US3620472A

US3620472A - System adapted to grasp the end of a wound strip

Info

Publication number: US3620472A
Application number: US801943A
Authority: US
Inventors: Jean Thevenaz
Original assignee: Paillard SA
Current assignee: Paillard SA
Priority date: 1968-03-20
Filing date: 1969-02-25
Publication date: 1971-11-16
Anticipated expiration: 1988-11-16
Also published as: AT276950B; DE1910087A1; JPS4921897B1; CH474772A

Abstract

The system is adapted to grasp the end of the outer convolution of a wound film, tape or the like strip. To this end it resorts to one or preferably two movable, spaced-apart members such as belts or pulleys engaging the periphery of the wound strip so that the relative difference in speed between the two members at their portions engaging said periphery urges the strip passing across the gap between the two members into said gap to form a slight bulge. When the end of the outer convolution reaches a position facing said gap, it passes over the bulge and is urged outwardly through the gap and away from the grasping system.

Description

United States Patent 1 I I l Inventor Jean Thevenaz Grandson, Switzerland Appl. No. 801,943 Filed Feb. 25, 1969 Patented Nov. 16, I971 Aasigncc Pnlllard S.A.

SIInte-Crols, Vaud, Switzerland Priority Mar. 20, 1968 Switzerland 4142/68 SYSTEM ADAPTED TO GRASP THE END OF A WOUND STRIP 4 Claims, 2 Drawing Figs.

US. Cl 242/192, 242/195, 352/158 Int. Cl Gllb 15/66, G1 lb 15/32 Field 0! Search 242/ l 92,

[56] References Cited UNITED STATES PATENTS 3,429,518 2/1969 McKee 242/192 X 3,454,961 7/1969 Tatter 242/197 Primary E.ranriner-George F. Mautz Attorneys-Emory L. Groff and Emory L. Groff. Jr.

ABSTRACT: The system is adapted to grasp the end of the outer convolution of a wound film, tape or the like strip. To this end it resorts to one or preferably two movable, spacedapart members such as belts or pulleys engaging the periphery of the wound strip so that the relative difference in speed between the two members at their portions engaging said periphery urges the strip passing across the gap between the two members into said gap to form a slight bulge. When the end of the outer convolution reaches a position facing said gap, it passes over the bulge and is urged outwardly through the gap and away from the grasping system PATENTEDNUV 16 IS?! INVENT OR jg/4N 771E V A/AZ.

BY my I ATTORNEY SYSTEM ADAPTED TO GRASP THE END OF A WOUND STRIP Various arrangements have previously been proposed for grasping the end of a wound strip, chiefly in the case of a kinematographic film or magnetic tape carried by a rotary reel.

Generally such arrangements include a rotary member adapted to cooperate with the outer convolution of the wound film or tape so as to drive the whole winding into rotation while a deflecting member in contact with the outer convolution of the winding is adapted to raise the free end of said outer convolution when it passes in front of it so as to urge it into a predetermined direction.

Arrangements of this type are of a delicate nature if it is desired to prevent the deflecting member from exerting too great a pressure on the film which leads to a premature wear of the latter. As a matter of fact, if the pressure of the deflecting member is not sufi'icient, the end of the film may engage the underside of said deflecting member instead of being guided in the desired direction.

The present invention has for its object a system for grasping the end of a wound strip so as to efficiently raise said end in order to urge said strip towards the desired location.

The accompanying drawings illustrate diagrammatically and by way of example an embodiment of the arrangement forming the object of the present invention and a modification thereof. In said drawings:

FIG. 1 is a side view of the embodiment considered.

FIG. 2 is a similar view ofits modification.

The arrangement illustrated is intended to provide an automatic grasping of the outer end of a kinematographic film F wound in a casing 1 secured to an arm 2 forming part of a kinematographic projector. Said casing is provided with sn opening 3 through which the grasping system can extend into the casing.

Said grasping system includes two rubber or the

like belts

4 and 5 moving between and over the pulleys 6 and 7 and over the pulleys 8 and 9 respectively.

The pulleys 6 and 8 which are positioned completely outside the casing 1 are revolvably carried by a support 10 forming the end ofa movable arm 11; these two pulleys 6 and 8 are rigid with corresponding toothed wheels, 12 and 13 respectively, which wheels mesh with each other so that they may rotate in opposite directions. Furthermore one of these wheels is rotatably driven by means which are not illustrated.

The pulley 7 adapted to engage the casing is carried by an arm 14 pivotally secured to the spindle carrying the cooperating pulley 6 and subjected to the action of a tractionally operating spring 15 urging said arm 14 clockwise. The pulley 9, also adapted to engage the casing, is carried at the end of a bent arm 16 screwed to the above-mentioned support 10 and carrying on its bent portion a block 17 made of a synthetic resin such as nylon the function of which will be disclosed hereinafter.

The arrangement disclosed operates as follows:

When the end of the film F is to be grasped so as to urge it out of the casing 1 and to feed it for instance into the projecting channel of a kinematographic apparatus, the grasping system is brought into the position illustrated, so that the sections of the

belts

4 and 5 passing over the pulleys 7 and 9 may engage the outer convolution of the wound film. Obviously, the contact between the belts and said convolution may be obtained, as desired. either by shifting the casing 1 through a pivotal movement of the arm 2 or else by shifting the filmgrasping system together with the movable arm 11.

The

belts

4 and 5 are driven in the direction of the arrows fl and f2 and the speeds of their portions facing the outer convolution of the wound film are opposed. Since the pulleys 7 and 9 revolve in opposite directions, the

belts

4 and 5 exert on the section of the film extending between them a gripping action which gives at least the outer convolution of the reel an outwardly convex shape as shown at 18.

Since the arm 14 is pivotally secured to the support 10 and subjected to the action of the spring 15, the friction between the film and the belt 4 urges said arm 14 into a pivotal movement in an anticlockwise direction, whereby the belt 4 moves slightly away from the film. Consequently, the frictional action between the belt 4 and the film is reduced with reference to that exerted between the belt 5 and the film and thereby the action of the belt 5 predominates so that the film is urged by said belt 5 in the direction of the arrow 19.

The free end of the film may be located at any point of the casing 1 when the arrangement is set for operation. By reason of the angular movement of the wound film produced by the belt 5, said free end of the film engages the 5 belt at a predetermined moment and then passes between the latter and the remainder of the wound film. By reason of the progression of the belt 5, said free end of the outer convolution of the film cannot assume an improper position since it is automatically urged by the belt 5 against the periphery of the winding. After it has passed over the top of the belt 5, said free end moves over the bulging convex part 18 of the film whereby it is again shifted away from the remainder of the reel. Said free end then impinges through its outer edge against the belt 4 as illustrated at 20 in FIG. 1; said end is therefore deflected and caused to follow the downwardly moving portion of the belt 4 adjacent the arm 16. The end of the film moves thus out of the grasping system in the direction of the arrow f3 and may for instance be engaged by a channel through which the film is automatically fed into a kinematographic projector.

The block 17 on the arm 16 is provided so as to prevent. in the case of a film of a highly flexible nature, the convex part 18 of the film from forming a complete loop which might extend beyond the grasping system and downwardly between the

belts

4 and 5.

FIG. 2 shows a modification wherein a feed reel 21 carries a wound film F. Said reel is secured to an arm 2.

As in the preceding case, the film-grasping system adapted to take hold of the end of the film includes two

belts

4 and 5 passing over the pulleys 6 and 7 and over the pulleys 8 and 9 respectively. The spindle carrying the pulley 8 is revolvably carried by a member 10' rigid with the casing of the kinematographic projector while the pulley 9 is revolvably carried at the end of an arm 22 rigidly secured to said member 10'. The spindle carrying said pulley 9 also carries a pivoting arm 23 which is subjected to the action of a spring 24 and carries a braking shoe 25. The spring 24 urges said shoe against the wound film F.

The pulleys 6 and 7 carrying the belt 4 are revolvably carried at the corresponding ends of a rigid arm 26 which is pivotally secured through the spindle of the pulley 6 to an arm 27 pivotally secured to the spindle of the cooperating pulley 8. A spring 28 connecting the

arms

22 and 26 urges the belt 4 both against the periphery of the film winding F and against the pulley 9 carrying the other belt 5.

As in the case of FIG. I, the pulleys 6 and 8 are driven in opposite directions by means of the interengaging

toothed wheels

12 and 13. The grasping system illustrated in FIG. 2 is adapted for use in the case of a film spool driven by its spindle in the direction of the arrow 19. The arm 2 carrying the spool urges the film winding F against the belt 5 passing over the pulley 9. The outer convolution of the film winding is at such a moment in contact with the braking shoe 25 and with the belt 4. The spring 28 is designed so as to limit the force urging the belt 4 against the outer convolution of the film so that the friction between said convolution and the belt 4 may be less than that between said convolution and the belt 5.

The film is carried by the spool 21 in a manner such that when the latter revolves in the direction of the arrow 19. the friction exerted by the braking shoe 25 causes the film convolutions to close.

By reason of the rotation of the spool 21, the free end of the outer convolution of the winding designated by the reference number 29 passes underneath the braking shoe 25. From this moment onwards the outer convolution includes a part which is braked by said shoe 25 while its free end is carried along by the belt at a speed which is higher than the peripheral speed of the film winding. Said outer convolution expands therefore with reference to the body of the winding and, as soon as it has passed over the pulley 9, it is subjected to the action of the belt 4 which urges it in the opposite direction. Up to such a moment, the action of the belt 4 was hardly perceptible since the friction of said belt on the outer convolution of the film was less than that exerted by the belt 5.

Since the outer convolution has slackened during the passage of its free end between the shoe 25 and pulley 9, the belt 4 can now make the end of the film progress as shown at 29 between the pulleys 7 and 9 whereby the outer convolution is made closer with the remainder of the wound film. The end of the film therefore is directed into the gap between the

belts

4 and 5 and then between the outer pulleys 6 and 8 beyond which it moves in the direction of the arrow f3.

During its passage through said gap between the

belts

4 and 5, the end of the film is clamped to a somewhat considerable extent between said belts and therefore the tractional stress exerted by said belts on the film is much higher than that exerted by the spool 21 which is driven in the usual manner by means ofa frictional clutch.

Obviously it is possible to provide various modifications and in particular the movable member engaging the film end may comprise rollers set in the position illustrated for the pulleys 7 and 9 instead of

belts

4 and 5. Said rollers may be rotatably driven by any suitable means such as a set of gears.

In order to obtain different frictional forces for the two rollers acting on the film, it is of course possible to act on the contacting pressure between each roller and the film but it is also possible to provide equal pressures and to give the rollers different coefficients of friction with the film.

It should be noted that in the case of FIG. 1 the shifting at 18 of the outer convolution does not require the movable members to progress in opposite directions with reference to each other and it is sufficient for their speeds to be different. ln such a case it is also possible to design the system in a manner such that the end of the film, tape of strip moves away from the remainder of the winding as illustrated at 20 in FIG. I; but at such a moment said end should cooperate with a deflecting or guiding member since the rotation of the rollers in the same direction would not be sufficient for the end of the film to be actually urged outwardly. Thus, it is apparent that the belt 4 may revolve in the case of FIG. 1 either in the same direction as the belt 5 or in the opposite direction. A particular case is that where the belt 4 is stationary and obviously it may be replaced by a mere braking shoe, the system including then merely a single belt 5 and a deflecting member so as to urge the end of the film away from the remainder of the film winding.

The system described or a similar system falling within the scope of the accompanying claims may serve for releasing the free end of any yielding wound strip such as the end ofa magnetic tape on a recording apparatus or the outer end of a strip of paper wound into a roll, as for instance, in the case of cash registers and calculating machines in which such paper rolls are used.

lclaim:

l. A system for grasping the end of a kinematographic film, a magnetic tape and similar wound strips, comprising a pair of spaced-apart grasping members forming a gap therebetween, each supported on an arm and having end portions adjacent the periphery of the outer convolution of said wound strip, means driving said grasping members, means moving said end portions into frictional engagement with said wound strip, means pivotally mounting one said support arm, and spring means resiliently urging the end portion of said grasping member on said pivotally mounted arm into engagement with said outer convolution whereby, a differential frictional driving force is applied to said outer convolution as said end por' tions of said grasping members engage the strip and said pivotally mounted arm is displaced against the force of said sprin means by said outer convolution to permit the graspin mem er on the other of said arms to direct the free en of 5a:

outer convolution into the gap between said spaced-apart grasping members.

2. A system as claimed in claim I, wherein said driving means includes meshed elements moving said grasping members in opposite directions.

3. A system as claimed in claim 1, wherein at least one of said pair of members comprises a belt, said system including two pulleys engaging said belt, one of said pulleys driving said belt.

4. A system as claimed in claim I, wherein each said member comprises a belt extending substantially in parallelism with each other, the system further including two pulleys engaging each belt, a support for the two pulleys of one of the belts and means for yieldingly connecting the pulleys cooperating with the other belt with said support whereby said other belt exerts on the wound strip a pressure which is less than that exerted by the first-mentioned belt.

Claims

1. A system for grasping the end of a kinematographic film, a magnetic tape and similar wound strips, comprising a pair of spaced-apart grasping members forming a gap therebetween, each supported on an arm and having end portions adjacent the periphery of the outer convolution of said wound strip, means driving said grasping members, means moving said end portions into frictional engagement with said wound strip, means pivotally mounting one said support arm, and spring means resiliently urging the end portion of said grasping member on said pivotally mounted arm into engagement with said outer convolution whereby, a differential frictional driving force is applied to said outer convolution as said end portions of said grasping members engage the strip and said pivotally mounted arm is displaced against the force of said spring means by said outer convolution to permit the grasping member on the other of said arms to direct the free end of said outer convolution into the gap between said spacedapart grasping members.

2. A system as claimed in claim 1, wherein said driving means includes meshed elements moving said grasping members in opposite directions.

4. A system as claimed in claim 1, wherein each said member comprises a belt extending substantially in parallelism with each other, the system further including two pulleys engaging each belt, a support for the two pulleys of one of the belts and means for yieldingly connecting the pulleys cooperating with the other belt with said support whereby said other belt exerts on the wound strip a pressure which is less than that exerted by the first-mentioned belt.