US2181049A - Hydraulic drive - Google Patents

Description

Nov. 21, 1939.

J K. DOUGLAS HYDRAULIC DRIVE Filed Jan. 19, 1939 2 Sheets-Sheet 1 INVENTOR. JAMES K.-Duu13| As W ATTORNEY.

K'IDOUGLAS HYDRAULIC DRIVE Filed Jan. 19, 1939 2 Sheets-Sheet 2 INVENTOR JAMES K DUUGLAS Y .I W

ATTORNEY:

Patented .21 1939 PATENT HYDRAULIC DRIVE James K. Douglas, Shorewood, Wis., assignor to The Oilgear Company, Milwaukee, Wla, a corporation of Wisconsin Application January 19, 1939, Serial No. 251,675

20 Claims.

, This invention relates to hydraulic drives of the type employed to drive machines which unwind paper or other sheet material from parent rolls and wind it into new rolls.

Such machines require that the parent rolls be gradually accelerated as they decrease in diameter, that the rewound rolls be gradually decelerated as they increase in diameter, that the parent rolls resist the unwinding of the material therefrom in order to maintain tension upon the material between the parent rolls and the rewound rolls, and that the tension on the material be controlled in order to control the density of the rewound rolls.

While the parent roll resists rotation'in order to maintain tension upon the material during the trewinding thereof, it is desirable that that part of 'the drive connected to the parent roll be able at times to drive or tend to drive the parent roll in order that the material may be readily threaded through the machine and in. order to compensate in part for the friction 0f the parent roll and its drive during certain parts of the rewinding taper into strips and then rewinds the strips into.

individual rolls.

Paper as manufactured ordinarily contains defects and such defects are removed by stopping the machine, severing the strips at each side of the defect, then pasting the severed ends together and then continuing the winding of the strips. will be removed from one strip than from 'another strip with the result that the rewound rolls do not increase in diameter at the same rate. It is therefore desirable that therewound rolls be driven simultaneously but independently of each other.

The present invention has as an object to provide a drive in which that part of the drive connected to the parent roll will cause or permit material to be unwound from the parent roll at a predetermined rate regardless of the diameter of the parent roll or the pull on the material.

Another object is to provide a machine, having a plurality of winding shafts for winding strips of sheet material thereon, with a drive which will rotate the shafts simultaneously but independently of each other and control the tension on each strip independently of the tension. on another strip. ,Another object is to provide amachine, having A greater amount of defective material an unwind shaft for supporting a parent roll of sheet material, a slitter for cutting the sheet ma t'erial into a plurality of strips and a rewind shaft for winding each strip" into a roll, with a drive having means for driving the slitter at a prede- 6 termined speed, means for causing or permitting the material to be unwound from the parent roll at a speed proportional to the slitter speed, means for "driving the rewind shafts simultaneously but independentlyof each other and means for con- 10 trolling the pull exerted by each rewind shaft upon the strip connected thereto independently of the pull exerted by another rewind shaft upon the strip connected thereto. 5

Another object is to provide a machine of the 15 above character with a drive which is adjustable to vary the speed thereof through a wide range.

Other objects and advantages will appear from the following description of a hydraulic drive embodying the invention and shown schematically go in the accompanying drawings in which the views are as follows: v

Fig. 1 is a diagrammatic view showing the invention embodied in a drive for-a slitting machine having a shaft to support a parent roll of paper, 35 a slitter for cutting the paper into a plurality of strips and a plurality of rewind shafts for drawing the paper from the parent roll through the slitter and winding the strips into individual rolls, the parts being shown in the positions occupied 30 whenthe machine is idle.

Fig. 2 is in part a section througha-pump, which supplies liquid for energizing the hydraulic motors that drive the several parts of the ma-- chine, and in part a diagram of a portion of the 35 hydraulic circuit.

Fig.3 is a detail view showing on a larger scale. the pump control valve shown in Fig.2, the valve beingjshown in the position occupied when the pump is at .zero stroke.

Fig. 4 is a section taken on the line H of, Fig. 3.

. Fig. 5 is a view showing a. bypass and brake valve with its valve member in position to cause a hydraulic motor to drive a winding shaft.

Fig. 6' is a view similar to Fig. 5 but showing the valve member in position to cause a brake load to be applied to the hydraulic motor.

, Fig. 7 is a viewshowing another valve with its valve member-in position to increase the drop in pressure across a hydrodynamic machine which is connected to the shaft that supports the parent roll of paper. Y For the purpose of illustration, the invention has been shown embodied in a drive for aslitting machine of-which, since it per se forms no part of the present invention, only as much has been shownoas is necessary for an explanation of the functions of the drive.

The slitting machine includes an unwind shaft I on which a roll 2 of paper 3 is fixed to rotate therewith, a slitter shown as consisting of a backing roll 4 and a plurality of rotary knives 5 coacting with roll 4 to trim the edges of paper 3 and to cut it into a plurality of strips, and a plurality of winding shafts 6 which correspond in number to the number of strips into which paper Us to be cut and upon which the strips are to be wound into. finished rolls 1. As shown, the machine includes two winding shafts G and 5 and slitter 4-5 is adapted to cut paper 3 into two strips 3 and 3 which are wound, respectively, upon shafts 6 and 6' into rolls I and l Unwind shaft l is connected by a drive 3 to a hydrodynamic machine 9 which functions to permit paper 3 to be unwound from roll 2 at a uni-- form rate, as will presently be explained, and

which has two opposed servo-motors l0 and II for moving its slide block l2 in one direction-or the other to adjust its displacement and thereby compensate for the decrease in the diameter of roll 2 as paper 3 is unwound therefrom.

Paper ordinarily has defects therein which are removed by severingthe strip at each side of'the defect, discarding the portion containing the defect and'then pasting together the adjacent ends of the other two portions of the strip. It is ordinarily necessary to cut a greater amount ,of defective material from one strip than from another strip with the result that the rolls of thewinding shafts do not increase in diameter at the same rate.

v The finished rolls should be of the same diameter. Therefore, when the roll on one winding shaft reaches the correct size, the machine 'is stopped, the strip severed from the finished roll which is then removed from its shaft, anew core is fixed upon that shaft, the severed end of the strip is fastened to the core and the machine is operated until the roll on the other shaft reaches the correct size.

It is therefore necessary that the winding shafts be driven simultaneously but independentby hydraulic motors l5 and I5 which are connected in parallel with each other and energized by liquid supplied by a pump l3 driven by a prime mover I! through a drive l3.

In order that the liquid supplied by pump l3 may be equally divided between winder motors l5 and I5", slitter 4-5is connected by two drives l3' and l3 to two'hydraulic motors 20' and 20" which are thus mechanically synchronized, both slitter motors are connected to pump IS in parallel with each other, and each slitter motcr has a winder motor connected in series therewith.

It is to be understood that, if slitter 4-5 simply trimmed the edges of paper 3 so that only one winding shaft would be required, the windin shaft and the slitter wouldeach be driven by a motor of suitable size and the two motors would be connected to pump IS in series with each other. Also, if slitter 45 were adapted to slit paper 3 into more than two strips, a winding shaft would be provided for each strip, each winding shaft would be driven by a separate motor, the slitters would be driven by as many motors as there were winder motors, each winder motor would b 9 nected in series with a slitter motor and all of the slitter motors would be connected to pump "5 in parallel with each other.

Any suitable type of pump may be employed but, for the purpose of illustration, pump l5 has been shown as being of the rolling piston type which is fully illustrated and described in Patent No. 2,074,068. It is deemed suflicient to state herein that pump it has its pistons and cylinders arranged radially in a cylinder barrel 22 which rotates upon a stationary valve shaft or pintle 23 having formed therein ports and passages through which liquid flows to and from cylinders, that the outer ends of the pistons re-act against an annular reaction surface 24 which in practice is formed ina separate rotatable thrust member carried by a slide block 25 but which has been shown as being formed in slide block 25, that pump IE will discharge liquid in a direction and at a rate depending upon the direction and the distance the axis of reaction surface 24 is offset from the axis of cylinder barrel 22, and that slide block 25 is arranged in a casing 25 which permits it to be moved transversely of pintle 23 but prevents it from moving in any other direction.

When cylinder barrel 22 is rotated in the direction of the arrow and slide block 25 is offset towards the right as viewed in Fig. 2, pump IE will deliver liquid into a channel 21, which is connected to the passages in pintle 23 on one side of the centerline thereof, and liquid will be returned to pump I 8 through'a channel 23 which is connected to the passages in pintle 23 on the other side 'of its centerline, pump l6 being protected from excessive pressures by a high pressure relief valve 29 which is connected to its outlet.

' If the liquid returned to pump l 6 through channel 28 is insuflicient to supply pump I 6, liquid may be drawn from a reservoir 30 by pump l5 through a foot valve 3| which is connected to its inlet and consists of a reliefvalve which discharges into reservoir 30 and a check valve which permits liquid to be drawn freely from reservoir 30 by pump IE but prevents liquid being discharged into reservoir 30 except through the relief valve.

Slide block 25 is adapted to be moved toward the left by a piston 32 which abuts or is fixed to the right side of slide block 25 and fitted in a cylinder 33 carried by casing 25, and it is adapted to be moved toward the right by a piston 34 which abuts or is fixed to the left side of slide block 25 and fittedin a cylinder 35 carried by casing 26. Piston 34 has a considerably larger effective pressure area than piston 32 in order that it may move slide block 25 toward the right when cylinders 33 and 35 are simultaneously supplied with liquid at the same pressure.

Liquid for operating servo-motors 3233 and 34-45 and for other purposes is supplied by a gear pump 36 which has been shown separated from pump I6 butwhi'ch iri practice'is arranged in the casing of pump l6 and driven in unison therewith according to the usual practice.

Gear pump 35 draws liquid from reservoir 30 and discharges it intoone end of a channel 31 the other end of which is connected to the inlet of a resistance valve 38 so-that gear pump 36 maintains pressure in channel 31 at all times.

Cylinder 33 is connected to channel 31 by a channel 39 so that slideblock 25 is constantly urged toward the left by a gear pump liquid acting upon piston 32.

The delivery of liquid to cylinder 35- is controlled by a rotary follow-up valve 42 which is journaled in coaxial bores 43 and 44 formed, respectivefly, in piston34 and in the end wall or head 45 of cylinder 35 as best shown in Fig. 3.

Valve 42 has a duct 45 formed therein with its outer end in constant communication with an annular port 41 which is formed in the wall of bore 44 and connected by a channel 48 to channel 31. The inner end of duct 46 opens into a spiral groove 49 which is formed in the peripheral surface of valve 42 and normally closed by the wall of bore 43. The arrangement is such that gear pump pressure prevails in groove 49 at all times. A second spiral groove 50 is formed in the peripheral surface of valve 42 a short distance from groove 49 and opensinto the right end of bore 43 from which a drain channel 54 extends through the hub of piston 35.

Grooves 49 and 50 are normally arranged upon opposite sides of-a port 52 which extends through the hub of piston 34 into communication with the interior of cylinder 35 and is of a width equal to the distance between grooves 49 and 50 so that rotation of valve 42 in one direction or the other will open one .or the other of grooves 49 and 50 to port 52. Valve 42 is adapted to be rotated by means of a lever 53 which is' fixed upon the outer end thereof and has rotary movement through a given angular distance, for instance 50, from the central or neutral position shown in Fig. 4, the movement of lever 53 in each direction being ordinarily limited by stops not shown.

When lever 53 is moved toward the right or in a clockwise direction in respect to Fig. 4, groove 49 will open to port 52-and permit liquid from gear'pump 36 to flow through channels 31 and 48, port 41, duct 46, 'groove 49 and port 52 into cylinder 35. The liquid entering cylinder 35 will move piston 34 and slide block 25 toward the right for the reason that piston 34 has a considerably greater pressure area than'piston 32 which is also subjected to gear pump pressure.

Piston 34 will start to move as soon as groove 49 opens to port 52 and it will continue to move as long as valve 42 is rotated. As soon as rotation of valve 42 ceases, port 52 will move out of communication with groove 49 and movement of piston 34 and slide block 25' will cease.

When lever 53 is moved toward the left or in a counter clock'wise direction in respect to Fig. 4. groove 50 will open to port 52 and permit liquid to escape from cylinder 35 through port 52 and groove 50 into the right end of bore 43 which is open to drain through channel 5|, thereby permitting the gear pump liquid acting upon piston 32 to move it and slide block 25 toward the left.

Piston 32 will start to move slide block .25 and piston 34 toward the left as soon as groove 59 opens to port 52 and it will continue to move as long as valve 42 is rotated. As soon as -rota-' tion of valve 42 ceases, port 52 will move out of communication with groove 50. and trap the liquid remaining in cylinder 35, thereby stopping further movement of slide block 25 and holding it in adjusting position.- Slide block 25 may'thus be moved in one direction or the other by'swinging lever 53 in one direction or the other, and the distance through which slide block 25 is moved is dependent upon the angular distance through which lever 531s moved.

drive it as will presently be' explained.

42 has a transverse passage 54 (Fig. 4) extending therethrough and adapted to connect a channel 55, which communicates with bore 44 at a point spaced from port 41, toa channel 56 which has one of its ends communicating-with bore 44 at a point diametrically opposite channel 55 and its other end connected to a drain channel 51 liquid, it blocks the ends of. channels 55 and 56 so that no liquid can escape from channel 55 into drain channel 51.

As previously explained, each winder motor is connected in series with a slitter motor and both slitter motors are connected to pump it in parallel with each other. a

As shown, channel 21 is divided into two branches and connected to the inlets of slitter motors 2!! and 20" the outlets of which are con nected, respectively, by two channels 69 and 59 to the inlets of winder motors l5 and I5". Since theslitter motors are inechanicallysynchronized and of the same size, the liquid disa charged by pump I6 is equally divided between .formed in its casing and controlled by a valve member 65 which is fitted in the casing, and

valve 5| has three ports 62 53 and M -formed" 'in its casing and controlled by a valve member I55 which is fitted inthe casing The casings of valves iii and M have both-ends thereof connected to drain channel 51 by channels 56"- and 56', respectively, to prevent the movement. of

valve members 65. and 65 from being hampered by gas or liquid entrappedin the ends of the.

valve casings. a

Ports I52 and 52 are connected, r'espectivelmby channels 51 and 61 to'the outlets of motors l5; and I 5". Ports 63 and 63'' are connectednespectively, by channels 68- and ta to :channels' and 50 intermediate the ends thereof. Ports,

64 and 54 are connected.byia branched channel 59 to one port of hydrodynamicmachine 9/the other port of Wm 012111318. channel 28 con;

nected thereto.

When valves 6 I audit l areadjustedlas shown f m Fig. 1, each winder'motor will have: its inlet connected to its outlet so that-the liquid discharged by pump 16 will not drive the winder motors but will flow through channel 21,, motors 22" and 20, channels GOFI and'BII channels 68* and 68', valves GI and'SI and channel 59' to hydrodynamic machine Bland drive or tend to or and 61 and the outlets thereof connected, I

respectively, to channels 53 and 58 I When motors l5 and ii" are. running and valve members "v and 6 5 ;are each shifted. to

the position shown in Fig. 6, ports .82- and 62'' will be blocked and the liquid discharge by mo tors l5 and N will be forced through relief valves Ill and which resist the passage of liquid therethrough and thereby apply brake loads upon motors I5 and l5".

During the winding operation, liquid is supplied to each of the winder motors at a substantially uniform rate and the strips are delivered to the winding shafts at a. substantially uniform rate but, since the rewound rolls increase in diameter as the strips are wound thereon, it is necessary that each winding shaft be driven at a high speedwhen the roll thereon is small and that it be gradually decelerated as the roll thereon increasesvin diameter. V

This is accomplished by delivering liquid to each winder motor at a rate in excess of the rate required to cause it to drive its winding shaft at the-highest speed necessary, bypassing the excess liquid through a resistance valve and increasing the bypassing rate in accordance with the increase in the diameter of the roll on the winding shaft. driven by that motor.

As shown, a resistance valve II- and an orifice choke I2 are connected in series between channel 68 and channel 6! so that the liquid discharged by motor 20 into channel 60 in excess of the liquid required to drive motor I 5 may flow from channel 60 through channel 68*, choke l2 and resistance valve 1| into channel 61', and a resistance valve II and an orifice 'choke 12 are connected in series between channel 68' and channel 61 so that the liquid discharged by motor 20" into channel 60' in excess of the liquid required to drive motor l5 may flow from channel 60" through channel 68, choke l2 and resistance valve H into channel 61".

Since the tension on a strip being wound into a roll is determined by the diameter of the roll and thetorque of the motor that drives it and since the torque of a constant stroke hydraulic motor is proportional to the dropin pressure across it, choke 12* is always so adjusted that it offers substantially no resistance to the relatively small volume of liquid that is bypassed when the diameter of roll P is smallest and resistance valve 1i is so adjusted that it causes the pressureinchannels 68' and ill to exceed the pressure in channel 61" by the amount necessary to cause motor I5 to exert the correct torque when roll 1' is of minimum diameter.

The particular machine chosen for illustration is ordinarilyemployed to slit and wind paper which requires that the paper be tightly wound near the cores of the rewound rolls and that the rolls gradually decrease in density toward the peripheries thereof, in which case choke '12" is fully opened, so that it does not offer any resistance at any time to the passage of liquid therethrough, and resistance'valve 'I I is adjusted as explained above so that the torque of motor ii' remains constant with the result that the tension on strip 3 gradually decreases as roll 1' increases in diameter. Consequently, roll I gradually decreases. in density as it increases in diameter.

If it is desired that the density of the rewound roll be approximately uniform, the torque of the winding motor must be gradually increased as the rewound roll increases in diameter in order to maintain an approximately uniform tension upon the strip.

This may be accomplished by so adjusting choke l2 that, when roll 1 reaches its maximum diameter at which time liquid is being bypassed at the maximum rate, the resistance offered by choke l2 together with the resistance of resistance valve 1 I is suflicient to enable motor Ii to exert upon strip 3 a tension at least as great as the desired tension.

Then when the diameter of roll I is minimum at which time liquid is being bypassed at the minimum rate, choke 12 will offer no resistance crease with the result that the tension on strip ii is maintained approximately constant.

Since that part of the drive connected to winding shaft 6* functions in exactly the same manner that the part of the drive connected to shaft 6 functions, resistance valve II and choke 12'' are adjusted in the same manner that resistance valve H and choke 12* are adjusted. While the drive may be adjusted to produce a. desired tension on the strip both at the beginning and at the end of the windingoperation,

the tension will not remain constant throughout the winding operation due -to the fact that the resistance of an orifice choke does not vary in proportion to the rate of flow therethrough. However, it is found in practice that .the tension is maintained well within the limits ordinarily required.

If it is desired to maintain the tension more nearly constant due to the delicate natureof the -material or for other reasons, an orifice choke may be connected in series with each winder motor as disclosed in Patent No. 2,082,473 and then that part of the drive connected to each winder motor would function as explained in that patent.

Bypassing liquid through resistance valves ll and ll and through chokes 12' and 12'' causes heat to be generated. In order to prevent the liquid in the circuit from becoming overheated and to permit the escape of foreign matter therefrom, at least a part of the liquid discharged into channel 69 is expelled into reservoir 30 and liquid from reservoir 30 is supplied to channel 69 by gear pump 36.

As shown, channel 69 is connected through an orifice choke 15 to the inlet of a low pressure relief valve IS the outlet of which is connected by a channel 11 to drain channel 51, and theoutlet of resistance valve 38 is connected by channel T8 to channel 69' at a point between hydrodynamic machine 9 and the point at which chan-' nel 88 is connected to choke 15.-

The arrangement is such that, when the drive is in operation, gear pump 38 is constantly supplying cool liquid to channel 69 at a given rate and heated liquid is being expelled from channel 68 into drain channel 51 at substantially the same rate.

Relief valve 16 is' adapted to open at a predetermihed pressure, for instance 70# per square inch, and choke "is so proportioned-that it.

causes a predetermined drop in pressure, for instance 30# per square inch, between channel 69 and relief valve I6. Consequently, sear pump 3! through choke l5, relief valve "and channel 11 A a snoca is enabled to maintain in channel 89 a pressure equal to the combined resistances of choke "I and relief valve '76, for instance 1084?, .per square inch. a

Resistance valve 38 is adapted to open at a pressure, for instance 85,# per square inch, which is lower than the pressuremaintained in channel 89 due to.the resistances of choke I5 and rehef valve 18, and itis unaffected by back pressure so' and this large volume of liquid would cause a large drop in pressure across choke I5 with a corresponding large increase inthe pressure in channel 89, therebyenabling hydrodynamic machine to start.

In order to protect gear pump 38 from .ex-- v cessive pressures, there is provided a relief valve 19 which is adapted to open at a pressure higher than the pressure normally maintained in channel 89. 'Relief valve I9 is ordinarily arranged within the casing of pump I8 as is customary but, for the purpose of illustration, it has been shown as having its inlet connected to channel 89 and its outlet connected to channel IT.

The pressure prevailing in channel89-in excess :of the pressure prevailingin return channel 28 causes hydrodynamic machine 9 to'exert upon unwind shaft I a rotative force which isdetermined by this pressure differential and by the displace" ment of hydrodynamic machine 9.

The drop in pressure across hydrodynamic machine 9 is controlled by a resistance valve 88 having its outlet connected to return channel '28 and its inlet connected to channel I8 and controlled by a valve meniber 8| which isfltted in a bore 82 formed in the valve casing. Valve member 8| is adapted to. be urged toward its seat by liquid suppliedto bore 82 and it is continuously. urged towardits seat by a spring '83 which is arranged in bore 8| and adapted to permit resistance valve 88 to open under a low pressure, for instance l5# per square inch.

Application of pressure to valve member 8| is under the control of a valve member 84 which is fitted in a valve casing as having two annu 'lar ports 88 and,8| formed therein and conby a channel 88 to channel 89 to bore 82. Valve mem-' nected, respectively, 89 and by a channel ber 84controls communication between ports 88 and 81 and between port 81 and a channel 98 which connects both drain channel 51.

.When valve member in Fig. l,.bore

ends of valve casing'85 to 82 is open to drain channel 51 through channel 89, valve casing 85 and channel 98 so that the pressure in bore 82 is zero and valve member 8| is urged towards its seat solely by spring 83.

When valve member 84 is shifted to the position shown in Fig. 7, pressure extends from channel 89 through channel 88, valve casing 85 and channel 89 to bore 82 so that valve member 8| is urged to its seat by the force of. spring 83 and by a force proportional to the pressure prevail- :ingin channel 89.

pressure for operating inlet of 84 is in the position shown The displacementof hydrodynamic machine 9 .is-adiusted in response to a variation inthe linear speed of paper 3 relative to thespeed of slitter 45. This is accomplished by driving a control pump at a speed proportional to the linear speed of paper 8, drivingxasecondcontrol pump at a speed proportional to-the speed of slitter 4-5, connecting the two control pumps in series, and operating the stroke control mechanism of by; drodynamic machine 9 in response to the volumetric output of one control pump varying relative to the volumetricoutput of the other con trol pump. a Y a As shown; a small control pump 95 is connected by a drive 98 to. slitter motor 28' so that it is driven at a speed proportional to the speed of slitter 4-5, and a second small control pump 91 is connected by a drive 98 to a roller 99 which is driven by paper 3.

It is ordinarily desirable that slitter 9--5 operate at speed which-is a certain amount, for instance 20%, faster than. the speed of paper ,3 in order that it may operate emciently upon paper 3. Therefore, drives 98 and 98 are ,so pro portioned that the two control pumps will discharge liquid at the same rate when paper 8 is being unwound from roll 2 at the desired rate relative to the speed of slitter 4-5, the slitter speed being determined by the displacement of pump I8 for the reason that s1itter'motors'28 and 88 are connected directly to the outlet of pump I8 by channel 21.

Control pump 95 has its dutlet connected by a channel I88 to the inlet of control pump 91 and its inlet connected'by a channel. IM to the outlet of pump 91, and two oppositely opening lowpressure relief valves I82 and I88 are con nected between channels I88 and I Iii to protect pumps 95 and 97 from excessive pressures.

Channel I8I is connected intermediate itsends to the stroke adjusting servo-motor I8 of hydrodynamic machine 9 by a channel IM'and to gear pump supply channel 31 by a channel I88 so that channel I8I is supplied with liquid at gear pump pressure andslide block I2 is. urged toward full stroke position byservo-motor I8 with a force proportional to gear pump pressure.

Channel I85 is also connected by a channel I88 to the inlet of a check valve I8'I which has its outlet connected to channel 21 so that, when the displacement of pump I8 is reduced to zero to stop the machine, gear pump 38 may supply liqvalve I89 the valve member of which has a smallvalve I 891s connected by a channel II8 to the a choke III the outlet of which has channel connected thereto, and channel H8 is connected intermediate its ends by a channel II2 to the stroke changing'servo-motor II on hydrodynamic machine 9.

The arrangement is" such that, when pump I8 is at zero stroke at which time passage 54 in pump control valve 42 (Figs; 3 and 4) connects channel 55 to channel 88, liquid from gear pump as may flow through channels 31, ms, I8I and I84 to servo-motdr I8 and cause it to move slide block I2 to the right until the displacement of hydrodynamic machine 9 is maximum, and liquid is expelledfrom servo motor through channels II2-and II8, chokeIII, channel 55, passage 84 and channel, 58 into drain channel.

hole drilled therethrough, the inlet of check.

draw liquid from channel and discharge it into channel I00 and thereby equalize the pressures in channels I00 and mi, and pump 91 will draw liquid'frp'm channel I00 and discharge it into channel I 0|.

If the paper is moving at the correct speed relative to the speed of slitter 4-5, pump 91 will draw liquid from channel I00 at the same rate that pump 95 discharges liquid into channel |0 0. Consequently, the pressure in channel I00will be the same as the pressure in channel IOI and this pressure will prevail in both of servo-motors I0 and II so that slide block I2 remains stationary.

If paper 3 is moving at too slow a rate, pump 95 will discharge liquid into channel I00 faster than pump 91 draws liquid therefrom, thereby causing .the pressure in channel I00 to rise and extend through channel I08, the drilled hole in -check valve I09, and channels H0 and 2 to servo-motor II and causeit to shift slide block I2 towards the left to decrease the displacement of hydrodynamic machine 9 and thereby increase the speed of the paper 3.

If paper 3 is moving at too fast a rate, pump 91 will draw liquid from channel I00 faster than pump 35 supplies liquid thereto, thereby causing the pressure in channels I00, I08: IIO'and H2 and in servo-motor III to drop sothat servo motor i0 is enabled to shift slide block I2 towards the right to increase the displacement of hydrodynamic machine 3 and thereby-decrease the speed of paper 3.

Since motors 20* and 20" have the inlets thereof connected directly to the outlet of pump I6 so that the speed of slitter 4-5 is determined by the displacement of pump I6, since winding shafts 6 and 6 can wind strips thereon only as fast as the strips are delivered theretofsince the outlet of hydrodynamic machine 9 is connected by channel 28 to the inlet of pump I6 so thatr hydrodynamic machine 9 cannot discharge liquid at a rate in excess of the rate required to supply pump I6, and since the displacement of hydrodynamic machine, 9 is adjusted in response to a variation in the speed of paper 3 relative .to the speed of slitter 4-5, it follows that the speed of the entire machine is determined by the displacement of pump I6.

Operation Assuming that the several-parts of the drive are in the positions shown in Fig. 1,. that a parent roll 2 of paper 3 is fixed upon unwind shaft I, that pumps I6 and 36 are running and'that pump\| 6 is at zero stroke, the drive will function as follows:

Gear pump will draw liquid from reservoir 30 and discharge it through channel 31,resistance valve 38, channels 18 and 69, choke 15, relief valve 16 and channel 11 into drain channel 51, thereby creating in all of channels open to the gear pump a predetermined pressure, for instance 100# per sq. in.

Pump I6 being at zero stroke, the drive is idle and servo-motor I! is open tohdrair' phannel 51 through passage 5 in valve -42 so that slide block I2- of hydrodynamic machine 0 is held in its maximum displacement position by gear pump pressure prevailing in-servo-motor I0 as previoully explained.

'by gear pump pressure.

' In order to unwind paper from roll 2, pump control valve 42 (Fig; 3) is rotated through a and thereby causes resistance valve 80 to create 1 between channel 69 and channel 28 a predetermined pressure diiferential, for instance l5# per sq. in., which is not sufficient to cause hydrodynamic machine 9 to drive unwind shaft I but which is sufllcient to overcome the greater part 14 of the friction in hydrodynamic machine 3 and in drive 8 so that paper 3 may be easily unwound from roll 2 by hand.

If it is desired to drive parent roll 2, valve member 84 may be shifted to the position shown in Fig. '1 so that resistance valve 80 is held closed Then when pump I6 delivers liquid into channel 21 and draws liquid from channel 28, the pressure differential between channels 69 and 28 will be equal to gear 2 pump pressure which is suflicient to cause hydrodynamic machine 0 to drive unwind shaft I and thereby cause paper to be unwound from roll 2.

The paper pulled from or delivered by roll 2 3 6 and 6 respectively. with bypass valves 6| 3 and 6| adjusted as shown in Fig. 1, winding shafts 6"and 6 may be easily rotated by hand. To cause the machine to operate at high speed,

pressure control valve 84-85 is adjusted as shown in Fig. '1, bypass valves 6| and 6| are 4 adjusted to block channels 66 and I38 but leaving'channels 61 and 61 in communication with channel as shown in Fig. 5 and lever 53 is operated to rotate valve '42 (Fig. 3) through 'a sufficient angular distance to block channel 55 4 and to cause pump I6 to discharge liquid at the rate necessary to cause meters 20 and 20 to drive slitter 4-5 at the desired speed.

When valve 84-85 is adjusted, gear pump pressure will hold resistance valve closed. When valves 6| and 6| are adjusted, the liquid discharged by slitter meters 20 and 20 will cause winder motors I5 and I5 to rotate shafts 6' and 6 to wind strips 3 and 3' thereon as fast as the strips are delivered thereto, and the liquid discharged by the slitter motors in excess -to rotate parent roll 2.

. Hydrodynamic machine 0 being at full stroke, it will "not unwind paper 3 from roll 2 at a speed proportional to the speed of slitter 4-5. Consequently', control pump will dischargefliquid into channel I00 faster than control pump" 01 draws liquid therefrom'so that, channel 55 havng been blocked when valve 42 was rotated to i increase the displacement of pump it, the-additional liquid discharged by pump 95 into channel H19 will flow through channels I08 and H2 to servo-motor H and cause'it to decrease the displacement of hydrodynamic machine 9 with a resultant acceleration of roll 2 until the paper is being unwound therefrom at the correct speed relative'to the speed of slitter 45 at which -95 so that pump. 95 continuously delivers into channel I minute quantities of' liquid in excess of the liquid drawn therefrom by pump 91, and these minute quantities cause the displace- ,ment of hydrodynamic machine 9 to be gradually reduced in the above described manner with the result that roll 2 is gradually accelerated as it decreases in diameter so that paper 3 is delivered to the winding shafts at a substantially uniform rate,

If thepull on paper 3 is not sumcient to rov tate roll 2, hydrodynamic machine 9 will exert suflicient torque to drive it and, if the pull on paper 3 is more than sufilcient to rotate roll 2,

.hydrodynamic machine 9 will retard the rotation thereof for the reason that it cannot discharge liquid into.channel 28 any faster than pump l6 draws liquid therefrom.v Consequently, paper 3 is unwound at a substantially uniform rate regardless of the pull thereon.

To stop the machine, lever 53 'is gradually rotated to reduce the displacement of pump it to zero. Since hydrodynamic machine 9 cannot discharge liquid into channel 28 any faster than pump l6 draws liquid therefrom, reducing the displacement of pump 16 to zero causes hydrodynamic machine 9 and roll 2 to be decelerated to a complete stop and the pull on paper ,3. gradually stops the winding shafts and winder motors.

If the displacement of pump 16 should be suddenly reduced to Zero, the pressure in channel 28 would become high enough to cause liquid to be expelled through foot valve 3| which would exert a heavy brake load on hydrodynamic machine 9 and thereby quickly bring it to rest.

The inertia of slitter 4-5 may drive motors 20 and 20 which, as winder motors I5 and I5" slow down, must exhaust increasing volumes of liquid through resistance valves 1 l and 1 l which quickly decelerates the slitter. During deceleration of the slitter, motors 20 and 20 are supplied with liquid from channel I05 through channel I06 and check valve I01.

If the strip attached to one winding shaft should break during the winding operation the bypass valve 6| or Bi associated with the motor that drives that shaft would-be shifted to the position shown in Fig. 6, thereby quickly stopping that winding shaft, and the displacement of pump l6 would be reduced to zero to stop the balance of the machine as previously explained.

Iftoo much paper should be unwound from roll 2., Pump control valve 42 may be rotated direction to windup the excess paper but the winder motors and the slitter motors would notrbe energized.

The invention herein set forth is susceptible of various'modifications and adaptations without departingfromthe scope thereof .as hereafter Y claimed.

- The invention is hereby claimed as follows:

1. The combination, with an unwind shaft, means for' fixing a parent roll of web material upon said shaft, a winding shaft, and means for fixing the end of said material for rotation with said winding "shaft, of ahydrodynamic machine mechanica1ly connected to said unwind shaft,

means for supplying liquid at a predetermined pressureto the inlet of said machine-to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parent roll, a hydraulic motor forrotating said winding shaft to cause it to wind said material into a new roll, a pump driven at a substantially constant speed and adapted to deliver liquid to said motor at a uniform rate in excess of the rate required to cause said motor to drive said I winding shaft at a speed suflicient to wind up said material-as fast as it is unwound from said parent roll, means for bypassing the liquid discharged by said pump in excess of the liquid re quired by said motor including a resistance to enable said motor to maintain tension upon said material, a normally closed channel connecting the outlet of said machine to the intake of said pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to-thereby vary the speed of said unwind shaft, and means responsive to the linear speed of said material varying relative to the rate at which said pump discharges liquid for adjust-- ing said displacement varying means to there y maintain the speed of said material substantially uniform.

2. The combination, with an unwind shaft, means for fixing a .parent roll of web material upon said shaft,'a winding shaft, and meansfor fixing the end of said material for rotation with said winding shaft, of a hydrodynamic machine mechanically connected to said unwind shaft, 'means for supplying liquid at a predetermined pressure to the inlet'of said machine to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parent roll, a hydraulic motor for rotating said winding shaft to cause it to wind-said material into a new roll, a pump driven at'a substantially constant speed and adapted to deliver liquid to said motor at a uniform rate in excess of the rate required to cause said-motor to drive said winding shaft at a speed suflicient to wind up said material as fast 'as it is-unwound from saidparent roll, means for bypassing the liquid discharged by saidpump in excess of the liquid required by said motor including a resistance to.

pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, means responsive to the linear speed of said material varying relative tos'the rate at which said pump discharges liquid for adjusting said displacement varying means to thereby maintain the speed of said material substantially uniform, means for ,adjusting the displacement of said pump from zero to maximum to thereby regulate the speeds of said shafts, and means responsive to the displacement of said pump being reduced to zero for causing said machine displacement varying means to increase the displacement tr said machine to a predetermined maximum, v

3. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, a winding shaft, and means for fixing the end of said material for rotation with said winding shaft, of a'hydrodynamic machine mechanically connected to said \unwlnd shaft, means for supplying liquid at a predetermined pressure to the inlet of said machine to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parent roll, ahydraulic motor for rotating said winding shaft to cause it to wind said material into'a new roll, a pump driven at a substantially constant speed and adapted to deliver liquid to said motor at a uniform rate in excess of the charged by said pump in excess of the liquid required by said motor including a resistance to enable said motor to maintain tension upon said material, a normally closed channel connecting the outlet of said machine to. the intake of said pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, means responsive to the linear speed of said material varying relative to the rate at which said pump discharges liquid for adjusting said displacement varying means to-thereby maintainv the speed of said material substantially uniform, and means for varying the drop in pressure across said hydrodynamic machine to thereby enable said machine to either rotate said parent roll or to exert sufficient torque to permit said material to beunwound by hand.

4. The combination, with .an unwind shaft,

' means for fixing a parent roll of web material :upon said shaft, a winding shaft, and means for fixing the end of said material for rotation with said'winding shaft, of a hydrodynamic machine mechanically'connected to said'unwind shaft, means for supplying liquid at a predetermined pressure to the inlet of said machine to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from 'said parent roll, a hydraulic motor for rotating said winding shaft to cause it to wind said material into a new roll, a pump driven at a substane tially constant speed and adapted to deliver liquid to said motor at a uniform rate in excess -of the rate required to cause said motor to drive said winding shaft at a speed sufllcient to wind up said material as fast as it is unwound from'said parent roll, means for bypassing) the liquid discharged by said pump in excess f the liquid required by said motor including a resistance to enable said motor to maintain tension upon said material, a normally closed channel connecting the outletof said machine to the intake of said pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, means responsive to the linear of said machine to a predetermined maximum, .1

and means for varying the drop in pressure across said hydrodynamic machine to thereby enable said machine to either rotate said parent roll or to exert sufiicient torque to permit said material to be unwound by hand.

5. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, a winding shaft, and meansior fixing the end of said material for rotation with said winding shaft, of a hydraulic motor for rotating said winding shaft to cause it to wind said material into a new roll, a variable displacement pump driven at a substantially constant speed and adapted to deliver liquid to said motor at a uniformn rate in-excess of the rate required to 5 cause said motor to drivesaid winding shaft at a speed sufficient to wind up said material as fast as it is unwound from said parent roll, means for bypassing the liquid discharged by said pump in excess of the liquid required by said motor ineluding a resistance to enable said motor to maintain tension upon such material, a hydrodynamic machine mechanically connected to said unwind shaft, a fluid channel connected to the inlet of said machine, means for directing the liquid dis- P charged by said motor and the bypassed liquid into said channel, an auxiliary pump for delivering liquid into said channel, resistance means for permitting liquid to escape from said channel to enable said auxiliary pump to change at least a part of the liquid therein and to maintain therein suificient pressure to cause said machine to drive saidunwind shaft and thereby cause said material to'be unwound from said parent'roll, a normally closed channel connecting the outlet of said I machine to the intake of said variable pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said variable pump, means for varyirfg the displacement of said machine to thereby vary the, speed of said thereby maintain the speed of said material substantially uniform.

6. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, a winding shaft, and means for fixing the end of said material for. rotation with I said winding shaft, of a hydraulic motor for rotating said winding shaft to cause it to wind said material into a new roll, a variable displacement pump driven at a substantially constant/speed and adapted to deliverl iquid to said motor at a uniform rate in excessgof the rate required to cause said motor to drive said winding shaft at a speed sumcient to wind up said material as fast as it is unwound from said parent roll, means for bypassing the liquid discharged by said pump in excess of the liquid required by said motor including a resistance to enable said motor to maintain tension upon such material, a hydrodynamic machine mechanically connected to said unwind shaft, a fluid channel connected to the inlet of said material substantially uniform, means re-' sponsive to the displacement of said variable v 2,181,040 said machine, means for directing the liquid discharged by said motor and the bypassed liquid into said channel, an auxiliary pump for delivering liquid into said channel, resistance means for permitting liquid to escape from said channel to enable said auxiliary pump to change at least a part of the liquid therein and to maintain therein sufficient pressure to cause said machine to drive'said unwind shaft and thereby cause said material to be unwound from said parent roll, a normally closed channel connecting the outlet of said machine to the intake of said variable ,pump whereby said machine cannot discharge liquid in excess of the. liquid consumed by said variable pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, means responsive to the linear speed of said material varying relative to the rate at which said variable pump discharges liquid for adjusting said displacement varying means to thereby maintain the speed of said material substantially uniform, and means responsive to the displacement of said variable pump being reduced to zero for causing said machine displacement varying means to increase the displacement of. said machine to a predetermined maximum.

'7. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, a winding shaft, and meansfor fixing the end of said material for rotation with said winding shaft,'of a hydraulic motor for rotating said winding shaft to causeit to wind said material into a new roll, a variable displacement pump driven at a substantially constant speed and adapted to deliver liquid to said motor at a uniform rate in excess of the rate required to cause said motor to drive said winding shaft at a speed sufficient to wind up said material as fast as it is unwound from said parent roll, means for bypassing the liquid discharged by said pump in excess of the liquid required by said motor including a resistance to enable said motor to maintain tension upon such material, a hydrodynamic machine mechanically connected to said unwind shaft, a fluid channel connected to the inlet of said machine, means for directing the liquid discharged by said motor and the bypassed liquid into said channeL-an auxiliary pump for delivering liquid into said channel, resistance means for therewith, of a hydrodynamic machine ,me-

permitting liquid to escape from said channel to enable said auxiliary pump to change at least apart of the liquid therein and to maintain therein sufficient pressure to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parent roll, a normally closed channel connecting the outlet of said machine to the'intake of said variable pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said variable pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, means responsive to the linear speed of said material varying relative to the rate at which said variable pump discharges liquid for adjusting said displacement varying means to thereby maintain the speed of pump being reduced to zero for causing said machine displacement varying means to increase the displacement of said machine to a predetermined maximum, and means for varying the drop in pressure across said hydrodynamic machine to thereby enable saidmachine to either rotate said parent roll or to exert sufilcient torque to permit said material to be unwound by hand."

8. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, 9. slitter for slitting said material into a plurality of strips, a winding shaft for each strip, and means for fixing the end-of. each strip to one of said winding shafts to rotate therewith, of a hydrodynamic machine mechanically ing shafts to cause said strips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected to said slitter to drive the same and of a number equal to the number of winder motors, a pumpdriven at a substantially constant speed and adapted to deliver liquid to said motors at a uniform rate in excess of the rate required to cause said winder motors to drive said winding shafts at speed suflicient to wind up said strips asfast as they are delivered to said winding shafts, said slitter motors being connected to said pump in parallel with each other and each of said winder motors being connected in series with a slitter motor, means for bypassing around each of said winder motors the liquid de-V livered thereto in excess of the liquid required thereby, a normally. closed channel connecting the outlet of saidmachine to the intake of said pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, and means responsive to the linear speed of said material varying relative to the rate at which said pump discharges liquid for adjusting said displacement varying means to thereby maintain the speed of said material substantially 9. The combination, with an unwind shaft, means for. fixing-a parentroll of web material upon said shaft, a slitter forslitting said material into a plurality of strips, a winding shaft for each'strip, and means for fixing the end of each strip to one of said winding shafts to rotate chanically connected to said unwind shaft, means for supplying liquid at a predetermined pressure to the inlet of said machine tov cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parent'roll, a plurality of hydraulic winder motors each individual to a winding shaft forrotating said winding shafts to cause said strips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected to said pump in parallelwith each other and each of said winder motors being connected .in series with a slitter motor, means for bypassing around a each of said winder motors theliquidr delivered thereto in excess of the liquidrequired thereby,

let of said machine to the intake of said pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement ofsaid machine to thereby vary the speed of said unwind shaft, and means responsive to the linear speed of said material varying relative to the rate at which said pump discharges liquid for adjusting said displacement varying means to thereby maintain the speed of 'said material substantially uniform, and means for varying the drop in pressure across said hydrodynamic machine to thereby enable said' machine to either rotate said parent roll or to exert sufficient torque to permit said material to be unwound by hand.

10. The combination, with an unwind shaft,

' means for fixing a parent roll of web material upon said shaft, a slitter for slitting said material into a plurality of strips, a winding shaft for each strip, and means for fixing the end of each strip to one of said winding shafts to rotate therewith, of a hydrodynamic machine mechanically connected to said unwind shaft, means for supplying liquid at a predetermined pressure to the inlet of said machine to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parent roll, a plurality of hydraulic winder motors each individual to a winding shaft for rotating said winding shafts to cause said strips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected to said slitter to drive the same and of a number equal to the number of winder motors, a pump driven at a substantially constant speed and adapted to deliver liquid to said motors at a uniform rate in excess of the rate required to cause said winder motors to drive said winding shafts at speeds sufficient to wind up said strips as fast as they are delivered to said winding shafts, said slitter motors being connected to said pump in parallel with each other and each of said winder motors being connected in series with a slitter motor, means for bypassing around each of said winder motors the liquid delivered theretoin excess of the liquid required thereby, a normally closed channel connecting the outlet of said machine to the intake of said pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, means responsive to the linear speed of said material varying relative to'the rate at which said pump discharges liquid for adjusting said displacement varying means to thereby maintain the speed of said material substantially uniform,

means for adjusting the displacement of said' pump from zero to maximum to thereby regulate the speeds of said shafts, and means responsive to the displacement of said pump being reduced to zero for causing said machine displacement varying'means to increase the disr 2,181,049 a normally closed channel connecting the outinlet of said machine to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said-parent roll, a plurality of hydraulic winder motors each individual to a winding shaft for rotating said winding shafts to cause said strips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected to said slitter to drive the same and of a number equal to the number of winder motors, a pump driven at a substantially contant speed and adapted to deliver liquid to said motors at a uniform rate in excess of the rate required to cause said winder motors to drive said winding shafts at speeds sumcient to wind up said strips as fast as they are delivered to said winding shafts, said slitter motors being connected to said pump in parallel with each other and each of'said winder motors being connected in series with a slitter. motor, means for bypassing around each of said winder motors the liquid delivered thereto in excess of the liquid required thereby, a normally closed channel connecting the outlet of said machine to the intake of said pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, means responsive to the linear speed of said material varying relative to the rate at which said pump discharges liquid for adjusting said displacement varying means to thereby maintain the speed of said material substantially uniform, means for adjusting the displacement of said pump from zero to maximum to thereby regulate the speeds of said shafts, means responsive to the displacement of said-pump being reduced to,zero for causing said machine displacement varying means to increase the displacement of said machine to a predetermined maximum, and means for varying the drop in pressure across said hydrodynamic machine to thereby enable said machine to either rotate said parent roll or to exert sufficient torque to ermit'said material to be unwound by hand.

2. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, 9. slitter for slitting said mators each individual to a winding shaft for rotating said winding shafts to cause said strips to be wound thereon, a plurality of mechanically,

synchronized hydraulic slitter motors connected to said slitter to drive the same and of a number equal to the number of winder motors, a pump driven at a substantially constant speed and adapted to deliver liquid. to said motors at a uniform rate in excess of the rate required .to

cause said winder motors to drive said winding shafts at speeds suflicient'to wind up said strips as fast as they are delivered to said winding shafts, said slitter motors being connected to said pump in parallel with each other and each of said winder motors being connected in-series with a slitter motor, means for by ing around each-of said winder motorsthe liquid delivered thereto in excess of the liquid required thereby,

a normally closed channel connecting the outlet of said machine to the intake of said pump whereby said machine cannotdiscl arge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, a control pump driven by said slitter,a'

ment varying meansto therebytmaintain the speed of said material substantially'uniform,

13. The combination, with an unwind shaft,

means for fixing a parent roll of web material upon said'shaft, a slitter for slitting said material into a plurality of strips, a winding shaft for each strip, and means for fixing the end of each strip to one of said winding shafts to rotate therewith, of a hydrodynamic machine me chanically connected to said unwind shaft, means for supplying liquid at a predetermined pressure to the inlet of said machine to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parentroll, a plurality of hydraulic. winder motors each individual to a winding shaft for rotating saidwinding shafts to cause said strips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected to said slitter to drive the same and of a number equal to the number of winder motors, a pump driven at a substantially constant speed and adapted to deliver liquid to said motors at l a uniform rate in excess of the rate required to whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, a control pump driven by said slitter, a second control pump driven by said material at a speed proportional to the linear speed thereof,

means responsive to the speed of one control.

pump varying relative to the speed of the other control pump for adjusting said displacement varying means to thereby maintain the speed of said material substantially uniform, and means for varying the drop in pressure across said machine to thereby enable said machine to either rotate said parent roll or to exert sufflcient torque to permit said material to be unwound by hand. 1

14. The combination, with an unwind shaft, means for fixinga. parent roll of web material upon said shaft, 9. slitter for slitting said material into a plurality of strips, a winding shaft for each strip, and means for fixing the end of each strip to'one of said winding shafts torotate therewith, of a hydrodynamic machine mechanically connected to said unwind shaft, means for supplying liquidat a predetermined pressure to material to be unwound from said parent roll, a

plurality of hydraulic winder motors each individual to a winding shaft for rotating said winding shafts to cause said strips to be wound there- 1 on, a plurality of mechanically synchronized hydraulic slitter-motors connected to said slitter to drive the same and of a number equal to the number of winder motors, a pump driven ata substantially constant speed and adapted to deliver liquid to said motors, at a uniform, rate in excess of the rate required to cause said winder motors to drive'isaid winding shafts at speeds sufficient to wind up said strips as fast as they are delivered to said winding shafts, said slitter:

motors being connected to said pump in parallel with each other and each of'said winder motors being connected in series with a slitter motor, means for bypassing around each of said winder motors the" liquid delivered thereto in excess of the liquid required thereby, a normally closed channel connecting the outlet of said machine to the intake of said pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, a control pump driven by said slitter, a, second control pump driven by said material at a speed proportional to the linear speed thereof, means responsive to thereby maintain the speed of said material substantially uniform, means for adjusting the displacement of said pump from zero to maximum to thereby regulate the speed of said slitter, and means responsive to the displacement 'of said pump being reduced to zero for causing said machine displacement varying means to increase the displacement of said machine to a predetermined maximum. I v

15. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, a slitter for slitting said material into a plurality of strips, a winding shaft for each strip, and means for fixing the end of each strip to one 'of said winding shafts to rotate therewith, of a plurality of hydraulic winder motors each individual to a winding shaft for rotating said winding shafts to cause saidstrips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected to aid slitter to drive the same and of a number equal to the number of winder motors, a variable displacement pump driven at a substantially constant speed and adapted to deliver liquid to said motors at a uniform rate in excess of the rate required tocause said winder motors to drive said winding shafts at speeds sumwith each other-andeach of said winder motors being connected'in series with, a slitter motor, means including a resistance forbypassing around each ofsaid nder motors the liquid delivered thereto in excess of the liquid required thereby, said resistances enabling said winder motors to maintain tension upon such strips, .a

hydrodynamic machine mechanically connected connecting the outlet of said machine to the intake of said ,variable pump whereby said ma-'v chine'cannotflilischarge liquid in excess of the liquid consumed by said variable pump, means for varying the displacement of said machine to; thereby vary the speed of said unwind shaft, and: means, responsive to the linear speed of said material varying relative to the speed'of said slitter for adjusting said displacement varying means to thereby maintain the speed of said material substantially uniform.

16. The combination, with an unwind shaft, means for fixing a parent roll of 'web' material upon said shaft, a slitter for slitting said material into a plurality of strips, a winding shaft for each strip. and means for fixing the end of each strip to one of said winding shafts to ro-' tate therewith, of a plurality of hydraulic winder motors each individual to a winding shaft forv rotating said winding shafts to cause'said strips to be wound thereon, aplurality of mechanically synchronized hydraulic slitter motors connected to said slitter to drive the same and of a number equal to the number of winder motors, a variable displacement pump driven at a substantially constant speed and adapted to deliver liquid to said motors at a uniform rate in excess of the rate required to cause said winder motors to drive said winding shafts at speeds sumcient to wind up said strips as fast as they are delivered to said winding shafts, said slitter motors being connected to said pump in parallel with each other and each of said winder motors being connected in series with a slitter motor, means including a resistance for bypassing around each of saidwinder motors the' liquid delivered thereto in excess of the liquid required thereby, said. resistances enabling said winder motors to maintain tension upon such strips, a hydrodynamic machine mechanically connected to said unwind shaft, a fluid channel connected to theinlet of said machine, means for directing the liquid discharged by said winder motors and the bypassed liquid into said channel, an auxiliary pump for delivering liquid into said channel, resistance means for permitting liquid to escape from said channel to enable said auxiliary pump to change at least a part of the liquid therein and to maintain therein sufllcient pressure to cause said machine, to drive said unwind shaft and thereby cause'said material to-be unwound from said parentroll, a normally closed channel connecting the outlet of said machine to the intake of said variable pump whereby said machine cannot discharge liquidin excess of the liquid consumed by said variable pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, means responsive to the linear speed of saidvmaterial varying relative to the speed of said slitter for adjusting said displacement varying means to thereby maintain the speed; of said material substantially uniform, and means responsive to.

the displacement of said variable pump being re-- duced to zero for causing said machine displacement varying means to increase the displacement of said machine to a predetermined maximum.

1'7. The combination, with an unwind shaft.

each individual to a winding shaft for rotating said winding shafts to causesaid strips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected to said slitter to drivethe same and of a number equal to the number of winder motors, a variable displacement pump driven at a substantially constantspeed and adapted to deliver liquid to said motors at a-uniform rate in excess of the rate required to cause said winder motors to drive said winding shafts at speeds sufilcientto wind up said strips as fast as they are delivered to said winding shafts, said slitter motors being connected to said pump in parallel with each other. and each of said winderrmotors being connected-in series with a slitter motor, means including a resistance for bypassing around each of said winder motors the liquid delivered thereto in excess of the liquid required thereby, said resistances enabling said winder motors to maintain tension upon such strips, a hydrodynamic machine mechanically connected to said unwind shaft, a fluid channel connected to the inlet of said machine, means for directing the liquid discharged by said winder motors and the bypassed liquid into said channel, an auxiliary pump for delivering liquid'into said channel, resistance means for permitting liquid to escape from said channel to enable said auxiliary pump to changeat least a part of theliquid therein and to maintain therein sufllcientpressure to cause said machine to drive said un-' wind shaft and thereby cause said material to be unwound from said parent roll, a normally closed channel connecting the outlet of said machine to the intake: of said variable pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said variable pump, means for varying the displacement of said machine to thereby vary thespeed of said unwind shaft, means responsive to the linear speed of said material varying relative to the speed of said slitter for adjusting-said displacement varying means to thereby maintain the speed of said material substantially uniform, means responsive to the displacement of said variable pump being reduced to zero for causing said machine displacement varying means to increase the displacementof said machine to a predetermined maximum, and means for varying'the drop in pressure across said hydrodynamic machine to thereby enable said machine to either rotate said parent roll or to exert sufficient torque-to permit said material to be unwound by hand.

18. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, 9. slitter for slitting said material into a pluralitylof strips, a winding shaft for each strip, and means for fixing the end of each strip to one of said winding shafts to rotate therewith, of a plurality of hydraulic winder motors each individual to a winding shaft for rotating said winding shafts to cause said strips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected to said slitter to drive the same and-of a number equal to the number of winder motors, a variable displacement pump driven at a substantially constant speed and adapted to deliver liquid to said motors at a uniform rate in exces's'of the rate required to cause said winder motors to drive said winding shafts at speeds sufilcient to wind up said strips as fast as they are delivered to said winding shafts, said slitter motors being connected to said pump in parallel with each other and each of said winder motors being connected in series with a slitter motor, means including a resistance for bypassing around each of said winder motors the liquid delivered thereto in excess of-the liquid required thereby, said resistances enabling said winder motors to maintain tension uponsuch strips, a hydrodynamic machine mechanically connected to said unwind shaft, a fluid channel connected to the inlet of said machine, means for directing the liquid discharged by said winder motors and the bypassed liquid into said channel, an auxiliary pump for delivering liquid into said channel, resistance means for permitting liquid to escape from said channel to enable said auxiliary pump to change at least a part of the liquid therein and to maintain therein suificient pressure to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parent roll, a normally closed channel connecting the outlet of said machine to the intake of said variable pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said variable pump,- means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, a control pump driven by said slitter, a second control pump driven by said material at a speed proportional to the linear speed thereof, and means responsive to the speed of one control pump varying relative to the speed of the other control pump for adjusting said displacement varying means to thereby maintain the speed of said material substantially uniform.

19. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, a slitter for slitting said material into a plurality of strips, a winding shaft for each strip, and means for fixing the end of each strip to one of said winding shafts to rotate therewith, of a plurality of hydraulic winder motors each individual to a winding shaft for rotating said winding shafts to cause said strips to be wound thereon; a plurality of mechanically synchronized hydraulic slitter motors connected to said slitter to drive the same and of a number equal to the number of winder motors, a variable displacement pump driven at a substantially constant speed and adapted to deliver liquid to said motors at a uniform rate in excess of the rate requiredto cause said winder motors to drive said winding shafts at speeds sumcient to wind up said strips as fast as they are delivered to said winding shafts, said slitter motors being connected to said pump in parallel with each other and each of said winder motors being connected in series with a slitter motor, means including a resistance for bypassing around each of said winder -motors the liquid delivered thereto in excess of the liquid required thereby, said resistances enabling said winder motors to maintain tension upon such strips, a hydrodynamic ma-' chine mechanically connected to said unwind shaft, a fluid channel connected to the inlet of said machine, means for directing the liquid discharged by said winder motors and. the bypassed liquid into said channel, an auxiliary pump for delivering liquid into said channel, resistance means for permitting liquid to escape from said channel to enable said auxiliary pump to change atleast a part of the liquid therein and to maintain therein suflicient pressure to cause said machine to drive said unwind shaft and thereby cause said material to be unwound from said parent roll, a normally closed channel connecting the outlet of said machine to the intake of said variable pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said variable pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, a control pump driven by said slitter, a second control pump driven by said material at a speed proportional to the linear speed thereof, means responsive to the speed of one control pump varying relative to the speed of the other control pump for adjusting said displacement varying means tothereby maintain the speed of said material substantially uniform, and means responsive to the displacement of said variable pump being reduced to zero for causing said machine displacement varying means to increase the dispiacement of said machine to a 'predetermined maximum.

20. The combination, with an unwind shaft, means for fixing a parent roll of web material upon said shaft, a slitter for slitting saidymaterial into a plurality of strips, a winding shaft for each strip, and means for fixing the end of each strip to one of said winding shafts to rotate therewith, of a plurality of hydraulic winder motors each individual to a winding shaft for rotating said winding shafts to cause said strips to be wound thereon, a plurality of mechanically synchronized hydraulic slitter motors connected 'to said slitter to drive the same and of a number of said winder motors being connected in series with a slitter motor, means including a resistance for bypassing around each of said winder motors the liquid delivered thereto in excess of the liquid required thereby, said resistances enabling said winder motors to maintain tension upon such strips, a hydrodynamic machine mechanically connected to said unwind shaft, a fluid channel connected to the inlet of said machine, means for directing the liquid discharged by saidwinder motors and the bypassed liquid into said channel, an auxiliary pump for delivering liquid into said channel, resistance means for permitting liquid to escape from said channel to enable said auxiliary pump to change at least a part of the liquid therein and to maintain therein sufiicient pressure to cause said machine to drive said unwind shaft and thereby cause-said material to be unwound from said parent roll, a normally closed channel connecting the outlet of said machine to the intake of said variable pump whereby said machine cannot discharge liquid in excess of the liquid consumed by said variable pump, means for varying the displacement of said machine to thereby vary the speed of said unwind shaft, a control pump driven by said slitter, a second control pump driven by said material at a speed pro-. portional to the linear speed thereof, means-responsive to the speed of one control pump vary- -35 equal to the number of winder motors, a variable means to thereby maintain the speed of said material substantially uniform, means responsive to the displacement of said variable pump being reduced to zero tor causing said machine displacement varying means to increase the displacement or said machine to a predetermined

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