US2988297A - Automatic control mechanism for reeling and unreeling - Google Patents

Description

June 13, 1961 w. F. PAWLOWSKI 2,988,297

AUTOMATIC CONTROL MECHANISM FOR REELING AND UNREELING Filed May 2. 1956 FIG! 38 RESULATING o FIGZ 1 2-REVERSING RELAY FOR INVERTING CONTROL ACTION |NVENTOR WALTER F. PAWLOWSKI ATTORNEY United States Patent 2,988,297 AUTOMATIC CONTROL MECHANISM FOR REELING AND UNREELING Walter F. Pawlowski, 39 Pleasant St., P.O. Box 517, Holbrook, Mass. Filed May 2, 1956, Ser. No. 582,193 7 Claims. (Cl. 242-7553) This invention relates to an automatic load control system which is particualrly adapted to tension control of winding and reeling where an air slip clutch is utilized between a motor and a winding reel for winding a web, rope, yarn, etc.

The principal object of the invention resides in the provision of means providing a pneumatic impulse signal whenever the load on the web or yarn drops below a desired predetermined value, said signal energizing a valve or the like for increasing the air pressure directed to the air slip clutch, whereby the load is re-imposed on the web or yarn being reeled; the provision of apparatus for steadily increasing pressure to an air slip clutch in order to maintain constant pull or tension on the material being reeled and preventing any possibility of hunting; and creating action only when the predetermined load condition varies, whereby a series of small successive positive corrections are occasioned in the clutch or loading signal for load deviations below the load set as the load builds up; and also avoiding slight or cyclic deviations, so that a stable system is provided as distinct from devices of the prior art which attempt to maintain the web control constant.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which:

FIG. 1 is a diagrammatic illustration of the system; and

FIG. 2 is a slight modification thereof.

In FIG. 1, the reference numeral 10 indicates a spool or reel which is being reeled onto another spool. or reel '14, the latter being driven by shaft 16 through a pressure air slip clutch 18 by means of motor 28. This web, rope or yarn is indicated at 22 and it is passed over a pair of idler rollers 24, 26 and an intermediate roller 28. Roller 28 is mounted on journals at 30 which are in turn mounted on a standard 32 directly connected to a load detecting device generally indicated by the numeral 34.

The load detecting device 34 comprises an air cylinder 36 fed by a line 38 and providing an air-filled chamber in which air will be compressed upon downward motion of the journalled roll 28 but which will maintain the same in predetermined position according to the load.

The line 38 passes through a conventional air regulating valve 40 which may be pre-set according to the pressure indicated on the dial 42; and this line comes from a source of supply by a pipe indicated at 44 through a shut-off valve 46 and a filter of conventional construction 48.

The load-detecting device 34 includes a bearing plate or the like 50 for supporting the standard 32 and roll '28, and this bearing plate, which is supported on the air in the cylinder, in turn carries a force lever 52 which rises and falls according to the load to act upon a valve indicated at 54. Valve 54 includes an actuator comprising a stem 55 having a ball 57, and valve 54 can vent to atmosphere via the clearance at the stem 55. Valve 54 is biased by a spring 56 to open or close a line 58 which is fed by the same source of supply through the pipe or regulating valve 60 and has a dial indicator 62 to indicate the pressure therein. The spring 56 may be omitted as the air pressure in line 58 serves the same purpose. The valve 54 opens or closes the air supply to a line 64 which leads to an air booster relay valve generally indicated at 66. This valve also is a commercial device well known in the art and only so much of the same is shown as to illustrate how it operates. When air is admitted as at 68, it lifts a piston 70 which in turn lifts a valve 72 from its valve seat in the main line of the regulated air supply at 74, and this in turn increases the air pressure applied to the air slip clutch 18 as through the line 76.

In order to provide the constant increments of increased pressure, a check valve is inserted in the line as at 78 and a load point indicating dial 80 is provided to show high and low points in the air surges in the line 64, 68. A metering needle valve is indicated at 82 and at 84tthere is a three-way selector valve which is operated manually to clear the line, including the pipe 68, to return the valve 72 to its pre-set position according to the hand-operated actuator 86. Valve 82 serves to adjust the rate at which pressure in line 64 can act on valve 66. Should check valve 78 be omitted, the valve 82 will also serve to regulate the rate at Which air pressure is bled from valve 66 to atmosphere at valve 54.

A capacity chamber or tank 88 is also included in this line as well as an adjustable needle valve to vent to the atmosphere as at 90. However, vent '90 is closed when check valve 78 is omitted. Valves 82 and 90 once being set for a particular operation do not have to be changed.

The mechanism described is provided to increase power transmission by means of the clutch 18 to the reeling device 14 to maintain a constant pull on the material 22 being processed. This increase in power requirement is a consequence of the steady building up of the mass of material at 14. By reason of the variation of the load on the cylinder 36 as transmitted by the standard '32, a signal is transmitted to the relay valve 66 by reason of the impulse of air received through pipe 58 normally shut off. This impulse proceeds through the line 64 to actuate the valve 66 as above described, thus increasing the pressure on the slip clutch 18. This action is built up in steady increments because of the presence of the check valve and there can be no reversal of the trend. There is no need for reversal of the trend of any specific application because of the fact that the reel at 14 is always being wound up.

However, the apparatus can be used to control the tension on unwinding also by the inclusion of a reversible relay 92 as shown in FIG. 2 for brake application, so that the tension may be maintained when unwinding also.

Should check valve 78 be omitted and vent 90 closed, as previously disclosed, the system will be directly applicable to unreeling applications without the necessity of utilizing the reversing relay.

The present apparatus rules out any possibility of hunting by leaving the clutch or air signal at a set value as long as the load set point is maintained. Corrective action takes place when the set load condition drops below that point by a set amount. The apparatus then acts to impose an added impulse to the existing clutch air signal which has been acting. The net control effect is to continually make small successive, positive corrections in the load on the clutch. There is no response to slight or transient or cyclic deviations above the load set point, and it is impossible for this apparatus to become cyclic or unstable as a consequence of reversing the trend of control requirements. Vent 90 when operative is in exception to the above, and provides for control response on application where required for load deviations above the set point. Simply stated, the actuation of the spring biased booster relay superimposes an output of air signal on the original output signal on the clutch, and this of course as described steadily builds up in exact conformance with the increasing load requirements.

The response of the system may be throttled or modulated by the needle valves and sensitivity is reduced by the introduction of the chamber 88. As a consequence, an exact setting of the needle valve restriction is easily obtained for given conditions and specific air supply pressure and different materials being processed. v In order to place the machine in operation, the operator turns the three-way selector valve 84 to vent the booster relay control to the atmosphere. Adjustment of the spring on the booster relay is then made to place a predetermined value of tension load at that particular instant. The operator then turns the valve to the position shown and the automatic operation described above then ensues. I

By making a notation of the load point for the clutch required for a particular load on a particular material, and noting the air pressure to the clutch initially as loaded on manual control, conditions may be reproduced for any 'future operations requiring the same performance.

Although this invention has been illustrated for use with air-operated clutches and brakes, it is nevertheless adaptable to such other control elements as mechanical clutches and brakes, variable speed electric drives and so on, by the addition to the system of some kind of actuating device which acts to affect the control element in the proper direction.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. Automatic winding and reeling control mechanism comprising a reel, means to rotate the reel for winding, a variable slip clutch between the reel and rotating means, and means to increase the pressure on the slip clutch comprising a booster air relay to vary the air pressure to the slip clutch, a source of air under pressure for the booster relay, the latter being connected to operate the clutch, a load detecting device for the material being wound, an air cylinder in the load detecting device supporting the same, means to preset the air pressure for the cylinder, the same being movable under load variation, a valve for the booster relay to vary the air pressure to the clutch, means on the load detecting device to actuate the valve, and means to prevent reverse flow of air through the valve.

2. Automatic control mechanism comprising a source of air under pressure, a load detecting device, an air booster relay, an air operated slip clutch device actuated by the source of air pressure, the booster relay being located in the air line between the air pressure source and the clutch, means for the booster relay for varying the air pressure passed thereby, and means associated with the load detecting device to actuate the means according to the load impressed on the load detecting device.

3. Automatic tension control for Winding and reeling comprising a reel to be rotated, an air actuated slip clutch therefor, means to energize the clutch, a source of air under pressure connected to supply pressure to the clutch, a booster relay in the air line to the clutch to vary the pressure thereon, air-operated means in the relay to control said clutch pressure, a valve, an air line through the valve to the booster relay, air-operated means to actuate the relay, an air regulator in the line between the air supply and the valve, a check valve in the line between the valve and the booster relay, air operated means preventing air return from the latter, so that the actuation of the relay is in predetermined positive increments, a load detector to sense the variation in the tension of the material being Wound, said detector comprising an air cylinder connected to the air supply, an air regulator for the cylinder, means movable with the cylinder and in contact with said material, and an element also movable with the cylinder and arranged to actuate the valve.

4. The control mechanism of claim 2 including a check valve in the line from the valve to the booster relay and an adjustable atmospheric vent in the line from the check valve to the booster relay.

5. The control mechanism of claim 2 including metering means for the air impressed on the booster relay.

6. The control mechanism of claim 2 including a check valve in the air line from the valve to the booster relay.

7. Automatic control mechanism comprising a load detecting device, driving means, driven means, means interposed between the driving and driven means and responsive to a variation of fluid pressure adapted selectively to establish, interrupt, and vary torque in the driven means, a source of fluid under pressure, a fluid line forming a circuit, a fluid booster relay, said torque varying means between the driving and driven means being actuated by the fluid source, the booster relay being located in the fluid line between the fluid source and the torque varying means, means associated with the booster relay for varying the fluid pressure passed thereby to the torque varying means, and means associated with the load detecting device to actuate the fluid pressure varying means according to the load impressed on the load detecting device.

References Cited in the file of this patent UNITED STATES PATENTS 1,982,685 Muller Dec. 4, 1934 2,214,201 Moulder Sept. 10, 1940 2,388,457 Ziegler Nov. 6, 1945 2,491,636 Amos Dec. 20, 1949 2,521,413 Scheuermann et al. Sept. 5, 1950 2,555,162 Stanford May 29, 1951 2,626,110 French Jan. 20, 1953 2,706,027 Ragland Apr. 12, 1955 2,764,263 Bricker Sept. 25, 1956

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