US3140837A - Endless tape winding cartridge - Google Patents

Description

July 14, 1964 s. CAILLIOT 3,140,837

ENDLESS TAPE WINDING CARTRIDGE Filed Oct. 16, 1961 4 Sheets-Sheet 1 mVENTOR Serge Cal/lief ATTOR NEY I y 964 s. CAlLLlOT 3,140,337

ENDLESS TAPE WINDING CARTRIDGE Filed 001;. 16, 1961 4 Sheets-Sheet 2 INVENTOR Serge Cailliol:

ATTORNEYS July 14, 1964 s. CAILLlOT vmmusss TAPE WINDING CARTRIDGE 4 Sheets-Sheet 3 Filed Oct. 16, 1961 mm g mm mm i 3 INVENTOR Serge Cailliot ,9, /,,,4%/ M ATTORNEYS July 14, 1964 s. CAILLIOT ENDLESS TAPE WINDING CARTRIDGE 4 Sheets-Sheet 4 Filed 001',- 16. 1961 INVENTOR Serge Cai "id n/4m ATTORNEYS United States Patent 3,140,837 ENDLESS TAPE WINDING (IARTRIDGE Serge Cailiiot, 38 Rue du Bois de Boulogne, Neuilly-sur-Seine, Seine, France Filed Oct. 16, 1961, Ser. No. 145,138 Claims priority, application France Oct. 21, 1960 9 Claims. (Ci. 242-5519) There are known types of tape-holding cartridges which permit recording tapes of the endless band type to be regularly unrolled for recording or reproducing in such a manner that the tape leaves the cartridge at a constant speed.

In my U.S. Patent No. 2,918,536 I have described a tape holding cartridge of this type which has the special advantage that it may be mounted on the turntable of a conventional record player, the design of the cartridge being such that the energy required to unwind the tape is very small.

This result is obtained by providing a dual drive within the tape-holding cartridge, and a certain amount of play between the different turns of the roll formed by the endless tape, which permits unnecessary friction between the contiguous turns to be avoided during unwinding of the tape.

The object of the present invention is to provide a tapeholding cartridge using the same type of dual drive described in the said U.S. patent, but in which the friction between contiguous turns of the tape is still further reduced, so that the tape may be driven with even less power, even if the roll formed by this tape is larger, and may therefore carry a longer recording.

This reduction in the friction between the turns may be obtained by preventing ovalization of the roll and its compression along a diameter substantially perpendicular to the path of travel followed by the tape as it is about to be wound about the outside of said roll.

It is this compression which causes the friction between adjacent turns all along the shorter axis of the ellipse thus formed by the roll, and also the friction resulting between the lower edge of the diiferent turns and the radial rollers which drive them in rotation, each point on the lower edg of the tape being subjected to radial displacements in varying directions during each revolution, while moving alternately toward and away from the axis of rotation of the device.

It should also be noted that, in the older embodiments, the portion of the tape between the driving spindle of the device and the peripheral guiding spindles along the path of travel of the tape, between the point at which the tape leaves the interior of the device and that at which it returns to the periphery of the roll, is kept under tension by imparting to the various radial rollers peripheral speed slightly greater than the one theoretically corresponding to the speed of the driving spindle.

This difference in speed gives rise to some friction between the tape and the radial driving rollers wherever they come in contact.

In the new embodiment according to the present invention, a certain number of the radial rollers which have the same diameter, are driven at a peripheral speed which corresponds exactly to the speed of the driving spindle, whereas others of said radial rollers which have a smaller diameter are driven at a slightly slower peripheral speed, because they are driven at the same angular speed of rotation as the other radial axes, from a plate fixed to the driving spindle.

To accentuate the braking effect of these radial rollers of smaller diameter, a non-driving roller is provided substantially in the middle of the zone occupied by the radial rollers of small diameter. That is to say, this roller is not driven by said plate, and may have either a normal diameter, or the same diameter as the other rollers intended to produce a braking effect.

In a preferred embodiment of the invention another angular zone, diametrically opposite the one containing the rollers of smaller diameter, that is to say, at the side where the tape returns toward the periphery of the roller, comprises radial accelerating rollers having a diameter slightly larger than that theoretically corresponding to the speed of the driving spindle, so that the average speed at which the turns of the tape are driven is substantially equal to the speed at which the tape as a Whole is driven by the driving spindle and is in any event no lower.

If, however, in this latter embodiment, the assembly comprising rollers of different diameters ensures the exertion of a slight tension on the tape between the driving spindle and the point at which it rolls itself up on the periphery of the roller, it is necessary to increase this tension in the part between the drive spindle and the peripheral vertical guide spindles outside which the tape passes as it unrolls from said driving spindle.

For this reason, in all the new embodiments of the invention, the tension on the tape as it leaves the driving spindle is provided by means of a longer radial shaft, provided with pressure means, which tends. to drive that part of the tape which passes outside the peripheral guide spindles at a slightly more rapid speed, by passing it between two grooved pulley wheels.

In this manner, the friction against the entire group of radial rollers, which existed in the original embodiment by reason of their role in accelerating the speed imparted by the driving spindle, no longer exists in the case of the rollers of normal diameter, which have neither an accelerating nor a retarding action.

It will be appreciated that the elimination of the ovalization of the roll of tape and the resulting friction against the various radial rollers notably reduces the power necessary to overcome the total of the friction between adjacent turns and between the roll of tape and said radial rollers.

The new means for maintaining the tension on the tape also has the advantage of permitting recording on the tape with greater safety outside the cartridge, while at the same time insuring adequate tension near the central spindle.

Other characteristics and advantages of the new cartridge according to the present invention will be better understood after reading the following description of two specific embodiments thereof, given purely by way of example, without limiting the scope of the invention thereto. This description will refer to the accompanying drawings on which:

FIG. 1 is a perspective view of a new cartridge carrying its protective cover;

FIG. 2 is a plan view of the device, with the cover removed, showing especially the arrangement of the different radial rollers and the device which maintains the tension on the tape near the central spindle, as well as the members which serve to maintain the concentricity of the roll of tape and lock it in place, either for transportation or when it is desired to prevent any movement of the endless tape inside the cartridge;

FIG. 3 is an exploded perspective view of the assembly of the apparatus showing especially the means for holding the roll of tape still;

FIG. 4 is a broken vertical section taken along the line IV-IV of FIG. 2, showing the mounting of the table carrying the driving spindle of the locking: bar of said table, and of the driving shaft;

FIG. 5 is a schematic diagram illustrating the possibility of using the new cartridge in combination with a recording or reproducing device of the magnetic tape type positioned outside the cartridge; and

FIG. 6 is a plan View similar to that of FIG. 2 showing a second embodiment of the invention, but omitting the means for locking the roll of tape in position.

FIG. 1 shows that the protective cover 1 comprises a slot 2 in its central part which aifords access to a member 3 which controls the release of the various elements shown in order to permit the driving of the tape. The displacement of the member 3 to the left of the figure permits the introduction of a plug 4 connected by means of a cord 5 to a recording or reproducing amplifier positioned outside the cartridge. The jack 4a, not visible on FIG. 1, which cooperates with the plug 4, is connected to the circuit of the magnetic head 6 visible on FIG. 2, by means of a cord 7, also shown on the same figure. There is shown in broken lines at 8 on FIG. 1 a strip of plastic material which permits the upper part of the roll of tape lying within the cartridge to be immobilized, when this roll is pressed against the inner wall of the cover.

FIG. 1 also shows that the cover comprises an upwardly projecting part 9, within which the tape moves at a level above that which it occupies at the periphery of the roller or at the level of the spindle 10 visible on FIG. 2. This raised part 9 contains vertical guide spindles 11 and 11a, and the device 12 which maintains the tension on the tape in the part 13 between the driving spindle 10 and the spindles 11.

In order to clarify the description, FIG. 2 shows a roll of tape consisting of only four turns, 14, 15, 16 and 17, so as to show the position of the innermost turn and that of the succeeding turns, the turn 17 being connected to the part of the tape guided by the spindle 11a, which is positioned after the device 12 for maintaining tension on the tape. This device will be described in greater detail with reference to the perspective view of FIG. 3. The tape coming from the inner turn 14 is brought into contact with the magnetic head 6 by a pressure member 18.

Those of the radial rollers which turn the roll of tape and have the same diameter are designated by reference numerals 19 and 19a. The non-driving roller which exerts a braking effect to prevent ovalization of the roll of tape is shown at 20, and, on the other side of this non-driving roller are the two driving rollers 21, the diameter of which is less than that of the rollers 19, so as to produce a braking action.

The assembly of rollers 19, 19a, and 21 is driven from the rotating turntable of the device in the same manner as in the machine shown in U.S. Patent No. 2,918,536, by means of small wheels 22 and 22a which play the same part as in the machine described in said prior patent, and which terminate at their inner ends in the pins 22b, the ends of which turn in appropriate openings in the posts 37 and 38.

The driving spindle 10 cooperates with a pressure member 23 in the position in which it drives the tape, which as it leaves the spindle 10 ascends a ramp 24 on a fixed vertical post 25 before reaching the vertical guiding spindles 11.

The portion connecting the innermost turn 14 of the roll of tape and the portion of the tape which is pressed against the driving spindle 10 passes around a guide roller 27 mounted on a lever 28 which permits it to be pressed by a spring 29 against the inner surface of the roll of tape. One end 30 of the spring is fixed to a projection extending from a fixed part of the machine.

FIG. 2 also shows brake means 31 for immobilizing the roll of tape. This means, when in position to hold the roll of tape still, bears against its lower part, so as to press the upper part of the roll against the elastic member 8 previously mentioned.

The pressure member 23 is pressed against the driving spindle 10 by the traction exerted on the pressure mem her by the spring 32, visible on FIGS. 2 and 3, when the member 3 is moved.

The device is removed from the driving plate 33, visible on FIG. 4, by withdrawing a radial bar 34, best seen on FIGS. 2 and 4.

The foregoing elements are shown in the exploded perspective view constituting FIGURE 3. In particular, it will be seen that the pressure member 23 is pivotally mounted by means of a lever 23a on a bearing 23b, and that the spring 32, which is attached at 32a to a plate 32b which turns with the control member 3, draws the swinging arm 23a by means of an attachment stud 230.

FIG. 3 shows the screw 6a which fits into the threaded hole 65 and by means of which the magnetic head 6 is attached to an intermediate fixed plate 35.

This figure also shows the jack 4a which cooperates with the plug 4.

A swinging lever 36 serves to hold the driving plate still. This lever terminates at one end in a horizontal arm 36a and at its other end in a vertical portion 36b, which is rotatably mounted to turn about a shaft 360 mounted on the fixed intermediate plate 35, when the control member 3 is displaced.

A spring, not shown on FIG. 3, tends to hold the lever 36 in locking position.

The vertical part 36b moves during this pivotal movement into an opening 36s, shown shaded in FIG. 3.

The roller 22a, which drives the shaft 19a of the device 12 for maintaining tension on the tape, is pressed against the plate 33 by means of a spring 33a visible 011 FIG. 4 and mounted inside the post 33 in which the end of said shaft 19a moves.

FIGS. 3 and 4 also show that the part of the tape between the guide spindle 11 and the guide spindle 11a (which engages the external part 18 of the magnetic tape) moves between two pulleys 12a and 121), the lower pulley 1211 being driven by a shaft 19a of the same diameter as the said shafts 19.

By reason of the peripheral speed of the pulley wheel 12a at the level of the groove therein which receives the lower part of the magnetic tape, the linear speed of which pulley wheel is greater than that of the shafts 19a, be cause of its greater diameter, this part of the tape tends to move at a linear speed greater than the average speed at which the tape unwinds from the driving spindle.

In this manner the strip remains taut between the driving spindle 1t) and the first guiding spindle 11.

As has been indicated, the friction inherent in the fact that the tape cannot follow the impulses imparted to it by the pulley 12a is much less than that in the previous embodiment in which the diameters of the radial driving rollers were calculated to drive each turn at a linear speed greater than the speed at which the tape is driven by the driving spindle.

FIGS. 1 and 2 also show that the cover 1 is positioned with respect to the peripheral part 39 of the device by means of three flat projections 40, which permit the raised part 9 to be located over the device 12 and the screw 41 opposite an eccentric hole 42 in the cover so that it can engage the threaded hole 41a in the top of the driving spindle 10.

FIG. 3 shows that the member 3 is provided with a square hole 43 which receives a shaft 43a of the same shape, fixed to the plate 32b.

In this manner, turning of the member 3 turns plate 3211 as well and, by means of the spring 32, urges the pressure member 23 against the spindle 10.

The control member 3 carries on its lower side a pin 44, the movement of which acts through a cranked lever 45 to control the swinging of the brake member 31 into and out of engagement with the catch 8 on the cover 1.

In like manner, the intermediate plate 321) carries a downwardly projecting pin 46 which controls the swinging of the lever 36 with respect to the opening 36e by acting on the horizontal portion 36a of this lever.

Referring now to FIGURE 4, reference numeral 47 designates the outer part of the driving spindle 10 which is made of a plastic material encircling a metallic member 47a, supported on a ball bearing which permits the parts 47 and 47a of the spindle to rotate with respect to a fixed pivot 49. Reference numeral 50 designates the upper part of the plate 35 which is fixed to said pivot. The cover 1 of the cartridge is attached by means of the said screw 41.

A supporting plate 51, which may be turned by a turntable and centered by the shaft 52 of the said turntable, drives the driving plate 33 and a ring of elastic material 33a fixed thereto, which in turn drives rollers 22 and 22a.

The driving plate 33 carries pins 53 which serve as locking means in cooperation with the vertical part 36b of the latching lever 36, the two positions of which permit or prevent the rotation of the driving plate 33 with respect to the plate 35.

Movement of the member 3 swings the release lever 36 and compresses a spring (not shown) which bears at one end against the pin 36f mounted on the upper surface of the lever 36, and at the other end against one of the posts 37. This spring is rotatable about a shaft (not shown) which is fixed to the plate 35.

The lever 36 is actuated by a pin 46 which projects downwardly from the lower surface of the plate 325.

The roll of tape is held stationary by an appropriate brake member 31 biassed by a spring 55 fixed to a sta tionary plate 39.

The driving plate 33 has a peripheral edge 33]; which bears at one point on the disassembling arm 34. This arm permits the spindle to be rapidly removed when the cover is taken off.

FIG. 5 shows the arrangement of a cartridge used with a recording tape on which a recording is being made by means of another magnetic tape recorder 57. The part of the magnetic tape 18 leaving the device 12 passes through an opening in the cover 1 at the level of the guide spindle Illa, before reaching the driving means for the device 57. The tape then returns through the same opening from the other side of the guide roller 11a and then rejoins the section connected to the periphery of the roll of tape.

It will now be understood that the rotation of the member 3 accessible through tl e window 2 in the cover, permits the introduction of the plug 4 into the jack 4a, and releases the safety devices, that is to say, the latch means preventing the rotation of the driving plate 33 when the part Sub is positioned in the space between the two pins 53, and the lock efiectuated by the brake men ber 31 and the catch 8 inside the cover, and which is brought about when the cranked lever 45 is actuated by the pin 46 on the plate 32b against the resistance of the spring 55.

The movement of the member 3 also urges the pressure member 23 against the tape passing around the outer part 47 of the spindle.

The radial driving rollers are shown to be inclined with respect to the horizontal, but this characteristic is not essential, and they may also be positioned horizontally.

The number of driving rollers has also been greatly increased inv order to give better support to the roll of tape, bearing in mind that it may be larger.

The apparatus has the advantage of permitting an instantaneous removal of the driving spindle, and of comprising no belt susceptible to stretching, the endless tape being driven by means of a pressure roller which insures a very reliable operation.

The apparatus also comprises an intermediate plate 51 which permits the driving plate 33 to be raised with respect to the level of the lower fixed portion 39 of the cartridge, which facilitates the driving of the rotating plate fixed to the driving spindle by means of the turntable of a conventional record player.

The apparatus may be equipped with a magnetic head of the single track type, or one for a two-faced tape hav- 6 ing a double track, with a Melius ring, or even with a head for any number of tracks, and especially with a stereophonic head which may be connected to the amplifier of the apparatus by a suitable cord.

The head may be fixed to the stationary part of the cartridge and it may be provided with a slide which permits the shifting of the reproducing or recording portions so as to pass from one track to another.

In the embodiment of FIG. 6 the radial non-driving roller has been designated by the reference numeral 20a, and the three braking rollers by reference numeral 21a.

The four rollers of normal diameter have been assigned reference numeral 19, and the four accelerating rollers reference numerals 58 and 59, the latter serving as the shaft of the device 12 which exerts tension on the tape.

The hisector 60 of the angular zone occupied by the four radial rollers of normal diameter 19 has been indicated in broken lines.

This bisector 6t is parallel to the portion of the tape 17 leaving the pin 11a at the periphery of the roll of tape.

It would of course be possible to employ a number of rollers of normal diameter slightly different from the number of braking and accelerating rollers (the latter numbers being referably equal), by suitably adjusting the diametral differences between the various types of rollers, so that the average peripheral speeds of the different rollers are substantially equal and not less than the speed at which the roll of tape is driven by the driving spindle.

When an odd number of braking rollers are used, the non-driving roller 2th: is preferably positioned within the angular zone occupied by the braking rollers.

It will be appreciated that the embodiments described may be modified as to detail, and various elements thereof replaced by their mechanical equivalents without thereby departing from the spirit of the invention.

What is claimed is:

1. In an improved tapeholding cartridge provided with means for driving an endless roll of tape rotatably mounted therein, said cartridge being of the type comprising a central plate adapted to be mounted on and driven by the turntable of a conventional record player, a central spindle driven by said plate, and connected thereto to drive the inner portion of said roll of tape, a stationary roller carrier in which said plate is rotatably inserted, and a plurality of radially projecting cylindrical rollers rotatably mounted in said carrier and driven by rotation of said central plate relative to said stationary roller carrier, said rollers being adapted to carry said roll of tape,

the improvement which comprises means near the periph-.

cry of said cartridge for driving a peripheral portion of said roll of tape more rapidly than its inner portion is driven by said spindle, and means driven by said central plate for driving some of said rollers at a peripheral speed substantially equal to that at which said tape is driven by said spindle and others of said radially disposed rollers at a slower peripheral speed.

2. A cartridge as claimed in claim 1 comprising peripheral guide means carried by said roller carrier for guiding said tape as it passes most directly between said peripheral driving means and said spindle, and in which a group of these radially disposed rollers having a lower peripheral speed are located in a specific sector and a non-driving roller is positioned within that sector, said non-driving roller extending in a direction substantially perpendicular to a line between said peripheral guide means and said driving spindle.

3. A cartridge as claimed in claim 2 comprising means for driving some of said radial rollers at a peripheral speed greater than that at which said tape is driven positioned in a sector diametrically opposite the most slowly driven rollers, in which the common bisector of the two sectors is substantially perpendicular to the direction in which the tape passes between said peripheral driving means and the outermost turn of said roll, and in which the arithmetic means of the peripheral speeds of the different radial rollers is at least substantially equal to the theoretical speed at which said tape is driven by said spindle.

4. A cartridge as claimed in claim 1 in which all of said rollers are driven at the same angular speed, and the peripheral driving means comprises one of said radial rollers, which terminates at the periphery of the roller carrier in a grooved pulley wheel positioned to engage the lower face of the tape, the diameter of the grooved portion of said pulley wheel being greater than that of any of said axially disposed rollers, said peripheral driving means also comprising a second pulley wheel positioned to engage the opposite face of said tape.

5. A cartridge as claimed in claim 1 comprising latch means for preventing rotation of said central plate, pressure means for pressing said tape against said spindle, means for connecting said cartridge to a power source, and a single control member the movement of which simultaneously permits access to said connecting means, moves said pressure means toward said spindle, and releases said central plate from said latch means.

6. A cartridge as claimed in claim 1 comprising means for driving some of said radial rollers at a greater peripheral speed than that at which said tape is driven and are positioned in a sector diametrically opposite a sector in which those driven at a slower peripheral speed are positioned, the common bisector of these two sectors being substantially perpendicular to the direction in which the tape passes between said peripheral driving means and the outermost turn of said roll, and in which the arithmetic mean of the peripheral speeds of the radial rollers is substantially equal to the theoretical speed at which said tape is driven by said spindle.

7. In an improved tape-holding cartridge provided with means for driving an endless roll of tape rotatably mounted therein, said cartridge being of the type comprising a central plate adapted to be mounted on and driven by the turntable of a conventional record player, a central spindle driven by said plate, and connected thereto to drive the inner portion of said roll of tape, a stationary roller carrier in which said plate is rotatably inserted, and a plurality of radially projecting cylindrical rollers rotatably mounted in said carrier and driven by rotation of said central plate relative to said stationary roller carrier, said rollers being adapted to carry said roll of tape, the improvement which comprises means near the periphery of said cartridge for driving a peripheral portion of said roll of tape more rapidly than its inner portion is driven by said spindle, and individual cylindrical means mounted near the inner end of each radially disposed roller to drive said roller, said cylindrical means being in peripheral engagement with and driven by said central plate at a speed such that at least some of said rollers are driven at a peripheral speed approximately the same as that at which said tape is driven, the ratio between the diameter of at least one of said radially disposed rollers and that of the cylindrical means near its end differing from the ratio between the diameters of others of said rollers and the cylindrical means near their respective ends, so that said at least one roller is driven at a peripheral speed diiferent from the peripheral speeds of said other rollers.

8. In an improved tape-holding cartridge provided with means for driving an endless roll of tape rotatably mounted therein, said cartridge being of the type comprising a central plate adapted to be mounted on and driven by the turntable of a conventional record player, a central spindle driven by said plate, and connected thereto to drive the inner portion of said roll of tape, a stationary roller carrier in which said plate is rotatably inserted, and a plurality of radially projecting cylindrical rollers rotatably mounted in said carrier, said rollers being adapted to carry said roll of tape, the improvement which comprises means for driving some of said rollers at a peripheral speed substantially equal to that at which said tape is driven by said spindle, and for driving others of said radially disposed rollers at a slower peripheral speed, and means near the periphery of said cartridge which drive a peripheral portion of said roll of tape more rapidly than its inner portion is driven by said spindle.

9. In an improved tape-holding cartridge provided with means for driving an endless roll of tape rotatably mounted therein, said cartridge being of the type comprising a central plate adapted to be mounted on and driven by the turntable of a conventional record player, a central spindle driven by said plate, and connected thereto to drive the inner portion of said roll of tape, a stationary roller carrier in which said plate is rotatably inserted, and a plurality of radially projecting cylindrical rollers rotatably mounted in said carrier and driven by rotation of said central plate relative to said stationary roller carrier, said rollers being adapted to carry said roll of tape, the improvement which comprises means near the periphery of said cartridge for driving a peripheral portion of said roll of tape more rapidly than its inner portion is driven by said spindle, and means driven by said central plate for driving said rollers at a substantially uniform angular speed, some of said rollers having larger diameters than others so as to be thereby driven at greater peripheral speeds, at least some of said rollers having diameters such as to be driven at a peripheral speed substantially equal to that at which said tape is driven.

References Cited in the file of this patent UNITED STATES PATENTS 2,037,601 Shirlow et al Apr. 14, 1936 2,363,403 De Napoli Nov. 21, 1944 2,918,536 Appert et al Dec. 22, 1959

Claims (1)

1. IN AN IMPROVE TAPE-HOLDING CARTRIDGE PROVIDED WITH MEANS FOR DRIVING AN ENDLESS ROLL OF TAPE ROTATABLY MOUNTED THEREIN, SAID CARTRIDGE BEING OF THE TYPE COMPRISING A CENTRAL PLATE ADAPTED TO BE MOUNTED ON AND DRIVEN BY THE TURNTABLE OF A CONVENTIONAL RECORD PLAYER, A CENTRAL SPINDLE DRIVEN BY SAID PLATE, AND CONNECTED THERETO TO DRIVE THE INNER PORTION OF SAID ROLL OF TAPE, A STATION ARY ROLLER CARRIER IN WHICH SAID PLATE IS ROTATABLY INSERTED, AND A PLURALITY OF RADIALLY PROJECTING CYLINDRICAL ROLLERS ROTATABLY MOUNTED IN SAID CARRIER AND DRIVEN BY ROTATION OF SAID CENTRAL PLATE RELATIVE TO SAID STATIONARY ROLLER CARRIER, SAID ROLLERS BEING ADAPTED TO CARRY SAID ROLL OF TAPE, THE IMPROVEMENT WHICH COMPRISES MEANS NEAR THE PERIPHERY OF SAID CARTRIDGE FOR DRIVING A PERIPHERAL PORTION OF SAID ROLL OF TAPE MORE RAPIDLY THAN ITS INNER PORTION IS DRIVEN BY SAID SPINDLE, AND MEANS DRIVEN BY SAID CENTRAL PLATE FOR DRIVING SOME OF SAID ROLLERS AT A PERIPHERAL SPEED SUBSTANTIALLY EQUAL TO THAT AT WHICH SAID TAPE IS DRIVEN BY SAID SPINDLE AND OTHERS OF SAID RADIALLY DISPOSED ROLLERS AT A SLOWER PERIPHERAL SPEED.

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