Abstract:
A camera comprising a film winder rotatable to wind successive exposed imaging areas of a filmstrip onto an exposed film roll, is characterized in that a minor spring source of motion is connected to the film winder to rotate the film winder to wind one exposed imaging area of the filmstrip onto the exposed film roll and can be re-energized to again rotate the film winder to wind another exposed imaging area of the filmstrip onto the exposed film roll, and a major spring source of motion is connected with the minor spring source of motion to re-energize the minor spring source of motion after each exposed imaging area of the filmstrip is wound onto the exposed film roll. Preferably, the major spring source of motion has the capacity to be energized once to re-energize the minor spring source of motion a total number of times at least equal to the total number of successive imaging areas of the filmstrip that are to be exposed.

Description:
FIELD OF THE INVENTION 
     The invention relates generally to the field of photography, and in particular to cameras. More specifically, the invention relates to a one-time-use camera with a multiple-spring film drive. 
     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. Typically, the one-time-use camera is a simple point-and-shoot type comprising a plastic main body part which supports a conventional film cartridge in a cartridge receiving chamber, an unexposed film roll in a film supply chamber, 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 rotatably engaged with a film spool inside the film cartridge, a single-blade shutter, a manually depressible shutter release button, a rotatable exposure or frame counter for indicating the number of exposures remaining to be made on the filmstrip, a direct see-through viewfinder, and in some models an electronic flash. A pair of plastic front and rear cover parts house the main body part between them to complete the camera unit. 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 camera unit and has respective openings for the taking lens, etc. 
     After each picture is taken with the one-time-use camera, the photographer rotates the manual thumbwheel in a film winding direction to similarly rotate the film spool inside the film cartridge. This winds an exposed section of the filmstrip into the film cartridge. 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 exposure counter to its next lower-numbered setting and to pivot a metering lever into engagement with the thumbwheel in order to prevent further manual rotation of the thumbwheel. 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. When 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 tears the outer box off the camera unit, 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. At least some of the used camera parts may be recycled, i.e. reused, to remanufacture the camera. 
     Problem 
     It would be of benefit to the consumer to motorize one-time-use cameras. Since electric motors are relatively expensive, especially in the context of a one-time-use camera, spring drives must be considered. Prior art spring devices that generally involved a single spring drive warrant improvement. 
     SUMMARY OF THE INVENTION 
     A camera comprising a film winder rotatable to wind successive exposed imaging areas of a filmstrip onto an exposed film roll, is characterized in that: 
     a minor spring source of motion is connected to the film winder to rotate the film winder to wind one exposed imaging area of the filmstrip onto the exposed film roll and can be re-energized to again rotate the film winder to wind another exposed imaging area of the filmstrip onto the exposed film roll; and 
     a major spring source of motion is connected with the minor spring source of motion to re-energize the minor spring source of motion after each exposed imaging area of the filmstrip is wound onto the exposed film roll. 
     Preferably, the major spring source of motion has the capacity to be energized once to re-energize the minor spring source of motion a total number of times at least equal to the total number of successive imaging areas of the filmstrip that are to be exposed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of a one-time-use camera according to a preferred embodiment of the invention; 
     FIG. 2 is an assembled perspective view a film metering assembly and multiple spring drive in the camera; 
     FIG. 3 is an elevation section view of a portion of the multiple spring drive; and 
     FIGS. 4, 5, 6 and 7 are perspective views similar to FIG. 2, depicting operation of the film metering assembly and multiple spring drive. 
    
    
     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, FIG. 1 partially shows a one-time-use camera 10 including an opaque main body part 12. A pair of opaque front and rear cover parts (not shown) house the main body part between them. 
     The main body part 12 has a rearwardly open cartridge receiving chamber 14 for a known film cartridge 16 and a rearwardly open film supply chamber 18 for an unexposed film roll (not shown). See FIG. 1. A backframe opening (not shown) is located between the cartridge receiving and film take-up chambers 14 and 18 for exposing successive imaging areas 20 of a filmstrip 22 initially stored on the unexposed film roll (not shown). The backframe opening (not shown) is aligned with a front aperture 24 in the main body part 12. A known shutter blade 26 normally covers the front aperture 24. The shutter blade 26 is supported on the main body part 12 at a body part post (not shown) that extends through a blade slot 28, to permit pivotal opening and closing movement of the shutter blade clockwise and counter-clockwise in FIG. 1 in order to uncover and recover the front aperture 24. A return spring (not shown) is connected to the shutter blade 26 and the main body part 12 to continuously urge the shutter blade closed. A metering drive gear 30 has a depending coaxial keyed stem 32 in coaxial engagement with one mating end 34 of a film spool inside the film cartridge 16, and is supported on the main body part 12 for rotation counter-clockwise in FIG. 1 as each exposed imaging area 20 of the filmstrip 22 is wound onto an exposed film roll 36 formed on the film spool and each fresh (unexposed) imaging area is advanced from the unexposed film roll (not shown) to the backframe opening. An anti-backup pawl (not shown) engages respective peripheral teeth 38 of the metering drive gear 30 to prevent clockwise rotation of the metering drive gear. A resilient cantilevered shutter release button 40 is manually depressible from an original non-depressed position shown in FIGS. 1 and 2 to initiate an exposure. A high energy lever 42 for pivoting the shutter blade 26 open is pivotally supported on the main body part 12 and is shown in FIG. 2 in a cocked ready position. A high energy spring (not shown) is connected to the high energy lever 42 and the main body part 12 to continuously urge the high energy lever counter-clockwise in FIG. 2 from its cocked ready position, initially to pivot the shutter blade 26 open. See FIG. 4. In FIG. 2, engagement of an end portion 44 of the high energy lever 42 with a notch portion 46 of an integral leg 48 of the shutter release button 40 retains the high energy lever 42 in its cocked ready position against the counter-clockwise urging of the high energy spring (not shown). A metering lever 50 is pivotally supported on the main body part 12 at an axis (not shown) in common with the high energy lever 42; although it is pivotable independently of the high energy lever. The metering lever 50 has an upstanding arresting pin 52 that engages respective peripheral teeth 54 of a first intermediate gear 56 continuously in mesh with the peripheral teeth 38 of the metering drive gear 30, to prevent any rotation of the metering drive gear. A return spring (not shown) is connected to the metering lever 50 and the main body part 12 to continuously urge the metering lever clockwise in FIG. 2 to maintain the arresting pin 52 engaged with any one of the peripheral teeth 54. A metering pawl 58 is pivotally and translationally supported on the main body part 12 and has a pawl tooth 60 that is received in respective metering perforations 62 in the filmstrip 22. Each metering perforation 62 corresponds to one of the imaging areas 20 of the filmstrip 22 A depending pin 64 on the metering lever 50 engages a notch portion 66 of the metering pawl 58 to prevent translation of the metering pawl when the arresting pin 52 is engaged with one of the peripheral teeth 54. The filmstrip 22 is then said to be &#34;metered&#34;, as shown in FIGS. 2 and 4, when one of its imaging areas 20 is at the backframe opening (not shown), the arresting pin 52 is engaged with one of the peripheral teeth 54, the pawl tooth 60 is located in one of the metering perforations 62, and the depending pin 64 engages the notch portion 66. A second intermediate gear 68 is coaxially connected to the first intermediate gear 56 and has respective peripheral teeth 70 which in FIGS. 2 and 4 are located within a dwell or gap 72 between successive peripheral teeth 74 of a reset gear 76, i.e. none of the teeth 70 and 74 are mutual engaged. The reset gear 76 has an upstanding reset pin 78 intended to be swung counter-clockwise against a depending tab 80 on the high energy lever 42 to swing the high energy lever clockwise in FIGS. 6 and 7 back to its cocked ready position when the metering drive gear 30 is rotated counter-clockwise. 
     A major high-torque torsion spring 82 has one end 84 fixed to a winding ratchet 86 and another end 88 fixed to a flange 90. The flange 90 is integral with a center shaft 92 and a drive gear 94. See FIGS. 1 and 2. The drive gear 94 is continuously in mesh with a driven gear 96 fixed to one end 98 of a minor low-torque torsion spring 100. The minor torsion spring 100 has another end 102 fixed to a flange 104 integral with an upstanding keyed stem 106 that coaxially engages another mating end (not shown) of the film spool inside the film cartridge 16. As shown in FIG. 3, the flange 104 and the upstanding keyed stem 106 are rotatably supported on a center shaft 108 integral with the driven gear 96. A release lever 110 is pivotally supported on the main body part 12 and has a pair of angled projections 112 and 114 that independently engage a locking pin 116 on the drive gear 94 to prevent spring-driven rotation of the drive gear counter-clockwise in FIGS. 1 and 2 and, in turn, gear-driven rotation of the driven gear 96 counter-clockwise in FIGS. 1 and 2. An anti-backup pawl 118 engages respective teeth 120 of the winding ratchet 86 to prevent unwinding rotation of the ratchet clockwise in FIGS. 1 and 2. 
     Operation 
     Beginning with FIG. 2, the winding ratchet 86 must be windingly rotated counter-clockwise to energize (wind) the major torsion spring 82. This can be done manually or with a suitable winding implement. The major torsion spring 82 is energized (wound) when the winding ratchet 86 is rotated counter-clockwise because the flange 90 is prevented from similarly rotating due to engagement of the angled projection 112 of the release lever 110 with the locking pin 116 on the drive gear 94. The minor torsion spring 100 is not energized (wound) since the drive gear 94 is not rotated. 
     In FIG. 4, the shutter release button 40 is manually depressed from its original non-depressed position to initiate an exposure. Several things occur as a result. The notch portion 46 of the integral leg 48 of the shutter release button 40 separates from the end portion 44 of the high energy lever 42. This allows the high energy spring (not shown) to pivot the high energy lever 42 counter-clockwise in FIG. 4 from its cocked ready position, initially to pivot the shutter blade 26 open. When the return spring (not shown) has re-closed the shutter blade 26, the high energy lever 42 will have pivoted to swing an edge portion 122 of the high energy lever against an opposite portion 124 of the metering lever 50 to pivot the metering lever counter-clockwise in FIG. 5 and the depending tab 80 on the high energy lever will have swung against the upstanding reset pin 78 on the reset gear 76 to begin to rotate the reset gear counter-clockwise in FIG. 5. Counter-clockwise rotation of the reset gear 76 moves one of the peripheral teeth 74 (adjacent the dwell 72) of the reset gear into engagement with one of the peripheral teeth 70 of the second intermediate gear 68. Counter-clockwise pivoting of the metering lever 50 separates the upstanding arresting pin 52 on the metering lever from one of the peripheral teeth 54 of the first intermediate gear 56, allowing the metering drive gear 30 to be rotated counter-clockwise in FIG. 5, and the depending pin 64 on the metering lever is separated from the notch portion 66 of the metering pawl 58, allowing the metering pawl to be translated. The filmstrip 22 is then said to be &#34;demetered&#34;. 
     When the shutter release button 40 is manually depressed from its original non-depressed position in FIG. 4, a follower arm 126 which is supported on the main body part 12 for translation and is pivotally connected to the release lever 110 is translated downward in FIG. 4 to pivot the release lever counter-clockwise. This separates the angled projection 112 of the release lever 10 from the locking pin 116 on the drive gear 94, allowing the major torsion spring 82 to slightly unwind and rotate the drive gear 94 counter-clockwise in FIG. 5 to swing the locking pin against the angled projection 114 of the release lever. Rotation of the drive gear 94, in turn, rotates the driven gear 96 counter-clockwise in FIG. 5 to partially energize (wind) the minor torsion spring 100. This occurs before the shutter blade 26 is pivoted open (and, therefore, before the upstanding arresting pin 52 on the metering lever 50 is separated from one of the peripheral teeth 54 of the first intermediate gear 56). When the shutter blade 26 has re-closed and then the upstanding arresting pin 52 on the metering lever 50 is separated from one of the peripheral teeth 54 of the first intermediate gear 56, the minor torsion spring 100 begins to unwind to rotate the flange 104 and its upstanding keyed stem 106 counter-clockwise in FIG. 5 to begin to windingly rotate the film spool inside the film cartridge 16. As a result, the exposed imaging area 20 of the filmstrip 22 at the backframe opening (not shown) will be wound toward the exposed film roll 20 inside the film cartridge 16 and an unexposed imaging area will be advanced from the unexposed film roll (not shown) toward the backframe opening. The metering pawl 58 is translated with the filmstrip 22 to the left in FIG. 5 since the pawl tooth 60 is in one of the metering perforations 62 in the filmstrip. The metering drive gear 30 begins to be rotated counter-clockwise in FIG. 5 in order to rotate the reset gear 76 counter-clockwise in FIG. 5. This begins to swing the upstanding reset pin 78 on the reset gear 76 counter-clockwise against the depending tab 80 on the high energy lever 42 to begin to swing the high energy lever clockwise in FIG. 5 back to its cocked ready position. 
     In FIG. 6, the shutter release button 40 is manually released from being manually depressed and is returned to its original non-depressed position. As a result, a return spring 128 which is connected to the follower arm 126 and the main body part 12 translates the follower arm upward in FIG. 6 to pivot the release lever 110 clockwise and separate the angled projection 114 of the release lever from the locking pin 116 on the drive gear 94. This allows the major torsion spring 82 to continue to slightly unwind and rotate the drive gear 94 counter-clockwise in FIG. 6 to swing the locking pin 116 on the drive gear back to the angled projection 112 of the release lever 110. Rotation of the drive gear 94, in turn, rotates the driven gear 94 counter-clockwise in FIG. 6 to further energize (wind) the minor torsion spring 100. The minor torsion spring 100 simultaneously continues to unwind to rotate the flange 104 and its upstanding keyed stem 106 counter-clockwise in FIG. 6 to continue to windingly rotate the film spool inside the film cartridge 16. As a result, the exposed imaging area 20 of the filmstrip 22 will be wound onto the exposed film roll 20 inside the film cartridge 16 and the unexposed imaging area will be advanced to the backframe opening. The pawl tooth 60 exits the metering perforation 62 for the exposed imaging area and enters the metering perforation for the unexposed imaging area as the filmstrip 22 is advanced to the left in FIG. 6. The metering drive gear 30 continues to be rotated counter-clockwise in FIGS. 6 and 7 in order to rotate the reset gear 76 counter-clockwise in FIGS. 6 and 7. This continues to swing the upstanding reset pin 78 on the reset gear 76 counter-clockwise against the depending tab 80 on the high energy lever 42 to continue to swing the high energy lever clockwise in FIG. 5 back to its cocked ready position. The dwell 72 on the reset gear 76 then receives one of the peripheral teeth 70 of the second intermediate gear 68. See FIG. 2. 
     When the depending pin 64 on the metering lever 50 returns to the notch portion 66 of the metering pawl 58, the return spring (not shown) pivots the metering lever clockwise in FIG. 7 to return the arresting pin 52 on the metering lever into engagement with one of the peripheral teeth 54 of the first intermediate gear 56. The filmstrip 22 is then re-metered. See FIG. 2. 
     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. cartridge receiving chamber 
     16. film cartridge 
     18. film supply chamber 
     20. imaging areas 
     22. filmstrip 
     24. front aperture 
     26. shutter blade 
     28. blade slot 
     30. metering drive gear 
     32. keyed stem 
     34. spool end 
     36. exposed film roll 
     38. peripheral teeth 
     40. shutter release button 
     42. high energy lever 
     44. end portion 
     46. notch portion 
     48. leg 
     50. metering lever 
     52. arresting pin 
     54. peripheral teeth 
     56. first intermediate gear 
     58. metering pawl 
     60. pawl tooth 
     62. perforations 
     64. pin 
     66. notch portion 
     68. second intermediate gear 
     70. peripheral teeth 
     72. dwell 
     74. peripheral teeth 
     76. reset gear 
     78. reset pin 
     80. tab 
     82. major high-torque torsion spring 
     84. one end 
     86. winding ratchet 
     88. another end 
     90. flange 
     92. center shaft 
     94. drive gear 
     96. driven gear 
     98. one end 
     100. minor low-torque torsion spring 
     102. another end 
     104. flange 
     106. keyed stem 
     108. center shaft 
     110. release lever 
     112. angled projection 
     114. angled projection 
     116. locking pin 
     118. anti-backup pawl 
     120. teeth 
     122. edge portion 
     124. opposite portion 
     126. follower arm 
     128. return spring