US1936485A

US1936485A - Flying shears

Info

Publication number: US1936485A
Application number: US495475A
Authority: US
Inventors: Hans L Schreck
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-11-13
Filing date: 1930-11-13
Publication date: 1933-11-21
Anticipated expiration: 1950-11-21

Description

NOV. 21, 1933. SCHRIECK 1,936,485

FLYING SHEARS Filed Nov. 13 1930 5 Sheets-Sheet l 5 Sheets-Sheet 2 Nov. 21, 1933. r H. I... scHREcK FLYING SHEARS Filed Nov. 13, 1930 Nov. 21, 1933. H. L. SCHRECK FLYING SHEARS Filed NOV. 13, 1930 5 Sheets-Sheet 3 Nov. 21, 1933. H. scHREcK FLYING SHEARS Filed Nov. 13, 1930 5 Sheets-Sheet 4 W MAX/M Nov. 21, 1933. H. L. SCHRECK FLYING SHEARS Filed NOV- 13, 1930 5 Sheets-Sheet 5 o o o o Patented Nov. 21, 1933 NlTED STATES FLYING SHEARS Hans 1L. Schreclr, Easton, Pa.

Application November 13, 1930 Serial No. 495,475

9 Claims.

This invention relates to metal working plants and more particularly to flying shears and associated apparatus, such'as are employed in said plants for cutting material fed thereto into convenient lengths for various uses or for further fabrication.

One of the objects of my invention is to provide an arrangement to be employed in connection with a rolling mill in which metal ingots are reduced to the diameter and section of the billets, bars or other articles desired, whereby those articles formed from the tops of the ingots, those formed from the intermediate portions and those formed from the bottoms thereof may be severed from the attenuated ingot, gathered into groups, and delivered to separate receiving points.

Another object of my invention is to provide a novel flying shear comprising operating means, the actuation whereof may be controlled by the material passing through said shear.

A further object of the invention is the provision of a novel metal working installation, in-

cluding an improved flying shear, a material feeding device, and means by which the relative speeds thereof may be controlled.

Other objects are the provision of improved means for regulating the cutting speed of the flying shear with relation to the speed of the rolling mill from which it receives material, and the provision of a flying sliear particularly adapted to be disposed between the roll stands of a rolling mill or the like.

Further objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings, in which certain embodiments of my invention are illustrated by way of example.

In the drawings,

Figure 1 is a somewhat diagrammatic plan view of a novel arrangement embodying one form of my improved flying shear, the feed and delivery tables, distributing beds, and other material handling mechanism employed in connection therewith;

Figure 2 is a view in side elevation of a flying shear and its driving mechanism forming one embodiment of my invention;

Figure 3 is a vertical cross-sectional view taken on line 33 of Figure 2 showing the rotary shear 0 blade carrying heads;

Figure 4 is a diagram of the electrical circuits employed in connection with the actuating elements of the shear;

Figure 5 is a view partly in horizontal crosssection and partly in plan of the shear and driving mechanism shown in elevation in Figure 2;

Figure 6 is a vertical cross-sectional view taken on line 66 of Figure 5, and showing the trans,-

mission gearing and brake constituting the operating clutch for the flying shear;

Figure 7 is a plan view of a modified form of shear and drive in which pinch rollers are employed for feeding the material to the shear knives, and in which both the pinch rollers and the shear knives are driven from a single motor through hydraulic change speed gearing;

Figure 8 is a view in end elevation 'of the pinch rollers and shear housings as seen from the left in Figure 71, certain interior parts being indicated by dotted lines;

Figure 9 is a plan view of a modified form of the shear shown in Figure 7 in which the pinch rollers are directly driven by the motor and a divided hydraulic change speed gear connects the motor with the shear knives; and

Figure 10 is a plan view of still another embodiment of my improved flying shear which is particularly adapted for use between the stands of a rolling mill.

In Figure 1 of the drawings, one embodiment of my improved flying shear is designated by the numeral 10 and may be positioned to receive -material from a rolling mill, the last roll stand of which is indicated at 11. The shear is adapted to be driven by a motor 12 through the reduction gearing 13, shaft 14, and transmission gearing 15. These elements are all properly housed and supported upon a suitable foundation and will be described in more detail hereinafter. A fly wheel 16 is mounted upon the shaft 14 in order to provide the proper stability and momentum for the flying shear.

An approach table 18 which includes a series of driven rollers 19 is provided for feeding the material from the rolling mill to the shear knives. These rollers are driven by the motor 12 through the chain and sprocket drive 20, the shafting 21 and 22 and the beveled gears indicated at 23.

Immediately adjacent the delivery side of the shear there is disposed a pit 25 in which is adapted to operate a scrap buggy (not shown) for the purpose of receiving the cropped ends or other waste material cut from the billets, bars, or other articles severed by the shear 10.

As a means for conveying the severed articles from the shear and distributing them to their proper receiving points, a roller conveyor is provided which comprises several flights. The first flight is located next to the delivery side of the shear 10 and comprises a delivery table 26 provided with the live rollers 27 and also provided with a flag switch 28 which is adapted to be contacted by the forward end of the material passing through the shear, whereby the shearing operation is effected. The switch 28 may be adjusted longitudinally of the table 26 in any suitable manner for the purpose of varying the length of the articles severed from the material.

The next three flights 30, 31, and 32 of the delivery conveyor are provided with skew rollers 33 and side guards 34, the skew rollers 33 serving to move the conveyed articles laterally of the conveyor against the side guards. It will be noted also that the last two rollers of the table 26 are skewed for the purpose of initiating this lateral movement as the articles pass from the table 26 to table 30. The side guards 34 of each of the tables are laterally offset from each other a slight distance to permit the assembling of the articles as clearly shown in the drawings. ,The rollers of tables 26 and 30 are driven by the motor 35 through suitable shafting and bevel gearing. The rollers of the tables 31 and 32 are driven by means of the motors 36 and 37 respectively.

At the end of the last flight 32 of the delivery conveyor there is provided a fixed stop 40 and at the further ends of flights 30 and 31 there are provided movable stops 41 and 42 respectively. These stops 41 and 42 are adapted to be downwardly retracted or depressed by operating mechanisms comprising gearing 44, motors 43, and suitable electrical connections (not shown) whereby the stops may be actuated, preferably at the will of the operator, although the operation of these stops may be made automatic by suitable means not forming a part of the present invention. By means of these stops and the action' of the skew rollers 33 and side guards 34 a desired number of articles may be grouped or assembled upon selected ones of these gathering tables or flights 30, 31, and 32.

For the purpose of receiving and transversely conveying the grouped or assembled articles from the gathering tables 30, 31, and 32, there are provided the broadside delivery beds 48, 49, and 50. These beds are identical and but one of them will be described in detail. These delivery bed conveyors comprise principally a plurality of steel rails 51 which are preferably arranged in pairs and are supported by the cross members 52. Between the rails of each pair are provided the chain troughs 53 within which chains 54 are adapted to travel. The chains '54 are provided with suitable lugs or abutments for the purpose of engaging the metal articles and moving them from their positions on the gathering tables 30, 31, and 32. The chains are adapted to pass around pulleys or sprockets 55 carried by the drive shaft 56 driven by the motor 57 and the gearing 58. At the opposite end of the transfer tables the chains pass around pulleys or sprockets 59 whiclmare adjustably carried by suitable take-up supports 60.

A plurality of cradles 63 are provided at the delivery ends of the transfer tables for the reception of the classified groups of articles.

It will be readily understood that the arrangement just described is particularly adapted for the cutting, assembling and delivery of billets or bars cut from different portions of an ingot which has been reduced in section by the rolling mill 11. Preferably, the billets sheared from the top portion of the ingot are collected uy the table 32; those from the intermediate portion by the table 31; and those sheared from the bottom of the ingot by the first table 30.

The flying shear which has just been described may be made to receive material directly from the rolling mill in which case the transfer tables 48, 49, and 50 may serve also as cooling beds; or the apparatus may be used to receive material from other cooling beds or storage points entirely separate from a rolling mill.

The shear blades and their mountings are of substantially the same design in all of the embodiments comprised herein. In all cases the shear housings are mounted upon suitable foundations 71 and are provided with bearings 72 for the

shafts

73 and 74 upon which are keyed the upper and lower shear

blade carrying heads

75 and 76. Gears 78 and 79 are respectively mounted upon the upper and

lower shafts

73 and 74 for the purpose of causing the shear heads to rotate in opposite directions in unison. The shear heads 75 and 76 are preferably H-shaped in cross-section for the greater part of their circumference, being provided with a hub portion 80 and the peripheral flange 81 connected by the web 82. A transverse radial strengthening web 83 is also provided. At one point on the circumference of each of the heads 75 and 76 a groove 85 is formed which is adapted to receive the shear blades 86 and their retaining wedges 87. A series of bolts 88 serve to draw the wedges 87 tightly within the grooves 85 and due to the inclined contacting surfaces 89 of the groove and wedge, the blades 86 are securely retained within the

heads

75 and 76. The heads are keyed in such positions on the

shafts

73 and 74 that the cutting edges 90 of the blades are caused to register once during each revolution thereof.

In the embodiment illustrated in Figures 2 and 5 the lower shear drive shaft 74 is extended laterally for a considerable distance to provide suitable connection with the operating means now to be described.

Keyed upon the shaft 74 adjacent the shear housing 70 is the sleeve 92 which carries the bevel gear 93. Further along the shaft 74 there is rotatably mounted a sleeve 94, bushings 95 and 96 serving to permit relative rotation between the shaft 74 and the sleeve 94. Upon the end of the sleeve 94 next to the shear blades there is carried the bevel gear 97 which is exactly similar to the gear 93 carried by the sleeve 92. Between the sleeves 92 and 94 the shaft 74 is provided with a bushing 98 upon which is rotatably mounted the hub 99 of the pinion wheel 100. The wheel 100 is provided with the lateral shrouds or casings 101 which terminate in the collars 102 which are spaced from the sleeves 92 and 94 by means of the bearing bushings 103 and 104. A seriesof stub shafts or pins 105 have their ends mounted in the hub 99 and in the rim of the wheel 100 respectively. These pins 105 are surrounded by bushings 106 upon which are rotatably mounted the bevel pinions 107. There are preferably four of such pinions equally spaced around the interior of the wheel 100 and they are all adapted to mesh with the bevel gears 93 and 97.

The sleeve 94 outwardly of the gear 97 is adapted to carry the gear 110 which is keyed to the sleeve as at 111. This gear 110 forms a part of a reduction gearing, the other member of which is shown at 112 as being mounted upon the countershaft 113 which is supported at one end within the bearings 114 carried by the foundation 77. The other end of the shaft 113 is rotatably mounted in bearings 115 carried by the motor base 116 and between which the shaft is adapted to carry the gear 117. This gear 117 together with the smaller gear 118 is adapted to provide a further reduction gearing. Upon an intermediate portion of the shaft 113 there is carried a fly wheel 120. The gear 118 is carried by a short shaft 121 which is operatively connected with the motor 122 by means of coupling 123 of any suitable type. The motor 122 and reduction gears 117, 118 are supported by the motor base 116.

It will thus be seen that the drive from the motor 122 is transmitted to the lower shear blade carrying shaft 74 through the following elements: coupling 123, shaft 121, gearing 117, 118, shaft 113, gearing 110, 112, sleeve 94, bevel gear 97, pinions 107, bevel gear 93, and keyed sleeve 92. This motion will only be transmitted when the pinion carrying wheel is retarded or stationary as will be readily understood.

In order to provide a clutchvmeanswhereby movement of the wheel 100 maybe controlled, there is provided a spring-set, solenoid brake of any suitable type but which is preferably constructed as shown in Figures 5 and 6 of the drawings. Brake shoes 125', provided with friction surfaces 126 are carried by the

levers

127 and 128 by means of the pivot pins 129. The lower ends of the

levers

127 and 128 are pivoted to the base 77 as at 130 and 131. A rod'l33 is pivotally connected to the upper end .of lever 127 by. means of the pivot pin 134. The opposite end of the lever 133 is adapted to pass freely through the lever 128 at a point near its upper end and is surround; ed by the spring 135 which is adapted to be. come pressed between the stop 136 carried by the shaft, 133 and the stop 137 associatedwith the upper, end of the lever 128'. It will be seen from theco'n struction just, described that the expansionof the, spring 135 between the stops 136 and 137 will-causethe brake shoes 125 to be applied with sufficient force to the periphery of the wheel 100'to prevent the rotation thereof and thus to permit the driving of the shaft 74 through the pinions 107. In

order to release the shoes 125 and permit the me tation of the wheel 100 a lever 140 is provided which is fulcrume'd upon a pin 141 at the upper end of the lever 128. The short arm of thislever is pivotally connected to an intermediate point of the shaft 133 as at 142. The end of the longer:

arm of the lever 140 is connected by means of, the

link 144 with the core or plunger 145 associated with the solenoid 146. The solenoid magnet 146-, is suitably secured to the base[7 7 and is adapted I to be actuated in accordance with the electrical.

control apparatus which will hereinafter .bejv .de-, scribed. It will be readily perceived thatwhen the core 145 of the solenoid is drawn downwardly the lever 140 through its connection with the rod 133 set brake 150, similar in construction to the clutch brake just described, is provided upon the right hand end of the shaft 74 as seen in Figure 5. This brake 150 is provided with shoes. 151 which are operated by pairs of levers 152 and153 connected by cross members 154 to which the rod 155 carrying the spring 156 is connected. The

solenoid 157 is adapted to be activated to release.

the brake shoes 151 from the brake drum 158 carried by the end of the shaft 74.

The driving motor 122 is adapted to run continuously, its'speed is preferably controlled in accordance with the speedof the rolling mill which delivers to the shear and the starting and stopping of the flying shear 10 is controlled by the alternate actuation of the clutch 148 and the brake 150.

The operation of the shear is as follows. When running idle, the shear brake 150 is set, the clutch 148 is released so that the wheel 100 carrying the pinions 107 is allowed to rotate freely, and the shear blades occupy a predetermined position near the cutting point. When the end of the material passing along the delivery table 26 strikes the flag switch 28 the shear brake 150 is released, the clutch 148 is setand the shear blades revolve, take a cut, and continue for just one revolution. A limit switch 160 which may be of any suitable type of reversing switch is preferably provided inconnection with the upper shear shaft 73. This switch 160' serves to reverse the current and stop the shear, at the end, of its cutting movement by releasing the clutch brake 148 and setting the shear brake 1'50, whereupon the shear is readyfor the next cut initiated by the tflagtor track switch 28,, The reversing of the ccntacts may also be, effected by'a manually operatedmaster switch if desired. 1

Ana propriate wiring diagram for the control of theoperationof ,the flying shear 10'is shown 1 in Eigure, 4. .The fiag switch 28 is seen to com-- prise a jflag or vane 162 which is urged rear-- wardly, by means of a suitable spring 163 and is adapted to be moved forwardly'by contact with thef-forwardyend 164 ofthe material being fed bridging conductors 166, about the center 167 through an angle of 90, thus alternately connecting diametrically opposite ones of the contacts 168, 169, -170,-and 171'.; Contacts 168 and 169 are both connected to=one side 270 of the current main. and the other side 271 is suitably connected by means of

conductors

172 and 173 with thesolenoids of brake 150 and clutch 148 respectively. The contacts and 171 are respectively connected to opposite contacts of the rotary limit 1 switch 160 which is a, reversing switch suitably geared to the shear shaft 73 for effecting a re-- versal of the operation of the brake 150 and the clutch 148 atthe end of one revolution of'the shear 10. The poles of the limit switch 160 are connected by means ofkthe conductors 1'75 and 176 to the brake 150 and the clutch 148 respectively. A master switch 180 is interposed between these conductors for manually reversing the operation of the device at-will.

After the operation of the shear has been halted by the actuation of the rotary limit 1 switch 160, the flag-switch ,28-is then ready to be actuated by the new forward end o'f the strip formed by the out just taken by the shear. If it is ficiently to-withdraw the sheared length more rapidly thanthe rate of feeding of the main portionlof the strip.

In the modification shownin Figures "7 and 8,

the shear knife and. associated elements, the

brake 150 and clutch 148 are of the same type purpose of securing greater compactness certain of the elements shown in the former embodiment have been omitted from the present construction and the positions of the clutch 148 and brake 150 have been interchanged. In this construction there has been added a pair of pinch rolls 200 as in the embodiment just described- For the suitably encased in housing 201, for the purpose of controlling the feeding rate of the material to the shear and permitting the use of this shear either in direct conjunction with the rolling mill or as a separate operating unit. A single motor 202 is employed for driving both the pinch rolls and the shear knives, and when working directly with a mill, it is proposed that the motor be controlled from the drive shafts of the mill to allow for the difference in delivery speed due to speed changes of the rolling mill. When operated independently of the rolling mill, for instance after a cooling bed or the like, the driving motor of the shear and pinch rolls can be either of a constant speed or of a variable speed as desired. These pinch rolls 200 are in effect measuring rolls for exactly determining the speed of the material being fed to the shear knives and this rate of speed is controlled by means of a speed changing gear 203 which is preferably of a well-known hydraulic type. This change speed gear may be used in conjunction with a constant speed motor 202 to vary the feed of the material through the pinch rolls in accordance with either the speed of the mill from which the material is received or to suit the conditions of independent operation of the flying shear. It will be noted from an inspection of Figure 7 that the motor 202 is adapted to drive the pinch rolls at one end and the other end of the motor is connectedby a chain or other suitable driving means 204 to a second variable speed gear 205 which is in turn connected to a fixed reduction gearing contained in the housing 206. This second speed changing gear 205 is necessary in order to permit variations in the speed of the shear knives and consequently in the length of the bars or articles that are to be cut. The shear disclosed in Figure? may be operated in exactly the same way as the one illustrated in the preceding figures of drawings by starting and stopping the shear knives with each cut by means of the fiag and limit reversing switches, but it is preferred to operate the shear. continuously as long as material is being supplied, thespeed of the shear knives with relation to the rate of feed of the pinch rolls determining'the length of the articles delivered regardless of anyfluctuation in the speed of the motor 202.

The operation of the shear knives is initiated as usual by the release of the brake 150 and setting of the clutch 148 which is effected in this instance by a cropping switch actuated by means of the flag or plate 208 which is pivoted at 209 and adapted, when in open position, to depend across the path of the material to be cut and above the intermediate rest or guide member 210 as clearly shown in Figure 8. When the front end of the material passes through the pinch rolls, it will lift the flag or plate 208, close the circuit, start the operating of the shear knives which will crop the front end of the material, and will continue in operation as long as material passes beneath the switch actuator 208. When the tail end of the bar has passed beneath the flag 208, the fiag will drop thus opening the circuit and stopping the operation of the shear.

The cropped ends of the material are allowed to fall-into the scrap buggy which is adapted to occupy the pit 25.

In the modification illustrated in Figure 9, the same pinch rolls 200 are employed in connection with the shear 10 and the cropping and starting and stopping are effected in the same way as in the embodiment shown in Figures '7 and 8. In this instance, however, the motor 202 is directly connected to the pinch rolls 200 by means of suitable coupling 212 and the hydraulic change speed gearing connecting the other end of the motor shaft to the shear driving mechanism is divided into two units, the pump unit 214 and the motor unit 215, which are connected by suitable pipes 216 for the transmission of the motive fluid of the gear.

This particular embodiment is not adapted for direct connection to a rolling mill and will, of course, be used only when the material is taken from a cooling bed or storage space when the speed of the shear is not dependent upon any fixed delivery speed of the material to be out. In other respects the shear will operate in the manner as the one previously described.

In order to determine the length of bars to be out by the shear knives in accordance with the feeding speed, it is proposed to provide a suitable speed indicating device on the pinch rolls which will permit a direct reading of the speed of the bar passing through said rolls in feet per minute. Thus, knowing the exact speed of the material passing through the pinch rolls and also knowing the required length of the pieces to be cut, it becomes a simple matter to so regulate the speed of the shear knives by means of the variable speed gear as to obtain the correct number of cuts per minute and this number may be read upon a second speed indicator connected 105 wi.h the shear knives. For example, if the delivery speed of the material to be cut is five hundred feet per minute as shown on the first .speed indicator and the bar to be delivered or cut is to be twenty feet in length, the shear knives will have to run at a speed of twenty-five revolutions per minute, or five hundred divided by twenty.

In the operation of rod mills or the like, a thirty foot bar is generally employed from which to roll the finished material, and if it were rolled out in one continuous piece, the finished bar would be too long to handle conveniently and to avoid this, it has been the practice to shear the rolled section after it has come through a predetermined number of passes. For use in this connection, wherein the shear is installed between certain of the roll stands ofthe mill, the embodiment of my improved flying shear which is illustrated in Figure 10 of the drawings is well adapted. The motor 220 in this embodiment is disposed with its axis parallel to the axis of the shear and the motor shaft is adapted to be connected with the drive shaft '74 by means of reduction gearing encased in the housing 221. The other elements illustrated are identical with the corresponding ones in the embodiments heretofore described.

The exact length of the bar cut off is not of great consequence in this operation and the .ac-

tuation of the shear may be accomplished by any' suitable manually operated switch or push button. A skilled operator may very-readily determine when to actuate the shear by following the movement of the tail end of the billet passing through the mill. Assuming the starting section of the billet to be, for example, 1% inches in diameter and the section of the bar which is to be cut to be inch in diameter, it follows that v the tail end of the 1% inch billet will always be at a certain fixed place for certain lengths of inch bar to be cut, and thus the operation is readily adapted to be performed either manually or by the provision of flag switches, analogous to that designated 28 in Figure 1, along the path of the material through the mill, except in cases 5 mea er where it might happen that the position of the flag would coincide with the position of a roll stand, in which case, of course, hand operation would have to be relied upon.

It is understood that various changes and modifications may be made in the embodiments herein disclosed without departing from the scope of the invention as defined in the following claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1.. In a flying shear, in combination, a pair of rotary shear blades, a drive shaft therefor, a motor for driving said shaft, transmission gearing between said shaft and said motor, an electrically operated clutch associated with said transmission gearing, an electrically operated brake for said shaft, and a two-position switch adapted to be actuated by material passing through said shears to release said brake and actuate said clutch.

2. In a flying shear, in combination, rotary shear heads, a motor for driving said heads, an electrically operated clutch for effecting an operative connection between said shear heads and said motor, an electrically operated brake for preventing rotation of said shear heads, a delivery table for conveying material operated on by said shear, a two-position switch adjustably carried by said table and adapted to be operated by material passing along said table to actuate said clutch and release said brake, and a reversing switch actuated by the rotation of said shear heads for releasing said clutch and applying said brake.

3. In a flying shear, in combination, a rotary shear blade, a motor for driving said blade, a clutch for effecting a driving connection between said motor and said blade, a brake for preventing the rotation of said blade, electricalmeans for releasing said clutch, electrical means for releasing said brake, a source of current, a switch actuated by the material acted upon by said shear for connecting said brake releasing means with said source of current and disconnecting said clutch releasing means from said source of current, a switch actuated by the rotation of said shear blade for reversing the connections effected by said first named switch, and a' manually controlled switch for reversing the connections effected by either of said other switches.

4. In a flying shear apparatus, in combination, shear blades, a rotary shaft for operating said blades, a set of pinch rollers for feeding material to said blades, 9. common motor for driving said shaft and rollers, a variable speed gear operatively disposed between said motor and said pinch rollers, another variable speed gear operatively disposed between said motor and said shaft, electrically controlled clutch gearing between said last named variable speed gear and said shaft, and an electrically controlled brake adapted to be applied to said shaft in alternationwith said clutch gearing.

5. In a flying shear apparatus, in combination,

a set of rotary shear blades adapted to take a out once during each revolution, a set oi. pinch rollers for feeding material to said shear blades, 9. motor for driving said rollers and said blades, a clutch for operatively connecting said blades with said motor, a brake associated with said blades and adapted to be actuated in alternation with said clutch, control means for said clutch and brake the hydraulic change speed gear.

disposed between said rollers and said blades in the path of the material passing therethrough,

speed of said blades with relation to that of the 84 pinch rollers in accordance with the length of the article to be cut. a v

6. In a flying shear apparatus, in combination, a base, a set of pinch rollers, a motor, and a hydraulic variable speed gear pump unit operatively connected and disposed in alignment along one side of said base, a set of rotary shear blades, brake and clutch means therefor,-and a hydraulic varible speed gear motor unit operatively con-= nected and aligned upon said base in parallel relation to said first named series of apparatus, said pinch rollers and said shear blades arranged for passage of material from the former through the latter, and piping connecting the named units of 7. In a metal working apparatus, in combination, a rotary flying shear, a driving shaft for said shear, a source of power, a material forwarding machine disposed in advance of said shear in the line of travel of said material, starting and stopping means for said shear comprising planetary difierential gearing operatively disposed between said driving shaft and said source of power, an electrically operated brake for the planet carrier of said difierential, and another electrically 5 operated brake for said driving shaft, and control means for said devices including a switch adapted to be actuated by the material passing through said apparatus for efiecting the application of said first named brake to enable the transm mission of power through said planetary gearing, and for releasing said last named brake to permit the rotation of said drive shaft.

8. In a flying shear, in combination, a rotary shear blade, a motor for driving said blade, a clutch for effecting a driving connection between said motor and said blade, a brake for preventing the rotation of said blade, electrical means for releasing said clutch, electricalmeans for releasing said brake, a source of current, a switch actuated by the material acted upon by saidshear for connecting said brake releasing means with said source of current and disconnecting said clutch releasing means from said source of current, and a switch actuated by the rotation of said shear blade for reversing the connections effected by said first named switch.

9. In a shearing apparatus, in combination, a flying shear comprising a pair of cooperating rotary knives, a driving shaft for said knives, an electrically operated brake adapted to be applied substantially directly to said shaft for stopping said shear, a bevel gear splined to said shaft, a sleeve rotatably mounted on said shaft, a similar but oppositely facing bevel gear on said sleeve, 9. driving gear splined to said sleeve and operatively connected to a source of power, a planet gear carrier mounted for rotation on said shaft between said bevel gears, planet gears on said carrier meshing with said bevel gears, and an electrically operated brake adapted to be applied to said planet carrier to effect the transmission of motion through said gearing, and meansfor acratus.

HANS L. scrrancx.