US1200938A - Moving-picture-film protector. - Google Patents

Description

H. E. HARBAUGH & D. P. SMEDLEY.

MOVING PICTURE FILM PROTECTOR.

APPLICATION FILED DEC. 3. 1915.

Patented Oct. 10, 1916.

2 SHEETS-SHEET 1.

H; E. HARBAUGH & D. P. SMEDLEY,

MOVING PICTURE FILM PROTECTOR.

APPLICATION FILED DEC-3,1915.

1 200,938. Patented Oct. 10,1916.

2 SHEETS-SHEET 2.

Witnesses:

P MGM UNITED STATES PATENT onFIoE. I

HARRY E. HARBAUGH AND DANIEL P. SMEDLEY, OF CINCINNATI, OHIO, ASSIGNORS OF ONE-THIRD T JOSEPH F. HENN EGAN, OF CINCINNATI, OHIO.

MOVING-PICTURE-FILM PROTECTOR."

Specification of Letters Patent.

Patented Oct. 10, 1916.

T 0 all whom itmag concern Be it known that We, HARRY E. HARBAUGH and DANIEL Z P. SMEDLEY, citizens of the United States, residing in Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Moving-Picture-Film Protectors, of which the following is a specification.

Our invention relates to moving-picture apparatus; and its object is to provide simple, sensitive and quickly acting means to prevent ignition of or other damage to films when broken or obstructed during their op eration, especially'when driven by an electric motor. 7 e

Our invention consists in the combination of parts and in the details of construction and arrangement of parts as will herein be more fully described and claimed.

In the drawings: Figure 1 is a side elevation representing diagrammatically a moving-picture projecting apparatus .With our invention applied thereto, the apparatus being represented by dotted lines only, and our invention being shown in full lines; Fig. 2 is a longitudinal vertical section of the circuit-breaker and the means by which it is under the control of the film, on the center line of its shaft, and also showing part of the film in relation thereto; .Fig. 3

,is a side elevation of the same, the film in slack position and the part directly coacting therewith being also indicated by dotted lines; Fig. A: is a plan View of the dowser forming part of our invention, the operating parts being shown in restrained position and being also shown in released position by dotted lines; and Figs. 5, 6 and 7 are similar side, front and rear elevations, respectively, of the same.

As shown in Fig. 1, our invention is applied to a moving-picture projecting apparatuswhich is well-known and in general use: but it will be understood that our invention is intended to be adapted to any practical moving-picture apparatus.

As shown, the moving-picture machine 1 is mounted on the lower film-magazine 2 and has mounted above it the upper filmmagazine 3, while on the bottom of the lower magazine 2 is the electric motor 4 that drives the machine 1. To the rear. the lamp-house 5 is mounted on a frame 6 on the rear of the lower magazine 2. which also carries the control or s itch-box 7. On the front of the lamp house 5 is the condenser-hood 8, and the machine 1 actuates the film 9 with suitable intermittent motion from the upper magazine 3 to the lower magazine 2 between the condenser in the hood 8 and the project- "6' ing lens 10 on the front of the machine.

As is well-known, the film 9 passes over the upper sprocket 11 and has a loop 12 in it just before passing onto the lower sprocket 13, as a result of being driven by the intermittent sprocket 14 just below where it is exposed to the condensed light and heat rays. After passing from the lower sprocket 13, the film 9 is guided to the take-up reel 15 in the lower magazine 2; and in the normal operation of the machine, this part of the film from the sprocket 13 into the magazine 2 is under considerable tension.

All of the above is well-known, and is described only to facilitate the following description of our invention, which comprises a circuit-breaker 16 governed by this part of the'film below the lower sprocket, and an electro-magnetically controlled dowser 17 in series with the circuit-breaker 16 and with all or part of the motor 4, ac-

cordingly as the motor is series or shunt wound. As here shown, the motor is shunt wound and the peculiar connections thereto will later be described.

The circuit-breaker 16 comprises a disk 18 of insulating material, mounted on a shaft 19 to turn therewith, and having diametrically opposite segments 20 connected by a conductor 21 extending across one side of the disk 18 well away from the shaft 19, and preferably provided with insulation 22 as shown. A casing 23 surrounds the disk 18 and has bosses 24 above and below, in which are held bushings 25 ofinsulating material containing the metal brush-holders 26, in which are held brushes 27, preferably of carbon. which bear against the periphery of the disk 18 andconnect with the'respectiye segments 20 or are disconnected therefrom I00 accordingly as the disk is rotated with the r shaft 19. Conductors 28 and 29 (Fig. 3) lead through suitable insulating bushings 30 in the bottom of the casing 23 and connect, respectively, with the brush-holders 26. Extending .laterally from the casing 23is a frame 31 with jaws 32 and 33,adapte'd to fit down over the top of thelower magazine 2 or other part of the apparatus close to the aforesaid stretch of film below the lower tor, with the shaft 19 projecting over to the operators side into its bearing 36. Just inside this bearing 36 an arm 38 is mounted on the shaft 19 and held fast thereto bya set-screw 39 in such a position that it projects upwardly and over toward the aforesaid stretch of the film 9. Near the free end of this arm 38, a stud 40 projects in and carries an idler-.roller 41 to rotate on the stud while bearing against said stretch of film.

,A set-screw 42 holds this stud 40 fast in the arm 38. The disk 18 of the circuit-breaker is preferably secured on the shaft 19 by providing the end part of the shaft with threads 43 and screwing the disk onto these threads.

The disk however, is not screwed entirely back against the adjacent collar 37, but is held against turning on the shaft 19 by a lock-nut 44 screwed onto the shaft 19 after the disk. Being heldby the set-screw 39, the arm 38 may be given any position along the shaft 19, and the stud 40 may be adjusted longitudinally in the arm 38 as held by the set-screw 42, so that the idler-roller 41 may have exactly the right amount of end playand the correct relation to film 9; and by the mounting above described, the disk 18 may have any angular adjustment to the shaft 19 and be locked in such adjustment by the nut 44. For convenience in making this adjustment, the nut 44 is preferably the form of a wing or thumb nut as shown.

The outer side of the casing 23'\is in the form of a removable plate 45 to permit ready access for this adjustment and forinspection of the other interior parts of the circuit-breaker. The brushes 27 are yieldably held against the disk 18 by helical springs 46 confined in the holders 26 and bushings 25 under plugs 47 in the outer ends of the bushings, which are held by pins 48 passed through the bushings and plugs. These bushings 25 may be adjusted in the bosses 24 of the casing 23 radially with respect to the disk 18, and be held in any such adjusted position by set-screws 49 in the bosses 24.

With the arrangement asiabove described, the parts are so adjusted that when the film 9 has its normal tension, the disk 18 will be held so that the brushes 27 make connection with the segments 20, by the bearing of the roller 41 on the film. Thus, under norto the arm 38, will result in' a falling of the arm 38 on account of its own weight and that of the parts carried on the arm. When the arm 28. falls far enough to rotatethe segments 20 away from the brushes 27, the connection between the conductors 28 and 29 will be. broken.

It will be seen that by the adjustments above described, the breaking of the current may be caused with more or less slackening of the film 9, as may be desired. Thus the device may be adjusted so that only very slight reductions in tension will not result in a breaking of the circuit; but only when such a slackening occurs as is caused by some serious derangement, such as breakage or obstruction 'of the film which will result in its stoppage in the line of projection long enough to become ignited. However, it will be understood that the parts may be so adjusted that the very slightest decrease in tension will result in a breakage of the circuit. I

The dowser comprises a shutter 50fixed on a yoke 51 pivoted on a transverse pin 52 in a bracket 53, on the under side of which is a metal strap 54 that passes around the front end part of the tapering condenser-hood 8 of the lamp-house-5, and has its lower ends drawn together by a bolt 55. Thus, the

' shutter 50, if raised into horizontal position as indicated by thefull lines in Figs. 4 to 7, inclusive, and as shown in Figrl, will be out of the line of projection; but ifin the vertical position indicated by the dotted lines in Figs. 4 to 7, inclusive, it will intencept' the light and heat rays at aconsiderable distance from the film; thereby preventing ignition of the film.

The shutter 50 has, projecting upward substantially at right angles to it, an armature 56, and an electro-magnet 57 has a core 58, against one end of which this armature 56 is held when the electro-magnet is energized, thus holding the shutter 50 in horizontal position. If the magnet 57 is denergized, the shutter 50 drops by its own weight to the vertical position. This magnet 57 is inclosed in a suitable box 59 with its bottom fixed to the bracket 53 near the front, and provided with laterally projecting cars 60 near the rear, which have openings-through which screws or bolts may be passed into the condenser-hood 8, thus codowser on the hood. 4

As shown diagrammatically in Fig. 1, the conductor 28 leads from one of the brushes on the circuit-breaker to one end of the coil of the electro-magnet 57, and another conoperating with'the strap 54 in holding the all of the ductor 61 leads. from the other end of this coil. These conductors 28 and 6.1 pass through suitableinsulating bushings 62 in the side of the magnet-box 59; preferably on the side away from the operator.

As above alluded to, the motor here shown is shunt-wound; and while the actual design of the motor is indicated by dotted lines, the motor is also represented diagrammatically, with an armature 63 and field-coils 63. The conductors 64 and 65 lead to the switchbox 7 where they may be connected with the source of current. The conductor 61 is connected to one end of the field-coils 63 and also to one of the brushes of the armature 63. The other conductor 65 is connected to the other end of the field-coils 63 and also to the conductor 61 leading to the electromagnet 57. The other conductor 29 from the circuit-breaker leads to the other brush of the armature 63. Thus, it will be seen that-the armature 63 of the'motor 4c is in series with the circuit-breaker and the electro-magnet 57 ofthe dowser 17 ;'-but the field-coils 63' of the motor 4 are in parallel with the above apparatus. This is more desirable than merely connecting the entire shunt-wound motor 4 in series with the other apparatus, because it results in only approximately the armature current passing through the coil of the electro-magnet '57. This minimizes the heating of this coal, which is so liable to occur, even with a moderately heavy current, because it merely holds parts stationary during this passage of current, and is thus somewhat subject to overheating like the motor when stalled. With series-wound motor, all of the parts of apparatus are connected in the series.

From the foregoing it will be seen that when the circuit is broken by the circuitbreaker under the conditions above described, not only will the electro-magnet 57 be denergized, allowing the shutter 50 to drop, but the current through the armature 63 of the shunt-wound motor 4 will be interrupted and the motor will stop; or; if a series motor, the current will be interrupted through both the armature and the field,

the film after breakage or clogging.

llvhen slides are to be projected from, with a the lamp-house 5 shifted by being slid over opening the circuit to stop the motor, this opening of course being made in the switchboX 7 as usual. Therefore, the shutter 50 will not be held up by the magnet. To provide for holding this shutter 50 up under these circumstances, we provide a holder 66 swinging on a vertical pivot 67 on the rear end of the magnet-box 59 and at one side thereof, preferably the side away from the operator. This holder extends along this side of the magnet-box 59 above the connections 28 and 61 and around the front of the box in front of the armature 56 when the shutter 50 is raised to horizontal position. Preferably, the armature has a lug 68 and the holder 66 has a slight hook 69 passing around this lug. Thus the security of holding is increased; but at the same time, because the holder 66 is pivoted so far away from these engaging parts, it swings itshook 69 freely away from the lug 68.

It will be seen from the above that the holder 56 may be manually brought into position to hold the shutter 50 up whenever this is desired. However when'the lamphouse 5 is again brought in ine with the machine 1 for operation of films, if the operator would forget to release the shutter 50 from armature 56. Thus, the dowser is automatically'set for automatic operation as soon as current is passed through it in starting the motor 4, and with the circuit-breaker closing the current as held by the film 9. When the motor is started "and the film is thus holding the circuit-breaker in circuit-closing position, the film will of course be in normal rapid motion, and there will be no danger of ignition but as soon as any interruption or stoppage occurs, the shutter 50 will now quickly fall and the motor will-be promptly stopped.

The arm 38 of the circuit-breaker may be thrown far back out of the way of the film, thus making it very convenient when threading the film through the machine. Also when a machine is provided with a loopsetter, this arm and its idler-roller 41 in no way interfere with the operation of the loopsetter, and are not improperly actuated as a setter if the parts of the circuit-breaker be properly adjusted. Atvthe same time, such a proper adjustment will amply provide for automatic stoppage of the heat rays and of the motor in any emergency likely to produce damage. It will be understood that in case of breakage of the film above the lower sprocket 13, the stoppage will occur as soon as the lower part of the broken film has passed from this sprocket, becoming slack enough to allow the arm 38 to drop.

The sensitiveness, quickness and. reliability of our apparatus is due alike to the simple construction both of the circuit-breaker and of the automatic dowser, involving a minimum of friction'and dispensing with the use of springs for providing any of the movements required in an emergency. The only springs employed are those pressing the brushes 27 against the disk periphery, and it will be understood that these provide only sufficient pressure to make proper electrical connection between the brushes and segments. A pressure causing so little resistance as not to be perceptible at the end of the arm 38 is sufiicient for this connection.

The result of the entire combination is to provide a control of the light very nearly identical with the feeding the film by the machine 1 through the feed-controlled means, herein exemplified by the film-controlled circuit-breaker, and the dowser controlled by the feed-controlled means.

In order to further increase the reliability of the device, we prefer to build up the core 58 of a number of thin iron wires as indicated in Figs; 6 and 7, thus almost entirely eliminating permanent magnetism in this core.

The effectiveness of this. electro-magnetic action is also insured by. giving the shutter 59 a pivotal mounting for its movement toward and away from'the magnet, instead of I a sliding or other mounting which involves more friction. The armature 56 and yoke 51 are preferably integral, and these and the armature .71 areof course made of soft iron.

Having fully described our invention, what we claim as new and desire to secure by Letters Patent is: n

1. In combination with a film, film-carrying means, and a lamp house containing a light source and shiftable to project light from saidlight source through said film or to project said light through a space. along side said film, a shutter, a mounting supported on and shiftable with said lamp house, a pivotal connection between said shutter and said mounting with its axis substantially at right angles to the direction of projection of said light, whereby said shutter may swing into or out of position to intercept the light, an armature connected to said shutter substantially at right angles thereto near said pivotal connection, an election or denergization 0 tro-magnet fixed on said mounting with its core substantially parallel with said direction of projection, and holding said armature adjacent to one end of its core when ening means, and a lamp house containing a,

light source and vshiftable to project light from said light source through said film or to project said light through a space along side said film, a shutter, a mounting supported on and shiftable with said lamp house, a pivotal connection between said shutter and said mounting with its axis substantially horizontal and substantially at right angles to the direction of projection of said light, whereby said shutter may fall into a substantially vertical position to intercept the light, an armature connected to said shutter substantially at right angles thereto near said pivotal connection, an electro-magnet fixed on said mounting with its core substantially parallel with said direction of projection, and holding said armature adjacent to one end of its core when energized. and-therebyholding said shutter up out of light-intercepting osition, and feedcontrolled means control in the energizam magnet. I

3.,v In vcombination with a film, film-carrying means, and means to project light through said film, a dowser to automatically intercept said light, means whereby said dowser is normally restrained from intercepting said light, manually applied automatically released means on said dowser for restraining said dowser while the normal restraint is interrupted, means to automatiically release said restraining means upon resumption of said normal restraint, and feed-controlled means controlling the nor mal restraint of the dowser.

4. In combination with a film, film-carry ing means, and means to project light through said film, a dowser to automatically intercept said light, electro-magnetic means whereby said dowser is normally restrained from intercepting said light, manually applied automatically released means on said dowser for restraining said dowser while the normal restraint is interrupted, means to automatically release said 'restraining means upon resumption of said normal restraint, and feed-controlled means controlling'the normal restraint of the dowser.

5. In combination witlra film, film-carrying means, and means to project light through said film, a dowser to automatically intercept said light, eleotro-magnetic means whereby said dowser is normally restrained said electrofrom intercepting said light, manually applied means on said dowser for restraining said dowser while the normal restraint is interrupted, means whereby said electro-magnetic means automatically releases this restraining means upon resumption of said normal restraint, and feed-controlled means controlling said electro-magnetic means and thereby controlling the normal restraint of the dowser.

6. In combination with a film, film-carrying means, and a lamp house containing a light source and shiftable to project light from said light source through said film or to project said light through a space along side said film, a dowser to automatically intercept said light, electro-magnetic means whereby said dowser is normally restrained from intercepting said light, manually applied automatically released means on said dowser for restraining said dowser while the normal restraint is interrupted, means to automatically release this restraining means upon resumption of said normal restraint, and feed-controlled means controlling said electro-magnetic means and thereby controlling the normal restraint of the dowser.

7. In combination with a film, film-carrying means, and a lamp housecontaining a light source and shiftable to project light from said light source through said film or to project said light through a space alongside said film, a dowser to automatically intercept said light, mounted on and shiftable with said lamp house, electro-magnetic means whereby said dowser is normally restrained from intercepting said light, but the normal restraint being interrupted while the lamp house is shifted, manually applied means onsaid dowser for restraining said dowser while the normal restraint is interrupted, means whereby said'electro-magnetic means automatically releases said means upon resumption of said normal restraint, and feed-controlled means controlling said electro-magnetic means and thereby controlling the normal restraint of the dowser.

8. In combination with a film, film carrying means, and means to projectlight through said film, a shutter, a mounting supported on said lamp house, a pivotal connection between said shutter and said mounting with its axis substantially at right angles to the direction of projection of said light, whereby said shutter may swin into or out of'position to intercept the lig t,;'an

armature connected to said shutter substantially at right angles thereto near said pivotal connection, an electro-magnet fixed on said mounting with its core substantially parallel with said direction of projection, and holding said armatureadjacent to one end of its core when energized and thereby holding said shutter out of light' interceptrestraining ing position, a holder supported on said mounting and manually applied to hold said shutter out of intercepting position when the,

electro-magnet is deenergized, but automatically drawn toward said electro-magnet to release said shutter when the electro-magnet is energized, and feed-controlled means controlling the energization or denergization of said electro-magnet.

9. In combination with a film, film-carrying means, and a lamp house containing a light source and shiftable to project light from said light source through said film or to project said light througha space along side said film, a shutter, a mounting, supported on and shiftable with said lamp house, a pivotal connection between said shutter and said mounting with its axis substantially at right angles to the direction of projection of said light, whereby said shutter may swing into or out of position to intercept the light, anarmature connected to said shutter substantially at right angles thereto near said pivotal connection, an electro-magnet fixed on said mounting with its core substantially parallel with said direction of projection, and holding said arma.

ture adjacent to one end of its core when energized and thereby holding said shutter up out of light-intercepting position, a holder supported on said mounting and manually applied to hold said shutter out of intercepting position when the electro-magnet is denergized, but automatically drawn toward said electro-magnet to release said shutter when the electro-magnet is energized, and feed-controlled means controlllng the energization or deenergization of said electro-magnet. I

i 10. In combination with a film, filmoarrying means, and a lamp house containing a light source and shiftable to project light from said light source through said film or to project said light through a space along side said film, a shutter, a mounting supported on and shiftable with said lamp house, a pivotal connection between said shutter and said mounting with its axis substantially horizontal and substantially at right angles to the direction of projection of said light, whereby said shutter may fall into a substantially vertical position tointercept the light, an armature connected to said shutter substantially at right angles thereto near said pivoted connection, an electro-magnet fixed on said mounting with its core substantially parallel with said direction of projection, and holding said arma ture adjacent to one'end of its core when energized and thereby holding said shutter up out of light intercepting position, a laterally swinging holder supported on said mounting and manually applied to hold said shutter up when the electro-magnet is deenergized,-but automatically drawn toward said electro-magnet to release said-shutter when the electro-magnet is energized, and feed-controlled means controlling the energization or deenergization of said electromagnet.

' 11. In combination with a film, filmcarrying means, and means to project light through said film, a shutter pivoted to fall into position to intercept the light, a main armature connected to said shutter near where it is pivoted, an electro-magnet holding said shutter up by holding said arma- V ture adjacent to one end of its core when energized, supporting means for said electromagnet and shutter, a holder, a pivot for said holder on said supporting means near the other end of said electro-magnet, said holder engaging with said main armature to hold said shutter up when the electromagnet is de'e'nergized, and an auxiliary armature connected to said holder on the side of said pivot remote from said main armature, and drawn toward the other end of said core, whereby said holder is drawn away from said main'armature when the electro-magnet is energized, and feed-controlled means controlling the energization or denergization' of said electro-magnetQ 12. In combi'riationQwith a film, filmcarrying means, and means to project light through said film, a shutter pivoted to fall into position to intercept the light, an

electro-magnet holding said shutter up when energized, a holder, a lug swinging with said shutter, a hook on said holder engaging with whereby said holder has its hook drawn away from said lug when the electro-magnetis energized, and feed-controlled means controlling the energizatlon or denergizing of said electro-magnet.

13. In combination with a film, film-- laterally, a hook on said holder engaging with the lug on said main armature to hold said shutter up when the electro-magnet is deenergized, and an auxiliary armature connected to said holder on the side of said pivot remote from said main entrance and drawn toward the other'end of said core whereby said holder has its hook drawn away from the lug on said main armature when the *electro-magnet is energized, and feed-controlled means controlling the energization or deenergization of said electro magnet.

HARRY E. HARBAUGH. DANIEL P.. SMEDLEY.

' Witnesses:

JAMES N. RAMsEY, CLARENCE PERDEW.

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