US3075679A

US3075679A - Web feeding device

Info

Publication number: US3075679A
Application number: US49562A
Authority: US
Inventors: Walter G Wadey
Original assignee: Sperry Rand Corp
Current assignee: Sperry Corp
Priority date: 1960-08-15
Filing date: 1960-08-15
Publication date: 1963-01-29
Anticipated expiration: 1980-01-29
Also published as: CH404328A; GB960646A; NL268096A

Description

Jan. 29, 1963 w. G. WADEY 3,

WEB FEEDING DEVICE Filed Aug. 15, 1960 l7' (SIGNAL /IS -15 sou/m5 SOURCE POWER SOURCE 4 I l7 l5 |5 L INVENTOR WALTER 6 WADEY ATTORNEY 3,tl75',679 WEE FEEDHNG DEVIQE Walter I Wadey, Wynnewood, Pm, assignor to hperry Corporation, New llorlr, N.Y., a corporation of Delaware Filed Aug. 15, 196d, Ser. No. 49,562 tilaiins. (til. ZZd-ltltl} The present invention relates to a means for moving tapes, sheets, or similar web-like materials. More particularly, the present invention provides a fluid operated means for controlling the rate of acceleration of weblilte materials to obtain variable but controlled velocities of the web.

Web feeding devices employing pneumatic forces to move the web are well known in the art. One device of the prior art employs pneumatic pressures to control the moving and stopping of the web material. In that dev ce, the tape is fed between a hollow continuously rotating capstan and a stationary casing. The web is set in motion by simultaneously applying pneumatic pressure to the casing and suction to the capstan in order to draw the web into frictional contact with the surface of the capstan. The web is stopped by acluating a valve which applies pressure to the capstan and suction to the casing in 0-d:r to draw the web materIal to the stationary casing. The speed of the web is controlled by an eiectromagnetic device which actuates a valve. Thus, this device, which is typical of the prior art, requires electrical and magnetic devices as well as find devices for controlling the speed of the web. in addition, devices of this type do not provfde a steady or even app'ication of force to the web. This results in excessive wear of the web material and the mechanism which drives it.

Therefore, it is an object of this invention to provide a web feeding mechanism in which wear of the web and and drive mechanism is reduced by providing a more evenly controlled motion of the web, this improvement being accomplished through the use of a fluid operated system.

More particularly, it is an object of the present invention to provide a fluid mechanism which is responsive to fluid signals for controlling the speed and the rate of acceleration of the web material, saidfluid mechanism being more economical, faster in response, and more even in application of fluid fcrees than previous devices. These advantages are obtained through the use of a fluid amplIfizr, the output of which is connected to the inte rior of a hollow web feeding device for the purpose of varying the fluid pressure at the surface of the feeding device.

Other and further objects will become apparent upon reading the following specification together with the accompanying drawings in which:

FIGURE 1 is a perspective view of one embodiment of the invention;

FIGURE 2 is a top view of the embodiment of FIG- URE 1;

FIGURE 3 depicts one manner in which the present invention may be utilized to move a web-like material in either one of two directions; and

FIGURE 4- is a sectional view of a fluid amplifier suitable for use in the present invention.

Referring to FIGURE 1, the principles of the invention are illustrated by a continuously rotating drum or web carrier 1 which is driven by shaft 3 from any conventional drive means. The web carrier is hollow and its cy'iadrical surface is made of a permeable maerial as indicated by the holes 5. The interior of the drum is connected by means of a ho low shaft 7, a housing 9, and a fluid conduit 11 to the output of a fluid amplifier 13. A source of fluid power (not shown) supplies a stout dflfifilfl Patented Jan. 29, 1963 2 power stream input to the amplifier 13 over the conduit 19. Left and right control jets of the fluid ampliher are connected by means of conduits l5- and 17 to suitable sources of fluid control signals l5 and 17 and are arranged to deflect the power stream to the

amplifier output conduits

11 or 21 in a manner to be described.

FEGURE 4 is a cross sectional view of a pure fluid amplifier suitable for use in the present invention. The terms fluid operated amplifier and pure fluid amplifier are sometimes used to distinguish between those fluid amplifiers which have movable mechanical parts and those fluid amplifiers which have no moving parts other than the working fluid. As used herein, the term fluid amplifier refers to pure fluid amplifiers. The amplifier comprises a substantially solid body of any su'table material such as metal or plastic. A power signal issues from power source in the form of a fluid stream and is applied over the conduit to the duct Ell. in the absence of control signals the power stream will pass through the orifice 3? and strike the body The ducts are symmetrically arranged and upon striking the body 37 the power stream will divide substantially equally between the

ducts

27 and 2% and appear as signals of substantially equal pressure in the conduits 11 and if a fluid control signal is applied over the conduit 17 to the duct 23, this signal will pass through an orifice and strike the power storm issuing from the orifice thus directing or deflecting the power stream to the right output duct 27. This causes an increase in pressure in the output duct 27 and a corresponding decrease in the pressure in the output duct 29. On the oiher hand, if a fluid control signal is applied over the conduit 15 to the duct 25 the control stream will pass through an orifice and deflect the power stream issuing from the orifice 39 t0 the left. Deflection of the power stream to the left of its normal position causes an increase in pressure in the duct 29 and a corresponding decrease in pressure in the duct 27". if control si nals are applied simultaneously to the ducts .5 and 25, these signals will appear as jet streams at both control orifices and tend to counteract each other. In this event, the fluid control signal having the greater amplitude will cause a deflection of the power stream, this deflection being dependent upon the difference in magnitude between the two control signals. Thus, control signals may be applied over conduit is, conduit 17, or both conduits simultaneously and the result will be an output signal in one of the ducts Z7 and 29 and an output signal of the opposite phase in the other output duct.

Referring again to FIGURE 1, the control signals applied to conduits l5 and El? control the power stream applied over the conduit 19' to thereby cause the immediate production of accurately controlled fluid pressures in the conduit ll. These fluid pressures are applied through the housing 9 and the hollow shaft 7 to the interior of the drum and, because of the permeability of the drum surface, cause variations in the fluid pressure at the surface of the drum. If the fluid pressure at the surface of the drum is increased, friction between the drum surface and the surface of the web Ed is decreased and the speed of the web is reduced. On the other hand, if the fluid pres sure at the surface of the drum is decreased the friction between the surfaces of the drum and the Web is increased thercby increasing the rate of movement of the web.

FIGURE 2 illustrates one manner in which the drum may be driven and fluid pressure applied to the interior Where the shaft it enters the housing. The conduit 11 connects with the interior of the housing and fluid pressure signals appearing on the conduit pass through the housing and the hollow shaft 7 to the interior of the drum. The hollow shaft is mounted in fixed relation to the housing 9 and is provided with a further fluidseal 10 at the point where it enters the rotating drum.

FIGURE 3 shows how the present invention may be utilized for controlling the direction and rate of movement of a tape such as that used in computing devices.- Two reels 22 and 2d are provided for winding and un-- winding the tape 3t These reels are adapted by conventional means to be driven in either direction depending upon the direction of movement of the tape. Idler capstans 26 and 23 serve as guides to maintain the tape in proper alignment during its movement. Tape drive drums 1 and la are connected by means such as that shown in FIGURES 1 and 2 to the two outputs of a fluid amplifier such as that shown in FIGURE 4. The drums are continuously driven in opposite directions as indicated by the arrows.

Assume that it is desired to move the tape from left to right. A control signal is applied to the conduit and as described with reference to FIGURE 3, deflects the power stream 19 to the left causing an increase in fluid pressure in the conduit 11 and a corresponding decrease in the fluid presure in the conduit 21. The increase of fluid presure in conduit 11 causes a corresponding increase in the surface presure at the surface of durm 1 and forces the tape away from the drum. At the same time, the decrease in pressure in the conduit 21 is transmitted to the surface of drum 1a. The decrease in pressure at the surface of drum 1a permits greater surface friction between the tape and this drum surface thus moving the tape to the right.

On the other hand if a control signal is applied to the condiut 17 the power stream will be deflected to the right causing an increase in pressure in the conduit 21 and a corresponding decrease in pressure in conduit 11. In this instance the tape will be forced away from the surface of drum 1a but will be permitted to come into frictional engagement with the surface of drum 1. This moves the tape from right to left.

It is obvious therefore that the fluid amplifier 15 quickly and accurately controls the acceleration and speed of the tape 30 with the speed of the tape being determined by the magnitude of the signals applied to the conduits 15 7 and 17.

If the fluid system of the present invention is sealed (except for the permeable surface of the drum or web carrier) the fluid system may be operated at negative as well as positive pressures with respect to the outside environment. In thiscase, suction may be applied to the interior of the drum to draw the tape or web material into engagement with the surface of the drum thereby causing movement of the web. Subsequent application of a less negative pressure or a positive pressure to the interior of the drum will reduce the surface tension thereby reducing the rate of movement of the web.

Although theembodiment of the invention which has been shown utilizes a continuously rotating drum as the web carrier, it is obvious that the web carrier may have other shapes and suitable motions depending upon the application of the invention to a particular use. In like manner, the present invention is suitable for use in devices which move web-like materials of different shapes and sizes, and is not limited in its application to the movement of tapes, this form being selected merely for the purpose of illustrating the utility of the invention.

While the novel features of the invention as applied to a preferred embodiment have been shown and described, it will be understood that various omissions and substitutions in the form and detail of the device illustrated, and changes in its operation may be made by those skilled in the art without departing from the spirit of the inven tion.

I claim:

1. A web feeding device comprising: means for producing a fluid power stream; web feeding means having a fluid permeable web driving surface; and means for varying the pressure at said web driving surface over a predetermined range of values to thereby drive said web at any one of several desired speeds by varying the frictional driving engagement between said web and said surface, said pressure varying means comprising means for producing a fluid stream having a momentum proportional to the desired web speed, means for applying said fluid stream to said power stream to selectively dezflect said power stream, and fluidconveying means for receiving and conveying to said permeable driving surface a portion of said power stream dependent upon the amount of deflection of said power stream with respect to said receiving means by said fluid stream.

2. A web feeding device comprising: means for producing a fluid power stream; web feedingrneans having a fluid permeable web driving surface; and means for varying the pressure at said web driving surface over a predetermined range of values to thereby drive said web at any one of several desired speeds by varying the frictional driving engagement between said web and said surface, said pressure varying means comprising first and 'second fluid ducts having openings for receiving said power stream, -means for exerting against said power stream a variable fluid pressure proportional to a desired webspeed to deflect and thereby vary the proportions of :said power stream received by said fluid ducts, at least one of said fluid ducts communicating with said permeable driving surface to vary the fluid pressure thereat in response to said variable fluid pressure.

3. Aweb feeding device as claimed in claim 2 wherein said web feeding means comprises a rotatable drum and said driving surface comprises the cylindrical surface of said drum.

4. A web feeding device comprising: means for producing a fluid power stream; first and second web driving means each having a fluid permeable Web driving surface; and means for varying the pressures at said web driving surfaces over a predetermined range of values to thereby drive said web at any one of several desired speeds by varying the frictional driving engagement between said web and said surfaces, said pressure varying means comprising first and second fluid ducts having openings for receiving said power stream, means for ex- .erting against said power stream a variable fluid pressure proportional to a desired web speed to deflect and there by vary the proportions of said power stream received by said fluid ducts; and fluid conveying means connecting Said first and second fluid ducts to said first and second permeable driving surfaces, respectively, to vary the fluid pressures thereat in response to said variable fluid pressure.

5. A web feeding device as claimed in claim 4 wherein said first and second web driving means comprise first and second rotatable drums, said permeable driving surfaces comprising the cylindrical surfaces of said drums, and means for rotating said drums in opposite directions.

References Cited in the file of this patent UNITED STATES PATENTS Harris Dec. 20, 1955 Pendleton Dec. 36, 1958 OTHER REFERENCES

Claims

1. A WEB FEEDING DEVICE COMPRISING: MEANS FOR PRODUCING A FLUID POWER STREAM; WEB FEEDING MEANS HAVING A FLUID PERMEABLE WEB DRIVING SURFACE; AND MEANS FOR VARYING THE PRESSURE AT SAID WEB DRIVING SURFACE OVER A PREDETERMINED RANGE OF VALUES TO THEREBY DRIVE SAID WEB AT ANY ONE OF SEVERAL DESIRED SPEEDS BY VARYING THE FRICTIONAL DRIVING ENGAGEMENT BETWEEN SAID WEB AND SAID SURFACE, SAID PRESSURE VARYING MEANS COMPRISING MEANS FOR PRODUCING A FLUID STREAM HAVING A MOMENTUM PROPORTIONAL TO THE DESIRED WEB SPEED, MEANS FOR APPLYING SAID FLUID STREAM TO SAID POWER STREAM TO SELECTIVELY DEFLECT SAID POWER STREAM, AND FLUID CONVEYING MEANS FOR RECEIVING AND CONVEYING TO SAID PERMEABLE DRIVING SURFACE A PORTION OF SAID POWER STREAM DEPENDENT UPON THE AMOUNT OF DEFLECTION OF SAID POWER STREAM WITH RESPECT TO SAID RECEIVING MEANS BY SAID FLUID STREAM.