US2006072A

US2006072A - Blanking press

Info

Publication number: US2006072A
Application number: US671953A
Authority: US
Inventors: Ferris Walter
Original assignee: Oilgear Co
Current assignee: Oilgear Co
Priority date: 1933-05-20
Filing date: 1933-05-20
Publication date: 1935-06-25
Anticipated expiration: 1952-06-25

Description

June 25, 1935. w. FERRIS BLANKING PRESS Filed May 20, 1933 s Sheets-Sheet 1 lNVENT OR VVALTER FERR'IS.

A QRN June 25, 1935. w. FERRIS BLANKING PRESS Fiied May 20, 1933 5 Sheets-Sheet 2 INVENTQR VVALTER FEE RIS- B ORY W. FERRIS BLANKING PRESS Filed May 20 June 25, 1935.

, 1933 5 Sheets-Sheet 5 INVENTOR WALTER FEHE'IS.

WNEY

W. FERRIS BLANKIN'G PRESS June 25, 1935.

5 Sheets-Sheet 4 Filed May 20 1933 llllllllllllll -Pl. f

A ORN loa Patented 1...... 25, 1935 2,006,072

UNITED STATES PATENT OFFICE' BLANKING PRESS Walter Ferris, Milwaukee, Wis., assignor to The Oilgear Company, Milwaukee, Wis., a corporation of Wisconsin Application May 20, 1933, Serial No. 671,953

g 10 Claims. (01. 1s4 zo) This invention relates to blanking presses of Fig. 3-is a sectional plan view taken substanthe type provided with a feed mechanism for tially on the irregular lines 33 of Fig. 2 and feeding strips of work step by step between a Fig. 4. 7 pair of dies which are actuated to form succes- Fig. 4 is a vertical section taken on the line 4-4 5 sive blanks from each strip as it is intermittently of Fig. 3.

fed between the dies, such as the press disclosed Fig. 5 is a sectional plan view taken on the line in my copending application, Serial No. 473,042, 55 of Fig. 4. which was filed August 4, 1930 and of which the Fig. 6 is a detail view taken on the line 66 of present application is a continuation as to mat Fi 1. ters common to both applications. Fig. 7 is a diagrammatic view showing the elec- 10 A blanking press of this character is ordinarily tric circuit which controls the trimming mechaadjusted to stamp as many blanks as possible nism and the position of the work just before the from each strip but it is important that the die trimming mechanism is actuated. be prevented from cutting through the end niar- Fig. 8 is a plan view showing two strips of work 35 gin of the strip in order to avoid injury to the die., having the adjacent ends trimmed therefrom. 5

The present invention has as anobject to pro- Fig. 9 is a view showing the punch or male die vide a blanking press which will trim from a passing between the adjacent ends of two strips strip that part which would partly overlie the of work. blanking dies after the last complete blank has Fig. 10 is a plan view of a strip from which two been stamped therefrom. series of blanks have been punched. 20

Another object is to provide a press which will The invention is shown incorporated in a press trim during one reciprocation of the press platen of the type disclosed in application Serial No. the trailing end of one strip and the leading end 570,822 filed October 24, 1931 by Walter Ferris, of the following strip to provide between said John P. Ferris and George L. Heiden. The Dress strips a space through which one of the dies may .ShOWn in that pp i ation is provided with mech- 25 pass during a succeeding reciprocation of the anism for feeding successive strips of work step press platen. by step through the press, mechanism for trans- Another object is to provide a trimming mechferring strips from a magazine to the feed mechanism which will accomplish the above function anism. mechanism for causing the ram to miss and which may be readily applied to existing a stroke when only a part of the lower die is so presses of different types. Y covered by the end of the strip, and timing mech- Another object is to provide a press with trimanism for actuating the transfer mechanism and ming mechanism which will automatically trim the stroke missing mechanism at predetermined. strips of various lengths close to the last blank intervals.

5 which may be stampedtherefrom. Press illustrated in the pa yi 86 Another object is to provide a trimming mechdrawings is substantially the same as the press anism which may be readily and economically shown in the above application-with the excep manufactured and readily and easily incorporated tion that the timing and Stroke sing mechain a press. nisms are omitted, a trimming shear is added,

0 Other objects and advantages will appear from and means are provided for operating the shear 40 the de c pt on hereinafter given of D ss in and the transfer mechanism in response to the which the invent on s p l end of a strip reaching a given point. Hence, Accorqine invflmtlon m 1t5 genera1 f the press has not been illustrated in all of its a Press 15 Pmvlded mechamsm wmch details norwill it be extensively described herein. trim the ends of the strips fed therethrough and The press has its mechanism carried by a which is actuated in response to the end of a strip frame having four comer posts I 2 3 and reaching a given point.

The invention is exemplified by the hydraulic :g g tig zfig gz fi iiggf si z z gf press illustrated in the accompanying drawings gs; z'

5 in which the views are as follows:

Fig. 1 is a front view of the press with a part The gllder 5 has a ram cylinder 7 ngidly of the platen broken away to expose a part of cured therein and provided with a ram 8 which the trimming mechanism. is attached at its lower end to a platen 9.

Fig. 2 is a side view of the press as viewed from The ram is reciprocated by liquid supplied to the right of Fig. 1 but with the magazine omitted. the cylinder 1 from a pump it which is arranged upon the girder 5 and driven by an electric motor II.

The platen 9 is guided for vertical reciprocation by two guide bars l2 one of which is arranged at each of its lateral sides and closely fitted in a vertical bore formed in a projection I3 carried by the platen.

Each of the guide bars I2 is rigidly secured at each of its ends to a front post of the frame by a bracket l4.

The platen 9 has attached to its lower end a male die or punch I5 which, during reciprocation of the platen, is moved into and out of a female die formed in or carried by a lower die block l6 arranged upon the bed 6.

Strips of work are fed step by step through the press and between the dies l5 and I6 by two grippers I! and I8 which are fixed in adjusted positions upon a bar l9 to be reciprocated thereby and are mounted upon a track 20 to slide thereon.

The track 28 is supported at each of its ends upon a slide 2| which is carried by the frame and provided with an adjusting screw 22 having a sprocket wheel 23 fixed upon its rear end.

Each screw 22 has its rear end journaled in a corner post and restrained from axial movement thereby and its front end threaded through a nut or lug fixed on the slide 2i One of the sprocket wheels 23 is provided with an operating handle 24 and connected by a chain 25 to the other sprocket wheel to permit the two screws 22 to be rotated in unison by the handle 24 and thereby move the slides 2| forward or rearward in unison to vary the distance between the path of the grippers H and I8 and the dies I5 and I6 and thereby adjust the mechanism to handle strips of different widths.

The grippers I! and 48 are opened and closed by a shaft 26 (Fig. 3) upon which the grippers are splined and which is joumaled at its center in a stationary bearing 21 fixed upon the track 28 at the center thereof.

The gripper shaft 26 is rotated through a given angular distance and restrained from axial movement by a lever 28 which is keyed thereon and arranged between the two side walls of the bearing 21.

The lever 28 is connected at its rear end by a connecting rod 29 and a lever mechanism 38 to a hydraulic clamping motor 3| (Fig. 2) which is arranged at the rear of the press frame near the top thereof and operated at predetermined intervals by liquid supplied thereto by the pump I8. When the piston of the clamping motor 3| is moved in one direction, the grippers are closed and, when the piston of the clamping motor 3| is moved in the opposite direction, the grippers are opened.

The grippers are reciprocated to feed work into and through the press by a quadrant 32 which is fixed upon a rock shaft 33 journaled in the press frame below the track 28.

The quadrant 32 extends upward between the front and rear rails of the track 28 and is connected by a chain or flexible band 34 to one end of the feed bar l9 and by a chain or flexible band 35 to the other end of the feed bar I9.

The shaft 33 has a lever 36 fixed thereon and connected by a connecting rod 31 to a pin 38 which is secured in an adjusted position in a radial slot 39 formed in a crank 48.

The crank 40 is fixed upon a shaft 4! and rotated therewith through substantially 180 in each direction at predetermined intervals by a double-acting hydraulic motor 42 which is connected to the shaft 4| through a rack and pinion (not shown).

When the shaft 4| is rotated in one direction, the crank 48 will depress the connecting rod 31 and cause the feed bar to move the grippers toward the left in respect to Fig. 1 and, when it is rotated in opposite direction, the crank 40 will raise the connecting rod 31 and cause the feed bar to move the grippers toward the right in respect to Fig. 1.

The grippers, the feed bar and the platen are operated in sequence in each direction of movement, and each of these members completes or substantially completes its movement before the next member starts to move.

As fully explained in application Serial No. 570,822, this is accomplished by connecting the ram cylinder 7, the feed motor 42, and the clamping motor 3| to the pump 18 in series with each other so that, assuming that the grippers have been previously closed upon a .strip of work and the press started by depressing a pedal 43 arranged at the bottom of the press frame, the liquid delivered by the pump will first operate the feed motor 42 which will advance the grippers and the strip a distance determined by the position of the pin 38 in the slot 39, then the liquid will operate the clamping motor 3! which will open the grippers, then liquid will flow to the ram cylinder I and advance the ram 8 until it stalls at the end of its down stroke, then the liquid delivered by the pump will operate the feed motor 42 which will retract the feed bar and the grippers, then the liquid will operate the clamping motor 3| which will close the grippers upon the strip in a new position, and then the liquid will retract the ram and raise the platen, thus completing a cycle of operation.

The press will operate continuously and the cycles follow each other in succession as long as the pedal 43 is held or latched down or it will come to rest at the completion of each cycle depending upon the adjustment of a control mechanism 44 (Fig. 2) which is carried by the press frame near the top thereof and controlled by the pedal 43 through a rod 45 and by a hand lever 46 through a rod 41, as explained in application Serial No. 570,822.

In order to avoid the possibility of a strip being partially retracted by the grippers when they are retracted, the press is ordinarily provided with two detents 48 one of which is arranged upon each side of the dies, the detent at the right of the dies having been omitted from the drawings in order to disclose the trimming mechanism.

Each detent is supported in an adjusted position relative to the path of the strip upon a rod 49 carried by an arm 58 which is arranged in an adjusted position relative to the dies upon a bar 5! carried by a corner post of the press frame.

The strip passes through a slot 52 in each detent and is permitted to move freely therethrough in the direction of feed but is prevented from being retracted by suitable dogs arranged within the detents.

Each strip must be placed in position to be engaged by the gripper l7, and this may be accomplished either manually or automatically.

If the strips are to be supplied to the feed mechanism manually, the end of each strip is placed against a vertical gage bar 53 extending through a socket 54 which is supported from the platen 9 and reciprocated therewith. The gage bar 58 is urged downward by a helical compression spring 55 and provided at its upper end with a suitable head to limit its downward movement relative to the socket.

The end of the strip is placed against the gage bar 58 when the platen is at or near its lowermost position; Then, when the platen rises, the gage bar moves upward out of the path .of the strip and, when the platen next descends, the

.gage bar engages the top of the strip and the spring 56 iscompressed.

The gage bar 58 does not interfere when strips are supplied automatically since the platen is always in its upper position before the strip is fed forward into the press.

If the strips are to be automatically supplied to the feed mechanism, a magazine 56 is arranged at the right of the press with its left end slightly in front of the path of the strip and its axis extending rearward at a small angle to the path of the strip, and it is supplied with a stack of strips and maintains the top of the stack substantially at the level of the jaws of the grippersfas fully illustrated and described in application Serial No. 570,822.

The strips are removed from the magazine in succession and inserted into the grippers H by transfer mechanism which is operated at intervals in unison with the feed mechanism through a chain 51 which connects a sprocket wheel 58 fixed on the rear end of the shaft 4| to a sprocket wheel 59 fixed on the rear end of a clutch shaft "which is arranged upon the right side of the press frame as shown in Fig. 2.

Theshaft 60 has its rear end journaled in a bearing 6| carried by the press frame and its front end journaled in the rear end of a crankshaft 62 which is arranged in axial alinement with theshaft 60 and journaled in two

bearings

68 and 84 carried by the press frame.

The crankshaft 62 has a single-toothed clutch jaw 65 fixed upon its rear end and a disk 66 fixed upon its front end and provided with a crankpin 61.

The clutch jaw 65 and the crankpin 61 are normally retained in a given angular position by a spring detent 68 which is carried by the press frame and normally engages a notch in the periphery of the disk 66 and thereby restrains the shaft 62 from rotation.

The clutch jaw 65 is adapted to be engaged by a clutch jaw 69 which is splined upon the clutch shaft 68 and engaged by the upper arm of a threearmed lever 10 which is pivoted upon the press frame and has its rear arm arranged immediately above a solenoid II and its front arm arranged immediately above a speed reducing valve I2 and engaged by a spring clip 13 which normally retains the lever 18 in its neutral position to keep the jaw 69 out of engagement with the jaw 65.

The valve 12 has its stem urged by a helical compression spring 14 upward against the front arm of the lever 18. When its stem is depressed, the valve 12 functions to reduce the stroke of the pump II and thereby reduces the speed of the press, as fully disclosed in application Serial No. 570,822.

The stem of the valve 12 may be depressed either automatically by the lever 10 or manually by a lever 15 which is pivoted upon the press frame and normally retained in its inoperative position by a spring clip 16.

The solenoid H is carried by the press frame and energized in response to theend of a strip of work passing a predetermined point, as will be presently explained. When the solenoid H is energized, it swings the lever 10 upon its pivot and causes it to move the clutch jaw 69 into engagement with the clutch jaw 65 and simultaneously operate the valve 12 to decelerate the press.

As previously explained, the feed shaft 4| is rotated through approximately 180 in either direction during each cycle of operation. However, the ratio between the sprocket wheel 58, which is fixed to the feed shaft 4 I, and the sprocket wheel 59, which is fixed to the crankshaft 60, is such that the crankshaft 68 is rotated through at least a complete revolution in each direction during each cycle of operation.

After the trailing end of a. strip of work has passed a given point and the feed bar l9 has reached the end of its advance stroke, the solenoid II is energized and causes the clutch jaw 69 to engage the clutch jaw 65. Then when the feed shaft 4| is rotated to retract the feed bar, the clutch shaft 68 rotates the crankshaft 62 through a complete revolution at the end of which the detent 68 engages the notch in the disk 66 and prevents the shaft 62 from, being rotated in the opposite direction when the clutch shaft is rotated in the opposite direction.

When the feed shaft 4| is next rotated in the opposite direction to readvance the feed bar I9, the clutch shaft 60 rotates the tooth on the clutch jaw 69 away from they tooth on the clutch jaw 65 and the solenoid is deenergized by the advance of a new strip of work. As the feed bar approaches the end of its advance stroke, the beveled rear faces on the teeth of the clutch jaws engage each other and force the clutch jaw 69 rearward along the shaft 60 and out of engagement with the clutch jaw 65, the spring 14 assisting in disengaging the clutch and in returning the front arm of the bar ID to its inoperative position beneath the spring clip 13. If desired, an additional spring 11 may be employed to assist in the return of the lever 1|) to its inoperative position.

The crankpin 61 on the crankshaft 62 is connected by a rod 18 to a lever 19 fixed upon the inner end of a shaft 80 which is journaled in a support 8| carried by the frame.

The shaft 80 has a lever 82 secured to its outer end at an angle to the lever 19 and in radial alinement with a lever 83 which is secured to the shaft 88 intermediate the ends thereof.

The levers 82 and 83 have an elongated pin 84 journaled in the outer ends thereof and urged outward or to the right in respect to Fig. 1 by a helical compression spring 85 which encircles the pin 84 between a suitable collar fixed thereon and the lever 83, the outward movement of the pin 84 being limited by a suitable head or collar fixed upon its inner or left end.

The pin 84 is connected at its outer end by a universal joint 86 to a vertical lift rod 81 which has its upper end loosely guided by a bracket 88 carried by the frame.

The lift rod 81 is provided at its lower end with a suction cup 89 which is made of flexible material, such as rubber, and connected to a vacuum pump (not shown) by a flexible tube 98 having a valve 9| connected therein and carried by the lift rod 81.

The valve 9| normally maintains communication between the suction cup 89 and the vacuum pump which exhausts air therefrom continuously until the stem of the valve 9| is forced inward to open the cup to the atmosphere.

Rotation of the crankshaft 62 causes the connecting rod I8 to raise and lower the outer end of the lever 19 and rock the shalt 88, thereby swinging the upper ends of the levers 82 and 83 and the pin 84 forward and downward through a predetermined angular distance during the first half-revolution of the shaft 62 and then returning them to their initial positions during the next half-revolution of the shaft 62.

The pin 84 swings the lower end of the lift rod 8! forward and downward until the suction cup 89 is pressed against the uppermost strip in the magazine, the vacuum pump exhausts air from the cup 89 and causes it to cling to the strip, then the pin 84 swings the lower end of the rod 81 upward and rearward and the cup 89 carries the strip with it.

The cup 89 reaches its initial position at substantially the same time that the feed bar I9 reaches the limit of its return stroke sothat the edge of the strip is passed between the jaws of the gripper I I, the free end of the strip being limited in its upward movement and guided into the gripper by an adjustable stop 92 carried by the press frame.

The gripper I! then closes upon the strip and, when the feed bar I9 advances, it carries the strip toward the dies and swings the lower end of the lift rod with it, the pin 84 sliding through the

levers

82 and 88 until the stem of the valve 9! abuts the support M and is operated thereby to open the suction cup 89 to the atmosphere and cause it to release the strip. The spring then swings the lower end of the lift rod 81 to its initial position.

With the exception of the means for automatically operating the three-armed lever I8, the press thus far described is substantially the same as the press disclosed in application Serial No. 570,822.

The press shown in that application, however, provided means for causing the ram to miss a stroke when the end of a strip arrived between the dies while, in the present invention, a shear is provided for trimming the ends ofthe strip.

The shape of the piece cut from the end of a strip depends upon the shape of the blank stamped from the strip and, since it may at times be desirable or necessary to trim both the trailing end of one strip and the leadingend of the next strip due to the shape of the blank, the press is shown provided with a shear for simultaneously trimming the adjacent ends of successive strips.

The shear is provided with a lower stationary shear blade I88 which is arranged upon the end of the die block I6 and with a lower stationary shear blade I8I which is arranged upon the end of a block I02 carried by the bed 6.

The stationary blades I88 and I8I cooperate, respectively,- with movable shear blades I83 and I84 fixed to ashear platen I85 which is carried by the press platen 9 to be reciprocated thereby.

The press platen 9 has a bottom plate I86 fastened to its underside and provided at its right end with a guideway I81 in which the shear platen I85 is closely fitted for vertical reciprocation. The plate I86 has the upper blanking die I5 attached to its underside.

The shear platen I85 is supported by a lug I88 (Fig. 4) which is fixed to the press platen 9 and provided with a'vertical bore I89 in which a post H8 is closely fitted for vertical reciprocation therein.

The post H8 has its lower end rigidly secured to the shear platen I85 at the rear edge thereof and its upper end provided with nuts III and a sleeve II2 encircling it between the nuts III and the lug I88.

The nuts III and the sleeve II2 limitthe downward movement of the shear platen I85 1 When the press is in operation, the shear platen I85 reciprocates with the press platen 9. If a blade I83 or I84 strikes a strip of work or other obstruction, the post II8 slides upward through the lug I88 unless the gag H8 has been advanced beneath the abutment H4 in which case force is transmitted from the press platen 9 through the abutment I I4 and the gag I I3 to the shear platen I85 and the blade is forced through the strip to shear it.

The gag I I3 is advanced beneath the abutment H4 by a solenoid II5 which is supported upon four posts III; carried by the shear platen I 85.

The solenoid II5 has its core II'I connected upon each side thereof by a link II8 to the rear end of a bell crank lever I I9 which is pivoted intermediate its ends upon the shear platen I85 'and has its upper end pivoted to the gag H3 near the rear end thereof.

The gag I I3 is retracted from beneath the abutment I I4 and the core I I1 is withdrawn from the solenoid II5 by two springs I28 one of which is connected to each link H8 and to the shear platen I85.

The solenoid II5 is energized in response to the closing of a switch I2I which is arranged in an adjusted position upon the front of the shear might engage the actuator and open the switch before the movable shear through the strip.

In order to avoid this danger, the solenoid II5 is controlled by a magnetically operated switch blade had passed I22 which is arranged in any suitable place and connected in circuit as shown in Fig. 7.

Electric current for energizing the solenoids II and II5 is supplied through. two conductors I23 and I24 which are connected through a manual switch I25 to a power line I26.

The solenoid II5 has one end of its winding connected to the conductor I23 and the other end thereof connected by a conductor I21 to one terminal of the switch I22 the other terminal of which is connected to the conductor I24. Thus, when the switch I22 is closed,'the solenoid will be energized and move the gag II3 beneath the abutment I I4 and thereby cause the movable shear blades to be forced through any strip which may be arranged upon the stationary shear blades.

The switch I22 is closed by an electromagnet I28 which has one end of its winding connected to the conductor I23 and the other end of its terminal of the switch I2I the other terminal of which is connected to the conductor I24. 4 The switch I22 is opened by an electromagnet I30 which has one end of its winding connected to the conductor I23 and the other end of its winding connected by a conductor I3I to one terminal of a switch I32 the other terminal of which is connected by a conductor I33 to the conductor I24.

The switch I32 is arranged upon the front of the die block I6 and spring biased to open position. The actuator of the switch I32 is urged by its spring into the path of an abutment I34 (Figs. 1, 6 and 7) which is carried by. the shear blade I03 and adjusted to engage the'actuator and operate the switch I32 after the movable shear blade has engaged the strip.

When the end of a strip passes the switch I2 I, the switch actuator moves outward or rearward and closes the switch to energize the magnet I28 which closes the switch I22 and thereby energizes the solenoid II5 which moves the gag II3 to its operative position.

If the following strip opens the switch I2I before the shear is operated, the magnet I28 will be deenergized but the switch I22 will remain closed. When the shear blade I03 penetrates the strip, the abutment I34 closes the switch I32 to energize the magnet I30 which opens the switch I22 and thereby deenergizes the solenoid II 5 and permits the springs I20 to retract the gas I I3.

The solenoid II, which initiates the operation of the transfer mechanism, has one end of its winding connected to the conductor I23 and the other end thereof connected by a conductor I35 to one terminal of a. normally open switch I36 whichis arranged close to the end of the magazine 56 and has its actuator urged by a spring against the strip being fed through the press. When the end of that strip passes the switch I36, the switch actuator is urged outward and closes the switch which is preferably spaced from the end of the strip in the magazine by a distance which is less than the distance each strip is advanced during each cycle of operation.

If the solenoid were controlled solely by the switch I36, the clutch jaw 69 would be urged against the clutch jaw 65 before the feed bar reached the end of its feed stroke and while the clutch shaft 60 was still rotating.

In order to insure the operation of the solenoid II at the proper time, the switch I36 has its other terminal connected by a conductor I31 to one terminal of a normally open switch I38 the other terminal of which is connected by a conductor I39 to the conductor I 24.

The switch I38 is arranged upon the front of the press and operated during the descent of the platen 9 as by being arranged adjacent the switch I32 and operated by the abutment I34 before the movable shear blades engage the strip.

Assuming that the magazine 56 is supplied with strips, that the press is being operated automatically to stamp Z-shaped blanks from the strip as the same are fed therethrough, that the strips A and B have reached the positions shown in Fig. 'I, and that the platen 9 is at the end of its down stroke so that the punch I5 extends through the strip, the operation will be as follows:

The feed bar I9 will be retracted, then the gripper I8 will close upon the strip A in a new position and the gripper II will grip the following strip B, and then the platen will rise to the top of its stroke.

The feed bar will then advance and move the strips A and B one step toward the left to the positions shown in Fig. 8. During this movement, the end of the strip A passes beyond the switch I2I which closes and causes the magnet I28 to close the switch I22, thereby energizing the solenoid H5 and causing it to move the gag II3 forward beneath the abutment H4. The strip B, following immediately behind the strip A, opens the switch I2I and thereby deenergizes the magnet I20 but it does not affect the position of the gag II 3 since the switch I22 remains closed.

When the feed bar I9 reaches the end of its advance stroke, the platen 9 descends and forces the punch I5 through the strip A and, since the gag'II3 is beneath the abutment II4, it simultaneously forces the shear blades I03 and I04 through the ends of the strips A and B, as shown in Fig. 8.

Just before the platen 9 reaches the end of its down stroke and after the movable shear blade I03 has engaged the strip A, the abutment I34 closes the switch I32 to energize the magnet I30 which opens the switch I22, thereby deenergizing the solenoid H5 and permitting the springs I20 to retract the gag II3 as soon as the pressure is removed therefrom. The switch I38 is also closed during the down stroke of the platen 9 but, since the switch I 36 remains open, the solenoid II is not energized.

The feed bar I9 is then retracted to start a second cycle of operation, and the cycles follow each other in succession. During the succeeding cycles, the shear blades I03 and I04 engage the upper surface of the strip being punched but, since the gag I I3 is not beneath the abutment II4, they are not forced therethrough until the end of the strip passes the switch I2I and then the shear is operated as previously described.

During one of the succeeding cycles of operation, the punch I 5 stamps the last possible blank from the trailing end of the strip A. During the next cycle the punch I5 passes freely through a space I40 between the strip, as shown in Fig. 9. The space I 40 was formed when the shear trimmed the trailing end of the strip A and the leading end of the strip B. During the next cycle of operation, the punch I5 stamps the first possible blank from the leading end of the strip B.

During one of the succeeding cycles of operation, the feed bar I9 advances the strip B until its trailing end passes beyond the magazine 56 and permits the switch I36 to close. The solenoid II is not immediately energized, however, since the switches I36 and I38 are connected in series. After the feed bar I9 completes its advance stroke, the platen 9 descends and the abutment I34 closes the switch I38, thereby energizing the solenoid II which swings the lever I0 upon its pivot. The lever I0 operates the valve I2 to decelerate the press and moves the clutch jaw 69 into engagement with the clutch jaw 65.

When the platen stalls at the end of its downstnoke, the feed bar I9 is retracted at reduced speed and the clutch shaft 60 drives the transfer mechanism at slow speed.

Duringthe first half-revolution of the shaft 60, the suction cup 89 is moved forward and downward against the top strip in the magazine and, during the next half-revolution of the shaft 60, it is moved upward and rearward and carries the leading end of the strip with it, the cup 89 reaching the end of its rearward movement at substantially the same time that the feed bar I9 reaches the end of its retraction stroke so that the leading end of the strip is passed into the jaws of the gripper H.

The grippers then close, then the ram ascends, and then the feed bar I9 advances. The feed bar carries the new strip past the switch I36 to close it and thereby deenergize the solenoid H, and it swings the stem of the air valve 9| against the support 80 to open the valve and thereby disengage the suction cup 89 from the strip. During the advance stroke of the feed bar I9, the clutch jaw 69 and the valve 12 are returned to their initial positions and the press resumes its high speed operation.

Operation of the shear in response to the end of a strip passing a given point enables the press to operate upon strips of different lengths in succession and to stamp a blank from the last avail able space on each strip regardless of the length thereof and without adjustment of the press to compensate for variation in the lengths of the strips.

After a strip has had one series of blanks stamped therefrom, as indicated by Figs. 7 to 9, it may be reversed and passed through the press a second time to have a second series of blanks stamped therefrom, as shown in Fig. 10.

The invention herein set forth is susceptible of various modifications and adaptations without departing from the scope thereof as hereafter claimed.

The invention is hereby claimed as follows:

1. A blanking press, comprising feed mechanism for feeding a strip of work step by step through the press, a stationary die and a movable die arranged upon opposite sides of the path of said strip, means for reciprocating said movable die toward and from said stationary die to enable said dies to form blanks in succession from said strip, a shear arranged at a given distance from said dies and having one of its blades fixed in a stationary position, and means responsive to the end of said strip reaching a given position relative to said dies for effecting operation of said shear to cause it to trim from the trailing end of said strip that part which would partly overlie said stationary die during a succeeding reciprocation of said movable die. I

2. A blanking press, comprising feed mechanism for feeding successive strips of work step by step through the press, a stationary die and a movable die arranged upon opposite sides of the path of said strips, means for reciprocating said movable die toward and from said stationary die to enable said dies to form blanks in succession from each strip, a shear arranged at a given distance from said dies and having one of its blades fixed in a stationary position, and means responsive to the end of a strip reaching a given position relative to said dies for effecting operation of said shear to cause it to trim from the trailing end of that strip and the leading end of the next strip those parts which would partly overlie said stationary die during a succeeding reciprocation of said movable die.

3. A blanking press, comprising feed mechanism for feeding a strip of work step by step through the press, a stationary die and a movable die arranged upon opposite sides of the path of said strip, means for reciprocating said movable die toward and from said stationary die to enable said dies to form blanks in succession from said strip, a shear arranged at a given distance from said dies and operable by said die reciprocating means, and means responsive to the end of said strip reaching a given position relative to said dies for effecting operation of said shear to cause it to trim from the trailing end of said strip that part which would partly overlie said stationary die during a succeeding reciprocation of said movable die.

4. A blanking press, comprising feed mechanism for feeding successive strips of work step by step through the press, a stationary die and a movable die arranged upon opposite sides of the path of said strips, means for reciprocating said movable die toward and from said stationary die to enable said dies to form blanks in succession from each strip, a shear arranged at a given distance from said dies and operable by said die reciprocating means, and means responsive to the end of a strip reaching a given position relative to said dies for effecting operation of said shear to cause it to trim from the trailing end of that strip and the leading end of the next strip those parts which would partly overlie said stationary die during a succeeding reciprocation of said movable die.

5. The combination, with a press having feed mechanism for feeding a strip of work step by step therethrough, a stationary die, a movable die for coacting with said stationary die to form blanks in succession from said strip, and aplaten for carrying said movable die and reciprocating it toward and from said stationary die, of means for permitting said movable die to pass freely the trailing end of said strip, comprising a shear arranged at a given distance from said dies and having one blade fixed in a stationary position and another blade carried by said platen to be reciprocated thereby, and means responsive to the end of said strip reaching a given position relative to said dies for effecting operation of said shear to cause it to trim from the trailing end of said strip that part which would partly overlie said stationary die during a succeeding reciprocation of said movable. die.

6. The combination, with a press having feed mechanism for feeding successive strips of work step by step therethrough, a'stationary die, a movable die for coacting with said stationary die to form blanks in succession from each strip, and a platen for carrying said movable die and reciprocating it toward and from said stationary die, of means for permitting said movable die to pass freely between the trailing end of each strip and the leading end of the succeeding strip, comprising a shear arranged at a given distance from said dies and having one blade fixed in a stationary position and another blade carried by said platen to be reciprocated thereby, and means responsive to the end of a strip reaching a given position relative to said dies for effecting operation of said shear to cause it to trim from the trailing end of that strip and the leading end of the next strip those parts which would partly overlie said stationary die during a succeeding reciprocation of said movable die.

7. The combination, with a press having feed mechanism for feeding a strip of work step by step therethrough, a stationary die, a movable die for coacting with said stationary die to form blanks in succession from said strip, and a platen for carrying said movable die and reciprocating it toward and from said stationary die, of means for permitting said movable die to pass freely the trailing end of said strip, comprising a shear arranged at a given distance from said dies and having one blade fixed in a stationary position and another blade carried by said platen to be reciprocated thereby, a gag for fixing said movable shear blade for positive movement with said platen, and means responsive to the end of said strip reaching a given position relative to said dies for effecting operation of said gag to cause said shear to trim from the trailing end of said strip that part which would partly overlie said stationary die during a succeeding reciprocation of said movable die. 7

8. The combination, with a press having feed mechanism for feeding successive strips of work step by step therethrough, a stationary die, a movable die for coacting with said stationary die to form blanks in succession from each strip, and a platen for carrying said movable die and reciprocating it toward and from said stationary die, of means for permitting said movable die to pass freely between the trailing end of each strip and the leading end of the succeeding strip, comprising a shear arranged at a given distance from said dies and having one blade fixed in a stationary position and another blade carried by said platen to be reciprocated thereby, a gag for fixing said movable shear blade for positive movement with said platen, and means responsive to the end of a strip reaching a given position relative to said dies for effecting operation of said gag to cause said shear to trim from the trailing end of that strip and the leading end of the next strip those parts which would partly overlie said stationary die during a succeeding reciprocation of said movable die.

9. The combination, with a press having feed mechanism for feeding successive strips of work step by step therethrough, a stationary die, a movable die for coacting with said stationary die to form blanks in succession from each strip, and a platen for carrying said movable die and reciprocating it toward and from said stationary die, of means for permitting said movable die to pass freely between the trailing end of each strip and the leading end of the succeeding strip, comprising a shear arranged at a given distance from said dies and having one blade fixed in a stationary position and another blade carried by said platen to be reciprocated thereby, an abutment carried by said platen, a gag for insertion between said abutment and said movable shear blade to fix said shear blade for positive movement with said platen, an electromagnet for operating said gag, and electrical' means responsive to the end of a strip reaching a given position relative to said dies for effecting operation of said magnet to thereby cause said shear to trim from the trailing end of that strip and the leading end of the next strip those parts which would partly overlie said stationary die during a succeeding reciprocation of said movable die.

10. The combination, with a press having feed mechanism for feeding a strip of work step by -tep therethrough, a stationary die, a movable die for coacting with said stationary die to form blanks in succession from said strip, and a platen for carrying said movable die and reciprocating it toward and from said stationary die, of means for permitting said movable die to pass freely the trailing end of said strip, comprising a shear arranged at a given distance from said dies and having one blade fixed in a stationary position and another blade carried by said platen to be reciprocated thereby, an abutment carried by said platen, a gag for insertion between said abutment and said movable shear blade to fix said shear blade for positive movement with said platen, an electromagnet for operating said gag, and electrical means responsive to the end of said strip reaching a given position relative to said dies for effecting operation of said magnet to thereby cause said shear to trim from the trailing end of said strip that part whichwould partly overlie said stationary die during a succeeding reciprocation of said movable die.

WALTER FERRIS.