US1565336A - Film-feeding mechanism for cinematographs - Google Patents

Description

Dec. 15, 1925- 1,565,336

F. SEUFERT I FILM FEEDING MECHANISM FOR CINEMATO GRAPHS Filed May 16 1924 -47 3 auto;

3251 %J Gum Y Patented Dec. 15,- 1925.

UNITED STATES PATENT OFFICE.

FILM-FEEDING MECHANISM FOR CINEMATOGRAPHS.

Application filed Kay 16, 1924. Serial No. 713,733.

To allwhom it may concern Be it known that I, FRIEDRICH SEUFERT, a citizen of Germany, residing at Munich, Bavaria, Germany, have invented certain i new and useful Improvements in Film- Feeding Mechanism for Ci-nematographs, of which the following is a specification.

The great ditlicultics connected with the mechanical transmission of stcp-by-step motion to the film band have long ago led to experiments to overcome the same by electric means. But these experiments have failed, because the mechanical transmission of the electro-magnetic forces were not free of faults, in that the picture could not be fed witlrprecision.

The object of this invention is to provide a construction, which will obviate these drawbacks.

In the accompan ing drawings, Fig. 1 is a sectional view I is a diagram of the electric connection illustrating the operation of the device.

On the shaft- 1 of the film sprocket wheel ;(not shown) are fixed two ratchet wheels 2 and'3. Cooperating with the ratchet wheel 2 is a pawl 4: fulcrumed at 5 in a lower 6.

The latter is fulcrumed at 7 in a stationary part (not shown) and has pivoted to it at 8 the armature 9 of an electro-magnet 10. The pawl 4 is in form of a double armed lever, one arm 4 acting as pawl proper and the other" 4 carrying a pin 11, which slidably engages a slot 12' extending longitudinally in an arm 12 fulcrumed at 13 in a stationary part (not shown). This arm 12 is adapted to act as pawl in cooperation with the ratchet 3. The lever 6 is acted upon by a spring 14 one end of which is fixed at 14 and the other connected to said leverat 14. The arm 4! of the pawl 4 is connected to a-projection 6 of the lever 6 by a spring 15. 16 denotesa stop for the lever 6.

Y W'hen the armature 9 is attracted by the 'electro-inagnet, the lever 6' will swing around its fulcrum. 1 toward the electromagnet. Owin to this movement, the pawl 4' will be force by the ratchet wheel to swing around ,its pivot 5 away from said-wheel, while the arm 4: will sw ng toward the ratchets, and

a by its pin 11 swin the pawl 12 into engagement with the rate et 3, locking the latter so the device and Fig. 2

the intermittent or step-by-step motion 0 that the intermittent rotary motion of the film'wheel will be controlled with great precision. 55

- The armature 9 is provided with a projec'tion 9 engaging a central bore in the clectro-magnet, vwhereby it is propcrly guided. The spring 14 has the tendency, when the elcctro-magnet is deenergized, to swing the lever 6 back into its norinal position to rest against the stop 16, while the spring has the tendency to swing the pawl 4 into engagement with the ratchet wheel 2.

For the operation of the electro-magnet, 6 I employ a commutator adapted to revolve with uniform speed. The'same comprises an insulation body 17 on which is mounted a commutator ring 18 and one or more conducting lates 19 insulated from one another, 7

'but con uctively connected to r-i'ng 18. C0-

operating with the ring 18, is a brush 20 connected to the positive pole of the electric source (not shown), while a second brush 21 is adapted to slide on the body portion and conductors and alternately make and break the circuit. The second brush 1 is connected to one pole of the electro-magnet, whose other ole is connected to the negative pole of the e ectric source.

The electro-magnet, through the operation of the commutator, will thus be alternately ener ized and disenergized, thereby causin the-feeding roll of the film, as hereinbefore described.

What I claim is In a film feeding device, the combination with the film feeding shaft, of two ratchet wheels fixed on said shaft, an electro-magnet, a'spring actnated lever having a stationary fulcrum and from which is pivotally suspended the armature of said electro-magnet, a spring actuated double armed lever pivoted to said first named lever and of which one arm cooperates as pawl with one of said ratchet wheels and a second pawl having a stationary fulcrum and cooperating with said second ratchet wheel, said second pawl being adapted to slidably engage the second arm of said double armed ever.

In testimonywhereof I aflix my si ature.

FRITZ SEUF RT.

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