GB2185240A - Coil control - Google Patents

Abstract

Apparatus for coiling or de-coiling continuous strip material, for example fine gauge metal strip, regulates the draught of the strip (11) unwound from or wound into a coil (12) by regulation of drive means (15) rotating the coil. A flight of the strip forms a bight with which a floating pulley or other element (17) coacts, changes in size of the bight shifting said element and so automatically operating a feedback control (21) to keep the tension of the flight substantially constant. <IMAGE>

Description

SPECIFICATION Coil control This invention relates to the controlled coiling or un-coiling of continuous lengths of material, e.g. during manufacture or continuous processing or consumption thereof and particularly to the handling of delicate or fine gauge continuous metal or other strip and/or the precision forming or other processing thereof.

The object of the invention is to provide simple and reliable coil control means which is easy to set up and operate, highly responsive so that snatching, tearing, excess tension or other damaging handling of the material is substantially completely avoided, and which has negligible power requirements or need for maintenance.

According the invention there is provided coil control means for regulating draught of continuous material being unwound from or wound into a coil including a carrier on which the coil is operatively mounted for rotation therewith; drive means for selective rotation of the carrier; a regulating element arranged for operative co-action with a bight formed in a flight of the material in its passage from or to the coil in use and constrained for floating movement in response to changes in size of said bight; and feedback means responsive to said movement of the regulating element to control operation of the drive means to keep the tension on said flight substantially constant irrespective of discrepancies between the input rate to and output rate from said flight.

Conveniently the drive means includes a pneumatically powered motor and the feedback means includes an air valve for regulating operation of the motor.

The regulating element may be a roller, jockey wheel or other freely rotatable element carried on a swinging arm urged into engagement with the bight in use by gravity and/or by a spring or other resilient means, angular movement of said arm operating the feedback means.

An example of the invention is now more particularly described with reference to the accompanying drawings, wherein: Figure 1 is a diagrammatic side elevation of coil control means in operation, and Figure 2 is an enlarged plan view of part of said means.

The drawings show de-coiling apparatus set up for continuous in-feed of strip material, e.g.

fine gauge metal strip to a high speed precision processing unit, e.g. a metal forming press 10 (not shown in detail). Said press may, for example, be used in forming blanks or stampings from high grade materials to extremely close tolerances for miniaturised electronic components, connectors etc for which continuous volume production at consistent high quality is required. Any drag or snatch on the strip material 11 e.g. during starting or stopping of the feed could cause it to break, tear or be stretched or deformed with consequent loss of quality and/or stoppage or malfunctioning of the press 10 and any drag or undue tensioning of the material in feed could adversely affect the press operation e.g. its internal feeding arrangements and/or the synchronisation of successive press operations on the strip.Overfeeding and consequent slack could lead to twisting or tangling of the strips.

The material is fed from a coil 12 operatively fixed on a carrier arbor 13 for rotation, in this example about a vertical axis though in other arrangements the coil may rotate about a horizontal or inclined axis. Arbor 13 is drivingly connected through a reduction gearbox 14 to a pneumatically powered motor 15 operable for selective rotation of the coil 12.

A flight of the strip material is led from coil 12 over a guide pulley 16 journalled for free rotation about a fixed axis and then beneath a floating pulley 1 7 before it is led into the press 10, the path of the strip extending between pulley 16 and the press forming a bight with which pulley 7 coacts, the latter rising and falling in response to changes in size of the bight. Thus if the input speed at which the press is consuming the material exceeds the output speed of material to the bight, i.e.

the rate of uncoiling, the bight will be reduced and pulley 1 7 will rise. Conversely if the uncoiling rate exceeds the input rate pulley 17 will fall.

Pulley 17 is freely pivotted at the distal end of a swinging arm 18 carried on a shaft 19 (Fig. 2) journalled on an operatively fixed supporting frame 20.

Shaft 19 is displaceable axially within a journal block 21, a radial pin 22 engaging a spiral camming formation 23 within block 21 so that as pulley 1 7 rises and falls causing angular movement of arm 18 shaft 19 is rectilinearly displaced horizontally.

A screw-adjustable push piece 24 on the inner end of shaft 19 engages an operating plunger 25 of a pneumatic control valve 26; when shaft 19 is displaced to the right as viewed in Fig. 2 plunger 25 is pushed inwards to increase the opening of the valve.

Valve 26 is connected in a pnuematic line 27 connecting an air supply (not shown) to motor 15, thus the operation of valve 26 regulates the speed of motor 1 5.

Conveniently the air supply may be provided in common with that used in operation of the press 10 and as the power required is minimal the expense and inconvenience of providing electrical circuits is avoided, also pneumatic motors and their associated controls have been found to be exceedingly durable, reliable and safe in service.

In operation the effective length of the bight controls the infeed thereto from coil 12 so that the tension applied to strip 11 is maintained substantially constant and the rate of feed is held within close limits with starting and stopping of the movement of the strip avoided during normal operation, thus substantially reducing the risk of damage due to snatch and inertia.

If the rate of unwinding from the coil 12 exceeds the rate at which the strip being consumed by press 10 the flight will increase in length making the bight larger and so allowing pulley 17 to drop. This shifts valve plunger 25 in a direction reducing passage of air through valve 26 thus slowing motor 15 and reducing the uncoiling rate. If the bight size increases beyond a predetermined maximum limit valve 26 will be shut completely halting motor 15 as push piece 24 is drawn out of contact with valve plunger 25.

An additional cut-out device is provided in the form of a microswitch 30 conveniently mounted on journal block 21 and provided with a resiliently loaded actuating member 31 directed along shaft 19. The latter carries a disc 32 which contacts member 31 and operates the switch if shaft 19 is displaced axially to the right as viewed in Fig. 2 beyond a certain maximum distance, i.e. if arm 18 is raised beyond a certain height in response to excessive decrease in bight size even with motor 15 running at top speed. Thus if for any reason the input to press 10 substantially exceeds the uncoiling output from coil 12, e.g. due to some fault, switch 30 will operate to turn off press 10 automatically and/or to activate an alarm warning of the malfunction.

A manually operated valve 35 is provided in air line 27 upstream of valve 26 enabling the air supply to be turned off eg. while adjustments are being made or during changeover of coils on arbor 13.

It will be understood that substantially the same arrangement as shown in Figs. 1 and 2 can be used with little or no modification for forming the strip material 11 into a coil, i.e.

coil winding. For example the output from press 10 may take the form of partly finished workpieces or other components which are still joined together in a continuous strip e.g.

in readiness for other processing and as these may require to be stored or transported in strip form they will need to be formed into a coil without any undue pressure or tension which could damage the forming of the components or break the strip (which may already be partly severed). By simply reversing motor 15 to wind the coil (or indeed leading the strip round arbor 13 in the opposite direction maintaining the same direction of rotation of motor 15) a coil can be safely and reliably formed under substantially constant pre-selected tension and at substantially constant rate of feed.

It will be appreciated that the invention can be applied to other forms of drive, for example using an electric motor, and/or may include other forms of regulating element and feedback means, for example angularly movable arm 18 may make direct contact with upper and lower limit switches setting the safety cut out limits and could be provided with other forms of motor speed regulator, for example an electrical rheostat device operated by movement of the arm. Instead of being carried on a swinging arm the floating pulley, roller or other regulating element which engages the bight could be guided for rectilinear movement e.g. by riding in or in vertical guides.

It will also be appreciated that pulley 17 or any other form of regulating element need not be arranged for movement having a vertical component it could be arranged to move in a generally horizontal path and could be resiliently loaded to coact with the bight by means of one or more springs, possibly with provision for a selective adjustment of the loading.

Claims (14)

1. Coil control means for regulating draught of continuous material being unwound from or wound into a coil including a carrier on which the coil is operatively mounted for rotation therewith; drive means for selective rotation of the carrier; a regulating element arranged for operative co-action with a bight formed in a flight of the material in its passage from or to the coil in use and constrained for floating movement in response to changes in size of said bight; and feedback means responsive to said movement of the regulating element to control operation of the drive means to keep the tension of said flight substantially constant irrespective of discrepancies between the input rate to and output rate from said flight.

2. Coil control means as in Claim 1 wherein the regulating element is a freely rotatable element carried on a swinging arm, the feedback means being operated by angular movement of said arm.

3. Coil control means as in Claim 2 wherein the rotatable element is urged into engagement with the bight in use by gravity.

4. Coil control means as in Claim 2 or 3 wherein the rotatable element is urged into engagement with the bight in use by a spring or other resilient means.

5. Coil control means as in Claim 2, 3 or 4 wherein the arm is mounted on a rotatable shaft for swinging movement, said shaft being journalled for pivotal and axial displacement and provided with a camming formation whereby it is shifted axially in response to swinging movement of the arm, said axial displacement operating to control the drive means.

6. Coil control means as in any preceding claim wherein the drive means includes a pneumatically powered motor and the feed back includes an air valve for regulating operation of the motor.

7. Coil control means as in Claim 6 so far as dependent on Claim 5 wherein the air valve includes an actuating plunger which is shifted by said axial displacement of the shaft on which the arm is mounted.

8. Coil control means as in any preceding claim including a cut-out device operating automatically to halt operation and/or activate an alarm if a malfunction should reduce the size of the bight beyond a predetermined minimum.

9. Coil control means substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

10. Apparatus for manufacture, continuous processing, or consumption of continuous strip material including coil control means as in any preceding claim.

11. Apparatus as in Claim 10 wherein the material is fine gauge metal strip.

12. Apparatus as in Claim 10 or 11 including a high speed precision forming press or other processing unit, the coil control means operating to in-feed strip material from a coil to said unit in use.

13. Apparatus as in 11 wherein the coil control means operates to receive output in strip form from the processing unit to form it into a coil.

14. Apparatus for manufacture, continuous processing or consumption of continuous strip material substantially as hereinbefore described with reference to and as shown in the accompanying drawings.