US3040945A - Self-threading motion picture machine - Google Patents

Description

June 26, 1962 F. A. LUNZER 3,

SELF-THREADING MOTION PICTURE MACHINE Filed Nov. 50, 1960 3 Sheets-Sheet 1 i Maul-m illllllll-nll L\\ f i v mmvron m FZEDEE/C ,4. 10/7252 i Y 92 F5 22 m June 26, 1962 F. A. LUNZER SELF-THREADING MOTION PICTURE MACHINE Filed Nov. 30, 1960 5 Sheets-Sheet 2 INVEN TOR.

F2D2l6 ,9. AU/YZER lrrop/vaks June 26, 1962 F. A. LUNZER SELF-THREADING MOTION PICTURE MACHINE 3 Sheets-Sheet 3 Filed Nov. 30, 1960 m T m W.

3,040,945 SELF-THREADING MOTION PECTURE MACHINE Frederic A. Lunzer, New York, N.Y., assignor to De Jur- Amsco Corporation, Long Island City, N.Y., a corporation of New York Filed Nov. 30, 1960, Ser. No. 72,688 4 Claims. (Cl. 226-91) The present invention relates to an improved selfthreading motion picture machine. 7

In motion picture machines provided with self-threading mechanisms, the film strip is automatically threaded through the machine, the film being advanced from the upper film sprocket, through the film gate (and the intermittent drive) to the lower film sprocket, a loop being formed in the film between each sprocket and the film gate by a loop-former. Upper and lower loopformers are according mounted for movement between a loop-forming position assumed during loop forming and a retracted position (for out of frictional contact with the film) assumed for and held during the running of the film in the subsequent operation of the machine. Latching means are provided for latching the loop-formers in their loop-forming position; and means is provided operated upon completion of the film threading step for unlatching the latching means to thereby cause the loopformers to move to their retracted position.

The prime object of the present invention centers about the construction and mechanical design of a selfthreading mechanism of this nature and functioning as above referred to, characterized by the following structural and functional improvements:

(1) The loop-formers, constructed and inter-meshed for movement in unison between their loop-forming and retracted positions, are movable from a normal retracted position to their loop-forming position manually by directly engaging and moving either (and preferably the upper) loop-former;

(2) The loop-formers are latched in their loop-forming position by a latching means associated directly with the lower loop-former and arranged between the same and the lower sprocket, designed so that when the film is advanced and engaged by the lower sprocket, the film engages and trips the latching means, thereby releasing the loop-formers for return movement to their retracted position out of frictional contact with the film; and

(3) Film guides are associated with the sprockets and the loop-formers, movable relative thereto to permit any removal of the film from the machine that may be desirable or made necessary before total passage of the film is achieved; and the lower film guide is so related to the latching means that movement of the lower film guide will also effect the tripping of the latching means.

A further object of the invention is the provision of an improved self-threading machine of this character in which all of the described parts are combined andinterrelated to produce a machine having compactness, an economy of parts, accessibility of parts and a facility of manipulation and operation.

To the accomplishment of the foregoing objects and such other objects as may hereinafter appear the present invention relates to the self-threading motion picture machine as sought to be defined in the appended claims and as described in the following specification and shown in the accompanying drawings, in which:

FIG. 1 is a side elevational view of the self-threading mechanism or apparatus of the present invention as ap plied to a motion picture projector and showing the parts in the position for loading or self-threading the film strip;

FIG. 2 is a similar view thereof shown on a somewhat enlarged scale but taken in cross-section in the plane of States Patent HQQ the line 22 of FIG. 3, and showing the parts in the position for the operation of the machine following the self-threading step;

FIG. 3 is a view of FIG. 2 taken in cross-section in the planes of the broken line 33;

FIG. 4 is a view taken on an enlarged scale of the latching means and its relation to the lower loop former;

FIG. 5 is a view of FIG. 4 taken in cross-section in the planes of the broken line 5-5; and

FIG. 6 is a perspective view of the parts of the selfthreading mechanism of the present invention showing the parts in an exploded condition.

Referring now more in detail to the drawings and having reference first to FIGS. 1 to 3 thereof, the self-threading mechanism of the invention is shown applied to a motion picture projector, the related parts of which comprise a framework providing a vertical supporting wall 10, a transversely arranged supporting wall 12, a film gate mount 14 hingedly connected at 16 to the transverse wall 12, the film gate mount carrying the objective or lens mount 18. The motion picture machine is as usual provided with means for feeding and guiding a film strip through the machine comprising an upper film sprocket 20, a lower film sprocket 22 and the film gate with which latter is associated the customary intermittent film drive means (not shown).

In self-threading mechanisms the film strip, such as the film 24 when presented as indicated in FIG. 1 to the upper film sprocket, is advanced from the upper film sprocket through the film gate (and the intermittent drive) to the lower film sprocket 22, a loop being formed in the film between each sprocket and the film gate by a loop-former. Accordingly upper and lower loop- formers 26 and 28 are provided, mounted for movement between a loop-forming position shown in FIG. 1 of the drawings during the loopforming step and a retracted position shown in FIG. 2 of the drawings, which latter positioning .is assumed for the continued running of the film in the operation of the machine. In the loop-forming step, loops are provided in the film strip 24 as shown in FIG. 2, and when the loopformers are moved to their retracted position, the loopformers are removed out of frictional contact with the film. Associated with the loop-formers are the upper and lower film guides 30 and 32 pivotally movable with reference to the sprockets 20 and 22 about the axes 34 and 36 respectively. The loop-formers and film guides are shaped and contoured as shown in FIGS. 1 to 3 (and particularly depicted in FIG. 6 of-the drawings) and these parts are preferably made of a suitable plastic material molded to these shapes and contours, the plastic material being preferable such as to produce transparent products.

Means are provided for interconnecting the loop- formers 26 and 28 for moving the same in unison between their loop-forming (film threading) and retracted positions; and for this purpose the loop-formers include intermeshing gear segments, one fixed to each loop-former. Accordingly metal segments 38 and 40 shaped as best shown in FIG. 6 of the drawings are afiixed respectively to the loop-formers 26 and 28 (in a manner to be described hereinafter) and these segments are formed with the intermeshing gear teeth 42 and 44. By means of this construction movement of either of the loop-formers will impart oted film guides 30 and 32 are also resiliently urged by being spring loaded to their normal machine operating positions as depicted in both FIGS. 1 and 2 of the drawings. To accomplish the spring loading of both the loop-formers and the film guides means is provided for 'so resiliently interconnecting each loop-former to its associated film guide as to accomplish these functions. This is accomplished by means of the upper spring 46 and the lower spring 48, these parts being best depicted in FIG. 6 of the drawings, each of which springs is anchored at its opposite ends to a loop-former and a film guide in a manner clearly shown in FIG. 2 and which will be further detailed hereinafter. By means of this construction and arrangement it will be seen that the film-formers will normally assume, under the action of the springs 46 and 48, the retracted position shown in FIG. 2, that the loopformers may be moved to their film threading position by directly manually engaging either the upper loop-former 26 or the lower loop-former 2'8 and moving the same against the tension of the springs 46 and 48, that the film guides 30 and 32 will be normally resiliently held by the same springs in their operative film guiding positions shown in FIGS. 1 and 2, and that these film guides 30 and 32 may be manually moved against the tensioning of the springs to positions away from the sprockets 20 and 22, the latter to permit any removal of the film from the machine that may be desirable or made necessary before total passage of the film through the machine is achieved, the movement of the lower film guide 32 against the action of the spring 48 being also desirable for effecting a tripping of latching means hereinafter further described.

When the loop-formers are moved to their film threading position, they are automatically latched in that position; and when the film has completed its self-threading step, the loop-formers are unlatched for return movement to their retracted position. The latching means which is provided for this purpose is associated with the lower loopformer and is made movable between latching and unlatching positions and is arranged so that it is spring loaded for movement to its latching position. This latching means 50 comprises a member configured as best shown in FIG. 6 of the drawings, pivotally mounted at 52 on the vertical projector wall 10, the said member being formed with an element 54 projecting into the path of the film strip (and projecting for this purpose toward and into the sprocket 22 as best shown in FIGS. 4 and the said latching means being also provided with a part such as a tooth 56 projecting inwardly therefrom, which tooth is adapted for engaging a part of the lower loop-former, and more particularly a part of the lower gear segment 40 thereof for latching the same; and for this purpose the lower gear segment 40 is provided in an arcuate slot 58 thereof with a cam or depressed part 60 for lodging the tooth 56 in its latching position. The latching means 50 is spring loaded by means of a spring 62 anchored at one end to a peg 63 and at its other end to a hook 64 formed in the. latching member. The upper gear segment 38 is also formed with an arcuate slot 66. By means of this construction it will be seen that when the loop-formers are moved to their film threading position (FIG. 1), the ' gear segments 38 and 40 are moved in unison to the po' sition shown in FIGS. 1 and 4 and the latching member 50 urged by the spring 62 moves to the position best shown in FIGS. 1 and 4, in which position the latching tooth 56 engages the cam or depression 60, thereby latching the gear segments and the loop-formers in the film threading position. It will be further seen that when the self-threaded film reaches the lower sprocket 22, the film engages the projecting. element 54, thereby lifting the latching member 50 to the position shown in FIG. 2 of the drawings, in which position the latching tooth 56 is removed out of the path of the depression 60, and thereby the gear segments and the loop-formers to which they are attached, are automatically released for movement to their retracted position as shown in FIG. 2.

As heretofore stated, the lower film guide 32 is so related to the latching means that movement of the lower film guide will also effect the tripping of the latching means. This is accomplished by providing the latching means with a transverse part 68' which is received by an opening 70 formed in an inner wall of the guide 32 as best shown in FIGS. 4 and 5 of the drawings. Thereby when the film guide 32 is lifted (against the action of the spring 48), the part 68 of the latching member will be engaged by the lower wall of the opening 70 and will thereby be moved to a tripping position.

Preferably to discourage inserting the film strip in the machine when the loop-formers are not in their film threading position, a guard member 72 is provided shaped as best indicated in FIG. 6, and independently pivoted about the axis of the upper sprocket 20 but which is arranged to be movable from the guarding position shown in FIG. 2 to the ungarding position shown in FIG. 1 by the movement of the upper loop-former 26. A guard roll 74 is mounted Within the guard member 72. By means of the independent movement of the guard member it may be lifted above the position shown in FIG. 1, to permit freedom of insertion of the film into the machine. However, when the parts assume the position shown in FIG. 2, the guard member is dropped to the condition depicted in FIG. 2.

FIG. 6 shows the separate parts which make up the self-threading mechanism and depicts the manner of assembling these parts. The gear segment 38 is attached to the loop-former 26 by means of the screws 76; the sprocket 20 is mounted by means of its shaft 78 in the bearing 80 provided in the vertical supporting wall 10; the upper film guide 30 is secured to the wall 10 pivotally by means of the screw bolt 82; the spring 46 is anchored at its opposite ends by means of the pegs 84 and 86 in turn fixed to the guide 30 and loop-former 26; and the gear segment 38 as well as the guard member 72 are pivotally mounted on the ferrule 88, and held in position by the collar 89 (see FIG. 3), the parts being otherwise assembled as indicated by the dot and dash lines shown associated with these parts. Similarly the gear segment 40 is attached to the loop-former 28' by means of the screws 90; the lower sprocket 22 is mounted by means of its shaft 92 in the bearing 94 provided in the wall 10; the lower film guide 32 is secured to the wall 10 pivotally by means of the screw or bolt 96; the spring 48 is anchored at its opposite ends by means of the pegs 98 and 100 in turn fixed to the guide 32 and the loop-former 28; and the gear segment "40 is pivotally mounted on the ferrule i102 and held in position by the collar 103 (see FIG. 5), the par-ts being other assembled as indicated by the dot and dash lines shown. To these parts is added a lower film guide 104 mounted in the boss bearing 106 by means of a bolt 108. A retaining screw 110 (-FIGS. 1 and 2) is also preferably used to guide the upper gear segment in its movements.

The operation of the self-threading mechanism of the present invention, the interrelation of the parts thereof, their related functioning and the described advantages obtained in the improved construction supplied will in the main be fully apparent from the above description thereof. It will be further apparent that many changes may be made therein without departing from the spirit of the invention defined in the following claims.

I claim:

1. A self-threading motion picture machine, in combination with means for feeding and guiding a film strip through the machine, mechanism for forming upper and lower film loops in the machine comprising a pivotally mounted upper loop-former and a pivotally mounted lower loop-former, said loop-formers including intermeshing segments, one fixed to each loop-former, interconnecting the loop-formers for moving the same in unison between a film threading position and a retracted position, the said loop-formers being spring loaded for movement to their retracted position and being manually movable against the spring loading to their film threading position, a latching means associated with said lower loop-former movable between latching and unlatching positions and being spring loaded for movement to its latching position, said latching means having an element projecting into the path of the film strip and having a part for then engaging a part of the lower loop-former to latch the same in its film threading position, the said element projecting into the path of the film strip being adapted to be engaged by the film strip for moving the latching means to its unlatching position and thereby release said loop-formers for movement in unison to their retracted position, an upper film guide associated with the upper loop former, a lower film guide associated with the lower loop former and movable about a pivot relative thereto, and means forming part of said latching means extending into the path of movement of said lower film guide whereby manual movement of said lower film guide about its pivot will move the latching means to an unlatching position.

2. In the self-threading motion picture machine of claim 1, a spring interconnecting each loop-former to its associated film guide, said spring defining the spring loading of the loop-former and acting for spring loading the film guide.

3. A self-threading motion picture machine for a motion picture machine in combination with upper and lower sprockets and a film gate for feeding and guiding a film strip through the machine, mechanism for forming a film loop between each sprocket and the film gate comprising an upper loop-former mounted for pivotal movement about the axis of the upper sprocket, a lower loop-former mounted for pivotal movement about the axis of the lower sprocket, said loop-formers including intermeshing segments, one fixed to each loop-former, interconnecting the loop-formers for moving the same in unison between a film threading position and a retracted position, the said loop-formers being manually movable to their threading position and being spring loaded for movement to their retracted position, a latching means arranged between the lower sprocket and the lower loop-former movable between latching and unlatching positions and spring loaded for movement to its latching position, said latching means having an element projecting toward the lower sprocket and into the path of the film strip and having a part for then engaging a part of the lower loop-former to latch the same in its film-threading position, the engagement of the film strip with said element causing the latching means to move to unlatching position and thereby releasing said loop-formers for movement in unison to their retracted position, an upper film guide associated with the upper sprocket and mounted on a pivot located between said upper sprocket and the film gate, a lower film guide associated with the lower sprocket and mounted on a pivot located between the lower sprocket and the film gate, and means forming part of said latching means extending into the path of movement of said lower film guide whereby manual movement of said lower film guide about its pivot will move the latching means to an unlatching position.

4. In the self-threading machine of claim 3, a spring interconnecting each loop-former .to its associated film guide, said spring defining the spring loading of the loop-former and acting for spring loading the film guide.

References Cited in the file of this patent UNITED STATES PATENTS 2,420,587 Dietrich May 13, 1947 2,832,258 Chevallaz Apr. 29, 1958 2,983,416 Hanken et al May 9, 196 1

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