US2747285A - Length control apparatus for use in feeding strip stock - Google Patents

Description

May 29, 1956 K. L. BANDY 2,747,285

LENGTH CONTROL APPARATUS FOR USE IN FEEDING STRIP STOCK Filed July 19 1951 4 Sheets-Sheet 1 Zinoentor KENNETH L. BANDY attorney May 29, 1956 K. L. BANDY LENGTH CONTROL APPARATUS FOR USE IN FEEDING STRIP STOCK Filed July 19, 1951 4 Sheets-Sheet 2 Snventor KENNETH L. BANDY Otto: cg

y 29, 1956 K. L. BANDY 2,747,285

LENGTH CONTROL APPARATUS FOR USE IN FEEDING STRIP STOCK Filed July 19, 1951 4 Sheets-Sheet s y I W 0. 3 m

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LENGTH CONTROL APPARATUS FOR USE IN FEEDING STRIP STOCK Filed July 19, 1951 v 4 Sheets-Sheet 4 SDS Snnentor KENNETH L. BANDY By I (Itt neg racy.

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United States Patent LENGTH CONTROL APPARATUS FOR USE IN FEEDING STRIP STOCK Kenneth L. Bandy, Youngstown, Ohio, assignor to The McKay Machine Company, Youngstown, Ohio, a corporation of Ohio Application July 19, 1951, Serial No. 237,650

7 Claims. (Cl. 33-132) This invention relates to improved apparatus for controlling the lengths of strip stock being fed intermittently toa press or a shear, for example. It has been heretofore proposed to associate a measuring roll with a strip stock feeding device and to provide control instrumentalities actuated by the measuring roll to slow down and stop the feeding device upon a desired length of strip being ejected therefrom. It has also been proposed to provide automatic restarting controls so that upon completion of a cycle of operation of a press or shears, for example, the strip feeding device is automatically restarted to feed a next succeeding length of strip, the general arrangement being thus operative to automatically feed predetermined lengths of strip in aniintermittent manner to such apparatus as presses and shears. The control devices heretofore proposed and used for the purposes indicated have objectionable operating characteristics in that they are unable to maintain the close length tolerances considered necessary in commercial practice, in that they are difficult to adjust with the precision required, and in that the time required for their recycling between successive measuring and control operations is so great as to diminish appreciably the productive capacity of the processing line in which they are associated.

It is accordingly the primary object of this invention to provide improved stock length control apparatus for continuous strip feeding devices which operates depend ably with greatly increased accuracy and consistency, which is easily set with precision, and which is capable of being recycled at high speed at the completion of each cycle of operation.

The present invention also provides improved apparatus for initiating the activation of a control circuit the function of which is to slow down the driving means for the strip feed device, and to thereafter actuate a control element, normally an electric switch, which is operative to stop the strip feeding device.

The above general objects and advantages of my invention are accomplished through the use of Vernier or clock gearing in the length measuring apparatus whereby -the larger unit of length-feet, for example.-is apportioned on a slow moving dial while the shorter unit of length-inches, for example-is apportioned or set out on a fast moving dial. Both dials being visible and interconnected by suitable gearing, it is possible to preset the length of stock to benfed with'extreme visual accu- Likewi'se, this arrangement enables the slow and stop limit switches associated with this length indicator to be actuated'with extreme accuracy in relation to the actual lengthv of stock already fed. While this Vernier control would normally require a long recycling time due tonecessity of spinning the inch dial or shaft while the foot dial or shaft is being returned ice the rotative positions of the two dials or shafts which, of course, does not require more than a single revolution of either. This arrangement enables the apparatus to be recycled in minimum length of time regardless of the length of stock being fed.

Yet another object of the present invention is the provision of adjustments whereby the length of stock travel between slowdown and final stop may be varied. It is, of course, desirable that there be sufficient time between slowdown and final stop to insure that the feed mechanism is operating on slow speeddrive, rather than coasting under its high speed inertia, before the final stop position is reached. It is further desirable, however, that the apparatus feed at slow speed only instantaneously, since continued feeding at this feed would merely consume time and reduce the efficiency of operation of the machine. Optimum operation would therefore dictate that final stop occur immediately upon completion of coasting to slow speed. Since various operations require various speeds of stock feed, and since slowdown or coasting time will vary with the stock speed, it is highly desirable that provision be made whereby the coasting time may be readily adjusted to compensate for various feed velocities, thereby facilitating efficient operation of the apparatus at all times.

Other objects and advantages of the invention will become apparent upon full consideration of the following specification and accompanying detailed drawing wherein is disclosed a certain preferred embodiment of my invention.

In the drawing:

Figure 1 is a front elevation of a conventional metal working press and a stock feed control therefor as set forth in the invention.

Figure 2 is a front elevation of a feed control as constructed according to the principles of the invention, showing in particular the arrangement of the length indicating dials;

Figure 3 is a sectional view taken substantially along line IIIIII of Figure 2, showing in detail the internal mechanism of my apparatus;

Figure 4 is a fragmentary sectional view taken substantially along line IVIV of Figure 3, showing a detail of the resetting mechanism;

Figure 5 is a sectional view taken substantially along line V-V of Figure 3, showing further details of the resetting mechanism;

Figure 6 is a schematic diagram of an electrical circuit which may be utilized in the operation of the feed controlling apparatus of my invention;

Figure 7 is a rear elevation of one of the length indicating dials utilized in my apparatus, showing means of conducting electrical current thereto;

Figure 8 is a sectional view taken substantially along line VI'IIVIII of Figure 7; and

Figure 9 is a front elevation of the indicating dial of Figure 7 showing the calibrations thereof and showing the relation of a stop switch thereto.

Referring now to Figure 3, which depicts my apparatus in greatest detail, the reference numeral 10 denotes a housing which may be a casting but which, for reasons of economy in production, I prefer to be of Welded construction. Rotatably jou-rnaled at one end in the housing 10, by means of ball bearing 11, is an actuating shaft 13. The inner or left hand end of shaft 13 is bored at 14 and 15 and serves as the outer and driven member of an overrunning clutch assembly. The inner and driving member of the overrunning clutch assembly comprises a driving shaft 16 which is rotatably journaled at one end in the bore 15 and near its other end in a flanged sleeve 17 which is retained in concentric relation to the shaft 13 by cap screws 18 and which is rotatably journaled in the housing by ball bearing 12. The driving shaft 16 is provided with a keyway at 19 by means of which a driving engagement is maintained with a measuring roll 20 (see Figure 1). The measuring roll 20 is held in contact with a sheet or strip of stock 21 and, in response to movement of the stock 21 into or out of the press 23, will rotate the drive shaft 16. A wobbler connection 22, comprising a pair of universal joints,

is provided between the measuring roll 20 and the drive shaft 16 to permit vertical adjustment of the measuring roll to accommodate various thicknesses of stock. It

should be noted that, while the driving shaft 16 will rotate in response to movement of the stock 21 in either direction, due to the operation of the overrunning clutch assembly described above, the actuating shaft 13 will rotate in response to inward movement only, and is thus undisturbed by removal or back-off of stock from the press 23.

Keyed to the shaft 13 at its outer or right hand end is a contact collar 24 (see Figures 8 and 9 for detail) which is formed generally of plastic, fiber or similar nonconducting material but which has a small insert 25 of .copper or similar conducting material which is longitudiis retained on the disc 26 by means of screws 29 and 30. Secured to the upper edge of the brush retaining member 28 are resilient conducting strips 31 and 32 which retain at their free ends brushes 33 and 34, and which yieldingly urge said brushes against the contact collar 24. It should be apparent that positioning of the insert or contact strip 25 in contact with the brushes 33 and 34 will complete a circuit between the brushes, and that positioning of the contact strip 25 in any other position will cause the brushes to bear against the insulating material of which the contact collar 24 is generally composed to thereby cause an interruption of the circuit.

Secured to the back face of the indicating disc 26, in concentric relation thereto, is a pair of collecting rings 35 and 36 each of which is in electrical communication with a conducting strip 31 or 32 by means of a conductor, not shown, positioned inside the brush retaining member 28, each of which connects a conducting strip 31 or 32 with a screw 29 or 30, which screws are in turn connected to the collecting rings 35 and 36 as shown.

As illustrated in Figure 7, the collecting rings 35 and 36 have resilient contact with brushes 37 and 38 which are yieldingly retained by the conducting strips 39 and 40. It should now be observed that positioning of the insert 25 in contact with brushes 33 and 34 will complete an electrical circuit from conducting strip 39 to conducting strip 40 regardless of the angular position of the indicating disc 26.

A pinion 42, which is formed integrally with the shaft 13, has driving engagement with a spur gear 43 which in turn, is secured to the outer and driving member 44 of an overrunning clutch assembly by cap screws 45. R0- tation of the actuating shaft 13 in response to inward movement of the stock 21 will cause the driving member 44 to rotate an idling shaft 46 which is journaled at 47 and .48 in the housing 10. A pinion 49 which forms an integral part of the idling shaft 46 has driving engagement with a spur gear '50. Said spur gear 50 is keyed to a slow speed actuating sleeve 41 which is rotatably positioned on the shaft 13. As may be observed, rotation of the driving shaft 16 to rotate the shaft 13, will tion.

cause the rotation of the slow speed actuating sleeve 41 by means of the differential reduction gears 42, 43, 49, and 50. In the embodiment herein described, the ratio of reduction is approximately 18 to 1, so that the shaft 13 may make 17 complete revolutions before the slow speed shaft 41 has completed one full revolution. This ratio is of course arbitrary and is primarily dependent upon the desired capacity of the control.

Rotat-ably retained on the slow speed sleeve 41, at its outer or right hand end is an indicating disc 51,- which has secured to its front face an annular ring 113 which is calibrated in increments of one foot to indicate complete revolutions of the disc 26 which is rotatably retained on the shaft 13. The indicating disc 51 has secured to its back face an assembly including a brush retaining member, not shown, contact strips 61 and '62, and brushes 63 and 64 which are connected to collecting rings 52 and 53 in a manner equivalent to that shown in Figure 9. Conducting strips 54 and 55 and brushes 56 and 57 provide means of conducting current to and from the collecting rings 52 and 53.

Keyed to the slow speed sleeve '41 and adjacent the back face of the indicating disc 51 is a contact collar 5'8 which, similar to the collar 24, retains an insert or contact strip 59 by means of which the electrical circuit between the brushes 63 and 64 is completed when contact is made therebetween. Disc 65 and contact collar 66 are retained on the slow speed sleeve 41 in the same manner as the disc 51 and collar 58.

The electrical components utilized in conjunction with the disc 65 and collar 66 are the same as those used with disc 51 and collar 58 and will be referred to by corresponding primed numerals. It should be understood that while the shaft 13 rotates, and with it the contact collar 24, and while the slow speed sleeve 41 and the attached contact collars 58 and 66 rotate about the shaft 13, and discs 26, 51, and 65 do not rotate but remain stationary. For this reason it is often advisable to provide each disc with an antifriction bushing as shown at 67 and 68 to reduce wear and eliminate the inaccuracies caused thereby.

The operation of the electrical circuits described which will be more fully explained later, is briefly as follows: The discs 26, 51, and 65 are set in angularly disposed relation to the initial or zero position. Movement of the shaft 13 and slow speed sleeve 41, caused by feeding of stock 21 into the press 23, rotates the collars 24, 58, and 66 in contact with their respective sets of brushes, which have been angularly displaced along with the discs, until contact is made with inserts 25, 59, and 59'. Contact is first made with the insert 59', which closes a circuit to cause the stock feeding mechanism to continue at slow speed. The circuits including inserts 59 and 25 are connected in series so that both must be closed to complete a circuit. As should be apparent, the insert 25 makes contact with its brushes 33 and 34 once per each revolu- The insert 59, which rotates in geared relation to the insert 25, then, in effect, serves as a counter of the revolutions made by the insert 25. Upon the insert 59 rotating into contact with brushes 63 and 64, contact of stock feed while no sacrifice is made in the capacity of the apparatus due to the utilization of the slow speed collar 59 to determine the number of revolutions to be made by the high speed collar, 24.

To set the discs in the desired position I have provided a shaft 70 which is rotatably journaled at 71 in the housing 10 and which has keyed to its outer end an adjusting wheel 72. A pinion 73 is formed integrally with the shaft 70 and engages corresponding gear teeth provided along the periphery of the disc 65. A sleeve 74 is rotatably retained on the. shaft 70 and is journaled at 75 in the housing to thereby retain the shaft 70 in alignment. A

. pinion 76 is integrally formed on the sleeve 74 and engages corresponding teeth provided in the indicating disc 51. According to the provisions of the invention the ratio or reduction between pinion 73 and disc 65 is equal to that between pinion 76 and indicating disc 51. The indicating disc 26 is adjustedby means of a gear 77 of insulating material which is keyed to the sleeve 74 and which engages a pinion 78 which is formed integrally with said disc 26. This arrangement provides that rotation of the sleeve 74, by means of an adjusting wheel 79 which is keyed thereto, will rotate the disc 26 at a ratio with respect to the disc 51 which is equal to that of the shaft 13 with respect to the slow speed sleeve 41. Inasmuch as general adjustment of the controlling apparatus will not include adjustment of the slowdown time, I have provided a locking screw 80 which engages threads in the outer adjusting wheel 72 and which is operative to bear against the inner adjusting wheel 79 to thereby lock the wheels 72 and '79 against relative rotation. Thus, it may be observed that an adjustment in the length of stock to be fed will not alter the slowdown period. If, however, it is deemed desirable to make this adjustment, it may be done by merely loosening the locking screw 80 and rotating the adjusting Wheel 72 alone.

After a measuring cycle has been completed, it is necessary to reset the control apparatus to render it in readiness for the next measuring cycle. To accomplish this I have provided a reset motor 81 which is securely mounted upon a horizontal platform 82 of the housing 10. Keyed to the shaft 83 of the motor 81 is a pinion 84 which is in engagement with an idling gear 85. The idling gear 85 is rotatably mounted on a shaft 86 which is secured to the housing 10 by means of a stud 87 which extends therethrough and engages a mating nut 88. Also engaging the idling gear 85 is a gear 89 which is rotatably mounted upon a horizontally disposed shaft 90, and which serves as the driving member of a friction clutch assembly 91. Rotatably and slidably mounted on the shaft 90 is a driven member 92 of the friction clutch 91. A pinion 93 is formed integrally with the driven member 92 at its outer or right hand end, and is adapted to engage the gear 50 which is keyed to the slow speed actuating sleeve 41. To actuate the friction clutch I have provided a solenoid 94 which is securely mounted on the housing 10, and which is adapted to swing an operating arm 95 through a small are. As may be best observed in Figure 5 the operating arm 95 is securely affixed to a crossrod 96 which is rotatably journaled at 97 and 98 in the sides of the housing 10. Secured to the crossrod 96, near its midpoint, is a yoke 99, the downwardly extending legs 100 and 101 of which slidably receive a flanged portion 102 provided integrally with the driven member 92 0f the clutch assembly 91.

In the illustrated embodiment of the invention the solenoid 94 when energized moves the operating arm 95 outwardly to impart an inward engaging movement to the driven member 92. Accordingly, pressure is applied to the friction disc 103 positioned between the driving and driven members 89 and 92 of the clutch to thereby lock the two members in driving relation. It will be understood, however, that in some cases it may be desired to utilize a spring, not shown, to engage the friction clutch 91, in which case the solenoid 94 may be utilized to disengage the members 89 and 92. Such an arrangement will be contemplated as being within the scope of this invention.

Rotation of the driven member 92 rotates the gear 50 and the slow speed shaft 41 which is keyed thereto. It should be particularly noted that the direction of rotation during reset is the same as that during rotation. This is necessary since the over-running clutch assemblies permit overrun in that direction only. To reset the high speed shaft 13, I have provided a pawl 104 which is pivotally secured to the face of the gear 50 (see Figure 4). Said pawl 104 is retained in resilient engagement with the shaft 13 by a tension type coil spring 105, and is adapted to engage a step-like section 106 which is formed in the shaft 13. Rotation of the gear 50 will cause rotation of the slow speed sleeve 41 until the pawl 104 engages the steplike section 106, whereupon the shaft 13 will rotate "in synchronism with the sleeve. To insure accurate resetting of the apparatus, I have provided a notched stop bar 107 which is pivotally mounted at 108 to the side of the housing 10. A solenoid 109 is mounted on the side of the housing 10 which is directly opposite the pivot mounting 108 and is pivotally secured at 110 to the stop bar 107. During reset the solenoid 109 is deenergized to allow the stop bar 107 to rest upon the highspeed shaft 13. Upon rotation of the shaft 13 to its initial position, a step-like portion 111 of the shaft contacts a corresponding notch 112 provided in the stop bar 107. Further rotation of the shaft 13, and therefore the sleeve 41, is thus prevented. A limit switch 113', which is securedto the side wall of the housing 10, is adapted to be actuated in response to vertical movement of the stop bar 107, and thus is tripped as the bar moves into contact with the step-like portion 111. The latter switch, when so tripped, is operative to release the friction clutch 91 and disengage the resetting motor 81 as will be understood. It should be noted that rebound of the shaft 13 and sleeve 41 is prevented since the overrunning clutch assemblies do not permit rotation of these parts in the reverse direction.

While the form of the invention herein shown provides for engagement of the stop bar 107 by means of the downward force of gravity, it will be apparent that a faster and more positive engaging action may be obtained by providing a second solenoid, not shown, acting in opposition to the solenoid 109, and operative to forcibly draw the stop bar onto the shaft 13.

In reference to the electrical diagram of Figure 6, feeding of the stock 21 into the press 23 is initiated by pressing the start button G to energize relay D. The latter relay, when closed energizes solenoid 109 to release the stop bar 107, starts the reset motor 81, and supplies power to the stock feed motor 114 and high speed winding HSW therefor. After feeding of the stock 21 at high speed for a predetermined distance'the slow down limit switch SDS closes energizing relay B and transferring energy from the high speed winding of the stock feed motor 114 to the low speed winding LSW therefor. Further feeding will then continue at a very slow speed until the successive closing of the primary and secondary stop switches PSS and SSS causes energization of relay A. At this point the feed motor is stopped, the stop bar is dropped into position and the solenoid 94 is energized to engage the clutch 91. The measuring apparatus is resetimmediately upon engagement of the clutch 91, and upon the shaft 13 reaching its initial position the limit switch 113 is tripped to release the clutch and render the apparatus in readiness for the succeeding cycle.

It will be noted that the switches PSS and SSS, which cause relay A to be energized, open at the beginning of the reset. To prevent relay A from being deenergized prematurely a holding circuit is provided which includes normally open contacts of the relay A. Connected in series relation to the last mentioned contacts, but in parallel relation to each other are normally closed contacts of the reset limit switch 113 and normally closed contacts of a limit switch 115 which may be positioned on the press 23 or other associated device and adapted to open in response to the completion of operating cycle of the said press or associated device. Thus it will be understood that upon completion of the resetting of the measuring device and of the operating cycle of the associated equipment the relay A will be deenergized to initiate a new feeding cycle. When desired, however, recycling may be prevented by pushing the stop button S to deenergize relay D.

Having thus described my invention, what I consider is novel and desire to secure by Letters Patent is:

1. Apparatus of the character described comprising an overrunning clutch having a driver adapted to be connected to a measuring roll and a driven element comnected with said shaft through reduction gearing and a second overrunning clutch, said sleeve being adapted to be driven in a forward direction, a second length-indicating dial associated with said sleeve and mounting a circuit controlling device adapted to establish a second control circuit upon said sleeve reaching a predetermined rotational position relative to said second dial, means including reduction gearing interconnecting said dials to rotate said dials to an adjusted position and to retain the same in such position, and recycling means to rotate said shaft and said sleeve in forward directions to their initial starting positions upon the completion of each cycle of operation.

2. Apparatus according to claim 1 further characterized in that said recycling means comprises means to rotate said sleeve independently of said shaft through overrunning of said second mentioned clutch, a single-tooth ratchet interconnecting said sleeve and shaft whereby continued rotation of said sleeve eventually results in rotation of said shaft with said shaft and sleeve being indexed with respect to each other, and a retractible stop limiting the rotation of said shaft and consequently of said sleeve to a predetermined position.

3. Apparatus according to claim 1 further characterized in that said means to rotate said dials comprises a common shaft for mounting a pair of gears of the associated reduction gearing,'and an outwardly disposed operating knob of said common shaft.

4. Apparatus according to claim 3 further including a gear wheel rotatably mounted on said sleeve and mounting a circuit control device adapted to establish a third control circuit upon said sleeve reaching a predetermined rotational position with respect to said gear wheel, said common shaft having a longitudinal bore therein, a shaft extending through said bore and mounting at one end a pinion gear meshing with the teeth of said gear wheel and at its other end an operating knob overlying the outer face of said first mentioned knob, and means to releaseably lock and two knobs together.

5. In apparatus for controlling the Bength of strip stock issuing from a strip feeding device having a variable speed drive, a shaft adapted to be directly connected with a strip measuring roll, a second shaft connected with said first mentioned shaft through an overrunning clutch, a third shaft interconected with said second shaft through speed reduction gearing, a length indicator dial associated with each of said sec ond third shafts and each mounting a control device, reduction gearing interconnecting .to establish control circuits upon said second and third shafts reaching predetermined rotative positions with respect to the respective dials, a wheel associated with said third shaft, means to adjust and retain the relative 'rotational position between said wheel and the dial associated With said third shaft, a control element carried by said wheel, and a further control element carried by said third shaft to engage the control element carried by said wheel upon said third shaft reaching a predetermined rotational position with respect to .said wheel to establish a further control circuit. a

6. Apparatus according'to claim 5 further including an overrunningclutch interconnecting said second and third shafts, recycling means to rotate said third shaft while overrunning said last mentioned clutch, a ratchettype interconnection between said third and second shafts whereby recycling rotation of said third shaft results in simultaneous rotation of said second shaft upon said shafts attaining a predetermined rotational alignment, and retractible stop means to limit the simultaneous recycling rotation of said second and third shafts.

7. In a control device for accurately monitoring the feeding of a predetermined length of strip material wherein such predetermined length comprises a plurality of unit increments plus a fractional part of an incremental unit, the combination of primary and secondary electrical control switches for controlling the feeding movement of said strip material, first means responsive to the feeding of strip material for closing said primary control switch once during the feeding of each incremental unit of said material, second means responsive to the feeding of said strip material for closing said secondary switch in response to the feeding of a predetermined portion of said length, said portion being less than said predetermined length by an amount not greater than one incremental unit, circuit means associated with said primary and secondary switches operative prior to the closing of said secondary switch to render said primary switch inoperative to control feeding movement of said strip material, and further circuit means operative upon closing of both said primary and secondary switches to discontinue feeding of said strip material.

References Cited in the fileof this patent UNITED STATES PATENTS 990,026 Zipper Apr. 18, 1911 1,286,927 Brink Dec. 10, 1918 2,110,716 Rhea Mar. 8, 1938 2,134,271 -Wolkin Oct. 25, 1938 2,298,492 Longfield Oct. 13, 1942 2,339,194 Reichelt Jan. 11, 1944

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