Control apparatus for varying focal length of cinematographic zoom lens

Claim 2

A cinematographic camera including, a. a zoom lens b. focal length varying means for varying the focal length of said zoom lens c. an intermittent film advance mechanism, said d. coupling means to synchroniously couple said means for varying the focal length with said film advance mechanism, said coupling means including means for advancing the focal length varying means continuously in one sense during successive predetermined film standstill periods and for stopping the focal length varying means at the position reached substantially at the end of each of said standstill periods and for maintaining the focal length varying means stopped at said position substantially throughout the respective following film advance period and until the focal length varying means is again advanced in said one sense.

Claim 3

A cinematographic camera provided with a zoom lens comprising focal length varying means for varying the focal length of the lens in one sense during successive ones of predetermined film standstill periods and for fixing the focal length substantially throughout each of the obturation periods at the focal length reached at the end of the next previous standstill period and wherein said focal length varying means comprises a shaft mounted for rotation to vary the lens focal length and having at least one ratchet wheel mounted thereon and a disengaging pawl mounted for operative reciprocating movement to intermittently rotate the ratchet wheel and shaft.

Claim 4

A cinematographic camera provided with a zoom lens comprising focal length varying means for varying the focal length of the lens in one sense during successive ones of predetermined film standstill periods and for fixing the focal length substantially throughout each of the obturation periods at the focal length reached at the end of the next previous standstill period and wherein said focal length varying means comprises a shaft mounted for rotation to vary the lens focal length and having at least one ratchet wheel mounted thereon and a disengaging pawl mounted for operative reciprocating movement to intermittently rotate the ratchet wheel and shaft.

Claim 5

The camera of claim 2 wherein a lever is provided for oscillating movement and being coupled to move the disengaging pawl in a reciprocating movement, one end of the lever being adapted to cooperate with an eccentric drive element supported by a drive shaft coupled to the film advance mechanism, said drive shaft rotating once for a predeteRmined step of the film advance.

Claim 6

The camera of claim 3 wherein at least two eccentric drive elements of different eccentricity are supported by the drive shaft, and said lever end is coupled to either one or the other of the two eccentric drive elements.

Claim 7

A cinematographic camera provided with a zoom lens comprising focal length varying means for varying the focal length of the lens during film standstill periods and for fixing the same during obturation periods and wherein said varying means comprises a shaft mounted for rotation to vary the lens focal length and having two oppositely pitched ratchet wheels mounted thereto and two disengaging pawls each associated with one of the wheels for operatively and intermittently rotating the associated wheel and said shaft in one or the other angular direction, and a control mechanism selectively movable to each of three positions and coupled to the disengaging pawls for selectively positioning one or the other disengaging pawl in operative relation with its associated ratchet wheel and concurrently positioning both pawls out of operative relationship with the ratchet wheels depending upon the selected position of the control mechanism.

Claim 8

A cinematographic camera provided with a zoom lens comprising focal length varying means for varying the focal length of the lens during film standstill periods and for fixing the same during obturation periods and wherein said varying means comprises a shaft mounted for rotation to vary the lens focal length and having two oppositely pitched ratchet wheels mounted thereto and two disengaging pawls each associated with one of the wheels for operatively and intermittently rotating the associated wheel and said shaft in one or the other angular direction, and a control mechanism selectively movable to each of three positions and coupled to the disengaging pawls for selectively positioning one or the other disengaging pawl in operative relation with its associated ratchet wheel and concurrently positioning both pawls out of operative relationship with the ratchet wheels depending upon the selected position of the control mechanism.