Shutter cocking and film metering device for a camera

Claim 2

A film winding and shutter cocking device comprising: a winding shaft rotatable in a winding direction; means connecting the winding shaft to the shutter for cocking the shutter upon rotation of the winding shaft through a shutter cocking angle; a rotatable member mounted coaxially of the winding shaft and rotatable independently of the winding shaft; a second shaft mounted coaxially of the winding shaft and rotatable independently thereof; means for connecting a film takeup spool to the second shaft for rotation therewith; a helical spring coiled about and normally gripping the winding shaft firmly for rotation therewith, said spring having a first end engaging the rotatable member for rotation therewith and a second end engaging the second shaft, the coils of said spring proceeding from the rotatable member to the second shaft coiling about the winding shaft in a direction opposite to the winding direction, whereby rotation of the second shaft in the winding direction relative to the rotatable member causes said helical spring to expand and loosen its grip on the winding shaft; and measuring means for stopping rotation of the rotatable member after said rotatable member has rotated through a winding angle less than the shutter cocking angle.

Claim 3

The device of claim 1 wherein: the rotatable member comprises a ratchet wheel; the measuring means comprises a pawl engageable with the ratchet wheel, a film-contacting roller contacting the film for rotation thereby as the film is wound on the takeup spool, and control means for holding said pawl out of engagement with the ratchet wheel until the roller has been rotated through a desired rotation angle and then moving said pawl into locking engagement with the ratchet wheel.

Claim 4

The device of claim 2 wherein the control means comprises: pivot means for supporting the pawl for rotation between a disengaged position in which the pawl does not engage the ratchet wheel and an engaged position in which the pawl does engage the ratchet wheel; resilient pawl-moving means for urging the pawl into the engaged position; a control shaft rotatable in response to rotation of the film-contacting roller; a circular first disk fixed to the control shaft; a circular second disk mounted coaxially of the control shaft and rotatable relative thereto; means for limiting the rotation of the first disk relative to the second disk to rotation between a normal and a driving position; means for resiliently biasing the first disk into the normal position; a first notch extending inward from the periphery of the first disk; a second notch extending inward from the periphery of the second disk, said second notch being aligned with the first notch when the first disk is in the driving position and out of alignment with the first notch when the first disk is in the normal position; an arm connected to the pawl for rotation therewith, said arm having a contact member normally resiliently urged into contact with the periphery of the second disk by the pawl-moving means when the pawl is in the disengaged position, said contact member being movable into an engaged position within the notches of the first and second disks when said notches are aligned, said movement advancing the pawl into the engaged position; and means operable following an exposure of the film for moving the pawl out of engagement with the ratchet wheel Into the disengaged position.

Claim 5

A shutter cocking and film advancing mechanism for a camera having a shutter comprising: a winding shaft passing through the outer casing of the camera, said winding shaft being rotatable through a predetermined shutter-cocking angle for cocking the shutter; a ratchet wheel mounted on the winding shaft and rotatable relative thereto; a hollow shaft mounted on the winding shaft and rotatable relative thereto; means on the hollow shaft for engaging a film spool; a helical spring within the hollow shaft coiled about and normally firmly gripping the winding shaft, said spring having a first end engaging the ratchet gear and a second end engaging the hollow shaft, said spring coiling about the winding shaft in a direction opposite to the direction of rotation of the winding shaft during a winding operation as said spring proceeds from the ratchet wheel to the hollow shaft, whereby rotation of the hollow shaft in the winding direction relative to the ratchet wheel causes the spring to unwrap slightly and loosen its grip on the winding shaft; a pawl pivotally mounted on a support and rotatable between a disengaged position and an engaged position in which the pawl engages the ratchet wheel and prevents rotation thereof in the winding direction; a pawl spring urging the pawl into the engaged position; means operable following an exposure to move the pawl to the disengaged position; an arm attached to and rotatable with the pawl; a friction roller placed to contact the film with its periphery and to be turned by frictional engagement with the film as said film is advanced; a control shaft connected to the friction roller and rotatable therewith; a circular first disk coaxially mounted on the control shaft for rotation therewith; a circular second disk, greater in diameter than the first disk, mounted coaxially with the first disk and rotatable relative thereto; an offcenter pin attached to one disk and extending in an axial direction from said disk through an arcuate opening in the other disk, whereby rotation of the disks relative to each other is limited to movement between a normal and a driving position, rotation of the first disk relative to the second disk in the direction of rotation of the control shaft during film winding moving the disks from the normal to the driving position; resilient means biasing the disks into the normal position; a contact member on the arm normally resiliently engaging the circular periphery of the second disk under the urging of the pawl spring, such normal engagement preventing rotation of the pawl from the disengaged to the engaged position; an inwardly extending first notch in the periphery of the first disk; an inwardly extending second notch in the periphery of the second disk; the first and second notches being aligned when the first and second disks are in the driving position and not aligned when said disks are in the normal position; the resilient engagement of the engagement of the contact member with the periphery of the second disk creating sufficient frictional drag to hold said disk motionless while the first disk rotates from the normal to the driving position; and rotation of the driving shaft through an angle less than the shutter-cocking angle sufficing to wind sufficient film to cause the friction roller to rotate the first disk through a full turn.

Claim 6

A shutter cocking and film advancing mechanism for a camera having a shutter comprising: a winding shaft passing through the outer casing of the camera, said winding shaft being rotatable through a predetermined shutter-cocking angle for cocking the shutter; a ratchet wheel mounted on the winding shaft and rotatable relative thereto; a hollow shaft mounted on the winding shaft and rotatable relative thereto; means on the hollow shaft for engaging a film spool; a helical spring within the hollow shaft coiled about and normally firmly gripping the winding shaft, said spring having a first end engaging the ratchet gear and a second end engaging the hollow shaft, said spring coiling about the winding shaft in a direction opposite to the direction of rotation of the winding shaft during a winding operation as said spring proceeds from the ratchet wheel to the hollow shaft, whereby rotation of the hollow shaft in the winding direction relative to the ratchet wheel causes the spring to unwrap slightly and loosen its grip on the winding shaft; a pawl pivotally mounted on a support and rotatable between a disengaged position and an engaged position in which the pawl engages the ratchet wheel and prevents rotation thereof in the winding direction; a pawl spring urging the pawl into the engaged position; means operable following an exposure to move the pawl to the disengaged position; an arm attached to and rotatable with the pawl; a friction roller placed to contact the film with its periphery and to be turned by frictional engagement with the film as said film is advanced; a control shaft connected to the friction roller and rotatable therewith; a circular first disk coaxially mounted on the control shaft for rotation therewith; a circular second disk, greater in diameter than the first disk, mounted coaxially with the first disk and rotatable relative thereto; an offcenter pin attached to one disk and extending in an axial direction from said disk through an arcuate opening in the other disk, whereby rotation of the disks relative to each other is limited to movement between a normal and a driving position, rotation of the first disk relative to the second disk in the direction of rotation of the control shaft during film winding moving the disks from the normal to the driving position; resilient means biasing the disks into the normal position; a contact member on the arm normally resiliently engaging the circular periphery of the second disk under the urging of the pawl spring, such normal engagement preventing rotation of the pawl from the disengaged to the engaged position; an inwardly extending first notch in the periphery of the first disk; an inwardly extending second notch in the periphery of the second disk; the first and second notches being aligned when the first and second disks are in the driving position and not aligned when said disks are in the normal position; the resilient engagement of the engagement of the contact member with the periphery of the second disk creating sufficient frictional drag to hold said disk motionless while the first disk rotates from the normal to the driving position; and rotation of the driving shaft through an angle less than the shutter-cocking angle sufficing to wind sufficient film to cause the friction roller to rotate the first disk through a full turn.