Abstract:
A rotary securing lens and mount assemblage has a lens and a mount for the lens which are secured to one another when the lens is rotated relative to the mount. The lens includes at least one cutting edge which is shaped to cut into the mount in order for the lens and the mount to become mutually engaged to be secured to one another when the lens is rotated.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     Reference is made to commonly assigned copending application Ser. No. 09/504,446, entitled DEFORMATION SECURING LENS AND MOUNT ASSEMBLAGE and filed Feb. 16, 2000 in the name of Anthony DiRisio. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to the field of photography, and in particular to a rotary engaging lens and mount assemblage for a camera. 
     BACKGROUND OF THE INVENTION 
     Film and cameras that are all in one, commonly referred to as single-use or one-time-use cameras, have become well known. The one-time-use camera is a simple point-and-shoot type comprising an opaque plastic main body part that supports a conventional film cartridge in a cartridge receiving chamber, an unexposed filmstrip substantially prewound from a film take-up spool in the film cartridge onto a film supply spool in a film supply chamber in order to form an unexposed film roll on the film supply spool, a fixed-focus taking lens, a film metering mechanism with a rotatably supported metering sprocket that engages the filmstrip, a manually rotatable film winding thumbwheel coaxially engaged with the film take-up spool in the film cartridge, a single-blade shutter for exposing successive frames of the filmstrip, a manually depressible shutter release button, a rotatable frame counter for indicating the number of exposures remaining to be made on the filmstrip, a direct see-through viewfinder having front and rear viewfinder lenses, and in some models an electronic flash. A pair of opaque plastic front and rear cover parts house the main body part between them to complete the camera. The rear cover part connects to the main body part and/or to the front cover part to make the main body part light-tight. A decorative cardboard outer box or label at least partially covers the front and rear cover parts and has respective openings for the taking lens, etc. 
     After each picture is taken with the one-time-use camera, the photographer manually rotates the thumbwheel in a film winding direction to similarly rotate the film take-up spool in the film cartridge. This winds an exposed frame of the filmstrip from a rear backframe (exposure) opening in the main body part into the film cartridge, and advances an unexposed frame of the filmstrip from the unexposed film roll to the backframe opening. The rewinding movement of the filmstrip the equivalent of slightly more than one frame width rotates the metering sprocket in engagement with the filmstrip to decrement the frame counter to its next lower-numbered setting and to pivot a metering lever into engagement with the thumbwheel. When the metering lever engages the thumbwheel, further rotation of the thumbwheel is prevented. Manually depressing the shutter release button to take another picture pivots the metering lever out of engagement with the thumbwheel to permit renewed rotation of the thumbwheel. After the maximum number of exposures available on the filmstrip have been made, and the filmstrip is completely wound into the film cartridge, the one-time-use camera is given to a photofinisher who separates the rear cover part from the main body part and removes the film cartridge with the exposed filmstrip from the cartridge receiving chamber. Then, he removes the exposed filmstrip from the film cartridge to develop the negatives and make prints for the customer. Most of the used parts such as the electronic flash can be recycled, i.e. reused, to remanufacture the one-time-use camera. 
     PRIOR ART PROBLEM 
     During original manufacture or remanufacture of the one-time-use camera, the taking lens must be secured to a mount for the lens. This must be done in a way that assures the lens is held fast to the mount. 
     By way of example, U.S. Pat. No. 5,642,235 issued Jun. 24, 1997 discloses a rotary securing lens and mount assemblage comprising a lens which has a central imaging portion and a circular rim portion with several engaging portions, and a mount for the lens which has several engageable portions equal in number to the engaging portions to engage with the respective engaging portions when the lens is rotated relative to the mount. 
     THE CROSS-REFERENCE APPLICATION 
     The cross-referenced application discloses a lens and mount assemblage that includes a lens and a mount for the lens which are secured to one another. The mount has elastic retaining members constructed to be deformed against the lens to secure the lens to the mount. A front cover part that fits over the lens and the mount has rigid deforming members arranged to deform the retaining members against the lens when the front cover part is fit over the lens and the mount 
     SUMMARY OF THE INVENTION 
     A rotary securing lens and mount assemblage comprising a lens and a mount for the lens which are secured to one another when the lens is rotated relative to the mount, is characterized in that: 
     one of the lens and mount includes a cutting edge which is shaped to cut into the other of the lens and mount in order for the lens and the mount to become mutually engaged to be secured to one another when the lens is rotated relative to the mount. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded front perspective view of a one-time-use camera that includes a rotary engaging lens and mount assemblage according to a preferred embodiment of the invention; 
     FIG. 2 is a sectional view of the lens and mount assemblage; 
     FIG. 3 is a perspective view of the lens; 
     FIG. 4 is an exploded front perspective view of the lens and mount assemblage; 
     FIG. 5 is an exploded front perspective view of the lens and mount assemblage, and a rotation tool for rotating the lens to engage with the mount; and 
     FIGS. 6-8 are front elevation views of the lens and the mount showing various stages of rotation of the lens relative to the mount in order to engage the lens with the mount. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention is disclosed as being embodied preferably in a one-time-use camera. Because the features of a one-time-use camera are generally known, the description which follows is directed in particular only to those elements forming part of or cooperating directly with the disclosed embodiment. It is to be understood, however, that other elements may take various forms known to a person of ordinary skill in the art. 
     Referring now to the drawings, FIGS. 1-8 show a one-time-use camera  10 . The one-time-use camera  10  includes a plastic opaque main body part  12 , a plastic opaque front cover part  14 , and a plastic opaque rear cover part  16 . The front cover part  14  and the rear cover part  16  house the main body part  12  between them and are connected releasably to one another and to the main body part  12  via known flexible hook-in-hole connections  18 . 
     As is typical, the main body part  12  has a rearwardly open cartridge receiving chamber  20  for a film cartridge (not shown) and a rearwardly open film supply chamber  22  for an unexposed filmstrip (not shown). See FIG.  1 . The unexposed filmstrip, except for a trailing end portion originally wound on a film take-up spool in the film cartridge is substantially pre-wound into an unexposed film roll in the film supply chamber  22  during manufacture of the one-time-use camera  10 . A rearwardly open, rectangular-shaped backframe (exposure) opening  24 , shown in FIG. 2, is located between the cartridge receiving chamber  20  and the film supply chamber  22  for exposing successive frames of the filmstrip when ambient light is received through a front taking lens  26 . The front taking lens  26  is secured to a mount  28  for the lens which is integrally formed with a lens plate  30  connected to the main body part  12 . The light is received through a front lens opening  32  in the front cover part  14 , through the front taking lens  26 , through a light admitting opening  33  in a bottom  34  of the mount  28 , and into the backframe opening  24 . See FIG. 2. A shutter blade  36  which normally blocks the light-admitting opening  33  is momentarily pivoted open to allow the light to enter the backframe opening  24  via the light-admitting opening. 
     A manual film winder or film winding thumbwheel  38 , rotatably supported on the main body part  12 , above the cartridge receiving chamber  20 , radially protrudes partially from an elongate narrow opening  40  in the rear cover part  16  and has a depending coaxial stem (not shown) in coaxial engagement with an exposed top end of the film take-up spool in the film cartridge. The film winding thumbwheel  38  is manually grasped or fingered to rotate the thumbwheel in a film winding direction  42 , i.e. counter-clockwise in FIG. 1, to rotate the film take-up spool in the same direction. The thumbwheel  38  is incrementally rotated decreasing angles of rotation to incrementally rotate the film take-up spool the same decreasing angles in order to wind the respective frames of the filmstrip from the unexposed film roll in the film supply chamber  22 , to the backframe opening  24  for exposure, and then onto the film take-up spool. The film take-up spool must be rotated the decreasing angles to wind the respective frames onto the spool, because the resulting film roll (not shown) on the spool increases in diameter with each added frame. 
     The mount  28  for the front taking lens  26  has a circular peripheral rib  44  with three evenly spaced (120° apart) engageable portions  46  that project radially inward, and an inner circular ring  48  with three raised pads  50  positioned adjacent the respective engageable portions, as shown in FIGS. 2 and 4. 
     The front taking lens  26  has a central imaging portion  52  and a circular rim portion  54  with three evenly spaced (120° apart) engaging portions  56  that are elongated partially about the circular rim portion and have individual curved cutting edges  58 . See FIGS. 2-4. Each one of the engaging portions  56  has a gradual diminution in width from the circular rim portion  54  to one of the cutting edges  58  to similarly taper the engageable portions widthwise. This is shown in FIG.  3 . Each one of the cutting edges  58  has a pair of extreme ends  60  and  62 , the first one ( 60 ) of which is a leading end and the other ( 62 ) is a trailing end when the front taking lens  26  is rotated in a cutting direction  64 , i.e. counter-clockwise in FIGS. 6-8. The cutting edges  58  are progressively narrowed from the leading ends  60  to the trailing ends  62  to similarly taper the cutting edges. 
     During manufacture of the one-time-use camera  10 , the front taking lens  26  is placed on the three raised pads  50  of the mount  28  to position the cutting edges  58  of the lens with respect to the engageable portions  56  of the mount. See FIGS. 5 and 6. Then, a manual rotation tool  66  is rotationally coupled with the front taking lens  26 , by inserting three evenly spaced pins  68  on the tool in individual peripheral notches or gaps  70  in the lens. 
     When the tool  66  is rotated in the cutting direction  64 , as shown in FIGS. 7 and 8, the front taking lens  26  is similarly rotated to move the cutting edges  58  of the lens, beginning with their leading ends  60 , to cut into the engageable portions  46  of the mount  28 . The phrase “cut into” is used in the ordinary dictionary sense to mean “to penetrate with or as if with an edged instrument.” As the cutting edges  58  of the front taking lens  26  progressively cut into the engageable portions  46  of the mount  28 , they firmly engage the engaging portions  56  of the front taking lens  26  with the engageable portions of the mount  28  to secure the lens to the mount. Then, the tool  66  is separated from the front taking lens  26 , and the front cover part  14  is connected to the rear cover part  16  at the hook-in-hole-connections  18 . 
     The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention. 
     PARTS LIST 
       10 . one-time-use camera 
       12 . main body part 
       14 . front cover part 
       16 . rear cover part 
       18 . hook-in-hole connections 
       20 . cartridge receiving chamber 
       22 . film supply chamber 
       24 . backframe opening 
       26 . front taking lens 
       28 . mount 
       30 . lens plate 
       32 . front lens opening 
       33 . light-admitting opening 
       34 . bottom 
       36 . shutter blade 
       38 . thumbwheel 
       40 . narrow opening 
       42 . film winding direction 
       44 . circular peripheral rib 
       46 . engageable portions 
       48 . inner circular rib 
       50 . raised pads 
       52 . central imaging portion 
       54 . circular rim portion 
       56 . engaging portions 
       58 . cutting edges 
       60 . leading ends 
       62 . trailing ends 
       64 . cuffing direction 
       66 . rotation tool 
       68 . pins 
       70 . notches