US1872474A

US1872474A - Automatic punch press

Info

Publication number: US1872474A
Application number: US417353A
Authority: US
Inventors: Bror J Lindgren
Original assignee: Niagara Machine and Tool Works
Current assignee: Niagara Machine and Tool Works
Priority date: 1929-12-30
Filing date: 1929-12-30
Publication date: 1932-08-16
Anticipated expiration: 1949-08-16

Description

9 Sheets-Sheet l NWN Allg'- 16, 1932- B. J. LINDGREN AUTOMATIC PUNCH PRESS w. SN

w Naw w, aww QQ F mvmawwlw l B. J. LINDGREN AUTOMATIC PUNCH PRESS Aug.v 16, 1,932.

Filed Deo.

9 SheetS-Sheet 2 Aug- 16, 1932- I3` .1. I INDGREN 1,872,474

AUTOMATIC PUNCH PRES S Filed Deu. so. 1929 9 sheets-sheet 5 il I [mmm

Aug- 16 1932 B. J. LlNDGRl-:N 1,872,474

AUTOMATIC PUNCH PRESS Filed Deo. 30, 1929 9 SheeILS-Sheel'I 4 Iva/@Wr 1929 9 Sheets-Sheet 5 1;2: :lll-5 1 B. J. LINDGREN AUTOMATIC PUNCH PRESS Filed Deo.

am en Awwwr Aug. 16, 1932.,

Aug. 16, 1932. B. J. I INDGREN AUTOMATIC PUNCH PRESS Filed Deu. .'50, 1929 9 Sheets-Sheet 6 All@ 16, 1932- B. J. I INDGREN AUTOMATIC PUNCH PRESS Filed Deo. S50. 1929 9 Sheets-Sheet 7 Aug. 16, 1932. B. J. I INDGREN AUTOMATIC PUNCH PRESS Filed Deo. 30, 1929 9 Sheets-Sheet 8 All@ 1.6, 1932 B. J. LlNDGRr-:N

AUTOMATIC PUNCH PRESS Filed Dec. 50, 1929 9 Sheets-Sheet 9 strips from overlapping one another or from Patented Aug. 1s, 1932 n UNITED STATES PATENT OFFICE BBOB J. LINDGREN, 0F BUFFALO, NEW YOBX, ASSIGNOR TO NIAGARA MACHINE AND TOOL WORKS, Ol BUFFALO, NEW YORK, A CORPORATION OF NEW YORK AUTOMATIC PUNCH PRESS Application led December 30, 1929. Serial No. 417,353.

guiding devices, gripping and converging' devices and scrap cutting devices, all of which are synchronized tothe operation of the punch press itself so that the entire oper-l ation of the various mechanisms is automatic.

One of the objects of this invention is to provide a device of this character which operates automatically to feed strips of comparatively heavy gage sheet metal in immediate succession to a punch press which punch ress is synchronized with themovement ofthe'feeding mechanism and punches the predetermined number of pieces from each stri as it is fed.

y A further object is to provide such a mechanism through which a continuous stream of blank strips is fed in which provision is made for gaging` or registering each strip fed so that an exact number of perfect pieces is punched from each strip, provision in particular, being made to prevent successive being spaced apart since such displacement would result in a piece of unpunched metal at one end of the strip and an imperfect punching at the other end of the strip.

A further object is to trim the trailing end of the strip being punched to an exact length a and to position or gage the advancing end of the stri being fed with reference to this trimme end so that the strips pass through the press substantially in end-to-end relation and so that there is no danger of one overlapping the other.

A still further object is t0 provide a simple and reliable means whereby those mechanisms which operatgt every time a piece is` punched fromthe rip and several times upon each stri such as the strip advancing mechanism an the scrap cutter, are synchronized` with those mechanisms which operate only once on' each strip of metal, such. as the initial feed, gaging and end trimming mech- Another object is to provide a simple mechanism for shearing the scrap strips into small pieces so that the scrap is in conven- -iilnt form to'be transported from the mac me.

Another purpose is to provide a machine in which delayed operations are effected in a simple and reliable mannerso that at no time 1s there any danger of interference between the same time or in their return movements.

AA further purpose is to provide a machine of this character which is readily adjustable to different y lengths widths and gages of -mechanisms operating in sequence at about 00 strips or to produce any desired number or kinds of punchings. l

Other aims are to provide such a mechanism which is reliable in `its action and will function continuously lto punch the desired numberbf pieces from the strips as the strips are continuousl fed, which is simple in construction consi ering the function which it erforms'which is readily accessible for ad-l ]ustment or repairs, which will not get out of order under severe and constant use and punch press embodying my in- -Bil Figure 3 is a front elevation of the machine, the feeding table and the feeding mechanism associated therewith being eliminated.

' Figure 4 is a vertical transverse section through the automatic punch press, .the same being taken approximately ,on line 4 4, Fig. 1. n

Figure 5 is a-vertical central fragmentary longitudinal section, through the punch press and a portion of the feeding table, on an enlarged scale the same being taken on line 5 5,

. Fig. 4.

Figure 6 is a vertical longitudinal section through the feeding table -and the adjacent portion of the punch press, showing the positions of the parts'durin the end trimming operation on the strip o sheet metal.

, trolling the feeding, end trimming and gag-A feeding and retracting movement and also the gaging mechanism.

Figure 10 is a fragmentary enlarged veitical section, similar to Fig. 8, lshowing the gaging mechanism in its operative position and the end trimming shear raised.

Figure 11 is a fragmentary enlarged view from thefront of the machine showing the ratchet drive and clutch for driving and conin mechanisms.

igure 12 is an enlarged fragmentary yview similar to Fig. 11, the ratchet wheel being eliminated.

Figure 13 is an enlarged-vertical transverse section taken on line 13-13, Fig. 14 showing the trip mechanism which renders the, feeding mechanism-inoperative at the. end of its controls synchronization of the feeding mechanism tothe gagingvmechani'sm the trip mechanism being Yshown in the position occu ied during the tripping movement.

igure 14 is' an en lar taken 'on `line 14-14, clutch which controls the feeding, end trimmingand gaging mechanism and its associated parts. I

Figure 15 is an enlarged transverse vertical section taken on line 15-15, Fig. 5, and show-l ing the trip mechanism, shown in Fig. 13, in

its position preparatory to being tripped.

Fi ure 16 is a view similar to Fig. lshowing t e next succeeding position of the parts of the trip mechanism vpreparatory to being tripped. f Figure 17 is a fragmentary vertical longitudinal section through the vcam controlling control ing the 'same in the clutch, the same beingrtaken on line 17 --17, Fig. 12 and showing the clutch thrown out.

Figure 18 is a view similar to Fig. 11 showing the cam controlling the clutch in its operkative position and the plutch in operation.

Figure 19 is a fragmentary vertical longitudinal-section taken on line 19-19, Fig. 18,

showin the clutch inoperation and the cam ing the clutch out. o

Figure 20' is an enlarged vertical transverse section through the punch press, taken on line 20-20, Fig.- 27 and" particularly showing one pair of step by step fingers forgripping and advancing thesheet of metal,

erative positions.-v n l I Figure 21 is a fragmentary sectional view the fingers being shown in'their'closed or 'op-f d horizontal section" ig. 12; showing the position for .th rowsimilar to Fig. 20 taken on line 21-21, Fig. 5 and showing the other pair of gripping and advancing fingers in their open positions.

Figure 22 is a fragmentary longitudinal section taken on line 22-22, Fig. 21.

Figure 23 is a fragmentary longitudinal section taken on line 23-23, Fig. 21.

Figure 24 is a fragmentary vertical transverse section taken on line 2li- '24, Fig. 27 and showing the knivesyfor cutting the' scrap into lengths.

Figure 25 is a view similar to Fig. 24 showing the scrap metal cutting knives open.

Figure 26 is a fragmentary, vertical, longitudinal section takenl on line 26-26, Fig. 24. v

Figure 27 is a horizontal, longitudinal section taken on line E27- 27, Fig. 5.

Figure 28 is a fragmentary, transverse sec tion taken on line 28-28, Fig. 1, showing a portion of the mechanism for openingand closing the sheet metal gripping and ad-v vancing ingers.

Figure 29 isa section takenon ,line portionv lof. the mechanism Fig. 1 of the same shown in Fig. 28.

Figure 30 is a gitudinal vsection. taken on line 30-30, Fig.

.y 29, of the 'same portion of the .mechanism shown in'Figs'. 28 and 29.

Figure 31 isa fragmentary, vertical, transverse section takenV on line 31-31, Fig. 5,

fragmentary, vertical, lon-V I showing particularly the means for vertical- 1y adjusting the gripping and advancing fingers to meet required conditions. Figure 32 is a fragmentary, vertical, transverse section taken on line 32--32, Fig.l 5, showing the cam drive`and associated parts for the opening and closing of the gripping and advancing fingers.

Figure 33 ,1s a fragmentary, longitudinal section taken on line 33-33, Fig. 2, showing the segment for reciprocating the gripping and advancing fingers and the adjusting means therefor. l Figure 34'is a vertical longitudinal section taken on line 34-34," Fig. 3, and showing the main clutch controlling the operation of the entire machine.

Figure 35 is a fragmentary enlarged sec u General orgamzatzon In its general organization, this invention comprises a continuously operated punch press ofany suitable type, step by :step means.

fork gripping and advancingtlie vblank strip of metal presented to the punch pressso that successive pieces are formed and punched fromthe strip ofmetal, a feeding table on I which the blank strips of sheet metal are laid preparatory'to feeding, a feeding. carriage is synchronized with the,y punch l press and and -mechanism associated therewith which upon the last advancing movement of the gage devices'to the step blank strip in the punch press to the dies moves the next succeeding blank strip on the table toward the press, a mechanism for positively'rendering the feeding mechanism inoperative upon' the completion of its feeding movement and also latching the feeding mechanism against accidental operation, a gage or guard mechanism which is arranged in the path of the strip being fed during the feeding operation and prevents the strip being fed from overrunning the, strip in the press, an end trimmer which trims the trailing end of the strip of s heet metal in the machine at a proper place with reference to the dies so that the front end of the strip being fed, when released by said gaging means, will always be positionedimmediately behind the trailing. end of the strip being punched and without danger of overlapping, a shear for trimming the scrap strip into convenient lengths, and the mechanism required to operate the abovemechanisms Vin proper synchronism and sequence to oneanother..

shown by way ofexample as being a circular disc 40 each of which is provided with a plurality7 of perforations 41, although the in ventlon is applicable to any form omchf ing. These are Vsuccessively formed from successive blank sheets or strips 42 of metal, by first punching nut `the perforations 41 and Athenadvancing the strip to bring the perforated part under a cutout die which punches out the piece'. In the machine shown in the drawings thirteen punchings are made from a single strip and hence the ratio of operation between the strip feeding, shearing, and by step advancing mechanism and the movement of the punch press will be one to thirteen, although it will be lunderstood that .this ratio is purely by `way of example, the invention being applicable lto any number of punchings from a strip, the ratio in operation of lthe said mechanisms being altered accordingly.

" The punch press itself may be of any usual and Well known construction, no claim being made to the punch press itself in the present invention but only in combination with the other mechanisms hereinafter described.

As shown in the drawings 'the moving parts of the press are carried .by a frame 43 made of cast metal sections and carrying an elec-v on the punch press frame 43 and at its op site end drives a pinion which m git-h a large main gear wheel 51, as shown in ig. 3. main crank shaft 52 of the punch press, which main crank shaft 52 is journalled centrally in the punchpress frame 43. As best shown in Fig. 5," the main crank shaft 52 is formed at its center to provide two oEset cranks 53 each of which is connected to an u per platen holder 54 by an adjustable pi an or connecting rod 55. Each of f\these`adjustable connecting rods or pitmen 55 preferably consists of an upper bearing member 56 connected `to each crank 53, a lower bearing member 57 connected to a wrist pin 58 of the upper platen holder 54 and'a screw 59 which is rotatably connected to the lower bearing member 57 and has a screw connection with the upper bearing member 56 so that upon turnin each of these screws the platen holder is adJusted vertically. At

its sides, this upper or movable platen hold? .er 54 is formed to provide railswhich are 'ded in guideways 60 Hin the punch press ldme so thatupon the crank shaft 52 the movable platen hol er 54 is reciprocated vertically.

To the under side of the movable platen holder is `removably securedan upper platen 61 and on the under side of this platen 61 are removably secured the male perforating die 62 and the male cutout die 63 as shownY in Fig. 5 or the dies may be formed integrally with the platen as shown in Figs. 20 and 2,1. These male dies cooperatel with a female perforating die64 and a female cutout die 65, each of which is secured to a lower stationary platen 66 which is carried by a stationary platen holder 67 mounted on the bed of the punch press.

In order to control the operation of the punch press a main driving clutch and brake 68 is provided between the counter shaft 49 and the hub of the pinion 50 which drives the main gear 51. This clutch and brake 68 may be of any suitable type and{as best shown in and the rotating clutch housing drum is engaged by brake arms rwhich are operatively connected with the clutch mechanism sov that when the clutch is opened the brake arms are applied to the brake housing drum and instantly stops the operation of the punch press. The clutch and brake 68 is controlled by a shipper rod 69 slidingly mounted in the punch press frame. This shipper rod is connected to a lever 70 which is fixed to a rock shaft 71 journalled in a suitable bracket on the mainframe and to the. other end of this rock shaft 71 a lever 72 is secured. The lever 72 is connected by an adjustable rod 73 with an arm 74 fixed to a rock shaft 75. A hand lever 76 at the other end of the rock shaft 75 actuates the `same to f Fig. 34 the clutch is of the multiple disk type open and close the clutch 68; and to operate the clutch from the other end'of the feed table 77, a second hand lever 78 is arranged at the outer end of the feed tablean'd connected indirectly to the hand lever 76 by a rod 79 so that when either of these hand lvers are operated the clutch and brake 68 is actuated to connect or disconnect the power shaft 49 withb the punch press and its associated mechanism.p

,Th ramal feeding amalgama' The blank strips 42 of metal to be punched are placeid upon the feed table indicated at v 77. This table is comparatively long and narrow and is composed of legs or standards 80, cross bars 81 connecting the upper ends of the legs 80, a top plate82 onv the cross barsA 81 and a side rail 83 for holding the blank strip 42 in position on the top plate 82. The

-top plate 82 is provided with a central longitudinal slot 84 through which the blank strip feeding carriage 155 works as hereinafter described.

' The blank metal .strips are placed upon' thefeedtable77betweenthe side rails 83 and on top of the trailing end' of the blank strip which is being moved step by step through the punch press. As soon-as a predetermined n umber'of punchings is ymade in the strip in the punch pres's,its rear end is trimmed off and the trailing'strip placed on the feed table 77 is moved against a gage gate which properly positions it with reference to the trimmed trailing end of the strip Vbeing punched and then releases it with the result that strips of accurate length are fed through'the punch press in immediate succession.- 'Since eight punchings Eare made from each blank strip in the machine illustrated it is apparent that.`

the feedin mechanism must o erate once to every eight punching operatlons of the punch press. This dinitial feeding mechanism is preferably constructed as follows:

The numeral 85 represents a crank pin which, as best shown in Figs. 1,- 3 and 5 projects outwardly from the end of the main crank shaft 52 of the punch press and is connected by a rod' 86 with the -end of a rock arml 87` mounted on the end of -a longitudinal rock shaft 88. lAs best shown irr Figs.

11 and 18 .atitsopposite end a slotted rock arm 89 is keyed to this rock shaft 88 and adjustloaded plunger 93 which is normally held yesA over the recess containing the pin 91but upon being pulled downwardly by means of rthe linger knob 94 permits the 'connecting rod and its pin 91 to be disconnected and rendered inoperative, thereby permitting of repairs or readjustments to the mechanism ac-y tuated by the ratchet without shutting down the punch press completely.

The ratchet arm carries a movable pawl or dog 95 which engages the teeth of a ratchf numberofpunching-s made in each blank strip -of metal. In the example illustrated eight punchings are made and consequently the ratchet wheel 96z would have eight, or multiples of eight,` teeth so that it is turned one complete revolution while eight punchings are made by the punch'press.

Keyed to theother end Aof the ratchet Wheel shaft'97 as best shown in Fig. 12 is a .cam wheel'99, this) cam wheel 99 having a projection 100 on one s1de which rides over (a removable tooth 101 mounted in the lower armof a bell crank lever 102. The tooth 101 of the bell crank lever lis normally urged against the cam` wheel 99 by a spring loaded pin 103-and when the'projection 100 on the cam wheel 99 engages the tooth 101 it moves thel upper arm of the vbell'crank arm 102 away from a clutch 104 so as to close the clutch. f

` This clutch, as best shown in Fig. 14 is mounted on its driven shaft 105, its'driving member comprisingan oscillating sleeve 106. This sleeve is journalled in a supporting bracket 107 and journals thev driven shaft 105. This drivin sleeve is oscillated from the rock shaft- 88, this driving sleeve'being formed to provide arms 108 which are connected to a rock arm 109 on the rock shaft 88 by a link 110, as best shown in Fig. 13. It therefore follows that the driving sleeve 106 is oscillated each time a punching is made inthe metalblank.

On the outer end of the driven clutch shaft Y is keyeda collar 111 which is held in the shaft by a washer 112 and a screw 113. ,A

In line with this key 115 the clutch driving sleeve 106 isprovide'd with a Vnotch 116,`so

that when the key 115 is released its spring urges it into the notch 116; and compels the driving sleeve 106, collar 111 and driven shaft. l

fao.

naamw.

105 to oscillate in unison. The coupling key 115 is provided, with an outwardly projecting wedge shaped tooth 117, the inner face of which is engaged by a corresponding wedge shaped tooth 118 mounted on the upper arm of the bell crank lever 102. 1t therefore follows that when the tooth 118 in the bell crank lever is held in the path of the tooth 117 on the coupling key 115 by the spring loaded pin 103, that the tooth on the bell crank lever 102 will -retract the coupling key 115 and hence permit the driving sleeve 106 of the clutch to oscillate idly without affecting the clutch driven shaft 105. lVhen, however, the projection 100 on the cam wheel 99 moves the tooth 101 of the bell crank arm 102 downwardly, the wedge or cam tooth 118 on the other end of this bell crank arm 102 is moved out of engagement with the sliding or coupling key 115, and this key moves into the notch 116 of the driving sleeve 106 of the clutch and forms a driving connection between this driving sleeve 106 and the driven clutch shaft'105; As the cam wheel 99 is rotated once for every eight operations of the punch press, it is apparent that the bell crank arm 102 is also tripped only once for every eight operations of the punch press and hence that the clutch 104 is closed so as to impart an oscillation to its driven clutch shaft 105 only once in every eight operations of the punch press, this number corresponding to the number of punchings which have been assumedv to be made in each metal blank strip, 42.

Fixed to the driven clutch shaft 105 is a rock arm 120 which is connected to a vertically reciprocating bar 121, this bar preferably having universal connections at its opposite ends. Thelower end of the bar 121 connects with a rock arm 122 keyed in a transverse shaft 123 which is j ournalled in a pedestal 124 rising from the machine bed.

Guided in this pedestal 124 is a frame or holder 125 whichr carries a rear end trim shear blade as hereinafter described and is reciprocated vertically from the shaft by a pair of rock arms 126 on the rockshaft 123 and links 127 connecting these rock arms 126 and the vertically reciprocating frame 125, asv best shown in Fig.f10. f

As best shown in Fig. 8, this frame or end trinnnerblade holder 125 is provided at one side with an ear 128which is pivotally connected to the upper end of a shipper rod 129.

The lower end of this shipper rod connects withv a` rock arm 130 fixed to a rock shaft 131, this rock shaft being suitably journalled otall su a )ort one end 'of a vertically mov- Y ll vable table 134. the other 'end of the table being supported by a pair of links `135 also lmounted on the fixed supporting arms 132. In the xed supporting larms 132 between the opposite direction from the rock arm 137 and I is pivotally connected to a shipper rod 140 having a slot 141 at its lower end. In this slot is arranged a pin 142 carried by a rock arm 143, which rock arm is fixed to a rock shaft 144, this rock shaft 144 also carrying a rock arm 145 which extends in the opposite direction from the rock arm 143. This last named rock arm 145 is connected by a link 146 with a rock arm 147 depending from a rock shaft 148. This rock shaft 148 also carrying a rock arm 149. The rock arm 145 and the link 146 are arranged to be moved upwardly beyond their dead center for a purpose which will presently appear. This last named rock arm 149 is connected by a depending link 1'50 to the inner end of a hori- Zontally longitudinally swinging bar 151. The outer end of the bar 151 is pivotally connected to the lower arm of a large rock lever 152 which is supported at its center in a cross rod 153 and the upper end of this rock lever 152 is pivotally connected to a horizontal reciprocating bar 154. The front end of this reciprocating bar 154 is connected to a feeding carriage 155 which is guided for longitudinal reciprocating movement at the front end of the table 77 in any suitable manner and carries an inclined finger 156 which is adapted to engage the rear or trailing end of the blank strip 42 upon the table 77 and feed it toward the punch press when the carriage is moved rearwardly. Since the clutch 104 which actuates the train of rock levers, rock arms and links just described is closed only once for every eight, or series of punchings to be made on each blank strip, the longitudinally reciprocating bar 151 is lowered to its operative position by the link 150 only once during the same cycle of punching operations and when so lowered is moved forwardly to effect a movement of the feeding carriage 155 toward the punch press by means which are preferably constructed as follows:

At the opposite end of the machine, as best shown in Figs. 2 and 5, a crank wheel 160 is mounted on the main crank shaft of the punch press and carries a crank pin 161 which is connected by a connecting lrod 162 toa vertically reciprocating slide 163. The crank pin 161 is preferablyv mounted for radial movement inthe crankwheel 160 to vary the throw thereof and thev radial position of the crank pin is determined and adjusted by a screw 159. This lslide 163 is guided for vertically reciprocating movement` on rails 164 in the machinetframe 43 for a purpose which will presently appear and is connected by a rod 165 with the inner end of a segmental igear rack 166. This segmental gear rack moves longitudinally of the machine and is fixed to a shaft 167, this shaft being supported by brackets 168 projecting outwardly from the machine frame 43.

To permit of adjusting this segmental gear rack 166, as best shown in Fig. 33, the shaft 167 is eccentrically mounted in a pair of bearing members 169 and is keyed thereto, these bearing members being journa-lle'd the brackets 168'. One of these eccentric bearLng members 169 is formed to provide a toothed wheel 170, the teeth of which are engaged by a spring loaded plunger 171 having a finger 'knob 172 by means of which the plunger can be pulled out of engagement with the teeth of the wheel 170 and thereby permit the bearing members 169 and the segmentall gear rack shaft 167 keyed thereto tobe turned. By reason of the eccentric mounting of the shaft 167 in the bearing members 169 it is apparent that the turning of the toothed wheel alters the center of the segmental gear rack 166 and permits of this adjustment. Upon moving the toothed adjusting wheel 170 to any desired adjusted position it 1s held in such adjustment by the spring loaded plunger 171.

The segmental gear rock meshes with teeth 173 formed in the central part of a transverse shaft 174, this shaft being journalled in bearings carried by a bearing block` 175 as best shown in Figs. 5, 27, and 31. This shaft is formed with driving teeth 177 at its opposite ends, these teeth forming pinions which mesh with teeth.178 formed on the upper side of two shipper bars 179 mounted for longitudinal reciprocating movement on opposite sides of the punch press and adjacent the sides of the path of the blank strips 42 through the punch press. These bars 17 9 are preferably hexagonal in cross section and are slidingly supported by blocks 180 and by the bearing block 175 for the shaft 174 which shaft reciprocates these bars through motion derived from the segmental gear rack 166.

These hexagonal shipper bars 179 extend to the opposite or front end of the punch press and at this end each of these bars connect with a rock arm 181 by means of a link 182, as best shown in Figs. 5, 6 and 7. These rock arms are arranged on opposite sides of the feed table 77 and are fixed to the ends of a transverse rock shaft 183 carried by supporting arms 184 projecting forwardly from the machine bed. Between the supporting arms 184, depending rock' arms 185 are fixed to this rock shaft and are arranged on opposite sides of the longitudinal swinging bar 151 which actuates the blank strip feed carriage 155. The lower ends of these rock arms 185 are connected by a cross rod 186 which is ar- -i ranged below vthe longitudinally swinging bar 151 and is arranged to enter a notch 187 provided at the rear end of the bar 151.

Inasmuch as the rock arm 185 is driven directly from the main crank shaft 52 of the punch press, it is apparent that it is reciprocated each time the punch press makes a punching operation or eight times to each strip of metal in the device illustrated. Since, however, the link 150 is lowered through the clutch 104, this link is lowered once t0 every eight operations ofthe punch press. Hence when eight punches have been f made in the blank strip 42 in the machine and another strip is ready to be fed the link 150 is lowered thereby lowering the longitudinal swinging bar 151 into the path of the cross rod 186 carried by the rock arms 185 and since these rock arms 185 rock continuously the cross rod 186 enters the notch 187 in the longitudinally swinging bar 151 and moves it toward the front end of the machine thereby moving the feeding carriage 155 rearwardly or toward the punch press and feeding the strip of metal on the table 77 to the punch press. As the link 150 and longitudinally swinging bar 151 are immediately elevated upon the finish of the rising movement of the slide 125 supporting the end trimming blade 211 and the opening ofthe clutch 104 by a tappet mechanism hereinafter described the driving connection between the rock arms' 185 and the strip feeding mechanism is immediately broken as soon as the strip is fed to the punch press and the carriage 155 is returned to its normal position at the front or outer end of the feed table 77.

The air buyfer for the feeding mechanism A11 air absorbing device, indicated generally at 190 is provided to prevent a violent return movement of the feeding carriage 155 and its associated actuating mechanism after a blank strip 42 has been fed toward the punch press. Such violent return movement would be liable to cause the notched bar 151 to be thrown forward so violently as to cause its notch 187 to be placed out of alignment for the proper reception of the bar 186. Such misalignment would cause a failure of the movement of the rock arm 152 at its proper period. This absorbing device 190 is arranged at the outer end of the feed table 77,4 as indicated at 190 and is preferably constructed as follows:

Carried by hangers 191 is a longitudinal sleeve 192 which supports an air cylinder `193. In this cylinder 193l is arranged a piston 194 and a piston rod 195, the other end of this piston rod 195 being secured to a head 196 which is pivotally connected to the longitudinally movable bar 154 which connects to the feed carriage 155, as best shown in Fig. 6. The piston 194, as best shown in the enlarged view Fig. 35, has a cup leather 197 and its rearward movement is resisted by the air cushion built up in the outer or front end of the air cylinder 193, this end of the air cylinder being closed by a head 198. An exhaust passage 199 is provided through this head-198, the escape of air through this exhaust passage 199 being controlled by a-needle` valve 200 which can be opened or closed to provide any desired escape o f air and hence any desired cushioning action of the absorber. iWhen, however, the feeding car- Vriage 155 has been practically returned t0 its initial .feeding position, it is desirable to exhaust quickly all of the air pressure in the air -absorber 190, since otherwise this air pressure or cushion might react to move the carriage rearwardly out of its normal return position at 'the' extremity of the feeding .table 77.

To provide this quick and complete exhaust of the air a second exhaustpassage 201 is provided inthe head'198, this exhaust passage 201 communicating 1with the exhaust passage 199 and being controlled by a plunger valve 202. This plunger valve 202 is normally held closed by a spring 203 which is adjustably held'under tension by an adjusting screw 204 and is opened by a stem 205 which extends through a slidewayprovided in the head 198 and into the air cylinder 193. The movement of the piston 194 toward the `head 198 is cushioned by the restricted escape of`the air pressure past the needle valve 200 but when thispiston strikes the stem 205 of the plunger valve 202 it opens this plunger valve and permits all of the air pressure in the .air cylinder to escape quickly through vthe exhaust passage 201.

The releasing and Zatchz'ngfmeekan'z'sm fory the feeding mechanism also operate to positively latch the notched bar-151 against dropping so 'that while it is inoperative it cannot accidentally dropl vand cause an accidental operation of the feeding carriage 155 which would, of course, result in crumpling the blank strip 42 placed on the feeding table preparatory to being fed andpossibly break parts of the machine or injure the operator. These means for releasing or rendering inoperative the feeding mechanism after a feeding stroke thereof and latching the feeding mechanism in such in- -operative position are preferably constructed as follows:

As shown in Figs: 13716, a collar 300 is I keyed in the driven sha t 105 of the clutch 104, which driven shaft oscillated once for every eight operations o'f the punch press as 105 after the clutch has been closed to actuate the feeding and other mechanisms ldrivenA by it.

Projecting in the opposite direction from the collar 300 is a rod 304 which passes through a block 305' which block is pivotally mounted on the en'd of a rock arm 306. The

connection between the rod 304and the block 305 preferably comprises a collar 307 against which the block 305 is yieldingly held by a helical compression spring 308. arm 306 is `fastened to a rock shaft 309 which also carries a rock arm 310 at the outer end of which a block 311 is pivotally secured. This blbck 311 is provided with a slideway receiving a sliding rod 312. This rod clutch shaft 105 is in its inoperative or idle position, as shown in Figs. 13 and 16, this rod i's in the path of the recessed end of a tappet arm 313. This tappet arm 313 is fixed to the rock shaft 88, this rock shaft being rocked each time a punching operation occurs, as previously explained. i

The lower end of the sliding rod 312 -is The rock `9e projects upwardly rom the block and when the pivotally connected to one Varm of a rock member 314 which is mounted on a stub shaft or pin 315 projecting outwardly from the punch. press frame. f The opposite varm of this rock member 314 is connected to a shipper rod 316, this shipper rod at its lower end being pivot-ally connected to a rock arm 317 which, as best shown in Figs. 5 and 7, projects forwardly from one end of the transverse rock shaft 144. Y

.During the retraction movement. of the carriage 155 the driven clutch shaft 105 is re-l turned to its normal position shown in Fig. 16 and the collar 300 movesthe rod 304, rock arm 306, rock shaft 309 vand rock arm 310 to bring the upper end of the sliding rod 312 under the tappet arm 313. The actual move` A ment of the rod 312 to its osition under the tappet arm 313is effected y the spring 308 rod 312 `downwardly which movement of the sliding rod 312 downwardly through the rock member 314, raises the shipper rod 316 and the rock arm 317I (Fig. 5) to rock the rock shaft 144counterclockwise as viewed in Fig.

5. This movement of the rock shaft 144 is suicient to throw its rock larm 145 and the link 146 connected thereto (Fig. 6) rearwardly beyond their dead center. Such rearward movement of the rock arm 145 and the link 146 rocks the

rock arms

147 and 149 forwardl and upwardly or counterclockwise as viewed in Fig. 6 and thereby elevates the link 150 and the horizontally swinging notched bar 151 pivotally connected with the lower end of the link 150. When the notched bar 151 is raised its notch 187 is freed from the cross rod 186 carried by the swinging rock arms 185 and the drivingconnection between L the feeding carriage 155 and the punch press is thereby broken and since this connection is broken at the same time that the feeding carriage has reached its retracted osition at the front end of the feeding table Z the feeding carriage remains in this position until the feeding mechanism is again placed in'opward movement of this slotted bar140 first throws this rock arm 145 and link 146 below their dead center and then moves these members to lower the horizontal notched bar 151 to engage the cross rod 186 of the swinging,

beams which actuate the feeding carriage.

After the link 146 and rock arm 145 have been rocked upwardly beyond their dead center ,to stop the feeding carriage in its retracted position the continued tappin of the tappet arm 313 on the upper end of t e slideration by the upward movement of the sloting rod 312 has no e'ect, this tapping continlted rod 140 as described.

Itis apparent that the action of the tappet arm in throwing the rock arm 145 `and link 146 shouldlbe deferred until after the carriage 155 haspbeen fully retracted. This deferred action is efected by the spring 308 which yieldingly urges the sliding rod 312 inwardly, as best shown in Fig. 7 During the first part of the advancing movement of the carriage 155, the collar 300 (Fig. 15) is moved to swing the sliding rod 312 outwardly clear of the tappet arm 313. The tappet arm thereupon comes down but doesnot strike the sliding rod 312'since at this time the sliding rod is inoperative. At the start of the retracting movement of the carriage 155, the collar 300 and the tappet arm 313 are moved in the reverse direction, but the reverse movement of the collar 300 merely serves to draw the sliding rod 312 against the end of the tappetv arm 313, the spring 308 compressing and permittin the rod 304 to move without moving the sliing rod 312. When, however, the carriage 155 is fully retracted, the tappet arm 313 rides beyond the end of the sliding rod 312 and the spring 308 snaps the sliding rod into its position under the tappet arm 313, as shown in Fig. 16. The tappet arm 313 thereupon comes down on the sliding rod 312 and throws the rock arm 145 and link 146 rearwardly be ond their dead center so as 'tolock or latch t elswinging notched bar 151 in its elevated position until the punch press isagain ready to have another strip fed to it,

as previously described.

Since the tappet arm 313 of this releasing mechanism rocks the rock shaft 144 (Fig. 6)

upwardly beyond the dead center of its rockl varm 145v and the link 146 connected to it, it

uing until the end of another feeding operation occurs when the tappet arm 313 again raises the horizontally swinging'notched bar 151 (Fig. 6) in the manner described.

The guiding nwchanz'sm The front or advancing end of the strip 42 being fed forwardly by the feeding carriage '155 1s guided downwardly by an inclined The end trimming mechanism To avoid waste of material, the maximum number of punehings are made-.in each stri For this purpose thetrailing end of the strip being punched is trimmed to exact length and the advancing end of the next succeedin strip is gaged and released in predetermined I relation to the trimmed rear end vof the strip in the press so that the strips go throughthe press in immediate succession and the'maximum number of punchings is made in each. The shearing or trimming blades comprise a movable blade 211 which is emovably attached to the lower end of the vertically movable slide or frame 125 which, as previously,described, formspart of the feeding 'mechanism and is moved vertically once l.for

every eight punchin operations of the punch press. This upper lade 211 cooperates with a lower fixed blade 212 which is adjustably mounted on the machinebed 43, the movable vblade 211 shearing against the front side of the ixed blade so that the -end of metal 213` cut from the trailing edge of the strip in the punch press falls outside of the punch press. The frame 125 can be guided in its movement in any suitable manner, but is preferably held against an outer vertical rail 214 by gibs 215, as best shown in Figs. 9 and 10.

To permit the piece 213 trimmed or rsheared from the trailing end of the blank strip 42 in the punch press to fall through the feeding table 77, the feeding table is provided with the movable section 134 which is mounted on the upper ends of the table supporting

rock arms

133 and 135 which form part of the mechanism for actuating the feeding carriage 155 as previously described. This table falls downwardly and forwardly when the shearing blades 211 and 212 come together and form an opening through which Lthe sheared end 213 falls clear of the machine.

It is apparent that the feeding movement of the feeding carriage must not start before the shearing operation' has been completed and hence the parts actuating the feeding.

carriage 155 through motion derived from the shearing mechanism are so designedthat and while the feeding is positive, the strips the shearing operation is completed before the carriage 155 starts to feed the blank strip on the table 77. This Vis effected by the provision of the slot and

pin connection

141 and 142 between the shipper rod 140 and the rock arm 143.

As best'shown in Figs. 6 and 8, the downward movement of the movable shear blade 211 and the movable table section 134 is practically complete before the upward movement of the shipper rod 140 causes the pin 142 to engage the bottom of the ,slot 141 and be moved so as to effect an engagement between the longitudinally swinging bar 151 and the actuating rock arm 185. This slot and

pin connection

141, 142 therefore effects a delayed action of the feeding carriage 155 and secures proper synchronism in the operations.

The gagz'ng mechanism It is apparent that 'in the punching of continuously fed strips of blank metal that the strips must be in immediate succession and end to end. since if gaps occur, or if one strip overlapped the other the strips. would be out of register with the dies and imperfect punchings would be made at the ends of the strip. To prevent this; a gaging device is provided which moves into the path of the strip bei ng fed, stops and positions it so that it is arranged in predetermined relation to the trimmed rear end of the strip being punched and then releases it so that it'takes a position against the trailing end of the strip in the punch press. By this means there is no tendency for the blank strips to overlap,

are properly gaged regardless of variations in their length. This gage must, of course, operate only 4when a strip is fed or once in `eight punching operations of the punch press through the press. n These shoes are comparatively wide and fiat and are adjustably secured to the machine frame in any suitable manner and are spaced apart a sufficient distance to allow the blank strips of metal 42 to be fed between them. 4 These shoes are also formed to provide a converging guide throat at their front ends to receive and `de the advancing ends of the blank strips eing fedbto the punch press and each is formed to provide a transverse slot 222 which extends inwardly from the samel side of each shoe.

Mounted for movement in and out of the slots 222 is a gage plate 223, this gage plate being mounted on a swinging arm 224 which,

' of being tightened thereon at any place so that the position of the gage plate can be altered to suit different lengths of blank strips being operated on.

The swinging arm 224 supporting the gage plate 223 is provided with an upward extension which receives the threaded end of a. link 228, the extension on the arm 224 being held between two adjusting nuts on the link 228. The other end of the link 228 is slotted as indicated at 229 and' this slot receives a in 230 of a rock arm 231which. rock arm 1s keyed to a rock shaft 232. This rock shaft '105 is journalled in brackets projecting inwardly from the pedestal 124, 'and at one end carries a rock arm 233 which is actuated by a shipper rod 234. Asbest shown in Fig. 8, this shipper rod 234 extends downwardly and connects with a rock arm 235 on a rock shaft 236, this rock shaft 236 being actuated by a rock arm. 237. ThisV last named rock arm is connected by a link 238 with a rock arm 239 mounted on the rock shaft 144, which, as previously described is rocked at the completion of the shearing operatlon to effect an advancing or feeding movement of thefeeding carriage 155.

During the normal operation offthe ma-` chine, i. e. while a blank strip in the punch press is being punched andthe strip` feedarm 235, shipper rod rw234, rock arm 233, rock shaft 232, rock armA 231, slotted rod 228 and the swinging arm 224 'on which the gage plate 223 is carried.

At the end of the shearing operation the slotted rod 140 is raised to a point where the pin 142 is engaged and this raises the rock shaft 143 and rocks the rdck shaft 144 so as to rock the rock arm 239A rearwardly. This movement moves the horizontal rod 238 rearwardly, elevates the shipper rod 234 and the rock arm 233 and rocks the rock arm 231 rearwardly so -as to free the pin 230 and rmit the slotted rod 228 to moverearward y and the swinging arm 224 and gage plate 223 to drop. The gage plate 223 therefore drops onto ille trailing trimmed end of the blank strip 42 in the punch press and as soon as this strip rides beyond the gage plate 223, the gage plate 223 drops into its operative position in the path of the blank strip 42 being fed by the feedingjcarriage 155. During the continued upward movement of the slotted rod 140 and continued elevation of the rock arm 143 in placing the feeding carriage 155 in operation, the pin 230 travels idly rearwardly through the lslot 229, the gage plate 223 being free to drop into the path of the strip being fed. The blank strip 42 being fed is then moved rearwardly by -the feeding carriage 155- and the leading end of the same is Amoved over the elevated movable table section 134, under the guide-plate 210, between the open blades 211 and 212 of the rear end trimmer and against the gage plate 223.

\ Upon the completion of the-retraction of the feeding carriage'fl, the collar 300011` the driven clutch shaft 105 (Fig. 16) moves the sliding rod 312 under the tappet arm 313 von-the rock/shaft 88 and this tappet arm 'striking the sliding rod 312 raises the shipper vrod 316and rock arm 317 (Fig. 5) and thereby rocks the transverse rock shaft 144 counterclockwis'e-as viewed in Fig. 5. This counterclockwise movement of the rock shaft 144 (Fig, 8) rocks the

rock arms

237 and 239 and the link 238 forwardly thereby depressing the shipper rod 234 and rock arm 233 and rocking the rock arm 231 forwardly. vThis f 'forward movement of the rock arm 231 causes its pin 230 to engage the front or outer end of the slot 229 -in ,the slotted rod 228 land thereby raises the swinging arm 224 and thestrips, tmmedtoexzactlength, are fed through the ,press in immediate succession and without danger of overlapping. The advancing mechanism After the blank strip 42 has entered the punch press, means must be provided for advancing it step-by-step or from station to station each time a punching `movement 'of` the dies is effected, this advancing operation being effected during the period when the dies are retracte and being preferably constructed as follo s:

Below each of the hexagonal shipper rods 179, which as previously described, slide leiigthwise of the punch press and in unison with the punching operations, is a second rod 240k which is preferably square in cross section but is rotatably mounted in the bearing blocks 175 and 180.

Mounted on these rods at suitable intervals are grippers indicated generally at 241 which grippers are lsecured to the shipper rods 179 and are providedl with gripping ele; ments which are actuated by the turning of thel lower rod 240 to grip the upper and lower sides of the blank strip of metal inthe unch press. at the opposite edges;J thereof. cans are provided for turning the lower rods 240 during the advancing longitudinal movement of the rods 179 so that the grippers 241 are actuated to grip the edges ofthe strip 42 in the punch .press and advance the same.

These means also turn the rods 240 to release the grippers 241 during the return lon-- ygitudinal stroke of the rods 179. By this means the blank strip 42 in the machine is advanced step-by-step through the machine, the length of the step being determined by the adjustment of the throw of thel crank pin 161 on the crank wheel 160. These means for turning the lower rods 240 to cause the grippers 241 to engage and disengage the edges of theblank strip in the punch press during the advancing and retracting movement, respectively, of the

rods

179 and 240, are pref` erably constructed as follows:

Asbest sliownin Fig. 32, a cam 242 is fast` to the main crank shaft 52 of the punch press, the salient and receding edges of this cam4 being engaged b a pair of rollers 243 Acarried by the epending arms of a. pair of bell crank levers 244. These bell crank levers are arranged in opposite sides of the main crank shaft 52 andthe horizontal arm of each `is connected by a shipper rod 245 with a rock arm 246 mounted on a longitudinal s ub rock shaft 247. This stub'shaft'carries ,another rock arm 248, the two rock arms 2,48 on each side of the machine being connected by a cross link 249 to insure the engagement of the rollers 243 with the driving cam 242 and in unisson. kEach of these stub shafts also cara rock arm 250 which is connected by a 251 with a rock arm 252 fast on a. rock to insure both of the-stub shafts 247 rocking shaft 253. The rock shafts 253 each extend longitudinally of the machine and are journalled in the

bearing'blocks

175 and 180. Between the bearing blocks 175 and 180, the rock shaft 253 is journalled inv a bracket 254 which can be of any suitable form but preferably is carried by the

bars

179 and 240 and the rock shaft 253 and is `held against sliding movement relative to the rock shaft 253 and l the lower square rod or bar 240 and slidingly receives the longitudinally reciprocating bar 179. In this bracket a toothed wheel 255 is secured to the rotatable lower shaft 240, the teeth of this wheel being engaged by a spring loaded plunger 256 carried b a' swinging arm 257. This swinging arm 257 is pivotally mounted on the hub of the toothed wheel 255 and the plunger 256 can be retracted from the teeth of the wheel 255by means of a Enger knob 258, thereby permitting anyl desired relative adjustment between the 'swinging arm 257 and the toothed wheel which turns the square shaft, as shown in Fig. 29, the shaft 240 being turned to eiect this adjustment by means of a hand'wheel 400 xed to this shaft and arranged immediately adjacent the toothed wheel 255, as bestshown in Figs. 29 and 30.

Adjacent the bracket 254, a rock arm 259 is keyed to the rock shaft and the end of this rock arm is connected to the swinging arm 257 which drives the toothed wheel 255. It is therefore apparent that as the rock shafts 253 on opposite sides of the machine are.

rocked, a similar movement is imparted to the lower longitudinal rods 240, the degree of rocking motion imparted being dependent upon the adjustment of the plunger 256 relative to the toothed wheel 255.

The grippers 241 are shown as being four -in number, these grippers being arranged within the punch press frame. As best shown in Figs. 20-23, each of these grippers includes a pair of U-shaped supporting members 260 which areclamped against the opposite sides of the longitudinally shifting bar 179 and are movable therewith` and at their lower ends rotatably support the hubs ofra pinion 261. Each of these pinions is provided with a square opening which slidingly'receives the lower rotatable shaft 240 so that'the gripper as a whole is fast to the upper longitudinally movable bar 179 and is slidingly connected to the lower rotatable bar so that upon turning this bar, the pinion 261 is also turned.

The supporting member 260 also supports a horizontal channeled member 262, the outer end of which is formed to provide a fixed jaw 263 which engages under the edge of -the blank strip 42. This under jaw is preferf. ably provided with a removable gripping ele-v ment 264 which is milled or roughened to provide a rough gripping face, this element being replaceable as it wears. In the channel of the channeled member 262 is arranged' a floating rack 265, the teeth of which engage with the teeth of the pinion I261, so that upon turning this pinion the rack is moved longitudinally along its channel. A rod 266 extends through this rack and at its outer end this rack is threaded and provided with a locked nut 267 and a helical spring 268 surrounds the outer end of this rod 266 and is interposed between the nut 267 andthe outer end of the channeled member 263. At the inner side of the gripper, a movable jaw 269 is pivoted to the Xed jaw 263, this mova le jaw being provided at its outer end with a milled under surface and being adaptedto grip theJ upper side of the blank strip 42 so that the adjacent edge of the blank strip is firmly held between these jaws. The movable jaw 269 is moved toward and from the fixed jaw 263 by a pair of

toggle links

270, 271 and the pivotal connection between these

toggle links

270, 271,is also connected to an operating link 272 which link 272 is connected to the inner end of the rod 266.

With this arrangement of thev parts the operation of the grippers 271 in gripping the edges of the blank 'strlp 42 in the machine and advancing it to 'its next station while the dies are withdrawn is as follows:

v At the start of the retracting movement of the dies, the cam 242 (Fig. 32) forces the shipper rods 245 down and through the rock arm 246, rock shaft 247, rock arm 250,. link 251, rock arm 252, rock shaft 253, (Fig. 29), link 260, adjustable arm 257, toothed wheel 255 and rotatable shaft 240. These shafts are thereby rotated in opposite 'directions and turn; the pinions 261 (Fig. 21) forming partof the gripper 241 in thek direction toV move the racks 265 outwardly. In each of the grippers 241 this outward movement ofthe racks 265 reacts against the spring 268 and nut 267 to yieldingly move the rod 266 outwardly. This movement of each rod 266 causes an outward movement of the toggle links 270, 271 through the operating link 272 and this causes the toggle links. to force the upper movable gripper jaw 269 ofv each gripper to move toward-the lower fixed gripper jaw 263 and grip the adjacent edge of the blank strip of metal 42 being punched. It will be noted that by the employment of the spring 268 that the

gripper jaws

269 and 263 are yieldingly held together so that these jaws adapt themselves to variations in the thickness of the blank strip being punched and i 240 which actuate .the grippers 241.