes and configurations and provide an alternative to carrying optical lenses in a large semi-rigid or soft dedicated photography bag. The lens case is waterproof and further provides a very high level of protection of its contents from environmental temperatures. In addition, the lens case is designed to protect against static force loads, cushion the lens against impacts, resist high impacts, and prevent unintentional opening of the lens case during its transport or storage. 
     Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures.  FIG. 1  is directed to a lens case or canister  10 . The lens case  10  has a body shell  20 , a ring-shaped mouth member  0 , a lid cap assembly gasket  50 , lid lock assembly  60 , base end cap  70 , and strap  80 . 
     With reference to  FIGS. 5 and 6  and continuing reference to  FIG. 1 , body shell  20  is a cylindrical tubing canister that has an outer rigid casing  22  and inner liner  26 . Outer rigid casing  22  has external surface  24  and internal surface  25 . Outer rigid casing  22  can be constructed from a cylindrical ABS tube that is cut to length to accommodate interchangeable lenses L with variable external lengths and external diameters. Various internal cavity diameters of the outer rigid case ranging from about 3 to about 4 inches can be used to accommodate lenses with complementary external diameters. In this disclosure, the external diameter of the lens is referred to as a lens diameter. 
     It should be understood by one of ordinary skill in the art that the outer rigid casing  22  can be constructed from any other suitable rigid material that is durable, tough, water-resistant, and relatively lightweight. Such materials include, but are not limited to, injection molded plastic, carbon fiber resin, or other metal or non-metallic alloy. 
     External surface  24  and the internal surface  25  of the outer rigid casing  22 , as well as the inner liner  26  are shown, in the non-limiting configurations of  FIGS. 5-6 . In the example shown in  FIGS. 5 and 6 , inner liner  26  extends from mouth member  30  to base end cap  70 . Grit-impregnated synthetic self-adhesive tape (not shown) may be attached to the external surface  24  to provide a firm grip of the lens canister  10 . Those of skill in the art will appreciate that any suitable material alternative is contemplated as being within the spirit and scope of the invention. 
     With continuing reference to  FIGS. 5 and 6 , inner liner  26  abuts internal surface  25  to form a soft-lined receptacle in which to receive the lens L. The inner liner  26  can be made from a thin, soft, and durable material, such as, but not limited to, Neoprene®. The inner liner  26  protects the external surface of the transported interchangeable lens L from damage upon entry into and exit from the lens case  10 . Inner liner  26  may also assist in dampening impacts to the lens case  10  during transport or storage. However, in some examples, such as shown in  FIGS. 5 and 6 , the inner liner may not contact the lens when the lens is stored in the lens case, but instead the lens case may provide for a gap of air around the lens for at least a portion of the height of the lens. The inner liner  26  may be removable for cleaning or replacement. 
     Referring back to  FIG. 1 , mouth member  30  is ring-shape and constructed from injection, molded and machined acrylic plastic. Those of skill in the art will appreciate that any suitable material alternative is contemplated as being within the spirit and scope of the invention. The mouth member  30  has grooves  32 , a flange  4  and stop notches  36 . The ring-shaped mouth member  30  is permanently bonded via epoxy  90  or cement  90  (See  FIGS. 5 and 6 ) to the outer rigid casing  22 , as shown in  FIG. 1 . A permanent adhesive bond with epoxy  90  or cement  90  is used to guarantee a water-tight seal, as well as to ensure a robust structure of the lens case  10 . 
     In  FIGS. 5 and 6 , outer diameter  33  of the mouth member  30  is illustrated. The mouth member  30  at outer diameter  33  can be bonded to the internal surface  25  of the outer rigid casing  22 , as shown in  FIG. 5 . Alternatively, in a non-limiting embodiment, the outer diameter  33  of the mouth member  30  can be bonded to the external surface  24  of the outer rigid casing  22  of the body shell  20 , as shown in  FIG. 6 . Smaller in external diameter interchangeable lenses L will be suited for the embodiment of  FIG. 6  with the mouth member  30  adhesively bonded to the external surface  24  of the outer rigid casing while a lens L with a longer external diameter can be used for the embodiment as represented in  FIGS. 1-5 . 
     Referring to  FIGS. 1 ,  2  and  3 , the lens canister  10  includes a lid cap assembly  40 . The lid cap assembly  40  has a thread ring  42 , cut-outs  44 , holes  45 , visco-elastic material  46 , and fasteners  48 . The lid cap assembly  40  is machined from a plastic material, in particular 0.25 inch thick ABS sheet, and has a disk-like circular shape. The lid cap assembly may be formed from a variety of other materials in different examples, such as other types of plastic, metals, or ceramics. The perimeter of the lid cap assembly  40  has semi-circular cut-outs  44  that enable a user to easily rotate the lid cap assembly  40  when closing or opening the lens case  10 . 
     In addition, the top side of the lid cap assembly  40  may employ various machined markings or etchings B, CW, and CCW. In a non-limiting embodiment of  FIG. 3 , markings B define a concentric pattern that increases the friction available for a user&#39;s finger to engage and manipulate the lid cap assembly, marking CW with arrow designates the functional rotation direction to close the lid case  10 , and marking CCW with arrow designates the functional rotation direction for opening the lens case  10 . Additional and alternative, markings may be used for product branding, as shown in a non-limiting embodiment of  FIG. 4 . 
     The thread ring  42  of the lid cap assembly  40  is constructed from injection molded and machined acrylic plastic. Those of skill in the art will appreciate that any suitable material alternative is contemplated as being within the spirit and scope of the invention. The underside of the lid cap assembly has a circular pocket  47  to accommodate the bonding and assembly of the thread ring  42 . 
     The lid cap assembly  40  including the thread ring  42  are permanently bonded with epoxy  90  and reinforced with fasteners  48 . In a non-limiting embodiment, the fasteners  48  in  FIGS. 1-6  are stainless steel screws. It should be understood by one of ordinary skill in the art that fasteners  48  can any other suitable material used to reinforce the types of materials used in the present invention. 
     Referring to  FIGS. 5 and 6  and with continuing reference to  FIG. 1 , gasket  50  is illustrated. The gasket  50  may be an O-Ring made from EPDM rubber. Those of skill in the art will appreciate that any suitable material alternative is contemplated as being within the spirit and scope of the invention. Thread ring  42  may be slotted such that the gasket  50  is stationary to the thread ring  42 . The gasket  50  ensures that a water and air-tight seal is formed within the rigid lens case  10  when the thread ring  42  of the lid cap assembly  40  is engaged with the grooves  32  of the mouth member  30 . 
     When the lid cap assembly  40  is engaged with the mouth member  30 , the lid cap assembly  40  may be rotated to the dosed position, compressing the gasket  50  against the external surfaces of the lid cap assembly  40  and the mouth member  30 , as shown in  FIG. 2 . The threaded interface between the lid lap assembly  40  and the mouth member  30  provides a rotational interference fit allowing the user to open and close the lens case  10  using a twisting motion. A clockwise (CW) direction closes the case, and a counterclockwise (CCW) direction opens the case. 
     The mouth member  30  captures the lid cap assembly  40  with a rotational motion provided by the user. As the user rotates the lid cap assembly  30  clockwise, the lid cap assembly  30  will translate downward, towards the body shell  20  until the gasket  50  is adequately compressed and the lens case  10  is closed. The flange  34  provides a smooth surface for the gasket  50  to sit and seal, via compression from the downward translation of lid cap assembly  30 . As a result, a water-proof seal between the interior and exterior of the lens case  10  is created. 
     With continuing reference to  FIG. 2 , the lens case  10  provides a high level of protection to optical lenses L from the ambient environment that exceeds existing soft or semi-rigid cases. The types of protection provided include water and moisture penetration, and thermal temperature changes. 
     Referring to  FIGS. 1 ,  2 ,  3 ,  5 , and  6 , the lid lock assembly  60  is composed of a pair of socket head machine screws  62  and compression springs  64 . The machine screws  62  are threaded thru the lid cap assembly  40 . Once the lid cap assembly  40  is rotated clockwise and the lens case  10  is closed, the machine screws  62  are then twisted clockwise to engage the matting set of stop notches  36  on the flange  34  of the mouth member  30 . The stop notches are recessed portions cut out of the flange  34  such that the periphery of the ring shaved mouth member  30  is riot truly annular. Each set of the stop notches  36  is positioned 180 degrees from the other set  36 . 
     With the machines screws  62  acting as biasing members and engaged into the stop notches  36 , the lid cap assembly  40  is restricted or prevented from rotating in a counter clockwise direction, thus locking the lid cap assembly  40  in the closed position. Compression springs  64  are mounted axially around the body of the machine screw  62 , applying a load on the back side of the head of the machine screw  62 . As a result, the springs  64  prevent the screws  62  from backing out and off from the lid assembly  40 . 
     In a non-limiting embodiment of  FIG. 2 , the lid lock assembly  60  can be used to aid in removing an overly tightened or jammed lid cap assembly  40 , when pressure and temperature changes make opening the lens case  10  more difficult. A can be seen in  FIG. 2 , machine screws  62  are spaced and offset from a line extending between them. Offset in this context means that machine screws  62  are on opposite lateral sides of the imaginary line extending between them. 
     As shown in  FIG. 2 , rotational leverage can be gained to help unscrew an overly tight, air locked, or jammed lid cap assembly  40  by wedging a sturdy straight edge or fixture D, such as the end of a desktop or table top the machine screws  62 , between the edges of machine screws  62 . Expressed another way, machine screws  62  are positioned to receive and cooperatively abut on opposing lateral sides a straight edge extending along tale line between them to provide rotational leverage for removably engaging the lid cap assembly. The lid lock assembly  60  is also designed such that it can easily be removed by the user if desired. 
     Referring to  FIGS. 1 ,  4 , and  5 , the base end cap  70  is illustrated. The base end cap  70  is constructed from machined  5052  aluminum plate, ABS, or acrylic materials, and has a disk like circular shape. Base end cap  70  forms a closed-end, floor with the body shell  20 . The perimeter of the base end cap  70  is circular with the exception of two protruding tabs  72  that enable the user to get a better grasp of the lens canister  10  when removing or replacing the lid cap assembly  40 . Through holes  74  serve as attachment points to strap  80  (described below). 
     Similar to the lid cap assembly  40 , the external surface of the base end cap  70  may include various machined markings B, as shown in  FIG. 4 . The internal side of the base end cap has a circular pocket  77  to accommodate the bonding and assembly to the body shell.  20 . The base end cap  70  is permanently adhesively bonded to the body shell  20  with epoxy  90  and additionally fixed with fasteners  78 , such as stainless steel screws. The protruding heads of the fasteners  78  also help protect the external surface of the base end cap  70 . 
     Referring to  FIGS. 1 and 5 , both the lid cap assembly  40  and the base end cap  70  include visco-elastic material or polyurethane foam, conventionally known as memory foam. In  FIGS. 1 and 5 , visco-elastic material  46  is bonded to the lid cap assembly  40  and visco-elastic material  76  is bonded to the base end cap  70 . Both visco-elastic materials  46  and  76  perform the same function, and have the same purpose. The correct thickness sizing of visco-elastic materials  46  and  76  is necessary to properly suspend an optical lens L in the rigid lens case  10 . 
     In the examples shown in  FIGS. 1 and 5 , visco-elastic material  46  is selected to have a volume sufficient for portions it to extend into the gap around the lens a distance sufficient to fully overlie mouth member  30  when lid cap assembly  40  is mounted to body shell  20  and visco-elastic material  46  conforms to the shape of the lens. By partially extending into the gap, visco-elastic material  46  serves to retain the lens in a central position. By overlying mouth member  30 , visco-elastic material  46  shields the lens from impact with mouth member  30 . 
     By nature, the visco-elastic materials  46  and  76  are very compliant. Thus, a single foam thickness will cover a relatively large set of lens L dimension. In addition, for encasing optical lenses L that are shorter in length (See  FIG. 5 ), additional visco-elastic materials, as well as additional foam disks of different densities are provided to the user. It should be appreciated by one of ordinary skill in the art that any extra foam material provided with the lens case  10  can include a different type of foam, such as closed cell polyethylene (not shown) to provide protection against impact and vibrations when used in conjunction with visco-elastic materials  46  and  76 . When multiple types of foam are used in a layered series, there is combined advantage because the visco-elastic materials  46  and  76  grab and contour to the end of the lens L, while the more rigid polyurethane layer (not shown) provides more resilient damping against the transmission of large impacts. 
     The visco-elastic materials  46  and  76  are composed of a 1-2 inch thick circular piece of visco-elastic polyurethane foam. The properties of this specific type of polyurethane foam enable the carried lens L to be very well isolated from shock and vibrations applied to the lens case  10 . 
     When the lens case  10  is completely closed, the soft visco-elastic materials  46  and  76  compress against and around the top and bottom end of the lens L. Both materials  46  and  76  mold to the external end shape of the stored optical lens L, thus suspending the lens L and preventing any lateral or side-to-side movement of the lens L within the case  10 . Visco-elastic materials  46  and  76  alleviate the need for lens L manufacturers to include custom foam supports that are specifically made for their commercially available lenses L. The lateral sides of the lens L are held away from the sides of the lens case  10  where there is a higher likelihood of external impact forces or static loads. Also, placement and removal of the lens L in and out of lens case  10  is fast and easy, since the user does not have to be concerned with bulky foam padding or it foam materials along the lateral sides of the lens case  10 . 
     The visco-elastic materials  46  and  76  suspend the lens L at the lens&#39; L strongest points (i.e., the front end of the lens L and the mounting point to the camera body), forming a pocket of air (not shown) around the outer surface of the lens L. The pocket of air further inhibits moisture from reaching the lens L because there is no material for moisture to wick through. Also, the pocket of air contributes positively to thermally insulating the lens L, since air is such a good insulator. Providing a pocket of air facilitates storing a wider variety of lens L, e.g. some lenses L may have projections or bulges along their length with which padding would interfere. 
     With reference to  FIGS. 1 ,  2 ,  4 , and  5 , strap  80  is attached to the base end cap  70  at through holes  74 . The strap  80  can be constructed of elastic or non-elastic cord. The strap  80  allows the user to more securely the lens case  10  by hand or remove the case  10  from a backpack or any other baggage with ease. The strap  80  can be stored in a configuration around the base end cap  70  when not in use, as shown by the phantom lines in  FIG. 2 . 
     In a non-limiting embodiment, the strap  80  may be stretched over (not shown) the lid cap assembly  40  to further compress the lid cap assembly  40  to the body shell  20 . In this non-limiting embodiment, strap  80  extends taut along the length of the lens case when stretched over the top of the lid cap assembly  40  and can serve as a handle during transport. 
     An illustrative example of an alternate closure arrangement between the mouth member and the lid cap is shown in  FIGS. 7-12  and described in the following paragraphs. Briefly, the lid cap and the mouth member of a lens case, in the alternate closure arrangement, are configured to be removably engageable in a two-stage interference fit. In the first stage of the two-stage interference fit, the lid cap is retained against the mouth member, but is translatable in a limited range of movement along the axis of the cylindrical body shell between a non fluid-tight position and a fluid-tight position. In the second stage, the lid cap is retained in a fluid-tight position. As will be appreciated, this type of interference fit may provide a user with a pressure-equilibrating option—specifically, between the air inside the lens case and the ambient air—while still protecting a lens stored inside the case, as well as a fluid-tight option (in which the air inside the lens case is sealed from the ambient environment). 
     A pressure-equilibrating option may be advantageous in some circumstances, such as might arise from the effects of different air pressures on a fluid-tight threaded closure. For example, it may be quite difficult to remove a threaded lid cap if the air pressure inside a container is, or has become, higher than the ambient air pressure, which may occur if the threaded closure is sealed at a low altitude location and then taken to a high altitude location. In such a case, the comparatively higher air pressure it the container may exert an upward force on the threaded lid cap, requiring a user to apply what may be a considerably greater rotational force then normal in order to break the friction lock of the threaded closure. 
     However, a lens case that features the alternate closure arrangement described below, for example when the lid cap is engaged with the mouth member in the first stage of the two-stage interference fit, may avoid this requirement. In the circumstances described above, for example, in which a lid cap is engaged with the mouth member in a fluid-tight position of the first stage of the two-stage interference fit, a comparatively higher air pressure inside the lens case would translate the lid cap away from the mouth member to a non fluid-tight position, at which point pressure equilibration between the inside of the lens case and the ambient air would occur, while still retaining the lid cap to the mouth member in a manner that would not require additional effort to disengage, as might be the case with a standard, or non pressure-equilibrating, rotational fit. 
       FIG. 7  shows a lens case or canister  100  featuring one illustrative embodiment of the alter late closure configuration briefly described above. Similar to lens case  10  as shown  FIGS. 1-6 , lens case  100  includes a cylindrical body shell  120 , a ring-shaped mouth member  130 , and a lid cap  140 . Except where indicated in the paragraphs below, components of the lens case  100 , such as body shell  120 , mouth member  130 , lid cap  140 , etc. may be assumed to have configurations and characteristics consistent with corresponding components of lens case  10 . For example, body shell  120  includes an outer rigid casing or wall  122  and a soft-lined interior surface  126 , and a base end cap  170  positioned at a bottom end to form a closed-end floor that includes a visco-elastic material (not shown) disposed thereon; mouth member  130  forms an opening sized to receive a camera lens; lid cap  140  includes a visco-elastic material  146  disposed to extend into the body shell when the lid cap is engaged with the mouth member, and so forth. As such, the following explanation assumes, but does not repeat the foregoing explanation of the form and function of the components already discussed. 
     In  FIG. 7 , mouth member  130  and lid cap  140  each include respective mating surfaces, indicated at  202 ,  204 . In the example embodiment shown and illustrated herein, the mouth member  130  assumes a male configuration, and thus the mating surface  202  is an outward-facing (or outer) annular surface, whereas lid cap  140  assumes a female configuration, with its mating surface  204  shown as an inward-facing (or inner) annular surface configured to receive the outer annular surface  202 . However, it will be appreciated that this configuration may be reversed, without departing from the scope of this disclosure. 
     Each mating surface includes an engagement thread arrangement  206 ,  208  disposed thereon. Specifically, in the embodiment of the lens case shown at  100 , each engagement thread arrangement consists of a series of three non-overlapping ridges  210 ,  212  that each protrude from and extend partway around the respective mating surfaces  206 ,  208 . 
     With additional reference to  FIGS. 8-10 , it can be seen that mouth member  130  includes an annular ledge  214  disposed generally downward of its engagement thread arrangement  206 . Alternately, ridges  210  can be thought of as extending generally upward, at an inclined orientation, relative to the ledge  214 . In particular, in the illustrated embodiment, each ridge  210  is shown to have a proximal or lower portion  216  that inclines upward from the ledge at a first angle, and a distal or upper portion  218  that inclines upward at a second, lesser angle, terminating in an upper end  220 . Ledge  21  defines the upper bound of a channel  222  formed in the mating surface  202 , in which is seated a peripheral gasket  224 . 
     As explained in greater detail below, the complementary mating surface  204  of the lid cap  140  includes a sealing surface  226  disposed to selectively, sealingly engage the peripheral gasket to form a fluid-tight closure therewith. 
     With reference to  FIGS. 8 and 9 , it can be seen that the corresponding ridges  212  of the complementary engagement thread arrangement  208  on the mating surface  204  of the lid cap  140  are of a length that allows the ridges of the respective thread arrangements to become engaged—specifically, the upper ends  220  of the ridges of the mouth member  130  are radially spaced from each other by a distance greater than the length of the ridges  212 , allowing the ridges of the lid cap to fit between the upper ends of the ridges of the mouth member in order to be rotationally engaged. Moreover, the radial symmetry of both thread arrangements allows the engagement thereof in a lumber of relative orientations of the lid cap to the mouth member—specifically, because each thread arrangement of the illustrated embodiment is shown to include three complementary ridges, the lid cap may rotationally engage the mouth member in any of three orientations, such as for ease of closing the lens case. As such, it is evident that the thread arrangements may include any number of ridges. 
     With the foregoing description in mind, and with reference to  FIGS. 10-12 , the engagement of the lid cap  140  with the mouth member  130  in the two-stage rotational interference fit is fairly straightforward.  FIG. 10  shows the upper portion of body shell  120 , including mouth member  130  and the engagement thread arrangement  206  disposed on the mating surface  202  thereof, and also shows one ridge  212  of the lid cap  140  (not shown) superimposed in three different example positions relative to one ridge  210  of the mouth member  130 . 
       FIG. 11 , which is a cross-sectional view along the line  11 - 11  of  FIG. 10 , shows the relative arrangement of various components of the mouth member  130  relative to the ridge  212 , and also shows lid cap  140 , for context.  FIG. 11  represents the lid cap and mouth member in a first stage of the two-stage rotational interference fit, for example after the lid cap has been placed on the mouth member in such a manner as to align the ridges for rotational engagement, and the lid cap has been rotated relative thereto so the ridges are engaged. In the first stage of the interference fit, the lid cap is translatable in a limited range of movement, represented by arrow B, relative to the mouth member. The range of movement is defined, in the illustrated embodiment, by the distance between ridge  210  and ledge  214 , through which beige  212  is movable. In particular, in the illustrated embodiment, it can be seen that in the lower limit of the range of movement, which is represented by ridge  212  and sealing surface  226  in dashed lines, the ridge  212  abuts the ledge  214 , preventing further downward movement, and the sealing surface  226  sealingly engages peripheral gasket  226 . As such, the lower limit of the range of movement is a fluid-tight position. Upward translation of the lid cap from this position results in the sealing surface  226  disengaging the peripheral gasket, at which point the engagement is non fluid-tight. Further upward movement is prevented when ridge  212  abuts ridge  210 . 
     Of course, the relative configurations of the complementary engagement thread arrangements may be varied from that illustrated, such as to provide a movement range of a desired size. For example, a more limited range of movement could be achieved by increasing the width of one or more of the ridges and/or raising the position of the ledge, and so forth. Moreover, as shown, due to the inclined orientation of the ridges  210  of the mouth member, the range of permitted translatable movement along the axis A of the body shell decreases as the ridge  212  is rotated further toward the proximal region  216  of the ridge  210 . At each point, however, the lower limit of the movement range corresponds to a fluid tight position as the sealing surface  226  sealingly engages the peripheral gasket  224 , whereas an upper position, in which the sealing surface  226  does not engage the peripheral gasket  224 , corresponds to a non fluid-tight position. A different orientation of the ridges  210 , of course, may result in different areas having different ranges of movement. 
     In the illustrated embodiment, further rotation of the lid cap relative to the mouth member will ultimately result in the orientation shown in  FIG. 12 , which is a cross-sectional view along the line  12 - 12  of  FIG. 10 , representing a second stage of the two-stage rotational interference fit. In the second stage, in which the ridge  212  of the lid cap is wedged between the proximal portion  216  of ridge  210  and the ledge  214 , the sealing surface  226  sealingly engages the peripheral gasket  224 , and the lid cap is retained in a fluid tight position. 
     From the foregoing description it should be apparent that modifications can be made to the components of lid cap  140  and mouth member  130  to achieve a two-stage rotational interference fit consistent with that described above. For example, it is not required for all embodiments to include a peripheral gasket and sealing surface, as other suitable methods of achieving a fluid-tight fit between rotationally engageable mating surfaces may be employed. In embodiments that do include a peripheral gasket and sealing surface, such components may be disposed, respectively, on the mouth member and lid cap, or vide versa, and may be positioned as desired on the mating surfaces thereof. As noted above, the ridge configuration of each threaded arrangement may be modified to still achieve a two-stage rotational interference fit substantially as described above, and so forth. 
     Regardless of the configuration of the closure arrangement or lens case, commercial embodiments may be supplied with additional components that a user may selectively employ to assure secure storage of a camera lens for other object) within a lens case constructed according to the present disclosure. An example set  300  of such components is illustrated in  FIG. 13 , which shows two stabilizing disks  302  and two guide members  304 . In commercial embodiments, set  300  may be offered to consumers as an additional, separate kit for use with a particular size of lens case, or may be bundled as a kit with a lens case, and so forth, according to desired commercial practices. Essentially, the example set  300  may allow a user to create a pair of customized cushioning rings that may be applied to the lens or other item prior to inserting the item in the lens case. 
     The stabilizing disks  302  thus may each have an outer diameter sized to fit within a lens case, and may be fabricated of a substantially rigid, yet deformable, shock-absorbing material, such as any of several polyurethane foams. Optionally, a set may include several pairs of stabilizing disks, for example having different outer diameters, thicknesses, and/or being fabricated of materials having different characteristics, for example to provide a user a variety of components from to create a customized ring. 
     Guide members  304 , which may be in the form of adhesive decals or otherwise, are shown to be substantially transparent, but to also include concentric circle indicia marked thereon. Although other configurations are possible, guide members  304  are shown to have a slightly greater outer diameter as the stabilizing disk, as explained below. 
     In one example use of the set  300 , a user may create a pair of customized cushioning ring for a camera lens or other item as follows: the item may be centered in a lens case, such as lens case  10  or  100 , and then a guide member  304  may be placed or adhered lightly to the top rim of the lens case. The user may then trace the outline of the item on the surface of the guide member, remove the traced guide member, and then remove the item from the lens case. The item may then be turned over, replaced back in the lens case, and the second guide member may be used in a similar manner to record a second outline of the item. 
     Each guide member may then be centered on one of the stabilizing disks, and the user may cut each outline out of the center of each stabilizing disk to create a pair of cushioning rings sized to respectively fit both ends of the item. The cushioning rings may be placed on the item, which may then be placed into the lens case. In this manner, lateral movement of the item inside the lens case may be further restricted, by using the customized cushioning rings to maintain a spaced relationship between the item and the interior surface of the lens case. 
     From the foregoing description it will be apparent that modifications can be made to the protective lens case  10 , or  100 , or set  300 , or to the various components and configurations thereof, without departing from the teachings of the invention. 
     The instant invention may be embodied in other forms or carried out in other was without departing from the spirit or essential characteristics thereof. The present disclosure is therefore to be considered as in all respects illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all equivalency are intended to be embraced therein. One of ordinary skill in the art would be able to recognize equivalent embodiments of the instant invention and be able to practice such embodiments using the teaching of the instant disclosure and only routine experimentation.