Film windup device for cameras provided with a focal plane shutter

Claim 2

A film windup device for cameras having a back cover provided with shutter means, shutter tensioning means connected with filmadvancing mechanism comprising, in combination, a frame counter having a scale plate which is advanced by one scale mark in connection with one frame film advance and returns to its initial position when the back cover of the camera is opened, clutch means for connecting or disconnecting the shutter tensioning means to or from the shutter means, control means engageable with said clutch means to disconnect the shutter tensioning means from the shutter means a cam combined with said scale plate and a return lever biased by means of spring to drive said control means which engages with said clutch means to disconnect the shutter tensioning means from the shutter means when said back cover is opened, whereby said cam holds said control means in engaged position during the predetermined angle rotation of said cam after the closure of the back cover.

Claim 3

A film windup device as claimed in claim 1 wherein said frame counter includes a ratchet wheel combined with said scale plate and said cam, a stop pawl arranged to cooperate with said ratchet wheel to prevent the return movement of said scale plate, a feed pawl arranged to cooperate with said ratchet wheel to advance said scale plate by one scale mark in connection with film advance, and said return lever drives said pawls to disengage from said ratchet wheel and releases the return movement of said scale plate when said back cover is opened.

Claim 4

A film windup device as claimed in claim 1 further comprising a shutter release means, wherein said control means includes a lever spring-biased to disengage from the clutch means, said shutter release means arranged to drive said lever to engage said clutch means and disconnect the shutter tensioning means from the shutter.

Claim 5

A film windup device for cameras having a back cover comprising film-advancing means, shutter means, clutch means for normally connecting said film-advancing means to said shutter means in operative engagement, film counter means, means for returning said film counter means to its initial position upon opening said back cover, means for disengaging said clutch means upon opening said back cover, and means for retaining said clutch means in its disengaged position for a predetermined film advance subsequent to closure of said back cover.

Claim 6

A film windup device for cameras having a back cover comprising film-advancing means, shutter means, clutch means for normally connecting said film-advancing means to said shutter means in operative engagement, film counter means, means for returning said film counter means to its initial position upon opening said back cover, means for disengaging said clutch means upon opening said back cover, and means for retaining said clutch means in its disengaged position for a predetermined film advance subsequent to closure of said back cover.

Claim 7

A film windup device for cameras according to claim 4 wherein said frame counter means includes a scale plate, a ratchet wheel mounted coaxially with said scale plate, a stop pawl mounted adjacent said ratchet wheel to prevent return movement of said scale plate, a feed pawl mounted adjacent said ratchet wheel to advance said scale plate by one scale mark corresponding to a film advance; and wherein said means for returning said film counter means to its initial position upon opening said back cover comprises a return lever mounted for rotary movement upon opening said back cover to disengage said feed pawl and said stop pawl from said ratchet wheel, and a spring member to urge said scale plate to its initial position.

Claim 8

A film windup device for cameras according to claim 4 wherein said means for disengaging said clutch means upon opening said back cover comprises a return lever mounted for rotary movement upon opening said back cover, a control lever mounted for movement responsive to movement of said return lever, a release lever mounted for movement responsive to movement of said control lever to disengage said clutch means.

Claim 9

A film windup device for cameras according to claim 6 wherein said frame counter means includes a scale plate, a ratchet wheel mounted coaxially with said scale plate, a stop pawl mounted adjacent said ratchet wheel to prevent return movement of said scale plate, a feed pawl mounted adjacent said ratchet wheel to advance said scale plate by one scale mark corresponding to a film advance, and wherein said means for returning said film counter means to its initial position upon opening said back cover includes said return lever mounted for rotary movement upon opening said back cover to disengage said feed pawl and said stop pawl from said ratchet wheel, and a spring member to urge said scale plate to its initial position, and wherein said means for retaining said clutch means in its disengaged position for a predetermined film advance subsequent to closure of said back cover includes a control cam mounted for movement with said scale plate, a projection on said control cam for engaging said control lever to retain said control lever in position to be responsive to movement of said return lever, and means for moving said control cam to disengage said projection from said control lever to move said control lever to its nonresponsive position with respect to said return lever after a predetermined film advance, thereby releasing said release lever and allowing said clutch means to connect said film-advancing means to said shutter means in operative engagement.