US2267478A

US2267478A - Reel drive mechanism

Info

Publication number: US2267478A
Application number: US347801A
Authority: US
Inventors: Stechbart Bruno
Original assignee: Bell and Howell Co
Current assignee: Bell and Howell Co
Priority date: 1940-07-26
Filing date: 1940-07-26
Publication date: 1941-12-23
Anticipated expiration: 1958-12-23

Description

D86. 23, a S EC REEL DRIVE MECHANISM Filed July 26, 1940 IN NTUR' .EIRLJNEI ET EHBART' ATTY.

Patented Dec. 23, 1941 Y 1 REELDRIVE MECHANTSM. f

Bruno Stechbart, Chicago; 111., assignor'to The 7 Bell & Howell Company; Chicago 111., a crpo-' rationof Illinois Application July 26, 1940, Serial No..34i,'801 2 Claims. (01. 242-55) My invention relates to take up reel drivesfor -motion picture projecting machines, although not limited to this use alone.

It is usual to drive the take up reel of a motion picture projecting machine by means of a constant power yielding drive device permitting the slowing up of rotation ofthe reel to accommodate the increasing diameter of the film roll on the reel to the constant rate of feed of the film by the film feed mechanism of the machine. Such drive devices are limited in such accommodation in that, if their power is increased to accommodate greater ranges of take up film roll diameters, undesirably excessive strain is exerted on the film at small take up film roll diameters.

One object of the present invention resides in the provision of a novel, simple and effective yielding reel drive which automatically increases the power exerted on the take up reel as the diameter of the film roll thereon increases to the end of increasing the range of film roll diameter which may be accommodated without exerting excessive strain on the film.

Another object of the invention resides in the provision in combination with such-a variable power yielding reel drive of a novel, simple and effective additional reeldrive device functioning in alternation therewith for the instant purpose ofproviding a film rewind reel drive.

With these objects in'view, my invention consists in certain features of novelty in the construction, combination and arrangement of parts by which the said objects and certain other objects, hereinafter appearing, are effected all as fully described with reference to the accompanying drawing and more particularly pointed out in the appended claims.

In the said drawing- Figure 1 is a side elevation of a reel drive mechanism embodying my invention; v

Figure 2 is a sectional view substantially on the line 2-2 of FigureB;

Figure 3 is a side elevation taken oppositely with respect to Figure 1; and

Figure 4 is a view similar to Figure 3, showing parts in different positions than those in which they are shown in Figures 1, 2 and 3.

Referring to the drawing, I designates a frame member or reel arm such as is usually attached to a motion picture projecting machine, a drive member assembly is rotatably mounted on the extending end of the arm I on a horizontal axis transverse to the arm and consists as follows:

A horizontal spindle 2 is provided with a head rotatably mounted in a horizontal transverse bore 4 through the arm I by means of a roller bearing 5. seeiFigure 2. The other end of the spindle 2is redu'ced,as designated at 6, forming a shoulder .l, and is screwthreaded into an axial bore 8 of a grooved belt pulley member 9 to clamp the pulley member against the shoulder I, thus securing the spindle and pulley member in assembly.

.4. carrier arm ll ispivotally mounted at one end, as designated at I2, on the arm I on a horiz'ontal axis'parallel to the axis of the drive member assembly, and a reeling spindle assembly is rotatably'mounted on the free end of the carrier arm below the drive memberv assembly on a horizontal axis parallel to the axis of the drive member assembly and consists as follows:

A horizontal spindle I3 is provided with a head It at one end and extends through and is rotatably mounted in a ho'rizontaltransversebore l5 through the free end of the carrier arm H by 3 at one end thereof and extends through and is l3 and passing through a washer 22.

means of ball bearings [6. The other end of the spindle I3 is reduced, as designated at IT, forming a shoulder l8, and an axially bored spur gear 19 is engaged on the reduced end I! and is clamped against the shoulder I8 to secure the gear withthe spindle l3 by means of a headed screw 2| axially screwthreaded into the spindle A reel mount spindle element 23 is secured in an axial bore 24 of the spindle l3 and projects from the headed end of this spindle for the detachable mounting thereon of a film reel 25, shown in Figure 1, in driven engagement therewith as is usual in motion picture machines.

A fiat flanged belt pulley 26 is formed on the head 3 of the spindle 2, a fiat flanged belt pulley 21 is formed on the head M of the spindle I3 in alinement with the pulley 25, and a flat belt 28 is trained about these pulleys, thus forming a frictional belt and pulley driving device between the driving member assembly and the reeling member assembly.

The driving member assembly is driven from a suitable source, such as the mechanism of a motion picture projecting machine, by means of a belt 29 trained over the pulley member 9.

The reeling member assembly being disposed below the driving member assembly, and the reeling member assembly being vertically movable by reason of it being carried on the pivotally mounted carrier arm I I, the weight of the reeling member assembly and elements carried therewith including a roll of film 3| on the reel 25 mounted on the reeling member assembly serves to move the reeling member assembly downwardly, so that the belt 28 on the pulleys 2B and 21, operating upwardly on the reeling member assembly, suspends the same against downward movement.

Accordingly, the tension of the belt 28 and the resultant tractive friction thereof on the

pulleys

21 and 28 automatically increases as the film roll 3| increases in diameter and weight, so that the power exerted on the reel increases as the film roll diameter increases and exerts adequate power on the reel at large film roll diameters without exerting excessive power on the reel at small film roll diameters, thus increasing the range of film roll diameter in taking up the film.

For the purpose of rewinding, the following is provided in addition to the gear l9. The pulley member 9 is provided with a spur gear 32 which is alined with the gear IQ for meshing therewith. These gears are disengaged when the reeling member assembly is suspended by the belt 28 for take up as shown in Figures 1, 2 and 3. When the reeling member assembly is positioned upwardly from its said suspended position, the gears l9 and 32 are meshed; as shown in Figure 4, for driving the reeling member assembly, the belt 28 being loose in this position.

A manually actuated latch member 33 is pivotally mounted on the arm I, as designated at r- 34, and is yieldably urged into latching position by a'spring 35. When the reeling member assembly is in said upper position, an upwardly facing latch formation 36 on the latch member engages under a latch stud 31 on the carrier arm II to releasably position the reeling member assembly' in such position with the gears I9 and 32 meshed.

As shown, the pulley 26 is smaller than the pulley 2.! for the desired driving ratio in taking up, and the gear I9 is smaller than the gear 32 for a desired high speed rewind. driving ratio, it being also noted that the two drives for the reeling member assembly drive the same oppositely, which is desirable on motion picture projecting machines.

While I have thus described my invention, I do not wish to be limited to the precise details described, as changes may be readily made without departing from the spirit of my invention, but

having thus described my invention, I claim as new and desire to secure by Letters Patent the following:

1. In a reel drive mechanism, the combination with a rotatable driving member and a rotatable reel member operative for reeling a strip thereon in the form of a roll increasing in diameter as the strip is reeled thereon, of means carrying said reel member for vertical movement with reference to said driving member, a frictional drive device operative between said driving and reel members and operative upwardly to support said reel member and a roll of the strip thereon whereby to increase the driving friction as the diameter of the roll of the strip on the reel increases, a second driving device operative between said driving and reel members and comprising elements engaged in an upper position of said reel member, and releasable means for positioning said reel member in said upper position.

2. In a reel drive mechanism, the combination with a frame member, of a rotatable driving member carried thereby on a horizontal axis, a carrier member pivotally mounted on said frame member on an axis parallel to that of said driving member, a rotatable reel member operative for reeling a strip thereon in the form of a roll increasing in diameter as the strip is reeled thereon and carried on said carrier member below said driving member on an axis parallel to that of said driving member for vertical movement with reference to said driving member, a frictional belt and pulley driving device operative between said driving and reel members and suspending said reel member to support said reel member and a roll of the strip thereon whereby to increase the driving friction as the diameter of the roll of the strip on the reel increases, a gear driving device operative between said driving and reel members comprising two spur gears carried respectively with said driving and reel members and meshing in an upper position of said reel member and disengaged in a lower 7 position thereof, and a releasable latch operative between said frame and carrier members for positioning said carrier member with said reel member in said upper position.

BRUNO STECHBART.