US3370801A - Skew pulley elevator - Google Patents

Description

3 Sheets-Sheet 1 Filed March 28, 1966 Feb. 27, 1968 Filed March 28, 1966 M. H. AMES SKEW PULLEY ELEVATOR 3 Sheets-Shem Feb. 27, 1968 M. H. AMES 3,370,801

Y ELEVATOR Filed March 28, 1966 s Sheets-Sheet INVENTOR. WZKdZ/M/ZAMZS Aria/V645 United States Patent 3,370,801 SKEW PULLEY ELEVATOR Malcolm H. Ames, Littlerock, Calif assignor to Panacolor, Inc., Hollywood, Calif., 21 corporation of Delaware Filed Mar. 28, 1966, Set. N 537,818 Claims. (Cl. 24255.01)

ABSTRACT OF THE DISCLOSURE This patent describes a novel pulley elevator apparatus comprising a stationary bed of parallel powered shafts each containing thereon a plurality of pulleys, in a plane parallel to said stationary bed, a movable bed of parallel channel members each containing thereon a plurality of pulleys, said bed being movable with respect to said stationary bed, said pulleys on said movable bed being rotatable around an independently resiliently disposed mounting having an axis generally perpendicular to the movable bed, and means for moving said movable bed with respect to said stationary bed.

This invention pertains to a novel skew pulley elevator particularly useful for accumulating and releasing photographic and other film during winding, unwinding, processing, packaging, and other manufacturing and developing operations.

An elevator is normally a device for accumulating or releasing film as needed while some part of a continuously running machine is stationary. Normally the elevator comprises a series of pulleys on a stationary shaft and another series of pulleys on a shaft, either above or below the fixed one, that moves in a venical path with respect to the fixed pulley. The film in such an elevator follows a helical path and a limitation on the usefulness of such an elevator is that the fixed and moveable shaft cannot be brought close together without producing excessive stress on the film. Excessive stress must be avoided to hold film loss and damage to a minimum. This problem reduces the range of elevator capacity in any given space since the minimum storage capacity is much greater than it would be if the fil'm strands were parallel instead of helical.

Designs have also been developed and elevators have been used where the pulleys on one of the shafts are larger and set at an angle which permits the film strands to be parallel. The skew angle is fixed in this construction and all pulleys on any shaft move together. While this construction increases the range of the elevator, it is expensive to construct and maintain.

Accordingly, it is a principal object of the present invention to provide a skew pulley elevator having several unique features which increase the elevator capacity for any given space without the need for structures which are expensive both initially and in operation.

iMore particularly it is an object of the present invention to provide a skew pulley elevator wherein the skew pulleys are independently mounted so that they are capableof swiveling to the best postion required by the film path whereby stress on the film is reduced.

A more specific object of the invention is to provide a skew pulley elevator wherein the skew pulleys are freely rotatable and independently resiliently mounted.

These and other objects of the present invention will be apparent from the more detailed description which follows read in conjunction with the accompanying drawings.

In the drawings:

FIGURE 1 is a top plan view of the novel skew pulley elevator of the present invention.

FIGURE 2 is an end view of the skew pulley elevator of this invention.

FIGURE 3 is an enlarged top view of one of the elevator pulleys utilized in the present invention and shows its relation to the driven pulleys.

FIGURE 4 is an enlarged side view of one of the pulley elevators showing its attachment to the elevator structure itself.

FIGURE 5 is a sectional view taken along the line 5-5 of FIGURE 4.

FIGURE 6 shows a top view of the stationary pulleys and drive mechanism employed in the present invention.

FIGURE 7 is a schematic drawing of the path of the film as it passes through the device of the present invention.

Briefly, the present invention comprises a stationary bed of parallel powered shafts each containing thereon a plurality of pulleys; in a plane parallel to said station ary bed, a bed of parallel channel sections each containing thereon a plurality of pulleys, said bed being moveable with respect to said stationary bed, said pulleys on said moveable bed each being rotatable around an independently resiliently disposed mounting having an axis generally perpendicular to the moveable bed so that each pulley is capable of moving toward or away from said bed and swiveling around the axis as tension on each pulley dictates, and means for moving said moveable bed with respect to said stationary bed.

Turning to the drawings in greater detail, the stationary bed is indicated generally as 10 and the moveable bed of pulleys as 12. The stationary bed contains a plurality of drive shafts 14 each containing thereon a plurality of pulleys 16. These shafts are powered by motor 18 which turns shaft 29. Shaft 20 is connected by chain 22 to each of the other pulley shafts.

The moveable bed 12 is vertically moveable with respect to bed 10 by the raising and lowering of hoist 24. The main supporting member 26 of hoist 24 carries a plurality of parallel channel members 28. To each of these channels is connected individually spring mounted pulleys 39. These pulleys are so mounted as to be able to freely swivel about pulley shaft 31 when mounted in place on channel 28. Thus, the swivel mounting permits the pulleys 30 to rotate as needed and the springs 32 permit the pulley to move toward and away from the channels 28 depending upon the tension applied to the pulley.

In operation, the film 34 enters the machine at 36 and follows a path through the machine generally as shown in FIGURE 7, leaving the machine via fixed pulley 38. According to this invention the shafts 14 are driven at a speed somewhat greater than the overall machine speed. The shafts 14 through friction drive the pulleys 16 which in turn drives the film 34, thereby making use of the friction to reduce the film tension rather than increasing it as has been the case with prior devices. The spring mounted pulleys 3t maintain contact between film 34 and the pulley itself and between pulleys 16 and the stationary shafts 14 thus insuring that each driving pulley 16 does its share of the work.

The hoist 24 is normally of the hydraulic type. However, the hoist may be powered in any conventional manner or operated manually. Normally, the hoist operates in response to some signal from another part of the film handling system to indicate that film needs to be stored in the elevator or released by it. This signaling system is already familiar to those skilled in the art and forms no part of this invention.

As will be immediately apparent to those skilled in the art, the novel pulley elevator of the present invention represents a substantial advance in the art of film handlin g since by the simple construction provided, the problems previously associated with the use of elevator pulleys having a fixed skew angle have been eliminated. In addition, .it can be seen that the skew pulley elevator con struction of the present invention being provided with independently and swivel mounted pulleys effectively reduces the tension on the film passing through the machine. In this Way, the loss of film during packaging, processing, and similar operations because of breakage and tearing is effectively reduced or eliminated. In addition, the novel pulley elevator of my'invention is less costly to construct and maintain.

Accordingly, while the foregoing description of the invention has been with particular reference to certain embodiments, it will be understood that these embodiments are presented solely for the purpose of illustration and 'are not intended to be limiting in any way. Rather, the invention is limited solely by the lawful scope of the appended claims.

I claim:

1. A novel pulley elevator apparatus comprising a stationary bed of parallel powered shafts each containing thereon 'a plurality of pulleys, in a plane parallel to said stationary bed a moveable bed of parallel support members each containing thereon a plurality of pulleys, said bed being moveable with respect to said stationary bed, independently resiliently disposed mountings on said movable bed having an axis generally perpendicular to said movable bed, said pulleys on said movable bed being rotatable around said mountings, and means for moving said movable bed with respect to said stationary bed.

2. The apparatus of claim 1 wherein the means for moving said moveable bed comprises a hoisting mechamsm.

3. The apparatus of claim 1 wherein the independently resiliently disposed mounting comprises a spring.

4. The apparatus of claim '1 wherein said parallel powered shafts are driven by a motor.

5. The apparatus of claim 1 wherein the number of pulleys on each shaft of the stationary bed is one greater than the number of pulleys on each support member of the move'able bed. 7

References Cited UNITED STATES PATENTS 1,490,669 4/1924 Higginson 24277.1 1,544,931 7/1925 Patterson 242 55.01 3,233,808 2/ 1-966 Alexeif et a1. 24255.01 X

FRANK J. COHEN, Primary Examiner.

NATHAN L. MINTZ, Assistant Examiner.

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