US1769772A - Safety and change-over mechanism for moving-picture-projecting machines - Google Patents

Description

"July 1, 1930. c, co 1,769,772

SAFETY AND CHANGE OVER MECHANISM FOR MOVING PICTURE PROJECTING MACHINES Filed Dec. 27, 1927 5 Sheets-Sheet l ZMTTORNEY y 1, 1930- H. c. CORNETTA 1,769,772

SAFETY AND CHANGE OVER MECHANISM FOR MOVING PICTURE PROJECTING MACHINES I Filed Dec. 27, 1927 3 Sheets-Sheet 2 nlllu y 1, 1930- H. c. CORNETTA 1,769,772

SAFETY AND CHANGE OVER MECHANISM FOR MOVING PICTURE PROJECTING MACHINES Filed Dec. 27, 1927 s Sheets-Sheet s 4112A TTORNEY Patented Jul 1, 1930 UNITED STATES PATENT OFFICE H ENBY c. OOBNETTA, OI BOSTON, MASSACHUSETTS Application filed December 27, 1927. Serial ll'o. 242,609.

chine is about to run out, it is necessary to start up or bring in another machine and to produce an instantaneous change over from one machine to another in order to avoid any 15 break in they icture. Before the second machine can be rought into operation it is nec-,

essary to start it up and spot the light to be sure that it is working properly. Usually the change over then is made y the two ma- 2o chine operators working together, one cutting off his machine at practically the same instant that the other operator cuts in the second machine.

In my prior application Serial No. 730,381

25 I have disclosed a mechanism in which the safety apparatus is used in producing a change over, the organization being such that a single operator can make the c ange over unaided. This arrangement has proved ve satisfactory and re resents a substantial a vance in this art. 0 resent invention aims further to improve an perfect apparatus of this character with a view to simplifying the apparatus, reducing the expense of manufae ture, facilitatin t e operation of the apparatus to effect t e change over, and devising a sturdy and more substantial construction. It is also an object of the invention to devise an apparatus which will perform both the functions of reventing ignition of the film in the case of accident, and also enabling a single operator to perform the operations of cutting out one machine and simultaneously cutting in another.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended 60 claims.

Referring now to the drawings,

Figure 1 is a diagrammatic view showin parts of a moving picture projector equip with apparatus em dying this invention;

Fig. 2 is a perspective view of the dowser and the operating means therefor;

Fig. 3 is a rear elevation of the parts shown in Fig. 2;

Fig. 4 is a front elevation of the dowser and adjacent parts;

Fig. 5 is a view, partly in side elevation and partly in cross-section, showing the connections between the dowser and the switches associated therewith; and

Fig. 6 is a diagrammatic view showing the electrical connections between two machines.

Referring first to Fig. 1, the apparatus there shown comprises a lamp house or casing 2 of any suitable construction provided with the usual cone 3 projecting from the front thereof. The beam of light transmitted through the cone strikes the film 4 which is being fed intermittently by the usual mechanism past the aperture in the machine casing 5. This film passes over the intermittently rotating sprocket feed roll 6 around 1 the loop setter roll 7, thence over another feed roll 8 and into the lower magazine 9 where it is wound up on the takeup reel, all of this mechanism being substantially like that of the usual moving picture pro ector.

This machine is equipped with a dowser or shutter 10 which is releasably held in its open position by an electro-magnetic mechanism which includes the electro-magnets 12, the arrangement being such, as will be described more fully hereinafter, that upon the energizing of the magnets the dowser-is released and dro s automatically into position to shut o the light from the film 4. The circuit in which this electro-ma etic mechanism is connected includes two switches indicated diagrammatically at 13 and 14, Fig. 1. The upper switch 13 is arranged to be operated automatically by the loop setter in case the loop is lost for any reason, and for this purpose the switch is provided with an operating lever 15 which bears against a knob 16 that is moved automatically on the loss of the loop, thus resulting in closing the switch 13. The lower switch 14 is arranged to be closed automatically uponthe breaking whereby the automatic dowser may also be of the film, the operating mechanism for the switch including a lever 17 carrying a roll 18 which bears against the film. All of this switch mechanism and the means for operating it automatically is like that shown and described in my pending application Serial No. 66,746 to which reference should be made fora complete explanation of the construction and operation of the mechanism. For present purposes it is sufficient to point out that if the film is broken, or its feeding movement is interrupted, one or the other of the switches 13 or 14 will be closed thus energizing the electro-magnetic mechanism 12, and automatically releasing the dowser. This cuts off the light from the film and prevents ignition of the film. While the switching mechanism shown in my earlier application has been illustrated here for purposes of explanation, it will be.understood that other automatically operated switches can be used to close the circuit which releases the dowser.

The present invention involves improvements in the mechanism for operating the dowser and also an improved arrangement used in effecting the change over.

Referring more es cially to Figs. 2 to 5, the dowser 10 pre erably comprises two plates spaced apart but secured to each other and mounted on an arm 26 which is cast integral with a hub 21. This hub is fastened to a bushing or sleeve 26 through which a shaft 22 extends, the bushing being mounted to rock in a bearing 23 which may conveniently be cast integral with a part 24 of the casing for the electro-magnetic mechanism.

A foot plate 25 is secured to this casing and is adapted to be fastened to the cone 3 projectin from the lamp house. This mounting 0 the dowser permits it to swing from the open position shown in Figs. 2, 3 and 4 into a closed position directly in front of the cone 3. The dowser hub 21 also carries a handle 27 b means of which the dowsercan be operate manually.

Securedfast to the bushing 26 is a short sleeve 28, Fig. 5,,having an arm 29 projecting forward therefrom, and a hardened'latch 30 is secured to the bottom of this arm. N ormally the outer end of this plate is engaged by another hardened plate 31, Fig. 3, which is secured to an armature 32 pivoted at 33 and having a part extending upwardly within the field. of the electro-magnets 12. A spring 34 of phosphor bronze, or other nonmagnetlc material, is interposed between the armature 32 and the magnets 12 and tends to hold the armature in its latching position, as shown in Fig. 3. For the pur ose of limiting the outward movement of t e armature under the influence of the s ring 34, a stop 35, Figs. 2 and 3, is provid d. The armaeither alternating or direct current, and the circuit connections will be readily understood from an inspection of Fig. 6 which shows the wiring diagram for two machines. If direct current is used it is preferable to include resistances in the supply circuit, the resistance boxes being indicated at 40-40. It will be observed that each machine is equipped with an automatic dowser under the control of the electro-magnetic mechanism and that each machine also is equipped with switches 13 and 14 under the control of the film for closing the circuit through the electro-magnets of its own machine to release the dowser in the event of an accident in the feeding of the film. When either machine is in o eration the dowser for that machine is hel in its open position, as shown in Figs. 2, 3 and 4, by the armature 32, the hardened latch 30 bein held between the stop 36 and the hardene member 31 of the armature, as clearly shown in Fig. 3. As soon as the electro-magnets 12 are energized, as, for example, by the closing of one of the switches 12 or 13, the armature is withdrawn, thus releasing the latch 30 and permitt the dowser to drop by gravit into its close position and thus shuttin o the light from the film. When the trou le has been remedled the dowser maybe again moved into its open position by operating the handle 27, and it will be held in this position by the grgagement of the armature with the latch For the purpose of enabling an operator to produce the change over, an electric switch 45 is associated with each dowser, this switch being adapted to close a circuit through the electro-magnetic mechanism of the other machine, provision being made for operating the switch substantially simultaneously with the opening movement ofthe dowser. As best shown in Fig. 3, the switch 45 comprises upper and lower spring contacts 46 and 47, respectlvely, insulated from each other and projecting forward over the ath of movement of an insulating pin 48 w 'ch is carried by an arm 49 projecting from a sleeve 50 secured fast on the shaft 22. A spring 51, Figs. 3 and 5, coiled about the shaft 22 tends to" rotate this shaft in a counter-clockwise direction, as shown in Fig. 3, to hold an arm 52 projecting from the sleeve 50 inst a stop 53. At its forward end the aft 22 has a disk 55 secured thereto and provided with a notch 56. It will be seen from an inspection of Fig. that the handle 27 is oilset so that its axis lies directly over the edge of the disk 55. A plunger 57 is mounted to slide axially in this handle. Normally this plunger is held in an upward or retracted position by a coiled spring 58, and a thumb piece 59 is secured to the end of the plunger 57 and projects beyond the end of the handle 28. y 59 the end of the plunger 57 can, at a certain position, be entered in the notch 56 and thus connect the shaft 22 operatively with the dowser and handle. That is, the shaft, handle and dowser will move in unison so of that machine.

as the pl r is .held in the notch 56. t will be see ri om an inspection of Fig. 3 that if the shaft 22 is rotated in a clockwise direction, the insulating pin 48 will move the lower contact 47 upward, thus closing the switch 45. that this movement has taken place, if t e thumb iece 59 is now released so as to disconnect t e shaft 22 from the dowser, the spring 51 will immediately return the arm 49, pin 48, and stop arm 52, to the positions in which they are shown in Fig. 8 where the switch 45 will be open.

In producing a change over, the machine to be brought in is started u the light is spotted, and the dowser 10 0 this machine then will'be closed At this time the other machine, of course, is running. When the operator is ready to cut in the idle machine, he gras the handle 27 of the dowser for that mac e, preses down on the thumb piece 59 to ge thepl r 57 in the notch 56, and t en, while ho ding the plunger in this position, the dower into its fully open position with e handle striking against t e stop 37. The dowser is immediately latched in this position b the armature, and the operator releases t e handle. This movement of the handle, however, has closed the switch 45, as above described, thus energizing the electro-m chine and automatica y releasing the dowser This cuts out the machine which has been working. The machine which has been idle has been brought in by the openirag movement of its dowser as just 'describe As soon as the thumb piece 59 is released, the switch 45 will immediately be opened again, as above described.

The circuit connections for producing these 0 rations will be clear from an inspection of ,ig. 6. It will also be observed that the inwardly on the thumb piece ets 12 of the other machange over from either machine to the other can be made in the manner above described.

Figs. 2 and 5 show the machine equipped with two switches like the switch 45, and such an arrangement is desirable in case three machines are used. The electrical connections between three such machines to enable the change over from any one of the three to another will be understood by those skilled in this art from the disclosure alread made.

A removable casing member 60, Figs. 3 and 4, is provided to cooperate with the casing part 24 in enclosing the switch 45, the electromagnets, and the immediatel associated parts, this casing being held in its closed position by two screws, one of which is shown at 61 in Fig. 3.

It will now be appreciated that this invention provides a very sim le mechanism for producing a change over m one machine to another. The fact that this mechanism utilizes the dowser which forms a part of the safety mechanism of the machine is an important practical advantage. The apparatus can be manufactured and installed economically, and is very easy to operate since the same motion necessary to move the dowser to its 0 11 position also operates the switch whic controls the dowser of the other machine. An improved dowser operating mechanism has also been provided which is very sturdy and substantial in construction and is extreme] reliable.

While I ave herein shown and described a preferred embodiment of my invention, it w1ll be understood that the invention may be embodied in other forms without departing from the spirit or scope thereof.

Having thus described my invention, what I desire to claim as new is:

1. In a mechanism for use with moving picture pro ecting machines, the combination of a dowser, a support on which said dowser is mounted for movement into an open or closed position, mechanism for normally holding said dowser in its open position and ncludirhg electro-ma etic means for releasmg the owser, said owser being adapted to be moved manually into its open position, an electric switch, and operating means for said switch arranged to be connected to said dowser to be operated therewith or tobe disconnected therefrom at will.

2. In a mechanism for use with moving picture projecting machines, the combination of a dowser, a support on which said dowser is mounted for movement into an open or closed position, mechanism for normally holding said dowser in its open position and including electro-magnetic means for releasing the dowser, a handle connected with said dowser to operate it manually, an electric switch associated with the dowser, and operating means for said switch arranged to be operatively connected with said handle or disconnected therefrom as desired.

3. In a mechanism for use with moving picture projecting machines, the combination 5 of a dowser, a support on which said dowser is mounted for movement into an open or closed position, mechanism for normally holding said dowser in its open position and including electro-magnetic means for releasing the dowser, an electric switch, a handle for operating said dowser, operating means for said switch, and means carried by said handle and operable by the hand which grasps the handle for operatively connecting said operating means with said handle.

4. In a mechanism for use with moving picture projecting machines, the combination of a dowser, a support on which said dowser is mounted for movement into an open or closed position, mechanism for normally holding said dowser in its open position and including electro-magnetic means for releasing the dowser, an electric switch, a pivoted handle for operating said dowser, operating means for said switch including a part movable about an axis, and means carried b said handle and operable by the hand whic grasps the handle for operativel connectin said handle with said part, w ereby sai handle may be utilized to operate said switch. 5. In a mechanism for use with moving picture projecting machines, the combination of a dowser, a support on which said dowser is mounted for movement into an open or as closed position, mechanism for normally holding said dowser in its open position and including electro-magnetic means for releasing the dowser, an electric switch, a pivoted handle for operating said dowser, o rating means for said switch including a s aft about the axis of which said handle ivots, and means carried by said handle an operable by the hand which grasps the handle for operatively connecting said shaft with said handle.

6. In a mechanism for use with moving picture projecting machines, the combination of a dowser, a support on which said dowser is mounted for movement into an open or closed position, a bushing mounted to rock in said support, said dowser being fastened to said bushing, a handle secured to said bushing for o ra for releasably hol ing sai dowser in its open position includinga latch and electromagnetic mechanism for rele the latch, a shaft extending through sai bushing and mounted to rock therein, an electric switch, means arranged to be moved by said shaft for operating said switch, and means carried by said handle for releasably connecting said shaft with said handle.

7. In a machanism for use with moving picture projecting machines, the combination a of a dowser, a-support on which said dowser is mounted for movement into an open or closed position, a bushin mounted to rock in said support, a hand e secured on said bushing for operating said dowser, means for releasably holding said dowser in its open position including a latch associated with said bushing and electro-magnetic mechanism for releasing the latch, a shaft extendin through said bushing and mounted to too therein, an electric switch, means arranged to be moved by said shaft for operating said switch, a spring tending to turn said shaft, and means carried by said handle and operable by the hand which grasps the handle for releasably connecting said shaft with said handle.

HENRY C. CORNETTA.

the dowser, means ill

Images