US2686051A

US2686051A - Film unwinding mechanism

Info

Publication number: US2686051A
Application number: US175577A
Authority: US
Inventors: Holme-Shaw Norman Mckay
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-07-24
Filing date: 1950-07-24
Publication date: 1954-08-10
Anticipated expiration: 1971-08-10

Description

Aug. 10, 1954 N. McK. HOLME-SHAW FILM UNWINDING MECHANISM Filed July 24. 1950 I N VEN TOR.

11 1 14 TTOR/VEY Patented Aug. 10, 1954 UNITED STATES smear OFFICE A FILM UNWINDING MECHANISM Norman McKay Holme Shaw,

' Frankenmuth, :Mich.

Application July 24, 1950,, Serial No. 175,577

'projector, without the necessity-of rewinding as is at present necessary.

One of the prime objectsof the invention is :to design a very simple, practical, neat-appearing standard and film plate on which a reversely wound strip of film may be placed, and from which it may be readily uncoiled, as it is fed to a conventional projector without rewinding, thus conserving time, unnecessary strains and wear and tear on the film.

Another object is to provide a standard and inclined film plate on which the film is removably mounted, and from which it is unwound as the film is fed to the projector.

A further object is to provide a mechanism including an inclined film plate of fiat, disk-like form, having a centrally disposed pin on which a relatively heavy conical-shaped knob member is releasably mounted, so that the inner periphery of the wound film engages therewith with friction sufficient to rotate said plate as the film is unwound and drawn through the projector.

Still a further object is to provide an anti friction, easy operating film plate and mechanism, which can be placed directly in the rear of a conventional projector and from which wound film may be drawn as the projector is operated.

With the above and other objects in view, the present invention consists in the combination and arrangement of parts, hereinafter more fully described, illustrated in the accompanying drawing, and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportion, and minor details of construction, without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawing:

Fig. 1 is an edge-elevational view of my new film supporting mechanism, the film being shown in section.

Fig. 2 is a front-elevational view thereof.

Fig. 3 is an enlarged, fragmentary section of the film plate and pin showing the conical knob arranged in position thereon.

Fig. 4 is a transverse-sectional, plan view of the conical knob taken on the line 4-4 of Fig. 1.

Referring now more specifically to the drawing in which I have shown the preferred embodiment of my invention, the mechanism in general is indicated at 'S and comprises a relatively heavy base 5 formed of any desired material with a curved, upwardly projecting arm 6 secured thereto-and'terminatin-g ina housing 7 in whichan anti-friction bearing is mounted, said housing being'disposed at an angle with relation to a horizontal line, and is bored to accommodate anti-friction bearings B in which the film plate shaft i,provided on thelower face of the film plate it, is mounted.

The film plate It is preferably formed with a hub W inwhich the shaft 9 is mounted, andis disposed at right anglesto the shaft 9 as shown, said shaft projecting through-the film plate and theupperend is splitas-at H 'andfor a purpose to be presently described.

A conical shaped knob member 52 is mounted on the split section it of the shaft 9, and this knob is relatively heavy, being centrally bored as at E3, and a transversely disposed pin i i spans said bore, said pin being releasably accommodated in the split section i l of the shaft 9 when the knob is mounted in position, so that the knob rotates with the film plate but is freely removable when desired.

When a strip of film F is fed through a pro jector (not shown) it is reversely wound on a conventional reel (not shown), and for the pres ent purpose the reel is vertically separable so that the wound film may be removed without unwinding; after removal from the reel the wound or coiled film is then placed on the film plate ii! over the split section l l of the shaft, after which the knob 12 is placed in position with pin i l in engagement with the section H, the lower end of the knob I2 being inserted through the opening in the coil, so that the inner periphery of the Wound film bears thereon.

It will be noted that the one end of the housing 1 is shouldered as at it to engage the hub it and, the bearings 8 minimize friction.

In operation, the inner free end G of the coiled film F is threaded in the projector (not shown), and as the projector is operated, the film plate I6 is rotated and progressively unwinds the film, said plate being freely revolvable with a minimum of friction or resistance. The contact of the film with the outer conical face of the knob is at the one edge only, so that there is a limited adherence or clinging action, and there is no tendency to form a tighter coil or slide the convolutions on each other. The film guides on the conical surface of the knob as it leaves the coil and the knob is movable axially on the shaft in response to excessive tension on the film. Thus, the knob moves axially in response to excessive unwinding tension and undue strains which might break the film are not placed thereon.

The fact that it is unnecessary to rewind the film preserves and insures longer life with a much better reproduction, because of absence of scratches, abrasions and marring produced by usual rewinding.

From the foregoing, it will be appreciated that I have designed an apparatus that eliminates film rewinding, protects from damaging tension, surface scratches and abrasions, and provides clearer film over a much longer span of time.

What I claim is:

1. A motion picture film strip unwinding apparatus comprising a base having an upwardly extending, angularly disposed housing, a shaft journaled in and projecting from the upper end of said housing, the projecting end section of said shaft being bifurcated, a substantially fiat film disc fixed on said shaft below said bifurcated section and disposed at substantially right angles to said shaft for supporting a roll of reversely coiled film on the disc with the shaft projecting through the central opening in the coiled roll, a relatively heavy, inversely disposed, conical knob having a central bore removably mounted on said shaft, said knob having a pin spanning said bore and adapted to seat in the bifurcated end of said shaft and prevent rotation of said knob on said shaft while allowing relative axial movement of said knob thereon in response to excessive tension on the unwinding film, the lower end of said knob extending through the central opening in the coiled roll to maintain the roll in position and permitting unwinding of the film from the inner periphery of said roll.

2. A motion picture film strip unwinding apparatus comprising a base having an upwardly extending housing, a shaft journaled in and projecting from the upper end of said housing, a film disc fixed in said shaft at substantially right angles thereto for supporting a roll of reversely coiled film on the disc with the shaft projecting through the opening in the coiled roll, a relatively heavy, inversely disposed, conical knob having an axially extending bore mounted on said shaft, means preventing rotation of said knob on said shaft while permitting relative axial movement of said knob in response to excessive tension on the unwinding film, the lower end of said knob extending through the opening in the roll to maintain the roll in position and permit unwinding of the film from the inner periphery of the roll.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,254,272 Ponon Jan. 22, 1918 1,393,985 Voulgre Oct. 18, 1921 1,946,604 Wittel Feb. 13, 1934 2,065,954 Mihaly Dec. 29, 1936 2,443,248 Hurley June 15, 1948 FOREIGN PATENTS Number Country Date 182,565 Great Britain July 26, 1922