US1970445A

US1970445A - Flying shear

Info

Publication number: US1970445A
Application number: US627341A
Authority: US
Inventors: Robert H Ellis
Original assignee: United Engineering and Foundry Co
Current assignee: United Engineering and Foundry Co
Priority date: 1932-08-03
Filing date: 1932-08-03
Publication date: 1934-08-14
Anticipated expiration: 1951-08-14

Description

Aug. 14,1934. R. H. ELLIS FLYING SHEAR Filed Aug. 3, 1932 OOOO OOQOQOQO w 7 NM owvoooooooooooooooooooo INVENTOR was Patented Aug. 14, 1934 UNITED STATES PATENT OFFICE I I FLYING SHEAR Application August 3, 1932, Serial No. 627,341

' 9 Claims. (01. 16468) This invention relates to flying shears or devices having similar operating characteristics, and more particularly to a control system for governing the operation of such apparatus.

The primary object of the invention generally stated is to provide a control system of novel form which is adapted to automatically regulate the operation of a flying shear in such a fashion as to determine the length of the first, or cropping, cut made by the shear, as well as the lengths of the subsequent or regular cuts.

Another object is to provide a system of this character which may be easily and readily adjusted to vary the lengths of the cuts anywhere from substantially zero up to the full length of the stock being operated upon, without necessitating any mechanical adjustment of the shear or the means employed to feed the stock into the shear.

A further object is to provide in such a system for automatically compensating for any variations in the speed of the stock which may be caused by variations in the speed of the feeding mechanism in such a way that such variations will not vary the lengths of the cuts.

A still further object is to provide for controlling the operation of a flying shear in such a Way that the shear may be caused to produce cuts of any desired length, and its cutting blades so governed as to have a peripheral speed corresponding to the linear speed of the stock being severed at the instant of cutting, irrespective of the speed of the stock.

These and various other objects, as well as the various other novel features and advantages of the invention, will be apparent from the following detailed description when read in conjunction with the accompanying drawing, of which Fig. 1 is a diagrammatic illustration of a control system comprising a single embodiment of the invention; Fig. 2 a diagrammatic side view of the shear and rolling mill shown in Fig. 1; and Fig. 3 an end view of the controller shown in Fig. 1, coupled to the motor employed for driving the shear.

Referring to the drawing, the numeral 1 designates generally a rotary drum type flying shear which iscoupled to a driving motor 2 and arranged to operateupon pieces of stock delivered to it from a rolling mill 3 or other feeding device over a conveyor table 4. vIn this embodiment of the invention shear 1 is of the type known in the art as a start and stop shear being adapted to perform a single out each time it is operated. For efiecting its operation motor 2 is connected in a circuit comprising conductors 5 and 6 which furnish it with current supplied by a pair of line conductors M and N. In this circuit there is provided a circuit breaker 7 for controlling the current supply to motor 2. For in turn controlling the operation of this circuit breaker a drum type controller 8 is provided, which is coupled directly to the drive shaft of the motor 2. Upon the drum 10 of this controller there is provided a continuous conductor band 9 and an iriterrupted conductor band 11 which are connected together by a connector 12. Cooperating with these conductor bands are a pair of brushes lfl and 15 which are supported by a yoke 13 pivotally mounted on the axis of the controller. One of these brushes 14 is connected to line conductor M and the other to the operating coil 7a of circuit breaker 7. From coil 7a this circuit is traced by wayof a conductor 18 and a conductor 19 through a controller 17 to line conductor N. The latter controller 17, which is also a rotary type controller, the details of which will presently be described, is adapted to complete the circuit through coil 7a momentarily each time it is rotated, and each time such circuit is completed the circuit breaker 7 is closed and the shear motor 2 set in operation.

To maintain the motor 2 energized for a suificient period for it to complete a cycle of operation each time it is set in motion, a holding circuit 21 is provided for the actuation coil 7a of the circuit breaker 'l, which is traced from conductor 18 through an auxiliary bridging member 7b on breaker 7 to conductor 19 in shunt circuit relation with controller 1'7. With this arrangement, each time the shear motor is started by the closing of circuit breaker '7 in response to the operation of controller 17 it is maintained energized until the brush 15 of controller 8 runs ofi band 11 of drum 10. When this occurs the breaker falls open and the motor stops. remaining out of service thereafter until the circuit breaker is again closed by controller 17.

In order that controller 8 will be in a position to operate and maintain the circuit for motor 2 until the shear has completed the cycle of operation each time circuit breaker 7 is closed, the interrupted conductor band 11 on its control drum 10 is so designed that the momentum of the shear and motor will move the controller sufiiciently after breaker 7 is deenergized to re-engage band 11 with brush 15. While to adapt the shear to start from a preselected position of rest each time .it is operated, a magnetic brake 22 is mounted on its drive shaft 23. For controlling this brake its actuating coil (not shown) is connected to conductors 5 and 6 on the same side of breaker '7 as motor 2 by a pair of conductors 24 and 25. Thus, when the circuit breaker '7 is open brake 22 is placed in operation to bring the motor to rest, and as the characteristics of the motor 2 and brake are substantially constant under all conditions of operation, the shear is brought to rest in substantially the same overtravel after each operation.

To vary the time elapsing between the time when the shear is set in motion and the time when the blades of the shear move into cutting opposition to perform a cut, yoke 13, carrying the brushes 14 and 15 on controller 8, is mounted for circumferential adjustment about the drum 10. To efiect this adjustment a lever 25, is secured to the yoke 13 and provided with a releasable latch 26 which is arranged to engage, a geared semi-circular race 57 rigidly mounted on the end of the frame in which the controller rotates (see Fig. 3). Another purpose of this ad justing feature of the controller, and the brake 22 employed on the shear motor, is to make it possible to vary the speed of the shear blades at the instant of cutting. This is done by setting the brake and controller in such positions that the shear motor will not have time to pick up full speed before the out is made. Consequently, by varying the time between the starting of motor 2 and the time of cut the speed of the blades at the instant of cutting may be varied by such adjustment. The speed of the blades may be further varied, of course, by the use of a variable resistance 20 provided in the shear motor circuit.

Referring to controller 17, as illustrated, the drum 27 of this controller is provided with a continuous conductor band 28 and a conductor segment 29 which are connected together by a connector 31. Cooperating with these is a pair of

brushes

32 and 33, respectively, which are mounted on a support 30 and connected to conductors 18 and 19 in the circuit through the actuating coil 7a of circuit breaker '7, previously traced. With this arrangement the circuit is completed through conductors 18 and 19 each time the conductor segment 29 makes contact with its associated brush 32. Hence, the shear is set in motion, as stated above, each time controller 1'7 is rotated, and consequently the length of the cuts made by the shear are determined by the speed at which the drum 27 is operated.

For driving controller 17 it is connected to a variable speed motor 34 through a magnetic clutch 35, the purpose of which latter will presently appear. The current for this motor is supplied to its armature, not shown, by

conductors

36 and 37 which are connected to line conductors M and N through a variable resistor 38. This resistor is employed to vary the speed of motor 34 to in turn vary the speed of drum 2'7, and hence the lengths of the cuts made by the shear. It will'be appreciated that the number of conductor segm'ents' 29 on the drum 27 may be varied, as well as the construction of the controller. i

To further control the operation of the shear so that variationsin the speed of the mill 3, or whateverother' feeding means is employed, will not vary the lengths of the cut, the field Windings of motor 34, (Iiot shown) are connected by conductors 39 m 41 to the armature (not shown) of a generator42 which is coupledto a motor 43 utilized to drive the mill. With this arrangement, whenever the speed of the mill varies the output of generator 42 will vary accordingly and correspondingly the field current of motor 34, which will result in a corresponding variation in the speed of motor 34 and controller 1'7, which will compensate in the operation of the shear for the variations in the speed to the stock and maintain the lengths of the cuts constant.

As shown, motor 43 may be connected to line conductors M and N by means of conductors 44 and 45, and the field windings (not shown) of generator 42 by conductors 46 and 47 through a variable resistor 48. This latter resistor is provided primarily for varying the output of the generator 42 so as to provide the necessary current for the field of motor 34. However, as will be appreciated, it may also be utilized for varying the speed of the latter motor in somewhat the same fashion as resistor 38.

To provide for automatically controlling the length of the first cut made by the shear upon each piece of stock passed through it, or in other words to provide for cropping cuts, a fiag switch 51 is mounted in the path of travel of the stock and is connected in a circuit 52 which is traced from line conductor M to line conductor N through the actuating coil 53a of a circuit breaker 53. This circuit breaker in turn is included in a circuit 56 traced from line conductor M to line conductor N through the magnetic clutch 35 connecting the controller 1'7 to its operating motor 34 and a magnetically operated stop 54 mounted on the shaft 55 of controller 17. The purpose of the clutch 35 is to permit the drum 27 of controller 17 being disconnected from motor 34 whenever the flag switch 51 is not engaged by a piece of stock, while the stop 54 is adapted to stop the drum 27 in a definite position each time the clutch'35 is released. This is for placing the drum in such a position for starting that the engagement of the front end of the stock with the flag switch will determine the first length of the cut. Obviously with such an arrangement the length of the first cut may be determined by the setting of stop 54, which may be adjustable. The details of construction of such a stop have been omitted, as well as those of the flag switch, inasmuch as such devices are so common in the art that it is not deemed necessary.

For operation the brushes on controller 8 are first adjusted so that the shear blades will have the proper cutting speed at the instant of cutting for the speed at which the strip is to be delivered to the shear, and the flag switch 51, which is adjustable, is so positioned, as is the mechanical stop 54, on the drum 27 of controller 17 that the length of the first cut will be determined. The motor 34 is then adjusted to give the proper speed to controller 1'7 to produce the lengths of cuts desired. With these adjustments made, when a piece of strip strikes the flag 51, circuit breaker 53 is energized which in turn releases the stop 54 of controller 17 and connects the drum 27 thereof to the motor 34 through the operation of the magnetic clutch 35 which is also energized by'the closing of the circuit breaker 53. Thus, the drum 27 is set in motion to complete'acircuit through the actuating coil 7a of the circuit breaker '7 as soon as the conductor segment 29 engages its cooperating brush 32 With the closing of the circuit breaker '7 the holding circuit 21' is established by the closing of bridging members '76 and motor 2 is started. At the same time brake 22 is released and controller 8 set in motion. Motor 2 once started continues to rotate until the conductor band 11 of controller 8 passes out of engagement'with its cooperating brush 15. When this latter occurs the circuit through the actuating coil 7a of circuit breaker"? is interrupted and the circuit breaker falls open deenergizing motor- 2'. At-the same time the magnetic brake 22 operates bringing the shear and motor to rest. During such period of operation a cut is made and the shear is returned to its starting position. Thereafter, each time the conductor segment 29 on drum 27 engages its associated brush 32, a similar cycle of operation is repeated and such continues as long as the flag switch 51 is maintained closed by the stock. As soon as the trailing end of the stock passes out of engagement with flag 51, circuit 52 is broken and circuit breaker 53 allowed to open. With the opening of this circuit breaker the magnetic clutch between the motor 34 and the controller 17 is. deenergized, disconnecting the controller from such motor and at the same time mechanical stop 54 is rendered operative to stop the drum 27 in a preselected position of rest, where it is in readiness to control the length of the first cut when another piece of stock is fed into the shear.

As will be readily appreciated'by those skilled in the art, the mechanical part comprising this system may take various other forms than those shown.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A control system for a rotary flying shear comprising means for driving the shear, means for continuously feeding a piece of stock into the shear, means for automatically starting the shear at intermittent intervals, means {or stopping the 2. A control system for a motor'driven flying.

shear comprising means for-continuously feeding a piece of stock into theshear, means for automatically starting the shear motor in response to the stock in a manner to control the length of the first cut, means for automatically stopping said shear motor after'each operation of the shear, and means for intermittently restarting the shear at regular predetermined intervals as long as said stock responsive means is engaged by the "stock to produce uniform cuts the length of which has no relation to the length of the first cut. 1

3. A control system for a flying shear, comprising a motor for operating the shear, means for starting said motor at intermittent intervals, means for stopping said motor after each cut, and means for varying the speed of said motor start ing means to vary the length of the cuts.

for starting said motor at intermittent intervals,

,said feeding means.

means for stopping the motor after each operation of the shear and means responsive to said stock feeding means for varying the operation of said motor starting means in accordance with any variation which may occur in the speed of 5. A control system for a flying'shear, comprising a motor for operating the shear, means for continuously feeding a piece of stock into the shear, means responsive to the stock for starting said motorin a manner to determine'the length of the first cut, means for stopping the motor after each cutting operation of the shear, means for intermittently restarting said motor as long as said stock responsive means is engaged by the stock, variable speed means for driving said intermittently operable motor starting means to determine the length of the cuts, and means re- 'sponsive to said stock feeding means for maintairring the operation of said motor restarting means synchronous with said stock feeding means.

6. A control system for a flying shear, comprising a motor'for operating said shear, a source of current supply for said motor, a circuit breaker for controlling said-motor, a controller coupled to said motor for controlling said circuit breaker, means operable in conjunction with said controller for closing said circuit breaker the controller being adapted to open the circuit breaker after each cutting operation of the shear, a magnetic brake for stopping said motor controlled by said circuit breaker, and means on said controller for varying the opening of said circuit breaker with respect to the cutting position of the shear.

'7. A control system for a flying shear, comprising a motor for driving the shear, a source of current supply for said motor, a circuit breaker for controlling said motor, means for feeding a piece of stock into said shear, a flag switch arranged in the path of travel of the stock for closing said circuit breaker to control the first cut, a controller actuated by said motor for opening said circuit breaker after each cutting operation of the shear, a controller for restarting said motor, a second motor releasably coupled to said latter controller for effecting its actuation, and means responsive to said flag switch for connecting and disconnecting said second motor to the 1astmentioned controller.

8. A control system for a flying shear, comprising a motor for driving the shear, a source of current for said motor, a circuit breaker for controlling said motor, a flag switch for closing said circuit breaker in response to the stock fed into the shear to control the length of the first cut, a

stock into the shear, and means responsive to said 1 feedingmeans for varying the'operation of said controller motor to maintain the lengths of the cuts constant. v

9. A control system for a flying shear,-comprising a motor for driving the shear, a'source of current for operating and a magnetic brake for stopping said motor, a main circuit breaker for controlling said motor and motor brake, a rotary on said auxiliary controller when actuated for intermittently closing said main circuit breaker, means on said first-mentioned controller for opening said main circuit breaker and applying said motor brake after each cut of the shear, means for feeding the stock into the shear generator driven by said feeding means, and means responsive to said generator for varying the speed of said auxiliary controller motor.

ROBERT H. ELLIS.