US2138478A - Change-over assembly - Google Patents

Description

Nov. 29, 1938.

F. PEDATELLA 2,138,478 CHANGE-OVER ASSEMBLY Fil ed Sept. '12, 1935 3 Sheets-Sheet l L as INVENTOR Nov. 29, 1938. PEDATELLA 2,138,478

CHANGE-OVER ASSEMBLY Filed Sept. 12, 1935 3 Sheets-Sheet 2 INVENTOR Nov. 29, 1938. F. PEDATELLA 2,138,478

bmmmovm'a ASSEMBLY Filed Sept. 12, 1935 5 Sheets-Sheet 5 MANUAL SWITCH Patented Nov. 29, 1938 UNITED "STATES 'oFFicE- Frank Iedatella, New Kensington, Pa... assignor I to Wilbert C. Black, New Kensington, Pa

Application September 12, 1935, Serial No. 40,260

6' Claims, (cuss-916.2)

This invention relates to an automatic changeover for changing over from one reel of film to another in motion picture projection, and relates to the combination of an automatic changeover of that nature with safety control means mechanically and electrically cooperative with changeover elements proper, to carry forward the operation of normal changeover, and to guard against destructive effects which may result from abnormal conditions of the film.

The object of my invention is to provide a changeover assembly, associated with safety control features, which is of improved simplicity, both electrically and mechanically,-which' is posi- 5 tive and wholly automatic in. its operation, and which is relatively inexpensive to manufacture and install.

In the accompanying drawings Fig. I is a view, partly in side elevation and partly in vertical section, of a projection assembly comprising, primarily, a lamp, or light, house and shutter therefor; a projection lens and mounting,'with shutter therefor; a sound head; and motor driven means for passing film between the light source and the projection lens.

Fig. II is a detail view, in side elevation, showing an automatic safety switch, or trap, operated by a loop of the film, and arranged to bring into play the safety control elements of the-assembly upon abnormal condition of the film loop.

Fig. III is an end elevation .of the switch, or trap, shown in Fig. II.

Fig. IV is a front elevation of a film-operated trigger mechanism, arranged to initiate normal changeover activity, and of a second film-operated, automatic safety switch, or trap," mounted in physical association with trigger mechanism.

Fig. V is a vertical, sectional view, through the trigger mechanism and trap" shown in Fig. IV, taken on the section line V-V of Fig. IV.

Fig. VI is a vertical, sectional view of a third automatic, film-operated safety switch, or trap, arranged also to effect safety control upon abnormal condition of the film.

Fig. VII is a horizontal, sectional view, through this third automatic safety switch, or trap, taken on the section line VIIVII of Fig. VI.

Fig. VIII is a front elevation of the shutter mounted in front of the lamp-house of the projection assembly, and of safety control contact elements associated with, and operated in accordance with movement of, the lamp-h se shutter.

Fig. IX is a vertical, sectional vi taken on the line IXIX of Fig. VIII.

I Fig. X is a front elevation of the shutter for the projection lens of the assembly, showing operating :means for the shutter, and circuit control contacts associated with the shutter control mechanism, and arranged to be operated thereby.

Fig. XI is a wiring diagram showing the wiring and contacts of two projection assemblies, together with the motor and sound-energizing circuitsfor theassemblieaand the conductors and contacts for eifecting normal changeover between motorsand sound sources, together with circuits and-contacts for controlling the shutters of the two projection assemblies, both in the normal changeover sequence, and upon-the existence of various abnormal conditions which may require the operation of safety control.

Referring 'to- Fig. I of the drawings, reference numeral I designates a lamp-house having therein. a light source for producing the imageprojectingflight-beam. Mounted before opening la of the'lamp-house'is a funnel-shaped lightshield 2, before which is mounted shutter mechanism designated generally by reference numeral 3, and actuated by mechanism housed in a casing 4, which-serves as a mounting pedestal for the shutter. In horizontal alignment with light shield 2 and shutter 3 is an assembly, of usual sort, carrying a projecting lens 5. A second shutter 6 is movably mounted before the lens 5 upona casing l, which serves as a pedestal for the shutter mechanism, and which contains operating means for moving the shutter.

The film, designated by reference letter A, is taken from a supply reel 8 by a winding reel 9 actuated by motor 10. The above elements, broadly considered, are well known in the art, and are'found in one form or the other in standard projection assemblies. --In accordance also with known practice in providing safety control for the assembly, I provide a plurality of filmoperated, automatic safety switches, or traps, arranged to control the operation of safety mechanism for preventing fire hazards due to abnormal conditions of the film; and, as is also usual, I provide means acted upon by the film, automatically to effect a changeover from one projection assembly to another at a predeter- .mined point in the unreeling of the film, such point being adjacent the film terminal. In my assembly, however, the several film-operated safety switches, or traps, are of novel and par ticularly efficient structure, and a film-operated means for initiating normal changeover is also of novel and particularly eflicient structure.

Referring still to Fig. I of the drawings, reference numeral ll designates generally a safety switch, or trap, positioned adjacent the supply reel 8, and effective upon abnormal .condition of a loop A of the film. The physical assembly of trigger mechanism for initiating normal changeover, and a safety switch, or trap, effective upon abnormal condition of the film, are shown diagrammatically, and are designated generally by reference numerals l2 and Ho. A' third-safety switch? or trap. 3 is shown-diagrammatically adjacent the winding reel 9 of the projection assembly.

It may be well generally to relate the operations of normal changeover, and the operation-of safety control, as automatically performed by my apparatus, before describing in detail the energiz- 1 ing and controlling circuits involved, and the specific mechanism associated withthe circuits. Let us assume that operating conditions in both projectors are normal, and that the film A on the supplycreel of. the active'projector approaches exhaustion; At a substantial interval before complete exhaustion of the film, trigger mechanism l2 acts, under the influence of the film, to-complete a circuit to the motor of the inactive projection assembly. .This lead gives time for the motor, of the inactive assembly .to gather speed beforethat assembly is caHedupon to continue the. projection and sound from;the-film mounted in-it; The starting of-ytheg motor of the hitherto inactive projection assembly is effected by elements of zthessafety control mechanism associated with that assembly. Inltially,:it.is desired to,emphasize, the ;-;fact that,;-.in my automatic changeoverqand v'safetycontrol, the safety control performsaduel function, taking'part in the sequential; progress -,-ofnormal changeoverfals well as performing its safety function. The effect produced by the; changeover mechanism of the inactive changeoyerassembly is to open the lamphouse shutter-3:0f that assembly, as-well-as completinga circuit'toqthe motor of .the inactive assembly. At a :point;closer to the film terminal of the active proiectionassembly, the film acts upon trigger mechanism, i2, to initiate such action that a movable part of the mechanism for controlling lens shutter 6 ofthe activeassembly is shifted. This shifting mechanically effects movement of the shutter 6 from its opened position to its closed position before the lens 5;' and, simultaneously, movement of this part, which closes the shutter before the projecting means of the previously active assembly, acts to break a circuit from that assembly to the sound head.

At the same time; a similar movable part in the means for-operating the shutter B of the hitherto inactive projection assembly is moved, opening the lens shutter associated with that assembly, and completing a circuit, associated with the film of that assembly to the sound; head. The final stage of normal changeover is effected by the film trap l2a, this trap acting to complete a controlling circuit'to the safetyicontrol means of the-assembly, which has been operative, to produce action closing the lamp-house shutter 3 of that assembly, and to cut the energizing circuit to the motor ill of the assembly. The changeover from one projection assembly to the other is then complete.

Initially, I shall refer to the film-operated switch mechanism, shown in detail in Figs. 1V and V of the drawings, it being understood that each of the pairsxof projection assemblies between which changeover'is made is equipped with identical switch mechanism. This switch mechanism, which has been designated generally by reference numeral [2, comprises two pivoted arms 15 and l5a, which are arranged, respectively, to

. mounted in the arm. The fingers I9 and 19a of the two arms [5 and Ilia project, respectively,

throughx'slots 2| and Ma. formed in the curved forward face 23 of housing 22, in which the arms are'm'ounted.

The film A passes, in contact with the upper regionof the curved forward face 23 of housing 22, through the slots in which the fingers i9 and l9a' project, and is held against this upper region of the housing face by a bar 24, which is carried by an arm 25, pivoted in the housing, and acted upon ,by past-center spring 26. In operative position, with the film A'inserted, the effect of spring'26 is'to holdthe bar 24 to the film. When the ,arm 25 is thrown upwardly, to a pastcenter. position, as shown in broken lines in Fig. V, the-.past-center spring so holds the arm until it has-manually beenlreturned .to its filmgrasping positiomi During operation of a projection assembly, with the parts :in-theposition shown in Fig. V, the fingers l9 and l9a' lie at the upper terminals of the .slots 23 and-23a in-which they move, and bear against the presented face of the film A. It will be noted that the spacing between the arms l5 and l5a, which carry the fingers l9 and Ilia, is relatively slight, so that the fingers are spaced apart a distance substantially less than the width ,of the On the film, adjacent itssupply reel terminal, are two apertures, spaced from each other longitudinally of the film, and each in line with one of the fingers l9 or- |9a. -These film openings lie well within the sprocket openings inthe film by which the film is transferred from the supply reel 8 to the winding reel 9. .As the film A approaches exhaustion, the more advanced one of the openings therein comes into alignment with the finger i9, which is constantly pressed outwardly against the film by its associated spring 20. The finger I9 being engaged by this film opening, the arm [5 is rotated about its pivot, during a short distance of film travel, and duringthis travel is so rotated about its pivot i8 that the proximal cam surface H on the arm acts upon spring contacts 15 to close them, and to complete a circuit, the effect of which will be hereinafter described.

Adjacent the lower end of curved face 23 is a roller 21, forming an element of trap l2a, which is carried by a yoke 28, having at its inner terminal a second roller 29. Roller 29 lies between a fixed plate 30, and a resilient plate 3ia, forming an element of spring contact-pair 3|. Omitting for the present the contact controlling function of the structure, the spring plate 3| forces roller 21 outwardly against the film, the rearward, or inward, limit of movement of the roller being defined by a nut 32, threaded to one arm of the yoke 28, and arranged to bear against an apertured-face 33 of the housing 22. This roller 2! acts, therefore, to hold film A outwardly a predetermined distance from the lower region of the curved housing face 23.

When finger l5 has'travelled a sumcient distance, it is freed of the opening in the film A, since the film is, by the roller 21, held away from the curved face 23 of the housing in which the finger rides. Theaction is thus momentarily to make and rapidly to break electrical connection through spring contacts l6. When the second finger 9a is engaged by the second film aperture, it similarlyis swung downwardly by the film, momentarily making its associated contacts Ito, and permitting these contacts to open as: the arm swings through the arc predetermined by the position of the film with respectto the face 23 of the housing. f

Referring to the wiring diagram of Fig. XI, it will be seen that the closing of contacts l6 com: pletes'a circuit a leading from the line conductor 22 to a coil 34 in the safety control mechanism of the inactive assembly. The effect of energizing coil 34 is to draw'into it a plunger, which makes contacts 35, completing a circuit from conductor b of the line' circuitto the motor l0 associated with the inactive assembly. This starts the motor of the inactive assembly, giving it the lead above referred to. Simultaneously, energization of coil 34 closes contacts 35a in the safety control of the inactive assembly in preparation for the completion of a circuit d to the sound mechanism of the inactive assembly; I

Reference will here be made to the specific structureof the safety control mechanism associated in each projection assembly. Referring to Figs. VIII and IX of the drawings, I have shown lamp-house shutter'3, which is mounted adjacent or in sliding contactwith a plate 36, haying therein an aperture 31 in line with light-cone 2 (Fig.1) in 'front of the lamp house. Coil 34, above referred to, is one of a pair of coils 34 and 34a arranged to act oppositely upon a plunger 38, which has a slotjand pin] connection 39, with an extended arm portion 3a of the shut ter 3. Movement of core38 to the left of Fig. VIII, into the position shown, under the ener-' gization of coil 34, shifts cam 40, on a cross-shaft 4|, and fixed to shutter extension 3a, into position permitting spring contacts 35 to close. On the otherface of plate 36, and at the opposite end of shaft 4|, is a second cam 40a. "I'his cam controls the spring contacts 35a, and, similarly. in the position illustrated in Fig. VIII of the drawings, is so shifted as to permit these contacts to close in preparation, as has been explained, for the completion of the sound circuit of the assembly.

The mechanical effect of moving core 38 to the left of Fig. VIII is to shift shutter 3 to the right, exposing opening 31 through plate 36. This removes the obstruction to the emission of light from the lamp-house of the inactive assembly.

It will be noted in Fig. VIII that the plunger 38 is of relatively great length, so that its projection in one direction or the other is substantially beyond coil 34 or coil 34a. As shown, this plunger has acted mechanically to separate spring contacts 42, which control the connection of the coil to the energizing circuit a, thus interrupting that circuit. Simultaneously, withdrawal of the plunger from physical contact with a pair of spring contacts 43 has permitted these contacts to close, thereby preparing a circuit d, the function of, which will be hereinafter described in connection with the feature of safety control.

This completes the effect directly attributable to the film-actuated swinging of arm |5, resulting in making its associated contacts |6. It may be observed that the action described is self-clearing, since the spring contacts l6 open when finger l9 rides out of its associated film aperture releasing thearm I5, and since coil 34, which opens the lamp-house shutter," which starts the motor of the inactive assembly, andwhich prepares a circuit to sound, is self-dee'nergizing because of the action of 'plu'nge'r'38- 'i The second finger lGa, in swingingdownwardly upon engagement with the opening in the film, by similarly completing momentarily .its associated s'pringQcontacts 6a,' completesa circuit e to the coil '44 associated with'theprojection shutter mechanism'of the active assembly, and with a coil 44a associated with the, projection shutter of the inactive assembly. Theclr'cuit '6, arranged to energize oppositely acting coilsffin the shutteroperatingmechanism of thetwo assemblies, takes current from the line conductor 6.

'Referri'ng'to, the shutter mechanism, as shown in Fig. X of the drawings, this shutter mechanism also comprisesan elongate core 45, which is moved in opposite directions by coils 44 and 44a. Projection shutter. 6 acts against a plate 48, which hastherein an aperturealigned with lens all as has been previously noted. On shutter 6 is an extended arm portion fiajwhichhas a slot and,pin' connection 41 withgthe'plunger 45. A cam 48, physicallymountedon the face of shutter arm 6a, actsin swinging movement of the shutter in one direction'or; the other'to open springcontacts 49, or to permit them to close. The shutter' swings about a centerfprovided by a shaft, passing through,. t hecam 48 and plate 46, similar to the shaft!" described in connection withthe safety control mechanism; 'Fig. X of thedr'awings shows the effectof the closing er contacts |6a upon the projection shutter mechanism of the still active assembly, In this positionofthe parts, the shuttenhasbeen closed by. swinging the shutter. proper'td the left, with the extended portion Gaof the shuttercarriedto the right byitsj'engagement with core 45. Simultaneously, plunger 45 has acted mechanically to separate springccntacts 50 controlling a circuit d. .to the sound mechanism of that assembly. Contacts 49 being open interrupt, the circuit d forming the other side of circuit 6, thus deenergizing the.c0'i1 44 in. the projection assembly. which is about to discontinue activity, and also energizing the coil 44a in the projection assembly which isto assume activity.

Taking the operating mechanism for the lens shutter in the other projection assembly, the action is the reverse of that described, and involves a movement of the plunger 45 from the position shown in Fig. X to the left. This action uncovers the aperture, previously shielded by shutter 6, and permits spring contacts 50 to close, thus completing the circuit d to the sound mechanism of that assembly, and permitting spring contacts 49 also to close. The closing of contacts 49 merely prepares a circuit to the open contacts l6 and |6a associated with the switch mechanism of this second assembly.

. Referring specifically to Figs. IV and V of the drawings, the roller 21, forced outwardly against the film A, by the spring plate 3|a of spring contact pair 3|, has been hereinabove mentioned under facejof thefixed plate 30.;

. -Sp ri ng c nt t 3L1 3 1 1 co o f'tothe e uat the motor which has been active to propel the 'running "Referring .to Fig. VIIIof the drawinga'thisfcoil fla shifts plunger 38 to th'ejright,as shown in Fig. VIII,;so that'cam 40 separates spring contacts 35, thus breakingjthe circuit -to the running motor associated with this'projectionfassembly, andalso separatingjat the safety control, thespring contacts 35a WhlCh "S6rV8, when'closed, to pre-. pare ,a circuit to the sound mechanism of that projection assembly. M

Simultaneously, shutter 3 is moved into posi tion to close the opening 31 inplate 36, thereby screening the lamp-'house'ofthe pro jectionassembly which isthus' goin'g out of action, Also the mechanical action of core 38 serves to open spring contacts 43; and to permit sprimg'contacts 42 to close, thus placing'this' safety control in condition to" be energized wh'enjthe' projection assembly, which has now become active, in turn, prepares to go out of action. This completes the changeover cycle, activity having been fully transferred from one projection assembly-to the other. l Referring to circuit 1; by which the final steps in eliminating a projection assembly from activity is effected during changeover, but referring to the right-hand sideof the wiring diagram, representing a projection assembly inwhich activity h as been setup, it should be noted that this circuit}, associated'with contacts 42, which are to be considered closed, is primarily involved in the safety"control 'function'of the mechanism. There are effective in it, to produce safety control action, the three automatic switches, or traps, ll, |2a and i3. As so designated, it is to be understood that reference numeral I211, relates generally to theswitch mechanism comprising the film-contacting roller 21 arranged to bear against the inner side of the film, and mounted in the switch housing 22 in association with switch mechanism I 2.

Safety switch, or trap, ll, shown in detail in Figs. II and III of the drawings, isoperated by the loop in film A, which is formed between its supply reel 8 and the point at which it is subjected to the projecting light-beam, which loop serves to prevent whipping of the film as it passes before the light-beam. This switch mechanism comprises a bell crank lever pivotally mounted at 52, on a supporting structure 53. The longer and outwardly projecting arm of the bell crank carries a roller 54, while'the shorter and inwardly projecting arm of'the bell crank has a terminal 55 of insulating material, which is arranged to act upon a pair of spring contacts 56. Pivot'ally mounted at 51, on the supporting structure 53,: is an arm 58, which has extending forwardly and upwardly therefrom a hook portion 58a, and which has extending rearwardly and downwardly therefrom a leg 58b, which contacts bell crank lever 5| adjacent its pivotal mount ing 52.

The loop offilm A is passed between roller 54 and hook 58a, and in normal condition the loop comes into contact with neither of them. If. however, due to abnormal lessening in tension,

the loop of film A should so {1 56185 forcefully to contact hook 28a, arm 58 isro tat ed about its: pivot 51,.andthe leg-58brotates bell' crank 5| causing its terminal 55 to make the contacts 56. If, on the contrary, due to abnormally high tension on the film A, the film isforcefully brought into contact with roller 54, bell crank 5| is swung about .its pivot'in the same direction 'of rotation as that previously'described, in such event also making contacts ,56. v

Contacts Q -being made by either noted abnormal condition of the film loop, solenoid coil 34a is energized, shifting the shutter 3 from its position exposing the opening 31 to its position closing the opening 31, breaking the circuit to the running motor, and also breaking the circult to" sound. In all respects the action of safety control is identical with the action described in connection with the ultimate stage of deactivating a projection assembly in changeover, save that the effect of separating sound control contacts 35a, is to interrupt an active circuit to sound, rather; than merely to interrupt a preparatory circuit to sound. I

The action of the safety switch, or trap; in, which comprises film-contactingroller 21, oc ours as a safety action if the film be broken at a point between that trap [2a and the supply reel 8.v Upon breakage of the film, the function of the safety switch, or trap, l'la,,is identical with that described in connection with the movement of the film terminal past the roller 21} This safety switch, or trap, 120, also acts, however, to eifect safety control under conditions which do not involve actual film breakage. ,Thus, if there is disengagement from the film of the sprocket forming part'of winding reel 9, or if such winding 'reel should for any cause fail to rotate, a loose loop is formed in the film intermediate the reels 8 and 9. This relief 'of tension against roller 21 vpermits the mechanism of safety switch 12a to act similarly to breakage of the film in effecting safety control. This quality of the safety switch, or trap, |2a is of importance, in that it serves frequently to anticipate, and prevent, film breakage.

The third safety switch, or trap, designated generally by reference numeral I3, is disposed relatively close to the winding reel 9. This safety switch, or trap, I 3, effects. safety control upon abnormal film conditions existing between safety switch l 2 and winding reel 9. Upon film breakage between the safety switches 12 and I3 it acts to eifect safety control. Also, if winding reel 9 should fail to operate, and the eifectshould be to form a loose loop adjacent the winding reel, rather than in the regions of the film lying closer to'supply reel 8, this safety switch acts to effect safety control in manner identical with that in which safety control is effected by either of safety switches H or I'Za;

Referring to Figs. VI and VII of the drawings, safety switch assembly l3 comprises a housing 59, which contains a spring contact pair 60, the spring contacts of the pair being convergently formed in their regions 60a adjacent the contact mounting 6|. Lying between the spring contacts of the pair is a roller 62 which is mounted on a yoke 63, carrying at its outer terminal a second roller 64.

In normal condition of the film A, the pressure of the film against outer roller 6 4 maintains roller 62 in inwardly forced position, so to act upon the converging region 60a of the spring contact elements as to maintain these. contact elements separated. When, however, breakage, or lack of tension, of film A relieves the inwardly directed pressure .onthe yoke 63, and rollers carried by it, the resilience of the spring contacts 60 acts to force the roller assembly outwardly, thus relieving the spring contacts of the separating efiect of roller 82, and permitting the spring contacts to close;

The safety control elements, above described, prevent fire hazard, and avoid destruction of a film, due to the existence of abnormal conditions, accompanied by continued activity of the motor actuating the winding reel 9. They also, by breaking the connection to the sound mechanism, prevent the emission of unpleasant noises under such conditions.

In my changeover and safety control assembly I provide, however, additional means, arranged to act upon the blowing of a fuse, or some such line circuit interruption as would cause the motor driving windingreel 9 to cease its activity, without, however, affecting the tensiomon the film. Undersuch circumstances, movementof the film being suspended, the light-beam from the lamphouse i, impinging uninterruptedly against a particular restricted area of the film, tends to injure the mm, or even to cause it to ignite. .Such additional safety means comprise a holding magnet 65, which is connected across the line conductors b and b. Opposed to the attractive force of holding magnet 65 is a spring 66, which exerts a force tending to move a contact element 81 to interconnect contact pairs 68, 69, and 10.

If, then, the line circuit be interrupted, these contact pairs 68, 69, and 10, are interconnected, completing three circuits to an emergency light system H. Interconnection of contacts 68 completes a conductor g; interconnection of contacts 69 completes a conductor h; and interconnection of contacts 10 completes a conductor 2'.

If, then, the projection assembly, to the left of the wiring diagram, be active, a circuit is completed, at contacts 68, through conductor g to the circuit f, leading to the coil 34a of the safety control mechanism associated in that projection assembly. Energization of coil 34a effects safety control in the manner previously described.- If, on the contrary, the projection assembly, shown to they right in the wiring diagram, be active, the

conductor h is completed at contacts 69, providing a circuit to the coil 34a of the safety control mechanism associated in that assembly, and similarly producing the typical safety control action.

If the interruption in the line circuit occurs at an interval during changeover, in which both safety control shutters are open, the interconnectionof contacts 10 completes a conductor a in electrical communication with both coils of both safety control mechanisms. This connection is effective to the coils 34a in the mechanism of both the projection assemblies; the safety control contacts 43, associated with the two coils 34a, being under such condition closed, while the contacts 42, controlling connection to the coils 34 of each assembly, are open.

I. wish to emphasize the fact that, both electrically and structurally, my changeover and safety control assembly is of great simplicity, and wish particularly to emphasize the fact that the mechanical elements constituting the safety control associated with the lamp-house shutter, the control associated with the projection lens shutter, the film-operated switch mechanism which lnitiateschangeover action, and the several types of safety switch incorporated in the assembly, are all of unusual simplicity, and structurally are so formed that they may be made at low cost. Considering my changeover and safety control assembly as mechanism comprising a number of particular elements, which are added to the projection assemblies themselves, my invention has merit in rendering financially possible, or financially attractive, to the operators of motion picture installations, the addition of automatic changeover and safety control therefor.

It should be understood that throughout the assembly parts which are in physical contact with conductive contact elements, such as the cams II, the film-operated arms 15 and l5a, the cams 40 and 48 carried by the lamp-house shut ter and .the projection lens shutter, respectively, and the various rollers 29 and 62, are all formed of insulating material. -Also, it should be noted that an insulating washer is provided on each spring contact element with which either of the cores 38 and 45 comes into physical contact. Further, it may be noted that in my complete assembly all coils, save the coil of holding magnet 65, are self-deenergizing, so that no measurable power consumption is involved in their operation. Holding magnet 65 may be so made that its power consumption is very slight.

I claim as my invention:

, 1. In a motion picture projection installation the combination of two projection assemblies each comprising a lamp-house a projector a filmpropelling motor and sound mechanism, a lamphouse shutter having electromagnetic shifting means therefor associated in each projection assembly, a projector shutter having electromagnetic shifting means therefor associated in each projection assembly, a film-operable switch element in each assembly arranged to cause shifting of the lamp-house shutter of the alternate assembly, a film-operable switch element in each assembly arranged to cause shifting of its proximal projector shutter, connection arranged to cause shifting of each projector shutter upon shifting of the projector shutter associated in the alternate assembly, said shifting of the two projector shutters being opposite in sense, a filmoperable switch element in each assembly arra ged to cause shifting of its proximal lamphouse shutter, a switch directly associated with each lamp-house shutter and operable by shifting movement thereof controlling the proximal film-propelling motor, and a switch simliarly associated with each lamp-house shutter and a switch similarly associated with each projector shutter cooperatively effective for controlling activity in the sound mechanism of the two assemblies.

2. In a motion picture projection installation the combination of a projection assembly comprising a lamp-house a lamp-house shutter sound mechanism and a film-propelling motor with electromagnetic means for shifting the lamphouse shutter between open and closed positions, switches associated with the lamp-house shutter arranged to control energization respectively of the film-propelling motor and the sound mecha- I sm of the assembly to inhibit operation of the same by shifting of the lamp-house shutter from open position to closed position, at least one switch element arranged to produce shifting of said lamp-house shutter from open position-to closed position upon relief of film tension there-- on, an additional switch element arranged to shift said lamp-house shutter from open position to closed position, with an identical alternate assembly, and identical switch elements in both assemblies arranged to be film operated each to produce shifting movement of the lamp-house shutter of the other assembly to open position.

3. In a motion picture projecting installation the combination of two projection assemblies each comprising a lamp-house a projector a film-propelling motor and sound mechanism, 'with switches arranged in each assembly to produce action energizing the film-propelling motor and sound mechanism of the alternate assembly, a switch element associated with electrical and mechanical means arranged upon relief of tension by complete film exhaustion in each assembly to terminate the activity of the film-propelling motor in that assembly, additional switch elements arranged similarly to act upon the same to produce a termination of activity of the filmpropelling motor under abnormal film conditions, independent connections for supplying'electrical current respectively to each of the film-propelling motors and the lamp-houses of the two assemblies, and an electromagnet controlled switch arranged to shift the lamp ho'use shutter of either assembly to closed position upon interruption of current supply to the film-propelling motor proximal thereto. V

4. In a motion picture projecting installation the combination of two projection assemblies each comprising a lamp-house a projector-a filmpropelling motor a lamp-house shutter, with electromagnetic means for'moving the lamp-house shutter into open position and into closed position, switches controlling individually the two motors of the projection assemblies mounted for operation 'each by movement of a lamp-house shutter, independent connections for supplying electrical current respectively to each of the filmpropelling motors and the lamp-houses'of the two assemblies, and an electromagnet controlled switch arranged to move either lamp-house shutter to closed position upon interruption of current supply tothe film-propelling motor proximal thereto.

5. In a motor picture projecting installation the combination of two projection assemblies each comprising a lamp-house a projector a filmpropelling motor a lamp house shutter movable alternatively into open and closed position, electromagnetic means for moving the lamp-house shutter into open position and into closed position, switches controlling individually the two motors of the projection assemblies mounted for operation each by movement of a lamp-house shutter, a fi n-contacting switch arranged upon release of film pressure thereon to cause energization of said electromagnetic means for moving the lamp-house shutter to closed position and by shutter movement to act upon the controlling switch associated with the shutter, at least one additional film-operated switch arranged under abnormal film conditions similarly to energize said electromagnetic means, independent connections for supplying electrical current respectively to each of the film-propelling motors and the lamp-houses of the two assemblies, and an electromagnet controlled switch arranged to move either lamp-house shutter to closed position upon interruption of current supply to the filmpropelling motor proximal thereto.

6. In a motor picture projection installation the combination of two projection assemblies each comprising a lamp house, a projector, a film-propelling motor, and sound mechanism, with a switchstructure in each projection assembly arranged to control a circuit to the filmpropelling motor of that projection assembly, electro-magnetic means arranged to operate the said switches of the two projection assemblies, and film-operable switches arranged to control energization of said electro-magnetic means, the said film-operated switch of each projection assembly being arranged to act upon the electromagnetic means of the alternate projection assembly to cause energization of the film-propelling motor thereof before deenergization of the film-propelling motor in its own projection assembly, said film-operated switches comprising each two electrical make-and-break devices severally operated by swinging fingers cooperating with the film.

FRANK PEDATELLA.

Images